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1.
A number of checkpointing and message logging algorithms have been proposed to support fault tolerance of mobile computing systems. However, little attention has been paid to the optimistic message logging scheme. Optimistic logging has a lower failure-free operation cost compared to other logging schemes. It also has a lower failure recovery cost compared to the checkpointing schemes. This paper presents an efficient scheme to implement optimistic logging for the mobile computing environment. In the proposed scheme, the task of logging is assigned to the mobile support station so that volatile logging can be utilized. In addition, to reduce the message overhead, the mobile support station takes care of dependency tracking and the potential dependency between mobile hosts is inferred from the dependency between mobile support stations. The performance of the proposed scheme is evaluated by an extensive simulation study. The results show that the proposed scheme requires a small failure-free overhead and the cost of unnecessary rollback caused by the imprecise dependency is adjustable by properly selecting the logging frequency. 相似文献
2.
Presented is an eigen filter to remove autogenic electrical stimulation artefacts and M-waves while preserving the volitional electromyographic signal. The optimality of the eigen filter is shown, along with simulated and measured data to indicate its superior performance over conventional prediction error filters. 相似文献
3.
For the purposes of new membrane material development for pervaporation separation based on crosslinked polyvinyl alcohol (PVA), IR spectroscopy and DSC were used to characterize the crosslinking reaction and the imidization of the (PVA)-amic acid system. The IR spectra and the thermal analysis were performed on specimens that had been reacted for several different times at 150°C. The crosslinking reaction between the hydroxy groups of PVA and the carboxylic groups of amic acid was faster than the imidization of the amic acid. The best reaction times were about 30 min for the crosslinking reaction and 90 min for the imidization. The effects of the reaction time and the amic acid content on the thermal and mechanical properties have also been investigated. 相似文献
4.
A semi-empirical equation of state for the freely jointed square-well chain fluid is developed. This equation of state is
based on Wertheim’s thermodynamic perturbation theory (TPT) and the statistical associating fluid theory (SAFT). The compressibility
factor and radial distribution function of square-well monomer are obtained from Monte Carlo simulations. These results are
correlated using density expansion. In developing the equation of state the exact analytical expressions are adopted for the
second and third virial coefficients for the compressibility factor and the first two terms of the radial distribution function,
while the higher order coefficients are determined from regression using the simulation data. In the limit of infinite temperature,
the present equation of state and the expression for the radial distribution function are represented by the Carnahan-Starling
equation of state. This semi-empirical equation of state gives at least comparable accuracy with other empirical equation
of state for the square-well monomer fluid. With the new SAFT equation of state from the accurate expressions for the monomer
reference and covalent terms, we compare the prediction of the equation of state to the simulation results for the compressibility
factor and radial distribution function of the square-well monomer and chain fluids. The predicted compressibility factors
for square well chains are found to be in a good agreement with simulation data. The high accuracy of the present equation
of state is ascribed to the fact that rigorous simulation results for the reference fluid are used, especially at low temperatures
and low densities.
This paper was presented at the 8th APCChE (Asia Pacific Confederation of Chemical Engineering) Congress held at Seoul between
August 16 and 19, 1999. 相似文献
5.
Catechol was found to be a common intermediate in the degradation of benzene and toluene byAlcaligenes xyhsoxidans Y234, and the ring cleavage of the catechol mediated by catechol 1,2-dioxygenase was a rate-determining step. Since benzene
induced higher level of catechol 1,2-dioxygenase than toluene, the cells pre-adapted to benzene showed higher degradation
rate of benzene and toluene. The degradation rate ofm-xylene was also increased significantly when benzene-adapted cells were inoculated.m-Xylene was metabolized via 3-methyl catechol which was effectively cleaved by catechol 1,2-dioxygenase. 相似文献
6.
Modeling of the flow velocity fields for the electrohydrodynamic (EHD) flow in a wire-to-plate type electrostatic precipitator
(ESP) was achieved. Solutions of the steady, two-dimensional Navier-Stokes equations have been computed. The equations were
solved in the conservative finite-difference form on a fine uniform rectilinear grid of sufficient resolution to accurately
capture the momentum boundary layers. The numerical procedure for differential equations was used by SIMPLEST [Michel, 2002],
a derivative of Patankar’s SIMPLE algorithm, to bring rapid convergence. The Phoenics (Version 3.5.1) CFD code, coupled with
Poisson’s and ion transport equations and electric body force in the momentum equation, developed in this study, was used
for the numerical simulation. From calculations for the flow employing different flow models, the Chen-Kimk-ε turbulent model appeared to be the most appropriate choice to obtain a quantitative image of the resulting mean flow field
and downstream wake flow of the rear wire, although this was obtained from a qualitative analysis due to the lack of experimental
verification. The flow velocity field pattern showed a strong EHD secondary flow, which was clearly visible in the downstream
regions of the corona wire despite the low Reynolds number for the electrode (ReCW=12.4). Secondary flow vortices were also caused by the EHD with increases in the discharge current 相似文献
7.
Pasupuleti Lakshmi Narayana Xiao-Song Wang Jong-Taek Yeom Anoop Kumar Maurya Won-Seok Bang Ommi Srikanth Maddika Harinatha Reddy Jae-Keun Hong Nagireddy Gari Subba Reddy 《应用聚合物科学杂志》2021,138(37):50956
In the present work, we developed an artificial neural networks (ANN) model to predict and analyze the polycaprolactone fiber diameter as a function of 3D melt electrospinning process parameters. A total of 35 datasets having various combinations of electrospinning writing process variables (collector speed, tip to nozzle distance, applied pressure, and voltage) and resultant fiber diameter were considered for model development. The designed stand-alone ANN software extracts relationships between the process variables and fiber diameter in a 3D melt electrospinning system. The developed model could predict the fiber diameter with reasonable accuracy for both train (28) and test (7) datasets. The relative index of importance revealed the significance of process variables on the fiber diameter. Virtual melt spinning system with the mean values of the process variables identifies the quantitative relationship between the fiber diameter and process variables. 相似文献
8.
Junyoung Kwon Thomas G. Parton Youngeun Choi Sang-Gil Lee Bruno Frka-Petesic Jaebeom Lee Silvia Vignolini Jihyeon Yeom 《Advanced functional materials》2023,33(29):2300927
High-index dielectric nanostructures offer strong magnetic and electric resonances in the visible range and low optical losses, stimulating research interest in their use for light manipulation technologies. Lithographic fabrication of dielectric nanostructures, while providing precise control over the pattern dimensions, limits the scalability of this approach for practical applications due to an inefficient fabrication process and limited production quantity. Here, the colloidal synthesis of high-index chiral dielectric nanostructures with a broom-like geometry made from trigonal Se is demonstrated. The anisotropic morphology and crystal structure of Se nanobrooms enable both linearly and circularly polarized scattering, as well as spectrum variation along the particle axis, which is, to the authors’ knowledge, the first observation of such behavior from dielectric colloidal nanostructures. To show the versatility of the highly scattering Se NB suspensions, 2D and 3D printing of Se NB inks are demonstrated as a proof of concept. This approach provides a way to manipulate light using aqueous dispersions of high-index dielectric nanostructures, unlocking their potential to fit in various morphologies and dimensions in 2D and 3D for broad applications. 相似文献
9.
A High‐Performance WSe2/h‐BN Photodetector using a Triphenylphosphine (PPh3)‐Based n‐Doping Technique 下载免费PDF全文
10.
Hyunjoo Kim Heon Y. Yeom Sooyong Kang Youjip Won 《Multimedia Tools and Applications》2010,50(2):313-333
In this work, we develop an efficient storage technique to support real-time streaming of layer encoded video in a single
hard disk. The size of a single hard disk drive will soon be able to hold multi-tera bytes and is going to handle relatively
larger number of files. We expect that disk layout in a single disk will be rather critical issue in determining the efficiency
of the storage system. We propose a novel storage technique, Inter-Object Layer Clustering for layer encoded video objects. In Inter-Object Layer Clustering, storage is partitioned into two regions: lower layer partition
and upper layer partition. Lower and upper layer partition harbor the lower layer and upper layer data blocks across all video
objects and cluster them together. We develop an elaborate performance model for this placement scheme. We examine the performance
of the proposed technique using analytical formulation as well as a physical experiment. We found that clustering the layers
across all objects brings 100% increase in the number of concurrent sessions compared to the case where file is stored in
temporal order when the clients’ access bandwidth is narrow. Inter-Object Layer Clustering shows 15% performance improvement
compared to the clustering of layers within the objects. 相似文献