A projection method and Kronecker product preconditioner for solving Sylvester tensor equations

The preconditioned iterative solvers for solving Sylvester tensor equations are considered in this paper.By fully exploiting the structure of the tensor equation,we propose a projection method based on the tensor format,which needs less flops and storage than the standard projection method.The structure of the coefficient matrices of the tensor equation is used to design the nearest Kronecker product(NKP) preconditioner,which is easy to construct and is able to accelerate the convergence of the iterative solver.Numerical experiments are presented to show good performance of the approaches.     

便携式拉曼光谱仪快速测定磷酸浓度

用便携式激光拉曼光谱仪测定磷酸浓度,利用P—O键对称伸缩振动峰(893—911cm-1)的峰值,以硝酸根特征峰为内标,建立了激光拉曼光谱法测定磷酸含量的模型,并对拉曼位移与磷酸浓度的关系进行了拟合。两种方法用于实际样品检测的结果准确度和精密度良好,均能够满足水体中磷酸含量测定的要求。     

双道原子荧光光谱法同时测定污泥中的砷和汞

利用硝酸-高氯酸消解处理试样,建立了原子荧光光谱法同时测定污泥中砷和汞的方法。并对消解体系、负高压、灯电流、载气流量、屏蔽气流量、硼氢化钠浓度等作了研究并予以优化。方法的线性范围:砷0.0—60.0ng/mL、汞0.0—6.0ng/mL,相关系数r≥0.9998;砷和汞的检出限均为0.03ng/mL;砷、汞相对标准偏差均不大于2%,试样加标回收率砷91.0%—104.0%和汞90.0%—96.0%。该方法操作简便、快速、灵敏度高,完全适用于污泥试样的检测。     

金叶含笑假种皮精油的提取与分析

通过水蒸气蒸馏法提取金叶含笑(Michelia foveolata)假种皮精油,并采用气相色谱-质谱联用法(GC-MS)对其化学成分进行鉴定.结果表明,金叶含笑假种皮精油提取率为1.30％ (V/W),共检出70个峰,鉴定了其中的61种化合物,61种化合物占挥发油总量的93.40％.其中桉树脑(10.41％)、芳樟醇(18.55％)、1a,2,3,4,4a,5,6,7b-八氢-1,1,4,7-四甲基-环丙苷菊(17.70％)、β-蒎烯(4.29％)、月桂烯(4.82％)、D-柠檬烯(2.79％)为主要成分.为金叶含笑精油的开发提供依据.     

普通物理实验“三层次”开放式教学模式中设计性实验研究

结合教学实践,探讨如何利用现有仪器设备和技术手段开发设计性实验项目,如何为学生自主选择设计性实验项目提供更宽泛的参考思路,从而更加有效地开展设计性实验课程.     

Interface interactions and the photoluminescence from asbestos-templated InP quantum wires

The photoluminescence of InP quantum wires embedded in the dielectric template has been studied by site-selective pump-probe spectroscopy. The enhancement of the emission in the spectral window around the pump frequency and the long-lasting memory of pumping have been observed and explained on the basis of changes in energy states of template defects under intensive pumping. The effect of wire–template interface upon the appearance of the photoluminescence spectrum is discussed.     

CRITICAL SCALING THEORY OF GENERALIZED PHASE TRANSITION AND ITS UNIVERSALITY

Generalized phase transition (GPT) refers to the transition process of material systems from one steady-state to another. It includes equilibrium phase transition (EPT) and nonequilibrium phase transition (NPT), and phase transitions intermediate between them. In this paper some results on the study of critical scaling relations of the NPT and EPT are obtained. We developed the critical scaling theory of EPT and advanced a universal critical scaling theory of GPT. The critical scaling relations(scaling laws) has more niversality. The critical exponents calculated from our theory are identical with the results of experiments and other theories about EPT and NPT systems. Because the basic model of the theory does not depend on the concrete material system, it has a certain unversality. Its results thus can be applied to generlized phase transition systems, such as the electrorheological fluid and magnetorheological fluid systems.     

Deformation of super Virasoro algebra in noncommutative quantum superspace

We present a twisted commutator deformation for N = 1,2 super Virasoro algebras based on GL_q(1,1) covariant noncommutative superspace.     

Relative Quasisymmetry and Quasimöbius Mappings in Quasi-metric Spaces

Acta Mathematica Sinica, English Series - The aim of this paper is to investigate the relationship between relative quasisymmetry and quasimöbius in quasi-metric spaces, and show that a...     

有极大次数的传递置换群

本文研究有有界运动的置换群,给出了非单位元恰有两个运动的有极大次数的传递置换群的结构和分类,推广了文献[1]的结果.