全文获取类型
收费全文 | 4433篇 |
免费 | 708篇 |
国内免费 | 505篇 |
专业分类
电工技术 | 446篇 |
综合类 | 277篇 |
化学工业 | 106篇 |
金属工艺 | 84篇 |
机械仪表 | 311篇 |
建筑科学 | 191篇 |
矿业工程 | 80篇 |
能源动力 | 83篇 |
轻工业 | 82篇 |
水利工程 | 123篇 |
石油天然气 | 80篇 |
武器工业 | 53篇 |
无线电 | 599篇 |
一般工业技术 | 409篇 |
冶金工业 | 80篇 |
原子能技术 | 101篇 |
自动化技术 | 2541篇 |
出版年
2024年 | 39篇 |
2023年 | 91篇 |
2022年 | 188篇 |
2021年 | 185篇 |
2020年 | 205篇 |
2019年 | 146篇 |
2018年 | 144篇 |
2017年 | 164篇 |
2016年 | 211篇 |
2015年 | 209篇 |
2014年 | 318篇 |
2013年 | 287篇 |
2012年 | 345篇 |
2011年 | 329篇 |
2010年 | 273篇 |
2009年 | 262篇 |
2008年 | 285篇 |
2007年 | 323篇 |
2006年 | 270篇 |
2005年 | 273篇 |
2004年 | 187篇 |
2003年 | 161篇 |
2002年 | 138篇 |
2001年 | 89篇 |
2000年 | 94篇 |
1999年 | 81篇 |
1998年 | 51篇 |
1997年 | 43篇 |
1996年 | 39篇 |
1995年 | 44篇 |
1994年 | 30篇 |
1993年 | 30篇 |
1992年 | 27篇 |
1991年 | 16篇 |
1990年 | 12篇 |
1989年 | 18篇 |
1988年 | 7篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1980年 | 5篇 |
1979年 | 5篇 |
1975年 | 2篇 |
1963年 | 1篇 |
1961年 | 1篇 |
1951年 | 1篇 |
排序方式: 共有5646条查询结果,搜索用时 15 毫秒
21.
Electronic commerce is an important application that has evolved significantly recently. However, electronic commerce systems
are complex and difficult to be correctly designed. Guaranteeing the correctness of an e-commerce system is not an easy task
due to the great amount of scenarios where errors occur, many of them very subtle. In this work we presents a methodology
that uses formal-method techniques, specifically symbolic model checking, to design electronic commerce applications and to automatically verify them. Also, a model checking pattern hierarchy has
been developed—it specifies patterns to construct and verify the formal model of e-commerce systems. We consider this research
the first step to the development of a framework, which will integrate the methodology, an e-commerce specification language
based on business rules, and a model checker.
Adriano Pereira received the B.S. and M.S. degrees in computer science in 2000 and 2002, respectively, and he is currently pursuing the Ph.D.
degree in computer science from the Federal University of Minas Gerais, Belo Horizonte, Brazil. His current interests are
on performance analysis and modeling of e-business and distributed systems, and formal methods.
Mark Song received the B.S., M.S. and Ph.D. degrees in computer science from the Federal University of Minas Gerais, Belo Horizonte,
Brazil. His current interests are on distributed systems and formal methods – especially BMC (Bounded Model Checking).
Gustavo Franco received the B.S. and M.S. degrees in computer science in 2001 and 2004, respectively, from the Federal University of Minas
Gerais, Belo Horizonte, Brazil. His research was on modeling the user behavior of e-business and distributed systems, and
formal methods. Actually his current interests are on software engeneering and project management of IT projects. 相似文献
22.
数值方法确定地基承载力特征值的探讨 总被引:2,自引:1,他引:1
介绍了目前地基承载力的确定方法,研究了数值计算的可行性,并对其数值计算地基承载力的可靠性进行验证,指出应进一步完善确定地基承载力的方法,更好地解决群桩基础承载力的确定问题。 相似文献
23.
24.
We describe how the tree identification phase of the IEEE 1394 high-performance serial bus (FireWire) protocol is modelled
in Promela and verified using SPIN. The verification of arbitrary system configurations is discussed.
Received July 2001/Accepted in revised form November 2002
Correspondence and offprint requests to: Alice Miller, Department of Computing Science, University of Glasgow, 17 Lilybank Gardens, Glasgow G12 8QQ, UK. Email: alice@dcs.gla.ac.uk 相似文献
25.
本文报导了采用一种新型高温陶瓷发热体高温管状炉,通以氩气保护,测量WRe合金丝的电阻-温度(1600℃)特性试验方法,该方法较真空炉简便、实用且试验费用低而准确,测量数据与美国研究报导一致。 相似文献
26.
Enrico Tronci 《International Journal on Software Tools for Technology Transfer (STTT)》2006,8(4-5):355-358
In today’s competitive market designing of digital systems (hardware as well as software) faces tremendous challenges. In
fact, notwithstanding an ever decreasing project budget, time to market and product lifetime, designers are faced with an
ever increasing system complexity and customer expected quality. The above situation calls for better and better formal verification
techniques at all steps of the design flow. This special issue is devoted to publishing revised versions of contributions
first presented at the 12th Advanced Research Working Conference on Correct Hardware Design and Verification Methods (CHARME) held 21–24 October 2003 in L’Aquila, Italy. Authors of well regarded papers from CHARME’03 were invited to submit
to this special issue. All papers included here have been suitably extended and have undergone an independent round of reviewing. 相似文献
27.
In this paper a methodology for the use of temporal logic as an executable imperative language is introduced. The approach, which provides a concrete framework, calledMetateM, for executing temporal formulae, is motivated and illustrated through examples. In addition, this introduction provides references to further, more detailed, work relating to theMetateM approach to executable logics. 相似文献
28.
Alessandra Lumini 《Pattern recognition》2007,40(3):1057-1065
Given the recent explosion of interest in human authentication, verification based on tokenized pseudo-random numbers and the user specific biometric feature (BioHashing) has received much attention. These methods have significant functional advantages over sole biometrics i.e. zero equal error rate. The main drawback of the base BioHashing method proposed in the literature relies in exhibiting low performance when an “impostor” B steals the pseudo-random numbers of A and he tries to authenticate as A. In this paper, we introduce some ideas to improve the base BioHashing approach in order to maintain a very low equal error rate when nobody steals the Hash key, and to reach good performance also when an “impostor” steals the Hash key. 相似文献
29.
Alessandra Lumini 《Pattern recognition》2006,39(4):714-716
We present a system for fingerprint verification that approaches the problem as a two-class pattern recognition problem. The features extracted by “FingerCode” are used to capture the ridge strength. This feature vector is then classified as genuine or impostor according to a novel approach to handle the fingerprint verification as a two-class problem. Moreover, we show that extracting the features from sub-images around the core permits to better represent the local information. 相似文献
30.
郭崎 《计算机辅助设计与图形学学报》2012,24(5):690-698
如何生成高质量的验证激励是功能验证中的核心问题之一.随着功能验证的不断进行,验证激励的有效性也随之降低.为了提高验证激励的质量,提出一种在线筛选技术来处理验证激励.该技术采用单分类支持向量机来在线地构建分类器,以对新生成的验证激励是否冗余进行预测,如果是冗余的,则不进入仿真阶段进行仿真.在此基础上,进一步提出指令序列核函数来衡量不同指令序列的相似程度.实验结果表明,与约束随机生成技术相比,文中技术可以减少约83%的验证激励及79%的验证时间. 相似文献