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   50篇
  免费   0篇
  国内免费   1篇
化学   6篇
力学   1篇
数学   39篇
物理学   5篇
  2021年   1篇
  2016年   2篇
  2015年   1篇
  2009年   2篇
  2007年   1篇
  2006年   3篇
  2005年   1篇
  2003年   1篇
  2001年   1篇
  1999年   2篇
  1997年   2篇
  1996年   3篇
  1995年   2篇
  1993年   2篇
  1991年   1篇
  1990年   1篇
  1989年   1篇
  1983年   1篇
  1979年   1篇
  1975年   1篇
  1974年   1篇
  1973年   4篇
  1972年   4篇
  1971年   1篇
  1970年   1篇
  1969年   3篇
  1968年   1篇
  1967年   1篇
  1966年   3篇
  1965年   2篇
排序方式: 共有51条查询结果,搜索用时 187 毫秒
1.
2.
Conclusion The proposed analytical method makes it possible to predict the strength distribution of an LRP of the type [0/±]s from its structure (the geometry of the packet, the number of layers, and the strength properties of the layers) in a plane stress state. Allowance is made for the random character of the strength properties of the layers, which makes it possible to evaluate the reliability of the LRP for both determinate and random loading. A criterion was formulated for the optimum design of the structure of an LRP with respect to ensuring maximum reliability for specific loading conditions. We also evaluated the effect of the parameters of the structure and the characteristics of the plane stress state on reliability. According to the results of a numerical analysis performed with the above-developed structural model of the failure of an LRP — with allowance for the random character of the strength properties of the layers — the imbalance of the laminated packet which occurs during failure can be ignored. The method used to predict the strength distribution of the LRP, involving determination of the strength distribution law of an RSE and subsequent examination of the loading of parallel-connected RSEs, is promising for other reinforcement schemes as well.Translated from Mekhanika Kompozitnykh Materialov, No. 5, pp. 805–812, September–October, 1988.  相似文献   
3.
A method is proposed for calculating statically determinate beams made of reinforced plastics with allowance for the reinforcement ratio, the rheological properties of the resin and the reinforcement, the effect of shears, the type of reinforcement distribution, and the time factor. In constructing the corresponding laws of deformation it is assumed that both components obey the "standard solid" law.Mekhanika Polimerov, Vol. 2, No. 1, pp. 100–107, 1966  相似文献   
4.
Energetic and structural stability of Al2B2H2n (n = 0—6) clusters is investigated by DFT calculations and a stochastic search algorithm.  相似文献   
5.
Applying structural mechanics methods for composite materials, we have worked out a procedure for predicting the elasticity modulus, the shear modulus, and Poisson's ratio for ferrocement taking into account the elastic properties of the components, the wire diameter, the mesh size, and the distance between the meshes. The results make it possible to exploit the potential of such reinforcement to the fullest.Translated from Mekhanika Kompozitnykh Materialov, Vol. 30, No. 4, pp. 526–530, July–August, 1994.  相似文献   
6.
The strength conditions of unidirectionally and orthogonally reinforced plastics subjected to uniaxial tension and compression in the direction of, and at an angle to, the reinforcement are developed, with consideration given to possible failure of the fibers, binder, or the bond between the fibers and binder. Proposed strength conditions take into account the structure of the material, the properties of its components, and stress concentration.Institute of Polymer Mechanics, Academy of Sciences of the Latvian SSR, Riga. Translated from Mekhanika Polimerov, No. 6, pp. 988–995, November–December, 1975.  相似文献   
7.
The question of the stress distribution in plastics reinforced with anisotropic fibers and subjected to transverse normal loading is considered. The stresses in the components are determined by the methods of the theory of elasticity using stress functions. The theoretical relations obtained are used to construct diagrams showing the distribution of the tangential, radial, and shear stresses in the composite and the isoclines of the concentration coefficient for a carbon-reinforced plastic. The results obtained for the carbon-reinforced plastic are compared with the analogous results for a glass-reinforced plastic.Institute of Polymer Mechanics, Academy of Sciences of the Latvian SSR, Riga. Translated from Mekhanika Polimerov, No. 2, pp. 244–252, March–April, 1973.  相似文献   
8.
Techniques that allow the elements present in the air to be determined in a simple and rapid manner are very attractive. Direct aerosol sampling techniques avoid the need to pretreat the filter via wet digestion in order to remove any sources of contamination, and they decrease the precipitation time significantly. Analyzers based on this technique can also determine the concentrations of elements in the air automatically in situ. This paper is concerned with the development of a novel analytical system that is based on electrostatically precipitating aerosols from the air into a graphite furnace. The equipment includes a Zeeman spectrometer with high frequency modulation polarization (MGA-915), and an electrostatic precipitation system incorporated into the analyzer. The high sensitivity of the system developed here means that it can be used to determine element concentrations in the air exhaled by humans, as well as those in ambient air.  相似文献   
9.
Two algorithms for establishing a connection between correlations before and after ordinalization under a wide spectrum of nonnormal underlying bivariate distributions are developed by extending the iteratively found normal-based results via the power polynomials. These algorithms are designed to compute the polychoric correlation when the ordinal correlation is specified, and vice versa, along with the distributional properties of latent, continuous variables that are subsequently ordinalized through thresholds dictated by the marginal proportions. The method has broad applicability in the simulation and random number generation world where modeling the relationships between these correlation types is of interest.  相似文献   
10.
Based on the system of equations describing the populations of highly excited helium atomic levels and the electron density and energy balance and on the Maxwell equations, we develop a model for an electrodeless high-frequency discharge in helium. We suggest a method of self-consistent calculation in a plasma-field system. The model developed is used to calculate the radiative characteristics of high-frequency electrodeless lamps. The derived dependences of line intensities on gas pressure, lamp radius, and discharge power are in good agreement with the experimental data.  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