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121.
Recently, the theory of sortability of partition property has been shown to be an effective tool to prove the existence of an optimal partition with that property. In this paper, we extend the theory to multi-partition where the partition is on t types of components. We apply our results to settle an optimal assignment problem whose proof was incomplete as given in the literature.  相似文献   
122.
This paper gives a p-adic analogue of the Mackey theory, which relates representations of a group of type G - H × t A to systems of imprimitivity.  相似文献   
123.
中物院远红外自由电子激光实验研究   总被引:2,自引:0,他引:2  
中国工程物理研究院基于射频直线加速器技术的远红外自由电子激光(FIR-FEL)实验取得阶段性进展,于2005年3月24晚8时30分首次出光, 并多次重复. 中心波长115μm, 谱宽1%.介绍了实验系统的主要组成部分和主要实验结果.  相似文献   
124.
顾永建 《大学物理》2002,21(1):29-31
提出一个令人困惑的电磁感应问题,并运用电磁学理论对其进行了详尽的理论分析。  相似文献   
125.
PbWO4晶体空位型缺陷电子结构的研究   总被引:12,自引:1,他引:11       下载免费PDF全文
姚明珍  梁玲  顾牡  段勇  马晓辉 《物理学报》2002,51(1):125-128
采用基于密度泛函理论的相对论性离散变分和嵌入团簇方法计算了PbWO4晶体中与氧空位和铅空位相关缺陷的态密度分布,并运用过渡态方法计算了其激发能.结果表明:PbWO4晶体中WO3+VO缺陷的O2p→W5d跃迁可引起350nm和420nm附近的吸收,并且发现VPb的存在可以使WO42基团的禁带宽度明显变小 关键词: PbWO4晶体 密度泛函 氧空位和铅空位 态密度分布  相似文献   
126.
Measurements from depolarized lidars provide a promising method to retrieve both cloud and aerosol properties and a versatile complement to passive satellite-based sensors. For lidar observations of clouds and aerosols, multiple scattering plays an important role in the scattering process. Monte Carlo simulations are carried out to investigate the sensitivity of lidar backscattering depolarization to cloud and aerosol properties. Lidar parameters are chosen to be similar to those of the upcoming space-based CALIPSO lidar. Cases are considered that consist of a single cloud or aerosol layer, as well as a case in which cirrus clouds overlay different types of aerosols. It is demonstrated that besides thermodynamic cloud phase, the depolarized lidar signal may provide additional information on ice or aerosol particle shapes. However, our results show little sensitivity to ice or aerosol particle sizes. Additionally, for the case of multiple but overlapping layers involving both clouds and aerosols, the depolarized lidar contains information that can help identify the particle properties of each layer.  相似文献   
127.
We apply a Bayesian approach to the problem of prediction in an unbalanced growth curve model using noninformative priors. Due to the complexity of the model, no analytic forms of the predictive densities are available. We propose both approximations and a prediction-oriented Metropolis-Hastings sampling algorithm for two types of prediction, namely the prediction of future observations for a new subject and the prediction of future values for a partially observed subject. They are illustrated and compared through real data and simulation studies. Two of the approximations compare favorably with the approximation in Fearn (1975, Biometrika, 62, 89–100) and are very comparable to the more accurate Rao-Blackwellization from Metropolis-Hastings sampling algorithm.  相似文献   
128.
盛勇  蒋刚  朱正和 《物理学报》2002,51(3):501-505
类氢类氦类锂镁离子经中间双激发态进行的双电子复合过程在研究惯性约束聚变电子温度中占有很重要的地位.用准相对论方法计算了双电子复合经不同Rydberg态跃迁通道的复合速率系数,并给出不同离化度离子的双电子复合速率系数随电子温度的变化规律.显示出离子的相关能对峰值的电子温度有很大影响,当类氢离子跃迁通道的旁观电子角动量为1时双电子复合系数最大,而类锂离子是旁观电子角动量为3时最大. 关键词: 双电子复合 镁离子 角动量  相似文献   
129.
We study the elastic properties of single A/B random copolymer chains, with a specific sequence and use them as theoretical model for so called HP proteins. HP proteins carry hydrophilic (P) and hydrophobic (H) monomers. We predict a rich structure in the force-extension relations which can be attributed to the information in the sequence. The variational method is used to probe local minima on the path of stretching and releasing for the chain molecules. At a given force, we find multiple configurations which are separated by energy barriers. A collapsed globular configuration consists of several domains which unravel cooperatively. Upon stretching, the unfolding path shows a stepwise pattern corresponding to the unfolding of each domain. While releasing, several cores can be created simultaneously in the middle of the chain, resulting in a different path of collapse. The long-range interactions and stiffness of the chain simplify the potential landscape given by the disorder in sequence. Received 5 March 2002 / Received in final form 16 May 2002 Published online 13 August 2002  相似文献   
130.
We prepared high quality Au(1 1 1) film on Si wafer through the spin coating and thermal decomposition of a gold ink, spin-coated-and-fired (SCAF) Au film. The X-ray measurements, XRD and pole-figure analysis, showed that the SCAF Au film has a (1 1 1) out-of-plane orientation with a random in-plane orientation. In order to confirm the chemical activity of the SCAF Au film, we demonstrate the formation of patterned structures with the film by using soft lithography technique. The chemical activities of this physically stable SCAF Au film to the alkanethiols were at least equivalent those of physically deposited the Au films. The possibility of the mass production of micro patterned structure with the SCAF Au film was also demonstrated over the wide region on Si wafer by the microcontact lithography. These suggest that the Au film will help the easy fabrication of various nanosized devices on Si wafer and other substrates.  相似文献   
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