全文获取类型
收费全文 | 76672篇 |
免费 | 736篇 |
国内免费 | 690篇 |
专业分类
电工技术 | 1454篇 |
综合类 | 52篇 |
化学工业 | 11612篇 |
金属工艺 | 3475篇 |
机械仪表 | 2673篇 |
建筑科学 | 1740篇 |
矿业工程 | 524篇 |
能源动力 | 1885篇 |
轻工业 | 6529篇 |
水利工程 | 855篇 |
石油天然气 | 2315篇 |
武器工业 | 41篇 |
无线电 | 7334篇 |
一般工业技术 | 16691篇 |
冶金工业 | 12728篇 |
原子能技术 | 2639篇 |
自动化技术 | 5551篇 |
出版年
2022年 | 585篇 |
2021年 | 912篇 |
2020年 | 706篇 |
2019年 | 792篇 |
2018年 | 1567篇 |
2017年 | 1572篇 |
2016年 | 1778篇 |
2015年 | 964篇 |
2014年 | 1581篇 |
2013年 | 3661篇 |
2012年 | 2400篇 |
2011年 | 2897篇 |
2010年 | 2423篇 |
2009年 | 2708篇 |
2008年 | 2696篇 |
2007年 | 2622篇 |
2006年 | 2251篇 |
2005年 | 1973篇 |
2004年 | 1897篇 |
2003年 | 1849篇 |
2002年 | 1765篇 |
2001年 | 1724篇 |
2000年 | 1703篇 |
1999年 | 1604篇 |
1998年 | 3699篇 |
1997年 | 2637篇 |
1996年 | 1981篇 |
1995年 | 1551篇 |
1994年 | 1372篇 |
1993年 | 1370篇 |
1992年 | 1024篇 |
1991年 | 1076篇 |
1990年 | 1096篇 |
1989年 | 1077篇 |
1988年 | 963篇 |
1987年 | 905篇 |
1986年 | 897篇 |
1985年 | 958篇 |
1984年 | 820篇 |
1983年 | 794篇 |
1982年 | 704篇 |
1981年 | 719篇 |
1980年 | 681篇 |
1979年 | 677篇 |
1978年 | 640篇 |
1977年 | 803篇 |
1976年 | 950篇 |
1975年 | 605篇 |
1974年 | 566篇 |
1973年 | 561篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
122.
Conclusions The chemical mutagenesis method is recommended for use in local purification installations for cleaning up of caprolactam-containing wastewater.Use of this method permits one to carry out a biochemical clean-up of wastewater having a caprolactam content up to 600 mg/liter while increasing the oxidative power of the aeration tank by a factor of two.Translated from Khimicheskie Volokna, No. 6, p. 46, November–December, 1985. 相似文献
123.
Z. P. Shul'man B. M. Khusid I. L. Ryklina É. A. Zal'tsgendler O. R. Dornyak É. V. Ivashkevich Z. A. Shabunina 《Journal of Engineering Physics and Thermophysics》1987,53(5):1285-1291
Dynamic processes are studied in media with softly and hardly internal destroyable configurations. A method is examined for the measurement of properties of media with spatial separation of the chemical transformation stages and thermal hydrodynamic measurements.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 53, No. 5, pp. 781–789, November, 1987. 相似文献
124.
N. V. Vostokov Yu. N. Drozdov Z. F. Krasil’nik O. A. Kuznetsov A. V. Novikov V. A. Perevoshchikov M. V. Shaleev 《Russian Microelectronics》2005,34(4):203-209
The results are presented of the fabrication of strain-relaxed graded Si1 − x
Gex/Si(001) buffer layers with a maximum Ge fraction of about 0.25 that have a low density of threading dislocations (<106 cm−2) and low surface roughness. The buffer layers are grown by atmospheric-pressure hydride CVD. It is found that chemical mechanical polishing can reduce their surface roughness to a level comparable with that of the original Si(001) substrates. It is shown that the polished buffer layers can serve as substrates for MBE-grown SiGe/Si heterostructures.__________Translated from Mikroelektronika, Vol. 34, No. 4, 2005, pp. 243–250.Original Russian Text Copyright © 2005 by Vostokov, Drozdov, Krasil’nik, Kuznetsov, Novikov, Perevoshchikov, Shaleev. 相似文献
125.
Ya. O. Shablovskii 《Inorganic Materials》2007,43(12):1345-1349
The pyroelectric properties of lithium sulfate have been studied theoretically on the hypothesis of a pseudosymmetry of the structure of its polar phase. Analytical expressions are proposed for the temperature dependences of its pyroelectric polarization and pyroelectric coefficient at low temperatures and near the polymorphic transformation. The pyroelectric and piezoelectric coefficients of a polar crystal are shown to be in direct proportion. 相似文献
126.
127.
128.
E. M. Gavrishchuk E. Yu. Vilkova O. V. Timofeev U. P. Borovskikh E. L. Tikhonova 《Inorganic Materials》2007,43(6):579-583
Chemical interaction between polished surfaces of polycrystalline zinc selenide and inorganic acid solutions of various concentrations has been studied. 相似文献
129.
O. E. Narivs’kyi 《Materials Science》2007,43(1):124-132
We have studied the micromechanism of corrosion fracture of heat-transfer plates of a heat exchanger. The operation of heat
exchangers under conditions of contamination of the plates with a sediment from water leads to their local corrosion under
the sediment. The conditions of operation of the heat exchangers being equal, heat-transfer plates made of AiSi316Ti steel
worked 2.36 times as long as those of AiSi304L steel. The corrosion fracture of plates under the sediment began from pitting
initiation near nonmetallic inclusions of a certain nature. Afterwards, these pittings built up into corrosion spots by the
mechanism of stress corrosion and hydrogen embrittlement.
__________
Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 43, No. 1, pp. 110–116, January–February, 2007. 相似文献
130.
O. A. Dolgopolov 《Glass and Ceramics》2005,62(5-6):155-156
Magnetic roll separators on rare-earth magnets are suitable for removing iron impurities from various materials. The advantages
of these magnetic separators over traditional ones are demonstrated.
__________
Translated from Steklo i Keramika, No. 5, p. 33, May, 2005. 相似文献