管内定型流传热过程的有效能损失

对管道内充分发展对流传热过程的有效能损失进行了分析．根据定型流状态下定热流与定壁温换热条件的特点,经代数推演,得到了这两种条件下的表征换热状态、流动功耗以及黏性变化的无量纲形式的有效能损失关系式,适用于不同截面形状的管道内的层流与湍流工况下的有效能分析．     

单形内顶角的不等式及其应用

本文首先给出了单形内顶角的概念，建立了单形内顶角的不等式，以此为基础上得到涉及单及形体积的两个不等式。     

光学腔内两正交偏振模振幅和相位的补偿

本文开展了光学腔内两正交偏振模振幅和相位补偿的实验研究。通过采用特殊腔型和两个λ/2波片,补偿腔内反射镜对水平偏振模和垂直偏振模的反射率差异,使两个偏振模的输出振幅相等。利用一组λ/4-λ/2-λ/4波片补偿光学腔内水平偏振模和垂直偏振模的相位差,使两个模的输出重合。通过上述的振幅和相位补偿方法,可实现任意偏振光经过环形腔后偏振不变,为任意偏振比特在腔内冷原子系综中的高效率高保真度存储提供了实验基础。     

混沌激光实现异质物大小和位置的光学检测

利用混沌激光实现一定浓度脂肪乳液中异质物大小和位置的光学检测,实验采用混沌激光作为光源,并将光信号分为两路,一路信号用于探测脂肪乳液中的异质物信息,另外一路直接经过光电探测器作为参考信号,将两路光信号由光电探测器接收,通过信号处理系统进行互相关,分析混沌激光的互相关峰值信息,可得到异质物的大小和位置信息;通过混沌激光实现异质物信息分析的理论模型,建立混沌相关信号峰值信息与异质物大小和位置之间的关系,并且通过实验验证。结果表明:采用混沌互相关法可以对异质物大小和位置坐标进行探测。     

Edge-pumped passively Q-switched thin Nd: YAG slab lasers

We report a high-power thin Nd: YAG slab laser with slab dimension of 1×10×60(mm) partially edgepumped by diode laser arrays.Passive Q-switching is achieved with a Cr4 : YAG microchip adopted as the saturable absorber mirror.The pulse duration is around 10ns while the pulse repetition rate is higher than 10kHz.The average output power of 70W is obtained with a slope efficiency of 36%.The diffraction limited beam quality in the thickness direction is obtained by controlling the pump beam diameter inside the slab.The laser head is very compact with size of only 60×74×150(mm).     

坑道内化爆冲击波的传播规律

装药在坑道内部爆炸时将产生沿坑道传播的空气冲击波,由于受到坑道洞壁的限制,空气冲击波在坑道内的传播规律异于在自由大气中的传播。利用三维数值模拟计算程序,对长坑道中的化爆流场进行了数值计算,归纳出空气冲击波沿坑道方向的传播规律。计算结果与试验结果符合较好。     

内爆炸加载条件下圆筒的膨胀、破裂规律研究

以经典热粘塑性本构关系 (John Cook本构关系和Powerlaw本构关系 )为基础 ,建立了更适当表征材料特征的新的、解耦的本构关系。采用SHPB(分离式霍普金森杆 )技术测定了常用弹箭材料 35CrMnSiA的不同应变率下的应力、应变关系 ,并采用拟合的方法确定了本构方程中的材料常数。与高速摄影技术测得的径向位移函数及圆筒材料的损伤演化方程相结合 ,建立了控制内爆炸加载圆筒膨胀 ,直至破裂的完备方程组 ,完成了内爆炸加载圆筒问题的数值模拟 ,计算结果与以往有关箭弹材料圆筒膨胀的实验结果符合较好。     

Optimal insider control and semimartingale decompositions under enlargement of filtration

We combine stochastic control methods, white noise analysis, and Hida–Malliavin calculus applied to the Donsker delta functional to obtain explicit representations of semimartingale decompositions under enlargement of filtrations. Some of the expressions are more explicit than previously known. The results are illustrated by examples.     

Structural Studies on Inclusion Compounds of β-Cyclodextrin with Some Substituted Phenols

A detailed structural study of the inclusion compounds of some substituted phenols such as catechol, guaiacol, protocatechuic aldehyde, vanillin, caffeic acid, ferulic acid and eugenol with -cyclodextrin (CD) was carried out by using UV-visible, fluorescence, 1H and solid-state 13C NMR spectroscopic and potentiometric investigations. Based on these studies guaiacol, catechol and eugenol were found to exhibit identical orientations - with the phenyl ring within the cavity and the hydroxyl and methoxyl groups projecting outside; protocatechuic aldehyde, caffeic acid, ferulic acid and vanillin display a different orientation - with the phenol part within the cavity and the aldehyde or carboxyl part projecting outside.     

DFT Studies on Non-IPR C68 and Endohedral Fullerene Sc3N@C68

The structures and spectra of 20 possible isomers of C78(CH2)3 have been studied by using AM1,INDO/CIS and DFT methods. The results show that the most stable isomer is 1,2,3,4,5,6-C78(CH2)3 (A) with annulene structures,where three -CH2 groups are added to the 6/6 bonds located at the same hexagon passed by the shortest axis of C78 (C2v). Compared with that of C78 (C2v),the first absorption in the electronic spectrum of C78(CH2)3 (A) is blue-shifted because of its wider LUMO-HOMO energy gap. While the IR frequencies of the C–C bonds on the carbon cage are red-shifted owing to the formation of annulene structures and the extension of the conjugated system. The chemical shifts of the carbon atoms in 13C NMR spectra are moved upfield upon the addition.