全文获取类型
收费全文 | 590篇 |
免费 | 9篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 94篇 |
化学工业 | 144篇 |
金属工艺 | 24篇 |
机械仪表 | 20篇 |
建筑科学 | 18篇 |
能源动力 | 23篇 |
轻工业 | 37篇 |
水利工程 | 5篇 |
石油天然气 | 1篇 |
无线电 | 35篇 |
一般工业技术 | 84篇 |
冶金工业 | 39篇 |
原子能技术 | 21篇 |
自动化技术 | 58篇 |
出版年
2022年 | 3篇 |
2021年 | 12篇 |
2020年 | 6篇 |
2019年 | 9篇 |
2018年 | 10篇 |
2017年 | 6篇 |
2016年 | 11篇 |
2015年 | 7篇 |
2014年 | 10篇 |
2013年 | 30篇 |
2012年 | 32篇 |
2011年 | 37篇 |
2010年 | 12篇 |
2009年 | 24篇 |
2008年 | 23篇 |
2007年 | 24篇 |
2006年 | 35篇 |
2005年 | 17篇 |
2004年 | 35篇 |
2003年 | 28篇 |
2002年 | 20篇 |
2001年 | 16篇 |
2000年 | 11篇 |
1999年 | 10篇 |
1998年 | 19篇 |
1997年 | 20篇 |
1996年 | 14篇 |
1995年 | 15篇 |
1994年 | 5篇 |
1993年 | 14篇 |
1992年 | 8篇 |
1991年 | 2篇 |
1989年 | 7篇 |
1988年 | 3篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 6篇 |
1984年 | 3篇 |
1983年 | 7篇 |
1982年 | 7篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1979年 | 5篇 |
1978年 | 8篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1971年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有603条查询结果,搜索用时 0 毫秒
61.
An attempt to determine protein denaturing potency of typical surfactants has been made by measuring specific rotation of
bovine serum albumin. The potencies obtained were examined in relation to the intensities of skin roughness in vivo caused
by the surfactants, and a noticeable correlation was found between them. This fact also suggested that the cause of skin roughness
may be attributed to a certain extent to adsorption of surfactants. In addition, this technique is very useful in predicting
the skin roughening potency of a surfactant without using human skin. 相似文献
62.
63.
64.
65.
Shozo Ishizaka John G. Stockner Katsumi Kobayashi Kunihiro Shima Kenji Katori Humitake Seki 《Water research》1983,17(12):1815-1821
Multi-elemental traces comprising particulate matter in natural water collected during summer in 1978 and 1979 from British Columbia, Canada, were analyzed by α-particle excited X-ray fluorometry. Common elements from all waters examined were Si, Cl, Ca and Fe. The similarity of their distribution in different aquatic environments was statistically analyzed. They were distributed homogeneously in the marine environment but heterogeneously in the freshwater environments. No heavy metals concerned with the environmental standards were detected for all waters examined. 相似文献
66.
67.
The temperature dependencies of in situ small-angle X-ray scattering (SAXS) of water adsorbed and of adsorption isotherm of water in hydrophobic carbon nanopores were measured over the temperature range of 293 to 328 K. The structures of water nanoclusters adsorbed in the nanopores were determined with the density fluctuation analysis of in situ SAXS data. The difference of the density fluctuations between adsorption and desorption was ascribed to the water structural difference. The structural transitions of the water nanoclusters were observed around 318 K for adsorption and 308 K for desorption. 相似文献
68.
Takuro Kida Katsumi Kurogochi 《International Journal of Circuit Theory and Applications》1982,10(1):43-56
New tolerance measures for lossless or dissipative ladder filters and their numerical evaluation procedures are proposed. The proposed measures provide the approximate values of the statistical mean and variance of the variation of the operating propagation function or characteristic function in nepers. These measures are derived by utilizing a first- to fourth-order Taylor series approximation and can be evaluated easily by a series of simple algebraic operations. Simple formulae are also presented which estimate the error incurred by the neglected terms of this Taylor series approximation. 相似文献
69.
Kiyoshi Itoh Katsumi Muramatsu Mabito Matsui Shigemichi Suzuki 《Computers & Graphics》1982,6(2):47-61
Network analysis is powerful in building formal network models of various computational systems or social systems and obtaining their functions and performance exactly because of simplicity of binary relations in networks. Traditionally, it takes lots of effort in network analysis because network analysis was performed by the use of lots of numerical data in batch processing form. Effective network analysis activity, satisfying the system requirements based on consideration for such traditional manner with high cost, requires semiautomatic or computer aided man-machine facilities with interactive editing, analysis, and result viewing functions. We have developed Graphical Editing and Analysis system for Network System (Geans) on DEC PDP-11/34 minicomputer with a graphic display which enables us to edit or modify various network representations and analyze their qualitative and quantitative property, smoothly and interactively with the use of graphics and data abstraction. Geans is composed of a network editing system with effective use of a graphic display, a network data management system with systematic use of network data abstraction, a network analysis system with construction of shared library routines and specific object problem oriented routines, and a node/arc shape definition system. Geans has been applied to various network models such as a transportation analysis problem, PERT/CPM planning, Petri Net analysis and a guidance system for an urban railway network, and moreover it is being applied to other analysis areas as evolving itself. 相似文献
70.
We propose a novel subcarrier allocation (SCA) based approach for compensating carrier frequency offset (CFO) and I/Q imbalances in direct-conversion OFDM receivers. From the matrix representation of OFDM signals with CFO and I/Q imbalances, maximum likelihood CFO estimation and the associated SCA are given. Then, an SCA-based algorithm is proposed for the I/Q imbalances compensation. Moreover, the proposed approach is extended to a blind compensation scheme for OFDM signals with asymmetric SCA. 相似文献