全文获取类型
收费全文 | 6288篇 |
免费 | 625篇 |
国内免费 | 231篇 |
专业分类
电工技术 | 385篇 |
综合类 | 274篇 |
化学工业 | 1289篇 |
金属工艺 | 245篇 |
机械仪表 | 435篇 |
建筑科学 | 349篇 |
矿业工程 | 97篇 |
能源动力 | 251篇 |
轻工业 | 629篇 |
水利工程 | 95篇 |
石油天然气 | 131篇 |
武器工业 | 13篇 |
无线电 | 776篇 |
一般工业技术 | 937篇 |
冶金工业 | 313篇 |
原子能技术 | 103篇 |
自动化技术 | 822篇 |
出版年
2024年 | 36篇 |
2023年 | 139篇 |
2022年 | 271篇 |
2021年 | 376篇 |
2020年 | 265篇 |
2019年 | 214篇 |
2018年 | 253篇 |
2017年 | 271篇 |
2016年 | 250篇 |
2015年 | 272篇 |
2014年 | 364篇 |
2013年 | 415篇 |
2012年 | 483篇 |
2011年 | 466篇 |
2010年 | 405篇 |
2009年 | 383篇 |
2008年 | 338篇 |
2007年 | 241篇 |
2006年 | 251篇 |
2005年 | 174篇 |
2004年 | 160篇 |
2003年 | 133篇 |
2002年 | 141篇 |
2001年 | 122篇 |
2000年 | 86篇 |
1999年 | 83篇 |
1998年 | 117篇 |
1997年 | 77篇 |
1996年 | 69篇 |
1995年 | 45篇 |
1994年 | 50篇 |
1993年 | 23篇 |
1992年 | 38篇 |
1991年 | 23篇 |
1990年 | 10篇 |
1989年 | 19篇 |
1988年 | 13篇 |
1987年 | 13篇 |
1986年 | 6篇 |
1985年 | 5篇 |
1984年 | 6篇 |
1983年 | 7篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 4篇 |
1977年 | 3篇 |
1976年 | 9篇 |
1974年 | 2篇 |
1914年 | 2篇 |
排序方式: 共有7144条查询结果,搜索用时 15 毫秒
111.
基于J2ME技术、MVC模式,在手机客户端开发了人力资源管理系统,实现了企业级人力资源管理的移动办公。系统分为服务器端和客户端两部分,服务器端负责接收客户端请求并处理,客户端接收用户请求,并通过MVC模式使得界面和模型数据分离,便于维护。 相似文献
112.
Hong‐Ming Zhan Zheng Xu Yong‐Can Wang Li‐Feng Lin Ming Chen Woong Kim Dan Wang Xi‐Bin Shao Seong‐Kyu Lee 《Journal of the Society for Information Display》2013,21(3):137-141
A type of fast response time (RT) liquid crystal (LC) was developed to adopt in fringe‐field switching (FFS) mode for shutter glass 3D display device, the average gray to gray level (GTG) RT can reduce from 7.43 ms to 4.48 ms at a refreshing rate of 60 Hz, and the transmittance can increase by 15.4% compared with conventional LC based on the same cell gap. Meanwhile, the correlation among optical efficiency, correlative color temperature (CCT) of module and retardation of LC for FFS mode was studied. Transmittance is proportional to the retardation of LC; however, the CCT is inversely proportional to the retardation. The fast response LC can keep almost the original optical efficiency and CCT. 相似文献
113.
High concentrations of manganese and iron in the Saigon River are major problems for the water supply in Ho Chi Minh City (HCMC), Viet Nam. To identify their sources and leaching processes, we surveyed water quality along the Saigon River and ran batch leaching tests using soil and sediment samples. Two important leaching processes were identified: acidic leaching from acid sulfate soil (ASS) in the middle reaches of the river, and Mn dissolution and Fe reduction from sediments in the downstream reaches. Low pH caused the concurrent release of Fe and Mn from the ASS. In contrast, anoxia caused the release of Fe but not Mn from the sediments, whereas low pH facilitated Mn dissolution. Sediments are a more important source of Mn because of their higher Mn contents (10 times) and release rates (14 times) than those from ASS. 相似文献
114.
115.
P2P系统中分配及检索目标的路由占据了大多数开销,通过公平性参数(FI)推导出影响路由公平性的因素.根据结论在没有增加任何负载的情况下对Chord finger选择算法进行改进,通过公平性参数(FI)及仿真对改进前后的Chord的公平性进行评估,结果表明改进后的EChord性能有较大提高. 相似文献
116.
文章介绍了煤矿现有的调度电话录音系统,设计了调度电话监控上传系统来实现录音文件的上传和调度电话查询系统实现录音文件的查询和远程回放。系统通过输入查询取代了传统的人工查询的工作方式,大大节约了生产调度成本,同时为煤矿人员考勤和定位也提供了准确依据。由于其配置容易、操作方便、实用性高,因此具有很好的维护性和推广性。 相似文献
117.
Miloš Hašan Edgar Velázquez‐Armendáriz Fabio Pellacini Kavita Bala 《Computer Graphics Forum》2008,27(4):1105-1114
Rendering animations of scenes with deformable objects, camera motion, and complex illumination, including indirect lighting and arbitrary shading, is a long‐standing challenge. Prior work has shown that complex lighting can be accurately approximated by a large collection of point lights. In this formulation, rendering of animation sequences becomes the problem of efficiently shading many surface samples from many lights across several frames. This paper presents a tensor formulation of the animated many‐light problem, where each element of the tensor expresses the contribution of one light to one pixel in one frame. We sparsely sample rows and columns of the tensor, and introduce a clustering algorithm to select a small number of representative lights to efficiently approximate the animation. Our algorithm achieves efficiency by reusing representatives across frames, while minimizing temporal flicker. We demonstrate our algorithm in a variety of scenes that include deformable objects, complex illumination and arbitrary shading and show that a surprisingly small number of representative lights is sufficient for high quality rendering. We believe out algorithm will find practical use in applications that require fast previews of complex animation. 相似文献
118.
Motion synthesis with decoupled parameterization 总被引:2,自引:0,他引:2
In real-time animation systems, motion interpolation techniques are widely used for their controllability and efficiency. The techniques sample the parameter space using example motions, and interpolate them to compute the blend weights corresponding to the given parameters. A main problem of the techniques is that, as the dimension n of the parameter space increases, the number of required example motions increases exponentially, i.e. O(c n ). To resolve the problem, this paper proposes to use two decoupled parameter spaces for controlling the upper body and the lower body separately. At each frame time, a parameterized motion space produces a source frame, and the target frame is synthesized by splicing the upper body of one source frame with the lower body of the other. In order to have the two source frames correlated with each other, a time-warping scheme has been developed. Furthermore, in order to handle the dynamic properties of the parameter samples of the upper body, we have developed an approximation technique for quickly determining the sample positions in its parameter space. This decoupled parameterization method alleviates the complexity problem, e.g. from O(c 6) to O(c 3), while providing the users with the capability of convenient control over the character. 相似文献
119.
基于JMS的安全通信模型研究与设计 总被引:2,自引:0,他引:2
面向消息中间件(MOM)的安全性是目前的一个研究热点,目的是设计确保数据传输完整性的安全机制.通过分析JMS的两种消息通信模型,针对它在安全性方面存在的不足,引入了数字签名和加密技术,提出了一个基于身份验证和混合加密的可扩展安全通信模型,并详细介绍了模型的各个组成部分.模型的基本思想是使用数字签名的信息进行双向身份认证,并且在消息传输的过程中,利用双方协商的会话密钥和非对称加密技术对消息进行加密.最后构建了原型系统对模型进行了验证,实验结果表明此模型提高了基于JMS的系统的安全性. 相似文献
120.
Wonpil Yu Jae-Yeong Lee Young-Guk Ha Minsu Jang Joo-Chan Sohn Yong-Moo Kwon Hyo-Sung Ahn 《Automation Science and Engineering, IEEE Transactions on》2009,6(4):633-640
This paper describes a concerted effort to design and implement a robotic service framework. The proposed framework is comprised of three conceptual spaces: physical, semantic, and virtual spaces, collectively referred to as a ubiquitous robotic space. We implemented a prototype robotic security application in an office environment, which confirmed that the proposed framework is an efficient tool for developing a robotic service employing IT infrastructure, particularly for integrating heterogeneous technologies and robotic platforms. 相似文献