Multiply scattered waves are sensitive to media changes owing to the effect of repeated sampling,superposition and amplification. Based on this characteristic,small-medium changes could be detected by using coda wave ...Multiply scattered waves are sensitive to media changes owing to the effect of repeated sampling,superposition and amplification. Based on this characteristic,small-medium changes could be detected by using coda wave interferometry. In recent years,coda wave interferometry has been widely used in estimating velocity variation with high precision in areas such as seismology and non-destructive testing. This paper systematically presents the principle and research status of coda wave interferometry,and especial focus is placed on the research of media velocity variations by using repeating earthquakes,artificial sources,and ambient noise. Applications of coda wave interferometry can contribute to the more subtle understanding of dynamic evolution process in the medium.展开更多
Wind electricity power has fluctuation, and accurate and reasonable wind electricity power prediction is very important for solving wind electricity network and combination. This paper takes an analysis of a lot of ac...Wind electricity power has fluctuation, and accurate and reasonable wind electricity power prediction is very important for solving wind electricity network and combination. This paper takes an analysis of a lot of actual data of a certain wind electricity field. Through wavelet neural network and time series method rolling, it can predict the overall power of wind electricity field. The result shows that for the original data of sampling time length and large sampling frequency, the model constructed by this paper has very good prediction effect. Because of the fan installation position, wind electricity fan flow effect and other random factor influence, wind electricity field overall power and single unit power distribution have difference. Through comparing with the time series parameters, it puts forward that single wind electricity unit power has smooth effect for overall power of wind electricity field. Finally, it summarizes the prediction effect and puts forward some reasonable suzestions for wind electricity network troblems.展开更多
The development and implementation of a computational method able to produce free energies in multiple dimensions,descriptively named the free energies from adaptive reaction coordinate forces(FEARCF) method is descri...The development and implementation of a computational method able to produce free energies in multiple dimensions,descriptively named the free energies from adaptive reaction coordinate forces(FEARCF) method is described in this paper.While the method can be used to calculate free energies of association,conformation and reactivity here it is shown in the context of chemical reaction landscapes.A reaction free energy surface for the Claisen rearrangement of chorismate to prephenate is used as an illustration of the method's efficient convergence.FEARCF simulations are shown to achieve flat histograms for complex multidimensional free energy volumes.The sampling efficiency by which it produces multidimensional free energies is demonstrated on the complex puckering of a pyranose ring,that is described by a three dimensional W(θ1,θ2,θ3) potential of mean force.展开更多
基金sponsored by the Task of Department of Earthquake Monitoring and Prediction,CEAthe Special Fund of Earthquake Scientific Research of China Earthquake Administration(201208003)
文摘Multiply scattered waves are sensitive to media changes owing to the effect of repeated sampling,superposition and amplification. Based on this characteristic,small-medium changes could be detected by using coda wave interferometry. In recent years,coda wave interferometry has been widely used in estimating velocity variation with high precision in areas such as seismology and non-destructive testing. This paper systematically presents the principle and research status of coda wave interferometry,and especial focus is placed on the research of media velocity variations by using repeating earthquakes,artificial sources,and ambient noise. Applications of coda wave interferometry can contribute to the more subtle understanding of dynamic evolution process in the medium.
文摘Wind electricity power has fluctuation, and accurate and reasonable wind electricity power prediction is very important for solving wind electricity network and combination. This paper takes an analysis of a lot of actual data of a certain wind electricity field. Through wavelet neural network and time series method rolling, it can predict the overall power of wind electricity field. The result shows that for the original data of sampling time length and large sampling frequency, the model constructed by this paper has very good prediction effect. Because of the fan installation position, wind electricity fan flow effect and other random factor influence, wind electricity field overall power and single unit power distribution have difference. Through comparing with the time series parameters, it puts forward that single wind electricity unit power has smooth effect for overall power of wind electricity field. Finally, it summarizes the prediction effect and puts forward some reasonable suzestions for wind electricity network troblems.
基金supported by the South African Research Chairs Initiative of the Department of Science and Technologythe National Research Foundation awarded to Kevin J. Naidoo
文摘The development and implementation of a computational method able to produce free energies in multiple dimensions,descriptively named the free energies from adaptive reaction coordinate forces(FEARCF) method is described in this paper.While the method can be used to calculate free energies of association,conformation and reactivity here it is shown in the context of chemical reaction landscapes.A reaction free energy surface for the Claisen rearrangement of chorismate to prephenate is used as an illustration of the method's efficient convergence.FEARCF simulations are shown to achieve flat histograms for complex multidimensional free energy volumes.The sampling efficiency by which it produces multidimensional free energies is demonstrated on the complex puckering of a pyranose ring,that is described by a three dimensional W(θ1,θ2,θ3) potential of mean force.
