Objective:This study aims to investigate the effect of 4 different dialysate temperatures on blood pressure during hemodialysis for patients with hypertension.Methods:Using a self-controlled method,the patients' bo...Objective:This study aims to investigate the effect of 4 different dialysate temperatures on blood pressure during hemodialysis for patients with hypertension.Methods:Using a self-controlled method,the patients' body temperature was set as T.Accordingly,the dialysate temperature was set as 37 ℃,T+0.5 ℃,T,and T-0.5 ℃.The changes in blood pressure,heart rate,mean arterial pressure and dialysis-induced adverse reactions at the 4 different dialysate temperatures were consistently monitored.Results:Patients who received hemodialysis with 37 ℃ and T+0.5 ℃ dialysate demonstrated an unstable blood pressure and a higher incidence of adverse reactions,Patients who received hemodialysis with T and T-0.5 ℃ dialysate showed a relatively stable blood pressure,heart rate,and mean arterial pressure during dialysis.In particular,dialysate at T-0.5 ℃ resulted in the most stable blood pressure,the fewest adverse reactions and the best self-assessed comfort scores(P 〈 0.01).Conclusions:The dialysate temperature during hemodialysis for patients with hypertension should be set to a temperature based on patients' preoperative body temperate T or 0.5 ℃ below T.This practice is suggested to enhance the stability of patients' blood pressure and heart rate during hemodialysis,reduce complications and improve patients' tolerance of hemodialysis.展开更多
To improve creep resistance of directional polytetrafluoroethylene (PTFE) films, epoxy grafted nano-SiO2 is mixed with PTFE powder before sintering and calender rolling. The aligned macromolecular chains (especiall...To improve creep resistance of directional polytetrafluoroethylene (PTFE) films, epoxy grafted nano-SiO2 is mixed with PTFE powder before sintering and calender rolling. The aligned macromolecular chains (especially those in amorphous region) of the composite films can be bundled up by the nanoparticles to share the applied stress together. In addition, incorporation of silica nanoparticles increases crystallinity of PTFE and favors microfibrillation of PTFE in the course of large deformation. As result, PTFE films exhibit lower creep strain and creep rate, and higher tensile strength and hardness. The work is believed to open an avenue for manufacturing high performance fluoropolymers by nano-inclusions.展开更多
During the slab continuous casting process, the flow field of molten steel in the mold plays a decisive role in the quality ofthe slab. In this paper, electromagnetic swirling flow in nozzle technology is proposed to ...During the slab continuous casting process, the flow field of molten steel in the mold plays a decisive role in the quality ofthe slab. In this paper, electromagnetic swirling flow in nozzle technology is proposed to control the flow field in mold.This technology can drive molten steel to rotate inside the submerged entry nozzle by electromagnetic force, therebycontrolling the flow field. This research shows that it can reduce the impact of molten steel on the bottom of nozzle andpartly reduce the negative pressure at the upper part of nozzle outlet which is even eliminated by optimizing the structureand angle of nozzle. The area of heat flux of the mold wall becomes larger, and the crest value of heat flux gets lower thanthat without swirling in nozzle and any nozzle optimization. The meniscus fluctuates smoothly, and the flow velocity at thetop surface is within a reasonable range. The temperature field distribution in the mold is uniform which was beneficial tothe growth of equiaxed crystal and decreased element segregation.展开更多
Homogenization of physical properties and the chemical composition through the control of liquid metal flow is essentialduring the continuous casting production of billets. This work was aimed at obtaining improved fi...Homogenization of physical properties and the chemical composition through the control of liquid metal flow is essentialduring the continuous casting production of billets. This work was aimed at obtaining improved finished products viacontinuous casting that implements two magnetic fields. These fields were realized via two electromagnetic stirringprocesses implemented in a single process: one in the nozzle and one in the mold. The qualitative effects of applyingdouble electromagnetic stirring (EMS) were verified through numerical simulation of 178 mm × 178 mm square billetsexposed to double electromagnetic fields during the continuous casting process. The accuracy of the numerical calculationswas verified via physical experiments. In addition, the final simulation results were compared with the intermediate results,to determine the true effects of different EMS on the metal flow in the mold. The results revealed that casting using EMSwith different directions of magnetic field in the mold and the nozzle has the best effect on the distribution of the fluid flowand minimal influence on the stability of the meniscus and yields the minimum metal-jet penetration into the mold.展开更多
文摘Objective:This study aims to investigate the effect of 4 different dialysate temperatures on blood pressure during hemodialysis for patients with hypertension.Methods:Using a self-controlled method,the patients' body temperature was set as T.Accordingly,the dialysate temperature was set as 37 ℃,T+0.5 ℃,T,and T-0.5 ℃.The changes in blood pressure,heart rate,mean arterial pressure and dialysis-induced adverse reactions at the 4 different dialysate temperatures were consistently monitored.Results:Patients who received hemodialysis with 37 ℃ and T+0.5 ℃ dialysate demonstrated an unstable blood pressure and a higher incidence of adverse reactions,Patients who received hemodialysis with T and T-0.5 ℃ dialysate showed a relatively stable blood pressure,heart rate,and mean arterial pressure during dialysis.In particular,dialysate at T-0.5 ℃ resulted in the most stable blood pressure,the fewest adverse reactions and the best self-assessed comfort scores(P 〈 0.01).Conclusions:The dialysate temperature during hemodialysis for patients with hypertension should be set to a temperature based on patients' preoperative body temperate T or 0.5 ℃ below T.This practice is suggested to enhance the stability of patients' blood pressure and heart rate during hemodialysis,reduce complications and improve patients' tolerance of hemodialysis.
基金financially supported by the National Natural Science Foundation of China (No.51173207)Sino-Hungarian Scientific and Technological Cooperation Project (No.2009DFA52660)+1 种基金Key projects of Guangdong Education Office (No.cxzd1101)Natural Science Foundation of Guangdong (Nos.2010B010800020,2011B090500004,2011BZ100051)
文摘To improve creep resistance of directional polytetrafluoroethylene (PTFE) films, epoxy grafted nano-SiO2 is mixed with PTFE powder before sintering and calender rolling. The aligned macromolecular chains (especially those in amorphous region) of the composite films can be bundled up by the nanoparticles to share the applied stress together. In addition, incorporation of silica nanoparticles increases crystallinity of PTFE and favors microfibrillation of PTFE in the course of large deformation. As result, PTFE films exhibit lower creep strain and creep rate, and higher tensile strength and hardness. The work is believed to open an avenue for manufacturing high performance fluoropolymers by nano-inclusions.
基金financial support from the National Natural Science Foundation of China(Nos.U1560207and U51504057)the National Key R&D Program of China:Upgrading and Industrialization of Key Basic Material Technology(No.2017YFB0304400)
文摘During the slab continuous casting process, the flow field of molten steel in the mold plays a decisive role in the quality ofthe slab. In this paper, electromagnetic swirling flow in nozzle technology is proposed to control the flow field in mold.This technology can drive molten steel to rotate inside the submerged entry nozzle by electromagnetic force, therebycontrolling the flow field. This research shows that it can reduce the impact of molten steel on the bottom of nozzle andpartly reduce the negative pressure at the upper part of nozzle outlet which is even eliminated by optimizing the structureand angle of nozzle. The area of heat flux of the mold wall becomes larger, and the crest value of heat flux gets lower thanthat without swirling in nozzle and any nozzle optimization. The meniscus fluctuates smoothly, and the flow velocity at thetop surface is within a reasonable range. The temperature field distribution in the mold is uniform which was beneficial tothe growth of equiaxed crystal and decreased element segregation.
基金financial support from the National Natural Science Foundation of China(Nos.U1560207and U51504057)the National Key R&D Program of China:Upgrading and Industrialization of Key Basic Material Technology(No.2017YFB0304400)
文摘Homogenization of physical properties and the chemical composition through the control of liquid metal flow is essentialduring the continuous casting production of billets. This work was aimed at obtaining improved finished products viacontinuous casting that implements two magnetic fields. These fields were realized via two electromagnetic stirringprocesses implemented in a single process: one in the nozzle and one in the mold. The qualitative effects of applyingdouble electromagnetic stirring (EMS) were verified through numerical simulation of 178 mm × 178 mm square billetsexposed to double electromagnetic fields during the continuous casting process. The accuracy of the numerical calculationswas verified via physical experiments. In addition, the final simulation results were compared with the intermediate results,to determine the true effects of different EMS on the metal flow in the mold. The results revealed that casting using EMSwith different directions of magnetic field in the mold and the nozzle has the best effect on the distribution of the fluid flowand minimal influence on the stability of the meniscus and yields the minimum metal-jet penetration into the mold.