全文获取类型
收费全文 | 19843篇 |
免费 | 2896篇 |
国内免费 | 2441篇 |
专业分类
电工技术 | 1851篇 |
技术理论 | 4篇 |
综合类 | 1576篇 |
化学工业 | 310篇 |
金属工艺 | 190篇 |
机械仪表 | 755篇 |
建筑科学 | 324篇 |
矿业工程 | 209篇 |
能源动力 | 168篇 |
轻工业 | 465篇 |
水利工程 | 312篇 |
石油天然气 | 223篇 |
武器工业 | 168篇 |
无线电 | 3766篇 |
一般工业技术 | 731篇 |
冶金工业 | 123篇 |
原子能技术 | 94篇 |
自动化技术 | 13911篇 |
出版年
2024年 | 82篇 |
2023年 | 432篇 |
2022年 | 636篇 |
2021年 | 772篇 |
2020年 | 841篇 |
2019年 | 653篇 |
2018年 | 588篇 |
2017年 | 777篇 |
2016年 | 910篇 |
2015年 | 1146篇 |
2014年 | 1802篇 |
2013年 | 1563篇 |
2012年 | 1878篇 |
2011年 | 1792篇 |
2010年 | 1213篇 |
2009年 | 1186篇 |
2008年 | 1397篇 |
2007年 | 1495篇 |
2006年 | 1125篇 |
2005年 | 1096篇 |
2004年 | 840篇 |
2003年 | 681篇 |
2002年 | 468篇 |
2001年 | 346篇 |
2000年 | 283篇 |
1999年 | 222篇 |
1998年 | 153篇 |
1997年 | 143篇 |
1996年 | 133篇 |
1995年 | 119篇 |
1994年 | 101篇 |
1993年 | 60篇 |
1992年 | 62篇 |
1991年 | 36篇 |
1990年 | 27篇 |
1989年 | 21篇 |
1988年 | 32篇 |
1987年 | 10篇 |
1986年 | 10篇 |
1985年 | 6篇 |
1984年 | 5篇 |
1983年 | 7篇 |
1982年 | 5篇 |
1981年 | 3篇 |
1980年 | 7篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 5篇 |
1976年 | 2篇 |
1972年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 14 毫秒
81.
82.
This paper presents a novel approach to computing tight upper bounds on the processor utilization for general real-time systems where tasks are composed of subtasks and precedence constraints may exist among subtasks of the same task. By careful analysis of preemption effects among tasks, the problem is formulated as a set of linear programming (LP) problems. Observations are made to reduce the number of LP problem instances required to be solved, which greatly improves the computation time of the utilization bounds. Furthermore, additional constraints are allowed to be included under certain circumstances to improve the quality of the bounds. 相似文献
83.
介绍采用射线方法检测功率管芯片与基座之间的焊接质量。试验证明,选用合适的透照参数可使X射线照相和X射线实时成像对焊接部位的检测均得到较高的对比灵敏度,但X射线照相法成本低廉,一次可透照多个工件,效率高,为该功率管焊接质量的理想检测方法。 相似文献
84.
把高速数字信号处理器(DSP)用于雷达的杂波模拟是一项很有前景、且正在被广泛应用的技术。文中从雷达杂波的分布特性出发,分析了低分辨率雷达的地物杂波的幅度概率密度分布和功率谱分布特性。并建立了一种有效的快捷的杂波模拟算法模型,以ADSP-TS101S为核心,设计完成了采用并行处理结构的一种雷达杂波实时模拟系统。 相似文献
85.
Interactive key frame selection model 总被引:1,自引:0,他引:1
Jian-quan Ouyang Jin-tao Li Huanrong Tang 《Journal of Visual Communication and Image Representation》2006,17(6):1145-1163
Video summarization can provide a fine representation of the content of video stream and reduce a large amount of data involved in video indexing, browsing, and retrieval. Moreover, Key frame selection is an important step in the research of content-based video analysis and retrieval. Although there exist a variety of methods for key frame selection, they are heuristic and closed systems, which cannot dynamically generate video summary with user’s preference. In this paper, an M-estimator and epipolar line distance constraint camera motion estimation algorithm is introduced as camera parameters is an important motion feature for key frame selection, and Broyden-Fletcher-Goldfarb-Shanno (BFGS) method is applied to optimize estimated parameters. Moreover, since Interactive Computing is a novel-computing model that represents the transition of algorithm to interaction, an interactive model of key frame selection (IKFS) is presented as a result of improving the model of key frame selection (KFS). The model of KFS and IKFS are proved to satisfy the criterion of induction and coinduction, respectively. Experimental results show that the processing scheme generates flexible and desirable summarizations whose distortion rate is lower than current method. Above all, IKFS is an extension to KFS. 相似文献
86.
本文设计了一种应用于油气藏永久性实时动态监测系统。该系统用光纤Bragg光栅(FBG)传感器作为井下永久性传感器,测量目的层的温度、压力等参数的模拟信号;在井口建立数据采集处理系统,将模拟信号解调成数字信号;通过GPRS无线移动通信网络传输到监测中心的数据库服务器上,并以Web形式发布到Internet网络上,同时提供移动用户浏览接口,且当数据异常时可以发送报警短消息。该系统实现了油气藏的远程实时动态监测,可以为油藏管理人员和技术人员及时、准确地做出决策提供可靠依据。 相似文献
87.
Cool 3D是一款特效图文制作软件,适用于动画片段、3D文字、图形等制作场合。Cool 3D中制作的特效素材应用于非线性编辑中,可以丰富素材的表现形式,提高节目编辑制作的整体质量。 相似文献
88.
DGPS在可控震源施工中的应用 总被引:1,自引:1,他引:0
在可控震源施工中,采用DGPS(差分全球卫星定位系统)实施实时点位监控,对保证施工质量、提高生产效率起着积极的作用。本文主要介绍PELTON ADVANCE Ⅲ GPS系统的安装和使用情况。 相似文献
89.
XIAN He-qun FENG Deng-guo 《通讯和计算机》2007,4(3):44-51
Even with attractive computational advantages, mobile agent technology has not developed its full potential due to various security issues. This paper proposes a method called Private Key Consignment to solve the problem of how to protect the data carried by mobile agents. It exploits new functionalities and mechanism provided by the trusted computing technology, and adopts both public key and symmetric key cryptographic means for data and key protection. The most notable feature of this method is that it protects the private key of the agent by consigning it to a tamper proof hardware, thus, enabling convenient and secure use of the private key. It provides a new scheme of mobile agents' data protection. 相似文献
90.
Kuo-Ming Chao Muhammad Younas Nick Godwin Pen-Choug Sun 《International Journal of Wireless Information Networks》2006,13(2):141-150
The popularity of grid services has widened their application to numerous domains and increased the utilization of computational resources. In order to create more incentives for the resources owners to lease their resources and prevent users from wasting the resources, the introduction of a market-oriented grid is inevitable. However, the issues for the negotiation between service provider and consumer over the supply and demand of resources can be complex, with highly interdependent issues. In this research, a simulated automated negotiation mechanism including a co-evolutionary mechanism and a modified game theory approach is proposed, to assist them in reaching an agreement over the conflicting issues. In the proposed architecture, the co-evolution process is able to reduce the multiple dimensional search space into a two-dimension search space and identify the appropriate negotiation strategies for the negotiating agents to form a payoff matrix which can be used for the game theory related stage of their interaction. The multiple stage negotiation process is introduced to improve the negotiation result. In this paper, an application which requires a large amount of computational resources to process the data generated from mobile devises is used to demonstrate that the proposed system is able to resolve the conflicts and obtain a valid solution. 相似文献