The adsorption of dedecyltrimethylammoium chloride(DTAC) and hexadecyltrimethylammoium chloride(CTAC) on muscovite mica substrates was examined using atomic force microscopy(AFM). Adsorption morphology images and inte...The adsorption of dedecyltrimethylammoium chloride(DTAC) and hexadecyltrimethylammoium chloride(CTAC) on muscovite mica substrates was examined using atomic force microscopy(AFM). Adsorption morphology images and interaction forces of cationic surfactants at solid-solution interfaces were measured in tapping mode and Pico Force mode, respectively. The images demonstrated that the adsorbed structure was varied by a variety of surfactant concentrations. The adsorbed layer on mica was monolayer at first, and then became bilayer. A striped adsorbed structure was observed in a higher concentration of CTAC,which could not be found in any other concentrations of DTAC. For force measurements, the repulsive force was exponentially decreasing with the concentration increasing till a net attractive force appeared. A largest attractive force could be observed at a certain concentration, which was close to the point of charge neutralization. The results also showed a significant impact of hydrocarbon chain length on adsorption. An adsorption simulation was established to give a clear understanding of the interaction between cationic surfactants and mica.展开更多
一音一母的基本原则拉丁字母有二十六个,其中六个一般用作韵母,即a e i o u y:其余二十个一般用作声母,即b c d fg h j k l m n p q r s t v w x z。任何一套字母,無論是作文字用或者作拼音用,为了便于学習,都應該“一音一母”,那就是說...一音一母的基本原则拉丁字母有二十六个,其中六个一般用作韵母,即a e i o u y:其余二十个一般用作声母,即b c d fg h j k l m n p q r s t v w x z。任何一套字母,無論是作文字用或者作拼音用,为了便于学習,都應該“一音一母”,那就是說,一个字母只代表一个音素,而一个音素也只用一个字母代表。根据这个原則,二十六个拉丁字母就只能代表二十六个不同的音素。汉語北京語音有几个音素呢?展开更多
我的三孩子永清现在是长春二道河子公社东盛路小学一年级的学生。她刚满八周岁便入学了,现在即将完成第一学期的学习任务。记得她入学不多天,便拉着我去买一张《汉语拼音方案绘图声母韵母表》,我按照孩子的意图给她用按钉按在正对着里...我的三孩子永清现在是长春二道河子公社东盛路小学一年级的学生。她刚满八周岁便入学了,现在即将完成第一学期的学习任务。记得她入学不多天,便拉着我去买一张《汉语拼音方案绘图声母韵母表》,我按照孩子的意图给她用按钉按在正对着里屋门的墙上。从这以后永清便天天b p m f……的念着。她把她的语文书拿给我看。我看了之后,不觉很为吃惊。心想:我小时候入学,书上星稀几个字。展开更多
基金Project(50974134)supported by the National Natural Science Foundation of China
文摘The adsorption of dedecyltrimethylammoium chloride(DTAC) and hexadecyltrimethylammoium chloride(CTAC) on muscovite mica substrates was examined using atomic force microscopy(AFM). Adsorption morphology images and interaction forces of cationic surfactants at solid-solution interfaces were measured in tapping mode and Pico Force mode, respectively. The images demonstrated that the adsorbed structure was varied by a variety of surfactant concentrations. The adsorbed layer on mica was monolayer at first, and then became bilayer. A striped adsorbed structure was observed in a higher concentration of CTAC,which could not be found in any other concentrations of DTAC. For force measurements, the repulsive force was exponentially decreasing with the concentration increasing till a net attractive force appeared. A largest attractive force could be observed at a certain concentration, which was close to the point of charge neutralization. The results also showed a significant impact of hydrocarbon chain length on adsorption. An adsorption simulation was established to give a clear understanding of the interaction between cationic surfactants and mica.
文摘一音一母的基本原则拉丁字母有二十六个,其中六个一般用作韵母,即a e i o u y:其余二十个一般用作声母,即b c d fg h j k l m n p q r s t v w x z。任何一套字母,無論是作文字用或者作拼音用,为了便于学習,都應該“一音一母”,那就是說,一个字母只代表一个音素,而一个音素也只用一个字母代表。根据这个原則,二十六个拉丁字母就只能代表二十六个不同的音素。汉語北京語音有几个音素呢?
文摘我的三孩子永清现在是长春二道河子公社东盛路小学一年级的学生。她刚满八周岁便入学了,现在即将完成第一学期的学习任务。记得她入学不多天,便拉着我去买一张《汉语拼音方案绘图声母韵母表》,我按照孩子的意图给她用按钉按在正对着里屋门的墙上。从这以后永清便天天b p m f……的念着。她把她的语文书拿给我看。我看了之后,不觉很为吃惊。心想:我小时候入学,书上星稀几个字。
