多孔β-TCP陶瓷药物载体的制备与体外释药速率的研究

本文用注浆成形的方法制备了以β-TCP为主晶相的多孔药物载体，体外测定了利福平的释药速率。实验结果表明，利福平在模拟体液中能够达到稳定的释放，可以作为骨结核手术后的辅助治疗。多孔β-TCP药物载体有望成为一种理想的药物缓释载体。     

Synthesis,characterization, and thermal properties of phosphorus‐containing,wholly aromatic thermotropic copolyesters

A series of phosphorus‐containing, wholly aromatic thermotropic copolyesters from acetylated 2‐(6‐oxide‐6H‐dibenz〈c,e〉〈1,2〉oxa phosphorin‐6‐yl)‐1,4‐dihydroxy phenylene, p‐acetoxybenzoic acid, terephthalic acid, and isophthalic acid were prepared by melting polycondensation. The structure and basic properties of the polymers, such as the glass‐transition temperature (T_g), melting temperature (T_m), thermal stability, crystallinity, and liquid crystallinity, were investigated with Fourier transform infrared, elemental analysis, differential scanning calorimetry (DSC), thermogravimetric analysis, wide‐angle X‐ray diffraction, and hot‐stage polarizing optical microscopy. The copolyesters had relatively high T_g values ranging from 183 to 192°C. The T_m values obtained from DSC curves for samples P‐20 and P‐25 were 290 and 287°C, respectively (where the number in the sample name indicates the molar fraction of the phosphorus‐containing monomer in the reactants). The initial flow temperatures of other samples observed with hot‐stage polarizing microscopy were 271–290°C. The 5% degradation temperatures in nitrogen ranged from 431 to 462°C, and the char yields at 640°C were 41–52%. All the copolyesters, except P‐40, were thermotropic and nematic. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1278–1284, 2002     

PVC／PU合金的制备与研究

叙述了选择混炼型聚氨酯(PU)与分子量适中的Ⅱ型聚氯乙烯(PVC)树脂制备PVC/PU合金的过程,讨论了PVC/PU共混比、填充剂、硫化体系、共混工艺等因素对PVC/PU合金性能的影响。结果表明:选择PVC/PU=60/40(质量比),硫化剂TD15份,白炭黑30份,混炼温度140—160℃,可制得性能优良的PVC/PU合金。动态力学性能实验显示了PVC/PU合金有较好的相容性。     

反相高效液相色谱法测定meso-四苯基卟啉钴的纯度

采用反相高效液相色谱法测定合成meso-四苯基卟啉钴的纯度;以甲醇乙腈二氯甲烷(体积比为55∶35∶10)为流动相,ShimpackCLCODS柱(150mm×6.0mmi.d,5μm)为分离柱,流速为1.5mL/min,检测波长420nm;meso四苯基卟啉钴的测定在1.0～10μg/mL时线性关系良好(相关系数r=0.9993),加标回收率为97.03%～101.42%,重复进样的相对标准偏差RSD为0.64%～2.92%(n=5)。方法的准确度高,精密度好,实际应用效果好。     

四种杀菌剂对枸杞黑果病的防治效果

枸杞黑果病是枸杞产区的主要病害．发病后造成黑花、黑蕾和黑果，使枸杞产量降低，品质变劣。为探明四种杀菌剂对枸杞黑果病的防治效果及最佳剂量，2003年对下述四种杀菌剂进行了田间药效对比试验，调查防效结果如下：20％三苯基醋酸锡WP450～281g／hm^2(以有效成分计，下同)，20％氟硅唑EC21．08g／hm^21．5％噻霉酮EW16、88～21．08g／hm^2、40％氟硅唑EC450g／hm^2和70％甲基托布津WP787．5g/hm^2对枸杞黑果病防效均在88．25％以上。经LSD检验各处理间防效无显著差异。     

SiC晶须对Si3N4陶瓷基复合材料机械强度的影响

制备了含10vol％,20vol％及30vol％SiC晶须的Si_3N_4基复合材料,对其室温及高温机械强度的测试研究表明,SiC晶须对基体的高温机械性能有明显的增强作用。含20vol％SiC晶须的复合材料1200℃下强度达780MPa,比基体材料提高50％。通过SEM和TEM研究,讨论了SiC晶须增强的原因。     

拟稳态法测定气相扩散系数

根据拟稳态一维扩散原理,建立了气相扩散系数的测定装置。在该装置上,测定了8个体系的气相扩散系数,其中CH_2Cl_2-空气,CH_2Cl_2-H_2,CH_3CH_2Br-空气,CH_3Cl_2Br-H_2,CHCl_3-H_2等5个体系的气相扩散系数实验值,迄今尚未见文献报道。实验结果表明,本测试装置稳定性好,实验误差小,实验装置体积小,测试过程较为简便。     

Zinc hydroxystannate and zinc stannate as flame‐retardant agents for flexible poly(vinyl chloride)

The flame‐retardant and smoke‐suppressant properties of inorganic tin compounds such as zinc hydroxystannate (ZHS) and zinc stannate (ZS) were investigated in a comparison with alumina trihydrate, magnesium hydroxide, and Sb₂O₃ through the limiting oxygen index test and smoke density test. The flame‐retardant mechanisms were studied through the char yield test, SEM, quantitative analysis, thermogravimetry and differential thermal analysis. The thermal degradation in air of flexible PVC treated with the above compounds was studied by thermal analysis from ambient temperature to 800°C. The results showed that tin compounds such as ZHS and ZS could be used as a highly effective flame retardant for flexible PVC, and it appears that the tin compound may exert its action in both the condensed and vapor phases, but mainly in condensed phases as a Lewis acid. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1469–1475, 2005     

Decentralized weighted control for a class of large‐scale systems with multi‐modes

In this paper, the control synthesis problem for a class of large‐scale systems with multi‐modes that are called large‐scale switched systems is addressed. By introducing the concept of decentralized switching signal and the relevant decentralized average dwell time, the asymptotic stability and weighted ?₂ gain performance are investigated. It should be noted that the decentralized switching covers general switching cases for large‐scale switched systems, namely, it admits both time‐dependent switching signal and arbitrary switching signal blended in the decentralized switching. Then, on the basis of the analysis results, the decentralized weighted control scheme including state feedback controller gains and switching signals is studied. Several design algorithms are proposed to meet different controller design problems. Finally, numerical examples are provided to illustrate theoretical findings within this paper. Copyright © 2013 John Wiley & Sons, Ltd.