Hydroxylation of inert benzene through the activation of the C_(sp2)-H bond is a representative reaction about the transformation of C-H bonds to C-O bonds,which has far-reaching guiding significance but remains a cha...Hydroxylation of inert benzene through the activation of the C_(sp2)-H bond is a representative reaction about the transformation of C-H bonds to C-O bonds,which has far-reaching guiding significance but remains a challenging scientific problem.To overcome this problem,a series of VOx-Ga_(2)O_(3)/SiO_(2)-Al_(2)O_(3)were prepared to achieve an efficient and economical hydroxylation path of benzene to phenol.The results showed that the phenol yield was 72.89%(selectivity>98.1%)under the optimum conditions.The reason is that the C-H bond in the benzene ring is activated by heterolysis over a VOx-Ga_(2)O_(3)/SiO_(2)-Al_(2)O_(3)catalyst.Meanwhile,the introduction of aluminum(Al)and gallium(Ga)made a qualitative change in the catalyst,enhancing the electron motion and spin motion of vanadium species,resulting in the increase of V4^(+)/V5^(+)ratio.In addition,the catalyst can provide an optimal acidic environment and a threedimensional cross-linked surface structure that facilitates product diffusion.展开更多
给出了Windows XP SP2防火墙的使用方法及应用实例.研究分析了Windows XP SP2防火墙(ICF)技术,在不同的联网环境下对个人防火墙和ICF分别进行了接入、安装、设置、应用实验.结果证明:Windows XP SP2的防火墙技术几乎拥有了其它个人防火...给出了Windows XP SP2防火墙的使用方法及应用实例.研究分析了Windows XP SP2防火墙(ICF)技术,在不同的联网环境下对个人防火墙和ICF分别进行了接入、安装、设置、应用实验.结果证明:Windows XP SP2的防火墙技术几乎拥有了其它个人防火墙技术的优点,且占用系统资源少,对于网络攻击具有较高的防范功能,增强了个人计算机的网络安全性.展开更多
基金the Support Program for Hongliu Young Teachers of Lanzhou University of Technology(02/062214)Young Talent Innovation Project of Lanzhou(2023-QN-103)Major science and technology projects of Gansu Province(22ZD6GA013).
文摘Hydroxylation of inert benzene through the activation of the C_(sp2)-H bond is a representative reaction about the transformation of C-H bonds to C-O bonds,which has far-reaching guiding significance but remains a challenging scientific problem.To overcome this problem,a series of VOx-Ga_(2)O_(3)/SiO_(2)-Al_(2)O_(3)were prepared to achieve an efficient and economical hydroxylation path of benzene to phenol.The results showed that the phenol yield was 72.89%(selectivity>98.1%)under the optimum conditions.The reason is that the C-H bond in the benzene ring is activated by heterolysis over a VOx-Ga_(2)O_(3)/SiO_(2)-Al_(2)O_(3)catalyst.Meanwhile,the introduction of aluminum(Al)and gallium(Ga)made a qualitative change in the catalyst,enhancing the electron motion and spin motion of vanadium species,resulting in the increase of V4^(+)/V5^(+)ratio.In addition,the catalyst can provide an optimal acidic environment and a threedimensional cross-linked surface structure that facilitates product diffusion.
文摘给出了Windows XP SP2防火墙的使用方法及应用实例.研究分析了Windows XP SP2防火墙(ICF)技术,在不同的联网环境下对个人防火墙和ICF分别进行了接入、安装、设置、应用实验.结果证明:Windows XP SP2的防火墙技术几乎拥有了其它个人防火墙技术的优点,且占用系统资源少,对于网络攻击具有较高的防范功能,增强了个人计算机的网络安全性.
