全文获取类型
收费全文 | 2153篇 |
免费 | 11篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 30篇 |
综合类 | 1篇 |
化学工业 | 287篇 |
金属工艺 | 101篇 |
机械仪表 | 112篇 |
建筑科学 | 6篇 |
矿业工程 | 59篇 |
能源动力 | 22篇 |
轻工业 | 26篇 |
水利工程 | 49篇 |
石油天然气 | 148篇 |
无线电 | 170篇 |
一般工业技术 | 635篇 |
冶金工业 | 246篇 |
原子能技术 | 186篇 |
自动化技术 | 87篇 |
出版年
2022年 | 24篇 |
2021年 | 29篇 |
2019年 | 27篇 |
2018年 | 58篇 |
2017年 | 58篇 |
2016年 | 63篇 |
2015年 | 28篇 |
2014年 | 50篇 |
2013年 | 77篇 |
2012年 | 66篇 |
2011年 | 57篇 |
2010年 | 60篇 |
2009年 | 55篇 |
2008年 | 67篇 |
2007年 | 73篇 |
2006年 | 58篇 |
2005年 | 51篇 |
2004年 | 76篇 |
2003年 | 39篇 |
2002年 | 36篇 |
2001年 | 45篇 |
2000年 | 44篇 |
1999年 | 30篇 |
1998年 | 45篇 |
1997年 | 37篇 |
1996年 | 38篇 |
1995年 | 32篇 |
1994年 | 27篇 |
1993年 | 39篇 |
1992年 | 29篇 |
1991年 | 27篇 |
1990年 | 22篇 |
1989年 | 30篇 |
1988年 | 23篇 |
1987年 | 22篇 |
1986年 | 22篇 |
1985年 | 23篇 |
1984年 | 23篇 |
1983年 | 25篇 |
1981年 | 23篇 |
1980年 | 25篇 |
1979年 | 28篇 |
1978年 | 25篇 |
1977年 | 40篇 |
1976年 | 44篇 |
1975年 | 34篇 |
1974年 | 35篇 |
1973年 | 30篇 |
1972年 | 25篇 |
1969年 | 25篇 |
排序方式: 共有2165条查询结果,搜索用时 0 毫秒
91.
E. V. Proskurkin I. V. Petrov A. Yu. Zhuravlev O. V. Ivanov D. A. Sukhomlin 《Steel in Translation》2012,42(7):600-605
The structure of zinc coatings is studied on the basis of the iron-zinc phase diagram, and the coating properties are compared. Corrosion tests indicate that diffusional zinc coatings are preferable in challenging operating conditions. Their structure consists mainly of intermetallides (iron-zinc phases) whose corrosion resistance is greater than that of pure zinc, primarily on account of passivation by zinc ferrites (ZnFeO2, ZnFe2O4), as well as ZnO. The coating life in various aggressive media is considered, together with the main applications of zinc coatings. 相似文献
92.
G. P. Kayukova А. V. Vakhin S. M. Petrov S. A. Sitnov 《Petroleum Science and Technology》2017,35(16):1680-1686
This work is devoted to studying the possibility of producing bitumen for road construction by using vacuum residue >420°C of heavy oil of the Ashal'chinskoe field in and natural asphaltite Spiridonovskoe field from Permian deposits in Tatarstan. The effect of natural asphaltite as a solid disperse phase element on the structural and group composition of the residual heavy oil product and its malacometrical qualities (penetration, extensibility, softening point, resistance to aging and adhesion) is revealed. The production of samples of compounded bitumen production was carried out by introducing the required amount of the shredded asphaltite to deasphaltizat vacuum residue of heavy oil and heating their mixture to 220°С with vigorous stirring. Changes in the composition and physical and chemical properties of deasphalting the residual heavy oil product, associated with the amount of injected asphaltite, showed the possibility of production of modified bitumen with better adhesion properties that correspond to road bitumen. 相似文献
93.
Hui Zhang Yahia A. Alhamed Abdulrahim Al-Zahrani Mohammad Daous Hitoshi Inokawa Yoshitsugu Kojima Lachezar A. Petrov 《International Journal of Hydrogen Energy》2014
Multi-walled carbon nanotubes, three types of activated carbons, single wall carbon nanotube and reduced graphene oxides were used to synthesize nano-sized Co catalysts for H2 preparation via NH3 decomposition. Catalyst samples were characterized by number of techniques such as N2 physisorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopes (XPS), Transmission electron microscopy (TEM), CO chemisorption, temperature-programmed reduction (H2-TPR) and temperature-programmed desorption (N2-TPD). The catalytic activities of the studied catalysts for H2 production via NH3 decomposition were measured in a fixed-bed micro-reactor. Co catalyst supported on multi-wall carbon nanotubes has shown the highest catalytic activity. The Co particles size was significantly affected by the variation of the post-treatment temperature. The Co particles size in the range of 4.7–64.8 nm can be effectively controlled by varying post-treatment temperature between 230 and 700 °C. The maximum TOF of NH3 decomposition was registered on cobalt catalyst post-treated at 600 °C. 相似文献
94.
A. N. Alekseev S. I. Petrov V. K. Nevolin K. A. Tsarik D. M. Krasovitskii V. P. Chalyi 《Russian Microelectronics》2012,41(7):400-404
Multilayered nitride heterostructures AlN/AlGaN/GaN/AlGaN are grown using a Nanofab-100 multichamber domestic complex involving a STE3N3 specialized installation of molecular beam epitaxy. The obtained heterostructures have high structural quality, smooth morphology, and a low dislocation density, which demonstrates the high potential of the nanotechnological complex. 相似文献
95.
It is shown that the initial state of uranium dioxide powder has no effect on the density, microstructure, and strength of
pellets. Pore-forming agents and U3O8 used in fabrication lower the pellet strength because their particles are not spherical. To increase pellet strength, it
is recommended that U3O8 be subjected to special processing to spheroidize the particles before mixing for uranium dioxide powder. 相似文献
96.
P. Yu. Greben’kov V. V. Vasil’ev V. N. Borisov V. N. Petrov A. S. Kardashov S. V. Porozov S. R. Yanov M. N. Nazarov M. N. Maidanik 《Thermal Engineering》2011,58(12):973-980
Results from the balance tests of a retrofitted P-67 boiler carried out in the period 2006–2008 are presented. The tests involved
assessment of the change with time of the heating-surface thermal efficiency coefficients in running the power unit at its
base loads in the range 740–800 MW, with seven to eight coarsegrinding mills switched into operation, with the open and closed
gate values installed in the channels supplying air-powder mixture to the fourth-tier burners, and with the fraction of air
supplied for lower blasting equal to 5–7% and that for the startup burners, 2%. The combined cleaning system operated in its
design mode with additional blowing operations according to special control signals. The furnace waterwalls and the convective
shaft surfaces were subjected to mechanical cleaning every year during current repairs. 相似文献
97.
D. Yu. Marchenko S. I. Petrov D. A. Sandzhieva A. G. Dedov 《Theoretical Foundations of Chemical Engineering》2016,50(4):648-654
The possibilities of using new reagent compositions based on diazo and azo dyestuff components that contain sulfonic groups are considered to determine nitrites in the presence of the contents of chlorides. New reagent compositions based on 1-hydroxynaphthalene-3,6-disulfonic acid in combination with 2,6- nitroorthanilic and 2,6-dichlorosulfanilic acids have been used to create indicator powders and indicator papers for the quantitative test determination of nitrite ions. Test methods based on sustainable indicator powders and indicator papers have been developed with the use of the ilPro portable spectrophotometer and PlustekSmartPhoto P60 compact mobile scanner combined with the Vuescan universal scan program. It has been shown that the sensitivity of the visual determination of nitrites in liquids using indicator papers is 0.5 mg/L. The sensitivity of the test method that uses indicator papers, the PlustekSmartPhoto P60 mobile scanner, and the ilPro portable spectrophotometer is 0.2 mg/L. Upon using the indicator powder and i1Pro portable spectrophotometer, the range of defined concentrations of nitrite ions is 0.01–5 mg/L. 相似文献
98.
Journal of Mining Science - 相似文献
99.
Stoiko Petrov Petrov 《应用聚合物科学杂志》1996,62(2):267-271
The possibility to obtain ultrafiltration polyacrylonitrile terpolymer membranes in the presence of formamide in dimethylformamide polymer solution was studied. Correlation between the changes in viscosity and rheological characteristics of the polymer solutions, on the one hand, and the equivalent pore radii, efficiency, and selectivity of membranes, on the other hand, were found. The concentration of formamide was varied from 0 to 4 mass %. The dynamic characteristics of the membranes were determined with regard to calibrators having different molecular weight. © 1996 John Wiley & Sons, Inc. 相似文献
100.
Togobitskaya D. N. Piptyuk V. P. Petrov A. F. Grekov S. V. Mirgorodskaya A. S. 《Metallurgist》2019,62(11-12):1115-1122
Metallurgist - A procedure is developed for calculating criteria for estimation and evaluation of chemical and structural micro-inhomogeneity of ferroalloy production melts. Models are proposed for... 相似文献