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991.
在作者已给出的描述三螺旋蛋白质分子的哈密顿函数基础上,得到了孤立子存在的临界温度和热容器,其结果与实验结果一致。  相似文献   
992.
A theory is proposed for the special complex cavity; it is in the form of a single resonant circuit having a TE0n&lrarr2;TE0,n+p mode converter and it features excellent mode selectivity, high power capability, and an asymmetric triangle profile of the RF field that is favourable to efficient operation for a 35-GHz second-harmonic gyromonotron employing this complex cavity with TE03 mode output are numerically illustrated and experimentally demonstrated. Power as high as 200 kW and efficiency as high as 30% have been obtained. These experimental results are record values for a gyrotron operating at the second-harmonic millimeter wavelength. Implications of the single-resonant complex cavity for the fundamental harmonic and third-harmonic high-average-power gyrotron design are discussed  相似文献   
993.
设计并制备了一个CMOS工艺兼容的温湿度传感器,讨论了感湿理论模型并用COVENTOR软件进行了模拟,给出了具体的结构参数及工艺制作步骤,最后对温湿度传感器进行了测量,对理论值和实际测量值做了比较并给出了分析结果.结果表明,传感器在25℃时的灵敏度为0.015pF/%RH,从15%RH~95%RH,电容实际变化量为1.23pF.  相似文献   
994.
In a previous paper by the authors, the computational expressions for the higher order terms of the radiative perturbation series have been developed, and numerical results have been obtained. In this paper, new computational expressions are developed that use the analytic Green's function and the GDOM code, which were developed recently by Qin and Box. Our analysis and numerical computations indicate that the new scheme dramatically improves the efficiency of the computation (by reducing the CPU-time to less than 2% of that required by the previous scheme), and the huge demand on memory usage has been completely removed. This new scheme allows us to expand the high order perturbation computations to more general cases, for example, to include azimuth dependence, and to use the perturbation theory in more potential applications.  相似文献   
995.
胶体金纳米颗粒的荧光光谱特性   总被引:5,自引:2,他引:3  
朱健  王永昌  王勤 《光子学报》2003,32(3):357-360
研究了胶体金纳米颗粒的荧光激发光谱和荧光发射光谱特性.增大激发光的波长,发射峰相应红移并在629nm达到最强,对应的灵敏激发波长为473nm.增加金纳米颗粒粒径,观察到发射谱的峰值先增大然后减小.发射峰产生的原因在于电子与带间空穴的复合导致非线性共振光散射.发射峰强度和金颗粒粒径的关系可以用表面等离子体震荡引起的局域场增强来解释,数值计算结果和实验结果能较好的吻合.  相似文献   
996.
Polyhedral oligosilsesquioxane (POSS)-reinforced thermosets based on octaglycidyl epoxy polyhedral oligosilsesquioxane cured with 4,4′-diaminodiphenyl sulfone (DDS) were prepared and studied for their cure, thermomechanical, and microstructural characteristics. Particular attention was paid to nanometer-scale deformation processes responsible for toughening, as revealed by transmission electron microscopy (TEM) in conjunction with the thermal properties. A cure analysis investigated with calorimetry and rheometry showed a significant dependence of the cure mechanism and kinetics on the DDS content, but all hybrid thermosets reacted completely below 300 °C into rigid solids. A dynamic mechanical analysis of this hybrid resin system showed that increasing the DDS concentration used during cure increased the dynamic storage modulus in the glassy (temperature < glass-transition temperature) and rubbery (temperature > glass-transition temperature) states, simply through an increase in the crosslink density. The phase structures revealed by TEM with selective POSS staining were drastically affected by the DDS concentration and manifested as altered nanomechanical deformation structures. It was qualitatively found that the main toughening mechanism in the studied POSS-reinforced thermosets was void formation at the nanometer scale, possibly templated by limited POSS aggregation. As the crosslinking density increased with the DDS concentration, microshear yielding between voids prevailed, providing a balance of stiffness, strength, and toughness. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 3299–3313, 2003  相似文献   
997.
有线电视交互式自动点播系统   总被引:1,自引:0,他引:1  
介绍在现有普通有线电视基础上,增加交互式自动节目点播系统的构成方法。  相似文献   
998.
999.
采用自制的近红外双波长脑血氧监测仪实时采集人脑血和氧的数据,应用功率谱和相关函数的方法对采集的脑血氧的数据波形进行分析.结果发现正常人脑血氧波形之间有着严格的相关性,功率谱曲线主频峰清晰,血氧的功率谱曲线吻合好;脑缺氧病人血氧波形间的相关性差,功率谱曲线表现为主频峰不清晰,功率谱曲线吻合性差。临床试验表明:脑血氧波形、功率谱和相关函数对于分析人脑血、氧生理状况及其变化具有较好的效果。  相似文献   
1000.
Bidirectional chirp-free tuning in Bragg reflection wavelength by as much as 12.52 mm has been achieved based on the principle of a beam of uniform strength. The experimental results are in good agreement with the theoretical analysis. The tuning device is simple in configuration, low cost, and easy to operate, which can be used in numerous applications, such as tunable fiber grating lasers and reconfigurable wavelength add-drop multiplexers, etc  相似文献   
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