Palladium-catalyzed regioselective amination of unactivated alkene remains a challenge and is of great interest.Herein,a three-component coupling of unactivated alkene,sulfonamide,and N-halo compounds accessing vicina...Palladium-catalyzed regioselective amination of unactivated alkene remains a challenge and is of great interest.Herein,a three-component coupling of unactivated alkene,sulfonamide,and N-halo compounds accessing vicinal haloamine has been conceived.This aminohalogenation represents a modular and regioselective strategy.The electrophilic halogenating agent enables regioselective anti-Markovnikov aminopalladation and facilitates subsequent halogenation events.And this protocol is characterized by gram-scale syntheses and late-stage functionalizations.Of note,the recovered byproduct phthalimide allows for reusing by conversion to the starting material.展开更多
数值模拟技术不仅帮助我们确立了以暗物质、暗能量为主导的LCDM(Λcold dark matter)标准宇宙学模型,也帮助我们对暗物质形成的结构体——暗晕的各种属性给出了精细的刻画,特别是暗物质晕的密度轮廓.本文首先回顾了这一领域自20世纪80...数值模拟技术不仅帮助我们确立了以暗物质、暗能量为主导的LCDM(Λcold dark matter)标准宇宙学模型,也帮助我们对暗物质形成的结构体——暗晕的各种属性给出了精细的刻画,特别是暗物质晕的密度轮廓.本文首先回顾了这一领域自20世纪80年代以来的发展历史.通过数值模拟,人们发现,暗晕密度轮廓并非理论模型预测的单一幂律分布,而是从内向外,幂指数从-1左右到-3逐渐变化;而且,暗晕的内部结构由其形成历史决定.此后,人们逐步对100万太阳质量以上暗晕的内部结构有了非常精准的刻画.但由于计算资源的限制,对比这一质量小的暗晕则依然了解甚少.最近通过新开发的多重模拟技术,我们才得以对从最小的地球大小的暗晕(10-6太阳质量)到最大的星系团暗晕(1015太阳质量)的内部结构给出精确描述.本文对这一重要进展进行了详细的解读.总之,对所有质量暗晕的密度轮廓的认识将会帮助我们理解物质在宇宙中的分布、暗晕形成在星系形成过程中的作用,同时也将帮助我们去探索如何更好地通过天体物理方法来确定暗物质的本质属性,但重子物质的各种复杂物理过程对暗晕内部结构,特别是密度轮廓的影响依然还是一个开放的问题,这也将是我们下一步需要研究的主要方向.展开更多
The ground-state properties of N=3 isotones and mirror nuclei have been investigated in the Rrelativistic Continuum Hartree-Bogoliubov theory with the NLSH effective interaction. Pairing correlations are taken into ac...The ground-state properties of N=3 isotones and mirror nuclei have been investigated in the Rrelativistic Continuum Hartree-Bogoliubov theory with the NLSH effective interaction. Pairing correlations are taken into account by a density-dependent 5-force. The calculations show that the proton density distributions of SB and 9C have a long tail, the core has an increasing tendency of 9C and the paired off valence protons make the halo distribution shrink. The cross sections for the 8B（gC）＋12C reaction which are consistent with the experimental data are calculated using the Glauber model. On the whole, we think that SB is a one-proton halo nucleus and 9C is a two-proton halo nucleus.展开更多
A series of novel N-[（1-aryl-3-phenyl-pyrazol-4-yl）methylene]-2-（halo-o-hydroxyphenyl）hydrazide derivatives was synthesized and the antibacterial activity of each of them was evaluated. The supposed reaction mecha...A series of novel N-[（1-aryl-3-phenyl-pyrazol-4-yl）methylene]-2-（halo-o-hydroxyphenyl）hydrazide derivatives was synthesized and the antibacterial activity of each of them was evaluated. The supposed reaction mechanism of acquiring compounds 3a--3d is that catalytic activity is enhanced by the electron-donating groups of the first phenyl ring while decreased by electron-withdrawing groups of that ring. The result of preliminary bioassay shows that the lowest minimal inhibitory concentration（MIC） of the title compounds against Escherichia coli is 2 ℃g/mL. MIC values against Monilia albiean and Staphloeoeeus aureus are as low as 4 ~g/mL. They will be a series of potential antibacterial compounds against fungi and gram-negative bacteria.展开更多
基金Financial support was provided by the National Natural Science Foundation of China(22231002 and 21871095)the Key-Area Research and Development Program of Guangdong Province(2020B010188001).
文摘Palladium-catalyzed regioselective amination of unactivated alkene remains a challenge and is of great interest.Herein,a three-component coupling of unactivated alkene,sulfonamide,and N-halo compounds accessing vicinal haloamine has been conceived.This aminohalogenation represents a modular and regioselective strategy.The electrophilic halogenating agent enables regioselective anti-Markovnikov aminopalladation and facilitates subsequent halogenation events.And this protocol is characterized by gram-scale syntheses and late-stage functionalizations.Of note,the recovered byproduct phthalimide allows for reusing by conversion to the starting material.
文摘数值模拟技术不仅帮助我们确立了以暗物质、暗能量为主导的LCDM(Λcold dark matter)标准宇宙学模型,也帮助我们对暗物质形成的结构体——暗晕的各种属性给出了精细的刻画,特别是暗物质晕的密度轮廓.本文首先回顾了这一领域自20世纪80年代以来的发展历史.通过数值模拟,人们发现,暗晕密度轮廓并非理论模型预测的单一幂律分布,而是从内向外,幂指数从-1左右到-3逐渐变化;而且,暗晕的内部结构由其形成历史决定.此后,人们逐步对100万太阳质量以上暗晕的内部结构有了非常精准的刻画.但由于计算资源的限制,对比这一质量小的暗晕则依然了解甚少.最近通过新开发的多重模拟技术,我们才得以对从最小的地球大小的暗晕(10-6太阳质量)到最大的星系团暗晕(1015太阳质量)的内部结构给出精确描述.本文对这一重要进展进行了详细的解读.总之,对所有质量暗晕的密度轮廓的认识将会帮助我们理解物质在宇宙中的分布、暗晕形成在星系形成过程中的作用,同时也将帮助我们去探索如何更好地通过天体物理方法来确定暗物质的本质属性,但重子物质的各种复杂物理过程对暗晕内部结构,特别是密度轮廓的影响依然还是一个开放的问题,这也将是我们下一步需要研究的主要方向.
基金Supported by Fundamental Research Funds for Cental Universities (XDJK2010D005,XDJK2010C049)National Natural Science Foundation of China (11075133,10205019)
文摘The ground-state properties of N=3 isotones and mirror nuclei have been investigated in the Rrelativistic Continuum Hartree-Bogoliubov theory with the NLSH effective interaction. Pairing correlations are taken into account by a density-dependent 5-force. The calculations show that the proton density distributions of SB and 9C have a long tail, the core has an increasing tendency of 9C and the paired off valence protons make the halo distribution shrink. The cross sections for the 8B（gC）＋12C reaction which are consistent with the experimental data are calculated using the Glauber model. On the whole, we think that SB is a one-proton halo nucleus and 9C is a two-proton halo nucleus.
基金Supported by the National Natural Science Foundation of China（Nos.20976135, 21176194）.
文摘A series of novel N-[（1-aryl-3-phenyl-pyrazol-4-yl）methylene]-2-（halo-o-hydroxyphenyl）hydrazide derivatives was synthesized and the antibacterial activity of each of them was evaluated. The supposed reaction mechanism of acquiring compounds 3a--3d is that catalytic activity is enhanced by the electron-donating groups of the first phenyl ring while decreased by electron-withdrawing groups of that ring. The result of preliminary bioassay shows that the lowest minimal inhibitory concentration（MIC） of the title compounds against Escherichia coli is 2 ℃g/mL. MIC values against Monilia albiean and Staphloeoeeus aureus are as low as 4 ~g/mL. They will be a series of potential antibacterial compounds against fungi and gram-negative bacteria.
