A simpler convenient and high-yield preparation for bis-imidazoles, which have a wide range of applications, from imidazole and dibromides in the presence of strong base is reported.
The effects of thermal treatment on microstructure of the Polyesters were studied. Annealing below Tc-n, physical diffusion PrOCesses dominate to yield an increasing crystallinity along with increased molecular weight...The effects of thermal treatment on microstructure of the Polyesters were studied. Annealing below Tc-n, physical diffusion PrOCesses dominate to yield an increasing crystallinity along with increased molecular weight transesterification reactions are limited to the end groups and the microstructure had not changed Annealing near Tc-n, chemical processes dominate and simultaneously make the microdomains ordered more perfectly. Analysis by 13C NMR Proved that interchain transesterification had occurred.展开更多
The existing methods of computing the flow distribution in compound channels with flood plains have been summarized. A new method called the momentum-exchange method was presented and verified with experimental and fi...The existing methods of computing the flow distribution in compound channels with flood plains have been summarized. A new method called the momentum-exchange method was presented and verified with experimental and field data. The results show that the new method is more effective than previous ones.展开更多
The domain of attraction of nonlinear functional difference systems is studied. A sufficient condition for determining the domain of attraction is given based on a non-negative parameter matrix whose spectral radius ...The domain of attraction of nonlinear functional difference systems is studied. A sufficient condition for determining the domain of attraction is given based on a non-negative parameter matrix whose spectral radius ρis less than one and on the characteristic space associated with ρ.展开更多
The 3-D turbulent flow structure and contaminant distribution in a 45°-bend has been studied in this paper. The Algebraic Stress Model and the Mixing Length Model are used in the fully turbulent region and the ne...The 3-D turbulent flow structure and contaminant distribution in a 45°-bend has been studied in this paper. The Algebraic Stress Model and the Mixing Length Model are used in the fully turbulent region and the near-wall region respectively. The computational results show that the calcutated and experimental longitudinal velocity profiles are in good agreement.Meanwhile, the profiles of velocity, turbulent energry, dissipation rate, Reynolds stresses and contaminant concentration in the bend have been analysed, and the features of the turbulent flow containing contaminat in a 45°-bend have been obtained.展开更多
The concentration distribution of oiled wastewater under the water surface in a two-dimensional open channel was studied by means of experimental and numerical method. The experiments were carried out under nine diffe...The concentration distribution of oiled wastewater under the water surface in a two-dimensional open channel was studied by means of experimental and numerical method. The experiments were carried out under nine different working conditions, which were formed by changing the discharge condition in the open channel and ratio of oil to water in oiled wastewater. The flow field and oil concentration field for each working condition were measured and solved numerically by using the k-2 turbulence model. The comparison of numerical results with measured data shows good conformity. The diffusion coefficient of the oiled wastewater in vertical direction was obtained. The distribution of oil concentration and diffusion coefficient was also discussed.展开更多
The total energy of the cubic_octahedral structure of H\++ cluster is calculated by means of the modified arrangernent channel quantum mechanics (MACQM). The present result shows that the face_centered cubic(FCC) stru...The total energy of the cubic_octahedral structure of H\++ cluster is calculated by means of the modified arrangernent channel quantum mechanics (MACQM). The present result shows that the face_centered cubic(FCC) structure ofnanometallic hydrogen manifests Kubo effect.展开更多
文摘A simpler convenient and high-yield preparation for bis-imidazoles, which have a wide range of applications, from imidazole and dibromides in the presence of strong base is reported.
文摘The effects of thermal treatment on microstructure of the Polyesters were studied. Annealing below Tc-n, physical diffusion PrOCesses dominate to yield an increasing crystallinity along with increased molecular weight transesterification reactions are limited to the end groups and the microstructure had not changed Annealing near Tc-n, chemical processes dominate and simultaneously make the microdomains ordered more perfectly. Analysis by 13C NMR Proved that interchain transesterification had occurred.
基金The work was supported by National Natural Sciences Foudation of China, with which the an-thors won the third award of the Science and Technology Progress Prize of National Education Commissionin 1996.
文摘The existing methods of computing the flow distribution in compound channels with flood plains have been summarized. A new method called the momentum-exchange method was presented and verified with experimental and field data. The results show that the new method is more effective than previous ones.
文摘The domain of attraction of nonlinear functional difference systems is studied. A sufficient condition for determining the domain of attraction is given based on a non-negative parameter matrix whose spectral radius ρis less than one and on the characteristic space associated with ρ.
文摘The 3-D turbulent flow structure and contaminant distribution in a 45°-bend has been studied in this paper. The Algebraic Stress Model and the Mixing Length Model are used in the fully turbulent region and the near-wall region respectively. The computational results show that the calcutated and experimental longitudinal velocity profiles are in good agreement.Meanwhile, the profiles of velocity, turbulent energry, dissipation rate, Reynolds stresses and contaminant concentration in the bend have been analysed, and the features of the turbulent flow containing contaminat in a 45°-bend have been obtained.
文摘The concentration distribution of oiled wastewater under the water surface in a two-dimensional open channel was studied by means of experimental and numerical method. The experiments were carried out under nine different working conditions, which were formed by changing the discharge condition in the open channel and ratio of oil to water in oiled wastewater. The flow field and oil concentration field for each working condition were measured and solved numerically by using the k-2 turbulence model. The comparison of numerical results with measured data shows good conformity. The diffusion coefficient of the oiled wastewater in vertical direction was obtained. The distribution of oil concentration and diffusion coefficient was also discussed.
文摘The total energy of the cubic_octahedral structure of H\++ cluster is calculated by means of the modified arrangernent channel quantum mechanics (MACQM). The present result shows that the face_centered cubic(FCC) structure ofnanometallic hydrogen manifests Kubo effect.
