The 2014 magnitude 6.5 Ludian earthquake caused a death toll of 617, many landslides and tens of thousands of collapsed buildings. A field investigation to evaluate the damage to buildings was carried out immediately ...The 2014 magnitude 6.5 Ludian earthquake caused a death toll of 617, many landslides and tens of thousands of collapsed buildings. A field investigation to evaluate the damage to buildings was carried out immediately after the occurrence of the earthquake. Severely damaged aseismic buildings, which were basically observed in the downtown of Longtoushan Town, were carefully examined one by one with the aim to improve design codes. This paper summarizes the damage observed to the investigated aseismic buildings in both the structural and local levels. A common failure mode was observed that most of the aseismic buildings, such as RC frame structures and confined masonry structures, were similarly destroyed by severe damage or complete collapse of the first story. The related strong ground motion, which was recorded at the nearby station, had a short duration of less than 20 s but a very large PGA up to 1.0 g. The RC frames based on the new design codes still failed to achieve the design target for ＂strong column, weak beam＂. Typical local failure details, which were related to the interaction between RC columns and infill walls and between constructional columns and masonry walls, are summarized with preliminary analyses.展开更多
For centuries, explorers and scientists from different countries had made their own conclusions on the source of the Mekong. However, the geographic source of the Mekong is still arguable because of the complexity of ...For centuries, explorers and scientists from different countries had made their own conclusions on the source of the Mekong. However, the geographic source of the Mekong is still arguable because of the complexity of the Mekong source water system, inaccessible environment and the varied technologies used by those explorers and scientists. The satellite remote sensing technology has been used to pinpoint the source of the Mekong, associated with the on-the-spot investigations made by the authors in June 1999 and September 2002. The actual length of the Mekong has also been calculated.展开更多
Trace elements(and their isotopes)in carbonates are commonly used to reconstruct paleoenvironment and paleoclimate.Understanding the processes and mechanisms of element incorporation into carbonates is thus crucial fo...Trace elements(and their isotopes)in carbonates are commonly used to reconstruct paleoenvironment and paleoclimate.Understanding the processes and mechanisms of element incorporation into carbonates is thus crucial for using such geochemical parameters as paleoclimate proxies.In contrast to laboratory-based experimental results,the partitioning of trace metals between solid and solution phases in natural carbonate precipitation systems has rarely been reported.In this study,we investigated the partition coefficients of metal ions between solid and solution in the channel of the natural Baishuitai travertine system,Yunnan,China.Our results show that the partition coefficients of Li+,Na+,Mg2+,Sr2+and Ba2+are<1,that of Ni2+is approximately 1,and those of Co2+,Mn2+,Zn2+and Cu2+are>1,consistent with the results found in previous experimental studies.Although the substitution for Ca2+is likely the main uptake process of these metals into calcite,depending on their ionic radius and charge,trace elements may also be incorporated by adsorption or physical entrapment.Our study shows that unlike laboratory experiments performed under specific conditions,the partitioning of metals between two phases in the natural travertine system could be controlled by several,even multiple,environmental factors(e.g.,carbonate deposition rate,temperature,and pH),which should be taken into account when using trace metals(and their isotopes)in carbonate archives as a paleoclimate proxy.展开更多
Sea surface electric field observations off the coast from Goa (15°25'N, 73°47'E) to Madras (13°04'N, 80°15'E) around Sri Lanka, in a distance range 25-135 km from coast, during 9-2...Sea surface electric field observations off the coast from Goa (15°25'N, 73°47'E) to Madras (13°04'N, 80°15'E) around Sri Lanka, in a distance range 25-135 km from coast, during 9-20 May 1983 were taken. In this paper we have examined the diurnal variation of electric field in the Arabian Sea, Indian Ocean and Bay of Bengal regions covered during the cruise of the research ship ORV Gaveshani. An aspect of electric field dependence on coastal distance and Aitken Nuclei concentration has also been studied. An attempt to examine the latitude dependence of field was also made. Results obtained in the above studies are presented and compared with those obtained elsewhere.展开更多
The so-called occupational disease, in fact, refers to enterprises and institutions or individual workers, because in the daily process of employment, contact with radioactive substances or dust and other toxic and ha...The so-called occupational disease, in fact, refers to enterprises and institutions or individual workers, because in the daily process of employment, contact with radioactive substances or dust and other toxic and harmful substances, which will cause a certain degree of threat to their own health, forming a certain harm. Therefore, the disease type of occupational disease will often bring serious physical and mental trauma to the workers, and even cause great harm and impact on their families. To this end, this needs the relevant departments to cause enough attention. The detection and evaluation of occupational diseases is an important way to effectively avoid occupational diseases. For this reason, this paper mainly starts with the routine detection and evaluation of occupational-disease-inductive factors, and from the perspective of a new health investigation. In addition, by combining the 130 researcher cases selected from January 2019 to January 2021, the comprehensive field investigation in the detection and evaluation of occupational-disease-inductive factors is a more comprehensive and objective analysis.展开更多
Rainstorm-induced flood hazards in mountainous areas often result in complex cascading effects by interacting with environmental and human systems.However,traditional studies typically categorize them simply as clearw...Rainstorm-induced flood hazards in mountainous areas often result in complex cascading effects by interacting with environmental and human systems.However,traditional studies typically categorize them simply as clearwater floods or debris floods/flows,overlooking their evolutionary characteristics and compound impacts.This study presents a novel classification-based approach to investigate the formation and destructive mechanisms of a catastrophic composite disaster of flash flood and debris flow in the Dayao Gully(DYG)catchment in Hanyuan County,Sichuan Province,China.The event resulted in 14 fatalities,25 missing persons,and extensive infrastructure damage.Through comprehensive field investigations and multi-method analysis,three distinct disaster zones were identified with different magnitudes and impacts:(1)a clearwater flood disaster region with minimal geomorphological changes under a 5-year return period rainfall;(2)a debris flood disaster region triggered by a 30-year return period rainfall,leading to intense sediment transport with a total deposit volume of 52,511 m^(3);and(3)a sediment-induced flood disaster region characterized by significant riverbed aggradation and infrastructure destruction due to sediment-induced blockage effects.The results reveal that the cascading characteristics of this composite disaster were primarily driven by intense rainfall,enhanced sediment transport motivated by supracritical shear stress,and interactions with human infrastructure(e.g.,bridges and buildings).This classification-based approach provides a quantitative assessment of spatial characteristics of cascading flood disasters,offering new insights into their evolutionary characteristics and highlighting the necessity for targeted disaster mitigation strategies in sedimentprone mountainous regions.展开更多
This paper gives a numerical study on the flow and temperature fields in an induced plasma reactor, which worked in 0.5 ATM with air as a working gas. We employed a two-dimensional mode of an inductively coupled plas...This paper gives a numerical study on the flow and temperature fields in an induced plasma reactor, which worked in 0.5 ATM with air as a working gas. We employed a two-dimensional mode of an inductively coupled plasma to calculate the temperature and flow field of the reactor as well as the generator. The algorithm is based on the solutions of the two-dimensional continuity, momentum, and energy equations in term of vorticity, stream function and enthalpy. An upwind finite-difference scheme was adopted to solve those equations with appropriate boundary conditions. The computed results show that there is a flat region with little parameter change in the reactor, that the diameter of the region is not much larger than that of the generator and that a deep change of parameter exists in the outer side of the region.展开更多
The Kashmir Basin,shaped by the collision of the Indian and Eurasian tectonic plates,features prominent faults,including the Balapur fault and other fault zones.This study focuses on the Gulmarg fault within the North...The Kashmir Basin,shaped by the collision of the Indian and Eurasian tectonic plates,features prominent faults,including the Balapur fault and other fault zones.This study focuses on the Gulmarg fault within the Northwestern Himalaya,using advanced geomagnetic techniques for delineation.Geomagnetic measurements reveal the characteristics of the newly identified Gulmarg fault.Ground magnetic surveys with Proton Precession Magnetometers along linear profiles and a magnetic grid highlight fault-related anomalies.The results indicate a fault running through the Gulmarg meadows,approximately 1.6 km from the Balapur fault,suggesting a potential coupling between the two.Three profiles across the fault exhibit distinctive magnetic variations,highlighting the intricate nature of the fault structure.Gridding methods also reveal anomalies associated with subsurface water and hydraulic activities,underscoring the importance of advanced geophysical techniques.This study emphasizes the significance of detailed investigations to unravel the complex geological processes shaping the Kashmir Basin.The study provides valuable insights into the tectonic activity in the Gulmarg region,underscoring the role of geophysical studies in enhancing our understanding of dynamic geological structures like the Gulmarg fault zone.展开更多
The use of foam,as the most economical soil conditioning technique,in earth pressure balance tunnel boring machine(EPB-TBM)tunneling projects has significant effects on operation efficiency,excavation cost,and operati...The use of foam,as the most economical soil conditioning technique,in earth pressure balance tunnel boring machine(EPB-TBM)tunneling projects has significant effects on operation efficiency,excavation cost,and operation time.This study mainly focuses on developing models to predict the foam(surfactant)consumption.For this purpose,five empirical models are developed based on a database containing 11048 datasets of real-time foam consumption from three EPB-TBM tunneling projects in Iran.This database includes the most effective machine operational parameters and soil geomechanical properties on the foam consumption.Multiple linear regression analysis,multiple non-linear regression analysis,M5Prime decision tree,artificial neural network,and least squares support vector machine techniques are used to construct the models.To evaluate the performance of developed models,three performance evaluation criteria(including normalized root mean square error,variance account for,and coefficient of determination)are used based on the training and testing datasets.The results show that the developed models have high performance and their validity is guaranteed according to the testing dataset.Furthermore,the M5Prime model,which demonstrates the best performance compared to other models,is applied to predict the foam consumption in 19 excavation rings of Kohandezh station in Isfahan metro,Iran.After conducting an excavation operation in this station and comparing the results,it was found that the M5Prime model accurately predicts foam consumption with an average error of less than 13%.Therefore,the developed models,particularly M5Prime model,can be confidently applied in EPB-TBM tunneling projects for predicting foam consumption with a low error rate.展开更多
We investigated migration of pollutant at the base of the Suzhou landfill after it had been operated for 13 years.The investigation was carried out by performing chemical analyses on the soil samples taken from the si...We investigated migration of pollutant at the base of the Suzhou landfill after it had been operated for 13 years.The investigation was carried out by performing chemical analyses on the soil samples taken from the silty clay deposit.Concentrations of chloride,chemical oxygen demand(COD)and the heavy metals in the soil samples were determined using the standard methods.The experimental data showed that the maximum migration depth of chloride was more than 10 m,while the maximum migration depth of COD varied between 1 and 3.5 m.It is believed that the difference is attributed to the variation in diffusion rate and leachate-soil interaction.The chloride profiles also indicated that adveetion may be the dominant contaminant transport mechanism at this site.The total contents ofCu,Pb and Cr are very close to the background levels and the concentration values of these metals mainly are lower than the threshold values specified by the Chinese soil quality standard and the European one.The water-extractable concentrations of COD in the surface of the silty clay generally exceed the limit value specified by the Chinese standard.The concentrations of copper and chromium in pore water are 1-2 orders of magnitude less than the total concentrations of these heavy metals within the soils,implying that heavy metals are mainly adsorbed by the soil particles.Finally,remediation methods were suggested for this landfill site.展开更多
A systematic investigation on spiders in a tea garden of Guilin Institute of Tea Sciences was conducted. The results showed that totally 687 specimens were collected, belonging to 34 species, 27genera, 14 families, 2 ...A systematic investigation on spiders in a tea garden of Guilin Institute of Tea Sciences was conducted. The results showed that totally 687 specimens were collected, belonging to 34 species, 27genera, 14 families, 2 suborders, and a new record species Trochosa suiningensis in Guangxi was found. Spider is a ma- jor developing natural enemy group of insect pests in tea garden, with features of wide distribution, large quantity, long duration, strong predatory and stress resist- ance, which has strong predation on adults and nymphs of Empoasca vitis and young larvae of Ectropis oblique. The population of spiders in tea garden significantly increases after middle June, and reaches the peak in July and August every year.展开更多
On August 20th,2019,a M4.2 earthquake occurred near Zhanan and Lixin Village,Tianya District,Sanya City,Hainan Province. We conduct field investigations in the vicinity of the epicenter which includes 25 natural villa...On August 20th,2019,a M4.2 earthquake occurred near Zhanan and Lixin Village,Tianya District,Sanya City,Hainan Province. We conduct field investigations in the vicinity of the epicenter which includes 25 natural villages based on the data provided by local government and finally complete the map of the earthquake intensity.Through the analysis of the houses and cracks in the earthquake area,the structure types and crack characteristics of the houses are basically unveiled. Furthermore,suggestions for earthquake disaster reduction in study area are obtained from the investigation.展开更多
In this paper,with Collection of Chinese Works by Matteo Ricci written by Zhu Weizheng and A summary Interpretation of Chinese literature of Matteo Ricci in Ming and Qing Dynasties written by Tang Kaijian as major res...In this paper,with Collection of Chinese Works by Matteo Ricci written by Zhu Weizheng and A summary Interpretation of Chinese literature of Matteo Ricci in Ming and Qing Dynasties written by Tang Kaijian as major research texts and historical basis,as well as intercultural communication as the major research method,the aesthetic adaptation of native music of traditional Chinese music,etiquette,sacrifice and religious customs under the description of Matteo Ricci is discussed and interpreted from the perspective of the spread of musical culture of the Maritime Silk Road,four stages of field investigation are planned,and related musical activities and local musical phenomena appearing in his literature have an on-site visit.In this way,the vital position and historical significance of Matteo Ricci’s cultural missionary activities in the music communication on the Maritime Silk Road are obtained.展开更多
Many highway bridges were severely damaged or completely collapsed during the 2008 Wenchuan earthquake. A field investigation was carried out in the strongly affected areas and over 320 bridges were examined. Damage t...Many highway bridges were severely damaged or completely collapsed during the 2008 Wenchuan earthquake. A field investigation was carried out in the strongly affected areas and over 320 bridges were examined. Damage to some representative highway bridges is briefly described and a preliminary analysis of the probable causes of the damage is presented in this paper. The most common damage included shear-flexural failure of the pier columns, expansion joint failure, shear key failure, and girder sliding in the transversal or longitudinal directions due to weak connections between girder and bearings. Lessons learned from this earthquake are described and recommendations related to the design of curved and skewed bridges, design of bearings and devices to prevent girder collapse, and ductility of bridge piers are presented. Suggestions for future seismic design and retrofitting techniques for bridges in moderate to severe earthquake areas are also proposed.展开更多
The May 12, 2008 Great Wenchuan Earthquake has resulted in more than 68,858 deaths and losses in the hundreds of billions RMB as of May 30, 2008, and these numbers will undoubtedly increase as more information becomes...The May 12, 2008 Great Wenchuan Earthquake has resulted in more than 68,858 deaths and losses in the hundreds of billions RMB as of May 30, 2008, and these numbers will undoubtedly increase as more information becomes available on the extent of the event. Immediately after the earthquake, the China Earthquake Administration （CEA） responded quickly by sending teams of experts to the affected region, eventually including over 60 staff members from the Institute of Engineering Mechanics （IEM）. This paper reports preliminary information that has been gathered in the first 18 days after the event, covering seismicity, search and rescue efforts, observed ground motions, and damage and loss estimates. The extensive field investigation has revealed a number of valuable findings that could be useful in improving research in earthquake engineering in the future. Once again, this earthquake has shown that the vertical component of ground motion is as significant as horizontal ground motions in the near-source area. Finally, note that as more information is gathered, the numbers reported in this paper will need to be adjusted accordingly.展开更多
The globally invasive cotton mealybug Phenacoccus solenopsis Tinsley,has recently invaded several Chinese regions,and continues to expand its range.This mealybug is a polyphagous insect pest,with at least 200 host pla...The globally invasive cotton mealybug Phenacoccus solenopsis Tinsley,has recently invaded several Chinese regions,and continues to expand its range.This mealybug is a polyphagous insect pest,with at least 200 host plants from 63 families,including cotton,food crops,fruits,ornamental plants,tobacco,and vegetables.Here,we describe the first finding of P.solenopsis in Shandong Province,and investigate the abundances of its natural enemies(predator Coccinella septempunctata L.and parasitoid Aenasius bambawalei Hayat).All three species were detected from ornamental and weed species in Linyi,Shandong,in September 2018,and were positively identified using DNA barcoding.BLAST analysis revealed significant identity(99.38-100%) between sequences of P.solenopsis obtained in this study and those published in the past.This invasive pest represents a major potential threat to agri-horticulture in Shandong,which is a key province of China for production and export of many vegetables,flowers,fruits,and other crops.This mealybug species has a wide range of potential distribution in Shandong and is easily dispersed with agricultural and horticultural transport products.Further monitoring and management strategies are required to limit the spread of this pest species.展开更多
This study constructs a preliminary inventory of landslides triggered by the M_(S) 6.8 Luding earthquake based on field investigation and human-computer interaction visual interpretation on optical satellite images.Th...This study constructs a preliminary inventory of landslides triggered by the M_(S) 6.8 Luding earthquake based on field investigation and human-computer interaction visual interpretation on optical satellite images.The results show that this earthquake triggered at least 5007 landslides,with a total landslide area of 17.36 km^(2),of which the smallest landslide area is 65 m^(2)and the largest landslide area reaches 120747 m^(2),with an average landslide area of about 3500 m^(2).The obtained landslides are concentrated in the IX intensity zone and the northeast side of the seismogenic fault,and the area density and point density of landslides are 13.8%,and 35.73 km^(-2) peaks with 2 km as the search radius.It should be noted that the number of landslides obtained in this paper will be lower than the actual situation because some areas are covered by clouds and there are no available post-earthquake remote sensing images.Based on the available post-earthquake remote sensing images,the number of landslides triggered by this earthquake is roughly estimated to be up to 10000.This study can be used to support further research on the distribution pattern and risk evaluation of the coseismic landslides in the region,and the prevention and control of landslide hazards in the seismic area.展开更多
A 3D torque converter design system is developed based on numerical investigation into flow field and CAD technology. The 3D steady-state flow field simulation is undertaken by using time averaged Reynolds equation an...A 3D torque converter design system is developed based on numerical investigation into flow field and CAD technology. The 3D steady-state flow field simulation is undertaken by using time averaged Reynolds equation and k-epsilon turbulence model, with mixing-plane boundary conditions at three section interfaces. The blades are designed according to the flow field characteristics by using a reverse design method in the system. The accurateness of numerical analysis and the validity of design system are verified by the fluid field experiment of desingn example of the torque converter. This kind of design and analysis system for torque converter based on integration of comput ationol fluid dynamics （CFD） and CAD is a powerful tool for torque converter manufacturing, but also a prettg important significance for research and development.展开更多
The Loess Plateau is an earthquake prone region of China, where the effects of loess deposit on ground motion were discovered during the 2008 Wenchuan earthquake(Ms8.0) and the 2013 Minxian-Zhangxian earthquake(Ms6.6)...The Loess Plateau is an earthquake prone region of China, where the effects of loess deposit on ground motion were discovered during the 2008 Wenchuan earthquake(Ms8.0) and the 2013 Minxian-Zhangxian earthquake(Ms6.6). The field investigations, observations, and analyses indicated that large number of casualties and tremendous economic losses were caused not only by collapse and damage of houses with poor seismic performance, landslides, but also amplification effects of site conditions, topography and thickness of loess deposit, on ground motion. In this paper, we chose Dazhai Village and Majiagou Village as the typical loess site affected by the two earthquakes for intensity evaluation, borehole exploration, temporary strong motion array, micro tremor survey, and numerical analysis. The aim is to explore the relations between amplification factors and site conditions in terms of topography and thickness of loess deposit. We also developed site amplification factors of ground motion for engineering design consideration at loess sites. The results showed that the amplification effects are more predominant with increase in thickness of loess deposit and slope height. The amplification mayincrease seismic intensity by 1 degree, PGA and predominant period by 2 times, respectively.展开更多
A large number of debris flows occurred simultaneously at around 8:30 to 8:50 a.m.on July 27,2011,at the center of Seoul,Korea.This area is located in the southern part of Seoul and is a densely populated district.As ...A large number of debris flows occurred simultaneously at around 8:30 to 8:50 a.m.on July 27,2011,at the center of Seoul,Korea.This area is located in the southern part of Seoul and is a densely populated district.As a result of the debris flow event,16 people were killed,30 houses were buried,and 116 houses were damaged around Umyeon Mountain,a relatively small mountain with a height of 312.6 m.Since the debris flow event,field investigations on the initiation and transportation zones of debris flows have been carried out.Rainfall data were collected from the automatic weather stations(AWSs) which are operated by the Korea Meteorological Administration(KMA).Video files recorded by residents were also acquired and used to analyze the flow characteristics of the debris flow.Field investigation shows that about 40 debris flows occurred around Umyeon Mountain and most of the debris flows were initiated by small slope failures.The effects of the precipitation that triggered the debris flows were analyzed as well.A landslide hazard map which considers slope gradient and aspect,strength of soil,hazard record,rainfall conditions,and vegetation,was constructed and compared with the initiation zones of debris flows.展开更多
基金Funding of IEM under Grant No.2014B04National Natural Science Foundation under Grant Nos.51108433 and 51308511China Postdoctoral Science Foundation under Grant No.2013M531083
文摘The 2014 magnitude 6.5 Ludian earthquake caused a death toll of 617, many landslides and tens of thousands of collapsed buildings. A field investigation to evaluate the damage to buildings was carried out immediately after the occurrence of the earthquake. Severely damaged aseismic buildings, which were basically observed in the downtown of Longtoushan Town, were carefully examined one by one with the aim to improve design codes. This paper summarizes the damage observed to the investigated aseismic buildings in both the structural and local levels. A common failure mode was observed that most of the aseismic buildings, such as RC frame structures and confined masonry structures, were similarly destroyed by severe damage or complete collapse of the first story. The related strong ground motion, which was recorded at the nearby station, had a short duration of less than 20 s but a very large PGA up to 1.0 g. The RC frames based on the new design codes still failed to achieve the design target for ＂strong column, weak beam＂. Typical local failure details, which were related to the interaction between RC columns and infill walls and between constructional columns and masonry walls, are summarized with preliminary analyses.
基金Supported by the National 863 Program of China (No.2003AA131170)the Special Funds of Director of Institute of Remote SensingApplications, Chinese Academy of Sciences+1 种基金the Funds of State Key Laboratory of Remote Sensing Sciencesthe Funds of StateKey Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing.
文摘For centuries, explorers and scientists from different countries had made their own conclusions on the source of the Mekong. However, the geographic source of the Mekong is still arguable because of the complexity of the Mekong source water system, inaccessible environment and the varied technologies used by those explorers and scientists. The satellite remote sensing technology has been used to pinpoint the source of the Mekong, associated with the on-the-spot investigations made by the authors in June 1999 and September 2002. The actual length of the Mekong has also been calculated.
基金financially supported by the National Key Research and Development Program of China (2019YFC1804400)the National Natural Science Foundation of China (U1612442, 41961144028, 41625012, 41830647)"Ten Thousand Talent" project of Ministry of Science and Technology of the People’s Republic of China。
文摘Trace elements(and their isotopes)in carbonates are commonly used to reconstruct paleoenvironment and paleoclimate.Understanding the processes and mechanisms of element incorporation into carbonates is thus crucial for using such geochemical parameters as paleoclimate proxies.In contrast to laboratory-based experimental results,the partitioning of trace metals between solid and solution phases in natural carbonate precipitation systems has rarely been reported.In this study,we investigated the partition coefficients of metal ions between solid and solution in the channel of the natural Baishuitai travertine system,Yunnan,China.Our results show that the partition coefficients of Li+,Na+,Mg2+,Sr2+and Ba2+are<1,that of Ni2+is approximately 1,and those of Co2+,Mn2+,Zn2+and Cu2+are>1,consistent with the results found in previous experimental studies.Although the substitution for Ca2+is likely the main uptake process of these metals into calcite,depending on their ionic radius and charge,trace elements may also be incorporated by adsorption or physical entrapment.Our study shows that unlike laboratory experiments performed under specific conditions,the partitioning of metals between two phases in the natural travertine system could be controlled by several,even multiple,environmental factors(e.g.,carbonate deposition rate,temperature,and pH),which should be taken into account when using trace metals(and their isotopes)in carbonate archives as a paleoclimate proxy.
文摘Sea surface electric field observations off the coast from Goa (15°25'N, 73°47'E) to Madras (13°04'N, 80°15'E) around Sri Lanka, in a distance range 25-135 km from coast, during 9-20 May 1983 were taken. In this paper we have examined the diurnal variation of electric field in the Arabian Sea, Indian Ocean and Bay of Bengal regions covered during the cruise of the research ship ORV Gaveshani. An aspect of electric field dependence on coastal distance and Aitken Nuclei concentration has also been studied. An attempt to examine the latitude dependence of field was also made. Results obtained in the above studies are presented and compared with those obtained elsewhere.
文摘The so-called occupational disease, in fact, refers to enterprises and institutions or individual workers, because in the daily process of employment, contact with radioactive substances or dust and other toxic and harmful substances, which will cause a certain degree of threat to their own health, forming a certain harm. Therefore, the disease type of occupational disease will often bring serious physical and mental trauma to the workers, and even cause great harm and impact on their families. To this end, this needs the relevant departments to cause enough attention. The detection and evaluation of occupational diseases is an important way to effectively avoid occupational diseases. For this reason, this paper mainly starts with the routine detection and evaluation of occupational-disease-inductive factors, and from the perspective of a new health investigation. In addition, by combining the 130 researcher cases selected from January 2019 to January 2021, the comprehensive field investigation in the detection and evaluation of occupational-disease-inductive factors is a more comprehensive and objective analysis.
基金supported by National Natural Science Foundation of Joint Fund for Changjiang River Water Science Research(U2340201)National Natural Science Foundation of China(52239006)Natural Science Foundation of Sichuan Province(2024NSFSC0005).
文摘Rainstorm-induced flood hazards in mountainous areas often result in complex cascading effects by interacting with environmental and human systems.However,traditional studies typically categorize them simply as clearwater floods or debris floods/flows,overlooking their evolutionary characteristics and compound impacts.This study presents a novel classification-based approach to investigate the formation and destructive mechanisms of a catastrophic composite disaster of flash flood and debris flow in the Dayao Gully(DYG)catchment in Hanyuan County,Sichuan Province,China.The event resulted in 14 fatalities,25 missing persons,and extensive infrastructure damage.Through comprehensive field investigations and multi-method analysis,three distinct disaster zones were identified with different magnitudes and impacts:(1)a clearwater flood disaster region with minimal geomorphological changes under a 5-year return period rainfall;(2)a debris flood disaster region triggered by a 30-year return period rainfall,leading to intense sediment transport with a total deposit volume of 52,511 m^(3);and(3)a sediment-induced flood disaster region characterized by significant riverbed aggradation and infrastructure destruction due to sediment-induced blockage effects.The results reveal that the cascading characteristics of this composite disaster were primarily driven by intense rainfall,enhanced sediment transport motivated by supracritical shear stress,and interactions with human infrastructure(e.g.,bridges and buildings).This classification-based approach provides a quantitative assessment of spatial characteristics of cascading flood disasters,offering new insights into their evolutionary characteristics and highlighting the necessity for targeted disaster mitigation strategies in sedimentprone mountainous regions.
文摘This paper gives a numerical study on the flow and temperature fields in an induced plasma reactor, which worked in 0.5 ATM with air as a working gas. We employed a two-dimensional mode of an inductively coupled plasma to calculate the temperature and flow field of the reactor as well as the generator. The algorithm is based on the solutions of the two-dimensional continuity, momentum, and energy equations in term of vorticity, stream function and enthalpy. An upwind finite-difference scheme was adopted to solve those equations with appropriate boundary conditions. The computed results show that there is a flat region with little parameter change in the reactor, that the diameter of the region is not much larger than that of the generator and that a deep change of parameter exists in the outer side of the region.
文摘The Kashmir Basin,shaped by the collision of the Indian and Eurasian tectonic plates,features prominent faults,including the Balapur fault and other fault zones.This study focuses on the Gulmarg fault within the Northwestern Himalaya,using advanced geomagnetic techniques for delineation.Geomagnetic measurements reveal the characteristics of the newly identified Gulmarg fault.Ground magnetic surveys with Proton Precession Magnetometers along linear profiles and a magnetic grid highlight fault-related anomalies.The results indicate a fault running through the Gulmarg meadows,approximately 1.6 km from the Balapur fault,suggesting a potential coupling between the two.Three profiles across the fault exhibit distinctive magnetic variations,highlighting the intricate nature of the fault structure.Gridding methods also reveal anomalies associated with subsurface water and hydraulic activities,underscoring the importance of advanced geophysical techniques.This study emphasizes the significance of detailed investigations to unravel the complex geological processes shaping the Kashmir Basin.The study provides valuable insights into the tectonic activity in the Gulmarg region,underscoring the role of geophysical studies in enhancing our understanding of dynamic geological structures like the Gulmarg fault zone.
文摘The use of foam,as the most economical soil conditioning technique,in earth pressure balance tunnel boring machine(EPB-TBM)tunneling projects has significant effects on operation efficiency,excavation cost,and operation time.This study mainly focuses on developing models to predict the foam(surfactant)consumption.For this purpose,five empirical models are developed based on a database containing 11048 datasets of real-time foam consumption from three EPB-TBM tunneling projects in Iran.This database includes the most effective machine operational parameters and soil geomechanical properties on the foam consumption.Multiple linear regression analysis,multiple non-linear regression analysis,M5Prime decision tree,artificial neural network,and least squares support vector machine techniques are used to construct the models.To evaluate the performance of developed models,three performance evaluation criteria(including normalized root mean square error,variance account for,and coefficient of determination)are used based on the training and testing datasets.The results show that the developed models have high performance and their validity is guaranteed according to the testing dataset.Furthermore,the M5Prime model,which demonstrates the best performance compared to other models,is applied to predict the foam consumption in 19 excavation rings of Kohandezh station in Isfahan metro,Iran.After conducting an excavation operation in this station and comparing the results,it was found that the M5Prime model accurately predicts foam consumption with an average error of less than 13%.Therefore,the developed models,particularly M5Prime model,can be confidently applied in EPB-TBM tunneling projects for predicting foam consumption with a low error rate.
基金supported by the National Natural Science Foundation of China(No.50538080)the National Science Fund for Distinguished Young Scholars(No.50425825),China
文摘We investigated migration of pollutant at the base of the Suzhou landfill after it had been operated for 13 years.The investigation was carried out by performing chemical analyses on the soil samples taken from the silty clay deposit.Concentrations of chloride,chemical oxygen demand(COD)and the heavy metals in the soil samples were determined using the standard methods.The experimental data showed that the maximum migration depth of chloride was more than 10 m,while the maximum migration depth of COD varied between 1 and 3.5 m.It is believed that the difference is attributed to the variation in diffusion rate and leachate-soil interaction.The chloride profiles also indicated that adveetion may be the dominant contaminant transport mechanism at this site.The total contents ofCu,Pb and Cr are very close to the background levels and the concentration values of these metals mainly are lower than the threshold values specified by the Chinese soil quality standard and the European one.The water-extractable concentrations of COD in the surface of the silty clay generally exceed the limit value specified by the Chinese standard.The concentrations of copper and chromium in pore water are 1-2 orders of magnitude less than the total concentrations of these heavy metals within the soils,implying that heavy metals are mainly adsorbed by the soil particles.Finally,remediation methods were suggested for this landfill site.
基金Supported by Basic Research Fund of Guangxi Zhuang Autonomous Region
文摘A systematic investigation on spiders in a tea garden of Guilin Institute of Tea Sciences was conducted. The results showed that totally 687 specimens were collected, belonging to 34 species, 27genera, 14 families, 2 suborders, and a new record species Trochosa suiningensis in Guangxi was found. Spider is a ma- jor developing natural enemy group of insect pests in tea garden, with features of wide distribution, large quantity, long duration, strong predatory and stress resist- ance, which has strong predation on adults and nymphs of Empoasca vitis and young larvae of Ectropis oblique. The population of spiders in tea garden significantly increases after middle June, and reaches the peak in July and August every year.
基金sponsored by the Disaster Risk Prevention Technology Innovation Team Fund of Hainan Earthquake Agency&Research Project of Hainan Earthquake Agency(HDKJ201904)。
文摘On August 20th,2019,a M4.2 earthquake occurred near Zhanan and Lixin Village,Tianya District,Sanya City,Hainan Province. We conduct field investigations in the vicinity of the epicenter which includes 25 natural villages based on the data provided by local government and finally complete the map of the earthquake intensity.Through the analysis of the houses and cracks in the earthquake area,the structure types and crack characteristics of the houses are basically unveiled. Furthermore,suggestions for earthquake disaster reduction in study area are obtained from the investigation.
文摘In this paper,with Collection of Chinese Works by Matteo Ricci written by Zhu Weizheng and A summary Interpretation of Chinese literature of Matteo Ricci in Ming and Qing Dynasties written by Tang Kaijian as major research texts and historical basis,as well as intercultural communication as the major research method,the aesthetic adaptation of native music of traditional Chinese music,etiquette,sacrifice and religious customs under the description of Matteo Ricci is discussed and interpreted from the perspective of the spread of musical culture of the Maritime Silk Road,four stages of field investigation are planned,and related musical activities and local musical phenomena appearing in his literature have an on-site visit.In this way,the vital position and historical significance of Matteo Ricci’s cultural missionary activities in the music communication on the Maritime Silk Road are obtained.
基金National Natural Science Foundation of China Under Grant No. 90715032 and 50808105National Basic Research Program of China Under Grant No. 2007CB714203
文摘Many highway bridges were severely damaged or completely collapsed during the 2008 Wenchuan earthquake. A field investigation was carried out in the strongly affected areas and over 320 bridges were examined. Damage to some representative highway bridges is briefly described and a preliminary analysis of the probable causes of the damage is presented in this paper. The most common damage included shear-flexural failure of the pier columns, expansion joint failure, shear key failure, and girder sliding in the transversal or longitudinal directions due to weak connections between girder and bearings. Lessons learned from this earthquake are described and recommendations related to the design of curved and skewed bridges, design of bearings and devices to prevent girder collapse, and ductility of bridge piers are presented. Suggestions for future seismic design and retrofitting techniques for bridges in moderate to severe earthquake areas are also proposed.
基金Partially the Project 2007CB714205 of the National Basic Research Program of China
文摘The May 12, 2008 Great Wenchuan Earthquake has resulted in more than 68,858 deaths and losses in the hundreds of billions RMB as of May 30, 2008, and these numbers will undoubtedly increase as more information becomes available on the extent of the event. Immediately after the earthquake, the China Earthquake Administration （CEA） responded quickly by sending teams of experts to the affected region, eventually including over 60 staff members from the Institute of Engineering Mechanics （IEM）. This paper reports preliminary information that has been gathered in the first 18 days after the event, covering seismicity, search and rescue efforts, observed ground motions, and damage and loss estimates. The extensive field investigation has revealed a number of valuable findings that could be useful in improving research in earthquake engineering in the future. Once again, this earthquake has shown that the vertical component of ground motion is as significant as horizontal ground motions in the near-source area. Finally, note that as more information is gathered, the numbers reported in this paper will need to be adjusted accordingly.
基金supported by the National Key Research and Development Program of China(2017YFC1200600 and 2016YFC1201200)the Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(caascx-2017-2022-IAS)
文摘The globally invasive cotton mealybug Phenacoccus solenopsis Tinsley,has recently invaded several Chinese regions,and continues to expand its range.This mealybug is a polyphagous insect pest,with at least 200 host plants from 63 families,including cotton,food crops,fruits,ornamental plants,tobacco,and vegetables.Here,we describe the first finding of P.solenopsis in Shandong Province,and investigate the abundances of its natural enemies(predator Coccinella septempunctata L.and parasitoid Aenasius bambawalei Hayat).All three species were detected from ornamental and weed species in Linyi,Shandong,in September 2018,and were positively identified using DNA barcoding.BLAST analysis revealed significant identity(99.38-100%) between sequences of P.solenopsis obtained in this study and those published in the past.This invasive pest represents a major potential threat to agri-horticulture in Shandong,which is a key province of China for production and export of many vegetables,flowers,fruits,and other crops.This mealybug species has a wide range of potential distribution in Shandong and is easily dispersed with agricultural and horticultural transport products.Further monitoring and management strategies are required to limit the spread of this pest species.
基金the National Natural Science Foundation of China(42077259).
文摘This study constructs a preliminary inventory of landslides triggered by the M_(S) 6.8 Luding earthquake based on field investigation and human-computer interaction visual interpretation on optical satellite images.The results show that this earthquake triggered at least 5007 landslides,with a total landslide area of 17.36 km^(2),of which the smallest landslide area is 65 m^(2)and the largest landslide area reaches 120747 m^(2),with an average landslide area of about 3500 m^(2).The obtained landslides are concentrated in the IX intensity zone and the northeast side of the seismogenic fault,and the area density and point density of landslides are 13.8%,and 35.73 km^(-2) peaks with 2 km as the search radius.It should be noted that the number of landslides obtained in this paper will be lower than the actual situation because some areas are covered by clouds and there are no available post-earthquake remote sensing images.Based on the available post-earthquake remote sensing images,the number of landslides triggered by this earthquake is roughly estimated to be up to 10000.This study can be used to support further research on the distribution pattern and risk evaluation of the coseismic landslides in the region,and the prevention and control of landslide hazards in the seismic area.
基金Natioual Hi-tech Research and Development Program-of China(863 Program. No.2007AA04Z132).
文摘A 3D torque converter design system is developed based on numerical investigation into flow field and CAD technology. The 3D steady-state flow field simulation is undertaken by using time averaged Reynolds equation and k-epsilon turbulence model, with mixing-plane boundary conditions at three section interfaces. The blades are designed according to the flow field characteristics by using a reverse design method in the system. The accurateness of numerical analysis and the validity of design system are verified by the fluid field experiment of desingn example of the torque converter. This kind of design and analysis system for torque converter based on integration of comput ationol fluid dynamics （CFD） and CAD is a powerful tool for torque converter manufacturing, but also a prettg important significance for research and development.
基金financially supported by National Natural Science Foundation of China (No.51478444 & No.41472297)
文摘The Loess Plateau is an earthquake prone region of China, where the effects of loess deposit on ground motion were discovered during the 2008 Wenchuan earthquake(Ms8.0) and the 2013 Minxian-Zhangxian earthquake(Ms6.6). The field investigations, observations, and analyses indicated that large number of casualties and tremendous economic losses were caused not only by collapse and damage of houses with poor seismic performance, landslides, but also amplification effects of site conditions, topography and thickness of loess deposit, on ground motion. In this paper, we chose Dazhai Village and Majiagou Village as the typical loess site affected by the two earthquakes for intensity evaluation, borehole exploration, temporary strong motion array, micro tremor survey, and numerical analysis. The aim is to explore the relations between amplification factors and site conditions in terms of topography and thickness of loess deposit. We also developed site amplification factors of ground motion for engineering design consideration at loess sites. The results showed that the amplification effects are more predominant with increase in thickness of loess deposit and slope height. The amplification mayincrease seismic intensity by 1 degree, PGA and predominant period by 2 times, respectively.
基金supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education,Science and Technology (2012014940)supported by a grant(Code#’08 RTIP B01-01) from the Regional Technology Innovation Program (RTIP)funded by the Ministry of Land Transport and Maritime Affairs of the Korean government
文摘A large number of debris flows occurred simultaneously at around 8:30 to 8:50 a.m.on July 27,2011,at the center of Seoul,Korea.This area is located in the southern part of Seoul and is a densely populated district.As a result of the debris flow event,16 people were killed,30 houses were buried,and 116 houses were damaged around Umyeon Mountain,a relatively small mountain with a height of 312.6 m.Since the debris flow event,field investigations on the initiation and transportation zones of debris flows have been carried out.Rainfall data were collected from the automatic weather stations(AWSs) which are operated by the Korea Meteorological Administration(KMA).Video files recorded by residents were also acquired and used to analyze the flow characteristics of the debris flow.Field investigation shows that about 40 debris flows occurred around Umyeon Mountain and most of the debris flows were initiated by small slope failures.The effects of the precipitation that triggered the debris flows were analyzed as well.A landslide hazard map which considers slope gradient and aspect,strength of soil,hazard record,rainfall conditions,and vegetation,was constructed and compared with the initiation zones of debris flows.
