理想导电柱体电磁散射的有限差分法

本文提出一种新的求解二维电磁散射的数值方法。应用辐射边界条件将无限大空间的电磁散射问题限制在有限区域内,采用有限差分技术数值求解波动方程、辐射边界条件及散射体表面边界条件,从而获得理想导电二维散射体的表面感应电流及近场分布。本文给出的圆形、椭圆形及方形截面柱体的数值计算实例表明,这种方法可获得与本征函数级数解或矩量法解相当吻合的结果,大大优于表面辐射条件法的结果,表明这种方法可能成为代替现有解析或数值方法的有效方法。     

Post-self-repair process of neuron cells under the influence of neutral and cationic nanoparticles

Alkylated nanoparticles induce malignant lysosome damages and unrepairable genome injuries which cannot be caused by aminated nanoparticles. Therefore, cells exposed to alkylated nanoparticles initiate post-self-repair effect by down regulating Fbw7 and accumulating cyclin E to maintain the replication of injured DNA.     

Effects of mini-Umklapp processes on heat transport in superlattices

Superlattice Umklapp processes contribute to phonon-phonon scattering and limit the thermal conductivity of insulating superlattices. The temperature dependence of the thermal conductivity is predicted using Callaway's phenomenological relaxation time approximation.     

The possibility of suppressing a near-by interfering point source by using a mode-selective array in shallow water

It is suggested that the available information—the differences in both range and depth between a target point source and an interfering point source—in a shallow water channel should be processed by a vertical mode-selective array. The processing gain of the mode-selective array for suppressing the near interference point source is estimated theoretically.     

Pressure broadening and shift of the first diffuse series doublet of indium due to the presence of helium and argon

The shift and half-width of In λ 3039 and In λ3256 was measured in Ar and He under pressures up to one thousand p.s.i. The temperature of the absorption tube was 850°C for In λ 3039 and 930°C for In λ 3256. The van der Waals interaction constant for In/Ar was found to be 1·5 x 10^-30 and 8·6 x 10^-31 cm⁶/sec for In λ 3039/Ar and In λ 3256/Ar respectively. In λ 3256 exhibited a small red shift in He for the range of r.d. (from 1 to 16) of He employed.     

Extraction of plumes in turbulent thermal convection

We present a scheme to extract the velocity of buoyant structures in turbulent thermal convection from simultaneous local velocity and temperature measurements. Applying this scheme to measurements taken at positions within the convection cell where the buoyant structures are dominated by plumes, we obtain the temperature dependence of the plume velocity and understand our results using the equations of motion. We further obtain the scaling behavior of the average local heat flux in the vertical direction at the cell center with the Rayleigh number and find that the scaling exponent is different from that measured for the Nusselt number. This difference leads to the conclusion that heat cannot be mainly transported through the central region of the convection cell.     

Ce:KNSBN晶体衍射特性研究

在非同时读出条件下测量了Ce:KNSNB晶体两波耦合体光栅衍射效率随写入光强比、写入光偏振态和写入光夹角的变化关系,并与同时读出条件下衍射效率变化规律的测量结果进行了比较,发现二者基本一致.利用耦合波理论对实验结果进行了理论分析和拟合,拟合结果和实验数据较好的吻合.     

Relative energies of isomers of C36F2

The symmetry unrestricted C₃₆F₂ isomers formed from fullerene C₃₆, the initial symmetry of which is C_6v, C_6h, or D_2d, have been extensively studied with semi-empirical (AM1 and PM3) calculations. Based on the relationship between the isomer's stability and the adding positions, three patterns of the adding sites of F₂ moiety in the additive reactions have been deducted. The results of the π-orbital axis vector (POAV) analysis indicate that the chemical reactivity of C₃₆ is the result of the high strain in the C₃₆ cage. But, in order to form stable compounds, the effects, which guide the F₂ moiety to select carbon atoms in the C₃₆ cage, are dominated by the conjugate effect in C₃₆F₂ system rather than the strain release in the C₃₆ cage.     

关于直线拟合的注记

讨论了使残差的最大绝对值为最小准则和使残差的绝对值之和为最小的准则的直线拟合问题 ,采用线性规划可解决此问题 .最后讨论了多项式拟合的情况 .