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   1467篇
  免费   78篇
  国内免费   3篇
电工技术   19篇
综合类   2篇
化学工业   280篇
金属工艺   22篇
机械仪表   27篇
建筑科学   81篇
矿业工程   1篇
能源动力   45篇
轻工业   107篇
水利工程   15篇
石油天然气   2篇
无线电   80篇
一般工业技术   411篇
冶金工业   190篇
原子能技术   12篇
自动化技术   254篇
  2024年   2篇
  2023年   9篇
  2022年   19篇
  2021年   41篇
  2020年   20篇
  2019年   27篇
  2018年   33篇
  2017年   30篇
  2016年   38篇
  2015年   44篇
  2014年   70篇
  2013年   87篇
  2012年   91篇
  2011年   133篇
  2010年   88篇
  2009年   80篇
  2008年   101篇
  2007年   114篇
  2006年   87篇
  2005年   86篇
  2004年   53篇
  2003年   48篇
  2002年   38篇
  2001年   27篇
  2000年   17篇
  1999年   17篇
  1998年   14篇
  1997年   16篇
  1996年   10篇
  1995年   11篇
  1994年   8篇
  1993年   9篇
  1992年   8篇
  1991年   3篇
  1990年   13篇
  1989年   9篇
  1988年   8篇
  1987年   7篇
  1986年   2篇
  1984年   4篇
  1983年   5篇
  1982年   5篇
  1981年   2篇
  1980年   1篇
  1979年   2篇
  1978年   2篇
  1977年   4篇
  1975年   2篇
  1974年   1篇
  1973年   1篇
排序方式: 共有1548条查询结果,搜索用时 789 毫秒
81.
The objective of the present work was to understand how the structural, surface, water vapour and gas barrier properties of wheat gluten (WG) coated paper could be influenced by the features of paper. For this purpose, a surface treated paper (TP) and an untreated paper (UTP) were compared. Penetration of WG-coating into the bulk of paper was more pronounced in UTP than TP. This led to the formation of a significant junction zone resulting in an interpenetrated structure for WG–UTP, suggesting a composite-like structure, while a bi-layer one was obtained for WG–TP. Differences in WG penetration were related to the hydrophilicity, roughness and porosity of the paper used. Even though the extent of penetration did not greatly affect the surface properties (water and oil resistance), the transfer properties (water vapour, O2 and CO2) of WG-coated papers were significantly improved when WG-coating highly penetrated: while the WG–TP behaved as a micro-perforated material, the WG–UTP behaved as WG-film.  相似文献   
82.
When Elliot first took over as editor of Psychoanalytic Psychology and invited Jeremy to join the editorial board, we met for lunch to brainstorm about new directions for the journal. One of the schemes we hatched was the idea of developing a special issue consisting of articles by prominent figures in the field, reflecting on the future of psychoanalysis. This article discusses some of the details of this issue. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
83.
Presented in this paper is a novel additive manufacturing technology for making three-dimensional parts with functionally graded materials (FGMs), called Freeze-form Extrusion Fabrication (FEF). The system development included a triple-extruder mechanism, extruder modeling and control, pastes extrusion planning for desired composition gradients, and software coding for motion and extrusion control. The effectiveness of the developed FEF system was demonstrated first by fabricating limestone (CaCO3) parts with graded colors and then by fabricating ‘green’ parts with graded compositions between alumina (Al2O3) and zirconia (ZrO2). The fabricated part went through post-processing, and the sintered part was analyzed using energy dispersive spectroscopy (EDS) to determine its material compositions.  相似文献   
84.
85.
This study examined the relationship of early alliance ruptures and their resolution to process and outcome in a sample of 128 patients randomly assigned to 1 of 3 time-limited psychotherapies for personality disorders: cognitive–behavioral therapy, brief relational therapy, or short-term dynamic psychotherapy. Rupture intensity and resolution were assessed by patient- and therapist-report after each of the first 6 sessions. Results indicated that lower rupture intensity and higher rupture resolution were associated with better ratings of the alliance and session quality. Lower rupture intensity also predicted good outcome on measures of interpersonal functioning, while higher rupture resolution predicted better retention. Patients reported fewer ruptures than did therapists. In addition, fewer ruptures were reported in cognitive–behavioral therapy than in the other treatments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
86.
This paper introduces methods for probabilistic uncertainty analysis of a frequency response function (FRF) of a structure obtained via a finite element (FE) model. The methods are applicable to computationally expensive FE models, making use of a Bayesian metamodel known as an emulator. The emulator produces fast predictions of the FE model output, but also accounts for the additional uncertainty induced by only having a limited number of model evaluations. Two approaches to the probabilistic uncertainty analysis of FRFs are developed. The first considers the uncertainty in the response at discrete frequencies, giving pointwise uncertainty intervals. The second considers the uncertainty in an entire FRF across a frequency range, giving an uncertainty envelope function. The methods are demonstrated and compared to alternative approaches in a practical case study.  相似文献   
87.
A multi-agent system for energy management of distributed power sources   总被引:1,自引:0,他引:1  
The field of energy management is an area increasingly studied. However, most solutions are based on centralized systems and barely fulfil criterion like fault tolerance or adaptability. Also, these systems are often difficult to design because of the “top–down” approach used: the designer generally knows how each component has to respond separately, but a centralized management system focuses his attention solely on the overall reaction of the system. That is why a distributed management solution based on the paradigm of Multi-Agent Systems (MASs) is proposed in this paper. In addition to a more natural conception, based on a “bottom–up” approach, this solution ensures better system reliability. After reviewing the previous works, an application of MAS to power management in a hybrid power source is presented. Then, the system is tested using a simulation model. The results show that this approach is perfectly valid and can respond to most problems of centralized energy management systems (EMSs).  相似文献   
88.
Abstract

The Water Poverty Index is an integrated tool developed on the basis of extensive consultation with a range of scientists, practitioners and policymakers. It is primarily designed for use at the community level to enable more holistic water-resource assessments on a site-specific basis. It can however be applied at different scales to suit different needs. One of the motivations to design such a tool was an attempt to move away from the conventional, purely deterministic, approaches to water assessment, relying primarily on models and large-scale data. In today's world such an approach is inappropriate, ill representing the complexities of modern water-allocation decisions where economic, political and social issues all have a powerful role to play. This paper highlights some applications of the Water Poverty Index at different spatial scales and discusses the implications of applying indicators at these different scales.  相似文献   
89.
Collaborative Information Seeking   总被引:1,自引:0,他引:1  
An examination of the roles and dimensions of collaborative search reveals new opportunities for information-seeking support tools.  相似文献   
90.
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