二元混合制冷剂CO2/R600的气液相平衡研究

采用PR状态方程及其混合法则对不同配比的二元混合制冷剂CO2/R600的气液相平衡进行了计算,将计算结果与相关文献数据进行了比对。结果表明,该文的计算结果与文献数据吻合较好,推算方法可用于CO2/R600混合制冷剂的基本热物性预测。     

基于Lorenz映射的混沌系统分支变换预报规律研究

尽管Lorenz系统具有混沌和非周期性质, 但其分支变换是可预报的.本文以强迫Lorenz系统为数学模型, 基于Lorenz映射, 研究了混沌系统分支变换的预报规律, 将原有关于分支开始变换条件和新分支持续时间的两条一般规律扩展到了3条, 并首次分析了系统当前状态达到变换条件所需时间的预报规律, 从而为预报混沌系统非周期演变提供了另一途径.结果表明: 映射尖点位置为分支变换的临界值, 当变量z超过相应临界值时, 系统在当前分支的运动即将结束, 下一循环将跳跃到另一分支运动; 系统在同一分支循环的次数随极值z_max单调减小, z_max 越小, 达到变换条件需循环的次数越多; 系统在新分支持续的时间是先前分支最大极值z_M 的单调增加函数, z_M越大, 持续时间增加的幅度也越大.此外, 外强迫影响着混沌系统分支变换的预报规律, 其不但使正负分支的变换条件出现差异, 且与新分支持续时间的增加速率和达到变换条件所需时间的递减速率密切相关. 关键词： Lorenz映射 分支变换 外强迫 预报规律     

对规范粒子极化矢量的一些讨论

对规范粒子的极化矢量做了较为系统的论述. 讨论内容包括极化矢量的具体形式和性质、求和规则和规范传播子之间的关系以及由其张成的投影算子的性质. 通过若干精选的例子, 进一步演示了计算牵涉规范粒子的过程时采用的基本方法和应当注意事项.     

Simulation of the nonlinear vibration of a string using the Cellular Automata based on the reflection rule

In this study, the nonlinear dynamic responses of a string are simulated using the Cellular Automata method based on the reflection rule. In the case of nonlinear systems, the velocity of wave propagation is not constant and depends on the amplitude. A new treatment of the dynamic time step is proposed for the Cellular Automata method considering the effect of the propagation velocity. As numerical examples, first, the dynamic responses of a string with linear characteristic are simulated using the Cellular Automata method. A typical resonance curve can be obtained. Second, the dynamic responses of a string with nonlinear characteristic are simulated using the proposed method. Some characteristic types of vibration can be obtained. It is concluded that the linear and nonlinear dynamic responses of a string may be obtained by simulation using the Cellular Automata method.     

Scale invariance rule in electromagnetic scattering

The volume integral equation formalism is used to prove the scale invariance rule for an arbitrarily sized scatterer with an arbitrary shape, morphology, and orientation. The only assumptions are that the scatterer is made of optically isotropic linear materials and is embedded in a homogeneous, linear, isotropic, and nonabsorbing infinite medium.     

基于统计滤波的单幅散斑条纹图的相位恢复技术

基于统计信号处理技术的贝叶斯（Bayes）估计原理，提出一种新的滤波方法。该方法能有效减少散斑条纹图中的噪声，而且仅用一幅散区斑条纹图就能获得准确的条纹相位分布，通过实例说明了该方法的处理过程。     

Fusion of infrared polarization and intensity images using support value transform and fuzzy combination rules

Infrared polarization and intensity imagery provide complementary and discriminative information in image understanding and interpretation. In this paper, a novel fusion method is proposed by effectively merging the information with various combination rules. It makes use of both low-frequency and high-frequency images components from support value transform (SVT), and applies fuzzy logic in the combination process. Images (both infrared polarization and intensity images) to be fused are firstly decomposed into low-frequency component images and support value image sequences by the SVT. Then the low-frequency component images are combined using a fuzzy combination rule blending three sub-combination methods of (1) region feature maximum, (2) region feature weighting average, and (3) pixel value maximum; and the support value image sequences are merged using a fuzzy combination rule fusing two sub-combination methods of (1) pixel energy maximum and (2) region feature weighting. With the variables of two newly defined features, i.e. the low-frequency difference feature for low-frequency component images and the support-value difference feature for support value image sequences, trapezoidal membership functions are proposed and developed in tuning the fuzzy fusion process. Finally the fused image is obtained by inverse SVT operations. Experimental results of visual inspection and quantitative evaluation both indicate the superiority of the proposed method to its counterparts in image fusion of infrared polarization and intensity images.     

相空间路径积分中的Feynman规则和广义Ward恒等式

基于Green函数的相空间生成泛函,导出了广义正则Ward恒等式.指出无须作出相空间生成泛函中对正则动量的路径积分,即可求得树图近似下的Feynman规则.对场的拉氏量添加一个四维散度项后,场的传播子发生了改变.     

A text-to-speech system with high intelligibility and naturalness for Chinese

I.IntroductionResearchesonChinesesynthesisdisclosethatonlywhenboththesegmentalandsupraseg-melltalfeaturesofthesyntheticspeecharesimilartothoseofthellaturalone,thesyntheticspeechwillsoundintelligibleandnatural[1].Amongekistingsynthetictechniques,theapproachbasedonacousticparametersca-nadustboththesegmentalandsuprasegmentalfeaturesofsyntheticunitsfiekiblyandcanbeconsideredasthemostreasonablesynthetictechniqueintheory.However,theparameterbasedsynthesizerisoverAfependentonthedevelopmentsofparamet…     

Estimation of Multinomial Probabilities under a Model Constraint

In this paper estimation of the probabilities of a multinomial distribution has been studied. The five estimators considered are: unrestricted estimator (UE), restricted estimator (RE) (under model ), preliminary test estimator (PTE) based on a test of the model , shrinkage estimator (SE) and the positive-rule shrinkage estimator (PRSE). Asymptotic distributions of these estimators are given under Pitman alternatives and the asymptotic risk under a quadratic loss has been evaluated. The relative performance of the five estimators is then studied with respect to their asymptotic distributional risks (ADR). It is seen that neither of the preliminary test and shrinkage estimators dominates the other, though each fares well relative to the other estimators. However, the positive rule estimator is recommended for use for dimension 3 or more while the PTE is recommended for dimension less than 3.