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   2355篇
  免费   142篇
  国内免费   3篇
电工技术   33篇
综合类   5篇
化学工业   628篇
金属工艺   72篇
机械仪表   48篇
建筑科学   199篇
矿业工程   4篇
能源动力   90篇
轻工业   187篇
水利工程   16篇
石油天然气   7篇
无线电   179篇
一般工业技术   473篇
冶金工业   126篇
原子能技术   12篇
自动化技术   421篇
  2023年   26篇
  2022年   42篇
  2021年   80篇
  2020年   51篇
  2019年   70篇
  2018年   60篇
  2017年   59篇
  2016年   90篇
  2015年   93篇
  2014年   109篇
  2013年   173篇
  2012年   146篇
  2011年   200篇
  2010年   107篇
  2009年   139篇
  2008年   147篇
  2007年   134篇
  2006年   106篇
  2005年   85篇
  2004年   88篇
  2003年   53篇
  2002年   59篇
  2001年   35篇
  2000年   34篇
  1999年   30篇
  1998年   34篇
  1997年   27篇
  1996年   33篇
  1995年   22篇
  1994年   21篇
  1993年   15篇
  1992年   15篇
  1991年   12篇
  1990年   7篇
  1989年   16篇
  1988年   5篇
  1987年   5篇
  1986年   10篇
  1985年   6篇
  1984年   11篇
  1983年   6篇
  1982年   4篇
  1981年   4篇
  1980年   2篇
  1979年   2篇
  1978年   3篇
  1977年   4篇
  1976年   3篇
  1975年   6篇
  1970年   3篇
排序方式: 共有2500条查询结果,搜索用时 15 毫秒
71.
Experience with the development and maintenance of large test suites specified using the Testing and Test Control Notation (TTCN-3) has shown that it is difficult to construct tests that are concise with respect to quality aspects such as maintainability or usability. The ISO/IEC standard 9126 defines a general software quality model that substantiates the term “quality” with characteristics and subcharacteristics. The domain of test specifications, however, requires an adaption of this general model. To apply it to specific languages such as TTCN-3, it needs to be instantiated. In this paper, we present an instantiation of this model as well as an approach to assess and improve test specifications. The assessment is based on metrics and the identification of code smells. The quality improvement is based on refactoring. Example measurements using our TTCN-3 tool TRex demonstrate how this procedure is applied in practise. B. Zeiss is supported by a Ph.D. scholarship from Siemens AG, Corporate Technology.  相似文献   
72.
Equality and subtyping of recursive types were studied in the 1990s by Amadio and Cardelli; Kozen, Palsberg, and Schwartzbach; Brandt and Henglein; and others. Potential applications include automatic generation of bridge code for multilanguage systems and type-based retrieval of software modules from libraries. In this paper, we present an efficient decision procedure for a notion of type equality that includes unfolding of recursive types, and associativity and commutativity of product types. Advocated by Auerbach, Barton, and Raghavachari, these properties enable flexible matching of types. For two types of size at most n, our algorithm takes O(n) iterations each of which takes O(n) time, for a total of O(n2) time.  相似文献   
73.
Volume rendered imagery often includes a barrage of 3D information like shape, appearance and topology of complex structures, and it thus quickly overwhelms the user. In particular, when focusing on a specific region a user cannot observe the relationship between various structures unless he has a mental picture of the entire data. In this paper we present ClearView, a GPU-based, interactive framework for texture-based volume ray-casting that allows users which do not have the visualization skills for this mental exercise to quickly obtain a picture of the data in a very intuitive and user-friendly way. ClearView is designed to enable the user to focus on particular areas in the data while preserving context information without visual clutter. ClearView does not require additional feature volumes as it derives any features in the data from image information only. A simple point-and-click interface enables the user to interactively highlight structures in the data. ClearView provides an easy to use interface to complex volumetric data as it only uses transparency in combination with a few specific shaders to convey focus and context information.  相似文献   
74.
Humans manage to adapt learned movements very quickly to new situations by generalizing learned behaviors from similar situations. In contrast, robots currently often need to re-learn the complete movement. In this paper, we propose a method that learns to generalize parametrized motor plans by adapting a small set of global parameters, called meta-parameters. We employ reinforcement learning to learn the required meta-parameters to deal with the current situation, described by states. We introduce an appropriate reinforcement learning algorithm based on a kernelized version of the reward-weighted regression. To show its feasibility, we evaluate this algorithm on a toy example and compare it to several previous approaches. Subsequently, we apply the approach to three robot tasks, i.e., the generalization of throwing movements in darts, of hitting movements in table tennis, and of throwing balls where the tasks are learned on several different real physical robots, i.e., a Barrett WAM, a BioRob, the JST-ICORP/SARCOS CBi and a Kuka KR?6.  相似文献   
75.
This article describes the concept of a "Central Data Management" (CDM) and its implementation within the large-scale population-based medical research project "Personalized Medicine". The CDM can be summarized as a conjunction of data capturing, data integration, data storage, data refinement, and data transfer. A wide spectrum of reliable "Extract Transform Load" (ETL) software for automatic integration of data as well as "electronic Case Report Forms" (eCRFs) was developed, in order to integrate decentralized and heterogeneously captured data. Due to the high sensitivity of the captured data, high system resource availability, data privacy, data security and quality assurance are of utmost importance. A complex data model was developed and implemented using an Oracle database in high availability cluster mode in order to integrate different types of participant-related data. Intelligent data capturing and storage mechanisms are improving the quality of data. Data privacy is ensured by a multi-layered role/right system for access control and de-identification of identifying data. A well defined backup process prevents data loss. Over the period of one and a half year, the CDM has captured a wide variety of data in the magnitude of approximately 5terabytes without experiencing any critical incidents of system breakdown or loss of data. The aim of this article is to demonstrate one possible way of establishing a Central Data Management in large-scale medical and epidemiological studies.  相似文献   
76.
77.
This study examines the effect of changing the floor from a 2-mm homogenous vinyl floor to a 4-mm heterogeneous vinyl floor (1.5-mm wear layer and 2.5-mm foam layer) on musculoskeletal symptoms in the lower extremities and low back among nursing assistants in a geriatric care centre. A pre-post design with a reference group consisting of nursing assistants from a similar geriatric care centre was used. Follow-up measurements were carried out 12 and 24 months after the intervention by means of questionnaires. At the 1-year follow-up, the pain intensity score in the feet of the intervention group had decreased compared with the baseline value and remained statistically significant at the 2-year follow-up. The decrease in pain intensity score of the feet in the intervention group was statistically significantly different from the reference group, both after 1 and 2 years. PRACTITIONER SUMMARY: The results show the importance of flooring in the workplace with regard to reducing musculoskeletal symptoms. Appropriate flooring is especially important in the female-dominated health care sector, where workers must stand or walk for long periods.  相似文献   
78.
Large-Scale Hydrogen Production   总被引:3,自引:0,他引:3  
There is a growing need for hydrogen in processing heavier and dirtier fossil fuels and a future hydrogen economy is widely suggested as the next generation fuel/energy source once fossil fuels diminish in availability. Sustainable fuels are still regarded as too expensive given the large amounts of natural gas and a projected, ample supply of fossil fuels beyond the next twenty-plus years. Today, the steam reforming of hydrocarbons is the most favorable route to H2. If CO2 sequestration were ever to become widely practiced, fossil fuels would continue to play an important role in the future hydrogen economy.  相似文献   
79.
Mark Michaelis 《硅谷》2005,(6):123-129
简介 最新发布的Visual Studio Test System(VSTS)包含了一套用于Visual Studio Team Test的完整功能。Team Test是Visual Studio集成的单元测试框架,它支持:  相似文献   
80.
Utilizing services of legacy and third party COTS components has become vital for the timely development and evolution of software systems. Component interfaces typically have to be adapted before they can be re-used in a system context. This paper presents an approach to generating component adapters. The approach focuses on mapping multiple events, and their associated parameters, generated from a source component to multiple calls in the target component. The novelty of our mechanism is that it allows developers to generate asynchronous as well as synchronous adapters. As a result we can generate adapters for components with incompatible event structure. A prototype called Asynchronous Component Adapter (ACA) was developed which demonstrates the idea with Java Beans, but the methodology can be applied to any component-based system that supports introspection like Microsoft .NET assemblies.  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