期刊文献+
共找到22,085篇文章
< 1 2 250 >
每页显示 20 50 100
Panel Discussion on“Development Trends of Computer Science in the New Era”
1
作者 Andrew Yao Nancy M.Amato +3 位作者 Ann Copestake Sukyoung Ryu Yike Guo Yaqin Zhang 《计算机教育》 2024年第3期26-29,共4页
At the panel session of the 3rd Global Forum on the Development of Computer Science,attendees had an opportunity to deliberate recent issues affecting computer science departments as a result of the recent growth in t... At the panel session of the 3rd Global Forum on the Development of Computer Science,attendees had an opportunity to deliberate recent issues affecting computer science departments as a result of the recent growth in the field.6 heads of university computer science departments participated in the discussions,including the moderator,Professor Andrew Yao.The first issue was how universities are managing the growing number of applicants in addition to swelling class sizes.Several approaches were suggested,including increasing faculty hiring,implementing scalable teaching tools,and working closer with other departments through degree programs that integrate computer science with other fields.The second issue was about the position and role of computer science within broader science.Participants generally agreed that all fields are increasingly relying on computer science techniques,and that effectively disseminating these techniques to others is a key to unlocking broader scientific progress. 展开更多
关键词 development trends Computer science
下载PDF
The Development Trend of Enterprise Business Administration and the Innovation of Management Mode
2
作者 Junjie An 《Proceedings of Business and Economic Studies》 2024年第3期70-74,共5页
In the context of the new period,the continuous growth of social and economic levels and the rapid update of information technology have significantly impacted the business management of Chinese enterprises,presenting... In the context of the new period,the continuous growth of social and economic levels and the rapid update of information technology have significantly impacted the business management of Chinese enterprises,presenting substantial challenges.The intensification of market competition exerts development pressure on many enterprises,and coupled with the unstable strength of some businesses,numerous problems in business management arise.These issues hinder the smooth execution of various business activities.Therefore,it is crucial to ensure effective business administration to conduct different business activities in an orderly manner,promptly avoid adverse risks,and strengthen control over multiple factors.The innovation and improvement of business administration are of great significance for enhancing the management level and market competitiveness of modern enterprises,accelerating their healthy development,and creating numerous opportunities.Consequently,this paper analyzes and explores the development trends of enterprise business administration and the innovation of management models for reference. 展开更多
关键词 Enterprise business administration development trend Management mode INNOVATION
下载PDF
Research on the Comprehensive Development Trend of National Fitness Activity Centers
3
作者 Liang Tao Jiaqi Wang 《Journal of World Architecture》 2024年第3期84-92,共9页
With the further advancement of the“National Fitness”strategy and the continuous development of the information age,the National Fitness Activity Centers have become more comprehensive.The comprehensiveness is refle... With the further advancement of the“National Fitness”strategy and the continuous development of the information age,the National Fitness Activity Centers have become more comprehensive.The comprehensiveness is reflected in the design of diversified sports functions and spaces.The article serves to explore the comprehensive development trend of National Fitness Activity Centers.Through summarizing and sorting out domestic and foreign cases,the trend of the comprehensive development of National Fitness Activity Centers is predicted at three levels:industry,city,and individual functions. 展开更多
关键词 National fitness National fitness activity center Comprehensive development trend
下载PDF
Coupling and Long-term Change Characteristics of Forest Carbon Sink and Forestry Economic Development in China
4
作者 Ying ZHANG Na MENG Keren ZHANG 《Asian Agricultural Research》 2024年第7期1-11,共11页
[Objectives]To analyze the changes in of forest carbon sink and forestry economic development,provide reference for relevant management decisions,ecological governance and resource and environment management,and promo... [Objectives]To analyze the changes in of forest carbon sink and forestry economic development,provide reference for relevant management decisions,ecological governance and resource and environment management,and promote the development of green low-carbon economy in China.[Methods]Based on the data of six forest resource inventories from 1989 to 2018 and related studies,the comprehensive evaluation model of forest carbon sink and forestry economic development,the coupling degree model of forest carbon sink and forestry economic development,and the coupling coordination degree model of forest carbon sink and forestry economic development were adopted.The coupling degree of forest carbon sink and forestry economic development from 1992 to 2018 was analyzed.Stepwise regression and ARIMA model were used to analyze the influencing factors and lagging characteristics of forest carbon sink.The coupling degree between forest carbon sink and forestry economic development in China from 2019 to 2030 was predicted by autoregression and ADF test.The coupling between forest carbon sink and forestry economic development in China and its long-term change characteristics were also discussed in this study.[Results](i)The investment of ecological construction and protection,the actual investment of forestry key ecological projects,GDP and the import of forest products had a significant impact on forest resources carbon stock.The total output value of forestry industry,the actually completed investment of forestry key ecological projects and the export volume of forest products had a significant impact on the forest carbon sink,and the actually completed investment of forestry key ecological projects has the greatest impact on the two.(ii)The impact of actually completed investment of forestry key ecological projects had a lag of 2 years on the forest resources carbon stock and a lag of 1 year on the forest carbon sink.When investing in forest carbon sink,it is necessary to make a good plan in advance,and do a good job in forest resources management and time optimization.(iii)From 1992 to 2018,the coupling degree of forest resources carbon stock,forest carbon sink and long-term development of forestry economy in China was gradually increasing.Although there were some fluctuations in the middle time,the coupling degree of forest resources carbon stock and the long-term development of forestry economy increased by 9.24%annually,and the degree of coupling coordination increased from"serious imbalance"in 1992 to"high-quality coordination"in 2018.From 1993 to 2018,the coupling degree of forest carbon sink and long-term development of forestry economy increased by 9.63%annually,slightly faster than the coupling coordination degree of forest resources carbon stock and long-term development of forestry economy.The coordination level also rose from level 2 in 1993 to level 10 in 2018.(iv)The prediction shows that the coupling coordination degree of forest resources carbon stock,forest carbon sink and the long-term development of forestry economy would increase from 2019 to 2030.The coupling coordination degree(D)values of both were close to 1,the coordination level was also 10 for a long time,and the degree of coupling coordination was also maintained at the"high-quality coordination"level for a long time.[Conclusions]Forest has multiple benefits of society,economy and ecology,and forest carbon sink is only a benefit output.The long-term coupling analysis of forest carbon sink and forestry economic development is a key point to multiple benefit analysis.The analysis shows that the spillover effect and co-evolution effect of forest carbon sink in China are significant.From 1992 to 2018,the coupling coordination degree of forest carbon sink and forestry economic development was gradually rising.The prediction analysis also indicate that the coupling coordination degree between the forest carbon sink and the long-term development of forestry economy will remain at the level of"high-quality coordination"for a long time from 2019 to 2030.Therefore,improving the level of forest management and maintaining the current trend of increasing forest resources are the key to achieving the goal of carbon peaking and carbon neutrality in China. 展开更多
关键词 Forest resources carbon stock Forest carbon sink Coupling coordination degree Forestry economic development Long-term trend
下载PDF
Evolution and Development Trend Prospect of Metal Milling Equipment
5
作者 Jie Wen Fugui Xie +1 位作者 Xinjun Liu Yi Yue 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第2期1-15,共15页
The world is currently undergoing profound changes which have never happened within the past century.Global competition in the technology and industry fields is becoming increasingly fierce.The strategic competition o... The world is currently undergoing profound changes which have never happened within the past century.Global competition in the technology and industry fields is becoming increasingly fierce.The strategic competition of the major powers further focuses on the manufacturing industry.Developed countries such as the United States,Germany,and Japan have successively put forward strategic plans such as“re-industrialization”and“return of manufacturing industry”,aiming to seize the commanding heights of a new round of global high-end technology competition and expand international market share.Standing at the historic intersection of a new round of scientific and technological revolution and China's accelerated high-quality development,the“14th Five-Year Plan”clearly pointed out that intelligent manufacturing is the main development trend to promote China's manufacturing to the medium-high end of the global value chain.This reflects the importance of advanced manufacturing for national strategic layout.To better grasp the development direction of advanced manufacturing equipment,the development process and current application status of manufacturing equipment are summarized,and thereafter the characteristics of manufacturing equipment in different development stages of the manufacturing industry are analyzed.Finally,the development trend of advanced milling equipment is prospected. 展开更多
关键词 Intelligent manufacturing High-quality development Milling equipment Evolution and development trend
下载PDF
Study on the technologies development trend of high speed EMUs
6
作者 Chunfang Lu Zunsong Ren Chengxian Ma 《High-Speed Railway》 2023年第1期1-5,共5页
High speed railway technologies are rapidly development in the world.The total distance of the high speed railway is more than 40,000 kilometers in China,and many types of high speed Electrical Multi-Units(EMUs)are op... High speed railway technologies are rapidly development in the world.The total distance of the high speed railway is more than 40,000 kilometers in China,and many types of high speed Electrical Multi-Units(EMUs)are operated.The top operation velocity of the train reaches 350 km/h.New science and technologies are developing rapidly.New generation technologies such as the information technology,intelligent manufacturing,new material and processing,innovating design philosophy have revolutionary influence on the high speed train.It promotes the high speed train performance such as intelligence,reliable operation and environment-friendly.Based on many years investigation of the trend of the technology development and requirement of general public,the trend of technology development in five aspects are presented in this paper.The five aspects include economic applicability,high speed and high efficiency,green and low carbon,intelligent safety,comfortable and high quality. 展开更多
关键词 High speed EMUs TECHNOLOGIES development trend Economic applicability Intelligence
下载PDF
Review and Development Trends of Dynamic Adaptive Building Skin Research Based on CiteSpace Analysis
7
作者 ZHAO Rui LI Haiying 《Journal of Landscape Research》 2023年第2期93-98,共6页
Building skin plays an important role in reducing energy consumption,and low-carbon ecology has become the development goal of architecture all over the world.Through the dynamic control of variable components on the ... Building skin plays an important role in reducing energy consumption,and low-carbon ecology has become the development goal of architecture all over the world.Through the dynamic control of variable components on the surface,the building with dynamic adaptive building skin can better adapt to the climate,thus achieving better energy saving effects.By searching the articles in the web of science database and using CiteSpace software for visualization analysis,this paper analyzes the research process,research hotspot and research trend of dynamic adaptive building skin from the perspectives of time,quantity,distribution domain,representative experts and articles,institutions,keywords,co-citations and main research contents.It is concluded that the development trend of dynamic adaptive building skin includes the application of efficiency simulation,new materials,bionic technology,and the combination of solar photovoltaics. 展开更多
关键词 Visualized analysis Cluster analysis development trend Performance simulation
下载PDF
Current situation and development trend of design methods for subgrade structure of high speed railways
8
作者 Yangsheng Ye Degou Cai +3 位作者 Qianli Zhang Shaowei Wei Hongye Yan Lin Geng 《Railway Sciences》 2023年第3期289-309,共21页
Purpose–This method will become a new development trend in subgrade structure design for high speed railways.Design/methodology/approach–This paper summarizes the structural types and design methods of subgrade bed ... Purpose–This method will become a new development trend in subgrade structure design for high speed railways.Design/methodology/approach–This paper summarizes the structural types and design methods of subgrade bed for high speed railways in China,Japan,France,Germany,the United States and other countries based on the study and analysis of existing literature and combined with the research results and practices of high speed railway subgrade engineering at home and abroad.Findings–It is found that in foreign countries,the layered reinforced structure is generally adopted for the subgrade bed of high speed railways,and the unified double-layer or multi-layer structure is adopted for the surface layer of subgrade bed,while the simple structure is adopted in China;in foreign countries,different inspection parameters are adopted to evaluate the compaction state of fillers according to their respective understanding and practice,while in China,compaction coefficient,subsoil coefficient and dynamic deformation modulus are adopted for such evaluation;in foreign countries,the subgrade top deformation control method,the subgrade bottom deformation control method,the subsurface fill strength control method are mainly adopted in subgrade bed structure design of high speed railways,while in China,dynamic deformation control of subgrade surface and dynamic strain control of subgrade bed bottom layer is adopted in the design.However,the cumulative deformation of subgrade caused by train cyclic vibration load is not considered in the existing design methods.Originality/value–This paper introduces a new subgrade structure design method based on whole-process dynamics analysis that meets subgrade functional requirements and is established on the basis of the existing research at home and abroad on prediction methods for cumulative deformation of subgrade soil. 展开更多
关键词 High speed railway Subgrade engineering Subgrade bed structure Design method Existing research development trend
下载PDF
Analysis of the Development Environment and Trend of Cross-Border E-commerce in China
9
作者 Yanxia Li Can Xu Ping Zhu 《Proceedings of Business and Economic Studies》 2023年第6期30-38,共9页
With the conclusion of the novel coronavirus pandemic and the increasingly complex market environment,China’s cross-border e-commerce has entered a new phase of development.The external landscape is evolving rapidly,... With the conclusion of the novel coronavirus pandemic and the increasingly complex market environment,China’s cross-border e-commerce has entered a new phase of development.The external landscape is evolving rapidly,and there is a gradual improvement in laws and regulations governing cross-border e-commerce,coupled with increased government support.Despite the impact of the COVID-19 pandemic on the market economy,overall development has been steadily improving.The Internet population is expanding,the online retail market is experiencing rapid growth,the consumption structure is undergoing transformation and upgrading,and the e-commerce market is demonstrating significant potential.The advancement of technologies such as big data,artificial intelligence,blockchain,and supply chain has provided more efficient operational support for the cross-border e-commerce industry.Against the backdrop of the emergence of new forms of cross-border e-commerce in China post-pandemic,this paper utilizes the PEST model to analyze the macro environment of cross-border e-commerce in China and project its future development trends. 展开更多
关键词 Cross-border e-commerce Environmental analysis development trend
下载PDF
The situation and development trend of health industrial park construction in China 被引量:4
10
作者 左旭 叶睿 孟开 《卫生软科学》 2018年第5期16-20,共5页
[目的] 描述我国健康产业园区基本现状,总结园区发展模式,为园区未来发展提供理论基础. [方法]利用百度搜索、CNKI和万方数据库全面搜索国内健康产业园区的相关信息和文献资料,基于文献内容 分析法和案例分析法对园区信息进行归纳与分... [目的] 描述我国健康产业园区基本现状,总结园区发展模式,为园区未来发展提供理论基础. [方法]利用百度搜索、CNKI和万方数据库全面搜索国内健康产业园区的相关信息和文献资料,基于文献内容 分析法和案例分析法对园区信息进行归纳与分析.[结果]共检索到健康产业园区3 5 个,涉及 1 8个省市,最 早的园区于1994年创办,园区平均面积为16.82 km2,平均投资金额为140.9亿元.从管理运营、投融资、产 业类型、研发方面归纳了园区的不同发展模式,发现园区建设中的问题并提出未来发展趋势.[结 论 ]我国健 康产业园区正在蓬勃发展,但是仍然存在重复建设缺乏特色,监管机制尚不完善等问题,还需政府进-步完善 审批、优惠等政策,引导园区健康发展. 展开更多
关键词 健康产业园区 发展模式 发展趋势
下载PDF
Trend and Countermeasures for the Development of Rural Resident Tourism Market
11
作者 王莹 徐东亚 《Journal of Landscape Research》 2009年第9期78-81,共4页
The development status of rural resident tourism market is introduced in this study,and its potential influencing factors are analyzed.With coastal areas as the study case,the future development trend of rural residen... The development status of rural resident tourism market is introduced in this study,and its potential influencing factors are analyzed.With coastal areas as the study case,the future development trend of rural resident tourism market in China is predicted from the aspects of market scale,consumption pattern,tourism level and tourism season,moreover,countermeasures are put forward for the healthy and sustainable development of rural resident tourism market. 展开更多
关键词 RURAL RESIDENT TOURISM development trend Market EXPLOITATION
下载PDF
Technical development of operational in-situ marine monitoring and research on its key generic technologies in China 被引量:1
12
作者 Yunzhou Li Juncheng Wang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第10期117-126,共10页
In China,operational in-situ marine monitoring is the primary means of directly obtaining hydrological,meteorological,and oceanographic environmental parameters across sea areas,and it is essential for applications su... In China,operational in-situ marine monitoring is the primary means of directly obtaining hydrological,meteorological,and oceanographic environmental parameters across sea areas,and it is essential for applications such as forecast of marine environment,prevention and mitigation of disaster,exploitation of marine resources,marine environmental protection,and management of transportation safety.In this paper,we summarise the composition,development courses,and present operational status of three systems of operational in-situ marine monitoring,namely coastal marine automated network station,ocean data buoy and voluntary observing ship measuring and reporting system.Additionally,we discuss the technical development in these in-situ systems and achievements in the key generic technologies along with future development trends. 展开更多
关键词 marine observation technology operational in-situ marine monitoring C-MAN station ocean data buoy VOS measuring and reporting system achievements in the key technologies development trend
下载PDF
Research and Development Trend of Shape Control for Cold Rolling Strip 被引量:22
13
作者 Dong-Cheng Wang Hong-Min Liu Jun Liu 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2017年第5期1248-1261,共14页
Shape is an important quality index of cold rolling strip. Up to now, many problems in the shape control domain have not been solved satisfactorily, and a review on the research progress in the shape control domain ca... Shape is an important quality index of cold rolling strip. Up to now, many problems in the shape control domain have not been solved satisfactorily, and a review on the research progress in the shape control domain can help to seek new breakthrough directions. In the past 10 years, researches and applications of shape control models, shape control means, shape detection technology, and shape con- trol system have achieved significant progress. In the aspect of shape control models, the researches in the past improve the accuracy, speed and robustness of the models. The intelligentization of shape control models should be strengthened in the future. In the aspect of the shape control means, the researches in the past focus on the roll opti- mization, mill type selection, process optimization, local strip shape control, edge drop control, and so on. In the future, more attention should be paid to the coordination control of both strip shape and other quality indexes, and the refinement of control objective should be strengthened. In the aspects of shape detection technology and shape control system, some new types of shape detection meters and shape control systems are developed and have successfully indus- trial applications. In the future, the standardization of shape detection technology and shape control system should be promoted to solve the problem of compatibility. In general,the four expected development trends of shape control for cold roiling strip in the future are intelligentization, coordi- nation, refinement, and standardization. The proposed research provides new breakthrough directions for improv- ing shape quality. 展开更多
关键词 Cold rolling strip - Shape control development trend Theory models Shape detectionControl system
下载PDF
Overview of advancement and development trend on magnesium alloy 被引量:81
14
作者 Tiancai Xu Yan Yang +2 位作者 Xiaodong Peng Jiangfeng Song Fusheng Pan 《Journal of Magnesium and Alloys》 SCIE 2019年第3期536-544,共9页
Magnesium alloys are characterized by their low density(approximately 1.8g/cm3 for magnesium alloys),high strength,large modulus of elasticity,good heat dissipation,good shock absorption,greater ability to withstand i... Magnesium alloys are characterized by their low density(approximately 1.8g/cm3 for magnesium alloys),high strength,large modulus of elasticity,good heat dissipation,good shock absorption,greater ability to withstand impact load than aluminum alloys,good corrosion resistance to organic matter and alkalinity.According to the statistical analysis of literature data collected by Web of Science Core Collection,it can be found that the growth rate of publications on magnesium alloy during 2008-2018 is significantly higher than the overall growth rate of alloy research papers.In the past 11 years,the Web of Science Core Collection has collected 21,440 papers on magnesium alloys,averaging nearly 2000 papers annually,of which 2768 papers were collected in 2018,an increase of 206%over 2008,accounting for more than one fifth o f the total literature on alloy research.Magnesium alloys have become an important lightweight metallic structural material and have been widely studied worldwide.As the only journal focusing on magnesium alloy research which devoted to the coverage and dissemination of global research on magnesium alloys.This article statistically analyzes all the academic articles published by Journal of Magnesium and Alloys(JMA)from 2013 to 2018 and compares them with all the articles containing magnesium alloy in their titles on the Web of Science during this period.The development trends of magnesium alloys are summarized based on these articles,and the influence and academic value of the articles published by JMA are summarized as well.This paper hopes to better realize the value of JMA,help better spread the academic research of magnesium alloys,and promote the development of global magnesium alloy research.©2019 Published by Elsevier B.V.on behalf of Chongqing University. 展开更多
关键词 Magnesium alloy developing trend Research hotspots IMPACT
下载PDF
Status and development trend of the welding consumables industry in China 被引量:8
15
作者 Zhang Huiwen Su Jinhua Chen Jian 《China Welding》 EI CAS 2017年第2期23-31,共9页
We analyzed the status and development of the welding consumables industry in China during the 12th Five-Year Plan (2011 -2015) period, and identified the major problems in the industry. We predicted the develop... We analyzed the status and development of the welding consumables industry in China during the 12th Five-Year Plan (2011 -2015) period, and identified the major problems in the industry. We predicted the development trends that are expected for the /3th Five-Year Plan (2016 -2020) period. We suggest some specific countermeasures and practices, which the Chinese welding industry should accelerate the transformation-upgrading and coordinated development of the industry and its firms , should work on improving their overall quality to improve the brand,s influence, enlarge their input into research and technology upgrading,and develop a low-carbon green production mode that could be put in place to promote the development of the Chinese welding consumables industry. 展开更多
关键词 welding consumables development trend
下载PDF
Research and development trends of hydrometallurgy:An overview based on Hydrometallurgy literature from 1975 to 2019 被引量:12
16
作者 Li-pan JIA Jiang-jiang HUANG +5 位作者 Ze-long MA Xu-heng LIU Xing-yu CHEN Jiang-tao LI Li-hua HE Zhong-wei ZHAO 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2020年第11期3147-3160,共14页
Modern hydrometallurgy has been developing for more than 100 years and the related articles keep piling up.Based on a bibliometric analysis of the articles in Hydrometallurgy,the most authoritative journal in the fiel... Modern hydrometallurgy has been developing for more than 100 years and the related articles keep piling up.Based on a bibliometric analysis of the articles in Hydrometallurgy,the most authoritative journal in the field of hydrometallurgy,we try to catch the research and development trends from a global perspective.Firstly,keywords burstness shows that rare earth,recycling,lithium,ionic liquid,and thorium are the hotspots in recent years,and the economic and technological reasons behind them were discussed in depth.Secondly,the proportion of biohydrometallurgy grows fast from 5%to 13%and the related articles are almost all about bioleaching.There are some new directions such as direct preparation of materials in hydrometallurgical processes and ion-imprinted techniques.Thirdly,the advanced instrument analysis methods such as XAFS(X-ray absorption fine structure),gene sequencing,and micro-CT promote the deep understanding of hydrometallurgy mechanism.Finally,the cooperation network and contribution of the main institutes were mapped. 展开更多
关键词 development trends LEACHING solvent extraction BIOHYDROMETALLURGY electro-hydrometallurgy CiteSpace
下载PDF
Status quo and development trend of lost foam casting technology 被引量:7
17
作者 Fan Zitian Jiang Wenming +1 位作者 Liu Fuchu Xiao Botao 《China Foundry》 SCIE CAS 2014年第4期296-307,共12页
Lost foam casting(LFC)technology has been widely applied to cast iron and cast steel.However,the development of LFC for Al and Mg alloys was relatively slower than that for cast iron and cast steel.The application of ... Lost foam casting(LFC)technology has been widely applied to cast iron and cast steel.However,the development of LFC for Al and Mg alloys was relatively slower than that for cast iron and cast steel.The application of LFC to Al and Mg alloys needs more effort,especially in China.In this paper,the development history of LFC is reviewed,and the application situations of LFC to Al and Mg alloys are mainly discussed.Meanwhile,the key problems of LFC for Al and Mg alloys are also pointed out.Finally,the prospects for LFC technology are discussed,and some special new LFC technologies are introduced for casting Al and Mg alloys.In future,the development trends of green LFC technology mainly focus on the special new LFC methods,metal material,coating,heat treatment,new foam materials as well as purification technology of tail gas,etc. 展开更多
关键词 lost foam casting(LFC) technology actuality development trend aluminum alloy magnesium alloy
下载PDF
State of research and trends in development of wood adhesives 被引量:8
18
作者 ZHAO Lei-feng LIU Yu XU Zheng-dong ZHANG Ya-zhuo ZHAO Fang ZHANG Shuang-bao 《Forestry Studies in China》 CAS 2011年第4期321-326,共6页
We aim to present an overview of the status of adhesives in the wood industry, especially in the area of wood-based panels. The review summarizes the current state of research of two kinds of adhesives, i.e., syntheti... We aim to present an overview of the status of adhesives in the wood industry, especially in the area of wood-based panels. The review summarizes the current state of research of two kinds of adhesives, i.e., synthetic adhesives and natural adhesives. Synthetic adhesives, consisting of urea-formaldehyde resins (UF), phenol-formaldehyde resins (PF), polyvinyl acetate emulsion (PVAc) and isocyanates, are widely used. For UF, most investigations are concerned with the reduction of free formaldehyde; for PF, most studies focus on finding new chemicals to replace phenol. PVAc has poor properties, but these can be improved by a blending reactions and copolymerization with other chemicals. Isocyanate is an environmentally friendly synthetic adhesive, but also suffers from inadequate properties. Natural adhesives, such as protein/starch, lignin and tannins, have poor bonding effect that limits their level of use, but their main advantages are that they are environmentally friendly and a renewable resource. Studies of modification can improve the bonding performances and gradually cause natural adhesives to become applied in industrial production. Some proposals for future development and the importance of environmentally friendly adhesives are provided, which will be helpful in future theoretical and experimental research. 展开更多
关键词 synthetic adhesives natural adhesives main features development trend
下载PDF
Application and development in railway vehicles trend of new welding technologies manufacturing industry 被引量:5
19
作者 王春生 刘杰 +1 位作者 王洪潇 段珍珍 《China Welding》 EI CAS 2015年第4期9-14,共6页
This paper introduces the application of new automatic welding technologies in railway vehicles manufacturing industry, and presents the state of art of advanced friction stir welding technology, semi-penetration lase... This paper introduces the application of new automatic welding technologies in railway vehicles manufacturing industry, and presents the state of art of advanced friction stir welding technology, semi-penetration laser welding technology and laser-arc hybrid welding technology in manufacturing aluminum alloy body shell, stainless steel body shell and bogie. This paper also analyzes the application and development trend of three welding technologies in the future. 展开更多
关键词 railway vehicles friction stir welding semi-penetration laser welding laser-arc hybrid welding development trend
下载PDF
Trend and Interannual Variability of Chinese Air Pollution since 2000 in Association with Socioeconomic Development: A Brief Overview 被引量:7
20
作者 LIN Jin-Tai PAN Da ZHANG Rui-Xiong 《Atmospheric and Oceanic Science Letters》 CSCD 2013年第2期84-89,共6页
Abstract Chinese air pollution has increased in this century along with the rapid socioeconomic development and resulting anthropogenic emissions. While recent emission control measures have shown encouraging re sults... Abstract Chinese air pollution has increased in this century along with the rapid socioeconomic development and resulting anthropogenic emissions. While recent emission control measures have shown encouraging re sults and have reduced the levels of sulfur dioxide and primary aerosols, the concentrations of other air pollutants continue to grow, particularly secondary pollutants in cluding ozone and secondary aerosols. Meanwhile, a va riety of intentional and unintentional socioeconomic events have temporarily changed the pace, and even the signs, of growth of air pollution. These events include the short-term emission restrictions imposed during the Sino-African Summit, the Beijing Olympics and Para lympics, the Shanghai World Exposition (Shanghai Expo), the Guangzhou Asian Olympics, and the Shenzhen Uni versiade, as well as the unintentional emission reductions associated with the recent economic recession and the annual Chinese New Year. This paper presents a brief overview of trends and temporary perturbations of Chi nese air pollution since 2000, summarizing studies on anthropogenic emission inventories, atmospheric meas urements, and inverse modeling. It concludes with rec ommendations for future research. 展开更多
关键词 air pollution trend and variability socioeconomic development satellite measurements bottom-upemission inventories top-down constraints
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部