基区重掺杂突变HBT带阶的扰动对电流影响研究

重掺杂禁带变窄效应引起异质结导带、价带带阶的扰动，从而使突变HBT异质结界面势垒的形状和高度发生了变化，这将对电流传输特性产生重要的影响.基于热场发射-扩散模型，对这一现象进行了深入的研究.得到的结论是：异质结界面势垒的扰动引起内建势的变化对电流影响的重要性远大于其引起隧道效应发生区域的变化，这是由于内建势的变化对电流的影响反映在指数项；因此对于突变HBT，精确考虑禁带变窄在导带与价带之间的分布对于器件性能的分析是非常重要的. 关键词： HBT 能带带阶 内建势 隧穿因子     

拉曼镊子分析单个苏云金芽孢杆菌伴孢晶体蛋白

应用拉曼镊子研究了来自同一亚种的两个苏云金芽孢杆菌(Bacillus thuringiensis,Bt)菌株的单个伴孢晶体蛋白的拉曼光谱。一束30mW、785nm的近红外激光导入倒置显微镜,形成光镊,俘获水溶液中的单个伴孢晶体蛋白,同时收集被俘伴孢晶体蛋白的拉曼信号。结果表明,单个晶体的拉曼光谱反映了晶体蛋白的分子结构和蛋白组成,得到的拉曼光谱信号更清晰、更灵敏。平均光谱和主成分分析均显示,同一亚种的H7、D4菌株的晶体蛋白的拉曼光谱比较接近。但在同一菌株内有两类不同的伴孢晶体存在,得到了群体分析方法难以得到的信息。本方法不需要复杂的纯化伴孢晶体过程,直接俘获单个伴孢晶体并收集其拉曼光谱,既可以得到群体伴孢晶体的信息,更可以得到群体内每个晶体蛋白之间的信息。     

傅里叶变换红外光谱诊断地中海贫血症

为建立简单快速的地中海贫血诊断方法,本研究探讨了以傅里叶变换红外光谱结合水平衰减全反射(FTIR-HATR)技术在地中海贫血诊断中的制样方法及光谱的数据处理方法.在制样预处理中,通过对样品进行稀释并干燥成膜消除水分子对光谱吸收干扰,保持ATR光谱中各波长对样品的穿透深度一致.结果表明,当1652 cm-1吸收度小于1.5时(即透射率T小于4%时),各波峰强度与血红蛋白浓度呈良好的线性关系(r>0.995)及实验重复性(RSD<4%).在数据处理上,改进的相对强度方法用于800～1780 cm-1和2480～3600 cm-1区间的分析.通过与常规的傅里叶去卷积谱及差谱方法相比,本方法可消除样品浓度所带来的影响因素,灵敏地揭示群体数据中组分与结构在不同组间的显著差异,如1638 cm-1处重叠的蛋白二级结构峰,1172 cm-1、1440 cm-1表征脂类物质的吸收峰,1064 cm-1表征磷酸化合物峰位及表征SH的2553 cm-1附近的吸收峰在正常组与地中海贫血组间存在显著差异.从而避免了几个峰位的相对强度所反映的信息不足及选择参比峰的困扰,对揭示整体的差异变化规律有着重要的作用.     

Topological Structure of Vortex Solution in Jackiw-Pi Model

By using o-mapping method, we discuss the topological structure of the self-duality solution in Jackiw-Pi model in terms of gauge potential decomposition. We set up relationship between Chern-Simons vortex solution and topological number, which is determined by Hopf index and Brouwer degree. We also give the quantization of flux in this case. Then, we study the angular momentum of the vortex, which can be expressed in terms of the flux.     

A facile access to chiral 4-isopropyl-, 4-benzyl-, and 4-phenyloxazolidine-2-thione

A highly practical procedure for preparing the chiral oxazolidine-2-thione auxiliaries using carbon disulfide and the corresponding chiral amino alcohols as the starting materials in the presence of potassium carbonate and hydrogen peroxide is presented.     

H2-free Semi-hydrogenation of Butadiene by the Atomic Sieving Effect of Pd Membrane with Tree-like Pd Dendrites Array

H₂-free semi-hydrogenation at room temperature shows great advantage for replacing the thermocatalytic process in industry owing to the high energy and resource saving, however, remains great challenges. Herein, a tree-like Pd dendrites array decorated Pd membrane was constructed as the core device in an electrochemistry assisted gas-fed membrane reactor for butadiene semi-hydrogenation. It reveals that hydrogen atomic sieving effect of this Pd-based membrane under electrochemical condition was the key for semi-hydrogenation. The configuration study of Pd nanostructured membrane demonstrates that the penetration of hydrogen atoms through Pd membrane from electrochemical side to chemical side is affected by the consumption of hydrogen atom in semi-hydrogenation step. Such atomic sieving property of nanostructured Pd membrane with 5.1 times increase in catalytic active surface area brings above 14 times higher in butadiene conversion than that of bare Pd foil, with ≈90 % of butenes selectivity at butadiene conversion ≈98 % over 300 h of H₂-free reaction under 15 mA cm⁻².     

1~Π态双原子分子中关于Λ量子干涉的微分干涉角(英文)

Sha等在静态池实验中观察到了转动能量转移中的碰撞量子干涉,并且计算了决定跃迁散射截面的积分干涉角(J.Chem.Phys.,1995,102:2772).由于积分干涉角是微分干涉角的平均效应,为了得到更精确的信息,进行了分子束实验.作者文运用含时微扰的一级波恩近似理论,提出了衡量干涉程度的1П态双原子分子中关于Λ量子干涉的微分干涉角.利用各向异性相互作用势计算了其干涉角.得到分子束实验中微分干涉角随实验参数,包括实验温度、碰撞伴、作用距离和转动量子数变化的关系.并且讨论了影响干涉角的各种参数.此理论模型对理解和进行分子束实验是非常重要的.     

三核锌配合物的合成及结构表征

A trinuclear Zn(Ⅱ) complex [Zn₃(L)₂(Cl)₂(OSO₃)₂(H₂O)₂]·2H₂O (1) (L=N¹-(2-aminoethyl)-N¹-(2-imidazolethyl)-ethane-1,2-diamine) was synthesized by reaction of ligand L with ZnSO₄·7H₂O at pH=9 in air. The complex has been characterized by elemental analysis, FTIR and X-ray single crystal diffraction. It reveals that the crystal of complex 1 belongs to monoclinic C2/c space group, a=3.516 9(7) nm, b=0.676 57(14) nm, c=1.502 2(3) nm, β=110.955(4)°, V=3.337 9(12) nm³, Z=4. In complex 1, two ligands L bridge three Zn(Ⅱ) centers to form trinuclear structure which was further connected by hydrogen bonding to form two-dimensional structure. CCDC: 609515.     

Facile access to α,β-dehydroalanine and α,β-dehydroamino butyric acid derivatives from DL-serines and threonines

Not only α,β-dehydroamino acids are important constituents for a number of bioactive peptides in nature, but also they are important building blocks for a variety of synthetic amino acids in organic synthesis. Methods to prepare dehydroamino acids have been reported extensively in the literature; however, efficient and convenient protocols are still required. Here we have developed a convenient method to prepare dehydroalanine (ΔAla) and dehydroamino butyric acid (ΔAbu) derivatives derived from DL-serines and DL-threonines, respectively. 4-Toluenesulfonyl chloride (TsCl) and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) were employed in this procedure, which carried out activation of hydroxyl group and β-elimination in one pot. Because it is convenient and easy to handle, this method will attract the attention of synthetic chemists.     

One-Parameter Indecomposable and Irreducible Representations of gl(2 | 1) Superalgebra

Using inhomogeneous boson–fermion realization, one-parameter indecomposable and irreducible representations of the gl(2 | 1) superalgebra are studied on subspace and quotient spaces of the universal enveloping algebra of Heisenberg–weyl superalgebra. All the finite-dimensional irreducible representations of one-parameter of the gl(2 | 1) superalgebra are naturally obtained as special cases. The parameter has relation to the Hubbard interaction parameter U in the Hubbard model for correlated electrons.