Phase transitions and positive definite couplings

The method of infrared bounds is extended to a large class of nearest neighbour interactions in classical spin systems. Temperature controlled bounds on fluctuations follow whenever the coupling function is a positive definite kernel. Existence of phase transitions is demonstrated for the RP ^Nmodel for d3.     

A high-temperature laser ion source for trace analysis and other applications

We report here on the development of a high-temperature laser ion source useful for trace analysis and other applications. It consists of a high temperature ionization chamber, three tunable dye lasers pumped by copper vapor lasers for stepwise resonant ionization and a Mattauch-Herzog mass spectrometer for the analysis of photo-ions. The principle of the laser ion source and its theoretical efficiency are discussed, where the efficiency of a laser ion source is the ratio of photo-ions extracted out to the number of atoms introduced into the cavity. Experimentally, an efficiency of 2×10^–3 has been achieved for technetium. The scheme of gated detection is described which is used for suppressing isobaric background of molybdenum. The possible improvements are briefly mentioned for achieving isotopic analysis of 10⁸ atoms of ^97,98Tc in the presence of 10¹⁵ atoms of molybdenum, as separated chemically from molybdenum ore. Such an analysis of technetium isotopes produced in molybdenite ore by a (v,e ^–) reaction, is expected to yield information about the solar neutrino flux.Permanent address: Bhabha Atomic Research Centre, Bombay 400085, India     

F-H实验仪与光栅光谱仪连用观测253.7nm谱线

通过F-H实验仪和光栅光谱仪的连用，可实时观测汞原子从6s6s1So态激发到6s6sSP1态，退激时，辐射出能量为4．9eV的光量子，其波长为253．7nm．     

On the euler equation: Bi-Hamiltonian structure and integrals in involution

We propose a bi-Hamiltonian formulation of the Euler equation for the free n-dimensional rigid body moving about a fixed point. This formulation lives on the physical phase space so(n), and is different from the bi-Hamiltonian formulation on the extended phase space sl(n), considered previously in the literature. Using the bi-Hamiltonian structure on so(n), we construct new recursion schemes for the Mishchenko and Manakov integrals of motion.     

Modular inclusion,the Hawking temperature,and quantum field theory in curved spacetime

A recent result by Borchers connecting geometric modular action, modular inclusion and spectrum condition, is applied in quantum field theory on spacetimes with a bifurcate Killing horizon (these are generalizations of black-hole spacetimes, comprising the familiar black-hole spacetime models). Within this framework, we give sufficient, model-independent conditions ensuring that the temperature of thermal equilibrium quantum states is the Hawking temperature.     

Mirror supersymmetry in the space of (super) extended Poincaré algebras p(p,q)

We classify extended Poincaré Lie superalgebras and Lie algebras of any signature (p, q), i.e. Lie superalgebras and ₂-graded Lie algebras g = g₀ + g₁, where g₀ = s₀(V) + V is the (generalized) Poincaré Lie algebra of the pseudo Euclidean vector space V = ^{p, q} of signature (p, q) and g₁ is a spin 1/2 s₀(V)-module extended to a s₀-module with kernel V.As a result of the classification, we obtain, if g₁ = S is the spinor module, the numbers L ⁺(n, s) (resp. L ^–(n, s)) of independent such Lie super algebras (resp. Lie algebras), which are periodic functions of the dimension n=p+q (mod 8) and the signature s=p–q (mod 8) and satisfy: L ⁺(–n, s)=L ^– (n, s).Supported by Max-Planck-Institut für Mathematik (Bonn).Supported by the Alexander von Humboldt Foundation, MSRI (Berkeley) and SFB 256 (Bonn University).     

A study of the discrete Pv equation: Miura transformations and particular solutions

We derive the form of the Miura transformation of the discrete P_v equation and show that it is indeed an auto-Bäcklund transformation, i.e. it relates the discrete P_v to itself. Using this auto-Bäcklund, we obtain the Schlesinger transformations of discrete P_v which relate the solution for one set of the parameters of the equation to that of another set of neighbouring parameters. Finally, we obtain particular solutions of the discrete P_v (i.e. solutions that exist only for some specific values of the parameters). These solutions are of two types: solutions involving the confluent hypergeometric function (on codimension-one submanifold of parameters) and rational solutions (on codimension-two submanifold of parameters).     

BaFCl∶Eu~（2＋）中F色心的浓度和光激励截面与温度和紫外线的辐照波长的关系

本文研究了ＢａＦＣｌ∶ＥＵ（２＋）在不同波长的紫外线辐照和不同的测定温度下的光激励发光性质．通过改变激励方式及激励光的扫描方向，给出了ＢａＦＣｌ∶Ｅｕ（２＋）光激励发光过程中，两种Ｆ色心的浓度比值和光激励截面比值与紫外线辐照波长和测定温度的关系．同时我们还研究了在激励读出过程中，对应两种Ｆ色心的光激励发光强度与激励温度的关系，并且给出了相应于Ｆ（Ｃｌ－）心的热激活能．     

利用体内~（19）FNMR研究5─氟尿嘧啶在小鼠肝脏及肿瘤组织中的代谢过程

利用体内１９ＦＮＭＲ研究了５─氟尿嘧啶在小鼠肝脏及植入肿瘤组织中的代谢过程．５─氟尿嘧啶在肝脏中的生物半衰期为１５～２０ｍｉｎ，而在Ｓ１８０肿瘤中的生物半衰期为５０─６０ｍｉｎ．除５─氟尿嘧啶的信号外．在肝脏中观测到了５─氟尿嘧啶的分解代谢产物ＦＵＰＡ和ＦＢＡＬ，而在肿瘤中则只有合成代谢产物氟代核苷酸的信号．实验结果表明．核磁共振是研究药物在体内代谢过程的有力方法．     

基于法布里-珀罗腔反射光相位特性设计的梳状滤波器

提出了一种用于设计密集波分复用全光网络中梳状滤波器的方法,该器件利用法布里-珀罗腔反射光相位的非线性性质,结合光的相位在一定光程差下随频率呈线性周期变化的特点,通过使这样两束相位匹配的光发生干涉,得到所需滤波特性。运用江膜特征矩阵对模型进行了模拟计算,并分析了计算结果,论证了这种结构的可行性。