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   1556篇
  免费   33篇
  国内免费   2篇
电工技术   26篇
综合类   6篇
化学工业   161篇
金属工艺   42篇
机械仪表   41篇
建筑科学   69篇
矿业工程   23篇
能源动力   24篇
轻工业   134篇
水利工程   7篇
石油天然气   6篇
无线电   127篇
一般工业技术   223篇
冶金工业   552篇
原子能技术   10篇
自动化技术   140篇
  2022年   8篇
  2021年   14篇
  2020年   9篇
  2019年   19篇
  2018年   17篇
  2017年   17篇
  2016年   26篇
  2015年   13篇
  2014年   33篇
  2013年   71篇
  2012年   30篇
  2011年   53篇
  2010年   39篇
  2009年   48篇
  2008年   54篇
  2007年   50篇
  2006年   42篇
  2005年   36篇
  2004年   37篇
  2003年   33篇
  2002年   21篇
  2001年   25篇
  2000年   27篇
  1999年   40篇
  1998年   135篇
  1997年   90篇
  1996年   61篇
  1995年   35篇
  1994年   42篇
  1993年   51篇
  1992年   23篇
  1991年   26篇
  1990年   26篇
  1989年   29篇
  1988年   23篇
  1987年   26篇
  1986年   15篇
  1985年   22篇
  1984年   10篇
  1983年   22篇
  1982年   19篇
  1981年   17篇
  1980年   14篇
  1979年   10篇
  1978年   9篇
  1977年   25篇
  1976年   29篇
  1975年   7篇
  1974年   8篇
  1973年   9篇
排序方式: 共有1591条查询结果,搜索用时 46 毫秒
141.
The electronic properties of two-dimensional (2D) materials, like graphene, are of considerable fundamental interest. This paper describes how physically adsorbed films probe these properties. The cases of an ideal 2D free electron gas and graphene are examined, with explicit results found for an adsorbed He film. In the free electron case, the scattering is proportional to the 2D structure factor of the film. Results are presented for He on graphene and the free electron gas in both the low coverage and fully commensurate limits.  相似文献   
142.
Scalability in Formal Concept Analysis   总被引:8,自引:0,他引:8  
  相似文献   
143.
Advances in integrated circuit technology have made failure site localization extremely challenging. Charge-induced voltage alteration (CIVA), low energy CIVA (LECIVA), light-induced voltage alteration (LIVA), Seebeck effect imaging (SEI) and thermally-induced voltage alteration (TIVA) are five recently developed failure analysis techniques which meet the challenge by rapidly and non-destructively localizing interconnection defects on ICs. The techniques take advantage of voltage fluctuations in a constant current power supply as an electron or photon beam is scanned across an IC. CIVA and LECIVA are scanning electron microscopy techniques that yield rapid localization of open interconnections. LIVA is a scanning optical microscopy (SOM) method that yields quick identification of damaged semiconductor junctions and determines transistor logic states. SEI and TIVA are SOM techniques that rapidly localize open interconnections and shorts respectively. LIVA, SEI, and TIVA can be performed from the backside of ICs by using the proper photon wavelength. This paper describes the CIVA, LECIVA, LIVA, TIVA, and SEI techniques in terms of the physics of signal generation, general data acquisition system required, and imaging results displaying the utility of each technique for localizing interconnection defects.  相似文献   
144.
Correction to Richard J Bloomer, Kelsey H Fisher-Wellman, Kelley G Hammond, Brian K Schilling, Adrianna A Weber and Bradford J Cole: Dietary supplement increases plasma norepinephrine, lipolysis, and metabolic rate in resistance trained men. Journal of the International Society of Sports Nutrition 2009, 6: 4  相似文献   
145.
This article presents a statistical approach to the scheduling of divisible workloads. Structured as a task farm with different scheduling modes including adaptive single and multi-round scheduling, this novel divisible load theory approach comprises two phases, calibration and execution, which dynamically adapt the installment size and number. It introduces the concept of a generic installment factor based on the statistical dispersion of the calibration times of the participating nodes, which allows automatic determination of the number and size of the workload installments. Initially, the calibration ranks processors according to their fitness and determines an installment factor based on how different their execution times are. Subsequently, the execution iteratively distributes the workload according to the processor fitness, which is continuously re-assessed throughout the program execution. Programmed as an adaptive algorithmic skeleton, our task farm has been successfully evaluated for single-round scheduling and generic multi-round scheduling using a computational biology parameter-sweep in a non-dedicated multi-cluster system.  相似文献   
146.
The primary drivers for space instruments are the environment and survivability, support assets, delivery cost, and lack of accessibility. Survivability deals primarily with environments, such as launch and depressurization, extremes of temperature, high vacuum, radiation, and hypervelocity impacts. The cost to deployment is directly coupled to launch services, which are inherently expensive. These costs are nonlinear functions of the mass and volume of satellite payloads. The “user interfaces” for space-borne instruments are high-cost assets because they include mission operations centers, satellite hacking station(s), and ground networks. All of these issues demand high reliability  相似文献   
147.
In many instances brewhouse performance cannot be predicted from a finished malt specification. This is particularly so for factors such as lautering, yeast performance, filtration and head character. There are two aspects involved in improving the brewing performance of malt. Firstly, an understanding of the malt characteristics affecting particular aspects of the brewing process and secondly an understanding of how the malting process affects or can be controlled to optimise these characteristics and thus their performance. In this work the relationship between barley variety, steeping pattern, malt quality and brewing performance is investigated. Six different barley varieties were micromalted in a Seeger micromalting unit under four different steeping regimes. Sub-samples were taken at intervals during steeping for enzyme analysis and measurement of water distribution. Following steeping, the samples were germinated and kilned using standard micromalting conditions. Finished malts were analysed by standard EBC methods for routine malt quality parameters including apparent attenuation limit. Worts were tested for total β-glucan content, β-glucan molecular weight distribution, filter plugging potential and carbohydrate levels. A sub set of malt samples were then micro-brewed and tested for β-glucan molecular weight (MW) distribution, beer filterability and foam stability.  相似文献   
148.
Data from several clinical samples and the Minnesota Multiphasic Personality Inventory–2 standardization group are presented to familiarize the reader with response patterns of different groups on a new validity scale designed to assist in the identification of exaggeration or fabrication of psychological disturbance. Sensitivity-specificity analyses are included along with suggestions for use of the F(p) Scale with other validity scales. Cautions about setting single cutoff scores are also discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
149.
150.
In this lead paper for this special section, we advance the perspective that new insights into parenting at risk can be gained by focusing on the dynamic emotional processes that occur during parent–child exchanges, with special emphasis on parental emotions as experienced and their regulation of emotion and underlying cognitions, as well as the role of developmentally rooted cognitions in shaping these associations. We discuss the very few but germinal studies that embody this perspective and introduce work in this section that examines emotion dynamics during parenting in real time. We believe this perspective will move us beyond static conceptualizations of parenting at risk, broadens our understanding of parenting as a process, and accelerates our ability to identify the essential targets of intervention when parenting is at risk. (PsycINFO Database Record (c) 2011 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