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931.
932.
H. Kaneko Y. Fujino S. Yamaguchi K. Asami K. Hashimoto M. Hirabayashi 《Corrosion Science》1983,23(11):1207-1217
The Rutherford backscattering with 2 MeV He+ and the 16O(d,p)17O1 nuclear reaction with 1.8 MeV D2+ were utilized to determine the concentration profiles of iron, molybdenum and oxygen in the surfaces of an amorphous Fe12Mo18C alloy polarized in 1 N HCl at potentials from ? 0.17 to 1.6 V(SCE). The thickness of the surface film was estimated as 20–200 nm. In the primary active region, selective dissolution of iron and carbon causes enrichment of molybdenum ions in the corrosion product film and of metallic molybdenum in the topmost part of the underlying alloy. A further potential increase led to a decrease in the molybdenum content in the film by transpassive dissolution. Molybdenum ions were not concentrated in the film formed in the stable passive region of 0.5–1.5 V(SCE). The high passivating ability of the amorphous alloy even in the aggressive HCl was ascribed to the homogeneity of the alloy structure as well as to the effect of molybdenum. 相似文献
933.
934.
To prepare high-modulus and high-strength PET fiber, a new method using zone drawing and zone annealing has been studied. The apparatus used for this method is the usual tensile tester equipped with a band heater 2 mm wide and a sample holder which can apply a high tension to the fiber. The experimental procedure consists of two stages: zone drawing and zone annealing. The zone drawing was done on the original as-spun fiber in order to produce a fiber with as high an orientation and as low a crystallinity as possible. The zone-drawn fiber was subsequently zone annealed under high tension by moving the band heater from one end to the other of the fiber at a temperature above the crystallization temperature at a considerably low moving speed. In spite of the simple apparatus and procedure, Young's modulus of the fiber obtained was 19.4 × 1010 dyn/cm2, which is comparable to the maximum value of the high-tenacity PET filament commercially available. In order to elucidate the change in the superstructure with zone drawing or zone annealing, optical, x-ray, IR, DSC, and dynamic mechanical measurements were performed. It is suggested that the zone-annealed fiber consists of almost perfectly oriented crystallites and fully extended amorphous chains. 相似文献
935.
936.
Ternary compound Ti3SiC2 was rapidly synthesized by pulse discharge sintering the powder mixture of 1TiH2/1Si/1.8TiC without preliminary dehydrogenation. Almost single-phase dense Ti3SiC2 was synthesized at 1400 °C for 20 min. The grain size of synthesized Ti3SiC2 strongly depends on sintering temperature. The synthesis mechanism of Ti3SiC2 was revealed to be completed via the reactions among the intermediate phases of Ti5Si3, TiSi2 and the other reactants in the starting powder. The Ti-Si liquid reaction occurring above the Ti-Ti5Si3 eutectic temperature at 1330 °C was found to assist the synthesis reaction and densification of Ti3SiC2. The dehydrogenation of TiH2 was accelerated by the synthesis reactions. 相似文献
937.
Tetsushi Fujinaga Makiko Takagi Masanori Hashimoto Shin Asari Kazuya Saito 《Thin solid films》2008,516(5):615-617
This study is aimed at improving the characteristics of silicon nitride (SiNx) film deposited by catalytic chemical vapor deposition (Cat-CVD) method. Cat-CVD method can deposit SiNx films that have low hydrogen content and high density at low temperature without any plasma damage to substrates. Usually silane (SiH4) and ammonia (NH3) are used for source gases. Then adding hydrogen (H2) gas to source gases makes characteristics of Cat-CVD SiNx improved. When using H2 gas, hydrogen content in SiNx film becomes lower and electronic reliability becomes higher. 相似文献
938.
A study on flammability limits of fuel mixtures 总被引:1,自引:0,他引:1
Kondo S Takizawa K Takahashi A Tokuhashi K Sekiya A 《Journal of hazardous materials》2008,155(3):440-448
Flammability limit measurements were made for various binary and ternary mixtures prepared from nine different compounds. The compounds treated are methane, propane, ethylene, propylene, methyl ether, methyl formate, 1,1-difluoroethane, ammonia, and carbon monoxide. The observed values of lower flammability limits of mixtures were found to be in good agreement to the calculated values by Le Chatelier's formula. As for the upper limits, however, some are close to the calculated values but some are not. It has been found that the deviations of the observed values of upper flammability limits from the calculated ones are mostly to lower concentrations. Modification of Le Chatelier's formula was made to better fit to the observed values of upper flammability limits. This procedure reduced the average difference between the observed and calculated values of upper flammability limits to one-third of the initial value. 相似文献
939.
I Nyoman Suprapta Winaya Tadaaki Shimizu Yousuke Nonaka Kazuaki Yamagiwa 《Fuel》2008,87(10-11):1974-1981
Porous bed materials capture volatile matter as carbon deposits during fluidized bed combustion of high-volatile fuels such as biomass and wastes. Carbon deposits burn in a dense bed mixed with bed materials; thereby enhancing horizontal dispersion of carbonaceous materials. Commercial scaling-up requires a model that simultaneously assesses carbon deposit combustion and horizontal solid dispersion. This study measured the carbon deposit combustion rate using a fluidized bed. A one-dimensional model of carbon deposit combustion in a fluidized bed is based on the carbon deposit burning rate. A two-dimensional model incorporates reactions and solid dispersion to predict the horizontal concentration profile. Experiments using a bubbling fluidized bed validated that model. 相似文献
940.
Masaki Harada Kouji Iida Kazuaki Okamoto Hideki Hayashi Koji Hirano 《Polymer Engineering and Science》2008,48(7):1359-1368
Poly(lactic acid) (PLA) blended with poly(ε‐caprolactone) (PCL) was prepared with various reactive processing agents. Four isocyanates‐lysine triisocyanate (LTI); lysine diisocyanate (LDI); 1,3,5‐tris(6‐isocyanatohexyl)‐1,3,5‐triazinane‐2,4,6‐trione (Duranate TPA‐100); 1,3,5‐tris(6‐isocyanatohexyl)biuret (Duranate 24A‐100)‐and an industrial epoxide‐trimethylolpropane triglycidyl ether (Epiclon 725)‐were used as reactive processing agents. PLA/PCL blended in the presence of LTI had the highest torque in a mixer test. The test specimens were prepared by injection molding. The mechanical properties, thermal properties, molecular weight, melt viscosity, phase behavior, and morphology were investigated using tensile strength, impact strength, differential scanning calorimetry, melt mass‐flow rate measurements, capillary rheometery, gel permeation chromatography, laser scanning confocal microscopy (LSCM), and visco‐elasticity atomic force microscopy (VE‐AFM). The impact strength increased considerably at 20 wt% PCL. The nominal tensile strain of PLA/PCL blended with LTI increased by 270%. The MFR values of PLA/PCL blends decreased with increasing LTI. Similar results were observed for shear viscosity. LSCM measurements showed that the diameters of PCL were dispersed about 0.4 μm in the presence of LTI. VE‐AFM showed that spherical particles with diameters of 50 nm were PCL‐rich domain. These results indicate that isocyanate groups of LTI react with both terminal hydroxyl or carboxyl groups of polymers, and the compatibility of PLA/PCL blends improves with LTI by reactive processing. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers 相似文献