加成型硅橡胶的制备及性能

合成了不同乙烯基含量的MQ树脂，探讨了不同因素（乙烯基硅橡胶分子量，含氢硅油种类，SiH/CH=CH2比例，填料种类）对于加成型有机硅橡胶物理力学性能的影响，当乙烯基硅橡胶的分子量在65万时，所制得的硫化胶拉伸强度远远大于分子量为10万的硫化胶，MQ树脂具有较好的增强效果，当MQ树脂乙烯基含量为2．87％，其拉伸强度达到了6．30MTa，但与SiO2增强的硫化胶相比，其撕裂强度较差，聚硅氧烷分子量越大，制得的硫化硅橡胶物理力学性能愈好，交联剂中的硅氢和生胶中的乙烯基比值1：3较好，它既能保证交联完全，又不致产生气泡。     

CaF2掺杂对ZnNb2O6陶瓷烧结行为及介电性能的影响

用传统固相法合成了CaF2掺杂ZnNb2O6微波介质陶瓷,通过XRD、SEM以及HP4291阻抗分析仪等测试手段对其烧结行为、晶体结构及微波介电性能进行了系统研究。结果表明,CaF2掺杂能有效地降低ZnNb2O6陶瓷的烧结温度,提高介电常数,但品质因数Q值有所下降。1100°C烧结w(CaF2)=0.5%(质量比)掺杂的ZnNb2O6陶瓷具有较好的介电性能:εr=31.6,Q×f=68THz,τf=-47×10-6°C-1。     

Hydroxymethylation of jojoba oil by lewis acid-catalyzed ene reaction with formaldehyde

Formaldehyde undergoes ethylaluminum dichloride-catalyzed ene reaction with jojoba oil to afford a mixture of 1∶1 and 1∶2 adducts. The hydroxymethyl products were identified by comparison with model adducts prepared from methyl oleate and oleyl acetate.     

Effect the Actual Structure of Boron and Catalytic Additions on Boron Nitride Synthesis

The bahavior of boron with different degrees of purity, fineness, and crystal structure perfection during nitriding at high temperature is studied by electron microscopy, x-ray diffraction, and chemical analysis. The effect of additives (Li₂CO₃, H₃BO₃, and NH₄Cl) on boron nitride synthesis is studied. A marked reduction is established in the temperature for forming a highly-ordered boron nitride structure on introducing additives. The chemistry of the amorphizing effect of ammonium chloride on the crystal structure of boron is suggested.     

烯丙基碘与锡和醛的选择性加成

烯丙基碘与锡和含有活性基团的醛可进行直接的亲核加成，水的存在不利于此反应的进行．比较了烯丙基碘、烯丙基溴进行反应时的活性，没想了烯丙基锡化物与羰基的加成反应机理．     

金属添加物对沥青结合MgO-C复合耐火制品性能的影响

在实际生产条件下，研究了含Mg－Al和Si－Al－Ba－Fe等复合金属添加物对沥青结合的MgO－C复合耐火制品抗热震性和抗氧化性的影响；结果表明，这两种金属添加物均能有效地改善沥青结合MgO－C制品的抗热震性和抗氧化性。将加有2％Mg－Al复合金属粉的改进型MgO－C衬砖在电弧炉和顶吹氧气转炉上进行了工业化试验，使电弧炉炉龄提高了28．6％、转炉炉龄提高11．1％。     

Anodic Oxidation of Carbon Fibres in Diammonium Hydrogen Phosphate Solution

Anodic surface treatment of high tensile-carbon fibres under galvanostatic conditions has been performed in diammonium hydrogen phosphate solution, containing an addition of ammonium rhodanide.

The oxidized fibres have been characterized by monofilament tensile strength, XPS measurements and surface energetic analysis. Additionally, the acid-base interactions have been evaluated by wetting with aqueous solutions of different pH values.

An addition of ammonium rhodanide to the diammonium hydrogen phosphate anodization bath affects the oxidation of carbon fibres in terms of decreasing both the amounts of the surface oxides as well as that of degradation by-products. At the optimal treatment conditions (I = 100 mA) no changes in the tensile strength or BET-surface area of the fibre have been observed. The rise in ILSS values of amine cured epoxy composites is not dependent on O_ls/C_ls ratio or surface free energy of the reinforcing fibres, but on the acidic as well as nitrogen functional groups on their surface.     

Promotion effect of bifunctional five‐membered cyclic dithiocarbonate on curing of one‐component epoxy resin by imines as latent initiator

This article deals with curing of a one‐component epoxy resin containing a bifunctional five‐membered cyclic dithiocarbonate 1 with an imine 2 as a latent initiator. When 1 was added to a mixture of epoxy resin and 2 , the curing rate and initial adhesive strength increased higher than that without 1 . It was supposed that the reaction of 1 and an amine released from 2 was much faster than the amine–epoxide reaction, and a thiol group formed by the reaction of 1 with the amine accelerated the amine–epoxide reaction. The adhesive strength of the one‐component epoxy resin containing 10 mol % of 1 exhibited the highest value. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 961–964, 2004     

Interactive Effects of Numerical Surface Form and Operand Parity in Cognitive Arithmetic.

In Experiment 1, adults (n = 48) performed simple addition, multiplication, and parity (i.e., odd-even) comparisons on pairs of Arabic digits or English number words. For addition and comparison, but not multiplication, response time increased with the number of odd operands. For addition, but not comparison, this parity effect was greater for words than for digits. In Experiment 2, adults (n = 50) solved simple addition problems in digit and word format and reported their strategies (i.e., retrieval or procedures). Procedural strategies were used more for odd than even addends and much more for word than digit problems. The results indicate that problem encoding and answer retrieval processes for cognitive arithmetic are interactive rather than strictly additive stages. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Monomer addition programs to generate constant gradient block copolymers

Equations are derived to calculate the monomer addition programs for semi-batch copolymerization reactions that allow to prepare gradient copolymers and block gradient copolymers containing arbitrary, pre-defined compositional gradients along the polymer chain. An analytical solution is given for the special case of ideal random copolymerizations, and numerical calculations are applied to discuss non-ideal situations. Three classes of addition programs are proposed and discussed with respect to time efficiency. Time-linear addition programs are shown to be insufficient to generate perfectly constant gradients over the whole compositional regions.