全文获取类型
收费全文 | 34265篇 |
免费 | 1122篇 |
国内免费 | 806篇 |
专业分类
电工技术 | 921篇 |
综合类 | 1099篇 |
化学工业 | 3939篇 |
金属工艺 | 3190篇 |
机械仪表 | 5158篇 |
建筑科学 | 1273篇 |
矿业工程 | 875篇 |
能源动力 | 1296篇 |
轻工业 | 641篇 |
水利工程 | 202篇 |
石油天然气 | 482篇 |
武器工业 | 380篇 |
无线电 | 1989篇 |
一般工业技术 | 2365篇 |
冶金工业 | 1303篇 |
原子能技术 | 264篇 |
自动化技术 | 10816篇 |
出版年
2024年 | 36篇 |
2023年 | 239篇 |
2022年 | 387篇 |
2021年 | 555篇 |
2020年 | 612篇 |
2019年 | 463篇 |
2018年 | 467篇 |
2017年 | 609篇 |
2016年 | 720篇 |
2015年 | 994篇 |
2014年 | 1652篇 |
2013年 | 1803篇 |
2012年 | 1718篇 |
2011年 | 2536篇 |
2010年 | 1577篇 |
2009年 | 1780篇 |
2008年 | 1841篇 |
2007年 | 2522篇 |
2006年 | 2394篇 |
2005年 | 2319篇 |
2004年 | 1985篇 |
2003年 | 1838篇 |
2002年 | 1453篇 |
2001年 | 1083篇 |
2000年 | 862篇 |
1999年 | 770篇 |
1998年 | 607篇 |
1997年 | 450篇 |
1996年 | 386篇 |
1995年 | 294篇 |
1994年 | 275篇 |
1993年 | 193篇 |
1992年 | 134篇 |
1991年 | 136篇 |
1990年 | 85篇 |
1989年 | 79篇 |
1988年 | 67篇 |
1987年 | 33篇 |
1986年 | 25篇 |
1985年 | 36篇 |
1984年 | 39篇 |
1983年 | 18篇 |
1982年 | 25篇 |
1981年 | 18篇 |
1980年 | 9篇 |
1979年 | 13篇 |
1978年 | 9篇 |
1977年 | 15篇 |
1976年 | 13篇 |
1975年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
基于虚拟仪器技术的多线程数据采集系统 总被引:4,自引:0,他引:4
本文论述了如何利用虚拟仪器技术以及多线程技术来进行数据采集,并介绍了在工业中的实际应用。 相似文献
72.
Complementary modelling of fluid separation processes 总被引:1,自引:0,他引:1
Optimal functioning of numerous technological processes depends primarily on relevant process design, properly selected column internals and sufficient understanding of the process behaviour. This can be achieved only with the help of accurate and reliable process models capable of considering process rates in a rigorous way, with respect to both transport phenomena and chemistry. In this article, a new modelling concept called complementary modelling is suggested for a large class of fluid separation processes. Since the conditions and criteria for these processes vary considerably, it is impossible to develop a unified modelling approach. Instead, a reasonable and effective combination of different modelling approaches provides solutions to many present and future tasks. The complementary modelling is discussed in detail and illustrated with several case studies. 相似文献
73.
国外几种脱硫醇工艺技术 总被引:1,自引:0,他引:1
硫醇是一种易挥发、有毒、腐蚀活性强的物质,在环保要求越来越严格的今天,必须将原油和凝析气中的硫醇加以脱除,才能达到环保要求。文章介绍了目前世界上采用的几种脱硫醇工艺。 相似文献
74.
75.
Li-Tang Yan 《Polymer》2006,47(18):6472-6480
The surface-directed spinodal decomposition (SDSD) of polymer binary mixture with different values of surface potential is numerically simulated in three-dimension (3D) by cell dynamic systems (CDS). Furthermore, the growth laws of the wetting layer are theoretically analyzed by the current equation and the dynamical scaling. The results show that the thickness of the wetting layer increases with the increasing surface potential. The crossover, which is later for larger values of surface potential, appears in the evolution curve of the wetting layer. Before the crossover, the growth law is the surface potential dependant growth law. Subsequently, the growth law is the typical Lifshitz-Slyozov (LS) growth law. The results indicate that the surface potential can result in the mutual transformation between completely wetting and partially wetting for the substrate interface. It can be found that the higher surface potential leads to the faster and stronger transmission of the effect of the substrate on the spinodal decomposition in the bulk. 相似文献
76.
Effects of circumferential pick spacing on boom type roadheader cutting head performance 总被引:4,自引:0,他引:4
E. Mustafa Eyyuboglu Naci Bolukbasi 《Tunnelling and Underground Space Technology incorporating Trenchless Technology Research》2005,20(5):418-425
Effects of equal and unequal circumferential pick spacing on the performance of boom type roadheaders having cylindrical cutting heads are investigated. For this purpose, two experimental cutting heads with equal and unequal circumferential spacing are designed and manufactured. The cutting head with unequal circumferential spacing is specifically designed to prevent tool-holder overlap at the nose section. Manufacturing difficulties associated with equal circumferential pick spacing due to tool-holder overlap are discussed with solid modeling and practical applications. The heads are tested at Park Cayirhan Coal Mine in Turkey and their cutting performances are analysed. Although better cutting performance for equal circumferential spacing are predicted by force–balance analysis, in situ measurements of instantaneous (net) traversing speed and cutting rate, pick consumption rate and machine vibration show that no significant difference exists between the performances of the two cutting heads. 相似文献
77.
介绍柳钢35t转炉方坯连铸机系统优化措施,通过优化使生产稳定性提高,铸坯质量得到改善,提高各项经济技术指标。 相似文献
78.
In this paper, we present the findings from an extensive study of the use of virtual reality (VR) models in large construction projects. The study includes two parts: The first part presents a quantitative questionnaire designed to investigate how VR models are experienced and assessed by the workforce at a building site. The second part includes a qualitative field survey of how VR models can be applied and accepted by professionals in the design and planning process of a large pelletizing plant. Through mainly studying persons who had little or no experience with advanced information technology (IT), we hoped to reveal the attitudes of the average person working at a construction site rather than of an IT expert. In summary, the study shows that the VR models in both projects have been very useful and well accepted by the users. Today’s information flow is, from a general point of view, considered to be insufficient and the hypothesis is that using VR models in the construction process have the potential to minimize waste of resources and improve the final result. 相似文献
79.
(Department of Automation & Computer Baotou Iron &Steel Instetute Baotou PRC) Wang ZhichunLi Wentao(Department of Net work Baotou Filiale of Inner MongoliaMobile Corporation Baotou PRC)Yang Zhanping 《微计算机信息》2003,19(5):45-45
This paper introduces hardware connections between computer and intellectualized instrument based on 89c51 sin-glechip .It gives the techniques to compile internet applications of Virtual Instruments with Delphi6. 相似文献
80.
虚拟企业模型并行仿真研究 总被引:4,自引:0,他引:4
随着各种全新的制造理念,特别是虚拟企业的出现,企业模型的规模不断扩大,使目前存在的大多数企业模型仿真系统的效率大大下降。该文针对此问题,通过深入分析虚拟企业模型结构,并在已有的构件化企业建模体系CEMS及其仿真系统的基础上,结合异步仿真技术和多线程技术提出了一种分层式企业模型仿真体系结构,为虚拟企业模型的快速高效的仿真提供了一种有效的方法。 相似文献