Reaction pathways for the formation of thiolate-gold nanoparticles are investigated by density functional theory （DFT） and a new mechanism upon solvent polarity and tetraalkylammonium is obtained. In solvents with h...Reaction pathways for the formation of thiolate-gold nanoparticles are investigated by density functional theory （DFT） and a new mechanism upon solvent polarity and tetraalkylammonium is obtained. In solvents with high polarities, [Au（I）SR]n polymers can be formed as the precursor of metal ions prior to the addition of a reducing agent; while a product of [Cl...AuCl（HSR）] is identified as the precursor in solvents with low polarities, such as toluene and chloroform. In addition, tetraalkylammonium also has an obvious effect on the reactions when it is used as a phase transfer agent in the two-phase synthesis. These findings offer a systematic analysis on the pathways to thiolate-stabilized nanoparticles and give a favorable explanation by comparison with those in an experimental system.展开更多
结合河南义马某矿的冲击地压特点,选择适当的监测方法并进行定点及区域电磁辐射监测,综合现场采集数据及之前实验确定电磁辐射强度临界值65 m V,电磁辐射脉冲临界值70次/s,基于电磁辐射机理对该矿冲击地压前后的电磁辐射最大值及均值的...结合河南义马某矿的冲击地压特点,选择适当的监测方法并进行定点及区域电磁辐射监测,综合现场采集数据及之前实验确定电磁辐射强度临界值65 m V,电磁辐射脉冲临界值70次/s,基于电磁辐射机理对该矿冲击地压前后的电磁辐射最大值及均值的变化规律进行分析,得出冲击地压前的能量变化规律及煤岩体的电磁辐射与其所受应力及变形破坏之间存在一定规律,证明电磁辐射对于冲击地压具有定性反馈作用及定位功能,对冲击地压防治具有指导意义,利用电磁辐射技术对爆破卸压前后进行效果验证,取得良好的工程效果。展开更多
基金supported by the National Basic Research Program of China(Grant Nos.2012CB821500 and 2010CB923303)the National Natural Science Foundation of China(Grant Nos.51133002 and 21074053)the Program for Changjiang Scholars and Innovative Research Team in University,China
文摘Reaction pathways for the formation of thiolate-gold nanoparticles are investigated by density functional theory （DFT） and a new mechanism upon solvent polarity and tetraalkylammonium is obtained. In solvents with high polarities, [Au（I）SR]n polymers can be formed as the precursor of metal ions prior to the addition of a reducing agent; while a product of [Cl...AuCl（HSR）] is identified as the precursor in solvents with low polarities, such as toluene and chloroform. In addition, tetraalkylammonium also has an obvious effect on the reactions when it is used as a phase transfer agent in the two-phase synthesis. These findings offer a systematic analysis on the pathways to thiolate-stabilized nanoparticles and give a favorable explanation by comparison with those in an experimental system.
文摘结合河南义马某矿的冲击地压特点,选择适当的监测方法并进行定点及区域电磁辐射监测,综合现场采集数据及之前实验确定电磁辐射强度临界值65 m V,电磁辐射脉冲临界值70次/s,基于电磁辐射机理对该矿冲击地压前后的电磁辐射最大值及均值的变化规律进行分析,得出冲击地压前的能量变化规律及煤岩体的电磁辐射与其所受应力及变形破坏之间存在一定规律,证明电磁辐射对于冲击地压具有定性反馈作用及定位功能,对冲击地压防治具有指导意义,利用电磁辐射技术对爆破卸压前后进行效果验证,取得良好的工程效果。
