[Objective]To investigate the effect of probiotic cocktails on growth performance,intestinal barrier function and antioxidant status in heat-stressed broilers.[Methods]One thousand 1-day-old broilers were randomly div...[Objective]To investigate the effect of probiotic cocktails on growth performance,intestinal barrier function and antioxidant status in heat-stressed broilers.[Methods]One thousand 1-day-old broilers were randomly divided into five groups:the thermoneutral(TN),heat stress(HS),heat stress with antibiotic(HS-AB),heat stress with probiotic cocktail 1(HS-P1),and heat stress with probiotic cocktail 2(HS-P2)groups.The broilers in TN and HS groups received a diet without supplements,and those in HS-AB,HS-P1 and HS-P2 groups were fed a diet supplemented with chlortetracycline(300 g/t)or probiotic cocktail 1 or 2(100 g/t),respectively.[Results]The results showed that heat stress reduced growth performance and increased inflammatory factors,NF-κB and Toll-like receptors in jejunal mucosa coinciding with higher expression of jejunal tight junction proteins,mucin and heat stress protein mRNA.[Conclusion]Dietary probiotic cocktails had protective effects against the heat stress-induced changes in the intestine,with increased serum antioxidant capacity and growth performance of broilers.The effect of these cocktails was similar to that of chlortetracycline.展开更多
In the present research,we proposed a scheme to address the issues of severe heat damage,high energy consumption,low cooling system efficiency,and wastage of cold capacity in mines.To elucidate the seasonal variations...In the present research,we proposed a scheme to address the issues of severe heat damage,high energy consumption,low cooling system efficiency,and wastage of cold capacity in mines.To elucidate the seasonal variations of environmental temperature through field measurements,we selected a high-temperature working face in a deep mine as our engineering background.To enhance the heat damage control cability of the working face and minimize unnecessary cooling capac-ity loss,we introduced the multi-dimensional heat hazard prevention and control method called"Heat source barrier and cooling equipment".First,we utilize shotcrete and liquid nitrogen injection to eliminate the heat source and implemented pressure equalization ventilation to disrupt the heat transfer path,thereby creating a heat barrier.Second,we establish divi-sional prediction models for airflow temperature based on the variation patterns obtained through numerical simulation.Third,we devise the location and dynamic control strategy for the cooling equipment based on the prediction models.The results of field application show that the heat resistance and cooling linkage method comply with the safety requirement throughout the entire mining cycle while effectively reducing energy consumption.The ambient temperature is maintained below 30℃,resulting in the energy saving of 10%during the high-temperature period and over 50%during the low-temperature period.These findings serve as a valuable reference for managing heat damage in high-temperature working faces.展开更多
A numerical investigation is conducted to explore the evolution of a plasma discharge and its interaction with the fluid flow based on a self-consistent fluid model which couples the discharge dynamics with the fluid ...A numerical investigation is conducted to explore the evolution of a plasma discharge and its interaction with the fluid flow based on a self-consistent fluid model which couples the discharge dynamics with the fluid dynamics.The effects of the applied voltage on the distribution of velocity and temperature in initially static air are parainetrically studied.Furthermore,the spatial structure of plasma discharge and the resulting force contours in streamwise and normal directions are discussed in detail.The result shows that the plasma actuator produces a net force that should always be directed away from the exposed electrode,which results in an ionic wind pushing particles into a jet downstream of the actuator.When the energy added by the plasma is taken into account,the ambient air temperature is increased slightly around the electrode,but the velocity is almost not affected.Therefore it is unlikely that the induced flow is buoyancy driven.For the operating voltages considered in this paper,the maximum induced velocity is found to follow a power law,i.e.,it is proportional to the applied voltage to the 3.5 power.This promises an efficient application in the flow control with plasma actuators.展开更多
文摘[Objective]To investigate the effect of probiotic cocktails on growth performance,intestinal barrier function and antioxidant status in heat-stressed broilers.[Methods]One thousand 1-day-old broilers were randomly divided into five groups:the thermoneutral(TN),heat stress(HS),heat stress with antibiotic(HS-AB),heat stress with probiotic cocktail 1(HS-P1),and heat stress with probiotic cocktail 2(HS-P2)groups.The broilers in TN and HS groups received a diet without supplements,and those in HS-AB,HS-P1 and HS-P2 groups were fed a diet supplemented with chlortetracycline(300 g/t)or probiotic cocktail 1 or 2(100 g/t),respectively.[Results]The results showed that heat stress reduced growth performance and increased inflammatory factors,NF-κB and Toll-like receptors in jejunal mucosa coinciding with higher expression of jejunal tight junction proteins,mucin and heat stress protein mRNA.[Conclusion]Dietary probiotic cocktails had protective effects against the heat stress-induced changes in the intestine,with increased serum antioxidant capacity and growth performance of broilers.The effect of these cocktails was similar to that of chlortetracycline.
基金supported by the National Natural Science Foundation of China (51874281)the Graduate Innovation Program of China University of Mining and Technology (2022WLKXJ006)the Postgraduate Research&Practice Innovation Program of Jiangsu Province (KYCX22_2612).
文摘In the present research,we proposed a scheme to address the issues of severe heat damage,high energy consumption,low cooling system efficiency,and wastage of cold capacity in mines.To elucidate the seasonal variations of environmental temperature through field measurements,we selected a high-temperature working face in a deep mine as our engineering background.To enhance the heat damage control cability of the working face and minimize unnecessary cooling capac-ity loss,we introduced the multi-dimensional heat hazard prevention and control method called"Heat source barrier and cooling equipment".First,we utilize shotcrete and liquid nitrogen injection to eliminate the heat source and implemented pressure equalization ventilation to disrupt the heat transfer path,thereby creating a heat barrier.Second,we establish divi-sional prediction models for airflow temperature based on the variation patterns obtained through numerical simulation.Third,we devise the location and dynamic control strategy for the cooling equipment based on the prediction models.The results of field application show that the heat resistance and cooling linkage method comply with the safety requirement throughout the entire mining cycle while effectively reducing energy consumption.The ambient temperature is maintained below 30℃,resulting in the energy saving of 10%during the high-temperature period and over 50%during the low-temperature period.These findings serve as a valuable reference for managing heat damage in high-temperature working faces.
基金supported by the Foundation for Innovative Research Groups of National Natural Science Foundation of China(No.51121004)National Natural Science Foundation of China(No.50976026)
文摘A numerical investigation is conducted to explore the evolution of a plasma discharge and its interaction with the fluid flow based on a self-consistent fluid model which couples the discharge dynamics with the fluid dynamics.The effects of the applied voltage on the distribution of velocity and temperature in initially static air are parainetrically studied.Furthermore,the spatial structure of plasma discharge and the resulting force contours in streamwise and normal directions are discussed in detail.The result shows that the plasma actuator produces a net force that should always be directed away from the exposed electrode,which results in an ionic wind pushing particles into a jet downstream of the actuator.When the energy added by the plasma is taken into account,the ambient air temperature is increased slightly around the electrode,but the velocity is almost not affected.Therefore it is unlikely that the induced flow is buoyancy driven.For the operating voltages considered in this paper,the maximum induced velocity is found to follow a power law,i.e.,it is proportional to the applied voltage to the 3.5 power.This promises an efficient application in the flow control with plasma actuators.