高能重离子碰撞中末态粒子快度分布的相对论动力论方程研究

用相对论动力论方程研究高能重离子碰撞时空演化,并利用它分析在s~(1/2)=31.2 GeV的α粒子束流下以及E_L=200 GeV/N的~(18)O粒子束流下末态粒子的快度分布,确定了不同系统的驰豫时间。     

一个N=1SUGRA统一模型

本文构造了一个定域超对称大统一SU(9)模型,讨论了规范对称破缺机制和由定域对称的辐射修正所引起的弱电对称性破缺。该模型容纳了三代通常费米子,具有重的色三重态,轻的WS二重态和标量物质粒子,得到了较流行的定域超对称SU(5)模型好的低能结果。Sin~2θw=0.205,α_c=0.135,Mx=6.6×10~(15)Gev,Ms=4.4×10~(11)Gev,Mw=85Gev,24≤m_L≤125.3Gev.mb～4Gev。     

关于新粒子分类的讨论

为了进一步探索新粒子的强作用,必须首先讨论它们的分类。本文仅限于讨论Su_3~(1)(?)Su_3~(2)模型和Su_3(?)Su_4模型,分类所依据的实验事实是: (1) 质量谱m_j=3.095 Gev,m(2.8)=2.800 Gev m_φ=3.684 Gev,m(3.4)=3.4100 Gev m_(φ′)=4.100 Gev,m(3.5)=3.5300 Gev m_(φ″)=4.400 Gev, (2) e~ e~-电磁衰变, Γ(J→e~ e~-)=4.8±0.6 kev Γ(φ→e~ e~-)=2.4 kev Γ(J→e~ e~-)∶Γ(φ→e~ e~-)=2∶1 其余衰变过程留待下一步讨论。(3) 新粒子3095、3684是自旋为1,宇称为一,G宇称为一,同位旋为零的粒子。     

左右对称弱电统一理论中的新规范玻色子

对SU(2)_L×SU(2)_R×U(1)_(L R)弱电统一理论进行唯象分析,不依赖Higgs机制,通过和高能弱作用实验比较,确定了全部理论参数。给出了对新规范玻色子V~±和X°质量的自洽计算方法。求得了mv160Gev,mx200Gev。本文已提交1985年国际轻子光子会议。     

产生γ射线脈冲星的一种可能的新机制

1983年实验发现了中间玻色子z~0,其质量m～94Gev,寿命τ≤10~(-20)秒。最近欧洲核子研究中心意外发现z~0的反常衰变比重很大,规范场理论预言只有5/1000,而实验发现占1/3～1/4,约大数十倍之多。特别是z~0能衰变为重电子U~±,它的质量m_U～50Gev,目前知道z~0至少有这样四个哀变道:(1)z~0→e~+e~-;(2)z~0→e~+e~-γ;(3)z~0→e~+U~-;(4)     

关于097事例的几点推测

(一)近几年来高能物理认为的“大沙漠”——即能量E>100Gev不会有任何新现象出现,看来这一观点是不正确的。最近高能物理实验发现在150—200Gev能域中可能存在W~±、Z°和夸克的激发态。在E>59Tev出现mini-Centauro和Geminion(“重子”对衰变)事例,在E>203Tev出现Centauros事例等,这都表明它们具有结构,而非一片“大沙漠”。 (二)最近实验意外地发现中间玻色子Z°的反常衰变分支比很大,占1/4→1/3,比规范场预言大数十倍,而且还有相当一部份衰变为:     

新粒子

一九七四年十一月,有两个高能物理实验组宣布发现了一个质量约为3.1Gev,寿命约为10~(-20)秒的粒子。我们知道,以前已发现的质量为2—3Gev 的粒子,寿命一般为10~(-23)—10~(-24)秒。可是,这个粒子,质量虽然大到3.1Gev,寿命却仍相当长。因此,这个发现成了高能物理中的一件重要的事。其实,事情可以追溯到一九七○年。当时,在BNL 的一个实验组,在研究[P+Be→(μ~+μ~-)+任何粒子]时,发现(μ~+μ~-)对的不变质量分布在3—4Gev 区域有一个“肩”。但由于实验分辨率差,没有能够看出它是一个共振。以后,到一九七四年春天,丁肇中组开始在BNL 探测反应[P+Be→(e~+e~-)+任何粒子],由于此反应截面小,所以实验相当难。他们化了很多力量使仪器的能量分辨率比七○年的实验好得多,结果到七四年八月,已经清楚地看到,(e~+e~-)对的不变质量分布在3.1Gev 处有一个峰,宽度与仪器的分辨率一致,而且没有连续分布的背景。以后几个月,他们又进一步做各种试验,到十月底,已完全肯定了八月的结果,他们在十一月宣布了这个结果,并把这个粒子称之为J。     

新型双核铕配合物电致红光材料

合成并用元素分析、红外光谱和核磁表征了共振配合物EuY(DBM)4(Ma)phen2(C1)和Eu2(DBM)4(Ma)phen2(C2).用真空蒸镀组装了发光器件,其结构是:Al0.9:Ag0.1/Alq/Eu-complex/TPD/ITO.在18V电压和55 mA cm-2电流下,器件C1的最大发光亮度是342 cd m-2;在18V电压和57mAcm-2电流下,器件C2的最大发光亮度是267 cd.m-2.在18V电压和55 mA cm-2电流下,器件C1的最大发光亮度是342 cd m-2.C1的发光亮度比C2大,其原因是Y3 的配体吸收的能量通过马来酸根迁移给了Eu3 .     

囚禁与物化

本文分析了层子的囚禁和物化(强子化),指出它们是物质结构新层次里出现的新特点。根据囚禁和强子化之间有紧密联系的观点,提出了一个层子强子化的模型。这一模型认为强子化过程就是层子在引起囚禁的等效位势作用下多次辐射介子的过程。利用这一模型得到了喷注中的平均多重数按质心系能量的对数增长,喷注张角和能量成反比,以及平均横动量是常数的结论。这一结果和10Gev 以下e~ e~-湮没所产生的喷注结构相符,同时也和10Gev以上出现的三喷注事件中层子喷注的结构相符。     

多重产生Kendall分布参数的估计

指出对PP碰撞分布参数α≈4.55。为检验分布的普适性,我们采用1971—1982年的74组实验数据(PP21组、P10组、π~tP29组、K~tP14组,束动量9.1—405Gev/c)作曲线拟合,用最小二乘法直接计算α的值。即取     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of