全文获取类型
收费全文 | 541篇 |
免费 | 1篇 |
专业分类
电工技术 | 7篇 |
化学工业 | 61篇 |
金属工艺 | 42篇 |
机械仪表 | 53篇 |
建筑科学 | 7篇 |
矿业工程 | 27篇 |
能源动力 | 2篇 |
轻工业 | 2篇 |
水利工程 | 5篇 |
石油天然气 | 32篇 |
无线电 | 56篇 |
一般工业技术 | 125篇 |
冶金工业 | 57篇 |
原子能技术 | 35篇 |
自动化技术 | 31篇 |
出版年
2022年 | 7篇 |
2021年 | 7篇 |
2020年 | 4篇 |
2019年 | 13篇 |
2018年 | 15篇 |
2017年 | 11篇 |
2016年 | 15篇 |
2015年 | 10篇 |
2014年 | 8篇 |
2013年 | 31篇 |
2012年 | 22篇 |
2011年 | 20篇 |
2010年 | 19篇 |
2009年 | 26篇 |
2008年 | 21篇 |
2007年 | 19篇 |
2006年 | 17篇 |
2005年 | 9篇 |
2004年 | 12篇 |
2003年 | 10篇 |
2002年 | 6篇 |
2001年 | 7篇 |
2000年 | 11篇 |
1999年 | 4篇 |
1998年 | 14篇 |
1997年 | 7篇 |
1996年 | 6篇 |
1995年 | 5篇 |
1994年 | 4篇 |
1993年 | 9篇 |
1989年 | 7篇 |
1988年 | 9篇 |
1987年 | 4篇 |
1986年 | 9篇 |
1985年 | 7篇 |
1984年 | 5篇 |
1982年 | 8篇 |
1981年 | 6篇 |
1980年 | 5篇 |
1979年 | 6篇 |
1978年 | 16篇 |
1977年 | 11篇 |
1976年 | 13篇 |
1975年 | 8篇 |
1974年 | 8篇 |
1973年 | 9篇 |
1972年 | 5篇 |
1970年 | 4篇 |
1964年 | 3篇 |
1963年 | 3篇 |
排序方式: 共有542条查询结果,搜索用时 15 毫秒
1.
2.
3.
A fiber optic phase modulator is described in which the phase of a light wave traveling in an optical fiber is modulated by a composite electromechanical resonator with Q≌1000. The instantaneous frequency of the wave at the modulator output varies according to a harmonic law. The interval of tuning of the instantaneous light wave frequency achieved in the experiment is 20 GHz, which corresponds to a modulation index of ≌106. It is demonstrated that a maximum value of the frequency tuning range is determined by the elastic limit of the resonator material. 相似文献
4.
The main technical measures for increasing the nominal safety of the No. 5 unit of the Kursk nuclear power plant are presented:
optimization of the neutron-physical characteristics of the core, adoption of a comprehensive monitoring, control, and protection
system, switching to cluster-type control rods, adoption of a system for limiting radioactive emissions during anticipated
accidents with pipeline rupture outside the containment system.
__________
Translated from Atomnaya énergiya, Vol. 100, No. 4, pp. 320–327, April, 2006. 相似文献
5.
M. Yu. Boyarskii A. I. Lunin G. G. Potapov S. D. Ladokhin 《Chemical and Petroleum Engineering》1993,29(12):623-627
Translated from Khimicheskoe i Neftyanoe Mashinostroenie, No. 12, pp. 20–23, December, 1993. 相似文献
6.
Yu. N. Dragoshanskii V. V. Shulika A. P. Potapov O. F. Denisov 《The Physics of Metals and Metallography》2006,101(6):519-523
It has been shown that the formation of nitride-oxide magnetically active electrically insulating coatings on ribbons of iron-based soft magnetic alloys using the method of ion-plasma deposition and subsequent magnetic annealing in an ac magnetic field leads to a substantial improvement of their static and dynamic magnetic properties. 相似文献
7.
Peter Potapov Matthew C. Hansen Stephen V. Stehman Thomas R. Loveland Kyle Pittman 《Remote sensing of environment》2008,112(9):3708-3719
Estimation of forest cover change is important for boreal forests, one of the most extensive forested biomes, due to its unique role in global timber stock, carbon sequestration and deposition, and high vulnerability to the effects of global climate change. We used time-series data from the MODerate Resolution Imaging Spectroradiometer (MODIS) to produce annual forest cover loss hotspot maps. These maps were used to assign all blocks (18.5 by 18.5 km) partitioning the boreal biome into strata of high, medium and low likelihood of forest cover loss. A stratified random sample of 118 blocks was interpreted for forest cover and forest cover loss using high spatial resolution Landsat imagery from 2000 and 2005. Area of forest cover gross loss from 2000 to 2005 within the boreal biome is estimated to be 1.63% (standard error 0.10%) of the total biome area, and represents a 4.02% reduction in year 2000 forest cover. The proportion of identified forest cover loss relative to regional forest area is much higher in North America than in Eurasia (5.63% to 3.00%). Of the total forest cover loss identified, 58.9% is attributable to wildfires. The MODIS pan-boreal change hotspot estimates reveal significant increases in forest cover loss due to wildfires in 2002 and 2003, with 2003 being the peak year of loss within the 5-year study period. Overall, the precision of the aggregate forest cover loss estimates derived from the Landsat data and the value of the MODIS-derived map displaying the spatial and temporal patterns of forest loss demonstrate the efficacy of this protocol for operational, cost-effective, and timely biome-wide monitoring of gross forest cover loss. 相似文献
8.
This paper presents the validation aspects of a unified numerical framework based on SPH formulation and devoted to the modeling of fluid–structure interaction problems involving large motion of the fluid and large deformation with a possible failure of the structure. The fluid domain is modeled according to an updated Lagrangian formulation. The solid domain (3D and shell models) uses the total Lagrangian formulation. The fluid–structure interaction is treated via a unilateral contact algorithm adapted to SPH context. The SPH framework is verified on academic test cases and validated by simulating an experiment involving the reservoir leakage. 相似文献
9.
10.
A. A. Altukhov M. S. Afanas'ev V. B. Kvaskov V. E. Lyubchenko A. Yu. Mityagin E. N. Murav'ev L. A. Pomortsev V. A. Potapov B. V. Spitsyn 《Inorganic Materials》2004,40(1):S50-S70
This review focuses on the critical issues and future directions in the application of diamond in high technology. Diamond nuclear radiation detectors, photosensors, photoemitters, spectral windows, active and passive microelectronic components, and microelectromechanical systems are discussed in detail. In Russia, high-technology diamond applications have not yet moved toward the manufacturing stage, even though Russia possesses immense resources of natural diamond and a considerable scientific potential in the field of creating unique synthetic diamonds, polycrystalline and single-crystal diamond films, and diamond-like compounds. We hope that the points raised in this review will provide the impetus for the development of diamond technology in Russia. 相似文献