A method to determine the design value of the extreme wave height is introduced in this paper. The method is, based on the theoretical distribution of wave heights or the experiential probability distribution of wave ...A method to determine the design value of the extreme wave height is introduced in this paper. The method is, based on the theoretical distribution of wave heights or the experiential probability distribution of wave heights, to calculate the mode of the extreme wave height and the design value with good assuredness. In fitting the experiential distribution of the observed wave heights, the paper adopts the simulating function of F(x) = 1 - exp[ ?axb exp( -cxd )] and the non-linear parameter in the function is determined by the Non-Linear Least Square Method. The practical application of the method has proved that it is not only simple and convenient, but also very effective in engineering design practice.展开更多
Ventilated cavitation plays an important role on the drag reduction of underwater vehicles and surface ships. For the modelling of ventilated cavitation, the minimum speed of the pressure wave is a crucial parameter f...Ventilated cavitation plays an important role on the drag reduction of underwater vehicles and surface ships. For the modelling of ventilated cavitation, the minimum speed of the pressure wave is a crucial parameter for the closure of the pressure-density coupling relationship. In this study, the minimum wave speed is determined based on a theoretical model coupling the wave equation and the bubble interface motion equation. The influences of several paramount parameters （e.g., frequency, bubble radius and void fraction） on the minimum wave speed are quantitatively demonstrated and discussed. Compared with the minimum wave speed in the traditional cavitation, values for the ventilated cavitation are much higher. The physical mechanisms for the above difference are briefly discussed with the suggestions on the usage of the present findings.展开更多
The linear dispersion relation of a trapezoidally corrugated slow wave structure （TCSWS） is analyzed and presented. The size parameters of the TCSWS are chosen in such a way that they operate in the x-band frequency...The linear dispersion relation of a trapezoidally corrugated slow wave structure （TCSWS） is analyzed and presented. The size parameters of the TCSWS are chosen in such a way that they operate in the x-band frequency range. The dispersion relation is solved by utilizing the Rayleigh-Fourier method by expressing the radial function in terms of the Fourier series. A highly accurate synthetic technique is also applied to determine the complete dispersion characteristics from experimentally measured resonances （cold test）. Periodic structures resonate at specific frequencies when the terminals are shorted numerical calculation, synthetic technique and cold appropriately. The dispersion characteristics obtained from test are compared, and an excellent agreement is achieved.展开更多
The indirect voltammetric determination of trace sulfate (2.0×10^(-6)～4.0×10^(-5) mol/L ) with the adsorptive complex wave of lead(Ⅱ)-tetrakis (4-trimethylammonium phenyl) porphyrin (PbTTMAPP) is reported....The indirect voltammetric determination of trace sulfate (2.0×10^(-6)～4.0×10^(-5) mol/L ) with the adsorptive complex wave of lead(Ⅱ)-tetrakis (4-trimethylammonium phenyl) porphyrin (PbTTMAPP) is reported.This method has been used for the analysis of natural waters with satisfactory results.展开更多
A spectroscopic method to determine thickness on chromatic polarization interferometry. With of quartz wave plate is presented. The method is based the polarization-resolved transmission spectrum （PRTS） curve, the p...A spectroscopic method to determine thickness on chromatic polarization interferometry. With of quartz wave plate is presented. The method is based the polarization-resolved transmission spectrum （PRTS） curve, the phase retardation of quartz wave plate can be determined at a wide spectral range from 200 to 2000 nm obviously. Through accurate judgment of extreme points of PRTS curve at long-wave band, the physical thickness of quartz wave plates can be obtained exactly. We give a measuring example and the error analysis. It is found that the measuring precision of thickness is mainly determined by the spectral resolution of spectrometer.展开更多
In this paper, we first develop the far field asymptotic solutions of the second-order scattering waves for the vertical plane problem taking the second-order Stokes waves as the incident waves. The asymptotic solutio...In this paper, we first develop the far field asymptotic solutions of the second-order scattering waves for the vertical plane problem taking the second-order Stokes waves as the incident waves. The asymptotic solutions satisfy the Laplace equation, the sea bed and free surface boundary conditions and are the out-going waves. Then the radiation conditions of the second-order mattering waves are derived by using the asymptotic solutions. By using the two-dimensinal finite clement method with the radiation conditions imposed on the ar- tificial boundaries, the computer program, known as 'NWF2', for determining nonlinear wave forces on large submerged bodies has been written. As a numerical example, nonlinear wave forces on a semi-circu- lar cylinder lying on the sea bed arc presented.展开更多
文摘A method to determine the design value of the extreme wave height is introduced in this paper. The method is, based on the theoretical distribution of wave heights or the experiential probability distribution of wave heights, to calculate the mode of the extreme wave height and the design value with good assuredness. In fitting the experiential distribution of the observed wave heights, the paper adopts the simulating function of F(x) = 1 - exp[ ?axb exp( -cxd )] and the non-linear parameter in the function is determined by the Non-Linear Least Square Method. The practical application of the method has proved that it is not only simple and convenient, but also very effective in engineering design practice.
基金Supported by the National Natural Science Foundation of China under Grant No 51506051
文摘Ventilated cavitation plays an important role on the drag reduction of underwater vehicles and surface ships. For the modelling of ventilated cavitation, the minimum speed of the pressure wave is a crucial parameter for the closure of the pressure-density coupling relationship. In this study, the minimum wave speed is determined based on a theoretical model coupling the wave equation and the bubble interface motion equation. The influences of several paramount parameters （e.g., frequency, bubble radius and void fraction） on the minimum wave speed are quantitatively demonstrated and discussed. Compared with the minimum wave speed in the traditional cavitation, values for the ventilated cavitation are much higher. The physical mechanisms for the above difference are briefly discussed with the suggestions on the usage of the present findings.
文摘The linear dispersion relation of a trapezoidally corrugated slow wave structure （TCSWS） is analyzed and presented. The size parameters of the TCSWS are chosen in such a way that they operate in the x-band frequency range. The dispersion relation is solved by utilizing the Rayleigh-Fourier method by expressing the radial function in terms of the Fourier series. A highly accurate synthetic technique is also applied to determine the complete dispersion characteristics from experimentally measured resonances （cold test）. Periodic structures resonate at specific frequencies when the terminals are shorted numerical calculation, synthetic technique and cold appropriately. The dispersion characteristics obtained from test are compared, and an excellent agreement is achieved.
文摘The indirect voltammetric determination of trace sulfate (2.0×10^(-6)～4.0×10^(-5) mol/L ) with the adsorptive complex wave of lead(Ⅱ)-tetrakis (4-trimethylammonium phenyl) porphyrin (PbTTMAPP) is reported.This method has been used for the analysis of natural waters with satisfactory results.
基金This work was supported by the National Ba sic Research Program of China (973 Program) under Grant No. 2006CB806000.
文摘A spectroscopic method to determine thickness on chromatic polarization interferometry. With of quartz wave plate is presented. The method is based the polarization-resolved transmission spectrum （PRTS） curve, the phase retardation of quartz wave plate can be determined at a wide spectral range from 200 to 2000 nm obviously. Through accurate judgment of extreme points of PRTS curve at long-wave band, the physical thickness of quartz wave plates can be obtained exactly. We give a measuring example and the error analysis. It is found that the measuring precision of thickness is mainly determined by the spectral resolution of spectrometer.
文摘In this paper, we first develop the far field asymptotic solutions of the second-order scattering waves for the vertical plane problem taking the second-order Stokes waves as the incident waves. The asymptotic solutions satisfy the Laplace equation, the sea bed and free surface boundary conditions and are the out-going waves. Then the radiation conditions of the second-order mattering waves are derived by using the asymptotic solutions. By using the two-dimensinal finite clement method with the radiation conditions imposed on the ar- tificial boundaries, the computer program, known as 'NWF2', for determining nonlinear wave forces on large submerged bodies has been written. As a numerical example, nonlinear wave forces on a semi-circu- lar cylinder lying on the sea bed arc presented.
