Novel one-step route for synthesizing sub-micrometer PSt hollow spheres via redox interfacial-initiated method in inversed emulsion

Interfacial-initiated polymerization of styrene (St) was carried out in inversed emulsion with cumene hydroperoxide (CHPO) and ferrous sulfate (FeSO₄)/disodium ethylenediaminetetraacetate (NaEDTA)/sodium formaldehyde sulfoxylate (SFS) as the redox initiation system. The water-soluble Fe²⁺-NaEDTA-SFS acted as the reducing component and the oil-soluble CHPO as the oxidant component of the redox initiation system. Therefore, the primary radicals were produced mainly at the oil/water interface to initiate the polymerization of St. Thus, sub-micrometer hollow polystyrene (PSt) spheres were obtained by one-stage polymerization, which was supported by the techniques of transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM).     

二厘米微波衰减标准装置不确定度的验证

采用传递比较法对二厘米微波衰减标准装置不确定度进行了验证。测量标准装置的重复性以组内实验标准偏差sn(A)定量表征，测量标准装置的稳定性用组间实验标准偏差sm定量表征。     

Sol-gel Preparation and Preliminary in vitro Evaluation of Fluorapatite／Hydroxyapatite Solid Solution Films

Fluorapatite/hydroxyapatite solid solution has better biological properties than other apatites, especially used as films or coatings. In this work, sol-gel preparation and in vitro behavior of fluorapatite/hydroxyapatite solid solution films on titanium alloy were investigated. Ca(NO3)2-4H20 and PO(OH)x(OEt)3-x were selected as precursors, and hexafluorophosphoric acid (HPFo) was used as a fluorine containing reagent. The Ca and P precursors were mixed with HPFo to keep the Ca/P molar ratio 1.67. The mixtures refluxed for 12 h were used as dipping sols for the preparation of the films. The phase of the films obtained at 600℃ was apatite. The F contents in the films increased with the concentrations of HPF6 in the dipping sols. The solid solution films were shown to have better stability than hydroxyapatite films, and a reasonably good bioactivity in the in vitro evaluation.     

STUDY ON PHASE PERCEPTION IN SPEECH

The perceptual effect of the phase information in speech has been studied by auditory subjective tests. On the condition that the phase spectrum in speech is changed while amplitude spectrum is unchanged, the tests show that: (1) If the envelop of the reconstructed speech signal is unchanged, there is indistinctive auditory perception between the original speech and the reconstructed speech; (2) The auditory perception effect of the reconstructed speech mainly lies on the amplitude of the derivative of the additive phase; (3) td is the maximum relative time shift between different frequency components of the reconstructed speech signal. The speech quality is excellent while td <10ms; good while 10ms< td <20ms; common while 20ms< td <35ms, and poor while td >35ms.     

住宅建筑结构中隔震技术的应用和经济评价

对当前隔震系统做了简单介绍 ,介绍了基础隔震的技术和施工方法等。讨论在住宅结构中推广隔震技术的方法 ,对各种类型的住宅结构做经济评价 ,讨论推广的可能性和难点。     

现代企业制度条件下企业管理的内涵

论述了在社会主义市场经济体制和现代企业制度条件下企业管理的主要内涵，提出了加强企业管理的途径和对策。     

高分子材料辐射接枝苯乙烯的研究进展

对各高分子材料辐射接枝苯乙烯的动力学，接枝方法及接枝材料的应用进行了综述，讨论限辐射剂量，剂量率，温度，后效应，溶剂，添加剂和高分子材料厚度及结晶性等方面对接枝反应的影响。     

氰化浸出体系中金的溶剂萃取

本文评述了金的碱性氰化溶液溶剂萃取研究与开发工作的最新进展。包括改性胺，季铵盐，磷氧化物及胍类萃取剂等。     

离体肾脏保存实验研究

本文讨论离体肾脏生存机理研究的意义和方法，研制,成功的一种携带式快速和精确控制保存环境温度的脉动灌流型人工生命维持系统，采用微处理器进行实时数据采集，处理和非线性多模式采样控制，用以维持设定的环境参数和维持最佳生存条件，本文是采用猪肾为实验材料，进行多例离体猪肾的保存实验，研究有关环境参数和保养液成分对保存效果的影响，取得良好结果，实验性猪同种异体移植亦已获得初成成功。     

语音时域分割研究

在语音时域挑选剩余可懂度低的可用置换集合,置换集合是语音TDS系统中不可缺少的重要环节,本文给出了可用置换选取的条件、客观评价标准和方法。