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81.
Rosario G. Garroppo Stefano Giordano Davide Iacono Luca Tavanti 《Wireless Networks》2011,17(6):1441-1459
In WiMAX systems the Base Station scheduler plays a key role as it controls the sharing of the radio resources among the users.
The goal of the scheduler is multiple: achieve fair usage of the resources, satisfy the QoS requirements of the users, maximize
goodput, and minimize power consumption, and at the same time ensuring feasible algorithm complexity and system scalability.
Since most of these goals are contrasting, scheduler designers usually focus their attention on optimizing one aspect only.
In this scenario, we propose a scheduling algorithm (called GTSN\mathrm{GTS_N}) whose goal is to contemporaneously achieve efficiency and fairness, while also taking into account the QoS requirements
and the channel state. GTSN\mathrm{GTS_N} exploits the properties of Time Utility Functions (TUFs) and Game Theory. Simulations prove that the performance of GTSN,\mathrm{GTS_N}, when compared to that of several well-known schedulers, is remarkable. GTSN\mathrm{GTS_N} provides the best compromise between the two contrasting objectives of fairness and efficiency, while QoS requirements are
in most cases guaranteed. However, the exponential complexity introduced by the game theory technique makes it rather impractical
and not computationally scalable for a large number of users. Thus we developed a suboptimal version, named sub-GTSN.\mathrm{GTS_N}. We show that this version retains most of the features and performance figures of its brother, but its complexity is linear
with the number of users. 相似文献
82.
认为web3.0和社交网络会让我们摆脱在公共空间中进行物理交流需求的想法需要再斟酌。事实上,当环境中的技术设施让我们能够用负担得起的可移动设备与世界相联系、让新的工作和社交模式能够在家里甚至喜爱的酒吧中产生的时候,很多在家工作的人和网友开始感受到一种需要重新建立起某些真正的社会团体的需求。因此很容易理解,在过去的几十年中,许多城市成为一种"合作"机制网络成长的摇篮。"合作"机制是一种实验,为喜欢与他人共享空间的人们提供廉价、灵活和非正规的生活和工作的解决方案。更准确地说,分享是这些措施中可持续性的关键,因为仅仅通过让一个 相似文献
83.
84.
The advantages and open questions of the combination of modulation excitation spectroscopy and phase sensitive detection (PSD) with X-ray absorption spectroscopy (XAS) for the analysis of heterogeneous catalysts at work are reviewed. The characteristic spectral signatures of two different edges (Pd K and Pt L3) are described in relation to the red-ox chemistry of Pd/Al2O3 and Pt/Al2O3 with respect to NO reduction by CO and CO oxidation, respectively. Both examples demonstrate that PSD makes XAS sensitive to potentially active species for the catalytic reaction. 相似文献
85.
This paper describes the energy consumption performance of sea-going ships engaged in the EU27 seaborne trades based on data and parameters resulting from the EX-TREMIS (EXploring non road TRansport EMISsions in Europe) database. EX-TREMIS is a comprehensive database of fleet and transport activity data, specific energy consumption, emission factors and total emissions from rail, maritime and air transport in the European Union. The EX-TREMIS maritime model derives from a mixture of top–down and bottom–up approaches for estimating pollutant emissions from shipping activities. The model did not use direct observations of actual trips, but empirically derived the number of equivalent-ships. Cargo type shipments were linked to seven ship type categories for which a further segmentation by ship size (three length classes), type and age of the main engine and type of fuel was applied. 相似文献
86.
87.
Erica Bazzan Mariaenrica Tin Alvise Casara Davide Biondini Umberto Semenzato Elisabetta Cocconcelli Elisabetta Balestro Marco Damin Claudia Maria Radu Graziella Turato Simonetta Baraldo Paolo Simioni Paolo Spagnolo Marina Saetta Manuel G. Cosio 《International journal of molecular sciences》2021,22(12)
Extracellular vesicles (EVs) are a family of particles/vesicles present in blood and body fluids, composed of phospholipid bilayers that carry a variety of molecules that can mediate cell communication, modulating crucial cell processes such as homeostasis, induction/dampening of inflammation, and promotion of repair. Their existence, initially suspected in 1946 and confirmed in 1967, spurred a sharp increase in the number of scientific publications. Paradoxically, the increasing interest for EV content and function progressively reduced the relevance for a precise nomenclature in classifying EVs, therefore leading to a confusing scientific production. The aim of this review was to analyze the evolution of the progress in the knowledge and definition of EVs over the years, with an overview of the methodologies used for the identification of the vesicles, their cell of origin, and the detection of their cargo. The MISEV 2018 guidelines for the proper recognition nomenclature and ways to study EVs are summarized. The review finishes with a “more questions than answers” chapter, in which some of the problems we still face to fully understand the EV function and potential as a diagnostic and therapeutic tool are analyzed. 相似文献
88.
Rainer Wesche Pierluigi Bruzzone Stephen March Claudio Marinucci Boris Stepanov Davide Uglietti 《Fusion Engineering and Design》2013,88(9-10):1495-1498
In the last few years, the critical current densities of long commercially available REBa2Cu3O7?x (RE-123, where RE represents Y or a rare earth element) coated conductors have reached values of 250 A/cm-width at 77 K and zero applied field. Even higher values of 600 A/cm-w (77 K, B = 0) have been demonstrated in shorter lengths. The attractive features of the use of these high-Tc superconductors (HTS) are operation temperatures above 20 K and/or magnetic fields higher than those envisaged for the ITER TF coils. Possible operation conditions for HTS fusion magnets have been studied taking into consideration the possible further improvements of RE-123 coated conductors. Investigations of stability and quench behavior indicate that stability is not a problem, whereas quench detection and protection need attention. Because of the high currents necessary for fusion magnets, many tapes need to be assembled into a transposed conductor. The qualification of HTS conductors for fusion magnets would require their test at magnetic fields of 11 T and currents well above 10 kA. The possibilities to test straight HTS conductor samples in SULTAN have been considered. For a test at 4.5 K, only the development of a low resistance joint between the HTS conductor under test and the NbTi transformer of SULTAN would be necessary. Tests up to 20 K would require that the HTS sample is connected with the NbTi transformer by a conduction-cooled HTS bus bar of large thermal resistance similar to the HTS module of a current lead. HTS conductor tests at temperatures around 50 K would be possible with modified cryogenics. 相似文献
89.
Davide Marano Gaetano Palumbo Salvatore Pennisi 《Analog Integrated Circuits and Signal Processing》2010,65(2):289-298
The present paper addresses a new compact low-power high-speed output buffer amplifier topology for large-size liquid crystal
display applications. The suggested buffer achieves fast driving performance, draws a low quiescent current during static
operation and offers a rail-to-rail common-mode input range. The circuit provides enhanced slewing capabilities with a limited
power consumption by simultaneously exploiting the push–pull output sections of two basic complementary-type input amplifiers
to realize a dual-path push–pull operation of the output stage. An auxiliary biasing network integrated in the input differential
stage allows the quiescent bias conditions of the class-AB output stage to be inherently controlled without additional current
dissipation. Post-layout simulation results confirm that the proposed amplifier can drive a 1-nF column line load within a
0.9-μs settling time under a 3-V full voltage swing, while drawing only 3.5-μA quiescent current. Monte Carlo simulations
are finally carried out, showing a good degree of robustness of the proposed output buffer against process and mismatch variations. 相似文献
90.