Offset approximation based on reparameterizing the path of a moving point along the base circle

This paper presents a novel algorithm for planar curve offsetting. The basic idea is to regard the locus relative to initial base circle, which is formed by moving the unit normal vectors of the base curve, as a unit circular arc first, then accurately to represent it as a rational curve, and finally to reparameterize it in a particular way to approximate the offset. Examples illustrated that the algorithm yields fewer curve segments and control points as well as C^1 continuity, and so has much significance in terms of saving computing time, reducing the data storage and smoothing curves entirely.

First-Principles Investigation of Energetics and Electronic Structures of Ni and Sc Co-Doped MgH2

First-principles calculations were used to study the energetics and electronic structures of Ni and Sc co-doped MgH2 system. The preferential positions for dopants were determined by the minimal total electronic energy. The results of formation enthalpy indicate that Ni and Sc co-doped MgH2 system is more stable than Ni single-doped system. The hydrogen desorption enthalpies of these two hydrides are investigated. Ni and Sc co-doping can improve the dehydrogenation properties of MgH2. The lowest hydrogen desorption enthalpy of 0.30 eV appears in co-doped system, which is significantly lower than that of Ni doping. The electronic structure analysis illustrates that the hybridization of dopants with Mg and H atom together weakens the Mg-H interaction. And the Mg-H bonds are more susceptible to dissociate by Ni and Sc co-doping because of the reduced magnitude of Mg-H hybridization peaks. These behaviors effectively improve the dehydrogenation properties of Ni and Sc co-doped cases.

A New Approach for Impulsive Stabilization of Liu's System

刘的系统的一个冲动的控制计划在这份报纸被介绍。有在确定的时间的推动的一些不太保守的条件被提供，它能为刘的系统的冲动的控制保证全球 asymptotical 稳定性和全球指数的稳定性。我们也为等距离介绍稳定的区域的估计冲动的间隔。而且，一个解说性的例子被给显示出建议结果的有效性。

Violations of Bell Inequality, Cauchy-Schwarz Inequality and Entanglement in a Two-Mode Three-Level Atomic System

Violations of Bell inequality, Cauchy-Schwarz inequality and entanglement in a two-mode three-level atomic system are investigated. It is shown that there are some states, which are entangled but do not violate Bell inequality in this system. Moreover, the relations of violations of Bell inequality, Cauchy-Schwarz inequality, and entanglement are discussed in detail.

First-Principles Investigation of the Effect of M-Doped (M = Zr, Hf) TiCoSb Half-Heusler Thermoelectric Material

The M-doping (M = Zr, Hf) effects on the electronic structures and thermoelectric performance of TiCoSb were studied by first-principles calculations. The band structure analysis shows that substituting Ti with M does not change the band structures of these systems significantly. Most of the M-doped systems have a lower band gap value than that of TiCoSb;especially Ti0.5Zr0.5CoSb has the lowest energy band gap value of 0.971 eV. Besides, the amplitudes of the density of states in the region of the valence bands for M-doped systems show a similar but slightly higher value than TiCoSb. Those suggest that these compounds could have better thermoelectric performance than TiCoSb. The phonon dispersion relations show that the larger mass of Zr/Hf with respect to Ti lowers the optical modes and induces mixing with the acoustic branches. Our calculations offer a valuable insight on how to characterize complicated crystal structures of thermoelectric materials and optimize the material composition.

On the Weak Drop Property for Polar of Closed Bounded Convex Sets

We define and study the weak drop property for the polar of a closed bounded convex set in a Banach space which is both a generalization of the weak drop property for dual norm in a Banach space and a characterization of the sub-differential mapping x →(?)p(x) from S(X) into 2S(X) that is norm upper semi-continuous and norm compact-valued.

On Weighted L^p-Approximation by Weighted Bernstein-Durrmeyer Operators

In the present paper, we establish direct and converse theorems for weight-ed Bernstein-Durrmeyer operators under weighted L^p-norm with Jacobi weight w（x）=x^a（1-x）β.All the results involved have no restriction a,β〈1-1/p,which indicates that the weighted Bemstein-Durrmeyer operators have some better approxi- mation properties than the usual Bernstein-Durrmeyer operators.

Anomalous Hall Effect in Spin-Polarized Two-Dimensional Hole Gas with Cubic-Rashbsa Spin-Orbit Interaction

Based on the Kubo formalism,the anomalous Hall effect in a magnetic two-dimensional hole gas withcubic-Rashba spin-orbit coupling is studied in the presence of 5-function scattering potential.When the weak,short-rangeddisorder scattering is considered in the Born approximation,we find that the self-energy becomes diagonal inthe helicity basis and its value is independent of the wave number,and the vertex correction to the anomalous Hallconductivity due to impurity scattering vanishes when both subbands are occupied.That is to say,the anomalous Halleffect is not vanishing or influenced by the vertex correction for two-dimensional heavy-hole system,which is in sharpcontrast to the case of linear-Rashba spin-orbit coupling in the electron band when the short-range disorder scattering isconsidered and the extrinsic mechanism as well as the effect of external electric field on the SO interaction are ignored.

Two-Mode Steady-State Entanglement in a Four-Level Atomic System

We investigate the continuous variable entanglement in a four-level atom according to the criterion proposed by Duan et al.[Phys.Rev.Lett.84(2000)2722].The atomic coherence is introduced using two external classical driving fields.We study the steady-state entanglement of the system in the presence of losses,concluding that the creation of entangled states can be achievable under certain conditions.

Optimal multi-degree reduction of C-Bezier surfaces with constraints

本文提出了一种在L_2范数下C-Bézier曲面带约束条件的降多阶逼近最优方法。利用C-Bézier基函数的转换矩阵,得到了降阶曲面控制顶点的显式矩阵表示。结合指定的边界约束条件,该法利用于对分片连续曲面或细分子曲面同时降多阶逼近,所得到的系列降阶曲面整体上保持G^1连续。数值实验表明该方法的优质高效。

Some Properties of the Full Function Space and the Substitution Space

In this paper, an equivalent relation among the reflexivity, weak sequential completeness and bounded completeness in full function space is given. Some results on weakly sequential compactness of subset and the property （u） in substitution spaces are obtained.

A novel blue-emitting KCa_4(BO_3)_3:Ce^(3+)phosphor for white LED application

A blue-emitting phosphor KCa_4（BO_3）_3 doped with Ce^（3＋） was prepared by solid state reaction. Its phase purity and synthesis temperature were investigated by powder X-ray diffraction（XRD）. The optical properties were studied by photoluminescence（PL） and photoluminescence excitation（PLE） spectra. In addition, the temperature-dependent PL measurement was also carried out. The phosphor showed a broad and strong blue emission centered at 428 nm under near ultraviolet light excitation at 370 nm. Ce^（3＋） ions in the three Ca sites of the host showed the similar centroid shift（εc） and crystal field splitting（εcfs）. The quantum efficiency of the phosphor with optimal doping concentration was 68% of that of commercial blue phosphor BaMgAl_（10）O_（17）：Eu^（2＋）. It indicated the promising applicability as a blue-emitting phosphor for UV-converting white light-emitting diodes.

Output nonlocality and nonclassicality in a two-mode entanglement laser

Output nonlocality and nonclassicality for the two modes are investigated in an entanglement laser system. Within the framework of a quantum theory of multiwave mixing, nonlocality and nonclassicality are discussed according to the violations of Bell inequality and Cauchy-Schwarz inequality. It is found that both nonlocality and nonclassicality can be fulfilled in the outside cavity fields under certain conditions. It is also shown that there are some nonclassical states that do not show nonlocality.