Ultraviolet(UV) absorption spectroscopy is used to detect the concentration of water chemical oxygen demand(COD). The UV absorption spectra of COD solutions are analyzed qualitatively and quantitatively. The partial l...Ultraviolet(UV) absorption spectroscopy is used to detect the concentration of water chemical oxygen demand(COD). The UV absorption spectra of COD solutions are analyzed qualitatively and quantitatively. The partial least square(PLS) algorithm is used to model COD solution and the modeling results are compared. The influence of environmental temperature and turbidity is analyzed. These results show that the influence of temperature on the predicted value can be ignored. However, the change of turbidity can affect the detection results of UV spectra, and the COD detection error can be effectively compensated by establishing the single-element regression model.展开更多
Self-localized structures in nonlinear coupled pendulum lattices are investigated by use of the method of multiple-scales under quasi-discreteness approximation.The upper cutoff and noncutoff kinks observed by Denardo...Self-localized structures in nonlinear coupled pendulum lattices are investigated by use of the method of multiple-scales under quasi-discreteness approximation.The upper cutoff and noncutoff kinks observed by Denardo et al.recently are theoretically explained qualitatively and a lower cutoff standing soliton is also predicated.展开更多
In the past ten years, the physics of homogeneously random system has been under extensive studies both experimentally and theoretically. In the theoretical aspect, the configurational averaging method, which averages...In the past ten years, the physics of homogeneously random system has been under extensive studies both experimentally and theoretically. In the theoretical aspect, the configurational averaging method, which averages an ensemble of all possible configurations, has been shown to be successful in comparison with both computer simulations and, to a certain extent, with the experiments. For instance, the coher-展开更多
The galactic spiral structure seems to be a gaseous phenomenon, and therefore should be explained with the gaseous theory. After discussing the persistence and origin mechanism of the self-gravitationa galactic shock ...The galactic spiral structure seems to be a gaseous phenomenon, and therefore should be explained with the gaseous theory. After discussing the persistence and origin mechanism of the self-gravitationa galactic shock wave of the interstellar gas by the numerical method, it is necessary to study qualitatively the influenco of the perturbed gravitational field on the galactic shock wave by the analytical method. Moreover, galactic shock waves are generally studied by the numerical method[3-5], so it is necessary to do some discussion of it analytically.展开更多
The complexing of Au(I) with thiourea has been successively investigated by Soviet scientists as well as by the potentiometric method. They have both postulated a complex of Au(I) with thiourea in the ratio of 1 to 2 ...The complexing of Au(I) with thiourea has been successively investigated by Soviet scientists as well as by the potentiometric method. They have both postulated a complex of Au(I) with thiourea in the ratio of 1 to 2 and studied the comlex formation of Au(I) with thiourea qualitatively.We have investigated the problem anew by the potentiometric method, and as a result, proposed a better method for determining the maximum coordination number of complex ions and stable gradient from potentiometric data. If we展开更多
A dual-frequency atomic force microscopy imaging system is set up to enhance the amplitude of higher harmonic signals.The experimental results of the dual-frequency imaging technology are given.Normally the image of t...A dual-frequency atomic force microscopy imaging system is set up to enhance the amplitude of higher harmonic signals.The experimental results of the dual-frequency imaging technology are given.Normally the image of the higher harmonic is helpful to optimize the imaging conditions in tapping mode and allows one to differentiate qualitatively between dissimilar materials that are hardly distinguishable by traditional atomic force microscopy.展开更多
The development of a self-sustained quantum electrodynamical(QED)cascade in a single strong laser pulse is studied analytically and numerically.A hydrodynamical approach is used to construct an analytical model of cas...The development of a self-sustained quantum electrodynamical(QED)cascade in a single strong laser pulse is studied analytically and numerically.A hydrodynamical approach is used to construct an analytical model of cascade evolution,which includes the key features of the cascade observed in 3D QED particle-in-cell(QED-PIC)simulations,such as the magnetic field dominance in the cascade plasma and laser energy absorption.The equations of the model are derived in closed form and solved numerically.Direct comparison between the solutions of the model equations and 3D QED-PIC simulations shows that our model is able to describe the complex nonlinear process of cascade development qualitatively well.Various regimes of the interaction based on the intensity of the laser pulse are revealed in both the solutions of the model equations and the results of the QED-PIC simulations.展开更多
基金supported by the National Natural Science Foundation of China(No.61475133)the Science and Technology Research and Development Project of Hebei Province(Nos.14273301D,15273304D,16273301D and 16213902D)
文摘Ultraviolet(UV) absorption spectroscopy is used to detect the concentration of water chemical oxygen demand(COD). The UV absorption spectra of COD solutions are analyzed qualitatively and quantitatively. The partial least square(PLS) algorithm is used to model COD solution and the modeling results are compared. The influence of environmental temperature and turbidity is analyzed. These results show that the influence of temperature on the predicted value can be ignored. However, the change of turbidity can affect the detection results of UV spectra, and the COD detection error can be effectively compensated by establishing the single-element regression model.
文摘Self-localized structures in nonlinear coupled pendulum lattices are investigated by use of the method of multiple-scales under quasi-discreteness approximation.The upper cutoff and noncutoff kinks observed by Denardo et al.recently are theoretically explained qualitatively and a lower cutoff standing soliton is also predicated.
文摘In the past ten years, the physics of homogeneously random system has been under extensive studies both experimentally and theoretically. In the theoretical aspect, the configurational averaging method, which averages an ensemble of all possible configurations, has been shown to be successful in comparison with both computer simulations and, to a certain extent, with the experiments. For instance, the coher-
文摘The galactic spiral structure seems to be a gaseous phenomenon, and therefore should be explained with the gaseous theory. After discussing the persistence and origin mechanism of the self-gravitationa galactic shock wave of the interstellar gas by the numerical method, it is necessary to study qualitatively the influenco of the perturbed gravitational field on the galactic shock wave by the analytical method. Moreover, galactic shock waves are generally studied by the numerical method[3-5], so it is necessary to do some discussion of it analytically.
文摘The complexing of Au(I) with thiourea has been successively investigated by Soviet scientists as well as by the potentiometric method. They have both postulated a complex of Au(I) with thiourea in the ratio of 1 to 2 and studied the comlex formation of Au(I) with thiourea qualitatively.We have investigated the problem anew by the potentiometric method, and as a result, proposed a better method for determining the maximum coordination number of complex ions and stable gradient from potentiometric data. If we
基金Supported by the National Natural Science Foundation of China under Grant No 11074019Beijing Natural Science Foundation under Grant No 4132038.
文摘A dual-frequency atomic force microscopy imaging system is set up to enhance the amplitude of higher harmonic signals.The experimental results of the dual-frequency imaging technology are given.Normally the image of the higher harmonic is helpful to optimize the imaging conditions in tapping mode and allows one to differentiate qualitatively between dissimilar materials that are hardly distinguishable by traditional atomic force microscopy.
基金This research was supported by the Russian Science Foundation(Grant No.20-12-00077)(PIC simulations,development of the analytical model,numerical scheme,and numerical solution of the model equations)the Foundation for the Advancement of Theoretical Physics and Mathematics“BASIS”(Grant No.19-1-5-10-1)(comparison to the simplified model developed in Ref.37).
文摘The development of a self-sustained quantum electrodynamical(QED)cascade in a single strong laser pulse is studied analytically and numerically.A hydrodynamical approach is used to construct an analytical model of cascade evolution,which includes the key features of the cascade observed in 3D QED particle-in-cell(QED-PIC)simulations,such as the magnetic field dominance in the cascade plasma and laser energy absorption.The equations of the model are derived in closed form and solved numerically.Direct comparison between the solutions of the model equations and 3D QED-PIC simulations shows that our model is able to describe the complex nonlinear process of cascade development qualitatively well.Various regimes of the interaction based on the intensity of the laser pulse are revealed in both the solutions of the model equations and the results of the QED-PIC simulations.
