BACKGROUND Gastrointestinal endoscopy technology has significantly improved the diagnostic accuracy and the successful treatment of gastrointestinal diseases.However,a series of ethical issues have emerged,such as exp...BACKGROUND Gastrointestinal endoscopy technology has significantly improved the diagnostic accuracy and the successful treatment of gastrointestinal diseases.However,a series of ethical issues have emerged,such as expanding treatment indications,which affect the fair distribution of medical resources.There is limited research on ethical issues in the field of digestive endoscopy.AIM To investigate the level of ethical awareness among gastrointestinal endoscopy practitioners and analyze the ethical issues involved in gastrointestinal endoscopy technology.METHODS A questionnaire survey was performed to collect relevant data(gender,age,degree of education,professional title,personnel category,the level of understanding medical ethical principles,ethics training and its learning pathways)from gastrointestinal endoscopy practitioners at the Second Hospital of Dalian Medical University and Dalian Friendship Hospital,including licensed physicians and nurses(including trainees and graduate students).RESULTS The majority of gastrointestinal endoscopy practitioners have received training on ethics,but there is still considerable room for improvement in their ethical awareness.Different learning pathways may affect the mastery of ethical principles, and understanding of ethical principles is more easily achieved through hospital ethics institutions.CONCLUSIONTo address the ethical issues in gastrointestinal endoscopy technology, it is necessary to enhance the humanisticeducation of gastrointestinal endoscopy practitioners, incorporate ethical standards into the technology assessmentprocess, and establish a patient-centered diagnostic and treatment model to improve the ethical awareness of practitionersand achieve a balance between technology and ethics.展开更多
在开源软件和开源平台中,开发人员可以通过提交issue来记录所发现的软件错误或提出新功能需求.由于缺乏经验、专业水平有限等原因,用户可能无法对issue内容进行准确有效地总结,导致issue标题质量较低,进而降低issue的解决效率.此外,现有...在开源软件和开源平台中,开发人员可以通过提交issue来记录所发现的软件错误或提出新功能需求.由于缺乏经验、专业水平有限等原因,用户可能无法对issue内容进行准确有效地总结,导致issue标题质量较低,进而降低issue的解决效率.此外,现有的issue标题自动生成方法主要面向GitHub等英文开源平台,当应用在Gitee等国产开源平台时表现不佳.同时,现有方法主要使用issue主体描述作为输入,忽略了issue中的代码片段等重要信息.为此,本文提出一种面向Gitee平台的issue标题自动生成方法GITG(Gitee Issue Title Generation),针对包含中文和英文文本的issue,使用构建的Gitee issue数据集对支持中文的预训练模型Chinese BART(Bidirectional and Auto-Regressive Transformers)进行微调,利用issue主体描述和代码片段的双模态信息来自动生成issue标题.为验证GITG的有效性,构建了包含18242个Gitee issue样本的数据集.实验结果表明,GITG在ROUGE-1、ROUGE-2和ROUGE-L指标上相较于iTAPE和iTiger分别至少提升了13.09%、10.18%和12.84%,在BLEU和METEOR指标上同样取得了性能提升.人工评价结果表明,GITG生成标题的平均得分在整体分数、流畅性、信息性和简洁性4个评价指标上相较iTAPE和iTiger分别至少提升了26.7%、20.8%、24.2%和20.0%.展开更多
Based on a comprehensive inspection and acceptance evaluation of the biological firebreak forest belt construction project in Huiyang Forest Area,this study systematically analyzes common issues encountered during the...Based on a comprehensive inspection and acceptance evaluation of the biological firebreak forest belt construction project in Huiyang Forest Area,this study systematically analyzes common issues encountered during the acceptance process.The findings indicate that primary challenges include low seedling survival rates,incongruities between tree species selection and site conditions,structural deficiencies within the forest belts,insufficient post-planting maintenance and management,and irregularities in documentation.To address these problems,the study proposes targeted countermeasures,such as optimizing tree species selection,enhancing supervision of planting techniques,and establishing a long-term ecological compensation-based management model.These recommendations are framed within the contexts of scientific planning,precise implementation,strengthened oversight,and innovative management mechanisms.The research aims to improve the construction quality and long-term fire prevention efficacy of biological firebreak forest belts,thereby providing practical guidance for analogous firebreak forest belt construction and acceptance initiatives in forest areas of South China.展开更多
This study summarizes the examination data of registration labels for ordinary cosmetics in Beijing from May 2021 to April 2024.It analyzes and categorizes the issues identified during label evaluations,explores the u...This study summarizes the examination data of registration labels for ordinary cosmetics in Beijing from May 2021 to April 2024.It analyzes and categorizes the issues identified during label evaluations,explores the underlying causes,and proposes regulatory countermeasures and recommendations for registrants,regulatory authorities,and social organizations.The objective is to offer practical insights and regulatory guidance to support the enhancement of cosmetic registration and regulatory standards.展开更多
It is with profound respect and gratitude that we dedicate this special issue of the Journal of Environmental Sciences to the memory of Professor Chuanyong Jing,whose outstanding contributions to environmental science...It is with profound respect and gratitude that we dedicate this special issue of the Journal of Environmental Sciences to the memory of Professor Chuanyong Jing,whose outstanding contributions to environmental sciences have advanced the field and continue to resonate with both academia and the broader environmental community.展开更多
Editors Yang Wang,Xi'an Jiaotong University Dongbo Shi,Shanghai Jiaotong University Ye Sun,University College London Zhesi Shen,National Science Library,CASTopic of the Special Issue What are the top questions tow...Editors Yang Wang,Xi'an Jiaotong University Dongbo Shi,Shanghai Jiaotong University Ye Sun,University College London Zhesi Shen,National Science Library,CASTopic of the Special Issue What are the top questions towards better science and innovation and the required data to answer these questions?展开更多
SAMR (SAC) and relevant departments jointly issued the Report on the Standardization Achievements of the 10th Anniversary of the Belt and Road Initiative (BRI) recently, to summarize the fruitful results in promoting ...SAMR (SAC) and relevant departments jointly issued the Report on the Standardization Achievements of the 10th Anniversary of the Belt and Road Initiative (BRI) recently, to summarize the fruitful results in promoting the connectivity of standardization among Belt and Road countries in the past 10 years.展开更多
System identification is a data-driven modeling technique that originates from the control field.It constructs models from data to mimic the behavior of dynamic systems.However,in the network era,scenarios such as sen...System identification is a data-driven modeling technique that originates from the control field.It constructs models from data to mimic the behavior of dynamic systems.However,in the network era,scenarios such as sensor malfunctions,packet loss,cyber-attacks,and big data affect the quality,integrity,and security of the data.These data issues pose significant challenges to traditional system identification methods.This paper presents a comprehensive survey of the emergent challenges and advances in system identification in the network era.It explores cutting-edge methodologies to address data issues such as data loss,outliers,noise and nonlinear system identification for complex systems.To tackle the data loss,the methods based on imputation and likelihood-based inference(e.g.,expectation maximization)have been employed.For outliers and noise,methods like robust regression(e.g.,least median of squares,least trimmed squares)and lowrank matrix decomposition show progress in maintaining data integrity.Nonlinear system identification has advanced through kernel-based methods and neural networks,which can model complex data patterns.Finally,this paper provides valuable insights into potential directions for future research.展开更多
Based on the latest demographic and labor data, this paper reveals the changes in China＇s labor supply and demonstrates that China＇s key employment issues are no longer quantitative contradictions but increasingly h...Based on the latest demographic and labor data, this paper reveals the changes in China＇s labor supply and demonstrates that China＇s key employment issues are no longer quantitative contradictions but increasingly have become structural issues related to labor market mismatch. Due to real and potential economic growth rates being consistent, cyclical unemployment is, at least for now, not striking. If traditional policy measures continue to be followed in disregard of frictional and structural attributes of the labor market to increase total employment, not only will China＇s employment issues persist but new labor market problems may arise as well China should focus on addressing structural unemployment contradictions.展开更多
In 2021,approximately 537 million people suffered from diabetes mellitus(DM)globally,and this figure will increase to approximately 783 million within the next quarter-century.The increasing burden of DM is a pressing...In 2021,approximately 537 million people suffered from diabetes mellitus(DM)globally,and this figure will increase to approximately 783 million within the next quarter-century.The increasing burden of DM is a pressing global public health issue.Therefore,the early identification of high-risk groups and implementation of effective intervention measures is imperative.展开更多
Single-atom nanozymes(SAzymes)exhibit exceptional catalytic efficiency due to their maximized atom utilization and precisely modulated metalcarrier interactions,which have attracted significant attention in the biomed...Single-atom nanozymes(SAzymes)exhibit exceptional catalytic efficiency due to their maximized atom utilization and precisely modulated metalcarrier interactions,which have attracted significant attention in the biomedical field.However,stability issues may impede the clinical translation of SAzymes.This review provides a comprehensive overview of the applications of SAzymes in various biomedical fields,including disease diagnosis(e.g.,biosensors and diagnostic imaging),antitumor therapy(e.g.,photothermal therapy,photodynamic therapy,sonodynamic therapy,and immunotherapy),antimicrobial therapy,and anti-oxidative stress therapy.More importantly,the existing challenges of SAzymes are discussed,such as metal atom clustering and active site loss,ligand bond breakage at high temperature,insufficient environment tolerance,biosecurity risks,and limited catalytic long-term stability.Finally,several innovative strategies to address these stability concerns are proposed—synthesis process optimization(space-limited strategy,coordination site design,bimetallic synergistic strategy,defect engineering strategy,atom stripping-capture),surface modification,and dynamic responsive design—that collectively pave the way for robust,clinically viable SAzymes.展开更多
This essay is a research report, which is based on results of grammatical error analysis and interviews with linguistic teachers. These researches are conducted in four language streams, namely, Chinese, Spanish, Kore...This essay is a research report, which is based on results of grammatical error analysis and interviews with linguistic teachers. These researches are conducted in four language streams, namely, Chinese, Spanish, Korean and Japanese. It will talk about problems identified in all these four language streams, with Chinese as the focus. Although according to various definitions, translation competence includes several parts, which are all required for a professional translator; this essay covers mainly the linguistic competence with tense and aspect issue as the main point. Meanwhile, some major causes of mistakes will be identified, such as interference of mother tongue, lack of second language proficiency. In the end, some possible ways for improvement are presented for reaching what are needed for a professional translator.展开更多
The current status of chemical fertilizers production and consumption in China as well as their important roles in Chinese modern agriculture are discussed with special concerns to the environmental issues related to ...The current status of chemical fertilizers production and consumption in China as well as their important roles in Chinese modern agriculture are discussed with special concerns to the environmental issues related to chemical fertilizer use. On the one hand, the total amount of chemical fertilizer produced is insufficient to meet the agricultural needs. On the other hand, the production and consumption of chemical fertilizers in China are obviously not balanced. In some areas over application of nitrogen fertilizers and loss of phosphate fertilizer due to soil erosion have resulted in some undesirable environmental problems such as increase of nitrate in water and eutrophication of water bodies. Maximum scientific uses of organic manures in combination with reasonable use of chemical fertilizers are part of good practices not only in increasing soil productivity and keeping sustainable agriculture development but also in mimimizing their detrimental effects on the environment.展开更多
Northeast India has a good deposit of sub-bituminous tertiary coal. The northeast Indian coals have unusual physico-chemical characteristics such as high sulfur, volatile matter and vitrinite content, and low ash cont...Northeast India has a good deposit of sub-bituminous tertiary coal. The northeast Indian coals have unusual physico-chemical characteristics such as high sulfur, volatile matter and vitrinite content, and low ash content. In addition, many environmental sensitive organic and mineral bound elements such as Fe, Mg, Bi, AI, V, Cu, Cd, Ni, Pb, and Mn etc. remain enriched in these coals. Such characteristics are associated with more severe environmental impacts due to mining and its utilization in coal based industries. Environmental challenges include large scale landscape damage, soil erosion, loss of forest ecosystem and wildlife habitat, air, water and soil pollution. Several physical and chemical methods are reported in literature for the removal of mineral matter, total sulfur and different forms of sulfur from high sulfur coal in northeast India. This paper may help different researchers and stakeholders to understand current state of research in the field. Initiatives may be taken towards sustainable use of coal resources by adopting innovative clean technologies and by implementing effective control measures and regulatory policies.展开更多
China is a country that is frequently affected by severe convective weather. Here, severe convective weather mainly refers to intense local heavy precipitation, thunderstorm-induced gale-force winds including those fr...China is a country that is frequently affected by severe convective weather. Here, severe convective weather mainly refers to intense local heavy precipitation, thunderstorm-induced gale-force winds including those from tornadoes and downbursts, and hail and lightning. These types of severe weather are usually small in spatial scale and rapid in their development, and are therefore difficult to capture by observational networks and are poorly resolved in typical operational numerical weather prediction （NWP） models. Furthermore, many of the important dynamic and physical processes involved are not well understood. Within China, the impacts of severe convective weather rank only after those of landfalling typhoons and widespread heavy precipitation and flooding. Studies （e.g., Zhang and Zhai, 2011） have shown tendencies for an increased frequency in short-duration extreme precipitation during the past several decades over most of eastern China, where the population is most dense. An in-depth understanding of severe convective weather in China, as well as being able to accurately predict it, is clearly of great importance.展开更多
Friction stir welding(FSW),a highly effi cient solid-state joining technique,was invented at The Welding Institute,UK,in 1991.Utilizing frictional and adiabatic heating,plastic deformation and solid-state diff usion,F...Friction stir welding(FSW),a highly effi cient solid-state joining technique,was invented at The Welding Institute,UK,in 1991.Utilizing frictional and adiabatic heating,plastic deformation and solid-state diff usion,FSW has been widely accepted as a“green”welding technology owing to its energy effi ciency and environment friendliness.Now,FSW has achieved broad application in various industries,such as aerospace and transportation,and is considered the most signifi cant development in the fi eld of material joining over the past two decades.Friction stir processing(FSP),later developed based on the fundamental principles of FSW,has been demonstrated as an eff ective and versatile metalworking technique for modifying and fabricating metallic materials.展开更多
文摘BACKGROUND Gastrointestinal endoscopy technology has significantly improved the diagnostic accuracy and the successful treatment of gastrointestinal diseases.However,a series of ethical issues have emerged,such as expanding treatment indications,which affect the fair distribution of medical resources.There is limited research on ethical issues in the field of digestive endoscopy.AIM To investigate the level of ethical awareness among gastrointestinal endoscopy practitioners and analyze the ethical issues involved in gastrointestinal endoscopy technology.METHODS A questionnaire survey was performed to collect relevant data(gender,age,degree of education,professional title,personnel category,the level of understanding medical ethical principles,ethics training and its learning pathways)from gastrointestinal endoscopy practitioners at the Second Hospital of Dalian Medical University and Dalian Friendship Hospital,including licensed physicians and nurses(including trainees and graduate students).RESULTS The majority of gastrointestinal endoscopy practitioners have received training on ethics,but there is still considerable room for improvement in their ethical awareness.Different learning pathways may affect the mastery of ethical principles, and understanding of ethical principles is more easily achieved through hospital ethics institutions.CONCLUSIONTo address the ethical issues in gastrointestinal endoscopy technology, it is necessary to enhance the humanisticeducation of gastrointestinal endoscopy practitioners, incorporate ethical standards into the technology assessmentprocess, and establish a patient-centered diagnostic and treatment model to improve the ethical awareness of practitionersand achieve a balance between technology and ethics.
文摘在开源软件和开源平台中,开发人员可以通过提交issue来记录所发现的软件错误或提出新功能需求.由于缺乏经验、专业水平有限等原因,用户可能无法对issue内容进行准确有效地总结,导致issue标题质量较低,进而降低issue的解决效率.此外,现有的issue标题自动生成方法主要面向GitHub等英文开源平台,当应用在Gitee等国产开源平台时表现不佳.同时,现有方法主要使用issue主体描述作为输入,忽略了issue中的代码片段等重要信息.为此,本文提出一种面向Gitee平台的issue标题自动生成方法GITG(Gitee Issue Title Generation),针对包含中文和英文文本的issue,使用构建的Gitee issue数据集对支持中文的预训练模型Chinese BART(Bidirectional and Auto-Regressive Transformers)进行微调,利用issue主体描述和代码片段的双模态信息来自动生成issue标题.为验证GITG的有效性,构建了包含18242个Gitee issue样本的数据集.实验结果表明,GITG在ROUGE-1、ROUGE-2和ROUGE-L指标上相较于iTAPE和iTiger分别至少提升了13.09%、10.18%和12.84%,在BLEU和METEOR指标上同样取得了性能提升.人工评价结果表明,GITG生成标题的平均得分在整体分数、流畅性、信息性和简洁性4个评价指标上相较iTAPE和iTiger分别至少提升了26.7%、20.8%、24.2%和20.0%.
文摘Based on a comprehensive inspection and acceptance evaluation of the biological firebreak forest belt construction project in Huiyang Forest Area,this study systematically analyzes common issues encountered during the acceptance process.The findings indicate that primary challenges include low seedling survival rates,incongruities between tree species selection and site conditions,structural deficiencies within the forest belts,insufficient post-planting maintenance and management,and irregularities in documentation.To address these problems,the study proposes targeted countermeasures,such as optimizing tree species selection,enhancing supervision of planting techniques,and establishing a long-term ecological compensation-based management model.These recommendations are framed within the contexts of scientific planning,precise implementation,strengthened oversight,and innovative management mechanisms.The research aims to improve the construction quality and long-term fire prevention efficacy of biological firebreak forest belts,thereby providing practical guidance for analogous firebreak forest belt construction and acceptance initiatives in forest areas of South China.
文摘This study summarizes the examination data of registration labels for ordinary cosmetics in Beijing from May 2021 to April 2024.It analyzes and categorizes the issues identified during label evaluations,explores the underlying causes,and proposes regulatory countermeasures and recommendations for registrants,regulatory authorities,and social organizations.The objective is to offer practical insights and regulatory guidance to support the enhancement of cosmetic registration and regulatory standards.
文摘It is with profound respect and gratitude that we dedicate this special issue of the Journal of Environmental Sciences to the memory of Professor Chuanyong Jing,whose outstanding contributions to environmental sciences have advanced the field and continue to resonate with both academia and the broader environmental community.
文摘Editors Yang Wang,Xi'an Jiaotong University Dongbo Shi,Shanghai Jiaotong University Ye Sun,University College London Zhesi Shen,National Science Library,CASTopic of the Special Issue What are the top questions towards better science and innovation and the required data to answer these questions?
文摘SAMR (SAC) and relevant departments jointly issued the Report on the Standardization Achievements of the 10th Anniversary of the Belt and Road Initiative (BRI) recently, to summarize the fruitful results in promoting the connectivity of standardization among Belt and Road countries in the past 10 years.
基金supported in part by the National Natural Science Foundation of China(62373060)the BNU Talent seed fund,and the Guangdong Provincial Key Laboratory IRADS for Data Science(2022B1212010006)Recommended by Associate Editor Zhengcai Cao.(Corresponding author:Liang Zhang.)。
文摘System identification is a data-driven modeling technique that originates from the control field.It constructs models from data to mimic the behavior of dynamic systems.However,in the network era,scenarios such as sensor malfunctions,packet loss,cyber-attacks,and big data affect the quality,integrity,and security of the data.These data issues pose significant challenges to traditional system identification methods.This paper presents a comprehensive survey of the emergent challenges and advances in system identification in the network era.It explores cutting-edge methodologies to address data issues such as data loss,outliers,noise and nonlinear system identification for complex systems.To tackle the data loss,the methods based on imputation and likelihood-based inference(e.g.,expectation maximization)have been employed.For outliers and noise,methods like robust regression(e.g.,least median of squares,least trimmed squares)and lowrank matrix decomposition show progress in maintaining data integrity.Nonlinear system identification has advanced through kernel-based methods and neural networks,which can model complex data patterns.Finally,this paper provides valuable insights into potential directions for future research.
文摘Based on the latest demographic and labor data, this paper reveals the changes in China＇s labor supply and demonstrates that China＇s key employment issues are no longer quantitative contradictions but increasingly have become structural issues related to labor market mismatch. Due to real and potential economic growth rates being consistent, cyclical unemployment is, at least for now, not striking. If traditional policy measures continue to be followed in disregard of frictional and structural attributes of the labor market to increase total employment, not only will China＇s employment issues persist but new labor market problems may arise as well China should focus on addressing structural unemployment contradictions.
基金supported by the Research Funds of the Center for Big Data and Population Health of IHM(grant number JKS2022015)the Key Scientific Research Fund of the Anhui Provincial Education Department(grant number2023AH050610)the Anhui Natural Science Foundation(grant number 1808085QH252)。
文摘In 2021,approximately 537 million people suffered from diabetes mellitus(DM)globally,and this figure will increase to approximately 783 million within the next quarter-century.The increasing burden of DM is a pressing global public health issue.Therefore,the early identification of high-risk groups and implementation of effective intervention measures is imperative.
基金supported by the National Natural Science Foundation of China[82003956]the National Key Research and Development Program of China[No.2022YFA1205802]+2 种基金financially supported by Henan Province Health Science and Technology Innovation Youth Talent Project(YQRC2023013 and YQRC2024013)the Key Project of Medical Science and Technology of Henan Province(SBGJ202302072)the Science and Technology Research Project of Henan Province(252102311236).
文摘Single-atom nanozymes(SAzymes)exhibit exceptional catalytic efficiency due to their maximized atom utilization and precisely modulated metalcarrier interactions,which have attracted significant attention in the biomedical field.However,stability issues may impede the clinical translation of SAzymes.This review provides a comprehensive overview of the applications of SAzymes in various biomedical fields,including disease diagnosis(e.g.,biosensors and diagnostic imaging),antitumor therapy(e.g.,photothermal therapy,photodynamic therapy,sonodynamic therapy,and immunotherapy),antimicrobial therapy,and anti-oxidative stress therapy.More importantly,the existing challenges of SAzymes are discussed,such as metal atom clustering and active site loss,ligand bond breakage at high temperature,insufficient environment tolerance,biosecurity risks,and limited catalytic long-term stability.Finally,several innovative strategies to address these stability concerns are proposed—synthesis process optimization(space-limited strategy,coordination site design,bimetallic synergistic strategy,defect engineering strategy,atom stripping-capture),surface modification,and dynamic responsive design—that collectively pave the way for robust,clinically viable SAzymes.
文摘This essay is a research report, which is based on results of grammatical error analysis and interviews with linguistic teachers. These researches are conducted in four language streams, namely, Chinese, Spanish, Korean and Japanese. It will talk about problems identified in all these four language streams, with Chinese as the focus. Although according to various definitions, translation competence includes several parts, which are all required for a professional translator; this essay covers mainly the linguistic competence with tense and aspect issue as the main point. Meanwhile, some major causes of mistakes will be identified, such as interference of mother tongue, lack of second language proficiency. In the end, some possible ways for improvement are presented for reaching what are needed for a professional translator.
文摘The current status of chemical fertilizers production and consumption in China as well as their important roles in Chinese modern agriculture are discussed with special concerns to the environmental issues related to chemical fertilizer use. On the one hand, the total amount of chemical fertilizer produced is insufficient to meet the agricultural needs. On the other hand, the production and consumption of chemical fertilizers in China are obviously not balanced. In some areas over application of nitrogen fertilizers and loss of phosphate fertilizer due to soil erosion have resulted in some undesirable environmental problems such as increase of nitrate in water and eutrophication of water bodies. Maximum scientific uses of organic manures in combination with reasonable use of chemical fertilizers are part of good practices not only in increasing soil productivity and keeping sustainable agriculture development but also in mimimizing their detrimental effects on the environment.
文摘Northeast India has a good deposit of sub-bituminous tertiary coal. The northeast Indian coals have unusual physico-chemical characteristics such as high sulfur, volatile matter and vitrinite content, and low ash content. In addition, many environmental sensitive organic and mineral bound elements such as Fe, Mg, Bi, AI, V, Cu, Cd, Ni, Pb, and Mn etc. remain enriched in these coals. Such characteristics are associated with more severe environmental impacts due to mining and its utilization in coal based industries. Environmental challenges include large scale landscape damage, soil erosion, loss of forest ecosystem and wildlife habitat, air, water and soil pollution. Several physical and chemical methods are reported in literature for the removal of mineral matter, total sulfur and different forms of sulfur from high sulfur coal in northeast India. This paper may help different researchers and stakeholders to understand current state of research in the field. Initiatives may be taken towards sustainable use of coal resources by adopting innovative clean technologies and by implementing effective control measures and regulatory policies.
基金supported by the Ministry of Science and Technology of China National "973" Fundamental Research Program(Grant No.2013CB430103)
文摘China is a country that is frequently affected by severe convective weather. Here, severe convective weather mainly refers to intense local heavy precipitation, thunderstorm-induced gale-force winds including those from tornadoes and downbursts, and hail and lightning. These types of severe weather are usually small in spatial scale and rapid in their development, and are therefore difficult to capture by observational networks and are poorly resolved in typical operational numerical weather prediction （NWP） models. Furthermore, many of the important dynamic and physical processes involved are not well understood. Within China, the impacts of severe convective weather rank only after those of landfalling typhoons and widespread heavy precipitation and flooding. Studies （e.g., Zhang and Zhai, 2011） have shown tendencies for an increased frequency in short-duration extreme precipitation during the past several decades over most of eastern China, where the population is most dense. An in-depth understanding of severe convective weather in China, as well as being able to accurately predict it, is clearly of great importance.
文摘Friction stir welding(FSW),a highly effi cient solid-state joining technique,was invented at The Welding Institute,UK,in 1991.Utilizing frictional and adiabatic heating,plastic deformation and solid-state diff usion,FSW has been widely accepted as a“green”welding technology owing to its energy effi ciency and environment friendliness.Now,FSW has achieved broad application in various industries,such as aerospace and transportation,and is considered the most signifi cant development in the fi eld of material joining over the past two decades.Friction stir processing(FSP),later developed based on the fundamental principles of FSW,has been demonstrated as an eff ective and versatile metalworking technique for modifying and fabricating metallic materials.
