全文获取类型
收费全文 | 461篇 |
免费 | 13篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 7篇 |
综合类 | 1篇 |
化学工业 | 120篇 |
金属工艺 | 7篇 |
机械仪表 | 16篇 |
建筑科学 | 4篇 |
矿业工程 | 4篇 |
能源动力 | 30篇 |
轻工业 | 15篇 |
水利工程 | 2篇 |
石油天然气 | 7篇 |
无线电 | 23篇 |
一般工业技术 | 133篇 |
冶金工业 | 7篇 |
原子能技术 | 8篇 |
自动化技术 | 91篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 13篇 |
2020年 | 8篇 |
2019年 | 10篇 |
2018年 | 15篇 |
2017年 | 11篇 |
2016年 | 18篇 |
2015年 | 8篇 |
2014年 | 24篇 |
2013年 | 31篇 |
2012年 | 39篇 |
2011年 | 35篇 |
2010年 | 11篇 |
2009年 | 23篇 |
2008年 | 25篇 |
2007年 | 25篇 |
2006年 | 26篇 |
2005年 | 28篇 |
2004年 | 15篇 |
2003年 | 16篇 |
2002年 | 14篇 |
2001年 | 15篇 |
2000年 | 8篇 |
1999年 | 10篇 |
1998年 | 1篇 |
1997年 | 9篇 |
1996年 | 4篇 |
1995年 | 5篇 |
1993年 | 4篇 |
1991年 | 5篇 |
1989年 | 3篇 |
1984年 | 2篇 |
1982年 | 1篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1965年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有475条查询结果,搜索用时 15 毫秒
1.
Pavel P. Fedorov Vera Y. Proydakova Sergey V. Kuznetsov Valery V. Voronov Alexandr A. Pynenkov Konstantin N. Nishchev 《Journal of the American Ceramic Society》2020,103(5):3390-3400
The thermal analysis and X-ray powder diffraction studies of the Li2SO4–Na2SO4 system, including the high-temperature X-ray diffraction technique, have elucidated four phases of variable composition: three solid solutions based on the α-Li2SO4, α-Na2SO4, and α-LiNaSO4 high-temperature polymorphs, and a low-temperature β-LiNaSO4 phase. α-Na2SO4-Base solid solution disintegrates into two phases via a monotectoid phase transformation. It is quite probable that the monotectoid process is related to the conversion of the second-order phase transition to the first-order phase transition. 相似文献
2.
Chernov Yacov Filatov Eugene Shurov Nikolay Smolenski Valery Tkachev Nikolai 《Metallurgical and Materials Transactions B》2019,50(4):1745-1751
Metallurgical and Materials Transactions B - Formation of calcium hexaboride by means of electrodeposition of boron oxide in molten CaCl2 with additives of CaO and B2O3 was analyzed. It was shown... 相似文献
3.
4.
5.
Valery D. Rumyantsev Alexander V. Chekalin Nikolay Yu. Davidyuk Nikolay A. Sadchikov Antonio Luque 《Progress in Photovoltaics: Research and Applications》2016,24(2):211-218
A method for the evaluation of p–n junction cell temperature in PV modules operating in the maximum power point (MPP) mode has been proposed. The method does not require specialized equipment and (for the concentrator modules) the data on the open circuit (OC) voltage temperature coefficients measured under pulse illumination. It consists of measuring several open circuit voltage magnitudes together with temperature measurements on the external module surface near one of the cells. In this procedure, a fast transition from MPP to OC operational mode is carried out, during which a time‐dependent voltage measurement is carried out with the help of a memory oscilloscope. A “reference” OC voltage magnitude in a “cold” module (a condition, as if the cells are kept at ambient temperature) is obtained by calculations, so that there is no necessity in a fast mechanical shuttering of the module aperture area. In the case of the concentrator modules, the module OC voltage temperature coefficient can be measured, if heat sinking process is artificially modified during outdoor measurements. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
6.
Valery V. Tatur 《International Journal of Circuit Theory and Applications》2015,43(4):415-420
A multistage generator of high‐voltage pulses with a doubling of output voltage built according to the Marx scheme is presented. A specific feature of the generator circuit design is the substitution of charging diodes for charging resistors and connection of the supplying voltage through an inductor. Such a design makes it possible to double the amplitude of pulses across a load, which is proportional to the number of connected stages, and to minimize the power loss during the charging of storage capacitors. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
7.
Skeeba Vadim Pushnin Valery Erohin Ivan Kornev Dmitry 《Materials and Manufacturing Processes》2015,30(12):1408-1411
The article describes a new method for integrated processing which combines high-energy heating by high frequency currents (HEH HFC) and abrasive grinding. Research clearly showed that implementation of integrated processing may lead to 2 … 2.5-fold increasing of the processing performance. It was established experimentally that the proposed integrated treatment results in increasing of the microhardness and the level of residual compressive stresses in the surface layer. This increases the contact–fatigue strength of steel parts up to 10% … 16%. 相似文献
8.
9.
Ilya Tkachenko Sergey N. Tkachenko Ekaterina S. Lokteva Nadezhda A. Mamleeva Valery V. Lunin 《臭氧:科学与工程》2020,42(4):357-370
ABSTRACT The aim of the research is to choose the most efficient adsorbent for two-stage ozone-sorption purification of groundwater containing both trichloroethylene (TCE) and tetrachloroethylene (PCE) between three carbon sorbents produced in Russia (AUT-M, CAUSORB-221, and AG-3). Sorption isotherms of TCE and PCE on AUT-M and CAUSORB-221 at 296 K were fitted by the Freundlich equation. The better TCE and PCE sorption ability of AUT-M in comparison with CAUSORB – 221 and AG-3 was demonstrated. The optimum parameters for ozonation and sorption stages of groundwater purification from TCE and PCE are elucidated using laboratory and pilot-plant scales. Prolonged test of this technology for purification of ground demonstrated that the higher achievable efficiency of destruction with ozone is 94% for TCE and 38% for PCE. Ozonation-sorption treatment of groundwater allows one to achieve TCE and PCE removal efficiency of 96-97% and 92-94% correspondingly. The most efficient carbon sorbent is microporous carbon fiber AUT-M. Using this sorbent, TCE and PCE concentrations in treated water decrease below the MPC level (5 μg/L) adopted in Russia. It is concluded that the combination of ozonation with sorption of residual contaminants by carbon sorbents is a promising way for the purification of waters containing chlorinated contaminants. 相似文献
10.
Valery A. Isidorov Sławomir Bakier Ewa Pirożnikow Monika Zambrzycka Izabela Swiecicka 《Journal of chemical ecology》2016,42(6):475-485
Honey bees harvest resins from various plant species and use them in the hive as propolis. While there have been a number of studies concerning the chemical composition of this antimicrobial product, little is known about selective behavior and bee preference when different potential plant sources of resin are available. The main objective of this paper was to investigate some aspects of behavioral patterns of honeybees in the context of resin acquisition. Samples of propolis originating from temperate zones of Europe and the supposed botanical precursors of the product were analyzed. Taxonomical markers of bud resins of two white birch species, aspen, black poplar, horse-chestnut, black alder, and Scots pine were determined through GC-MS analysis. All these trees have been reported as sources of propolis, but comparisons of the chemical composition of their bud resins with the compositions of propolis samples from seven European countries have demonstrated the presence of taxonomical markers only from black poplar, aspen, and one species of birch. This suggests selective behavior during the collection of bud resins by honeybees. To examine the causes of such selectivity, the antimicrobial properties of bud resins were determined. Horse-chestnut resins had lower antimicrobial activity than the other resins which did not differ significantly. 相似文献