全文获取类型
收费全文 | 471809篇 |
免费 | 4611篇 |
国内免费 | 1187篇 |
专业分类
电工技术 | 7339篇 |
综合类 | 2530篇 |
化学工业 | 71824篇 |
金属工艺 | 25647篇 |
机械仪表 | 17161篇 |
建筑科学 | 9457篇 |
矿业工程 | 5311篇 |
能源动力 | 8952篇 |
轻工业 | 24388篇 |
水利工程 | 7115篇 |
石油天然气 | 16451篇 |
武器工业 | 41篇 |
无线电 | 45732篇 |
一般工业技术 | 107043篇 |
冶金工业 | 61536篇 |
原子能技术 | 14213篇 |
自动化技术 | 52867篇 |
出版年
2021年 | 4045篇 |
2019年 | 3940篇 |
2018年 | 21359篇 |
2017年 | 20519篇 |
2016年 | 17782篇 |
2015年 | 5070篇 |
2014年 | 7850篇 |
2013年 | 16656篇 |
2012年 | 14023篇 |
2011年 | 22964篇 |
2010年 | 19259篇 |
2009年 | 17938篇 |
2008年 | 19344篇 |
2007年 | 19852篇 |
2006年 | 10455篇 |
2005年 | 10457篇 |
2004年 | 9911篇 |
2003年 | 9712篇 |
2002年 | 8855篇 |
2001年 | 8338篇 |
2000年 | 8175篇 |
1999年 | 7575篇 |
1998年 | 16343篇 |
1997年 | 12050篇 |
1996年 | 9172篇 |
1995年 | 7086篇 |
1994年 | 6404篇 |
1993年 | 6697篇 |
1992年 | 5390篇 |
1991年 | 5475篇 |
1990年 | 5384篇 |
1989年 | 5202篇 |
1988年 | 5119篇 |
1987年 | 4798篇 |
1986年 | 4758篇 |
1985年 | 5192篇 |
1984年 | 4966篇 |
1983年 | 4762篇 |
1982年 | 4430篇 |
1981年 | 4461篇 |
1980年 | 4518篇 |
1979年 | 4710篇 |
1978年 | 4827篇 |
1977年 | 5035篇 |
1976年 | 5774篇 |
1975年 | 4447篇 |
1974年 | 4461篇 |
1973年 | 4555篇 |
1972年 | 4053篇 |
1971年 | 3705篇 |
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
891.
V. A. Matochkin 《Steel in Translation》2007,37(5):445-447
892.
V. A. Kudrin 《Metallurgist》2007,51(11-12):649-651
The most important element of manufacturing processes that employ new metallurgical technologies is improving the quality of the scrap metal used in the given process. Introducing modern scrap-processing equipment is especially important in this regard. At the same time, it is also necessary to use the latest technological advances in order to reduce the oxidation loss of iron during refining in arc steelmaking furnaces. 相似文献
893.
I. F. Kurunov V. N. Loginov S. S. Lyapin N. S. Polyakov V. N. Titov 《Metallurgist》2007,51(7-8):425-433
The use of schungite as a partial replacement for coke is practiced in Russia at a number of metallurgical plants, both in
the production of foundry iron (its primary use) and in making conversion pig iron. The largest amount of coke is replaced
when foundry iron is being made, the replacement coefficient in this case having a value within the range 0.8–1.3. Studies
that included continuous monitoring of the temperature of the carbon blocks in blast furnaces with volumes of 1719, 3200,
and 5580 m3 unambiguously demonstrate that the thickness of the slag crust in blast furnaces increases with the use of schungite. Protecting
the lining of the hearth through the use of schungite is also accompanied by a decrease in coke consumption.
__________
Translated from Metallurg, No. 8, pp. 53–57, August, 2007. 相似文献
894.
895.
N. E. Esipova E. V. Blinov T. G. Movchan I. O. Bannykh 《Russian Metallurgy (Metally)》2007,(2):148-152
The corrosion resistance of the convex and concave sides of bent plates from a high-nitrogen non-magnetic steel has been studied in aqueous solutions of sulfuric and hydrochloric acids. Weighing and hydrogen methods are used to control the corrosion rate of bent-sample sides and to find a number of effects that complement the picture of the stress corrosion of iron alloys and support the existence of the mechanochemical deformation sign effect. 相似文献
896.
Radioimmunoassay was employed to examine distribution of antigenic structures of bovine serum albumin (BSA), absorbed by the gastrointestinal tract, in the blood serum and organs of intact rats. It was shown that 3 h after administering 3H-BSA an appreciable amount of its antigenic structures could be identified in the blood serum, liver, spleen, and carcass of the animals. The total amount of antigenic determinants of BSA which got into the internal environment of the body from the intestine amounted to about 0.2% of the dose administered. The highest specific content of antigenic structures of BSA supplied via the intestinal barrier was detected in the spleen. 相似文献
897.
The manometric technique was employed to study the initiated oxidation of 7 samples of whitefish lipids of varying sites, to measure the kinetic parameters depending on the fatty acid composition and concentration of tocopherol. Changes in oxidative stability of lipids of varying localization was shown, a higher stability of muscle tissue lipids was noted as compared with brain and depot lipids. The possibility of testing oxidative stability of lipids according to the kinetic parameters is discussed. 相似文献
898.
M.V.C. Sastri 《International Journal of Hydrogen Energy》1985,10(2):133
899.
D.R Hayhurst D.A Lavender N.G Worley A Salim 《International Journal of Pressure Vessels and Piping》1985,20(4):289-317
Constant stress creep data for a wrought 1%Cr, , steel obtained from six tests carried out at 565°C have been fitted and extrapolated using the θ-projection method. Creep curves for high stresses were fitted well, but curves extrapolated to stress levels below those used in the θ-projection did not represent well the available data for primary-secondary creep. To enable a satisfactory extrapolation of results, it was found necessary to redefine the failure condition to be less sensitive to the shape of the latter sections of the tertiary creep curve. This was achieved by defining lifetime as the point on the curve at which the strain rate reached a fixed multiple of the creep rate at half the rupture time. The extrapolated data compare well with the results of tests carried out independently on a cast 1%Cr, , steel. The extrapolation procedure not only predicts the ‘knee’ in the log stress-log lifetime curve but allows extrapolation of lifetimes by over a factor of thirty. In addition, acceptable predictions have been made of constant load experimental data. 相似文献
900.