传输线衰减常数与柱形谐振器Q值的关系

文中严格地讨论了任意截面形状，任意模式的柱形谐振腔Ｑ值与构成该谐振器的传输线衰减常数间的关系，给出了更一般的公式，推广了Ｄａｖｉｄｓｏｎ和Ｓｉｍ－ｍｏｎｄｓ＾［１］、Ｂａｒｌｏｗ和Ｃｕｌｌｅｎ＾［２］以及Ｙｅｈ和Ｓｈｉｍａｂｕｋｕｒｏ＾［３，４］的结果。     

Radiation transmission through a composite pure water layer of uniform and depth-dependent extinction characteristics

The paper describes the calculation of the beam solar radiation transmission across the uniform salinity upper convecting zone (UCZ) and the salinity stratified gradient zone (GZ), when the extinction coefficient is not only wavelength but also salinity-concentration dependent, assuming that the effect of scattering to be negligible. The results are useful in determining the effects of dissolved salt ions on pure water transmission, at least according to the existing measured data in the literature.     

The analysis of solvation in ionic liquids and organic solvents using the Abraham linear free energy relationship

The contentions made in an earlier paper [J Chem Technol Biotechnol 80 : 133–137 (2005)] that the coefficients of the Abraham solvation equation do not provide meaningful information on the molecular properties of ionic liquid solvents is refuted. The objections noted in the earlier paper disappear when the solvation equation model is correctly applied to the experimental data. It is further shown that the coefficients of the Abraham solvation equations can be used to characterize ionic liquids and can be used to select solvents for the solubility of gaseous solutes. Copyright © 2006 Society of Chemical Industry     

A comparative study of color measurement lntstrumentation

A multiplant Quality Improvement Team [QIT] was firmed to develop and implement an evaluation program for various color measurement .systems as potential replacements for the then-current aging systems. The emphasis qf this article is the analytical methodology utilized to evaluate the various color systems. The evaluation program consisted cf two phases. Phase I was a general overview/review of several systems, while Phase II was an extensive internal comparative evaluation measurement systems. These were Milton-Roy's ColorMate HDS, HunterLab's Ultrascan, Datacolor's CS-5, and BYK-Gardner's The Color Sphere [TCS]. The main comparison criteria were interinstrument agreement [agreement between two instruments ofthe same system], user-friendly software and computer interface capability, vendor amenability to a long-term logistical and maintenance relationship, and price. All systems were evaluated by duplicate measurements on various color tiles, yarns, and polymer flakes-over 1600 measurements on each system. The systems were compared with an instrument matrix, a decision matrix, and a product matrix. The instrument matrix was a comparison qfinstrument parameters, software/math treatments, and economics. The decision matrix was a forced ranking of each system by each criteria category [1–4 scale, with 1 representing the best and 4 representing the worst]. The product matrix accentuated the relative importance ofone criterion category over another by multiplying the forced ranking by the criticality of the category. The criticality of a given category wus determined by consensus within the QIT. Thr combination qf the three matrices allowed the evaluator[.s] t o select the color rneasuremmt system that best satixfied the color measurement needs and requirements of their facility and their products. For this evaluation, all ofthe evaluated systems were superior to the then-current agingsystems. As a result of this methodology, one instrument emerged as clearly superior. © 1994 John Wrley & Sons, Inc.     

Paving the way for CRM success: The mediating role of knowledge management and organizational commitment

Customer relationship management (CRM) has become one of the most influential technologies in the world, and companies are increasingly implementing it to create value. However, despite significant investment in CRM technology infrastructure, empirical research offers inconsistent support for its positive impact on performance. This study develops and tests a research model analyzing the process through which CRM technology infrastructure translates into organizational performance, drawing on the resource-based view (RBV) and the knowledge-based view (KBV) of the firm. Based on an international sample of 125 hotels, the results suggest that organizational commitment and knowledge management fully mediate this process.     

Effect of introduction of structural defects on protective ability of polyesters

Permeability of a polymer plays an important role in conferring the protective ability of organic coating to the steel surface against atmospheric corrosion. Although the relationship between structure of polymers and their permeability has been extensively studied in various applications like membranes, packaging, etc., such detailed study is lacking in the area of coatings. The systematic study of structure–permeability relationship of polymers in clear coatings can give guidelines in selecting the binder for the required application. This article deals with the effect of introduction of structural defects into a straight chain aliphatic polyesters on the protective ability of their clear coatings against corrosion. The mild steel panels coated with clear coatings based on the polyesters were exposed to humidity in humidity chamber. A novel technique of detecting the onset of corrosion was used instead of conventional methods that detect the failure of the coating due to corrosion. It was observed that even at 1–10% mole defect introduced by replacement of straight chain diols with branched diols, the protective ability of clear coatings was affected drastically.     

大学教学与科研关系的探讨

大学职能的发展历经了从教学主导到教学科研并举的演变。教学与科研在大学的发展历程和具体运作过程中存在着不可避免的矛盾。二者结合是优化资源配置、发展创新教育的最佳途径,对大学进行有效的分层定位是协调二者关系的关键。具体包括在宏观战略上明确定位,同时加强组织重构、分类管理等。此外,大学文化之于教学与科研和谐也十分重要。     

Finite difference method for dynamic response analysis of anchorage system简

Based on some assumptions, the dynamic analysis model of anchorage system is established. The dynamic governing equation is expressed as finite difference format and programmed by using MATLAB language. Compared with theoretical method, the finite difference method has been verified to be feasible by a case study. It is found that under seismic loading, the dynamic response of anchorage system is synchronously fluctuated with the seismic vibration. The change of displacement amplitude of material points is slight, and comparatively speaking, the displacement amplitude of the outside point is a little larger than that of the inside point, which shows amplification effect of surface. While the axial force amplitude transforms considerably from the inside to the outside. It increases first and reaches the peak value in the intersection between the anchoring section and free section, then decreases slowly in the free section. When considering damping effect of anchorage system, the finite difference method can reflect the time attenuation characteristic better, and the calculating result would be safer and more reasonable than the dynamic steady-state theoretical method. What is more, the finite difference method can be applied to the dynamic response analysis of harmonic and seismic random vibration for all kinds of anchor, and hence has a broad application prospect.     

反射衰减诊断激光光束的应用分析

介绍了普通光学元件反射诊断激光光束的应用,提出了利用平面平晶的平面反射进行光能衰减,详细论述了采用该方法进行光能衰减的可行性,分析了平面平晶反射衰减中反射光S偏振态和P偏振态能量的差异,对激光束诊断的影响和解决方法,结合半导体绿激光器的光束诊断进行了应用分析。实验证明,该方法结构简单、调整方便、误差小,利用普通平面平晶反射衰减即可满足激光强度的匹配要求,实现了待测激光束无失真取样,达到很好的测试效果。     

Effects of γ/γ interfacial structures on continuous coarsening of lamellar microstructure in TiAl alloy during aging

The effects of γ/γ interfacial structures on continuous coarsening of the fully lamellar microstructure in Ti-48Al alloy aged at 1 150 ℃ were investigated by using transmission electron microscopy(TEM). Continuous lamellar coarsening can be achieved not only by migration of interface faults(such as ledges, edges and curved interfaces) but also by migration and decomposition of perfect γ/γ lamellar interfaces. Thermal grooves, initiative positions of interfacial dissociation, can frequently form at the triple point junctions between the 120°-rotational ordered γ domain boundaries within γ lamellae and the lamellar interfaces. During the early stage of aging at 1 150 ℃, the interface migration and dissociation took place preferentially at the 120°-rotational ordered lamellar interfaces. Comparing the relative thermal stability of the true-twin, pseudo-twin and 120°-rotational ordered γ/γ lamellar interfaces shows that the 120°-rotational ordered lamellar interface is the most unstable. The reason of this phenomenon was analyzed through the comparisons of the interfacial energies and atomic arrangements of the three types of γ/γ lamellar interfaces.