Fission Barrier for ^240Pu in the Quadrupole Constrained Relativistic Mean Field Approach

The fission barrier for ^240pu is investigated beyond the second saddle point in the potentiM energy surface by the constrained relativistic mean field method with the newly proposed parameter set PK1. The microscopic correction for the centre-of-mass motion is essentiM to provide the correct potential energy surface. The shell effects that stabilize the nuclei against the fission is also investigated by the Strutinsky method. The shapes for the ground state, fission isomer and saddle-points, etc, are studied in detail.     

Depletion effects and gelation in a binary hard-sphere fluid

A study of the binary hard-sphere fluid with size ratio [sgrave]_B/[sgrave]_A = 0.1 is reported. Molecular dynamics and Monte Carlo simulations have been carried out over the mole fraction (x _A) range 0.002-0.1 and over the high density range where several recent authors have predicted a thermodynamic demising transition on the basis of integral equations. In this region, there is no evidence of such first-order thermodynamic phase separation, or two fluid phases. The effect of the depletion force, arising from the entropic exclusion of B spheres from between two A spheres, as x _B is increased at constant packing fraction y _A, is to cause a large increase in the partial pressure of A and the radial distribution function of A at contact, a reduction on the mobility of A, and eventually, at a sufficient x _B, the gelation of component A to an open, low coordination, amorphous structure. This gelation transition of A shows discontinuities similar to a glass transition; it can be traced back to the hard sphere glass formation as x _B approaches zero. Thermodynamic properties are reported over the range studied, and used to evaluate the predictions of current theories and the accuracy of equations of state. The Boublik—Mansoori—Carnahan—Starling—Leland equation is found to be remarkably accurate in this region, over the whole fluid range, but shows systematic deviations at high packing densities.     

纳米晶ZrO2：Pr^3＋与ZrO2：Pr^3＋，Sm^3＋发光研究

采用化学共沉淀法制备了纳米晶ZrO2：pr^3＋粉体，所制备的纳米晶ZrO2：Pr^3＋粉体中Pr^3＋的强室温特征发射的两个主发射带为^1D2-^2H4和^3P0-^3H4跃迁。不同热处理温度下纳米晶ZrO2：Pr^3＋晶体结构不同，因此它们的发光不同；ZrO2基质向Pr^3＋有能量传递，在高温煅烧得到的单斜相配位场中能量传递较好。荧光强度与Pr^3＋浓度的关系研究表明：^3P0和^1D2功能级有不同的猝灭规律，由于[^1D2,^3H4]→[^1G4,^3F4]的交叉弛豫，使得^1D2-^3H4跃迁的猝灭浓度很低，在我们的实验中，掺0．1mol％Pr^3＋时^1D2-^3H4地跃迁发射最强，掺2mol％Pr^3＋时^3R0-^3H4跃迁发射最强。文章制备的纳米晶ZrO2：Pr^3＋，Sm^3＋中Sm^3＋的^4G（5-2）～^6H（7／2）跃迁荧光峰因Pr^3＋加入而增强，这除了两种离子某些能级相近产生荧光发射的叠加效应外，还存在Pr^3＋→Sm^3＋的能量传递。     

Novel Interaction Solutions to Kadomtsev-Petviashvili Equation

In this paper, based on the forms and structures of Wronskian solutions to soliton equations, a Wronskian form expansion method is presented to find a new class of interaction solutions to the Kadomtsev-Petviashvili equation. One characteristic of the method is that Wronskian entries do not satisfy linear partial differential equation.     

硼酸铝钕[NdAl3（BO3）4]晶体的晶场能级与发光特性

本文利用晶场理论分析了NdAl_3(BO_3)晶体的光谱特性和相应的能级结构。计算出该晶体的晶场参数,并由此得到了在晶场作用下4~F_(3/2),4~I_(11/2)和4~I_(9/2)三个谱项的所有斯塔克(Stark)子能级的本征波函数。利用所得的波函数和荧光分支比的实验值,用Judd-Ofelt理论估算了4~F_(3/2)→4~I_(11/2)的子能级间跃迁几率的相对值,并讨论了相应的偏振特性,较好地说明了激光和荧光实验的结果。     

CsI（T1）晶体量能器中硅光二极管的核计数器效应研究

研究了由于电磁簇射在CsI（T1）晶体后端的泄漏而引起的硅光二极管“核计数器”效应．通过GEANT模拟和实验测量分析其在BESⅢ的CsI（T1）晶体量能器中对能量测量的影响．     

Determination of Four Active Ingredients in Vc Yinqiao Tablets by Capillary Zone Electrophoresis with Amperometric Detection†

A simple, reliable and reproducible method, based on capillary zone electrophoresis with amperometric detection （CZE-AD）, has been developed for simultaneous determination of four active ingredients in Vc Yinqiao tablets including paracetamol, vitamin C, caffeic acid and chlorogenic acid. A carbon-disk electrode was used as working electrode and 0.95 V （versus SCE） was selected as detection potential. The optimal conditions of CZE experiment were 30 mmol·L^-1 borate solution （pH 9.5） as running buffer, 14 kV as separation voltage and 8 s （14 kV） as electro-kinetic sampling time. Under the selected optimum conditions, paracetamol, vitamin C, caffeic acid and chlorogenic acid could be perfectly separated within 22 min, and their detection limits （S/N=3） ranged from 5×10^-7 to 1 ×10^-6 mol·L^-1. This proposed method demonstrated good reproducibility with relative standard deviations of less than 3% for both migration time and peak current （n=7）. The utility of this method was demonstrated by monitoring a kind of compound medicine named Vc Yinqiao tablets and the assay results were satisfactory.     

Does There Exist Only One Solution of the Dyson-Schwinger Equation for the Quark Propagator in the Case of Non-Zero Current Quark Mass

It is shown on general ground that there exist two qualitatively distinct solutions of the Dyson-Schwinger equation for the quark propagator in the case of non-zero current quark mass. One solution corresponds to the “Nambu- Goldstone” phase and the other one corresponds to the “Wigner” phase in the chiral limit.     

Knockout reaction induced by ~6 He at 61.2 MeV/u

A knockout reaction induced by ⁶He at 61.2 MeV/u was carried out at the HIRFL-RIBLL radioactive beam line. The α core fragments at forward angles were detected in coincidence with the recoiled protons at large angles. From this coincident measurement the valence nucleon knockout mechanism and the core knockout mechanism can be separated according to the polar angle correlation between the core fragments and the recoiled protons. It is demonstrated that, when reconstructing the resonant state of a weakly bound nucleus, the contamination resulting from the core knockout mechanism should be eliminated in order to obtain the correct structure information.     

Asymmetric Synthesis of Anisodine

Anisodine was synthesized from 3α-hydroxy-6β-acetyltropine in 11 steps. Laevorotary isomer of anisodine was prepared from the asymmetric dihydroxylation of compound 10 via the osmium catalyzed process employing p-chlorobenzoyl dihydroquinidine as the chiral ligands.