全文获取类型
收费全文 | 4272篇 |
免费 | 5篇 |
国内免费 | 27篇 |
专业分类
电工技术 | 34篇 |
综合类 | 2篇 |
化学工业 | 670篇 |
金属工艺 | 271篇 |
机械仪表 | 179篇 |
建筑科学 | 58篇 |
矿业工程 | 69篇 |
能源动力 | 97篇 |
轻工业 | 122篇 |
水利工程 | 125篇 |
石油天然气 | 616篇 |
无线电 | 242篇 |
一般工业技术 | 1036篇 |
冶金工业 | 397篇 |
原子能技术 | 265篇 |
自动化技术 | 121篇 |
出版年
2021年 | 57篇 |
2019年 | 48篇 |
2018年 | 119篇 |
2017年 | 108篇 |
2016年 | 120篇 |
2015年 | 48篇 |
2014年 | 93篇 |
2013年 | 119篇 |
2012年 | 111篇 |
2011年 | 142篇 |
2010年 | 138篇 |
2009年 | 127篇 |
2008年 | 117篇 |
2007年 | 106篇 |
2006年 | 90篇 |
2005年 | 72篇 |
2004年 | 60篇 |
2003年 | 73篇 |
2002年 | 71篇 |
2001年 | 78篇 |
2000年 | 70篇 |
1998年 | 57篇 |
1997年 | 46篇 |
1995年 | 48篇 |
1993年 | 42篇 |
1992年 | 60篇 |
1991年 | 71篇 |
1990年 | 49篇 |
1989年 | 74篇 |
1988年 | 93篇 |
1987年 | 79篇 |
1986年 | 67篇 |
1985年 | 65篇 |
1984年 | 64篇 |
1983年 | 62篇 |
1982年 | 64篇 |
1981年 | 67篇 |
1980年 | 68篇 |
1979年 | 87篇 |
1978年 | 91篇 |
1977年 | 54篇 |
1976年 | 71篇 |
1975年 | 77篇 |
1974年 | 92篇 |
1973年 | 85篇 |
1972年 | 91篇 |
1971年 | 59篇 |
1970年 | 73篇 |
1969年 | 55篇 |
1968年 | 45篇 |
排序方式: 共有4304条查询结果,搜索用时 31 毫秒
1.
Zagidullin S. Kh. Dolganov V. L. Lozhkin I. G. 《Chemical and Petroleum Engineering》2022,57(9-10):765-769
Chemical and Petroleum Engineering - The hydrodynamics of oxidation towers used for bitumen production were studied using a model tower having transparent walls. Experiments were carried out in two... 相似文献
2.
D. M. Mukhammadiev F. Kh. Ibragimov T. D. Mukhammadiev 《Journal of Machinery Manufacture and Reliability》2020,49(3):256-262
The dynamic characteristics of a saw gin as a subsystem with lumped and distributed parameters are considered in the paper. On the basis of investigation of the machine assembly, graphs are drawn that allow establishing the maximum values of the angle of relative rotation and the angle of rotation of the saw cylinder shaft under torsion. 相似文献
3.
4.
5.
6.
The characteristics of pulsation processes in dc plasmatrons with the cathode located in the channel center and the anode in the form of a cylindrical or a conical channel wall are investigated in plasmas of argon and nitrogen at atmospheric pressure. The fast Fourier transform of signals and their subsequent computer processing are used to obtain the dependences of the frequency of fluctuations of the arcing voltage on the working parameters of the plasmatron, namely, the electric arc current, the flow rate of plasma-forming gas, and the channel diameter. For plasmatrons with the self-adjusting length of the electric arc, analysis is performed of the mechanism of reclosing of the anode region of the arc, i.e., of the electric arc shunting associated with the stretching of the current filament by a flow of gas and with the electrodynamic interaction of different filament regions. A formula is derived which defines the dependence of the characteristic frequency of fluctuations of the arcing voltage on the external parameters of the problem, namely, the arc current, the flow rate of the working gas, and the characteristic channel diameter. It is demonstrated that the pattern of the dependence of the frequency of voltage fluctuations on the gas flow rate may vary with the values of the parameter of magnetohydrodynamic interaction. The formula generalizes the experimental results of numerous researchers obtained in a wide range of variation of the external parameters. 相似文献
7.
8.
The paper considers local-area computer networks with a protocol that supports carrier-sense multiple access with instantaneous conflict detection and is a generalization of slotted ALOHA. An approach based on recurrent processes is applied to analyze the asymptotic behavior of the number of waiting calls under conditions of low retrial rate.Translated from Kibernetika i Sistemnyi Analiz, No. 4, pp. 54–61, July–August, 1991. 相似文献
9.
G. A. Zeinalova A. E. Mushailov A. Kh. Mamedova É. A. Nagieva 《Chemistry and Technology of Fuels and Oils》1989,25(2):78-80
Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 2, pp. 14–15, February, 1989. 相似文献
10.