精神分裂症患者头发5种元素含量变化及临床意义

采用原子吸收光谱法测定了９６例精神分裂症患者和１０１名正常对照组的头发Ｚｎ、Ｃｕ、Ｆｅ、Ｃａ、Ｍｇ元素含量。结果发现，精神分裂症患者头发ｎ和Ｍｇ元素含量明显低于对照组，而Ｃｕ、Ｆｅ和Ｃａ元素含量明显高于对照组。提示精神分裂症的发病，可能与Ｚｎ和Ｍｇ元素含量降低，Ｃｕ、Ｆｅ和Ｃａ元素含量升高有关。     

Oscillation condition for a series piezoelectric sensor. Application to the determination of urease activity in plant seeds

The oscillating conditions for a series piezoelectric quartz crystal (SPQC) are proposed and verified experimentally. The influence of the cell constant and oscillator phase on the oscillational ability of the SPQC was investigated. It is shown that the SPQC possesses excellent oscillational ability in low or high conductivity solutions, but in solution of intermediate conductivity, the oscillational ability decreases with increasing oscillator phase or decreasing cell constant, sometimes resulting in a cease-to-oscillate zone. The SPQC was applied to determine the urease activity in plant seeds with a detection limit of 0.004 U ml⁻¹, based on the change in conductivity.     

μ-酰基与μ-烯基铁硫原子簇配合物的合成及结构

由芳香族酰氯或α,β-不饱和酰氯与十二羰基三铁-硫醇-三乙胺体系反应,制得了通式为[(μ-RS)(μ-R′CO)Fe,(CO)_6](A)的六个铁硫原子簇配合物,以及通式为((μ-RS)(μR″CH=CR′)Fe_2(CO)_6](B)的六个铁硫配合物。对两种类型的配合物生成的过程及转化进行了初步的讨论。     

金汞齐富集冷原子荧光测汞法的研究

本文介绍了一种用于测定汞的金汞齐富集热解系统。研究了该系统与冷原子荧光测汞仪联用的工作条件和干扰,在最佳条件下的检出下限为4×10~(-13)克汞,分析周期3分钟,相对标准偏差2.5%(1.5×10~(-9)克汞)。     

高温超导体制备条件的人工神经网络识别

高温超导体的制备条件要求严格,其掺杂量大小、烧结温度控制等都直接影响实验样本的超导性质。近几年高温超导研究已积累大量实验数据,如何应用人工智能方法处理这些数据寻找更好的合成条件颇有意义。人工神经网络方法在许多领域己显示其处理复杂数据和模式识别的优越性,但尚未应用到化合物制备研究方面。本文对此作了初步尝试。     

Ab initio study of the electronic spectrum of dichlorocarbene CCl2

The equilibrium geometries, excitation energies, force constants and vibrational frequencies for seven low-lying electronic states X ¹A₁, ¹B₁, ³B₁, ¹A₂, ³A₂, ¹B₂ and ³B₂ of dichlorocarbene CCl₂ have been calculated at the MRSDCI level with a double-zeta plus polarization basis set. Our calculated equilibrium geometry for the X ¹A₁ state, excitation energy for X ¹A₁ → ¹B₁ and vibrational frequencies for the X ¹A₁ and ¹B₁ states are in good agreement with experimental data. The electronic transition dipole moments, oscillator strengths for the ¹B₁ → X ¹A₁ and ¹B₂ → X ¹A₁ transitions, radiative lifetimes for the ¹B₁ and ¹B₁ states are calculated using MRSDCI wavefunctions, predicting results in reasonable agreement with experiment.     

Exponentially fitted symplectic methods for the numerical integration of the Schrödinger equation

The computation of the energy eigenvalues of the one-dimensional time-independent Schrödinger equation is considered. Exponentially fitted and trigonometrically fitted symplectic integrators are obtained, by modification of the first and second order Yoshida symplectic methods. Numerical results are obtained for the one-dimensional harmonic oscillator and Morse potential.AMS subject classification: 65L15Funding by research project 71239 of Prefecture of Western Macedonia and the E.U. is gratefully acknowledged.