Manganese nodules are deposit rich in manganese and other metals which "grow" on the ocean floor. The study of manganese nodule growth rate and deep sea sediment has both scientific and economic significance...Manganese nodules are deposit rich in manganese and other metals which "grow" on the ocean floor. The study of manganese nodule growth rate and deep sea sediment has both scientific and economic significance. Natural <sup>10</sup>Be (half-life= 1.5 Ma )is produced from spallations of atmospheric nitrogen and oxygen induced by cosmic ray in the stratosphere. After several years of residence in the atmosphere, the <sup>10</sup>Be falls on the earth or deposits in the ocean, accumulating in marine展开更多
Deep-sea sediment disturbance may occur when collecting polymetallic nodules,resulting in the creation of plumes that could have a negative impact on the ecological environment.This study aims to investigate the poten...Deep-sea sediment disturbance may occur when collecting polymetallic nodules,resulting in the creation of plumes that could have a negative impact on the ecological environment.This study aims to investigate the potential solution of using polyaluminum chloride(PAC)in the water jet.The effects of PAC are examined through a self-designed simulation system for deep-sea polymetallic nodule collection and sediment samples from a potential deep-sea mining area.The experimental results showed that the optimal PAC dose was found to be 0.75 g/L.Compared with the test conditions without the addition of PAC,the presence of PAC leads to a reduction in volume,lower characteristic turbidity,smaller diffusion velocity,and shorter settling time of the plume.This indicates that PAC inhibits the entire development process of the plume.The addition of PAC leads to the flocculation of mm-sized particles,resulting in the formation of cm-sized flocs.The flocculation of particles decreases the rate of erosion on the seabed by around 30%.This reduction in erosion helps to decrease the formation of plumes.Additionally,when the size of suspended particles increases,it reduces the scale at which they diffuse.Furthermore,the settling velocity of flocs(around 10^(-2) m/s)is much higher that of compared to sediment particles(around 10^(-5) m/s),which effectively reduces the amount of time the plume remains in suspension.展开更多
On the basis of the measurement of 210Pbex and 137Cs activities in the sediment cores taken from the intertidal zone on the west coast of the Bohai Gulf, the average sedimentation rates of modern sediments are calcula...On the basis of the measurement of 210Pbex and 137Cs activities in the sediment cores taken from the intertidal zone on the west coast of the Bohai Gulf, the average sedimentation rates of modern sediments are calculated. The results indicate that in the sandy area of the intertidal zone (from Daogouzi to the Duliujian River), the sedimentation rate from 1955 to 1963 is 3.43-4.06 cm/a, and is within the range of 0.65 ̄1.59 cm/a since 1963. The average sedimentation rate in the muddy area (around Qikou) is approximately 1.81 cm/a. The results above suggest that the sandy area of the intertidal zone has experienced rapid sedimentation from the 1950s to the 1960s, and the sedimentation slows down after the 1960s, and the sedimentation rates increase from north to south spatially. The rapid sedi- mentation from the 1950s to the 1960s in the sandy area is due to the fact that North China has plentiful precipitation during this period and the intertidal zone is supplied with abundant matter sources for sedimentation. After the 1960s, the weakened sedimentation may be a result of the reduction of sand transported to the intertidal zone, which is a consequence of diminished rainfall in North China and intensive human activities in the Haihe basin.展开更多
Objective:To investigate the clinical diagnostic significance of peripheral blood T-cell test(T-spot test)for tuberculosis(TB)infection combined with erythrocyte sedimentation rate(ESR)in pulmonary TB.Methods:41 patie...Objective:To investigate the clinical diagnostic significance of peripheral blood T-cell test(T-spot test)for tuberculosis(TB)infection combined with erythrocyte sedimentation rate(ESR)in pulmonary TB.Methods:41 patients with a clinical diagnosis of TB during hospitalization from January 2020 to April 2023 in our hospital were selected as the experimental group,and 45 patients without TB(bronchopneumonia patients)were selected as the control group.The diagnostic specificity,sensitivity,and accuracy of the T-spot TB test,ESR test,and the combined test of the two were calculated respectively.Results:The sensitivity,specificity,and accuracy of the T-spot TB test combined with ESR for the diagnosis of TB in the experimental group were significantly higher than the individual results of the T-spot TB test and ESR test alone(P<0.05).Conclusion:The T-spot TB test combined with the ESR test for TB diagnosis has greater clinical value than carrying out the tests individually.展开更多
Analyzed and calculated are pressure changes and body deformation of the sample inside of the corer in the process of sampling of deep-sea shallow sediment with a non-piston corer for gas hydrate investigation, Two co...Analyzed and calculated are pressure changes and body deformation of the sample inside of the corer in the process of sampling of deep-sea shallow sediment with a non-piston corer for gas hydrate investigation, Two conclusions are drawn: (1) the stress increments associated with the corer through the sampling process do not affect the stabilization of the gas hydrate; (2) the body deformation of the sample is serious and the "incremental filling ratio" (IFR) is less than unit, For taking samples with in-situ pressure and structure, combining with the design theories of the pressure tight corer, we have designed a kind of piston corer, named the gas hydrate pressure tight piston corer, Several tests on the sea have been conducted. Test results indicate that the piston corer has a good ability of taking sediment samples on the seafloor and maintaining their original in-situ pressure, meeting the requirement of exploration of gas hydrate in deep-sea shallow sediment layers.展开更多
Based on Pb technique, sedimentation rates of 11 cores collected from the Huanghe River estuary were determined. CaCO3 distribution of 4 cores chosen from among these was measured. Profiles of 210Pb in the cores showe...Based on Pb technique, sedimentation rates of 11 cores collected from the Huanghe River estuary were determined. CaCO3 distribution of 4 cores chosen from among these was measured. Profiles of 210Pb in the cores showed that the distribution of 210Pb activity decayed with depth, appeared in stages and in more than one segment. The sedimentation rates,210Pb and CaCO3 data have similar distribution trend in the 4 cores. Jhe profiles of Pb and CaCO3 were used to study sedimentation in -tensity, transportation trend of material and sedimentation features in the coring area.展开更多
On the basis of accelerator mass spectrometer radiocarbon (AMS ^14C) dating, sedimentation rates of 11 cores collected from the northern to southern Okinawa Trough are discussed. The sedimentation rates in the Okina...On the basis of accelerator mass spectrometer radiocarbon (AMS ^14C) dating, sedimentation rates of 11 cores collected from the northern to southern Okinawa Trough are discussed. The sedimentation rates in the Okinawa Trough roughly range from 11 to 39cm/ka, and the average is 23.0cm/ka. China's continental matter is the main sediment source of the middle Okinawa Trough and has important contribution to the northern and southern Okinawa Trough. The sedimentation rates during the marine oxygen isotope (MIS) 2 are uniformly higher than those during MIS 1 in the northern and middle Okinawa Trough while they are on the contrary in the southern Okinawa Trough. Sedimentation rates in the Okinawa Trough can be one of the proxies of sediment source and an indicator of cooling events.展开更多
The large deep-sea area from the southwestern Qiongdongnan Basin to the eastern Dongsha Islands,within the continental margin of northern South China Sea,is a frontier of natural gas hydrate exploration in China.Multi...The large deep-sea area from the southwestern Qiongdongnan Basin to the eastern Dongsha Islands,within the continental margin of northern South China Sea,is a frontier of natural gas hydrate exploration in China.Multiform of deep-sea sedimentations have been occurred since late Miocene,and sediment waves as a potential quality reservoir of natural gas hydrate is an most important style of them.Based on abundant available data of seismic,gravity sampling and drilling core,we analyzed the characteristics of seismic reflection and sedimentation of sediment waves and the occurrence of natural gas hydrate hosted in it,and discussed the control factors on natural gas hydrate accumulation.The former findings revealed the deep sea of the northern South China Sea have superior geological conditions on natural gas hydrate accumulation.Therefore,it will be of great significance in deep-sea natural gas hydrate exploration with the study on the relationship between deep-sea sedimentation and natural gas hydrate accumulation.展开更多
Spectrometry of <sup>238</sup>U, <sup>234</sup>U, <sup>230</sup>Th and, <sup>232</sup>Th in three Okinawa Trough cores showed that, based on the<sup>230</sup>...Spectrometry of <sup>238</sup>U, <sup>234</sup>U, <sup>230</sup>Th and, <sup>232</sup>Th in three Okinawa Trough cores showed that, based on the<sup>230</sup>Th/<sup>232</sup>Th activity ratio, the sedimentation rates were about 2.5 cm/ka, 2.8 cm/ka and 8.5 cm/ka respectivelyduring the Holocene and about 20.1 cm/ka, 12.29 cm/ka, 8.8 cm/ka and 12.6 cm/ka respectively during theWurm glacial. To examine the past global climatic and oceanographic changes, the stable oxygen isotopesδ<sup>18</sup>O and CaCO<sub>3</sub> were measured. The Th content and Th/U ratio showed that variations of terrigenous materialinput from the continental shelf were associated with glacial and interglacial changes and sea展开更多
Background: ESR and CRP measurements reflect different aspects of systemic inflammation. Generally, they are either elevated or depressed at the same time. This study was aimed at evaluating the clinical ability of th...Background: ESR and CRP measurements reflect different aspects of systemic inflammation. Generally, they are either elevated or depressed at the same time. This study was aimed at evaluating the clinical ability of these markers in the early diagnosis of pulmonary tuberculosis. Materials and Methods: A total of 50 (male 39, female 21) patients who tested positive to Acid Alcohol Fast Bacilli (AAFB) were studied. ESR and CRP values were estimated using standard procedures. Results: The mean ESR value among the AAFB positive patients was 53.16 ± 4.92 mm/hr while the CRP value was 0.273 ± 0.035 mg/L. Gender and age were not found to have any influence on the ESR and CRP values. No relationship was found to exist between ESR and CRP (r = 0.17;p = 0.235) and age (r = 0.125;p = 0.388). Conclusion: A moderately elevated ESR and low CRP values exist at the early diagnosis of tuberculosis. There is no correlation between ESR and CRP at the onset of tuberculosis;hence CRP cannot be used as a screening tool for early diagnosis of tuberculosis.展开更多
This paper introduces a slurry suspension settlement prediction model for cohesive sediment in a still water environment. With no sediment input and a still water environment condition, control forces between settling...This paper introduces a slurry suspension settlement prediction model for cohesive sediment in a still water environment. With no sediment input and a still water environment condition, control forces between settling particles are significantly different in the process of sedimentation rate attenuation, and the settlement process includes the free sedimentation stage, the log-linear attenuation stage, and the stable consolidation stage according to sedimentation rate attenuation. Settlement equations for sedimentation height and time were established based on sedimentation rate attenuation properties of different sedimentation stages. Finally, a slurry suspension settlement prediction model based on slurry parameters was set up with a foundation being that the model parameters were determined by the basic parameters of slurry. The results of the settlement prediction model show good agreement with those of the settlement column experiment and reflect the main characteristics of cohesive sediment. The model can be applied to the prediction of cohesive soil settlement in still water environments.展开更多
The excessive deformation of deep-sea sediments caused by the vibration of the mining machine will adversely affect the efficiency and safety of mining.Combined with the deep-sea environment,the coupled thermo-hydro-m...The excessive deformation of deep-sea sediments caused by the vibration of the mining machine will adversely affect the efficiency and safety of mining.Combined with the deep-sea environment,the coupled thermo-hydro-mechanical problem for saturated porous deep-sea sediments subject to the vibration of the mining vehicle is investigated.Based on the Green-Lindsay(G-L)generalized thermoelastic theory and Darcy’s law,the model of thermo-hydro-mechanical dynamic responses for saturated porous deep-sea sediments under the vibration of the mining vehicle is established.We obtain the analytical solutions of non-dimensional vertical displacement,excess pore water pressure,vertical stress,temperature,and change in the volume fraction field with the normal mode analysis method,and depict them graphically.The normal mode analysis method uses the canonical coordinate transformation to solve the equation,which can quickly decouple the equation by ignoring the modal coupling effect on the basis of the canonical mode.The results indicate that the vibration frequency has obvious influence on the vertical displacement,excess pore water pressure,vertical stress,and change in volume fraction field.The loading amplitude has a great effect on the physical quantities in the foundation,and the changes of the physical quantities increase with the increase in loading amplitude.展开更多
In order to provide a scientific basis for laying out a unified standard of the reference value (Wintrobe) of Chinese people's erythrocyte sedimentation rate (ESR). this paper studies the relationship between the ...In order to provide a scientific basis for laying out a unified standard of the reference value (Wintrobe) of Chinese people's erythrocyte sedimentation rate (ESR). this paper studies the relationship between the reference values (Wintrobe) of Chinese healthy people's ESR, and the test is done according to the Wintrobe Laws and five geographical factors. It is found that the altitude is the modt important factor affecting the reference value (Wintrobe) of Chinese people's ESR. As altitude increases gradually, the reference value (Wintrobe) of people's ESR decreases accordingly, the correlation is quite obvious. By using the method of regression analysis, two multivariate regression equations and ten univariate regression equations are deduced If the geographical index values in a particular area are known, the reference value (Wintrobe) of Chinese people's ESR of this region can be established by means of the regression equations. Furthermore, according to the dependent relationship of the reference value (Wintrobe) of Chinese people's ESR on geographical factors.China can be divided into sin districts: Qinghai-Tibet, Southwest. Northwest. Southeast, North and Northeast China.展开更多
Reference values of erythrocyte sedimentation rate(ESR)are the key to interpret ESR blood test in clinic.The common local reference ESR values are more accuracy in blood test that are established with natural geograph...Reference values of erythrocyte sedimentation rate(ESR)are the key to interpret ESR blood test in clinic.The common local reference ESR values are more accuracy in blood test that are established with natural geographical factors by using the multiple linear regression(MLR)model and the artificial neural network(ANN).These knowledge-based methods have limitations since the knowledge domains of ESR and natural geographical factors are limited.This paper presents a new cases-depended model to establish reference ESR values with natural geographical factors and location using case-based reasoning(CBR)since knowledge domain of ESR and geographical factors is weak.Overall 224 local normal ESR values of China that calculated from 13623 samples were obtained,and the corresponding natural geographical factors and location that include altitude,sunshine hours,relative humidity,temperature,precipitation,annual temperature range and annual average wind speed were obtained from the National Geomatics Center of China.CBR was used to predict the unseen local reference ESR values with cases.The average absolute deviation(AAD),mean square error(MSE),prediction accuracy(PA),and Pearson correlation coefficient(r)between the observed and estimated data of proposed model is 33.07%,9.02,66.93% and 0.78,which are better than those of ANN and MLR model.The results show that the proposed model provides higher prediction accuracy than those of the artificial neural network and multiple linear regression models.The predicted values are very close to the observed values.Model results show significant agreement of cases data.Consequently,the model is used to predict the unseen local reference ESR with natural geographical factors and location.In spatial,the highest ESR reference areas are distributed in the southern-western district of China that includes Sichuan,Chongqing,Guangxi and Guizhou provinces,and the reference ESR values are greater than 23 mm/60 min.The higher ESR reference values are distributed in the middle part and northern-eastern of China which include Hubei,Henan,Shaanxi,Shanxi,Jilin and Heilongjiang provinces,and the reference ESR values are greater than 18 mm/60min.The lowest ESR reference values are distributed in the northern-western of China that includes Tibet and Xinjiang,and the reference ESR values are lower than 5 mm/60min.展开更多
Coastal salt-marshes represent an important coastal wetland system. The total area of coastal wetlands exceeds 5000 km2 in Jiangsu Province, China, but it is decreasing rapidly in response to the intense reclamation a...Coastal salt-marshes represent an important coastal wetland system. The total area of coastal wetlands exceeds 5000 km2 in Jiangsu Province, China, but it is decreasing rapidly in response to the intense reclamation activities and coastal erosion along a part of the coastline. Hence, two types of plants, Spartina angelica and Spartina alterniflora, were introduced successively into the Jiangsu coastal areas, in order to protect the coastline from erosion and to increase the accumulation rate. Pb-210 and Cs-137 analyses were carried out for sediment samples from the salt-marshes of Wanggang to determine the sedimentation rate, on the basis of an evaluation of the background activity values and the factors affecting the enrichment of Pb-210. Analysis of a typical sediment column of the tidal flat shows that there is weak absorption of Pb-210 in the silt-dominated sediment. Because of the influences of factors such as storm events, bioturbation, material sources and analytical error, some abnormal data points appear in the Pb-210 record. After ignoring these data the calculated sedimentation rate was 3.3 cm yr-1 on average. Based upon analysis of the Cs-137 dating, the rate since 1963 was 3.1 cm yr-1 on average, similar to the data by Pb-210 dating and the previous studies. The dating results show that there were three stages of sedimentation, with the most rapid accretion being taking place after Spartina angelica was introduced into the area. The study also shows that at the stage of Spartina alterniflora growth, the accretion rate was higher than on the flat surface with the same elevation without the cover of this plant.展开更多
The sedimentation rate is an important environmental parameter to understand the evolution of coastal geomorphology. The tidal flat around Qidong foreland is located in the junction between Yangtze Estuary and Jiangsu...The sedimentation rate is an important environmental parameter to understand the evolution of coastal geomorphology. The tidal flat around Qidong foreland is located in the junction between Yangtze Estuary and Jiangsu coast,where the land-ocean interactions are strong and highly sensitive to environmental changes. The QDZ-1 core sediments collected at Qidong foreland was analyzed for137 Cs dating and grain size.The results showed that silt is the main sedimentary type with a trend of gradually fining from the bottom to the top,conforming to the sedimentation characteristic of the silt muddy tidal flat. The sedimentation rate could be divided into three distinct stages: 1963 to 1986 was 2. 61 cm/yr,1963 to 2011 was 1. 82 cm/yr,and 1986 to 2011 was 1. 10 cm/yr. Based on these,further explanation was made for the significance of environmental changes. According to the estimation of sedimentation rate,the impact of extreme environmental change was reflected by the sudden increase in sand proportion at the depth of 172. 5 cm. Since the introduction of Spartina alterniflora in the 1970 s,it has played an important role in tidal flat development. The tidal flat has a high sedimentary rate during this time. With continuous accretion of the tidal flat,low tidal flat turns to high tidal flat,the sedimentation rate gradually declines,and tidal flat sedimentation appears.展开更多
BACKGROUND A disease caused by a novel coronavirus virus,named coronavirus disease 2019(COVID-19),broke out in Wuhan,China in December 2019,and spread around the word.As of March 4,2020,93090 confirmed cases and 2984 ...BACKGROUND A disease caused by a novel coronavirus virus,named coronavirus disease 2019(COVID-19),broke out in Wuhan,China in December 2019,and spread around the word.As of March 4,2020,93090 confirmed cases and 2984 deaths have been reported in more than 80 countries and territories.It has triggered global public health security.However,the features and prognosis of COVID-19 are incompletely understood.CASE SUMMARY We here report that the erythrocyte sedimentation rate(ESR)increased in a confirmed COVID patient.The high level of ESR sustained for a long time even after the patient recovered from COVID-19,while all results related to tumor,tuberculosis,rheumatic diseases,anemia,etc.cannot explain the abnormal elevation of ESR presented in this case.CONCLUSION Although the increased ESR cannot be explained by all existing evidence,it possibly links the abnormal pathologic change in some COVID-19 patients and negative prognosis,and provides the clue to dissect the mechanism of illness progressing in COVID-19 and its prognosis.展开更多
In this study, using the constant rate of supply model, sedimentation rates of Izmir Bay were calculated and discussed. For this purpose, eight sediment cores were collected from inner part of the bay and sedimentatio...In this study, using the constant rate of supply model, sedimentation rates of Izmir Bay were calculated and discussed. For this purpose, eight sediment cores were collected from inner part of the bay and sedimentation rates were calculated from vertical distribution of^(210)Pb.^(210)Pb activities were determined indirectly from ^(210)Po activities.Sedimentation rates ranged from 0.10 to 0.52 cm/year. The highest sedimentation rates were determined in stations close to the Poligon stream. It was concluded that main transporting mechanism for sediments is river and streams in the area. In addition, sediment cores taken from the harbor were mixed due to bioturbation, water circulation and/or other factors.展开更多
Objective: To analyze the clinical value of blood sedimentation rate, C-reactive protein (CRP) and D-dimer (D-D) expression levels in elderly patients before hip replacement for judging the prognosis after operation. ...Objective: To analyze the clinical value of blood sedimentation rate, C-reactive protein (CRP) and D-dimer (D-D) expression levels in elderly patients before hip replacement for judging the prognosis after operation. Methods 88 patients who needed hip replacement in orthopaedic surgery of our hospital from January 2014 to December 2017 were selected as the research object. According to the prognosis of patients, they were divided into two groups. 42 patients with good prognosis were treated as observation group and 46 patients with poor prognosis were treated as control group. The ESR and CRP of the two groups were recorded and analyzed before and after operation. The expression level of D-D, perioperative changes, and the prognostic value of the area under the curve (AUC) were compared by drawing the patient's working characteristic curve (ROC curve). Results The expression levels of ESR, CRP and D-D in the observation group were significantly higher than those in the control group (P < 0.05). The expression levels of CRP in the observation group were significantly higher than those in the control group (P < 0.05). The expression levels of ESR and CRP in the observation group before discharge were significantly higher than those in the control group (P < 0.05). There was significant difference between the two groups (P < 0.05);the level of ESR expression before and 2 days after operation was significantly lower than that before discharge (P < 0.05);the level of ESR expression before operation was significantly lower than that 2 days after operation (P < 0.05);and the CRP and D-D table before operation were compared between the two groups (P < 0.05). The level of CRP and D-D expression in two groups was significantly higher than that before discharge (P < 0.05). In this study, two groups of patients were infected. The incidence of thrombosis in the observation group was higher than that in the control group, but the difference was not statistically significant (P > 0.05). The Harris score of the observation group was significantly higher than that of the control group (P < 0.05). Conclusion There are abnormal levels of ESR, CRP and D-D expression in elderly patients with hip replacement before operation, and they have certain clinical value in evaluating the prognosis of elderly patients after hip replacement.展开更多
The North Branch, separated by the Chongming Island, was once the main channel in the estuary of the Changjiang River. Reclamation and a decrease in runoffto the North Branch had led to the narrowing and shallowing of...The North Branch, separated by the Chongming Island, was once the main channel in the estuary of the Changjiang River. Reclamation and a decrease in runoffto the North Branch had led to the narrowing and shallowing of the channel. The Yuantuojiao Point is located at the intersecting point connecting the North Branch of the Changjiang River and the Jiangsu coastline. Erosion cliffs are developed between the typical silty-muddy tidal flat and the salt marsh occupied by Spartina alterniflorea, and this has changed rapidly over the past few years. The sediment grain size analysis results of the surficial and two core samples indi- cate that the Yuantuoiiao Point tidal fiat experienced continuous accretional processes. Based upon 137Cs analysis results of the YT and YY Cores sampled from the tidal flat at the Yuantuojiao Point, the average sed- imentation rate of the YT Core was 2.30 cm/a from 1963 to 2007, and 2.38 cm/a from 1954 to 2007 for the YY Core. The sedimentation rates of both core locations have declined since the 1960s corresponding to the seaward reclamation at the Yuantuojiao Point. The average sedimentation rates at the Yuantnojiao Point were similar to that of the silty-muddy tidal flat at the northern ]iangsu coast, but lower than that of the south of the Changjiang River Estuary. According to field morphological investigations from 2006 to 2008 on the salt marsh at the Yuantuojiao Point, cliffs retreated markedly by storm surges and disappeared gradu- ally because of the rapid sedimentation on the silty-muddy tidal flat. The maximum annual retreat reached 10 m. The recent sedimentation and morphological changes of the Yuantuojiao Point tidal flat not only displayed the retreat of the salt marsh and the disappearance of cliffs, but also was accompanied by rapid sedimentation of the silty-muddy tidal flat and the salt marsh, indicating the responses to the tidal currents, storm surges, Spartina alterniflorea trapping sediments and large-scale reclamation. The sediment grain size and their trends, southward coastal flow, and sandspits of the longshore bars suggest that the main sediment source at the Yuantuoijao Point, estuary of the North Branch was possibly from the Changjiang River before 1958, since then, it has been from the south of the submarine radial sand ridges of the southern Huanghai Sea (Yellow Sea).展开更多
文摘Manganese nodules are deposit rich in manganese and other metals which "grow" on the ocean floor. The study of manganese nodule growth rate and deep sea sediment has both scientific and economic significance. Natural <sup>10</sup>Be (half-life= 1.5 Ma )is produced from spallations of atmospheric nitrogen and oxygen induced by cosmic ray in the stratosphere. After several years of residence in the atmosphere, the <sup>10</sup>Be falls on the earth or deposits in the ocean, accumulating in marine
基金supported by the National Natural Science Foundation of China(Nos.52225107,U2106224,U1906234,51822904,and U1706223)the Fundamental Research Funds for the Central Universities(No.202041004)
文摘Deep-sea sediment disturbance may occur when collecting polymetallic nodules,resulting in the creation of plumes that could have a negative impact on the ecological environment.This study aims to investigate the potential solution of using polyaluminum chloride(PAC)in the water jet.The effects of PAC are examined through a self-designed simulation system for deep-sea polymetallic nodule collection and sediment samples from a potential deep-sea mining area.The experimental results showed that the optimal PAC dose was found to be 0.75 g/L.Compared with the test conditions without the addition of PAC,the presence of PAC leads to a reduction in volume,lower characteristic turbidity,smaller diffusion velocity,and shorter settling time of the plume.This indicates that PAC inhibits the entire development process of the plume.The addition of PAC leads to the flocculation of mm-sized particles,resulting in the formation of cm-sized flocs.The flocculation of particles decreases the rate of erosion on the seabed by around 30%.This reduction in erosion helps to decrease the formation of plumes.Additionally,when the size of suspended particles increases,it reduces the scale at which they diffuse.Furthermore,the settling velocity of flocs(around 10^(-2) m/s)is much higher that of compared to sediment particles(around 10^(-5) m/s),which effectively reduces the amount of time the plume remains in suspension.
基金financed by the Hi-tech Research and Development Program of China(“863”Program)under contract No.2002AA648010
文摘On the basis of the measurement of 210Pbex and 137Cs activities in the sediment cores taken from the intertidal zone on the west coast of the Bohai Gulf, the average sedimentation rates of modern sediments are calculated. The results indicate that in the sandy area of the intertidal zone (from Daogouzi to the Duliujian River), the sedimentation rate from 1955 to 1963 is 3.43-4.06 cm/a, and is within the range of 0.65 ̄1.59 cm/a since 1963. The average sedimentation rate in the muddy area (around Qikou) is approximately 1.81 cm/a. The results above suggest that the sandy area of the intertidal zone has experienced rapid sedimentation from the 1950s to the 1960s, and the sedimentation slows down after the 1960s, and the sedimentation rates increase from north to south spatially. The rapid sedi- mentation from the 1950s to the 1960s in the sandy area is due to the fact that North China has plentiful precipitation during this period and the intertidal zone is supplied with abundant matter sources for sedimentation. After the 1960s, the weakened sedimentation may be a result of the reduction of sand transported to the intertidal zone, which is a consequence of diminished rainfall in North China and intensive human activities in the Haihe basin.
文摘Objective:To investigate the clinical diagnostic significance of peripheral blood T-cell test(T-spot test)for tuberculosis(TB)infection combined with erythrocyte sedimentation rate(ESR)in pulmonary TB.Methods:41 patients with a clinical diagnosis of TB during hospitalization from January 2020 to April 2023 in our hospital were selected as the experimental group,and 45 patients without TB(bronchopneumonia patients)were selected as the control group.The diagnostic specificity,sensitivity,and accuracy of the T-spot TB test,ESR test,and the combined test of the two were calculated respectively.Results:The sensitivity,specificity,and accuracy of the T-spot TB test combined with ESR for the diagnosis of TB in the experimental group were significantly higher than the individual results of the T-spot TB test and ESR test alone(P<0.05).Conclusion:The T-spot TB test combined with the ESR test for TB diagnosis has greater clinical value than carrying out the tests individually.
基金The project was financially supported bythe National Natural science Foundation of China (Grant No.50675055)
文摘Analyzed and calculated are pressure changes and body deformation of the sample inside of the corer in the process of sampling of deep-sea shallow sediment with a non-piston corer for gas hydrate investigation, Two conclusions are drawn: (1) the stress increments associated with the corer through the sampling process do not affect the stabilization of the gas hydrate; (2) the body deformation of the sample is serious and the "incremental filling ratio" (IFR) is less than unit, For taking samples with in-situ pressure and structure, combining with the design theories of the pressure tight corer, we have designed a kind of piston corer, named the gas hydrate pressure tight piston corer, Several tests on the sea have been conducted. Test results indicate that the piston corer has a good ability of taking sediment samples on the seafloor and maintaining their original in-situ pressure, meeting the requirement of exploration of gas hydrate in deep-sea shallow sediment layers.
基金This research was supported by the National Natural Science Foundation of China
文摘Based on Pb technique, sedimentation rates of 11 cores collected from the Huanghe River estuary were determined. CaCO3 distribution of 4 cores chosen from among these was measured. Profiles of 210Pb in the cores showed that the distribution of 210Pb activity decayed with depth, appeared in stages and in more than one segment. The sedimentation rates,210Pb and CaCO3 data have similar distribution trend in the 4 cores. Jhe profiles of Pb and CaCO3 were used to study sedimentation in -tensity, transportation trend of material and sedimentation features in the coring area.
基金This study was supported by the National Natural Science Foundation of China under contract Nos 40176018,40421150011 and 49776292the Ministry of Science and Technology,State Oceanic Administration,China,and IFR EMER,France.
文摘On the basis of accelerator mass spectrometer radiocarbon (AMS ^14C) dating, sedimentation rates of 11 cores collected from the northern to southern Okinawa Trough are discussed. The sedimentation rates in the Okinawa Trough roughly range from 11 to 39cm/ka, and the average is 23.0cm/ka. China's continental matter is the main sediment source of the middle Okinawa Trough and has important contribution to the northern and southern Okinawa Trough. The sedimentation rates during the marine oxygen isotope (MIS) 2 are uniformly higher than those during MIS 1 in the northern and middle Okinawa Trough while they are on the contrary in the southern Okinawa Trough. Sedimentation rates in the Okinawa Trough can be one of the proxies of sediment source and an indicator of cooling events.
基金Supported by the National Basic Research Program of China(973 Program)(Nos.2009CB219508,2009CB219502)the National High Technology Research and Development Program of China(863 Program) (No.2006AA09A202)
文摘The large deep-sea area from the southwestern Qiongdongnan Basin to the eastern Dongsha Islands,within the continental margin of northern South China Sea,is a frontier of natural gas hydrate exploration in China.Multiform of deep-sea sedimentations have been occurred since late Miocene,and sediment waves as a potential quality reservoir of natural gas hydrate is an most important style of them.Based on abundant available data of seismic,gravity sampling and drilling core,we analyzed the characteristics of seismic reflection and sedimentation of sediment waves and the occurrence of natural gas hydrate hosted in it,and discussed the control factors on natural gas hydrate accumulation.The former findings revealed the deep sea of the northern South China Sea have superior geological conditions on natural gas hydrate accumulation.Therefore,it will be of great significance in deep-sea natural gas hydrate exploration with the study on the relationship between deep-sea sedimentation and natural gas hydrate accumulation.
基金Contribution No. 2911 from Institute of Oceanology, Chinese Academy of Sciences. This research was supported by the National Natural Science Foundation of China.
文摘Spectrometry of <sup>238</sup>U, <sup>234</sup>U, <sup>230</sup>Th and, <sup>232</sup>Th in three Okinawa Trough cores showed that, based on the<sup>230</sup>Th/<sup>232</sup>Th activity ratio, the sedimentation rates were about 2.5 cm/ka, 2.8 cm/ka and 8.5 cm/ka respectivelyduring the Holocene and about 20.1 cm/ka, 12.29 cm/ka, 8.8 cm/ka and 12.6 cm/ka respectively during theWurm glacial. To examine the past global climatic and oceanographic changes, the stable oxygen isotopesδ<sup>18</sup>O and CaCO<sub>3</sub> were measured. The Th content and Th/U ratio showed that variations of terrigenous materialinput from the continental shelf were associated with glacial and interglacial changes and sea
文摘Background: ESR and CRP measurements reflect different aspects of systemic inflammation. Generally, they are either elevated or depressed at the same time. This study was aimed at evaluating the clinical ability of these markers in the early diagnosis of pulmonary tuberculosis. Materials and Methods: A total of 50 (male 39, female 21) patients who tested positive to Acid Alcohol Fast Bacilli (AAFB) were studied. ESR and CRP values were estimated using standard procedures. Results: The mean ESR value among the AAFB positive patients was 53.16 ± 4.92 mm/hr while the CRP value was 0.273 ± 0.035 mg/L. Gender and age were not found to have any influence on the ESR and CRP values. No relationship was found to exist between ESR and CRP (r = 0.17;p = 0.235) and age (r = 0.125;p = 0.388). Conclusion: A moderately elevated ESR and low CRP values exist at the early diagnosis of tuberculosis. There is no correlation between ESR and CRP at the onset of tuberculosis;hence CRP cannot be used as a screening tool for early diagnosis of tuberculosis.
基金supported by the Research Funds for the Central Universities (Grant No. 2009B13514)the Doctoral Fund of the Ministry of Education of China (Grant No. 20100094110002)
文摘This paper introduces a slurry suspension settlement prediction model for cohesive sediment in a still water environment. With no sediment input and a still water environment condition, control forces between settling particles are significantly different in the process of sedimentation rate attenuation, and the settlement process includes the free sedimentation stage, the log-linear attenuation stage, and the stable consolidation stage according to sedimentation rate attenuation. Settlement equations for sedimentation height and time were established based on sedimentation rate attenuation properties of different sedimentation stages. Finally, a slurry suspension settlement prediction model based on slurry parameters was set up with a foundation being that the model parameters were determined by the basic parameters of slurry. The results of the settlement prediction model show good agreement with those of the settlement column experiment and reflect the main characteristics of cohesive sediment. The model can be applied to the prediction of cohesive soil settlement in still water environments.
基金the National Natural Science Foundation of China(No.12072309)the Youth Fund Foundation of Education Bureau of Hunan Province of China(No.19B546)the High-Level Talent Gathering Project in Hunan Province of China(No.2019RS1059)。
文摘The excessive deformation of deep-sea sediments caused by the vibration of the mining machine will adversely affect the efficiency and safety of mining.Combined with the deep-sea environment,the coupled thermo-hydro-mechanical problem for saturated porous deep-sea sediments subject to the vibration of the mining vehicle is investigated.Based on the Green-Lindsay(G-L)generalized thermoelastic theory and Darcy’s law,the model of thermo-hydro-mechanical dynamic responses for saturated porous deep-sea sediments under the vibration of the mining vehicle is established.We obtain the analytical solutions of non-dimensional vertical displacement,excess pore water pressure,vertical stress,temperature,and change in the volume fraction field with the normal mode analysis method,and depict them graphically.The normal mode analysis method uses the canonical coordinate transformation to solve the equation,which can quickly decouple the equation by ignoring the modal coupling effect on the basis of the canonical mode.The results indicate that the vibration frequency has obvious influence on the vertical displacement,excess pore water pressure,vertical stress,and change in volume fraction field.The loading amplitude has a great effect on the physical quantities in the foundation,and the changes of the physical quantities increase with the increase in loading amplitude.
文摘In order to provide a scientific basis for laying out a unified standard of the reference value (Wintrobe) of Chinese people's erythrocyte sedimentation rate (ESR). this paper studies the relationship between the reference values (Wintrobe) of Chinese healthy people's ESR, and the test is done according to the Wintrobe Laws and five geographical factors. It is found that the altitude is the modt important factor affecting the reference value (Wintrobe) of Chinese people's ESR. As altitude increases gradually, the reference value (Wintrobe) of people's ESR decreases accordingly, the correlation is quite obvious. By using the method of regression analysis, two multivariate regression equations and ten univariate regression equations are deduced If the geographical index values in a particular area are known, the reference value (Wintrobe) of Chinese people's ESR of this region can be established by means of the regression equations. Furthermore, according to the dependent relationship of the reference value (Wintrobe) of Chinese people's ESR on geographical factors.China can be divided into sin districts: Qinghai-Tibet, Southwest. Northwest. Southeast, North and Northeast China.
基金Under the auspices of National Natural Science Foundation of China(No.40971060)
文摘Reference values of erythrocyte sedimentation rate(ESR)are the key to interpret ESR blood test in clinic.The common local reference ESR values are more accuracy in blood test that are established with natural geographical factors by using the multiple linear regression(MLR)model and the artificial neural network(ANN).These knowledge-based methods have limitations since the knowledge domains of ESR and natural geographical factors are limited.This paper presents a new cases-depended model to establish reference ESR values with natural geographical factors and location using case-based reasoning(CBR)since knowledge domain of ESR and geographical factors is weak.Overall 224 local normal ESR values of China that calculated from 13623 samples were obtained,and the corresponding natural geographical factors and location that include altitude,sunshine hours,relative humidity,temperature,precipitation,annual temperature range and annual average wind speed were obtained from the National Geomatics Center of China.CBR was used to predict the unseen local reference ESR values with cases.The average absolute deviation(AAD),mean square error(MSE),prediction accuracy(PA),and Pearson correlation coefficient(r)between the observed and estimated data of proposed model is 33.07%,9.02,66.93% and 0.78,which are better than those of ANN and MLR model.The results show that the proposed model provides higher prediction accuracy than those of the artificial neural network and multiple linear regression models.The predicted values are very close to the observed values.Model results show significant agreement of cases data.Consequently,the model is used to predict the unseen local reference ESR with natural geographical factors and location.In spatial,the highest ESR reference areas are distributed in the southern-western district of China that includes Sichuan,Chongqing,Guangxi and Guizhou provinces,and the reference ESR values are greater than 23 mm/60 min.The higher ESR reference values are distributed in the middle part and northern-eastern of China which include Hubei,Henan,Shaanxi,Shanxi,Jilin and Heilongjiang provinces,and the reference ESR values are greater than 18 mm/60min.The lowest ESR reference values are distributed in the northern-western of China that includes Tibet and Xinjiang,and the reference ESR values are lower than 5 mm/60min.
基金The Key Project of the N ational Natural Science Foundation of China,N o.40231010 N ational N atural Science Foundation ofChina,N o.40476041The M inistry ofEducation Ph.D .SubjectProgram ,N o.20020284007
文摘Coastal salt-marshes represent an important coastal wetland system. The total area of coastal wetlands exceeds 5000 km2 in Jiangsu Province, China, but it is decreasing rapidly in response to the intense reclamation activities and coastal erosion along a part of the coastline. Hence, two types of plants, Spartina angelica and Spartina alterniflora, were introduced successively into the Jiangsu coastal areas, in order to protect the coastline from erosion and to increase the accumulation rate. Pb-210 and Cs-137 analyses were carried out for sediment samples from the salt-marshes of Wanggang to determine the sedimentation rate, on the basis of an evaluation of the background activity values and the factors affecting the enrichment of Pb-210. Analysis of a typical sediment column of the tidal flat shows that there is weak absorption of Pb-210 in the silt-dominated sediment. Because of the influences of factors such as storm events, bioturbation, material sources and analytical error, some abnormal data points appear in the Pb-210 record. After ignoring these data the calculated sedimentation rate was 3.3 cm yr-1 on average. Based upon analysis of the Cs-137 dating, the rate since 1963 was 3.1 cm yr-1 on average, similar to the data by Pb-210 dating and the previous studies. The dating results show that there were three stages of sedimentation, with the most rapid accretion being taking place after Spartina angelica was introduced into the area. The study also shows that at the stage of Spartina alterniflora growth, the accretion rate was higher than on the flat surface with the same elevation without the cover of this plant.
基金Supported by National Natural Science Foundation of China(Grant No.:41501003,41701101,41807403)Open Foundation of Research Institute of Jiangsu Coastal Development(Grant No.:RIJCD11008)
文摘The sedimentation rate is an important environmental parameter to understand the evolution of coastal geomorphology. The tidal flat around Qidong foreland is located in the junction between Yangtze Estuary and Jiangsu coast,where the land-ocean interactions are strong and highly sensitive to environmental changes. The QDZ-1 core sediments collected at Qidong foreland was analyzed for137 Cs dating and grain size.The results showed that silt is the main sedimentary type with a trend of gradually fining from the bottom to the top,conforming to the sedimentation characteristic of the silt muddy tidal flat. The sedimentation rate could be divided into three distinct stages: 1963 to 1986 was 2. 61 cm/yr,1963 to 2011 was 1. 82 cm/yr,and 1986 to 2011 was 1. 10 cm/yr. Based on these,further explanation was made for the significance of environmental changes. According to the estimation of sedimentation rate,the impact of extreme environmental change was reflected by the sudden increase in sand proportion at the depth of 172. 5 cm. Since the introduction of Spartina alterniflora in the 1970 s,it has played an important role in tidal flat development. The tidal flat has a high sedimentary rate during this time. With continuous accretion of the tidal flat,low tidal flat turns to high tidal flat,the sedimentation rate gradually declines,and tidal flat sedimentation appears.
基金Supported by the Central Publicinterest Scientific Institution Basal Research Fund,Chinese Academy of Medical Sciences,No.2019PT320003Science and Technology Support Plan Fund of Zunyi City,No.NS(2020)1and Science Plan Fund of Zunyi City,No.HZ(2020)4.
文摘BACKGROUND A disease caused by a novel coronavirus virus,named coronavirus disease 2019(COVID-19),broke out in Wuhan,China in December 2019,and spread around the word.As of March 4,2020,93090 confirmed cases and 2984 deaths have been reported in more than 80 countries and territories.It has triggered global public health security.However,the features and prognosis of COVID-19 are incompletely understood.CASE SUMMARY We here report that the erythrocyte sedimentation rate(ESR)increased in a confirmed COVID patient.The high level of ESR sustained for a long time even after the patient recovered from COVID-19,while all results related to tumor,tuberculosis,rheumatic diseases,anemia,etc.cannot explain the abnormal elevation of ESR presented in this case.CONCLUSION Although the increased ESR cannot be explained by all existing evidence,it possibly links the abnormal pathologic change in some COVID-19 patients and negative prognosis,and provides the clue to dissect the mechanism of illness progressing in COVID-19 and its prognosis.
文摘In this study, using the constant rate of supply model, sedimentation rates of Izmir Bay were calculated and discussed. For this purpose, eight sediment cores were collected from inner part of the bay and sedimentation rates were calculated from vertical distribution of^(210)Pb.^(210)Pb activities were determined indirectly from ^(210)Po activities.Sedimentation rates ranged from 0.10 to 0.52 cm/year. The highest sedimentation rates were determined in stations close to the Poligon stream. It was concluded that main transporting mechanism for sediments is river and streams in the area. In addition, sediment cores taken from the harbor were mixed due to bioturbation, water circulation and/or other factors.
文摘Objective: To analyze the clinical value of blood sedimentation rate, C-reactive protein (CRP) and D-dimer (D-D) expression levels in elderly patients before hip replacement for judging the prognosis after operation. Methods 88 patients who needed hip replacement in orthopaedic surgery of our hospital from January 2014 to December 2017 were selected as the research object. According to the prognosis of patients, they were divided into two groups. 42 patients with good prognosis were treated as observation group and 46 patients with poor prognosis were treated as control group. The ESR and CRP of the two groups were recorded and analyzed before and after operation. The expression level of D-D, perioperative changes, and the prognostic value of the area under the curve (AUC) were compared by drawing the patient's working characteristic curve (ROC curve). Results The expression levels of ESR, CRP and D-D in the observation group were significantly higher than those in the control group (P < 0.05). The expression levels of CRP in the observation group were significantly higher than those in the control group (P < 0.05). The expression levels of ESR and CRP in the observation group before discharge were significantly higher than those in the control group (P < 0.05). There was significant difference between the two groups (P < 0.05);the level of ESR expression before and 2 days after operation was significantly lower than that before discharge (P < 0.05);the level of ESR expression before operation was significantly lower than that 2 days after operation (P < 0.05);and the CRP and D-D table before operation were compared between the two groups (P < 0.05). The level of CRP and D-D expression in two groups was significantly higher than that before discharge (P < 0.05). In this study, two groups of patients were infected. The incidence of thrombosis in the observation group was higher than that in the control group, but the difference was not statistically significant (P > 0.05). The Harris score of the observation group was significantly higher than that of the control group (P < 0.05). Conclusion There are abnormal levels of ESR, CRP and D-D expression in elderly patients with hip replacement before operation, and they have certain clinical value in evaluating the prognosis of elderly patients after hip replacement.
基金The National Natural Science Foundation of China under contract Nos 41071006 and 40676052the Jiangsu Natural Science Foundation under contract No. BK2010050the Research Fund for the Doctoral Program of Higher Education of China under contract No.20100091110011
文摘The North Branch, separated by the Chongming Island, was once the main channel in the estuary of the Changjiang River. Reclamation and a decrease in runoffto the North Branch had led to the narrowing and shallowing of the channel. The Yuantuojiao Point is located at the intersecting point connecting the North Branch of the Changjiang River and the Jiangsu coastline. Erosion cliffs are developed between the typical silty-muddy tidal flat and the salt marsh occupied by Spartina alterniflorea, and this has changed rapidly over the past few years. The sediment grain size analysis results of the surficial and two core samples indi- cate that the Yuantuoiiao Point tidal fiat experienced continuous accretional processes. Based upon 137Cs analysis results of the YT and YY Cores sampled from the tidal flat at the Yuantuojiao Point, the average sed- imentation rate of the YT Core was 2.30 cm/a from 1963 to 2007, and 2.38 cm/a from 1954 to 2007 for the YY Core. The sedimentation rates of both core locations have declined since the 1960s corresponding to the seaward reclamation at the Yuantuojiao Point. The average sedimentation rates at the Yuantnojiao Point were similar to that of the silty-muddy tidal flat at the northern ]iangsu coast, but lower than that of the south of the Changjiang River Estuary. According to field morphological investigations from 2006 to 2008 on the salt marsh at the Yuantuojiao Point, cliffs retreated markedly by storm surges and disappeared gradu- ally because of the rapid sedimentation on the silty-muddy tidal flat. The maximum annual retreat reached 10 m. The recent sedimentation and morphological changes of the Yuantuojiao Point tidal flat not only displayed the retreat of the salt marsh and the disappearance of cliffs, but also was accompanied by rapid sedimentation of the silty-muddy tidal flat and the salt marsh, indicating the responses to the tidal currents, storm surges, Spartina alterniflorea trapping sediments and large-scale reclamation. The sediment grain size and their trends, southward coastal flow, and sandspits of the longshore bars suggest that the main sediment source at the Yuantuoijao Point, estuary of the North Branch was possibly from the Changjiang River before 1958, since then, it has been from the south of the submarine radial sand ridges of the southern Huanghai Sea (Yellow Sea).