半导体加热器性能的优化分析

应用非平衡态热力学及有限时间热力学理论导出半导体加热器在导热、热漏及焦耳热等三种主要不可逆因素影响下的供热率和供热系数,并由此讨论了加热器的优化性能,得到一些对半导体加热器的最佳设计和运行均有指导意义的结论。     

平面连杆间歇机构的综合方法与研究

本文根据间歇机构的基本设计要求,利用优化方法、图解法及解析法对间歇机构进行分级综合,简化了复杂的六杆间歇机构,编制了实用的优化程序,得到一种八杆间歇机构。该机构可利用四杆机构轨迹重合使间歇角大于180°。     

The homogeneity restriction and forecasting performance of VAR‐type demand systems: an empirical examination of US meat consumption

This paper compares the forecast performance of vector‐autoregression‐type (VAR) demand systems with and without imposing the homogeneity restriction in the cointegration space. US meat consumption (beef, poultry and pork) data are studied. One up to four‐steps‐ahead forecasts are generated from both the theoretically restricted and unrestricted models. A modified Diebold–Mariano test of the equality of mean squared forecast errors (MSFE) and a forecast encompassing test are applied in forecast evaluation. Our findings suggest that the imposition of the homogeneity restriction tends to improve the forecast accuracy when the restriction is not rejected. The evidence is mixed when the restriction is rejected. Copyright © 2002 John Wiley & Sons, Ltd.     

关于一类三热源制冷机的等效联合系统

讨论了三热源制冷机等联合系统的必要条件和基本优化关系，并纠正了有关研究中的错误。     

Anaerobic oxidation of methane: Geochemical evidence from pore-water in coastal sediments of Qi’ao Island (Pearl River Estuary), southern China

The concentrations of CH4 and SO4^2- in pore-water and the carbon isotope compositions of total dissolved inorganic （TCO2） and OH4 were determined for three coastal sedimentary cores collected from Qi＇ao Island （Pearl River Estuary）, southern China. Results show that methane concentration changes dramatically at the base of the sulfate-reducing zone and sulfate concentration gradients are linear for all stations. In addition, the carbon isotope of methane becomes heavier at the sulfate-methane transition （SMT）, which causes ∑CO2-δ^13C to become the minimum. The geochemical profiles of pore-water render indirect evidence for anaerobic oxidation of methane （AOM）. Based on numerical modeling of AOM and sulfate-reducing rates, the portion of total sulfate reduction occurring via AOM is 9.0%, 84% and 45.5%, respectively, and the percentage of TCO2 added to the pore-water is 4.7%, 72.4% and 29.45% correspondingly for three sites. Furthermore, it is found that the methane concentration, methane diffusive flux and the depth of SMT are controlled by the quantity and quality of sedimentary organic matter incorporated into the sediments. The great amount of organic material is favorable for rapid depletion of sulfate via sedimentary organic matter degradation, and on the other hand, causes the increase of the methane flux in the SMT, which results in a portion of sulfate reduction supported by AOM. Accordingly, the SMT was shifted towards the sediment surface.     

Sm ∨ Pn的邻强边染色

为了解决图的邻强边染色问题中一个图的色数算法问题,通过特别的方法来记图的染色过程,同时分4种情况讨论了星和路联图的邻强边染色问题,指出在染色过程中给定的4种情况的染色方法各不相同,并通过对图的着色得到了星和路联图的邻强边色数.     

基于核酸适配体Q5的石斑鱼虹彩病毒快速检测技术

石斑鱼虹彩病毒(Grouper iridovirus,SGIV)在不同鱼群之间迅速传播,其致死率极高,严重制约了我国海水石斑鱼(Epinephelus tauvina)养殖业健康可持续发展。为了及早发现和鉴定出病原,降低经济损失,促进渔业发展,开发方便快捷的石斑鱼虹彩病毒检测技术已迫在眉睫。本研究基于核酸适配体Q5,研发出一种核酸适配体Q5-荧光分子探针(Aptamer Q5-based fluorescent molecular probe,Q5-AFMP),并且对Q5-AFMP检测感染石斑鱼虹彩病毒的特异性,以及Q5-AFMP在细胞水平和组织水平检测石斑鱼虹彩病毒感染的灵敏度进行分析。研究结果表明:Q5-AFMP能够在细胞水平和组织水平高特异性检测出石斑鱼虹彩病毒的感染,而且具有较高的灵敏度。因此Q5-AFMP能够用于石斑鱼虹彩病毒的快速检测和诊断。     

极性晶体中强耦合磁极化子的性质

本文利用Ｈｕｙｂｒｅｃｈｔｓ的线性组合算符法和一简单的么正变换研究了极性晶体内强耦合磁极化子的特性。导出了磁极化子的基态能量和回旋共振频率。并对晶体作了数值计算,从而对强耦合晶体进行了定量的探讨。结果表明：磁极化子的基态能量随磁场Ｂ的增加而减少,回旋共振频率随磁场Ｂ的增加而加大     

非惯性系中动量定理的应用

本文给出了非惯性系中动量定理及守恒定律的应用     

SH-guided waves in layered piezoelectric/piezomagnetic plates

The propagation of shear horizontal (SH) guided waves in a coupled plate consisting of a piezoelectric layer and a piezomagnetic layer is studied. Both the layers are transversely isotropic and perfectly bonded along the interface. The upper and the lower surfaces of the plate are assumed to be mechanically free, electrically open and magnetically closed. Two different cases are considered. One is that the bulk shear wave velocity of piezoelectric material is larger than that of piezomagnetic material. The other is that the bulk shear wave velocity of piezomagnetic material is larger than that of piezoelectric material. The dispersion relation is obtained while the phase velocity is among the bulk shear wave velocity of two different layers. The numerical results show that the phase velocity approaches the smaller bulk shear wave velocity of the material in the system with the increase in the wave number for different modes. The thickness ratio and the properties of the piezoelectric material have great effect on the dispersion behaviors. The results of this paper can offer some fundamental theory to the application of piezoelectric/piezomagnetic composites or structures.