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71.
Second-order optical nonlinearity of a disazo dye attached polymer was investigated. The optical loss of the film is 1.5 dB/cm at 633 nm. The second-order nonlinear coefficient chi /sup (2)/ of the poled film is comparable to that of lithium niobate at 1.55 mu m. The chi /sup (2)/ is greater than that of a monoazo dye attached polymer throughout the fundamental wavelength of 1.06-1.70 mu m.<> 相似文献
72.
Hirofumi Matsuda Makoto Kuwabara Kohichi Hamamoto 《Journal of the American Ceramic Society》1998,81(1):229-232
Thin, semiconducting BaTiO3 ceramic wires prepared in the present study exhibited reversible stress-induced, nonlinear current—;voltage characteristics across several grain boundaries. A remarkable change in resistance with the application (by the three-point bending method) of only ∼1% tensile deformation indicated that the BaTiO3 wires may have potential as stress-sensing devices. Resistance in the BaTiO3 wires bot increased and decreased with increasing tensile stress parallel to the electric fields, far below the ferroelectric transition temperature, T c ; in Sr-substituted wires near T c , on the other hand, resistance only increased. Detailed studies of the patterns and fluctuation of polarization at grain boundaries could be meaningful, because stress-sensing characteristics may be induced by changes in the relative angle between polarization vectors of adjacent grains. 相似文献
73.
Hirofumi Kakemoto Tohru Higuchi Hajime Shibata Satoshi Wada Takaaki Tsurumi 《Journal of Materials Science: Materials in Electronics》2008,19(4):311-314
The modification of thermoelectric figure of merit was estimated from enhanced mobility of [100] oriented beta-FeSi2 film. beta-FeSi2 on Si(001) substrate was prepared by molecular beam epitaxy method using an Fe source. The crystallographic orientation of
beta-FeSi2 film on Si(001) substrate was characterized by using X-ray diffraction. Using scanning electron microscopy, surface morphology
and film thickness of samples were observed and estimated, respectively. The mobility of beta-FeS2 film on Si(001) substrate were also characterized by Hall measurement at room temperature. A part of the enhancement of figure
of merit was evaluated as the functions of mobility and crystallographic orientation of samples. 相似文献
74.
Kuge S. Kato T. Furutani K. Kikuda S. Mitsui K. Hamamoto T. Setogawa J. Hamade K. Komiya Y. Kawasaki S. Kono T. Amano T. Kubo T. Haraguchi M. Nakaoka Y. Akiyama M. Konishi Y. Ozaki H. Yoshihara T. 《Solid-State Circuits, IEEE Journal of》2000,35(11):1680-1689
A 200-MHz double-data-rate synchronous-DRAM (DDR-SDRAM) was developed. The chip contains a delay-locked loop (DLL) which performs over a wide range of operating conditions. Post-mold-tuning allows precise replica programming. A 200-MHz intra-chip data bus is suitable for DDR operation 相似文献
75.
This paper describes a bidirectional isolated DC/DC converter considered as a core circuit for next‐generation 3.3‐kV/6.6‐kV high‐power‐density power conversion systems. The DC/DC converter is intended to use power switching devices based on SiC and/or GaN, which will be available on the market in the near future. A 350‐V, 10‐kW, and 20‐kHz DC/DC converter is designed, constructed, and tested in this paper. It consists of two single‐phase full‐bridge converters with the latest trench‐gate Si‐IGBTs and a 20‐kHz transformer with a nano‐crystalline soft‐magnetic material core and litz wires. The transformer plays an essential role in achieving galvanic isolation between the two full‐bridge converters. The overall efficiency from the DC‐input to DC‐output terminals is accurately measured to be as high as 97%, excluding gate drive circuit and control circuit losses from the whole loss. Moreover, loss analysis is carried out to estimate effectiveness in using SiC‐based power switching devices. The loss analysis clarifies that the use of SiC‐based power devices may bring a significant reduction in conducting and switching losses to the DC/DC converter. As a result, the overall efficiency may reach 99% or higher. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 163(2): 75–83, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20505 相似文献
76.
A new method has been developed to measure the three-dimensional temperature distribution of polymer melts in the reservoir of the heating barrel in the dynamic state. The procedure involves the use of a small-sheathed thermocouple in the nozzle of the machine. The tip of the thermocouple can be varied in depth from the surface to the center of the nozzle. The polymer melt of a shot is found to have a three-dimensional temperature distribution dependent on the geometry of the screw and the order of shot. These results reflect clearly the thermal histories of the polymer melt in the channel of the screw during plastication and conveyance, and indicate part of the dynamics of injection molding. Further, these measurements contribute to optimization of the design for the screw and the process conditions. 相似文献
77.
Takeharu Amano 《The Science of the total environment》2010,408(3):480-1238
We have previously developed a novel photocatalyst, DNA-attached titanium dioxide (DNA-TiO2), useful for the recovery and decomposition of chemicals [Suzuki et al. Environ. Sci. Technol. 42, 8076, 2008]. Chemicals accumulated in DNA near the surface of TiO2 and were degraded under UV light. The efficiency of their removal was dependent on the amount of DNA adsorbed on TiO2, indicating the attachment of larger amounts of DNA to result in higher efficiency. In this study, we succeeded in improving the performance of DNA-TiO2 by increasing the amount of DNA adsorbed by regulating the external pH. The adsorption of DNA by TiO2 dramatically increased at pH2, to about fourfold that at other pH values (pH4-10). Repeating the process of DNA addition increased the adsorption further. The attached DNA was stable on the surface of TiO2 at pH2-10 and 4-56 °C, the same as DNA-TiO2 prepared at pH7. As the DNA-TiO2 prepared at pH2 retained much DNA on its surface, chemicals (methylene blue, ethidium bromide, etc.) which could intercalate or react with DNA were effectively removed from solutions. The photocatalytic degradation was slow at first, but the final degradation rate was higher than for non-adsorbed TiO2 and DNA-TiO2 prepared at pH7. These results indicated that preparation of DNA-TiO2 at pH2 has advantages in that much DNA can be attached and large amounts of chemicals can be concentrated in the DNA, resulting in extensive decomposition under UV light. 相似文献
78.
79.
Carbon doping and etching by CBr4 were studied for GaxIn1−xAsyP1−y (0≤y≤1) on GaAs grown by metalorganic chemical vapor deposition. It was found that the hole concentration drastically decreases
with decreasing y when the flow rate of CBr4 is constant. When y is under 0.5, the conduction type of GaInAsP changes ton-type. In the region of 0<y<0.6, the surface
morphology was degraded and the carrier compensation became higher than could be estimated from the C concentration. This
seems to be due to the micro defects because this range of composition is within the unstable region which is theoretically
predicted. The etching effect by CBr4 was observed during the growth. The rate of etching for InAsP component is about three times larger than that for the GaAsP
component. The thermodynamic analysis suggests that the etching is due to the increase of the partial pressure of GaBr and
InBr. 相似文献
80.