A STUDY OF COMPLEX PARTICLE EMISSION IN THE PRE-EQUILIBRIUM STATISTICAL MODEL

A concept of the quasi-composite system in the process of the pre-equilibrium emission is presented in this paper. On the basis of the principle of detailed balance, the existence of the factor, [γ_βω(π_β, 0,ν_β, 0, E—U)/g_π,ν, has been proved with an account of the distinguishability between protons and neutrons. A formula for the rate of the complex particle emission in the pre-equilibrium process there by can be obtained. The theoretical calculation results fit the experimental data quite well, especially in the high energy part of the energy spectrum the agreement are much better than ever before.     

THE BEHAVIOR OF THE PHASE-SHIFT IN THE BAKAMJIAN-THOMAS THEORY

The behavior of the phase-shift of the Bakamjian-Thomas theory and its relationwith the phenomenological nuclear force V=V_RiV_I at high energy are explored.Two limits are obtained:It is found that the repulsive core with a sharp outer edge may induce a characteris-tic oscillation of Re δ₁,and Im δ₁ is sensitive to V₁.The conclusion is that the analy-sis of the phase-shift extending to higher energy is relevant in determining therepulsive core and the imaginary part of the nuclear force.     

A DISCUSSION OF THE STRENGTH AND THE RANGE OF THE PHENOMENOLOGICAL NUCLEAR FORCE USING EXPERIMENTAL DATA IN HIGH ENERGY SCATTERING

Under the framework of the Bakamjian-Thomas theory,we discuss the qualitativeproperties of the phenomenological nuclear force V=V_R-iV₁ at high energy arediscussed by a comparision with the small angle scattering data.Because these data inhigh energy are insensitive to the spin,we suppose that the nuclear force at highenergies is spin-independent.The followings are obtained:i)for the Gaussian potential,X₃≌200 MeV and β₃≌0.95 fm,which are thestrength and the range of V₁ respectively;ii)in V_R,there is no hard repulsive core.Under a rough estimation,supposingthe range β₁>0.45 fm,we find the strength of the repulsive force,X₁<480 MeV;iii)all parameters are vary very slowly with energy.     

INTRODUCTION OF THE CONCEPT OF THE DEPAIRING PROBABILITY TO EXPLORE NUCLEAR HIGH SPIN STATES

In order to explore nuclear high spin states,a physical concept of depairingprobability has been suggested,which is based on the CAP and the RAL effects inthe nuclear rotating system.We think that the depairing process,might be gradualat begin—then dramatic and finally gradual again.According to the concept ofthe depairing probability and the particle-rotor model,a formula for the spectrum ofrotational energy has been obtained,and the spectra for more than fifty nuclei have been calculated by using this for-mula.The calculated results are found to be in reasonable agreement with experi-mental data,and are able to reproduce the experimentally observed various backbending phenomena on the plots of g_eff—ω_eff².     

晶面结构非均匀性对金刚石晶形的影响

 不仅考虑表面能，同时也引入表面结构非均匀性自由焓G_stⁱ，通过热力学分析，解释了随着晶体的逐渐长大而{110}面常在金刚石的外形中消失的机理，并用逆推法计算了有关数值。     

GaInP材料生长及其性质研究

用常压MOCVD在半绝缘GaAs衬底上生长了Ga_xIn_1-xP(x=0.476～0.52)外延层,对外延层进行了X光双晶衍射、Hall和光致发光(PL)测试.77K下电子迁移率达3300cm²/V.s(浓度为1.4×10¹⁶cm^-3).载流子浓度随生长温度升高,随Ⅴ/Ⅲ比的增大而降低,并提出P空位(V_p)是自由载流子的一个重要来源,17KPL谱中,Ga_0.5In_0.5P(Tg=650℃,Ⅴ/Ⅲ=70)的峰能为1.828eV,半峰宽为19meV.另外,在1.849eV处还有一较弱的峰,GaInP峰能和其计算的带隙最大相差113meV,这可能与GaInP中杂质或缺陷以及其中存在有序结构有关.     

Ca2CuO3的高压结构性质研究

 采用金刚石压砧高压装置（DAC）,对具有Cu—O链结构的Ca₂CuO₃的多晶粉末样品进行了高压同步辐射能散X射线衍射实验。实验结果表明,在0～34 GPa压力范围内,Ca₂CuO₃晶体没有发生结构相变,用Birch-Murnaghan状态方程拟合,得到在压力导数B′₀=4时,零压体弹模量B₀=165.4±1.8 GPa。     

金属性氧化物LaCuO3的高氧压合成及Cu3+态的XPS研究

 本文在成功地用超高氧压（~6.5 GPa）及高温（~980 ℃）合成和结构测定的基础上，首次对金属性化合物中LaCuO₃中的Cu³⁺离子给予标定，并研究了它与绝缘体中Cu³⁺的区别。本论文中合成的LaCuO₃为金属性化合物，电导率测量表明在大于13 K无超导电性迹象。XPS测量给出了LaCuO₃中Cu2p_3/2内层电子结合能相对于La₂CuO₄或CuO中的Cu²⁺向高结合能方向移动了约2.6 eV，这一量值远大于NaCuO₂（绝缘体）中的Cu2p_3/2相对于CuO中的Cu²⁺移动的值，约为1.3 eV。Auger谱测量表明，LaCuO₃的修正了的Auger参数与CuO的基本相同，但L₃VV的Auger电子动能相对CuO移动了2.8 eV。这些位移说明在金属性化合物LaCuO₃中，Cu³⁺处在八面体位置上，它与近邻的Cu³⁺连成单个Cu—O—Cu桥，因此可作为对比p型高T_c含铜氧化物的XPS谱的标准。     

A METHOD OF DATA ANALYSIS OF THE MAGNETIC SPECTROMETER

A method of data analysis of the magnetic spectrometer with heavy ion is discussed. The determination of the charge state, the atomic number, the atomic mass and the energy of reaction products are described. The paper also deals with the soft ware correction of B_ρ non-linear dispersion, kinematic and the difference of flight path.     

Quantum cutting downconversion by cooperative energy transfer from Bi3+ to Yb3+ in Y2O3 phosphor

Bi~(3+) and Yb~(3+) codoped cubic Y2O3 phosphors are prepared by pechini sol-gel method.Strong near-infrared (NIR) emission around 980 nm from Yb~(3+)(2F5/2 → 2F7/2) is observed under ultraviolet light excitation.A broad excitation band ranging from 320 to 360 nm,owing to the 6s 2 →6s6p transition of Bi~(3+) ions,is recorded when the Yb~(3+) emission is monitored,which suggests a very efficient energy transfer from Bi~(3+) ions to Yb~(3+) ions.The Yb~(3+) concentration dependences of both the Bi~(3+) and the Yb~(3+) emissions are investigated.The decay curve of Bi ~(3+) emission under the excitation of 355 nm pulse laser is used to explore the Bi~(3+) →Yb~(3+) energy transfer process.Cooperative energy transfer (CET) is discussed as a possible mechanism for the near-infrared emission.     

THE INFLUNCES OF IMPURITIES IN GAS MIXTURE UPON THE SIGNAL PERFORMANCES OF THE DRIFT CHAMBER

Operating the drift chamber with the gas mixture of Ar+CH₄, some performances of the drift chamber such as the pulse heights, the energy resolutions, the counting rates and the thresholds of the counting rate plateau have been measured under the different components of the nitrogen, oxygen and air in the gas mixture respectively. The permeability of different materials which used to make the gas pipeline have also been compared.     

与Al发生扩散反应的非晶(Fe0.99Mo0.01)78Si9B13晶化

 高压下与Al发生扩散反应的非晶(Fe_0.99Mo_0.01)₇₈Si₉B₁₃（FMSB）的晶化产物与纯FMSB的不同。与Al反应的FMSB非晶在3.0~5.0 GPa、780~900 K热处理时,晶化为α-Fe(Al)和次亚稳非晶合金;在这一压力范围以外,720~900 K热处理时,晶化为α-Fe(Si)、Fe₃B或Fe₂B。与Al发生反应的FMSB非晶可能通过与Al的扩散反应在Al/FMSB界面开始晶化。压力和温度对晶化过程的影响主要是由于α-Fe固溶体的Gibbs自由能随压力、温度和Al含量的变化。     

THE SPECTROSCOPY OF FOUR-BARYON SYSTEM

In this paper, using SU(6) symmetry theory four-baryon system is discussed and a method of analyzing experimental spectra is provided. Because of the gound states of _ΛΛ⁴H, _ΛΛ⁴He_{, Λ}⁴He and ⁴He are in the same I. R. of SU(6), on can derives masses for _ΛΛ⁴H, _ΛΛ⁴He from the experimental data of _Λ⁴H, _Λ⁴He, and ⁴He. Calculation shows that these J^π=0⁺ double Λ hypernuclei _ΛΛ⁴H, _ΛΛ⁴He are not likely bound states.     

流体静高压原位磁测量的误差研究（三）——综合兼顾两种影响

 先后选用1至3片非晶Fe_46.3Co_0.03Ni_46.5Si_3.75V_0.92B_2.5合金薄带作样品,插入13层密绕直螺线管内,分别在高静水压容器内和其他四种不同环境中测量它们的磁化曲线、磁导率曲线和起始磁化曲线,再次研究了初级线圈采用多层直螺线管对铁镍合金样品的误差。（１）实验结果表明：既存在样品材料被磁化而形成的退磁场H',也存在漏磁通引起周围铁器磁化而形成的退磁场H'。（２）为了缩小H'的影响,只用1片非晶合金薄带作样品时,H'的影响变得严重,导致μ_m和μ_i出现惊人的误差：Δμ_m/μ_m=50%,Δμ_i/μ_i＝104%。（３）为了综合兼顾这两种影响,采用3片非晶合金薄带作样品时,虽然H'的影响增大一点,但是H'的影响被更多地削弱,所以环境磁化引起的误差反而减小：Δμ_m/μ_m=29%,Δμ_i/μ_i＝15.5%。     

函数的H-导数和分形动力学

 给出了函数的Hausdorff测度与H-导数。从而，为开展自给的分形动力学提供了解析的数学工具。同时，给出了分形动力学的演化方程组并做了初步讨论与分析。     

THE BACKGROUND DARKNESS OF X-RAY FILMS IN EC EXPERIMENT AND ENERGY CALIBRATION

The D_B-D₁ relations are presented in this paper by measuring background darkness of the X-ray films in No.K0—K7 chambers,in addition,different distributions of the background darkness of X-ray films are measured.They may be taken as somemuseful parameters in energy calibration and other respects for future EC experiments.     

CO2焊接短路过渡过程的动态分析─短路液桥的动态变化与力学测算

CO₂气体保护焊接是一种高效、节能和低成本的焊接方法,在钢结构焊接生产中得到了广泛的应用。但也存在着诸如:金属飞溅、焊缝成形较差等问题,要解决这些问题,必须首先对CO₂焊接过程的电弧形态以及熔滴变化情况从理论上深入分析研究。本文以高速摄影与光线示波器同步进行拍摄,记录了CO₂悍接短路过渡中熔滴的长大、缩颈、脱落的全过程以及相对应的电流电压波形。利用影片数据分析处理系统对所得影片及记录波形进行了分析处理,得到了熔滴过渡形成金属液桥爆断瞬间的最大电流值及所受合力的大小。从理论上更进一步研究了短路过渡的机理,建立了短路过渡的模型,这对正确调节焊接工艺规范,保证焊接质量具有重大的指导意义,研究结果表明:在常规短路过渡CO₂焊接中,抑制飞溅是提高CO₂焊接质量的关键,利用焊接规范来调节短路频率和短路峰值电流是抑制飞溅的主要途径。     

高压对复合氧化物纳米固体内部缺陷结构的影响

 详细研究了不同压力下压制的NiFe₂O₄纳米固体材料的正电子寿命谱，分析了材料内部界面上缺陷结构随压制压力的变化，并与La_0.7Sr_0.3MnO₃纳米固体的缺陷结构随压力的变化进行了比较。实验结果表明，随着压制压力的增加，NiFe₂O₄纳米固体内部界面上自由体积缺陷和微孔隙缺陷的体积均被明显地压缩了，但自由体积缺陷的压缩幅度要高得多，反映出NiFe₂O₄纳米固体界面上原子排列的有序程度在高压下逐渐增强的规律。对具有不同微结构变化特征的复合氧化物纳米固体材料，其内部的缺陷结构在高压下具有不同的变化规律，进而引起其宏观物性的不同变化。     

Direct Hard Photoproduction of J/ψ andγ in High Energy Pb-Pb and Ca-Ca Collisions at LHC

Direct hard PhotoProduction of J/ψ and γ at LHC Pb-Pb collisions with CMS energy 5.5ATeV, and Ca-Ca collisions with CMS energy 7ATeV, are discussed in the process: A+A→A+J/ψ(γ) + X. It turns out that the processes can be used to testing the gluon distribution in the nucleus, as well as to studying the mechanism of large P_t gluon and heavy quark fragmentation of J/ψ.     

THE ENERGY DEPENDENCE OF THE CONDENSATION PROBABILITY IN THE COMPLEX PARTICLE EMISSION PROBABILITY

The condensation probability γ_β is studied by assuming that γ_β=γ_β(A, E)[ε_β/MeV]^χ When χ=0.425, the best agreement between the calculated dσ/dε and the experimental data is obtained for 18 reactions. For the same composite systems, the extracted γ_β(A, E) are nearly the same. When the mass of the composite system increases, the γ_β(A, E) increases too. For the α-decay nucleus ²¹⁰Po, γ_β(A, E) is larger than the others considerably.