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   531745篇
  免费   6106篇
  国内免费   1920篇
化学   281943篇
晶体学   6506篇
力学   24930篇
综合类   22篇
数学   62481篇
物理学   163889篇
  2020年   4426篇
  2019年   5221篇
  2018年   6541篇
  2017年   6492篇
  2016年   9770篇
  2015年   6160篇
  2014年   9569篇
  2013年   24498篇
  2012年   18607篇
  2011年   22764篇
  2010年   15828篇
  2009年   16040篇
  2008年   20832篇
  2007年   20803篇
  2006年   19180篇
  2005年   17497篇
  2004年   15955篇
  2003年   14024篇
  2002年   12929篇
  2001年   15220篇
  2000年   11319篇
  1999年   8545篇
  1998年   7012篇
  1997年   7169篇
  1996年   6733篇
  1995年   6507篇
  1994年   6343篇
  1993年   6260篇
  1992年   6912篇
  1991年   7061篇
  1990年   6620篇
  1989年   6632篇
  1988年   6616篇
  1987年   6483篇
  1986年   6149篇
  1985年   8564篇
  1984年   8706篇
  1983年   7169篇
  1982年   7543篇
  1981年   7338篇
  1980年   7009篇
  1979年   7386篇
  1978年   7575篇
  1977年   7610篇
  1976年   7778篇
  1975年   7187篇
  1974年   7206篇
  1973年   7533篇
  1972年   5034篇
  1971年   4104篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
11.
Physics of Atomic Nuclei - In the FRAGM experiment at the heavy-ion accelerator $$-$$ accumulator complex ITEP $$-$$ TWA, yields of cumulative charged $$\pi$$ mesons have been measured in a...  相似文献   
12.
Crystallography Reports - Exposure to environmental arsenic is associated with serious of health issues such as cancer, diabetes and developmental delays in infants and children. In human liver,...  相似文献   
13.
Technical Physics - The heat transfer in a contact–film–substrate system was analyzed under conditions in which the heat removal from a sample to the substrate is insufficient to avoid...  相似文献   
14.
Russian Physics Journal - The paper presents mathematical simulation of localized plastic deformation of metal-intermetallic laminated composites after equal channel angular pressing. Deformation...  相似文献   
15.
JETP Letters - Photonically controlled metastructures containing resonant conducting dipole and chiral elements with CdS and CdSe in gaps have been proposed, implemented, and studied in a waveguide...  相似文献   
16.
We give a characterization of the cyclic subgroup separability and weak potency of the fundamental group of a graph of polycyclic-by-finite groups and free-by-finite groups amalgamating edge subgroups of the form × D,where h has infinite order and D is finite.  相似文献   
17.
Crystallography Reports - Reactions of nitrilotriacetic acid with 2-aminoethanol, 2-amino-2-(hydroxymethyl)propane-1,3-diol, and 2,2'-(ethylenedioxy)bis(ethylamine) afford the following salts...  相似文献   
18.
Crystallography Reports - The first representative of the eudialyte group with a primitive unit cell has been investigated by X-ray diffraction analysis, electron probe microanalysis, and IR...  相似文献   
19.
Gohl  J. A.  Thiele-Sardina  T. C.  Rencheck  M. L.  Erk  K. A.  Davis  C. S. 《Experimental Mechanics》2021,61(7):1209-1213
Background

Peel tests are frequently used to perform measurements of adhesive strength for pressure sensitive adhesive (PSA) tapes. Current lab methodologies for 90° peel tests translate the model substrate orthogonally to the peel direction in order to maintain the peel angle, precluding testing from immovable substrates.

Objective

It was our objective to develop a peel fixture capable of testing temporary pavement marking (TPM) tapes and other PSA tapes from immovable substrates such as roadways surfaces.

Methods

We present a modular peel fixture for conducting peel experiments directly on immovable substrates. The fixture was validated through a series of peel tests on consumer tapes to reproduce the linear width dependence and viscoelastic rate dependence found in traditional peeling setups. To test the capabilities of the fixture, a series of peel tests were conducted with various tapes on controlled surfaces, and a commercial tape on various immovable substrates.

Results

We demonstrate the ability of our fixture to reproduce results reported for traditional peel tests from literature. In addition, we were able to conduct peel tests directly on immovable substrates such as the benchtop.

Conclusions

This fixture shows potential for both traditional peeling tests, and for use in in-situ peel experiments from substrates relevant to the end application of the PSA tape.

  相似文献   
20.
Nonlinear Dynamics - In this paper, we analyze the effect which the choice of a friction model has on tippe top inversion in the case where the resulting action of all dissipative forces is...  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