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以天然石墨为起始原料,采用改进的Hummer方法,通过强酸氧化水解和超声分散制备了氧化石墨烯,然后通过肼还原和重氮化反应得到含有羟基的石墨烯(G-OH),再通过酯化反应在石墨烯表面上引入了α-氯代羰基,从而得到了含有单电子转移活性自由基聚合(SET-LRP)引发基团的石墨烯(G-Cl).最后,在石墨烯表面原位引发N,N-二甲基丙烯酰胺(DMAA)单体的SET-LRP聚合,得到了G-PDMAA复合材料,G-PDMAA在常规的有机溶剂和水中具有良好的分散性. 相似文献
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在水相条件下用阴离子醚化剂(3-氯-2-羟基丙磺酸钠)通过一锅法对经微生物改造的纤维素阴离子化,其中的氢氧化钠溶液既作为反应物、溶剂,又作为催化剂,反应条件温和、取代度适中、转化率较高。采用元素分析、核磁共振、傅里叶红外光谱等表征方法研究了纤维素衍生物的取代度和结构,结果表明,获得的纤维素产物已阴离子化。对纤维素衍生物进行了抑制真菌评估,证明其具其有一定的抑菌特性。纤维素衍生物的生态亲和性决定其可应用于文物保护、农业和防疫等领域。 相似文献
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On the basis of analysing terrestrial heat flow and mantle heat flow values, the crustal temperatureat depth was calculated for Liaohe Rift Basin in North China, and a conceptual model of thermal struc-ture of the crust and upper mantle of the Basin has been suggested. Results indicate that Liaohe Basinis characterized by a relatively high mantle heat flow (0.98 HFU) but low crustal heat flow (0.57HFU),both caused by upwelling of the asthenosphere and crustal thinning during rifting process in early Eo-gene in thc region studied. This sort of thermal structure of the crust and upper mantle seems to beinherent in the region in between tectonically stable and active areas and has been considered to be theproduct of the history of geological evolution of the Basin since Mesozoic era. 相似文献
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Some equivalent conditions on the classes of lighted-tailed and heavily heavy-tailed and lightly heavy-tailed d. f. s are
introduced. The limit behavior of
and
are discussed. Some properties of the subclass D
K
c
and subclass D
K
c
are obtained.
Supported by the National Natural Science Foundation of China (10271087). 相似文献
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胶体颗粒在聚电解质多层膜表面的可控组装 总被引:1,自引:1,他引:1
利用原子力显微镜和扫描电子显微镜研究了磺化聚苯乙烯胶体颗粒在由聚二甲基二烯丙基氯化铵和聚苯乙烯磺酸钠层状自组装而成的多层膜表面的组装.该组装受表面性质影响,通过对多层膜的最外层的组装条件或利用盐溶液对多层膜进行后处理可以控制胶体颗粒在膜表面的组装密度. 相似文献