全文获取类型
收费全文 | 986篇 |
免费 | 23篇 |
国内免费 | 8篇 |
专业分类
电工技术 | 9篇 |
综合类 | 1篇 |
化学工业 | 152篇 |
金属工艺 | 12篇 |
机械仪表 | 15篇 |
建筑科学 | 94篇 |
矿业工程 | 29篇 |
能源动力 | 44篇 |
轻工业 | 47篇 |
水利工程 | 5篇 |
石油天然气 | 8篇 |
无线电 | 116篇 |
一般工业技术 | 117篇 |
冶金工业 | 89篇 |
原子能技术 | 6篇 |
自动化技术 | 273篇 |
出版年
2022年 | 6篇 |
2021年 | 9篇 |
2020年 | 6篇 |
2019年 | 10篇 |
2018年 | 14篇 |
2017年 | 15篇 |
2016年 | 15篇 |
2015年 | 15篇 |
2014年 | 17篇 |
2013年 | 91篇 |
2012年 | 41篇 |
2011年 | 37篇 |
2010年 | 26篇 |
2009年 | 37篇 |
2008年 | 40篇 |
2007年 | 53篇 |
2006年 | 57篇 |
2005年 | 59篇 |
2004年 | 53篇 |
2003年 | 53篇 |
2002年 | 34篇 |
2001年 | 31篇 |
2000年 | 32篇 |
1999年 | 31篇 |
1998年 | 23篇 |
1997年 | 22篇 |
1996年 | 24篇 |
1995年 | 19篇 |
1994年 | 15篇 |
1993年 | 8篇 |
1992年 | 6篇 |
1991年 | 11篇 |
1990年 | 6篇 |
1989年 | 6篇 |
1988年 | 4篇 |
1987年 | 6篇 |
1986年 | 6篇 |
1985年 | 14篇 |
1984年 | 10篇 |
1983年 | 6篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1979年 | 9篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1975年 | 3篇 |
1973年 | 2篇 |
1968年 | 3篇 |
1963年 | 3篇 |
排序方式: 共有1017条查询结果,搜索用时 71 毫秒
71.
72.
Bill Boni 《Network Security》2002,2002(6):16-17
There is a war going on in cyberspace and the ‘good guys’ appear to be losing it. The combat is not just cyber terrorists probing and defacing military, political or economic targets, but much more commonly at this point, between cyber criminals and managers of IT staffs supporting E-commerce operations. The facts are that a class of ‘elite’ hackers is now commonly able to attack sites, extract credit card account information then cover their tracks by destroying digital evidence along their path. These intruders have become more brazen as they have become more successful. 相似文献
73.
Bill Robert Fleck Martin Troya Javier Mayerhofer Tanja Wimmer Manuel 《Software and Systems Modeling》2019,18(2):1017-1046
Software and Systems Modeling - Many model transformation scenarios require flexible execution strategies as they should produce models with the highest possible quality. At the same time,... 相似文献
74.
Patricia R. Barbosa Yugandhar Sarkale Edwin K. P. Chong Yun Li Sofia Suvorova Bill Moran 《Asian journal of control》2019,21(4):1630-1643
We investigate the challenging problem of integrating detection, signal processing, target tracking, and adaptive waveform scheduling with lookahead in urban terrain. We propose a closed‐loop active sensing system to address this problem by exploiting three distinct levels of diversity: (1) spatial diversity through the use of coordinated multistatic radars; (2) waveform diversity by adaptively scheduling the transmitted waveform; and (3) motion model diversity by using a bank of parallel filters matched to different motion models. Specifically, at every radar scan, the waveform that yields the minimum trace of the one‐step‐ahead error covariance matrix is transmitted; the received signal goes through a matched‐filter, and curve fitting is used to extract range and range‐rate measurements that feed the LMIPDA‐VSIMM algorithm for data association and filtering. Monte Carlo simulations demonstrate the effectiveness of the proposed system in an urban scenario contaminated by dense and uneven clutter, strong multipath, and limited line‐of‐sight. 相似文献
75.
Bill 《Windows IT Pro Magazine》2009,(8):41-41
Windows XP模式可用在Windows 7的Professiona Enterprise和Ultimate版本中。它实质上由两部分构成版的Virtual PC,名为Windows Virtual PC:通过Windows Firewall进行配置并能自动更新的Windows XP Professiona SP3虚拟机(VM)。如果OEM选择安装Windows XP模式,可以预先在新计算机上安装它,也可以通过微软站点下载它。 相似文献
76.
Multiple object tracking is a fundamental subsystem of many higher level applications such as traffic monitoring, people counting, robotic vision and many more. This paper explains in details the methodology of building a robust hierarchical multiple hypothesis tracker for tracking multiple objects in the videos. The main novelties of our approach are anchor-based track initialization, prediction assistance for unconfirmed track and two virtual measurements for confirmed track. The system is built mainly to deal with the problems of merge, split, fragments and occlusion. The system is divided into two levels where the first level obtains the measurement input from foreground segmentation and clustered optical flow. Only K-best hypothesis and one-to-one association are considered. Two more virtual measurements are constructed to help track retention rate for the second level, which are based on predicted state and division of occluded foreground segments. Track based K-best hypothesis with multiple associations are considered for more comprehensive observation assignment. Histogram intersection testing is performed to limit the tracker bounding box expansion. Simulation results show that all our algorithms perform well in the surroundings mentioned above. Two performance metrics are used; multiple-object tracking accuracy (MOTA) and multiple-object tracking precision (MOTP). Our tracker have performed the best compared to the benchmark trackers in both performance evaluation metrics. The main weakness of our algorithms is the heavy processing requirement. 相似文献
77.
As writing teachers, we seek to validate the knowledge that students bring to the classroom while introducing and cultivating new methods, strategies, techniques and technologies that may serve them now and in the future. In this article we describe an approach we take that integrates curricular and extracurricular co-apprenticeship strategies using public writing models in conjunction with social networking tools. With publication as a final goal, we urge students to move from expressing personal problems to addressing social issues, using a private, non-commercial learning network NoDiff <http://NoDiff.com> as a safe zone for skills development, knowledge production and social inquiry. In taking this approach, we resist dichotomies that place professional skills training in strict opposition to critical pedagogy. We argue that many of the so-called “extracurricular” composing activities that most of today's students engage in lay the groundwork for both professional and civic participation. Acknowledging that we as composition teachers are also beginners in the world of 21st century communication, we emphasize both (1) the continual transference of skills and knowledge among teachers and learners; and (2) the importance of providing what is often lacking in skills-based ‘new literacy’ training, namely a critical pedagogical approach to learning as social engagement and critical intervention. 相似文献
78.
79.
Bill C. H. Chang Asanga Ratnaweera Saman K. Halgamuge Harry C. Watson 《Genetic Programming and Evolvable Machines》2004,5(2):203-214
In this paper, a modified particle swarm optimisation algorithm is proposed for protein sequence motif discovery. Protein sequences are represented as a chain of symbols and a protein sequence motif is a short sequence that exists in most of the protein sequence families. Protein sequence symbols are converted into numbers using a one to one amino acid translation table. The simulation uses EGF protein and C2H2 Zinc Finger protein families obtained from the PROSITE database. Simulation results show that the modified particle swarm optimisation algorithm is effective in obtaining global optimum sequence patterns, achieving 96.9 and 99.5 classification accuracy respectively in EGF and C2H2 Zinc Finger protein families. A better true positive hit result is achieved when compared to the motifs published in PROSITE database. 相似文献
80.
Bill Venners 《程序员》2009,(5):81-83
Twitter将部分应用从Ruby迁移到了Scala。三位开发者详谈决策背后的因素、Scala在现实应用中遇到的困难以及Scala对编程风格的影响。 相似文献