全文获取类型
收费全文 | 10972篇 |
免费 | 425篇 |
国内免费 | 182篇 |
专业分类
电工技术 | 181篇 |
技术理论 | 2篇 |
综合类 | 1257篇 |
化学工业 | 642篇 |
金属工艺 | 1374篇 |
机械仪表 | 856篇 |
建筑科学 | 4047篇 |
矿业工程 | 432篇 |
能源动力 | 43篇 |
轻工业 | 475篇 |
水利工程 | 87篇 |
石油天然气 | 81篇 |
武器工业 | 18篇 |
无线电 | 158篇 |
一般工业技术 | 595篇 |
冶金工业 | 494篇 |
原子能技术 | 7篇 |
自动化技术 | 830篇 |
出版年
2024年 | 9篇 |
2023年 | 42篇 |
2022年 | 86篇 |
2021年 | 107篇 |
2020年 | 111篇 |
2019年 | 91篇 |
2018年 | 102篇 |
2017年 | 144篇 |
2016年 | 148篇 |
2015年 | 238篇 |
2014年 | 850篇 |
2013年 | 503篇 |
2012年 | 776篇 |
2011年 | 746篇 |
2010年 | 766篇 |
2009年 | 748篇 |
2008年 | 665篇 |
2007年 | 818篇 |
2006年 | 679篇 |
2005年 | 597篇 |
2004年 | 514篇 |
2003年 | 441篇 |
2002年 | 398篇 |
2001年 | 379篇 |
2000年 | 359篇 |
1999年 | 258篇 |
1998年 | 154篇 |
1997年 | 154篇 |
1996年 | 147篇 |
1995年 | 127篇 |
1994年 | 86篇 |
1993年 | 72篇 |
1992年 | 52篇 |
1991年 | 46篇 |
1990年 | 32篇 |
1989年 | 26篇 |
1988年 | 21篇 |
1987年 | 16篇 |
1986年 | 14篇 |
1985年 | 23篇 |
1984年 | 10篇 |
1983年 | 4篇 |
1982年 | 14篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1964年 | 1篇 |
1957年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
在软件复用基本理论和技术的基础上,阐述了软件体系结构对软件复用的意义,提出了基于软件体系的软件复用开发方法以及在建筑陶瓷三维虚拟展示系统开发过程中的应用。 相似文献
72.
The usefulness of Software Architecture (SA) documentation depends on how well its Architectural Knowledge (AK) can be retrieved by the stakeholders in a software project. Recent findings show that the use of ontology-based SA documentation is promising. However, different roles in software development have different needs for AK, and building an ontology to suit these needs is challenging. In this paper we describe an approach to build an ontology for SA documentation. This approach involves the use of typical questions for eliciting and constructing an ontology. We outline eight contextual factors, which influence the successful construction of an ontology, especially in complex software projects with diverse AK users. We tested our ‘typical question’ approach in a case study and report how it can be used for acquiring and modeling AK needs. 相似文献
73.
S. Chaturvedi C. Dunne Z. Ashktorab R. Zachariah B. Shneiderman 《Computer Graphics Forum》2014,33(8):52-68
An important part of network analysis is understanding community structures like topological clusters and attribute‐based groups. Standard approaches for showing communities using colour, shape, rectangular bounding boxes, convex hulls or force‐directed layout algorithms remain valuable, however our Group‐in‐a‐Box meta‐layouts add a fresh strategy for presenting community membership, internal structure and inter‐cluster relationships. This paper extends the basic Group‐in‐a‐Box meta‐layout, which uses a Treemap substrate of rectangular regions whose size is proportional to community size. When there are numerous inter‐community relationships, the proposed extensions help users view them more clearly: (1) the Croissant–Doughnut meta‐layout applies empirically determined rules for box arrangement to improve space utilization while still showing inter‐community relationships, and (2) the Force‐Directed layout arranges community boxes based on their aggregate ties at the cost of additional space. Our free and open source reference implementation in NodeXL includes heuristics to choose what we have found to be the preferable Group‐in‐a‐Box meta‐layout to show networks with varying numbers or sizes of communities. Case study examples, a pilot comparative user preference study (nine participants), and a readability measure‐based evaluation of 309 Twitter networks demonstrate the utility of the proposed meta‐layouts. 相似文献
74.
《Graphical Models》2014,76(6):620-632
We present a novel line drawing approach for 3D models by introducing their skeleton information into the rendering process. Based on the silhouettes of the input 3D models, we first extract feature lines in geometric regions by utilizing their curvature, torsion and view-dependent information. Then, the skeletons of the models are extracted by our newly developed skeleton extraction algorithm. After that, we draw the skeleton-guided lines from non-geometric regions through the skeleton information. These lines are combined with the feature lines to render the final line drawing result using the line optimization. Experimental results show that our algorithm can render line drawings more effectively with enhanced skeletons. The resulting artistic effects can capture the local geometries as well as the global skeletons of the input 3D models. 相似文献
75.
通过比较SVG和Canvas两种绘图机制,辨析了使用Canvas在网页中绘图方案的优缺点。使用一个在线写字本案例,论述了Canvas捕获用户的鼠标事件根据用户输入来绘图的过程。最后总结了Canvas绘图的特性以及应用前景。 相似文献
76.
赵金 《数码设计:surface》2014,(9):83-85
广府和潮汕同是岭南文化的主体,但又都是独立的文化分支,在建筑及其装饰上也各有特色和侧重。文章就岭南传统建筑中广府地区的陶塑装饰和潮汕地区的嵌瓷装饰予以介绍并比较,找出区别与文化间的共通处,并希望在当下社会语境中这些传统建筑装饰能被更多人重新审视。 相似文献
77.
冷先平 《数码设计:surface》2014,(10):74-76
湖北传统民居建筑装饰图形的艺术生产是一种客观的、有目的的、感性、对象化的实践;本文通过作为文化资本的湖北传统民居建筑装饰图形艺术生产与消费关系的分析,旨在探明这种特殊的文化资本在其艺术生产与消费实践中文化资本积累的动态过程。 相似文献
78.
为了更好地模拟素描的笔画和突显肖像素描中五官的部分,提出基于人脸特征和线积分卷积的肖像素描生成方法.首先进行人脸分割,由人脸特征点确定GrabCut算法中每个特征的初始trimap,然后根据分割结果使用线积分卷积算法绘制肖像素描.文中使用了基于分割结果的多分辨率白噪声和方向场,并提出了基于分割结果的自适应性边界提取算法.实验结果表明,该算法改善了肖像素描的生成效果. 相似文献
79.
介绍了我国近年来制定和颁布的建筑涂料产品质量标准和检测技术标准,讨论了这些标准的特征和优越性,并对其发展进行了展望。 相似文献
80.
Isotactic polypropylene and ethylene-1-hexene copolymers containing 32 and 57 mol% of 1-hexene copolymers blends (i-PP/EH32 and i-PP/EH57) were prepared by solution blending, precipitating followed by drying and hot pressing. The two blends were subject to investigation on structure and mechanical properties of these blends under uniaxial drawing. The i-PP/EH32 and i-PP/EH57 represented the immiscible and miscible blends, respectively. The tensile stresses and strains at breaking point of i-PP/EH57 were remarkably higher than those of i-PP/EH32 at room temperature. From wide-angle X-ray diffraction (WAXD) measurement, it was observed that the orientation of crystallites occurred early and then propagated gradually up to about drawing ratio 8 because chains of EH57 copolymer were incorporated into the amorphous regions between lamellae of i-PP. In the WAXD patterns of i-PP/EH57, the oriented spot reflections coexsisted with unoriented ring reflections up to draw ratio higher than in pure i-PP. On the other hand, the two-phase structure was observed from TEM and AFM in i-PP/EH32, and on the drawing, separation at the interface between two-phase was observed in i-PP/EH32 even at the low strain. 相似文献