Preparation of polypropylene/montmorillonite nanocomposites by intercalative polymerization： Effect of in situ polymer matrix functionalization on the stability of the nanocomposite structure

The copolymerization of propylene and 5-hexenyl-9-borabicyclo[3.3.1]nonane (5-hexenyl-9-BBN) has been conducted with an MgCl2/TiCl4 catalyst intercalated in an organically modified montmorillonite (OMMT) with triethylaluminum (AlEt3) cocatalyst and diphenyldimethoxysilane (DDS) external donor. This polymerization process simultaneously results in both the exfoliation of MMT layers to realize the preparation of polypropylene (PP)/MMT nanocomposites and the implantation of reactive borane groups in the formed PP matrix. The polymer-borne borane groups have been able to undergo an effi-cient hydrolysis process under very mild reaction conditions (40℃, 3 h, in THF), introducing hydroxy groups into PP without sacrificing the polymerization-formed nanocomposite structure (the exfoliation of MMT). The resultant hydroxyl-functionalized PP/MMT nanocomposites exhibit enhanced structural stability against processing compared with those based on unfunctionalized PP matrix.     

Experimental investigation of incremental reactivity of di-tert-butyl peroxide

Large quantities of di-tert-butyl peroxide (DTBP) have been emitted into the troposphere due to human activities. Its role in the atmospheric photochemical reaction has not been understood. This study presents the results of the photochemical reactions of DTBP and NOx, which have been simulated in a self-made smog chamber under the temperature of (29±1)℃. Both the wall decays of ozone and NO2 could be neglected, compared to the results in simulative experiments. The effective intensity of UV light used in the experiments was 1.28×10-3 s-1, which was expressed by the rate constant of NO2 photolysis in purified air. The reaction mechanism was proposed according to our results and reports of other researchers. The maximum values of incremental reactivity (IR) in the three simulative ex- periments were 9.53×10-2, 5.23×10-2 and 3.78×10-2, respectively. The incremental reactivity decreased with the increase of initial concentrations of DTBP. The IR value of DTBP obtained in this study was comparable to that of acetylene reported in our previous research.     

DNA编码的模型分析

提出了适应DNA计算的DNA编码问题.对等码长的DNA编码问题的数学模型进行分析.以优化码长作为目标,分析了约束条件.以杂交反应为核心将约束条件分为基本约束和控制生化实验的约束,而控制生化实验的约束包含组合约束和热力学约束.控制移动不匹配的下值才能控制杂交反应,由此改进了移动距离.引入窗口距离解决了错配总量和分布的控制问题.     

二甲醚HCCI发动机微量排放物的研究

根据优化气相色谱仪工作条件,对二甲醚均质充量压燃(HCCI)发动机排气中的甲醛和甲酸甲酯进行了检测.通过二甲醚简化反应机理与Fluent的耦合联算,以及结合Woschni传热模型和DME详细反应机理的Chemkin反应动力学数值模拟,对二甲醚HCCI发动机的燃烧过程及其微量排放物(甲醛、甲酸和甲酸甲酯)进行了预测分析.结果表明:在一定条件下,甲醛、甲酸和甲酸甲酯存在于排气中,其排放量均随过量空气系数的减小而减小,发动机转速、进气温度和压力对其影响也很大.     

纳米四水羟基硝酸氧铋的制备及在氮气气氛下的热分解动力学

利用反相微乳液法制备出了纳米四水羟基硝酸氧铋[Bi6O4(OH)4](NO3)6(H2O)4,并以热分析为手段对纳米[Bi6O4(OH)4](NO3)6(H 2O)4的热分解过程和非等温热分解动力学机理进行了研究.动力学研究确定了[Bi6O4(OH)4](NO3)6(H2O)4脱硝酸根反应属于球对称的三维扩散的D3机理,热分解表观活化能为E=98.90033 kJ/mol,lnA=27.13109.     

N-(5-三氟甲基-1,3,4-噻二唑-2-基)-N''-芳氧乙酰基硫脲的合成及其生物活性

通过2-氨基-5-三氟甲基.1,3,4-噻二唑与芳氧乙酰基异硫氰酸酯反应,合成了9个新的芳氧乙酰基硫脲,其结构用红外光谱、核磁共振氢谱和元素分析确证.初步的生物活性测试试验表明,部分目标化合物具有良好的植物生长调节活性,其中3b、3e、3i的生长素活性优良,3d、3e的细胞分裂素活性较好.三氟甲基增进了目标化合物的生物活性.     

Ghrelin对大鼠孤束核葡萄糖反应神经元的影响

采用玻璃微电极记录神经元活动的实验方法,研究大鼠孤束核(NTS)微量注射ghrelin对孤束核内葡萄糖反应神经元的活动的调节作用;在孤束核中记录到的82个神经元中,有37(45.13%)个葡萄糖反应神经元中,其中11个给予葡萄糖后电活动增强,26个电活动减弱,分别称之为葡萄糖受体神经元(GRNs)和葡萄糖敏感神经元(GSNs)。在11个GRNs中有9个(81.81%)给予ghrelin后电活动减弱,1个(9.095%)电活动增强;在26个GSNs中23个(88.46%)给予ghrelin后电活动减弱,1个(16.67%)电活动增强。结果提示,ghrelin可以通过改变NTS内葡萄糖反应神经元的电活动来调节能量代谢和摄食活动。     

矿化垃圾反应床处理渗滤液的微生物学特性

研究了矿化垃圾生物反应床处理渗滤液时,不同床层高度、气温状况和水力负荷下矿化垃圾微生物学特性的变化规律.结果表明：床体浅层（0-20 cm）通透性好,细菌总数是床体厌氧区的数十倍,生理生化过程强烈,酶活性高,是污染物降解的最佳区域;气温的日变化对细菌总数影响不大,但在25-30℃时有利于维持微生物数量及其重要酶的活性;反应床对水力负荷有一定的耐冲击能力,但当矿化垃圾与渗滤液的体积比小于20（水力负荷超过16 cm.d^-1）时,床层微生物及酶面临胁迫环境,出水水质急剧变差.     

Zr-MCM-41介孔分子筛的合成及催化乙氧基化反应

以乙二胺为碱性介质合成了Zr-MCM-41介孔分子筛。通过XRD、Hammett、BET等方法对分子筛结构表征,结果表明,合成的分子筛具有典型的六方介孔结构特征;将其用于催化乙氧基化反应,并考察了硅锆原子比、反应温度及催化剂用量等因素对反应活性的影响。     

氟碳乳液的合成与表征

采用氧化还原引发体系,在复合乳化剂作用下,以三氟氯乙烯、烷基乙烯基醚类以及带特殊官能团的乙烯基类为共聚单体,制备了氟碳乳液。通过理论计算确定了主要单体配比,讨论了聚合时间、反应温度、搅拌强度等各种工艺条件对乳液性能的影响。通过红外光谱(FT-IR)、差示扫描量热(DSC)等测试手段对聚合物的结构进行了表征。