全文获取类型
收费全文 | 1756篇 |
免费 | 50篇 |
国内免费 | 7篇 |
专业分类
电工技术 | 23篇 |
化学工业 | 319篇 |
金属工艺 | 56篇 |
机械仪表 | 26篇 |
建筑科学 | 78篇 |
矿业工程 | 2篇 |
能源动力 | 39篇 |
轻工业 | 90篇 |
水利工程 | 16篇 |
石油天然气 | 3篇 |
无线电 | 145篇 |
一般工业技术 | 248篇 |
冶金工业 | 567篇 |
原子能技术 | 9篇 |
自动化技术 | 192篇 |
出版年
2023年 | 13篇 |
2022年 | 20篇 |
2021年 | 31篇 |
2020年 | 24篇 |
2019年 | 25篇 |
2018年 | 33篇 |
2017年 | 23篇 |
2016年 | 29篇 |
2015年 | 18篇 |
2014年 | 40篇 |
2013年 | 77篇 |
2012年 | 48篇 |
2011年 | 86篇 |
2010年 | 44篇 |
2009年 | 52篇 |
2008年 | 50篇 |
2007年 | 57篇 |
2006年 | 69篇 |
2005年 | 47篇 |
2004年 | 30篇 |
2003年 | 48篇 |
2002年 | 32篇 |
2001年 | 32篇 |
2000年 | 24篇 |
1999年 | 38篇 |
1998年 | 75篇 |
1997年 | 36篇 |
1996年 | 42篇 |
1995年 | 23篇 |
1994年 | 25篇 |
1993年 | 46篇 |
1992年 | 30篇 |
1991年 | 26篇 |
1990年 | 14篇 |
1989年 | 28篇 |
1988年 | 25篇 |
1987年 | 25篇 |
1986年 | 24篇 |
1985年 | 28篇 |
1984年 | 22篇 |
1983年 | 34篇 |
1982年 | 28篇 |
1981年 | 29篇 |
1980年 | 17篇 |
1979年 | 19篇 |
1978年 | 18篇 |
1977年 | 26篇 |
1976年 | 25篇 |
1975年 | 19篇 |
1972年 | 12篇 |
排序方式: 共有1813条查询结果,搜索用时 15 毫秒
1.
John D. Rodney S. Deepapriya M. Cyril Robinson C. Justin Raj Suresh Perumal Byung Chul Kim S. Krishnan S. Jerome Das 《International Journal of Hydrogen Energy》2021,46(54):27585-27596
The production of hydrogen, a favourable alternative to an unsustainable fossil fuel remains as a significant hurdle with the pertaining challenge in the design of proficient, highly productive and sustainable electrocatalyst for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Herein, the dysprosium (Dy) doped copper oxide (Cu1-xDyxO) nanoparticles were synthesized via solution combustion technique and utilized as a non-noble metal based bi-functional electrocatalyst for overall water splitting. Due to the improved surface to volume ratio and conductivity, the optimized Cu1-xDyxO (x = 0.01, 0.02) electrocatalysts exhibited impressive HER and OER performance respectively in 1 M KOH delivering a current density of 10 mAcm?2 at a potential of ?0.18 V vs RHE for HER and 1.53 V vs RHE for OER. Moreover, the Dy doped CuO electrocatalyst used as a bi-functional catalyst for overall water splitting achieved a potential of 1.56 V at a current density 10 mAcm?2 and relatively high current density of 66 mAcm?2 at a peak potential of 2 V. A long term stability of 24 h was achieved for a cell voltage of 2.2 V at a constant current density of 30 mAcm?2 with only 10% of the initial current loss. This showcases the accumulative opportunity of dysprosium as a dopant in CuO nanoparticles for fabricating a highly effective and low-cost bi-functional electrocatalyst for overall water splitting. 相似文献
2.
Evangelopoulos Xenophon Brockmeier Austin J. Mu Tingting Goulermas John Y. 《Machine Learning》2019,108(4):595-626
Machine Learning - We propose a set of highly scalable algorithms for the combinatorial data analysis problem of seriating similarity matrices. Seriation consists of finding a permutation of data... 相似文献
3.
4.
Yachao Dong Christos T. Maravelias Norman F. Jerome 《Optimization and Engineering》2018,19(4):937-976
We study a maritime inventory routing problem, in which shipments between production and consumption nodes are carried out by a fleet of vessels. The vessels have specific capacities and can be chartered under different agreements. The inventory levels of all consumption nodes and some production nodes should be maintained within specified bounds; for the remaining production nodes, orders should be picked up within pre-defined time windows. We propose a discrete-time mixed-integer programming model. In the face of new information and uncertainty, this optimization model has to be re-solved, as the horizon is rolled forward. We discuss how to account for different sources of uncertainty. We present a rolling-horizon reoptimization framework that allows us to study different policies that impact the quality of the implemented solution, so we can identify the optimal set of policies. 相似文献
5.
Alan Bivens Rashim Gupta Ingo McLean Boleslaw Szymanski Jerome White 《International Journal of Network Management》2004,14(2):131-146
Rapid growth of computer network sizes and uses necessitate analysis of network application middleware in terms of its scalability as well as performance. In this paper we analyze a distributed network management middleware based on agents that can be dispatched to locations where they can execute close to the managed nodes. The described middleware operates between the network protocol layer and the application layer and uses standard TCP protocol and SNMP probes to interface the network. By aggregating requests from many users into a single agent, our system allows multiple managers to probe problem areas with minimal management traffic overhead. We discuss and quantify the benefits of the described middleware by implementing real‐time network managers using our system. The main result of this paper is a comparison of scalability and efficiency of our agent‐based management middleware and traditional SNMP‐based data collection. To this end, we measured traffic in both real and simulated networks. In the latter case, we designed, used and described here a method of separating simulated application flow into separate subflows to simplify design of simulations. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
6.
Albrecht Jason E.; O'Brien Edward J.; Mason Robert A.; Myers Jerome L. 《Canadian Metallurgical Quarterly》1995,21(2):364
An implicit assumption of several causal reasoning models is that readers adopt the goals of a narrative's protagonist during text comprehension. In apparent violation of this assumption, readers participating in Experiment 1 of the present study drew inferences relevant to a protagonist's goal even when that goal was already satisfied from the perspective of the protagonist. In Experiments 2 and 3, participants were explicitly asked to view the text situation from the point of view of the protagonist. In this case, the goals of the reader and the protagonist should be the same. In these experiments, participants focused on the goals of the protagonist only when those goals had not been satisfied from the perspective of the protagonist. These results are discussed in terms of reader- and character-based perspectives and in terms of text characteristics that cue perspective taking. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
7.
8.
Nicholas Biery Marc De Graef Jack Beuth Rafel Raban Andrew Elliott Tresa M. Pollock Curt Austin 《Metallurgical and Materials Transactions A》2002,33(10):3127-3136
Tensile experiments have been performed on specimens of four different investment-cast TiAl-based alloys with variations in
casting conditions. The average ductilities obtained in these experiments vary between approximately 0.8 to 2.0 pct plastic
strain to failure in tension. By using the three-parameter form of the Weibull relation, with the 0.2 pct offset yield strength
as the minimum failure strength, the resulting variability in the data can be quantified and is found to be similar for those
alloys with similar microstructural scale (grain size). Large variations in lamellar volume fraction, segregation, and phase
distribution have a minor influence on property variability, compared to changes in the scale of the grain structure caused
by either variations in cooling rate during casting or the addition of grain refiners. 相似文献
9.
Jen-Chwen Lin T. Leo Ngai Y. Austin Chang 《Metallurgical and Materials Transactions A》1986,17(7):1241-1245
Defect equilibria for binary semiconducting compound phases which exhibit ionized native donor and acceptor defects were considered,
and equations describing the pressure-temperature-composition relationships for these compound phases were derived. These
equations were used to analyze experimental data from the literature for tin telluride. Excellent agreement was obtained between
calculated thermodynamic and phase boundary values and experimental data. The approach presented is readily extended to obtain
equations for the thermodynamic properties of ternary and higher order semiconducting compound phases. 相似文献
10.