全文获取类型
收费全文 | 852篇 |
免费 | 121篇 |
国内免费 | 84篇 |
专业分类
电工技术 | 84篇 |
综合类 | 99篇 |
化学工业 | 6篇 |
金属工艺 | 13篇 |
机械仪表 | 123篇 |
建筑科学 | 24篇 |
矿业工程 | 9篇 |
能源动力 | 2篇 |
轻工业 | 7篇 |
水利工程 | 5篇 |
石油天然气 | 47篇 |
武器工业 | 2篇 |
无线电 | 59篇 |
一般工业技术 | 81篇 |
冶金工业 | 5篇 |
原子能技术 | 1篇 |
自动化技术 | 490篇 |
出版年
2023年 | 6篇 |
2022年 | 9篇 |
2021年 | 5篇 |
2020年 | 10篇 |
2019年 | 11篇 |
2018年 | 18篇 |
2017年 | 19篇 |
2016年 | 22篇 |
2015年 | 46篇 |
2014年 | 55篇 |
2013年 | 38篇 |
2012年 | 71篇 |
2011年 | 78篇 |
2010年 | 57篇 |
2009年 | 75篇 |
2008年 | 63篇 |
2007年 | 79篇 |
2006年 | 67篇 |
2005年 | 59篇 |
2004年 | 47篇 |
2003年 | 39篇 |
2002年 | 35篇 |
2001年 | 28篇 |
2000年 | 19篇 |
1999年 | 15篇 |
1998年 | 12篇 |
1997年 | 14篇 |
1996年 | 7篇 |
1995年 | 8篇 |
1994年 | 11篇 |
1993年 | 7篇 |
1992年 | 5篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1984年 | 5篇 |
1983年 | 2篇 |
1982年 | 1篇 |
排序方式: 共有1057条查询结果,搜索用时 15 毫秒
11.
This paper presents a system that supports a point-based approach to CADCAM that was first suggested by McLaughlin. The core to the approach is the ability to interpolate a grid of points in a geometrically meaningful way that does not suffer from the disadvantages of the standard interpolation schemes based on NURBS. The essential features of the approach are based on recursive subdivision between existing points to generate intermediate points that are consistent with a smooth curvature profile. There are many advantages to this approach. Time-consuming surface fitting is not necessary; there are no problems with ensuring continuity between surfaces; data exchange can be carried out exactly. By chosing to work entirely with points, all of the standard interrogations available in CAE systems, including visualisations, FE analysis and NC machining, which are dependent on NURBS curves and surfaces have to be replicated. The feasibility of the point-based approach is illustrated by showing how geometric interrogations and machine tool paths can be accurately generated using just points. 相似文献
12.
Semi‐regular triangle remeshing algorithms convert irregular surface meshes into semi‐regular ones. Especially in the field of computer graphics, semi‐regularity is an interesting property because it makes meshes highly suitable for multi‐resolution analysis. In this paper, we survey the numerous remeshing algorithms that have been developed over the past two decades. We propose different classifications to give new and comprehensible insights into both existing methods and issues. We describe how considerable obstacles have already been overcome, and discuss promising perspectives. 相似文献
13.
多边形是构成三维模型表面的基本元素,多边形的三角剖分及三角形的三角细分是计算机三维快速建模及纹理帖图的基本技术。本文在研究平面多边形的三角剖分及其三角网格化相关理论的基础上,利用面向对象技术及递归程序设计方法,实现多边形的三角剖分及其三角细分的算法设计,并对该算法的执行效率进行分析。实验结果表明,该算法具有较高的运算效率及实用价值,对实际应用有较好的参考作用。 相似文献
14.
Shape artifacts, especially for convex input polyhedra, make Doo and Sabin’s generalization of bi-quadratic (bi-2) subdivision surfaces unattractive for general design. Rather than tuning the eigenstructure of the subdivision matrix, we improve shape by adding a point and enriching the refinement rules. Adding a guiding point can also yield a polar bi-2 subdivision algorithm. Both the augmented and the polar bi-2 subdivision are complemented by a new Primal Bi-2 Subdivision scheme. All surfaces are and can be combined. 相似文献
15.
16.
Spirals are curves with one-signed, monotone increasing or decreasing curvature. They are commonly useful in a variety of applications, either for aesthetic or for engineering requirements. In this paper we propose a new iterative subdivision scheme for generating planar spiral segments from two points and their tangent vectors. The subdivision process consists of two main steps, computing new points and adjusting tangent vectors adaptively for each iteration. We categorize this iterative scheme as geometry... 相似文献
17.
18.
19.
20.