检索结果-南通市图书馆

On the Notion of Cobordism for Bounded Manifolds

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 1994年第1期10卷 59-63页

作者： gan danyan Department of Mathematics Zhejiang University Hangzhou,310027 China 1. Department of Mathematics Zhejiang University 310027 Hangzhou China

The usual concept of eobordism is concerned with closed *** this paper, we generalise the concept of cobordism to the extent of bouncded manifolds and obtain a homotopy theorem similar to the theorem of Thom.

关键词： On the Notion of Cobordism for Bounded Manifolds

EMBEDDED 2-SPHERES IN INDEFINITE 4-MANIFOLDS

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 1996年第3期17卷 257-262页

作者： gan danyan(Depedmellt of Mathematics and Center for Mathematical Sciences, Zhejiang University Hangzhou310027, China.)(Project supported by the National Natural Science Foundation of China and by the Zhejiang NaturalScience Foundation.) ZHEJIANG UNIV DEPT MATHHANGZHOU 310027PEOPLES R CHINA ZHEJIANG UNIV CTR MATH SCIHANGZHOU 310027PEOPLES R CHINA

The main results are as *** be an element of H2, where γ, δ1,…δn. arestandard generators. Suppose2≤n≤9.(1) If for some i and some i, then ζ can be represented by a smoothly embedded 2-sphere.(2) If ζ is a characteristic homology class, then ζ cannot be represented by a smoothlyembedded 2-sphere except for ζ2 = 16l+1 - n, l = 0 and (3) If ζ= dη for some d∈Z, where η is a primitive ordinary homology class with η2 = 0,then ζ is eqivalent to (d; d, 0,..., 0) and can be represented by a smoothly embedded 2-sphere.

关键词： Representing Characteristic Ordinary Primitive

Atomically dispersed materials:Ideal catalysts in atomic era

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第1期17卷 18-38页

作者： Tao gan Dingsheng Wang Department of Chemistry Tsinghua UniversityBeijing 100084China

Catalysts can accelerate the chemical reaction rate and effectively promote the molecules transformation,which is of great significance in the research of chemical industry and material *** extreme utilization of reactive sites has led to the emergence and development of atomically dispersed materials(ADMs).The highly active coordination unsaturated metal sites and fully utilized metal atoms make ADMs show great potential in catalytic *** adjustment of coordination environment and electronic structure provides more possibilities for constructing reactive centers with different *** review summarized the application and research progress of ADMs in different *** design strategy and structure–activity relationship of ADMs for specific reactions were summarized and ***,we also provided advices for the challenges and opportunities faced by ADMs in catalytic reactions.

关键词： atomically dispersed materials catalysis organic synthesis battery sensor enzyme

Progress Report on ASO-S: 2022–2024

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

空间科学学报 2024年第4期44卷 687-689页

作者： gan Weiqun Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210023

The Advanced Space-based Solar Observatory(ASO-S)marked China's first comprehensive solar mission in *** upon the previous reports covering 2018-2020 and 2020-2022,we present here an update on the ASO-S made from 2022 to *** August 2022,ASO-S completed its Phase D study and was successfully launched on October 9,*** commissioning phase was carried out and concluded within the first nine months following the *** data and associated analysis software have been opened to the community and the research on the early ASO-S data has been well *** anticipate also the achievements in data research pertaining to ASO-S in the near future.

关键词： Space astronomy Solar physics Spacecraft

Distributed Least Squares Algorithm of Continuous-Time Stochastic Regression Model Based on Sampled Data

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2024年第2期37卷 609-628页

作者： ZHU Xinghua gan Die LIU Zhixin The Key Laboratory of Systems and Control Academy of Mathematics and Systems ScienceChinese Academy of Sciencesand School of Mathematical SciencesUniversity of Chinese Academy of SciencesBeijing 100190China Zhongguancun Laboratory Beijing 100094China

In this paper,the authors consider the distributed adaptive identification problem over sensor networks using sampled data,where the dynamics of each sensor is described by a stochastic differential *** minimizing a local objective function at sampling time instants,the authors propose an online distributed least squares algorithm based on sampled data.A cooperative non-persistent excitation condition is introduced,under which the convergence results of the proposed algorithm are established by properly choosing the sampling time *** upper bound on the accumulative regret of the adaptive predictor can also be ***,the authors demonstrate the cooperative effect of multiple sensors in the estimation of unknown parameters by computer simulations.

关键词： Cooperative excitation condition distributed least squares regret sampled data stochastic differential equation

在线全文

学校读者我要写书评

暂无评论

从怪异7维球面到怪异4维欧氏空间

高等数学研究 2017年第4期20卷 1-6页

作者：干丹岩浙江大学数学科学学院浙江杭州310027

本文简要地介绍了微分拓扑学在20世纪深入发展中一系列卓越的成果,包括由***发现的第一个怪异7维球面,不存在光滑化的组合流形的构作,当n≠4时瓗n上只有唯一的微分结构的证明,Freedman关于拓扑4维流形的定理,它推导出4维广义Poincaré... 详细信息

本文简要地介绍了微分拓扑学在20世纪深入发展中一系列卓越的成果,包括由***发现的第一个怪异7维球面,不存在光滑化的组合流形的构作,当n≠4时瓗n上只有唯一的微分结构的证明,Freedman关于拓扑4维流形的定理,它推导出4维广义Poincaré猜测的解决,Donaldson关于光滑4维流形的定理,进而得到瓗4上存在怪异微分结构等重要内容.

关键词：微分拓扑学怪异微分结构

A Sustainable Dual Cross‑Linked Cellulose Hydrogel Electrolyte for High‑Performance Zinc‑Metal Batteries

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第6期16卷 63-75页

作者： Haodong Zhang Xiaotang gan Yuyang Yan Jinping Zhou Hubei Engineering Center of Natural Polymers‑Based Medical Materials Key Laboratory of Biomedical Polymers of Ministry of EducationCollege of Chemistry and Molecular SciencesWuhan UniversityWuhan 430072People’s Republic of China Zhongnan Hospital of Wuhan University Institute of Hepatobiliary Diseases of Wuhan UniversityTransplant Center of Wuhan UniversityWuhan 430072People’s Republic of China

Aqueous rechargeable Zn-metal batteries(ARZBs)are considered one of the most promising candidates for grid-scale energy ***,their widespread commercial application is largely plagued by three major challenges:The uncontrollable Zn dendrites,notorious parasitic side reactions,and sluggish Zn^(2+) ion *** address these issues,we design a sustainable dual crosslinked cellulose hydrogel electrolyte,which has excellent mechanical strength to inhibit dendrite formation,high Zn^(2+) ions binding capacity to suppress side reaction,and abundant porous structure to facilitate Zn^(2+) ions ***,the Zn||Zn cell with the hydrogel electrolyte can cycle stably for more than 400 h under a high current density of 10 mA cm^(−2).Moreover,the hydrogel electrolyte also enables the Zn||polyaniline cell to achieve high-rate and long-term cycling performance(>2000 cycles at 2000 mA g^(−1)).Remarkably,the hydrogel electrolyte is easily accessible and biodegradable,making the ARZBs attractive in terms of scalability and sustainability.

关键词： Cellulose Dual cross-linked Aqueous rechargeable Zn-metal batteries Hydrogel electrolyte

N-Heterocyclic carbene-catalyzed enantioselective(dynamic) kinetic resolutions and desymmetrizations

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第2期67卷 482-511页

作者： Yi Zhang Hui Cai Xiuhai gan Zhichao Jin National Key Laboratory of Green Pesticide Key Laboratory of Green Pesticide and Agricultural BioengineeringMinistry of EducationGuizhou UniversityHuaxi DistrictGuiyang550025China

N-heterocyclic carbene-catalyzed enantioselective kinetic resolutions,dynamic kinetic resolutions,and desymmetrization reactions are systematically *** content is organized according to the activation modes involved i... 详细信息

关键词： N-heterocyclic carbene kinetic resolution dynamic kinetic resolution desymmetrization organocatalysis

Blast waveform tailoring using controlled venting in blast simulators and shock tubes

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第7期37卷 14-26页

作者： Edward Chern Jinn gan Alex Remennikov David Ritzel Faculty of Engineering and Information Sciences University of WollongongWollongongNSW2522Australia Dyn-FX Consulting Ltd 19 Laird Ave NorthAmherstburgONN9V 2T5Canada

A critical challenge of any blast simulation facility is in producing the widest possible pressure-impulse range for matching against equivalent high-explosive *** tubes and blast simulators are often constrained with the lack of effective ways to control blast wave profiles and as a result have a limited performance *** wave shaping techniques employed in some facilities are reviewed but often necessitate extensive geometric modifications,inadvertently cause flow anomalies,and/or are only applicable under very specific *** paper investigates controlled venting as an expedient way for waveforms to be tuned without requiring extensive modifications to the driver or existing geometry and could be widely applied by existing and future blast simulation and shock tube *** use of controlled venting is demonstrated experimentally using the Advanced Blast Simulator(shock tube)at the Australian National Facility of Physical Blast Simulation and via numerical flow simulations with Computational Fluid *** venting is determined as an effective method for mitigating the impact of re-reflected waves within the blast *** control method also allows for the adjustment of parameters such as tuning the peak overpressure,the positive phase duration,and modifying the magnitude of the negative phase and the secondary shock of the blast *** paper is concluded with an illustration of the potential expanded performance range of the Australian blast simulation facility when controlled venting for blast waveform tailoring as presented in this paper is applied.

关键词： Advanced blast simulator Shock wave propagation Far-field explosion Blast loads Blast waves Computational fluid dynamics