全文获取类型
收费全文 | 22735篇 |
免费 | 831篇 |
国内免费 | 326篇 |
专业分类
电工技术 | 487篇 |
综合类 | 658篇 |
化学工业 | 4406篇 |
金属工艺 | 1304篇 |
机械仪表 | 894篇 |
建筑科学 | 725篇 |
矿业工程 | 339篇 |
能源动力 | 394篇 |
轻工业 | 1360篇 |
水利工程 | 453篇 |
石油天然气 | 1494篇 |
武器工业 | 87篇 |
无线电 | 1219篇 |
一般工业技术 | 5198篇 |
冶金工业 | 2222篇 |
原子能技术 | 926篇 |
自动化技术 | 1726篇 |
出版年
2022年 | 295篇 |
2021年 | 448篇 |
2020年 | 380篇 |
2019年 | 406篇 |
2018年 | 584篇 |
2017年 | 611篇 |
2016年 | 645篇 |
2015年 | 610篇 |
2014年 | 739篇 |
2013年 | 1127篇 |
2012年 | 840篇 |
2011年 | 889篇 |
2010年 | 778篇 |
2009年 | 777篇 |
2008年 | 692篇 |
2007年 | 692篇 |
2006年 | 547篇 |
2005年 | 464篇 |
2004年 | 473篇 |
2003年 | 523篇 |
2002年 | 694篇 |
2001年 | 619篇 |
2000年 | 362篇 |
1999年 | 225篇 |
1990年 | 212篇 |
1989年 | 244篇 |
1988年 | 230篇 |
1987年 | 229篇 |
1986年 | 251篇 |
1985年 | 266篇 |
1984年 | 291篇 |
1983年 | 271篇 |
1982年 | 261篇 |
1981年 | 262篇 |
1980年 | 265篇 |
1979年 | 284篇 |
1978年 | 360篇 |
1977年 | 335篇 |
1976年 | 353篇 |
1975年 | 333篇 |
1974年 | 400篇 |
1973年 | 377篇 |
1972年 | 358篇 |
1971年 | 330篇 |
1970年 | 281篇 |
1969年 | 277篇 |
1968年 | 268篇 |
1967年 | 250篇 |
1966年 | 216篇 |
1965年 | 213篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
V. A. Mozhzherin V. Ya. Sakulin V. P. Migal’ A. P. Margishvili A. A. Konstantinov 《Refractories and Industrial Ceramics》2008,49(4):245-250
In the OAO Borovich Refractory Combine production has been assimilated for a complete set of refractories for continuous steel
casting, i.e. from a pipe for protecting a stream of metal to a submerged nozzle. In technical and life characteristics the
products correspond to that of world analogs, they provide accident free steel pouring, make it possible to reduce the specific
consumption of refractories per ton of steel, to increase CBCM productivity, to reduce billet scrap, and to reduce steel cost.
Translated from Novye Ogneupory, No. 8, pp. 4–9, August 2008. 相似文献
42.
43.
44.
Ya. Z. Gaft 《Chemical and Petroleum Engineering》2006,42(9-10):576-581
Characteristics and design diagrams of pump shaft seals, their reliability and leak-tightness indices, and comparative analysis of cost of leak-tightening are given. 相似文献
45.
46.
Ya. A. Ilyushin V. E. Kunitsyn 《Journal of Communications Technology and Electronics》2008,53(5):545-549
The possibility for determining the structure of the surface layer of a cometary nucleus from the data of bistatic radar sensing is investigated. A rigorous solution formulated for this problem on the basis of vector equations of the electromagnetic field is presented. 相似文献
47.
Porous carbon nanofibers are synthesized by CVD method from acetylene with use of iron-containing catalysts. Activation of the nanofibers in melted potassium hydroxide results in increasing surface area from initial 300–400 m2 g−1 to 1700 m2 g−1. As follows from XRD data, activated nanofibers do not contain regular packages of graphene layers, but retain high electric conductivity. Deposition of copper improves electrochemical hydrogen storing characteristics of carbon nanofibers. Carbon nanomaterials obtained can be used as hydrogen storing materials in batteries instead of hydride forming metals. 相似文献
48.
The photoelectric parameters of silicon solar cells degraded under the action of 60Co gamma-radiation can be partly restored using an ultrasonic treatment (UST). The growth of the maximum output power of solar cells after the UST is related to a redistribution of the radiation defects and an increase in the homogeneity of a semiconductor crystal structure. 相似文献
49.
50.
The storage time before salvaging of decommissioned nuclear-powered submarines and the floating storage time of reactor units from salvaged submarines can total decades. During this time, radioactive contamination of seawater occurs as a result of the corrosion of the pressure hull in the region of the reactor system and rupturing of the pressure hull - as a result of corrosion of the components of the reactor system. A computational analysis shows that under standard storage conditions the specific activity of water is 105–106 times lower than the intervention level. In the case when the hull and the reactor system are destroyed even with remaining fuel, the specific activity of the sea water near the point of sinking also does not exceed the intervention level because of the slow emission of fission products and transuranium nuclides.Translated from Atomnaya Énergiya, Vol. 97, No. 3, pp. 210–218, September, 2004. 相似文献