全文获取类型
收费全文 | 85602篇 |
免费 | 175篇 |
国内免费 | 88篇 |
专业分类
电工技术 | 1882篇 |
综合类 | 94篇 |
化学工业 | 10966篇 |
金属工艺 | 7527篇 |
机械仪表 | 6261篇 |
建筑科学 | 1524篇 |
矿业工程 | 912篇 |
能源动力 | 776篇 |
轻工业 | 1379篇 |
水利工程 | 1293篇 |
石油天然气 | 2168篇 |
武器工业 | 1篇 |
无线电 | 8023篇 |
一般工业技术 | 22437篇 |
冶金工业 | 6898篇 |
原子能技术 | 1431篇 |
自动化技术 | 12293篇 |
出版年
2018年 | 9354篇 |
2017年 | 10032篇 |
2016年 | 5301篇 |
2015年 | 651篇 |
2014年 | 219篇 |
2013年 | 215篇 |
2012年 | 2993篇 |
2011年 | 9232篇 |
2010年 | 8863篇 |
2009年 | 7550篇 |
2008年 | 7281篇 |
2007年 | 9510篇 |
2006年 | 192篇 |
2005年 | 4068篇 |
2004年 | 2307篇 |
2003年 | 1923篇 |
2002年 | 809篇 |
2001年 | 175篇 |
2000年 | 258篇 |
1999年 | 90篇 |
1998年 | 92篇 |
1997年 | 83篇 |
1993年 | 85篇 |
1992年 | 95篇 |
1991年 | 109篇 |
1989年 | 92篇 |
1988年 | 118篇 |
1987年 | 96篇 |
1986年 | 85篇 |
1980年 | 83篇 |
1979年 | 100篇 |
1978年 | 119篇 |
1976年 | 93篇 |
1975年 | 97篇 |
1974年 | 110篇 |
1973年 | 106篇 |
1972年 | 109篇 |
1969年 | 124篇 |
1968年 | 177篇 |
1967年 | 166篇 |
1966年 | 183篇 |
1965年 | 165篇 |
1964年 | 92篇 |
1961年 | 93篇 |
1960年 | 106篇 |
1958年 | 87篇 |
1957年 | 131篇 |
1956年 | 123篇 |
1955年 | 139篇 |
1954年 | 153篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
A. I. Nikolaev F. D. Larichkin O. A. Nikolaeva 《Theoretical Foundations of Chemical Engineering》2008,42(5):675-679
The main rules and principles which govern the choice of new variants for chemical technology of combined processing of titanium-rare-metal raw materials are considered. The existing variants of the technology are characterized from the viewpoint of their technological, economical, and ecological efficiency and social importance for a given region. A realistic choice of a technology from a large number of available variants should take into account the entire combination of their advantages and disadvantages The implementation of a rational technological scheme will result in the creation of economically profitable and efficient domestic production satisfying the demands of Russian industry in rare-metal and titanium materials. Directions are noted in which it is expedient to continue studies on designing a rational technology of loparite concentrate or some other concentrate. 相似文献
102.
P. S. Gordienko V. A. Kolzunov L. G. Zorina T. A. Kaidalova S. B. Yarusova 《Theoretical Foundations of Chemical Engineering》2008,42(5):680-683
The possibility of processing fluorine-containing wastes of fluorite ore, which include fluorite, calcite, quartz, and anorthite, has been investigated. A manufacturing flow chart of the complex processing of the ore waste materials with the production of sodium fluoride, alumina, soda ash, and raw materials suitable for the production of Portland cement and wollastonite is suggested. 相似文献
103.
V. N. Babak T. B. Babak L. P. Kholpanov 《Theoretical Foundations of Chemical Engineering》2008,42(6):852-867
Mass transfer with solvent evaporation in the vapor-liquid two-phase film evaporators used for the removal of undesirable
impurities from liquid solutions at low pressure is studied. The average concentrations of solution components in the falling
liquid film are determined. The most efficient operating conditions for impurity removal, in which the resistance to mass
transfer is concentrated in the liquid phase, are found.
Original Russian Text ? V.N. Babak, T.B. Babak, L.P. Kholpanov, 2008, published in Teoreticheskie Osnovy Khimicheskoi Tekhnologii,
2008, Vol. 42, No. 6, pp. 654–670. 相似文献
104.
Some sulfides of gold and silver: Composition,mineral mineral assemblage,and conditions of formation
Characteristic mineral assemblage and special features of the composition of Au and Ag sulfides of gold-silver deposits have been established. The forms of the occurrence of Au and Ag in the minerals of the early and last stages have been analyzed. The conditions for the formation of uytenbogaardtite and petrovskaite in supergene and low-temperature hydrothermal processes have been considered. A thermodynamic model explaining their genesis in the oxidation zones is presented. 相似文献
105.
The kinetics of the reaction of olefin synthesis from dimethyl ether and methanol is studied. A kinetic model of the nine-route reaction under study is constructed. The constants of the model are estimated using experimental data. The adequacy of the model to the results of experiments is shown 相似文献
106.
The results of the oxidation of carbon nanofibers and materials obtained on their basis are presented; these results demonstrate that the nanofibers were formed by carbon with different degrees of crystal structure ordering. The experimental data supported previous hypotheses that amorphous carbon results from the decomposition of metal carbides. The subsequent formation of spatial structures and the appearance of crystalline carbon species resulted from catalytic graphitization. It was demonstrated that sorbents can be prepared based on carbon nanofibers after pyrolytic consolidation followed by activation, and these sorbents are more effective than well-known sorbents. 相似文献
107.
Yu. V. Pokonova 《Solid Fuel Chemistry》2008,42(6):369-372
Impregnants prepared from shale phenols for cellular materials had a cohesive strength of 2.4–18.5 J/m2 and a specific elongation of 160–170%. The adhesive strength toward a metal was 3.5–6.0 J/m2; in the case of concrete, it was greater than the concrete strength. 相似文献
108.
Cross-linking additions of silicon carbide and waste material from ferroalloy production make it possible to increase the
heat-resistance index for mullite-containing refractories. For briquette specimens based on a charge containing aluminum powder
it reaches 45 thermal cycles (1300°C – water).
Translated from Novye Ogneupory, No. 11, pp. 44–46, November 2008. 相似文献
109.
I. I. Nemets Yu. N. Trepalina E. A. Doroganov 《Refractories and Industrial Ceramics》2008,49(3):205-208
Physicotechnical properties are provided for concretes based on mechanically-activated phosphate suspensions previously modified
with magnesium and aluminum hydroxides and silicic acid. The results obtained demonstrate the efficiency of using modifying
additions in order to increase the strength and heat resistance of corundum concretes.
Translated from Novye Ogneupory, No. 5, pp. 32–35, May 2008. 相似文献
110.
A method is considered to solve a conditional optimization problem with a linear-fractional objective function over permutations.
The performance of sub algorithms to solve this problem is evaluated. The practical efficiency of the algorithm is analyzed
by conducting numerical experiments.
__________
Translated from Kibernetika i Sistemnyi Analiz, No. 4, pp. 133–146, July–August 2007. 相似文献