全文获取类型
收费全文 | 1081篇 |
免费 | 94篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 6篇 |
综合类 | 3篇 |
化学工业 | 577篇 |
金属工艺 | 7篇 |
机械仪表 | 19篇 |
建筑科学 | 29篇 |
能源动力 | 27篇 |
轻工业 | 141篇 |
水利工程 | 4篇 |
石油天然气 | 1篇 |
无线电 | 79篇 |
一般工业技术 | 171篇 |
冶金工业 | 27篇 |
原子能技术 | 1篇 |
自动化技术 | 84篇 |
出版年
2024年 | 2篇 |
2023年 | 20篇 |
2022年 | 173篇 |
2021年 | 177篇 |
2020年 | 38篇 |
2019年 | 36篇 |
2018年 | 47篇 |
2017年 | 29篇 |
2016年 | 53篇 |
2015年 | 40篇 |
2014年 | 52篇 |
2013年 | 70篇 |
2012年 | 56篇 |
2011年 | 89篇 |
2010年 | 47篇 |
2009年 | 38篇 |
2008年 | 36篇 |
2007年 | 30篇 |
2006年 | 27篇 |
2005年 | 26篇 |
2004年 | 19篇 |
2003年 | 10篇 |
2002年 | 9篇 |
2001年 | 5篇 |
2000年 | 3篇 |
1999年 | 5篇 |
1998年 | 3篇 |
1997年 | 5篇 |
1996年 | 7篇 |
1995年 | 6篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有1176条查询结果,搜索用时 15 毫秒
21.
The Alder ene functionalization reaction of double bonds containing macromolecules such as polyisobutene oligomer (PIB) and a styrene-butadiene-styrene triblock copolymer (SBS) samples with maleic anhydride (MAH) or diethyl maleate (DEM) as enophiles is described. The analysis of the products by means of different techniques assesses the addition of the polar molecules to the reactive vinylidene units of the polymer with functional degrees (FD) depending on the type of enophile and polymer reactivity. The role of the reaction conditions and the use as Lewis acids as catalysts are discussed in terms of their influence on the addition reaction extent and on the polymer molecular weight. 相似文献
22.
Cecilia Laschi Gioel Asuni Eugenio Guglielmelli Giancarlo Teti Roland Johansson Hitoshi Konosu Zbigniew Wasik Maria Chiara Carrozza Paolo Dario 《Autonomous Robots》2008,25(1-2):85-101
This paper presents a sensory-motor coordination scheme for a robot hand-arm-head system that provides the robot with the capability to reach an object while pre-shaping the fingers to the required grasp configuration and while predicting the tactile image that will be perceived after grasping. A model for sensory-motor coordination derived from studies in humans inspired the development of this scheme. A peculiar feature of this model is the prediction of the tactile image. The implementation of the proposed scheme is based on a neuro-fuzzy module that, after a learning phase, starting from visual data, calculates the position and orientation of the hand for reaching, selects the best-suited hand configuration, and predicts the tactile feedback. The implementation of the scheme on a humanoid robot allowed experimental validation of its effectiveness in robotics and provided perspectives on applications of sensory predictions in robot motor control. 相似文献
23.
Boraldi F Annovi G Guerra D Paolinelli Devincenzi C Garcia-Fernandez MI Panico F De Santis G Tiozzo R Ronchetti I Quaglino D 《Proteomics. Clinical applications》2009,3(9):1084-1098
Pseudoxanthoma elasticum (PXE) is a genetic disorder associated to mutations in the ABCC6 gene; however, the pathogenetic mechanisms leading to elastic fibre calcifications and to clinical manifestations are still unknown. Dermal fibroblasts, directly involved in the production of the extracellular milieu, have been isolated from healthy subjects and from patients affected by PXE, cultured in vitro and characterized for their ability to produce reactive oxygen species, for structural and functional properties of their cell membranes, for changes in their protein profile. Data demonstrate that oxidative stress has profound and endurable consequences on PXE fibroblast phenotype being responsible for: reduced levels of global DNA methylation, increased amount of carbonylated proteins and of lipid peroxidation products, altered structural properties of cell membranes, modified protein expression. Data shed new light on the pathogenetic pathways in PXE, by identifying a network of proteins affecting elastic fibre calcification through inefficient vitamin K recycling, and highlight the role of differentially expressed proteins as targets for validating the efficacy of future therapeutic strategies aiming to delay and/or revert the pathologic phenotype of PXE fibroblasts. Moreover, data open new perspectives for investigating PXE-like phenotypes in the absence of ABCC6 mutations. 相似文献
24.
Daniel Vázquez-Nion Federica Troiano Patricia Sanmartín Chiara Valagussa Francesca Cappitelli Beatriz Prieto 《Materials and Structures》2018,51(6):158
Salt crystallisation is a very common and powerful weathering agent that can modify the petrophysical properties of building stone such as granite. In addition, the weathering can affect the susceptibility of the stone to biological colonisation. The aims of the present study were to examine the properties of a granite weathered by sodium chloride crystallisation and to evaluate the effects of the weathering on the secondary bioreceptivity of the stone to subaerial phototrophic biofilms. For this purpose, granite samples were subjected to a laboratory-based accelerated salt weathering test, and changes in weight, open porosity, bulk density, capillary water content, abrasion pH and surface roughness of the samples were determined. Samples of both weathered and non-weathered granite were then inoculated with a multi-species phototrophic culture derived from a natural subaerial biofilm and incubated under standardised laboratory conditions for 3 months. The weight loss produced by the weathering process was consistent with significant changes in abrasion pH and surface roughness. The bioreceptivity of the stone was also altered. According to the bioreceptivity index, the granite under study was characterised by ‘mild primary bioreceptivity’, but ‘high secondary bioreceptivity’ after the salt weathering process. Study of the secondary bioreceptivity of stone materials can provide very useful information about response to weathering effects, and the findings can be used to improve the selection of materials for building purposes. 相似文献
25.
Chiara Braghin Natasha Sharygina Katerina Barone-Adesi 《Formal Aspects of Computing》2011,23(5):627-648
This article describes an approach for the automated verification of mobile systems. Mobile systems are characterized by the
explicit notion of location (e.g., sites where they run) and the ability to execute at different locations, yielding a number of security issues. To
this aim, we formalize mobile systems as Labeled Kripke Structures, encapsulating the notion of location net that describes the hierarchical nesting of the threads constituting the system. Then, we formalize a generic security-policy specification language that includes rules for expressing and manipulating the code location. In contrast to many other approaches, our technique
supports both access control and information flow specification. We developed a prototype framework for model checking of
mobile systems. It works directly on the program code (in contrast to most traditional process-algebraic approaches that can
model only limited details of mobile systems) and uses abstraction-refinement techniques, based also on location abstractions,
to manage the program state space. We experimented with a number of mobile code benchmarks by verifying various security policies.
The experimental results demonstrate the validity of the proposed mobile system modeling and policy specification formalisms
and highlight the advantages of the model checking-based approach, which combines the validation of security properties with
other checks, such as the validation of buffer overflows. 相似文献
26.
27.
Imon Banerjee Asan Agibetov Chiara Eva Catalano Giuseppe Patané Michela Spagnuolo 《The Visual computer》2016,32(10):1337-1349
In the digital era, patient-specific 3D models (3D-PSMs) are becoming increasingly relevant in computer-assisted diagnosis, surgery training on digital models, or implant design. While advanced imaging and reconstruction techniques can create accurate and detailed 3D models of patients’ anatomy, software tools that are able to fully exploit the potential of 3D-PSMs are still far from being satisfactory. In particular, there is still a lack of integrated approaches for extracting, coding, sharing and retrieving medically relevant information from 3D-PSMs and use it concretely as a support to diagnosis and treatment. In this article, we propose the SemAnatomy3D framework, which demonstrates how the ontology-driven annotation of 3D-PSMs and of their anatomically relevant features (parts of relevance) can assist clinicians to document more effectively pathologies and their evolution. We exemplify the idea in the context of the diagnosis of rheumatoid arthritis of the hand district, and show how feature extraction tools and semantic 3D annotation can provide a rich characterization of anatomical landmarks (e.g., articular facets, prominent features, ligament attachments) and pathological markers (erosions, bone loss). The core contributions are an ontology-driven part-based annotation method for the 3D-PSMs and a novel automatic localization of erosion and quantification of the OMERACT RAMRIS erosion score. Finally, our results have been compared against a medical ground truth. 相似文献
28.
Eugenio CapraAuthor Vitae Chiara FrancalanciAuthor Vitae 《Journal of Systems and Software》2011,84(1):144-161
Open Source (OS) was born as a pragmatic alternative to the ideology of Free Software and it is now increasingly seen by companies as a new approach to developing and making business upon software. Whereas the role of firms is clear for commercial OS projects, it still needs investigation for projects based on communities. This paper analyses the impact of firms’ participation on popularity and internal software design quality for 643 SourceForge.net projects. Results show that firms’ involvement improves the ranking of OS projects, but, on the other hand, puts corporate constraints to OS developing practices, thus leading to lower structural software design quality. 相似文献
29.
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: |
30.
Antonino Valenza Chiara Borsellino Luigi Calabrese Guido Di Bella 《Applied Composite Materials》2006,13(4):217-235
Composite materials are widely employed in sailing sports, a possible application is for the mast pole or other sail poles. In the paper the attention is focused on the spinnaker poles mechanical performances; in particular the focus is on axial and ring compressive properties of three different carbon fibre/epoxy resin spinnaker poles, to investigate both the diameter and stacking sequence effect on the mechanical performance of the structure. Starting from the stacking sequence used in the production of a particular spinnaker pole, the effect of a lamina at 0° in the middle of wall thickness is investigated with the purpose to obtain a more stiff structure. Moreover to test the proposed stacking sequence on different size products, a prototype with lower diameter is realized. To properly evaluate axial and ring stiffness, axial compression test and ring stiffness one are performed. Then a numerical model is developed to support the design of the finished product: A simple and versatile numerical analysis (FEA with software ANSYS), by simulating ring stiffness and pull-direction compression tests, is carried out in elastic regime. Such model should be suitable for designing and/or verifying the mechanical performance of pole structures, even though differing from those above described, for materials, geometry and stacking sequence. 相似文献