全文获取类型
收费全文 | 43509篇 |
免费 | 3272篇 |
国内免费 | 5338篇 |
专业分类
电工技术 | 2104篇 |
技术理论 | 66篇 |
综合类 | 5478篇 |
化学工业 | 6016篇 |
金属工艺 | 937篇 |
机械仪表 | 2510篇 |
建筑科学 | 15569篇 |
矿业工程 | 1700篇 |
能源动力 | 1246篇 |
轻工业 | 719篇 |
水利工程 | 2251篇 |
石油天然气 | 1037篇 |
武器工业 | 737篇 |
无线电 | 1925篇 |
一般工业技术 | 4084篇 |
冶金工业 | 983篇 |
原子能技术 | 139篇 |
自动化技术 | 4618篇 |
出版年
2024年 | 145篇 |
2023年 | 646篇 |
2022年 | 863篇 |
2021年 | 1255篇 |
2020年 | 1273篇 |
2019年 | 962篇 |
2018年 | 917篇 |
2017年 | 1120篇 |
2016年 | 1382篇 |
2015年 | 1481篇 |
2014年 | 3846篇 |
2013年 | 2629篇 |
2012年 | 3176篇 |
2011年 | 3385篇 |
2010年 | 2836篇 |
2009年 | 2960篇 |
2008年 | 2897篇 |
2007年 | 3490篇 |
2006年 | 3130篇 |
2005年 | 2841篇 |
2004年 | 2509篇 |
2003年 | 1867篇 |
2002年 | 1369篇 |
2001年 | 1056篇 |
2000年 | 888篇 |
1999年 | 687篇 |
1998年 | 480篇 |
1997年 | 412篇 |
1996年 | 338篇 |
1995年 | 285篇 |
1994年 | 217篇 |
1993年 | 174篇 |
1992年 | 146篇 |
1991年 | 81篇 |
1990年 | 65篇 |
1989年 | 55篇 |
1988年 | 42篇 |
1987年 | 28篇 |
1986年 | 17篇 |
1985年 | 22篇 |
1984年 | 30篇 |
1983年 | 19篇 |
1982年 | 15篇 |
1981年 | 10篇 |
1980年 | 14篇 |
1979年 | 8篇 |
1961年 | 4篇 |
1958年 | 4篇 |
1957年 | 6篇 |
1951年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 375 毫秒
941.
942.
《化学反应工程》多媒体课件的开发及应用 总被引:17,自引:11,他引:6
本文介绍用VB语言开发《化学反应工程》多媒体课件的性能特点,讨论实现中的一些主要技术及课件的使用情况。 相似文献
943.
基于MATLAB的化工课程设计软件开发 总被引:1,自引:0,他引:1
在MATLAB平台上开发化工原理课程设计软件。本文以冷却塔设计为例介绍了该软件的主要内容结构和功能 ,它具有操作简单、使用方便、效率高、数值稳定性好等特点 ,使计算结果可视化 相似文献
944.
Motif analysis for automatic segmentation of CT surface contours into individual surface features 总被引:2,自引:0,他引:2
This paper presents a new layer-based technique for automatic high-level segmentation of 3-D surface contours into individual surface features through motif analysis. The procedure starts from a contour-based surface model representing a composite surface area of an object. For each of the surface contours, a relative turning angle (RTA) map is derived. The RTA map usually contains noise and minor features. Algorithms based on motif analysis are applied for extracting a main profile of the RTA map free from background noise and other minor features. All feature points on the extracted profile are further identified from the extracted main profile through further motif analysis. The original contour is thus partitioned into individual segments with the identified feature points. A collection of consecutive contour segments among different layers form an individual 3-D surface feature of the original composite surface. The developed approach using motif analysis is particularly useful for the identification of smooth joins between individual surface features and for the elimination of superposed noise and unwanted minor features. 相似文献
945.
Knowledge-base V&V primarily addresses the question: “Does my knowledge-base contain the right answer and can I arrive at it?” One of the main goals of our work is to properly encapsulate the knowledge representation and allow the expert to work with manageable-sized chunks of the knowledge-base. This work develops a new methodology for the verification and validation of Bayesian knowledge-bases that assists in constructing and testing such knowledge-bases. Assistance takes the form of ensuring that the knowledge is syntactically correct, correcting “imperfect” knowledge, and also identifying when the current knowledge-base is insufficient as well as suggesting ways to resolve this insufficiency. The basis of our approach is the use of probabilistic network models of knowledge. This provides a framework for formally defining and working on the problems of uncertainty in the knowledge-base.
In this paper, we examine the project which is concerned with assisting a human expert to build knowledge-based systems under uncertainty. We focus on how verification and validation are currently achieved in . 相似文献
946.
Published online: 19 July 2001 相似文献
947.
948.
用户接口是任何交互式系统中至关重要的关键部件之一。它的开发已成为系统设计和实现中最为困难费时的“瓶颈“。用户接口管理系统UIMS接受了这一新的挑战,已成为人机交互和软件工程学科中的重要研究方向。本文将试图较全面地介绍和总结UIMS结构模型和表示方法等。 相似文献
949.
介绍了用Windows平台重新开发的集散控制系统控制组态软件 ,从软件工程的多个层面分析、探讨了软件重新开发的设计、实现方法。 相似文献
950.
Chaikin G 《Applied ergonomics》1984,15(3):197-201
The Department of Defense (DoD) Human Factors Standardization Program is the most far-reaching standardization programme in the USA. It is an integrated component of the overall DoD Standardization Program. While only ten major documents are contained in the human factors standardization area, their effects on human factors engineering programmes are profound and wide-ranging. Preparation and updating of the human engineering standardisation documents have grown out of the efforts of several military agencies, contractors, consultants, universities and individuals. New documents, engineering practice studies and revision efforts are continuously planned by the Tri-Service (Army, Navy, Air Force) Human Factors Standardization Steering Committee in collaboration with industry groups and technical societies. The present five-year plan and other standardisation documents are readily available for review and input by anyone with relevant interests. Human factors specialists and other readers of this journal may therefore influence the direction of the human factors standardisation programme and the content of its military specifications, standards and handbooks. 相似文献