全文获取类型
收费全文 | 2235篇 |
免费 | 119篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 29篇 |
综合类 | 4篇 |
化学工业 | 508篇 |
金属工艺 | 91篇 |
机械仪表 | 87篇 |
建筑科学 | 56篇 |
矿业工程 | 7篇 |
能源动力 | 78篇 |
轻工业 | 329篇 |
水利工程 | 12篇 |
石油天然气 | 23篇 |
无线电 | 156篇 |
一般工业技术 | 356篇 |
冶金工业 | 396篇 |
原子能技术 | 19篇 |
自动化技术 | 208篇 |
出版年
2023年 | 23篇 |
2022年 | 80篇 |
2021年 | 93篇 |
2020年 | 54篇 |
2019年 | 70篇 |
2018年 | 72篇 |
2017年 | 87篇 |
2016年 | 69篇 |
2015年 | 44篇 |
2014年 | 84篇 |
2013年 | 169篇 |
2012年 | 114篇 |
2011年 | 125篇 |
2010年 | 98篇 |
2009年 | 91篇 |
2008年 | 99篇 |
2007年 | 63篇 |
2006年 | 67篇 |
2005年 | 68篇 |
2004年 | 47篇 |
2003年 | 50篇 |
2002年 | 34篇 |
2001年 | 24篇 |
2000年 | 34篇 |
1999年 | 29篇 |
1998年 | 61篇 |
1997年 | 50篇 |
1996年 | 41篇 |
1995年 | 33篇 |
1994年 | 21篇 |
1993年 | 23篇 |
1992年 | 12篇 |
1991年 | 10篇 |
1990年 | 14篇 |
1989年 | 20篇 |
1988年 | 16篇 |
1987年 | 16篇 |
1986年 | 11篇 |
1985年 | 16篇 |
1984年 | 17篇 |
1982年 | 10篇 |
1980年 | 12篇 |
1979年 | 13篇 |
1977年 | 13篇 |
1976年 | 11篇 |
1975年 | 9篇 |
1974年 | 14篇 |
1973年 | 10篇 |
1972年 | 10篇 |
1964年 | 8篇 |
排序方式: 共有2359条查询结果,搜索用时 0 毫秒
1.
Patrick R. Taylor Ph.D. Milton Manrique Ph.D. 《JOM Journal of the Minerals, Metals and Materials Society》1996,48(6):43-45
Due to several inherent advantages, plasma processing technology may become a very useful tool in the production of new materials. An increasing research effort based on experimental as well as theoretical investigations has been invested in this area for the synthesis of advanced materials. In describing the thermal-plasma processing technique, this article employs examples from research at the Plasma Processing Laboratory at the University of Idaho. 相似文献
2.
Under carefully chosen conditions, solidification theory may be applied to solid-state transformations, and this has been
done here for composition-invariant diffusion transformations. The predictions of the modeling are compared with isovelocity
experiments in two iron systems, Fe-7.29 wt pct Cr and Fe-3.1 wt pct Ni. The ferrite to austenite phase transformation is
used to demonstrate that stabilization of a planar transformation front at absolute stability is the natural lower velocity
limit for a composition-invariant (massive) transformation. The results of the model, which includes nonequilibrium effects,
clearly show that steady-state plane-front growth leading to composition invariance can be obtained at various temperatures
depending on the growth velocity. In the lower velocity range, at the limit of absolute stability (of the order of 10 μm/s in the systems studied), the transformation interface moves under conditions of local equilibrium, and the temperature
corresponds to the lower solvus temperature. At higher velocity (of the order of the interface diffusion rate, which in these
systems is of the order of cm/s), the transformation is predicted to proceed at temperatures close to T
0. At even higher rates, atom attachment kinetic undercooling will decrease the transformation temperature with respect to
T
0. In some cases, this temperature might even drop below the lower solvus.
This article is based on a presentation made at the symposium entitled “The Mechanisms of the Massive Transformation,” a part
of the Fall 2000 TMS Meeting held October 16–19, 2000, in St. Louis, Missouri, under the auspices of the ASM Phase Transformations
Committee. 相似文献
3.
4.
Ricardo Lima Author Vitae Author Vitae Claudio Reineri Author Vitae Author Vitae 《Computers & Electrical Engineering》2008,34(6):520-530
This paper presents a novel concept for power quality hardware and software architecture. Software tools related to detection, classification and characterization of power quality events can be integrated into a Distribution Control Center in which the interconnection between different subsystems is being carried out through the Internet allowing flexibility to the system. This system is implemented using wavelet analysis applied in all proposed algorithms. Different power quality events are taken as examples to illustrate the capabilities of the proposed method. The obtained results reveal that the proposed architecture is feasible to be implemented as an integral part of a control center system.The proposed system has the property of fast and accurate detection and classification of any power quality disturbance event and introduces a new PQ index determination that allows characterizing any type of disturbance including the non-periodic signals. 相似文献
5.
6.
7.
Lima A.M.N. Deep G.S. Neto J.S.R. Freire R.C.S. Lobo P.C. 《IEEE transactions on instrumentation and measurement》1994,43(2):133-138
An identification procedure to estimate the parameters of a thermoresistive solar radiation sensor is presented. The proposed technique employs only electrical excitation for the sensor. The estimation algorithm is recursive and is applied to the sensor model derived from the thermodynamic equilibrium differential equations. The simulation and the experimental results demonstrate the validity of the proposed approach 相似文献
8.
Morphological analysis of poly(o-methoxyaniline) thin-films deposited by spin coating technique 总被引:1,自引:0,他引:1
John Paul H. Lima Adnei M. de Andrade 《Journal of Materials Science: Materials in Electronics》2006,17(8):593-596
Morphological study of conducting polymer thin films obtained by spin coating is reported. Poly(o-methoxyaniline) films were deposited onto glass substrates and analyzed by profilometry and atomic force microscopy (AFM).
It is shown that final thickness is correlated by a power law with spin speed with a solution concentration varying coefficient
and that surface roughness decreases with increasing spin speed. 相似文献
9.
Rui A. S. Lapa José L. F. C. Lima 《Journal of Automated Methods and Management in Chemistry》1991,13(3):119-122
The construction of a microcomputer-controlled electrode switch for
use in potentiometric determinations is described. This can be coupled to most of the analytical equipment usually found in laboratories, to enable a setting up of automatic systems capable of performing sequential determinations with several ion-selective
electrodes. The assessment of its analytical usage and behaviour are discussed. 相似文献
10.