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101.
Lot streaming for product assembly in job shop environment 总被引:3,自引:1,他引:2
Assembly job shop scheduling problem (AJSP) is an extension of classical job shop scheduling problem (JSP). AJSP starts with JSP and appends an assembly stage to the completed jobs. Lot streaming (LS) technique is a process of splitting jobs into smaller sub-jobs such that successive operations can be overlapped. This paper combines, for the first time, LS and AJSP, extending LS applicability to both machining and assembly. To solve this complex problem, an efficient algorithm is proposed using genetic algorithms and simple dispatching rules. Experimental results suggest that equal size LS outperforms varied size LS with respect to the objective function. 相似文献
102.
Image preview is a convenient way to browse large or multiple images on small displays. However, current signal-level image
resampling algorithms may remove many features of interest in the preview image. In this paper, we propose perceptual image
preview which retains more perceptual features such that users can inspect features of interest by viewing the preview image
only and without zooming in. This technology has two components, structure enhancement and perceptual feature visualization.
Structure enhancement enhances the image structure while suppressing subtle details using a gradient modulation method, thus
making the succedent perceptual features more apparent. For perceptual feature visualization, features of interest detected
in the picture is visualized on the structure enhanced preview image. We demonstrate with two examples of most commonly used image quality features, image blur and noise. The effectiveness of the proposed method is validated
by experimental results. 相似文献
103.
William G. Booty Isaac Wong David Lam Oskar Resler 《Environmental Modelling & Software》2009,24(8):889-900
The Environmental Effects Monitoring (EEM) Statistical Assessment Tool (SAT) Decision Support System (DSS) has been developed to provide a user-friendly data analysis, display and decision support tool for Canada's federal environmental effects monitoring program for the pulp and paper and mining industries. The target users include industries, consultants, regional EEM coordinators, National EEM Office and scientists involved in EEM-related research. The tool allows the assessment of the effects of effluent from industrial or other sources on fish and benthic populations. Effect endpoints, which are used as indicators of potentially important effluent effects, are measured at effluent-exposed sites and are compared statistically to measures at reference sites, in order to determine if changes have occurred and the magnitude of the changes. The main driver of the EEM-SAT DSS is its rule-based expert system. The results are used in assessing the adequacy of existing regulations for protecting aquatic environments. 相似文献
104.
In this paper, we propose a distributed congestion-aware channel assignment (DCACA) algorithm for multi-channel wireless mesh networks (MC–WMNs). The frequency channels are assigned according to the congestion measures which indicate the congestion status at each link. Depending on the selected congestion measure (e.g., queueing delay, packet loss probability, and differential backlog), various design objectives can be achieved. Our proposed distributed algorithm is simple to implement as it only requires each node to perform a local search. Unlike most of the previous channel assignment schemes, our proposed algorithm assigns not only the non-overlapped (i.e., orthogonal) frequency channels, but also the partially-overlapped channels. In this regard, we introduce the channel overlapping and mutual interference matrices which model the frequency overlapping among different channels. Simulation results show that in the presence of elastic traffic (e.g., TCP Vegas or TCP Reno) sources, our proposed DCACA algorithm increases the aggregate throughput and also decreases the average packet round-trip compared with the previously proposed Load-Aware channel assignment algorithm. Furthermore, in a congested IEEE 802.11b network setting, compared with the use of three non-overlapped channels, the aggregate network throughput can further be increased by 25% and the average round-trip time can be reduced by more than one half when all the 11 partially-overlapped channels are used. 相似文献
105.
A. Saleem C.B. Wong J. Pu P.R. Moore 《Simulation Modelling Practice and Theory》2009,17(10):1575-1586
This paper outlines a method to identify the friction parameters for servo-pneumatic systems using a mixed-reality environment. To acquire system friction parameters accurately can be extremely difficult once the servo-system has been assembled because of its highly nonlinear nature, which causes a great difficulty in servo-pneumatic system modelling and control. In this research, a mixed-reality environment has been employed to determine the friction parameters effectively and efficiently through online identification. Traditionally, friction parameters identification can be performed manually or automatically using traditional optimization methods or modern ones such as neural networks. The advantages of the proposed method are the high accuracy in the estimated parameters, its simplicity and its speed. An experimental case study has been conducted and the results showed the accuracy and effectiveness of the proposed method. 相似文献
106.
Jungkyu Kim Michael Junkin Deok-Ho Kim Seunglee Kwon Young Shik Shin Pak Kin Wong Bruce K. Gale 《Microfluidics and nanofluidics》2009,7(2):149-167
Biosensors based on nanotechnology are rapidly developing and are becoming widespread in the biomedical field and analytical
chemistry. For these nanobiosensors to reach their potential, they must be integrated with appropriate packaging techniques,
which are usually based on nano/microfluidics. In this review we provide a summary of the latest developments in nanobiosensors
with a focus on label-based (fluorescence and nanoparticle) and label-free methods (surface plasmon resonance, micro/nanocantilever,
nanowires, and nanopores). An overview on how these sensors interface with nano/microfluidics is then presented and the latest
papers in the area summarized. 相似文献
107.
This paper presents theoretical and experimental investigations on electroosmotic control of stream width in hydrodynamic
focusing. In the experiments, three liquids (aqueous NaCl, aqueous glycerol and aqueous NaCl) are introduced by syringe pumps
to flow side by side in a straight rectangular microchannel. External electric fields are applied on the two aqueous NaCl
streams. Under the same inlet volumetric flow rates, the applied electric fields are varied to control the interface positions
and consequently the width of the focused aqueous glycerol stream. The electroosmotic effect on the width of the aqueous glycerol
is measured using fluorescence imaging technique. The electroosmotic effect under different flow rates, different viscosity,
and aspect ratio are investigated. The results indicate that the electroosmotic effect on the pressure-driven flow becomes
weaker with the increase in flow rates, viscosity ratio or aspect ratio of the channel. The measured results of the focused
width of the non-conducting fluid agree well with the analytical model. 相似文献
108.
Yan Wang Kwei-Jay Lin Duncan S. Wong Vijay Varadharajan 《Service Oriented Computing and Applications》2009,3(2):129-146
In service-oriented computing (SOC) environments, service clients interact with service providers for services or transactions.
From the point view of service clients, the trust status of a service provider is a critical issue to consider, particularly
when the service provider is unknown to them. Typically, the trust evaluation is based on the feedback on the service quality
provided by service clients. In this paper, we first present a trust management framework that is event-driven and rule-based.
In this framework, trust computation is based on formulae. But rules are defined to determine which formula to use and what
arguments to use, according to the event occurred during the transaction or service. In addition, we propose some trust evaluation
metrics and a formula for trust computation. The formula is designed to be adaptable to different application domains by setting
suitable arguments. Particularly, the proposed model addresses the incremental characteristics of trust establishment process.
Furthermore, we propose a fuzzy logic based approach for determining reputation ranks that particularly differentiates new
service providers and old (long-existing) ones. This is further incentive to new service providers and penalize poor quality
services from service providers. Finally, a set of empirical studies has been conducted to study the properties of the proposed
approaches, and the method to control the trust changes in both trust increment and decrement cases. The proposed framework
is adaptable for different domains and complex trust evaluation systems.
相似文献
Vijay VaradharajanEmail: |
109.
We propose performing space-variant optical logic operations in a space-invariant optical system by selectively assigning encoding states that are operation dependent. With this method, encoders using liquid-crystal cells and liquid-crystal light valves to perform space-variant encoding for all 16 Boolean functions are designed. Multiple-instruction-multiple-data processing can then be realized in optical logic systems. 相似文献
110.
Engineering linear F(ab')2 fragments for efficient production in Escherichia coli and enhanced antiproliferative activity 总被引:1,自引:0,他引:1
Zapata Gerardo; Ridgway John B. B.; Mordenti Joyce; Osaka Gary; Wong Wai Lee T.; Bennett Gregory L.; Carter Paul 《Protein engineering, design & selection : PEDS》1995,8(10):1057-1062
We developed a novel bivalent antibody fragment, the linear(L-) F(ab')2, comprising tandem repeats of a heavy chain fragmentVHCH1VHCH1 cosecreted with a light chain.Functional humanized L-F(ab')2 directed against p185HER2 wassecreted from Escherichia coli at high titer (100 mg/l) andpurified to homogeneity. The L-F(ab')2 binds two equivalentsof antigen with an apparent affinity (Kd = 0.46 nM) that iswithin 3-fold of the corresponding thioether-linked F(ab')2fragment The N-terminal site binds antigen with an affinity(Kd = 1.2 nM) that is 4-fold greater than that for the C-terminalsite, as shown by the comparison of L-F(ab')2 variants containinga single functional binding site. L-F(ab')2 has greater antiproliferativeactivity than the thioether-linked F(ab')2 against the p185HER2-overexpressingtumor cell line BT474. Linear and thioether-linked F(ab')2 havevery similar pharmacokinetic properties in normal mice, andtheir serum permanence times are respectively 7- and 8-foldlonger than the corresponding Fab fragment L-F(ab')2 offersa facile route to bivalent antibody fragments that are potentiallysuitable for clinical applications, and that may have improvedbiological activity compared with thioether-linked F(ab')2 fragments. 相似文献