全文获取类型
收费全文 | 1522篇 |
免费 | 31篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 22篇 |
综合类 | 3篇 |
化学工业 | 342篇 |
金属工艺 | 145篇 |
机械仪表 | 38篇 |
建筑科学 | 42篇 |
矿业工程 | 18篇 |
能源动力 | 156篇 |
轻工业 | 17篇 |
水利工程 | 4篇 |
石油天然气 | 3篇 |
武器工业 | 1篇 |
无线电 | 62篇 |
一般工业技术 | 343篇 |
冶金工业 | 88篇 |
原子能技术 | 3篇 |
自动化技术 | 268篇 |
出版年
2024年 | 4篇 |
2023年 | 14篇 |
2022年 | 34篇 |
2021年 | 33篇 |
2020年 | 35篇 |
2019年 | 26篇 |
2018年 | 29篇 |
2017年 | 68篇 |
2016年 | 95篇 |
2015年 | 45篇 |
2014年 | 82篇 |
2013年 | 119篇 |
2012年 | 54篇 |
2011年 | 66篇 |
2010年 | 75篇 |
2009年 | 90篇 |
2008年 | 47篇 |
2007年 | 67篇 |
2006年 | 50篇 |
2005年 | 41篇 |
2004年 | 39篇 |
2003年 | 43篇 |
2002年 | 47篇 |
2001年 | 32篇 |
2000年 | 21篇 |
1999年 | 27篇 |
1998年 | 26篇 |
1997年 | 23篇 |
1996年 | 22篇 |
1995年 | 12篇 |
1994年 | 14篇 |
1993年 | 12篇 |
1992年 | 7篇 |
1991年 | 8篇 |
1990年 | 10篇 |
1989年 | 8篇 |
1988年 | 15篇 |
1987年 | 17篇 |
1986年 | 21篇 |
1985年 | 12篇 |
1984年 | 17篇 |
1983年 | 4篇 |
1982年 | 8篇 |
1981年 | 11篇 |
1980年 | 3篇 |
1979年 | 6篇 |
1978年 | 6篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1971年 | 1篇 |
排序方式: 共有1555条查询结果,搜索用时 31 毫秒
991.
《Composites Part A》2007,38(1):94-99
The effects of hydrolysis of the AlN particulates on corrosion behavior of Al/AlNp composite were examined by analyzing potentiostatic anodic current transient, cyclic voltammetry curves and potentiodynamic cathodic polarization curves. It is found that the degree of hydrolysis of AlN particulates in the composite increase with the pre-hot water treatment time, which increase the occurrence of metastable pits in the composite. In addition, hydrolysis of AlN particulates also affects the electrochemical corrosion behaviors of the composite, and makes Al/AlNp composite show intergranular corrosion behavior to some extent. 相似文献
992.
Zbigniew A. Banaszak BoŻena Skolud Marek B. Zaremba 《Journal of Intelligent Manufacturing》2003,14(1):83-106
This paper presents a logistics framework to cope with the problem of planning and control of production flows processed on a set of work cells distributed among component firms of a virtual enterprise (VE). The constraints theory framework is employed to study constraint-based production flow coordination rules. The article discusses relationships linking structural parameters (e.g. buffer capacity, machine tool efficiency, and automated storage/retrieval systems) of VE components with material flow control guaranteeing efficient completion of work orders, and specified by such parameters as batch delivery periods, work-in-process (WIP) and make-span. The results are summarized in the form of a performance evaluation scheme. Examples using a software package that implements the proposed flow coordination methodology are provided. 相似文献
993.
Electrodeposition of metals from non-aqueous solutions 总被引:2,自引:0,他引:2
Electrodeposition of metals from non-aqueous solutions is reviewed. Attention is paid mainly to surface morphology of deposits and their adhesion. The major reasons for carrying out electrodeposition in non-aqueous electrolytes (such as conventional organic solvents, ionic liquids and molten salts) are the water and air stability and the wide electrochemical window of these media. The following metals have been electrodeposited and investigated for the last 15 years: aluminum, zinc, silver, palladium, tantalum, zirconium, gadolinium, plutonium, nickel, cobalt, and other alloys. 相似文献
994.
In this paper, constrained approximate boundary controllability for linear disturbed parameter dynamical systems described by partial differential equations of parabolic-type with mixed boundary conditions is considered. Using methods of spectral analysis for linear self-adjoint operators and general constrained controllability results, given by Son (1990), necessary and sufficient conditions for constrained approximate boundary controllability are formulated and proved. Moreover, in illustrative examples the constrained approximate boundary controllability of 1D distributed parameter dynamical systems is investigated. The constrained controllability conditions obtained represent an extension of the unconstrained controllability results given by Glothin (1974) 相似文献
995.
《Materials Letters》2006,60(21-22):2558-2560
A novel chemical synthesis technique that a large quantity of rod-shaped LaNi5 alloy has been successfully synthesized using a solid reduction method was reported. The as-prepared alloy, proven via the XRD spectrum, was single-phased and hexagonal. The SEM and TEM photographs showed that the alloy was rod-shaped with a diameter in the range of 300–500 nm, and length of about 6–10 μm. The SAED pattern of LaNi5 alloy clearly indicated the orientation alignment along the c-axis. 相似文献
996.
《Materials science & engineering. C, Materials for biological applications》2006,26(2-3):378-382
The evolution of thin InN overlayer grown on InP (100) rich In substrate was investigated at room temperature by photoluminescence method versus the duration of nitridation process. The main important parameters were the duration of the process, and the angle of the reactive nitrogen flow. The nitridation was performed by a glow discharge source (GDS). The correlations between the electronic properties, gathered from photoluminescence (PL) measurements, and the chemical composition of InN–InP interfaces, derived from Auger electron spectroscopy (AES) were found. AES revealed that the nitridation process proceeds quickly in time showing self-limiting behavior. It is more effective for grazing nitrogen flux. The interface state density distributions, NSS(E), were determined via advanced computer-aided analysis of dependencies of band edge PL efficiency, YPL, versus excitation light intensity, Φ. The analysis showed that the substrates were well passivated with NSS(E) minima on the order of 5·1011 cm− 2 eV− 1. The nitrogen flux angle during the nitridation was found to have an influence on YPL(Φ) spectra. In all analyzed cases the grazing nitrogen flux generated the interface with slightly improved NSS(E) distribution. Finally, the behavior of YPL versus Φ and NSS(E) was precisely examined. 相似文献
997.
Marek Berezowski 《Chemical engineering science》2006,61(4):1342-1345
The basin boundaries for two attractors were found for a mathematical model of a chemical tubular reactor with recycle. The basin boundaries were found to be fractal. Their topological dimension and entropy were determined. 相似文献
998.
The novel compound 2(1,3-dioxolan-2-yl)phenoxymethyloxirane was synthesized and anionically polymerized with potassium hydroxide, potassium hydride and potassium tert-butoxide. Polymers were characterized by 1H and 13C NMR spectroscopy, size exclusion chromatography and electrospray mass spectrometry. Copyright © 2004 Society of Chemical Industry 相似文献
999.
The paper reports the dry-sliding tribological behavior of Fe100−x–Nix (x=20,23,25,30) alloys with various martensite fractions. For all the alloys, the friction coefficient decreased with increasing applied load and increased with increasing sliding speed, but there was nearly no difference between the different alloys. The wear rate of the alloys increased with increasing applied load and decreased slightly with increasing sliding speed. Microstructures had great influence on the wear behavior of these alloys. The Fe77Ni23 alloy with well-proportioned martensite exhibited the best wear resistance. 相似文献
1000.
This paper presents the results of viscosity determinations on aqueous solutions of bovine serum albumin (BSA) at a wide range of concentrations and at temperatures ranging from 5 degrees C to 45 degrees C. On the basis of these measurements a general formula connecting the relative viscosity eta r with temperature T and concentration c of the dissolved proteins was established: [formula: see text] The quantities alpha, beta, B, D and delta E are described in the text below. A simple substantiation of the formula was also given. This relation gives immediately the Mooney approximation and allows the prediction of the values of the parameter S and a self-crowding factor K in this approximation. By applying an asymptotic form of the formula such rheological quantities as the intrinsic viscosity and Huggins coefficient were calculated. 相似文献