To determine the grid resolutions of the WRF model in the typhoon simulation,some sensitivity analysis of horizontal and vertical resolutions in different conditions has been carried out.Different horizontal resolutio...To determine the grid resolutions of the WRF model in the typhoon simulation,some sensitivity analysis of horizontal and vertical resolutions in different conditions has been carried out.Different horizontal resolutions(5,10,20,30 km),nesting grids(15 and 5 km),different vertical resolutions(35-layers,28-layers,20-layers)and different top maximum pressures(1 000,2 000,3 500,5 000 Pa)had been used in the mesoscale numerical model WRF to simulate the Typhoon Kai-tak.The simulation results of typhoon track,wind speed and sea level pressure at different horizontal and vertical resolutions have been compared and analyzed.The horizontal and vertical resolutions of the model have limited effect on the simulation effect of the typhoon track.Different horizontal and vertical resolutions have obvious effects on typhoon strength(defined by wind speed)and intensity(defined by sea level pressure,SLP),especially for sea level pressure.The typhoon intensity simulated by the high-resolution model is closer to the real situation and the nesting grids can improve computational accuracy and efficiency.The simulation results affected by vertical resolution using 35-layers is better than the simulation results using 20-layers and 28-layers simulations.Through comparison and analysis,the horizontal and vertical resolutions of WRF model are finally determined as follows:the two-way nesting grid of 15 and 5 km is comprehensively determined,and the vertical layers is 35-layers,the top maximum pressure is 2 000 Pa.展开更多
To know the temperature status of track and wheels on tank,the finite element calculation of temperature field was implemented with ANSYS software.The detailed temperature distributions for road wheel,drive wheel,idle...To know the temperature status of track and wheels on tank,the finite element calculation of temperature field was implemented with ANSYS software.The detailed temperature distributions for road wheel,drive wheel,idle wheel and track loop were obtained.The effect of factors,such as tank speed,environment temperature,sun radiant energy,ground deformation resistant and tank load,on the temperature of road wheel was studied.The sensitivity analysis shows that the effect of tank load on the temperature is the most,and the effect of ground deformation resistant is the least.The temperature testing device for road wheel on tank was developed to perform the experiments in real time.The calculated temperatures are in accord well with the experimental values.展开更多
A barotropic prirnitive equation model is used to simulate the tropical cyclone motion.Tropical cyclone movements under different environmental flow backgrounds were examined and sensitivity of tropical cyclone tracks...A barotropic prirnitive equation model is used to simulate the tropical cyclone motion.Tropical cyclone movements under different environmental flow backgrounds were examined and sensitivity of tropical cyclone tracks were discussed.Conclusions of practical significance have been obtained in this paper.展开更多
Background Few clinical studies or randomized clinical trial results have reported the impact of fast track surgery on postoperative insulin sensitivity. This study aimed to investigate the effects of fast track surge...Background Few clinical studies or randomized clinical trial results have reported the impact of fast track surgery on postoperative insulin sensitivity. This study aimed to investigate the effects of fast track surgery on postoperative insulin sensitivity in patients undergoing elective open colorectal resection. Methods Controlled, randomized clinical trial was conducted from November 2008 to January 2009 with one-month post-discharge follow-up. Seventy patients with colorectal carcinoma requiring colorectal resection were randomized into two groups： a fast track group （35 cases） and a conventional care group （35 cases）. All included patients received elective open colorectal resection with combined tracheal intubation and general anesthesia. Clinical parameters （complication rates, return of gastrointestinal function and postoperative length of stay）, stress index and insulin sensitivity were evaluated in both groups perioperatively. Results Sixty-two patients finally completed the study, 32 cases in the fast-track group and 30 cases in the conventional care group. Our findings revealed a significantly faster recovery of postoperative insulin sensitivity on postoperative day 7 in the fast-track group than that in the conventional care group. We also found a significantly shorter length of postoperative stay and a significantly faster return of gastrointestinal function in patients undergoing fast-track rehabilitation. Conclusion Fast track surgery accelerates the recovery of postoperative insulin sensitivity in elective surgery for colorectal carcinoma with a shorter length of postoperative hospital stay.展开更多
基金The National Natural Science Foundation of China under contract Nos 51809023,51839002 and 51879015the Open Research Foundation of the Key Laboratory of the Pearl River Estuarine Dynamics and Associated Process Regulation,the Ministry of Water Resources under contract No.2018KJ03
文摘To determine the grid resolutions of the WRF model in the typhoon simulation,some sensitivity analysis of horizontal and vertical resolutions in different conditions has been carried out.Different horizontal resolutions(5,10,20,30 km),nesting grids(15 and 5 km),different vertical resolutions(35-layers,28-layers,20-layers)and different top maximum pressures(1 000,2 000,3 500,5 000 Pa)had been used in the mesoscale numerical model WRF to simulate the Typhoon Kai-tak.The simulation results of typhoon track,wind speed and sea level pressure at different horizontal and vertical resolutions have been compared and analyzed.The horizontal and vertical resolutions of the model have limited effect on the simulation effect of the typhoon track.Different horizontal and vertical resolutions have obvious effects on typhoon strength(defined by wind speed)and intensity(defined by sea level pressure,SLP),especially for sea level pressure.The typhoon intensity simulated by the high-resolution model is closer to the real situation and the nesting grids can improve computational accuracy and efficiency.The simulation results affected by vertical resolution using 35-layers is better than the simulation results using 20-layers and 28-layers simulations.Through comparison and analysis,the horizontal and vertical resolutions of WRF model are finally determined as follows:the two-way nesting grid of 15 and 5 km is comprehensively determined,and the vertical layers is 35-layers,the top maximum pressure is 2 000 Pa.
文摘To know the temperature status of track and wheels on tank,the finite element calculation of temperature field was implemented with ANSYS software.The detailed temperature distributions for road wheel,drive wheel,idle wheel and track loop were obtained.The effect of factors,such as tank speed,environment temperature,sun radiant energy,ground deformation resistant and tank load,on the temperature of road wheel was studied.The sensitivity analysis shows that the effect of tank load on the temperature is the most,and the effect of ground deformation resistant is the least.The temperature testing device for road wheel on tank was developed to perform the experiments in real time.The calculated temperatures are in accord well with the experimental values.
文摘A barotropic prirnitive equation model is used to simulate the tropical cyclone motion.Tropical cyclone movements under different environmental flow backgrounds were examined and sensitivity of tropical cyclone tracks were discussed.Conclusions of practical significance have been obtained in this paper.
文摘Background Few clinical studies or randomized clinical trial results have reported the impact of fast track surgery on postoperative insulin sensitivity. This study aimed to investigate the effects of fast track surgery on postoperative insulin sensitivity in patients undergoing elective open colorectal resection. Methods Controlled, randomized clinical trial was conducted from November 2008 to January 2009 with one-month post-discharge follow-up. Seventy patients with colorectal carcinoma requiring colorectal resection were randomized into two groups： a fast track group （35 cases） and a conventional care group （35 cases）. All included patients received elective open colorectal resection with combined tracheal intubation and general anesthesia. Clinical parameters （complication rates, return of gastrointestinal function and postoperative length of stay）, stress index and insulin sensitivity were evaluated in both groups perioperatively. Results Sixty-two patients finally completed the study, 32 cases in the fast-track group and 30 cases in the conventional care group. Our findings revealed a significantly faster recovery of postoperative insulin sensitivity on postoperative day 7 in the fast-track group than that in the conventional care group. We also found a significantly shorter length of postoperative stay and a significantly faster return of gastrointestinal function in patients undergoing fast-track rehabilitation. Conclusion Fast track surgery accelerates the recovery of postoperative insulin sensitivity in elective surgery for colorectal carcinoma with a shorter length of postoperative hospital stay.
文摘为确定一送两受式无砟轨道电路发送信号的频率范围,根据无砟轨道电路一次侧参数的频率特性和一送两受式无砟轨道电路调整态、分路态和断轨态的四端网系数表达式,在不同的道砟最小电阻、表面电导系数、输入端阻抗和输出端阻抗初始值下,用图解法对断轨灵敏度和分路灵敏度频率特性进行了仿真分析.结果表明:当一次侧参数为无砟轨道电路标准参数时,一送两受式轨道电路信号频率不应大于700 Hz.
