全文获取类型
收费全文 | 18786篇 |
免费 | 2288篇 |
国内免费 | 1398篇 |
专业分类
电工技术 | 3084篇 |
技术理论 | 11篇 |
综合类 | 2192篇 |
化学工业 | 582篇 |
金属工艺 | 292篇 |
机械仪表 | 1450篇 |
建筑科学 | 2479篇 |
矿业工程 | 671篇 |
能源动力 | 314篇 |
轻工业 | 808篇 |
水利工程 | 407篇 |
石油天然气 | 319篇 |
武器工业 | 171篇 |
无线电 | 2303篇 |
一般工业技术 | 918篇 |
冶金工业 | 571篇 |
原子能技术 | 19篇 |
自动化技术 | 5881篇 |
出版年
2024年 | 148篇 |
2023年 | 438篇 |
2022年 | 887篇 |
2021年 | 1082篇 |
2020年 | 1046篇 |
2019年 | 593篇 |
2018年 | 535篇 |
2017年 | 627篇 |
2016年 | 640篇 |
2015年 | 704篇 |
2014年 | 1450篇 |
2013年 | 1182篇 |
2012年 | 1595篇 |
2011年 | 1444篇 |
2010年 | 1107篇 |
2009年 | 983篇 |
2008年 | 1025篇 |
2007年 | 1205篇 |
2006年 | 955篇 |
2005年 | 890篇 |
2004年 | 736篇 |
2003年 | 648篇 |
2002年 | 541篇 |
2001年 | 494篇 |
2000年 | 357篇 |
1999年 | 280篇 |
1998年 | 176篇 |
1997年 | 143篇 |
1996年 | 98篇 |
1995年 | 93篇 |
1994年 | 78篇 |
1993年 | 67篇 |
1992年 | 37篇 |
1991年 | 34篇 |
1990年 | 29篇 |
1989年 | 15篇 |
1988年 | 10篇 |
1987年 | 16篇 |
1986年 | 9篇 |
1985年 | 7篇 |
1984年 | 5篇 |
1981年 | 7篇 |
1980年 | 13篇 |
1975年 | 4篇 |
1974年 | 4篇 |
1966年 | 6篇 |
1965年 | 4篇 |
1963年 | 4篇 |
1955年 | 2篇 |
1954年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
32.
压电类智能层合结构的力学和计算模型综述 总被引:2,自引:0,他引:2
综述了压电类智能层合结构的力学和计算模型。基于大量国内外有关压电类智能层合结构的文献 ,根据各自采用的运动学假设、场变量的近似、压电层的表达法以及曲率和温度的影响 ,对压电层合结构的力学和计算模型进行了分类 ,阐述了各种理论的特点及一般形式。 相似文献
33.
Koji Kamei Kunihiko Fujita Eva Jettmar Sen Yoshida Kazuhiro Kuwabara 《Interacting with computers》2002,14(6):438-759
In this paper, we present and discuss Community Organizer, a system designed to support network communities. The main characteristic of Community Organizer is the use of spatial representations for the relationships among community members including the communications exchanged among these members. These spatial representations reflect the degree of closeness of interests and concerns among the members, and are intended to provide users with clues on how to form network communities. In order to investigate the effectiveness of the proposed spatial representations, we conducted experiments with two different versions of the software. One version offered meaningful spatial representations while the other version did not. The subjects who used the former software version felt a greater sense of ‘community’, enjoyed using the software more, and actively used it longer than the subjects using the latter software version (control condition). These results indicated that the proposed spatial representations are effective in supporting network community formation. 相似文献
34.
本文给出一种全新的页面描述语言文本,它是一种真正的程序设计语言,而且是一种面向对象的智能语言。本语言已具有绿色软件的品格。 相似文献
35.
本文介绍智能控制在回转窑配料系统中的应用情况,并阐述该控制器设计、构成、软件系统特点及现场运行效果。 相似文献
36.
What has become known as Community Operational Research has been around in the UK for many years. The election of Jonathan Rosenhead as President of the UK OR Society in 1986–87 was the catalyst for bringing together and expanding activities which had been carried out largely by individuals working in isolation on a voluntary basis. The following five years have seen the establishment of the Community OR Unit at Northern College, the Centre for Community OR at Hull University and the Community OR Network, which supports the activities of volunteer OR workers across the UK. This paper reviews the range and types of work which have been undertaken by various practitioners. An assessment of the success of community OR is made and a number of issues which have arisen are discussed. Finally, given the diverse nature of community OR, its practice and practitioners, there is some discussion about the future of the area. 相似文献
37.
This article discusses the phenomenon of youth violence from a psychology of gender perspective. Although other factors are discussed--including gun availability, violence-related media influence, family and caretaker factors, and effects of teasing and bullying--the intention is to highlight new thinking on the potential relationship between boys' traditional masculine socialization experiences and violence. In this new perspective, traditional masculine socialization estranges and isolates many boys from their genuine inner lives and vital connections to others, which is theorized to heighten their risk of engaging in acts of violence. The authors identify school and community programs that may be helpful in counteracting damaging socialization experiences and supporting boys' healthier emotional and psychological development. Finally, the article discusses approaches that psychologists and other mental health professionals can use to help address this vital issue. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
38.
目前,钻井中井下检测信号的传输主要运用泥浆脉冲、电磁波等方式。随着井深的增加、复杂结构井和欠平衡井的增多以及对传输速度要求的提高,电缆信号传输必然是今后智能钻井的发展方向。通过对半个多世纪来各类电缆信号传输的设计进行归类,详细介绍了其设计原理,提出了电缆信号传输设计的基本要求与难点。 相似文献
39.
论社区服务产业化 总被引:2,自引:0,他引:2
刘波 《重庆理工大学学报(自然科学版)》2003,17(1):127-131
社区经济作为一种优化的资源配置方式,利用社区服务为载体,将社区内互不相联的各种经济成份变为利益共同体,建立一种新的经济生产方式,从而带动社区乃至更广区域的经济发展。 相似文献
40.
Community violence has emerged as a major risk factor for the development of mental health problems in children and adolescents. If mental health providers are to meet the needs of children and communities dealing with community violence, then they will need to integrate principles from various subdisciplines in psychology (e.g., developmental psychology, school psychology, developmental psychopathology) as well as disciplines outside of psychology (e.g., sociology, public health, medicine) to understand fully the developmental impact of exposure to community violence. The development of such a model is necessary to identify the pathways, risk, and protective factors on which prevention and intervention programs can be built. The goal of this article is to present an ecological-transactional model of community violence as a conceptual framework for understanding the existing literature and for guiding future research on community violence exposure and child development. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献