The pressure dependences of elastic and lattice dynamic properties of AlAs from ab initio calculations

Ab initio calculations,based on norm-conserving nonlocal pseudopotentials and density functional theory(DFT),are performed to investigate the structural,elastic,dielectric,and vibrational properties of aluminum arsenide(AlAs) with a zinc-blende(B3) structure and a nickel arsenide(B81) structure under hydrostatic pressure.Firstly,the path for the phase transition from B3 to B81 is confirmed by analyzing the energies of different structures,which is in good agreement with previous theoretical results.Secondly,we find that the elastic constants,bulk modulus,static dielectric constants,and the optical phonon frequencies vary in a nearly linear manner under hydrostatic pressure.What is more,the softening mode of the transversal acoustic mode at the X point supports the phase transition in AlAs.     

Production of Tetraquark State T_(cc) at B-Factories

We study production of the tetraquark state Tcc via virtual photon at the B-factories in the QCD factor- ization framework. We predict the cross section of tetraquark state production in the leading order at the B-factories.     

对称广义中心对称半正定矩阵模型修正的矩阵逼近法及其应用

设X,B分别是实测的位移矩阵和载荷矩阵, C是有限元模型估计,找对称广义中心对称半正定矩阵(A)使‖C-(A)‖F=min(A:AX=B)‖C-A‖F.我们证明这样的(A)存在唯一,并应用它来修正动力模型.数值结果证明方法是行之有效的.     

ESTIMATIONS OF THE CONSTANTS IN INVERSE INEQUALITIES FOR FINITE ELEMENT FUNCTIONS

In this paper, we estimate the constants in the inverse inequalities for the finite ele- ment functions. Furthermore, we obtain the least upper bounds of the constants in inverse inequalities for the low-order finite element functions. Such explicit estimates of the con- stants can be used as computable error bounds for the finite element method.     

考虑变负荷能耗特性的技术经济最佳热化系数研究

最佳热化系数可指导热电联机组容量配置,实现热电联产经济效益的最大化。本文提出了考虑变负荷能耗特性的技术经济最佳热化系数确定方法,建立热电联产系统变工况分析模型,计算获得了案例机组的变负荷能耗特性,优化得到了技术经济最佳热化系数。结果表明：不考虑、考虑变负荷能耗特性的技术经济最佳热化系数分别为0.750、0.702,不考虑变负荷能耗特性年节约费用的偏差达22.0%,考虑变负荷能耗特性后可获得更加精准的热电联产技术经济效益。     

超临界水临界区域判定方法研究

对超临界水在临界区域进行合理的判定和区域划分,对于深入理解超临界水在临界过渡区域的流动和换热相关特征具有重要的作用。本文分析了超临界水从拟液态区向拟汽态区过渡的过程中,其导热系数、动力粘度、定压比热和膨胀系数等相关参数的变化规律特征,并归纳了已有超临界水在临界区域的划分判定模型。分析结果表明,在临界过渡区域,超临界水的流动特征参数和换热特征参数均会发生一系列连续剧烈的变化;只有同时考虑超临界水的膨胀特性和最大比热特性,才能更加合理地对临界区域进行划分。在此分析基础上,本工作完善了超临界水的三区分析判定模型,得到了新的超临界水在临界区域的判定划分数据,并由此拟合得到了新的超临界水分区边界计算关系式。新的计算关系式的误差范围在±0. 3℃之内,满足计算分析的要求。     

简谈普适气体常量R——贯穿普化教育的重要常量

The universal gas constant R is an important constant in physics, and one of the vital fundamental constant throughout the teaching of general chemistry. This article aims to present a general review about the universal gas constant to the science and engineering majored students, including its history, determination, physical meaning and applications in chemical education. The choice of R values under various conditions is also provided to help students better understand and master basic concepts.     

功能材料在蛋白质组研究中的应用进展

随着对蛋白质组鉴定深度、定量准确性及分析速度越来越高的要求,对蛋白质组学方法的研发提出了新的挑战。为了应对这些挑战,传统的蛋白质组学方法因其灵敏度低、准确性差以及耗时长等不足已经难以满足蛋白质组学研究领域不断提出的新需求。而将通过光、电、磁、热、化学、生化等作用合成具有特定功能的材料用于蛋白质组的研究,可以克服传统蛋白质组学分析技术的局限性,为蛋白质组学研究起到促进作用。该文对功能材料在蛋白质组研究中应用的新进展进行综述。     

一个对2,4,6-三硝基苯酚和Fe3+离子具有双重荧光传感行为的层状镉(Ⅱ)-有机配位聚合物

通过水热法合成了一个由三连接的2,3-喹啉二甲酸桥联扭曲的Cd²⁺八面体形成的二维层状配位聚合物[Cd（QDA）]_n（1）。该配合物发射出较强的蓝色荧光并具有很高的热稳定性和化学稳定性。更为重要的是,该配合物在乙醇分散体系中可快速识别痕量的2,4,6-三硝基苯酚和Fe³⁺离子,其对2,4,6-三硝基苯酚的淬灭常数（K_sv）和检测限（LOD）分别为6.61×10⁴ L·mol^-1和0.83 μmol·L^-1,对Fe³⁺离子的淬灭常数和检测限分别为1.74×10⁴ L·mol^-1和2.70 μmol·L^-1。     

A Complex Higher-Dimensional Lie Algebra with Real and Imaginary Structure Constants as Well as Its Decomposition

A new Lie algebra G of the Lie algebra sl（2） is constructed with complex entries whose structure constants are real and imaginary numbers. A loop algebra G corresponding to the Lie algebra G is constructed, for which it is devoted to generating a soliton hierarchy of evolution equations under the framework of generalized zero curvature equation which is derived from the compatibility of the isospectral problems expressed by Hirota operators. Finally, we decompose the Lie algebra G to obtain the subalgebras G1 and G2. Using the G2 and its one type of loop algebra G2, a Liouville integrable soliton hierarchy is obtained, furthermore, we obtain its bi-Hamiltonian structure by employing the quadratic-form identity.