全文获取类型
收费全文 | 1100篇 |
免费 | 106篇 |
国内免费 | 59篇 |
专业分类
电工技术 | 19篇 |
综合类 | 46篇 |
化学工业 | 32篇 |
金属工艺 | 33篇 |
机械仪表 | 145篇 |
建筑科学 | 28篇 |
矿业工程 | 12篇 |
能源动力 | 10篇 |
轻工业 | 10篇 |
水利工程 | 1篇 |
石油天然气 | 2篇 |
武器工业 | 4篇 |
无线电 | 170篇 |
一般工业技术 | 73篇 |
冶金工业 | 13篇 |
原子能技术 | 12篇 |
自动化技术 | 655篇 |
出版年
2024年 | 1篇 |
2023年 | 7篇 |
2022年 | 6篇 |
2021年 | 15篇 |
2020年 | 29篇 |
2019年 | 22篇 |
2018年 | 12篇 |
2017年 | 18篇 |
2016年 | 26篇 |
2015年 | 38篇 |
2014年 | 64篇 |
2013年 | 42篇 |
2012年 | 83篇 |
2011年 | 116篇 |
2010年 | 87篇 |
2009年 | 108篇 |
2008年 | 88篇 |
2007年 | 71篇 |
2006年 | 83篇 |
2005年 | 52篇 |
2004年 | 64篇 |
2003年 | 48篇 |
2002年 | 32篇 |
2001年 | 32篇 |
2000年 | 18篇 |
1999年 | 25篇 |
1998年 | 18篇 |
1997年 | 17篇 |
1996年 | 10篇 |
1995年 | 6篇 |
1994年 | 2篇 |
1993年 | 9篇 |
1992年 | 4篇 |
1991年 | 7篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 3篇 |
排序方式: 共有1265条查询结果,搜索用时 0 毫秒
51.
Influence of Mesh Geometry on Three-Dimensional Finite-Element Analysis of Tunnel Excavation 总被引:2,自引:0,他引:2
Finite element (FE) analysis has become an important tool for predicting building response to tunnel-induced ground movement. Because tunnel construction is a three-dimensional (3D) process, the trend is to apply 3D FE analysis to tunnel-soil-building interaction problems instead of applying the plane-strain models that are commonly used in engineering practice. Since 3D FE analyses require large amounts of computational resources, the geometric dimensions of the 3D models are often kept to a minimum to reduce calculation time. There is, however, a lack of published information concerning appropriate mesh dimensions. This paper investigates the influence of the geometry and the dimension of a 3D FE model on tunnel-induced surface settlement predictions. The paper shows how the vertical boundaries can influence the results. It demonstrates that reasonable results can be obtained by increasing the length of incremental tunnel excavation and by scaling back the settlement values to give a required tunnel volume loss. This study therefore not only highlights the limitations of 3D modeling but also shows its potential for engineering practice. 相似文献
52.
The “fractional tree” algorithm for broadcasting and reduction is introduced. Its communication pattern interpolates between two well known patterns—sequential pipeline and pipelined binary tree. The speedup over the best of these simple methods can approach two for large systems and messages of intermediate size. For networks which are not very densely connected the new algorithm seems to be the best known method for the important case that each processor has only a single (possibly bidirectional) channel into the communication network. 相似文献
53.
Web Caching技术和CDN技术及其比较分析 总被引:10,自引:0,他引:10
对为提高服务网络质量而出现的一“拉”一“推”两种技术——WebCaching技术和CDN技术作了简要介绍,并从两者各自常见的体系结构出发对两种技术的性能和特点进行了比较分析,结论是CDN技术在减小源服务器负载等方面优于单纯的WebCaching技术;最后指出进一步的研究方向。 相似文献
54.
55.
基于径向基函数多步离散数据插值的人脸变形研究 总被引:5,自引:0,他引:5
文章介绍了如何把基于径向基函数多步离散数据插值的方法用在人脸变形技术上,该方法是在对脸部定义的特征点进行分层的基础上,和已知特征点位移的条件下,利用一种基于迭代的插值方法求出特征点周围的网格点位移,从而进行人脸变形。这种方法既保证了脸部局部区域变形的精确性和平滑性,又减少了运算的复杂度。在人脸动画方面该算法也得到了广泛的应用。 相似文献
56.
本文采用模糊控制策略,对有限元网格划分过程中难以控制的因素-网格密度作出自适应控制。同时借鉴先验自适应的思想,在后验控制过程中综合考虑了边界属性的影响,避免了较多层次的网格局部细化与退化,采用此方法,不仅保证了计算精度,而且可以提高运算效率。 相似文献
57.
This paper presents a set of procedures for improving the topology of unstructured quadrilateral finite element meshes. These procedures are based on the topology of the finite element mesh, and all operations act only on local regions of the mesh. The goal is to optimize the topology such that the smoothing process can produce the best possible element quality. Topological improvement procedures are presented both for elements that are interior to the mesh and for elements connected to the boundary. Also presented is a discussion of efficiency and optimal ordering of the procedures. Several example meshes are included to show the effectiveness of the current approach in improving element qualities in a finite element mesh. 相似文献
58.
Semi-formal design of reliable mesh generation systems 总被引:2,自引:0,他引:2
A reliable mesh generation infrastructure is designed based on software engineering principles. Formal methods, software design documents and clear modular decomposition criteria are introduced to improve the quality of mesh generation software. The design document for a simple 2D mesh generation data structure is presented using a semi-formal specification. The proposed semi-formal documentation system avoids any ambiguity during the software design process and will help in driving the software test cases. Using the proposed software, design techniques result in a consistent software design that is easy to extend and modify. 相似文献
59.
60.
针对多接口多信道无线Mesh网络,提出了一种基于链路负载和链路“潜在的”干扰度的权值的分布式静态信道分配算法。给出基于链路负载和链路“潜在的”干扰度的权值的定义和基于权值的链表的构建方法;阐述了算法的设计思想和实现步骤。仿真实验测试结果表明,该算法不但能适应业务流量分布均匀或不均匀的状态,而且能相应地提高网络吞吐量,提升网络性能。 相似文献