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41.
The problem of extraction of medial axis transformation of a gray image with reference to skeletonization, image representation
and uncertainty management in a vision system has been addressed. The Fuzzy Medial Axis Transformation (fmat) of a fuzzy setf is a set of fuzzy disks whose sup isf. Unfortunately, specifying thefmat sometimes requires more storage space than specifyingf itself. The present paper describes some techniques to improve the compact representation offmat; thereby making it practically useful to an image for its skeleton extraction and compact representation, for shape analysis
and template matching, for representation and retrieval, for uncertainty management in recognition and for creating new images
of various poses. The algorithms involve reduction of redundancy infmat, its approximation, and reduction of the searching spaces for its computation. Computational aspects for the convenience
of writing an efficient program have been described. Some applications of thefmat have also been mentioned.
This work was done while SKP held annrc-nasa Senior Research Associateship at the Lyndon B Johnson Space Center, Houston, Texas. 相似文献
42.
43.
Wave propagation in a thinly two layered laminated medium with stress couples under initial stresses
P. Pal Roy 《Acta Mechanica》1984,54(1-2):1-21
Summary The present paper is an attempt to provide an approximate treatment based on Biots theory of incremental deformation to study the wave propagation in two thinly layered laminated medium under initial stresses. The cross-sectional distortion which plays an important role in the coupling of adherent layers is taken into account. The theory is derived in the context of plane strain deformation and the frequency equation for phase velocity of waves propagated has been obtained. It has been shown that under certain conditions when wave length becomes small compared to thickness of each layer, the wave approaches to Rayleigh waves at the two outer surfaces with the possibility of Stoneley waves at the interface.
Notation and Nomenclature
For Medium—I M i, Li elastic coefficients - C i bending moment - h i thickness - P i initial stress - i fraction of the total thickness occupied by theith layer - b i couple-stress coefficient For the equivalent anisotropic continuum H total thickness - M, L elastic coefficients - P average initial stress - s 11 (1) ,s 22,s 12 (1) incremental stress components - u 1,v 1 displacement components alongx, y directions respectively - 1 density - e xx,e yy,e xy (1) strain components with respect to rotated axes - w 1 rotational component aboutz-axis - f 1 x, f 1 y components of incremental boundary forces per unit initial area For Medium-II N j,Q j elastic coefficients - D j bending moment - K j thickness - R j initial stress - j fraction of the total thickness occupied by thejth layer - g j couple-stress coefficients For the equivalent anisotropic continuum K total thickness - N, Q elastic coefficients - R average initial stress - s 11 (2) ,s 22,s 12 (2) incremental stress components - u 2,v 2 displacement components alongx, y directions respectively - 2 density - e xx, eyy,e xy (2) strain components with respect to rotated axes - w 2 rotational component aboutz-axis - f 2 x, f 2 y components of incremental boundary forces per unit initial area With 5 Figures 相似文献44.
Our study illustrates the development of a microfluidics (MF) platform combining fluorescence microscopy and femtosecond/picosecond-resolved spectroscopy to investigate ultrafast chemical processes in liquid-phase diffusion-controlled reactions. By controlling the flow rates of two reactants in a specially designed MF chip, sub-100 ns time resolution for the exploration of chemical intermediates of the reaction in the MF channel has been achieved. Our system clearly rules out the possibility of formation of any intermediate reaction product in a so-called fast ionic reaction between sodium hydroxide and phenolphthalein, and reveals a microsecond time scale associated with the formation of the reaction product. We have also used the developed system for the investigation of intermediate states in the molecular recognition of various macromolecular self-assemblies (micelles) and genomic DNA by small organic ligands (Hoechst 33258 and ethidium bromide). We propose our MF-based system to be an alternative to the existing millisecond-resolved "stopped-flow" technique for a broad range of time-resolved (sub-100 ns to minutes) experiments on complex chemical∕biological systems. 相似文献
45.
Tarasankar Pal 《Materials and Manufacturing Processes》2006,21(3):315-317
Cetylpyridinium chloride (CPC)-stabilized gold organosol in toluene has been prepared by using a two-phase (water-toluene) extraction of AuCl4- followed by its reduction with sodium borohydride in the presence of the surfactant, CPC. The surfactant-stabilized gold nanoparticles were exploited to examine their optical properties when exposed to various solvent systems by measuring the changes in the localized surface plasmon resonance (LSPR) spectrum. 相似文献
46.
Group III-V compound B-Sb films were synthesized from B/Sb/…/B multilayer films deposited by electron gun evaporation onto
silicon substrate and subjecting the above multilayer to rapid thermal annealing at 773 K for 3 min. The films were characterized
by XRD, TEM, XPS and optical studies. XPS studies indicated the ratio of B: Sb ∼ 1. XRD and electron diffraction patterns
indicated the reflections from (100), (111), (102) and (112) planes of zinc blende BSb. Band gap evaluated from optical studies
was ∼ 0·51 eV. Refractive index of the films varied between 1·65 and 2·18 with increasing energy of incident photon and plasma
frequency (ωp) was estimated to be ∼2·378×10−14 s−1. The effective mass was computed to be ∼ 0·0845 me. 相似文献
47.
Robert Rieger Martin Schuettler Dipankar Pal Chris Clarke Peter Langlois John Taylor Nick Donaldson 《IEEE transactions on neural systems and rehabilitation engineering》2006,14(4):427-437
In this paper, we describe the design and testing of a system for recording electroneurographic signals (ENG) from a multielectrode nerve cuff (MEC). This device, which is an extension of the conventional nerve signal recording cuff, enables ENG to be classified by action potential velocity. In addition to electrical measurements, we provide preliminary in vitro data obtained from frogs that demonstrate the validity of the technique for the first time. Since typical ENG signals are extremely small, on the order of 1 1 microV, very low-noise, high-gain amplifiers are required. The ten-channel system we describe was realized in a 0.8 microm CMOS technology and detailed measured results are presented. The overall gain is 10 000 and the total input-referred root mean square (rms) noise in a bandwidth 1 Hz-5 kHZ is 291 nV. The active area is 12 mm(2) and the power consumption is 24 mW from +/-2.5 V power supplies. 相似文献
48.
Correlation between ionic conductivity and fluidity of polymer gel electrolytes containing NH4CF3SO3
Nonaqueous polymer gel electrolytes containing ammonium triflate (NH4CF3SO3) and dimethylacetamide (DMA) with polymethylmethacrylate (PMMA) as the gelling polymer have been synthesized which show high
value of conductivity (~ 10-2 S/cm) at 25°C. The conductivity of polymer gel electrolytes containing different concentrations of NH4CF3SO3 shows a small decrease with the addition of PMMA and this has been correlated with the variation of fluidity of these gel
electrolytes. The small decrease in conductivity with PMMA addition shows that polymer plays the role of stiffener and this
is supported by FTIR results which also indicates the absence of any active interaction between polymer and NH4CF3SO3 in these gel electrolytes. 相似文献
49.
A methodology is described for evolving a Rough-fuzzy multi layer perceptron with modular concept using a genetic algorithm to obtain a structured network suitable for both classification and rule extraction. The modular concept, based on "divide and conquer" strategy, provides accelerated training and a compact network suitable for generating a minimum number of rules with high certainty values. The concept of variable mutation operator is introduced for preserving the localized structure of the constituting knowledge-based subnetworks, while they are integrated and evolved. Rough set dependency rules are generated directly from the real valued attribute table containing fuzzy membership values. Two new indices viz., "certainty" and "confusion" in a decision are defined for evaluating quantitatively the quality of rules. The effectiveness of the model and the rule extraction algorithm is extensively demonstrated through experiments alongwith comparisons. 相似文献
50.
Incorporating Ancestors' Influence in Genetic Algorithms 总被引:1,自引:1,他引:1
A new criterion of fitness evaluation for Genetic Algorithms is introduced where the fitness value of an individual is determined by considering its own fitness as well as those of its ancestors. Some guidelines for selecting the weighting coefficients for quantifying the importance to be given to the fitness of the individual and its ancestors are provided. This is done both heuristically and automatically under fixed and adaptive frameworks. The Schema Theorem corresponding to the proposed concept is derived. The effectiveness of this new methodology is demonstrated extensively on the problems of optimizing complex functions including a noisy one and selecting optimal neural network parameters. 相似文献