两亲性嵌段聚合物的同步辐射小角x射线散射研究

应用同步辐射小角x射线散射(SAXS)方法研究了不同聚合条件下苯乙烯对乙烯基苯甲酸两亲性嵌段聚合物的聚集行为,结果发现该聚合物在选择性溶液中自组装形成胶束.胶束的形态和结构取决于嵌段聚合物的组成、浓度以及溶剂的性质等因素 关键词： 小角x射线散射 两亲性嵌段聚合物 分形维数 粒径     

MORPHOLOGY OF BLACK CARBON AEROSOLS AND UBIQUITY OF 50-NANOMETER BLACK CARBON AEROSOLS IN THE ATMOSPHERE

Different-sized aerosols were collected by an Andersen air sampler to observe the detailed morphology of the black carbon （BC） aerosols which were separated chemically from the other accompanying aerosols, using a Scanning Electron Microscope equipped with an Energy Dispersive X-ray Spectrometer （SEM-EDX）. The results indicate that most BC aerosols are spherical particles of about 50 nm in diameter and with a homogeneous surface. Results also show that these particles aggregate with other aerosols or with themselves to form larger agglomerates in the micrometer range. The shape of these 50-nm BC spherical particles was found to be very similar to that of BC particles released from petroleum-powered vehicular internal combustion engines. These spherical BC particles were shown to be different from the previously reported fullerenes found using Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry （MALDI-TOF-MS）.     

尘埃粒子的时空结构及其性质

讨论了尘埃粒子解的时空结构及其性质，导出了尘埃粒子的内空间的离散结构.证明了尘埃粒子内部的物质球是一个无坐标的平直球，因而具有最小的体积和整体的关联性.导出了在尘埃粒子的内外时空中的径向测地线并说明其连续性.阐述了由这个解所揭示的物质、引力与时空之间的内在联系. 关键词： 尘埃粒子 离散时空 测地线     

超子中子星性质的温度效应

从相对论平均场理论出发,考虑核子、超子和介子的相互作用,研究了温度对中子星组成粒子、状态方程和中子星质量等的影响.发现温度越高,超子在中子星内部出现时的重子数密度越低.当密度较高时,中子星的核心区主要由超子组成,即中子星转变成以奇异粒子为主要成分的超子星,并且这种转变受到温度的影响,温度越高,转变密度越低.由于超子的出现,中子星核心高密度区域的状态方程,对于不同温度,差别不大,所以有限温度中子星的最大质量都在1.8M_⊙附近.这与观测结果相符.     

Axisymmetric Collision Problem for Two Identical Elastic Solids of Revolution

A direct central collision of two identical bodies of revolution is studied. A nonstationary mixed boundary-value problem with an unknown moving boundary is formulated. Its solution is represented by a series in term of Bessel functions. An infinite system of Volterra equations of the second kind for the unknown expansion coefficients is derived by satisfying the boundary conditions. The basic characteristics of the collision process are determined depending on the curvature of the frontal surface of the bodies     

Letter: Models of Relativistic Particle with Curvature and Torsion Revisited

Models, describing relativistic particles, where Lagrangian densities depend linearly on both the curvature and the torsion of the trajectories, are revisited in D=3 space forms. The moduli spaces of trajectories are completely and explicitly determined using the Lancret program. The moduli subspaces of closed solitons in the three sphere are also determined.     

Letter: Axial Torsion-Dirac Spin Effect in Rotating Frame with Relativistic Factor

In the framework of spacetime with torsion and without curvature, the Dirac particle spin precession in the rotational system is studied. We write out the equivalent tetrad of the rotating frame, in the polar coordinate system, through considering the relativistic factor, and the resultant equivalent metric is a flat Minkowski one. The obtained rotation-spin coupling formula can be applied to the high speed rotating case, which is consistent with the expectation.     

Standardization of Methods for Characterizing the Surface Geometry of Solids

Since a comprehensive survey published in 1999 [1] much work was done in standardizing measuring methods to characterize the surface geometry of dispersed and/or porous solids and to certify reference materials. The present paper is an extension of a short communication [2]. It gives a survey on existing standards and reports on new drafts and proposals.     

Eigenvalue Spectrum of a Dirac Particle in Static and Spherical Complex Potential

It has been observed that a quantum theory need not be Hermitian to have a real spectrum. We study the non-Hermitian relativistic quantum theories for many complex potentials, and obtain the real relativistic energy eigenvalues and corresponding eigenfunctions of a Dirac-charged particle in complex statically and spherically symmetric potentials. Complex Dirac–Eckart, complex Dirac–Rosen–Morse II, complex Dirac–Scarf and complex Dirac–Poschl–Teller potential are investigated.     

单粒子势模型下价核子的密度分布

依据实验事实，利用单粒子势模型，计算了一些核态外层价核子的密度分布.计算给出了价核子在核外部分布的概率和贡献，以此作为晕核态的判断标准.通过研究均方根半径随结合能变化的规律，指出了晕核态存在的条件，尤其是质子晕核态存在的条件.这些对判断和寻找晕核态有现实的指导意义. 关键词： 单粒子势模型 价核子 密度分布 中子晕核态 质子晕核态