Mixing between the 23S1 and 13D1 Ds

Mixing between the 2³S₁ and 1³D₁ D_s is studied within the ³P₀ model. If mixing between these two 1^- states exists, D_s1^*(2700)^± and D_sJ^*(2860)^± could be interpreted as the two orthogonal mixed states with mixing angle θ≈ -80° in the case of a special β for each meson. However, in the case of a universal β for all mesons, D_s1^*(2700)^± could be interpreted as the mixed state of 2³S₁ and 1³D₁ with mixing angle 12° < θ < 21° but D_sJ^*(2860)^± seems difficult to interpret as the orthogonal partner of D_s1^*(2700)^±.     

Hypertriton and light nuclei production at Λ-production subthreshold energy in heavy-ion collisions

High-energy heavy-ion collisions produce abundant hyperons and nucleons. A dynamical coalescence model coupled with the ART model is employed to study the production probabilities of light clusters, deuteron (d), triton (t), helion (³He), and hypertriton (_Λ³H) at subthreshold energy of Λ production (≈ 1 GeV per nucleon). We study the dependence on the reaction system size of the coalescence penalty factor per additional nucleon and entropy per nucleon. The Strangeness Population Factor (S₃ / (³He × (Λ/p))) shows an extra suppression of hypertriton comparing to light clusters of the same mass number. This model predicts a hypertriton production cross-section of a few μb in ³⁶Ar+³⁶Ar, ⁴⁰Ca+⁴⁰Ca and ⁵⁶Ni+⁵⁶Ni in 1 A GeV reactions. The production rate is as high as a few hypertritons per million collisions, which shows that the fixed-target heavy-ion collisions at CSR (Lanzhou/China) at Λ subthreshold energy are suitable for breaking new ground in hypernuclear physics.     

Gd2O2S:Eu荧光谱及能级的高压研究

 在21 500~11 500 cm^-1光谱区间内测量了Gd₂O₂S:Eu的荧光光谱，测量是在室温和液氮条件下进行的，对122条低温谱线和96条常温谱线进行了指认。识别了Eu³⁺离子⁵D_0~2及⁷F_0~6的39个斯塔克能级中的35个能级。在0~15 GPa压力范围内，研究了Gd₂O₂S:Eu高压下的发射光谱。在压力作用下，发现所有观测到的谱线都红移，强度降低。6个⁵D_0~2能级下降速度大于⁷F_J，⁵D₂、⁷F_2~5多重态的斯塔克劈裂变大，而⁵D₁和⁷F₁的劈裂变小。     

定义在分形集上函数的H-导数

 分形的生成含有降维与升维两种形式,采用适当的方式总可以对分形集加以定向化,分形的内禀测度是Hausdorff测度。因此,定义在分形集上的函数可以看作是在Hausdorff测度下定义在区间[0, h]。在函数图像也是分形的前提下,依函数的Hausdorff测度的定义,给出了定义在分形集上的函数f(p)关于Hausdorff测度p的导数以及一些性质。     

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 MASS GAP IN 2+1 DIMENSIONAL SU(3) LATTICE CAUGE THEORY

We present a variational calculation of C=+1 and C=－1 glueball masses in 2+1 dimensional SU(3) lattice gauge theory using a Hamiltonian in which the ground state is exactly known.In the range 0<1/g²≤6,we obtain good scaling behaviour am₊=36.1g² and am_－=5.98g².     

Study of the Superdeformed State of 196Pb in the Relativistic Mean Field Theory

Based on the constrained relativistic mean field (RMF) theory, the superdeformed states of ¹⁹⁶Pb are systematically investigated with four different interactions, TMA, PK1, NL3 and NL-SH. The potential surface, the quadruple deformation of ground and superdeformed states, and the excitation energies of superdeformed states are calculated. The results show that the shape of ¹⁹⁶Pb is oblate for the ground state with deformation β₂≈－0.15, and prolate for the superdeformed states with deformation β₂≈0.60. The calculated excitation energy and the depth of the potential well of the superdeformed state are approximately equal to 4.5MeV and 1.6MeV, respectively. These results are in good agreement with the current experimental data. It indicates that RMF theory can well describe the energy of the band head of superdeformed rotational band in ¹⁹⁶Pb.     

Decays of Dsj*(2317) and Dsj(2460) Mesons in the Quark Model

We study the decay widths of the narrow resonances D_sj^*(2317) and D_sj(2460) in the chiral quark model, together with the well-known D^* and D_s^* mesons. All the parameters in our calculation are taken from Godfrey and Isgur's quark model except the π⁰－η mixing angle which is fixed by the D_s^* decay widths. The calculated electromagnetic decay widths agree with those from other groups and the experimental data available quite well. However, the pionic decay widths of D_sj(2317) and D_sj(2460) are too small to fit the experimental data. We suspect that the simple chiral quark pion axial-vector interaction Hamiltonian is not suitable for hadron strong decays of D_sj(2317) and D_sj(2460).     

Fine-Structure Splittings of Nitrogen Isoelectronic Sequence： Competitions among Spin-Orbit Interactions, Breit Interactions and Electron Correlations

Using the multi-configuration Dirac-Fock self-consistent field method and the relativistic configuration interaction method with quantum-electrodynamics corrections performed by the GRASP code, we calculate the fine-structure energy levels of the ground-state configuration （1s^22s^22p^3） of the nitrogen isoelectronic sequence, according to the L-S coupling scheme with atomic number Z up to 22. Based on the calculated results, we elucidate the mechanism of the orderings of fine-structure energy levels of 2^ D3/2,5/2 and 2^P1/2,3/2 respectively, i.e. for 2^D3/2,5/2 orderings, the competition between the spin-orbit interactions and the Breit interactions; for 2^P1/2,3/2 orderings, the electron correlations, especially the electron correlations owing to the 2p^5 configuration interactions.     

ON THE MESONIC MOLECULES (αp,μ－) AND (αp,2μ－)

ACQM is applied to study the μ^－-mesenic molecules (αp,μ^－) and (αp,2μ^－).It is found that the ground state X²Σ⁺ of (αp,2μ^－) is the repulsive one and the ground state X¹Σ⁺ of (αp,2μ^－) is a bound state with the equilibrium proton-proton separation R_e=0.0078bohr and the minimum energy E=－551.78a.u..     

Description of the New Nuclide 259Db and Its α-Decay Chain in Relativistic Mean Field Theory

The new nuclide ²⁵⁹Db and its α decay chain are systematically studied in the framework of the relativistic mean field (RMF) theory with NL3 and TM1 effective interactions. The nuclide ²⁵⁹Db and its α-decay daughter nuclei are calculated in a RMF framework with and without the pairing correlation. With the pairing gaps obtained from the RCHB, the deformed RMF+BCS has been carried out for these nuclei. It has been found that the DRMF+BCS well reproduces the data and implies that the new nuclide ²⁵⁹Db and its α decay daughter nuclei are highly deformed. The α-decay energy Q_α for different channel has been given and it seems that the ground state to ground state Q_α values from DRMF+BCS reproduce the data well. Furthermore the single particle levels of the α decay chain are studied carefully and the explanation for the stability is also presented.     

Eu3+离子掺杂钛酸盐纳米管的直接水热合成与发光性能

 采用纳米管制备和离子掺杂同步进行的直接水热合成方法，合成了纯钛酸盐纳米管（TNT）和Eu³⁺离子掺杂的纳米管（TNT-Eu）；并利用X射线衍射（XRD）、透射电子显微镜（TEM）、光致发光谱仪研究了纳米管的形貌特征、物相组成、热稳定性和发光性能。结果显示：这种方法简便易行、稳定性好、产率高。钛酸盐纳米管物相可近似表示为(H,Na)₂Ti₃O₇或(H,Na)₂(Ti,Eu)₃O₇。高温处理对钛酸盐纳米管的结构产生很大的影响，450 ℃下纳米管的层状结构被破坏，晶体结构转化为锐钛矿型的TiO₂。TNT-Eu样品的发光性能较强，出现的393.5 nm、593 nm、614 nm的谱带归属于⁵D₀-⁷F₁和⁵D₀-⁷F₂电子的跃迁。     

g-factors in the ground state and in the γ-bands in 160,162,164Dy

The g-factors of some members of the ground state band and of the 2⁺ state in the %-vibrational band have been measured in ^160,162,164Dy using the Coulomb Excitation Transient Field technique, induced by ⁵⁸Ni projectiles at 230, 210 and 217 MeV, respectively. The g-factors in the ground state band are consistent with a constant value, while that of the 2⁺_% states is about 20% larger in average than those in the ground state band. Results are discussed in the frame of the systematics in this nuclear region.     

Pure annihilation type decays B0→Ds- K2*+ and Bs→Da2 in perturbative QCD approach

We calculate the branching ratios of pure annihilation type decays B⁰→D_s^- K₂^*+ and B_s→Da₂ using the perturbative QCD approach based on k_T factorization. The branching ratios are predicted to be (60.6_{-16.5-10.4-2.1}^{+17.3+4.3+3.2} )× 10^-6 for B⁰→D_s^- K₂^*+, (1.1_-0.4-0.2-0.1^+0.4+0.1+0.1)×10^-6 for B_s→D⁰a₂⁰ and (2.3_-0.8-0.4-0.1^+0.8+0.2+0.1)×10^-6 for B_s→D^-a₂⁺. They are large enough to be measured in the ongoing experiment. Due to the shortage of contributions from penguin operators, there are no direct CP asymmetries for these decays in the Standard Model. We also derive simple relations among these decay channels to reduce theoretical uncertainties for the experiments to test the accuracy of theory and search of new physics signal.     

Skyrme-Hartree-Fock Description of the Nuclear Structure in Ca Isotopes (Ⅰ)Binding Energy and Shell Effects,Radii and Density Distributions

The ground state properties of Ca isotopes far from stability line were systematically studied using the Skyrme Hartree Fock model.The shell effects on the binding energy and two neutron separation energy are discussed.The isospin dependency of the unclear radii and nucleon density distributions and the shell effects on these properties are also studied.It is shown that the neutron magic number affests the width of nuclear surface and the nucleon density distributions beyond the nuclear surface.The change of proton rms radii R_rms with neutron number excess I=(N-Z)/A follows R_rms=3/5(1+αI+βI²)r_pZ^1/3.The effect of the centrifugal potential on the nuclear density in the outer trach of nuclear surface is clearly shown.     

Al and Ag diffusion study in α-titanium

The diffusion of implanted Al and Ag in !-Ti has been studied in the 948-1073 and 823-1073 K temperature ranges by using the nuclear reaction analysis and Rutherford backscattering techniques, respectively. The measurements show that for both solutes, the diffusion coefficients follow a linear Arrhenius plot, the characteristic diffusion parameters D₀ and Q being the following: for Al, D₀=(1.4ǃ.2) ᎒^-2 m² s^-1 and Q=326ᆞ kJ/mol and for Ag, D₀=(1ǂ.75) ᎒^-4 m² s^-1 and Q=279Lj kJ/mol. The above parameters are typical of a normal substitutional behavior.     

Study of D0→π－l+νl Decay

In this paper, the D⁰→π^－l⁺ν_l decay process is studied by applying light-cone QCD sum rules. The form factor of D→π transition is calculated by choosing a correlation function with a chiral current to eliminate the effect caused by the uncertainty of the twist-3 function of the pion. Therefore the calculated result of the form factor is improved, and the branching ratio of the D⁰→π^－l⁺ν_l decay process is consistent with the new experimental data.     

吡咯俘精酸酐的光致各向异性研究

将有机光致变色化合物—吡咯取代俘精酸酐掺杂于PMMA中形成薄膜.在紫外光照射下,薄膜由无色态转换为呈色态.用650 nm线偏振激光照射薄膜,在由呈色态转变为无色态时产生光致各向异性.对633 nm的探测光具有正单轴晶体特性,光轴方向平行于激发光振动方向,光致二向色性率(D_⊥-D_∥)可达0.2,光致双折射率(n_∥-n_⊥)可达2×10^-3.实验还测量了光致各向异性与曝光量的特性曲线,发现最佳曝光量为13～20 J/cm²;理论分析了其原因.这些结果为俘精酸酐材料在光信息处理方面的应用提供了实验数据.     

PRODUCTION OF A 3－+ GLUEBALL IN J/ψ RADIATIVE DECAY

The multiple angular-correlation function for the sequential decays J/ψ→γ+G(3^－+), G(3^－+)→M₁M₂, where G is a J^pc=3^－+ state and M₁ and M₂ are spinless mesons, is deduced. A 3^－+ glueball state is discussed and the ratios of the helicity amplitudes of J/ψ→γ+G(3^－+) are calculated. One ratio is independent of the glueball's mass and very small.     

压力对GdoBr:Eu晶场参数的影响

 在室温下测量了GdoBr:Eu的常压和高压荧光谱，光谱范围在13 000~21 500 cm^-1之间，压力至12 GPa。由光谱数据得到了Eu³⁺晶场能级随压力的变化曲线。⁷F_0～5能级随压力的变化规律比较复杂，而⁵D_0~2各能均随压力的升高几乎线性地降低。在基态谱项⁷F的49个状态上进行了晶场拟合计算，所得常压下的5个非零晶场参数分别为：B₀²＝-1 124.0 cm^-1，B₀⁴＝-969.6 cm^-1，B₄⁴＝827.9 cm^-1，B₀⁶＝889.6 cm^-1，B₄⁶＝377.0 cm^-1。高压下的计算结果表明，B₀⁴、B₀⁶这两个晶场参数随压力的增加而增大，B₄⁶随压力的增加而减小，而B₀²、B₄⁴随压力的变化有些起伏。晶场强度在8 GPa以下随压力增加而减小，其后开始变强。