Countable network weight and multiplication of Borel sets

A space Borel multiplies with a space if each Borel set of is a member of the -algebra in generated by Borel rectangles. We show that a regular space Borel multiplies with every regular space if and only if has a countable network. We give an example of a Hausdorff space with a countable network which fails to Borel multiply with any non-separable metric space. In passing, we obtain a characterization of those spaces which Borel multiply with the space of countable ordinals, and an internal necessary and sufficient condition for to Borel multiply with every metric space.

     

Weak separation properties for self-similar sets

We develop a theory for self-similar sets in that fulfil the weak separation property of Lau and Ngai, which is weaker than the open set condition of Hutchinson.

     

Coating and water permeation properties of SiO2 thin films prepared by the sol-gel method on nylon-6 substrates

Nylon-6 substrates were coated with SiO₂ thin films by the sol-gel method and their water permeability coefficient was evaluated. Methyltriethoxysilane (MTES) and tetraethoxysilane (TEOS) were used as starting materials. The addition of MTES to TEOS has enabled the formation of crack-free thin films on the substrates. The thin films strongly adhered to the substrates. The water permeability coefficients of nylon-6 substrates coated with these thin films decreased with the increase in the ratio of TEOS to the total alkoxides. The pretreatment of the nylon-6 substrates with -aminopropyltriethoxysilane was found to be effective to suppress the water permeability. The water permeability was suppressed by about 40% under the optimal condition.     

An application of the generalized alternating polynomials to the numerical solution of Fredholm integral equations

Generalized alternating polynomials have been introduced by the author earlier. In the present paper their indirect analogue is constructed for numerical solution of the Fredholm linear integral equations. Although the proposed method is a particular case of the general projection scheme, its valuable feature is the presence of a sequence of parameters, which, for sufficiently smooth kernels and inhomogeneous terms, serves as an indicator of the quality of approximation.     

硅灰石矿物发光原料中Fe2+的去除与CaSiO3∶Eu3+的光谱特性

提出了用草酸．邻菲哕啉去除硅灰石中Fe^2 的方法，研究了浸取剂的浓度、浸取时间和温度等条件对Fe^2 的去除率的影响，在最佳的浸取条件下，Fe^2 的去除率达到98．35％。在去除猝灭剂后的硅灰石矿物中，掺加适量的稀土激活剂Eu^3 ，通过高温固相法制成荧光发光材料，发光强度明显提高，接近于化学试剂合成的发光材料。     

聚醚酮酮（PEKK）／4，4′-二苯氧基二苯砜（DPODPS）多嵌段共聚物的合成与性能

采用溶液缩聚法由酰氯端基聚醚酮酮(PEKK)齐聚物和4，4′-二苯氧基二苯砜(DPODPS)制备了PEKK／DPODPS多嵌段共聚物，用DSC、TGA等方法对共聚物进行了表征和性能测试。结果表明，随着共聚物中DPODPS含量的增加，共聚物的熔融温度逐渐降低，而其玻璃化转变温度则逐渐升高。当DPODPS质量分数在32．63％～40．73％范围内时，所得共聚物的Tg为185～193℃，比纯PEKK的Tg高出20～28℃；其Tm为322～346℃，比纯PEKK的Tm降低35～59℃，这既保持了纯PEKK的耐热性，又改善了熔融加工性能。该组成范围内的共聚物的拉伸强度(σi)为86．6～84．2MPa，拉伸模量(M)为3．1～3．4GPa，断裂伸长率(ε)为18．5％～20．3％。     

多环麝香的分子结构和香气之间的关系

本文综述了多环麝香的当前进展,并提出了系统的分类方法。对各种多环麝香(茚满型,萘满型,异色满型,氢化引达省型,苊型)香味与分子结构之间关系的研究进行了总结,还作了比较。并描述了多环分子中环上取代基的性质,数量和位置对麝香香味的影响。     

交联助剂对PPC／NBR弹性体结构和性能的影响

研究了马来酸酐（ＭＡ）及异氰脲酸三烯丙酯（ＴＡＩＣ）对聚丙撑碳酸酯／丁腈橡胶共混弹性体结构和性能的影响，发出加入ＭＡ或ＴＡＩＣ能有效地改善交联网络；加入适量ＭＡ能显著改善共混弹性体热氧老化稳定性；加入ＴＡＩＣ使共混弹性体具有优良的高弹特性和力学性能。     

改进型甲醇合成催化剂NC208的催化特性

采用ＴＰＤ、ＸＲＤ、ＢＥＴ和Ｈ２Ｓ中毒试验等方法，对比研究三组份（Ｃｕ－Ｚｎ－Ａｌ）甲醇合成催化剂Ｃ２０７和添加少量金属氧化物的改进型催化剂ＮＣ２０８．结果表明，工作态ＮＣ２０８催化剂表面Ｃｕ＋／Ｃｕ０的比值和价态稳定性大于Ｃ２０７．     

α－甲基苯乙烯对HIPS／SBS共混物流变行为及力学性能的影响

用锥板式流变仪研究了α－ＭＳ对ＨＩＰＳ／ＳＢＳ共混物流动行为的影响，结果表明：不同α－ＭＳ用量的共混物和如曲线相似．均随增加τ＿ｗ增大、η＿ａ下降。流动指数，ｎ均小于１为非牛顿假塑性流体。加入少量（约２．５％）α－ＭＳ使共混物熔融指数提高３倍，其总体力学性能变化不大。