XeCl准分子激光诱导的氮分子多光子电离

本文采用分子束和改装过的质谱装置,进行了氯化氙准分子激光诱导的氨分子紫外光电离的研究。我们不仅在(m/e)=16,17处分别观察到NH_2~+和NH_3~+离子峰,而且还在(m/e)=18处观察到NH_4~+离子峰。为搞清各种离子特别是NH_4~+离子的产生机理,测量了各种离子产率与样品压强和激光功率的依赖关系。     

Study of the Electrical Double Layer of a Spherical Micelle: Functional Theoretical Approach

The electrical double layer theory is the base of the colloid stability theory (DLVO theory), and the PB eq. is a key to the study of the layer1,2. For a spherical particle, the PB eq. is (1) where and are the dielectric constant of the medium, the valence of ions, the elementary charge, the concentration of ions far away from the particle, the Boltzmann's constant and the temperature of the system, respectively. Since this eq. is a second order nonlinear differential one, only the anal…     

Banach空间中φ-渐进非扩展映像不动点的迭代构造

在Mann的迭代算法基础上，运用Banach空间中的广义投影，使渐进非扩展映像每次迭代生成的序列都投影到一个闭凸的集合中．并证明了该算法的强收敛性．     

EFFECT OF SIMULATED WEIGHTLESSNESS ON THE RESPONSE CHARACTERISTICS OF HUMAN BRAIN

In order to systematically investigate the effects of simulated weightlessness on thefunction state of human brain, 15° head-down tilt (HDT) was used to simulate weightless-ness, and the response changes of event-related EEG power spectra, medium-frequencysynchronous potentials and slow-waves were examined in the present study. It was foundthat HDT had characteristic effects on the above EEG responses, suggesting that the ef-fects mainly occurred in the brain's regulatory system, therefore, resulting in changes ofthe brain function state.     

非晶态(Fe1-xWx)84.5B15.5合金的低温电阻率反常

研究了(Fe_1-xW_x)_84.5B_15.5(x=0—0.1)非晶态合金的电阻率ρ与温度T(4.2—300K)的关系。实验结果表明,在所研究浓度区域内均出现电阻率与温度关系的极小值,电阻率极小值的温度T_min在x=0.06时出现峰值。用x=0.02—0.1浓度区域内,当Tmin时,又出现了电阻率与温度关系的极大值,电阻率极大值的温度T_max在26—35K之间。低温电阻率反常现象与类Kondo效应及局域磁矩之间RKKY相互作用有关。 关键词：     

晶态硅中氢化单空位的络合物模型

本文对氢化单空位模型中SiH键间的相互作用对总能量的影响进行了计算。据用全略微分重迭(CNDO/2)方法计算的结果,单空位中四个氢原子有较明显的相互作用,四氢原子络合成组是含氢单晶硅中一种合理的氢相关组态模型。 关键词：     

Solvent-free Synthesis, Crystal Structure and Thermal Stability of Ionic Liquid 1-Hexadecyl-3-methylimidazolium Bromide

Ionic liquid 1-hexadecyl-3-methylimidazolium bromide [C16mim]Br was synthesized by solvent-free alkylation of N-methylimidzole with hexadecyl bromide. A large transparent single crystal of 1-hexadecyl-3-methylimidazolium bromide monohydrate （[C16mim]Br·H2O）, 4 mm in length, was firstly obtained in the water-trichloromethane-toluene growth system （Vwater＇Vtrichloromethane＇Vtoluene = 0.1：1：2）. The crystal structure was determined by single-crystal X-ray diffraction method. It crystallizes in the triclinic system, space group P1, with a = 5.4962（15）, b = 7.839（2）, c = 27.279（8） A, α = 94.375, β = 91.500, γ = 101.999°, Z = 2, V = 1145.2（5） A3, C20H41BrN2O, Mr = 405.46, Dc = 1.176 Mg/m3, μ = 1.804 mm^-1, F（000） = 436, the final R = 0.0523 and wR = 0.1345. The 3D supramolecular structure is constructed through weak interactions between imidazolium cations, Br- anions and lattice water molecules. The long alkyl chain to the imidazolium ring and lattice water molecules play an important role in the self-assembly process. Moreover, it is proposed that [C16mim]Br in water has aggregation behavior and the possible self-assembled structure is the interdigitated pattern. Finally, thermal stability of [C16mim][Br]·H2O was also studied by DSC and TGA analysis.     

毛细管电泳非接触电导分离检测金属氧化物纳米粒子

采用毛细管电泳非接触电导检测技术,以碳酸钠-碳酸氢钠为缓冲体系,同时分离测定了纳米二氧化钛和三氧化二铝两种金属氧化物的悬浮粒子.考察了缓冲溶液种类、浓度及pH对分离效果的影响,探讨了激发频率、激发电压对检测信号信噪比的影响.在最佳分离检测条件下,不同粒径的二氧化钛和三氧化二铝悬浮粒子在8 min内可实现完全分离.所选择的最佳条件为:① pH 10.5缓冲溶液为5 mmol·L-1碳酸钠和碳酸氢钠混合溶液;②分离电压20 kV;③进样条件20 kV,6 s;④激发频率460 kHz;⑤交流激发电压4 V(给出最高的S/N比值).