全文获取类型
收费全文 | 3632篇 |
免费 | 184篇 |
国内免费 | 14篇 |
专业分类
电工技术 | 38篇 |
综合类 | 1篇 |
化学工业 | 761篇 |
金属工艺 | 73篇 |
机械仪表 | 82篇 |
建筑科学 | 160篇 |
矿业工程 | 1篇 |
能源动力 | 113篇 |
轻工业 | 239篇 |
水利工程 | 33篇 |
石油天然气 | 13篇 |
无线电 | 365篇 |
一般工业技术 | 772篇 |
冶金工业 | 423篇 |
原子能技术 | 34篇 |
自动化技术 | 722篇 |
出版年
2023年 | 27篇 |
2022年 | 82篇 |
2021年 | 93篇 |
2020年 | 78篇 |
2019年 | 70篇 |
2018年 | 118篇 |
2017年 | 103篇 |
2016年 | 115篇 |
2015年 | 99篇 |
2014年 | 140篇 |
2013年 | 225篇 |
2012年 | 219篇 |
2011年 | 273篇 |
2010年 | 194篇 |
2009年 | 225篇 |
2008年 | 209篇 |
2007年 | 187篇 |
2006年 | 129篇 |
2005年 | 101篇 |
2004年 | 98篇 |
2003年 | 95篇 |
2002年 | 83篇 |
2001年 | 43篇 |
2000年 | 52篇 |
1999年 | 60篇 |
1998年 | 111篇 |
1997年 | 81篇 |
1996年 | 61篇 |
1995年 | 29篇 |
1994年 | 33篇 |
1993年 | 28篇 |
1992年 | 30篇 |
1991年 | 21篇 |
1990年 | 18篇 |
1989年 | 18篇 |
1988年 | 23篇 |
1987年 | 15篇 |
1986年 | 25篇 |
1985年 | 22篇 |
1984年 | 18篇 |
1983年 | 12篇 |
1982年 | 12篇 |
1981年 | 10篇 |
1980年 | 17篇 |
1979年 | 14篇 |
1977年 | 12篇 |
1976年 | 22篇 |
1974年 | 12篇 |
1973年 | 10篇 |
1972年 | 7篇 |
排序方式: 共有3830条查询结果,搜索用时 0 毫秒
41.
42.
Unraveling Unprecedented Charge Carrier Mobility through Structure Property Relationship of Four Isomers of Didodecyl[1]benzothieno[3,2‐b][1]benzothiophene 下载免费PDF全文
Yusuke Tsutsui Guillaume Schweicher Basab Chattopadhyay Tsuneaki Sakurai Jean‐Baptiste Arlin Christian Ruzié Almaz Aliev Artur Ciesielski Alan R. Kennedy Vincent Lemaur Yoann Olivier Rachid Hadji Lionel Sanguinet Frédéric Castet Silvio Osella Dmytro Dudenko David Beljonne Jérôme Cornil Paolo Samorì Shu Seki Yves H. Geerts 《Advanced materials (Deerfield Beach, Fla.)》2016,28(33):7106-7114
43.
Kalashnyk Nataliya Ledieu Julian Gaudry Émilie Cui Can Tsai An-Pang Fournée Vincent 《Nano Research》2018,11(4):2129-2138
Nano Research - The formation of long-range ordered aperiodic molecular films on quasicrystalline substrates is a new challenge that provides an opportunity for further surface functionalization.... 相似文献
44.
45.
46.
Why would people use Short Message Service (SMS) to say something they would not say in person? There is a trend that SMS is becoming more and more popular because it facilitates more extended modes of communications. Using technology acceptance model, we hypothesize the attitude of SMS would be influenced by its perceived effectiveness for communications, perceived ease of use, and subjective norm. Besides the special aspects of communications, conflict avoidance and privacy protection will enforce the impact of perceived effectiveness of SMS for communication. We investigated 953 SMS users and the results support most of our hypotheses. Furthermore, our analyses also show there are differences between females and males on the influence mechanism behind their attitude towards SMS. 相似文献
47.
The performance evaluation is regarded as a multiple criteria decision making (MCDM) problem and has a significant impact on the operations of the enterprise. This paper develops an integrated MCDM approach that combines the voting method and the fuzzy TOPSIS (technique for order preference by similarity to ideal solution) method to evaluate the performance of multiple manufacturing plants in a fuzzy environment. Fuzzy TOPSIS helps decision-makers carry out analysis and comparisons in ranking their preference of the alternatives with vague or imprecise data. Since the evaluation result is often greatly affected by the weights used in the evaluation process, the voting method is used in this study to determine the appropriate criteria weights. A case study demonstrating the applicability of the proposed model is presented. The case company is the world’s largest manufacturer of power supplies. It has three primary manufacturing bases located in Wujiang, Dongguan, and Tianjin, China. The proposed approach is used to evaluate the performance of the company’s five manufacturing plants in Wujiang, which produce switch power, telecom power, DC/DC converters, uninterruptible power systems (UPS) and AC/DC adapters. 相似文献
48.
A large number of methods have been proposed for ranking fuzzy numbers in the last few decades. Nevertheless, none of these methods can always guarantee a consistent result for every situation. Some of them are even non-intuitive and not discriminating. Chen proposed a ranking method in 1985 to overcome these limitations and simplify the computational procedure based on the criteria of total utility through maximizing set and minimizing set. However, there were some shortcomings associated with Chen’s ranking method. Therefore, we propose a revised ranking method that can overcome these shortcomings. Instead of considering just a single left and a single right utility in the total utility, the proposed method considers two left and two right utilities. In addition, the proposed method also takes into account the decision maker’s optimistic attitude of fuzzy numbers. Several comparative examples and an application demonstrating the usage, advantages, and applicability of the revised ranking method are presented. It can be concluded that the revised ranking method can effectively resolve the issues with Chen’s ranking method. Moreover, the revised ranking method can be used to differentiate different types of fuzzy numbers. 相似文献
49.
Gregory Chockler Seth Gilbert Vincent Gramoli Peter M. Musial Alex A. Shvartsman 《Journal of Parallel and Distributed Computing》2009
This paper presents a new algorithm for implementing a reconfigurable distributed shared memory in an asynchronous dynamic network. The algorithm guarantees atomic consistency (linearizability) in all executions in the presence of arbitrary crash failures of the processing nodes, message delays, and message loss. The algorithm incorporates a classic quorum-based algorithm for read/write operations, and an optimized consensus protocol, based on Fast Paxos for reconfiguration, and achieves the design goals of: (i) allowing read and write operations to complete rapidly and (ii) providing long-term fault-tolerance through reconfiguration, a process that evolves the quorum configurations used by the read and write operations. The resulting algorithm tolerates dynamism. We formally prove our algorithm to be correct, we present its performance and compare it to existing reconfigurable memories, and we evaluate experimentally the cost of its reconfiguration mechanism. 相似文献
50.
Information estimates such as the direct method of Strong, Koberle, de Ruyter van Steveninck, and Bialek (1998) sidestep the difficult problem of estimating the joint distribution of response and stimulus by instead estimating the difference between the marginal and conditional entropies of the response. While this is an effective estimation strategy, it tempts the practitioner to ignore the role of the stimulus and the meaning of mutual information. We show here that as the number of trials increases indefinitely, the direct (or plug-in) estimate of marginal entropy converges (with probability 1) to the entropy of the time-averaged conditional distribution of the response, and the direct estimate of the conditional entropy converges to the time-averaged entropy of the conditional distribution of the response. Under joint stationarity and ergodicity of the response and stimulus, the difference of these quantities converges to the mutual information. When the stimulus is deterministic or nonstationary the direct estimate of information no longer estimates mutual information, which is no longer meaningful, but it remains a measure of variability of the response distribution across time. 相似文献