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461.
Yogesh Sharma N. Sharma G. V. Subba Rao B. V. R. Chowdari 《Bulletin of Materials Science》2009,32(3):295-304
Cadmium ferrite, CdFe2O4, is synthesized by urea combustion method followed by calcination at 900°C and characterized by X-ray diffraction (XRD),
scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM) and selected area electron diffraction
(SAED) techniques. The Li-storage and cycling behaviour are examined by galvanostatic cycling, cyclic voltammetry (CV) and
impedance spectroscopy in the voltage range, 0·005–3·0 V vs Li at room temperature. CdFe2O4 shows a first cycle reversible capacity of 870 (± 10) mAhg−1 at 0·07C-rate, but the capacity degrades at 4 mAhg−1 per cycle and retains only 680 (± 10) mAhg−1 after 50 cycles. Heat-treated electrode of CdFe2O4 (300°C; 12 h, Ar) shows a significantly improved cycling performance under the above cycling conditions and a stable capacity
of 810 (± 10) mAhg−1 corresponding to 8·7 moles of Li per mole of CdFe2O4 (vs theoretical, 9·0 moles of Li) is maintained up to 60 cycles, with a coulombic efficiency, 96–98%. Rate capability of
heat-treated CdFe2O4 is also good: reversible capacities of 650 (± 10) and 450 (± 10) mAhg−1 at 0·5 C and 1·4 C (1 C = 840 mAg−1) are observed, respectively. The reasons for the improved cycling performance are discussed. From the CV data in 2–15 cycles,
the average discharge potential is measured to be ∼0·9 V, whereas the charge potential is ∼2·1 V. Based on the galvanostatic
and CV data, ex situ-XRD, -TEM and -SAED studies, a reaction mechanism is proposed. The impedance parameters as a function of voltage during the
1st cycle have been evaluated and interpreted.
Dedicated to Prof. C N R Rao on his 75th birthday, and his contributions to science for the past 56 years 相似文献
462.
Yogesh M. Rane Rajshree C. Mashru Mayur G. Sankalia Vijay B. Sutariya Punit P. Shah 《Drug development and industrial pharmacy》2013,39(9):1008-1023
In the present work effect of chitosan on microcrystal formulation for dissolution enhancement of oxcarbazepine using controlled crystallization technique coupled with spray drying was explored. The work was extended for exploration of simplified approach for stable particle size reduction. The study was performed with an experimental design approach i. e. a fractional factorial design of resolution 5 (with all 2 factor interaction) for the screening of predefined independent variables drug concentration, chitosan concentration, feed rate, inlet temperature and percent aspiration for spray drying. Whereas percent drug dissolved, wettability time, flowability in terms of angle of repose and particle size were designated as response variables. Resultant models were analyzed using multiple linear regression analysis, which generated equation to plot response surface curves along with desirability function. Results showed that chitosan concentration had significant effect on dissolution enhancement of oxcarbazepine at a level of 2% w/v. Increase in drug concentration showed decreased dissolution rate however on particle size it did not show statistically significant effect. Topographical characterization was carried out by SEM which showed that feed rate, percent aspiration and inlet temperature had significant effect on particle morphology. For deriving optimized formulation results were analyzed using desirability function for the maximum percent drug dissolved and least drug polymer matrix particle size. DSC studies showed that drug was molecularly associated with chitosan matrix or particles. 相似文献
463.
J. P. Agrawal D. C. Gupta M. P. Chouk Yogesh Khare 《Propellants, Explosives, Pyrotechnics》1993,18(3):155-160
Liquid rubbers, i.e. polysulphide (PS) and polybutadiene-acrylic acid-acrylonitrile (PBAN) have been blended with Dobeckot E-4 (commercial novolak epoxy resin) in different proportions. These systems have been cured using polyamine/polyamide curing agents and were characterized using gel time, % elongation, tensile strength and bond strength with composite propellants, heat resistance, dioctyl adipate(DOA) absorption, oxygen index, thermal conductivity and brittleness temperature. The data generated for various characteristics indicate that the formulations E-PS-9 and E-PBAN-2 are promising inhibition systems for composite propellants. The inhibition of composite propellants has been done with rayon thread impregnated with the formulations E-PS-9 and E-PBAN-2 using filament winding technique. The successful static evaluation of inhibited composite propellants at ambient, elevated and sub-zero temperatures proves the suitability of these systems for inhibition. 相似文献