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51.
A. Kannammal S. Subha Rani 《International journal of imaging systems and technology》2014,24(1):111-120
In this article, an attempt is made to provide two level securities for medical images using watermarking and encryption. Watermarking provides security and encryption, authenticates medical image and provides integrity. Watermarking is performed by using a new nontensor product wavelet filter banks, which have the ability to reveal singularities in different directions. Natural image is taken as the original image and the medical image is taken as a watermark image. The medical image is embedded into the LH sub band of the natural image. The encryption is performed by RSA, AES, and RC4 algorithms. A qualitative comparative analysis of the proposed algorithm is done for different encryption methods. The proposed algorithm has the ability to withstand different attacks like noise, rotation, contrast, and brightness attacks. Performance analysis is made by calculating PSNR, SSIM, NC, and CV. 相似文献
52.
Hybrid, solid polymer electrolyte films consisting of poly (vinyl chloride) (PVC), poly (acrylonitrile) (PAN) and, propylene carbonate (PC) with different concentrations of LiClO4 are prepared by means of a using solvent-casting technique. The structure and complex formation are studied by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The temperature dependence of the ionic conductivities of the polymer films is explained in terms of a free volume model. The conductivities of PVC–PAN–LiClO4–PC complexes are determined at different salt concentrations. The highest ionic conductivity (8.35 × 10−5 S cm−1) is obtained for 8 wt.% LiClO4 in the polymer complex at 304 K. The thermal stability of the electrolyte is examined by thermogravimetric/differential thermal analysis (TG/DTA). 相似文献
53.
Influence of alkali treatment and fibre length on mechanical properties of short Agave fibre reinforced epoxy composites 总被引:1,自引:0,他引:1
Composites based on short Agave fibres (untreated and alkali treated) reinforced epoxy resin using three different fibre lengths (3 mm, 7 mm and 10 mm length) are prepared by using hand lay up and compression mould technique. The materials were characterized in terms of tensile, compressive, flexural, impact, water absorption properties and machinability behaviour. All mechanical tests showed that alkali treated fibre composites withstand more fracture strain than untreated fibre composites. As evidenced by the dynamic mechanical analysis (DMA) tests, the thermo-mechanical properties of the composite with alkali treated Agave fibre were considerably good as alkali treatment had facilitated more sites of fibre resin interface. The machinability and atomic force microscope (AFM) studies were carried out to analyze the fibre–matrix interaction in untreated and alkali treated Agave fibre–epoxy composites. 相似文献
54.
Ramaswamy BR Kim JW Isobe T Chang KH Amano A Miller TW Siringan FP Tanabe S 《Journal of hazardous materials》2011,192(3):1739-1745
Ultra high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) determination of four paraben preservatives (methyl, ethyl, propyl and butyl) and two antimicrobial agents (triclosan and triclocarban) belonging to personal care products (PCPs) in 20 species of fish from Manila Bay (Philippines) was performed. Detection of PCPs with greater frequency indicates the ubiquitous contamination of Manila Bay. Concentrations of total paraben were one order of magnitude higher than the antimicrobials in almost all fish, except in Stolephorus indicus and Leiognathus equulus. A positive correlation was observed between parabens concentration and fish length (r = 0.31-0.49; p<0.05 to <0.001) and fish weight (r = 0.28-0.49; p<0.05 to <0.001), but not for the antimicrobials. The estimated dietary exposure values of the four parabens in the Philippines through fish is four orders of magnitude lower than the acceptable daily intake (ADI) of 10mg/kg/day, but the values of antimicrobials are just half of the ADI of TCS. To our knowledge, this is the first report of PCPs contamination in fish from Philippines. 相似文献
55.
56.
Crevice corrosion of titanium and its alloys in 10% sodium chloride was investigated at 100°C with the aid of microelectrodes. Potential, pH and chloride ion concentration inside the crevice were monitored using an Ag/AgCl electrode, a tungsten microelectrode and a Ag/AgCl chloride ion selective microelectrode, respectively. The pH and Cl? concentrations within the crevice were calculated from the standard potential‐pH and potential‐log[Cl?] calibration curves. The effect of Mo on the crevice corrosion of titanium was also studied. The passivation behavior on the titanium and Ti‐15%Mo alloy was studied using electrochemical impedance studies. There was no apparent change in pH and Cl? ion activity inside the crevice for the alloy at 100°C, whereas a marginal decrease in pH and increase in Cl? ion concentration were observed for pure titanium. Thus pure titanium is susceptible to crevice corrosion in hot 10% NaCl solutions at 100°C. The chloride ion activity was found to be reduced for the alloy so that the pH inside the crevice increased. The corrosion reaction resistance (Rt) was found to increase with the addition of Mo as an alloying element. It also increases with externally applied anodic potential. Hence, Mo is an effective alloying element, which enhances the crevice corrosion resistance of titanium. 相似文献
57.
C. S. Gopinath M. Rajendran U. V. Varadaraju S. Subramanian 《Journal of Superconductivity and Novel Magnetism》1998,11(1):139-140
Structural and x-ray photoelectron spectroscopy (XPS) studies of the Tl1?xPbxSr1+xLa1?xCuO5?y (0.0≤x≤0.5) system have been carried out. The unit cell parameters increase with x. Irrespective of x the Tc is retained in this series and the optimum hole concentration (nh) is maintained for x≤ 0.5. An increase in Tl 4f and O ls binding energy with x suggests a reduction in their oxidation state. Origin of holes is discussed in terms of charge transfer between Tl, Pb and CuO2 layers. 相似文献
58.
Formation of sulphatoniobates can be considered as resulting from the high temperature acid-base reaction of isopolyniobic acid and sulphur trioxide. The nature of attachment of the SO3 group has been adjudged from the properties of the available atomic orbitals on the oxygen atoms of H8Nb6O19. The hydrolysis of the sulphatoniobates and the nature and properties of the resulting isopolyniobic acid has been explained. The possible way of stabilisation of the sulphatoniobates and their proper nomenclature have been discussed. 相似文献
59.
A new class of compounds, viz., monothiocarbohydrazones, have been found to be hypergolic with anhydrous and red fuming nitric acids. A study of the ignition delays of the various thiocarbohydrazonenitric acid systems as a function of particle size and fuel/oxidizer ratio reveals no significant effect by these parameters. The observed ignition delays have been explained in terms of the chemical reactivity and structure of these compounds. 相似文献
60.
This paper discusses the significance of segmental and prosodic knowledge sources for developing a text-to-speech system for
Indian languages. Acoustic parameters such as linear prediction coefficients, formants, pitch and gain are prestored for the
basic speech sound units corresponding to the orthographic characters of Hindi. The parameters are concatenated based on the
input text. These parameters are modified by stored knowledge sources corresponding to coarticulation, duration and intonation.
The coarticulation rules specify the pattern of joining the basic units. The duration rules modify the inherent duration of
the basic units based on the linguistic context in which the units occur. The intonation rules specify the overall pitch contour
for the utterance (declination or rising contour), fall-rise patterns, resetting phenomena and inherent fundamental frequency
of vowels. Appropriate pauses between syntactic units are specified to enhance intelligibility and naturalness. 相似文献