The geometric potential of a double-frequency corrugated surface

For an electron confined to a surface reconstructed by double-frequency corrugations, we give the effective Hamiltonian by the formula of geometric influences, obtain an additive scalar potential induced by curvature that consists of attractive wells with different depth. The difference is generated by the multiple frequency of the double-frequency corrugation. Subsequently, we investigate the effects of geometric potential on the transmission probability, and find the resonant tunneling peaks becoming rapidly sharper and the transmission gaps being substantially widened with increasing the multiple frequency. As a potential application, double-frequency corrugations can be employed to select electrons with particular incident energy, as an electronic switch, which are more effective than a single-frequency ones.     

Manipulating electronic and magnetic properties of black phosphorene with 4d series transition metal adsorption

We carry out first-principles calculations within density-functional theory to investigate the structural, electronic and magnetic properties of 4d transition metal (TM) decorated monolayer black phosphorene (BP). The results indicate that the TM adsorption on BP can have dilute magnetic semiconductor (DMS) properties. The spin polarized semiconducting state is realized in BP by adsorption of Y, Nb and Ru, while a half-metal state is obtained by Tc adsorption. In the case of two same types of TMs adsorption on BP, only [email protected] shows DMS state. In particular, two different types of TMs decorated BP can induce magnetic moments, localized mainly on the 4d TMs and the neighboring P atoms. Furthermore, the 4d TMs may enrich the electronic properties of BP, such as half-metallic, metallic and semiconducting features. These findings suggest that the 4d TM adsorbed BP can be used as a potential next-generation spintronics and magnetic storage material.     

Green synthesis and application of nanoscale zero-valent iron/rectorite composite material for P-chlorophenol degradation via heterogeneous Fenton reaction

A zero-valent iron/rectorite nanocomposite (NZVI/rectorite) was developed as a heterogeneous H₂O₂ catalyst for P-chlorophenol degradation. The physicochemical properties of NZVI/rectorite were characterized by various techniques including X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive spectrometry, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller analysis. Results showed that NZVI sphere nanoparticles were successfully loaded on the rectorite surface with less aggregation and good dispersion. Moreover, compared with acid-leached rectorite (30.91 m²/g), the NZVI/rectorite appeared to have larger surface area (50.75 m²/g). In addition, the effects of pH, reaction time, initial P-chlorophenol concentration, catalyst amount, and H₂O₂ dosage on the P-chlorophenol degradation were systematically investigated. Results showed that NZVI/rectorite presents better properties for the degradation and mineralization of P-chlorophenol compared with pristine NZVI due to the large surface area, low aggregation, and good dispersion of the former. The degradation mechanisms of P-chlorophenol by NZVI/rectorite were adsorption and reduction coupled with a Fenton-like reaction. Four successive runs of the stability and regeneration study also showed that the NZVI/rectorite were unchanged even after 100% of P-chlorophenol degradation ratio. This study has extended the application of NZVI/rectorite as environment function material for the removal of P-chlorophenol from the environment.     

Coordination numbers for rigid spheres and local compositions

The coordination numbers of rigid spheres were simulated on a computer to obtain an improved empirical equation when surrounding spheres are of uniform size. In the case of two different species of surrounding spheres, the coordination numbers vary as a function of local composition and radius ratios. By fitting simulation results, correlations were proposed, which are expected to be of practical use in thermodynamic of real solutions.     

400GeV/cpp碰撞多粒子产生的自仿射分形

利用４００ＧｅＶ／ｃｐｐ碰撞多粒子产生的实验数据进行了自仿射分形分析，并与自相似分析相比较，结果表明在实验分辨能力范围内，自仿射分形分析具有嵔虾玫谋甓刃形     

局部组成模型在K+,Na+∥Cl-,SO2-4,NO3--H2O体系中的应用

首次将电解质溶液的局部组成模型用于新疆罗布泊硝酸钾矿所属体系K^ ，Na^ ／／C^-，SO4^2-，NO3^-，H2O五元体系。利用前期研究所获得的盐的活度积、盐-盐作用参数。预测了该体系及其所包含的五个四元体系的溶解度,除五元体系稍有偏差外,其他体系均与文献值符合较好．     

中国股市价格-交易量动态因果关系研究

研究了中国股票市场交易量是否含有预测未来收益变动的有价值信息 .实证结果表明 :交易量和收益序列存在即期的正相关关系 ;过去交易量包含未来绝对收益变动的有价值信息 ;中国股票市场交易量和收益序列存在双向的线性因果关系 ,交易量不仅传递价格绝对变动量的信息 ,而且在很大程度上还传递价格变动方向的信息 .     

Determination of90Sr and 137Cs concentrations in the IAEA reference material Soil-6

Vezetéknév This revised version was published online in August 2006 with corrections to the Cover Date.     

关于地质时间本质的思考

通过对新疆北部志留—泥盆系界线的讨论，以及对乌吐布拉克组的地层归属问题的探讨，和国际志留—泥盆系界线的理论根据的浅析，提出地质时间本质的含义。