全文获取类型
收费全文 | 11901篇 |
免费 | 1170篇 |
国内免费 | 430篇 |
专业分类
电工技术 | 299篇 |
技术理论 | 1篇 |
综合类 | 824篇 |
化学工业 | 2015篇 |
金属工艺 | 384篇 |
机械仪表 | 530篇 |
建筑科学 | 3567篇 |
矿业工程 | 451篇 |
能源动力 | 204篇 |
轻工业 | 2168篇 |
水利工程 | 182篇 |
石油天然气 | 154篇 |
武器工业 | 27篇 |
无线电 | 617篇 |
一般工业技术 | 931篇 |
冶金工业 | 518篇 |
原子能技术 | 144篇 |
自动化技术 | 485篇 |
出版年
2024年 | 61篇 |
2023年 | 268篇 |
2022年 | 386篇 |
2021年 | 566篇 |
2020年 | 559篇 |
2019年 | 427篇 |
2018年 | 367篇 |
2017年 | 407篇 |
2016年 | 446篇 |
2015年 | 437篇 |
2014年 | 996篇 |
2013年 | 1008篇 |
2012年 | 973篇 |
2011年 | 887篇 |
2010年 | 710篇 |
2009年 | 667篇 |
2008年 | 528篇 |
2007年 | 667篇 |
2006年 | 630篇 |
2005年 | 504篇 |
2004年 | 380篇 |
2003年 | 348篇 |
2002年 | 321篇 |
2001年 | 225篇 |
2000年 | 184篇 |
1999年 | 116篇 |
1998年 | 82篇 |
1997年 | 69篇 |
1996年 | 47篇 |
1995年 | 38篇 |
1994年 | 33篇 |
1993年 | 21篇 |
1992年 | 27篇 |
1991年 | 20篇 |
1990年 | 24篇 |
1989年 | 14篇 |
1988年 | 7篇 |
1987年 | 7篇 |
1986年 | 4篇 |
1985年 | 7篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1974年 | 3篇 |
1963年 | 3篇 |
1962年 | 2篇 |
1957年 | 3篇 |
1954年 | 1篇 |
1951年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.
John E. Sohn 《The Journal of Adhesion》1985,19(1):15-27
Enhanced matrix-filler adhesion is realized after filler treatment with a surface treatment process. The hydrosol/coupling agent treatment was applied to a wide range of inorganic and organic fillers, and adhesion to a variety of matrix resins was improved. Scanning Electron Microscopy (SEM) was used to determine the locus of failure in the filled systems. The locus of failure shows the relative degree of adhesion between the filler and the polymer matrix. Significant improvement in adhesion in humid environments is also observed. 相似文献
32.
矿化剂对氧化铬绿色釉呈色性能的影响 总被引:2,自引:0,他引:2
针对氧化铬绿色釉存在色调暗不够鲜艳的缺点,研究了矿化剂对其呈色性能的影响,经分光光度分析的扫描电镜测试,表明矿化剂具有一定的助熔作用和还原性,从而提高了氧化铬绿色釉的鲜艳度和着色力,增强了装饰性,同时矿化剂还能降低烧成温度,节约能源,具有应用价值。 相似文献
33.
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
34.
提出了一种应用于电子束曝光机束流测量中的自动跟踪工频陷波器,给出电路结构,基于对其工作原理的分析,介绍了提高陷波器跟踪精度的设计要点及调试方法。 相似文献
35.
Véronique Baroghel-Bouny Patrick Belin Matthias Maultzsch Dominique Henry 《Materials and Structures》2007,40(8):759-781
Within the framework of the evaluation and the prediction of chloride-induced corrosion risks, simple and rapid AgNO3 spray tests can be proposed for various issues. This paper forms the first part of a series. In this first part, the Maultzsch
procedure (spraying of 0.1-N AgNO3 solution + K2CrO4) as well as the procedure based on the use of a sole AgNO3 solution have been investigated on a broad range of concretes. These procedures have also been compared to the Collepardi
procedure (spraying of 0.1-N AgNO3 + fluoresceine). The feasibility of these colorimetric techniques on saturated specimens cast in laboratory, after non-steady-state
diffusion tests carried out in various conditions, is discussed. In addition, the results obtained from applying such spray
tests in field conditions on cores drilled out from various RC test specimens exposed to a marine environment (tidal zone)
and to a road and cold environment (freezing-thawing cycles and spraying of deicing salts) are presented. Colorimetric methods
have in particular been applied here to the assessment of the average chloride penetration depth and of its evolution versus
time (kinetics). Moreover, the detection threshold of these techniques has been investigated in various environments. The
possible sources of discrepancy on the results have been analysed. 相似文献
36.
绿色植物能吸收CO2 ,释放O2 ,清除有毒污染物 ,阻滞灰尘 ,杀灭细菌等致病微生物 ;在矿区环境污染治理时 ,应切实加强矿区绿化工作 ,扩大植被覆盖率 ,保持矿区生态平衡 ,促进矿区的可持续发展。 相似文献
37.
Koenen Karestan C.; Stellman Jeanne Mager; Stellman Steven D.; Sommer John F. Jr. 《Canadian Metallurgical Quarterly》2003,71(6):980
Risk factors affecting the course of posttraumatic stress disorder (PTSD) are poorly understood. As part of a larger study on characterizing exposure to herbicides in Vietnam, the authors investigated this issue in a random sample of 1,377 American Legionnaires who had served in Southeast Asia during the Vietnam War and were followed over a 14-year period. High combat exposure, perceived negative community attitudes at homecoming, minority race, depression symptoms at Time 1, and more anger at Time 1 predicted a more chronic course. Community involvement at Time 1 was protective and associated with decreased risk at Time 2. Discomfort in disclosing Vietnam experiences was associated with an increased risk for developing PTSD but did not predict its course. Combat exposure predicted PTSD course more strongly than any other risk factor. Findings suggest recovery from PTSD is significantly influenced by perceived social support. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
38.
39.
40.