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81.
82.
Toshikazu Ekino Takashi Doukan Hironobu Fujii 《Journal of Low Temperature Physics》1996,105(3-4):563-568
We report tunneling measurements of the electron-doped superconductor Nd1.85Ce0.15Cu04–gd using break junctions. The observed finest gap structure is well expressed by the BCS density of states with the energy gap of = 6.1 meV and a very small broadening parameter, having the ratio 2/kBTc = 8.2 with Tc = 17.3 K. These features are similar to our tunneling results for the hole-doped cuprate superconductors. Therefore we find no essential difference in the gap structure, in spite of a common believing of the pairingsymmetry difference between them. 相似文献
83.
Kiyohiko Itokawa Naoki Kita Akio Sato Hideaki Matsue Daisuke Mori Hironobu Watanabe 《Electrical Engineering in Japan》2005,152(3):55-64
5‐GHz‐band wireless access systems, such as the RLAN (Radio Local Area Network) system of IEEE 802.11a, HiperLAN/2, HiSWANa, and AWA, are deployed for indoor use at transmission rates over 20 Mbps. These 5‐GHz access systems are expected to extend service areas from the office to the so‐called “hot spots” in public areas. Underground shopping malls are one type of service area where the application of such nomadic wireless access service can be expected. In order to design radio zone configurations, it is necessary to know broadband propagation characteristics of an underground mall environment even if results obtained by previous measurements in the narrow band are available. This paper presents results of an experimental study on the propagation characteristics for broadband wireless access systems in an underground mall environment. First, broadband propagation path losses are measured and formulated considering the shadowing by human body. A ray trace simulation is used to clarify the basic propagation mechanism in such a closed environment. Next, it was determined that values of the delay spread at different distances during rush hour periods did not exceed 65 ns, which is lower than the permitted maximum value of the present 5‐GHz systems. The final conclusion is that the above propagation characteristics corroborate results of transmission tests carried out by using the AWA equipment. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 152(3): 55–64, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20059 相似文献
84.
Mahmood Riyaz Kyung-Ho Park Mohamed Ali Hironobu Kan 《Bulletin of Engineering Geology and the Environment》2010,69(3):443-454
This paper discusses the influence of the geological setting of islands and reefs in the Maldives on the impact of the 26
December 2004 Indian Ocean Tsunami. Geological and geomorphological data (including orientation, location, size, ellipticity,
reef-island distance, proportion of reef area to island area) were collected for completely flooded and <25% flooded islands.
The results show that although the different parameters may interact to reduce or magnify the impact, the reef-island distance
is the most important factor. The critical minimum distance between the reef and the island shoreline required for the wave
to set up is estimated as 89 m on the eastern and 140 m on the western sides of the island, respectively. Circular islands
with short reef-island distance and small percent of reef area seem to be safer in the context of tsunami. The result of this
study can be applied to identify islands that are naturally protected/resilient against natural disasters such as tsunami
and those where the hazard is greatest. 相似文献
85.
In the present paper, an improved method has been proposed to produce a probability table needed for the resonance self-shielding calculations with the sub-group method. The proposed method is based on a relation between the effective cross section and the cross section moment, which is obtained from a numerical analysis. Using the proposed method, more accurate probability tables can be obtained with less number of the tabulated steps than the conventional method. This enables us to reduce computation time and computer memory storage for the sub-group calculations. 相似文献
86.
Hironobu Umemoto Takashi Morimoto Moroyuki Yamawaki Yoshie Masuda Atsushi Masuda Hideki Matsumura 《Thin solid films》2003,430(1-2):24-27
Laser spectroscopic as well as mass-spectrometric techniques were employed to examine the deposition chemistry in the catalytic chemical vapor deposition processes of the SiH4/NH3 system. The absolute densities of NH, NH2 and SiH3 radicals were measured under various conditions. The densities of the stable products, H2 and N2, as well as those of the reactants, NH3 and SiH4, were also measured. The NH2 density is always higher than that of NH and both densities decrease by the addition of SiH4. The SiH3 density increases nonlinearly with the increase in the SiH4 pressure. The SiH3 density was found to be much higher than that of NH2 under near practical deposition conditions to fabricate Si3N4 films (an NH3 to SiH4 flow-rate ratio of 50:1, a total pressure of 20 Pa and a catalyzer temperature of 2300 K). No aminosilane molecules were identified, suggesting that the contribution of aminosilyl radicals to the film deposition is minor. Thus, NH2 and SiH3 must be the major deposition species to form Si3N4. 相似文献
87.
Ignition and flame propagation characteristics of 18 kinds of coal and a petroleum coke were investigated through a laser ignition experiment. Flame stability was strongly influenced by amount of volatile matter and pyrolysis rate. Lean limit of flame propagation was strongly influenced by amount of volatile matter. Flame propagation was observed when pyrolized volatile matter was mixed with surrounding air or oxygen, until the concentration of pyrolized volatile matter reached a constant value. Flame propagation velocity was strongly influenced by pyrolysis rate. As the pyrolysis rate increased, the flame propagation velocity increased. The flame propagation velocity of petroleum coke was higher than that of coal with the same volatile content. The flame propagation of petroleum coke was superior to what was expected based on the volatile content, primarily because the high pyrolysis rate caused a shorter ignition delay than what would be expected given the volatile content. A database for the lean limit of flame propagation was used to develop a flame stability model to estimate lean flammability of a large-scale burner. The model could predict the effect of the coal rank, the particle diameter distribution for lean flammability limit. The estimated lean flammability limit of petroleum coke (volatile content 11.5%) was equal to that of lv bituminous coal with volatile content of about 15%. 相似文献
88.
用准急压冷法制成Fe_2O_3-SrO-TeO_2系半导体玻璃并对其直流电导率进行了测定。玻璃形成范围为(以摩尔计);0≤Fe_2O_3≤23%;0≤SrO≤18%;75%≤TeO_2<100%。通过Seebeck系数的测定确认Fe_2O_3-SrO-TeO_2系玻璃为n型半导体玻璃。200℃的直流电导率为3.72×10 ̄(-5)~1.82×10 ̄(-6)S·cm ̄(-1)。直流电导率随着Fe_2O_3含量的增加而增加,165℃时的载流子迁移率和浓度分别为1.12×10 ̄(-9)~3.67×10 ̄-7cm ̄2·V ̄(-1)·S ̄(-1)和2.17×10 ̄(21)~8.33×10 ̄19cm ̄(-3).讨论的结果表明Fe_2O_3-SrO-TeO_2系玻璃的电导机理符合小极化子跳越理论。 相似文献
89.
Tessui Nakagawa Takayuki Ichikawa Ryo Iida Haiyan Leng Nobuhiko Takeichi Tetsu Kiyobayashi Hiroyuki Takeshita Hironobu Fujii 《Journal of Alloys and Compounds》2007,430(1-2):217-221
The in-situ XRD measurements on dehydrogenation/rehydrogenation of the Li–Mg–N–H system were performed in this work. The ballmilled mixture of 8LiH and 3Mg(NH2)2 as a hydrogenated phase gradually changed into Li2NH as a dehydrogenated phase during heat-treatment at 200 °C in vacuum for 50 h. Neither Mg-related phases nor other intermediate phases were recognized in the dehydrogenated phase. With respect to the hydrogenation process, the dehydrogenated state gradually returned to the mixed phase of the LiH and Mg(NH2)2 without appearance of any intermediate phases during heat treatment at 200 °C under 5 MPa H2 for 37 h and during slow cooling down to room temperature through 24 h. In the hydrogenation process at 200 °C under 1 MPa H2, however, the growing up of the LiNH2 and LiH phase was observed in the XRD profiles before the 3Mg(NH2)2 and 8LiH phases were formed as the final hydrogenated state. This indicates that the LiNH2 and LiH phase essentially appears as an intermediate state in the Li–Mg–N–H system composed of 3Mg(NH2)2 and 8LiH. 相似文献
90.
Hironobu Tan Masanori Bun-Ya Aiko Hirata Tatsuyuki Kamiryo 《Yeast (Chichester, England)》1994,10(8):1065-1074
PXP-18 is a 14-kDa major peroxisomal protein of the yeast Candida tropicalis and a homologue of the non-specific lipid-transfer protein (nsLTP) of mammals. Mammalian nsLTP is thought to facilitate the contact of membranes, to stimulate lipid-transfer between them. If PXP-18 functions like nsLTP, it must be present on organelle membranes. Immunoelectron microscopy of C. tropicalis cells indicated that gold particles, which visualized PXP-18, localized exclusively in the matrix of peroxisomes. Subcellular fractionation followed by Western blotting revealed the association of PXP-18 with peroxisomes in C. tropicalis cells. An enzyme-linked immunosorbent assay revealed that almost all the PXP-18 associated with peroxisomes was detectable after the solubilization of the organelle but not before, implying the predominance of PXP-18 inside peroxisomes. This differential assay was applied to the intracellular import of the intact and truncated PXP-18s expressed in Saccharomyces cerevisiae cells. Most of the intact PXP-18 was shown to be imported into the matrix of host-cell peroxisomes, whereas the truncated PXP-18, which lacked the C-terminal tripeptide Pro-Lys-Leu, no longer targeted peroxisomes. These results are consistent with the view that PXP-18 is the matrix protein of peroxisomes and must function in a system other than that of lipid transfer. 相似文献