全文获取类型
收费全文 | 2157篇 |
免费 | 13篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 30篇 |
综合类 | 1篇 |
化学工业 | 289篇 |
金属工艺 | 104篇 |
机械仪表 | 112篇 |
建筑科学 | 6篇 |
矿业工程 | 59篇 |
能源动力 | 22篇 |
轻工业 | 26篇 |
水利工程 | 49篇 |
石油天然气 | 148篇 |
无线电 | 170篇 |
一般工业技术 | 636篇 |
冶金工业 | 246篇 |
原子能技术 | 186篇 |
自动化技术 | 87篇 |
出版年
2022年 | 24篇 |
2021年 | 29篇 |
2019年 | 27篇 |
2018年 | 58篇 |
2017年 | 58篇 |
2016年 | 63篇 |
2015年 | 28篇 |
2014年 | 50篇 |
2013年 | 77篇 |
2012年 | 66篇 |
2011年 | 57篇 |
2010年 | 60篇 |
2009年 | 55篇 |
2008年 | 67篇 |
2007年 | 73篇 |
2006年 | 58篇 |
2005年 | 51篇 |
2004年 | 76篇 |
2003年 | 39篇 |
2002年 | 36篇 |
2001年 | 45篇 |
2000年 | 44篇 |
1999年 | 30篇 |
1998年 | 45篇 |
1997年 | 37篇 |
1996年 | 38篇 |
1995年 | 32篇 |
1994年 | 27篇 |
1993年 | 39篇 |
1992年 | 29篇 |
1991年 | 27篇 |
1989年 | 31篇 |
1988年 | 23篇 |
1987年 | 22篇 |
1986年 | 23篇 |
1985年 | 23篇 |
1984年 | 23篇 |
1983年 | 26篇 |
1982年 | 22篇 |
1981年 | 23篇 |
1980年 | 25篇 |
1979年 | 29篇 |
1978年 | 25篇 |
1977年 | 40篇 |
1976年 | 45篇 |
1975年 | 34篇 |
1974年 | 35篇 |
1973年 | 30篇 |
1972年 | 25篇 |
1969年 | 25篇 |
排序方式: 共有2171条查询结果,搜索用时 31 毫秒
81.
A. P. Mikhailov A. P. Petrov O. G. Proncheva N. A. Marevtseva 《Mathematical Models and Computer Simulations》2017,9(5):580-586
A model of information warfare in a society when one of the parties periodically destabilizes the system by a short-term jump-wise increase in the intensity of the propaganda in the media is analyzed. The model has the form of two nonlinear ordinary differential equations with a periodic discontinuous right-hand side. The asymptotical solution to the periodic solutions are constructed for the case of low-intensity dissemination of information through interpersonal communication. The transient regime is investigated numerically. 相似文献
82.
Double‐layered hydrogels of super‐macroporous poly(2‐hydroxyethyl methacrylate) (PHEMA) cryogel core and poly(ethylene oxide) (PEO) hydrogel outer layer for encapsulation of the enzyme urease were constructed. The enzyme was entrapped into the pores of PHEMA cryogel by soaking and then the core was covered with a PEO layer. The leaking of urease from the core was prevented when the density of the PEO network was increased by incorporation of the crosslinking agent, poly(ethylene glycol) diacrylate. The hybrid system exhibited a nearly constant enzyme activity with time and maintained its structural integrity after several reactions of hydrolysis of urea. The potential of double‐layered hydrogels containing urease for establishment of water pollution with copper was investigated as well. Copyright © 2011 Society of Chemical Industry 相似文献
83.
We consider several programs used to tune PI/PID controllers based on transient characteristics of control systems; the tuning procedure does not require approximation by the corresponding analytical solution. We demonstrate that such programs can be downloaded from Internet. 相似文献
84.
85.
I. B. Petrov A. V. Favorskaya A. V. Sannikov I. E. Kvasov 《Mathematical Models and Computer Simulations》2013,5(5):409-415
The purpose of the present paper is to develop a grid-characteristic method for high-performance computer systems using unstructured tetrahedral hierarchical meshes, a multiple time step and the high-order interpolation for simulating complex spatial dynamic processes in heterogeneous environments. This method has the precise formulation of contact conditions and is suitable for the physically correct solution of seismology and seismic prospecting problems in complex heterogeneous environments. The use of the hierarchical meshes allows us to take into account a large number of nonhomogeneous inclusions (cracks, cavities, etc.). The use of this grid-characteristic method makes it possible to use a multiple time step and thereby increase productivity and significantly reduce the computation time. The methods developed for high-order interpolation on unstructured tetrahedral meshes can solve the problems of seismology and seismic prospecting with approximation in space of up to the fifth degree (inclusive). 相似文献
86.
87.
The influence of the thickness of the silicon film and hole concentration in the p-channel nanodimensional MOS transistor based on the SOI structure is considered. The formulas for the computation of these dependences are derived and graphic dependences are presented. 相似文献
88.
89.
N. N. Petrov T. V. Koval’ N. V. Shel’deshov N. N. Bukov 《Protection of Metals and Physical Chemistry of Surfaces》2017,53(1):133-138
In this work, the effect of the ionic form of a KU 2-8 synthetic cation-exchange polyelectrolyte, which was used as a filler in the moisture-sensitive layer, on the behavior of two-layer anticorrosion systems with a low-resistivity damp-proof layer has been studied. The behavior of matrices with sodium (KU 2-8-Na+), magnesium (KU 2-8-Mg2+), nickel (KU 2-8-Ni2+), and zinc ions (KU 2-8-Zn2+) has been investigated. The remarkable effect of the nature of studied counterions on moisture-sensitive, protective properties, and behavior of coatings upon cathode polarization of surface has been demonstrated. 相似文献
90.
M. V. Vartanov M. V. Arkhipov V. K. Petrov R. S. Mishchenko 《Russian Engineering Research》2017,37(9):814-816
A two-point contact model in robotic assembly is considered, in a quasi-static formulation. In the experiments, a robot equipped with a force and torque sensor is employed. The consistency of theoretical analysis with physical experiments is discussed. 相似文献