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   2496篇
  免费   27篇
  国内免费   3篇
电工技术   24篇
综合类   2篇
化学工业   375篇
金属工艺   47篇
机械仪表   61篇
建筑科学   99篇
矿业工程   16篇
能源动力   55篇
轻工业   218篇
水利工程   31篇
石油天然气   19篇
无线电   174篇
一般工业技术   308篇
冶金工业   659篇
原子能技术   14篇
自动化技术   424篇
  2022年   14篇
  2019年   15篇
  2018年   15篇
  2017年   13篇
  2016年   26篇
  2015年   17篇
  2014年   33篇
  2013年   111篇
  2012年   69篇
  2011年   85篇
  2010年   79篇
  2009年   71篇
  2008年   87篇
  2007年   103篇
  2006年   97篇
  2005年   97篇
  2004年   91篇
  2003年   76篇
  2002年   72篇
  2001年   66篇
  2000年   46篇
  1999年   44篇
  1998年   69篇
  1997年   72篇
  1996年   71篇
  1995年   63篇
  1994年   36篇
  1993年   67篇
  1992年   67篇
  1991年   34篇
  1990年   40篇
  1989年   56篇
  1988年   43篇
  1987年   50篇
  1986年   36篇
  1985年   39篇
  1984年   57篇
  1983年   46篇
  1982年   24篇
  1981年   26篇
  1980年   31篇
  1979年   30篇
  1978年   29篇
  1977年   24篇
  1976年   23篇
  1975年   26篇
  1974年   32篇
  1973年   20篇
  1972年   13篇
  1971年   12篇
排序方式: 共有2526条查询结果,搜索用时 15 毫秒
31.
This article is the twenty-fourth of a series of articles discussing various open research problems in automated reasoning. The problem proposed for research asks one to find an appropriate theory for modulating across argument and across literal boundaries. Because demodulation has proved so useful—is most cases, even crucial—to automated reasoning, extending this concept to permit canonicalization to be applied at the predicate and at the clause and subclause levels merits exploration. For evaluating a proposed solution to this research problem, we suggest problems from mathematics, logic, program verification, database inquiry, and the world of puzzles.This work was supported by the Applied Mathematical Sciences subprogram of the Office of Energy Research, U.S. Department of Energy, under Contract W-31-109-Eng-38.  相似文献   
32.
Fuzzy-XCS: A Michigan Genetic Fuzzy System   总被引:1,自引:0,他引:1  
  相似文献   
33.
34.
The effects of personal characteristics and perceptions of interdisciplinary collaboration on discharge planning communication were examined for nurses, physicians, and social workers in two hospitals. The model for the study explained 61.7% of the variance in discharge planning communication for nurses. For all 142 health professionals, communication openness with social workers, problem solving between nurses and physicians, and collaboration with social workers were important to discharge planning communication. For nurses, communication satisfaction with patients and families also was important.  相似文献   
35.
Calendering of rigid and semirigid PVC (and ABS) compounds require an understanding of compound rheology and critical processing parameters. Compound rheology is modified with processing aids and lubricants. The choice of processing aid can be critical to achieving the desired rheology needed for calendering. This paper will focus on defining calendering rheology parameters as a function of a super high molecular weight MMA/SAN copolymer processing aid. These rheology parameters will be defined in terms of mill roll gap pressure, adhesive force (compound roll release) melt temperature, and shear rate. The ability to measure these parameters via a computerized two roll mill and relate this data to the actual calendering line will also be discussed.  相似文献   
36.
The goal ofthis article is to present an informal introduction and tutorial on aestheticallypleasing kaleidoscopic images. The article is intended for the non-mathematical reader interested in computer art. Simple generating formulas and recipes are included.  相似文献   
37.

Optimization models are developed for simultaneously determining the pipe layout and the pipe design for storm sewer systems. The pipe design process includes computation of commercial diameters, slopes, and crown elevations for the storm sewer pipes. The optimization models aim to minimize the total costs of the layout and the pipe design for most of system elements. The optimization models are formulated as a 0–1 Integer Nonlinear Programming problem and solved using the General Algebraic Modeling System without the use of heuristic models which were characteristic of all previous models for the simultaneous determine of the pipe layout and pipe design of sewer networks. The models are based upon two different optimization approaches: (1) considers one or more commercial diameters of pipe connecting two manholes and (2) considers only one commercial diameter in a pipe connecting two manholes. The commercial diameters, pipe slopes, crown elevations, and total costs of the storm sewer system were compared for the two approaches using an example that illustrates the savings in cost by allowing multiple pipe sizes. The two new optimization modeling approaches developed herein can simultaneously determine the minimum cost pipe design (commercial diameters, slopes, and crown elevations) and pipe layout of storm sewer systems and satisfy all design constraints.

  相似文献   
38.
We propose a novel pose-invariant face recognition approach which we call Discriminant Multiple Coupled Latent Subspace framework. It finds the sets of projection directions for different poses such that the projected images of the same subject in different poses are maximally correlated in the latent space. Discriminant analysis with artificially simulated pose errors in the latent space makes it robust to small pose errors caused due to a subject’s incorrect pose estimation. We do a comparative analysis of three popular latent space learning approaches: Partial Least Squares (PLSs), Bilinear Model (BLM) and Canonical Correlational Analysis (CCA) in the proposed coupled latent subspace framework. We experimentally demonstrate that using more than two poses simultaneously with CCA results in better performance. We report state-of-the-art results for pose-invariant face recognition on CMU PIE and FERET and comparable results on MultiPIE when using only four fiducial points for alignment and intensity features.  相似文献   
39.
In this article we overview the design and implementation of the second generation of Kansas Lava. Driven by the needs and experiences of implementing telemetry decoders and other circuits, we have made a number of improvements to both the external API and the internal representations used. We have retained our dual shallow/deep representation of signals in general, but now have a number of externally visible abstractions for combinatorial and sequential circuits, and enabled signals. We introduce these abstractions, as well as our abstractions for reading and writing memory. Internally, we found the need to represent unknown values inside our circuits, so we made aggressive use of associated type families to lift our values to allow unknowns, in a principled and regular way. We discuss this design decision, how it unfortunately complicates the internals of Kansas Lava, and how we mitigate this complexity. Finally, when connecting Kansas Lava to the real world, the standardized idiom of using named input and output ports is provided by Kansas Lava using a new monad, called Fabric. We present the design of this Fabric monad, and illustrate its use in a small but complete example.  相似文献   
40.
The results of two experiments showed that an illusion of memory can be produced by unconscious perception. In a first phase of those experiments, a long list of words was presented for study. For the test of recognition memory given in the second phase of each experiment, presentation of a "context" word preceded that of most recognition test words. Ss were to judge whether or not the test words had been presented during the earlier study phase of the experiment. Effects of a context word on this recognition memory decision were opposite when Ss were aware vs. unaware of its presentation. For example, as compared to a condition in which no context word was presented, the probability of false recognition was increased when Ss were unaware but decreased when Ss were aware of the presentation of a context word that matched the recognition test word. Results are discussed in terms of unconscious influences on an attribution process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  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