The mean path length(MPL)of photons is a critical parameter to calculate tissue absorption coefficient as well as blood oxygenation using modified Beer-Lambert law,where in the differential path factor(DPF)is often as...The mean path length(MPL)of photons is a critical parameter to calculate tissue absorption coefficient as well as blood oxygenation using modified Beer-Lambert law,where in the differential path factor(DPF)is often assumed as constant over range of tissue absorption.By utilizing the Monte Carlo(MC)simulation of photon migrations in the leg,this study used four approaches to estimate MPL,and compared them with that determined by the MPL definition.The simulation results indicate that the DPF is remarkably affected by tissue absorption,at approximate 10% variation.A linear model is suggested to calculate MPL for measurements of tissue absorption as well as blood oxygenation using modified Beer-Lambert law.展开更多
A hybrid grid-point statistical interpolation-ensemble transform Kalman filter (GSI-ETKF) data assimilation system for the Weather Research and Forecasting (WRF) model was developed and applied to typhoon track foreca...A hybrid grid-point statistical interpolation-ensemble transform Kalman filter (GSI-ETKF) data assimilation system for the Weather Research and Forecasting (WRF) model was developed and applied to typhoon track forecast with simulated dropsonde observations. This hybrid system showed significantly improved results with respect to tropical cyclone track forecast compared to the standard GSI system in the case of Muifa in 2011. Further analyses revealed that the flow-dependent ensemble covariance was the major contributor to the better performance of the GSI-ETKF system than the standard GSI system; the GSI-ETKF system was found to be potentially able to adjust the position of the typhoon vortex systematically and better update the environmental field.展开更多
In order to have efficient and highly stereoselective cyclopropanating reagents, the cyclopropabation reaction of ethylene promoted with Samarium（Ⅱ） carbenoid [Simmons-Smith（SS）reagent] were studied by means of B...In order to have efficient and highly stereoselective cyclopropanating reagents, the cyclopropabation reaction of ethylene promoted with Samarium（Ⅱ） carbenoid [Simmons-Smith（SS）reagent] were studied by means of B3LYP hybrid density functional method. The geometries for reactants, transition states and products are completely optimized. All transition states were verified by the vibrational analysis and the intrinsic reaction coordinate （IRC） calculations. The results showed that, identical with the lithium carbenoid, CH3SmCH2X（X=Cl, Br and Ⅰ） can fairly react with ethylene via both methylene transfer pathway （pathway A） and carbometalation pathway （pathway B）. And the cyclopropanation reaction via methylene transfer pathway proceeds with a lower barrier and at lower temperatures.展开更多
Based on a questionnaire survey of Chinese public hospitals, this paper explores the consequence and realization path of balanced scorecard （BSC, hereafter） usage. The results show that BSC usage can improve hospita...Based on a questionnaire survey of Chinese public hospitals, this paper explores the consequence and realization path of balanced scorecard （BSC, hereafter） usage. The results show that BSC usage can improve hospital performance remarkably. With the structural equation model analysis, we further find that, this function is realized in an indirect way through the perception of organizational fairness and organizational commitment. The BSC has direct effect to improve the perception of organizational fairness and organizational commitment, which further influence the performance. The results not only complement empirical evidences for BSC usage, but also provide guidance to regulators and hospitals to implement BSC in compensation contract.展开更多
We examine the high density limit of the adsorption isotherms of hydrogen on MOF-5. The isotherms are calculated using quantum GCMC simulations over the pressure range： 0-150 atm （1 atm = 1.01325 ~ 105 Pa） in the s...We examine the high density limit of the adsorption isotherms of hydrogen on MOF-5. The isotherms are calculated using quantum GCMC simulations over the pressure range： 0-150 atm （1 atm = 1.01325 ~ 105 Pa） in the subcritical and supercritical state at 30, 50, 77, 113, 196 and 296 K. The fluid phase density in the pores for each temper- ature is calculated and shown to reach values higher than normal liquid density. The fluid phase density obtained at 30 K is observed to correspond to a highly compressed liquid. The radial distribution function of the adsorbed phase at 30 and 50 K are calculated. The adsorption isotherms are compared with available experimental data at 30, 50, 77 and 298 K.展开更多
基金Research Funds from North University of China(No.130087)
文摘The mean path length(MPL)of photons is a critical parameter to calculate tissue absorption coefficient as well as blood oxygenation using modified Beer-Lambert law,where in the differential path factor(DPF)is often assumed as constant over range of tissue absorption.By utilizing the Monte Carlo(MC)simulation of photon migrations in the leg,this study used four approaches to estimate MPL,and compared them with that determined by the MPL definition.The simulation results indicate that the DPF is remarkably affected by tissue absorption,at approximate 10% variation.A linear model is suggested to calculate MPL for measurements of tissue absorption as well as blood oxygenation using modified Beer-Lambert law.
基金supported by the Project for public welfare (Meteorology) of China(Grant No.GYHY201206006)the National Natural Science Foundation of China(Grant Nos.40975067 and 41175094)
文摘A hybrid grid-point statistical interpolation-ensemble transform Kalman filter (GSI-ETKF) data assimilation system for the Weather Research and Forecasting (WRF) model was developed and applied to typhoon track forecast with simulated dropsonde observations. This hybrid system showed significantly improved results with respect to tropical cyclone track forecast compared to the standard GSI system in the case of Muifa in 2011. Further analyses revealed that the flow-dependent ensemble covariance was the major contributor to the better performance of the GSI-ETKF system than the standard GSI system; the GSI-ETKF system was found to be potentially able to adjust the position of the typhoon vortex systematically and better update the environmental field.
基金This work was supported by the Northwest Normal University Science Foundation of Gansu Province （No. NWNU-QN-2001-08）.
文摘In order to have efficient and highly stereoselective cyclopropanating reagents, the cyclopropabation reaction of ethylene promoted with Samarium（Ⅱ） carbenoid [Simmons-Smith（SS）reagent] were studied by means of B3LYP hybrid density functional method. The geometries for reactants, transition states and products are completely optimized. All transition states were verified by the vibrational analysis and the intrinsic reaction coordinate （IRC） calculations. The results showed that, identical with the lithium carbenoid, CH3SmCH2X（X=Cl, Br and Ⅰ） can fairly react with ethylene via both methylene transfer pathway （pathway A） and carbometalation pathway （pathway B）. And the cyclopropanation reaction via methylene transfer pathway proceeds with a lower barrier and at lower temperatures.
文摘Based on a questionnaire survey of Chinese public hospitals, this paper explores the consequence and realization path of balanced scorecard （BSC, hereafter） usage. The results show that BSC usage can improve hospital performance remarkably. With the structural equation model analysis, we further find that, this function is realized in an indirect way through the perception of organizational fairness and organizational commitment. The BSC has direct effect to improve the perception of organizational fairness and organizational commitment, which further influence the performance. The results not only complement empirical evidences for BSC usage, but also provide guidance to regulators and hospitals to implement BSC in compensation contract.
基金support of Natural Sciences and Engineering Research Council of Canadaof the H2Can strategic network and the Centre québécois sur les matériaux fonctionnels(CQMF/Fonds de recherche du Que′bec-Nature et technologies)
文摘We examine the high density limit of the adsorption isotherms of hydrogen on MOF-5. The isotherms are calculated using quantum GCMC simulations over the pressure range： 0-150 atm （1 atm = 1.01325 ~ 105 Pa） in the subcritical and supercritical state at 30, 50, 77, 113, 196 and 296 K. The fluid phase density in the pores for each temper- ature is calculated and shown to reach values higher than normal liquid density. The fluid phase density obtained at 30 K is observed to correspond to a highly compressed liquid. The radial distribution function of the adsorbed phase at 30 and 50 K are calculated. The adsorption isotherms are compared with available experimental data at 30, 50, 77 and 298 K.
