From point of view of physics, especially of mechanics, we briefly introduce fractional operators (with emphasis on fractional calculus and fractional differential equa- tions) used for describing intermediate process...From point of view of physics, especially of mechanics, we briefly introduce fractional operators (with emphasis on fractional calculus and fractional differential equa- tions) used for describing intermediate processes and critical phenomena in physics and mechanics, their progress in theory and methods and their applications to modern me- chanics. Some authors’ researches in this area in recent years are included. Finally, prospects and evaluation for this subject are made.展开更多
本文主要介绍了近年来泛函重整化群(FunctionalRenormalizationGroup,f RG)在量子色动力学(Quantum Chromodynamics,QCD)相变及其临界现象研究中的一些进展,主要侧重于与QCD的临界终点(Critical End Point,CEP)相关的非微扰临界指数的...本文主要介绍了近年来泛函重整化群(FunctionalRenormalizationGroup,f RG)在量子色动力学(Quantum Chromodynamics,QCD)相变及其临界现象研究中的一些进展,主要侧重于与QCD的临界终点(Critical End Point,CEP)相关的非微扰临界指数的计算、重子数的涨落等。fRG是一种非微扰连续场论的理论方法,其基本思想是通过重整化群能标从高能向低能的演化,连续不断地将不同尺度的量子涨落以及热涨落积分到理论体系当中。本文讨论了非微扰有效势重整化群流方程和不动点方程的各种求解方法,包括泰勒展开、空间维数ε=4-d展开以及最近被提出的非局域势直接求解方法。还系统地讨论了与QCD的临界终点等临界现象密切相关的重子数的涨落,探讨了实验观测到的净质子数分布的峰度,也就是四阶矩随碰撞能量非单调依赖关系的可能原因。展开更多
Amorphous systems undergo the jamming transition when the density increases, temperature drops, or external shear stress decreases, as described by the jamming phase diagram which was proposed to unify different proce...Amorphous systems undergo the jamming transition when the density increases, temperature drops, or external shear stress decreases, as described by the jamming phase diagram which was proposed to unify different processes such as the glass transition, random close packing, and yielding under shear stress. At zero temperature and shear stress, the jamming transition occurs at a critical density at Point J. In this paper, we review recent studies of the material properties of marginally jammed solids and the glassy dynamics in the vicinity of Point J. As the only singular point in the jamming phase diagram, Point J exhibits special criticality in both mechanical and vibrational quantities. Dynamics approaching the glass transition in the vicinity of Point J show critical scalings, suggesting that the molecular glass transition and the colloidal glass transition are equivalent in the hard sphere limit. All these studies shed light on the long-standing puzzles of the glass transition arid unusual properties of amorphous solids.展开更多
In 1822, almost 200 years ago, Baron Charles Cagniard de Latour (1777-1859) discovered the critical phenomena or critical state [1] [2]. At that time, it was described as a curiosity. However, it is now used as an adv...In 1822, almost 200 years ago, Baron Charles Cagniard de Latour (1777-1859) discovered the critical phenomena or critical state [1] [2]. At that time, it was described as a curiosity. However, it is now used as an advanced extraction and analytical technology in industry and research. Extraction with supercritical fluids (SFs) was welcome from the very beginning. In the present paper, the application to chromatography of the critical phenomena of compressed gases or overheated liquids as supercritical fluids will be discussed. Supercritical Fluid Chromatography (SFC) received an uneasy welcome, mainly because of the lack of commercially available analytical instruments. Even today, only a small number of industrial companies are manufacturing SFC instrumentation. A very small spectrum of columns is manufactured specially for SFC. SFC is not accepted by Pharmacopeia committees for the analysis of drugs and medical forms to the same extent as Gas Chromatography, High-Performance Liquid Chromatography or even Thin Layer Chromatography. The present status and future perspectives for SFC will be discussed.展开更多
基金the National Natural Science Foundation of China (Grant Nos. 10272067, 10372007 , 10572006) the Doctoral Program Foundation of Ministry of Education of China (Grant No. 20030422046) New Century Training Programme Foundation for the Talents by Ministry of Education of China.
文摘From point of view of physics, especially of mechanics, we briefly introduce fractional operators (with emphasis on fractional calculus and fractional differential equa- tions) used for describing intermediate processes and critical phenomena in physics and mechanics, their progress in theory and methods and their applications to modern me- chanics. Some authors’ researches in this area in recent years are included. Finally, prospects and evaluation for this subject are made.
文摘本文主要介绍了近年来泛函重整化群(FunctionalRenormalizationGroup,f RG)在量子色动力学(Quantum Chromodynamics,QCD)相变及其临界现象研究中的一些进展,主要侧重于与QCD的临界终点(Critical End Point,CEP)相关的非微扰临界指数的计算、重子数的涨落等。fRG是一种非微扰连续场论的理论方法,其基本思想是通过重整化群能标从高能向低能的演化,连续不断地将不同尺度的量子涨落以及热涨落积分到理论体系当中。本文讨论了非微扰有效势重整化群流方程和不动点方程的各种求解方法,包括泰勒展开、空间维数ε=4-d展开以及最近被提出的非局域势直接求解方法。还系统地讨论了与QCD的临界终点等临界现象密切相关的重子数的涨落,探讨了实验观测到的净质子数分布的峰度,也就是四阶矩随碰撞能量非单调依赖关系的可能原因。
文摘Amorphous systems undergo the jamming transition when the density increases, temperature drops, or external shear stress decreases, as described by the jamming phase diagram which was proposed to unify different processes such as the glass transition, random close packing, and yielding under shear stress. At zero temperature and shear stress, the jamming transition occurs at a critical density at Point J. In this paper, we review recent studies of the material properties of marginally jammed solids and the glassy dynamics in the vicinity of Point J. As the only singular point in the jamming phase diagram, Point J exhibits special criticality in both mechanical and vibrational quantities. Dynamics approaching the glass transition in the vicinity of Point J show critical scalings, suggesting that the molecular glass transition and the colloidal glass transition are equivalent in the hard sphere limit. All these studies shed light on the long-standing puzzles of the glass transition arid unusual properties of amorphous solids.
文摘In 1822, almost 200 years ago, Baron Charles Cagniard de Latour (1777-1859) discovered the critical phenomena or critical state [1] [2]. At that time, it was described as a curiosity. However, it is now used as an advanced extraction and analytical technology in industry and research. Extraction with supercritical fluids (SFs) was welcome from the very beginning. In the present paper, the application to chromatography of the critical phenomena of compressed gases or overheated liquids as supercritical fluids will be discussed. Supercritical Fluid Chromatography (SFC) received an uneasy welcome, mainly because of the lack of commercially available analytical instruments. Even today, only a small number of industrial companies are manufacturing SFC instrumentation. A very small spectrum of columns is manufactured specially for SFC. SFC is not accepted by Pharmacopeia committees for the analysis of drugs and medical forms to the same extent as Gas Chromatography, High-Performance Liquid Chromatography or even Thin Layer Chromatography. The present status and future perspectives for SFC will be discussed.
