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   131篇
  免费   0篇
化学   39篇
晶体学   2篇
力学   27篇
数学   11篇
物理学   52篇
  2022年   3篇
  2021年   5篇
  2019年   3篇
  2018年   3篇
  2016年   2篇
  2015年   1篇
  2014年   1篇
  2013年   4篇
  2012年   2篇
  2011年   4篇
  2010年   6篇
  2009年   6篇
  2008年   5篇
  2007年   4篇
  2006年   4篇
  2005年   6篇
  2004年   2篇
  2003年   7篇
  2002年   1篇
  2001年   2篇
  2000年   2篇
  1999年   1篇
  1998年   1篇
  1997年   2篇
  1995年   2篇
  1994年   2篇
  1993年   5篇
  1992年   2篇
  1991年   3篇
  1990年   2篇
  1989年   2篇
  1988年   4篇
  1987年   1篇
  1986年   3篇
  1985年   2篇
  1984年   1篇
  1983年   1篇
  1982年   2篇
  1981年   1篇
  1980年   1篇
  1979年   1篇
  1978年   1篇
  1977年   4篇
  1976年   5篇
  1975年   2篇
  1974年   2篇
  1973年   1篇
  1971年   1篇
  1969年   1篇
  1966年   1篇
排序方式: 共有131条查询结果,搜索用时 31 毫秒
91.
The structure and electrochemical properties of polyethylene terephthalate track membranes modified in acetylene plasma are studied. It is found that polymer deposition on the track membrane surface using acetylene polymerization in plasma results in the case of formation of a semipermeable layer covering pores in formation of a composite nanomembrane featuring asymmetry of conductivity in solutions of electrolytes: a rectifying effect similar to that of a p-n junction in semiconductors. It is shown that the observed effect of conductivity asymmetry is caused by a significant decrease in the diameter of pores in the plasma-deposited polymer layer and a change in the pore geometry, same as existence of an interface between the initial membrane and polymer layer that have a different concentration of carboxyl groups in the surface layer. The impedance spectroscopy method allowed obtaining information on ion transfer in the studied membranes.  相似文献   
92.
93.
94.
The application of the FRONT package for calculation of supported thin-walled structures is considered. The main focus is on the specific features of the package which permit using the finiteelement method to analyze large problems for complex structures. Issues of automatic computation are considered. The high computational efficiency of the package is illustrated by some examples.Translated from Vychislitel'naya i Prikladnaya Matematika, No. 60, pp. 44–47, 1986.  相似文献   
95.
The equivalence of the solvability of a stochastic differential inclusion and an ordinary differential equation is established and the connection between the solutions is clarified.Translated from Teoriya Sluchainykh Protsessov, No. 16, pp. 48–55, 1988.  相似文献   
96.
97.
The results of experimental investigations of the aerodynamic coefficients and the pressure on the windward face of delta-wings with a conical break are given. A comparison between the magnitudes of the aerodynamic quality of delta-wings with a conical break and models of a wing-cone with a -shaped symmetrically grouped scheme is carried out at a Mach number of 5.96.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 6, pp. 100–104, November–December, 1976.  相似文献   
98.
The structure of lanthanum quenched from a liquid state at cooling rates of 2.5 × 105–107 K/s is investigated. It is shown that a mixture of the face-centered cubic β-La phase stable above 583 K and the metastable lanthanum modification with a seven-layer hexagonal lattice consisting of alternating atomic layers ABCABAC… is formed in rapidly cooled foils. A mechanism is proposed for the formation of the metastable polytype, according to which the polytype is formed as a result of saturation of the main β-phase with well-ordered stacking faults.  相似文献   
99.
The paper reports on a study of light reflection and of the magnetorefractive effect in CoFe-Al2O3 multilayer and granular films in the IR region at λ = 2.5–25 μm. These films exhibit a noticeable tunneling magnetoresistance of 5–8%. It has been found that the spectra of the magnetorefractive effect have features at λ ≈ 6.7 and ≈8.1 μm originating from phonon mode excitation in the dielectric matrix. It has been established that the magnitude of the magnetorefractive effect exceeds 2.5% for multilayer films, a value substantially larger than that for granular ones. Magnetoreflection has been analyzed for two film systems with roughly equal tunneling magnetoresistance. It has been shown that magnetoreflection for granular films can be described in a first approximation by the modified Hagen-Rubens relation, while the enhanced effect exhibited by multilayer films requires inclusion of interference of the magnetooptical response.  相似文献   
100.
A comparative investigation has been made of the action of 14 steroid glycosides of the spirostan and furostan series on highly purified Na,K-ATPase from the medullary layer of porcine kidneys (90% purity in terms of protein). It has been shown that alliospirosides A, B, and D, isolated from the collective fruit ofAllium sepa L., are capable of inhibiting the activity of the Na,K-ATPase The inhibition of the activity of the transport enzyme by alliospirosides A and B is of the uncompetitive type and by alliospiroside D of the competitive type. It is desirable to test alliospirosides on the intact organism.Institute of Physiology, Academy of Sciences of the Republic of Uzbekistan. Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 558–566, July–August, 1993.  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