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61.
Ali Reza Allafchian Seyed Amir Hossein Jalali Farzane Aghaei Hamid Reza Farhang 《IET nanobiotechnology / IET》2018,12(5):574
The metal nanoparticles, due to interesting features such as electrical, optical, chemical and magnetic properties, have been investigated repeatedly. Also, the mentioned nanoparticles have specific uses in terms of their antibacterial activity. The biosynthesis method is more appropriate than the chemical method for producing the nanoparticles because it does not need any special facilities; it is also economically affordable. In the current study, the silver nanoparticles (AgNPs) were obtained by using a very simple and low‐cost method via Glaucium corniculatum (L.) Curtis plant extract. The characteristics of the AgNPs were investigated using techniques including: X‐ray diffraction, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy. The SEM and TEM images showed that the nanoparticles had a spherical shape, and the mean diameter of them was 53.7 and 45 nm, respectively. The results of the disc diffusion test used for measuring the anti‐bacterial activity of the synthesised nanoparticles indicated that the formed nanoparticles possessed a suitable anti‐bacterial activity.Inspec keywords: silver, nanoparticles, antibacterial activity, nanomedicine, nanofabrication, X‐ray diffraction, transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectraOther keywords: green synthesis, silver nanoparticles, Glaucium corniculatum Curtis extract, antibacterial activity, metal nanoparticles, biosynthesis method, X‐ray diffraction, transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, SEM, TEM, spherical shape, disc diffusion test, Ag 相似文献
62.
Double Auction-based Scheduling of Scientific Applications in Distributed Grid and Cloud Environments 总被引:1,自引:0,他引:1
Economy models have long been considered as a promising complement to the classical distributed resource management not only
due of their dynamic and decentralized nature, but also because the concept of financial valuation of resources and services
is an inherent part of any such model. In its broadest sense, scheduling of scientific applications in distributed Grid and
Cloud environments can be regarded as a market-based negotiation between a scheduling service optimizing user-centric objectives
(execution time, budget), and a resource manager optimizing provider-centric metrics (resource utilization, income, job throughput).
In this paper, we propose a new instantiation of the negotiation protocol between the scheduler and resource manager using
a market-based Continuous Double Auction (CDA) model. We analyze different scheduling strategies that can be applied and identify
general strategic patterns that can lead to a fast and cheap work ow execution. In the experimental study, we demonstrate
that under certain circumstances one can benefit by applying an aggressive scheduling strategy. 相似文献
63.
Abbas Nayebi Author Vitae Hamid Sarbazi-Azad Author Vitae Gunnar Karlsson Author Vitae 《Journal of Systems and Software》2010,83(8):1310-1317
This paper investigates a class of mobile wireless sensor networks that are unconnected most of the times; we refer to them as delay-tolerant wireless sensor networks (DTWSN). These networks inherit their characteristics from both delay tolerant networks (DTN) and traditional wireless sensor networks. After introducing DTWSNs, three main problems in the design space of these networks are discussed: routing, data gathering, and neighbor discovery. A general protocol is proposed for DTWSNs based on opportunistic broadcasting in delay-tolerant networks with radio device on-off periods. Three performance measures are defined in the study: the energy for sending queries to ask for data from possible neighbors (querying energy), data transfer energy, and absorption time (delay). A simple yet accurate approximation for the data-transfer energy is proposed. An analytic model is provided to evaluate the querying energy per contact (epc). Simulation results for the data propagation delay show that the querying energy per contact measure obtained from the analytic model is proportional to the product of the querying energy and the delay. A practical rule of thumb for an optimal query interval in terms of delay and energy is derived from different parts of the study. 相似文献
64.
We address the problem of control and synchronization of a class of uncertain chaotic systems. Our approach follows techniques of sliding mode control and adaptive estimation law. The adaptive algorithm is constructed based on the sliding mode control to ensure perfect tracking and synchronization in presence of system uncertainty and external disturbance. Stability of the closed-loop system is proved using Lyapunov stability theory. Our theoretical findings are supported by simulation results. 相似文献
65.
As a result of the emerging use of mesh-based multicomputers (and recently mesh-based multiprocessor systems-on-chip), issues
related to processor management have attracted much attention. In a mesh-based multiprocessor, after repeated submesh allocations
and de-allocations, the system network may be fragmented, i.e. there might be unallocated nodes in the network. As a result,
in a system with contiguous processor allocation, no new tasks can start running due to the lack of enough free adjacent processors
to form a suitable submesh. Although there might be enough free processors available, they remain idle until the allocator
can find a set of adjacent free nodes forming a submesh to be used for the new task. This can lead to low system performance.
Task migration was introduced as a solution to this problem through migration of tasks running on some submeshes to other
free areas in order to reduce fragmentation by chaining the newly freed areas and disengaging nodes to form larger submeshes.
In this paper, we propose a novel structured and formulated way to code task migration, which is helpful for congestion detection
in different steps of task migration algorithms. Moreover, considering the fact that the 3D mesh-based multicomputers are
now very popular, a new task migration algorithm in 3D meshes is proposed. We also address the special case of the 2D migration
in a 3D mesh multicomputer. 相似文献
66.
An optimal algorithm based on branch-and-bound approach is presented in this paper to determine lot sizes for a single item in material requirement planning environments with deterministic time-phased demand and constant ordering cost with zero lead time, where all-units discounts are available from vendors and backlog is not permitted. On the basis of the proven properties of optimal order policy, a tree-search procedure is presented to construct the sequence of optimal orders. Some useful fathom rules have been proven, which make the algorithm very efficient. To compare the performance of this algorithm with the other existing optimal algorithms, an experimental design with various environments has been developed. Experimental results show that the performance of our optimal algorithm is much better than the performance of other existing optimal algorithms. Considering computational time as the performance measure, this algorithm is considered the best among the existing optimal algorithms for real problems with large dimensions (i.e. large number of periods and discount levels). 相似文献
67.
Time delays are encountered in many physical systems, and they usually threaten the stability and performance of closed-loop systems. The problem of determining all stabilising proportional-integral-derivative (PID) controllers for systems with perturbed delays is less investigated in the literature. In this study, the Rekasius substitution is employed to transform the system parameters to a new space. Then, the singular frequency (SF) method is revised for the Rekasius transformed system. A novel technique is presented to compute the ranges of time delay for which stable PID controller exists. This stability range cannot be readily computed from the previous methods. Finally, it is shown that similar to the original SF method, finite numbers of singular frequencies are sufficient to compute the stable regions in the space of time delay and controller coefficients. 相似文献
68.
A. S. Ibraheam Y. Al-Douri J. M. S. Al-Fhdawi Hamid S. AL-Jumaili K. D. Verma U. Hashim R. M. Ayub A. Rahim Ruslinda M. K. Md Arshad A. H. Reshak S. B. Abd Hamid 《Microsystem Technologies》2016,22(12):2893-2900
The Cu2Zn1?xCdxSnS4 quinternary alloy nanostructures with different Cd contents were grown using spin coating technique on porous silicon (63.93 %) substrate. The structural properties of Cu2Zn1?xCdxSnS4/PS were investigated by X-ray diffraction and field emission-scanning electron microscope (FE-SEM). The optical properties studied through photoluminescence technique, indicated that the band gap is shifted as Cd content increases from 1.84 eV at x = 0 to 1.76 eV at x = 1. The electrical characterization of the Ag/n-PS/Cu2Zn1?xCdxSnS4/Ag diode through current to voltage (I–V) characterization shows the highest photo-response of (value if any) at Cu2Zn0.4Cd0.6SnS4 composition. 相似文献
69.
Hao Chen Juan He Raymond Lanzafame Istvan Stadler Hamid El Hamidi Hui Liu Jonathan Celli Michael R. Hamblin Yingying Huang Emily Oakley Gal Shafirstein Ho‐Kyoon Chung Shin‐Tson Wu Yajie Dong 《Journal of the Society for Information Display》2017,25(3):177-184
While OLEDs have struggled to find a niche lighting application that can fully take advantage of their unique form factors as thin, flexible, lightweight and uniformly large‐area luminaire, photomedical researchers have been in search of low‐cost, effective illumination devices with such form factors that could facilitate widespread clinical applications of photodynamic therapy (PDT) or photobiomodulation (PBM). Although existing OLEDs with either fluorescent or phosphorescent emitters cannot achieve the required high power density at the right wavelength windows for photomedicine, the recently developed ultrabright and efficient deep red quantum dot light emitting devices (QLEDs) can nicely fit into this niche. Here, we report for the first time the in‐vitro study to demonstrate that this QLED‐based photomedical approach could increase cell metabolism over control systems for PBM and kill cancerous cells efficiently for PDT. The perspective of developing wavelength‐specific, flexible QLEDs for two critical photomedical fields (wound repair and cancer treatment) will be presented with their potential impacts summarized. The work promises to generate flexible QLED‐based light sources that could enable the widespread use and clinical acceptance of photomedical strategies including PDT and PBM. 相似文献
70.
Quantum Information Processing - We present a general problem of quantum entanglement quantified by von Neumann entropy for N-level atomic system. Time evolution of state vector of the entire... 相似文献