全文获取类型
收费全文 | 213356篇 |
免费 | 5125篇 |
国内免费 | 2138篇 |
专业分类
电工技术 | 5096篇 |
技术理论 | 2篇 |
综合类 | 2331篇 |
化学工业 | 34027篇 |
金属工艺 | 9840篇 |
机械仪表 | 7364篇 |
建筑科学 | 7321篇 |
矿业工程 | 1774篇 |
能源动力 | 5546篇 |
轻工业 | 18614篇 |
水利工程 | 2210篇 |
石油天然气 | 5683篇 |
武器工业 | 203篇 |
无线电 | 24287篇 |
一般工业技术 | 37908篇 |
冶金工业 | 35091篇 |
原子能技术 | 4684篇 |
自动化技术 | 18638篇 |
出版年
2022年 | 1513篇 |
2021年 | 2671篇 |
2020年 | 1916篇 |
2019年 | 2093篇 |
2018年 | 3022篇 |
2017年 | 3190篇 |
2016年 | 3202篇 |
2015年 | 2904篇 |
2014年 | 4409篇 |
2013年 | 9937篇 |
2012年 | 6674篇 |
2011年 | 8780篇 |
2010年 | 7214篇 |
2009年 | 7891篇 |
2008年 | 7850篇 |
2007年 | 7811篇 |
2006年 | 7016篇 |
2005年 | 6425篇 |
2004年 | 5655篇 |
2003年 | 5166篇 |
2002年 | 5107篇 |
2001年 | 4983篇 |
2000年 | 4808篇 |
1999年 | 5123篇 |
1998年 | 11308篇 |
1997年 | 8197篇 |
1996年 | 6456篇 |
1995年 | 4899篇 |
1994年 | 4155篇 |
1993年 | 3933篇 |
1992年 | 2938篇 |
1991年 | 2789篇 |
1990年 | 2605篇 |
1989年 | 2598篇 |
1988年 | 2507篇 |
1987年 | 2226篇 |
1986年 | 2138篇 |
1985年 | 2424篇 |
1984年 | 2237篇 |
1983年 | 2037篇 |
1982年 | 1914篇 |
1981年 | 1968篇 |
1980年 | 1812篇 |
1979年 | 1827篇 |
1978年 | 1779篇 |
1977年 | 2115篇 |
1976年 | 2694篇 |
1975年 | 1559篇 |
1974年 | 1553篇 |
1973年 | 1612篇 |
排序方式: 共有10000条查询结果,搜索用时 224 毫秒
991.
992.
R. P. Okatov F. K. Nizametdinov B. N. Tsai T. T. Bondarenko 《Journal of Mining Science》2003,39(2):139-142
Using the synthesis of the kinetic concept on solid strength and the Coulomb - Mohr strength theory as the base, the failure conditions taking into account the time and temperature factors are obtained. 相似文献
993.
A Sketch-Based Interface for Clothing Virtual Characters 总被引:5,自引:0,他引:5
Emmanuel Turquin Jamie Wither Laurence Boissieux Marie-Paule Cani John F. Hughes 《Computer Graphics and Applications, IEEE》2007,27(1):72-81
This interactive system for garment creation determines a garment's shape and how the character wears it based on a user-drawn sketch. The system then uses distances between the 2D garment silhouette and the character model to infer remaining distance variations in 3D 相似文献
994.
A. A. Khrushchinskii S. A. Kuten’ N. M. Budevich V. F. Minenko O. M. Zhukova N. K. Luk’yanov 《Journal of Engineering Physics and Thermophysics》2007,80(6):1170-1177
Measurements of the beta-activity of milk, serving as the main source of information on the radioactive contamination of the
environment by the iodine isotope 131I, carried out on a DP-100 radiometer in the early post-Chernobyl period (1986) in Belarus, have been mathematically simulated.
The results obtained allow the conclusion that the indicated measurements should be analyzed again with consideration for
all of the nuclides present in milk.
__________
Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 80, No. 6, pp. 102–108, November–December, 2007. 相似文献
995.
Optical Splitting Trees for High-Precision Monocular Imaging 总被引:1,自引:0,他引:1
McGuire M. Matusik W. Pfister H. Chen B. Hughes J.F. Nayar S.K. 《Computer Graphics and Applications, IEEE》2007,27(2):32-42
In this article, we consider the design of monocular multiview optical systems that form optical splitting trees, where the optical path topology takes the shape of a tree because of recursive beam splitting. Designing optical splitting trees is challenging when it requires many views with specific spectral properties. We introduce a manual design paradigm for optical splitting trees and a computer-assisted design tool to create efficient splitting-tree cameras. The tool accepts as input a specification for each view and a set of weights describing the user's relative affinity for efficiency, measurement accuracy, and economy. An optimizer then searches for a design that maximizes these weighted priorities. Our tool's output is a splitting-tree design that implements the input specification and an analysis of the efficiency of each root-to-leaf path. Automatically designed trees appear comparable to those designed by hand; we even show some cases where they are superior. With the help of the optimizer, the system demonstrates high dynamic range, focusing, matting, and hybrid imaging implemented on a single, reconfigurable camera containing eight sensors 相似文献
996.
997.
998.
Composite powder based on AlB has been obtained by crushing pieces of industrial-waste Al - B fiber composite material at room temperature. The original design of a high precision microhardness tester made it possible to estimate the properties of powder particles both in the near-surface layers and under them. The aluminum fraction in the powder was established to represent a new structurally nonhomogenous material with increased microhardness (1.5 GPa), which grows up to 4 GPa in the near-surface layers. This is caused by formation of defects and stable oxides on external and internal interfaces in the aluminum matrix during crushing. To optimize the process of AlB powder sintering, adhesion on clean and real Al - B and Al/Al interfaces at various temperatures was investigated. By sintering at 910 K, new ceramic materials have been obtained with a density of 2200 kg/m3 and a strength of 90 MPa. 相似文献
999.
P. A. Borodovskii A. F. Buldygin A. S. Tokarev E. V. Chernyavskii 《Russian Microelectronics》2005,34(5):316-324
A further investigation is conducted into a new microwave method for evaluating bulk lifetime in silicon ingots 相似文献
1000.