全文获取类型
收费全文 | 23107篇 |
免费 | 1928篇 |
国内免费 | 1794篇 |
专业分类
电工技术 | 1723篇 |
技术理论 | 1篇 |
综合类 | 2589篇 |
化学工业 | 736篇 |
金属工艺 | 784篇 |
机械仪表 | 1673篇 |
建筑科学 | 1027篇 |
矿业工程 | 656篇 |
能源动力 | 316篇 |
轻工业 | 342篇 |
水利工程 | 430篇 |
石油天然气 | 787篇 |
武器工业 | 292篇 |
无线电 | 3117篇 |
一般工业技术 | 820篇 |
冶金工业 | 520篇 |
原子能技术 | 167篇 |
自动化技术 | 10849篇 |
出版年
2024年 | 58篇 |
2023年 | 151篇 |
2022年 | 303篇 |
2021年 | 400篇 |
2020年 | 477篇 |
2019年 | 365篇 |
2018年 | 333篇 |
2017年 | 494篇 |
2016年 | 578篇 |
2015年 | 792篇 |
2014年 | 1374篇 |
2013年 | 1168篇 |
2012年 | 1606篇 |
2011年 | 1919篇 |
2010年 | 1484篇 |
2009年 | 1455篇 |
2008年 | 1593篇 |
2007年 | 1919篇 |
2006年 | 1654篇 |
2005年 | 1512篇 |
2004年 | 1220篇 |
2003年 | 1212篇 |
2002年 | 951篇 |
2001年 | 830篇 |
2000年 | 629篇 |
1999年 | 449篇 |
1998年 | 362篇 |
1997年 | 306篇 |
1996年 | 261篇 |
1995年 | 213篇 |
1994年 | 160篇 |
1993年 | 138篇 |
1992年 | 94篇 |
1991年 | 67篇 |
1990年 | 36篇 |
1989年 | 53篇 |
1988年 | 34篇 |
1987年 | 29篇 |
1986年 | 18篇 |
1985年 | 17篇 |
1984年 | 21篇 |
1983年 | 32篇 |
1982年 | 14篇 |
1981年 | 11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
31.
储运罐区计算机监测系统的开发与应用 总被引:3,自引:1,他引:2
储运罐区计算机监测系统是石化企业自动控制的薄弱环节。中国石油集团公司抚顺石油一厂使用ZYG-101型电子智能液位仪,以及使用FIX组态软件完成该系统的数据库组态、工艺流程显示、实时和历史趋势显示、报警和报表等处理过程,通过二次表的串行口与计算机进行通信,由计算机实时监测每个罐的各种重要参数。运行证明:该系统测量误差小,数据实时性好.易于存储及远程传送,较理想地达到储运罐区的自动检测功能。 相似文献
32.
Mark Taylor John Miles Dino Bouchlaghem Chimay Anumba 《Canadian Metallurgical Quarterly》2007,21(1):59-62
IT systems for engineers are becoming more numerous and complex and will further proliferate in the future. It is infeasible to expect users to be trained to work with a plethora of systems, especially as many of them will only see occasional use. Therefore, in the near future, systems will need user interfaces that allow intuitive access and usage. This paper examines a new style of user interface based on virtual reality. 相似文献
33.
A new spreadsheet-cell-object-oriented algorithm for the first-order reliability method is proposed and illustrated for cases with correlated nonnormals and explicit and implicit performance functions. The new approach differs from the writers earlier algorithm by obviating the need for computations of equivalent normal means and equivalent normal standard deviations. It obtains the solution faster and is more efficient, robust, and succinct. Other advantages include ease of initialization prior to constrained optimization, ease of randomization of initial values for checking robustness, and fewer required optimization constraints during spreadsheet-automated search for the design point. Two cases with implicit performance functions, namely an asymmetrically loaded beam on Winkler medium and a strut with complex supports are analyzed using the new approach and discussed. Comparisons are also made between the proposed approach and that based on Rosenblatt transformation. 相似文献
34.
35.
The goal of the PMS project is to produce an environment in which the intelligent online assessment of the design for large-scale ADA programming projects is provided. The focus is on the representation of knowledge about the design process for an individual module. Changes in pseudocode complexity are measured in terms of partial metrics. These metrics can take the designers inferences about the pseudocode program structure into account when assessing module complexity. Next, a model of the stepwise refinement process is given which demonstrates how pseudocode elaboration decisions can be modelled in partial metric terms. Finally, the decisions associated with each refinement step for 17 example refinements taken from the computer science literature are described using partial metrics. 相似文献
36.
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
37.
SD2300是兴威帆电子公司生产的一种新型高精度实时时钟芯片。TMS320F2812是TI公司最新推出的DSP芯片,该芯片广泛地运用于测控和控制场合。文中给出了基于SD2300和TMS320F2812的时钟输入、低功耗“软件时间锁”的硬件和软件设计方法。 相似文献
38.
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
39.
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
40.
T.J. Williams P. Bernus J. Brosvic D. Chen G. Doumeingts L. Nemes J.L. Nevins B. Vallespir J. Vlietstra D. Zoetekouw 《Control Engineering Practice》1994,2(6):939-960
This paper is a summary of the major technical report (Williams et al., 1993) of the IFAC/IFIP Task Force on Architectures for Integrating Manufacturing Activities and Enterprises. It presents a synopsis of the investigations of pertinent architectures undertaken, and the findings generated relating to the suitability of various architectures for the integration task. It also presents the Task Force's recommendations for achieving a “complete” architecture in terms of the necessary capabilities by “completing” a currently available architecture. The Task Force also outlined how a “best” architecture could be achieved by selecting and combining the best features of the available architectures. 相似文献