全文获取类型
收费全文 | 186806篇 |
免费 | 1817篇 |
国内免费 | 235篇 |
专业分类
电工技术 | 2827篇 |
综合类 | 147篇 |
化学工业 | 29331篇 |
金属工艺 | 9811篇 |
机械仪表 | 6116篇 |
建筑科学 | 3727篇 |
矿业工程 | 1920篇 |
能源动力 | 3073篇 |
轻工业 | 10853篇 |
水利工程 | 2909篇 |
石油天然气 | 8725篇 |
武器工业 | 12篇 |
无线电 | 16356篇 |
一般工业技术 | 40921篇 |
冶金工业 | 32497篇 |
原子能技术 | 7140篇 |
自动化技术 | 12493篇 |
出版年
2021年 | 1831篇 |
2019年 | 1818篇 |
2018年 | 3277篇 |
2017年 | 3367篇 |
2016年 | 3680篇 |
2015年 | 1896篇 |
2014年 | 3342篇 |
2013年 | 7146篇 |
2012年 | 4988篇 |
2011年 | 6222篇 |
2010年 | 5055篇 |
2009年 | 5507篇 |
2008年 | 5635篇 |
2007年 | 5564篇 |
2006年 | 4684篇 |
2005年 | 4363篇 |
2004年 | 4105篇 |
2003年 | 3956篇 |
2002年 | 3870篇 |
2001年 | 3823篇 |
2000年 | 3720篇 |
1999年 | 3645篇 |
1998年 | 8540篇 |
1997年 | 6117篇 |
1996年 | 4537篇 |
1995年 | 3411篇 |
1994年 | 3014篇 |
1993年 | 3159篇 |
1992年 | 2468篇 |
1991年 | 2504篇 |
1990年 | 2613篇 |
1989年 | 2524篇 |
1988年 | 2527篇 |
1987年 | 2347篇 |
1986年 | 2411篇 |
1985年 | 2507篇 |
1984年 | 2356篇 |
1983年 | 2265篇 |
1982年 | 2091篇 |
1981年 | 2331篇 |
1980年 | 2184篇 |
1979年 | 2401篇 |
1978年 | 2514篇 |
1977年 | 2585篇 |
1976年 | 3313篇 |
1975年 | 2327篇 |
1974年 | 2371篇 |
1973年 | 2422篇 |
1972年 | 2200篇 |
1971年 | 1954篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Russian Journal of Nondestructive Testing - The main elements of a developed portable radiometric system (PRS) and options for its application are discussed. When developing the PRS detector... 相似文献
62.
63.
V. A. Eremenko V. N. Karpov V. V. Timonin N. G. Barnov I. O. Shakhtorin 《Journal of Mining Science》2015,51(6):1113-1125
The authors have determined the causes of drop in performance of induced block caving using fans of blastholes 105 mm in diameter and single blastholes 250 mm in diameter, as well as the sources of increased drilling cost and expansion of start-up time of production blocks in Abakan underground mine. Alternatives of improvement in drilling efficiency under current conditions are discussed. 相似文献
64.
Gavshina O. V. Doroganov V. A. Doroganov E. A. Onishchuk V. I. Trepalina Yu. N. 《Refractories and Industrial Ceramics》2019,60(4):350-354
Refractories and Industrial Ceramics - Results of studying the rheotechnological properties of moldable refractory mixes based on bauxite suspensions plasticized with refractory clay are presented.... 相似文献
65.
V.A. Dekhtyarenko T.V. Pryadko D.G. Savvakin V.I. Bondarchuk G.S. Mogylnyy 《International Journal of Hydrogen Energy》2021,46(11):8040-8047
The influence of phase composition and microstructure of Ti42.75Zr27Mn20.25V10 alloy on its hydrogenation kinetic and phase composition of hydrogenated product was studied. It is established that the process of dissociation of hydrogen molecules begins on the surface of Laves phase crystallites. The dissolution of atomic hydrogen in the material volume leads to the formation of cracks in the intermetallic crystallites, which further appear as additional centers of dissociation of hydrogen molecules and noticeably accelerate the diffusion of hydrogen into the bulk material. It was shown that the Laves phase acts as a donor of atomic hydrogen for the BCC solid solution during hydrogenation of two-phase structure, initiating intensive hydrogenation of the BCC phase at room temperature. 相似文献
66.
Kooij Julian F. P. Flohr Fabian Pool Ewoud A. I. Gavrila Dariu M. 《International Journal of Computer Vision》2019,127(3):239-262
International Journal of Computer Vision - Anticipating future situations from streaming sensor data is a key perception challenge for mobile robotics and automated vehicles. We address the problem... 相似文献
67.
Zinov’eva I. V. Fedorov A. Ya. Milevskii N. A. Zakhodyaeva Yu. A. Voshkin A. A. 《Theoretical Foundations of Chemical Engineering》2021,55(4):663-670
Theoretical Foundations of Chemical Engineering - A choline chloride–sulfosalicylic acid deep eutectic solvent (DES) is proposed for dissolving the oxides Co(II), Cu(II), Zn(II), Fe(III),... 相似文献
68.
Chertkov Yu. B. Anikin M. N. Lebedev I. I. Naimushin A. G. Smol’nikov N. V. 《Atomic Energy》2021,131(1):42-45
Atomic Energy - The results of calculations and experimental determination of the neutronics characteristics of the IRT-T research reactor are presented. The IRT-T reactor is a pool reactor with... 相似文献
69.
Anh Tuan Thanh Pham Oanh Kieu Truong Le Dung Van Hoang Truong Huu Nguyen Trang Huyen Cao Pham Phuong Thanh Ngoc Vo Thang Bach Phan Vinh Cao Tran 《Journal of the European Ceramic Society》2021,41(6):3493-3500
Structure modification has been found to tune significantly the transparent-conducting performance, especially mobility and conductivity of hydrogenated Ga-doped ZnO (HGZO) films. The strong correlation between film thickness and mobility of the films is revealed. The mobility increases quickly with increasing the thickness from 350 to 900 nm, and then tends to be saturated at further thicknesses. A higher mobility than 50 cm2/Vs can be achieved, which is an extra-high value for polycrystalline ZnO films deposited by using the sputtering technique. The thickness-dependent mobility originates from scatterings on grain boundaries and dislocation-induced defects controlled by thin-film growth. Based on the Volmer-Weber model, an expansion model is built up to describe the thickness-dependent crystal growth of the HGZO films, especially at the thick films. As a result, the 800 nm-thick HGZO film obtains the highest performance with high mobility of 51.5 cm2/Vs, low resistivity of 5.3 × 10?4 Ωcm, and good transmittance of 83.3 %. 相似文献
70.
High Temperature - Experimental findings suggest that a strongly ionized, arc He plasma of atmospheric pressure does not exist in the state of the local thermodynamic equilibrium (LTE) expected for... 相似文献