The adsorption behavior of symmetric triblock copolymers, Am/2BnAm/2, from a nonselective solvent at solid-liquid interface has been studied by Monte Carlo simulations on a simple lattice model. Either segment A or se...The adsorption behavior of symmetric triblock copolymers, Am/2BnAm/2, from a nonselective solvent at solid-liquid interface has been studied by Monte Carlo simulations on a simple lattice model. Either segment A or segment B is attractive, while the other is non-attractive to the surface. Influences of the adsorption energy, bulk concentration, chain composition and chain length on the microstructure of adsorbed layers are presented. The results show that the total surface coverage and the adsorption amount increases monotonically as the bulk concentration increases. The larger the adsorption energy and the higher the fraction of adsorbing segments, the higher the total surface coverage is exhibited. The product of surface coverage and the proportion of non-attractive segments are nearly independent of the chain length, and the logarithm of the adsorption amount is a linear function of the reciprocal of the reduced temperature. When the adsorption energy is larger, the adsorption amount exhibits a maximum as the fraction of adsorbing segment increases. The adsorption isotherms of copolymers with different length of non-attractive segments can be mapped onto a single curve under given adsorption energy. The adsorption layer thickness decreases as the adsorption energy and the fraction of adsorbing segments increases, but it increases as the length of non-attractive segments increases. The tails mainly govern the adsorption layer thickness.展开更多
In this paper, the glitching activity and process variations in the maximum power dissipation estimation of CMOS circuits are introduced. Given a circuit and the gate library, a new Genetic Algorithm (GA)-based techni...In this paper, the glitching activity and process variations in the maximum power dissipation estimation of CMOS circuits are introduced. Given a circuit and the gate library, a new Genetic Algorithm (GA)-based technique is developed to determine the maximum power dissipation from a statistical point of view. The simulation on 1SCAS-89 benchmarks shows that the ratio of the maximum power dissipation with glitching activity over the maximum power under zero-delay model ranges from 1.18 to 4.02. Compared with the traditional Monte Carlo-based technique, the new approach presented in this paper is more effective.展开更多
Surplus production models are the simplest analytical methods effective for fish stock assessment and fisheries management. In this paper, eight surplus production estimators(three estimation procedures) were tested o...Surplus production models are the simplest analytical methods effective for fish stock assessment and fisheries management. In this paper, eight surplus production estimators(three estimation procedures) were tested on Schaefer and Fox type simulated data in three simulated fisheries(declining, well-managed, and restoring fisheries) at two white noise levels. Monte Carlo simulation was conducted to verify the utility of moving averaging(MA), which was an important technique for reducing the effect of noise in data in these models. The relative estimation error(REE) of maximum sustainable yield(MSY) was used as an indicator for the analysis, and one-way ANOVA was applied to test the significance of the REE calculated at four levels of MA. Simulation results suggested that increasing the value of MA could significantly improve the performance of the surplus production model(low REE) in all cases when the white noise level was low(coefficient of variation(CV) = 0.02). However, when the white noise level increased(CV= 0.25), adding the value of MA could still significantly enhance the performance of most models. Our results indicated that the best model performance occurred frequently when MA was equal to 3; however, some exceptions were observed when MA was higher.展开更多
In this paper, the evaluation of a preliminary design of a PGAA （prompt gamma activation analysis） facility based on Monte Carlo simulations is presented and discussed. The implementation of the PGAA method at the C...In this paper, the evaluation of a preliminary design of a PGAA （prompt gamma activation analysis） facility based on Monte Carlo simulations is presented and discussed. The implementation of the PGAA method at the CDTN （nuclear technology development centre） would increase the applications of the TRIGA reactor. The preliminary design is based on a quasi vertical hollow cylinder （called neutron extractor） in the reactor pool to extract the neutron flux. This study evaluates the neutron flux in the upper position of the cylinder in the suggested position of the samples to be analyzed by the PGAA. The calculations of the radioactive capture reaction rates and of the detection limits for some isotopes were performed. Through all these calculations, the feasibility of the application of the PGAA method at the IPR-R1 installations was evaluated. According to the obtained results, it can be concluded that is possible to apply the PGAA method at the IPR-R1 reactor, even with its design restrictions.展开更多
基金the National Natural Science Foundation of China (No. 20025618, No. 20236010) Shanghai Municipal Education Commission of China.
文摘The adsorption behavior of symmetric triblock copolymers, Am/2BnAm/2, from a nonselective solvent at solid-liquid interface has been studied by Monte Carlo simulations on a simple lattice model. Either segment A or segment B is attractive, while the other is non-attractive to the surface. Influences of the adsorption energy, bulk concentration, chain composition and chain length on the microstructure of adsorbed layers are presented. The results show that the total surface coverage and the adsorption amount increases monotonically as the bulk concentration increases. The larger the adsorption energy and the higher the fraction of adsorbing segments, the higher the total surface coverage is exhibited. The product of surface coverage and the proportion of non-attractive segments are nearly independent of the chain length, and the logarithm of the adsorption amount is a linear function of the reciprocal of the reduced temperature. When the adsorption energy is larger, the adsorption amount exhibits a maximum as the fraction of adsorbing segment increases. The adsorption isotherms of copolymers with different length of non-attractive segments can be mapped onto a single curve under given adsorption energy. The adsorption layer thickness decreases as the adsorption energy and the fraction of adsorbing segments increases, but it increases as the length of non-attractive segments increases. The tails mainly govern the adsorption layer thickness.
基金Supported by NSF of the United States under contract 5978 East Asia and Pacific Program 9602485
文摘In this paper, the glitching activity and process variations in the maximum power dissipation estimation of CMOS circuits are introduced. Given a circuit and the gate library, a new Genetic Algorithm (GA)-based technique is developed to determine the maximum power dissipation from a statistical point of view. The simulation on 1SCAS-89 benchmarks shows that the ratio of the maximum power dissipation with glitching activity over the maximum power under zero-delay model ranges from 1.18 to 4.02. Compared with the traditional Monte Carlo-based technique, the new approach presented in this paper is more effective.
基金supported by the special research fund of Ocean University of China (201022001)
文摘Surplus production models are the simplest analytical methods effective for fish stock assessment and fisheries management. In this paper, eight surplus production estimators(three estimation procedures) were tested on Schaefer and Fox type simulated data in three simulated fisheries(declining, well-managed, and restoring fisheries) at two white noise levels. Monte Carlo simulation was conducted to verify the utility of moving averaging(MA), which was an important technique for reducing the effect of noise in data in these models. The relative estimation error(REE) of maximum sustainable yield(MSY) was used as an indicator for the analysis, and one-way ANOVA was applied to test the significance of the REE calculated at four levels of MA. Simulation results suggested that increasing the value of MA could significantly improve the performance of the surplus production model(low REE) in all cases when the white noise level was low(coefficient of variation(CV) = 0.02). However, when the white noise level increased(CV= 0.25), adding the value of MA could still significantly enhance the performance of most models. Our results indicated that the best model performance occurred frequently when MA was equal to 3; however, some exceptions were observed when MA was higher.
文摘In this paper, the evaluation of a preliminary design of a PGAA （prompt gamma activation analysis） facility based on Monte Carlo simulations is presented and discussed. The implementation of the PGAA method at the CDTN （nuclear technology development centre） would increase the applications of the TRIGA reactor. The preliminary design is based on a quasi vertical hollow cylinder （called neutron extractor） in the reactor pool to extract the neutron flux. This study evaluates the neutron flux in the upper position of the cylinder in the suggested position of the samples to be analyzed by the PGAA. The calculations of the radioactive capture reaction rates and of the detection limits for some isotopes were performed. Through all these calculations, the feasibility of the application of the PGAA method at the IPR-R1 installations was evaluated. According to the obtained results, it can be concluded that is possible to apply the PGAA method at the IPR-R1 reactor, even with its design restrictions.
