全文获取类型
收费全文 | 5049篇 |
免费 | 536篇 |
国内免费 | 127篇 |
专业分类
电工技术 | 167篇 |
综合类 | 606篇 |
化学工业 | 147篇 |
金属工艺 | 43篇 |
机械仪表 | 84篇 |
建筑科学 | 1431篇 |
矿业工程 | 711篇 |
能源动力 | 103篇 |
轻工业 | 338篇 |
水利工程 | 319篇 |
石油天然气 | 298篇 |
武器工业 | 26篇 |
无线电 | 172篇 |
一般工业技术 | 231篇 |
冶金工业 | 397篇 |
原子能技术 | 56篇 |
自动化技术 | 583篇 |
出版年
2024年 | 17篇 |
2023年 | 64篇 |
2022年 | 125篇 |
2021年 | 181篇 |
2020年 | 185篇 |
2019年 | 94篇 |
2018年 | 101篇 |
2017年 | 117篇 |
2016年 | 159篇 |
2015年 | 185篇 |
2014年 | 389篇 |
2013年 | 337篇 |
2012年 | 333篇 |
2011年 | 388篇 |
2010年 | 299篇 |
2009年 | 312篇 |
2008年 | 300篇 |
2007年 | 312篇 |
2006年 | 263篇 |
2005年 | 250篇 |
2004年 | 217篇 |
2003年 | 183篇 |
2002年 | 168篇 |
2001年 | 122篇 |
2000年 | 101篇 |
1999年 | 85篇 |
1998年 | 74篇 |
1997年 | 43篇 |
1996年 | 60篇 |
1995年 | 44篇 |
1994年 | 36篇 |
1993年 | 22篇 |
1992年 | 26篇 |
1991年 | 14篇 |
1990年 | 6篇 |
1989年 | 13篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1986年 | 12篇 |
1985年 | 7篇 |
1983年 | 4篇 |
1982年 | 5篇 |
1981年 | 5篇 |
1979年 | 3篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1975年 | 4篇 |
1974年 | 5篇 |
1959年 | 3篇 |
1955年 | 4篇 |
排序方式: 共有5712条查询结果,搜索用时 15 毫秒
11.
Dennis L. Nielson 《Geothermics》1996,25(4-5)
The exploration for a geothermal resource on Ascension Island utilized a strategy that initially employed geologic mapping. On the basis of this, subsurface faults were mapped using an aeromagnetic survey. The faults were then explored using electrical resistivity surveys to define areas of potential hydrothermal fluid up-welling. The results of all of these techniques were used to site temperature gradient holes. A deep geothermal exploration well was then drilled in the area with highest heat flow adjacent to a rhyolite-to-trachyte volcanic complex. 相似文献
12.
应用数学理论知识和CAD技术对施工图进行建模,从而获得准确的放样参数指导施工,并结合工程实例对计算机辅助施工放样过程进行了具体的介绍。 相似文献
13.
Guay Stéphane; Boisvert Jean-Marie; Freeston Mark H. 《Canadian Metallurgical Quarterly》2003,15(3):392
The goal of this study was to examine whether data from 3 different measures of communication (i.e., self-report, quasi-observational, and observational) can predict relationship adjustment and stability 1 year later when used conjointly in a sample of 62 young couples. The 3 measures of communication were the Communication Skills Test-Revised (CST-R), the Communication Box (CB), and the Demand/Withdraw Pattern Questionnaire (DWPQ). Through hierarchical multiple regression analyses, results revealed that the CST-R and the DWPQ predict both genders' relationship adjustment 1 year later when used conjointly. Logistic regression analyses revealed that none of the measures of communication significantly predicted relationship stability. In conclusion, the combination of the CST-R and the DWPQ appears to be useful for longitudinally predicting relationship adjustment. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
14.
Myers Mark G.; MacPherson Laura; McCarthy Denis M.; Brown Sandra A. 《Canadian Metallurgical Quarterly》2003,15(2):163
The goal of the present studies was to construct and validate a short form of the 50-item Smoking Consequences Questionnaire (SCQ; T. H. Brandon & T. B. Baker, 1991), a measure of smoking outcome expectancies. In Study 1, a 21-item short form (S-SCQ) was derived from a sample of 107 young adults previously treated for substance abuse. In Study 2, the measure was cross-validated on 125 adolescents in treatment for substance abuse. Confirmatory factor analyses revealed good model fit and factorial invariance for the 4 S-SCQ subscales across both samples. Validation analyses on each sample found that subscale scores generally correlated significantly with smoking-related variables. The present studies provide initial evidence for the utility of the S-SCQ when used with young adults and adolescents. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
15.
We have evaluated the extent of public concerns about water management in the Palestinian Territory (PT) through a survey of the main Palestinian newspaper over the last thirteen years divided in three periods: pre (1984–1987), during (1988–1991), and post national uprising period (1992–1996). The public concern in the PT about various water management aspects was clear and influenced by the prevailing political conditions indicating (1) poor concerns in the first and second period where full Israeli military control of the PT and harsh practices prevailed with relatively more emphasis on regional water issues and (2) extensive-strong concerns in the third period when the peace process started and a partial lift of some of the Israeli water practices took place, along with an increased freedom in expressing public concerns which was granted with more emphasis on local issues and problems. Lack and limitation of water available to Palestinians, alternative solutions, and water quality and pollution control constituted the overwhelming majority of the topics of concern to the public for the three periods studied. Palestinian concerns were always greater than regional ones for the three periods and all of the topics considered. Public concern in the PT about all other water management aspects was poor and negligible especially in the first two periods. A massive increase in public concern has been observed in the third period in which the public expressed their concern over most water management aspects, indicating a possible change in public attitude toward water and water management and reflecting the change of the political status by the start of the peace process and the signing of the peace agreements. 相似文献
16.
17.
地面立体摄影测量在露天矿山的应用 总被引:1,自引:0,他引:1
本文针对露天矿验收测量的特点,论述了露天矿验收地面立体摄影测量方法及其内业处理系统,并将地面立体摄影测量结果与EDM解析法测量结果进行了比较。 相似文献
18.
黄土塬区复杂的地表条件难以获得可供解释的物探资料,本文给出了勘探天然气的地震技术,在野外弯线地震数据采集中,冲沟区运用了弯线高分辨率技术;塬上区采用非纵测线和地震测深观测系统,大药量、深井和强化组合法的接收条件。初步解决了弯线地震资料处理中二维滤波、静校正、速度分析等技术难题。摸索出一套以地震为骨架,构造解释与岩性解释相结合,重力-电法-地震联合解释落实古生界天然气构造圈闭的综合物探解释技术,并以实例展示方法的有效性。 相似文献
19.
20.
GIS支持下的岩土工程勘察设计区域化 总被引:1,自引:0,他引:1
通过分析我国岩土工程勘察设计的现状和GIS在岩土工程勘察设计中应用的情况,提出了GIS支持下的岩土工程勘察设计区域化设想,论述了其结构体系,并展望其应用前景。 相似文献