In the study of complex networks almost all theoretical models have the property of infinite growth, but the size of actual networks is finite. According to statistics from the China Internet IPv4 （Internet Protocol ...In the study of complex networks almost all theoretical models have the property of infinite growth, but the size of actual networks is finite. According to statistics from the China Internet IPv4 （Internet Protocol version 4） addresses, this paper proposes a forecasting model by using S curve （logistic curve）. The growing trend of IPv4 addresses in China is forecasted. There are some reference values for optimizing the distribution of IPv4 address resource and the development of IPv6. Based on the laws of IPv4 growth, that is, the bulk growth and the finitely growing limit, it proposes a finite network model with a bulk growth. The model is said to be an S-curve network. Analysis demonstrates that the analytic method based on uniform distributions （i.e., Barabasi-Albert method） is not suitable for the network. It develops an approximate method to predict the growth dynamics of the individual nodes, and uses this to calculate analytically the degree distribution and the scaling exponents. The analytical result agrees with the simulation well, obeying an approximately power-law form. This method can overcome a shortcoming of Barabasi-Albert method commonly used in current network research.展开更多
A novel technique combining photoelectronic microscopy and computer imaging tracing was used to investigate the synthesis of thioether(2-[3-methyl-4-(2,2,2-trifluoro-ethoxy)-pyridine-2-(methylsulfanyl)]-1H-benzoimidaz...A novel technique combining photoelectronic microscopy and computer imaging tracing was used to investigate the synthesis of thioether(2-[3-methyl-4-(2,2,2-trifluoro-ethoxy)-pyridine-2-(methylsulfanyl)]-1H-benzoimidazole),which is an intermediate for lansoprazole.Visualization in sub-microcosmic surroundings was realized to study interfacial phenomenon.The reaction kinetics study by a visualization technique was carried out in a mini-reactor,and the concentration-gray scale standard curves for thioether were obtained by analyzing the gray scales of digital images.Based on the concentration-gray scale standard curves,the reactant concentrations at different times were calculated,and the reaction kinetics curve and reaction rate equation were obtained.Also the total mass-transfer resistance from bulk phase to interface of sodium imidazole and bromopyridine was obtained.Liquid-liquid interface of synthesizing thioether was observed and its mass transfer mechanism was discussed.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 70871082)the Shanghai Leading Academic Discipline Project (Grant No. S30504)
文摘In the study of complex networks almost all theoretical models have the property of infinite growth, but the size of actual networks is finite. According to statistics from the China Internet IPv4 （Internet Protocol version 4） addresses, this paper proposes a forecasting model by using S curve （logistic curve）. The growing trend of IPv4 addresses in China is forecasted. There are some reference values for optimizing the distribution of IPv4 address resource and the development of IPv6. Based on the laws of IPv4 growth, that is, the bulk growth and the finitely growing limit, it proposes a finite network model with a bulk growth. The model is said to be an S-curve network. Analysis demonstrates that the analytic method based on uniform distributions （i.e., Barabasi-Albert method） is not suitable for the network. It develops an approximate method to predict the growth dynamics of the individual nodes, and uses this to calculate analytically the degree distribution and the scaling exponents. The analytical result agrees with the simulation well, obeying an approximately power-law form. This method can overcome a shortcoming of Barabasi-Albert method commonly used in current network research.
文摘A novel technique combining photoelectronic microscopy and computer imaging tracing was used to investigate the synthesis of thioether(2-[3-methyl-4-(2,2,2-trifluoro-ethoxy)-pyridine-2-(methylsulfanyl)]-1H-benzoimidazole),which is an intermediate for lansoprazole.Visualization in sub-microcosmic surroundings was realized to study interfacial phenomenon.The reaction kinetics study by a visualization technique was carried out in a mini-reactor,and the concentration-gray scale standard curves for thioether were obtained by analyzing the gray scales of digital images.Based on the concentration-gray scale standard curves,the reactant concentrations at different times were calculated,and the reaction kinetics curve and reaction rate equation were obtained.Also the total mass-transfer resistance from bulk phase to interface of sodium imidazole and bromopyridine was obtained.Liquid-liquid interface of synthesizing thioether was observed and its mass transfer mechanism was discussed.
