Tris(ethyl­enediamine)zinc(II) molybdate(VI), [Zn(en)3][MoO4]

The crystal structure of the title compound, [Zn(C₂H₈N₂)₃][MoO₄], is composed of [MoO₄]²⁻ anions and [Zn(en)₃]²⁺ complex cations (en is ethyl­enediamine), both with symmetry 2, which are held together in a three‐dimensional network via hydrogen‐bonding inter­actions. The [Zn(en)₃]²⁺ cations in the crystal structure exhibit two configurations, viz. Λ(δδδ) and Δ(λλλ), as a pair of enantiomers.     

制粉优化控制系统

本文介绍了制粉系统近年流行的几种控制方式,结合实际控制的效果和系统的控制指标,探讨制粉自动控制技术的开发方式和应用.     

儿茶酚胺类物质荧光分析方法研究进展

作为神经递质和激素,儿茶酚胺不仅直接参与行为活动以及血压,心率呼吸和睡眠等植物神经功能调控,而且还与一些功能性疾病如神经分裂症,忧郁症以及器官性病变的出现有关。荧光方法是儿茶酚胺定性定量分析的一种重要方法,本文介绍了近十几年来荧光方法在儿茶酚胺分析中的应用。     

理科大学物理实验课课程体系的研究与实验

通过对80年代以来物理实验课改革的研究与实践，提出了理科大学物理实验课课程体系的建设意见。     

DMAIC流程在自动焊接质量改进中的应用

本文按照六西格玛DMIAC流程对A企业自动焊接质量进行改进.按照DMAIC流程对问题进行定义,明确改进目标。然后测定导致自动焊质量问题的可能原因,并对相关测量系统的能力进行评定和改进.在此基础上进一步分析导致质量问题的根本原因,并设计了一个2~((-2))试验方案,找出影响焊接缺陷的显著因素并进行优化,使得自动焊过程的缺陷水平降为DPHU低于0.05,超过了预期目标,成本节省显著。最后,为了保持改进成果,对过程建立了适当的在控制方法.     

Study of sawtooth oscillations on the HT-7 tokamak using 2D tomography of soft x-ray signal

It is the first time so far as we know that two arrays of multi-channel soft x-ray detectors are used to generate twodimensional （2D） images of sawtooth oscillation on the HT-7 tokamak using the Fourier-Bessel harmonic reconstruction method, and using the singular value decomposition to analyse the data from soft x-ray cameras. By these two arrays, 2D image reconstruction of soft x-ray emissivity can be obtained without assumption of plasma rigid rotation. Tomographic reconstruction of the m=1 mode structure is obtained during the precursor oscillation of the sawtooth crash. The crescent-shaped mode structure appearing on the contour map of the soft x-ray emissivity is consistent with the quasiinterchange mode. The characteristics of the m=1/n=1 mode structure observed in the soft x-ray tomography are as follows： the magnetic surface is made up of the crescent-shaped “hot core” and the circular “cold bubble”. The structure of the magnetic surface rotates in the direction of the electron diamagnetic drift and the rotation frequency is the oscillation frequency of soft x-ray signals.     

二维抛物型方程的高精度多重网格解法

提出了数值求解二维抛物型方程的一种新的高精度加权平均紧隐格式，利用Fourier分析方法证明了该格式是无条件稳定的，为了克服传统迭代法在求解隐格式是收敛速度慢的缺陷，利用了多重网格加速技术，大大加快了迭代收敛速度，提高了求解效率，数值实验结果验证了方法的精确性和可靠性。     

Cr：Mg2SiO4晶体红外光致发光谱的研究

报道了在室温和液氮温度下分别用1064nm和532nm激光诱导的Cr:Mg_2SiO_4晶体的红外光致发光谱,并详细分析光谱的结构和特点.在假设Cr:Mg_2SiO_4晶体中同时存在(CrO_6)~(9-)和(CrO_4)~(4-)两种络离子的基础上讨论了红外光致发光的产生机理,理论计算证明假设是合理的.     

Ferrocenecarbaldehyde isonicotinyl hydrazide

The chiral structure of ferrocenecarbaldehyde isonicotinyl hydrazide, [Fe(η⁵‐C₅H₅)(η⁵‐C₁₂H₁₀N₃O)], shows the molecule exhibits an E configuration, has a CN bond length of 1.284(4) Å and an N N bond length of 1.388(3) Å. Copyright © 2004 John Wiley & Sons, Ltd.