MOOC(Massive Open Online Course)即"大规模在线开放课程",因其大规模和开放性等特点,已成为国内外互联网上的热点,与之相关的非正式言论和正式的学术研究纷至沓来。对MOOC实践和研究的深入分析既是MOOC现实发展的需要,也是...MOOC(Massive Open Online Course)即"大规模在线开放课程",因其大规模和开放性等特点,已成为国内外互联网上的热点,与之相关的非正式言论和正式的学术研究纷至沓来。对MOOC实践和研究的深入分析既是MOOC现实发展的需要,也是其可持续发展的要求。国内MOOC的发展已然将成燎原之势,在相关实践中亮点与不足并存,与之对应的是,国内对MOOC的学术研究状况既有亮点,亦有较大的上升空间。本文试图在全球MOOC发展热潮的背景下,参照国外MOOC相关研究成果,梳理国内MOOC相关的学术和非学术文献,综合国内MOOC相关学术会议情况,探讨国内MOOC研究的特点和值得关注的问题。展开更多
BACKGROUND： Severe acute pancreatitis is a subtype of acute pancreatitis, associated with multiple organ failure and systemic inflammatory response syndrome. In this qualitative review we looked at the principles of ...BACKGROUND： Severe acute pancreatitis is a subtype of acute pancreatitis, associated with multiple organ failure and systemic inflammatory response syndrome. In this qualitative review we looked at the principles of pathogenesis, classification and surgical management of severe acute pancreatitis. We also looked at the current shift in paradigm in the management of severe acute pancreatitis since the guideline developed by the British Society of Gastroenterology.DATA SOURCES： Studies published between 1st January 1991 and 31st December 2015 were identified with Pub Med, MEDLINE, EMBASE and Google Scholar online search engines using the following Medical Subject Headings： “acute pancreatitis, necrosis, mortality, pathogenesis, incidence” and the terms “open necrosectomy and minimally invasive necrosectomy”.The National Institute of Clinical Excellence（NICE） Guidelines were also included in our study. Inclusion criteria for our clinical review included established guidelines, randomized controlled trials and non-randomized controlled trials with a follow-up duration of more than 6 weeks.RESULTS： The incidence of severe acute pancreatitis within the UK is significantly rising and pathogenetic theories are still controversial. In developed countries, the most common cause is biliary calculi. The British Society of Gastroenterology,acknowledges the Revised Atlanta criteria for prediction of severity. A newer Determinant-based system has been developed.The principle of surgical management of acute necrotizing pancreatitis requires intensive care management, identifying infection and if indicated, debridement of any infected necrotic area. The current procedures opted for include standard surgical open necrosectomy, endoscopic necrosectomy and minimally invasive necrosectomy. The current paradigm is shifting towards a step-up approach.CONCLUSIONS： Severe acute pancreatitis is still a subject of grey areas in its surgical management even though new studies have been recorded since the origin of the 展开更多
就在一年间，MOOC （Massive Open Online Course，大规模在线课程）热遍全球。MOOC的发展让大学充满激情却又面临挑战。高等院校必须重新思考自己的定位大学究竟是什么？它是学习环境的设计者？学生学习的促进者？学分的认证者？学习...就在一年间，MOOC （Massive Open Online Course，大规模在线课程）热遍全球。MOOC的发展让大学充满激情却又面临挑战。高等院校必须重新思考自己的定位大学究竟是什么？它是学习环境的设计者？学生学习的促进者？学分的认证者？学习产出的评估者？还只是学位的授予者？大学将如何迎接这即将来临的疾风骤雨？展开更多
The Open Quantum Materials Database(OQMD)is a high-throughput database currently consisting of nearly 300,000 density functional theory(DFT)total energy calculations of compounds from the Inorganic Crystal Structure D...The Open Quantum Materials Database(OQMD)is a high-throughput database currently consisting of nearly 300,000 density functional theory(DFT)total energy calculations of compounds from the Inorganic Crystal Structure Database(ICSD)and decorations of commonly occurring crystal structures.To maximise the impact of these data,the entire database is being made available,without restrictions,at www.oqmd.org/download.In this paper,we outline the structure and contents of the database,and then use it to evaluate the accuracy of the calculations therein by comparing DFT predictions with experimental measurements for the stability of all elemental ground-state structures and 1,670 experimental formation energies of compounds.This represents the largest comparison between DFT and experimental formation energies to date.The apparent mean absolute error between experimental measurements and our calculations is 0.096 eV/atom.In order to estimate how much error to attribute to the DFT calculations,we also examine deviation between different experimental measurements themselves where multiple sources are available,and find a surprisingly large mean absolute error of 0.082 eV/atom.Hence,we suggest that a significant fraction of the error between DFT and experimental formation energies may be attributed to experimental uncertainties.Finally,we evaluate the stability of compounds in the OQMD(including compounds obtained from the ICSD as well as hypothetical structures),which allows us to predict the existence of~3,200 new compounds that have not been experimentally characterised and uncover trends in material discovery,based on historical data available within the ICSD.展开更多
With the proliferation of the Internet of Things(IoT),various services are emerging with totally different features and requirements,which cannot be supported by the current fifth generation of mobile cellular network...With the proliferation of the Internet of Things(IoT),various services are emerging with totally different features and requirements,which cannot be supported by the current fifth generation of mobile cellular networks(5G).The future sixth generation of mobile cellular networks(6G)is expected to have the capability to support new and unknown services with changing requirements.Hence,in addition to enhancing its capability by 10–100 times compared with 5G,6G should also be intelligent and open to adapt to the ever-changing services in the IoT,which requires a convergence of Communication,Computing and Caching(3C).Based on the analysis of the requirements of new services for 6G,this paper identifies key enabling technologies for an intelligent and open 6G network,all featured with 3C convergence.These technologies cover fundamental and emerging topics,including 3C-based spectrum management,radio channel construction,delay-aware transmission,wireless distributed computing,and network self-evolution.From the detailed analysis of these 3C-based technologies presented in this paper,we can see that although they are promising to enable an intelligent and open 6G,more efforts are needed to realize the expected 6G network.展开更多
＂慕课＂是英文MOOCs的音译．即“大规模在线开放课程”（Massively Open Online Course）的英文简称。这一大规模在线课程掀起的风暴始于2011年秋天．在短短一年多时间席卷全球数十个国家．600多万名参与学习者遍布全世界220多个国家...＂慕课＂是英文MOOCs的音译．即“大规模在线开放课程”（Massively Open Online Course）的英文简称。这一大规模在线课程掀起的风暴始于2011年秋天．在短短一年多时间席卷全球数十个国家．600多万名参与学习者遍布全世界220多个国家，其影响范围之广、扩张速度之快、冲击力之强，犹如地震海啸，一些人将互联网技术引发的这场教育变革称为“MOOCs风暴”。展开更多
文摘MOOC(Massive Open Online Course)即"大规模在线开放课程",因其大规模和开放性等特点,已成为国内外互联网上的热点,与之相关的非正式言论和正式的学术研究纷至沓来。对MOOC实践和研究的深入分析既是MOOC现实发展的需要,也是其可持续发展的要求。国内MOOC的发展已然将成燎原之势,在相关实践中亮点与不足并存,与之对应的是,国内对MOOC的学术研究状况既有亮点,亦有较大的上升空间。本文试图在全球MOOC发展热潮的背景下,参照国外MOOC相关研究成果,梳理国内MOOC相关的学术和非学术文献,综合国内MOOC相关学术会议情况,探讨国内MOOC研究的特点和值得关注的问题。
文摘BACKGROUND： Severe acute pancreatitis is a subtype of acute pancreatitis, associated with multiple organ failure and systemic inflammatory response syndrome. In this qualitative review we looked at the principles of pathogenesis, classification and surgical management of severe acute pancreatitis. We also looked at the current shift in paradigm in the management of severe acute pancreatitis since the guideline developed by the British Society of Gastroenterology.DATA SOURCES： Studies published between 1st January 1991 and 31st December 2015 were identified with Pub Med, MEDLINE, EMBASE and Google Scholar online search engines using the following Medical Subject Headings： “acute pancreatitis, necrosis, mortality, pathogenesis, incidence” and the terms “open necrosectomy and minimally invasive necrosectomy”.The National Institute of Clinical Excellence（NICE） Guidelines were also included in our study. Inclusion criteria for our clinical review included established guidelines, randomized controlled trials and non-randomized controlled trials with a follow-up duration of more than 6 weeks.RESULTS： The incidence of severe acute pancreatitis within the UK is significantly rising and pathogenetic theories are still controversial. In developed countries, the most common cause is biliary calculi. The British Society of Gastroenterology,acknowledges the Revised Atlanta criteria for prediction of severity. A newer Determinant-based system has been developed.The principle of surgical management of acute necrotizing pancreatitis requires intensive care management, identifying infection and if indicated, debridement of any infected necrotic area. The current procedures opted for include standard surgical open necrosectomy, endoscopic necrosectomy and minimally invasive necrosectomy. The current paradigm is shifting towards a step-up approach.CONCLUSIONS： Severe acute pancreatitis is still a subject of grey areas in its surgical management even though new studies have been recorded since the origin of the
文摘就在一年间，MOOC （Massive Open Online Course，大规模在线课程）热遍全球。MOOC的发展让大学充满激情却又面临挑战。高等院校必须重新思考自己的定位大学究竟是什么？它是学习环境的设计者？学生学习的促进者？学分的认证者？学习产出的评估者？还只是学位的授予者？大学将如何迎接这即将来临的疾风骤雨？
基金the U.S.Department of Energy,Office of Science,Office of Basic Energy Sciences under Award Number DE-SC00010543(JWD)the Ford-Boeing-Northwestern Alliance(JES)+2 种基金support by DOE under Grant No.DE-FG02-07ER46433(BM and AT)The Dow Chemical Company(MA)and the National Science Foundation under grant DRL-1348800(CW)supported by the Office of Science of the U.S.Department of Energy under Contract No.DE-AC02-05CH11231.
文摘The Open Quantum Materials Database(OQMD)is a high-throughput database currently consisting of nearly 300,000 density functional theory(DFT)total energy calculations of compounds from the Inorganic Crystal Structure Database(ICSD)and decorations of commonly occurring crystal structures.To maximise the impact of these data,the entire database is being made available,without restrictions,at www.oqmd.org/download.In this paper,we outline the structure and contents of the database,and then use it to evaluate the accuracy of the calculations therein by comparing DFT predictions with experimental measurements for the stability of all elemental ground-state structures and 1,670 experimental formation energies of compounds.This represents the largest comparison between DFT and experimental formation energies to date.The apparent mean absolute error between experimental measurements and our calculations is 0.096 eV/atom.In order to estimate how much error to attribute to the DFT calculations,we also examine deviation between different experimental measurements themselves where multiple sources are available,and find a surprisingly large mean absolute error of 0.082 eV/atom.Hence,we suggest that a significant fraction of the error between DFT and experimental formation energies may be attributed to experimental uncertainties.Finally,we evaluate the stability of compounds in the OQMD(including compounds obtained from the ICSD as well as hypothetical structures),which allows us to predict the existence of~3,200 new compounds that have not been experimentally characterised and uncover trends in material discovery,based on historical data available within the ICSD.
基金This work is supported by the National Natural Science Youth Fund of China granted by No.61901452 and Innovative Project of ICT/CAS granted by No.20196110
文摘With the proliferation of the Internet of Things(IoT),various services are emerging with totally different features and requirements,which cannot be supported by the current fifth generation of mobile cellular networks(5G).The future sixth generation of mobile cellular networks(6G)is expected to have the capability to support new and unknown services with changing requirements.Hence,in addition to enhancing its capability by 10–100 times compared with 5G,6G should also be intelligent and open to adapt to the ever-changing services in the IoT,which requires a convergence of Communication,Computing and Caching(3C).Based on the analysis of the requirements of new services for 6G,this paper identifies key enabling technologies for an intelligent and open 6G network,all featured with 3C convergence.These technologies cover fundamental and emerging topics,including 3C-based spectrum management,radio channel construction,delay-aware transmission,wireless distributed computing,and network self-evolution.From the detailed analysis of these 3C-based technologies presented in this paper,we can see that although they are promising to enable an intelligent and open 6G,more efforts are needed to realize the expected 6G network.
文摘＂慕课＂是英文MOOCs的音译．即“大规模在线开放课程”（Massively Open Online Course）的英文简称。这一大规模在线课程掀起的风暴始于2011年秋天．在短短一年多时间席卷全球数十个国家．600多万名参与学习者遍布全世界220多个国家，其影响范围之广、扩张速度之快、冲击力之强，犹如地震海啸，一些人将互联网技术引发的这场教育变革称为“MOOCs风暴”。
