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液氮间接冷却晶体单色器第一晶体热变形模拟计算 总被引:4,自引:0,他引:4
针对上海光源U27波荡器光源, 用ANSYS有限元软件对晶体单色器第一晶体液氮间接冷却进行数值模拟, 给出晶体表面倾斜误差与热负载、冷却条件和布喇格角范围等因素的关系, 为晶体单色器的设计与制造提供热缓释依据. 晶体距光源中心24m时最大垂直入射功率密度约为60W/mm2, 在布喇格角调节范围小于30°时, 晶体厚度大于30mm, 晶体吸收总功率上限可到240W, 即可满足SSRF储存环电子束流升级到400mA的需求, 采用正常液氮(78K)冷却晶体, 晶体表面热变形倾斜误差可控制在3arcsec以下. 相似文献
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A symmetry analysis and a simple dangling bond model are presented for the VZn^- in ZnGeP2, identifying a possible Jahn-Teller distortion mechanism which could naturally explain the localization of the defect wavefunction on two of the nearest-neighbouring P atoms, as deduced for the electron nuclear double resonance experiments. 相似文献
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Improvement of Atomic-Layer-Deposited Al2O3/GaAs Interface Property by Sulfuration and NH3 Thermal Nitridation 下载免费PDF全文
Fermi level pinning at the interface between high-h gate dielectric and GaAs induced by unstable native oxides is a major obstacle for high performance GaAs-based metal-oxide-semiconductor (MOS) devices. We demonstrate the improved Al2O3/GaAs interracial characteristics by (NH4)2S immersion and NH3 thermal pretreatment prior to A1203 deposition. X-ray photoelectron spectroscopy (XPS) analysis confirms that sulfuration of GaAs surface by (NH4 )2S solution can effectively reduce As-O bonds while Ga-O bonds and elemental As still exist at Al2O3 /GaAs interface. However, it is found that N incorporation during the further thermal nitridation on sulfurated GaAs can effectively suppress the native oxides and elemental As in the sequent deposition of Al2O3. Atomic force microscopy (AFM) shows that the further thermal nitridation on sulfurated GaAs surface can also improve the surface roughness. 相似文献
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PAN Feng 《中国物理C(英文版)》1991,15(2):178-186
VCS representantions of SO5 SU2 SU2 U1 U1 and SO5 U1 U1 are discussed.Reduced matrix elements for SO5 SU2 SU2 are derived.The multiplicity of a weight for SO5 is determined by using the K-matrix technique. 相似文献
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A new type of rf excited diffusively cooled all-metal slab waveguide CO2 laser is presented, in which the waveguide channel is constructed by two copper side walls and two copper electrodes, and the discharge is confined in the slab waveguide channel in terms of the voltage division structure. From this type of structure, over 1 kW laser power is obtained with an efficieney of more than 13%. 相似文献
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Cadmium dizinc diborate (CdZn2B2O6) single crystals have been grown for the first time. The crystal structure of CdZn2B2O6 is the same as that of the Cd3Zn3B4O12. The x-ray diffraction, infrared and Raman spectra, differential scanning calorimetry analysis and density indicate that the physical and chemical properties of both crystals are very similar. Especially, the nonlinear optical coefficients of CdZn2B2O6 and Cd3Zn3B4O12 crystals are 2.6 and 2.4 times as large as that of KH2PO4 crystal respectively. Chemical etching experiments indicated that these crystals are very stable in neutral solution and not hygroscopic in air at room temperature. 相似文献
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We investigate the thermal expansion property of the Tb2Fe14Cr3 compound by means of x-ray diffraction. The result shows that the Tb2Fe14Cr3 compound has a hexagonal Th2Ni17-type structure. Negative thermalexpansion is found in the Tb2Fe14Cr3 compound from 296 to 493K by x-ray dilatometry. The coefficient of the average thermal expansion is α=-2.82 × 10-5K-1. In the temperature range 493--692K, the coefficient of the average thermal expansion is α=1.59 × 10-5K-1. The physical mechanism of thermal expansion anomaly of the Tb2Fe14Cr3 compound is discussed according to the temperature dependence of magnetization measured by a superconducting quantum interference device. 相似文献
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Charge trapping characteristics of the metal-insulator-silicon (MIS) capacitors with Si02/HfO2//A12O3 stacked dielectrics are investigated for memory applications'. A capacitance-voltage hysteresis memory window as large as 7.3 V is achieved for the gate voltage sweeping of ±12 V, and a fiat-band voltage shift of 1.5 V is observed in terms of programming under 5 V and I ms. Furthermore, the time- and voltage-dependent charge trapping characteristics are also demonstrated, the former is related to charge trapping saturation and the latter is ascribed to variable tunnelling barriers for electron injecting and discharging under different voltages. 相似文献
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Comparison of TiO2 and ZrO2 Films Deposited by Electron-Beam Evaporation and by Sol-Gel Process 下载免费PDF全文
TiO2 and ZrO2 films are deposited by electron-beam (EB) evaporation and by sol-gel process. The film properties are characterized by visible and Fourier-transform infrared spectrometry, x-ray diffraction analysis, surface roughness measure, absorption and laser-induced damage threshold (LIDT) test. It is found that the sol-gel films have lower refractive index, packing density and roughness than EB deposited films due to their amorphous structure and high OH group concentration in the film. The high LIDT of sol-gel films is mainly due to their amorphous and porous structure, and low absorption. LIDT of EB deposited film is considerably affected by defects in the film, and LIDT of sol-gel deposited film is mainly effected by residual organic impurities and solvent trapped in the film. 相似文献
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Microwave Response of MgB2/A12O3 Superconducting Thin Films by Microstrip Resonator Technique 下载免费PDF全文
Double-sided superconducting MgB2 thin films are deposited onto c-A120a substrates by the hybrid physical chemical vapour deposition method. The microwave response of MgB2/A12O3 is investigated by microstrip resonator technique. A grain-size model is introduced to the theory of microstrip resonators to analyse microwave properties of the films. We obtain effective penetration depth of the films at OK (λe0 = 463nm) and surface resistance (R8 = 1.52 mΩ at 11 K and 8. 73 GHz) by analysing the resonant frequency and unload quality factor of the microstrip resonator, which suggests that the impurities and disorders of grain boundaries of MgB2/A12 Oa result in increasing penetration depth and surface resistance of the films. 相似文献
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电子束脱除SO2和NOx的概述 总被引:4,自引:0,他引:4
综述了电子束脱硫脱氮的原理、特点和发展.中国成都电厂的电子束脱硫脱氮装置的运行,标志着我国工业应用阶段的开始.Removal SO 2 and NO x by electron beam is reviewed. Its basic procedure is described. The electron beam method has many advantages compared to chemical one. The first industrial facility in China has been built in Chengdu Electric Power Plant and it is ruming successfully. 相似文献
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We report a modification method for ZrO2 thermal barrier coatings (TBCs) by high-intensity pulsed ion beam (HIPIB) irradiation. Based on the temporal and spatial distribution models of the ion beam density detected by Faraday cup in the chamber and the ions accelerating voltage, the energy deposition of the beam ions in ZrO2 is calculated by Monte Carlo method. Taking this time-dependent nonlinear deposited energy as the source term of two-dimensional thermal conduction equation, we obtain the temporal and spatial ablation process of ZrO2 thermal barrier coatings during a pulse time. The top-layer TBC material in thickness of about 0.2 μm is ablated by vaporization and the coating in thickness of 1 μm is melted after one shot at the ion current density of 200 A/cm^2. This calculation is in reasonable agreement with those measured by HIPIB irradiation experiments. The melted top coat becoming a dense modification layer due to HIPIB irradiation seals the gaps among ZrO2 crystal dusters, and hence barrels the direct tunnel of oxygen. 相似文献
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A Two-Parameter Deformed Two-Dimensional Interacting Boson Model With Uqp(U3)Uqp(U2)Uqp(SO2) Symmetry 下载免费PDF全文
A two-parameter deformed two-dimensional interacting boson model with Uqp(U3) Uqp(U2) Uqp(SO2)symmetry is constructed.It is found that the energy spectrum and transition matrix elements depend very sensitively on the second parameter of deformation. 相似文献
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The structure and magnetic properties of Y2Fe14Al3 compound are investigated by means of x-ray diffraction and magnetization measurements. The Y2Fe14Al3 compound has a hexagonal Th2Ni17-type structure. Negative thermal expansion is found in Y2Fe14Al3 compound in the temperature range from 403 to 491K by x-ray dilatometry. The coefficient of the average thermal expansion is α^- = -2.54Х 10^-5 K^-1. The spontaneous magnetostrictive deformations from 283 to 470 K are caJculated by means of the differences between the experimental values of the lattice parameters and the corresponding values extrapolated from the paramagnetic range. The result shows that the spontaneous volume magnetostrictive deformation ωs decreases from 5.74 × 10^-3 to nearly zero with temperature increasing from 283 to 470K, the spontaneous linear magnetostrictive deformation λc along the c-axis is larger than the spontaneous linear magnetostrictive deformation λa in basal-plane in the same temperature below 350 K. 相似文献