He—H2非弹性碰撞截面理论研究

当Ｈｅ原子入射能量Ｅ＝０．０５ｅＶ时，计算了Ｈｅ－Ｈ２碰撞弹性散射（００－００）和第一激发态（００－０２）的角分布（微分散射截面）。最多计算５０个分波，使弹性散射和碰撞激发的散射截面收敛。     

新疆山地森林鸟类的分布及食性和营巢特征的初步研究

通过对新疆山地森林鸟类的考察和研究,将其归结为137种另30亚种,对其分布特征、栖境、食性、营巢进行了研究,并发现鸟类的分布对山地森林的发育情况呈现出某种一致性.     

Energy Distributions of the Szekeres Universes in Teleparallel Gravity

In order to evaluate the energy distribution (due to matter and fields including gravitation) associated with a space-time model of Szekeres class I and II metrics, we consider the Einstein, Bergmann–Thomson and Landau–Lifshitz energy definitions in the teleparallel gravity (the tetrad theory of gravitation (TG)). We have found that Einstein and Bergmann–Thomson energy distributions give the same results, Landau–Lifshitz distribution is disagree in TG with these definitions. These results are the same as a previous works of Aygün et al., they investigated the same problem by using Einstein, Bergmann–Thomson, Landau–Lifshitz (LL) and Møller energy-momentum complexes in GR. However, both GR and TG are equivalent theories that is the energy densities are the same using different energy-momentum complexes in both theories. Also, our results are support the Cooperstock’s hypothesis.     

氢化与非氢化石墨烯纳米条带的密度泛函研究

基于密度泛函理论的第一性原理计算方法,研究了宽度N=8的边缘氢化和非氢化条带的结构和电子性质. 研究表明,扶手形无氢化石墨纳米条带的边缘碳原子是以三重键相互结合,它在边缘的成键强度比氢化时要高,具有更强的化学活性,可作为纳米化学传感器的基础材料. 能带结构计算表明,无论是扶手形条带还是锯齿形条带,它们都是具有带隙的半导体,且无氢化条带的带隙要比氢化的条带带隙宽度大,氢化对于条带的电子性质具有显著修饰作用. 通过锯齿形石墨纳米条带顺磁性、铁磁性和反铁磁性的计算,发现反铁磁的状态最稳定,并且边缘磁性最强,这有利于条带在自旋电子器件中的应用. 关键词： 石墨纳米条带 成键机理 电子结构 自旋分布     

Analytical estimation of ATF beam halo distribution

In order to study the backgrounds in the ATF2 beam line and the interaction point (IP), this paper has developed an analytical method to give an estimation of the ATF beam halo distribution based on K. Hirata and K. Yokoya''s theory. The equilibrium particle distribution of the beam tail in the ATF damping ring is presented, with each electron affected by several stochastic processes such as beam-gas scattering, beam-gas bremsstrahlung and intra-beam scattering, in addition to the synchrotron radiation damping effects. This is a general method which can also be applied to other electron rings.     

Effect of Al3+ substitution on structural,cation distribution,electrical and magnetic properties of CoFe2O4

We present the structural, cation distribution, electrical and magnetic studies of CoAl_xFe_2−xO₄ (x = 0.0, 0.2, 0.4, 0.6, 0.8) ferrites. The Rietveld-fitted X-ray diffraction (XRD) patterns confirm the formation of single-phase cubic spinel structures with $Fd\overline{3}m$ space group for all the samples. A comprehensive analysis of XRD-based cation distribution has been performed to see the effect of Al³⁺ ions substitution on various structural parameters such as site ionic radii, edge length, bond length and interionic distances. The dielectric constant and direct current (DC) conductivity decreases with increasing Al³⁺ substitution up to x = 0.4. However, with further increase in Al³⁺ substitution, both the dielectric constant and the DC conductivity increase. The presentation of dielectric data in the complex electric modulus form reveals the presence of a non-Debye-type relaxation behaviour in the considered ferrites. The power law behaviour of alternating current (AC) conductivity indicates a strong correlation among electrons in these systems. The isothermal magnetisation versus applied field curves with high-field slope and significant coercivity suggest that the studied materials are highly anisotropic with canted spin structures. The samples exhibit ferrimagnetic behaviour at 300 K and the magnetisation decreases with increasing Al³⁺ concentration. The as-prepared samples are promising candidates for various industrial applications.     

Long-range triplet Josephson current driven by the bias voltage

We study the long-range triplet Josephson current in a clean junction composed of two s-wave superconductors and a normal-metal/ferromagnet/normal-metal trilayer. Through applying the bias voltages on the metal regions by two antiparallel half-metal electrodes, we show that the amplitude and direction of this long-range current can be controlled flexibly. Such current arises from the fact that the applied voltage can produce a nonequilibrium spin-dependent quasiparticle distribution in the metal regions so that the Cooper pairs entering these regions acquire extra momenta, which will lead to a spin-transition process in the metal regions. This process can produce the parallel spin-triplet pairs in the central ferromagnet layer. In particular, if the voltage is applied only to one metal region, we further find that the recently discovered long-range superharmonic Josephson current will appear because of the transport of an even number of parallel spin-triplet pairs.     

Distribution of electrical energy consumption for the efficient degradation control of THMs mixture in sonophotolytic process

Sonophotolytic degradation of THMs mixture with different electrical energy ratio was carried out for efficient design of process. The total consumed electrical energy was fixed around 50 W, and five different energy conditions were applied. The maximum degradation rate showed in conditions of US:UV = 1:3 and US:UV = 0:4. This is because the photolytic degradation of bromate compounds is dominant degradation mechanism for THMs removal. However, the fastest degradation of total organic carbon was observed in a condition of US:UV = 1:3. Because hydrogen peroxide generated by sonication was effectively dissociated to hydroxyl radicals by ultraviolet, the concentration of hydroxyl radical was maintained high. This mechanism provided additional degradation of organics. This result was supported by comparison between the concentration of hydrogen peroxide sole and combined process. Consequently, the optimal energy ratio was US:UV = 1:3 for degradation of THMs in sonophotolytic process.