Condensed Cramer rule for some restricted quaternion linear equations

In this paper, we derive an alternative more condensed Cramer rule for the unique solution of some restricted left and right systems of quaternion linear equations. The findings of this paper extend some known results in the literature.     

The rotational dimension of a graph

Given a connected graph G = (N, E) with node weights s∈? and nonnegative edge lengths, we study the following embedding problem related to an eigenvalue optimization problem over the second smallest eigenvalue of the (scaled) Laplacian of G: Find v_i∈?^|N|, i∈N so that distances between adjacent nodes do not exceed prescribed edge lengths, the weighted barycenter of all points is at the origin, and is maximized. In the case of a two‐dimensional optimal solution this corresponds to the equilibrium position of a quickly rotating net consisting of weighted mass points that are linked by massless cables of given lengths. We define the rotational dimension of G to be the minimal dimension k so that for all choices of lengths and weights an optimal solution can be found in ?^k and show that this is a minor monotone graph parameter. We give forbidden minor characterizations up to rotational dimension 2 and prove that the rotational dimension is always bounded above by the tree‐width of G plus one. © 2010 Wiley Periodicals, Inc. J Graph Theory 66:283‐302, 2011     

Trigonometric Widths and Best N-Term Approximations of the Generalized Periodic Besov Classes BΩp,θ

In this paper,we determine the estimates exact in order for the trigonometric widths and the best n-term trigonometric approximations of the generalized classes of periodic functions BΩp,θ in the space Lq for some values of parameters p,q.     

An accurate theory for the square-well potential: from long to short well width

Density function theory (DFT) is combined with the first-order mean spherical approximation (FMSA) to study the radial distribution function (RDF) of the square-well (SW) potential. The combination (DFT + FMSA) is based on the direct correlation function (DCF) of the FMSA. Upon comparison with computer simulation data, DFT + FMSA is shown to give better performance than FMSA for mid- and long-range attractions. For short-range and very short-range attractions, the theory successfully corrects the deficiencies of the original FMSA. Comparisons include the evaluation of contact values, gap height at a discontinuity and profiles of the RDF. This work provides an accurate and consistent way to handle the SW potential.     

衍射光强取样分析法测定划痕宽度：实验部分

根据衍射光强取样分析法理论部分的测量原理设计了一套实验方案，比较了该方法一义、显痛实际宽度的测试结果，给出了其对测量误差，并分析了误差的主要来泊，该方法速度快，精度高，有推广和应用的价值。     

LP—MOCVD研制InGaAs/InP应变量子阱LD

本文指出在LP-MOCVD生长过程中,采用量子阱有源区和上限制层不同的生长温度以及生长非掺杂过渡层等技术能有效地控制InGaAs/InP量子阱激光器的p-n结结位,给出了采用DEZn和H₂S做掺杂源在InP材料中p型和n型杂质溶度和p-n结控制的条件,并研制出有源区阱层InGaAs与InP存在0.5%压缩应变量子阱激光器,这一结构LD实现室温脉冲激射,得到峰值功率为106mW以上,阈值电流密度为2.6kA/cm².     

塞曼效应与边缘离子温度的光谱测量

通过理论推导得到了谱线实际宽度和塞曼展宽之间的关系。在磁感应强度分别为1、2、2．5和3T的情况下，用数值方法进行了求解，用得到的结果拟合出了校正因子随离子温度变化的经验公式和拟合曲线，结果表明：离子温度较低时，塞曼效应对谱线宽度的影响很大，温度较高时，塞曼效应对谱线宽度的影响可以忽略。     

量子阱中的束缚极化子的路径积分变分研究

利用Feynman路径积分变分方法，推导了整个电声子耦合区域的量子阱中束缚极化子的基态能。对其数值结果研究表明：当量子阱的约束势达到一定值，极化子的基态能修正－△E随电声子耦合常数α的增加激剧增大，约束势导致有效电声子耦合从无约束势时的弱耦合向居间耦合或强耦合渡越。更重要的是，我们发现存在一个量子阱的临界有效宽度lz0,当lZ小于临界值时，－△E随lz变小很快增大；当lz大于临界值时，随lz变大，－△E几乎不变。