全文获取类型
收费全文 | 21775篇 |
免费 | 2466篇 |
国内免费 | 1799篇 |
专业分类
电工技术 | 1181篇 |
技术理论 | 1篇 |
综合类 | 2673篇 |
化学工业 | 402篇 |
金属工艺 | 328篇 |
机械仪表 | 1153篇 |
建筑科学 | 3204篇 |
矿业工程 | 660篇 |
能源动力 | 266篇 |
轻工业 | 359篇 |
水利工程 | 931篇 |
石油天然气 | 399篇 |
武器工业 | 130篇 |
无线电 | 2552篇 |
一般工业技术 | 982篇 |
冶金工业 | 923篇 |
原子能技术 | 208篇 |
自动化技术 | 9688篇 |
出版年
2024年 | 99篇 |
2023年 | 257篇 |
2022年 | 583篇 |
2021年 | 566篇 |
2020年 | 671篇 |
2019年 | 518篇 |
2018年 | 477篇 |
2017年 | 572篇 |
2016年 | 610篇 |
2015年 | 730篇 |
2014年 | 1217篇 |
2013年 | 1129篇 |
2012年 | 1477篇 |
2011年 | 1632篇 |
2010年 | 1364篇 |
2009年 | 1301篇 |
2008年 | 1521篇 |
2007年 | 1714篇 |
2006年 | 1480篇 |
2005年 | 1431篇 |
2004年 | 1337篇 |
2003年 | 1185篇 |
2002年 | 886篇 |
2001年 | 782篇 |
2000年 | 570篇 |
1999年 | 403篇 |
1998年 | 292篇 |
1997年 | 222篇 |
1996年 | 198篇 |
1995年 | 167篇 |
1994年 | 145篇 |
1993年 | 104篇 |
1992年 | 84篇 |
1991年 | 63篇 |
1990年 | 43篇 |
1989年 | 42篇 |
1988年 | 22篇 |
1987年 | 19篇 |
1986年 | 10篇 |
1985年 | 25篇 |
1984年 | 27篇 |
1983年 | 14篇 |
1982年 | 9篇 |
1981年 | 7篇 |
1980年 | 6篇 |
1979年 | 6篇 |
1966年 | 3篇 |
1959年 | 3篇 |
1957年 | 2篇 |
1956年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
This article is based on experiences with data and text mining to gain information for strategic business decisions, using host-based analysis and visualisation (A/V), primarily in the field of patents. The potential advantages of host-based A/V are pointed out and the features of the first such A/V software, STN®AnaVist™, are described in detail. Areas covered include the user interfaces, initial set of documents for A/V, data mining, text mining, reporting, and suggestions for further development. 相似文献
42.
43.
William Kent 《Computer Standards & Interfaces》1991,13(1-3):201-206
OSQL is the object-oriented database language developed for the Iris object-oriented database management system at Hewlett-Packard Laboratories. Its three fundamental constructs are objects, types, and functions. This paper provides an overview of the underlying concepts and some important features of OSQL. 相似文献
44.
The conditioned cue preference (CCP) task was used to study the information required to discriminate between spatial locations defined by adjacent arms of an 8-arm radial maze. Normal rats learned the discrimination after 3 unreinforced preexposure (PE) sessions and 4 food paired-unpaired training trials. Fimbria-fornix lesions made before, but not after, PE, and hippocampus lesions made at either time, blocked the discrimination, suggesting that the 2 structures processed different information. Lateral amygdala lesions made before PE facilitated the discrimination. This amygdala-mediated interference with the discrimination was the result of a conditioned approach response that did not discriminate between the 2 arm locations. A hippocampus/fimbria-fornix system and an amygdala system process different information about the same learning situation simultaneously and in parallel. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
45.
46.
通过对无锡市运河实验中学改扩建项目的回顾,阐述如何发掘原有校园空间环境的价值,并且通过借鉴中国古典园林的设计手法,使得老校园焕发出新生机。 相似文献
47.
48.
ASP技术由于其方便 ,灵活及可扩充性等特点和简明、高效的技术优势 ,在Web数据库的开发中获得了广泛的应用。简述了开发Web数据库的重要性 ,介绍了ASP技术的特点及其数据库访问原理 ,ADO对象。实例介绍了ASP实现医院门诊在线查询的方法 相似文献
49.
Mou Weimin; Biocca Frank; Owen Charles B.; Tang Arthur; Xiao Fan; Lim Lynette 《Canadian Metallurgical Quarterly》2004,10(4):238
In 3 experiments, the authors investigated spatial updating in augmented reality environments. Participants learned locations of virtual objects on the physical floor. They were turned to appropriate facing directions while blindfolded before making pointing judgments (e.g., "Imagine you are facing X. Point to Y"). Experiments manipulated the angular difference between the learning heading and the imagined heading and between the actual heading and the imagined heading. The effect of actual-imagined on pointing latency was observed for naive users but not for users with brief training or instructions concerning the fact that objects can move with body movements. The results indicated that naive users used an environment-stabilized reference frame to access information arrays, but with experience and instruction the nature of the representation changed from an environment stabilized to a body stabilized reference frame. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
50.