DEPENDENCE OF PHASE TRANSITION ON THE MASS NUMBER OF HOT NUCLEI

The dependence of phase transition,associated with the disassembly of hot nuclei,on the mass number of hot nuclei is investigated.By studying six hot nuclei ranging from ⁵⁶Ni* to ²³⁸U*,we find that in the curves of excitation energy of hot nuclei vs.Thermodynamic temperature T(E*) of ⁶³Cu* and heavier ones there are always two temperature plateaus,but in T(E*) of ⁵⁶Ni the first temperature plateau (at lower excitation energy) shrinks into a kink.     

IMPROVEMENT OF THERMODYNAMICAL MONTE CARLO SIMULATION IN SU(2) PURE GAUGE FIELD THEORY ——AN APPROACH TO CONTINUUM PHYSICS LIMIT

The thermodynamical quantities of SU(2) pure lattice gauge field have been simulated first time on the asymmetric lattice (ξ>1).The finite size effect and continuum physics limits have also been studied.The results show that the use of asymmetric lattice is of benefit to calculate the thermodynamical quantities and study the behavior of continuum physics limits.In addition,it is explained that the efficiency of the whole Monte Carlo simulation and the calculation of heat capacity will be improved quite a lot by using bias sampling technique.     

ON THE BEHAVIOR OF PHASE TRANSITION SHOWN IN DISASSYMBLY PROCESSES OF VERY HOT AND DILUTE FINITE NUCLEAR SYSTEMS

The behaviors of phase transition shown in disassymbly processes of very hot and dilute finite nuclear system have been exposed by using canonical (microcanonical) ensemble Monte Carlo simulation.It is explained that they result from the competition between Coulomb interaction and the effect of finiteness.     

甘氨酸钙络合物的熔融法合成及表征

以甘氨酸和氢氧化钙为原料,采用熔融法合成了甘氨酸钙络合物,最佳合成条件为:原料摩尔比n甘氨酸:nCa(OH)2=2:1,在熔融状态下,反应温度150℃左右,反应时间40min,并通过元素分析、红外光谱、X-射线粉末衍射、差热-热重等实验手段对该络合物进行了表征,确定其化学式为Ca(NH2CH2COO)2,所得产品的产率达94.1%.     

TDDFT Study on the Electronic Excitations and First Hyperpolarizabilities of Mixed-metal Carbonyl Clusters W2Ir2（μ-L）（CO）8（η^5-C5H4Me）2（L = dppe/dppf）

Mixed-metal carbonyl clusters of W2Ir2（CO）10（η^5-C5H4Me）2 1 and W2Ir2（μ-L）（CO）8（η^5-C5H4Me）2 （L = dppe 2, dppf 3） have been studied by TDDFT method focusing on their electronic and nonlinear optical properties. These three clusters exhibit the first static hyperpolarizabilities of medium magnitude （βtot-10×10^-30 esu）. The origin of β is discussed by the new proposed orbital-pair decomposition scheme by Barandes et al. The result suggests that the β values of the two clusters are mainly originated from d-d electron transition within the metal skeleton, and d-p （π＊） electron transition from metals to carbonyls and phenyl. The additional coordination by the electron donor group, ferrocene, makes cluster 3 own much larger β values, and the relatively longer range charge transfer from d orbitals of ferrocene to d orbirals of Ir and W is responsible for the enhanced β values.     

Structural characteristics of different types of nanoparticles synthesised in mesomorphic metal alkanoates

The class of thermotropic ionic liquid crystals (LCs) of the metal alkanoates possesses a number of unique properties, such as intrinsic ionic conductivity, high dissolving ability and ability to form time-stable mesomorphic glasses. These ionic LCs can be used as nanoreactors for the synthesis and stabilisation of different types of nanoparticles (NPs). Thus, some semiconductors, metals and core/shell NPs were chemically synthesised in the thermotropic ionic liquid crystalline phase (smectic A) of the cadmium octanoate (CdC₈) and of the cobalt octanoate (CoC₈). By applying the scanning electron microscopy, the cadmium and cobalt octanoate composites containing CdS, Au, Ag and core/shell Au/CdS NPs have been studied. NPs’ sizes and dispersion distribution of the NPs’ size in the nanocomposites have been obtained.     

Ionic conductivity of polycrystalline samples of KBrKI solid solutions

Ionic conductivity of KBr_xI_1?x(0?x?1) mixed crystals, σ_x, has been measured as a function of temperature in the range of 370°C to close to their melting points. The variation in conductivity, σ_x, with composition in the intrinsic region was found to be non-linear, having a maximum value at x=0.3. The maximum conductivity of KBr_xI_1?x mixed crystals was never far outside the range of conductivity of the component crystals. Several expressions of the relative conductivity, σ_x/σ₁ (σ₁ refers to KBr) have been suggested.     

催化光度法测定痕量钒——钒(Ⅴ)-溴甲酚紫-过氧化氢体系

催化光度法测定钒已有报道[1～3],在0.45 mol·L-1磷酸介质及加热条件下,过氧化氢氧化溴甲酚紫褪色反应非常缓慢,而痕量钒对此反应具有较高的催化活性,且在一定浓度范围内,钒量与褪色反应程度呈线性关系,据此可建立测定痕量钒的方法.方法的检出限为1.9×10-6g·L-1,测定范围为0.003～1.8 mg·L-1.方法操作简便,重现性好,用于钢样中痕量钒的测定,结果满意.     

酶促开环聚合合成双亲性H型嵌段共聚物及其自组装

通过固定化酶Novozyme435（NV435）催化聚乙二醇（PEG）开环聚合己内酯（CL）得到端基带有羟基的ABA型三嵌段聚合物,用2,2-二氯代乙酰氯将聚合物的端羟基功能化形成H型大分子引发剂,在CuCl／HMTETA体系中引发4-乙烯基吡啶（4VP）进行原子转移自由基聚合反应（ATRP）,得到了具有两亲性的H型五嵌段聚合物（PVP）2-b—PCL-b．PEG-PCL-（PVP）2,用红外光谱（FT IR）,核磁共振（^1H NMR）,凝胶渗透色谱（GPC）对其结构与分子量及其分子量分布进行了表征,结果表明：H型五嵌段聚合物分子量46121g／mol,分子量分布1．30．并利用动态光散射（DLS）和原子力显微镜（AFM）对聚合物在水溶液中的自组装行为进行了研究,H型嵌段聚合物的胶束呈球形结构,平均直径为70nm左右．