2,2’—二硫代双(4,6—二叔丁基苯酚)的晶体和分子结构

一种塑解剂经高压液体色谱分离制备出主要成份2,2′—二硫代双(4,6二叔丁基苯酚)。由质谱分析得到分子量为474化学式为C_(28)H_(2)O_2S_2、晶体呈现孪生。基体单晶属三斜晶系,空间群为(?)PI(NO.2),晶体结构用直接法解出,=0.07。研究结果表明该分子是二硫代酚类化合物。在EI场中,S—S键断裂是主要断裂过程。晶体中,分子的一个环上的羟基是无序分布的。羟基与最邻近的硫原子形成氢键。     

Micromagnetic analysis of transition noise for high-density perpendicular recording

In this paper, specific issues related to high-density perpendicular magnetic recording processes, such as transition noise properties and cross-track correlation lengths, were investigated with the help of micromagnetic analysis. The effects of media parameters were taken into consideration, including intergranular exchange coupling, and exchange distribution, irregular grain shapes, magnetization saturation distribution, and anisotropy distribution. The micromagnetic simulation results showed that the effect of anisotropy distribution on transition noise is more significant than magnetization saturation distribution, and it is crucial to reduce this effect to achieve a high signal-to-noise ratio. Additionally, a new method to further estimate the partial erasure threshold was proposed to approximate the partial erasure effects, and the relation between the microtrack jitter and total track jitter was investigated.     

On existence of solutions for some hyperbolic-parabolic-type chemotaxis systems

In this paper, we discuss the local and global existence ofweak solutions for some hyperbolic–parabolic systems modellingchemotaxis.     

Numerical solution of differential equations using Sinc method based on the interpolation of the highest derivatives

In general, we will use the numerical differentiation when dealing with the differential equations. Thus the differential equations can be transformed into algebraic equations and then we can get the numerical solutions. But as we all have known, the numerical differentiation process is very sensitive to even a small level of errors. In contrast it is expected that on average the numerical integration process is much less sensitive to errors. In this paper, based on the Sinc method we provide a new method using Sinc method incorporated with the double exponential transformation based on the interpolation of the highest derivatives (SIHD) for the differential equations. The error in the approximation of the solution is shown to converge at an exponential rate. The numerical results show that compared with the exiting results, our method is of high accuracy, of good convergence with little computational efforts. It is easy to treat nonhomogeneous mixed boundary condition for our method, which is unlike the traditional Sinc method.     

AFC^＊一代数上的映射

本文讨论AFC^＊一代数中的一些映射的线性性质和它们的局部性质之间的关系．研究AFC^＊一代数A上的保持乘法的局部自同构Ф在A中矩阵单位系上的作用。证明了Ф是A上的自同构。对于UHF代数上满等距的结构，还证明了UHF代数上的2-局部（满线性）等距是线性的．     

凸域内弦的平均长度

本文研究了凸域内弦的平均长度.通过广义支持函数与凸域的弦幂积分,建立了凸域内弦的平均长度的一般公式,并用此公式得出了圆域和矩形域内弦的平均长度.     

Magnetically rotational reactor for absorbing benzene emissions by ionic liquids

A magnetically rotational reactor （MRR） has been developed and used in absorbing benzene emissions. The MRR has a permanent magnet core and uses magnetic ionic liquid [bmim]FeCl4 as absorbent. Benzene emissions were carried by N2 into the MRR and were absorbed by the magnetic ionic liquid. The rotation of the permanent magnet core provided impetus for the agitation of the magnetic ionic liquid, enhancing mass transfer and making benzene better dispersed in the absorbent. 0.68 g benzene emissions could be absorbed by a gram of [bmim]FeCl4, 0.27 and 0.40 g/g higher than that by [bmim]PF6 and [bmim]BF4, respectively. The absorption rate increased with increasing rotation rate of the permanent magnet.     

Field Quantization and Spontaneous Emission in Left-handed Material

Recently, research on left-handed materials （LHMs） has attracted considerable attentions. The LHMs are a kind of man-made metameterials which have negative permittivity and negative permeability. These metameterials have many novel properties such as inverse light pressure, and reverse Doppler effect, which lead to many potential applications of LHMs such as superlenses which, in principle, can achieve arbitrary subwavelength resolution. However, though the properties mentioned above are seen to be classical, the quantum phenomena in LHMs have also attracted attentions such as the modified spontaneous emission of atoms in LHME.