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71.
Yoshiyuki Tomita 《Journal of Materials Science》1989,24(4):1357-1362
The modified heat treatment, which produces a mixed structure of martensite and lower bainite through short-term isothermal
transformation at just above the martensitic transformation temperature,M
s
temperature, followed by oil quenching (after conventional austenitization), has been applied to three high-carbon low-alloy
steels with different levels of nickel and chromium contents at similar molybdenum levels, in which carbon was allowed to
replace relatively expensive additions of nickel and chromium, for their ultra-high strength application. The significant
conclusions are as follows: an ultra-high strength steel of 1900 M Pa yieldstress grade with a high toughness level can be
obtained when about 60 vol % lower bainite is associated with 473 K tempered martensite of 0.60% C-1.80% Ni-0.80% Cr-0.25%
Mo steel. If approximately 25 vol % lower bainite appears in 673 K tempered martensite of the steel, a 1700 M Pa yield-stress
grade steel with high toughness and moderate ductility levels can be attained. However, alloying nickel is essential to some
extent for development of the mechanical properties with the modified heat treatment suggested in the present work. 相似文献
72.
Hayato Takasago Eishi Gofuku Mitsuyuki Takada Yoshiyuki Morihiro 《Journal of Electronic Materials》1989,18(5):651-655
When electric resistivity of Thick Film Resistor (TFR) is adjusted to the desired value, laser beam is irradiated onto the
resistor material so that a part of the resistor material is instantaneously vaporized and cut away. This conventional laser
trimming method to adjust the resistivity of TFRs is an indispensable technique for manufacturing elec-tronic devices such
as hybrid ICs. A peculiar phenomena was revealed by us, that is, when specially selected pulse laser beams were irradiated
to TFR, the TFR was surface modified without cutting grooves, and then resistivity of the TFR was decreased. We completed
the advanced laser process to apply this peculiar phenomena. 8 By comparing with conventional trimming processes, we can show
prominent features of the advanced process, for example, resistivity of fine size TFR (300 micrometers-width and under) can
be easily controlled. The decrease in resistivity of the TFR is considered to result from the decrease in specific resistivity
of glass in the TFR. Because it is considered that the glass in the TFR is heavily doped with ruthenium impurities during
the surface modification due to results of morphology observations and x-ray diffraction analysis. We have applied this advanced
laser process to fine size TFR (300 micrometers-width), and developed high density hybrid ICs. 相似文献
73.
74.
Jun Kawaji Shuichi Suzuki Yoshiyuki Takamori Makoto Morishima 《Electrochimica acta》2010,55(27):8018-8022
To improve methanol-oxidation performances of membrane-electrode assemblies composed of a hydrocarbon-based ionomers, the resistances involved in the reaction were decreased. Electrochemical impedance spectroscopy revealed that the proton-conductive resistance (Ri) in the anode was decreased from 0.54 to 0.40 Ω cm2 by increasing a loading ratio of platinum-ruthenium to carbon support of anode catalyst from 54 to 73 wt.%. In addition, Ri was decreased to be 0.25 Ω cm2 by increasing ion-exchange capacity (IEC) of the ionomer from 1.4 to 2.9 mequiv. g−1. Consequently, the polarization resistance of the anode was significantly decreased, in turn, increasing current density of methanol oxidation at the potential of 0.45 V from 0.110 to 0.244 A cm−2. 相似文献
75.
Fatigue tests were conducted for 1800 MPa-class spring steels at various stress ratios. For comparison, similar fatigue tests were conducted for conventional steels whose tensile strength was lower than 1200 MPa. The spring steels exhibited fish-eye fractures, and the origins of these fractures were oxide, TiN and the matrix itself. In contrast, the conventional steels never exhibited fish-eye fractures. The fatigue strength of these steels decreased monotonously as the stress ratio increased, when the fatigue strength was evaluated in terms of stress amplitude. However, the fatigue strength degradation was less than that expected from a modified-Goodman line, and the best fit line was obtained by connecting the fatigue limit at zero mean stress to true fracture strength instead of tensile strength. This research also reviewed application of a power low to the stress ratio effect evaluation. In these results, the difference between the spring and conventional steels was negligible. 相似文献
76.
Speed-up of computing time for numerical analysis of particle charging process by using discrete element method 总被引:1,自引:0,他引:1
Hiroshi Mio Masatoshi Akashi Yoshiyuki Shirakawa Shinroku Matsuzaki 《Chemical engineering science》2009,64(5):1019-1026
The objective of this paper is to improve the computing time for numerical analysis of particle charging process by using discrete element method. The rule for ignoring the calculations of contact forces and updating trajectories of unmoved particles were discussed. When the relative displacement of a particle within certain calculation steps became less than 0.1% of particle radius, this particle was determined to be unmoved and the calculations of this particle were ignored. The computing time was improved significantly when this new method was used, and its calculation speed was more than two times faster than that of original. It was found that this speed-up method is more useful for the cases that the particle becomes unmoved in short time or the height of charged bed is large. The simulation of charging process in an industrial-scale surge hopper was studied by using new method, the calculation speed became 2.88 times faster than that of original, and the quite similar particle size segregation between original and new methods was given. This new method for speed-up of the charging process in DEM is very useful, and the charging processes of the industrial scale storages can be simulated by using this method. 相似文献
77.
Masayoshi Iwahara Toshiatsu Tanaka Yoshiyuki Nomura 《Journal of the Institute of Brewing》2001,107(6):345-348
The effects of edible fruiting of Basidiomycetes on growth of Saccharomyces cerevisiae and other yeast strains were examined. The growth rates were significantly increased in the presence of fruiting bodies but there was no significant difference growth yield between cultures with and without fruiting bodies. Growth rates of yeast cells were promoted in both synthetic and natural media. 相似文献
78.
Takaya Yamamoto Tomihiro Takano Yoshiyuki Takuma Makoto Inoue Gen Arao 《Electrical Engineering in Japan》2010,170(3):19-27
Dispersed generators such as wind power systems, photovoltaic systems, and cogeneration systems are expected to mitigate the environmental burden of energy consumption, and their installation has been promoted recently. Micro‐Grid is focused on as a method to solve some problems in a commercial electric power line when installing a large number of dispersed generators, and some demonstrative research on Micro‐Grid for large‐scale systems is being carried out now. Also, small cogeneration systems for houses, such as gas engines and fuel cells, are expected to improve CO2 emissions. However, if the power and heat demand of a family are relatively small or are unbalanced, the cogeneration system does not operate effectively. The authors have studied the application of Micro‐Grid for home energy supply, and have developed a control system to solve this problem. The system achieves a reduction of CO2 emissions and energy costs by sharing electric power and heat among some houses with cogeneration systems. This paper presents an outline of the newly developed system, and in particular describes the effect of the reduction in CO2 emissions compared with a conventional energy supply method, and the case in which dispersed generators are installed in some houses and operate independently. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 170(3): 19–27, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20879 相似文献
79.
Yoshiyuki Sakamoto Hitoshi Kumagai Shinichi Matsunaga 《Journal of Applied Electrochemistry》2013,43(9):967-973
A novel electrochemical ionic liquid membrane reactor capable of separating NO from a mixture of NO and oxygen with high current efficiency at low temperatures was designed and tested. This reactor consists of a combination of an ionic liquid and a thin film of anodised alumina with two platinum electrodes. During operation of the reactor, NO is electrically transported from the cathode side to the anode side. 相似文献
80.