检索结果-南通市图书馆

Monomorphism categories associated with symmetric groups and parity in finite groups

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2013年第3期56卷 525-530页

作者： ZHANG yuehui Department of Mathematics Shanghai Jiao Tong University

Monomorphism categories of the symmetric and alternating groups are studied via Cayley's em-bedding Theorem. It is shown that the parity is well defined in such categories. As an application, the parity in a finite group G is classified. It is proved that any element in a group of odd order is always even and such a group can be embedded into some alternating group instead of some symmetric group in the Cayley's theorem. It is also proved that the parity in an abelian group of even order is always balanced and the parity in an nonabelian group is independent of its order.

关键词： monomorphism categories Cayley’s theorem parity balanced group

Compilation of reaction kinetics parameters determined in the Key Development Project for Air Pollution Formation Mechanism and Control Technologies in China

在线全文

学校读者我要写书评

暂无评论

Journal of environmental Sciences 2023年第1期123卷 327-340页

作者： yuehui Liu Ming Zhou Keding Lu State Key Joint Laboratory of environmental Simulation and Pollution Control State Environmental Protection Key Laboratory of Atmospheric Ozone Pollution ControlCollege of Environmental Sciences and EngineeringPeking UniversityBeijing 100871China

A compilation of new advances made in the research?eld of laboratory reaction kinetics in China’s Key Development Project for Air Pollution Formation Mechanism and Control Technologies was *** advances are grouped into six broad,interrelated categories,including volatile organic compound(VOC)oxidation,secondary organic aerosol(SOA)formation,new particle formation(NPF)and gas-particle partitioning,ozone chemistry,model parameters,and secondary inorganic aerosol(SIA)formation,highlighting the laboratory work done by Chinese *** smog chamber applications,the current knowledge gained from laboratory studies is reviewed,with emphasis on summarizing the oxidation mechanisms of long-chain alkanes,aromatics,alkenes,aldehydes/ketones in the atmosphere,SOA formation from anthropogenic emission sources,and oxidation of aromatics,isoprene,and limonene,as well as SIA ***?ow tube applications,atmospheric oxidation mechanisms of toluene and methacrolein,SOA formation from limonene oxidation by ozone,gas-particle partitioning of peroxides,and sulfuric acid-water(H2SO4-H2O)binary nucleation,methanesulfonic acid-water(MSA-H2O)binary nucleation,and sulfuric acid-ammonia-water(H2SO4-NH3-H2O)ternary nucleation are discussed.

关键词： Smog chamber Flow tube VOC oxidation SOA formation New particle formation Gas-particle partitioning SIA formation

Injective objects of monomorphism categories

在线全文

学校读者我要写书评

暂无评论

Frontiers of Mathematics in China 2016年第2期11卷 401-409页

作者： Keyan SONG yuehui ZHANG School of Mathematics and Statistics Southwest University Chongqing 400715 China Department of Mathematics Shanghai Jiao Tong University Shanghai 200240 China

For an acyelic quiver Q and a finite-dimensional algebra A, we give a unified form of the indecomposable injective objects in the monomorphism category Mon（Q, A） and prove that Mon（Q, A） has enough injective objects.

关键词： Monomorphism categories injective objects

Recent progress in porous intermetallics:Synthesis mechanism,pore structure,and material properties

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第15期74卷 89-104页

作者： Yao Jiang yuehui He Haiyan Gao State Key Laboratory of Powder Metallurgy Central South UniversityChangsha410083China

Intermetallic compounds have the characteristics of long-range ordered structure and combination of metallic and covalent bonds,showing intrinsic brittleness and outstanding performance *** synthesis mechanism,pore structure characterization and material properties of powder metallurgy porous intermetallics are reviewed in this *** with traditional porous materials,porous intermetallics have good thermal impact resistance,machinability,thermal and electrical conductivity similar to metals,as well as good chemical corrosion resistance,rigidity and high-temperature property similar to *** mechanisms of preparation and pore formation of porous intermetallics mainly include four aspects:(1)the physical process based on the interstitial space between the initial particles and its evolution in the subsequent procedures;(2)the chemical combustion process based on the violent reaction between the initial powder components;(3)the reaction kinetics process based on the difference between the diffusion rates of elements;(4)the phase transition process based on the difference between the phase *** characterization parameters to the pore structure description for porous intermetallics include mainly overall porosity,open porosity,permeability,maximum pore size,pore size distribution and tortuosity *** terms of microstructure characterization of porous intermetallics,three-dimensional pore morphology scanning technology has the potential to reveal the internal characteristics of pore *** research on material properties of porous intermetallics mainly focuses on electrochemical catalytic activity,generalized oxidation resistivity at high temperature,resistance against chemical corrosion and mechanical properties,which have obvious advantages over traditional porous *** the field of the development of porous intermetallics,it is expected to expand their applications by further reducing the pore size to the nanoscale

关键词： Intermetallic compound Porous material Preparation mechanism Pore structure Material property

论中国共产党以自我革命引领社会革命的彰显机理

在线全文

学校读者我要写书评

暂无评论

北京科技大学学报（社会科学版） 2025年第1期41卷 1-7页

作者：庞跃辉吴成国重庆交通大学马克思主义学院重庆400074

主动自我革命是马克思主义先进政党的优良品格,积极引领社会革命是马克思主义先进政党的崇高使命。以马克思主义为指导的中国共产党,在奋斗进程中义无反顾进行自我革命,并以主动自我革命积极引领社会革命,努力实现党的自我不断革命与引... 详细信息

主动自我革命是马克思主义先进政党的优良品格,积极引领社会革命是马克思主义先进政党的崇高使命。以马克思主义为指导的中国共产党,在奋斗进程中义无反顾进行自我革命,并以主动自我革命积极引领社会革命,努力实现党的自我不断革命与引领社会深广革命的良性互动、协同发展。在深入分析中国共产党以自我革命引领社会革命的彰显机理内在本质基础上,深刻把握中国共产党以自我革命引领社会革命的彰显机理的重要表征、生成逻辑、生发动能,教育党员干部在有力推进自我革命中彰显引领社会革命的思想自觉与行动自觉,从而进一步增强和显示党组织的战斗力、凝聚力、影响力,对于在新发展征程推进党的建设新的伟大工程具有重要现实意义和深远影响。

关键词：中国共产党自我革命社会革命生成逻辑彰显机理

KLT-based local linear prediction of chaotic time series

在线全文

学校读者我要写书评

暂无评论

Journal of Systems engineering and electronics 2009年第4期20卷 694-699页

作者： Meng Qingfang Peng Yuhua Chen yuehui School of Information Science and engineering Univ. of Jinan Jinan 250022 P. R. China School of Information Science and engineering Shandong Univ. Jinan 250100 P. R. China

In the reconstructed phase space, based on the Karhunen-Loeve transformation （KLT）, the new local linear prediction method is proposed to predict chaotic time series. ＆ noise-free chaotic time series and a noise added chaotic time series are analyzed. The simulation results show that the KLT-based local linear prediction method can effectively make one-step and multi-step prediction for chaotic time series, and the one-step and multi-step prediction accuracies of the KLT-based local linear prediction method are superior to that of the traditional local linear prediction.

关键词： Karhunen-Loeve transformation local linear prediction phase space reconstruction chaotic time series.

Categories of exact sequences with projective middle terms

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2014年第3期57卷 477-482页

作者： SONG KeYan ZHANG yuehui Department of Mathematics Shanghai Jiao Tong University

Let A be a finite-dimensional algebra over an algebraically closed field k,ε the category of all exact sequences in A-rood, Mp （respectively, Ml） the full subcategory of C consisting of those objects with projective （respectively, injective） middle terms. It is proved that Mp （respectively, MI） is contravariantly finite （respectively, covariantly finite） in ε. As an application, it is shown that Mp = MI is functorially finite and has Auslander-Reiten sequences provided A is selfinjective. Keywords category of exact sequences, contravariantly finite subcategory, functorially finite subcategory Auslander-Reiten sequences, selfinjective algebra

关键词： category of exact sequences contravariantly finite subcategory functorially finite subcategory Auslander-Reiten sequences selfinjective algebra

Molecular epigenetic mechanisms for the memory of temperature stresses in plants

在线全文

学校读者我要写书评

暂无评论

Journal of Genetics and Genomics 2022年第11期49卷 991-1001页

作者： Zhaoxu Gao Yue Zhou yuehui He State Key Laboratory of Protein and Plant Gene Research School of Advanced Agricultural SciencesPeking-Tsinghua Center for Life SciencesPeking UniversityBeijing 100871China Peking University Institute of Advanced Agricultural Sciences WeifangShandong 261325China

The sessile plants encounter various stresses;some are prolonged,whereas some others are *** is crucial for plant growth and development,and plants often encounter adverse high temperature fluctuations(heat stresses)as well as prolonged cold exposure such as seasonal temperature drops in winter when grown in temperate *** plants can remember past temperature stresses to get adapted to adverse local temperature changes to ensure survival and/or reproductive ***,we summarize chromatin-based mechanisms underlying acquired thermotolerance or thermomemory in plants and review recent progresses on molecular epigenetic understanding of‘remembering of prolonged cold in winter’or vernalization,a process critical for various over-wintering plants to acquire competence to flower in the coming *** addition,perspectives on future study in temperature stress memories of economically-important crops are discussed.

关键词： Heat stress Thermomemory Cold memory Vernalization Chromatin modification epigenetics

MICROSTRUCTUReS OF TiAl BASeD ALLOYS PRePAReD BY HOT PReSSING eLeMeNTAL POWDeRS

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 1998年第3期8卷 42-47页

作者： Yong, Liu Baiyun, Huang yuehui, He Bing, Wang Central South Univ of Technology Changsha China

１ＩＮＴＲＯＤＵＣＴＩＯＮＴｉＡｌｂａｓｅｄａｌｏｙｓｈａｖｅｂｅｅｎｒｅｇａｒｄｅｄａｓｐｒｏｍｉｓｉｎｇｈｉｇｈｔｅｍｐｅｒａｔｕｒｅｓｔｒｕｃｔｕｒｅｍａｔｅｒｉａｌｓ，ｆｏｒｔｈｅｉｒｈｉｇｈｓｐｅｃｉｆｉｃ... 详细信息

１ＩＮＴＲＯＤＵＣＴＩＯＮＴｉＡｌｂａｓｅｄａｌｏｙｓｈａｖｅｂｅｅｎｒｅｇａｒｄｅｄａｓｐｒｏｍｉｓｉｎｇｈｉｇｈｔｅｍｐｅｒａｔｕｒｅｓｔｒｕｃｔｕｒｅｍａｔｅｒｉａｌｓ，ｆｏｒｔｈｅｉｒｈｉｇｈｓｐｅｃｉｆｉｃｓｔｒｅｎｇｔｈ，ｒｉｇｉｄｉｔｙ...

关键词： TiAl based alloy hot press powder metallurgy