利用内禀荧光探针研究蛋白相互作用中硫氧还蛋白的氧化还原态

细胞内蛋白质的氧化还原状态直接影响细胞的增殖、分化及凋亡,而氧化还原状态的改变对调控细胞的生存或死亡尤为重要。硫氧还蛋白(Thioredoxin, TRX)是一种广泛存在于生物体内的氧化还原调节蛋白,其在细胞内氧化还原状态的变化是发挥其氧化还原调控作用的重要过程。以TRX为对象并以其中的色氨酸残基(Trp)作为内禀荧光探针,利用蛋白质定点突变、SDS-聚丙烯酰胺凝胶电泳(SDS-PAGE)、荧光光谱和圆二色谱等技术和方法,研究TRX与谷胱甘肽过氧化物酶(glutathione peroxidase, GPX3)相互作用过程中氧化还原态的变化。通过观测TRX以及突变体中色氨酸荧光光谱的变化,研究蛋白相互作用的电子转移模式以及TRX氧化态-还原态之间的相互转化。结果表明氧化态的TRX与还原态的GPX3之间存在相互作用并发生电子交换,解释了二者之间电子传递模式为GPX3将电子传递给TRX,为揭示TRX在细胞信号传递过程中的物理化学机制提供了实验依据。     

Mathematical characterization and identification of remodeling,growth, aging and morphogenesis

A clear demarcation between various processes of material evolution is established and the implications of the symmetry type on our ability to distinguish between them are investigated. The general features of the various types of material evolution are emphasized by establishing a spatio-temporal analogy between material uniformity and processes of material evolution.     

利用自电离探测技术研究Sm原子Rydberg态光谱

采用孤立实激发与自电离探测技术相结合的方法对Sm原子偶宇称高激发态进行了系统研究.按照不同的自电离通道将所测数据进行了分类和比较,并进行了详细讨论.不仅报道了许多收敛于不同电离限的Rydberg态的能级位置和跃迁的相对强度等信息,而且还把处于同一能域内的Rydberg态和价态进行了辨识.另外,不但提供了一种有效识别不同类型的高激发态的鉴别技术,而且还对处于41800 cm^-1到43800 cm^-1能域内的Rydberg态和价态的光谱特性进行了详细分析和讨论. 关键词： 自电离探测 Rydberg态 Sm原子     

Effect of CDW and magnetic interactions on the electrons of the manganite systems

We address a model study which includes the co-existence of the charge density wave (CDW) and ferromagnetic interactions in order to explain the colossal magnetoresistance (CMR) in manganites. The Hamiltonian consists of the ferromagnetic Hund's rule exchange interaction between e_g and t_2g spins, Heisenberg core spin interactions and the CDW interaction present in the e_g band electrons. The core electron magnetization, induced e_g electron magnetization and the CDW gap are calculated using Zubarev's Green's function technique and determined self-consistently. The effect of core electron magnetization and the CDW interaction on the induced magnetization as well as on the occupation number in the different spin states of the e_g band electrons are investigated by varying the model parameters of the system like the CDW coupling, the exchange coupling, the Heisenberg coupling and the external field. It is observed that the induced magnetization exhibits re-entrant behaviour and exists within a narrow temperature range just below the Curie temperature. This unusual behaviour of the e_g band electrons will throw some new insights on the physical properties of the manganite systems.     

用能量自洽法研究部分卤化钙分子CaX (X=Br, Cl, F)的解析势能函数

采用研究解析势能函数的能量自洽法Energy Consistent Method (ECM), 研究了部分卤化钙分子CaX (X=Br, Cl, F) 的C2S+、A2和B2S+态等基态和低激发态的解析势能曲线。并与曾经常使用的Morse 势、Huxley-Murrell-Sorbie (HMS)势和基于实验的Rydberg- Klein-Rees (RKR) 数据进行了比较。结果表明,这些 ECM 势能不仅能与RKR 数据符合得很好,而且还能得到实验方法难以得到、常用的Morse 势和HMS 势函数可能会产生较大误差、但在许多研究中又非常重要的渐近区和离解区的势能数据,得到了物理性质优秀的全程解析势能。     

具有自旋轨道耦合项的Manning-Rosen势的赝自旋对称解

近似研究了具有任意自旋轨道耦合项的Manning-Rosen势的Dirac方程。在赝自旋对称的条件下获得了关联的二分量的旋量及相应的能量方程。最后,对 和Hulthén 势两类特殊情况进行了简单 讨论。     

Neutron halos in the excited states for N=127 isotones

Properties of the ground states and the excited states of N=127 isotones are investigated by using the nonlinear relativistic mean field theory with the interactions PK1. By analyzing the rms of proton and neutron, the single particle energies of valence nucleon and the density distributions of neutron, proton and the last neutron, it can be found that there exists a neutron halo in the excited states of 3d5/2, 4s1/2 and 3d3/2 in 209Pb. It is also predicted that there exists a neutron halo in the excited states of 3d5/2, 4s1/2 and 3d3/2 in 207Hg, 208Tl, 210Bi and 211Po.     

Search for chiral bands in A ～ 110 neutron-rich nuclei

High spin states in A ～ 110 neutron-rich 106Mo, 110Ru and 112Ru nuclei have been reinvestigated by measuring the prompt γ-rays from the spontaneous fission of 252Cf. Two similar sets of bands are observed to high spins in each of three nuclei. Through analyzing of characters of the band structures, the chiral doublet bands are suggested in 106Mo, 110Ru and 112Ru.     

Partial wave analysis of J/ψ→pp(-)π~0 and measurement of J/ψ→pp(-)η, pp(-)η'

Based on 58 million J/ψ data collected with the BES Ⅱ detector at the BEPC, Partial Wave Analysis(PWA) is performed on J/ψ→pp(-)π~0. The new excited baryon N(2065) is confirmed. Clear signals for other N~* states are observed and the corresponding masses, widths and spin-parity are also measured. Processes such as J/ψ→pp(-)η,pp(-)η' are also studied and the branching ratios are measured.     

Acoustic spectroscopy and electrical characterization of SiO2/Si structures with ultrathin SiO2 layers formed by nitric acid oxidation

Ultrathin silicon dioxide (SiO₂) layers formed on Si substrate with nitric acid have been investigated using both acoustic deep-level transient spectroscopy (A-DLTS) and electrical methods to characterize the interface states. The set of SiO₂/Si structures formed in different conditions (reaction time, concentrations of nitric acid (HNO₃), and SiO₂ thickness [3–9 nm]) was prepared. The leakage current density was decreased by post-oxidation annealing (POA) treatment at 250°C in pure nitrogen for 1 h and/or post-metallization annealing (PMA) treatment at 250°C in a hydrogen atmosphere for 1 h. All structures of the set, except electrical investigation, current-voltage (I - V), and capacitance — voltage (C - V) measurements, were investigated using A-DLTS to find both the interface states distribution and the role of POA and/or PMA treatment on the interface-state occurrence and distribution. The evident decreases of interface states and shift of their activation energies in the structures with PMA treatment in comparison with POA treatment were observed in most of the investigated structures. The results are analyzed and discussed.