首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   256篇
  免费   5篇
电工技术   6篇
化学工业   76篇
机械仪表   4篇
建筑科学   13篇
能源动力   9篇
轻工业   10篇
水利工程   9篇
石油天然气   1篇
无线电   27篇
一般工业技术   26篇
冶金工业   19篇
自动化技术   61篇
  2024年   1篇
  2023年   3篇
  2022年   7篇
  2021年   9篇
  2020年   4篇
  2019年   8篇
  2018年   9篇
  2017年   7篇
  2016年   12篇
  2015年   9篇
  2014年   8篇
  2013年   16篇
  2012年   12篇
  2011年   15篇
  2010年   17篇
  2009年   11篇
  2008年   6篇
  2007年   6篇
  2006年   6篇
  2005年   5篇
  2004年   5篇
  2003年   4篇
  2002年   2篇
  2000年   4篇
  1999年   2篇
  1998年   6篇
  1997年   4篇
  1996年   7篇
  1995年   3篇
  1994年   4篇
  1993年   1篇
  1992年   4篇
  1990年   2篇
  1989年   1篇
  1987年   5篇
  1985年   2篇
  1984年   3篇
  1983年   6篇
  1982年   4篇
  1981年   2篇
  1979年   4篇
  1978年   1篇
  1977年   6篇
  1976年   2篇
  1975年   1篇
  1974年   1篇
  1973年   2篇
  1972年   1篇
  1965年   1篇
排序方式: 共有261条查询结果,搜索用时 15 毫秒
71.
Nowadays protection engineers are suffering from very complex implementations of protection system analysis due to massive quantities of inconsistent data, let alone coming from diverse intelligent electronic devices (IEDs). Thus, a novel Rough-Set-based data mining strategy has been formulated to resolve the inconsistency in a distance protective relay's decision system (i.e. a transformed relay event report) in such a way that the relay's timing characteristics hidden in its decision algorithm of protection operations have been successfully discovered. Using Rough Set Theory, the inherent uncertainty and vagueness in the relay event report have been resolved using the concepts of discernibility, elementary sets and set approximations. The timing characteristics that have been successfully discovered are in relation to the relay trip assertion activity, impedance element activation, fault characteristics, circuit breaker operation and its overall decision system approximation.  相似文献   
72.
The oregano leaves’ extract (ORLE) was used for the formation of silver nanoparticles (AgNPs(ORLE)). ORLE and AgNPs(ORLE) (2 mg/mL) were dispersed in polymer hydrogels to give the pHEMA@ORLE_2 and pHEMA@AgNPs(ORLE)_2 using hydroxyethyl–methacrylate (HEMA). The materials were characterized by X-ray fluorescence (XRF) spectroscopy, X-ray powder diffraction analysis (XRPD), thermogravimetric differential thermal analysis (TG-DTA), derivative thermogravimetry/differential scanning calorimetry (DTG/DSC), ultraviolet (UV-Vis), and attenuated total reflection mode (ATR-FTIR) spectroscopies in solid state and UV–Vis in solution. The crystallite size value, analyzed with XRPD, was determined at 20 nm. The antimicrobial activity of the materials was investigated against Gram-negative bacterial strains Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli (E. coli). The Gram-positive ones of the genus of Staphylococcus epidermidis (S. epidermidis) and Staphylococcus aureus (S. aureus) are known to be involved in microbial keratitis by the means of inhibitory zone (IZ), minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). The IZs, which developed upon incubation of P. aeruginosa, E. coli, S. epidermidis, and S. aureus with paper discs soaked in 2 mg/mL of AgNPs(ORLE), were 11.7 ± 0.7, 13.5 ± 1.9, 12.7 ± 1.7, and 14.3 ± 1.7 mm. When the same dose of ORLE was administrated, the IZs were 10.2 ± 0.7, 9.2 ± 0.5, 9.0 ± 0.0, and 9.0 ± 0.0 mm. The percent of bacterial viability when they were incubated over the polymeric hydrogel discs of pHEMA@AgNPs(ORLE)_2 was interestingly low (66.5, 88.3, 77.7, and 59.6%, respectively, against of P. aeruginosa, E. coli, S. epidermidis, and S. aureus) and those of pHEMA@ORLE_2 were 89.3, 88.1, 92.8, and 84.6%, respectively. Consequently, pHEMA@AgNPs(ORLE)_2 could be an efficient candidate toward the development of non-infectious contact lenses.  相似文献   
73.
74.
This paper addresses the problem of body mapping in robotic imitation where the demonstrator and imitator may not share the same embodiment [degrees of freedom (DOFs), body morphology, constraints, affordances, and so on]. Body mappings are formalized using a unified (linear) approach via correspondence matrices, which allow one to capture partial, mirror symmetric, one-to-one, one-to-many, many-to-one, and many-to-many associations between various DOFs across dissimilar embodiments. We show how metrics for matching state and action aspects of behavior can be mathematically determined by such correspondence mappings, which may serve to guide a robotic imitator. The approach is illustrated and validated in a number of simulated 3-D robotic examples, using agents described by simple kinematic models and different types of correspondence mappings.  相似文献   
75.
We study deterministic gossiping in ad hoc radio networks with large node labels. The labels (identifiers) of the nodes come from a domain of size N which may be much larger than the size n of the network (the number of nodes). Most of the work on deterministic communication has been done for the model with small labels which assumes N = O(n). A notable exception is Peleg's paper, where the problem of deterministic communication in ad hoc radio networks with large labels is raised and a deterministic broadcasting algorithm is proposed, which runs in O(n2log n) time for N polynomially large in n. The O(nlog2n)-time deterministic broadcasting algorithm for networks with small labels given by Chrobak et al. implies deterministic O(n log N log n)-time broadcasting and O(n2log2N log n)-time gossiping in networks with large labels. We propose two new deterministic gossiping algorithms for ad hoc radio networks with large labels, which are the first such algorithms with subquadratic time for polynomially large N. More specifically, we propose: a deterministic O(n3/2log2N log n)-time gossiping algorithm for directed networks; and a deterministic O(n log2N log2n)-time gossiping algorithm for undirected networks.  相似文献   
76.
Standard psycholexical studies of personality structure have produced a similar 6-factor solution in 7 languages (Dutch, French, German, Hungarian, Italian, Korean, Polish). The authors report the content of these personality dimensions and interpret them as follows: (a) a variant of Extraversion, defined by sociability and liveliness (though not by bravery and toughness); (b) a variant of Agreeableness, defined by gentleness, patience, and agreeableness (but also including anger and ill temper at its negative pole); (c) Conscientiousness (emphasizing organization and discipline rather than moral conscience); (d) Emotionality (containing anxiety, vulnerability, sentimentality, lack of bravery, and lack of toughness, but not anger or ill temper); (e) Honesty-Humility; (f) Intellect/Imagination/Unconventionality. A potential reorganization of the Big Five factor structure is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
77.
This paper describes a software developed for educational purposes that integrates most required procedures in design of facilities layout. It can be used to explain the steps that have to be taken in facilities planning process. The input for this program include: history of demand for the products to be manufactured, bill of materials, route sheets, elements of cost, type of layout desired, type of material handling system preferred, inventory policies implemented, and financial status of the company. The output of the program include: production capacity, number of equipment, number of skilled and unskilled labor, production cost of the product, layout of the production, service, and support facilities, size and layout of receiving and shipping, the size and layout of the storage and warehouse, number of material handlers, total area required, total capital invested and/or borrowed, and financial report.  相似文献   
78.
79.
When a gas mixture flows through a passage and a highly exothermic reaction takes place on the wall very steep temperature gradients may develop and, though the passage be narrow, radiation from wall to wall may be important. General equations for this are set up for a cylindrical passage and solved by iterating on the concentration and temperature distributions on the wall. It is shown how the effect of radiation is to ameliorate the steep gradient and maximum temperature and to increase the length required for 99% conversion. Various approximations are discussed.  相似文献   
80.
The theory of continuous distribution of dislocations is applied to the phenomenological plane plasticity. It is shown that Hencky's laws are equivalent to each other and that Geiringer's relations can be used to determine the patterns of dislocation distribution. The deformation curvature caused by the presence and motion of dislocations and by the lattice deformation is also discussed.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号