全文获取类型
收费全文 | 434篇 |
免费 | 2篇 |
国内免费 | 1篇 |
学科分类
工业技术 | 437篇 |
出版年
2020年 | 6篇 |
2019年 | 5篇 |
2018年 | 10篇 |
2017年 | 15篇 |
2016年 | 17篇 |
2015年 | 4篇 |
2014年 | 5篇 |
2013年 | 17篇 |
2012年 | 12篇 |
2011年 | 10篇 |
2010年 | 18篇 |
2009年 | 10篇 |
2008年 | 10篇 |
2007年 | 7篇 |
2006年 | 14篇 |
2005年 | 5篇 |
2004年 | 8篇 |
2003年 | 13篇 |
2002年 | 19篇 |
2001年 | 6篇 |
2000年 | 8篇 |
1999年 | 10篇 |
1998年 | 15篇 |
1997年 | 12篇 |
1996年 | 7篇 |
1995年 | 8篇 |
1993年 | 9篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 6篇 |
1989年 | 4篇 |
1988年 | 9篇 |
1986年 | 4篇 |
1985年 | 9篇 |
1984年 | 8篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1980年 | 11篇 |
1979年 | 6篇 |
1978年 | 8篇 |
1977年 | 11篇 |
1976年 | 7篇 |
1975年 | 5篇 |
1974年 | 8篇 |
1973年 | 4篇 |
1972年 | 5篇 |
1967年 | 3篇 |
1965年 | 3篇 |
1962年 | 3篇 |
排序方式: 共有437条查询结果,搜索用时 15 毫秒
1.
The electrical properties and microstructure of (Ba,Y)TiO3 PTCR ceramics were studied. The results indicate that the Mn ions increase the intergranular barrier height and produce a high-resistance layer on the grain surface. The temperature-dependent resistances of the grain bulk, surface layer, and grain boundaries, the temperature coefficient of resistance, and the magnitude of the varistor effect were assessed as a function of Mn content. 相似文献
2.
3.
Various heat insulation materials produced at home and abroad are compared. The advantage of using natural nano-structured
materials is substantiated.
Translated from Novye Ogneupory, No. 7, pp. 41–44, July 2008. 相似文献
4.
5.
A. A. Nechitaĭlov T. K. Zvonareva A. D. Remenyuk V. A. Tolmachev D. N. Goryachev O. S. El’tsina L. V. Belyakov O. M. Sreseli 《Semiconductors》2008,42(10):1249-1254
Catalytic properties of composite amorphous carbon-platinum layers produced by magnetron cosputtering have been studied. The layers were characterized by electron microscopy, IR spectroscopy, ellipsometry, gravimetry, and spectrophotometric chemical analysis. The catalytic activity of the layers was studied in an air-hydrogen fuel cell by measuring its load and power characteristics. 相似文献
6.
A. A. Belyakov 《Power Technology and Engineering (formerly Hydrotechnical Construction)》1995,29(5):307-312
A brief account of the concept developed in 1993 on orders of the Ministry of Fuel and Power of the Russian Federation by a group of authors: A. E. Asarin, T. P. Dotsenko, V. D. Novozhenin, G. L. Sarukhanov (State Planning, Surveying, and Research Institute), V. F. Samarin, R. P. Stepanov, V. I. Fedoryak, M. A. Shestopal (State River Transport Planning Institute), and A. A. Belyakov (Moscow State Construction University). 相似文献
7.
8.
The forms of extraction of silicon compounds in rice husk, proposed as a source of silicon dioxide, were examined. A model in which the silica particles distributed in the plant cells of rice husk are separated by organic layers from mineralizer impurities was proposed. Crystallization of silicon dioxide begins after elimination of the layers of carbon formed at the site. 相似文献
9.
Porosity in nanoporous ceramics produced by pyrolysis of organosilicon polymer at a temperature of 600°C was investigated using the BET method. Samples were molded from fractionated granules produced by single or double milling in a planetary mill of a polymer previously solidified and heat-treated at 200°C. Specific surface area depending on nanopores sharply decreases after the granules reach a size over 250 m in single milling and over 1000 m in double milling. An explanation for these facts is given in the context of synergism. 相似文献
10.
Birgit Batke Gerlinde Lauterbach Wilhelm Pritzkow Volkmar Voerckel Vladimir A. Belyakov 《Advanced Synthesis \u0026amp; Catalysis》1989,331(3):424-430
The products of the autoxidation of phenyl cyclopropane ( I ), phenyl cyclobutane ( II ), phenyl cyclopentane ( III ), phenyl cyclohexane ( IV ), phenyl cycloheptane ( V ) and phenyl cyclooctane ( VI ) were analyzed after reduction of the reaction mixtures with LiAlH4. As products of the attack on the α-C H bonds the corresponding 1-phenyl cycloalkanols and 1-phenyl alkan-1-ols were found. In the case of phenyl cyclopropane some SR2 ring opening probably takes place. The oxidabilities $ {\rm k}_{\rm p} /\sqrt {{\rm k}_{\rm t}} $, the chain termination constants kt, the absolute chain propagation constants kp and the relative chain propagation constant (kp)rel were determined for the phenyl cycloalkanes I — VI . As it is to be expected on the basis of the I-strain concept the autoxidation rate of phenyl cyclopentane ( III ) is considerably higher than that of phenyl cyclobutane ( II ) and phenyl cyclohexane ( IV ). 相似文献