998 resultados para 501.6
Resumo:
无水碳酸钾存在下6-氯-5,12-萘并萘醌与4-羟基偶氮苯在干燥DMF中反应的主要产物在某些反应条件下不是6[4-(苯基偶氮基)苯氧基]-5,12-萘并萘醌(1)。该未知反应产物2经核磁共振方法研究证实是6-(N,N-二甲氨基)-5,12-萘并萘醌。本文对化合物2的~1H-和~(13)C化学位移、偶合信息和结构作了详细归属,并推测其反应进程,实验结果表明,化合物2是由化合物1与溶剂DMF反应生成。
Resumo:
用DSC研究了PA1010/6共聚物初生态及次生态样品的熔融行为,发现初生态样品的高温熔融峰(T1)和低温熔融峰(T2)对组成有不同的依赖关系;首次发现PA1010/6共聚物次生态的冷结晶现象,并讨论了冷结晶温度(TC)、冷结晶时间(tc)与组成的关系.
Resumo:
Reaction of the half-sandwich rhenium(v) complexes [Re-Cl-4(C(5)Me(5))] or [Re(O)Cl-2(C(5)Me(5))] with H2S in chloroform in the presence of pyridine leads to the chiral dithiolato complex [ReO((S)(SCH2)C(5)Me(4))(C(5)Me(5))] 1.
Resumo:
Melt mixing of nylon 8 with neodymium oxide particles was carried out with a single-screw extruder. The crystal behaviors of plain nylon 6 and the neodymium oxide filled nylon 6 mixture were studied by means of isothermal crystallization kinetic analysis. Isothermal crystallization thermograms obtained by differential scanning calorimetry (DSC) were analyzed based on the Avrami equation. The neodymium oxide particles acted as a nucleating agent in the mixture. The overall rate of di-isothermal crystallization of the neodymium oxide filled nylon 6 mixture is higher than that of plain nylon 6. The mechanism and modes of plain nylon 6 were the same as those of neodymium oxide filled PA6 mixture.
Resumo:
The redox behaviours of 12-molybdophosphoric acid (12-MPA) and 12-molybdosilicic acid (12-MSA) in aqueous acid media are characterized at the carbon fiber (CF) microelectrode. The preparation of CF microelectrode modified with 12-MPA or 12-MSA monolayer and the oxidation-reduction properties of the modified electrode in aqueous acid media or 50% (v/v) water-organic media containing some inorganic acids are studied by cyclic voltammetry. 12-MPA or 12-MSA monolayer modified CF microelectrode with high stability and redox reversibility in aqueous acidic media can be prepared by simple dip coating. The cyclic voltammograms of 12-MPA and 12-MSA and their modified CF microelectrodes in aqueous acid solution exhibit three two-electron reversible waves with the same half-wave potentials, which defines that the species adsorbed on the CF electrode surface are 12-MPA and 12-MSA themselves. The acidity of electrolyte solution, the organic solvents in the electrolyte solution, and the scanning potential range strongly influence on the redox behaviours and stability of 12-MPA or 12-MSA monolayer modified electrodes. On the other hand, the catalytic effects of the 12-MPA and 12-MSA and chlorate anions in aqueous acidic solution on the electrode reaction processes of 12-MPA or 12-MSA are described.
Resumo:
尼龙6/SBS共混物形态与性能的研究张皓瑜张维广陈长江吕树刚(中国科学院长春应用化学研究所,长春130022)尼龙6是一种重要的大品种工程塑料,在汽车、家电等领域得到了广泛的应用,但由于其吸水率较高,使制品的尺寸稳定性变差,抗疲劳强底低,尤其是冲击韧…
Resumo:
本文采用聚氯乙烯-尼龙6树脂分离富集溶解于王水中的样品中的痕量金,然后用亚硫酸钠和碘化钾的混合溶液洗脱,并用硫代米酮显色。方法的检测限为1.2×10-9g/g,样品的标准回收为97%~106/,对痕量金样品的分析结果令人满意。
Resumo:
用锥板粘度仪测试仪测试了稀土氧化钕(Nd2O3)填充尼龙6体系的流变行为,填充体系的熔融粘度明显低于空白尼龙6,体系的粘度随稀土氧化物含量的增加而降低,填充后试样具有良好的流动性和加工稳定性。