全文获取类型
收费全文 | 6143篇 |
免费 | 766篇 |
国内免费 | 483篇 |
专业分类
电工技术 | 318篇 |
技术理论 | 1篇 |
综合类 | 626篇 |
化学工业 | 245篇 |
金属工艺 | 190篇 |
机械仪表 | 396篇 |
建筑科学 | 809篇 |
矿业工程 | 352篇 |
能源动力 | 111篇 |
轻工业 | 184篇 |
水利工程 | 130篇 |
石油天然气 | 225篇 |
武器工业 | 25篇 |
无线电 | 635篇 |
一般工业技术 | 382篇 |
冶金工业 | 280篇 |
原子能技术 | 28篇 |
自动化技术 | 2455篇 |
出版年
2024年 | 29篇 |
2023年 | 126篇 |
2022年 | 217篇 |
2021年 | 256篇 |
2020年 | 232篇 |
2019年 | 212篇 |
2018年 | 160篇 |
2017年 | 207篇 |
2016年 | 231篇 |
2015年 | 265篇 |
2014年 | 499篇 |
2013年 | 368篇 |
2012年 | 514篇 |
2011年 | 539篇 |
2010年 | 451篇 |
2009年 | 423篇 |
2008年 | 396篇 |
2007年 | 410篇 |
2006年 | 316篇 |
2005年 | 297篇 |
2004年 | 237篇 |
2003年 | 190篇 |
2002年 | 183篇 |
2001年 | 118篇 |
2000年 | 113篇 |
1999年 | 69篇 |
1998年 | 63篇 |
1997年 | 57篇 |
1996年 | 38篇 |
1995年 | 43篇 |
1994年 | 32篇 |
1993年 | 20篇 |
1992年 | 13篇 |
1991年 | 8篇 |
1990年 | 13篇 |
1989年 | 6篇 |
1988年 | 5篇 |
1987年 | 9篇 |
1986年 | 5篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1978年 | 2篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1956年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有7392条查询结果,搜索用时 406 毫秒
131.
为配合刑事侦查工作和公安网上追逃的迫切需要,对人脸模拟画像的检索作初步研究.首先,根据网上追逃数据库中的人脸照片设计出一种半自动的归一化算法.其次,研究了人脸模拟画像和人脸照片的边缘检测方法,给出一种自适应的人脸照片边缘检测算法,从而得到三种用于人脸模拟画像检索的统计特征.最后,建立了人脸模拟画像检索的实验数据库,给出相似性量度,并对实验数据进行了分析.为构建实用的人脸模拟画像检索系统的开发提供了理论支持;对金盾工程的完善起到良好的促进作用. 相似文献
132.
Ad hoc是一种无线自组织多跳网络。采用无中心的分布式控制,无线节点或终端相互合作而成,独立于固定的基础设施。各节点平等、无中心,动态拓扑。网络拓扑对网络规划、仿真、管理都有非常重要的意义。针对Ad hoc拓扑结构频繁、快速变化的特点,本文主要提出了N种移动自组网络拓扑发现的算法,并基于笔者的实践提供了一个简单的算法实现,该算法主要针对同一个管理机构下的IP网络的拓扑自动发现,更复杂的拓扑发现算法可在此基础上进一步扩展。 相似文献
133.
134.
Sebastiano Battiato Giovanni Maria Farinella Giovanni Giuffrida Catarina Sismeiro Giuseppe Tribulato 《Multimedia Tools and Applications》2009,42(1):5-30
Traditionally, direct marketing companies have relied on pre-testing to select the best offers to send to their audience.
Companies systematically dispatch the offers under consideration to a limited sample of potential buyers, rank them with respect
to their performance and, based on this ranking, decide which offers to send to the wider population. Though this pre-testing
process is simple and widely used, recently the industry has been under increased pressure to further optimize learning, in
particular when facing severe time and learning space constraints. The main contribution of the present work is to demonstrate
that direct marketing firms can exploit the information on visual content to optimize the learning phase. This paper proposes
a two-phase learning strategy based on a cascade of regression methods that takes advantage of the visual and text features
to improve and accelerate the learning process. Experiments in the domain of a commercial Multimedia Messaging Service (MMS)
show the effectiveness of the proposed methods and a significant improvement over traditional learning techniques. The proposed
approach can be used in any multimedia direct marketing domain in which offers comprise both a visual and text component.
Sebastiano Battiato was born in Catania, Italy, in 1972. He received the degree in Computer Science (summa cum laude) in 1995 and his Ph.D in Computer Science and Applied Mathematics in 1999. From 1999 to 2003 he has lead the “Imaging” team c/o STMicroelectronics in Catania. Since 2004 he works as a Researcher at Department of Mathematics and Computer Science of the University of Catania. His research interests include image enhancement and processing, image coding and camera imaging technology. He published more than 90 papers in international journals, conference proceedings and book chapters. He is co-inventor of about 15 international patents. He is reviewer for several international journals and he has been regularly a member of numerous international conference committees. He has participated in many international and national research projects. He is an Associate Editor of the SPIE Journal of Electronic Imaging (Specialty: digital photography and image compression). He is director of ICVSS (International Computer Vision Summer School). He is a Senior Member of the IEEE. Giovanni Maria Farinella is currently contract researcher at Dipartimento di Matematica e Informatica, University of Catania, Italy (IPLAB research group). He is also associate member of the Computer Vision and Robotics Research Group at University of Cambridge since 2006. His research interests lie in the fields of computer vision, pattern recognition and machine learning. In 2004 he received his degree in Computer Science (egregia cum laude) from University of Catania. He was awarded a Ph.D. (Computer Vision) from the University of Catania in 2008. He has co-authored several papers in international journals and conferences proceedings. He also serves as reviewer numerous international journals and conferences. He is currently the co-director of the International Summer School on Computer Vision (ICVSS). Giovanni Giuffrida is an assistant professor at University of Catania, Italy. He received a degree in Computer Science from the University of Pisa, Italy in 1988 (summa cum laude), a Master of Science in Computer Science from the University of Houston, Texas, in 1992, and a Ph.D. in Computer Science, from the University of California in Los Angeles (UCLA) in 2001. He has an extensive experience in both the industrial and academic world. He served as CTO and CEO in the industry and served as consultant for various organizations. His research interest is on optimizing content delivery on new media such as Internet, mobile phones, and digital tv. He published several papers on data mining and its applications. He is a member of ACM and IEEE. Catarina Sismeiro is a senior lecturer at Imperial College Business School, Imperial College London. She received her Ph.D. in Marketing from the University of California, Los Angeles, and her Licenciatura in Management from the University of Porto, Portugal. Before joining Imperial College Catarina had been and assistant professor at Marshall School of Business, University of Southern California. Her primary research interests include studying pharmaceutical markets, modeling consumer behavior in interactive environments, and modeling spatial dependencies. Other areas of interest are decision theory, econometric methods, and the use of image and text features to predict the effectiveness of marketing communications tools. Catarina’s work has appeared in innumerous marketing and management science conferences. Her research has also been published in the Journal of Marketing Research, Management Science, Marketing Letters, Journal of Interactive Marketing, and International Journal of Research in Marketing. She received the 2003 Paul Green Award and was the finalist of the 2007 and 2008 O’Dell Awards. Catarina was also a 2007 Marketing Science Institute Young Scholar, and she received the D. Antonia Adelaide Ferreira award and the ADMES/MARKTEST award for scientific excellence. Catarina is currently on the editorial boards of the Marketing Science journal and the International Journal of Research in Marketing. Giuseppe Tribulato was born in Messina, Italy, in 1979. He received the degree in Computer Science (summa cum laude) in 2004 and his Ph.D in Computer Science in 2008. From 2005 he has lead the research team at Neodata Group. His research interests include data mining techniques, recommendation systems and customer targeting. 相似文献
Giuseppe TribulatoEmail: |
Sebastiano Battiato was born in Catania, Italy, in 1972. He received the degree in Computer Science (summa cum laude) in 1995 and his Ph.D in Computer Science and Applied Mathematics in 1999. From 1999 to 2003 he has lead the “Imaging” team c/o STMicroelectronics in Catania. Since 2004 he works as a Researcher at Department of Mathematics and Computer Science of the University of Catania. His research interests include image enhancement and processing, image coding and camera imaging technology. He published more than 90 papers in international journals, conference proceedings and book chapters. He is co-inventor of about 15 international patents. He is reviewer for several international journals and he has been regularly a member of numerous international conference committees. He has participated in many international and national research projects. He is an Associate Editor of the SPIE Journal of Electronic Imaging (Specialty: digital photography and image compression). He is director of ICVSS (International Computer Vision Summer School). He is a Senior Member of the IEEE. Giovanni Maria Farinella is currently contract researcher at Dipartimento di Matematica e Informatica, University of Catania, Italy (IPLAB research group). He is also associate member of the Computer Vision and Robotics Research Group at University of Cambridge since 2006. His research interests lie in the fields of computer vision, pattern recognition and machine learning. In 2004 he received his degree in Computer Science (egregia cum laude) from University of Catania. He was awarded a Ph.D. (Computer Vision) from the University of Catania in 2008. He has co-authored several papers in international journals and conferences proceedings. He also serves as reviewer numerous international journals and conferences. He is currently the co-director of the International Summer School on Computer Vision (ICVSS). Giovanni Giuffrida is an assistant professor at University of Catania, Italy. He received a degree in Computer Science from the University of Pisa, Italy in 1988 (summa cum laude), a Master of Science in Computer Science from the University of Houston, Texas, in 1992, and a Ph.D. in Computer Science, from the University of California in Los Angeles (UCLA) in 2001. He has an extensive experience in both the industrial and academic world. He served as CTO and CEO in the industry and served as consultant for various organizations. His research interest is on optimizing content delivery on new media such as Internet, mobile phones, and digital tv. He published several papers on data mining and its applications. He is a member of ACM and IEEE. Catarina Sismeiro is a senior lecturer at Imperial College Business School, Imperial College London. She received her Ph.D. in Marketing from the University of California, Los Angeles, and her Licenciatura in Management from the University of Porto, Portugal. Before joining Imperial College Catarina had been and assistant professor at Marshall School of Business, University of Southern California. Her primary research interests include studying pharmaceutical markets, modeling consumer behavior in interactive environments, and modeling spatial dependencies. Other areas of interest are decision theory, econometric methods, and the use of image and text features to predict the effectiveness of marketing communications tools. Catarina’s work has appeared in innumerous marketing and management science conferences. Her research has also been published in the Journal of Marketing Research, Management Science, Marketing Letters, Journal of Interactive Marketing, and International Journal of Research in Marketing. She received the 2003 Paul Green Award and was the finalist of the 2007 and 2008 O’Dell Awards. Catarina was also a 2007 Marketing Science Institute Young Scholar, and she received the D. Antonia Adelaide Ferreira award and the ADMES/MARKTEST award for scientific excellence. Catarina is currently on the editorial boards of the Marketing Science journal and the International Journal of Research in Marketing. Giuseppe Tribulato was born in Messina, Italy, in 1979. He received the degree in Computer Science (summa cum laude) in 2004 and his Ph.D in Computer Science in 2008. From 2005 he has lead the research team at Neodata Group. His research interests include data mining techniques, recommendation systems and customer targeting. 相似文献
135.
Atsushi Kawamoto 《Structural and Multidisciplinary Optimization》2009,37(4):429-433
This paper deals with the design of compliant mechanisms in a continuum-based finite-element representation. Because the displacements
of mechanisms are intrinsically large, the geometric nonlinearity is essential for designing such mechanisms. However, the
consideration of the geometric nonlinearity may cause some instability in topology optimization. The problem is in the analysis
part but not in the optimization part. To alleviate the analysis problem and eventually stabilize the optimization process,
this paper proposes to apply the Levenberg–Marquardt method to the nonlinear analysis of compliant mechanisms. 相似文献
136.
Viscoelastic material design with negative stiffness components using topology optimization 总被引:1,自引:1,他引:0
An application of topology optimization to design viscoelastic composite materials with elastic moduli that soften with frequency
is presented. The material is a two-phase composite whose first constituent is isotropic and viscoelastic while the other
is an orthotropic material with negative stiffness but stable. A concept for this material based on a lumped parameter model
is used. The performance of the topology optimization approach in this context is illustrated using three examples. 相似文献
137.
Cameron Talischi Glaucio H. Paulino Chau H. Le 《Structural and Multidisciplinary Optimization》2009,37(6):569-583
Traditionally, standard Lagrangian-type finite elements, such as linear quads and triangles, have been the elements of choice
in the field of topology optimization. However, finite element meshes with these conventional elements exhibit the well-known
“checkerboard” pathology in the iterative solution of topology optimization problems. A feasible alternative to eliminate
such long-standing problem consists of using hexagonal (honeycomb) elements with Wachspress-type shape functions. The features
of the hexagonal mesh include two-node connections (i.e. two elements are either not connected or connected by two nodes),
and three edge-based symmetry lines per element. In contrast, quads can display one-node connections, which can lead to checkerboard;
and only have two edge-based symmetry lines. In addition, Wachspress rational shape functions satisfy the partition of unity
condition and lead to conforming finite element approximations. We explore the Wachspress-type hexagonal elements and present
their implementation using three approaches for topology optimization: element-based, continuous approximation of material
distribution, and minimum length-scale through projection functions. Examples are presented that demonstrate the advantages
of the proposed element in achieving checkerboard-free solutions and avoiding spurious fine-scale patterns from the design
optimization process. 相似文献
138.
On topology optimization of linear and nonlinear plate problems 总被引:1,自引:0,他引:1
In this paper we propose a new restriction method based on employing C
0-continuous fields of density defined on a set of meshes different from the one used for the finite element analysis. The
optimization procedure starts with using a coarse density-mesh compared to the finite element one. Once the convergence is
obtained in the optimization steps, a finer density-mesh is nominated for the further steps. Linear and nonlinear plate behaviors
are considered and formulated by Kirchhoff or Mindlin–Reissner hypothesis. Comparison is made with element/nodal based approaches
using filter. The results show excellent and robust performance of the proposed method. 相似文献
139.
Product features and task effects on experienced richness, control and engagement in voicemail browsing 总被引:1,自引:0,他引:1
Marco Rozendaal David V. Keyson Huib de Ridder 《Personal and Ubiquitous Computing》2009,13(5):343-354
A recent focus is on creating engaging user experiences with digital products and services such as voicemail. This study aims
to design towards increased levels of engagement in voicemail browsing by using the ‘Richness, Control and Engagement’ (RC
& E) framework. This framework explains the levels of engagement in terms of the levels of richness and control that are shaped
by the features of a product and the user’s expertise. A product was developed that utilized gestures and sound to access
digital voicemail contents. An experiment was conducted in which 28 participants interacted with the product while varying
(1) the number of features of the user interface, (2) the amount of voicemail content and (3) the type of task. Results showed
that the levels of engagement could be predicted according to the levels of richness and control experienced when a task-term
was added to the framework. Implications of the refined RC & E framework for interaction design practice are discussed. 相似文献
140.
本文通过对企业的品牌策略及其特征的分析,结合具体实例,从产品自身、系列产品和不同类产品形象的"家族"产品三个方面,提出了新产品开发设计如何与品牌策略融合,从而为企业降低新产品开发的风险,提高人们对品牌的认知度,提升企业整体文化形象提供了一种思维方法。 相似文献