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981.
Giuseppe Anastasi Marco Conti Mario Di Francesco Andrea Passarella 《Ad hoc Networks》2009,7(3):537-568
In the last years, wireless sensor networks (WSNs) have gained increasing attention from both the research community and actual users. As sensor nodes are generally battery-powered devices, the critical aspects to face concern how to reduce the energy consumption of nodes, so that the network lifetime can be extended to reasonable times. In this paper we first break down the energy consumption for the components of a typical sensor node, and discuss the main directions to energy conservation in WSNs. Then, we present a systematic and comprehensive taxonomy of the energy conservation schemes, which are subsequently discussed in depth. Special attention has been devoted to promising solutions which have not yet obtained a wide attention in the literature, such as techniques for energy efficient data acquisition. Finally we conclude the paper with insights for research directions about energy conservation in WSNs. 相似文献
982.
Combined microwaves and convection heating: A conjugate approach 总被引:2,自引:0,他引:2
Microwave treatment has been gaining increasing recognitions in the food industry and household frameworks alike. Better energy and finishing efficiencies can be obtained by adding an additional transport mechanism, such as forced air convection heating. In this work, transient distributions of temperature and moisture during the combined treatment is analyzed by a full computational fluid dynamics model, coupled with custom moisture diffusion and evaporation notations. 相似文献
983.
Daghino S Turci F Tomatis M Favier A Perotto S Douki T Fubini B 《Environmental science & technology》2006,40(18):5793-5798
Some soil fungi growing on asbestos fibers release chelators and antioxidants. The bioweathering potential of fungi has thus been envisaged as a possible route for bioremediation of asbestos rich soils, where no inactivation procedures have been established so far. The present study reports fungal-mediated modification of the surface reactivity of the fibers and of their potential to damage DNA in vitro. Verticillium sp. and Paecilomyces sp. were selected among the fungi isolated from fragments of chrysotile bearing rocks, as the most potent in iron extraction, and studied in parallel with F. oxysporum, previously reported to modify the surface reactivity of asbestos fibers. One sample of chrysotile from the Western Alps and a sample of UICC (Union Internationale Contre le Cancer) crocidolite were incubated with or without fungi. All fungi extracted iron from both fibers (7.3% from crocidolite and 33.6% from chrysotile by Verticillium sp.), releasing it into the medium. F. oxysporum and Paecilomyces sp. suppressed the potential of the fibers to release hydroxyl radical, while Verticillium sp. suppressed it on crocidolite but enhanced it on chrysotile, a hallmark of ongoing mobilization of reactive iron. Fibers incubated in the growth medium, but in the absence of fungi, exhibited a remarkable potential to damage DNA in vitro, measured by the generation of 8-oxo-7,8-dihydro-2'-deoxyguanosine, while all the fungi reduced such effect. Fungi may thus be regarded as appropriate candidates for bioremediation of asbestos rich soils whereby the reactive iron ions responsible for DNA damage are progressively removed from the fibers. 相似文献
984.
Di Santo R Costi R Artico M Ragno R Lavecchia A Novellino E Gavuzzo E La Torre F Cirilli R Cancio R Maga G 《ChemMedChem》2006,1(1):82-95
TIBO- and TBO-like sulfone derivatives 1 and 2 were designed, synthesized, and tested for their ability to block the replication cycle of HIV-1 in infected cells. The anti-HIV-1 activities of sulfones 3, which were intermediates in the syntheses of 1 and 2, were also evaluated. Surprisingly, the sulfone analogues of TIBO R82913 (compounds 1) were inactive, whereas interesting results were obtained for truncated derivatives 2. Compound 2 w was the most potent among this series in cell-based assays (EC50=0.07 microM, CC50>200 microM, SI>2857). It was twofold less potent than R82913, but more selective. An X-ray crystallographic analysis was carried out to establish the absolute configuration of 2 w and its enantiomer 2 x, which were obtained by semipreparative HPLC of 2 v, one of the most potent racemates. Compounds 1-3 were proven to target HIV-1 RT. In fact, representative derivatives inhibited recombinant HIV-1 RT in vitro at concentrations similar to those active in cell-based assays. 3D QSAR studies and docking simulations were developed on TIBO- and TBO-like sulfone derivatives to rationalize their anti-HIV-1 potencies and to predict the activity of novel untested sulfone derivatives. Predictive 3D QSAR models were obtained with a receptor-based alignment by docking of TIBO- and TBO-like derivatives into the NNBS of RT. 相似文献
985.
Luca Benini Davide Bertozzi Alessandro Bogliolo Francesco Menichelli Mauro Olivieri 《The Journal of VLSI Signal Processing》2005,41(2):169-182
Technology is making the integration of a large number of processors on the same silicon die technically feasible. These multi-processor systems-on-chip (MP-SoC) can provide a high degree of flexibility and represent the most efficient architectural solution for supporting multimedia applications, characterized by the request for highly parallel computation. As a consequence, tools for the simulation of these systems are needed for the design stage, with the distinctive requirement of simulation speed, accuracy and capability to support design space exploration. We developed a complete simulation platform for a MP-SoC called MP-ARM, based on SystemC as modelling and simulation environment, and including models for processors, the AMBA bus compliant communication architecture, memory models and support for parallel programming. A fully operating linux version for embedded systems has been ported on this platform, and a cross-toolchain has been developed as well. Our MP simulation environment turns out to be a powerful tool for the MP-SOC design stage. As an example thereof, we use our tool to evaluate the impact on system performance of architectural parameters and of bus arbitration policies, showing that the effectiveness of a particular system configuration strongly depends on the application domain and the generated traffic profile.Luca Benini received the B.S. degree (summa cum laude) in electrical engineering from the University of Bologna, Italy, in 1991, and the M.S. and Ph.D. degrees in electrical engineering from Stanford University in 1994 and 1997, respectively. He is an associate professor in the department of electronics and computer science in the University of Bologna. He also holds visiting researcher positions at Stanford University and the Hewlett-Packard Laboratories, Palo Alto, CA.Dr. Benini’s research interests are in all aspects of computer-aided design of digital circuits, with special emphasis on low-power applications, and in the design of portable systems. He is co-author of the book: Dynamic Power management, Design Techniques and CAD tools, Kluwer 1998.Dr. Benini is a member of the technical program committee for several technical conferences, including the Design Automation Conference, the International Symposium on Low Power Design and the International symposium on Hardware-Software Codesign.Davide Bertozzi received the B.S. degree in electrical engineering from the University of Bologna, Bologna, Italy, in 1999.He is currently pursuing the Ph.D. degree at the same University and is expected to graduate in 2003. His research interests concern the development of SoC co-simulation platforms, exploration of SoC communication architectures and low power system design.Alessandro Bogliolo received the Laurea degree in electrical engineering and the Ph.D. degree in electrical engineering and computer science from the University of Bologna, Bologna, Italy, in 1992 and 1998.In 1995 and 1996 he was a Visiting Scholar at the Computer Systems Laboratory (CSL), Stanford University, Stanford, CA.From 1999 to 2002 he was an Assistant Professor at the Department of Engineering (DI) of the University of Ferrara, Ferrara, Italy. Since 2002 he’s been with the Information Science and Technology Institute (STI) of the University of Urbino, Urbino, Italy, as Associate Professor. His research interests are mainly in the area of digital integrated circuits and systems, with emphasis on low power and signal integrity.Francesco Menichelli was born in Rome in 1976. He received the Electronic Engineering degree in 2001 at the University of Rome “La Sapienza”. From 2002 he is a Ph.D. student in Electronic Engineering at “La Sapienza” University of Rome.His scientific interests focus on low power digital design, and in particular in level tecniques for low power consumption, power modeling and simulation of digital systems.Mauro Olivieri received a Master degree in electronic engineering “cum laude” in 1991 and a Ph.D. degree in electronic and computer engineering in 1994 from the University of Genoa, Italy, where he also worked as an assistant professor. In 1998 he joined the University of Rome “La Sapienza”, where he is currently associate professor in electronics. His research interests are digital system-on-chips and microprocessor core design. Prof. Olivieri supervises several research projects supported by private and public fundings in the field of VLSI system design. 相似文献
986.
While it is quite obvious that photons have an essential role in photochemical and photocatalytic processes, it is not simple to analyse the radiation process.A simple approach is presented on the assumption that photons can be treated as immaterial reactants. It is then possible to evaluate the radiation process in terms of parameters such as conversion, selectivity and yield, which are common in the conventional reaction engineering, and of an additional parameter, a volume efficiency factor, which accounts for the exploitation of the reaction volume as the result of the inevitable attenuation of the radiation in the transport through the participating medium.Attention has also been focused on the validation of kinetic data when, as it is usually done, they are interpreted in terms of volume averages.Finally, guidelines have been prepared to support preliminary phases of analysis and/or design of a photocatalytic reactor. 相似文献
987.
Abstract. The problem of identifying the time location and estimating the amplitude of outliers in nonlinear time series is addressed. A model‐based method is proposed for detecting the presence of additive or innovational outliers when the series is generated by a general nonlinear model. We use this method for identifying and estimating outliers in bilinear, self‐exciting threshold autoregressive and exponential autoregressive models. A simulation study is performed to test the proposed procedures and comparing them with the methods based on linear models and linear interpolators. Finally, our results are applied for detecting outliers in the Canadian lynx trappings and in the sunspot numbers data. 相似文献
988.
A. Pozio M. De Francesco G. Monteleone R. Oronzio S. Galli C. D’Angelo M. Marrucci 《International Journal of Hydrogen Energy》2008
Extended application of hydrogen as energy carrier demands an economical, safe and reliable technology for storage. In particular, chemical hydrides appear as capable and promising to overcome the issues related to hydrogen safety and handling and to be considered competitive with respect to conventional fuels. 相似文献
989.
Andrea Francesco Abate Maria De Marsico Stefano Ricciardi Daniel Riccio 《Journal of Visual Languages and Computing》2009,20(3):156-168
This work investigates face recognition based on normal maps, and the performance improvement that can be obtained when exploiting it within a multimodal system, where a further independent module processes visible images. We first propose a technique to align two 3D models of a face by means of normal maps, which is very fast while providing an accuracy comparable to well-known and more general techniques such as Iterative Closest Point (ICP). Moreover, we propose a matching criterion based on a technique which exploits difference maps. It does not reduce the dimension of the feature space, but performs a weighted matching between two normal maps. In the second place, we explore the range of performances offered by different linear and nonlinear classifiers, when applied to the normal maps generated from the above aligned models. Such experiments highlight the added value of chromatic information contained in normal maps. We analyse a solid list of classifiers which were selected due to their historical reference value (e.g. Principal Component Analysis) or to their good performances in the bidimensional setting (Linear Discriminant Analysis, Partitioned Iterated Function Systems). Last but not least, we perform experiments to measure how different ways of combining normal maps and visible images can enhance the results obtained by the single recognition systems, given that specific characteristics of the images are taken into account. For these last experiments we only consider the classifier giving the best average results in the preceding ones, namely the PIFS-based one. 相似文献
990.