Interpolation of Schur multiplier spaces

Let denote the space of all Schur mulptiliers on the Schatten class . It is proved that there is a linear map which is a contraction on both and but which is not bounded on for all . Consequently, for any , is not an interpolation space between and . Received April 3, 1998 / in final form September 22, 1999 / Published online July 20, 2000     

On the Best Constants in Some Non-Commutative Martingale Inequalities

The optimal orders are determined for the best constants inthe non-commutative Burkholder–Gundy, Doob and Stein inequalitiesobtained recently in non-commutative martingale theory. 2000Mathematics Subject Classification 46L53, 46L51.     

Conversion issues between microwave radiance and brightness temperature

Microwave radiances are usually converted into brightness temperatures for data assimilation and retrievals. The Rayleigh-Jeans approximation has been believed to be a good approximation for the conversion at low frequencies, but inaccurate at high frequencies. However, the simplified radiative transfer models under the Rayleigh-Jeans approximation (hereafter referred as BT-RTE) have been successfully applied in radiance simulations for frequencies below 183 GHz, which has somewhat puzzled the radiative transfer community. This paper clarifies the confusion. In addition, the conversion formula for the third and the fourth Stokes components are derived.Simulations for a polarized sensor, the Special Sensor Microwave Imager and Sounder, show that the BT-RTE is generally accurate. Results for a polarimetric sensor, WINDSAT, show that the third and the fourth Stokes radiances should be converted using the exact conversion formula given in this study rather than using a direct Planck function conversion.     

高超声速飞行流场中的最大氧离解度分析简

针对大气层内高超声速飞行时的化学非平衡现象,建立了沿驻点线流动的空气中氧离解度的计算模型. 模型假设氮气在氧气未充分离解时不发生离解,并且不涉及边界层内的复合反应. 理论计算发现,空气中氧的离解度随飞行高度的增加呈先增后减的非单调变化规律,其原因是由于化学反应平衡移动与非平衡效应相互作用的结果. 这一结论得到了数值模拟结果的验证,同时也解释了文献中当飞行高度较高时真实气体效应减弱的现象. 基于驻点线的近似理论模型,计算得到了轴对称钝头体绕流流场中的最大氧离解度及边界层外缘温度随飞行速度和高度变化的等值线图谱,相关结果可以为工程设计所用.     

远程超低飞行轨道分析

研究了一种新的远程导弹飞行轨道的可行性,它的最大飞行高度约100 km.这种超低弹道,借鉴卫星模式,利用离心力抵抗重力.与卫星轨道运行不同的是,超低弹道周围的稀薄空气影响至关重要,必须考虑.计算和分析结果表明,在相同载荷条件和射程条件下,超低弹道和经典的最小能量弹道对于火箭动力的需求大致相当,射程10000km以上基本相同,头部半径为5cm的轴对称外形,沿超低弹道飞行时,其驻点热流在高度26km左右达到最大值50MW/m2,约为最小能量弹道驻点热流最大值的50%.由于超低弹道对升力没有要求,飞行过程中的气动加热问题,沿用成熟方法如烧蚀防热即可解决.总体而言,超低弹道对于火箭动力与外形气动力/热要求,现有技术容易满足,因此利用它增强远程导弹的突防能力是现实可能的.     

质量相近4N核间宇称相关势的折叠模型

基于对4N核结团结构的考虑,采用合理的核轨道波函数,并利用折叠模型导出了质量相近4N核间的宇称相关势.该势没有引进任何自由参数并具有明确的解析形式.将其用于研究12C+16O系统弹性散射角分布时,很好地再现了角分布的振荡结构.     

相同质量4N核间的半微观光学势

在LCNO理论框架下,基于独立α粒子模型和¹⁶O+¹⁶O系统的准分子态结构,计算得出了该系统的半微观光学势,使用该势满意地再现了¹⁶O+¹⁶O弹性散射激发函数中的粗共振结构.     

Vector-valued Littlewood-Paley-Stein theory for semigroups

We develop a generalized Littlewood-Paley theory for semigroups acting on L^p-spaces of functions with values in uniformly convex or smooth Banach spaces. We characterize, in the vector-valued setting, the validity of the one-sided inequalities concerning the generalized Littlewood-Paley-Stein g-function associated with a subordinated Poisson symmetric diffusion semigroup by the martingale cotype and type properties of the underlying Banach space. We show that in the case of the usual Poisson semigroup and the Poisson semigroup subordinated to the Ornstein-Uhlenbeck semigroup on Rⁿ, this general theory becomes more satisfactory (and easier to be handled) in virtue of the theory of vector-valued Calderón-Zygmund singular integral operators.     

20Ne+12C系统与深光学势下的双α转移效应

基于核分子轨道理论分析了²⁰Ne+¹²C系统所展示的基本特征,并且再现了该系统弹性散射激发函数和角分布,研究结果表明,使用一个深光学势的双α转移效应,是产生这两个系统弹性散射激发函数之间差别的重要原因.     

Co-pyrolysis behaviors and kinetics of plastics–biomass blends through thermogravimetric analysis

Co-pyrolysis behaviors of plastics–biomass blends were investigated using a thermogravimetric (TG) analysis from room temperature to 873 K with a heating rate of 5–40 K min^?1 in an inert atmosphere. The selected biomass sample was sawdust of pine wood (WS). Polyvinyl chloride (PVC), low-density polyethylene (LDPE), high-density polyethylene (HDPE), and polypropylene (PP) were selected as plastic samples. The difference of mass loss between experimental and theoretical ones (calculated as arithmetic sums of those from each separated component) was used as a criterion of synergetic effect. The experimental results indicated that a significant synergetic effect existed during the high-temperature region of plastics and WS co-pyrolysis process, specially, the dehydrochlorination reaction of PVC and the degradation of hemicellulose and cellulose in the WS during the co-pyrolysis process showed synergetic effect, as well as the reaction of plastics (LDPE, HDPE, and PP) and WS. Based on the TG data with different heating rates, the kinetics parameters, especially activation energy, were calculated using the Friedman method. The activation energy of plastics, WS, and their blends were from 92.8 to 359.5 kJ mol^?1. The activation energy of the PVC–WS blends was at a range of 180.2–254.5 kJ mol^?1 in the second stages. The activation energies range of LDPE–WS, HDPE–WS, and PP–WS blends were 164.5–229.6, 213.2–234.3, and 198.4–263.6 kJ mol^?1, respectively.