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   214篇
  免费   2篇
化学   132篇
晶体学   3篇
力学   2篇
数学   3篇
物理学   76篇
  2019年   2篇
  2018年   3篇
  2017年   3篇
  2016年   7篇
  2013年   5篇
  2012年   4篇
  2011年   4篇
  2010年   5篇
  2009年   9篇
  2008年   6篇
  2007年   7篇
  2006年   3篇
  2005年   2篇
  2004年   2篇
  2003年   2篇
  2002年   5篇
  2001年   4篇
  2000年   2篇
  1999年   1篇
  1998年   1篇
  1997年   2篇
  1996年   3篇
  1995年   2篇
  1993年   4篇
  1992年   5篇
  1991年   7篇
  1990年   8篇
  1989年   10篇
  1988年   1篇
  1987年   2篇
  1986年   6篇
  1985年   9篇
  1984年   2篇
  1983年   1篇
  1982年   5篇
  1981年   3篇
  1980年   2篇
  1979年   3篇
  1978年   2篇
  1977年   6篇
  1976年   9篇
  1975年   7篇
  1974年   7篇
  1973年   9篇
  1972年   3篇
  1971年   2篇
  1970年   5篇
  1969年   5篇
  1968年   6篇
  1967年   1篇
排序方式: 共有216条查询结果,搜索用时 15 毫秒
61.
62.
63.
64.
65.
Ion-selective electrodes (ISEs) with membranes based on ion exchangers plasticized with o-nitrophenyl octyl ether (NPOE), diethyl sebacate (DES), or dibutyl phthalate (DBP) are used for the determination of ionic liquids (ILs) in water. The membrane composition is optimized with respect to the ion-exchanger concentration and the plasticizer.  相似文献   
66.
The motion of a heavy Brownian particle in a low-dimensional bounded solid structure under the effect of a phonon’s excitation fluctuations is considered. Because of the finiteness of the system, the fluctuation spectrum has zero spectral density at zero frequency. The effect of this kind of noise, which is conditionally called “green” noise, is studied both analytically by using the averaging method and numerically on the basis of predictor-corrector algorithms. The effective potential is introduced, and its form is shown to govern the particle dynamics. Considering a Gaussian potential well (a trap) as an example, it is demonstrated that green noise leads to abrupt phase transitions in the system as a result of very small parameter variations (a catastrophe-type effect). The results are compared with the case of white noise in an unbounded structure. From numerical calculations, it follows that the boundedness of the structure, which changes the noise spectrum, favors a considerable increase in the lifetime of the particle in the trap.  相似文献   
67.
We report on double-differential inclusive cross-sections of the production of secondary protons, charged pions, and deuterons, in the interactions with a 5% λ int thick stationary lead target, of proton and pion beams with momentum from ±3 GeV/c to ±15 GeV/c. Results are given for secondary particles with production angles 20°<θ<125°. Cross-sections on lead nuclei are compared with cross-sections on beryllium, copper, and tantalum nuclei.  相似文献   
68.
The paper deals with the problem of constructing systems with discontinuous quasizero reconstructing force on the basis of structures where an elastic element moves between two directrices of prescribed design shape perpendicularly to their axis of symmetry. A spring is considered as an elastic element. The cases where the elastic element works only in compression or only in tension are considered.  相似文献   
69.
Hadron generation in the Geant4 simulation tool kit is compared with inclusive spectra of secondary protons and pions from the interactions with beryllium nuclei of +8.9 GeV/c protons and pions, and of −8.0 GeV/c pions. The data were taken in 2002 at the CERN Proton Synchrotron with the HARP spectrometer. We report on significant disagreements between data and Monte Carlo simulation especially in the polar-angle distributions of secondary protons and pions. On leave of absence at Ecole Polytechnique Fédérale, Lausanne, Switzerland.  相似文献   
70.
The structural relaxation of a bulk Pd40Cu30Ni10P20 metallic glass is studied by measuring the electrical resistivity and infralow-frequency (0.05 Hz) internal friction. It is demonstrated that the structural relaxation in thermally aged samples can be restored by quenching them from a supercooled liquid state. It is found that the degree of relaxation after quenching can exceed the initial one by several times.  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