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81.
Due to challenges with relentless scaling of conventional bulk complementary metal-oxide- semiconductor (CMOS) devices, non-conventional CMOS devices have been of great interest to scale metaboxide-semiconductor field effect transistors (MOSFETs) to the 32nm gate length and below effectively. Among non-conventional CMOS devices, quadruple-gate (QG) MOSFETs have been gaining interest because they are sup- posed to provide excellent electrostatic controllability for ultra-large-scale integration (ULSI) applications. A number of attempts have been made to analyze QG MOSFETs analytically with a great amount of success. Sharma et al. have presented an an- alytical threshold voltage model for QG MOSFETs using an isomorphic polynomial function for solv- ing the 3D Poisson equation. Chiang has presented a number of models of scaling length,threshold voltage and subthreshold current for QG MOS- FETs adopting a concept of the so-called equivalent number of gates (ENGs).  相似文献   
82.
An all-fiber optical laser pulse multi-pass stretcher using a chirped fiber Bragg grating (CFBG) is demonstrated. Pulses from a 1 053-nm mode-locked fiber seed oscillator are stretched by multiple passing through a chirped fiber grating set in a fiber regenerative amplifier structure. We stretch the pulse from 16 ps to 1.855 ns after it transmits seven loops in the stretcher. The main factors that affect the stretching results are discussed.  相似文献   
83.
李威  詹杰  邵士勇  梅海平  饶瑞中 《光学学报》2008,28(10):1844-1848
在大气光学领域中,天空亮度分布有着重要的应用.简要介绍了天空亮度的测量原理,在分析同类测量仪器的基础上,提出了一种用于白天的,可见及近红外波段天空亮度测量仪器的设计,介绍了系统的组成和探测器的选择.经过定标,仪器能够得到天空亮度的绝对值,其结果反映了真实天空亮度分布的变化.该仪器弥补了传统的天空亮度测量仪器住测量波段、实时性、便携性等方面的不足,更好地满足了实际的科研需求.  相似文献   
84.
太阳米粒结构相关哈特曼-夏克波前传感模拟研究   总被引:2,自引:2,他引:2  
基于互相关因子和绝对差分算法以及相关哈特曼-夏克波前传感器的基本原理,根据室内模拟太阳米料结构研究了低对比度扩展目标情况下应用相关哈特曼-夏克波前传感器探测波前误差的可行性,结果表明,相关哈特曼-夏克波前传感器能够有效探测光学波前误差。  相似文献   
85.
SmCo5+x wt% Fe (x=0x=0, 5 and 10) nanocomposite powders were synthesized by mechanical milling and were consolidated into bulk shape by spark plasma sintering (SPS) technique. The evolution of structure and magnetic properties were systematically investigated in milled powders as well as in SPS samples. A maximum coercivity of 8.9 kOe was achieved in spark plasma sintered SmCo5+5 wt% Fe sample. The exchange spring interaction between the hard and soft magnetic phases was evaluated using δMH measurements and the analysis revealed that the SPS sample containing 5 wt% Fe had a stronger exchange coupling between the magnetic phases than that of the sample with10 wt% Fe.  相似文献   
86.
Using the Lie algebraic method the vibrational energy levels of HCCF and HCCD are calculated for 102 and 110 vibrational bands, respectively, using the local Hamiltonian. A comparative study is made between the two. Better results are obtained than those published earlier from local mode analysis.  相似文献   
87.
Abstract

ESR spectra of γ-irradiated frozen aqueous solutions of a number of organic compounds such as alcohols, ether, acetone and tetrahydrofurans have been examined in the presence and absence of mineral acids such as H2SO4. The presence of the acid is found to cause an intensification of the organic radical ESR spectra as compared with the acid free solutions. Also, the presence of the organic compounds in frozen aqueous H2SO4 suppresses the formation of both H-atoms and SO4 ? radical ions. These results have been explained on the basis of reactions of the electrons and holes, or excitons, primarily formed by the action of radiation on the substrate ice.  相似文献   
88.
Abstract

In this study, the molecular weights of the polymer from vinyl benzoate has been reported for different dose rates and different temperatures. The mol.wt. remains around 4000. With increasing dose, the molecular weight increases to about 14,000. The degrees of polymerization and the kinetic chain lengths calculated from the experimentally determined G R values have been compared which show that the kinetic chain length is larger than the D ? Pn.

From a plot of the (D ? Pn)?1 vs. R p , an intercept is obtained which is equal to 3.25 × 10?2 which is higher than obtained in conventional polymerization. By examining the effect of temperature on mol.wt., the dependence of R p on dose rate and the absence of induction period it has been concluded that chain transfer occurs to impurities that are generated during radiolysis.  相似文献   
89.
波前拟合能力分析是变形次镜研制工作的重要组成部分,是基于变形次镜的新型自适应光学系统研制的重要基础.以拟合误差为评价标准,采用有限元计算所得驱动器影响函数对1.8 m望远镜变形次镜四个备选方案进行了泽尼克(Zernike)多项式、Kolmogorov湍流大气畸变相位屏拟合能力分析.结果表明73单元变形次镜波前拟合能力较...  相似文献   
90.
张学军  饶坚  邓杨保  蒋练军  田野 《物理学报》2014,63(19):193601-193601
采用相空间积分方法严格导出了各态历经条件下单势阱粒子溢流模型中系统温度和阱内粒子数涨落的解析表达式,着重讨论了热力学量涨落与总粒子数和势阱体积之间的关系.研究表明,系统总粒子数越少以及势阱体积越小,热力学涨落越显著,并且热力学涨落与阱内粒子的溢出密切相关.粒子的溢出和系统负比热及热力学大幅涨落的发生存在一一对应的关系,这一对应关系的根源可以从表观能量逆均分来理解.  相似文献   
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