全文获取类型
收费全文 | 1214篇 |
免费 | 150篇 |
国内免费 | 97篇 |
专业分类
电工技术 | 27篇 |
综合类 | 128篇 |
化学工业 | 45篇 |
金属工艺 | 33篇 |
机械仪表 | 94篇 |
建筑科学 | 93篇 |
矿业工程 | 18篇 |
能源动力 | 20篇 |
轻工业 | 24篇 |
水利工程 | 19篇 |
石油天然气 | 12篇 |
武器工业 | 8篇 |
无线电 | 78篇 |
一般工业技术 | 95篇 |
冶金工业 | 9篇 |
原子能技术 | 8篇 |
自动化技术 | 750篇 |
出版年
2023年 | 12篇 |
2022年 | 23篇 |
2021年 | 19篇 |
2020年 | 21篇 |
2019年 | 13篇 |
2018年 | 17篇 |
2017年 | 20篇 |
2016年 | 25篇 |
2015年 | 34篇 |
2014年 | 52篇 |
2013年 | 60篇 |
2012年 | 79篇 |
2011年 | 109篇 |
2010年 | 90篇 |
2009年 | 72篇 |
2008年 | 88篇 |
2007年 | 94篇 |
2006年 | 82篇 |
2005年 | 90篇 |
2004年 | 68篇 |
2003年 | 67篇 |
2002年 | 56篇 |
2001年 | 38篇 |
2000年 | 33篇 |
1999年 | 25篇 |
1998年 | 27篇 |
1997年 | 23篇 |
1996年 | 18篇 |
1995年 | 12篇 |
1994年 | 15篇 |
1993年 | 13篇 |
1992年 | 7篇 |
1991年 | 8篇 |
1990年 | 7篇 |
1989年 | 9篇 |
1988年 | 5篇 |
1987年 | 3篇 |
1985年 | 2篇 |
1984年 | 6篇 |
1983年 | 4篇 |
1982年 | 7篇 |
1981年 | 2篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1976年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有1461条查询结果,搜索用时 15 毫秒
1.
结合NGN及3G演进的固定、移动视频业务实际需求状况,论述H.264/AVC的重要技术进展及其务实发展策略。 相似文献
2.
基于模式理论光栅椭偏参数反演的数值模拟 总被引:5,自引:2,他引:3
将一种广泛用于求解系统优化问题的方法——正单纯形法,求解光栅的椭偏方程。首先,利用求解光栅的傅立叶模式理论对TE和TM波的复反射系数进行求解。然后计算出其相应的椭偏参数(△,Ψ),并在该值的基础上加入不同偏差的随机高斯噪声,将加入噪声后的值(△m,Ψm)作为模拟测量值。最后使用优化算法进行反演。通过对几种常用面形光栅椭偏参数的数值模拟,一方面表明傅立叶模式理论计算光栅的椭偏参数不仅精度高。而且速度快;另一方面表明利用正单纯形法得到的光栅参数值很接近于正演时假设的参数值,从而从理论上证明了利用椭偏法测量光栅各种光学参数的可行性。 相似文献
3.
4.
本文给出了带有给定切线多边形的保形有理三次B样条曲线,其部分权因子可通过选取切点的位置来确定,由此方法还导出了保形有理三次B样条插值曲线,最后,给出了两个例子。 相似文献
5.
José Luis García-Lapresta 《Information Sciences》2006,176(4):352-365
In this paper we have introduced a class of decision rules related to simple majority, by considering individual intensities of preference. These intensities will be shown by means of linguistic labels. In order to compare the amount of opinion obtained by each alternative, we have considered the total ordered monoid generated by the sums of the original labels, according to an addition and an ordering. In this general framework different sets of linguistic labels can be employed and these sets can be represented by means of diverse mathematical objects. Moreover, on these mathematical representations of linguistic labels several orderings can be considered. Thus, flexibility is an important feature of this new class of group decision making procedures. Some examples of putting in practice the simple majority decision rules based on linguistic labels are provided, and the main properties of these voting systems are analyzed. It is worth emphasizing that these properties are satisfied for any total ordered monoid, regardless of the mathematical representation of linguistic labels or the ordering used to compare collective opinions. 相似文献
6.
7.
Yu. I. Petunin E. A. Djomina D. A. Klyushin M. Yu. Savkina 《Cybernetics and Systems Analysis》2006,42(3):449-455
Spline regression is used to analyze the influence of radiation on the cancer probability in a group of participants of Chernobyl
accident mitigation, depending on the exposure dose. A new method is proposed to approximate modified polygons by linear splines
with two nodes. An algorithm for the identification of a transition point is outlined.
__________
Translated from Kibernetika i Sistemnyi Analiz, No. 3, pp. 168–176, May–June 2006. 相似文献
8.
This paper introduces the Precise Rendering Method, which generates accurately anti-aliased and highlighted images from tessellated polygons. The Precise Rendering Method first solves the aliasing problems of hidden surface removal by using the Cross Scanline Algorithm. This algorithm can exactly calculate polygon areas projected onto each pixel by using horizontal and vertical scanlines. Aliasing artifacts in shading are then prevented by the Reflection Intergration Method, which analytically integrates the intensity of reflection in the solid angle defined by surface normals at vertices of the projected area. Several synthesized images are created to show the efficiency of the Precise Rendering Method. 相似文献
9.
An algorithmic approach was used to select recoveries for non-sharp sequence designs. Simple distillation columns were employed. The non-key component distribution was modeled using the Fenske equation. The combination of producing impure products and allowing non-key component distribution, results in a large search space. With this large search space size and software limitations, five problems were solved (see summary table in the Design Examples sub-section). The optimal non-key component distribution was found to be significant but not necessarily maximal. Parallel processing was selected as optimal in contrast to the more traditional sequential processing. 相似文献
10.
Andrzej Lingas 《Information Processing Letters》2007,104(6):220-227
In 1986, Keil provided an O(n2) time algorithm for the problem of covering monotone orthogonal polygons with the minimum number of r-star-shaped orthogonal polygons. This was later improved to O(n) time and space by Gewali et al. in [L. Gewali, M. Keil, S.C. Ntafos, On covering orthogonal polygons with star-shaped polygons, Information Sciences 65 (1992) 45-63]. In this paper we simplify the latter algorithm—we show that with a little modification, the first step Sweep1 of the discussed algorithm—which computes the top ceilings of horizontal grid segments—can be omitted.In addition, for the minimum orthogonal guard problem in the considered class of polygons, our approach provides a linear time algorithm which uses O(k) additional space, where k is the size of the optimal solution—the algorithm in [L. Gewali, M. Keil, S.C. Ntafos, On covering orthogonal polygons with star-shaped polygons, Information Sciences 65 (1992) 45-63] uses both O(n) time and O(n) additional space. 相似文献