全文获取类型
收费全文 | 2377篇 |
免费 | 175篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 27篇 |
综合类 | 2篇 |
化学工业 | 651篇 |
金属工艺 | 28篇 |
机械仪表 | 59篇 |
建筑科学 | 90篇 |
矿业工程 | 5篇 |
能源动力 | 107篇 |
轻工业 | 319篇 |
水利工程 | 15篇 |
石油天然气 | 8篇 |
无线电 | 165篇 |
一般工业技术 | 373篇 |
冶金工业 | 56篇 |
原子能技术 | 28篇 |
自动化技术 | 623篇 |
出版年
2024年 | 8篇 |
2023年 | 28篇 |
2022年 | 115篇 |
2021年 | 158篇 |
2020年 | 70篇 |
2019年 | 112篇 |
2018年 | 98篇 |
2017年 | 111篇 |
2016年 | 105篇 |
2015年 | 92篇 |
2014年 | 120篇 |
2013年 | 189篇 |
2012年 | 184篇 |
2011年 | 190篇 |
2010年 | 156篇 |
2009年 | 134篇 |
2008年 | 122篇 |
2007年 | 89篇 |
2006年 | 75篇 |
2005年 | 60篇 |
2004年 | 65篇 |
2003年 | 38篇 |
2002年 | 28篇 |
2001年 | 28篇 |
2000年 | 22篇 |
1999年 | 17篇 |
1998年 | 17篇 |
1997年 | 21篇 |
1996年 | 13篇 |
1995年 | 7篇 |
1994年 | 7篇 |
1993年 | 10篇 |
1992年 | 3篇 |
1991年 | 6篇 |
1990年 | 7篇 |
1989年 | 2篇 |
1988年 | 6篇 |
1985年 | 7篇 |
1984年 | 3篇 |
1983年 | 6篇 |
1981年 | 3篇 |
1980年 | 5篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1974年 | 4篇 |
1973年 | 1篇 |
1969年 | 1篇 |
1956年 | 1篇 |
排序方式: 共有2556条查询结果,搜索用时 15 毫秒
81.
Interfacing human and computer with wireless body area sensor networks: the WiMoCA solution 总被引:1,自引:0,他引:1
Elisabetta Farella Augusto Pieracci Luca Benini Laura Rocchi Andrea Acquaviva 《Multimedia Tools and Applications》2008,38(3):337-363
Wireless Body Area Sensor Networks (WBASN) are an emerging technology enabling the design of natural human–computer interfaces
(HCI). Automatic recognition of human motion, gestures, and activities is studied in several contexts. For example, mobile
computing technology is being considered as a replacement of traditional input systems. Moreover, body posture and activity
monitoring can be used for entertainment and health-care applications. However, until now, little work has been done to develop
flexible and efficient WBASN solutions suitable for a wide range of applications. Their requirements pose new challenges for
sensor network designs, such as optimizing traditional solutions for use as environmental monitoring-like applications and
developing on-the-field stress tests. In this paper, we demonstrate the flexibility of a custom-designed WBASN called WiMoCA
with respect to a wide range of posture and activity recognition applications by means of practical implementation and on-the-field
testing. Nodes of the network mounted on different parts of the human body exploit tri-axial accelerometers to detect its
movements. The advanced digital Micro-electro-mechanical system (MEMS) based inertial sensor has been chosen for WiMoCA because
it demonstrated high flexibility of use in many different situations, providing the chance to exploit both static and dynamic
acceleration components for different purposes. Furthermore, the sensibility and accuracy of the sensing element is perfectly
adequate for monitoring human movement, while keeping cost low and size compact, thus meeting our requirements. We implemented
three types of applications, stressing the WBASN in many aspects. In fact, they are characterized by different requirements
in terms of accuracy, timeliness, and computation distributed on sensing nodes. For each application, we describe its implementation,
and we discuss results about performance and power consumption.
相似文献
Andrea AcquavivaEmail: |
82.
Multimodal support to group dynamics 总被引:1,自引:1,他引:0
Fabio Pianesi Massimo Zancanaro Elena Not Chiara Leonardi Vera Falcon Bruno Lepri 《Personal and Ubiquitous Computing》2008,12(3):181-195
The complexity of group dynamics occurring in small group interactions often hinders the performance of teams. The availability
of rich multimodal information about what is going on during the meeting makes it possible to explore the possibility of providing
support to dysfunctional teams from facilitation to training sessions addressing both the individuals and the group as a whole.
A necessary step in this direction is that of capturing and understanding group dynamics. In this paper, we discuss a particular
scenario, in which meeting participants receive multimedia feedback on their relational behaviour, as a first step towards
increasing self-awareness. We describe the background and the motivation for a coding scheme for annotating meeting recordings
partially inspired by the Bales’ Interaction Process Analysis. This coding scheme was aimed at identifying suitable observable
behavioural sequences. The study is complemented with an experimental investigation on the acceptability of such a service.
相似文献
Fabio Pianesi (Corresponding author)Email: |
Massimo ZancanaroEmail: |
Elena NotEmail: |
Chiara LeonardiEmail: |
Vera FalconEmail: |
Bruno LepriEmail: |
83.
This paper presents the design and the implementation of a coarse-grain reconfigurable machine used as an accelerator for a programmable RISC core, to speed up the execution of computationally demanding tasks like multimedia applications. We created a VHDL model of the proposed architecture and implemented it on a FPGA board for prototyping purposes; then we mapped on our architecture some DSP and image processing algorithms as a benchmark. In particular, we provided the proposed architecture with subword computation capabilities, which turns out to be extremely effective especially when dealing with image processing algorithms, achieving significant benefits in terms of speed and efficiency in resource usage. To create the configuration bitstream (configware) we created a tool based on a graphical user interface (GUI) which provides a first step towards the automation of the programming flow of our design: the tool is meant to ease the life of the programmer, relieving him from the burden of calculating the configuration bits by hand. Synthesis results indicate that the area occupation and the operating frequency of our design are reasonable also when compared to other similar design. In addition to this, the amount of clock cycles taken by our machine to perform a given algorithm is orders of magnitude smaller than the one required by a corresponding software implementation on a RISC microprocessor. 相似文献
84.
Malatesta M Frigato E Baldelli B Battistelli S Foà A Bertolucci C 《Microscopy research and technique》2007,70(7):578-584
Reptiles represent an interesting animal model to investigate the influence of temperature on molecular circadian clocks. The ruin lizard Podarcis sicula lives in a continental climate and it is subjected to wide range of environmental temperatures during the course of the year. As consequence, ruin lizard daily activity pattern includes either the hibernation or periods of inactivity determined by hypothermia. Here we showed the rhythmic expression of two clock genes, lPer2 and lClock, in the liver of active lizards exposed to summer photo-thermoperiodic conditions. Interestingly, the exposition of lizards to hypothermic conditions, typical of winter season, induced a strong dampening of clock genes mRNA rhythmicity with a coincident decrease of levels. We also examined the qualitative and quantitative distribution of lPER2 and lCLOCK protein in different cellular compartments during the 24-h cycle. In the liver of active lizards both proteins showed a rhythmic expression profile in all cellular compartments. After 3 days at 6 degrees C, some temporal fluctuations of the lCLOCK and lPER2 are still detectable, although, with some marked modifications in respect to the values detected in the liver of active lizards. Besides demonstrating the influence of low temperature on the lizard liver circadian oscillators, present results could provide new essential information for comparative studies on the influence of temperature on the circadian system across vertebrate classes. 相似文献
85.
Modeling and Managing Interactions among Business Processes 总被引:3,自引:0,他引:3
Most workflow management systems (WfMSs) only support the separate andindependent execution of business processes. However, processes often needto interact with each other, in order to synchronize the execution of theiractivities, to exchange process data, to request execution of services, orto notify progresses in process execution. Recent market trends also raisethe need for cooperation and interaction between processes executed in differentorganizations, posing additional challenges. In fact, in order to reduce costsand provide better services, companies are pushed to increase cooperation and toform virtual enterprises, where business processes span across organizationalboundaries and are composed of cooperating workflows executed in differentorganizations. Workflow interaction in a cross-organizational environment iscomplicated by the heterogeneity of workflow management platforms on top ofwhich workflows are defined and executed and by the different and possiblycompeting business policies and business goals that drive process executionin each organization.In this paper we propose a model and system that enable interactionbetween workflows executed in the same or in different organizations. Weextend traditional workflow models by allowing workflows to publish andsubscribe to events, and by enabling the definition of points in the processexecution where events should be sent or received. Event notifications aremanaged by a suitable event service that is capable of filtering andcorrelating events, and of dispatching them to the appropriate targetworkflow instances. The extended model can be easily mapped onto anyworkflow model, since event specific constructs can be specified by means ofordinary workflow activities, for which we provide the implementation. Inaddition, the event service is easily portable to different platforms, anddoes not require integration with the WfMS that supports the cooperatingworkflows. Therefore, the proposed approach is applicable in virtually anyenvironment and is independent on the specific platform adopted 相似文献
86.
Paolo Baldan Fabio Gadducci Ugo Montanari 《Electronic Notes in Theoretical Computer Science》2007,176(1):85
In the theory of graph rewriting, the use of coalescing rules, i.e., of rules which besides deleting and generating graph items, can coalesce some parts of the graph, turns out to be quite useful for modelling purposes, but, at the same time, problematic for the development of a satisfactory partial order concurrent semantics for rewrites. Rewriting over graphs with equivalences, i.e., (typed hyper)-graphs equipped with an equivalence over nodes provides a technically convenient replacement of graph rewriting with coalescing rules, for which a truly concurrent semantics can be easily defined. The expressivity of such a formalism is tested in a setting where coalescing rules typically play a basic role: the encoding of calculi with name passing as graph rewriting systems. Specifically, we show how the (monadic fragment) of the solo calculus, one of the dialect of those calculi whose distinctive feature is name fusion, can be encoded as a rewriting system over graph with equivalences. 相似文献
87.
Fabio Fioravanti Alberto Pettorossi Maurizio Proietti 《Electronic Notes in Theoretical Computer Science》2000,30(2)
We address the problem of specializing a constraint logic program w.r.t. a constrained atom which specifies the context of use of the program. We follow an approach based on transformation rules and strategies. We introduce a novel transformation rule, called contextual constraint replacement, to be combined with variants of the traditional unfolding and folding rules. We present a general Partial Evaluation Strategy for automating the application of these rules, and two additional strategies: the Context Propagation Strategy which is instrumental for the application of our contextual constraint replacement rule, and the Invariant Promotion Strategy for taking advantage of invariance properties of the computation. We show through some examples the power of our method and we compare it with existing methods for partial deduction of constraint logic programs based on extensions of Lloyd and Shepherdson's approach. 相似文献
88.
Paulo Augusto Cunha Libanio 《国际水》2013,38(3):513-533
This article examines the use of output-based aid and payment for environmental services to reduce water pollution in Brazil. Two nationwide initiatives are reviewed. First, the output-based aid concept of the River Basin Clean-up Programme (PRODES) to tackle the problem of sanitation deficit in urban areas is presented. Second, the payment for environmental services scheme supported by Brazil’s National Water Agency (ANA) through the Water Producer Programme to promote water conservation on rural properties is discussed. Both programmes are evaluated not only as financing mechanisms for water conservation but also as strategies for implementing Brazil’s water policy. 相似文献
89.
Krüger A McAlpine P Borrani F Edelmann-Nusser J 《Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine》2012,226(2):170-175
In the biomechanical literature only a few studies are available focusing on the determination of joint loading within the lower extremities in snowboarding. These studies are limited to analysis in a restricted capture volume due to the use of optical video-based systems. To overcome this restriction the aim of the present study was to develop a method to determine net joint moments within the lower extremities in snowboarding for complete measurement runs. An experienced snowboarder performed several runs equipped with two custom-made force plates as well as a full-body inertial measurement system. A rigid, multi-segment model was developed to describe the motion and loads within the lower extremities. This model is based on an existing lower-body model and designed to be run by the OpenSim software package. Measured kinetic and kinematic data were imported into the OpenSim program and inverse dynamic calculations were performed. The results illustrate the potential of the developed method for the determination of joint loadings within the lower extremities for complete measurement runs in a real snowboarding environment. The calculated net joint moments of force are reasonable in comparison to the data presented in the literature. A good reliability of the method seems to be indicated by the low data variation between different turns. Due to the unknown accuracy of this method the application for inter-individual studies as well as studies of injury mechanisms may be limited. For intra-individual studies comparing different snowboarding techniques as well as different snowboard equipment the method seems to be beneficial. The validity of the method needs to be studied further. 相似文献
90.
The problem of line breaking consists of finding the best way to split paragraphs into lines. It has been cleverly addressed by the total‐fit algorithm exposed by Knuth and Plass in a well‐known paper. Similarly, page‐breaking algorithms break the content flow of a document into page units. Formatting languages—such as the World Wide Web Consortium standard Extensible Stylesheet Language Formatting Objects (XSL‐FO)—allow users to set which content should be kept in the same page and how many isolated lines are acceptable at the beginning/end of each page. The strategies most formatters adopt to meet these requirements, however, are not satisfactory for many publishing contexts as they very often generate unpleasant empty areas. In that case, typographers are required to manually craft the results in order to completely fill pages. This paper presents a page‐breaking algorithm that extends the original Knuth and Plass line‐breaking approach and produces high‐quality documents without unwanted empty areas. The basic idea consists of delaying the definitive choice of breaks in the line‐breaking process in order to provide a larger set of alternatives to the actual pagination step. The algorithm also allows users to decide the set of properties to be adjusted for pagination and their variation ranges. An application of the algorithm to XSL‐FO is also presented, with an extension of the language that allows users to drive the pagination process. The tool, named FOP+, is a customized version of the open‐source Apache Formatting Objects Processor formatter. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献