采用离子动量成像谱仪研究了能量为1.0 ke V的电子束碰撞条件下CF_(4)分子的解离动力学.实验上,对解离离子的三维动量进行了成像测量,通过离子飞行时间关联谱识别了CF_(4)^(2+)异构化生成F_(2)^(+)分子的两个通道:F_(2)^(+)+CF_(2)^(+)...采用离子动量成像谱仪研究了能量为1.0 ke V的电子束碰撞条件下CF_(4)分子的解离动力学.实验上,对解离离子的三维动量进行了成像测量,通过离子飞行时间关联谱识别了CF_(4)^(2+)异构化生成F_(2)^(+)分子的两个通道:F_(2)^(+)+CF_(2)^(+)与CF^(+)+F_(2)^(+)+F,得到了两个通道的离子动能及动能释放分布.对于其中的三体解离通道,我们进一步采用Dalitz图与Newton图等三体动力学分析方法对解离碎片的动量关联进行了分析.该通道以两个带电离子的背对背出射为主,中性的F原子作为旁观者只得到极小的反冲动量.展开更多
Pyrolytic resin carbon anode for lithoum ion batteries was prepared from thermosetting phenolic resin. Pyrolysis of the primary phenolic resin and the dewatered one was studied by thermal gravimetric analysis. Structu...Pyrolytic resin carbon anode for lithoum ion batteries was prepared from thermosetting phenolic resin. Pyrolysis of the primary phenolic resin and the dewatered one was studied by thermal gravimetric analysis. Structures and characteristics of the carbon materials were determined by X-ray diffraction, Brunauer-Emmer-Teller surface area analysis and electrochemical measurements. With the increase of pyrolyzing temperature and soaking time, the resin carbon material has larger crystallite sizes of L_c and L_a, lower specific surface area, smaller irreversible capacity and higher initial coulombic efficiency. The pyrolyzing temperature and soaking time are optimized to be 1050℃ and 2h. The resin carbon anode obtained under the optimum conditions shows good electrochemical performances with reversible capacity of 387mA·h/g and initial coulombic efficiency of 69.1%.展开更多
基金supported by the Major Research Plan of the National Natural Science Foundation of China(91441132)Fundamental Research Funds for the Central Universities,China(3132016127,3132016326)~~
文摘使用MP2/6-311++G(2d,2p)方法和基组,计算了丁酸甲酯单分子解离反应体系详细的势能面。应用RRKM理论,计算了在1000-5000 K的温度范围内的正则系综的速率常数。与此同时,在微正则系综下,我们计算了温度为1000-5000 K对应的能量从451.92到1519.52 k J?mol^(-1)的速率常数。计算结果表明反应通道2、4和5的非谐振效应比较明显。因此对于丁酸甲酯单分子解离反应体系来说其非谐振效应是不能忽视的。
文摘采用离子动量成像谱仪研究了能量为1.0 ke V的电子束碰撞条件下CF_(4)分子的解离动力学.实验上,对解离离子的三维动量进行了成像测量,通过离子飞行时间关联谱识别了CF_(4)^(2+)异构化生成F_(2)^(+)分子的两个通道:F_(2)^(+)+CF_(2)^(+)与CF^(+)+F_(2)^(+)+F,得到了两个通道的离子动能及动能释放分布.对于其中的三体解离通道,我们进一步采用Dalitz图与Newton图等三体动力学分析方法对解离碎片的动量关联进行了分析.该通道以两个带电离子的背对背出射为主,中性的F原子作为旁观者只得到极小的反冲动量.
文摘Pyrolytic resin carbon anode for lithoum ion batteries was prepared from thermosetting phenolic resin. Pyrolysis of the primary phenolic resin and the dewatered one was studied by thermal gravimetric analysis. Structures and characteristics of the carbon materials were determined by X-ray diffraction, Brunauer-Emmer-Teller surface area analysis and electrochemical measurements. With the increase of pyrolyzing temperature and soaking time, the resin carbon material has larger crystallite sizes of L_c and L_a, lower specific surface area, smaller irreversible capacity and higher initial coulombic efficiency. The pyrolyzing temperature and soaking time are optimized to be 1050℃ and 2h. The resin carbon anode obtained under the optimum conditions shows good electrochemical performances with reversible capacity of 387mA·h/g and initial coulombic efficiency of 69.1%.
