全文获取类型
收费全文 | 806篇 |
免费 | 63篇 |
专业分类
电工技术 | 7篇 |
综合类 | 1篇 |
化学工业 | 235篇 |
金属工艺 | 15篇 |
机械仪表 | 15篇 |
建筑科学 | 11篇 |
矿业工程 | 3篇 |
能源动力 | 22篇 |
轻工业 | 26篇 |
水利工程 | 3篇 |
石油天然气 | 1篇 |
无线电 | 90篇 |
一般工业技术 | 292篇 |
冶金工业 | 37篇 |
原子能技术 | 7篇 |
自动化技术 | 104篇 |
出版年
2023年 | 11篇 |
2022年 | 40篇 |
2021年 | 37篇 |
2020年 | 25篇 |
2019年 | 17篇 |
2018年 | 33篇 |
2017年 | 25篇 |
2016年 | 27篇 |
2015年 | 15篇 |
2014年 | 40篇 |
2013年 | 52篇 |
2012年 | 44篇 |
2011年 | 68篇 |
2010年 | 29篇 |
2009年 | 33篇 |
2008年 | 52篇 |
2007年 | 34篇 |
2006年 | 32篇 |
2005年 | 37篇 |
2004年 | 34篇 |
2003年 | 40篇 |
2002年 | 27篇 |
2001年 | 12篇 |
2000年 | 11篇 |
1999年 | 16篇 |
1998年 | 13篇 |
1997年 | 7篇 |
1996年 | 8篇 |
1995年 | 13篇 |
1994年 | 6篇 |
1993年 | 6篇 |
1992年 | 3篇 |
1991年 | 6篇 |
1990年 | 1篇 |
1989年 | 4篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1981年 | 2篇 |
1977年 | 1篇 |
1974年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有869条查询结果,搜索用时 15 毫秒
61.
Evgueni Jak Peter C. Hayes Sergei Degterov Arthur D. Peiton 《Metallurgical and Materials Transactions B》2001,32(5):793-800
Experimental and thermodynamic modeling studies have been carried out on the Zn-Fe-Si-O system. This research is part of a
wider program to characterize zinc/lead industrial slags and sinters in the PbO-ZnO-SiO2-CaO-FeO-Fe2O3 system. Experimental investigations involve high-temperature equilibration and quenching techniques followed by electron
probe X-ray microanalysis (EPMA). Liquidus temperatures and solid solubilities of the crystalline phases were measured in
the temperature range from 1200 °C to 1450 °C (1473 to 1723 K) in the zinc ferrite, zincite, willemite, and tridymite primary-phase
fields in the Zn-Fe-Si-O system in air. These equilibrium data for the Zn-Fe-Si-O system in air, combined with previously
reported data for this system, were used to obtain an optimized self-consistent set of parameters of thermodynamic models
for all phases. 相似文献
62.
Denis V. Anokhin Yuli K. Godovsky Sergei N. Magonov Natalia N. Makarova Wim Bras 《Polymer》2007,48(16):4837-4848
The structure and phase transitions of cyclolinear polyorganosiloxane copolymer containing 12-member polysiloxane rings have been studied using synchrotron WAXS, DSC, TEM, variable-temperature AFM and polarized optical microscopy. The primary structure of this polymer can be viewed as a necklace of disk-shaped entities (cyclic groups) connected via flexible linkers.In the mesomorphic state, the presence of two different LC phases has been derived from the analysis of WAXS fiber diffractograms. The morphology of one of the phases shows a conventional hexagonal packing of LC chains where the chain axes are perpendicular to the plane of the 2D hexagonal lattice. The other one, so-called R-phase, has a vertically oriented rectangular 2D lattice formed by inter-chain correlations between the bulky polysiloxane cycles (disks). To our knowledge, such a disk-necklace mesophase in which the LC lattice is parallel to the backbone direction has not been reported in the literature so far. 相似文献
63.
The structure and function of the target-language generation module for KBMT-89 is described. The lexical selection module (which includes thematic-role subcategorization, a meaning distance metric, and syntactic subcategorization) is presented. We also describe the generation mapping rules, and rule interpretation in the generation of f-structures for target language utterances. 相似文献
64.
Sergei V. Kalinin Rui Shao Dawn A. Bonnell 《Journal of the American Ceramic Society》2005,88(5):1077-1098
In the last two decades, scanning probe microscopies (SPMs) have become the primary tool for addressing structure and electronic, mechanical, optical, and transport phenomena on the nanometer and atomic scales. Here, we summarize basic principles of SPM as applied for oxide materials characterization and present recent advances in high-resolution imaging and local property measurements. The use of advanced SPM techniques for solutions of material related problems is illustrated on the examples of grain boundary transport in polycrystalline oxides and ferroelectric domain imaging and manipulation. Future prospects for SPM applications in materials science are discussed. 相似文献
65.
Marcus A. Worsley Peter J. Pauzauskie Sergei O. Kucheyev Joseph M. Zaug Alex V. Hamza Joe H. Satcher Theodore F. Baumann 《Acta Materialia》2009,57(17):5131-5136
Here, we present the synthesis and characterization of low-density single-walled carbon nanotube-based aerogels (SWNT-CA). Aerogels with varying nanotube loading (0–55 wt.%) and density (20–350 mg cm?3) were fabricated and characterized by four-probe method, electron microscopy, Raman spectroscopy and nitrogen porosimetry. Several properties of the SWNT-CAs were highly dependent upon nanotube loading. At nanotube loadings of 55 wt.%, shrinkage of the aerogel monoliths during carbonization and drying was almost completely eliminated. Electrical conductivities are improved by an order of magnitude for the SWNT-CA (55 wt.% nanotubes) compared to those of foams without nanotubes. Surface areas as high as 184 m2 g?1 were achieved for SWNT-CAs with greater than 20 wt.% nanotube loading. 相似文献
66.
Samuel Cupillard Sergei Glavatskih Michel J. Cervantes 《Tribology International》2009,42(10):1487-1495
Analysis of a 3D inlet textured slider bearing with a temperature dependent fluid is performed. Numerical simulations are carried out for a laminar and steady flow. Hot and cold lubricant mixing in the groove is modelled and examined for different operating conditions. Thermohydrodynamic performance of the bearing is analyzed for different texture lengths.Results show that texture has a stronger and positive influence on load carrying capacity when thermal effects are considered. This beneficial effect is at a maximum for the longest dimples with a length shorter than the pad length. Texture is also beneficial for the load carrying capacity when the sliding speed and inlet flow rate are varied. The load carrying capacity of the slider can be increased by up to 16% in severe operating conditions (high sliding speed). 相似文献
67.
Mouna Marrakchi Sergei V. Dzyadevych Florence Lagarde Claude Martelet Nicole Jaffrezic-Renault 《Materials science & engineering. C, Materials for biological applications》2008,28(5-6):872-875
This paper investigates the development of a biosensor associating two distinct enzymatic activities, that of the beta-galactosidase and that of the glucose oxidase, in order to apply it for the quantitative detection of lactose in milk. To eliminate interferences with glucose, a differential mode of measurement was used. Results show a linear calibration curve for lactose concentration between 60 and 800 μM (0.03 to 0.3 g/L). Tests with real commercial milk samples were carried out to validate the conductometric biosensor. 相似文献
68.
We present measurements and simulations of a transmission-line network that has been designed for cloaking applications in the microwave region. Here the network is not used for cloaking but for channelling electromagnetic fields through an electrically dense array of metal objects, which alone is basically impenetrable to the impinging electromagnetic radiation. With the designed transmission-line network the waves emitted by a source placed in an air-filled waveguide are coupled into the network and guided through the array of metallic objects. Our goal is to illustrate the simple manufacturing, assembly, and the general feasibility of cloaking devices based on the transmission-line approach. Most importantly, we demonstrate both with measurements and with numerical simulations the excellent coupling of waves between the network and the surrounding medium. 相似文献
69.
The strain-rate-intensity factor is the coefficient of the principal singular term in an expansion of the equivalent strain rate in a series in the vicinity of maximum-friction surfaces. Its value controls the physical processes in a thin material layer near the frictional interfaces. The objective of the present paper is to study the effects of the pressure dependence of the yield criterion on the strain-rate-intensity factor. The results can be used to develop new methods for predicting the evolution of material properties in the vicinity of surfaces with high friction in metal-forming processes. 相似文献
70.
Jonas Poelmans Sergei O. Kuznetsov Dmitry I. Ignatov Guido Dedene 《Expert systems with applications》2013,40(16):6601-6623
This is the first part of a large survey paper in which we analyze recent literature on Formal Concept Analysis (FCA) and some closely related disciplines using FCA. We collected 1072 papers published between 2003 and 2011 mentioning terms related to Formal Concept Analysis in the title, abstract and keywords. We developed a knowledge browsing environment to support our literature analysis process. We use the visualization capabilities of FCA to explore the literature, to discover and conceptually represent the main research topics in the FCA community. In this first part, we zoom in on and give an extensive overview of the papers published between 2003 and 2011 on developing FCA-based methods for knowledge processing. We also give an overview of the literature on FCA extensions such as pattern structures, logical concept analysis, relational concept analysis, power context families, fuzzy FCA, rough FCA, temporal and triadic concept analysis and discuss scalability issues. 相似文献