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   111篇
  免费   19篇
  国内免费   27篇
化学   51篇
晶体学   1篇
力学   6篇
综合类   4篇
数学   25篇
物理学   70篇
  2022年   2篇
  2021年   4篇
  2018年   1篇
  2017年   2篇
  2016年   1篇
  2015年   1篇
  2014年   4篇
  2013年   19篇
  2012年   8篇
  2011年   7篇
  2010年   7篇
  2009年   5篇
  2008年   11篇
  2007年   3篇
  2006年   8篇
  2005年   5篇
  2004年   5篇
  2003年   8篇
  2002年   24篇
  2001年   5篇
  2000年   7篇
  1999年   2篇
  1998年   3篇
  1997年   5篇
  1996年   1篇
  1995年   3篇
  1991年   1篇
  1989年   1篇
  1988年   1篇
  1987年   1篇
  1983年   1篇
  1971年   1篇
排序方式: 共有157条查询结果,搜索用时 15 毫秒
151.
We investigate the local existence of smooth solutions of a 3D ideal magnetohydrodynamics (MHD) equations in a bounded domain and give a blow-up criteria to this equations with respect to vorticists.  相似文献   
152.
针对微型计算机接口课程的网络虚拟实验提出了基于组件的3D网络虚拟实验实现方法.利用3DMAX的坐标轴变换技术与材质技术实现了组件局部坐标系的调整与模型的材质;利用Java3D的模型导入技术与交互式编程技术解决了导入实验板模型时丢失材质、模型的重装、虚拟场景与实验板的操作等问题.以微型计算机接口课程教学实验中基础的8255并行接口实验作为实例设计了一个虚拟实验,为虚拟实验室的开发与应用提供了实用的案例.  相似文献   
153.
It has been realized that resonance frequencies of imperfect the transformation acoustics in R^2 are located near Dirichlet acoustic cloaking based on a small perturbation of eigenvalues of the cloaked region [Chin. Phys. Lett. 26 (2009) 014301; 29 (2012) 124301]. In this work, we study the performance of the three-dimensional approximate cloaking system based on the transformation acoustics and show that the cloaking effect may be deteriorated at zeroth order Neumann eigenvalues of the concealed region. In particular, transmitted fields into the concealed region can be extremely resonated at frequencies corresponding to the zeroth-order Neumann eigenvalues while scattered fields are suppressed well for any frequency. To enhance the cloaking effect at resonance frequencies, we introduce a lossy medium inside the cloaked region and show that the new proposal can reduce the intensity of transmitted fields significantly due to the lossy medium.  相似文献   
154.
This study focused on the influences of a variety of reaction parameters and guest molecules such as H2O and C3H8 on the deactivation of supported Co3O4 catalysts for CO oxidation.Additionally,the physical features of and carbon deposition on some samples after the reaction under the chosen conditions were determined by BET and X-ray diffraction as well as by carbon analyses to deduce the precursors associated with catalyst deactivation.Activity maintenance profiles of the catalysts for CO oxidation at 100°...  相似文献   
155.
A novel technique to determine the position of spacecraft orbits is proposed. The technique is based on the cross-correlation function of HF SAR images and is able to determine the relative position of orbits with an accuracy of ~ /4 or better, where is the wavelength of the HF radar pulse at its center frequency. The performance of the proposed technique was confirmed by simulation which was carried out under the condition of design facts of the SELENE LRS mission. The highly accurate orbit positioning ena...  相似文献   
156.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.  相似文献   
157.
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