助剂对可生物降解聚碳酸亚丙酯/聚丙烯非织造布切片性能的影响

采用熔融共混法研究助剂马来酸酐(MAH)、马来酸酐接枝聚丙烯(PP-2)对可生物降解聚碳酸亚丙酯(PPC)/聚丙烯(PP)非织造布切片结构与性能的影响.红外谱图表明MAH和PP-2的酸酐官能团与PPC发生了开环反应.MAH、PP-2可显著提高切片的拉伸强度,当MAH,PP-2用量为1%和2%时,切片拉伸强度较不添加助剂时分别提高了116%和101%.MAH,PP-2的加入降低了切片的熔体流动速率,提高了特性黏数,同时提高了切片的玻璃化转变温度(Tg)和热分解温度,扩大了切片的使用和加工温度范围.当MAH用量为1%时,切片Tg提高了4℃.当MAH,PP-2用量为1%和2%时,切片5%热分解温度分别提高了44℃和20℃.加入MAH、PP-2的切片断面的微观形貌图显示切片内部凹陷和空洞较少,较为平整,PP-2改善切片相容性的效果优于MAH.PPC和PP置于磷酸缓冲液中30天的降解率分别为4.30%和0%,说明PP在磷酸缓冲液中几乎不降解.加了助剂的切片30天的降解率在3.80%以上,说明制备的PPC/PP非织造布切片是可降解的,对环境友好.开环反应、增加切片界面黏附力、降低界面张力等可能是助剂提高切片性能的作用机理.     

Modulateur electrooptique pour l'extraction d'une impulsion lumineuse d'un train

The performance of a new light modulator are presented. It uses the Pockels effect in order to select a single pulse from a train. The repetition rate of commutation is greater than 100 Hz, the contrast ratio exceeds 10⁴ and the lifetime is about 5 x 10⁷ shots. The main advantage of this modulator is an easy working-up.     

水化与非水化－2－乙基己基磷酸单－2－乙基己基酯钠盐的红外吸收强度研究

本文对水化与非水化２－乙基己基磷酸单－２－乙基已基酯钠盐在简化结构的假定下进行了简正分析，给出了谱带的指认；并利用ＣＮＤＯ／２方法进行了红外吸收强度计算。结果表明该分子在水化后Ｐ＝Ｏ和Ｐ—Ｏ—Ｃ谱带的吸收强度都增加，经过四个实际样品的检验证明港带强度增加的计算值与实验值符合很好。这一结果为应用极性基团红外谱带强度变化来研究其水化作用提供了理论基础。     

复杂流体的聚集态结构,性质及应用

综合报道了油－水、油－油分散体系中中各种聚集体，如胶团，微乳状液、凝胶、Ｌｉｅｓｅｇａｎｇｒｉｎｇ及分形图形等的形成机理，结构和特性，以及流体中聚集结构的形成在实际生产中的意义。     

四氢合铝阴离子的自洽势场分子轨道从头计算

本文用自编的LCAO-SCF-MO从头计算通用程序,计算了A1H₄^-阴离子的分子轨道的能级和系数,结果较已发表的工作有较大改进。     

Mindo/3 study of 1,2-didehydrocyclooctatetraene and related planar conjugated eight-membered carbocycles

MINDO/3 calculations indicate the 1,2-didehydrocyclooctatetraene ($\text{2}$) and 1,2,5,6-tetradehydrocyclooctatetraene ($\text{10}$) and their benzo derivatives have planar skeletons. In addition, in the cases of $\text{2}$ and its benzo derivatives, the acetylenic structure is found to be thermodynamically more stable than the cumulenic one.     

Total Synthesis of Three New Dihydrostilbenes from Bulbophllum odoratissimum

Natural stilbenoids are presently well known by their various kinds of bioactivity, such as antitumor, anti-inflammatory and platelet antiaggregation1. In our previous studies of naturally-occurring cytotoxic agents present in traditional Chinese medicine…     

硼酸与甲阶酚醛树脂的配位反应及配合物的结构

本文通过对溶液pH值的测定和外光谱分析，研究了硼酸与甲阶酚醛树脂的配位反应。结果表明：在室温下硼酸能与甲阶酚醛树脂中的羟基发生配位反应，并产生H^ 使溶液的pH值降低；溶液的酸性强弱与甲阶酚醛树脂中的羟甲基含量和硼酸的用量有关；硼酸以硼酸根离子的形式与树脂中的酚羟基和邻位羟甲基发生配位反应，形成了一个含有两个氧原子和一个硼原子的六元环，使甲阶酚醛树脂发生交联。     

负载型纳米TiO2复合载体的制备及其酸性研究

采用溶胶-凝胶法在γ-Al2O3上制备出负载型纳为TiO2，并用XRD，TEM对TiO2的晶型及粒子大小进行了表征。结果表明，在550℃煅烧后，TiO2仍为锐钛矿结构，且通过控制制备条件，TiO2粒径可控制在5nm-10nm之间及15nm-20nm之间，TiO2都以纳米粒子的形式高分散负载在γ-Al2O3上。另外，还用NH3-TPD对复合载全进行酸性表征。实验发现，纳米TiO2对复合载体的酸量影响较大。复合载体的酸量并不是随TiO2含量的增加而一直下降，而是先降低，当TiO2含量达到30％后又开始增加。纳米TiO2对复合载体的酸强度和酸度分布影响较小。     

Layer-by-Layer Construction of Novel Biofunctional Fluorescent Microparticles for Immunoassay Applications

A novel class of biofunctional fluorescent microparticles for application in immunoassays was constructed by using the layer-by-layer self-assembly method to deposit multiple layers of fluorescently labeled polyelectrolytes onto colloidal particles, followed by deposition of a protein (immunoglobulin G, IgG) layer. Microelectrophoresis experiments revealed alternating negative and positive zeta-potentials with deposition of each successive polyelectrolyte layer, indicating that the alternate electrostatic adsorption of polyelectrolytes of opposite charge was successfully achieved. Transmission electron microscopy images showed a change of the particle surface texture after polyelectrolyte multilayer deposition. Fluorescence microscopy image (FMI) analysis provided direct measurement of the fluorescence intensity of single microparticles. The observed systematic increase of the fluorescence intensity of individual microparticles with increasing polyelectrolyte layer number from FMI analysis further demonstrated the controlled regular adsorption of polyelectrolyte layers onto the polystyrene (PS) particles. Protein immobilization onto the polyelectrolyte multilayer-coated particles was verified by the different surface properties of the microparticles with respect to surface charge under pH conditions above and below the isoelectric point of the proteins. The assembly of IgG and fluorescein isothiocyanate-labeled IgG onto polyelectrolyte multilayer-coated PS microparticles and their potential use was ultimately confirmed by a solid phase immunotest. Copyright 2001 Academic Press.