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   3264篇
  免费   461篇
  国内免费   405篇
化学   1981篇
晶体学   31篇
力学   124篇
综合类   12篇
数学   566篇
物理学   1416篇
  2024年   5篇
  2023年   198篇
  2022年   198篇
  2021年   237篇
  2020年   242篇
  2019年   153篇
  2018年   110篇
  2017年   121篇
  2016年   120篇
  2015年   185篇
  2014年   241篇
  2013年   273篇
  2012年   427篇
  2011年   382篇
  2010年   254篇
  2009年   280篇
  2008年   177篇
  2007年   170篇
  2006年   107篇
  2005年   38篇
  2004年   10篇
  2003年   25篇
  2002年   16篇
  2001年   57篇
  2000年   22篇
  1999年   43篇
  1998年   27篇
  1997年   7篇
  1990年   1篇
  1985年   3篇
  1959年   1篇
排序方式: 共有4130条查询结果,搜索用时 187 毫秒
1.
Designs, Codes and Cryptography - According to a magnific method due to I. Tamo and A. Barg, a class of polynomials over finite fields, called good polynomials, was introduced and used to construct...  相似文献   
2.
Liang  Guiming  Huang  Yunbao  Li  Haiyan  Lin  Jingliang 《Nonlinear dynamics》2021,105(4):3393-3407
Nonlinear Dynamics - The modal truncation is usually used in the dynamic response analysis of flexible multibody systems, in which, appropriate selection of modal shapes is very critical to achieve...  相似文献   
3.
《中国物理 B》2021,30(6):60314-060314
Besides its fundamental importance, non-reciprocity has also found many potential applications in quantum technology. Recently, many quantum systems have been proposed to realize non-reciprocity, but stable non-reciprocal process is still experimentally difficult in general, due to the needed cyclical interactions in artificial systems or operational difficulties in solid state materials. Here, we propose a new kind of interaction induced non-reciprocal operation, based on the conventional stimulated-Raman-adiabatic-passage(STIRAP) setup, which removes the experimental difficulty of requiring cyclical interaction, and thus it is directly implementable in various quantum systems. Furthermore, we also illustrate our proposal on a chain of three coupled superconducting transmons, which can lead to a non-reciprocal circulator with high fidelity without a ring coupling configuration as in the previous schemes or implementations. Therefore, our protocol provides a promising way to explore fundamental non-reciprocal quantum physics as well as realize non-reciprocal quantum device.  相似文献   
4.
A reliable and sensitive strategy which can assess nucleic acid levels in living cells would be essential for fundamental research of biomedical applications. Some nanomaterial-based fluorescence biosensors recently developed for detecting nucleic acids, however, are often with expensive, complicated and timeconsuming preparation process. Here, by using a facile bottom-up synthesis method, a two-dimensional(2 D) coordination polymer(CP) nanosheet, [Cu(tz)](Htz = 1,2,4-triazole), was successfully...  相似文献   
5.
《中国化学快报》2022,33(11):4882-4885
We construct MUC1 vaccines using β-cyclodextrin grafted chitosan (CS-g-CD) as carrier via host-guest interaction. These vaccines based on non-covalent assembling can provoke robust immune responses, including high level of specific antibodies and cytokines. The induced antibodies can specifically recognize tumor cells and mediate cytotoxicity against tumor cells. These results indicate that CS-g-CD with strong immunostimulatory activities can be a straightforward platform for peptide-based vaccine construction.  相似文献   
6.
7.
将TiNi基记忆合金薄膜与光纤相结合可制成智能化、集成化且成本经济的微机电系统和微传感器件.本文采用磁控溅射法在二氧化硅光纤基底上制备TiNi记忆合金薄膜,系统讨论了溅射工艺参数以及后续退火处理对薄膜质量的影响.采用自研制光纤镀膜掩膜装置在直径为125μm的光纤圆周表面上形成均匀薄膜.实验表明:在靶基距、背底真空度、Ar气流量和溅射时间一定的条件下,溅射功率存在最佳值;溅射压强较大时,薄膜沉积速率较低,但薄膜表面粗糙度较小.进行退火处理后,薄膜形成较良好的晶体结构,Ti49.09Ni50.91薄膜中马氏体B19′相和奥氏体B2相共存,但以B19′为主.根据本文研究结果,在玻璃光纤基底上制备高质量的TiNi基记忆合金薄膜是可实现的,本工作为下一步研制微机电系统和微型传感器做了基础准备.  相似文献   
8.
Acta Mathematicae Applicatae Sinica, English Series - This paper proposes a method for modelling volatilities (conditional covariance matrices) of high dimensional dynamic data. We combine the...  相似文献   
9.
Teng  Shuai  Chen  Gongfa  Gong  Panpan  Liu  Gen  Cui  Fangsen 《Meccanica》2020,55(4):945-959
Meccanica - Based on the classification ability of a convolutional neural network (CNN), this paper proposes a structural damage detection method in which a CNN is used to classify the location and...  相似文献   
10.
Chen  Jianrong  Zhang  Yunong 《Numerical Algorithms》2020,83(2):529-547
Numerical Algorithms - In this paper, the future unknown-transpose matrix inequality (FUTMI) as well as scalar inequality is formulated and investigated for the first time. This particular class of...  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