检索结果-南通市图书馆

Boosting cationic and anionic redox activity of Li-rich layered oxide cathodes via Li/Ni disordered regulation

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2025年第1期100卷 533-543页

作者： Zewen Liu Zhen Wu Hao Wang Xudong Zhang Yuanzhen Chen Yongning Liu shengwu Guo Shenghua Chen Yanli Nan Yan Liu State Key Laboratory for Mechanical Behavior of Materials Xi'an Jiaotong University School of Materials Science and Engineering Xi'an University of Architecture and Technology hefei Advanced Computing Center Operation Management Corp Ltd Network Information Center Xi'an Jiaotong University

Lithium-rich layered oxides （LLOs） are increasingly recognized as promising cathode materials for nextgeneration high-energy-density lithium-ion batteries （LIBs）.However,they suffer from voltage decay and low initial Coulombic efficiency （ICE） due to severe structural degradation caused by irreversible O ***,we introduce a three-in-one strategy of increasing Ni and Mn content,along with Li/Ni disordering and TM–O covalency regulation to boost cationic and anionic redox activity simultaneously and thus enhance the electrochemical activity of *** target material,Li1.2Ni0.168Mn0.558Co0.074O2（L1）,exhibits an improved ICE of 87.2%and specific capacity of 293.2 mA h g-1and minimal voltage decay of less than 0.53 m V cycle-1over 300 cycles at 1C,compared to Li1.2Ni0.13Mn0.54Co0.13O2（Ls）(274.4 mA h g-1for initial capacity,73.8%for ICE and voltage decay of 0.84 mV/cycle over 300 cycles at 1C).Theoretical calculations reveal that the density of states （DOS） area near the Fermi energy level for L1 is larger than that of Ls,indicating higher anionic and cationic redox reactivity than ***,L1 exhibits increased O-vacancy formation energy due to higher Li/Ni disordering of 4.76%（quantified by X-ray diffraction Rietveld refinement） and enhanced TM–O covalency,making lattice O release more difficult and thus improving electrochemical *** increased Li/Ni disordering also leads to more Ni2+presence in the Li layer,which acts as a pillar during Li+de-embedding,improving structural *** research not only presents a viable approach to designing low-Co LLOs with enhanced capacity and ICE but also contributes significantly to the fundamental understanding of structural regulation in high-performance LIB cathodes.

关键词： Ice

NATURAL FILTRATIONS FOR A CLASS OF SEMI-MARTINGALES

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science in China,Ser.A 1986年第6期 595-603页

作者：何声武汪嘉冈 East China Normal University Shanghai Fudan University

Let X be a sem-martingale with respect to its natural filtration. Suppose X has weak property of predictable representation, i.e. every continuous local martingale can be represented as a predictable integral with respect to the continuous martingale part of X, and every purely discontinuous local martingale can be represented as a predictable integral with respect to the difference of the jump measure of X and its predictable dual projection. The local (predictable) characteristics of X being used, the necessary and sufficient conditions for quasi-left-continuity, total continuity and the property of predictable representation of the natural filtration of X are given.

关键词： NATURAL FILTRATIONS FOR A CLASS OF SEMI-MARTINGALES SEMI

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

关于平稳序列的相关函数的一个问题

华东师范大学学报(自然科学版) 1981年第2期 9-14页

作者：何声武华东师范大学数学系

本文考虑下列问题:给定复数 R0,R1,…,Rn 使矩阵An+1 =（■）为非负定阵,Rn+1 为另一个复数,问:什么时候矩阵An+2 =（■）也是非负定阵。我们给出了 Rn+1 应满足的充要条件。这个问题来自平稳随机序列的相关函数。

关键词：非负定复数无限维无穷维非负定矩阵平稳随机序列关联函数相关函数平稳序列

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

离散型σ-域流

华东师范大学学报(自然科学版) 1984年第2期 1-6页

作者：何声武郑伟安华东师范大学数学系

1.设（Ω,??,P）为一完备概率空间,F=（Ft）t≥0为一满足通常条件的σ-域流,（Tn）n≥0为一列严格递增的停时(即Tn<∞??Tn 详细信息

1.设（Ω,??,P）为一完备概率空间,F=（Ft）t≥0为一满足通常条件的σ-域流,（Tn）n≥0为一列严格递增的停时(即Tn<∞??Tn

关键词：随机过程可测停时命题概率论可料时随机变量离散型跳跃过程充要条件

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

抽象Burkill积分

华东师范大学学报(自然科学版) 1982年第1期 1-8页

作者：何声武汪振鹏华东师范大学数学系

设(Ω,??)是一可测空间.??与??是Ω的两个可测分割,记??≥??,若??是??的加细.分割全体按此半序为向上定向集.设ρ为定义在??上有集限函数,ρ(Φ)=0.对任一B∈??及分割??,记Sφ(B,??)=??ρ(BA).若极限存在且有限,则称ρ在B上可积,I_φ(B... 详细信息

设(Ω,??)是一可测空间.??与??是Ω的两个可测分割,记??≥??,若??是??的加细.分割全体按此半序为向上定向集.设ρ为定义在??上有集限函数,ρ(Φ)=0.对任一B∈??及分割??,记Sφ(B,??)=??ρ(BA).若极限存在且有限,则称ρ在B上可积,I_φ(B)为φ在B上的积分.设μ为??上的有限测度,称ρ关于μ绝对连续,若对任意ε>0,存在δ>0,使得对任一B∈??,如μ(B)0,存在正整数N,使??≥??时有|S_φ(Ω,??)-I_φ(Ω)|<ε及(ii)σ(??)=??,则

关键词：集函数可积 Burkill 绝对连续积分积分学

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

荷载均衡法在高烈度地震区房屋加层中的应用

武汉科技大学学报 2017年第3期40卷 230-233页

作者：俞晓曹博宇汤斌万胜武贺伟明武汉科技大学城市建设学院湖北武汉430065 桂林理工大学土木与建筑工程学院广西桂林541004

根据高烈度地震区房屋加层改造的特点提出了荷载均衡法,即在确定加层减荷方案时注重考虑减荷分布的均匀性以及原有结构减荷量与加层增荷量的相互平衡。将该方法应用于抗震设防烈度为8度的某框架结构教学楼加层改造工程中,制定了3个不同... 详细信息

根据高烈度地震区房屋加层改造的特点提出了荷载均衡法,即在确定加层减荷方案时注重考虑减荷分布的均匀性以及原有结构减荷量与加层增荷量的相互平衡。将该方法应用于抗震设防烈度为8度的某框架结构教学楼加层改造工程中,制定了3个不同的减荷方案,运用PKPM和YJK软件分别进行结构计算分析与比较。结果表明,采用优选的加层减荷施工方案后,无需对原结构的梁柱进行加固,减少了加固工程费用,缩短了施工工期。

关键词：高烈度地震区建筑物改造加层荷载均衡框架结构

在线全文

学校读者我要写书评

暂无评论

规则与奇异停时

华东师范大学学报(自然科学版) 1988年第3期 1-7页

作者：钱士贤何声武中山大学数学系华东师范大学数理统计系

本文定义了规则与奇异时,其特征是纯断的局部可积增过程的可料对偶投影为绝对连续或奇异过程当且仅当增过程的跳时为规则或奇异的。讨论了规则时与奇异时的基本性质,给出了任一停时的规则—奇异分解,也讨论了与这两类停时有关的两个随... 详细信息

本文定义了规则与奇异时,其特征是纯断的局部可积增过程的可料对偶投影为绝对连续或奇异过程当且仅当增过程的跳时为规则或奇异的。讨论了规则时与奇异时的基本性质,给出了任一停时的规则—奇异分解,也讨论了与这两类停时有关的两个随机事件的σ代数以及相应的随机过程一般理论的概念与问题。

关键词：停时增过程可料对偶投影绝对连续奇异

Fertile organs and in situ spores of a matoniaceous fern from the Lower Jurassic of West Hubei

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1999年第14期44卷 1333-1337页

作者： Yongdong Wang shengwu Mei Acad Sinica Nanjing Inst Geol & Palaeontol Nanjing 210008 Peoples R China

Fossil matoniaceous plants represented by Phlebopteris have been formerly descrinbea and illustrated from the Mesozoic of China mainly based on vegetative leaves, and no information is provided on the fine structure of fertile organs. Recent reinvestigation of the Hsiangchi Flora from the Lower Jurassic of West Hubei, China, obtained a rich collection of well preserved Phlebopteris specimens (both sterile and fertile). Studies on Phlebopteris polypodioides Brongniart using LM and SEM reveal not only the structures of sori and sporangia, but also the details of in situ spores. Comparisons have been made between the in situ spores and other related fossil and extant matoniaceous spores, as well as the dispersed genera.

关键词： Phlebopteris Matoniaceae in situ spores Lower Jurassic Hubei.

Pedestrian detection algorithm based on video sequences and laser point cloud

在线全文

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2015年第3期9卷 402-414页

作者： Hui LI Yun LIU shengwu XIONG Lin WANG School of Information Science and Technology Qingdao University of Science and Technology Qingdao 266061 China School of Computer Science Wuhan University of Technology Wuhan 430070 China

Pedestrian detection is a critical problem in the field of computer vision. Although most existing algorithms are able to detect pedestrians well in controlled environ- ments, it is often difficult to achieve accurate pedestrian de- tection from video sequences alone, especially in pedestrian- intensive scenes wherein pedestrians may cause mutual oc- clusion and thus incomplete detection. To surmount these dif- ficulties, this paper presents pedestrian detection algorithm based on video sequences and laser point cloud. First, laser point cloud is interpreted and classified to separate pedes- trian data and vehicle data. Then a fusion of video image data and laser point cloud data is achieved by calibration. The re- gion of interest after fusion is determined using feature in- formation contained in video image and three-dimensional information of laser point cloud to remove false detection of pedestrian and thus to achieve pedestrian detection in inten- sive scenes. Experimental verification and analysis in video sequences demonstrate that fusion of two data improves the performance of pedestrian detection and has better detection results.

关键词： computer vision pedestrian detection video se-quences laser point cloud