非因子化方法研究D+→K0K+衰变

在领头阶和αs 修正阶,用QCD因子化方法,并对它的软胶子效应用光锥QCD求和规则分析D⁺→K⁰K⁺衰变过程,我们分析发现朴素因子化方法的结果远离实验结果,QCD因子化方法结果靠近实验结果,但是,在QCD因子化方法中,若考虑软胶子效应,其结果与实验结果相一致.另外,计算发现,软胶子效应在该衰变道中有相当大的贡献,因此不能被忽略     

瞬子效应在0++胶球的QCD求和规则中的作用

利用包含瞬子效应的QCD求和规则计算了0⁺⁺胶球的质量上限,结果为1.3GeV.还探讨了变动瞬子参量时对QCD求和规则的影响,发现包含瞬子修正的QCD求和规则在瞬子大小为1/3fm时变得很稳定     

含QCD修正的p-A碰撞Drell-Yan过程的核效应

在微扰QCD α_s级近似下,采用双重Q²重标度模型,计算了p-A碰撞Drell-Yan截面与p-N碰撞Drell-Yan截面之比,即核效应函数R_QCD(x_A,Q²).计算结果与没有QCD修正的R(x_A,Q²)值比较,在0.03≤x_A≤0.3之间都有不同程度的压低,与实验符合的情况有所改善.说明对核Drell-Yan过程核效应的研究,QCD修正是有一定意义的,并且在计入这种修正后,双重Q²重标度模型仍然是有效的.     

重夸克与轻夸克强子事例多重数差别

利用色偶极子模型计算了e⁺e^—→h′s轻夸克与重夸克强子事例多重数差别,结果与实验在误差范围内一致.并与微扰QCD模型及朴素模型的结果作了比较.     

π介子分布振幅及其相关的遍举过程

本文在QCD求和规则的基础上,通过分析π介子相关的遍举过程对QCD的检验情况,讨论了π介子分布振幅的行为,用一种尝试的分布振幅计算了F_π(Q²)和Br(χ→2π),得到的F_π(Q²)与实验数据相符合,Br(χ→2π)与实验数据在数量级上相符合.     

北京正负电子对撞机上QCD的精确检验

广义的Crewther关系式可以把正负电子湮没过程中强子产生的分支比R=σ(e⁺e^－→强子)/σ(e⁺e^－→μ⁺μ^－),同轻子核子深度非弹性散射中的Bjorken求和规则和Gross-UewellynSmith求和规则联系起来,提供一个没有标度和重整化方案任意性的有关量子色动力学(QCD)物理量的基本关系式.强子产生分支比R可以在升级后的北京正负电子对撞机或τ–粲工厂上进行精确的测量,从而提供对QCD的精确检验.     

ψ(2S)强衰变中矢量-张量介子末态的反常压制

利用在北京正负电子对撞机上北京谱仪采集的3.6×10⁶ ψ(2S)事例,测量了ψ(2S)新的强子衰变道ψ(2S)→ρα₂和K^*0K₂^*0+c.c.的分支比,发现二者相对于J/ψ的相应衰变道明显压制,破坏了微扰QCD理论预言的“15%规则”,从而继前已报道的ψ(2S)→ωf₂确认了另外两例末态为矢量与张量介子的ψ(2S)反常衰变.     

用改进的格点哈密顿量计算2+1维QCD0++胶球质量

用改进的格点哈密顿量和截断本征方程法计算2+1维QCD 0⁺⁺胶球质量,结果显示较好的标度行为.     

部分子关联函数的性质

利用共线极限下的时序微扰理论将关联函数的切割法则推广到包含ans(μ²)阶的微扰QCD修正,并指出该法则的适用范围.     

混合效应在QCD求和规则下对标量胶球质量的影响

在QCD求和规则的框架下考虑了纯胶球和普通介子态的混合效应对二者质量的影响.在关联函数的构造中,胶子流和夸克流都被认为既和胶球态有耦合,也和夸克态有耦合.利用QCD低能定理,构造了一个混合关联函数.通过这些关系及两共振态近似,得出了0⁺⁺胶球和夸克态的质量,它们与各自的纯态的质量相差不大.     

Observing electrochemiluminescence behavior of quinoline in acetonitrile at a glassy carbon electrode

Electrochemiluminescence (ECL) behavior of quinoline in acetonitrile at a glassy carbon electrode was studied. Quinoline in 0.1 mol/L tetrabutylammonium bromide (TBAB) acetonitrile solution exhibited excellent ECL properties using conventional cyclic voltammetry (CV). One ECL peak was observed at −0.5 V. Effects of various factors were investigated. UV-visible absorption spectra measurements confirmed the production of new products after cycling the mixed solution. Fluorescence and ECL spectra measurements got the evidence that the luminophors were the products of quinoline. A possible mechanism process was proposed.     

Electrogenerated chemiluminescence of benzo 15‐crown‐5 derivatives

Novel electrogenerated chemiluminescence (ECL) reagents C1 , C2 , and C3 with high fluorescence quantum yields bearing 15‐crown‐5 moiety have been synthesized and characterized. The photophysical, electrochemical, and ECL characters of these compounds have been studied in a 1:1 (v/v) PhH/MeCN mixed solvent. The ECL intensity is enhanced distinctly with the increase in the fluorescence quantum yield. Their ECL behaviors have been studied using annihilation and co‐reactant methods (tri‐n‐propylamine (TPrA) was used as a co‐reactant), respectively. The stable ECL emissions of compounds C1 – C3 can be ascribed to the typical and simple monomer ECL emission via S‐route. Copyright © 2008 John Wiley & Sons, Ltd.     

Potential-modulated electrochemiluminescence of a tris(2,2′-bipyridine)ruthenium(II) / lidocaine system under 430 kHz ultrasound irradiation

The electrochemiluminescence (ECL) of tris(2,2′-bipyridine)ruthenium(II) (Ru(bpy)₃²⁺) in the presence of lidocaine was investigated under ultrasound (US) irradiation. The sonoelectrochemical experiments are conducted by indirect irradiation of ultrasound with a piezoelectric transducer operating at 430 kHz. In a supporting electrolyte at pH 11, the Ru(bpy)₃²⁺/lidocaine system gave weak ECL peaks around +1.2 V and +1.45 V, respectively. The ECL signal at +1.2 V was attributed to redox reactions of the oxidative intermediates of Ru(bpy)₃²⁺ and lidocaine, while the signal at +1.45 V was assumed to be caused by an advanced oxidation process due to the generation of hydroxyl radicals (OH) at the electrode surface. In this study, the potential modulation approach is employed in the study of ECL process upon US irradiations because it can suppress the noise components from sonoluminescence effectly and improve the resolution of ECL-potential profiles. It is found ECL signals were greatly enhanced upon US irradiation at the output power of 30 W, however, the relative intensity of ECL signal at +1.2 V was larger than that obtained with a rotating disk electrode even though the mass transport effect is equilvalent. The experiment results suggest that the chemical effect (i.e., generation of OH) by 430 kHz US becomes remarkable in the electrochemical process. Detailed ECL reaction routes under US are proposed in this study.     

CdSe/ZnS电化学发光法测定去甲肾上腺素

以巯基丙酸为稳定剂制备了水溶性CdSe/ZnS量子点，并采用滴涂法制备了CdSe/ZnS修饰的金电极（CdSe/ZnS/GE），研究其电化学发光（ECL）性质，考察了pH、CdSe/ZnS浓度、扫描速度、静置时间等实验条件对ECL强度的影响。结果表明，在碱性溶液中，去甲肾上腺素（NE）在鲁米诺溶液中对CdSe/ZnS的电化学发光信号有明显的增敏作用，由此建立了一种检测去甲肾上腺素的新方法。当去甲肾上腺素的浓度（C_NE）在2.3×10^-5~1.0×10^-8 mol/L范围内时，去甲肾上腺素的浓度与相对电化学发光强度呈现良好的线性关系。线性回归方程为ΔI_ECL=118.788C_NE-15.333（R=0.994 4），最低检测限（S/N=3）为0.33×10^-8 mol/L。     

Electrogenerated chemiluminescence of chosen terbium complexes deposited into Al2O3 layer at the aluminium cathode

Cathodic electrogenerated luminescence of terbium(III)-(acetylacetonate)₃-1,10-phenanthroline, terbium(III)-(salicylate)₃ and terbium(III)-(salicylate)₃-1,10-phenanthroline complexes were studied. In this experiment terbium complexes were coated upon aluminium porous oxide layer by physical adsorption from methanolic or acetonate solution. The hexagonally ordered porous aluminium oxide has been prepared in a two-step anodization process in sulphuric acid solution. The primary step of cathodic ECL in this method is tunnel emission of hot electrons through barrier oxide layer. Electrochemiluminescence was achieved by recombination of the radical species, such as reduced ligand's aromatic moiety and strong oxidizing agent, i.e. sulphate radicals. This study was conducted to investigate ECL spectra, kinetic and integral ECL intensity relative to the porous aluminium oxide layer thickness.     

三联吡啶钌超分子包合物及其SiO2复合纳米粒的电化学发光信号放大

利用环糊精类物质能够形成超分子包合物的性质,研究了电中性的β-环糊精（β-CD）和负电性的羧甲基-β-环糊精（CM-β-CD）与电化学发光（ECL）活性物质三联吡啶钌（Ru（bpy）₃²⁺）形成超分子包合物的能力及其对ECL的增强作用。结果表明：形成的超分子包合物能够增强Ru（bpy）₃²⁺的ECL,其中CM-β-CD具有更强的增强作用。相对于Ru（bpy）₃²⁺,CM-β-CD增强了1.42倍,而β-CD仅为1.28倍。以制备的表面电荷为负的SiO₂纳米粒为载体,考察了其对Ru（bpy）₃²⁺超分子包合物的吸附能力。结果表明,与Ru（bpy）₃²⁺的CM-β-CD超分子包合物相比,SiO₂纳米粒载体对Ru（bpy）₃²⁺的β-CD 超分子包合物表现出了更强的吸附能力。制备了ECL信号放大能力最强的β-CD-Ru（bpy）₃²⁺超分子包合物的SiO₂复合纳米粒。     

核子(强子)结构和性质的QCD研究

核子 (强子 )是夸克、胶子的束缚态 ,由量子色动力学 QCD描述。由于 QCD的基本特性(高能标度下的渐近自由、低能标度下色禁闭及动力学手征对称性破缺 ) ,对核子 (强子 )结构和性质的 QCD图象是标度相关的 .在高能标度下描述强子的是与探测强子结构的硬过程相联系的QCD部分子模型 .强子的夸克、胶子结构信息通过 QCD部分子求和规则得到 .QCD微扰论是适用的理论 .在低能标度时 ,必须发展 QCD非微扰途径来描述核子 (强子 )物理 .这里简要地讨论各种非微扰途径 (格点 QCD、Dyson- Schwinger方程、有效场论、QCD求和规则 )的某些结果和进展 ,并指出 QCD真空结构在描述低能标度下强子物理中担任重要角色 . The nucleon (hadron) is the bound state of guarks and gluons, which is described by the quantum chromodynamics (QCD). Due to the basic properties of QCD (the asymptotic freedom at the high energy scale, the color confinement and the dynamical chiral symmetry breaking at the low energy scale), the QCD picture for the nucleon’s (hadron’s) structure and property is scale dependent. At high energy scale, the QCD parton model, which is relative to the hard process for testing the...     

ITO玻璃上鲁米诺的电化学发光行为研究

鲁米诺在ITO玻璃上有良好的电化学发光,检测灵敏度极高,检测下限可达到10-15mol.L-1数量级。研究表明,鲁米诺的电化学氧化反应分两步进行,均伴随有电化学发光产生。虽然第一步反应的发光相对较弱,但该电化学反应是可逆反应,对研究电化学发光传感器十分有利,结合ITO玻璃有良好的透光性,可进一步研制电化学发光流动电解池。文章还考察了电学参数和溶解氧对ITO玻璃上鲁米诺ECL的影响,并探讨了发光机理。     

Quantum chromodynamics

Quantum Chromodynamics (QCD) is a quantum field theory of the strong interaction with non-abelian gauge fields mediating the interactions between quarks. The experimentally observed strong interactions are to be epiphenomena of these fundamental interactions. The experimental successes of QCD form the basis for our present optimism that a theory of the strong force has been found. However, QCD is still very vulnerable to default on both experimental and theoretical grounds. In this article we offer the reader a review of the properties and attempted solutions of QCD. Each section of this review can be read independently of the others. In the introduction we describe the properties of QCD and the hoped for confinement and PCAC phase transitions. This is followed by a section on the renormalization of non-abelian gauge field theories: the functional methods and the path integral, the BPHZ program, the BRS transformation and proof of renormalizability, the Slavnov-Taylor identities and Schwinger-Dyson equations. The renormalization group equations are derived and applied to physical processes. Two dimensional prototypes of QCD, the abelian Schwinger model and 2-D QCD, are reviewed. An extensive review of the perturbative development of QCD is given with emphasis on infrared divergences, exponentiation of leading logarithms, the Cornwall-Tiktopoulos equation and a non-perturbative approach to QCD. A self contained section on topological solitons follows with discussions of homotopy theory, vortices, monopoles and especially instantons, and the periodic vacuum. Recent results, the attempt to study phase transitions in QCD using the dilute gas approximation and Borel resummations in QCD, are examined. Most of the major areas of interest in QCD are covered in this review; the prime exceptions are lattice gauge theories and phenomenological QCD like the parton and potential models.