全文获取类型
收费全文 | 2956篇 |
免费 | 129篇 |
国内免费 | 141篇 |
专业分类
电工技术 | 39篇 |
综合类 | 100篇 |
化学工业 | 168篇 |
金属工艺 | 76篇 |
机械仪表 | 121篇 |
建筑科学 | 84篇 |
矿业工程 | 21篇 |
能源动力 | 41篇 |
轻工业 | 30篇 |
水利工程 | 4篇 |
石油天然气 | 46篇 |
武器工业 | 5篇 |
无线电 | 319篇 |
一般工业技术 | 213篇 |
冶金工业 | 16篇 |
原子能技术 | 20篇 |
自动化技术 | 1923篇 |
出版年
2024年 | 3篇 |
2023年 | 39篇 |
2022年 | 53篇 |
2021年 | 57篇 |
2020年 | 49篇 |
2019年 | 32篇 |
2018年 | 33篇 |
2017年 | 59篇 |
2016年 | 81篇 |
2015年 | 80篇 |
2014年 | 171篇 |
2013年 | 175篇 |
2012年 | 149篇 |
2011年 | 261篇 |
2010年 | 174篇 |
2009年 | 165篇 |
2008年 | 228篇 |
2007年 | 224篇 |
2006年 | 245篇 |
2005年 | 204篇 |
2004年 | 149篇 |
2003年 | 136篇 |
2002年 | 85篇 |
2001年 | 50篇 |
2000年 | 36篇 |
1999年 | 62篇 |
1998年 | 37篇 |
1997年 | 21篇 |
1996年 | 29篇 |
1995年 | 20篇 |
1994年 | 18篇 |
1993年 | 18篇 |
1992年 | 17篇 |
1991年 | 20篇 |
1990年 | 6篇 |
1989年 | 12篇 |
1988年 | 6篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1979年 | 2篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1974年 | 1篇 |
排序方式: 共有3226条查询结果,搜索用时 234 毫秒
1.
In this paper, we present LinkingPark, an automatic semantic annotation system for tabular data to knowledge graph matching. LinkingPark is designed as a modular framework which can handle Cell-Entity Annotation (CEA), Column-Type Annotation (CTA), and Columns-Property Annotation (CPA) altogether. It is built upon our previous SemTab 2020 system, which won the 2nd prize among 28 different teams after four rounds of evaluations. Moreover, the system is unsupervised, stand-alone, and flexible for multilingual support. Its backend offers an efficient RESTful API for programmatic access, as well as an Excel Add-in for ease of use. Users can interact with LinkingPark in near real-time, further demonstrating its efficiency. 相似文献
2.
3.
Semantic search is gradually establishing itself as the next generation search paradigm, which meets better a wider range of information needs, as compared to traditional full-text search. At the same time, however, expanding search towards document structure and external, formal knowledge sources (e.g. LOD resources) remains challenging, especially with respect to efficiency, usability, and scalability.This paper introduces Mímir—an open-source framework for integrated semantic search over text, document structure, linguistic annotations, and formal semantic knowledge. Mímir supports complex structural queries, as well as basic keyword search.Exploratory search and sense-making are supported through information visualisation interfaces, such as co-occurrence matrices and term clouds. There is also an interactive retrieval interface, where users can save, refine, and analyse the results of a semantic search over time. The more well-studied precision-oriented information seeking searches are also well supported.The generic and extensible nature of the Mímir platform is demonstrated through three different, real-world applications, one of which required indexing and search over tens of millions of documents and fifty to hundred times as many semantic annotations. Scaling up to over 150 million documents was also accomplished, via index federation and cloud-based deployment. 相似文献
4.
通过对广州市电视台综合信息平台网络系统的应用现状及安全风险进行分析,提出基于网络层、系统层、用户层和安全策略管理全方位的网络信息安全体系. 相似文献
5.
Young-Soo Lee Do-Hyeon Park Hee-Taik Kim Kyong-Ok Yoo 《Korean Journal of Chemical Engineering》1995,12(1):23-28
Much SO2, another perilous air pollutant, was emitted during the oxidative regeneration of sulfided sorbent by H2S. In order to prevent emission of SO2, we carried out oxidative regeneration with the physical mixture of CaO and sulfided sorbent and investigated the effect
of regeneration temperature and oxygen concentration on the reactivity of CaO with S02. The effluent gases were analyzed by G.C. and the properties of sorbent were characterized by XRD. SEM, TG/DTA and EPMA.
Deterioration of reactivity of CaO with S02 resulted in increment of emission of SO12 due to the structural changes of CaO above 750°C and that at 850°C was more severe. Furthermore EPMA and XRD analysis revealed
that product layer diffusion through the solid product, CaSO4, was the rate limiting step for CaO sulfidation. The reaction of CaO w:.th SO2 was first order approximately and that was accelerated by high O2 concentration. 相似文献
6.
We consider a language of operations which pass parameters by means of a stack. An algebra over the set of type signatures is introduced, which allows the type signature of a program to be obtained from the type signatures of its constituent operations.Although the theories apply in principle to any stack based language, they have been evolved with particular regard to the proposed ANSI Standard Forth language, which is currently implemented in a type free manner. We hope this work will stimulate an interest in Forth amongst those applying algebraic techniques in software engineering, and we hope to lay the theoretical foundations for implementing practical type checkers to support Forth. 相似文献
7.
8.
9.
Qing Li 《Computer Standards & Interfaces》1991,13(1-3):99-103
The term ‘object-oriented database’ has been used to refer to different characteristics and mechanisms supported by semantic databases and (behaviorally) object-oriented ones. While this indicates the current confusion due to the lack of a common model, it also suggests the potential desirability of combining these two kinds of modeling facilities into the same nutshell. This paper summarizes from these two paradigms the features common to both, the features influenced/adopted by each other, and the features which are presented in one paradigm but missing from the other. After a brief analysis and discussion of these features, we conclude this paper by proposing our major theme: a complete object data model should take the union of the facilities offered by these two kinds of models. 相似文献
10.
A method to produce monodisperse magnetic composite spheres with diameters from less than 100 nm to more than 1 μm in water solution is reported. The spheres consist of a dielectric silica core and a cobalt/cobalt oxide shell which can be protected from further oxidation with an outer shell of silica or, alternatively, they can be covered with the polymer polyvinylpyrrolidone as a stabilizer. The formation of a uniform magnetic shell proceeds with the adsorption of metallic cobalt seeds, produced by the reduction of cobalt chloride with sodium borohydride, on a self‐assembled layer of polyelectrolytes on the silica core. In the second step, an outer silica shell can be formed by the hydrolysis and condensation of (3‐aminopropyl)trimethoxysilane and tetraethoxysilane. The double‐shell composite spheres show excellent sphericity, monodispersity, and a magnetic hysteresis loop at room temperature. 相似文献