Objective: To observe the clinical efficacy of grain-sized moxibustion in treating chemotherapy-induced myelosuppression for non-small cell lung cancer (NSCLC) and its effect on quality of life (QOL). Methods: Eighty ...Objective: To observe the clinical efficacy of grain-sized moxibustion in treating chemotherapy-induced myelosuppression for non-small cell lung cancer (NSCLC) and its effect on quality of life (QOL). Methods: Eighty NSCLC patients admitted to the Inpatient Department of Zhejiang Cancer Hospital between September 2016 and March 2018 were recruited and divided into an observation group and a control group by random number method, with 40 cases in each group. The two groups both received chemotherapy with paclitaxel plus cisplatin (TP regimen). The control group received oral administration of leucogen tablets starting from the first day of chemotherapy, 20 mg each time, three times a day, for consecutive 14 d;the observation group was additionally given grain-sized moxibustion, once a day, five days per week at a two-day interval, until the fourteenth day. The myelosuppression severity was observed and compared between the two groups prior to chemotherapy, at the 3rd, 7th and 14th days of chemotherapy;the QOL in the two groups was evaluated before chemotherapy, at the 14th and 21st days of chemotherapy. Results: Regarding myelosuppression, the peripheral blood indicators increased significantly at the 3rd day of chemotherapy in both groups (P<0.05 or P<0.01);at the 7th and 14th days of chemotherapy, the peripheral blood indicators presented a decreasing tendency in the two groups, but the level in the observation group was still significantly higher than that before chemotherapy (P<0.01);at the 3rd, 7th and 14th days of chemotherapy, the peripheral blood indicators in the observation group were higher than those in the control group (P<0.05 or P<0.01);the occurrence rate of myelosuppression in the observation group was significantly lower than that in the control group (P<0.01). The QOL score in the observation group was markedly higher than that in the control group at the 14th and 21st days of chemotherapy (both P<0.05). Conclusion: Grain-sized moxibustion can effectively improve myelosuppression after chemotherapy for NSCLC, reducing its occurrence and enhancing the patient's QOL.展开更多
Objective To investigate whether grain-sized moxibustion at Xinshu(BL15)and Shenshu(BL23)can alleviate cognitive decline and other pathologic features in early-stage Alzheimer disease(AD)using transgenic mice with 5 f...Objective To investigate whether grain-sized moxibustion at Xinshu(BL15)and Shenshu(BL23)can alleviate cognitive decline and other pathologic features in early-stage Alzheimer disease(AD)using transgenic mice with 5 familial AD mutations(5XFAD).Methods The genotype of transgenic mice was detected by polymerase chain reaction.A total of 40 transgenic mice(1.5 months old)were randomly and equally allocated to an AD model group(5XFAD group)or a grain-sized moxibustion group(5XFAD+GM group),with 20 wild-type(WT)mice(C57BL/6J)serving as the normal control group(WT group).Mice in the 5XFAD+GM group were treated by grain-sized moxibustion at bilateral Xinshu(BL15)and Shenshu(BL23).Mice in the WT group and 5XFAD group received no treatment but were restrained to ensure exposure to a similar experimental condition.Cognitive function and memory were assessed with the Morris water maze and Y-maze tests.The amyloidβ40(Aβ40)and amyloidβ42(Aβ42)levels in the brain were evaluated by enzyme-linked immunosorbent assay;amyloid plaque deposition in brain tissue sections was detected by thioflavin-S staining;the expression of glial fibrillary acidic protein(GFAP),cluster of differentiation 11b(CD11b),brain-derived neurotrophic factor(BDNF),and choline acetyltransferase(ChAT)in the hippocampus and prefrontal cortex was analyzed by immunohistochemistry.Results In the Morris water maze test,compared with the 5XFAD group,mice in the 5XFAD+GM group had a shorter escape latency and more target area crossings and spent more time in the target quadrant(P<0.05).In the Y-maze test,compared with the 5XFAD group,the number of training times of the 5XFAD+GM group was significantly decreased(P<0.05),together with more correct responses(P<0.05).Compared with the 5XFAD group,the levels of Aβ40 and Aβ42 in the brain tissue of the 5XFAD+GM group were significantly lower(P<0.05);in the hippocampus and prefrontal cortex,the total number of amyloidβplaque deposition were significantly lower(P<0.05);the expression levels of GFAP and CD11b were significantly reduced(P<0.05);and the expression levels of ChAT and BDNF were significantly increased(P<0.05).Conclusion Grain-sized moxibustion at Xinshu(BL15)and Shenshu(BL23)greatly improves learning and memory functions,decreases the levels of Aβ40 and Aβ42,inhibits amyloidβplaque deposition,decreases the expression of GFAP and CD11b,and increases the expression of ChAT and BDNF in AD mice to inhibit the progression of AD.展开更多
In order to clarify the formation mechanism of linear dunes on the northern margin of Qarhan Salt Lake, northwestern China, we analyzed the grain-size and sorting parameters of the dune and interdune sands. The surfac...In order to clarify the formation mechanism of linear dunes on the northern margin of Qarhan Salt Lake, northwestern China, we analyzed the grain-size and sorting parameters of the dune and interdune sands. The surface sands (0-30 ram) from the dune base to the crest of both flanks and interdune corridors were sampled along transects from upwind to downwind through the dune field. The results indicated that the grain-size distribution differed at different positions between and within the dunes. The frequency curve for dune sands mainly showed a bimodal distribution, while the interdune sediments showed a trimodal distribution. The grain size distribution of the linear dunes showed a finer crest pattern, i.e. the crests were composed of sands that were generally finer, better sorted than those of base sands. In addition, at the dune field scale, the dune crest sands were tending to become much finer but sorting became worse along the downwind transects. However, the grain-size parameters of sediments in the interdune corridors showed no clear pattern. The results demonstrated that the grain size and sorting parameters exhibited a systematic change not only at the individual scale but also at the dune field scale. Our results quantitatively estimate the limited role of cohesive sediments on the formation of linear dune under unidirectional wind regime. More attention should be paid to a long-term wind regime observation, internal sedimentary structures and their formation ages.展开更多
Sediment cores were collected from the subaqueous delta of the Changjiang Estuary. Sediment grain-size profiles and their fractal dimensions were analyzed, to elucidate responses to long-term sedimentary processes. In...Sediment cores were collected from the subaqueous delta of the Changjiang Estuary. Sediment grain-size profiles and their fractal dimensions were analyzed, to elucidate responses to long-term sedimentary processes. In addition, the environmental sensitive populations of grain size have been extracted. The sediment cores can be divided into two parts, according to the sedimentary structures present. The upper part (0-12 cm) is interpreted as being the active layer, which is influenced frequently by changes in the short-term hydrodynamic environment. The lower part extends from a depth of 12 cm, to the bottom of the core. The pattern of fluctuation is linked to sediment grain size. Moreover, two grain-size sensitive populations can be identified. The fine sensitive population is 6.0-7.2 μm, which is a similar grain size to the suspended sediment from up-river. The coarse sensitive population varies from 40.7 to 57.5 μm, revealing complex changes. Thus, the riverine inputs from the Changjiang River may be an important source, which contributes to seasonal fluctuations of grain-size distribution, over the area. The sediments, with grain-sizes ranging from 0.9 to 20.3 μm, are characterised by self-similar in the fractal non-scale region. The fraetal dimension is eonsistant with the grain-size parameter varatioins, which could be used as a replacement index to reveal and reconstruct the sedimentary environmental evolution.展开更多
The grain-size distribution characteristics and grain-size parameters of sediment in two vertical sections of Daniugou peatland in the Changbai Mountains were systematically investigated.A comparative analysis of the ...The grain-size distribution characteristics and grain-size parameters of sediment in two vertical sections of Daniugou peatland in the Changbai Mountains were systematically investigated.A comparative analysis of the sediment granularity using a discriminative function with Hongyuan peat,red clay,loess-paleosol,fluvial deposit as well as lacustrine deposit was also conducted.It turns out that the vertical section of Daniugou peat ash is primarily constituted by clay and silt particles,and the content of sand is relatively small.Grain-size frequency curves generally show a single-peak modality while a bimodal pattern is detected in the upper layer.The grain-size component and peak pattern of grain-size frequency curves also illustrate that peat ash materials were transported to the peatland by long-range aeolian dust during the deposition process,while there existed short-distance dust influence in peat deposition of the upper layer.Comparisons of grain-size parameters and the discriminative Y-value of Daniugou peat ash with those of typical aeolian sediments show close similarities,suggesting the possibility that atmospheric dust transport processes were involved in the accumulation of peat again.Moreover,the variations of grain-size distribution suggest the local environmental deterioration which is just the driving force of local dust elevation.Grain-size analysis of peatland sediment is demonstrated to be one effective method to extract information about regional and global environmental evolution,and more attention should be paid to current local ecological environment and to seeking a balance between economic development and environmental protection in Northeast China.展开更多
The palaeo-mobile dune sands and fluvio-lacustrine facies with palaeosols in Milanggouwan stratigraphic section of the Salawusu River valley situated at the southeast of the Mu Us Desert experienced abundant remarkabl...The palaeo-mobile dune sands and fluvio-lacustrine facies with palaeosols in Milanggouwan stratigraphic section of the Salawusu River valley situated at the southeast of the Mu Us Desert experienced abundant remarkable alternative changes of coarse and fine rhythms in grain-size since 150 ka BP, and the grain-size parameters Mz,σ, Sk, Kg and SC/D also respond to the situation of multi-fluctuational alternations between peak and valley values. Simultaneity the grain-size eigenvalues F5, F16, F25, F50, F75, F84 and F95 are respondingly manifested as greatly cadent jumpiness. Hereby, the Milanggouwan section can be divided into 27 grain-size coarse and fine sedimentary cycles, which can be regarded as a real and integreted record of climate-geological process of desert vicissitude resulted from the alternative evolvement of the ancient winter and summer monsoons of East Asia since 150 ka BP.展开更多
Patterns of grain-size distributions of suspended sediment in relation to resuspension, settling, and tidal processes are investigated, based on in situ measurements over the Dafeng intertidal flat, on the Jiangsu coa...Patterns of grain-size distributions of suspended sediment in relation to resuspension, settling, and tidal processes are investigated, based on in situ measurements over the Dafeng intertidal flat, on the Jiangsu coast, in the summer of 2002 and 2003. The suspended sediment here is dominated by fine and very fine silt, with a mean grain-size of 7 - 13 μm. The patterns of the grainsize distributions of suspended sediment during a tidal cycle are characterized by two types: one stable type representing insignificant spatial and temperal variations; and the other bimedal type with significant variations. The main factors influencing the grainsize distributions include resnspension, settling, suspended sediment imported into intertidal flats during the flood phase, and the grain-size distribution of seabed sediment. Resuspension increases the coarse particle content, enhances the mean grain-size of suspended sediment, and results in grain-size distributions for the suspended sediment similar to those of seabed sediment; the settling process has opposite effects on the suspended sediment. When resuspension occurs, the gain-size distributions of suspended sediment in the lower part of water column respond significantly to the current velocity. Where the influence of resuspension and settling processes is weak, the grain-size distributions of suspended sediment appear to be stable and almost identical for the various parts of intertidal flats during different measurement periods. Such distributions are referred to the background grain-size distribution, for which the mean grain-size over the Dafeng intertidal flat is around 7 μm.展开更多
The TMS5e sequence from the Tumen section, at the southern edge of Tengger Desert in the northwestern China, is synchronous with Marine Isotope Stage 5e (MIS5e). It consists of 16 layers of aeolian dune sands, 11 la...The TMS5e sequence from the Tumen section, at the southern edge of Tengger Desert in the northwestern China, is synchronous with Marine Isotope Stage 5e (MIS5e). It consists of 16 layers of aeolian dune sands, 11 layers of lacustrine loess-like facies, and 5 layers of lacustrine facies. The results of grain-size analysis shows that the pa- laeo-mobile dune sands, palaeo-fixed to semi-fixed dune sands and loess-like sandy loams are mainly composed of sands, ranging from 70% to 96%; their silt contents ranged from 4% to 20%, and their clay contents ranged from 1% to 5%; the climate under which the aeolian dune sands were deposited is similar to that under which modern mobile dune sands form, which is caused by the dominance of the cold, dry East Asian winter monsoon. In contrast, the lacustrine loess-like facies and lacustrine facies had a lower sand contents than those of the three aeolian dune sands, but have higher silt and clay contents, most of their sand content ranged from 30% to 60%, their silt contents ranged from 35% to 55%, and their clay contents ranged from 6% to 20%. The lacustrine loess-like facies and lacustrine facies formed under the influence of the warm, humid East Asian summer monsoon based on their similarity with modern sediments. The grain-size indicator Mz (mean grain diameter) and the SC/D value in the TMS5e sequence indicate climatic insta- bility at the southern edge of the Tengger Desert during MIS5e, with at least 14 fluctuations between a warm, humid climate and a cold, dry climate, divided into five stages: TMS5e5 (139 kyr to 129.3 kyr B.P.), TMS5e4 (129.3 kyr to 124 kyr B.P.), TMS5e3 (124 kyr to 119.5 kyr B.P.), TMS5e2 (119.5 kyr to 116.5 kyr B.P.), and TMS5el (116.5 kyr to 113.7 kyr B.P.). These correspond roughly to MIS5e5, MIS5e4, MIS5e3, MIS5e2, and MIS5el, respectively, in the GRIP ice core data.展开更多
In general,sediments in nature comprise populations of various diameters.Accurate information regarding the sources and depositional mechanisms of the populations can be obtained through their temporal and spatial com...In general,sediments in nature comprise populations of various diameters.Accurate information regarding the sources and depositional mechanisms of the populations can be obtained through their temporal and spatial comparisons.In this study,the grain size distribution of surface sediments from the Bering Sea and western Arctic Ocean were fitted and partitioned into populations using a log-normal distribution function.The spatial variations in the populations indicate differences in their sources and deposition mechanisms.The sediments on most of the Bering Sea Shelf originated from the Yukon River,and were transported westward by waves and currents.However,the presence of a coarser population outside Anadyr Bay was the result of Anadyr River transport.Additionally,a northward transport trend of fine suspended particles was observed on the west side of the Bering Sea Shelf.The sediments in Hope Valley in the south Chukchi Sea also originated from the Yukon River.The coarser population on the central Chukchi Sea Shelf originated from coast of Alaska to the east,not the Yukon River,and was transported by sea ice and bottom brine water.The populations of sediments from the Chukchi Basin and the base of the Chukchi Sea Slope are the result of sea ice and eddy action.Surface sediments from the western high Arctic Ocean predominantly comprised five populations,and two unique populations with mode diameters of 50–90μm and 200–400μm,respectively,were ubiquitous in the glacial and interglacial sediments.It was difficult to distinguish whether these two populations originated from sea ice or icebergs.Therefore,caution should be exercised when using either the>63μm or>250μm fractions in sediments as a proxy index for iceberg and ice sheet variation in the high Arctic Ocean.展开更多
Field observational previously indicated a mouth bar of a fan delta could exhibit a fining-or coarseningupward trend,which bring a new challenge to the identification of mouth bar in subsurface studies due to the lack...Field observational previously indicated a mouth bar of a fan delta could exhibit a fining-or coarseningupward trend,which bring a new challenge to the identification of mouth bar in subsurface studies due to the lack of morphological descriptions.Previous studies have indicated that effluent behavior in rivermouth system can affect the vertical grain-size trend of mouth bar,but the drivers and magnitude of this phenomenon are not understood.We conducted flume experiments to investigate the mechanism and controlling factors of vertical grain-size trend of mouth bar.Experiment with a steeper slope of the substrate layer,greater discharge,higher sediment/water ratio,and coarser sediment induced a finingupward trend of mouth bar,because the effluent was dominated by strong inertia.Mouth bar in the experiment with a gentler slope of the substrate layer,smaller discharge,lower sediment/water ratio,and finer sediment exhibited a coarsening-upward trend dominated by the friction-dominated effluent.The relationship between the vertical grain-size trend of mouth bar and the gradients of foreset bedding in small-scale flume models and the cut-off of 15°-18°are applicable in natural systems.Identifying depositional setting to infer depositional process in river-mouth system and analyzing the plane geometry of sandbodies are two steps in the interpretation of ancient fan deltaic rock record.展开更多
This study deals with the relationship between sea-level changes and paleoclimatic fluctuations based on the analysis of stratigraphy, grain sizes, palynology, and radiometric dating of the Yellow River delta since th...This study deals with the relationship between sea-level changes and paleoclimatic fluctuations based on the analysis of stratigraphy, grain sizes, palynology, and radiometric dating of the Yellow River delta since the Late Pleistocene. Evidence from the sedimentary record, grain sizes, and pollen provides a paleoenvironmental history of the Late Pleistocene from the boreholes of the delta. Based on a combination of grain-size analysis with lithological studies, marine deposit units contain the intervals of 13.85–16.9, 18.5–19.69, 27.9–34.8, 36.4–37.2, 48.4–51.6, and 54.1–55.9 m, and transitional facies units contain the intervals of 10.25–13.85, 16.9–18.5, 19.69–27.9, 34.8–36.4, 37.2–48.4, 51.6–54.1, and 55.9–60 m, compared with fluvial(terrestrial facies) deposit units(3.36–10.25 m). Based on pollen analysis and pollen assemblages, there were three warm-wet periods from 9.1–0.16 ka BP, 16.1–60 ka BP, and 90.1–94.6 ka BP From the top to the bottom of the borehole, the paleoclimate has an evident fluctuation: warm and moist(Holocene Optimum) —cool and dry(Younger Dryas Event)—mild semi cool—cool and dry—warm and moist. There were three warm-wet periods from 9.1–0.16 ka BP, 16.1–60 ka BP, and 90.1–94.6 ka BP, corresponding to the Holocene Optimum stage, MIS 3, and MIS 5, respectively. The warm period allowed monsoonal evergreen and broadleaved deciduous forests that corresponded to Holocene hypsithermal climatic conditions and the Late Pleistocene climatic Optimum. Three warm-wet periods occurred in marine deposit units from 9.1–0.16 ka BP, 60.1–16.1 ka BP, and 94.6–90.1 ka BP. These periods correspond to the Cangzhou transgression, Xianxian transgression, and Huanghua transgression, respectively. From 90.1–60.1 ka BP, 17.5–9.1 ka BP, and 0. 16 ka BP–1855 AD, three dry and cold phases are recognized. The phases indicate the fluvial(flood plain) sedimentary environment, corresponding to cooler and mild dry periods based on palynological results and grain-size distribution.展开更多
The grain-size of suspended particulate matter (SPM) in the Huanghe Estuary and its adjacent sea area was investigated with an in situ laser particle size analyzer (LISST-100) in November 2006.The spatial distribu...The grain-size of suspended particulate matter (SPM) in the Huanghe Estuary and its adjacent sea area was investigated with an in situ laser particle size analyzer (LISST-100) in November 2006.The spatial distribution of the grain-size parameters was very complicated.The results show that (1) the mean particle size of SPM ranged from 3.00Φ to 6.41Φ,with an average value of 4.66Φ;(2) the frequency distribution patterns of the SPM grain-size showed three different types,which were mono-mode,dual-mode and tri-mode,respectively;(3) C-M chart suggested that the transportation-processes of the SPM not only included suspended mode,but also the bed load transportation mode.The bed load transportation mode mainly occurred at the bottom layer.The characteristics and space distribution of SPM grain-size might be mainly controlled by sediment discharge of the Huanghe River,hydrodynamics condition,surface sediment types,and biological process within the study area.展开更多
Layer LJ3 of Linjiang stratigraphic section in Dongjiang River valley in the south of the Nanling Mountains is a set of red sandy sediments.Measured by thermoluminescence(TL) dating,it was found to be formed in MIS2-9...Layer LJ3 of Linjiang stratigraphic section in Dongjiang River valley in the south of the Nanling Mountains is a set of red sandy sediments.Measured by thermoluminescence(TL) dating,it was found to be formed in MIS2-9,500 ± 800 yr to 19,600 ± 1,800 yr B.P.After analy-sis of the grain sizes of the 16 samples(LJ3-100 to LJ3-85) in this layer,it was discovered that(1) The contents of each grain group in dif-ferent samples are similar.(2) The values of Md,Mz,,Sk,and Kg vary from LJ3-100 to LJ3-85 in a narrow range.(3) The segments of each sample in the accumulative curves extend parallel with similar slopes.All the three aspects reveal the Aeolian characteristics of Layer LJ3.Therefore,it is thought that Layer LJ3 consists of red sandy sediments formed in MIS2 in the south of Nanling Mountain,which reflects the arid climate at that time.展开更多
Reconstructions of past climatic changes on the northeastern Tibetan Plateau(NETP) can provide insights into the Asian summer monsoon(ASM) variability. However, the regional climate changes on both orbital and suborbi...Reconstructions of past climatic changes on the northeastern Tibetan Plateau(NETP) can provide insights into the Asian summer monsoon(ASM) variability. However, the regional climate changes on both orbital and suborbital time scales since the late Glacial remain controversial. Here we present the results of high-resolution geochemical and grain-size analyses of a sediment core from Genggahai Lake, a small, shallow lake in this area. Changes of the accumulation rate of the core sediments show a similar trend with variations of the coarse fraction. Accordingly, the chronological framework is constructed using a grain-size age model. In addition, the histories of chemical weathering and aeolian activity since the late Glacial are reconstructed based on the Al/Ti ratios and coarse fractions, respectively. The results suggest that an enhanced chemical weathering and a weakened aeolian activity occurred on the NETP under a warmer, wetter climate during the early to mid-Holocene(11.3–6.3 ka cal BP), compared with the late Glacial(17.1–11.3 ka cal BP) and the late Holocene(6.3 ka cal BP to present), which responded mainly to the strengthened ASM on orbital time scale. In addition, the synchronous occurrences of weakened chemical weathering, low lake level and intense aeolian activity on suborbital time scale reflect several episodes of weakened ASM. Furthermore, these episodes largely coincide with the centennial-to millennial-scale cold events in the North Atlantic, which demonstrates the close connection between the ASM and the cooling at high latitudes.展开更多
The quantitative analysis of sediment sources in a sink is an important scientific topic and challenge in provenance research.The characteristics of heavy minerals,combined with the geochemical constituents of detrita...The quantitative analysis of sediment sources in a sink is an important scientific topic and challenge in provenance research.The characteristics of heavy minerals,combined with the geochemical constituents of detrital grains,provide a reliable provenance-tracing approach.We developed a mineral identification method to analyze the multiple grain-size fraction of sediments,from which the elemental geochemistry of hornblende was used to compare the characteristics of sediments from the Huaihe River and Huanghe(Yellow)River in eastern China.Elements that were statistically identified as being able to discriminate sediment provenance were employed to perform a quantitative analysis of the sources of sediments of the abandoned Huanghe River.Results reveal that the Huaihe River is characterized by a high amphibole content of>60%and that the Huanghe and abandoned Huanghe rivers have greater abundances of limonite and carbonate minerals compared with those of the Huaihe River.The contents of trace elements and rare earth elements in hornblende show that the sediments of the abandoned Huanghe River are similar to those of the Huanghe River but different from those of the Huaihe River.Furthermore,chemical mass balance was used to calculate the relative contributions of different provenances of sediment from the abandoned Huanghe River,and nine trace elements of hornblende were identified as discriminators of provenance.Approximately 2%of the hornblende in the abandoned Huanghe River is derived from the Huaihe River and 98%from the Huanghe River.Considering the proportion of hornblende in the total sediment,it is inferred that the contribution of Huaihe River sediment to the abandoned Huanghe River is approximately 0.5%.This study shows that mineral analysis using multiple grain-size fractions(within the wide range of 1Φto 6Φ)with assessment in elemental geochemistry of hornblende can characterize the provenance of fluvial material in coastal zones.展开更多
Suspended sediment concentration(SSC) is an important parameter in marine sedimentology. With the development of technology, many acoustic and optical devices, such as the Laser In-Situ Scattering and Transmissometry,...Suspended sediment concentration(SSC) is an important parameter in marine sedimentology. With the development of technology, many acoustic and optical devices, such as the Laser In-Situ Scattering and Transmissometry, have been designed to measure in situ SSC and grain size distribution. But due to fund or other restrictions, many experiments were only conducted in laboratory, using an indoor laser grain-size analyzer and gravimetric method to measure grain size distribution and concentration, respectively. In this study the laboratory experiment is simplified by omitting the tiring step of gravimetric method. The connections between SSC and other parameters(obscuration, D50 and sorting index) were investigated based on 124 surface sediment samples collected from different offshore areas. A new method is developed for determining SSC in laboratory using a laser grain-size analyzer.展开更多
This research paper analyses the grain-size characteristics of the Quaternary deposits at Xingshan near Siping, Jilin province in China by employing graphic measures to study the grain size distribution and its mode o...This research paper analyses the grain-size characteristics of the Quaternary deposits at Xingshan near Siping, Jilin province in China by employing graphic measures to study the grain size distribution and its mode of transport and deposition. The Quaternary deposits at Xingshan lie unconformable on Cretaceous rocks made of siltstone, mudstone and sandstone. The average grain size is between 8.06 to 8.55Φ (0.002 6 ~0.003 7 mm). The Quaternary deposits at Xingshan mainly compose of very fine silt to clay. The compositions of the grade are clay 63% and silt 37%. The clay size components are weathered debris transported and deposited by flowing water from the SE highlands or hills to the low lying NW Xingshan plains whereas the silty components accumulated by aoelian process. The Quaternary deposits at Xingshan accumulated in the middle and late Pleistocene interglacial periods from (459.12~39.03) ka to (88.92~7.56) ka. The standard deviation ranged from 0.96 to 1.36Φ, indicating that the sediments are moderately to poorly sorted, Coefficient of skewness ranged from 0.16~0.31 with an average skewness of 0.218, (Positively skewed towards fine). Kurtosis values (0.84~1.05) from the grain size distribution and visual inspection of the frequency curves indicate platykurtic to mesokurtic curves and unimodal to bimodal grain-size distribution. The type of deposit formation is sand dune and the source is at a distal from its provenance.展开更多
AIM: To observe the efficacy and mechanism of grain-sized moxibustion at different acupoints in a rat model of ulcerative colitis (UC). METHODS: Sprague-Dawley rats were randomly divided into control, UC model, grain-...AIM: To observe the efficacy and mechanism of grain-sized moxibustion at different acupoints in a rat model of ulcerative colitis (UC). METHODS: Sprague-Dawley rats were randomly divided into control, UC model, grain-sized moxibustion at a single acupoint (CV 12), grain-sized moxibustion at two acupoints (CV 12 and CV 4), grain-sized moxibustion at three acupoints (CV 12, CV 4, and ST 36), and medication groups (n = 8/group). The UC model was established by enema of trinitrobenzene sulfonic acid. Direct moxibustion was used once a day for 7 d. Disease activity index (DAI) was evaluated before and after the treatment. Morphologic changes of intestinal tissue were observed under an optical microscope. The expression of tumor necrosis factor (TNF)-alpha and p38 mitogen-activated protein kinase (p38MAPK) in colonic tissue was detected using Western blot, and the levels of occludin and zonula occludens-1 (ZO-1) mRNAs were detected using reverse transcription PCR. RESULTS: Compared with the control group, the intestinal mucosae were incomplete in the model group, glandular structures were irregular, and submucosae were edematous, hyperemic, and infiltrated with inflammatory cells. The DAI scores and expression of TNF-alpha and p38MAPK were increased significantly in the model group compared to controls (Ps < 0.01), while the mRNA levels of occludin and ZO-1 were reduced significantly (Ps < 0.01). Compared with the model group, colonic mucosa and the arrangement of glands were complete and regular in the treatment groups. DAI scores and the expression of TNF-alpha and p38MAPK were reduced significantly in moxibustion groups compared to controls (Ps < 0.01), while the mRNA levels of occludin and ZO-1 were increased significantly (Ps < 0.01). The improvements in the above indices in the three acupoints group and the medication group were superior to those in the single and two acupoints groups (all P < 0.05). CONCLUSION: Reduction of TNF-alpha and p38MAPK and increased expression of occludin and ZO-1 in colonic tissue represent a potential mechanism for improved intestinal mucosal tissue repair with grain-sized moxibustion.展开更多
A 700-year record (1.0-1.5 a resolution) of the East Asian winter monsoon (EAWM), based on grain-size analysis and AMSI4C dating of Core EC2005 from the inner-shelf mud wedge of the East China Sea (ECS), was com...A 700-year record (1.0-1.5 a resolution) of the East Asian winter monsoon (EAWM), based on grain-size analysis and AMSI4C dating of Core EC2005 from the inner-shelf mud wedge of the East China Sea (ECS), was compared with the Dongge stalagmite 8180 record during the mid-Holocene. The upper muddy section of Core EC2005 has been formed mainly by suspended sediments derived from the Changjiang (Yangtze) River mouth since 7.3 ka BP. High precipitation and a strengthened EAWM might have played key roles in the high sedimentation rate (1 324-1 986 crn/ka) between 5.9-5.2 ka BP. The EAWM strengthened when the Asian summer monsoon weakened, especially around 5 500 a BE which corresponded to a worldwide cold event. The EAWM during the mid-Holocene shows statistically significant solar periodicities at 62 and 11 a. The 5 500 a BP cold event might be resulted from orbital forcing and changes in solar activity.展开更多
Seven cores were collected from different sediment zones of tidal flats at Xin- yanggang in north Jiangsu province in August 2007. Sediment grain-size distribution and radioisotopes of ^137Cs and ^210Ppb analysis were...Seven cores were collected from different sediment zones of tidal flats at Xin- yanggang in north Jiangsu province in August 2007. Sediment grain-size distribution and radioisotopes of ^137Cs and ^210Ppb analysis were carried out for these cores. Sediment rates of the cores and radioisotopes distribution in surface sediment in different zones of the tidal flat were calculated from the ^137Cs and ^210Ppb activities in sediments cores. The results indicated that each tidal zone had experienced different evolution phases, hydrological dynamics in the tidal flats made the grain-size of the surface sediment change gradually. ^137Cs and ^210Ppb activities on the superficial layer of the cores varied spatially and the reason was discussed. On tidal flats, the fluctuation of ^137Cs and ^210Ppb activities in the cores reflected the special sedimentary characteristics. Vegetation affects the grain-size distribution and the vertical profiles of ^137Cs and ^210Ppb in the upper depths. ^137Cs and ^210Ppb chronology got the comparable average sediment rates on the tidal flat. The characteristics of ^137Cs and ^210Ppb in the cores reflected various depositional dynamical environments in different tidal zones and gave information on the different evolvement phases of the tidal zones. Based on the information of grain-size distribution, texture of the cores, sediment rates and topography, the evolution lines of the tidal flat were reconstructed.展开更多
文摘Objective: To observe the clinical efficacy of grain-sized moxibustion in treating chemotherapy-induced myelosuppression for non-small cell lung cancer (NSCLC) and its effect on quality of life (QOL). Methods: Eighty NSCLC patients admitted to the Inpatient Department of Zhejiang Cancer Hospital between September 2016 and March 2018 were recruited and divided into an observation group and a control group by random number method, with 40 cases in each group. The two groups both received chemotherapy with paclitaxel plus cisplatin (TP regimen). The control group received oral administration of leucogen tablets starting from the first day of chemotherapy, 20 mg each time, three times a day, for consecutive 14 d;the observation group was additionally given grain-sized moxibustion, once a day, five days per week at a two-day interval, until the fourteenth day. The myelosuppression severity was observed and compared between the two groups prior to chemotherapy, at the 3rd, 7th and 14th days of chemotherapy;the QOL in the two groups was evaluated before chemotherapy, at the 14th and 21st days of chemotherapy. Results: Regarding myelosuppression, the peripheral blood indicators increased significantly at the 3rd day of chemotherapy in both groups (P<0.05 or P<0.01);at the 7th and 14th days of chemotherapy, the peripheral blood indicators presented a decreasing tendency in the two groups, but the level in the observation group was still significantly higher than that before chemotherapy (P<0.01);at the 3rd, 7th and 14th days of chemotherapy, the peripheral blood indicators in the observation group were higher than those in the control group (P<0.05 or P<0.01);the occurrence rate of myelosuppression in the observation group was significantly lower than that in the control group (P<0.01). The QOL score in the observation group was markedly higher than that in the control group at the 14th and 21st days of chemotherapy (both P<0.05). Conclusion: Grain-sized moxibustion can effectively improve myelosuppression after chemotherapy for NSCLC, reducing its occurrence and enhancing the patient's QOL.
基金This work was supported by the Natural Science Foundation of Zhejiang Province(浙江省自然科学基金,No.LY13H270002).
文摘Objective To investigate whether grain-sized moxibustion at Xinshu(BL15)and Shenshu(BL23)can alleviate cognitive decline and other pathologic features in early-stage Alzheimer disease(AD)using transgenic mice with 5 familial AD mutations(5XFAD).Methods The genotype of transgenic mice was detected by polymerase chain reaction.A total of 40 transgenic mice(1.5 months old)were randomly and equally allocated to an AD model group(5XFAD group)or a grain-sized moxibustion group(5XFAD+GM group),with 20 wild-type(WT)mice(C57BL/6J)serving as the normal control group(WT group).Mice in the 5XFAD+GM group were treated by grain-sized moxibustion at bilateral Xinshu(BL15)and Shenshu(BL23).Mice in the WT group and 5XFAD group received no treatment but were restrained to ensure exposure to a similar experimental condition.Cognitive function and memory were assessed with the Morris water maze and Y-maze tests.The amyloidβ40(Aβ40)and amyloidβ42(Aβ42)levels in the brain were evaluated by enzyme-linked immunosorbent assay;amyloid plaque deposition in brain tissue sections was detected by thioflavin-S staining;the expression of glial fibrillary acidic protein(GFAP),cluster of differentiation 11b(CD11b),brain-derived neurotrophic factor(BDNF),and choline acetyltransferase(ChAT)in the hippocampus and prefrontal cortex was analyzed by immunohistochemistry.Results In the Morris water maze test,compared with the 5XFAD group,mice in the 5XFAD+GM group had a shorter escape latency and more target area crossings and spent more time in the target quadrant(P<0.05).In the Y-maze test,compared with the 5XFAD group,the number of training times of the 5XFAD+GM group was significantly decreased(P<0.05),together with more correct responses(P<0.05).Compared with the 5XFAD group,the levels of Aβ40 and Aβ42 in the brain tissue of the 5XFAD+GM group were significantly lower(P<0.05);in the hippocampus and prefrontal cortex,the total number of amyloidβplaque deposition were significantly lower(P<0.05);the expression levels of GFAP and CD11b were significantly reduced(P<0.05);and the expression levels of ChAT and BDNF were significantly increased(P<0.05).Conclusion Grain-sized moxibustion at Xinshu(BL15)and Shenshu(BL23)greatly improves learning and memory functions,decreases the levels of Aβ40 and Aβ42,inhibits amyloidβplaque deposition,decreases the expression of GFAP and CD11b,and increases the expression of ChAT and BDNF in AD mice to inhibit the progression of AD.
基金funded by the National Natural Science Foundation of China (41171010, 41130533, 41301003)
文摘In order to clarify the formation mechanism of linear dunes on the northern margin of Qarhan Salt Lake, northwestern China, we analyzed the grain-size and sorting parameters of the dune and interdune sands. The surface sands (0-30 ram) from the dune base to the crest of both flanks and interdune corridors were sampled along transects from upwind to downwind through the dune field. The results indicated that the grain-size distribution differed at different positions between and within the dunes. The frequency curve for dune sands mainly showed a bimodal distribution, while the interdune sediments showed a trimodal distribution. The grain size distribution of the linear dunes showed a finer crest pattern, i.e. the crests were composed of sands that were generally finer, better sorted than those of base sands. In addition, at the dune field scale, the dune crest sands were tending to become much finer but sorting became worse along the downwind transects. However, the grain-size parameters of sediments in the interdune corridors showed no clear pattern. The results demonstrated that the grain size and sorting parameters exhibited a systematic change not only at the individual scale but also at the dune field scale. Our results quantitatively estimate the limited role of cohesive sediments on the formation of linear dune under unidirectional wind regime. More attention should be paid to a long-term wind regime observation, internal sedimentary structures and their formation ages.
基金The National Basic Research Program of China under contract No 2002CB412401the National Natural Science Foundation of China under contract Nos 40876043 & 40106009+1 种基金the Jiangsu Natural Science Foundation under contract NoBK2006131the NCET Program under contract NoNCET-06-0446
文摘Sediment cores were collected from the subaqueous delta of the Changjiang Estuary. Sediment grain-size profiles and their fractal dimensions were analyzed, to elucidate responses to long-term sedimentary processes. In addition, the environmental sensitive populations of grain size have been extracted. The sediment cores can be divided into two parts, according to the sedimentary structures present. The upper part (0-12 cm) is interpreted as being the active layer, which is influenced frequently by changes in the short-term hydrodynamic environment. The lower part extends from a depth of 12 cm, to the bottom of the core. The pattern of fluctuation is linked to sediment grain size. Moreover, two grain-size sensitive populations can be identified. The fine sensitive population is 6.0-7.2 μm, which is a similar grain size to the suspended sediment from up-river. The coarse sensitive population varies from 40.7 to 57.5 μm, revealing complex changes. Thus, the riverine inputs from the Changjiang River may be an important source, which contributes to seasonal fluctuations of grain-size distribution, over the area. The sediments, with grain-sizes ranging from 0.9 to 20.3 μm, are characterised by self-similar in the fractal non-scale region. The fraetal dimension is eonsistant with the grain-size parameter varatioins, which could be used as a replacement index to reveal and reconstruct the sedimentary environmental evolution.
基金Under the auspices of National Natural Science Foundation of China (No 40871089, 40830535)State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment, Chinese Academy of Sciences (No SKLLQG0910)
文摘The grain-size distribution characteristics and grain-size parameters of sediment in two vertical sections of Daniugou peatland in the Changbai Mountains were systematically investigated.A comparative analysis of the sediment granularity using a discriminative function with Hongyuan peat,red clay,loess-paleosol,fluvial deposit as well as lacustrine deposit was also conducted.It turns out that the vertical section of Daniugou peat ash is primarily constituted by clay and silt particles,and the content of sand is relatively small.Grain-size frequency curves generally show a single-peak modality while a bimodal pattern is detected in the upper layer.The grain-size component and peak pattern of grain-size frequency curves also illustrate that peat ash materials were transported to the peatland by long-range aeolian dust during the deposition process,while there existed short-distance dust influence in peat deposition of the upper layer.Comparisons of grain-size parameters and the discriminative Y-value of Daniugou peat ash with those of typical aeolian sediments show close similarities,suggesting the possibility that atmospheric dust transport processes were involved in the accumulation of peat again.Moreover,the variations of grain-size distribution suggest the local environmental deterioration which is just the driving force of local dust elevation.Grain-size analysis of peatland sediment is demonstrated to be one effective method to extract information about regional and global environmental evolution,and more attention should be paid to current local ecological environment and to seeking a balance between economic development and environmental protection in Northeast China.
基金National Natural Science Foundation of China No. 49971009+5 种基金 State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment CAS No. SKLLQG0008 The Key National Project for Basic Research No. G2000048701
文摘The palaeo-mobile dune sands and fluvio-lacustrine facies with palaeosols in Milanggouwan stratigraphic section of the Salawusu River valley situated at the southeast of the Mu Us Desert experienced abundant remarkable alternative changes of coarse and fine rhythms in grain-size since 150 ka BP, and the grain-size parameters Mz,σ, Sk, Kg and SC/D also respond to the situation of multi-fluctuational alternations between peak and valley values. Simultaneity the grain-size eigenvalues F5, F16, F25, F50, F75, F84 and F95 are respondingly manifested as greatly cadent jumpiness. Hereby, the Milanggouwan section can be divided into 27 grain-size coarse and fine sedimentary cycles, which can be regarded as a real and integreted record of climate-geological process of desert vicissitude resulted from the alternative evolvement of the ancient winter and summer monsoons of East Asia since 150 ka BP.
基金The study was supported by the National Natural Science Foundation of China under contract Nos 40231010 and 2002CB412408by the Post-doctoral Research Foundation of Shanghai under contract No.05R214119.
文摘Patterns of grain-size distributions of suspended sediment in relation to resuspension, settling, and tidal processes are investigated, based on in situ measurements over the Dafeng intertidal flat, on the Jiangsu coast, in the summer of 2002 and 2003. The suspended sediment here is dominated by fine and very fine silt, with a mean grain-size of 7 - 13 μm. The patterns of the grainsize distributions of suspended sediment during a tidal cycle are characterized by two types: one stable type representing insignificant spatial and temperal variations; and the other bimedal type with significant variations. The main factors influencing the grainsize distributions include resnspension, settling, suspended sediment imported into intertidal flats during the flood phase, and the grain-size distribution of seabed sediment. Resuspension increases the coarse particle content, enhances the mean grain-size of suspended sediment, and results in grain-size distributions for the suspended sediment similar to those of seabed sediment; the settling process has opposite effects on the suspended sediment. When resuspension occurs, the gain-size distributions of suspended sediment in the lower part of water column respond significantly to the current velocity. Where the influence of resuspension and settling processes is weak, the grain-size distributions of suspended sediment appear to be stable and almost identical for the various parts of intertidal flats during different measurement periods. Such distributions are referred to the background grain-size distribution, for which the mean grain-size over the Dafeng intertidal flat is around 7 μm.
基金Foundation item:Under the auspices of State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,Chinese Academy of Sciences (No.SKLLQG0901,SKLLQG1013)Research Fund for the Doctoral Program of Higher Education of China (No.20094407120004)
文摘The TMS5e sequence from the Tumen section, at the southern edge of Tengger Desert in the northwestern China, is synchronous with Marine Isotope Stage 5e (MIS5e). It consists of 16 layers of aeolian dune sands, 11 layers of lacustrine loess-like facies, and 5 layers of lacustrine facies. The results of grain-size analysis shows that the pa- laeo-mobile dune sands, palaeo-fixed to semi-fixed dune sands and loess-like sandy loams are mainly composed of sands, ranging from 70% to 96%; their silt contents ranged from 4% to 20%, and their clay contents ranged from 1% to 5%; the climate under which the aeolian dune sands were deposited is similar to that under which modern mobile dune sands form, which is caused by the dominance of the cold, dry East Asian winter monsoon. In contrast, the lacustrine loess-like facies and lacustrine facies had a lower sand contents than those of the three aeolian dune sands, but have higher silt and clay contents, most of their sand content ranged from 30% to 60%, their silt contents ranged from 35% to 55%, and their clay contents ranged from 6% to 20%. The lacustrine loess-like facies and lacustrine facies formed under the influence of the warm, humid East Asian summer monsoon based on their similarity with modern sediments. The grain-size indicator Mz (mean grain diameter) and the SC/D value in the TMS5e sequence indicate climatic insta- bility at the southern edge of the Tengger Desert during MIS5e, with at least 14 fluctuations between a warm, humid climate and a cold, dry climate, divided into five stages: TMS5e5 (139 kyr to 129.3 kyr B.P.), TMS5e4 (129.3 kyr to 124 kyr B.P.), TMS5e3 (124 kyr to 119.5 kyr B.P.), TMS5e2 (119.5 kyr to 116.5 kyr B.P.), and TMS5el (116.5 kyr to 113.7 kyr B.P.). These correspond roughly to MIS5e5, MIS5e4, MIS5e3, MIS5e2, and MIS5el, respectively, in the GRIP ice core data.
基金financially supported by the scientific research foundation of Third Institute of Oceanography,MNR(Grant no.2018006)Chinese Polar Environment Comprehensive Investigation&Assessment Programmes(Grant no.2016-03-02)the National Natural Science Foundation of China(Grant nos.41306205,41876229)。
文摘In general,sediments in nature comprise populations of various diameters.Accurate information regarding the sources and depositional mechanisms of the populations can be obtained through their temporal and spatial comparisons.In this study,the grain size distribution of surface sediments from the Bering Sea and western Arctic Ocean were fitted and partitioned into populations using a log-normal distribution function.The spatial variations in the populations indicate differences in their sources and deposition mechanisms.The sediments on most of the Bering Sea Shelf originated from the Yukon River,and were transported westward by waves and currents.However,the presence of a coarser population outside Anadyr Bay was the result of Anadyr River transport.Additionally,a northward transport trend of fine suspended particles was observed on the west side of the Bering Sea Shelf.The sediments in Hope Valley in the south Chukchi Sea also originated from the Yukon River.The coarser population on the central Chukchi Sea Shelf originated from coast of Alaska to the east,not the Yukon River,and was transported by sea ice and bottom brine water.The populations of sediments from the Chukchi Basin and the base of the Chukchi Sea Slope are the result of sea ice and eddy action.Surface sediments from the western high Arctic Ocean predominantly comprised five populations,and two unique populations with mode diameters of 50–90μm and 200–400μm,respectively,were ubiquitous in the glacial and interglacial sediments.It was difficult to distinguish whether these two populations originated from sea ice or icebergs.Therefore,caution should be exercised when using either the>63μm or>250μm fractions in sediments as a proxy index for iceberg and ice sheet variation in the high Arctic Ocean.
基金supported by the National Natural Science Foundation of China(No.41772101)。
文摘Field observational previously indicated a mouth bar of a fan delta could exhibit a fining-or coarseningupward trend,which bring a new challenge to the identification of mouth bar in subsurface studies due to the lack of morphological descriptions.Previous studies have indicated that effluent behavior in rivermouth system can affect the vertical grain-size trend of mouth bar,but the drivers and magnitude of this phenomenon are not understood.We conducted flume experiments to investigate the mechanism and controlling factors of vertical grain-size trend of mouth bar.Experiment with a steeper slope of the substrate layer,greater discharge,higher sediment/water ratio,and coarser sediment induced a finingupward trend of mouth bar,because the effluent was dominated by strong inertia.Mouth bar in the experiment with a gentler slope of the substrate layer,smaller discharge,lower sediment/water ratio,and finer sediment exhibited a coarsening-upward trend dominated by the friction-dominated effluent.The relationship between the vertical grain-size trend of mouth bar and the gradients of foreset bedding in small-scale flume models and the cut-off of 15°-18°are applicable in natural systems.Identifying depositional setting to infer depositional process in river-mouth system and analyzing the plane geometry of sandbodies are two steps in the interpretation of ancient fan deltaic rock record.
基金granted by the national Natural Science Foundation(Grant No.41406079,41676052)the NSFC-Shandong Joint Fund for Marine Science Research Centers(No.U1606401)+2 种基金the National Key Research and Development Program of China(Grant No.2017YFC0306603)the China Ocean Mineral Resources R&D Association Project(Grant No.DY135-S1-1-02)the Foundation of Geological Survey of China(Grant No.DD20190578)。
文摘This study deals with the relationship between sea-level changes and paleoclimatic fluctuations based on the analysis of stratigraphy, grain sizes, palynology, and radiometric dating of the Yellow River delta since the Late Pleistocene. Evidence from the sedimentary record, grain sizes, and pollen provides a paleoenvironmental history of the Late Pleistocene from the boreholes of the delta. Based on a combination of grain-size analysis with lithological studies, marine deposit units contain the intervals of 13.85–16.9, 18.5–19.69, 27.9–34.8, 36.4–37.2, 48.4–51.6, and 54.1–55.9 m, and transitional facies units contain the intervals of 10.25–13.85, 16.9–18.5, 19.69–27.9, 34.8–36.4, 37.2–48.4, 51.6–54.1, and 55.9–60 m, compared with fluvial(terrestrial facies) deposit units(3.36–10.25 m). Based on pollen analysis and pollen assemblages, there were three warm-wet periods from 9.1–0.16 ka BP, 16.1–60 ka BP, and 90.1–94.6 ka BP From the top to the bottom of the borehole, the paleoclimate has an evident fluctuation: warm and moist(Holocene Optimum) —cool and dry(Younger Dryas Event)—mild semi cool—cool and dry—warm and moist. There were three warm-wet periods from 9.1–0.16 ka BP, 16.1–60 ka BP, and 90.1–94.6 ka BP, corresponding to the Holocene Optimum stage, MIS 3, and MIS 5, respectively. The warm period allowed monsoonal evergreen and broadleaved deciduous forests that corresponded to Holocene hypsithermal climatic conditions and the Late Pleistocene climatic Optimum. Three warm-wet periods occurred in marine deposit units from 9.1–0.16 ka BP, 60.1–16.1 ka BP, and 94.6–90.1 ka BP. These periods correspond to the Cangzhou transgression, Xianxian transgression, and Huanghua transgression, respectively. From 90.1–60.1 ka BP, 17.5–9.1 ka BP, and 0. 16 ka BP–1855 AD, three dry and cold phases are recognized. The phases indicate the fluvial(flood plain) sedimentary environment, corresponding to cooler and mild dry periods based on palynological results and grain-size distribution.
基金The Ministry of Science and Technology of China under contract No. 2005CB422304the National Natural Science Foundation of China under contract No. 40976020
文摘The grain-size of suspended particulate matter (SPM) in the Huanghe Estuary and its adjacent sea area was investigated with an in situ laser particle size analyzer (LISST-100) in November 2006.The spatial distribution of the grain-size parameters was very complicated.The results show that (1) the mean particle size of SPM ranged from 3.00Φ to 6.41Φ,with an average value of 4.66Φ;(2) the frequency distribution patterns of the SPM grain-size showed three different types,which were mono-mode,dual-mode and tri-mode,respectively;(3) C-M chart suggested that the transportation-processes of the SPM not only included suspended mode,but also the bed load transportation mode.The bed load transportation mode mainly occurred at the bottom layer.The characteristics and space distribution of SPM grain-size might be mainly controlled by sediment discharge of the Huanghe River,hydrodynamics condition,surface sediment types,and biological process within the study area.
基金funded by the National Natural Science Foundation of China (No 40471139)National Basic Research Program of China (No 2004CB 720206)the State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment, Chinese Academy of Sci-ences Foundation (No SKLLQG0309)
文摘Layer LJ3 of Linjiang stratigraphic section in Dongjiang River valley in the south of the Nanling Mountains is a set of red sandy sediments.Measured by thermoluminescence(TL) dating,it was found to be formed in MIS2-9,500 ± 800 yr to 19,600 ± 1,800 yr B.P.After analy-sis of the grain sizes of the 16 samples(LJ3-100 to LJ3-85) in this layer,it was discovered that(1) The contents of each grain group in dif-ferent samples are similar.(2) The values of Md,Mz,,Sk,and Kg vary from LJ3-100 to LJ3-85 in a narrow range.(3) The segments of each sample in the accumulative curves extend parallel with similar slopes.All the three aspects reveal the Aeolian characteristics of Layer LJ3.Therefore,it is thought that Layer LJ3 consists of red sandy sediments formed in MIS2 in the south of Nanling Mountain,which reflects the arid climate at that time.
基金This research was supported by the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDA20090000)the National Natural Science Foundation of China (Grants 41901103)the Foundation for Excellent Youth Scholars of "Northwest Institute of Eco-Environment and Resources", CAS
文摘Reconstructions of past climatic changes on the northeastern Tibetan Plateau(NETP) can provide insights into the Asian summer monsoon(ASM) variability. However, the regional climate changes on both orbital and suborbital time scales since the late Glacial remain controversial. Here we present the results of high-resolution geochemical and grain-size analyses of a sediment core from Genggahai Lake, a small, shallow lake in this area. Changes of the accumulation rate of the core sediments show a similar trend with variations of the coarse fraction. Accordingly, the chronological framework is constructed using a grain-size age model. In addition, the histories of chemical weathering and aeolian activity since the late Glacial are reconstructed based on the Al/Ti ratios and coarse fractions, respectively. The results suggest that an enhanced chemical weathering and a weakened aeolian activity occurred on the NETP under a warmer, wetter climate during the early to mid-Holocene(11.3–6.3 ka cal BP), compared with the late Glacial(17.1–11.3 ka cal BP) and the late Holocene(6.3 ka cal BP to present), which responded mainly to the strengthened ASM on orbital time scale. In addition, the synchronous occurrences of weakened chemical weathering, low lake level and intense aeolian activity on suborbital time scale reflect several episodes of weakened ASM. Furthermore, these episodes largely coincide with the centennial-to millennial-scale cold events in the North Atlantic, which demonstrates the close connection between the ASM and the cooling at high latitudes.
基金Supported by the National Natural Science Foundation of China(Nos.41576057,41876092)。
文摘The quantitative analysis of sediment sources in a sink is an important scientific topic and challenge in provenance research.The characteristics of heavy minerals,combined with the geochemical constituents of detrital grains,provide a reliable provenance-tracing approach.We developed a mineral identification method to analyze the multiple grain-size fraction of sediments,from which the elemental geochemistry of hornblende was used to compare the characteristics of sediments from the Huaihe River and Huanghe(Yellow)River in eastern China.Elements that were statistically identified as being able to discriminate sediment provenance were employed to perform a quantitative analysis of the sources of sediments of the abandoned Huanghe River.Results reveal that the Huaihe River is characterized by a high amphibole content of>60%and that the Huanghe and abandoned Huanghe rivers have greater abundances of limonite and carbonate minerals compared with those of the Huaihe River.The contents of trace elements and rare earth elements in hornblende show that the sediments of the abandoned Huanghe River are similar to those of the Huanghe River but different from those of the Huaihe River.Furthermore,chemical mass balance was used to calculate the relative contributions of different provenances of sediment from the abandoned Huanghe River,and nine trace elements of hornblende were identified as discriminators of provenance.Approximately 2%of the hornblende in the abandoned Huanghe River is derived from the Huaihe River and 98%from the Huanghe River.Considering the proportion of hornblende in the total sediment,it is inferred that the contribution of Huaihe River sediment to the abandoned Huanghe River is approximately 0.5%.This study shows that mineral analysis using multiple grain-size fractions(within the wide range of 1Φto 6Φ)with assessment in elemental geochemistry of hornblende can characterize the provenance of fluvial material in coastal zones.
基金sponsored by Marine Commonweal Scientific Research Foundation (201005009)
文摘Suspended sediment concentration(SSC) is an important parameter in marine sedimentology. With the development of technology, many acoustic and optical devices, such as the Laser In-Situ Scattering and Transmissometry, have been designed to measure in situ SSC and grain size distribution. But due to fund or other restrictions, many experiments were only conducted in laboratory, using an indoor laser grain-size analyzer and gravimetric method to measure grain size distribution and concentration, respectively. In this study the laboratory experiment is simplified by omitting the tiring step of gravimetric method. The connections between SSC and other parameters(obscuration, D50 and sorting index) were investigated based on 124 surface sediment samples collected from different offshore areas. A new method is developed for determining SSC in laboratory using a laser grain-size analyzer.
文摘This research paper analyses the grain-size characteristics of the Quaternary deposits at Xingshan near Siping, Jilin province in China by employing graphic measures to study the grain size distribution and its mode of transport and deposition. The Quaternary deposits at Xingshan lie unconformable on Cretaceous rocks made of siltstone, mudstone and sandstone. The average grain size is between 8.06 to 8.55Φ (0.002 6 ~0.003 7 mm). The Quaternary deposits at Xingshan mainly compose of very fine silt to clay. The compositions of the grade are clay 63% and silt 37%. The clay size components are weathered debris transported and deposited by flowing water from the SE highlands or hills to the low lying NW Xingshan plains whereas the silty components accumulated by aoelian process. The Quaternary deposits at Xingshan accumulated in the middle and late Pleistocene interglacial periods from (459.12~39.03) ka to (88.92~7.56) ka. The standard deviation ranged from 0.96 to 1.36Φ, indicating that the sediments are moderately to poorly sorted, Coefficient of skewness ranged from 0.16~0.31 with an average skewness of 0.218, (Positively skewed towards fine). Kurtosis values (0.84~1.05) from the grain size distribution and visual inspection of the frequency curves indicate platykurtic to mesokurtic curves and unimodal to bimodal grain-size distribution. The type of deposit formation is sand dune and the source is at a distal from its provenance.
基金Supported by Social Development Research Project of Scientific and Technological Department of Liaoning Province,ChinaNo.2012225018
文摘AIM: To observe the efficacy and mechanism of grain-sized moxibustion at different acupoints in a rat model of ulcerative colitis (UC). METHODS: Sprague-Dawley rats were randomly divided into control, UC model, grain-sized moxibustion at a single acupoint (CV 12), grain-sized moxibustion at two acupoints (CV 12 and CV 4), grain-sized moxibustion at three acupoints (CV 12, CV 4, and ST 36), and medication groups (n = 8/group). The UC model was established by enema of trinitrobenzene sulfonic acid. Direct moxibustion was used once a day for 7 d. Disease activity index (DAI) was evaluated before and after the treatment. Morphologic changes of intestinal tissue were observed under an optical microscope. The expression of tumor necrosis factor (TNF)-alpha and p38 mitogen-activated protein kinase (p38MAPK) in colonic tissue was detected using Western blot, and the levels of occludin and zonula occludens-1 (ZO-1) mRNAs were detected using reverse transcription PCR. RESULTS: Compared with the control group, the intestinal mucosae were incomplete in the model group, glandular structures were irregular, and submucosae were edematous, hyperemic, and infiltrated with inflammatory cells. The DAI scores and expression of TNF-alpha and p38MAPK were increased significantly in the model group compared to controls (Ps < 0.01), while the mRNA levels of occludin and ZO-1 were reduced significantly (Ps < 0.01). Compared with the model group, colonic mucosa and the arrangement of glands were complete and regular in the treatment groups. DAI scores and the expression of TNF-alpha and p38MAPK were reduced significantly in moxibustion groups compared to controls (Ps < 0.01), while the mRNA levels of occludin and ZO-1 were increased significantly (Ps < 0.01). The improvements in the above indices in the three acupoints group and the medication group were superior to those in the single and two acupoints groups (all P < 0.05). CONCLUSION: Reduction of TNF-alpha and p38MAPK and increased expression of occludin and ZO-1 in colonic tissue represent a potential mechanism for improved intestinal mucosal tissue repair with grain-sized moxibustion.
基金Supported by the National Natural Science Foundation of China (Nos. 40576032 and 40776030)Doctor Foundation of China University of Petroleum
文摘A 700-year record (1.0-1.5 a resolution) of the East Asian winter monsoon (EAWM), based on grain-size analysis and AMSI4C dating of Core EC2005 from the inner-shelf mud wedge of the East China Sea (ECS), was compared with the Dongge stalagmite 8180 record during the mid-Holocene. The upper muddy section of Core EC2005 has been formed mainly by suspended sediments derived from the Changjiang (Yangtze) River mouth since 7.3 ka BP. High precipitation and a strengthened EAWM might have played key roles in the high sedimentation rate (1 324-1 986 crn/ka) between 5.9-5.2 ka BP. The EAWM strengthened when the Asian summer monsoon weakened, especially around 5 500 a BE which corresponded to a worldwide cold event. The EAWM during the mid-Holocene shows statistically significant solar periodicities at 62 and 11 a. The 5 500 a BP cold event might be resulted from orbital forcing and changes in solar activity.
基金National Basic Research Program of China, No.2002CB412401 Scientific Research Foundation of Graduate School of Nanjing University National Natural Science Foundation of China, No.40776023
文摘Seven cores were collected from different sediment zones of tidal flats at Xin- yanggang in north Jiangsu province in August 2007. Sediment grain-size distribution and radioisotopes of ^137Cs and ^210Ppb analysis were carried out for these cores. Sediment rates of the cores and radioisotopes distribution in surface sediment in different zones of the tidal flat were calculated from the ^137Cs and ^210Ppb activities in sediments cores. The results indicated that each tidal zone had experienced different evolution phases, hydrological dynamics in the tidal flats made the grain-size of the surface sediment change gradually. ^137Cs and ^210Ppb activities on the superficial layer of the cores varied spatially and the reason was discussed. On tidal flats, the fluctuation of ^137Cs and ^210Ppb activities in the cores reflected the special sedimentary characteristics. Vegetation affects the grain-size distribution and the vertical profiles of ^137Cs and ^210Ppb in the upper depths. ^137Cs and ^210Ppb chronology got the comparable average sediment rates on the tidal flat. The characteristics of ^137Cs and ^210Ppb in the cores reflected various depositional dynamical environments in different tidal zones and gave information on the different evolvement phases of the tidal zones. Based on the information of grain-size distribution, texture of the cores, sediment rates and topography, the evolution lines of the tidal flat were reconstructed.