Glacier dynamics in the Himalayan midlatitudes,particularly in regions like the Shishapangma,are not yet fully understood,especially the localized topographic and climatic impacts on glacier deformation.This study ana...Glacier dynamics in the Himalayan midlatitudes,particularly in regions like the Shishapangma,are not yet fully understood,especially the localized topographic and climatic impacts on glacier deformation.This study analyzes the spatiotemporal characteristics of glacier surface deformation in the Shishapangma region using the Small Baseline Subset(SBAS)Interferometric Synthetic Aperture Radar(In SAR)technique.The analysis reveals an average deformation rate of-4.02±17.65 mm/yr across the entire study area,with glacier regions exhibiting significantly higher rates of uplift(16.87±13.20 mm/yr)and subsidence(20.11±14.55 mm/yr)compared to non-glacier areas.It identifies significant surface lowering on the mountain flanks and localized uplift in certain catchments,emphasizing the higher deformation rates in glacial areas compared to non-glacial ones.We found a strong positive correlation between temperature and cumulative deformation(correlation coefficient of 0.63),particularly in glacier areas(0.82).The research highlights the role of temperature as the primary driver of glacier wastage,particularly at lower elevations,with strong correlations found between temperature and cumulative deformation.It also indicates the complex interactions between topographic features,notably,slope gradient,which shows a positive correlation with subsidence rates,especially for slopes below 35°.South-,southwest-,and west-facing slopes exhibit significant uplift,while north-,northeast-,and east-facing slopes predominantly subside.Additionally,we identified transition zones between debris-covered glaciers and clean ice as areas of most intense deformation,with average rates exceeding 30 mm/yr,highlighting these as potential high-risk zones for geohazards.This study comprehensively analyzes the deformation characteristics in both glacier and non-glacier areas in the Shishapangma region,revealing the complex interplay of topographic,climatic,and hydrological factors influencing glacier dynamics.展开更多
The shale gas development process is complex in terms of its flow mechanisms and the accuracy of the production forecasting is influenced by geological parameters and engineering parameters.Therefore,to quantitatively...The shale gas development process is complex in terms of its flow mechanisms and the accuracy of the production forecasting is influenced by geological parameters and engineering parameters.Therefore,to quantitatively evaluate the relative importance of model parameters on the production forecasting performance,sensitivity analysis of parameters is required.The parameters are ranked according to the sensitivity coefficients for the subsequent optimization scheme design.A data-driven global sensitivity analysis(GSA)method using convolutional neural networks(CNN)is proposed to identify the influencing parameters in shale gas production.The CNN is trained on a large dataset,validated against numerical simulations,and utilized as a surrogate model for efficient sensitivity analysis.Our approach integrates CNN with the Sobol'global sensitivity analysis method,presenting three key scenarios for sensitivity analysis:analysis of the production stage as a whole,analysis by fixed time intervals,and analysis by declining rate.The findings underscore the predominant influence of reservoir thickness and well length on shale gas production.Furthermore,the temporal sensitivity analysis reveals the dynamic shifts in parameter importance across the distinct production stages.展开更多
基于2000—2021年中国知识基础设施工程(CNKI)和Web of Science核心数据库(WOS)中以智慧水利为主题的相关研究文献,采用VOSviewer、CiteSpace等软件构建智慧水利研究领域文献量时序分布、发文机构和研究热点演变的各类知识图谱,分析了...基于2000—2021年中国知识基础设施工程(CNKI)和Web of Science核心数据库(WOS)中以智慧水利为主题的相关研究文献,采用VOSviewer、CiteSpace等软件构建智慧水利研究领域文献量时序分布、发文机构和研究热点演变的各类知识图谱,分析了当前智慧水利研究进展。结果表明:智慧水利文献量均逐年递增,但CNKI数据库文献量与WOS数据库相比存在明显差距;智慧水利领域已形成核心研究机构,对其前沿发展做出了重要贡献;CNKI数据库中智慧水利研究侧重以流域为单位构建数字流域与智慧水利框架,WOS数据库则侧重从地理地球视角出发开展研究,两者均以物联网、深度学习等为基础搭建智慧水利平台。展开更多
Great Wall Motor(GWM),a leading automotive manufacturer,places a strong emphasis on environmental sustainability and social responsibility.The company focuses on comprehensively evaluating and enhancing its supply cha...Great Wall Motor(GWM),a leading automotive manufacturer,places a strong emphasis on environmental sustainability and social responsibility.The company focuses on comprehensively evaluating and enhancing its supply chain to align with these objectives.This evaluation spans the entire product life cycle,encompassing design,manufacturing,packaging,distribution,usage,and recycling and disposal processes.Key areas of focus include optimizing raw material selection,improving product recyclability,reducing energy consumption and waste emissions,and minimizing carbon emissions during transportation.Through these endeavors,GWM not only enhances its environmental performance by reducing carbon emissions and resource consumption but also bolsters its brand image and competitiveness in the market.GWM’s dedication to environmental innovation and technological leadership serves as a driving force behind sustainable development and social responsibility within the industry.展开更多
目的:通过回顾性研究分析,比较2017年美国放射学会提出的甲状腺成像报告和数据系统(the Thyroid Imaging Report and Data System recommended by American College of Radiology, ACR-TIRADS)与弹性成像单独或联合诊断在甲状腺结节良...目的:通过回顾性研究分析,比较2017年美国放射学会提出的甲状腺成像报告和数据系统(the Thyroid Imaging Report and Data System recommended by American College of Radiology, ACR-TIRADS)与弹性成像单独或联合诊断在甲状腺结节良恶性鉴别中的临床价值。方法:选取2012年1月至2017年10月在南京中医药大学附属中西医结合医院就诊的503例甲状腺结节患者,共653个结节。收集患者的一般临床资料、甲状腺超声和弹性成像报告及术后病理,对所有结节采用ACR-TITADS、弹性成像的分级法和评分法进行分级,并总结二者联合的4种方法。方法 1,弹性成像与ACR-TIRADS中任一诊断为恶性结节,则判定联合诊断为恶性;方法 2,弹性成像与ACRTIRADS共同诊断为恶性结节,则判定联合诊断为恶性;方法 3,弹性成像评分分值与ACR-TIRADS分级结果相加;方法 4,弹性成像评分分值与ACR-TIRADS计分分值相加。以术后病理为金标准,构建受试者工作特征曲线,计算曲线下面积(area under the curve, AUC),并根据约登指数选取最佳诊断临界值,比较各方法单独和联合诊断的效能。结果:随着各诊断方法类别1~4的递增,检出结节的恶性率逐渐增加。ACR-TIRADS诊断甲状腺结节良恶性的AUC有高于弹性超声的趋势,但差异无统计学意义(0.853比0.848,P=0.745)。方法 1诊断甲状腺结节良恶性的灵敏度、阴性预测值较高(96.94%、84.85%);方法 2的诊断特异度、阳性预测值较高(88.96%、95.53%);方法 3的灵敏度高于方法4(88.78%比85.92%,P<0.001);方法 4的AUC与方法 3之间差异无统计学意义(0.913比0.901,P=0.088)。结论:ACR-TIRADS在甲状腺结节性质诊断中的效能优于弹性成像,而弹性成像评分分值与ACR-TIRADS分级结果相加、弹性成像评分分值与ACR-TIRADS计分分值相加都优于ACR-TIRADS或弹性成像单独诊断,其中方法 4在鉴别甲状腺结节良恶性中具有更高的价值。展开更多
Based on the 1990, 2000 and 2011 Landsat TM/ETM+ remote sensing data, glacier information of three periods in the Chinese Tianshan Mountains were extracted by using ratio threshold method(TM3/TM5) and visual interpret...Based on the 1990, 2000 and 2011 Landsat TM/ETM+ remote sensing data, glacier information of three periods in the Chinese Tianshan Mountains were extracted by using ratio threshold method(TM3/TM5) and visual interpretation, combined with digital processing of satellite images and analysis in GIS. The climate data in the surrounding area were analyzed by using linear regression, Mann-Kendall abrupt test, and Morlet wavelet analysis. Study results showed that: over the 23 years investigation, the glacier areas have markedly decreased. In the last 12 years(2000 to 2011), the rate of retreat has begun to accelerate. The most dramatic glacier shrinkage occurred in the central region, the lowest in the eastern region. The mean summer temperature and warm precipitation in Chinese Tianshan Mountains had an increasing trend, with rates of 0.22°C /10 a and 5.1mm/10 a from 1960 to 2011, respectively. Mean summer temperature have experienced a strong increase in 1998. The analysis of the results showed that the rise of mean summer temperature was the main factor that contributed to glacier shrinkage. Regional differences of glacier area changes were investigated by analyzing glacier behavior in five study sub-regions; regional differences are related to local climate, to the relative proportion of glaciers in different size classes, altitudinal and aspect distribution of glaciated areas. In addition, the lag theory indicated that glaciers may accelerate the retreat in the next decade, considering climate trends recognized for the period 2000-2011.展开更多
基金funded by The Natural Science Foundation of Chongqing(CSTB2023NSCQMSX0990)the Humanities and Social Sciences research project of Chongqing Municipal Education Commission(22SKSZ030)the Science and Technology Research Program of Chongqing Municipal Education Commission(Grant No.KJZD-K202400510)。
文摘Glacier dynamics in the Himalayan midlatitudes,particularly in regions like the Shishapangma,are not yet fully understood,especially the localized topographic and climatic impacts on glacier deformation.This study analyzes the spatiotemporal characteristics of glacier surface deformation in the Shishapangma region using the Small Baseline Subset(SBAS)Interferometric Synthetic Aperture Radar(In SAR)technique.The analysis reveals an average deformation rate of-4.02±17.65 mm/yr across the entire study area,with glacier regions exhibiting significantly higher rates of uplift(16.87±13.20 mm/yr)and subsidence(20.11±14.55 mm/yr)compared to non-glacier areas.It identifies significant surface lowering on the mountain flanks and localized uplift in certain catchments,emphasizing the higher deformation rates in glacial areas compared to non-glacial ones.We found a strong positive correlation between temperature and cumulative deformation(correlation coefficient of 0.63),particularly in glacier areas(0.82).The research highlights the role of temperature as the primary driver of glacier wastage,particularly at lower elevations,with strong correlations found between temperature and cumulative deformation.It also indicates the complex interactions between topographic features,notably,slope gradient,which shows a positive correlation with subsidence rates,especially for slopes below 35°.South-,southwest-,and west-facing slopes exhibit significant uplift,while north-,northeast-,and east-facing slopes predominantly subside.Additionally,we identified transition zones between debris-covered glaciers and clean ice as areas of most intense deformation,with average rates exceeding 30 mm/yr,highlighting these as potential high-risk zones for geohazards.This study comprehensively analyzes the deformation characteristics in both glacier and non-glacier areas in the Shishapangma region,revealing the complex interplay of topographic,climatic,and hydrological factors influencing glacier dynamics.
基金supported by the National Natural Science Foundation of China (Nos.52274048 and 52374017)Beijing Natural Science Foundation (No.3222037)the CNPC 14th five-year perspective fundamental research project (No.2021DJ2104)。
文摘The shale gas development process is complex in terms of its flow mechanisms and the accuracy of the production forecasting is influenced by geological parameters and engineering parameters.Therefore,to quantitatively evaluate the relative importance of model parameters on the production forecasting performance,sensitivity analysis of parameters is required.The parameters are ranked according to the sensitivity coefficients for the subsequent optimization scheme design.A data-driven global sensitivity analysis(GSA)method using convolutional neural networks(CNN)is proposed to identify the influencing parameters in shale gas production.The CNN is trained on a large dataset,validated against numerical simulations,and utilized as a surrogate model for efficient sensitivity analysis.Our approach integrates CNN with the Sobol'global sensitivity analysis method,presenting three key scenarios for sensitivity analysis:analysis of the production stage as a whole,analysis by fixed time intervals,and analysis by declining rate.The findings underscore the predominant influence of reservoir thickness and well length on shale gas production.Furthermore,the temporal sensitivity analysis reveals the dynamic shifts in parameter importance across the distinct production stages.
文摘基于2000—2021年中国知识基础设施工程(CNKI)和Web of Science核心数据库(WOS)中以智慧水利为主题的相关研究文献,采用VOSviewer、CiteSpace等软件构建智慧水利研究领域文献量时序分布、发文机构和研究热点演变的各类知识图谱,分析了当前智慧水利研究进展。结果表明:智慧水利文献量均逐年递增,但CNKI数据库文献量与WOS数据库相比存在明显差距;智慧水利领域已形成核心研究机构,对其前沿发展做出了重要贡献;CNKI数据库中智慧水利研究侧重以流域为单位构建数字流域与智慧水利框架,WOS数据库则侧重从地理地球视角出发开展研究,两者均以物联网、深度学习等为基础搭建智慧水利平台。
文摘Great Wall Motor(GWM),a leading automotive manufacturer,places a strong emphasis on environmental sustainability and social responsibility.The company focuses on comprehensively evaluating and enhancing its supply chain to align with these objectives.This evaluation spans the entire product life cycle,encompassing design,manufacturing,packaging,distribution,usage,and recycling and disposal processes.Key areas of focus include optimizing raw material selection,improving product recyclability,reducing energy consumption and waste emissions,and minimizing carbon emissions during transportation.Through these endeavors,GWM not only enhances its environmental performance by reducing carbon emissions and resource consumption but also bolsters its brand image and competitiveness in the market.GWM’s dedication to environmental innovation and technological leadership serves as a driving force behind sustainable development and social responsibility within the industry.
文摘目的:通过回顾性研究分析,比较2017年美国放射学会提出的甲状腺成像报告和数据系统(the Thyroid Imaging Report and Data System recommended by American College of Radiology, ACR-TIRADS)与弹性成像单独或联合诊断在甲状腺结节良恶性鉴别中的临床价值。方法:选取2012年1月至2017年10月在南京中医药大学附属中西医结合医院就诊的503例甲状腺结节患者,共653个结节。收集患者的一般临床资料、甲状腺超声和弹性成像报告及术后病理,对所有结节采用ACR-TITADS、弹性成像的分级法和评分法进行分级,并总结二者联合的4种方法。方法 1,弹性成像与ACR-TIRADS中任一诊断为恶性结节,则判定联合诊断为恶性;方法 2,弹性成像与ACRTIRADS共同诊断为恶性结节,则判定联合诊断为恶性;方法 3,弹性成像评分分值与ACR-TIRADS分级结果相加;方法 4,弹性成像评分分值与ACR-TIRADS计分分值相加。以术后病理为金标准,构建受试者工作特征曲线,计算曲线下面积(area under the curve, AUC),并根据约登指数选取最佳诊断临界值,比较各方法单独和联合诊断的效能。结果:随着各诊断方法类别1~4的递增,检出结节的恶性率逐渐增加。ACR-TIRADS诊断甲状腺结节良恶性的AUC有高于弹性超声的趋势,但差异无统计学意义(0.853比0.848,P=0.745)。方法 1诊断甲状腺结节良恶性的灵敏度、阴性预测值较高(96.94%、84.85%);方法 2的诊断特异度、阳性预测值较高(88.96%、95.53%);方法 3的灵敏度高于方法4(88.78%比85.92%,P<0.001);方法 4的AUC与方法 3之间差异无统计学意义(0.913比0.901,P=0.088)。结论:ACR-TIRADS在甲状腺结节性质诊断中的效能优于弹性成像,而弹性成像评分分值与ACR-TIRADS分级结果相加、弹性成像评分分值与ACR-TIRADS计分分值相加都优于ACR-TIRADS或弹性成像单独诊断,其中方法 4在鉴别甲状腺结节良恶性中具有更高的价值。
基金supported by the National Science Foundation of China (Grant No. 41271024)the Fund Project for National Basic Science Talents Cultivation (Grant No. J1210065)the Fundamental Research Funds for the Central Universities- Excellent Graduate Innovation Project (Grant No. Lzujbky-2014-274)
文摘Based on the 1990, 2000 and 2011 Landsat TM/ETM+ remote sensing data, glacier information of three periods in the Chinese Tianshan Mountains were extracted by using ratio threshold method(TM3/TM5) and visual interpretation, combined with digital processing of satellite images and analysis in GIS. The climate data in the surrounding area were analyzed by using linear regression, Mann-Kendall abrupt test, and Morlet wavelet analysis. Study results showed that: over the 23 years investigation, the glacier areas have markedly decreased. In the last 12 years(2000 to 2011), the rate of retreat has begun to accelerate. The most dramatic glacier shrinkage occurred in the central region, the lowest in the eastern region. The mean summer temperature and warm precipitation in Chinese Tianshan Mountains had an increasing trend, with rates of 0.22°C /10 a and 5.1mm/10 a from 1960 to 2011, respectively. Mean summer temperature have experienced a strong increase in 1998. The analysis of the results showed that the rise of mean summer temperature was the main factor that contributed to glacier shrinkage. Regional differences of glacier area changes were investigated by analyzing glacier behavior in five study sub-regions; regional differences are related to local climate, to the relative proportion of glaciers in different size classes, altitudinal and aspect distribution of glaciated areas. In addition, the lag theory indicated that glaciers may accelerate the retreat in the next decade, considering climate trends recognized for the period 2000-2011.
