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81.
Ying-Chung Chen Kwok-Keung Chong Teen-Hang Meen Long Wu Mau-Phon Houng 《Journal of the American Ceramic Society》1991,74(7):1710-1714
The effect of humidity on the bismuth superconductor is investigated under 90% humidity at 30°C for 250 h. Nearly none of the peaks of high- T c phase (2223) can be observed in the X-ray pattern after the test. The silver contact resistance of the sample also increases prominently in the time interval from 60 h to 100 h. When the humidity-tested sample is heated again under sintering conditions (845°C for 50 h in air), the high- T c phase appears again. 相似文献
82.
C.H. Huang N.F. Wang Y.Z. Tsai C.C. Liu C.I. Hung M.P. Houng 《Materials Chemistry and Physics》2008,110(2-3):299-302
The characterizations of SiOCH films using oxygen plasma treatment depends linearly on the O2/CO flow rate ratio. According to the results of Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses, it was found that the carbon composition decreases with increasing O2/CO flow rate ratio, because more carbon in the Si–O–C and Si–CH3 bonds on the film surface would be converted by oxygen radicals. It was believed that the oxygen plasma could oxidize the SiOCH films and form a SiOx interfacial capping layer without much porosity. Moreover, the result of FTIR analysis revealed that there was no water absorbed on the film. A SiO2-like capping layer formed at the SiOCH film by the O2/CO flow rate ratio of 0.75 had nearly the same dielectric properties from the result of capacitance–voltage (C–V) measurement in our research. 相似文献
83.
本文根据应用较广的胶结锚杆的变形特性和荷载形式,考虑到胶结锚杆杆体、胶结层和岩体的不同物理力学性质,建立了一种新的模拟单元,它包括模拟胶结锚杆的胶结层、锚头部位的胶结层、杆体以及对岩体不连续面的锚钉效应的六节点等参数胶结单元、五节点等参数胶结单元、三节点等参数的杆体单元和二节点锚钉单元。 相似文献
84.
Ceramic/ceramic composites in the Ti-B-C system were fabricated by a novel process referred to as transient plastic phase processing (TPPP). The basic concept is based on the following reaction:
where the transient plastic phase is a phase with a wide range of stoichiometry and a yield point that is a strong function of that stoichiometry. The reactant phase is one that will react with the transient phase in such a way so as to shift the composition of the latter toward its harder and more refractory composition. The composite is formed in two stages: In the first, pressure is applied to shape and fully densify the reactants while the transient phase is soft, i.e., before reaction. Once the reactants are densified, the reaction is allowed to proceed, forming a new phase and rendering the matrix more refractory. If the volume change upon reaction is small, then the density of the final compact will remain near theoretical. Using this approach ceramic/ceramic composites in the Ti─B─C system were hotpressed to full density and complex shapes at temperatures as low as 1600°C. 相似文献
"soft" transient plastic matrix
+ reactant phase → hard matrix
+ reinforcement phase
where the transient plastic phase is a phase with a wide range of stoichiometry and a yield point that is a strong function of that stoichiometry. The reactant phase is one that will react with the transient phase in such a way so as to shift the composition of the latter toward its harder and more refractory composition. The composite is formed in two stages: In the first, pressure is applied to shape and fully densify the reactants while the transient phase is soft, i.e., before reaction. Once the reactants are densified, the reaction is allowed to proceed, forming a new phase and rendering the matrix more refractory. If the volume change upon reaction is small, then the density of the final compact will remain near theoretical. Using this approach ceramic/ceramic composites in the Ti─B─C system were hotpressed to full density and complex shapes at temperatures as low as 1600°C. 相似文献
85.
Molybdenum doped TiO2 (MTO) thin films were prepared by radio frequency (RF) magnetron sputtering at room temperature and followed by a heat treatment in a reductive atmosphere containing 90% N2 and 10% H2. XRD and FESEM were employed to evaluate the microstructure of the MTO films, revealing that the addition of molybdenum enhances the crystallization and increases the grain size of TiO2 films. The optimal electrical properties of the MTO films were obtained with 3 wt% Mo doping, producing a resistivity of 1.1×10?3 Ω cm, a carrier density of 9.7×1020 cm?3 and a mobility of 5.9 cm2/Vs. The refractive index and extinction coefficient of MTO films were also measured as a function of film porosity. The optical band gap of the MTO films ranged from 3.28 to 3.36 eV, which is greater than that of the un-doped TiO2 film. This blue shift of approximately 0.14 eV was attributed to the Burstein–Moss effect. 相似文献
86.
Yeong-Her Wang Meng Hwang Liu Mau Phon Houng Chen J.F. Cho A.Y. 《Electron Devices, IEEE Transactions on》1994,41(10):1734-1741
The negative differential resistance (NDR) phenomena were observed in GaSb/AlSb/InAs/-GaSb/AlSb/InAs resonant interband tunnel structures. Electrons have resonantly achieved interband tunneling through the InAs/GaSb broken-gap quantum well. The InAs well width causes significant variations of the peak current density and NDR behaviors. The peak current density varies exponentially with the AlSb barrier thickness. The multiple NDR behavior was observed with appropriate InAs well and AlSb barrier thicknesses, e.g., 30 Å thick AlSb barrier and 240 Å wide InAs well. Only single negative resistance has, otherwise, been seen. The three-band model was used to interpret the effect of the InAs well and AlSb barrier on the current-voltage characteristics of GaSb/AlSb/InAs/GaSb/AlSb/InAs structures 相似文献
87.
Ping-Kuan ChangPo-Tsung Hsieh Chun-Hsiung LuChih-Hung Yeh Mau-Phon Houng 《Solar Energy Materials & Solar Cells》2011,95(9):2659-2663
A structure is developed to help improve the TCO/p contact and efficiency of the solar cell. A p-i-n amorphous silicon (a-Si:H) solar cell with high-conversion efficiency is presented via use of a double p-type window layer composed of microcrystalline silicon and amorphous silicon carbide. The best efficiency is obtained for a glass/textured TCO/p-μc-Si:H/p-a-SiC:H/buffer/i-a-Si:H/n-μc-Si:H/GZO/Ag structure. Using a SnO2/GZO bi-layer and a p-type hydrogenated microcrystalline silicon (p-μc-Si:H) layer between the TCO/p-a-SiC:H interface improves the photovoltaic performance due to reduction of the surface potential barrier. Layer thickness, B2H6/SiH4 ratio and hydrogen dilution ratio of the p-μc-Si:H layer are studied experimentally. It is clearly shown that the double window layer can improve solar cell efficiency. An initial conversion efficiency of 10.63% is achieved for the a-Si:H solar cell. 相似文献
88.
Ping-Kuan ChangPo-Tsung Hsieh Fu-Ji TsaiChun-Hsiung Lu Chih-Hung YehNa-Fu Wang Mau-Phon Houng 《Thin solid films》2012,520(15):5042-5045
This paper considers the intrinsic layer of hydrogenated amorphous silicon (a-Si:H) solar cells. The deposition temperatures (Td) and electrode distances (between cathode and anode, E/S) are important factors for a-Si:H solar cells. Thus, this study examines the effects of deposition temperatures and electrode distances in the intrinsic layer of a-Si:H solar cells with regard to enhanced the short-circuit current density (Jsc) and thereby conversion efficiency. It is shown that the Jsc of a-Si:H solar cells can be increased by proper choice of Td and E/S of the i-a-Si:H layers. The Jsc of the a-Si:H solar cells is largely dependent on light absorption of the i-a-Si:H layer. It is demonstrated that the absorption coefficient in an i-a-Si:H layer can be increased to provide higher Jsc under fixed thickness. Results show that the optimized parameters improve the Jsc of a-Si:H solar cells to 16.52 mA/cm2, yielding an initial conversion efficiency of 10.86%. 相似文献
89.
We calculated the nucleon self-energies in iso-spin asymmetric nuclear matter and obtained the nuclear symmetry energy by taking difference of these of neutron and proton. We find that the scalar (vector) self-energy part gives a negative (positive) contribution to the nuclear symmetry energy, consistent with the result from relativistic mean-field theories. Also, we found exact four-quark operator product expansion for nucleon sum rule. Among them, twist-4 matrix elements which can be extracted from deep inelastic scattering experiment constitute an essential part in the origin of the nuclear symmetry energy from QCD. Our result also extends early success of QCD sum rule in the symmetric nuclear matter to the asymmetric nuclear matter. 相似文献
90.