Effects of shear flow on long-ranged correlations,spinodal demixing kinetics,and the location of the critical point and cloud point

A derivation of an expression for the shear rate-dependent Ornstein Zernike structure factor is discussed, together with the resulting anomalous behavior of the turbidity. The predicted scaling behavior of the turbidity, comprising the effect of both temperature and shear rate, is in good agreement with experiments on binary fluids. Then initial spinodal decomposition is discussed, and an explicit expression for the time- and shear rate-dependent effective diffusion coefficient is derived, which shows all the typical characteristics of anisotropic light scattering patterns that are observed experimentally for binary fluids. Next it is shown that the spinodal is shifted linearly with the (bare) Peclet number for not too large Peclet numbers, whereas the cloud point is singularly displaced into the unstable region due to a shear now. This is in agreement with an experiment on a two-polymer/solvent mixture and binary fluid mixtures. It is argued that light scattering is useless to determine the location of the spinodal of a sheared system.Paper presented at the Twelfth Symposium on Thermophysical Properties, June 19–24, 1994, Boulder, Colorado, U.S.A.     

高效离心风机的设计研究

该文在总结国内外高效离心风机的设计经验基础上,掌握和利用已有的经验,遵循一系列离心风机优化准则,成功的完成了高效机车用牵引电机通风机的设计.性能样机经台架试验,比原风机的性能有较大幅度的提高,效率达到86%,在国内同样风机中效率是较高的.     

Conditions for the Acceptance of Deontic Conditionals.

Recent psychological research has investigated how people assess the probability of an indicative conditional. Most people give the conditional probability of q given p as the probability of if p then q. Asking about the probability of an indicative conditional, one is in effect asking about its acceptability. But on what basis are deontic conditionals judged to be acceptable or unacceptable? Using a decision theoretic analysis, we argue that a deontic conditional, of the form if p then must q or if p then may q, will be judged acceptable to the extent that the p & q possibility is preferred to the p & not-q possibility. Two experiments are reported in which this prediction was upheld. There was also evidence that the pragmatic suitability of permission rules is partly determined by evaluations of the not-p & q possibility. Implications of these results for theories of deontic reasoning are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Application of the blind source separation method to feature extraction of machine sound signals

As the result of vibration emission in air, a machine sound signal carries important information about the working condition of machinery. But in practice, the sound signal is typically received with a very low signal-to-noise ratio. To obtain features of the original sound signal, uncorrelated sound signals must be removed and the wavelet coefficients related to fault condition must be retrieved. In this paper, the blind source separation technique is used to recover the wavelet coefficients of a monitored source from complex observed signals. Since in the proposed blind source separation (BSS) algorithms it is generally assumed that the number of sources is known, the Gerschgorin disk estimator method is introduced to determine the number of sound sources before applying the BSS method. This method can estimate the number of sound sources under non-Gaussian and non-white noise conditions. Then, the partial singular value analysis method is used to select these significant observations for BSS analysis. This method ensures that signals are separated with the smallest distortion. Afterwards, the time-frequency separation algorithm, converted to a suitable BSS algorithm for the separation of a non-stationary signal, is introduced. The transfer channel between observations and sources and the wavelet coefficients of the source signals can be blindly identified via this algorithm. The reconstructed wavelet coefficients can be used for diagnosis. Finally, the separation results obtained from the observed signals recorded in a semi-anechoic chamber demonstrate the effectiveness of the presented methods .     

Numerical simulation of substrate effects on spinodal decomposition in polymer binary mixture: Effects of the surface potential

The surface-directed spinodal decomposition (SDSD) of polymer binary mixture with different values of surface potential is numerically simulated in three-dimension (3D) by cell dynamic systems (CDS). Furthermore, the growth laws of the wetting layer are theoretically analyzed by the current equation and the dynamical scaling. The results show that the thickness of the wetting layer increases with the increasing surface potential. The crossover, which is later for larger values of surface potential, appears in the evolution curve of the wetting layer. Before the crossover, the growth law is the surface potential dependant growth law. Subsequently, the growth law is the typical Lifshitz-Slyozov (LS) growth law. The results indicate that the surface potential can result in the mutual transformation between completely wetting and partially wetting for the substrate interface. It can be found that the higher surface potential leads to the faster and stronger transmission of the effect of the substrate on the spinodal decomposition in the bulk.     

ΝΗ<Subscript>3</Subscript> decomposition in a proton conducting solid electrolyte cell

The reaction of NH₃ decomposition was studied on Ag in a proton conducting double chamber cell-reactor. The proton conductor was a strontia-ceria-ytterbia (SCY) perovskite of the form SrCe_0.95Yb_0.05O_3−α. The reaction was studied at 350–700 °C and atmospheric total pressure. The proton transference number (PTN) was calculated by simultaneous measurement of the imposed current and the proton flux and it was found to vary between 0.5 and 0.7. The effects of imposed current, temperature and inlet gas composition on the reaction rate and the PTN, were examined. Although the faradaic efficiency (Λ) remained near unity in all experiments, reaction rate enhancements (ρ) as high as 57 were achieved. An up to 90% decrease in the activation energy of the reaction was observed when protons were electrochemically “pumped” away from the catalyst.     

C/C + +源代码风格检测工具的实现

文中给出了评价C／C 源代码风格的规则分类和检查工具的总体结构，阐述了代码检查工具的核心技术——扩展词法分析和扩展语法分析，给出了代码检测工具的应用实例。     

一种固定阈值的毫米波图像边缘检测方法

文章提出了一种固定阈值的毫米波图像边缘检测方法。根据图像的统计特征确定出像素的标准梯度强度，并采用单阈值对图像进行边缘粗定位，然后施行非最大抑制处理和滤波，得到最终检测结果。由于该算法对各幅毫米波图像设置相同的阈值，故能实现自动检测，同时还具有计算量小的特点。实验结果表明该方法进行毫米波图像边缘检测的有效性和可行性。