首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   119篇
  免费   3篇
  国内免费   12篇
化学   15篇
力学   3篇
数学   103篇
物理学   13篇
  2024年   1篇
  2023年   3篇
  2022年   5篇
  2021年   3篇
  2020年   1篇
  2019年   1篇
  2018年   1篇
  2017年   6篇
  2016年   2篇
  2015年   3篇
  2014年   4篇
  2013年   27篇
  2011年   2篇
  2010年   7篇
  2009年   6篇
  2008年   12篇
  2007年   3篇
  2006年   2篇
  2005年   7篇
  2004年   3篇
  2003年   3篇
  2002年   1篇
  2001年   3篇
  2000年   1篇
  1999年   4篇
  1998年   2篇
  1997年   10篇
  1996年   4篇
  1995年   1篇
  1994年   6篇
排序方式: 共有134条查询结果,搜索用时 484 毫秒
81.
纪培胜  赵凯 《数学学报》1999,42(6):0-1016
证明了AFC-代数B上的有界D-模映射是完全有界的,这里D是B的一个SVmasa.  相似文献   
82.
《Current Applied Physics》2020,20(5):619-627
Carbon based Perovskite Solar cells (C–PSCs) have emerged as the most promising candidates for commercialisation in the field of perovskite photovoltaics, as they are highly stable, low cost and make use of easily scaled manufacturing techniques. However, the limited conductivity of the carbon electrode inhibits performance and represents a significant barrier to commercial application. Τhis work presents a scalable method for enhancing the carbon electrode conductivity through the integration of aluminium and copper grids into prefabricated C–PSCs. Adhered to the cells using an additional low temperature carbon ink, the metallic grids were found to dramatically reduce top electrode series resistance, leading to a large improvement in fill factor and efficiency. After grid integration, the 1 cm2 C–PSCs yielded power conversion efficiency (PCE) of 13.4% and 13% for copper and aluminium respectively, while standard C–PSCs obtained PCE of 11.3%. Performance is also significantly augmented in the case of larger-scale 11.7 cm2 modules, where PCEs went from 7.7% to 10% and 11% for aluminium and copper grids respectively. This technique offers a fast and low temperature route to high-performance, large-area C–PSCs and could therefore have serious potential for application to the high-volume manufacture of perovskite cells and modules.  相似文献   
83.
84.
85.
We present the method of proving the reconstructibility of graph classes based on the new type of decomposition of graphs — the operator decomposition. The properties of this decomposition are described. Using this decomposition we prove the following. Let P and Q be two hereditary graph classes such that P is closed with respect to the operation of join and Q is closed with respect to the operation of disjoint union. Let M be a module of graph G with associated partition (A,B,M), where AM and B⁄∼M, such that G[A]∈P, G[B]∈Q and G[M] is not (P,Q)-split. Then the graph G is reconstructible.  相似文献   
86.
Motivated by algebraic structures appearing in Rational Conformal Field Theory we study a construction associating to an algebra in a monoidal category a commutative algebra (full centre) in the monoidal centre of the monoidal category. We establish Morita invariance of this construction by extending it to module categories.As an example we treat the case of group-theoretical categories.  相似文献   
87.
88.
设H_8是非交换非余交换的8维半单Hopf代数,C[K_4]是克莱因四元群的群代数,M_3(C)是复数域上的3阶全矩阵代数.通过方阵和方阵对的弱相似给出了同构意义下M_3(C)上全部的C[K_4]-模代数结构.在此基础上结合H_8与C[K_4]的关系,刻划了同构意义下M_3(C)上所有的H_8-模代数结构.  相似文献   
89.
《Electrophoresis》2017,38(7):977-982
Microfluidic systems with modular components are attractive alternatives to monolithically integrated microfluidic systems because of their flexibility. In this study, we apply the modular concept on a water‐head‐pressure‐driven microfluidic oscillator and obtain a widely tunable flow rate and fluidic switching period. Modular fluidic resistors can be easily mounted onto and demounted from a main chip by means of plastic male connectors. The connectors enable a leak‐free connection between the modular resistors and main chip (leakage pressure > 140 kPa). With modular resistors, we show independent control of the flow rate and flow switching period of the oscillator system in a wide range (2.5 s–6.4 h and 2 μL/min–2 mL/min). This modular approach can be used to enhance the flexibility of instruction‐embedded microfluidic circuits in which their operational range is limited.  相似文献   
90.
相关Hopf模的对偶   总被引:7,自引:2,他引:5  
张良云 《数学学报》1997,40(1):73-79
本文的目的就是给出相关Hopf模的对偶性质.在第一部分,证明了相关Hopf模的对偶模仍是相关Hopf模.特别地,Hopf模的对偶仍是Hopf模.在第二、第三两部分,分别给出相关Hopf模的对偶相关Hopf模的基本结构定理及Maschke定理.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号