吸附和扩散是研究催化反应动力学和基于吸附的分离过程时所首要关注的问题。笔者从工程的角度综述了沸石上分子的吸附和扩散的最新研究动态，详细描述了用来研究沸石的吸附和扩散性能所采用的一种新颖的锥形元件振荡微天平（Tapered ele...吸附和扩散是研究催化反应动力学和基于吸附的分离过程时所首要关注的问题。笔者从工程的角度综述了沸石上分子的吸附和扩散的最新研究动态，详细描述了用来研究沸石的吸附和扩散性能所采用的一种新颖的锥形元件振荡微天平（Tapered element oscillating microbalance，TEOM）技术，并用实例阐述了这种TEOM技术的应用性。介绍了为提高沸石的传质性能而采用脱硅产生介孔的技术的发展水平。从工程的视角总结了沸石分子筛科学研究的现状和存在的问题。最后，展望了改性沸石传质性能的研究前景。展开更多
In the plasma sheath a narrow plasma channel generated by ultraintense laser pulses is simplified as a special cylindrical and hollow plasma waveguide with the infinite thickness of the plasma cladding. The electromag...In the plasma sheath a narrow plasma channel generated by ultraintense laser pulses is simplified as a special cylindrical and hollow plasma waveguide with the infinite thickness of the plasma cladding. The electromagnetic wave （EM） propagation properties of the plasma channel near the cutoff and far from the cutoff are considered. Theoretical analysis shows that TE0m and TM0m and hybrid modes emerge in the plasma channel, which is influenced by the normalized frequency parameter B and numerical aperture NA. The cutoffs of the various modes are approximated. Single-mode operation is possible without a high-frequency limitation in the channel.展开更多
文摘吸附和扩散是研究催化反应动力学和基于吸附的分离过程时所首要关注的问题。笔者从工程的角度综述了沸石上分子的吸附和扩散的最新研究动态，详细描述了用来研究沸石的吸附和扩散性能所采用的一种新颖的锥形元件振荡微天平（Tapered element oscillating microbalance，TEOM）技术，并用实例阐述了这种TEOM技术的应用性。介绍了为提高沸石的传质性能而采用脱硅产生介孔的技术的发展水平。从工程的视角总结了沸石分子筛科学研究的现状和存在的问题。最后，展望了改性沸石传质性能的研究前景。
基金supported by National Natural Science Foundation of China(No.60971122)the Jiangshu Province Science Foundation(No.BK2011727)the Open Research Program in China's State Key Laboratory of Millimeter Waves(No.K201103)
文摘In the plasma sheath a narrow plasma channel generated by ultraintense laser pulses is simplified as a special cylindrical and hollow plasma waveguide with the infinite thickness of the plasma cladding. The electromagnetic wave （EM） propagation properties of the plasma channel near the cutoff and far from the cutoff are considered. Theoretical analysis shows that TE0m and TM0m and hybrid modes emerge in the plasma channel, which is influenced by the normalized frequency parameter B and numerical aperture NA. The cutoffs of the various modes are approximated. Single-mode operation is possible without a high-frequency limitation in the channel.
