Homogeneous immunoassays

Applied Biochemistry and Biotechnology -     

晶界内耗研究的新进展

由不同取向差的纯Al双晶的内耗实验观察到，不同类型晶界的弛豫参量有明屁差别。用耦合模型对内耗数据的分析表明，小角度晶界内耗的基本机制是位错攀移，而大角度晶界内耗的基本机制是晶界扩散。在此基础上，对多晶中晶界内耗的一些特征也作了解释。     

单轴晶体内表面入射e光线的双反射

基于光线遵从的Fermat原理,从几何学的角度讨论和分析了在单轴晶体中入射的e光线在界面上的双反射,得到了确定光线反射方向的一般公式,并对几种特殊情况进行了讨论.指出了上述结果与由电磁波的边界条件计算所得结果是一致的.     

On interrelation between the internal pressure and the cohesion energy density

The question about the definition of the “internal pressure” concept is being discussed. It is shown that the previously found differential relation between the cohesion energy density and the internal pressure is one of the examples of an absolutely general interrelation between definitely connected differential functions. It is ascertained that the ratio (the internal pressure divided by the cohesion energy density) is a structuresensitive parameter inherent to the calorific (thermal) equation of a liquid state.     

Mindlin板几何非线性分析的附加内部剪应变法

本文在几何非线性分析的Ｍｉｎｄｌｉｎ板元中引入单元附加内部剪应变，有效地解决了薄板情况下的剪切自锁问题．文中导出了相应的能量相容条件，给出了有限元非线性列式的全过程及有关簿板及中厚板大挠度问题的数值结果．     

Anomalies of attenuation and phase velocity of surface acoustic waves in YBa2Cu3O7‒δ thin films in the vicinity of Tc

We present measurements of the attenuation and phase velocity of surface acoustic waves in thin YBa₂Cu₃O films as a function of temperature, in magnetic fields up to 3.6 T applied parallel to the c-axis of the films. We have observed anomalies in both, the attenuation and the phase velocity in the vicinity of the superconducting critical temperature which do not depend on the magnetic field. Possible origins of these anomalies, observed, to our knowledge, for the first time in YBa₂Cu₃O thin films, are discussed and compared to bulk acoustic wave experiments. We present a kind of feedback technique for surface acoustic waves which improves the sensitivity of this type of measurement. The actual sensitivity limits are mentioned. Received: 7 August 1997 / Revised: 7 November 1997 / Accepted: 17 November 1997     

Dependence of the rate constants on the treatment of internal rotation modes: the reaction OH + CH3SH --> CH3S + H2O as an example

The title reaction has been used as an example to test the importance of using a hindered rotor treatment instead of a harmonic oscillator model for calculating vibrational partition functions corresponding to low-frequency internal rotation modes. First, a normal-mode analysis according to the Ayala and Schlegel's algorithm has been used to identify the internal rotation modes of methanethiol and the transition state structure. Then, after calculation of the energy barrier for each internal rotation, the corresponding hindered rotor partition functions have been calculated following the CW scheme of Chuang and Truhlar. The results show that the anharmonic treatment produces a rather modest improvement of the rate constants at room temperature or below.     

Drift tube investigations on the reactions of O 2 + with CH4 and of CO 2 + with NO in various buffer gases

The influence of internal excitation on the reactions of O ₂ ⁺ + CH₄ and of CO ₂ ⁺ + NO has been investigated using a slow flow drift tube. The rate coefficients for these reactions obtained as a function of relative kinetic energy in various buffer gases like He, Ne, Ar, and Kr showed higher values under conditions where the internal excitation of the reactant ions was enhanced. For both reactions the lowest reactivity at all kinetic energies was observed to occur in He, indicating that He is the least effective buffer for collisionally inducing internal excitation of molecular ions.     

Ab initio study of the ground state and conformational stability of peroxyacetyl nitrate in internal rotation about the peroxide bond

The molecular and electronic structure of the ground state of peroxyacetyl nitrate (PAN) was calculated by the unrestricted Hartree-Fock-Roothaan method with the use of the standard 3–21G and 6–31G basis set. The potential curve of the internal rotation about the peroxide bond of PAN was calculated with the 6–31G basis set. The curve contains two maxima. The ground state of PAN is characterized by a structure in which groups of atoms adjacent to the peroxide bond lie in planes that are perpendicular to each other (the dihedral angle ϱ(COON) is 89.9°). The calculated barriers to rotation are 19.6 and 66.8 kJ mol⁻¹. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 600–604, April, 1998.     

Adsorption Behavior of a Water-soluble Porphyrin at the Glass-water Interface as Studied by Synchronous Total Internal Reflection Fluorescence Spectroscopy

Total imernal reflection fluorescence spectroscopy (TIRF) and synchronous scanning technique were combined to study the adsorption behavior of the meso-tetrakis (4-sulfonatophenyl)porphyrin (TPPS) at the glass-water interface without any surfactant. The pH dependence of synchronous fluorescence signal at the interface was analyzed. Both unprotonated (TPPS^4-) and diprotonated (H2TPPS^2-) forms of TPPS were observed at the interface. But the interface favored the adsorption of. The apparent estimated pKa2 value shifted from 5.00 in the bulk solution to 2.7 at the interface. STIRF provides a good technique to study multi-component systems at the interface.