~(188)Tl的πh_(9／2)vi_(13／2)扁椭球转动带的旋称反转研究

利用能量为170MeV的35Cl束流,通过157Gd(35Cl,4n)熔合蒸发反应研究了188Tl的高自旋态能级结构．依据实验结果建立了188Tl基于πh9／2(?)vi13／2组态的转动带．根据双奇Tl核能级结构的相似性,指定了188Tlπh9／2(?)vi13／2扁椭球转动带的自旋值．结果表明在188Tl中,πh9／2(?)vi13／2扁椭球转动带在低自旋区具有旋称反转性质．利用包含了质子-中子剩余相互作用的准粒子-转子模型,定性地解释了πh9／2(?)vi13／2扁椭球转动带的低自旋区旋称反转现象．     

Rotational bands in 169Re

Based on the systematic investigation of the data available for nuclei with A≥ 40, a Z ^1/3-dependence for the nuclear charge radii is shown to be superior to the generally accepted A ^1/3 law. A delicate scattering of data around R _c/Z ^1/3 is inferred as owing to the isospin effect and a linear dependence of R _c/Z ^1/3 on N/Z (or (N - Z)/2) is found. This inference is well supported by the microscopic Relativistic Continuum Hartree-Bogoliubov (RCHB) calculation conducted for the proton magic Ca, Ni, Zr, Sn and Pb isotopes including the exotic nuclei close to the neutron drip line. With the linear isospin dependence provided by the data and RCHB theory, a new isospin-dependent Z ^1/3 formula for the nuclear charge radii is proposed. Received: 23 September 2001 / Accepted: 21 January 2002     

145Tb的高自旋态能级纲图

利用能量为161—175MeV的³²S束流,通过反应¹¹⁸Sn(³²S,1p4n)产生了¹⁴⁵Tb的高自旋态.进行了γ射线的激发函数、γγt符合测量.首先建议了由24条能级和42条γ跃迁组成的¹⁴⁵Tb核的能级纲图,并指定了各条能级的自旋值及部分低位能级的宇称.用一个πh_11/2价质子与¹⁴⁴Gd核芯激发态的耦合定性地解释了¹⁴⁵Tb的一些低位激发态.     

Gauge-independent computation of t-quark mass

We study a gauge-independent formulation for the effective mass of quark based on the momentum subtraction renormalization condition. To this end a gauge-independent quark propagator is introduced, and with the aid of the resulting mass anomalous dimension, we can discuss the threshold effects in a gauge-independent manner. As an example we find an earlier computation of the top quark mass is modified. We find 2M_t=51±1 GeV.     

Liquid-membrane type 8-quinolinol-5-sulfonate ion selective electrode and its application to potentiometric titration

A nitrobenzene extract of the ion-pair consisting of 8-quinolinol-5-sulfonate (Hqs^?) and the cation of zephiramine (Z⁺Cl^?, benzyldimethyltetradecylammonium chloride) was used as an ion-exchanging liquid membrane for the electrode responding to Hqs^? ion. The potential response showed the Nernstian slope with the Hqs^? activities varying from 10^?2 to 10^?4.5 mol l^?1. The break points in the potential-pH plot with the constant analytical concentration of H₂qs correspond to the values of the negative logarithm of the acid dissociation constant of H₂qs. The present electrode was successfully applied to the potentiometric titration of copper(II) with H₂qs.     

The design of molecular sensing interfaces with lipid-bilayer assemblies

We describe the current status of techniques for preparing planar lipid bilayers, the fusion of sensory elements and the design of bilayer interfaces for analytical applications. Advances in bilayer fabrication have allowed preparation of lipid bilayers with membrane resistance of >1 GΩ (“gigaseal”) in flow, microfluidic and array formats, which have enabled single-channel and multi-channel recording. Not only biological but also engineered channels have been adopted as sensory elements for lipid-bilayer-based biosensors. Synthetic and inorganic channels are also emerging for designing membranes for lipid-bilayer sensors. We discuss the potential of lipid bilayers containing biological, engineered or synthetic channels for the design of biosensors, including drug-screening biosensors.     

Generation of a triplet diradical from a donor-acceptor cross conjugate upon acid-induced electron transfer

Enhancement of the electron acceptor ability of a para-quinodiimine unit by double protonation leads to the proton-induced intramolecular electron transfer from the donor unit to the cross-conjugated acceptor, giving rise to ground state triplet diradical reversibly.