SPC数据采集与处理系统

SPC数据采集与处理系统实现了SPC数据的计算机采集与处理 ,大大提高了SPC分析的效率与准确性 ,对推动目前国内SPC应用 ,提高产品质量管理水平具有重要的现实意义。本文具体介绍了SPC数据采集与处理系统的结构与组成及软件实现和处理功能。     

超声波声孔效应中气泡动力学的研究

在超声快速制取组织细胞病理切片的过程中，发现激励信号对切片制取效果有明显的影响.为了掌握超声激励信号对组织细胞的影响规律，达到快速制取病理切片的最佳状态，从气泡空化模型入手，通过改变激励信号频率、声压、气泡初始半径和液体黏滞系数等参量，研究了声孔效应中气泡动力学激励机制.数值计算表明：空化泡振动随激励声压增强而升高，随液体黏滞系数增强而减弱；一定频率范围内空化泡振动能保持在膨胀、收缩和振荡的稳定空化状态，存在空化泡稳态振动的最佳激励频率；一定初始半径能保证空化泡产生稳定的振动，存在空化泡稳态振动幅度最大的初始半径.实际操作中，在频率、声压、初始半径和黏滞系数综合作用的若干空化阈内，声孔效应使超声快速法制取细胞组织切片获得最佳效果. 关键词： 声孔效应 超声空化 气泡振动 稳态空化域     

Preparation, characterization and photocatalytic activity of polycrystalline Bi2O3/SrTiO3 composite powders

Bi₂O₃/SrTiO₃ composite powders have been prepared and their photocatalytic activities were investigated by photooxidation of methanol. These powders were characterized by UV-Visible diffuse reflectance spectra, SEM and X-ray diffraction (XRD). The results revealed that all the Bi₂O₃/SrTiO₃ composite powders exhibited higher photocatalytic activity than pure SrTiO₃, Bi₂O₃ and TiO₂ (P25) under visible light irradiation (λ>440 nm). The effects of the Bi₂O₃ contents on the photocatalytic activities of the composite powders were examined, the photocatalytic activities increased with the content of Bi₂O₃ increasing to a maximum of 83% and then decreased under visible light irradiation. The effects of the calcination temperatures on the photocatalytic activities of the composite powders were also investigated.     

The prediction of the peak width at half height in HPLC

The prediction of the peak width at half height is an important aspect in the optimization of the chromatographic operating conditions. In this paper, a linear relationship, between the peak widths at half height and the retention values with various isocratic elution is observed. In gradient elution, however, the relationship between the peak widths at half height and the so-called invented retention values that correspond to the mobile phase composition by eluting the solute from the column end is developed. We believe that there is almost the same band width at half height inside the column (in unit of length) for different solutes. The peak width at half height in the chromatogram (in unit of time) is mainly determined by the capacity factor of the solute when it is eluted from the column end. The larger the capacity factor of a solute eluted from the column end, the more slowly will be the solute eluted from the column end and the wider will be the peak width at half height. It is possible to predict the peak width at half height in various isocratic and gradient elutions by using this linear relationship.     

解可分离约束双凹规划问题的一种外逼近方法[英文]

在本文中，我们提出了双凹规划问题和更一般的广义凹规划问题。我们给出了双凹规划问题的整体最优性条件，并构造了一个有限终止外逼近算法。     

位置参数估计量的损失函数之估计

本文考虑损失函数的估计问题,分别对于球对称分布和均匀分布情形给出了其参数的J-S型估计量的损失之估计,它们满足[1]中提出的条件(Ⅰ)和(Ⅱ).     

Studies on self-pumped phase conjugation in Cu-doped (K0.5Na0.5)0.2(Sr0.61Ba0.39)0.9Nb2O6 crystals

The use of Cu-doped (K_0.5Na_0.5)_0.2(Sr_0.61Ba_0.39)_0.9Nb₂O₆ as self-pumped phase conjugators using internal reflection is reported. Reflectivities as high as 63% at 5145.5 nm and 60% at 632.8 nm were realized. It was found that the photorefractive response changes significantly at different doping concentration. The responses of the crystals to the laser wavelength, incident angle and dopant concentration are studied.     

微分脉冲溶出伏安法同时测定食品中的锌铁锰

在1％乙二胺-0．1mol／L酒石酸钠-pH11．82 Britton—Robinson缓冲溶液体系中用微分脉冲溶出伏安法同时测定锌、铁、锰三种微量元素。它们的峰电位分别为-1184，-1392和-1456mV(vs．Ag/AgCl)；线性范围分别为：0.001—0.015，0．005—0．05和0．04—0．7μg／mL，最低检出浓度分别为0．0007，0．0014和0．0193μg／mL。本法操作简便、准确、灵敏度较高，用于食品中这三种元素的分析，结果令人满意。