BARYON-MESON VERTEX STRUCTURE OF THE SYSTEM INCLUDING S QUARK

Baryon-meson vertex structure of the system including s quark was studied from one-gluon- exchange quark-antiquark pair creation model. The theoretical coupling constants are in good agreement with the experimental data except for the cases including π meson, in which the theoretical results are not large enough in comparison with the measured values.     

从培养能力的角度看设计性实验

针对传统实验那种安排过死、刻板机械的特点，把设计性实验运用于教具设计与制作课程之中，充分地培养了学生动手、动脑的综合能力。     

STUDYING NUCLEAR FISSION RATE FROM THE POINT OF VIEW OF BROWNIAN MOTION

The problem of the nuclear fission rate is studied from the point of view of Brownian motion. The Fokker-Plank equation is solved by means of the rate ei-genvalue method. The viscosity tensors, the inertia coefficients and the temperature are functions of nuclear deformation. Their effects on the fission rate are also stu-died.     

用数理统计确定回归方程的形式

从数理统计角度分析热敏电阻随温度变化的回归方程,得出的回归方程与理论公式形式一致,建议用Excel的数据分析工具对实验数据进行数理统计。     

SPECTROSCOPIC METHODS FOR CHARACTERIZATION OF NONVIRAL GENE DELIVERY SYSTEMS FROM A PHARMACEUTICAL POINT OF VIEW

Introduction of nucleic acids into mammalian and plant cells has become, in recent years, a well established procedure in basic and applied research, and the methods involved therein are now useful for the development of gene-based medicines as a new class of pharmaceuticals.

The incorporation of the gene of interest into a plasmid construct by molecular biology techniques, the complexation and condensation of nucleic acids by means of cationic agents, is the first step for enabling DNA to get into the cells of interest in a biologically active state. Monitoring this condensation procedure for scientific and quality control purposes is mostly performed by optical spectroscopy methods.

A fluorimetric, high-throughput-assay has been developed for the characterization of non-viral gene delivery systems. Protamine sulfate and cationic DOTAP liposomes were used to condense the plasmid DNA. The DNA was labeled with nucleic acid stains, and the quenching of fluorescence by the addition of condensing agents was measured. PicoGreen? was compared to a number of common nucleic acid stains (ethidium bromide, ethidium- homodimer-2, acridine orange, BOBO-1, POPO-1, TOTO-1, YOYO-1, BOBO-3, POPO-3, TOTO-3, YOYO-3, BO-PRO-1, PO-PRO-1, TO-PRO-1, YO-PRO-1, BO-PRO-3, PO-PRO-3, TO-PRO-3, YO-PRO-3), and was found to be an advantageous nucleic acid stain for the fluorimetric characterization of condensation. Stability of nucleic acid-dye complex, reproducibility and the signal-to-noise ratio make PicoGreen? a dye of choice for condensation experiments.

Condensation was quantified by the fitting of condensation curves to the “Hill equation”. Relative fluorescence intensity, Hill slope and kinetics of DNA-condensation provide the calculated values for advanced characterization of DNA-condensation.

Fluorescence spectroscopy are compared to agarose gel electrophoresis as another approach for biophysical characterization of DNA-condensation. Advantages and disadvantages of the two methods are discussed.     

隐形技术和物理

本文简要介绍了隐形技术的物理实质、隐形技术的种类及应用。     

STUDY OF THE REACTION K-p → πo Λ

It is shown that at high energy all available data for differential and integrated cross sections and the Λ-polarization in the reaction K^-p → π^o Λ can be fitted by using a simple Regge pole model with phenomenological residue functions. The characteristics of helicity and helicity non-flip amplitudes are also examined.     

THE STUDY AND PRODUCTION OF PWC'S FOR THE FIRST MODULE OF L3 HADRON CALORIMETER

This paper reports the study and production and the performance of 60 PWC's which were the first module of L3 hadron calorimeter.125 Volts plateau and 3.4%/100V plateau slope were obtained with the gas mixture of Ar:CO₂=80:20.We also checked the dark current of some chambers and found that the dark current could be reduced by "cooking".The chambers worked well when they were assembled in a calorimeter module and tested by the beam of SPS at CERN.     

从光子与光栅相互作用的观点来推演光栅方程

根据光的量子特性,假定光子与光栅相互碰撞,推导出光栅方程,并将其扩展到空间,提出空间光栅方程.     

从光子与光栅相互作用的观点来推演光栅方程

根据光的量子特性,假定光子与光栅相互碰撞,推导出光栅方程,并将其扩展到空间,提出空间光栅方程.     

ONE BOSON EXCHANGE N-N,N-Δ AND Δ-Δ INTERACTION FROM QUARK POTENTIAL MODEL

The equivalent one-boson-exchange potentials of the N-N, N-Δ and Δ-Δ interaction were calculated rigorously in momentum space with the vertex functions derived from quark-pair-creation model.The results of the N-N interaction were compared with those calculated approximately in coordinate space and the conventional one-boson-exchange potentials. A11 of the results indicate that they have very similar behaviour for the medium- and Long-range parts.     

RADIATIVE DECAYS OF CHAKMONIUM AND CONSTITUENT QUARK MASSES

The problems of both El and M1 transitions of charmonium are discussed in the nonrelativistic potential model. It is found that these problems could be resolved by assuming larger constituent quark masses. With m_c=2.50GeV, m_b=5.84GeV in the typical linear plus Coulomb potential model we get satisfactory results for the mass spectra, the El and M1 transition rates, and the relative values of leptonic widths for the ψ and T families. The implication of the large constituent quark masses is also discussed.     

过冷沸腾起始点和净蒸汽产生点的实验研究

本文报告了使用Ｒ－１２作工质进行的自然循环过冷沸腾起始点和净蒸汽产生点的实验结果。实验过程中使用可视化方法观察确定过冷沸腾起始点和净蒸汽产生点。在相当宽广的工质压力、入口过冷度及加热功率范围内研究了上述参数对过冷沸腾起始点和净蒸汽产生点的影响,在此基础上提出了计算自然循环过冷沸腾起始点和净蒸汽产生点的计算方法。     

THE ANTISYMMETRIC EFFECT OF NUCLEON AND QUARK IN SCATTERING PROCESS

Using the resonant group equation and considering the limiting case of interaction tending to zero, we investigate the antisymmctric effect of nucleon and quark in scattering process quantitatively. The following results are obtained: (ⅰ) The antisymmetric effect is equivalent to a short range interaction, whose range is about the rms radius of scattering particle. (ⅱ) The smaller the rms radius of the particle is, the broader the distributed energy range of the antisymmetrie effect. (ⅲ) The more the freedom of the particle is, the weeker the equivalent interaction. (ⅳ) When the mean kinetic energy per nucleon in the incident nucleus is larger sufficiently than the kinetic energy of nucleon in the target resulted from the uncertainty principle, the antisymmetrie effect can be neglected.     

NUCLEON-MESOK VERTEX INTERACTION FROM ONE GLUON EXCHANGE TRAkSITION POTENTIAL Vq→qqq—THE COUPLING- CONSTANTS AND THE FORPI FACTORS

In this paper the matrix elements of the nucleon-meson vertexes from one gluon exchange transition potential V_q→qqq are calculated by using the generator coordinate method. We have found that the coup1ing constants of the nucleon-meson vertexes are roughly in agreement with the experimental data and the form factors of the vertexes are quite like the Gauss functions.     

THE SPECTRAL REPRESENTATION OF PROPAGATOR FOR FERMION FIELD AND QUARK CONFINEMENT

The properties of fermion causal Green's function is discussed according to the theory of spectral representation. The definition of effective mass is established from the view point of field theory, and the approximate expression of S_F' (p) as |p²|«M² and the asymptotic formula of S_F' (p) as p²→+∞ is given. In terms of these result the problem of quark confinement is discussed. We find that: (ⅰ) Based on the theory of spectral re presentation the concept of relative confinement is allowed, and if renormalization effect is strong, the quarks can demonstrate definitely lighter effective mass when they are far away from the mass shell; (ⅱ) Based on the theory of spectral representation the concept of absolute confinement is unallowable, even the absolute confinement is taken as the limit of relative confinement. That is if the concept of absolute confinement is introduced, we must discard a part of elementary hypothesis of spectral representation theory.     

THE COMPOSITE MODEL OF LEPTON AND QUARK WITH ONLY ONE CONSTITUENT SCALAR

We propose a composite model of leptons and quarks containing two constituent fermions of spin 1/2 and a constituent scalar. The constituent fermions are massless and color singlets. Leptons, quarks and weak vector bosons are composites confined by SU(3)_H local gauge interaction, where leptons are made of three constituent fermions and quarks are two-body composites of a scalar and a fermion. The number of the constituent particles is less in our model. There are less exotic leptons and quarks. Quark-lepton parallelism holds. Weak interactions appear only at the composite level as residual short-range interactions among hypercolor singlets. The violation of parity occurs by the mechanism of dynamical symmetry breaking.     

THE DUAL ABSORPTIVE MODE AND πP ELASTIC SCATTERING REVISITED

Using the Regge pole phase rule for contrilbutions to both amplitudes the DAM is applied to ^πp elastic scattering in the p_lab≥10 GeV/c and |t|≤0.8(GeV/c)² region. It is found that the DAM has a mixed success in describing ^πp scattering. The p contribution to both amplitudes is in accord with the DAM while the f-non-flip contribution does not have a peripheral zero.The Pomeron imaginary part is in accord with the DAM with a non-negligible Pomeron phase so that the DAM approximation Rep=O is unsatisfactory. There is also a Pomeron-flip contribution contrary to the expectation of the model. The O-flip contribution is taken into account and a small f-flip contribution i s also required.     

三棱镜偏向角与棱镜顶角的关系

从几何光学理论系统地讨论了棱镜偏向角与顶角的关系,并由Matlab绘出棱镜顶角A与棱镜最小入射角、材料折射率n的关系曲线.结果表明,在测量三棱镜折射率及使用棱镜光谱仪时,对棱镜的顶角是有一定要求的.