全文获取类型
收费全文 | 22519篇 |
免费 | 1908篇 |
国内免费 | 1791篇 |
专业分类
电工技术 | 1721篇 |
技术理论 | 1篇 |
综合类 | 2582篇 |
化学工业 | 718篇 |
金属工艺 | 781篇 |
机械仪表 | 1675篇 |
建筑科学 | 941篇 |
矿业工程 | 656篇 |
能源动力 | 312篇 |
轻工业 | 341篇 |
水利工程 | 430篇 |
石油天然气 | 786篇 |
武器工业 | 293篇 |
无线电 | 3003篇 |
一般工业技术 | 756篇 |
冶金工业 | 517篇 |
原子能技术 | 166篇 |
自动化技术 | 10539篇 |
出版年
2024年 | 58篇 |
2023年 | 136篇 |
2022年 | 300篇 |
2021年 | 391篇 |
2020年 | 455篇 |
2019年 | 350篇 |
2018年 | 319篇 |
2017年 | 478篇 |
2016年 | 568篇 |
2015年 | 777篇 |
2014年 | 1342篇 |
2013年 | 1141篇 |
2012年 | 1583篇 |
2011年 | 1886篇 |
2010年 | 1455篇 |
2009年 | 1426篇 |
2008年 | 1565篇 |
2007年 | 1894篇 |
2006年 | 1633篇 |
2005年 | 1492篇 |
2004年 | 1205篇 |
2003年 | 1199篇 |
2002年 | 936篇 |
2001年 | 790篇 |
2000年 | 613篇 |
1999年 | 436篇 |
1998年 | 344篇 |
1997年 | 293篇 |
1996年 | 256篇 |
1995年 | 198篇 |
1994年 | 154篇 |
1993年 | 130篇 |
1992年 | 82篇 |
1991年 | 61篇 |
1990年 | 34篇 |
1989年 | 43篇 |
1988年 | 29篇 |
1987年 | 27篇 |
1986年 | 16篇 |
1985年 | 14篇 |
1984年 | 19篇 |
1983年 | 31篇 |
1982年 | 13篇 |
1981年 | 9篇 |
1980年 | 6篇 |
1979年 | 8篇 |
1977年 | 8篇 |
1976年 | 4篇 |
1974年 | 3篇 |
1959年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
本文介绍了笔者设计并实现的一种新型的面向对象的程序设计语言,着重讨论了在设计过程中采用的新的概念,并和其它类似语言作了比较. 相似文献
22.
基于SDL的通信软件维护模型SMM 总被引:1,自引:0,他引:1
软件维护是软件生存周期的一个重要且花费很大的阶段,维护工作的自动化是软件行业十分迫切的需要。本文提出了一个基于ITU-TSDL语言的通信软件维护模型SMM。在此模型中,软件维护被分成三个部分:建立面向维护的数据库,制定维护规范和基于功能转换的自动维护。该模型将有助于软件维护支撑环境的建立 相似文献
23.
This paper reviews the current state of industry with regard to the introduction of software metrics. It discusses the benefits that organizations have derived from metrication, it looks at why organizations have sought to introduce metrics programmes, how they have gone about introducing those programmes and the problems that they have encountered during implementation. The review found that, on the whole, only the sanitized aspects of metrics experiences have actually been published. This seems to be especially the case with respect to practitioner resistance. Very few organizations admit to having encountered resistance during the introduction of a metrics programme. The paper also includes the results of a pilot study, conducted by the first author, which examines the attitudes that developers hold towards the introduction of software metrics. The key findings of this pilot study are that positive attitudes to metrics correlate highly with levels of education and to job satisfaction. 相似文献
24.
R. Hughes 《Information Systems Journal》1994,4(3):169-183
Abstract. This paper examines critically the function point analysis mark II (FPA mark II) method of measuring the functionality of information systems. Although the focus of the paper is on FPA mark II as devised by Symons, both this and the Albrecht method, from which the FPA mark II was developed, are briefly discussed. The published attempts to validate FPA mark II are reviewed and then the problems encountered by the author in applying the approach are described. The final part of the paper is concerned with the fit between SSADM and FPA mark II. 相似文献
25.
Torsten Bohlin Stefan F. Graebe 《International Journal of Adaptive Control and Signal Processing》1995,9(6):465-490
Grey box identification refers to the practice of identifying dynamical systems in model structures exploiting partial prior information. This contribution reviews a method for stochastic grey box identification and surveys experiences and lessons of applying it to a number of industrial processes. Issues to be addressed include advantages and costs of introducing stochastics into the model, the question of what contribution must be expected from the model designer as opposed to what can be formalized in computer algorithms, and an outlook on future plans to resolve present shortcomings. 相似文献
26.
Reorganisation and evolution of class hierarchies is important for object-oriented system development and has received considerable attention in the literature. The contributions of this paper are: (1) a formal study of a set of extension relations and transformations on class hierarchies; (2) a presentation of a small set of primitive transformations which form a minimal and complete basis for the extension relations; and (3) an analysis of the impact of these transformations at the object level.The study leads to a better understanding of evolution and reuse of object-oriented software and class hierarchies. It also provides a terminology and a means of classification for design reuse. The theory presented in this paper is based on the Demeter data model, which gives a concise mathematical foundation for classes and their inheritance and part-of relationships. Parts of the theory have been implemented in the Demeter System
TM
C++, a CASE tool for object-oriented design and programming. 相似文献
27.
28.
大黑汀大坝安全监测应用分析软件的开发与应用 总被引:1,自引:1,他引:0
周世虎 《水电自动化与大坝监测》2007,31(4):48-50,63
在大坝安全监测工作中,结合实际工程情况和工作需要,利用Visual Basic 6.0编程语言,开发出一套实用的安全监测应用分析软件,解决了数据共享、监测成果检查、自动化与人工测值比较、各种数据报表输出、历史数据提取、过程线分布图绘制等许多实际应用问题,极大地提高了工作效率,实现了大坝安全监测自动化。 相似文献
29.
Thomas Thelin 《Empirical Software Engineering》2003,8(3):309-313
This thesis describes six empirical investigations of two techniques applied to software inspections, namely reading techniques and fault content estimation techniques. The first part of the thesis presents a series of experiments of a novel reading technique called usage-based reading. The second part investigates fault content estimation applied to the software inspection process. The estimation methods used are capture-recapture and curve fitting. 相似文献
30.
本文论述了包钢热电厂综合管理信息系统的设计思想、功能模块、数据库和实现方法。该系统实现了生产数据及相关信息的数据采集与各类指标的管理统计、设备及材料的管理等各项业务处理,使得生产信息准确、唯一地传递,为生产经营者提供全面查询、分析、预测的依据,基本达到“无纸办公”的水平。 相似文献