全文获取类型
收费全文 | 1040篇 |
免费 | 63篇 |
专业分类
电工技术 | 16篇 |
化学工业 | 374篇 |
金属工艺 | 25篇 |
机械仪表 | 30篇 |
建筑科学 | 36篇 |
能源动力 | 28篇 |
轻工业 | 46篇 |
水利工程 | 1篇 |
石油天然气 | 3篇 |
武器工业 | 1篇 |
无线电 | 68篇 |
一般工业技术 | 175篇 |
冶金工业 | 86篇 |
原子能技术 | 8篇 |
自动化技术 | 206篇 |
出版年
2024年 | 3篇 |
2023年 | 11篇 |
2022年 | 71篇 |
2021年 | 81篇 |
2020年 | 31篇 |
2019年 | 36篇 |
2018年 | 42篇 |
2017年 | 32篇 |
2016年 | 34篇 |
2015年 | 46篇 |
2014年 | 50篇 |
2013年 | 77篇 |
2012年 | 65篇 |
2011年 | 64篇 |
2010年 | 63篇 |
2009年 | 56篇 |
2008年 | 33篇 |
2007年 | 45篇 |
2006年 | 38篇 |
2005年 | 19篇 |
2004年 | 21篇 |
2003年 | 15篇 |
2002年 | 17篇 |
2001年 | 3篇 |
2000年 | 8篇 |
1999年 | 5篇 |
1998年 | 11篇 |
1997年 | 14篇 |
1996年 | 11篇 |
1995年 | 9篇 |
1994年 | 8篇 |
1993年 | 10篇 |
1992年 | 6篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 5篇 |
1987年 | 7篇 |
1986年 | 5篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1981年 | 9篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1976年 | 4篇 |
1966年 | 1篇 |
1953年 | 1篇 |
排序方式: 共有1103条查询结果,搜索用时 15 毫秒
101.
Julien Jumel Michal K. Budzik Martin E.R. Shanahan 《Engineering Fracture Mechanics》2011,78(18):3253-3269
A first order correction is proposed taking into account both interface elasticity and transverse anticlastic curvature of flexible substrate(s) in the DCB (and related tests). Adherends are represented by Kirchhoff–Love plates, and the interface by a Winkler-type elastic foundation. Two functions are introduced, representing evolution of beam deflection along the sample midline and anticlastic curvature along the plate. A method of virtual work is used to find the associated equilibrium equation. The two-dimensional sample deformation is determined semi-analytically. Sample rigidity and energy release rate are computed for various geometrical configurations and compared to more common models. 相似文献
102.
Michal Košťál František Cvachovec Bohumil Ošmera Wolfgang Hansen Vlastimil Juříček 《Annals of Nuclear Energy》2010
The present paper deals with measured as well as calculated energy spectra of neutron and photon beams from the AKR-2 experimental reactor after having passed through Fe layers and Fe/H2O combined layers. The experiment results are compared with calculations presented in various nuclear data libraries, such as, ENDF/B VI.2., ENDF/B VII., BROND 3, JENDL 3.3 and JEFF 3.1. Two models were used to calculate the neutron transport. The first takes into account the atomic structure of the material, whereas the other neglects the effect of inter-atomic bonds assuming the atomic nucleus behaviour to follow the free gas model. 相似文献
103.
104.
The electrochemical behaviour of samarium was investigated in LiF-BeF2 system on an inert (Mo) electrode by cyclic voltammetry and chronopotentiometry at 804, 833, 847 and 872 K. Redox process Sm3++e-→Sm2+ was recognized and analysed. Cyclic voltammetry data suggested that at potential sweep rates lower than 0.25 V/s, the reduction was limited by the diffusion of Sm3+ ions. It was not possible to observe reduction process of Sm2++2e-→Sm0 due to insufficient electrochemical stability of LiF-BeF2. Diffusion coefficients of Sm3+ ions in LiF-BeF2 were calculated from voltammetric and chronopotentiometric data in the temperature range 804-872 K. Diffusion coefficient values obeyed Arrhenius law. Activation energy was calculated to be 102.5 kJ/mol. 相似文献
105.
In a 2001 report titled Energy Research at DOE: Was It Worth It? a National Research Council (NRC) committee defined a set of simplifying rules to estimate the net economic benefits from technologies supported by the Department of Energy (DOE). We evaluate the efficacy of the NRC rules compared to published literature on acceleration of technology introduction into markets, technology diffusion, and infrastructure change. We also offer considerations for revisions of the rules that call for the use of technology and sector-specific data, advanced forecasting techniques, and sensitivity analysis to test the robustness of the methodology. 相似文献
106.
Yaniv Assaf Pazit Pianka Pia Rotshtein Michal Sigal Talma Hendler 《Israel journal of chemistry》2003,43(1-2):155-163
Diffusion Tensor Imaging (DTI) is used to characterize the diffusion properties of deviated white matter caused by brain tumors. DTI was recently shown to be very helpful in delineating white matter both within brain lesions and surrounding them. Displacement of white matter fibers may be one of the consequences of tumor growth adjacent to white matter. The combination of white matter mapping with DTI and gray matter mapping using functional MRI, in some cases, facilitated assessment of the relation between the shifted cortical areas and the corresponding white matter tracts. We found that the fractional anisotropy extracted from DTI is increased by 38% in areas of non-edematous shifted white matter fibers. By contrast, trace apparent diffusion coefficient (ADC) values in those areas were found to be similar to contralateral side and normal control values. Analysis of the three diffusion tensor eigenvalues revealed that the increase in the fractional anisotropy is a result of two processes. The first is the increase in the diffusion parallel to the fibers—λ1 (by 18%), and the second is the decrease in the diffusion perpendicular to fibers—λ3 (by 34%) as compared with the contralateral side. These opposing changes cause an increase in the diffusion anisotropy but no change in the trace ADC. It is suggested that the pressure caused by the tumor may lead to an increase in white matter fiber tension, thus causing an increase in λ1. On the other hand, the same pressure causes increased fiber density per unit area, leading to a higher degree of restricted diffusion in the extracellular space and, hence, a reduction in λ3. 相似文献
107.
Adolphsen Chris Litke Alan Schwarz Andreas Turala Michal Anzivino Giuseppina Horisberger Roland Hubbeling Leonardus Hyams Bernard Breakstone Alan Cence Robert Parker Sherwood Walker James T. 《IEEE transactions on nuclear science》1986,33(1):57-59
Silicon detectors with 256 strips, having a pitch of 25 ?m, and connected to two 128 channel NMOS VLSI chips each (Microplex), have been tested in relativistic charged particle beams at CERN and at the Stanford Linear Accelerator Center. The readout chips have an input channel pitch of 47.5 ?m and a single multiplexed output which provides voltages proportional to the integrated charge from each strip. The most probable signal height from minimum ionizing tracks was 15 times the rms noise in any single channel. Two-track traversals with a separation of 100 ?m were cleanly resolved. 相似文献
108.
T. Egami W. Dmowski R. J. McQueeney M. Arai N. Seiji H. Yamauchi 《Journal of Superconductivity》1995,8(5):587-590
Significant changes in the local atomic structure and lattice dynamics were observed by pulsed neutron inelastic scattering measurements on YBa2Cu4O8 both around the superconducting transition temperature and around the spin-gap temperature. These observations and earlier results of numerical calculations on the enhancement of electron-lattice interaction by electron correlation lead to a novel picture of unconventional lattice-induced superconductivity related to antiferroelectric instability. 相似文献
109.
Vakil Eli; Arbell Nurit; Gozlan Michal; Hoofien Dan; Blachstein Haya 《Canadian Metallurgical Quarterly》1992,60(5):802
Applied qualitative analysis to the information recalled by control Ss and closed-head-injured (CHI) patients. The Logical Memory subtest of the Wechsler Memory Scale (WMS) was administered to 40 CHI and 40 control Ss. Recall was tested immediately after administration, 40 min later, and 24 hrs later. The analysis took into account the importance of recalled information as determined by a prior rating according to 3 levels of importance. Results suggest that CHI patients have difficulty selectively retrieving the most important information after a long delay. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
110.
Marcin Janicki Marcin Daniel Michal Szermer Andrzej Napieralski 《Microelectronics Journal》2004,35(10):831-840
The proper design and simulation of modern electronic microsystems oriented towards environment monitoring requires accurate models of various ambient sensors. In particular, this paper presents a comprehensive model of an ion sensitive field effect transistor (ISFET). The model can be employed straightforwardly for simulations at device, circuit or system level.First, the model was validated with electrical measurements and simulations of real structures performed for different ion concentration and temperature values. Then, the ISFET sensor model was employed for mixed-signal simulations in VHDL-AMS, when the analysis of a microsystem consisting of the ISFET sensor and a sigma-delta analogue-to-digital converter was carried out. Additionally, the presence of other ions than hydrogen in the measured solution was also taken into account in the simulations. 相似文献