全文获取类型
收费全文 | 11240篇 |
免费 | 62篇 |
专业分类
电工技术 | 156篇 |
综合类 | 4篇 |
化学工业 | 741篇 |
金属工艺 | 344篇 |
机械仪表 | 91篇 |
建筑科学 | 115篇 |
矿业工程 | 23篇 |
能源动力 | 112篇 |
轻工业 | 101篇 |
水利工程 | 25篇 |
石油天然气 | 7篇 |
无线电 | 431篇 |
一般工业技术 | 451篇 |
冶金工业 | 470篇 |
原子能技术 | 112篇 |
自动化技术 | 8119篇 |
出版年
2022年 | 19篇 |
2021年 | 29篇 |
2019年 | 21篇 |
2018年 | 28篇 |
2017年 | 18篇 |
2016年 | 49篇 |
2015年 | 28篇 |
2014年 | 251篇 |
2013年 | 335篇 |
2012年 | 821篇 |
2011年 | 2369篇 |
2010年 | 1165篇 |
2009年 | 1025篇 |
2008年 | 750篇 |
2007年 | 660篇 |
2006年 | 514篇 |
2005年 | 650篇 |
2004年 | 568篇 |
2003年 | 625篇 |
2002年 | 310篇 |
2001年 | 41篇 |
2000年 | 17篇 |
1999年 | 39篇 |
1998年 | 44篇 |
1997年 | 44篇 |
1996年 | 36篇 |
1995年 | 36篇 |
1994年 | 32篇 |
1993年 | 29篇 |
1992年 | 38篇 |
1991年 | 19篇 |
1990年 | 20篇 |
1989年 | 29篇 |
1988年 | 20篇 |
1987年 | 25篇 |
1986年 | 27篇 |
1985年 | 38篇 |
1984年 | 26篇 |
1983年 | 33篇 |
1982年 | 30篇 |
1981年 | 31篇 |
1980年 | 28篇 |
1979年 | 33篇 |
1978年 | 22篇 |
1977年 | 24篇 |
1976年 | 25篇 |
1975年 | 28篇 |
1974年 | 39篇 |
1972年 | 17篇 |
1955年 | 17篇 |
排序方式: 共有10000条查询结果,搜索用时 109 毫秒
1.
Elli Ntakou Ralph Masiello Farnaz Farzan Shay Bahramirad Aleksi Paaso M.A. Nayeem Maigha Maigha Daniel Kushner 《The Electricity Journal》2019,32(4):45-49
This paper presents part of the work ComEd and Quanta Technology have performed to quantify the locational and temporal value of DER to avoid distribution grid upgrade investments. It focuses on the formulation of a robust and efficient algorithm for DER optimal dispatch on a distribution feeder to mitigate the violation of current and voltage limits using the allocated cost of capacity and locational marginal value of real and reactive DER injection/withdrawal. 相似文献
2.
Pavel Strunz Debashis Mukherji Přemysl Beran Ralph Gilles Lukas Karge Michael Hofmann Markus Hoelzel Joachim Rösler Gergely Farkas 《Metals and Materials International》2018,24(5):934-944
An addition of boron largely increases the ductility in polycrystalline high-temperature Co–Re alloys. Therefore, the effect of boron on the alloy structural characteristics is of high importance for the stability of the matrix at operational temperatures. Volume fractions of ε (hexagonal close-packed—hcp), γ (face-centered cubic—fcc) and σ (Cr2Re3 type) phases were measured at ambient and high temperatures (up to 1500 °C) for a boron-containing Co–17Re–23Cr alloy using neutron diffraction. The matrix phase undergoes an allotropic transformation from ε to γ structure at high temperatures, similar to pure cobalt and to the previously investigated, more complex Co–17Re–23Cr–1.2Ta–2.6C alloy. It was determined in this study that the transformation temperature depends on the boron content (0–1000 wt. ppm). Nevertheless, the transformation temperature did not change monotonically with the increase in the boron content but reached a minimum at approximately 200 ppm of boron. A probable reason is the interplay between the amount of boron in the matrix and the amount of σ phase, which binds hcp-stabilizing elements (Cr and Re). Moreover, borides were identified in alloys with high boron content. 相似文献
3.
4.
Navab SinghAuthor Vitae Moitreyee Mukherjee-RoyAuthor VitaeSohan Singh MehtaAuthor Vitae 《Microelectronics Journal》2003,34(4):237-245
The patterning of contact holes by selecting out-of-focus image plane (defocus) using attenuated phase shift masks (APSM) has been studied. Defocus is found to enhance the image modulation at low partial coherence for contact holes with negative local average of mask function. Semi-dense holes up to 130 nm in 8% APSM have been printed by 0.5 μm defocus at a partial coherence of 0.31 using KrF scanner with highest numerical aperture of 0.68. However, these holes were closed with in-focus imaging. Defocus is also found to be beneficial for patterning the pitches that have extensive side lobes with in-focus imaging. 相似文献
5.
Removal of gold from basic solutions containing [Au(CN)2]? has been demonstrated using the inherently conducting polymer polypyrrole. Polymers containing sulfonated aromatic dopants have been found to display a significant ability to remove gold from such solutions. Experiments performed in solutions containing both gold and copper cyanide complexes indicate that the recovery process is not highly selective. However, the polypyrroles used display significantly faster rates of gold recovery than activated carbon. © 2003 Society of Chemical Industry 相似文献
6.
Ralph Ralola 《今日电子》2006,(11):33-33
日本国家高级工业科学与技术研究所的一个研究组正在利用快速移动的细菌来驱动微转子马达,这是第一个在无机材料中加进了细菌的微机械器件。这种生物分子马达能比传统的马达更有效的将化学能转化为机械能,还能在大型结构中发挥自修复和自组织的潜能,有望用在微型机器人和微小电子系统中。 相似文献
7.
Adaptive motion control using neural network approximations 总被引:1,自引:0,他引:1
In this paper, we present a new adaptive technique for tracking control of mechanical systems in the presence of friction and periodic disturbances. Radial Basis Functions (RBFs) are used to compensate for the effects of nonlinearly occurring parameters in the friction and periodic disturbance model. Theoretical analysis, such as stability and transient performance, is provided. Furthermore, the performance of the adaptive RBF controller and its non-adaptive counterpart are compared. 相似文献
8.
Cherng-Min MaAuthor Vitae 《Pattern recognition》2003,36(8):1775-1782
Generally, a reduction operation (e.g., thinning and shrinking) on 3D binary images can be represented as a set of reduction templates where every object voxel of the image satisfying any template is turned to a background voxel. Generally, it is rather difficult, error-prone and time-consuming for verifying the topological soundness of a 3D parallel reduction operation. This paper proposes sufficient conditions of time complexity O(n) for verifying the topological soundness of 3D parallel 6-subiteration reduction operations of n templates where such a kind of 3D reduction operations is performed alternatively from the six orthogonal directions to turn object voxels to background voxels. By such sufficient conditions, the topology soundness of a 3D 6-subiteration parallel reduction operation can be verified by checking each and every of its templates. 相似文献
9.
In this paper, we present a control methodology for a class of discrete time nonlinear systems that depend on a possibly exogenous scheduling variable. This class of systems consists of an interpolation of nonlinear dynamic equations in strict feedback form, and it may represent systems with a time-varying nonlinear structure. Moreover, this class of systems is able to represent some cases of gain scheduling control, Takagi-Sugeno fuzzy systems, as well as input-output realizations of nonlinear systems which are approximated via localized linearizations. We present two control theorems, one using what we call a “global” approach (akin to traditional backstepping), and a “local” approach, our main result, where backstepping is again used but the control law is an interpolation of local control terms. An aircraft wing rock regulation problem with varying angle of attack is used to illustrate and compare the two approaches. 相似文献
10.
Shawn Hu Author Vitae Author Vitae 《Automatica》2007,43(7):1243-1248
This paper is concerned with stability analysis of discrete-time networked control systems over a communication channel subject to packet loss whose behavior is modeled by an i.i.d Bernoulli process with a packet dropping probability bounded by a constant. A necessary and sufficient condition for stability is obtained. A packet dropping margin is introduced as a measure of stability robustness of a system against packet dropping, and a formula for it is derived. A design method is proposed for achieving a large margin subject to a constraint that the system has a set of prescribed nominal closed-loop poles. 相似文献