The benzoin group caged compound has received strong interests due to its excellent photo- deprotection properties and wide use in chemical and biological studies. We used timeresolved infrared spectroscopy to investi...The benzoin group caged compound has received strong interests due to its excellent photo- deprotection properties and wide use in chemical and biological studies. We used timeresolved infrared spectroscopy to investigate the photochemical reaction of the benzoin caged compound, o-（2-methylbenzoyl）-DL-benzoin under 266 nm laser irradiation. Taking advantage of the specific vibrational marker bands and the IR discerning capability, we have detected and identified the uncaging product 2-methylbenzoic acid, and two intermediate radicals of benzoyl and 2-methylbenzoate benzyl in the transient infrared spectra. Our results provide spectral evidence to support the homolytic cleavage reaction of C-C=O bond in competition with the deprotection reaction. Moreover, the product yields of 2-methylbenzoic acid and benzoyl radical were observed to be affected by solvents and a largely water contalning solvent can be in favor of the deprotection reaction.展开更多
A mathematical model has been built up for compound cage rotor induction machine with the rotor resistance and leakage inductance in the model identified through Kalman filtering method. Using the identified parameter...A mathematical model has been built up for compound cage rotor induction machine with the rotor resistance and leakage inductance in the model identified through Kalman filtering method. Using the identified parameters, simulation studies are performed, and simulation results are compared with testing results.展开更多
Two new cage compounds,4-trinitroethyl-10-nitro-2,6,8,12-tetraacetylhexaazaisowurtzitane（3） and 4-trinitroethyl- 2,6,8,10,12-pentanitrohexaazaisowurtzitane（4）,containing trinitromethyl group were synthesized by a ...Two new cage compounds,4-trinitroethyl-10-nitro-2,6,8,12-tetraacetylhexaazaisowurtzitane（3） and 4-trinitroethyl- 2,6,8,10,12-pentanitrohexaazaisowurtzitane（4）,containing trinitromethyl group were synthesized by a novel method,and their structures were confirmed by IR,;H NMR,MS and single crystal X-ray.DSC result shows that compound 4 has surprising thermal stability and could be a potential energetic compound.展开更多
利用绿色非离子表面活性剂烷基糖苷APG08-10和阳离子表面活性剂十八烷基三甲基氯化铵1831为复合模板剂,正硅酸乙酯为硅源,导向制备出笼状介孔二氧化硅。通过氮气物理吸附、透射电镜对其结构进行表征,得到比表面积S BET 540.2 m^(2)/g,孔...利用绿色非离子表面活性剂烷基糖苷APG08-10和阳离子表面活性剂十八烷基三甲基氯化铵1831为复合模板剂,正硅酸乙酯为硅源,导向制备出笼状介孔二氧化硅。通过氮气物理吸附、透射电镜对其结构进行表征,得到比表面积S BET 540.2 m^(2)/g,孔容0.72 m 3/g,孔径3.8 nm,粒径90 nm左右的笼状介孔二氧化硅纳米材料。展开更多
建立电机定子绕组等效热模型,通过对电机定转子之间气隙热传递关系的确定,给出了定转子之间的热交换问题的解决方法。以此为基础,建立复合笼条转子感应电动机(induction motor with compound cage rotor,IMCCR)电磁场和全域温度场二维...建立电机定子绕组等效热模型,通过对电机定转子之间气隙热传递关系的确定,给出了定转子之间的热交换问题的解决方法。以此为基础,建立复合笼条转子感应电动机(induction motor with compound cage rotor,IMCCR)电磁场和全域温度场二维有限元模型,通过电磁场与温度场的单向弱耦合,计算电机额定负载和不同负载时电机定转子全域稳态温度场,分析定子绕组温度及转子槽的温度,通过与实验结果的对比,验证了该电机温度场计算模型的合理性以及计算结果的正确性。研究转子槽中使用不同电阻率和磁导率材料时的电机温度场,分析不同材料特性对电机温度场分布的影响,对指导电机的优化设计具有重要意义。展开更多
基金This work was supported by the National Natural Science Foundation of China （No.21333012 and No.21425313） and the National Basic Research Program of China （No.2013CB834602）.
文摘The benzoin group caged compound has received strong interests due to its excellent photo- deprotection properties and wide use in chemical and biological studies. We used timeresolved infrared spectroscopy to investigate the photochemical reaction of the benzoin caged compound, o-（2-methylbenzoyl）-DL-benzoin under 266 nm laser irradiation. Taking advantage of the specific vibrational marker bands and the IR discerning capability, we have detected and identified the uncaging product 2-methylbenzoic acid, and two intermediate radicals of benzoyl and 2-methylbenzoate benzyl in the transient infrared spectra. Our results provide spectral evidence to support the homolytic cleavage reaction of C-C=O bond in competition with the deprotection reaction. Moreover, the product yields of 2-methylbenzoic acid and benzoyl radical were observed to be affected by solvents and a largely water contalning solvent can be in favor of the deprotection reaction.
文摘A mathematical model has been built up for compound cage rotor induction machine with the rotor resistance and leakage inductance in the model identified through Kalman filtering method. Using the identified parameters, simulation studies are performed, and simulation results are compared with testing results.
基金the National Natural Science Foundation of China(No.20772011)the Basic Research Foundation of Beijing Institute of Technology(No.3090050320906) for financial support for this work.
文摘Two new cage compounds,4-trinitroethyl-10-nitro-2,6,8,12-tetraacetylhexaazaisowurtzitane（3） and 4-trinitroethyl- 2,6,8,10,12-pentanitrohexaazaisowurtzitane（4）,containing trinitromethyl group were synthesized by a novel method,and their structures were confirmed by IR,;H NMR,MS and single crystal X-ray.DSC result shows that compound 4 has surprising thermal stability and could be a potential energetic compound.
文摘利用绿色非离子表面活性剂烷基糖苷APG08-10和阳离子表面活性剂十八烷基三甲基氯化铵1831为复合模板剂,正硅酸乙酯为硅源,导向制备出笼状介孔二氧化硅。通过氮气物理吸附、透射电镜对其结构进行表征,得到比表面积S BET 540.2 m^(2)/g,孔容0.72 m 3/g,孔径3.8 nm,粒径90 nm左右的笼状介孔二氧化硅纳米材料。
文摘建立电机定子绕组等效热模型,通过对电机定转子之间气隙热传递关系的确定,给出了定转子之间的热交换问题的解决方法。以此为基础,建立复合笼条转子感应电动机(induction motor with compound cage rotor,IMCCR)电磁场和全域温度场二维有限元模型,通过电磁场与温度场的单向弱耦合,计算电机额定负载和不同负载时电机定转子全域稳态温度场,分析定子绕组温度及转子槽的温度,通过与实验结果的对比,验证了该电机温度场计算模型的合理性以及计算结果的正确性。研究转子槽中使用不同电阻率和磁导率材料时的电机温度场,分析不同材料特性对电机温度场分布的影响,对指导电机的优化设计具有重要意义。
