全文获取类型
收费全文 | 2652篇 |
免费 | 88篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 38篇 |
综合类 | 5篇 |
化学工业 | 494篇 |
金属工艺 | 50篇 |
机械仪表 | 59篇 |
建筑科学 | 123篇 |
矿业工程 | 10篇 |
能源动力 | 67篇 |
轻工业 | 198篇 |
水利工程 | 12篇 |
石油天然气 | 5篇 |
无线电 | 302篇 |
一般工业技术 | 422篇 |
冶金工业 | 642篇 |
原子能技术 | 23篇 |
自动化技术 | 291篇 |
出版年
2023年 | 27篇 |
2022年 | 38篇 |
2021年 | 58篇 |
2020年 | 28篇 |
2019年 | 40篇 |
2018年 | 48篇 |
2017年 | 53篇 |
2016年 | 54篇 |
2015年 | 62篇 |
2014年 | 71篇 |
2013年 | 118篇 |
2012年 | 101篇 |
2011年 | 134篇 |
2010年 | 97篇 |
2009年 | 99篇 |
2008年 | 111篇 |
2007年 | 97篇 |
2006年 | 83篇 |
2005年 | 97篇 |
2004年 | 53篇 |
2003年 | 51篇 |
2002年 | 59篇 |
2001年 | 60篇 |
2000年 | 32篇 |
1999年 | 56篇 |
1998年 | 166篇 |
1997年 | 110篇 |
1996年 | 82篇 |
1995年 | 52篇 |
1994年 | 46篇 |
1993年 | 42篇 |
1992年 | 29篇 |
1991年 | 24篇 |
1990年 | 37篇 |
1989年 | 37篇 |
1988年 | 25篇 |
1987年 | 21篇 |
1986年 | 18篇 |
1985年 | 19篇 |
1984年 | 14篇 |
1983年 | 17篇 |
1982年 | 12篇 |
1981年 | 17篇 |
1980年 | 12篇 |
1979年 | 16篇 |
1978年 | 21篇 |
1977年 | 14篇 |
1976年 | 26篇 |
1971年 | 19篇 |
1970年 | 14篇 |
排序方式: 共有2741条查询结果,搜索用时 31 毫秒
51.
The properties of the flux line lattice in the thin strands of superconducting niobium wire networks with thickness and width comparable to the penetration depth are investigated in the limit of very few flux lines. An angle dependent upper critical field is observed that is consistent with the existence of surface superconductivity. Our results indicate the existence of a flux line lattice in the complete field range Bc1 B Bc 1.4 Bc2. The flux line lattice undergoes a dimensional crossover when the transversal correlation length Rc is of the order of the strand width. The field dependence of the Labusch parameter due to surface pinning is determined and compared to a model for surface pinning by Bean-Livingston barriers. 相似文献
52.
Essential role of beta-adrenergic receptor kinase 1 in cardiac development and function 总被引:1,自引:0,他引:1
53.
Stephen Gilmore L��szl�� G?nczy Nora Koch Philip Mayer Mirco Tribastone D��niel Varr�� 《Software and Systems Modeling》2011,10(3):287-311
Systems based on the service-oriented architecture (SOA) principles have become an important cornerstone of the development
of enterprise-scale software applications. They are characterized by separating functions into distinct software units, called
services, which can be published, requested and dynamically combined in the production of business applications. Service-oriented
systems (SOSs) promise high flexibility, improved maintainability, and simple re-use of functionality. Achieving these properties
requires an understanding not only of the individual artifacts of the system but also their integration. In this context,
non-functional aspects play an important role and should be analyzed and modeled as early as possible in the development cycle.
In this paper, we discuss modeling of non-functional aspects of service-oriented systems, and the use of these models for
analysis and deployment. Our contribution in this paper is threefold. First, we show how services and service compositions
may be modeled in UML by using a profile for SOA (UML4SOA) and how non-functional properties of service-oriented systems can
be represented using the non-functional extension of UML4SOA (UML4SOA-NFP) and the MARTE profile. This enables modeling of
performance, security and reliable messaging. Second, we discuss formal analysis of models which respect this design, in particular
we consider performance estimates and reliability analysis using the stochastically timed process algebra PEPA as the underlying
analytical engine. Last but not least, our models are the source for the application of deployment mechanisms which comprise
model-to-model and model-to-text transformations implemented in the framework VIATRA. All techniques presented in this work
are illustrated by a running example from an eUniversity case study. 相似文献
54.
Jason Heikenfeld Paul Drzaic Jong‐Souk Yeo Tim Koch 《Journal of the Society for Information Display》2011,19(2):129-156
Abstract— The commercial success of monochrome electronic paper (e‐Paper) is now propelling the development of next‐generation flexible, video, and color e‐Paper products. Unlike the early battles in the 1980s and 1990s between transmissive and emissive display technologies, there is a extraordinary diversity of technologies vying to become the next generation of e‐Paper. A critical review of all major e‐Paper technologies, including a technical breakdown of the performance limitations based on device physics and commentary on possible future breakthroughs, is presented. In addition, the visual requirements for color e‐Paper are provided and compared to standards used in conventional print. It is concluded that researchers have much work remaining in order to bridge the significant gap between reflective electronic displays and print‐on‐paper. 相似文献
55.
Experimental test of a robust formation controller for marine unmanned surface vessels 总被引:1,自引:0,他引:1
Daniel Schoerling Chris Van Kleeck Farbod Fahimi Charles Robert Koch Alfons Ams Peter Löber 《Autonomous Robots》2010,28(2):213-230
Experiments with two formation controllers for marine unmanned surface vessels are reported. The formation controllers are
designed using the nonlinear robust model-based sliding mode approach. The marine vehicles can operate in arbitrary formation
configurations by using two leader-follower control schemes. For the design of these controller schemes 3 degrees of freedom
(DOFs) of surge, sway, and yaw are assumed in the planar motion of the marine surface vessels. Each vessel only has two actuators;
therefore, the vessels are underactuated and the lack of a kinematic constraint puts them into the holonomic system category.
In this work, the position of a control point on the vessel is controlled, and the orientation dynamics is not directly controlled.
Therefore, there is a potential for an oscillatory yaw motion to occur. It is shown that the orientation dynamics, as the
internal dynamics of this underactuated system, is stable, i.e., the follower vehicle does not oscillate about its control
point during the formation maneuvers. The proposed formation controller relies only on the state information obtained from
the immediate neighbors of the vessel and the vessel itself. The effectiveness and robustness of formation control laws in
the presence of parameter uncertainty and environmental disturbances are demonstrated by using both simulations and field
experiments. The experiments were performed in a natural environment on a lake using a small test boat, and show robust performance
to parameter uncertainty and disturbance. This paper reports the first experimental verification of the above mentioned approach,
whose unique features are the use of a control point, the zero-dynamic stability analysis, the use of leader-follower method
and a nonlinear robust control approach. 相似文献
56.
Claire M. Côte Chris J. Moran Christopher J. Hedemann Christian Koch 《Environmental Modelling & Software》2010,25(12):1664-1671
Concerns about the difficulties in securing water have led the Australian coal mining industry to seek innovative ways to improve its water management and to adopt novel strategies that will lead to less water being used and more water being reused. Simulation tools are essential to assess current water management performance and to predict the efficiency of potential strategies. As water systems on coal mines are complex and consist of various inter-connected elements, a systems approach was selected, which views mine site water management as a system that obtains water from various sources (surface, groundwater), provides sufficient water of suitable quality to the mining tasks (coal beneficiation, dust suppression, underground operations) and maintains environmental performance. In this paper, the model is described and its calibration is illustrated. The results of applying the model for the comparison of the water balances of 7 coal mines in the northern Bowen Basin (Queensland, Australia) are presented. The model is used to assess the impact of applying specific water management strategies. Results show that a simple systems model is an appropriate tool for assessing site performance, for providing guidance to improve performance through strategic planning, and for guiding adoption of site objectives. 相似文献
57.
Nils Hasler Carsten Stoll Bodo Rosenhahn Thorsten Thormhlen Hans-Peter Seidel 《Computers & Graphics》2009,33(3):211
The paper presents a method to estimate the detailed 3D body shape of a person even if heavy or loose clothing is worn. The approach is based on a space of human shapes, learned from a large database of registered body scans. Together with this database we use as input a 3D scan or model of the person wearing clothes and apply a fitting method, based on ICP (iterated closest point) registration and Laplacian mesh deformation. The statistical model of human body shapes enforces that the model stays within the space of human shapes. The method therefore allows us to compute the most likely shape and pose of the subject, even if it is heavily occluded or body parts are not visible. Several experiments demonstrate the applicability and accuracy of our approach to recover occluded or missing body parts from 3D laser scans. 相似文献
58.
59.
This article presents a method for classifying color points for automotive applications in the Hue Saturation Intensity (HSI)
Space based on the distances between their projections onto the SI plane. Firstly the HSI Space is analyzed in detail. Secondly
the projection of image points from a typical automotive scene onto the SI plane is shown. The minimal classes relevant for
driver assistance applications are derived. The requirements for the classification of the points into those classes are obtained.
Several weighting functions are proposed and a fast form of an euclidean metric is investigated in detail. In order to improve
the sensitivity of the weighting function, dynamic coefficients are introduced. It is shown how to compute them automatically
in order to get optimal results for the classification. Finally some results of applying the metric to the sample images are
shown and the conclusions are drawn.
Calin Rotaru is a PhD candidate at the Department of Computer Science, University of Hamburg, Germany. His PhD work focuses on the topic color machine vision for driver assistance systems and is supported by Volkswagen AG, Group Research Electronics. He graduated (2002) with the topic “Stereo Camera Based Object Recognition” for Driver Assistance Systems from the Faculty of Automation and Computer Science of the Technical University of Cluj-Napoca, Romania. His research interests include color machine vision, smart vision systems, multisensorial data fusion and vision in driver assistance systems. Thorsten Graf received the diploma (M.Sc.) degree in computer science and the Ph.D. degree (his thesis was on “Flexible Object Recognition Based on Invariant Theory and Agent Technology”) from the University of Bielefeld, Bielefeld, Germany, in 1997 and 2000, respectively. In 1997 he became a Member of the “Task Oriented Communication” graduate program, University of Bielefeld, funded by the German research foundation DFG. In June 2001 he joined Volkswagen Group Research, Wolfsburg, Germany. Since then, he has worked on different projects in the area of driver assistance systems as a Researcher and Project Leader. He is the author or coauthor of more than 40 publications and owns several patents. His research interests include image processing and analysis dedicated to advanced comfort/safety automotive applications. Dr. Jianwei Zhang is full professor and director of the Institute of Technical Aspects of Multimodal Systems, Department of Computer Science, University of Hamburg, Germany. He is one of the Chair Professors “Human-Computer Interaction” of the Department of Computer Science of Tsinghua University. He received his Bachelor (1986) and Master degree (1989) from the Department of Computer Science of Tsinghua University, and his PhD (1994) from the Department of Computer Science, University of Karlsruhe, Germany. His research interests include multimodal information processing, robot learning, service robots, smart vision systems and Embodied Intelligence. In these areas he has published over 120 journal and conference papers, six book chapters and two research monographs. He leads numerous basic research and application projects, including the EU basic research programs and the Collaborative Research Centre supported by the German Research Council. Dr. Zhang has received multiple awards including the IEEE ROMAN Best Paper 2002. 相似文献
Jianwei ZhangEmail: |
Calin Rotaru is a PhD candidate at the Department of Computer Science, University of Hamburg, Germany. His PhD work focuses on the topic color machine vision for driver assistance systems and is supported by Volkswagen AG, Group Research Electronics. He graduated (2002) with the topic “Stereo Camera Based Object Recognition” for Driver Assistance Systems from the Faculty of Automation and Computer Science of the Technical University of Cluj-Napoca, Romania. His research interests include color machine vision, smart vision systems, multisensorial data fusion and vision in driver assistance systems. Thorsten Graf received the diploma (M.Sc.) degree in computer science and the Ph.D. degree (his thesis was on “Flexible Object Recognition Based on Invariant Theory and Agent Technology”) from the University of Bielefeld, Bielefeld, Germany, in 1997 and 2000, respectively. In 1997 he became a Member of the “Task Oriented Communication” graduate program, University of Bielefeld, funded by the German research foundation DFG. In June 2001 he joined Volkswagen Group Research, Wolfsburg, Germany. Since then, he has worked on different projects in the area of driver assistance systems as a Researcher and Project Leader. He is the author or coauthor of more than 40 publications and owns several patents. His research interests include image processing and analysis dedicated to advanced comfort/safety automotive applications. Dr. Jianwei Zhang is full professor and director of the Institute of Technical Aspects of Multimodal Systems, Department of Computer Science, University of Hamburg, Germany. He is one of the Chair Professors “Human-Computer Interaction” of the Department of Computer Science of Tsinghua University. He received his Bachelor (1986) and Master degree (1989) from the Department of Computer Science of Tsinghua University, and his PhD (1994) from the Department of Computer Science, University of Karlsruhe, Germany. His research interests include multimodal information processing, robot learning, service robots, smart vision systems and Embodied Intelligence. In these areas he has published over 120 journal and conference papers, six book chapters and two research monographs. He leads numerous basic research and application projects, including the EU basic research programs and the Collaborative Research Centre supported by the German Research Council. Dr. Zhang has received multiple awards including the IEEE ROMAN Best Paper 2002. 相似文献
60.
Ordered binary decision diagrams are the state-of-the-art representation of switching functions. In order to keep the sizes of OBDDs tractable, heuristics and dynamic reordering algorithms are applied to optimize the underlying variable order. When finite state machines are represented by OBDDs the state encoding can be used as an additional optimization parameter. In this paper, we analyze local encoding transformations which can be applied dynamically. First, we investigate the potential of re-encoding techniques. We then propose the use of an XOR-transformation and show why this transformation is most suitable among the set of all encoding transformations. The presented theoretical framework establishes a new optimization technique for OBDDs. 相似文献