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   780篇
  免费   46篇
  国内免费   3篇
电工技术   11篇
综合类   1篇
化学工业   302篇
金属工艺   28篇
机械仪表   13篇
建筑科学   15篇
矿业工程   3篇
能源动力   44篇
轻工业   20篇
水利工程   12篇
石油天然气   4篇
无线电   47篇
一般工业技术   174篇
冶金工业   87篇
原子能技术   9篇
自动化技术   59篇
  2024年   2篇
  2023年   10篇
  2022年   8篇
  2021年   29篇
  2020年   28篇
  2019年   21篇
  2018年   32篇
  2017年   34篇
  2016年   36篇
  2015年   23篇
  2014年   39篇
  2013年   74篇
  2012年   39篇
  2011年   47篇
  2010年   41篇
  2009年   29篇
  2008年   41篇
  2007年   30篇
  2006年   33篇
  2005年   28篇
  2004年   19篇
  2003年   9篇
  2002年   10篇
  2001年   13篇
  2000年   7篇
  1999年   3篇
  1998年   16篇
  1997年   10篇
  1996年   12篇
  1995年   10篇
  1994年   7篇
  1993年   11篇
  1992年   10篇
  1991年   2篇
  1990年   2篇
  1989年   8篇
  1988年   6篇
  1987年   10篇
  1986年   9篇
  1985年   5篇
  1984年   3篇
  1983年   2篇
  1982年   3篇
  1981年   5篇
  1977年   6篇
  1976年   1篇
  1975年   1篇
  1974年   1篇
  1972年   1篇
  1970年   2篇
排序方式: 共有829条查询结果,搜索用时 15 毫秒
91.
Sufficient conditions for a full order observer design for deterministic linear time-invariant differential difference systems is suggested. The observer parameters are constrained so that its coefficient matrices corresponding to delayed and nondelayed states commute. Then, a desired degree of stability for the observer can be achieved.  相似文献   
92.
Performed 2 experiments with 91 experimentally naive high school students to study the comparative influence of frequency and meaningfulness (m) on free recall. In Exp. I, the free-recall scores of 3 lists of words matched for m but varying in frequency levels were compared. In Exp. II, free recall of 3 lists of words matched for their frequency but varying in their m values were compared. Findings reveal that it is the frequency and not m of the words that influences free-recall, and that the influence of frequency is noticeable in the early trials of free-recall learning. Findings are discussed in terms of the existing theories of verbal learning. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
93.
Argues that the genetic and social variables were so confounded in S. Scarr and R. A. Weinberg's (see record 1977-07996-001) article on Black children adopted by White families that the results are consistent with virtually any theory of race differences in IQ. It is difficult to see any scientific or applied value in transracial adoption studies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
94.
95.
A large number of equal energy signals of period 2n ? 1, n ? 0 can be generated from signal generators described by primitive and irreducible polynomials of a degree n and whose correlation is small. Binary signals are generated using difference set sequences. Trace functions are used to find initial states of the shift register which generates difference set sequences. Periodic and nonperiodic auto and cross correlation of binary signals are studied and their bounds are derived. Then ternary signals are obtained from the binary signals that have lower correlation than the binary signals.  相似文献   
96.
97.
A systolic-like modular architecture is presented for hardware-efficient implementation of two-dimensional (2-D) discrete wavelet transform (DWT). The overall computation is decomposed into two distinct stages; where column processing is performed in stage-1, while row processing is performed in stage-2. Using a new data-access scheme and a novel folding technique, the computation of both the stages are performed concurrently for transposition-free implementation of 2-D DWT. The proposed design can offer nearly the same throughput rate, and requires the same or less the number of adders and multipliers as the best of the existing structures. The storage space is found to occupy most of the area in the existing 2-D DWT structures but the proposed structure does not require any on-chip or off-chip storage of input samples or storage/transposition of intermediate output. The proposed one, therefore, involves considerably less hardware complexity compared with the existing structures. Apart from that, it has less duration of cycle period in comparison to the existing structures, and has a latency of cycles while all the existing structures have latency of cycles, the filter order being small compared to the input size .  相似文献   
98.
99.
100.
In this note the maximum likelihood detector forMpulse-position-modulated (PPM) signals in Laguerre communications is derived. A decision-directed maximum likelihood estimator for the delay ofMPPM signals is 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