Investigating the spatiotemporal variation of human activity intensity and its determinants is a crucial basis for further revealing the mechanism of human-environment interaction and optimizing the human development ...Investigating the spatiotemporal variation of human activity intensity and its determinants is a crucial basis for further revealing the mechanism of human-environment interaction and optimizing the human development mode.In this study,the human activity intensity on the Qinghai-Tibet Plateau(QTP)from 1990 to 2020 was measured based on the quantitative model of land use data and the actual regional background,and the under-lying natural and socioeconomic determinants were investigated using spatial econometric methods.The results demonstrate that(1)the human activity intensity in QTP has increased by 11.96%,and there are differences in different spatial scales;the areas with high human activity intensity are distributed in the Hehuang Valley where Xining City and its surrounding areas are located,as well as the One-River and Two-River Area where Lhasa City and surrounding areas are located.(2)Human activity intensity has significant positive spatial spillover,suggesting that local changes will cause changes in the same direction in adjacent areas.(3)The human activ-ity intensity in QTP is affected by various determinants.Concerning socioeconomic factors,the economic level has no significant impact on the human activity intensity in QTP,which differs from the general regional law.Both urbanization and traffic conditions have a significant positive effect,and the impact intensity continues to increase.Concerning natural factors,topographic relief has a significant positive effect;the impacts of temper-ature and vegetation coverage have changed from insignificant to a significant positive effect;the impacts of precipitation and river network density have not been verified;there is no linear relationship between altitude and human activity intensity in the entire QTP,while it exists in local regions.Finally,this study proposes three policy implications for the realization of a more harmonious human-environment relationship in QTP.展开更多
目的探讨微孔板法、实时荧光PCR熔解曲线技术(简称“熔解曲线法”)、多色巢式实时荧光定量PCR技术(简称“Xpert法”)和罗氏药物敏感性试验(L-J药敏试验,简称“比例法”)用于快速筛查耐多药结核病(MDR-TB)的临床价值。方法从医院信息系统...目的探讨微孔板法、实时荧光PCR熔解曲线技术(简称“熔解曲线法”)、多色巢式实时荧光定量PCR技术(简称“Xpert法”)和罗氏药物敏感性试验(L-J药敏试验,简称“比例法”)用于快速筛查耐多药结核病(MDR-TB)的临床价值。方法从医院信息系统(hospital information system,HIS)连续收集2014年7月至2018年3月重庆市公共卫生医疗救治中心收治的确诊为结核病,且具有微孔板法、比例法、熔解曲线法、Xpert法检测MTB对利福平、异烟肼耐药性诊断结果的2792例患者资料;其中微孔板法、比例法采用阳性分离菌株检测,熔解曲线法和Xpert法采用患者标本直接检测。纳入同时具有微孔板法和比例法耐药性检测结果的1488例患者作为研究对象,其中341例行微孔板法+比例法+Xpert法检测利福平耐药性,87例行微孔板法+比例法+熔解曲线法检测利福平耐药性,66例行微孔板法+比例法+熔解曲线法检测异烟肼耐药性。以比例法为标准,采用SPSS13.0软件分别计算微孔板法、熔解曲线法、Xpert法检测利福平和(或)异烟肼耐药性的敏感度、特异度、符合率、Kappa值等。结果以比例法为标准,微孔板法、Xpert法、熔解曲线法检测利福平耐药性的敏感度、特异度、阳性预测值、阴性预测值、符合率、Kappa值分别为97.2%(731/752)、96.9%(713/736)、96.9%(731/754)、97.1%(713/734)、97.0%(1444/1488)、0.94,97.2%(140/144)、94.9%(187/197)、93.3%(140/150)、97.9%(187/191)、95.9%(327/341)、0.92,97.1%(33/34)、84.9%(45/53)、80.5%(33/41)、97.8%(45/46)、89.7%(78/87)、0.79;微孔板法和熔解曲线法检测异烟肼耐药性的敏感度、特异度、阳性预测值、阴性预测值、符合率、Kappa值分别为94.8%(751/792)、95.7%(667/697)、96.3%(751/780)、94.2%(667/708)、97.9%(1418/1448)、0.91,97.3%(36/37)、86.2%(25/29)、90.0%(36/40)、96.2%(25/26)、92.4%(61/66)、0.84。结论微孔板法、熔解曲线法、Xpert法检测利福平和(或)异烟肼耐药性均具有较高的敏感度和特异度,适合快速筛查耐多药结核病;微孔板法还能获得各药物最低药物浓度,为临床用药剂量的选择提供参考依据。展开更多
Rural human settlement is a significant indicator of the living standards of rural residents,and its improvement can contribute to promoting the positive interaction between inhabited environment and the social,econom...Rural human settlement is a significant indicator of the living standards of rural residents,and its improvement can contribute to promoting the positive interaction between inhabited environment and the social,economic,and resource environment in the countryside.Based on 557 valid questionnaires of satisfaction evaluation of human settlement in the peripheral metropolitan area of Beijing,this paper analyzed the elemental characteristics and factors influencing human settlement quality using multivariate statistical analysis and a structural equation model.The result shows that,first,the rural residents in a peripheral metropolitan area of Beijing are generally satisfied with the quality of human settlement(satisfaction rate is 66.2%).Specifically,the natural and social environment of the countryside is excellent and harmonious and corresponding standard of countryside infrastructure is advanced,but the quality of public services and follow-up management of facilities are in urgent need of improvement and the imbalance between revenue and expenditure of rural households has led to a continuous increase in the pressures of life.Second,factors such as social atmosphere,appearance of the village,entertainment,living costs,fundamental public services,and production costs have significant effects on human settlement quality in this peripheral metropolitan area,with social atmosphere as the main one.Living costs and supporting services are the main constraints to improvement in the quality of human settlement.展开更多
Scanning electron microscope(SEM)metrology is critical in semiconductor manufacturing for patterning process quality assessment and monitoring.Besides feature width and feature-feature space dimension measurements fro...Scanning electron microscope(SEM)metrology is critical in semiconductor manufacturing for patterning process quality assessment and monitoring.Besides feature width and feature-feature space dimension measurements from critical dimension SEM(CDSEM)images,visual inspection of SEM image also offers rich information on the quality of patterning.However,visual inspection alone leaves considerable room of ambiguity regarding patterning quality.To narrow the room of ambiguity and to obtain more statistically quantitative information on patterning quality,SEM-image contours are often extracted to serve such purposes.From contours,important information such as critical dimension and resist sidewall angle at any location can be estimated.Those geometrical information can be used for optical proximity correction(OPC)model verification and lithography hotspot detection,etc.Classical contour extraction algorithms based on local information have insufficient capability in dealing with noisy and low contrast images.To achieve reliable contours from noisy and low contrast images,information beyond local should be made use of as much as possible.In this regard,deep convolutional neural network(DCNN)has proven its great capability,as manifested in various computer vision tasks.Taking the full advantages of this maturing technology,we have designed a DCNN network and applied it to the task of extracting contours from noisy and low contrast SEM images.It turns out that the model is capable of separating the resist top and bottom contours reliably.In addition,the model does not generate false contours,it also can suppress the generation of broken contours when ambiguous area for contour extraction is small and non-detrimental.With advanced image alignment algorithm with sub-pixel accuracy,contours from different exposure fields of same process condition can be superposed to estimate process variation band,furthermore,stochastic effect induced edge placement variation statistics can easily be inferred from the extracted contours.展开更多
Background Real-time 3D rendering and interaction is important for virtual reality(VR)experimental education.Unfortunately,standard end-computing methods prohibitively escalate computational costs.Thus,reducing or dis...Background Real-time 3D rendering and interaction is important for virtual reality(VR)experimental education.Unfortunately,standard end-computing methods prohibitively escalate computational costs.Thus,reducing or distributing these requirements needs urgent attention,especially in light of the COVID-19 pandemic.Methods In this study,we design a cloud-to-end rendering and storage system for VR experimental education comprising two models:background and interactive.The cloud server renders items in the background and sends the results to an end terminal in a video stream.Interactive models are then lightweight-rendered and blended at the end terminal.An improved 3D warping and hole-filling algorithm is also proposed to improve image quality when the user's viewpoint changes.Results We build three scenes to test image quality and network latency.The results show that our system can render 3D experimental education scenes with higher image quality and lower latency than any other cloud rendering systems.Conclusions Our study is the first to use cloud and lightweight rendering for VR experimental education.The results demonstrate that our system provides good rendering experience without exceeding computation costs.展开更多
During the sustainable development of land surface system,different territories undertake different functions.The understanding and representation of territorial differentiation of the land surface system is the main ...During the sustainable development of land surface system,different territories undertake different functions.The understanding and representation of territorial differentiation of the land surface system is the main purpose of comprehensive function regionalization research.Focusing on the theoretical gap of comprehensive geographical regionalization,that is,the spatial decoupling of the physical environment and human activities,the non-nested relationship of spatial scale transformation,and the persistence and uncertainty of the dynamic evolution of territorial functions,this research proposed the identification principles and division methods of comprehensive functional regions.Based on the major function zoning in China,the systematic classification method with function orientation was employed to delineate the comprehensive functions of each territory,such as ecological security,food production and urban development.Then,the geographical regionalization method,which follows the principles of interconnection of different regionalization objectives at different levels and a combination of top-down decomposition and bottom-up aggregation,was used to determine the geographic boundaries.To meet the objective requirements of flexible and dynamic boundaries,two sets of land regionalization schemes for 2035 and 2050 were finally formed,each of which had three spatial levels.The first-level regionalization identified four major regions,which comprehensively represented the relatively stable state of China’s land development and protection pattern under the leading role of physical environment differentiation.The second-level regionalization identified 12 regions,which comprehensively represented the spatial layout of a new development pattern of multi-and inter-provinces coordinating the innovation chain,industrial chain and supply chain based on a relatively independent and complete natural carrier.The third-level regionalization identified 80 sub-regions,which comprehensively represented the functional differentiation patterns of sub-provinces during sustainable development.Compared with the current geographical differentiation research,the study of territorial function differentiation has academic values for the development of integrated geography in exploring the territorial system of the humanenvironment relationship,and it can provide a scientific basis for determining the territorial model of sustainable development and optimizing the pattern of spatial development and protection in China.展开更多
基金the National Natural Sci-ence Foundation of China(Grant No.42001139)the Second Ti-betan Plateau Scientific Expedition and Research Program(Grant No.2019QZKK0406)+1 种基金the National Natural Science Foundation of China(Grant No.42230510)the China Postdoctoral Science Foundation(Grant No.2020M670472).
文摘Investigating the spatiotemporal variation of human activity intensity and its determinants is a crucial basis for further revealing the mechanism of human-environment interaction and optimizing the human development mode.In this study,the human activity intensity on the Qinghai-Tibet Plateau(QTP)from 1990 to 2020 was measured based on the quantitative model of land use data and the actual regional background,and the under-lying natural and socioeconomic determinants were investigated using spatial econometric methods.The results demonstrate that(1)the human activity intensity in QTP has increased by 11.96%,and there are differences in different spatial scales;the areas with high human activity intensity are distributed in the Hehuang Valley where Xining City and its surrounding areas are located,as well as the One-River and Two-River Area where Lhasa City and surrounding areas are located.(2)Human activity intensity has significant positive spatial spillover,suggesting that local changes will cause changes in the same direction in adjacent areas.(3)The human activ-ity intensity in QTP is affected by various determinants.Concerning socioeconomic factors,the economic level has no significant impact on the human activity intensity in QTP,which differs from the general regional law.Both urbanization and traffic conditions have a significant positive effect,and the impact intensity continues to increase.Concerning natural factors,topographic relief has a significant positive effect;the impacts of temper-ature and vegetation coverage have changed from insignificant to a significant positive effect;the impacts of precipitation and river network density have not been verified;there is no linear relationship between altitude and human activity intensity in the entire QTP,while it exists in local regions.Finally,this study proposes three policy implications for the realization of a more harmonious human-environment relationship in QTP.
文摘目的探讨微孔板法、实时荧光PCR熔解曲线技术(简称“熔解曲线法”)、多色巢式实时荧光定量PCR技术(简称“Xpert法”)和罗氏药物敏感性试验(L-J药敏试验,简称“比例法”)用于快速筛查耐多药结核病(MDR-TB)的临床价值。方法从医院信息系统(hospital information system,HIS)连续收集2014年7月至2018年3月重庆市公共卫生医疗救治中心收治的确诊为结核病,且具有微孔板法、比例法、熔解曲线法、Xpert法检测MTB对利福平、异烟肼耐药性诊断结果的2792例患者资料;其中微孔板法、比例法采用阳性分离菌株检测,熔解曲线法和Xpert法采用患者标本直接检测。纳入同时具有微孔板法和比例法耐药性检测结果的1488例患者作为研究对象,其中341例行微孔板法+比例法+Xpert法检测利福平耐药性,87例行微孔板法+比例法+熔解曲线法检测利福平耐药性,66例行微孔板法+比例法+熔解曲线法检测异烟肼耐药性。以比例法为标准,采用SPSS13.0软件分别计算微孔板法、熔解曲线法、Xpert法检测利福平和(或)异烟肼耐药性的敏感度、特异度、符合率、Kappa值等。结果以比例法为标准,微孔板法、Xpert法、熔解曲线法检测利福平耐药性的敏感度、特异度、阳性预测值、阴性预测值、符合率、Kappa值分别为97.2%(731/752)、96.9%(713/736)、96.9%(731/754)、97.1%(713/734)、97.0%(1444/1488)、0.94,97.2%(140/144)、94.9%(187/197)、93.3%(140/150)、97.9%(187/191)、95.9%(327/341)、0.92,97.1%(33/34)、84.9%(45/53)、80.5%(33/41)、97.8%(45/46)、89.7%(78/87)、0.79;微孔板法和熔解曲线法检测异烟肼耐药性的敏感度、特异度、阳性预测值、阴性预测值、符合率、Kappa值分别为94.8%(751/792)、95.7%(667/697)、96.3%(751/780)、94.2%(667/708)、97.9%(1418/1448)、0.91,97.3%(36/37)、86.2%(25/29)、90.0%(36/40)、96.2%(25/26)、92.4%(61/66)、0.84。结论微孔板法、熔解曲线法、Xpert法检测利福平和(或)异烟肼耐药性均具有较高的敏感度和特异度,适合快速筛查耐多药结核病;微孔板法还能获得各药物最低药物浓度,为临床用药剂量的选择提供参考依据。
基金supported jointly by the Key Research Program of the Chinese Academy of Sciences[grant number KZZD-EW-06-01]the State Key Program of National Natural Science of China[grant number 40830741]
文摘Rural human settlement is a significant indicator of the living standards of rural residents,and its improvement can contribute to promoting the positive interaction between inhabited environment and the social,economic,and resource environment in the countryside.Based on 557 valid questionnaires of satisfaction evaluation of human settlement in the peripheral metropolitan area of Beijing,this paper analyzed the elemental characteristics and factors influencing human settlement quality using multivariate statistical analysis and a structural equation model.The result shows that,first,the rural residents in a peripheral metropolitan area of Beijing are generally satisfied with the quality of human settlement(satisfaction rate is 66.2%).Specifically,the natural and social environment of the countryside is excellent and harmonious and corresponding standard of countryside infrastructure is advanced,but the quality of public services and follow-up management of facilities are in urgent need of improvement and the imbalance between revenue and expenditure of rural households has led to a continuous increase in the pressures of life.Second,factors such as social atmosphere,appearance of the village,entertainment,living costs,fundamental public services,and production costs have significant effects on human settlement quality in this peripheral metropolitan area,with social atmosphere as the main one.Living costs and supporting services are the main constraints to improvement in the quality of human settlement.
文摘Scanning electron microscope(SEM)metrology is critical in semiconductor manufacturing for patterning process quality assessment and monitoring.Besides feature width and feature-feature space dimension measurements from critical dimension SEM(CDSEM)images,visual inspection of SEM image also offers rich information on the quality of patterning.However,visual inspection alone leaves considerable room of ambiguity regarding patterning quality.To narrow the room of ambiguity and to obtain more statistically quantitative information on patterning quality,SEM-image contours are often extracted to serve such purposes.From contours,important information such as critical dimension and resist sidewall angle at any location can be estimated.Those geometrical information can be used for optical proximity correction(OPC)model verification and lithography hotspot detection,etc.Classical contour extraction algorithms based on local information have insufficient capability in dealing with noisy and low contrast images.To achieve reliable contours from noisy and low contrast images,information beyond local should be made use of as much as possible.In this regard,deep convolutional neural network(DCNN)has proven its great capability,as manifested in various computer vision tasks.Taking the full advantages of this maturing technology,we have designed a DCNN network and applied it to the task of extracting contours from noisy and low contrast SEM images.It turns out that the model is capable of separating the resist top and bottom contours reliably.In addition,the model does not generate false contours,it also can suppress the generation of broken contours when ambiguous area for contour extraction is small and non-detrimental.With advanced image alignment algorithm with sub-pixel accuracy,contours from different exposure fields of same process condition can be superposed to estimate process variation band,furthermore,stochastic effect induced edge placement variation statistics can easily be inferred from the extracted contours.
基金the National Key Research and Development Project of China(2018YFB1004904)National Natural Science Foundation of China(U1909204).
文摘Background Real-time 3D rendering and interaction is important for virtual reality(VR)experimental education.Unfortunately,standard end-computing methods prohibitively escalate computational costs.Thus,reducing or distributing these requirements needs urgent attention,especially in light of the COVID-19 pandemic.Methods In this study,we design a cloud-to-end rendering and storage system for VR experimental education comprising two models:background and interactive.The cloud server renders items in the background and sends the results to an end terminal in a video stream.Interactive models are then lightweight-rendered and blended at the end terminal.An improved 3D warping and hole-filling algorithm is also proposed to improve image quality when the user's viewpoint changes.Results We build three scenes to test image quality and network latency.The results show that our system can render 3D experimental education scenes with higher image quality and lower latency than any other cloud rendering systems.Conclusions Our study is the first to use cloud and lightweight rendering for VR experimental education.The results demonstrate that our system provides good rendering experience without exceeding computation costs.
基金supported by the Key Project of the National Natural Science Foundation of China(Grant No.42230510)the Second National Comprehensive Scientific Investigation and Research Project on the Tibetan Plateau(Grant No.2019QZKK0401)the Special Project of Spatial Planning of the Ministry of Natural Resources(Grant No.202012111978)。
文摘During the sustainable development of land surface system,different territories undertake different functions.The understanding and representation of territorial differentiation of the land surface system is the main purpose of comprehensive function regionalization research.Focusing on the theoretical gap of comprehensive geographical regionalization,that is,the spatial decoupling of the physical environment and human activities,the non-nested relationship of spatial scale transformation,and the persistence and uncertainty of the dynamic evolution of territorial functions,this research proposed the identification principles and division methods of comprehensive functional regions.Based on the major function zoning in China,the systematic classification method with function orientation was employed to delineate the comprehensive functions of each territory,such as ecological security,food production and urban development.Then,the geographical regionalization method,which follows the principles of interconnection of different regionalization objectives at different levels and a combination of top-down decomposition and bottom-up aggregation,was used to determine the geographic boundaries.To meet the objective requirements of flexible and dynamic boundaries,two sets of land regionalization schemes for 2035 and 2050 were finally formed,each of which had three spatial levels.The first-level regionalization identified four major regions,which comprehensively represented the relatively stable state of China’s land development and protection pattern under the leading role of physical environment differentiation.The second-level regionalization identified 12 regions,which comprehensively represented the spatial layout of a new development pattern of multi-and inter-provinces coordinating the innovation chain,industrial chain and supply chain based on a relatively independent and complete natural carrier.The third-level regionalization identified 80 sub-regions,which comprehensively represented the functional differentiation patterns of sub-provinces during sustainable development.Compared with the current geographical differentiation research,the study of territorial function differentiation has academic values for the development of integrated geography in exploring the territorial system of the humanenvironment relationship,and it can provide a scientific basis for determining the territorial model of sustainable development and optimizing the pattern of spatial development and protection in China.