The Zhujiang River Mouth Basin,a primary depocenter for terrigenous sediments in the western Pacific,presents a semienclosed tectonic setting with limited exchange with the open ocean.This unique feature enables syste...The Zhujiang River Mouth Basin,a primary depocenter for terrigenous sediments in the western Pacific,presents a semienclosed tectonic setting with limited exchange with the open ocean.This unique feature enables systematic linkages among sedimentary processes,climate change,regional sea-level fluctuations,and tectonic events.To explore these linkages,this study focuses on Well PY35 in the Baiyun Sag of the Zhujiang River Mouth Basin.By integrating microfossil analysis with Milankovitch cycle analysis of well log data,an astronomical time scale(ATS)(17.54-7.80 Ma)and a high-resolution stratigraphic framework were established,allowing for the calculation of sedimentation rates across different hierarchical sequences and time intervals.The results indicate that between 17.54 Ma and 7.80 Ma,the sedimentation rate initially increased and then decreased,ranging from 6.1 cm/ka to 45.7 cm/ka,with an average rate of 22.2 cm/ka.During the Middle Miocene Climatic Optimum(MMCO),sedimentation rates were moderate and exhibited an increasing trend,largely driven by increased sediment input due to enhanced weathering from rising temperatures and by expanded accommodation space resulting from tectonic subsidence.Meanwhile,the Middle Miocene Climate Transition(MMCT)was marked by a notable rise in sedimentation rates,consistent with a major sea-level fall due to global cooling,which promoted the direct seaward progradation of marginal sediments.The Late Middle Miocene to Late Miocene had the lowest sedimentation rates,which can be attributed to reduced weathering under cold and arid conditions,along with a sea-level rise induced by regional tectonics.The short-term increase in the sedimentation rate observed at 10.4 Ma may have been driven by sea-level fluctuations.This study provides both theoretical and empirical support for understanding the influence of abrupt climate changes on sedimentary processes.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
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
A new expression for calculating suspended fine-sediment deposition rate is developed based on theoretic analysis and experiments. The resulting equation is applied to simulation of fine sediment deposition in the rec...A new expression for calculating suspended fine-sediment deposition rate is developed based on theoretic analysis and experiments. The resulting equation is applied to simulation of fine sediment deposition in the reclaimed land in the Hangzhou Bay, China. The hydrodynamic environment in this area is solved by use of a long wave model, which gives the 2D-velocity field and considers bathymetric changes due to fine sediment deposition. The expression is proved convenient to use in engineering practice, and the predicted deposition rate agrees with the annual data available from field measurements from the first year to the third year after the construction of the long groin as a reclaiming method.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
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
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
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
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
Flume experiments were carried out to study bed load transport rate during rive bed scouring and ar-moring.A theoretical differential equation linking the transport rate to the probability of incipient motion of non-u...Flume experiments were carried out to study bed load transport rate during rive bed scouring and ar-moring.A theoretical differential equation linking the transport rate to the probability of incipient motion of non-uniform sediment is solved.The transport rate is shown to decrease exponentially with time,according to the theory,which is in good agreement with the experiment data.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
Objective: to analyze the changes of erythrocyte sedimentation rate (ESR) in patients with tuberculous pleurisy, and to study the clinical significance of routine measurement, in order to provide scientific basis for ...Objective: to analyze the changes of erythrocyte sedimentation rate (ESR) in patients with tuberculous pleurisy, and to study the clinical significance of routine measurement, in order to provide scientific basis for clinical diagnosis and treatment. Methods: a total of 58 patients with tuberculous pleurisy admitted to our hospital from 2021.1 to 2021.7 were included in the study. The basic data of the patients and the measurement results of erythrocyte sedimentation index were analyzed by retrospective analysis, and the change law and clinical application value were discussed. Results: in 58 patients with tuberculous pleurisy, 28 cases (48.28%) had rapid erythrocyte sedimentation rate. The proportion of ESR between 20 years old and 40 years old was 55.56%, and between 40 years old and 60 years old and above 60 years old was 66.67% and 40.54%, respectively. There was no significant difference in esR between patients of different ages, P > 0.05. A total of 23 cases (53.49%) of male patients and 5 cases (33.33%) of female patients showed rapid erythrocyte sedimentation rate (ESR).展开更多
Fecal indicator bacteria, such as total coliforms and E. coli, are a challenge to control in urban and rural stormwater runoff. To assess the challenges of improving bacterial water quality standards in surface waters...Fecal indicator bacteria, such as total coliforms and E. coli, are a challenge to control in urban and rural stormwater runoff. To assess the challenges of improving bacterial water quality standards in surface waters, microcosm experiments were conducted to assess how decay rates of total coliforms and E. coli are affected by sediments and associated organic matter. Samples were collected at a lake embayment to create laboratory microcosms consisting of different combinations of unsterilized and sterilized water and sediment. Calculated first-order decay rate constants ranged from 0.021 to 0.047 h-1 for total coliforms and 0.017 and 0.037 h-1 for E. coli, depending on how each microcosm was prepared. It is evident that sediment in contact with the water column decreases bacteria decay rate, showing that care should be taken when designing stormwater treatment measures. In addition, high organic carbon content in the sediment temporarily increased bacteria concentrations in the water column. The results demonstrate that stormwater treatment measures, such as extended detention basins and constructed wetlands, must hold water for several days to allow for reduction of bacterial concentrations to acceptable levels. In addition, to troubleshoot detention basins and constructed wetlands for causes of high effluent bacterial concentrations, analyses of sediment, organic carbon, and water column depth should be conducted.展开更多
基金The National Natural Science Foundation of China under contract Nos 42372170,42472055,42272177,and 42077410the Safety Discipline“double first-class”to found Project of China under contract No.AQ20240305.
文摘The Zhujiang River Mouth Basin,a primary depocenter for terrigenous sediments in the western Pacific,presents a semienclosed tectonic setting with limited exchange with the open ocean.This unique feature enables systematic linkages among sedimentary processes,climate change,regional sea-level fluctuations,and tectonic events.To explore these linkages,this study focuses on Well PY35 in the Baiyun Sag of the Zhujiang River Mouth Basin.By integrating microfossil analysis with Milankovitch cycle analysis of well log data,an astronomical time scale(ATS)(17.54-7.80 Ma)and a high-resolution stratigraphic framework were established,allowing for the calculation of sedimentation rates across different hierarchical sequences and time intervals.The results indicate that between 17.54 Ma and 7.80 Ma,the sedimentation rate initially increased and then decreased,ranging from 6.1 cm/ka to 45.7 cm/ka,with an average rate of 22.2 cm/ka.During the Middle Miocene Climatic Optimum(MMCO),sedimentation rates were moderate and exhibited an increasing trend,largely driven by increased sediment input due to enhanced weathering from rising temperatures and by expanded accommodation space resulting from tectonic subsidence.Meanwhile,the Middle Miocene Climate Transition(MMCT)was marked by a notable rise in sedimentation rates,consistent with a major sea-level fall due to global cooling,which promoted the direct seaward progradation of marginal sediments.The Late Middle Miocene to Late Miocene had the lowest sedimentation rates,which can be attributed to reduced weathering under cold and arid conditions,along with a sea-level rise induced by regional tectonics.The short-term increase in the sedimentation rate observed at 10.4 Ma may have been driven by sea-level fluctuations.This study provides both theoretical and empirical support for understanding the influence of abrupt climate changes on sedimentary processes.
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.
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.
文摘A new expression for calculating suspended fine-sediment deposition rate is developed based on theoretic analysis and experiments. The resulting equation is applied to simulation of fine sediment deposition in the reclaimed land in the Hangzhou Bay, China. The hydrodynamic environment in this area is solved by use of a long wave model, which gives the 2D-velocity field and considers bathymetric changes due to fine sediment deposition. The expression is proved convenient to use in engineering practice, and the predicted deposition rate agrees with the annual data available from field measurements from the first year to the third year after the construction of the long groin as a reclaiming method.
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.
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Flume experiments were carried out to study bed load transport rate during rive bed scouring and ar-moring.A theoretical differential equation linking the transport rate to the probability of incipient motion of non-uniform sediment is solved.The transport rate is shown to decrease exponentially with time,according to the theory,which is in good agreement with the experiment data.
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.
文摘Objective: to analyze the changes of erythrocyte sedimentation rate (ESR) in patients with tuberculous pleurisy, and to study the clinical significance of routine measurement, in order to provide scientific basis for clinical diagnosis and treatment. Methods: a total of 58 patients with tuberculous pleurisy admitted to our hospital from 2021.1 to 2021.7 were included in the study. The basic data of the patients and the measurement results of erythrocyte sedimentation index were analyzed by retrospective analysis, and the change law and clinical application value were discussed. Results: in 58 patients with tuberculous pleurisy, 28 cases (48.28%) had rapid erythrocyte sedimentation rate. The proportion of ESR between 20 years old and 40 years old was 55.56%, and between 40 years old and 60 years old and above 60 years old was 66.67% and 40.54%, respectively. There was no significant difference in esR between patients of different ages, P > 0.05. A total of 23 cases (53.49%) of male patients and 5 cases (33.33%) of female patients showed rapid erythrocyte sedimentation rate (ESR).
文摘Fecal indicator bacteria, such as total coliforms and E. coli, are a challenge to control in urban and rural stormwater runoff. To assess the challenges of improving bacterial water quality standards in surface waters, microcosm experiments were conducted to assess how decay rates of total coliforms and E. coli are affected by sediments and associated organic matter. Samples were collected at a lake embayment to create laboratory microcosms consisting of different combinations of unsterilized and sterilized water and sediment. Calculated first-order decay rate constants ranged from 0.021 to 0.047 h-1 for total coliforms and 0.017 and 0.037 h-1 for E. coli, depending on how each microcosm was prepared. It is evident that sediment in contact with the water column decreases bacteria decay rate, showing that care should be taken when designing stormwater treatment measures. In addition, high organic carbon content in the sediment temporarily increased bacteria concentrations in the water column. The results demonstrate that stormwater treatment measures, such as extended detention basins and constructed wetlands, must hold water for several days to allow for reduction of bacterial concentrations to acceptable levels. In addition, to troubleshoot detention basins and constructed wetlands for causes of high effluent bacterial concentrations, analyses of sediment, organic carbon, and water column depth should be conducted.
