全文获取类型
收费全文 | 14735篇 |
免费 | 2419篇 |
国内免费 | 1960篇 |
专业分类
电工技术 | 1690篇 |
技术理论 | 4篇 |
综合类 | 1690篇 |
化学工业 | 374篇 |
金属工艺 | 226篇 |
机械仪表 | 1690篇 |
建筑科学 | 396篇 |
矿业工程 | 216篇 |
能源动力 | 313篇 |
轻工业 | 138篇 |
水利工程 | 159篇 |
石油天然气 | 265篇 |
武器工业 | 110篇 |
无线电 | 1829篇 |
一般工业技术 | 937篇 |
冶金工业 | 232篇 |
原子能技术 | 115篇 |
自动化技术 | 8730篇 |
出版年
2024年 | 69篇 |
2023年 | 203篇 |
2022年 | 459篇 |
2021年 | 544篇 |
2020年 | 526篇 |
2019年 | 416篇 |
2018年 | 431篇 |
2017年 | 582篇 |
2016年 | 744篇 |
2015年 | 818篇 |
2014年 | 1032篇 |
2013年 | 914篇 |
2012年 | 1197篇 |
2011年 | 1180篇 |
2010年 | 924篇 |
2009年 | 954篇 |
2008年 | 985篇 |
2007年 | 1120篇 |
2006年 | 905篇 |
2005年 | 846篇 |
2004年 | 755篇 |
2003年 | 586篇 |
2002年 | 477篇 |
2001年 | 395篇 |
2000年 | 354篇 |
1999年 | 253篇 |
1998年 | 213篇 |
1997年 | 218篇 |
1996年 | 159篇 |
1995年 | 166篇 |
1994年 | 134篇 |
1993年 | 108篇 |
1992年 | 112篇 |
1991年 | 48篇 |
1990年 | 49篇 |
1989年 | 47篇 |
1988年 | 39篇 |
1987年 | 29篇 |
1986年 | 21篇 |
1985年 | 21篇 |
1984年 | 18篇 |
1983年 | 15篇 |
1982年 | 7篇 |
1981年 | 7篇 |
1980年 | 6篇 |
1979年 | 6篇 |
1977年 | 6篇 |
1976年 | 4篇 |
1975年 | 4篇 |
1957年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
Using Web resources to construct multilingual medical thesaurus for cross-language medical information retrieval 总被引:1,自引:0,他引:1
Due to the language barrier, non-English users are unable to retrieve the most updated medical information from the U.S. authoritative medical websites, such as PubMed and MedlinePlus. However, currently, there is no any cross-language medical information retrieval (CLMIR) system that can help Chinese-speaking consumers cross the language barrier in finding useful English medical information. A few CLMIR systems utilize MeSH (Medical Subject Headings) to help overcome the language barrier. Unfortunately, the traditional Chinese version of MeSH is currently unavailable.In this paper, we employ a semi-automatic term translation method to construct a Chinese–English MeSH by exploiting abundant multilingual Web resources, including Web anchor texts and search–result pages. Through this method, we have developed a Chinese–English Mesh Compilation System to assist knowledge engineers in compiling a Chinese–English medical thesaurus with more than 19,000 entries. Furthermore, this thesaurus has been used to develop a prototypical system for cross-language medical information retrieval, MMODE, which can help consumers retrieve top-quality English medical information using Chinese terms. 相似文献
33.
34.
35.
36.
This study examined whether objects are attended in serial or in parallel during a demanding visual search task. A component of the event-related potential waveform, the N2pc wave, was used as a continuous measure of the allocation of attention to possible targets in the search arrays. Experiment 1 demonstrated that the relative allocation of attention shifts rapidly, favoring one item and then another. In Experiment 2, a paradigm was used that made it possible to track the absolute allocation of attention to individual items. This experiment showed that attention was allocated to one object for 100-150 ms before attention began to be allocated to the next object. These findings support models of attention that posit serial processing in demanding visual search tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
37.
Windows 95/98环境下PC机并行打印端口控制步进电机的研究 总被引:1,自引:0,他引:1
介绍了在Windows95/98环境下利用IBM-PC机打印端口控制步进电机运动的实现方法,并给出了关键程序的实现代码。 相似文献
38.
39.
F. Pasquarelli 《Journal of scientific computing》1995,10(3):289-304
The multidomain technique for elliptic problems, that allows the fulfillment of the interface conditions by means of a suitable combination of the continuity of the solution and of its normal derivative, is considered. Some choices of this combination are investigated and, in particular, a choice that allows the solution of the multidomain problem through two solutions for each subproblem, is proposed. The scheme has been discretized with a collocation method and some numerical tests are reported. Moreover the method is compared with the more classical Dirichlet/Neumann one as well as with the capacitance matrix method.This research has been supported by a grant from M.P.I. (40%). 相似文献
40.
Attempts have been made to extend SQL to work with multimedia databases. We are reserved on the representation ability of extended SQL to cope with the richness in content of multimedia data. In this paper we present an example of a multimedia database system, Computer Aided Facial Image Inference and Retrieval system (CAFIIR). The system stores and manages facial images and criminal records, providing necessary functions for crime identification. We would like to demonstrate some core techniques for multimedia database with CAFIIR system. Firstly, CAFIIR is a integrated system. Besides database management, there are image analysis, image composition, image aging, and report generation subsystems, providing means for problem solving. Secondly, the richness of multimedia data urges feature-based database for their management. CAFIIR is feature-based. A indexing mechanism,iconic index, has been proposed for indexing facial images using hierarchical self-organization neural network. The indexing method operates on complex feature measures and provides means for visual navigation. Thirdly, special retrieval methods for facial images have been developed, including visual browsing, similarity retrieval, free text retrieval and fuzzy retrieval. 相似文献