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   1358篇
  免费   113篇
电工技术   25篇
综合类   4篇
化学工业   378篇
金属工艺   20篇
机械仪表   36篇
建筑科学   68篇
矿业工程   1篇
能源动力   36篇
轻工业   161篇
水利工程   6篇
石油天然气   2篇
武器工业   1篇
无线电   108篇
一般工业技术   219篇
冶金工业   86篇
原子能技术   11篇
自动化技术   309篇
  2023年   9篇
  2022年   47篇
  2021年   73篇
  2020年   47篇
  2019年   43篇
  2018年   39篇
  2017年   34篇
  2016年   55篇
  2015年   58篇
  2014年   45篇
  2013年   96篇
  2012年   70篇
  2011年   101篇
  2010年   70篇
  2009年   71篇
  2008年   65篇
  2007年   58篇
  2006年   55篇
  2005年   48篇
  2004年   37篇
  2003年   45篇
  2002年   38篇
  2001年   25篇
  2000年   16篇
  1999年   18篇
  1998年   21篇
  1997年   12篇
  1996年   15篇
  1995年   18篇
  1994年   21篇
  1993年   10篇
  1992年   8篇
  1991年   3篇
  1990年   6篇
  1989年   7篇
  1988年   5篇
  1987年   5篇
  1986年   8篇
  1985年   8篇
  1984年   9篇
  1983年   6篇
  1982年   6篇
  1981年   9篇
  1980年   4篇
  1979年   4篇
  1978年   5篇
  1977年   2篇
  1976年   9篇
  1975年   2篇
  1974年   2篇
排序方式: 共有1471条查询结果,搜索用时 15 毫秒
1.
Poly(ADP-ribose) polymerases (PARP) are proteins responsible for DNA damage detection and signal transduction. PARP inhibitors (PARPi) are able to interact with the binding site for PARP cofactor (NAD+) and trapping PARP on the DNA. In this way, they inhibit single-strand DNA damage repair. These drugs have been approved in recent years for the treatment of ovarian cancer. Although they share some similarities, from the point of view of the chemical structure and pharmacodynamic, pharmacokinetic properties, these drugs also have some substantial differences. These differences may underlie the different safety profiles and activity of PARPi.  相似文献   
2.
Atom scattering is becoming recognized as a sensitive probe of the electron–phonon interaction parameter λ at metal and metal-overlayer surfaces. Here, the theory is developed, linking λ to the thermal attenuation of atom scattering spectra (in particular, the Debye–Waller factor), to conducting materials of different dimensions, from quasi-1D systems such as W(110):H(1 × 1) and Bi(114), to quasi-2D layered chalcogenides, and high-dimensional surfaces such as quasicrystalline 2ML-Ba(0001)/Cu(001) and d-AlNiCo(00001). Values of λ obtained using He atoms compare favorably with known values for the bulk materials. The corresponding analysis indicates in addition, the number of layers contributing to the electron–phonon interaction, which is measured in an atom surface collision.  相似文献   
3.
4.
This paper presents a novel approach to the localization of moving targets in a complex environment based on the measurement of the perturbations induced by the target presence on an independently‐generated time‐varying electromagnetic field. Field perturbations are measured via a set of sensors deployed over the domain of interest and used to detect and track a possible target by resorting to a particle Bernoulli filter (PBF). To comply with real‐time operation, the PBF works along with an artificial neural network (ANN) model of the environment trained offline via finite elements (FEs). The performance of the proposed algorithm is assessed via simulation experiments.  相似文献   
5.
Examined whether the method of constant stimuli with the standard presented first produces a constant error that depends on adaptation level. 120 university students were shown 5 series of 5 pairs of standard and variable lines. They had to decide whether the standard or the variable was longer or shorter than the preceding variable, or standard, respectively. In order to establish when the constant error occurred, the point of subjective equality was determined for each response. It was found that the 1st response was nearly random. The constant error was present from the 2nd response, and its magnitude did not change in succeeding series, contrary to expectations from adaptation-level theory. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
6.
The objective of this paper is to identify and analyse factors that are important for winning acceptance of wind-energy parks on the local level. The developers of wind-energy parks need to know how to manage “social acceptance” at the different stages of planning, realisation and operation. Five case studies in France and Germany focused on factors of success in developing a wind-energy project on a given site and illuminated how policy frameworks influence local acceptance. Our hypothesis is that these factors fall into two categories: institutional conditions, such as economic incentives and regulations; and site-specific conditions (territorial factors), such as the local economy, the local geography, local actors, and the actual on-site planning process (project management).  相似文献   
7.
A new approach for the estimation and the validation of a structural equation model with a formative-reflective scheme is presented. The basis of the paper is a proposal for overcoming a potential deficiency of PLS path modeling. In the PLS approach the reflective scheme assumed for the endogenous latent variables (LVs) is inverted; moreover, the model errors are not explicitly taken into account for the estimation of the endogenous LVs. The proposed approach utilizes all the relevant information in the formative manifest variables (MVs) providing solutions which respect the causal structure of the model. The estimation procedure is based on the optimization of the redundancy criterion. The new approach, entitled redundancy analysis approach to path modeling (RA-PM) is compared with both traditional PLS Path Modeling and LISREL methodology, on the basis of real and simulated data.  相似文献   
8.
This paper describes the spatial distribution of customer demand, supply of customer services and facility investment, as the outcome of a three-level game-like interaction between customers (e.g., shoppers), suppliers (e.g., retailers) and developers (e.g., landlords). Treating both the suppliers and developers at each centre as competitors, oligopolistic equilibria of the Nash-Stackelberg type are developed, and conditions for their existence and uniqueness established. Uncertain customer demand is specified in probabilistic terms, representing the suppliers' perception of expected customer behaviour.  相似文献   
9.
10.
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