Objective:To analyze the characteristics,dynamic changes,and outcomes of the first imaging manifestations of 3 patients with severe COVID-19 in our hospital.Methods:Computed tomography(CT)findings of 3 patients with s...Objective:To analyze the characteristics,dynamic changes,and outcomes of the first imaging manifestations of 3 patients with severe COVID-19 in our hospital.Methods:Computed tomography(CT)findings of 3 patients with severe COVID-19 who tested positive by the nucleic acid test in our hospital were selected,mainly focusing on the morphology,distribution characteristics,and dynamic changes of the first CT findings.Results:3 patients with severe pneumonia were older,with one aged 80.The first chest CT examination for all 3 patients differed.Imaging showed a leafy distribution of consolidation,primarily affecting the lower lobes of both lungs and extending subpleurally.A grid-like pattern was observed,along with changes in the consolidation and air bronchogram.These changes had slower absorption,especially in patients with underlying diseases.Conclusion:CT manifestations of severe COVID-19 have specific characteristics and the analysis of their characteristics and dynamic changes provide valuable insights for clinical treatment.展开更多
The impact of socioeconomic development on land-use and land-cover change(LUCC)in river basins varies spatially and temporally.Exploring the spatiotemporal evolutionary trends and drivers of LUCC under regional dispar...The impact of socioeconomic development on land-use and land-cover change(LUCC)in river basins varies spatially and temporally.Exploring the spatiotemporal evolutionary trends and drivers of LUCC under regional disparities is the basis for the sustainable development and management of basins.In this study,the Weihe River Basin(WRB)in China was selected as a typical basin,and the WRB was divided into the upstream of the Weihe River Basin(UWRB),the midstream of the Weihe River Basin(MWRB),the downstream of the Weihe River Basin(DWRB),the Jinghe River Basin(JRB),and the Luohe River Basin(LRB).Based on land-use data(cultivated land,forestland,grassland,built-up land,bare land,and water body)from 1985 to 2020,we analyzed the spatiotemporal heterogeneity of LUCC in the WRB using a land-use transfer matrix and a dynamic change model.The driving forces of LUCC in the WRB in different periods were detected using the GeoDetector,and the selected influencing factors included meteorological factors(precipitation and temperature),natural factors(elevation,slope,soil,and distance to rivers),social factors(distance to national highway,distance to railway,distance to provincial highway,and distance to expressway),and human activity factors(population density and gross domestic product(GDP)).The results indicated that the types and intensities of LUCC conversions showed considerable disparities across different sub-basins,where complex conversions among cultivated land,forestland,and grassland occurred in the LRB,JRB,and UWRB,with higher dynamic change before 2000.The conversion of other land-use types to built-up land was concentrated in the UWRB,MWRB,and DWRB,with substantial increases after 2000.Additionally,the driving effects of the influencing factors on LUCC in each sub-basin also exhibited distinct diversity,with the LRB and JRB being influenced by the meteorological and social factors,and the UWRB,MWRB,and DWRB being driven by human activity factors.Moreover,the interaction of these influencing factors indicated an enhanced effect on LUCC.This study confirmed the spatiotemporal heterogeneity effects of socioeconomic status on LUCC in the WRB under regional differences,contributing to the sustainable development of the whole basin by managing sub-basins according to local conditions.展开更多
Organized by: Beijing Normal University, National Natural Science Foundation of China Hosted by: Institute of Resources Science, Beijing Normal UniversityKey Laboratory of Environmental Change and Natural Disaster, Mi...Organized by: Beijing Normal University, National Natural Science Foundation of China Hosted by: Institute of Resources Science, Beijing Normal UniversityKey Laboratory of Environmental Change and Natural Disaster, Ministry of Education of ChinaTopics:1) Detecting and monitoring LUCC2) Temporal-spatial characteristics in LUCC3) Driving model for LUCC4) Forecasting and modeling LUCC 5) Phenological and biochemical response on LUCC6) Regional LUCC and microclimate 7) LUCC in the context of global change8) Impact of global change on the sustainable land-use modelingAbstract submission: The official language of this conference is English. We invite papers written in English and an abstract of less than one page of standard A4 size to the Conference Secretariat by Apr 15, 2001. Registration Fee: 280 US$ (300 US$ after July 15, 2001)Add:No. 19, Xinjiekouwai Street, 100875, Institute of Resources Science, Beijing Normal University, Beijing, ChinaTel:86-10-62207656 or 62209024 Fax:010-62208178http:// 202.112.93.50/LUCCD2001/index.htmlE-mail: Pwang@bnu.edu.cn Cyh@bnu.edu.展开更多
Dynamic quantitative assessment of soil organic C and N is an available approach to understand the exact impact of land management on soils fertility. In this study the biomass of plants and content of soil organic C ...Dynamic quantitative assessment of soil organic C and N is an available approach to understand the exact impact of land management on soils fertility. In this study the biomass of plants and content of soil organic C and N were compared in four typical land use systems which were planted with Ryegrass (Lolium multiflorum Lam.), Bahiagrass (Paspalum notatum Flugge.), Citrus (Citrus reticulata Blanco.), and Masson pine (Pinus Massoniana Lamb.) during 10 years in south China. Although biomass of plants in these four land use systems was nearly at the same level in the former investigation, total biomass for Ryegrass (RG), Bahiagrass (BG) was 3.68 and 3.75 times higher than that for Citrus (CT), and 2.06 and 2.14 times higher than that for Masson pine (MP) over 10 years of cultivation, respectively. Especially, underground total biomass for both RG and BG was over 10 times larger than that for CT and MP, indicating that forage grasses was much more beneficial to increase organic C and N storage in soils than CT and MP. The change content of soil organic C and N mainly occurred within soil depth of the 0–40 cm. The increased content of soil organic carbon and nitrogen was for 1.5 t·hm?2 and 0.2 t·hm?2 in the soil with planting RG and BG, and was for 1.2 t·hm?2 and 0.02 t·hm?2 in the soil with planting CT. An average loss was for 0.4 t·hm?2 and 0.04 t·hm?2 in the soil with planting MP during 10-year period. Keywords Soil organic carbon - Soil organic nitrogen - Dynamic change - Land use - Quantitative assessment CLC number S153.61 Document code A Foundation item: This research was partly supported by National Natural Science Foundation of China (30100144), and by Scientific Committee of Shenyang City (1011501900).Biography: WANG Xiao-ju (1967-), mail, Ph.D. Researcher in Center for Environmental Science in Saitama. Saitama Prefecture 347 0115, Japan.Responsible editor: Zhu Hong展开更多
[ Objective ] The dynamic change of heterobacteria and vibrios in larvae industrialized culture system was studied to provide scientific reference for healthy cultivation of shrimp. [ Method ] The heterobacteria, vibr...[ Objective ] The dynamic change of heterobacteria and vibrios in larvae industrialized culture system was studied to provide scientific reference for healthy cultivation of shrimp. [ Method ] The heterobacteria, vibrios and pathogenic vibrio parahaemolyticus were monitored in larvae industrialized culture system. [ Result] The heterobacteria, vibrios and pathogenic vibrio parahaemolyticus were the most in fertilized eggs of shrimp but the least in nauplius, then their number would increase with growth. During whole rearing period, both boterobacteria in larvae, vibrios in water would increase by one order of magnitude, while both vibrios in larvae and heterobacteria in water would increase by two orders of magnitude. There were many heterobacteria and vibrios but few vibrio parahaemolyticus in living bait. The correlation coefficients between larvae and heterobacteria and vibrios in water were 0. 704 and 0. 840 in culture system respectively, while the correlation among heterobacteria, vibrios in living bait and larvae, water were weak or negative. [ Conclusion ] There was a dynamic relation between water and larvae in rearing period, and restrictly control of culture condition would restrain the occurrence of disease caused by vibrio parahaemolyticus, besides that bacteria number in bait was not obviously correlated with bacteria nubmer in culture system.展开更多
Background:As is widely known,an increasing number of forest areas were managed to preserve and enhance the health of forest ecosystems.However,previous research on forest management has often overlooked the importanc...Background:As is widely known,an increasing number of forest areas were managed to preserve and enhance the health of forest ecosystems.However,previous research on forest management has often overlooked the importance of structure-based.Aims:Our objectives were to define the direction of structure-based forest management.Subsequently,we investigated the relationships between forest structure and the regeneration,growth,and mortality of trees under different thinning treatments.Ultimately,the drivers of forest structural change were explored.Methods:On the basis of 92 sites selected from northeastern China,with different recovery time (from 1 to 15years) and different thinning intensities (0–59.9%) since the last thinning.Principal component analysis (PCA)identified relationships among factors determining forest spatial structure.The structural equation model (SEM)was used to analyze the driving factors behind the changes in forest spatial structure after thinning.Results:Light thinning (0–20%trees removed) promoted forest regeneration,and heavy thinning (over 35% of trees removed) facilitated forest growth.However,only moderate thinning (20%–35%trees removed) created a reasonable spatial structure.While dead trees were clustered,and they were hardly affected by thinning intensity.Additionally,thinning intensity,recovery time,and altitude indirectly improve the spatial structure of the forest by influencing diameter at breast height (DBH) and canopy area.Conclusion:Creating larger DBH and canopy area through thinning will promote the formation of complex forest structures,which cultivates healthy and stable forests.展开更多
Objective] This study was performed to investigate the trait changes and their correlations as wel as the dynamic changes of biological yield of Xuzishu 3, which wil help to enhance the yield and anthocyanin content o...Objective] This study was performed to investigate the trait changes and their correlations as wel as the dynamic changes of biological yield of Xuzishu 3, which wil help to enhance the yield and anthocyanin content of sweetpotato by cul-tivation. [Method] We systematical y measured the agronomic traits, qualitative char-acters and biological yield of Xuzishu 3 during six growing periods to investigate the dynamic changes of its essential characters and yield accumulation. [Result] The characters of Xuzishu 3 appeared most prosperous after the 90th d except for an-thocyanin content. Extremely significant positive correlations were found between ev-ery two of the dry matter rates of above-ground parts (including leaf petioles, leaves and stems), reducing sugar content and potato weight per plant. Assimilated product distributed more in stems and leaves than in storage roots before the 90th d in growing period. Photosynthetic capacity and net assimilation rate gradual y de-creased after the 90th d, but the assimilated product distributing to storage roots in-creased quickly and maximized in the 135th d. [Conclusion] Xuzishu 3 is a late ma-turing variety requiring more fertilizer, and the accumulation of anthocyanin fluctuates during the growth period of Xuzishu 3. So yield of Xuzishu 3 can be increased by applying more fertilizer and extending the growth period reasonably, meanwhile the anthocyanin content can be increased by means of control ing temperature, light, water and phytohormone within 60 d after planting.展开更多
BACKGROUND Inflammation-related markers including neutrophil-to-lymphocyte ratio(NLR),platelet-to-lymphocyte ratio(PLR),monocyte-to-lymphocyte ratio(MLR),systemic immune-inflammation index(SII),systemic inflammation r...BACKGROUND Inflammation-related markers including neutrophil-to-lymphocyte ratio(NLR),platelet-to-lymphocyte ratio(PLR),monocyte-to-lymphocyte ratio(MLR),systemic immune-inflammation index(SII),systemic inflammation response index(SIRI)and prognostic nutritional index(PNI)could reflect tumor immune microenvironment and predict prognosis of cancers.However,it had not been explored in alpha-fetoprotein(AFP)producing gastric cancer(GC).AIM To determine the predictive value of inflammation-related peripheral blood markers including as NLR,PLR,MLR,SII,SIRI and PNI in the prognosis of AFPproducing GC(AFPGC).Besides,this study would also compare the differences in tumor immune microenvironment,clinical characteristics and prognosis between AFPGC and AFP-GC patients to improve the understanding of this disease.METHODS 573 patients enrolled were retrospectively studied.They were divided into AFP+group(AFP≥20 ng/mL)and AFP-group(AFP<20 ng/mL),comparing the levels of NLR/PLR/MLR/SII/SIRI/PNI and prognosis.In AFP+group,the impact of NLR/PLR/MLR/SII/SIRI/PNI and their dynamic changes on prognosis were further explored.RESULTS Compared with AFP-patients,AFP+patients had higher NLR/PLR/MLR/SII/-SIRI and lower PNI levels and poorer overall survival(OS).In the AFP+group,mortality was significantly lower in the lower NLR/PLR/MLR/SII/SIRI group and higher PNI group.Moreover,the dynamic increase(NLR/PLR/MLR/SII/-SIRI)or decrease(PNI)was associated with the rise of mortality within 1 year of follow-up.CONCLUSION Compared with AFP-patients,the level of inflammation-related peripheral blood markers significantly increased in AFP+patients,which was correlated with OS of AFP+patients.Also,the gradual increase of SII and SIRI was associated with the risk of death within one year in AFP+patients.AFPGC should be considered as a separate type and distinguished from AFP-GC because of the difference in tumor immune microenvironment.It requires basic experiments and large clinical samples in the future.展开更多
[Objective] The aim was to study the effects of combined of manure and fertilizer on the content of nutrients in purplish soil as well as release dynamics of enzyme activities.[Method] The effects of manure and fertil...[Objective] The aim was to study the effects of combined of manure and fertilizer on the content of nutrients in purplish soil as well as release dynamics of enzyme activities.[Method] The effects of manure and fertilizer application on the content of AOM,NH+4-N and NO-3-N in soil as well as release dynamics of enzyme activities were studied by means of simulation culturing.[Result] In the treatments of combined application of simulation culture experiment,the content of active organic matters,NH+4-N,NO-3-N and soil enzyme activities changed dynamically,which showed a shape of inverted "S" with two or more peaks.Compared with the treatment of fertilization,their peaks were relatively flat and occurred relatively late,while the treatment of fertilization had only one but the highest peak.The content of active organic matter came to top around 10 d in the order of cow5fertilizer5pig5fertilizer5cow manurepig manurefertilizer Ⅰfertilizer Ⅱ;the activity of urease came to top around 10 d in all treatments and in the order of pig manurecow5fertilizer5cow manurefertilizer Ⅰfertilizer Ⅱpig5fertilizer5.The activity of saccharase was in the order of pig5fertilizer5pig manurecow5fertilizer5cow manureCKfertilizer Ⅱfertilizer Ⅰ.[Conclusion] The study could provide the theoretical basis for reasonable application of manure and fertilizer.展开更多
[Objective] The paper was to study the dynamic changes of nitrogen in saline-alkaline paddy field and its potential environment impacts. [Method] With typical sodic saline-alkaline paddy fields of Songnen Plain as stu...[Objective] The paper was to study the dynamic changes of nitrogen in saline-alkaline paddy field and its potential environment impacts. [Method] With typical sodic saline-alkaline paddy fields of Songnen Plain as study object,field test method was used to explore the dynamic changes was strong alkof nitrogen in paddy field of the region and its potential impact on environment. [Result] The soil in test regionaline with high CEC and C/N ratios,as well as poor preserving capacity of fertilizer. During the two-year field experiment,the indicators of salinization fluctuated. Initially,the concentrations of total nitrogen and ammonia nitrogen reached their maximum values,then decreased over time as a result of heavy rain. The maximum of nitrate concentration appeared later than those of total nitrogen and ammonia nitrogen. Ammonia volatilization accounted for 18.9%-28.8% of the nitrogen loss. The total nitrogen concentration in surface water was higher than the national Class Ⅲ surface water environmental quality standard. The concentration of ammonia from the recession flow of agricultural field was considerably high,which would potentially threaten the fishery in the downstream of Chagan Lake. [Conclusion] The study provided theoretical basis for saline-alkaline soil management and conservation of water and fishery resources.展开更多
This paper reports the dynamic changes of soil and water loss in the red soil region of Southern China since the 1950s. The red soil region covers eight provinces: Jiangxi, Zhejiang, Fujian, Anhui, Hubei, Hunan, Guang...This paper reports the dynamic changes of soil and water loss in the red soil region of Southern China since the 1950s. The red soil region covers eight provinces: Jiangxi, Zhejiang, Fujian, Anhui, Hubei, Hunan, Guangdong and Hainan. From the 1950s to 1986, the annual rate of soil erosion increased by 3.4%. From 1986 to 1996 and from 1996 to 2000, the annual rates of soil erosion decreased by 2.0% and 0.32%, respectively. Field surveys showed that from 2000 to 2005, the area of soil and water loss decreased annually by 1.2%. This decrease was a result of large-scale erosion control activities across China. Although the eroded soil has been restored, the restoration process is very slow and full restoration will take a long time. Our report suggests that controlling soil and water loss is a challenging task, and additional measures must be taken to effectively control the soil erosion in the red soil region.展开更多
Through a case study of Shenzhen City,China,this study focused on a quantitative method for analyzing the spatial processes involved in green infrastructure changes associated with rapid urbanization.Based on RS,GIS a...Through a case study of Shenzhen City,China,this study focused on a quantitative method for analyzing the spatial processes involved in green infrastructure changes associated with rapid urbanization.Based on RS,GIS and SPSS statistics software,the approach includes selection of the square analysis units and representative landscape metrics,quantification of the change types of landscape metrics in all analysis units through two indices and hierarchical cluster analysis of the above analysis units with different landscape metric change types(i.e.spatial attributes).The analyses verify that there is a significant sequence of continuous changes in green infrastructure in Shenzhen.They are the perforation,the segmentation,the fragmentation,the evanescence and the filling-in processes,which have a good spatio-temporal correspondence with urbanization and reflect the synthetic influence of urban planning,government policies and landforms.Compared with other studies on quantifying the spatial pattern,this study provides an alternative probe into linking the spatial pattern to spatial processes and the corresponding ecological processes in the future.These spatio-temporal processes offer many opportunities for identifying,protecting and restoring key elements in an urban green infrastructure network for areas in the early stages of urbanization or for non-urbanized areas.展开更多
AIM: To evaluate the dynamic ocular biometric changes of a modified form-deprivation myopia model in young guinea pigs. METHODS: The animals were randomly assigned to two groups: the monocularly deprived facemask grou...AIM: To evaluate the dynamic ocular biometric changes of a modified form-deprivation myopia model in young guinea pigs. METHODS: The animals were randomly assigned to two groups: the monocularly deprived facemask group (MDF, with all the right eyes covered, n=24) and the normal control group(free of facemask, n=24). Each group was then equally divided into four subgroups which were followed up for 2, 4, 6 and 8 weeks, respectively. Parameters measured from every eye included refraction, corneal curvature, axial length and the dry weight of sclera at the posterior pole. RESULTS: All the facemasks remained in place during the follow-up. The covered eyes developed myopia with the vitreous chamber lengthening and the dry weight of posterior sclera reduced at each time point compared with the contralateral uncovered (P<0.05 at all time points). The changes had a linear correlation with the deprivation time (P<0.05). There were no significant differences in all the parameters between the uncovered eyes of MDF group and the normal control group (P>0.05 at all time points). CONCLUSION: Monocular form deprivation with the facemask is highly effective and non-invasive in inducing axial myopia in guinea pigs. The axial myopia is mainly caused by the increased vitreous chamber length and the weakened posterior sclera rigidity. The form-deprivation eye didn't interfere with the natural development of the contralateral eye.展开更多
The decrease of total cultivated area and the lower per capita available arable land resource are now serious problems in Shandong Province, a major agricultural province in China. These problems will become more seri...The decrease of total cultivated area and the lower per capita available arable land resource are now serious problems in Shandong Province, a major agricultural province in China. These problems will become more serious along with the further development of economy. In this paper, based on the statistical information at provincial and county levels, the changes of arable land in Shandong Province and their driving forces during the last 50 years are analyzed. The general changing trends of arable land and per capita available arable land are reducing, and the trends of decrease will continue when the economy is developing. The result of GIS spatial analysis shows that the change of the arable land use in Shandong Province has a regional difference. Eight variables having influences on cultivated land change are analyzed by principal component analysis. The results show that the dynamic development of economy, pressure of social system and progress of scientific techniques in agriculture are the main causes for cultivated land reduction. The principal factors which can be considered as driving forces for arable land change include per capita net living space, total population and per ha grain yield. By using regressive equation, along with analysis on population growth and economic development, cultivated areas in Shandong Province in 2005 and 2010 are predicted respectively. The predicted cultivated areas in Shandong will be 6435.47 thousand hain 2005 and 6336.23 thousand ha in 2010 respectively.展开更多
Using the theory and method of the ecological footprint, and combining the changes of regional land use, resource environment, population, society and economy, this paper calculated the ecological footprint, ecologica...Using the theory and method of the ecological footprint, and combining the changes of regional land use, resource environment, population, society and economy, this paper calculated the ecological footprint, ecological carrying capacity and ecological surplus/loss in 1986-2002 on the Loess Plateau in northern Shaanxi Province. What is more, this paper has put forward the concept of ecological pressure index, set up ecological pressure index models, and ecological security grading systems, and the prediction models of different ecological footprints, ecological carrying capacity, ecological surplus and ecological safety change, and also has assessed the ecological footprint demands of 10,000 yuan GDE The results of this study are as follows: (1) the ecological carrying capacity in northern Shaanxi shows a decreasing trend, the difference of reducing range is the fastest; (2) the ecological footprint appears an increasing trend; (3) ecological pressure index rose to 0.91 from 0.44 during 1986-2002 on the Loess Plateau of northern Shaanxi with an increase of 47%; and (4) the ecological security in the study area is in a critical state, and the ecological oressure index has been increasing rapidlv.展开更多
According to dimensionless analysis of the coalbed methane (CBM) production data of Fanzhuang block in southern Qinshui basin, the dimensionless gas production rate is calculated to quantitatively divide the CBM wel...According to dimensionless analysis of the coalbed methane (CBM) production data of Fanzhuang block in southern Qinshui basin, the dimensionless gas production rate is calculated to quantitatively divide the CBM well production process into four stages, i.e., drai- nage stage, unstable gas production stage, stable gas pro- duction stage, and gas production decline stage. By the material balance method, the coal reservoir permeability change in different stages is quantitatively characterized. The characteristics and control mechanisms of change in coalbed permeability (CICP) during different production stages are concluded on five aspects, i.e., permeability trend variation, controlling mechanism, system energy, phase state compositions, and production performance. The study reveals that CICP is characterized by first decline, then recovery, and finally by increase and is controlled directly by effective stress and matrix shrinkage effects. Further, the duration and intensity of the matrix shrinkage effect are inherently controlled by adsorption and desorp- tion features.展开更多
The spatial calculating analysis model is based on GIS overlay. It will compartmentalize the land in research district into three spatial types: unchanged parts, converted parts and increased parts. By this method we ...The spatial calculating analysis model is based on GIS overlay. It will compartmentalize the land in research district into three spatial types: unchanged parts, converted parts and increased parts. By this method we can evaluate the numerical model and dynamic degree model for calculating land-use change rates. Furthermore, the paper raises the possibility of revising the calculating analysis model of spatial information in order to predicate more precisely the dynamic changing level of all types of land uses. In the most concrete terms, the model is used mainly to understand changed area and changed rates (increasing or decreasing) of different land types from microcosmic angle and establish spatial distribution and spatio-temporal principles of the changing urban lands. And we will try to find out why the situation can take place by combining social and economic situations. The result indicates the calculating analysis model of spatial information can derive more accurate procedure of spatial transference and increase of all kinds of land from microcosmic angle. By this model and technology we can conduct the research of land-use spatio-temporal structure evolution more systematically and more deeply, and can obtain a satisfactory result. The result will benefit the rational planning and management of urban land use of developed coastal areas in China in the future.展开更多
Based on the data of the repeated gravity observation network in Chinese mainland since 1998, we analyzed the temporal changes of regional gravity field before the 2008 Yutian Ms7.3 earthquake. The result shows some m...Based on the data of the repeated gravity observation network in Chinese mainland since 1998, we analyzed the temporal changes of regional gravity field before the 2008 Yutian Ms7.3 earthquake. The result shows some mid-to-long term (two to ten years) changes during the earthquake' s preparation. Notable fea- tures are a gravity increase lasting several years and a relatively large-scaled gradient zone of gravity change, the former indicating a continuous energy accumulation and the latter a possible location of seismic rupture. These gravity changes showed a trend of increase-accelerated increase-decelerated increase, similar to that of the Tangshan Ms7.8 earthquake in 1976. The maximum accumulated gravity change related to the earthquake reached 200 × 10 -8 ms -2.展开更多
In the present paper, a comparison of the performance between moving cutting data-rescaled range analysis (MC- R/S) and moving cutting data-rescaled variance analysis (MC-V/S) is made. The results clearly indicate...In the present paper, a comparison of the performance between moving cutting data-rescaled range analysis (MC- R/S) and moving cutting data-rescaled variance analysis (MC-V/S) is made. The results clearly indicate that the operating efficiency of the MC-R/S algorithm is higher than that of the MC-V/S algorithm. In our numerical test, the computer time consumed by MC-V/S is approximately 25 times that by MC-R/S for an identical window size in artificial data. Except for the difference in operating efficiency, there are no significant differences in performance between MC-R/S and MC-V/S for the abrupt dynamic change detection. Mc-R/s and MC-V/S both display some degree of anti-noise ability. However, it is important to consider the influences of strong noise on the detection results of MC-R/S and MC-V/S in practical application展开更多
Our study explored the dynamic changes in andthe relationship between the DNA damage marker8-hydroxy-2'-deoxyguanosine (8-OHdG) and theDNA repair marker 8-hydroxyguanine DNAglycosidase 1 (hOGG1) according to the ...Our study explored the dynamic changes in andthe relationship between the DNA damage marker8-hydroxy-2'-deoxyguanosine (8-OHdG) and theDNA repair marker 8-hydroxyguanine DNAglycosidase 1 (hOGG1) according to the length ofoccupational employment in nickel smeltingworkers. One hundred forty nickel-exposedsmelting workers and 140 age-matched unexposedoffice workers were selected from the Jinchangcohort. The 8-OHdG levels in smelting workers wassignificantly higher than in office workers (Z=-8.688,P〈0.05) and the 8-OHdG levels among nickelsmelting workers in the 10-14 y employment lengthcategory was significantly higher than among allpeers. The hOGG1 levels among smelting workerswere significantly lower than those of non-exposedworkers (Z=-8.948, P〈0.05). There were significantdifferences between employment length andhOGG1 levels, with subjects employed in nickelsmelting for 10-14 y showing the highest levels ofhOGG1. Correlation analysis showed positivecorrelations between 8-OHdG and hOGG1 levels(r=0.413; P〈0.01). DNA damage was increased withemployment length among nickel smelting workersand was related to the inhibition of hOGG1 repaircapacity.展开更多
基金Qinghai Provincial Health Commission Medical and Health Science and Technology Project Guiding Topics“Analysis of Dynamic Changes in Chest Imaging of New Coronavirus Pneumonia in Qinghai Province”(2022-wjzdx-63)。
文摘Objective:To analyze the characteristics,dynamic changes,and outcomes of the first imaging manifestations of 3 patients with severe COVID-19 in our hospital.Methods:Computed tomography(CT)findings of 3 patients with severe COVID-19 who tested positive by the nucleic acid test in our hospital were selected,mainly focusing on the morphology,distribution characteristics,and dynamic changes of the first CT findings.Results:3 patients with severe pneumonia were older,with one aged 80.The first chest CT examination for all 3 patients differed.Imaging showed a leafy distribution of consolidation,primarily affecting the lower lobes of both lungs and extending subpleurally.A grid-like pattern was observed,along with changes in the consolidation and air bronchogram.These changes had slower absorption,especially in patients with underlying diseases.Conclusion:CT manifestations of severe COVID-19 have specific characteristics and the analysis of their characteristics and dynamic changes provide valuable insights for clinical treatment.
基金supported by the Natural Science Basic Research Program of Shaanxi Province(2019JLZ-15)the Water Science and Technology Program of Shaanxi Province(2018slkj-4)the Research Fund of the State Key Laboratory of Eco-hydraulics in Northwest Arid Region,Xi'an University of Technology(2019KJCXTD-5)。
文摘The impact of socioeconomic development on land-use and land-cover change(LUCC)in river basins varies spatially and temporally.Exploring the spatiotemporal evolutionary trends and drivers of LUCC under regional disparities is the basis for the sustainable development and management of basins.In this study,the Weihe River Basin(WRB)in China was selected as a typical basin,and the WRB was divided into the upstream of the Weihe River Basin(UWRB),the midstream of the Weihe River Basin(MWRB),the downstream of the Weihe River Basin(DWRB),the Jinghe River Basin(JRB),and the Luohe River Basin(LRB).Based on land-use data(cultivated land,forestland,grassland,built-up land,bare land,and water body)from 1985 to 2020,we analyzed the spatiotemporal heterogeneity of LUCC in the WRB using a land-use transfer matrix and a dynamic change model.The driving forces of LUCC in the WRB in different periods were detected using the GeoDetector,and the selected influencing factors included meteorological factors(precipitation and temperature),natural factors(elevation,slope,soil,and distance to rivers),social factors(distance to national highway,distance to railway,distance to provincial highway,and distance to expressway),and human activity factors(population density and gross domestic product(GDP)).The results indicated that the types and intensities of LUCC conversions showed considerable disparities across different sub-basins,where complex conversions among cultivated land,forestland,and grassland occurred in the LRB,JRB,and UWRB,with higher dynamic change before 2000.The conversion of other land-use types to built-up land was concentrated in the UWRB,MWRB,and DWRB,with substantial increases after 2000.Additionally,the driving effects of the influencing factors on LUCC in each sub-basin also exhibited distinct diversity,with the LRB and JRB being influenced by the meteorological and social factors,and the UWRB,MWRB,and DWRB being driven by human activity factors.Moreover,the interaction of these influencing factors indicated an enhanced effect on LUCC.This study confirmed the spatiotemporal heterogeneity effects of socioeconomic status on LUCC in the WRB under regional differences,contributing to the sustainable development of the whole basin by managing sub-basins according to local conditions.
文摘Organized by: Beijing Normal University, National Natural Science Foundation of China Hosted by: Institute of Resources Science, Beijing Normal UniversityKey Laboratory of Environmental Change and Natural Disaster, Ministry of Education of ChinaTopics:1) Detecting and monitoring LUCC2) Temporal-spatial characteristics in LUCC3) Driving model for LUCC4) Forecasting and modeling LUCC 5) Phenological and biochemical response on LUCC6) Regional LUCC and microclimate 7) LUCC in the context of global change8) Impact of global change on the sustainable land-use modelingAbstract submission: The official language of this conference is English. We invite papers written in English and an abstract of less than one page of standard A4 size to the Conference Secretariat by Apr 15, 2001. Registration Fee: 280 US$ (300 US$ after July 15, 2001)Add:No. 19, Xinjiekouwai Street, 100875, Institute of Resources Science, Beijing Normal University, Beijing, ChinaTel:86-10-62207656 or 62209024 Fax:010-62208178http:// 202.112.93.50/LUCCD2001/index.htmlE-mail: Pwang@bnu.edu.cn Cyh@bnu.edu.
基金National Natural Science Foundation of China (30100144) and by Scientific Committee of Shenyang City (1011501900).
文摘Dynamic quantitative assessment of soil organic C and N is an available approach to understand the exact impact of land management on soils fertility. In this study the biomass of plants and content of soil organic C and N were compared in four typical land use systems which were planted with Ryegrass (Lolium multiflorum Lam.), Bahiagrass (Paspalum notatum Flugge.), Citrus (Citrus reticulata Blanco.), and Masson pine (Pinus Massoniana Lamb.) during 10 years in south China. Although biomass of plants in these four land use systems was nearly at the same level in the former investigation, total biomass for Ryegrass (RG), Bahiagrass (BG) was 3.68 and 3.75 times higher than that for Citrus (CT), and 2.06 and 2.14 times higher than that for Masson pine (MP) over 10 years of cultivation, respectively. Especially, underground total biomass for both RG and BG was over 10 times larger than that for CT and MP, indicating that forage grasses was much more beneficial to increase organic C and N storage in soils than CT and MP. The change content of soil organic C and N mainly occurred within soil depth of the 0–40 cm. The increased content of soil organic carbon and nitrogen was for 1.5 t·hm?2 and 0.2 t·hm?2 in the soil with planting RG and BG, and was for 1.2 t·hm?2 and 0.02 t·hm?2 in the soil with planting CT. An average loss was for 0.4 t·hm?2 and 0.04 t·hm?2 in the soil with planting MP during 10-year period. Keywords Soil organic carbon - Soil organic nitrogen - Dynamic change - Land use - Quantitative assessment CLC number S153.61 Document code A Foundation item: This research was partly supported by National Natural Science Foundation of China (30100144), and by Scientific Committee of Shenyang City (1011501900).Biography: WANG Xiao-ju (1967-), mail, Ph.D. Researcher in Center for Environmental Science in Saitama. Saitama Prefecture 347 0115, Japan.Responsible editor: Zhu Hong
基金the National High Technology Research and Development Program of China (863 Program) (2006AA10A406)National Key Technology Research and Development Program of China (2006BAD01A13)Public Agriculture Specific Research Program (nyhyzx07-042)~~
文摘[ Objective ] The dynamic change of heterobacteria and vibrios in larvae industrialized culture system was studied to provide scientific reference for healthy cultivation of shrimp. [ Method ] The heterobacteria, vibrios and pathogenic vibrio parahaemolyticus were monitored in larvae industrialized culture system. [ Result] The heterobacteria, vibrios and pathogenic vibrio parahaemolyticus were the most in fertilized eggs of shrimp but the least in nauplius, then their number would increase with growth. During whole rearing period, both boterobacteria in larvae, vibrios in water would increase by one order of magnitude, while both vibrios in larvae and heterobacteria in water would increase by two orders of magnitude. There were many heterobacteria and vibrios but few vibrio parahaemolyticus in living bait. The correlation coefficients between larvae and heterobacteria and vibrios in water were 0. 704 and 0. 840 in culture system respectively, while the correlation among heterobacteria, vibrios in living bait and larvae, water were weak or negative. [ Conclusion ] There was a dynamic relation between water and larvae in rearing period, and restrictly control of culture condition would restrain the occurrence of disease caused by vibrio parahaemolyticus, besides that bacteria number in bait was not obviously correlated with bacteria nubmer in culture system.
基金financially supported by the Innovation Foundation for Doctoral Program of Forestry Engineering of Northeast Forestry University,grant number:LYGC202117the China Scholarship Council(CSC),grant number:202306600046+1 种基金the Research and Development Plan of Applied Technology in Heilongjiang Province of China,grant number:GA19C006Research and Demonstration on Functional Improvement Technology of Forest Ecological Security Barrier in Heilongjiang Province,grant number:GA21C030。
文摘Background:As is widely known,an increasing number of forest areas were managed to preserve and enhance the health of forest ecosystems.However,previous research on forest management has often overlooked the importance of structure-based.Aims:Our objectives were to define the direction of structure-based forest management.Subsequently,we investigated the relationships between forest structure and the regeneration,growth,and mortality of trees under different thinning treatments.Ultimately,the drivers of forest structural change were explored.Methods:On the basis of 92 sites selected from northeastern China,with different recovery time (from 1 to 15years) and different thinning intensities (0–59.9%) since the last thinning.Principal component analysis (PCA)identified relationships among factors determining forest spatial structure.The structural equation model (SEM)was used to analyze the driving factors behind the changes in forest spatial structure after thinning.Results:Light thinning (0–20%trees removed) promoted forest regeneration,and heavy thinning (over 35% of trees removed) facilitated forest growth.However,only moderate thinning (20%–35%trees removed) created a reasonable spatial structure.While dead trees were clustered,and they were hardly affected by thinning intensity.Additionally,thinning intensity,recovery time,and altitude indirectly improve the spatial structure of the forest by influencing diameter at breast height (DBH) and canopy area.Conclusion:Creating larger DBH and canopy area through thinning will promote the formation of complex forest structures,which cultivates healthy and stable forests.
基金Supported by Earmarked Fund for China Agriculture Research System(CARS-11-B03)Key Technology Research and Development Program of Jiangsu Province(BE2013437)the Agricultural Science Independent Innovation Foundation of Jiangsu Province[CX(11)4057]~~
文摘Objective] This study was performed to investigate the trait changes and their correlations as wel as the dynamic changes of biological yield of Xuzishu 3, which wil help to enhance the yield and anthocyanin content of sweetpotato by cul-tivation. [Method] We systematical y measured the agronomic traits, qualitative char-acters and biological yield of Xuzishu 3 during six growing periods to investigate the dynamic changes of its essential characters and yield accumulation. [Result] The characters of Xuzishu 3 appeared most prosperous after the 90th d except for an-thocyanin content. Extremely significant positive correlations were found between ev-ery two of the dry matter rates of above-ground parts (including leaf petioles, leaves and stems), reducing sugar content and potato weight per plant. Assimilated product distributed more in stems and leaves than in storage roots before the 90th d in growing period. Photosynthetic capacity and net assimilation rate gradual y de-creased after the 90th d, but the assimilated product distributing to storage roots in-creased quickly and maximized in the 135th d. [Conclusion] Xuzishu 3 is a late ma-turing variety requiring more fertilizer, and the accumulation of anthocyanin fluctuates during the growth period of Xuzishu 3. So yield of Xuzishu 3 can be increased by applying more fertilizer and extending the growth period reasonably, meanwhile the anthocyanin content can be increased by means of control ing temperature, light, water and phytohormone within 60 d after planting.
文摘BACKGROUND Inflammation-related markers including neutrophil-to-lymphocyte ratio(NLR),platelet-to-lymphocyte ratio(PLR),monocyte-to-lymphocyte ratio(MLR),systemic immune-inflammation index(SII),systemic inflammation response index(SIRI)and prognostic nutritional index(PNI)could reflect tumor immune microenvironment and predict prognosis of cancers.However,it had not been explored in alpha-fetoprotein(AFP)producing gastric cancer(GC).AIM To determine the predictive value of inflammation-related peripheral blood markers including as NLR,PLR,MLR,SII,SIRI and PNI in the prognosis of AFPproducing GC(AFPGC).Besides,this study would also compare the differences in tumor immune microenvironment,clinical characteristics and prognosis between AFPGC and AFP-GC patients to improve the understanding of this disease.METHODS 573 patients enrolled were retrospectively studied.They were divided into AFP+group(AFP≥20 ng/mL)and AFP-group(AFP<20 ng/mL),comparing the levels of NLR/PLR/MLR/SII/SIRI/PNI and prognosis.In AFP+group,the impact of NLR/PLR/MLR/SII/SIRI/PNI and their dynamic changes on prognosis were further explored.RESULTS Compared with AFP-patients,AFP+patients had higher NLR/PLR/MLR/SII/-SIRI and lower PNI levels and poorer overall survival(OS).In the AFP+group,mortality was significantly lower in the lower NLR/PLR/MLR/SII/SIRI group and higher PNI group.Moreover,the dynamic increase(NLR/PLR/MLR/SII/-SIRI)or decrease(PNI)was associated with the rise of mortality within 1 year of follow-up.CONCLUSION Compared with AFP-patients,the level of inflammation-related peripheral blood markers significantly increased in AFP+patients,which was correlated with OS of AFP+patients.Also,the gradual increase of SII and SIRI was associated with the risk of death within one year in AFP+patients.AFPGC should be considered as a separate type and distinguished from AFP-GC because of the difference in tumor immune microenvironment.It requires basic experiments and large clinical samples in the future.
基金Supported by"11th Five-Year Plan"National Key Technology Research and Development Program(2006BAD25B08)~~
文摘[Objective] The aim was to study the effects of combined of manure and fertilizer on the content of nutrients in purplish soil as well as release dynamics of enzyme activities.[Method] The effects of manure and fertilizer application on the content of AOM,NH+4-N and NO-3-N in soil as well as release dynamics of enzyme activities were studied by means of simulation culturing.[Result] In the treatments of combined application of simulation culture experiment,the content of active organic matters,NH+4-N,NO-3-N and soil enzyme activities changed dynamically,which showed a shape of inverted "S" with two or more peaks.Compared with the treatment of fertilization,their peaks were relatively flat and occurred relatively late,while the treatment of fertilization had only one but the highest peak.The content of active organic matter came to top around 10 d in the order of cow5fertilizer5pig5fertilizer5cow manurepig manurefertilizer Ⅰfertilizer Ⅱ;the activity of urease came to top around 10 d in all treatments and in the order of pig manurecow5fertilizer5cow manurefertilizer Ⅰfertilizer Ⅱpig5fertilizer5.The activity of saccharase was in the order of pig5fertilizer5pig manurecow5fertilizer5cow manureCKfertilizer Ⅱfertilizer Ⅰ.[Conclusion] The study could provide the theoretical basis for reasonable application of manure and fertilizer.
基金Supported by Major Projects of State Water Pollution Control and Management (2008ZX07207-006-04)Shanghai Leading Academic Discipline Project (B604)~~
文摘[Objective] The paper was to study the dynamic changes of nitrogen in saline-alkaline paddy field and its potential environment impacts. [Method] With typical sodic saline-alkaline paddy fields of Songnen Plain as study object,field test method was used to explore the dynamic changes was strong alkof nitrogen in paddy field of the region and its potential impact on environment. [Result] The soil in test regionaline with high CEC and C/N ratios,as well as poor preserving capacity of fertilizer. During the two-year field experiment,the indicators of salinization fluctuated. Initially,the concentrations of total nitrogen and ammonia nitrogen reached their maximum values,then decreased over time as a result of heavy rain. The maximum of nitrate concentration appeared later than those of total nitrogen and ammonia nitrogen. Ammonia volatilization accounted for 18.9%-28.8% of the nitrogen loss. The total nitrogen concentration in surface water was higher than the national Class Ⅲ surface water environmental quality standard. The concentration of ammonia from the recession flow of agricultural field was considerably high,which would potentially threaten the fishery in the downstream of Chagan Lake. [Conclusion] The study provided theoretical basis for saline-alkaline soil management and conservation of water and fishery resources.
基金funded by the "973" Program of China (2007CB407206)the ISSCAS Innovation Program (ISSASIP0602)the Knowledge Innovation Project of the Chinese Academy of Sciences (KZCX2-YW-438)
文摘This paper reports the dynamic changes of soil and water loss in the red soil region of Southern China since the 1950s. The red soil region covers eight provinces: Jiangxi, Zhejiang, Fujian, Anhui, Hubei, Hunan, Guangdong and Hainan. From the 1950s to 1986, the annual rate of soil erosion increased by 3.4%. From 1986 to 1996 and from 1996 to 2000, the annual rates of soil erosion decreased by 2.0% and 0.32%, respectively. Field surveys showed that from 2000 to 2005, the area of soil and water loss decreased annually by 1.2%. This decrease was a result of large-scale erosion control activities across China. Although the eroded soil has been restored, the restoration process is very slow and full restoration will take a long time. Our report suggests that controlling soil and water loss is a challenging task, and additional measures must be taken to effectively control the soil erosion in the red soil region.
基金Under the auspices of National Natural Science Foundation of China (No. 41001112,40635028)
文摘Through a case study of Shenzhen City,China,this study focused on a quantitative method for analyzing the spatial processes involved in green infrastructure changes associated with rapid urbanization.Based on RS,GIS and SPSS statistics software,the approach includes selection of the square analysis units and representative landscape metrics,quantification of the change types of landscape metrics in all analysis units through two indices and hierarchical cluster analysis of the above analysis units with different landscape metric change types(i.e.spatial attributes).The analyses verify that there is a significant sequence of continuous changes in green infrastructure in Shenzhen.They are the perforation,the segmentation,the fragmentation,the evanescence and the filling-in processes,which have a good spatio-temporal correspondence with urbanization and reflect the synthetic influence of urban planning,government policies and landforms.Compared with other studies on quantifying the spatial pattern,this study provides an alternative probe into linking the spatial pattern to spatial processes and the corresponding ecological processes in the future.These spatio-temporal processes offer many opportunities for identifying,protecting and restoring key elements in an urban green infrastructure network for areas in the early stages of urbanization or for non-urbanized areas.
文摘AIM: To evaluate the dynamic ocular biometric changes of a modified form-deprivation myopia model in young guinea pigs. METHODS: The animals were randomly assigned to two groups: the monocularly deprived facemask group (MDF, with all the right eyes covered, n=24) and the normal control group(free of facemask, n=24). Each group was then equally divided into four subgroups which were followed up for 2, 4, 6 and 8 weeks, respectively. Parameters measured from every eye included refraction, corneal curvature, axial length and the dry weight of sclera at the posterior pole. RESULTS: All the facemasks remained in place during the follow-up. The covered eyes developed myopia with the vitreous chamber lengthening and the dry weight of posterior sclera reduced at each time point compared with the contralateral uncovered (P<0.05 at all time points). The changes had a linear correlation with the deprivation time (P<0.05). There were no significant differences in all the parameters between the uncovered eyes of MDF group and the normal control group (P>0.05 at all time points). CONCLUSION: Monocular form deprivation with the facemask is highly effective and non-invasive in inducing axial myopia in guinea pigs. The axial myopia is mainly caused by the increased vitreous chamber length and the weakened posterior sclera rigidity. The form-deprivation eye didn't interfere with the natural development of the contralateral eye.
基金The National Natural Science Foundation of China, No.49971004
文摘The decrease of total cultivated area and the lower per capita available arable land resource are now serious problems in Shandong Province, a major agricultural province in China. These problems will become more serious along with the further development of economy. In this paper, based on the statistical information at provincial and county levels, the changes of arable land in Shandong Province and their driving forces during the last 50 years are analyzed. The general changing trends of arable land and per capita available arable land are reducing, and the trends of decrease will continue when the economy is developing. The result of GIS spatial analysis shows that the change of the arable land use in Shandong Province has a regional difference. Eight variables having influences on cultivated land change are analyzed by principal component analysis. The results show that the dynamic development of economy, pressure of social system and progress of scientific techniques in agriculture are the main causes for cultivated land reduction. The principal factors which can be considered as driving forces for arable land change include per capita net living space, total population and per ha grain yield. By using regressive equation, along with analysis on population growth and economic development, cultivated areas in Shandong Province in 2005 and 2010 are predicted respectively. The predicted cultivated areas in Shandong will be 6435.47 thousand hain 2005 and 6336.23 thousand ha in 2010 respectively.
基金National Natural Science Foundation of China, No.40371003 Ministry of Education of China, No.01158 Master Research Project of Shaanxi Normal University
文摘Using the theory and method of the ecological footprint, and combining the changes of regional land use, resource environment, population, society and economy, this paper calculated the ecological footprint, ecological carrying capacity and ecological surplus/loss in 1986-2002 on the Loess Plateau in northern Shaanxi Province. What is more, this paper has put forward the concept of ecological pressure index, set up ecological pressure index models, and ecological security grading systems, and the prediction models of different ecological footprints, ecological carrying capacity, ecological surplus and ecological safety change, and also has assessed the ecological footprint demands of 10,000 yuan GDE The results of this study are as follows: (1) the ecological carrying capacity in northern Shaanxi shows a decreasing trend, the difference of reducing range is the fastest; (2) the ecological footprint appears an increasing trend; (3) ecological pressure index rose to 0.91 from 0.44 during 1986-2002 on the Loess Plateau of northern Shaanxi with an increase of 47%; and (4) the ecological security in the study area is in a critical state, and the ecological oressure index has been increasing rapidlv.
基金financial support from the various funding agencies including the Major State Basic Research Development Program of China (973 Program, 2009CB219604)the National Natural Science Foundation of China (41272175)+1 种基金the Key Project of the National Science & Technology (2011ZX05034-001)the China Scholarship Council
文摘According to dimensionless analysis of the coalbed methane (CBM) production data of Fanzhuang block in southern Qinshui basin, the dimensionless gas production rate is calculated to quantitatively divide the CBM well production process into four stages, i.e., drai- nage stage, unstable gas production stage, stable gas pro- duction stage, and gas production decline stage. By the material balance method, the coal reservoir permeability change in different stages is quantitatively characterized. The characteristics and control mechanisms of change in coalbed permeability (CICP) during different production stages are concluded on five aspects, i.e., permeability trend variation, controlling mechanism, system energy, phase state compositions, and production performance. The study reveals that CICP is characterized by first decline, then recovery, and finally by increase and is controlled directly by effective stress and matrix shrinkage effects. Further, the duration and intensity of the matrix shrinkage effect are inherently controlled by adsorption and desorp- tion features.
基金State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingNo.WKL((020)0302)
文摘The spatial calculating analysis model is based on GIS overlay. It will compartmentalize the land in research district into three spatial types: unchanged parts, converted parts and increased parts. By this method we can evaluate the numerical model and dynamic degree model for calculating land-use change rates. Furthermore, the paper raises the possibility of revising the calculating analysis model of spatial information in order to predicate more precisely the dynamic changing level of all types of land uses. In the most concrete terms, the model is used mainly to understand changed area and changed rates (increasing or decreasing) of different land types from microcosmic angle and establish spatial distribution and spatio-temporal principles of the changing urban lands. And we will try to find out why the situation can take place by combining social and economic situations. The result indicates the calculating analysis model of spatial information can derive more accurate procedure of spatial transference and increase of all kinds of land from microcosmic angle. By this model and technology we can conduct the research of land-use spatio-temporal structure evolution more systematically and more deeply, and can obtain a satisfactory result. The result will benefit the rational planning and management of urban land use of developed coastal areas in China in the future.
基金supported by the National Natural Science Foundation of China(40574012)
文摘Based on the data of the repeated gravity observation network in Chinese mainland since 1998, we analyzed the temporal changes of regional gravity field before the 2008 Yutian Ms7.3 earthquake. The result shows some mid-to-long term (two to ten years) changes during the earthquake' s preparation. Notable fea- tures are a gravity increase lasting several years and a relatively large-scaled gradient zone of gravity change, the former indicating a continuous energy accumulation and the latter a possible location of seismic rupture. These gravity changes showed a trend of increase-accelerated increase-decelerated increase, similar to that of the Tangshan Ms7.8 earthquake in 1976. The maximum accumulated gravity change related to the earthquake reached 200 × 10 -8 ms -2.
基金Project supported by the National Basic Research Program of China(Grant No.2012CB955902)the National Natural Science Foundation of China(Grant Nos.41275074,41475073,and 41175084)
文摘In the present paper, a comparison of the performance between moving cutting data-rescaled range analysis (MC- R/S) and moving cutting data-rescaled variance analysis (MC-V/S) is made. The results clearly indicate that the operating efficiency of the MC-R/S algorithm is higher than that of the MC-V/S algorithm. In our numerical test, the computer time consumed by MC-V/S is approximately 25 times that by MC-R/S for an identical window size in artificial data. Except for the difference in operating efficiency, there are no significant differences in performance between MC-R/S and MC-V/S for the abrupt dynamic change detection. Mc-R/s and MC-V/S both display some degree of anti-noise ability. However, it is important to consider the influences of strong noise on the detection results of MC-R/S and MC-V/S in practical application
基金supported by grants from the National Major Special Project of Cancer Early Detection and Treatment in Jinchang City(No.CZB20120064)the Project of Employees Health Status and Disease Burden Trend Study in Nonferrous Metals Corporation(No.JKB20120013)
文摘Our study explored the dynamic changes in andthe relationship between the DNA damage marker8-hydroxy-2'-deoxyguanosine (8-OHdG) and theDNA repair marker 8-hydroxyguanine DNAglycosidase 1 (hOGG1) according to the length ofoccupational employment in nickel smeltingworkers. One hundred forty nickel-exposedsmelting workers and 140 age-matched unexposedoffice workers were selected from the Jinchangcohort. The 8-OHdG levels in smelting workers wassignificantly higher than in office workers (Z=-8.688,P〈0.05) and the 8-OHdG levels among nickelsmelting workers in the 10-14 y employment lengthcategory was significantly higher than among allpeers. The hOGG1 levels among smelting workerswere significantly lower than those of non-exposedworkers (Z=-8.948, P〈0.05). There were significantdifferences between employment length andhOGG1 levels, with subjects employed in nickelsmelting for 10-14 y showing the highest levels ofhOGG1. Correlation analysis showed positivecorrelations between 8-OHdG and hOGG1 levels(r=0.413; P〈0.01). DNA damage was increased withemployment length among nickel smelting workersand was related to the inhibition of hOGG1 repaircapacity.