全文获取类型
收费全文 | 6810篇 |
免费 | 702篇 |
国内免费 | 260篇 |
专业分类
电工技术 | 371篇 |
综合类 | 414篇 |
化学工业 | 1149篇 |
金属工艺 | 422篇 |
机械仪表 | 493篇 |
建筑科学 | 407篇 |
矿业工程 | 191篇 |
能源动力 | 214篇 |
轻工业 | 790篇 |
水利工程 | 118篇 |
石油天然气 | 221篇 |
武器工业 | 31篇 |
无线电 | 756篇 |
一般工业技术 | 837篇 |
冶金工业 | 350篇 |
原子能技术 | 108篇 |
自动化技术 | 900篇 |
出版年
2024年 | 40篇 |
2023年 | 155篇 |
2022年 | 324篇 |
2021年 | 399篇 |
2020年 | 279篇 |
2019年 | 197篇 |
2018年 | 238篇 |
2017年 | 248篇 |
2016年 | 259篇 |
2015年 | 309篇 |
2014年 | 383篇 |
2013年 | 496篇 |
2012年 | 482篇 |
2011年 | 509篇 |
2010年 | 380篇 |
2009年 | 401篇 |
2008年 | 371篇 |
2007年 | 313篇 |
2006年 | 332篇 |
2005年 | 243篇 |
2004年 | 156篇 |
2003年 | 184篇 |
2002年 | 175篇 |
2001年 | 147篇 |
2000年 | 102篇 |
1999年 | 96篇 |
1998年 | 104篇 |
1997年 | 61篇 |
1996年 | 70篇 |
1995年 | 66篇 |
1994年 | 38篇 |
1993年 | 37篇 |
1992年 | 30篇 |
1991年 | 25篇 |
1990年 | 21篇 |
1989年 | 13篇 |
1988年 | 14篇 |
1987年 | 9篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1983年 | 6篇 |
1981年 | 9篇 |
1980年 | 6篇 |
1977年 | 6篇 |
1976年 | 6篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1969年 | 4篇 |
1951年 | 2篇 |
排序方式: 共有7772条查询结果,搜索用时 0 毫秒
71.
72.
BPEL 流程建模中的交叠模式分析与转换 总被引:1,自引:0,他引:1
由图形化流程建模语言生成可执行的业务流程语言(business process execution language,简称BPEL)时,对于源模型中顺序与并发结构交织的情况(称为交叠模式),传统的复制相关活动方法缺少系统分析及形式化描述.针对这一现状,提出基于工作流网的UML活动图生成BPEL方法,以自由选择工作流网作为活动图的理论基础,利用活的、有界的自由选择网系统的合成规则,定义合理的自由选择工作流网中的两种交叠模式,针对其中一种给出复制相关活动的形式化转换方法,并借助Petri网的并发正则表达式证明转换等价性,说明另一种交叠模式中复制相关活动方法的适用范围.针对BPEL流程建模及图形化流程语言生成块状语言过程中的交叠模式转换问题,给出形式化的描述与解决方法. 相似文献
73.
74.
75.
以Visual Studio.net为开发平台,SQL Server2000为后台数据库进行设计与开发,实现对中草药资源信息进行数据分析和监测预警。系统不但可改进传统的管理方法,而且还可提高种植专业化水平,并为中草药资源可持续发展提供决策依据。 相似文献
76.
Unpacking the effect of IT capability on the performance of export-focused SMEs: a report from China 总被引:2,自引:1,他引:1
Abstract. Export-focused small and medium-sized enterprises (SMEs) in China face a number of barriers to success, two primary ones being the liability of foreignness and resource scarcity. In order to transcend these challenges and be able to survive/prosper in the hypercompetitive international market, where players include large resourceful multinational organizations with experience in varied national contexts, these firms need to develop different organizational capabilities. In this paper, we specifically examine the role of a key organizational capability – information technology (IT) capability – and its different dimensions, in determining performance of export-focused SMEs in China. Our study reveals that IT capability has a positive impact on such firms' performance. This finding indicates the need for their owners/managers to invest in IT capability. Further, the study also highlights specific sub-dimensions of IT capability that export-focused Chinese SMEs should (or should not) develop, so as to derive maximum performance-related gains for the minimum amount spent on IT. 相似文献
77.
As music can be represented symbolically, most of the existing methods extend some string matching algorithms to retrieve musical patterns in a music database. However, not all retrieved patterns are perceptually significant because some of them are, in fact, inaudible. Music is perceived in groupings of musical notes called streams. The process of grouping musical notes into streams is called stream segregation. Stream-crossing musical patterns are perceptually insignificant and should be pruned from the retrieval results. This can be done if all musical notes in a music database are segregated into streams and musical patterns are retrieved from the streams. Findings in auditory psychology are utilized in this paper, in which stream segregation is modelled as a clustering process and an adapted single-link clustering algorithm is proposed. Supported by experiments on real music data, streams are identified by the proposed algorithm with considerable accuracy.
相似文献
Man Hon WongEmail: |
78.
Genetic Parallel Programming: design and implementation 总被引:1,自引:0,他引:1
This paper presents a novel Genetic Parallel Programming (GPP) paradigm for evolving parallel programs running on a Multi-Arithmetic-Logic-Unit (Multi-ALU) Processor (MAP). The MAP is a Multiple Instruction-streams, Multiple Data-streams (MIMD), general-purpose register machine that can be implemented on modern Very Large-Scale Integrated Circuits (VLSIs) in order to evaluate genetic programs at high speed. For human programmers, writing parallel programs is more difficult than writing sequential programs. However, experimental results show that GPP evolves parallel programs with less computational effort than that of their sequential counterparts. It creates a new approach to evolving a feasible problem solution in parallel program form and then serializes it into a sequential program if required. The effectiveness and efficiency of GPP are investigated using a suite of 14 well-studied benchmark problems. Experimental results show that GPP speeds up evolution substantially. 相似文献
79.
80.