Aircraft icing has long been a plague to aviation for its serious threat to flight safety. Even though lots of methods for anti-icing have been in use or studied for quite a long time, new methods are still in great d...Aircraft icing has long been a plague to aviation for its serious threat to flight safety. Even though lots of methods for anti-icing have been in use or studied for quite a long time, new methods are still in great demand for both civil and military aircraft. The current study in this paper uses widely used Dielectric Barrier Discharge（DBD） plasma actuation to anti-ice on a NACA0012 airfoil model with a chord length of 53.5 cm in a closed-circuit icing wind tunnel. An actuator was installed at the leading edge of the airfoil model, and actuated by a pulsed low-temperature plasma power source. The actuator has two types of layout, a striped electrode layout and a meshy electrode layout.The ice accretion process or anti-icing process was recorded by a CCD camera and an infrared camera. Instantaneous pictures and infrared contours show that both types of DBD plasma actuators have the ability for anti-ice under a freestream velocity of 90 m/s, a static temperature of -7℃,an Median Volume droplet Diameter（MVD） of 20 lm, and an Liquid Water Content（LWC） of 0.5 g/m^3. The detected variations of temperatures with time at specific locations reveal that the temperatures oscillate for some time after spraying at first, and then tend to be nearly constant values.This shows that the key point of the anti-icing mechanism with DBD plasma actuation is to achieve a thermal equilibrium on the model surface. Besides, the power consumption in the anti-icing process was estimated in this paper by Lissajous figures measured by an oscilloscope, and it is lower than those of existing anti-icing methods. The experimental results presented in this paper indicate that the DBD plasma anti-icing method is a promising technique in the future.展开更多
The authors regret to inform that Figs.2 and 3 were misplaced.The correct figures and figure captions appear below:The authors would like to apologize for any inconvenience caused.
The fourth China International Consumer Products Expo,which was held from April 13 to 18,broke records for scale,as well as for numbers of new products,visitors and exhibited brands.A total of 4,019 brands from 71 cou...The fourth China International Consumer Products Expo,which was held from April 13 to 18,broke records for scale,as well as for numbers of new products,visitors and exhibited brands.A total of 4,019 brands from 71 countries and regions were presented at this year’s six-day expo in Haikou,the capital of south China’s Hainan Province,with those figures respectively increasing by 19 percent and 9 percent from last year,according to organizers.展开更多
Background:Crohn’s disease,described by Dr.Burrill Crohn and his colleagues in 1932,continues to be of great research and clinical interest.It was initially perceived as a distinct condition and it has evolved since ...Background:Crohn’s disease,described by Dr.Burrill Crohn and his colleagues in 1932,continues to be of great research and clinical interest.It was initially perceived as a distinct condition and it has evolved since into a complex disease,with debates still going regarding its classification and etiology.Even though more that 80 years of research have passed,numerous significant questions regarding the disease’s causes and best possible treatment strategies still remain.Methods:This article reviews both historical and contemporary perspectives on Crohn’s disease,including its initial description,the research developments that happened in the years to follow,as well as the way it is regarded nowadays.It refers to notable contributions from medical figures,such as Dr.Crohn and his colleagues,examines related advances made in medical research and mentions the challenges and the treatment strategies that are still being discussed.Results:This article highlights the evolution of Crohn’s disease from a distinct condition to a more heterogeneous one.Furthermore,it refers to advancements made in medical research,such as the identification of CARD15(NOD2)gene mutations and the role of dysbiosis,and it examines current therapeutic approaches.Conclusion:Even though significant progress has been made since the initial description of Chron’s disease,there is no definitive cure,even though it has been determined that genetic and environmental factors are of great importance.The ongoing research could possibly lead to future discoveries and therefore aid in the discovery of efficient management and treatment of Crohn’s disease.展开更多
基金supported by the National Natural Science Foundation of China (No.11472221)
文摘Aircraft icing has long been a plague to aviation for its serious threat to flight safety. Even though lots of methods for anti-icing have been in use or studied for quite a long time, new methods are still in great demand for both civil and military aircraft. The current study in this paper uses widely used Dielectric Barrier Discharge（DBD） plasma actuation to anti-ice on a NACA0012 airfoil model with a chord length of 53.5 cm in a closed-circuit icing wind tunnel. An actuator was installed at the leading edge of the airfoil model, and actuated by a pulsed low-temperature plasma power source. The actuator has two types of layout, a striped electrode layout and a meshy electrode layout.The ice accretion process or anti-icing process was recorded by a CCD camera and an infrared camera. Instantaneous pictures and infrared contours show that both types of DBD plasma actuators have the ability for anti-ice under a freestream velocity of 90 m/s, a static temperature of -7℃,an Median Volume droplet Diameter（MVD） of 20 lm, and an Liquid Water Content（LWC） of 0.5 g/m^3. The detected variations of temperatures with time at specific locations reveal that the temperatures oscillate for some time after spraying at first, and then tend to be nearly constant values.This shows that the key point of the anti-icing mechanism with DBD plasma actuation is to achieve a thermal equilibrium on the model surface. Besides, the power consumption in the anti-icing process was estimated in this paper by Lissajous figures measured by an oscilloscope, and it is lower than those of existing anti-icing methods. The experimental results presented in this paper indicate that the DBD plasma anti-icing method is a promising technique in the future.
文摘The authors regret to inform that Figs.2 and 3 were misplaced.The correct figures and figure captions appear below:The authors would like to apologize for any inconvenience caused.
文摘The fourth China International Consumer Products Expo,which was held from April 13 to 18,broke records for scale,as well as for numbers of new products,visitors and exhibited brands.A total of 4,019 brands from 71 countries and regions were presented at this year’s six-day expo in Haikou,the capital of south China’s Hainan Province,with those figures respectively increasing by 19 percent and 9 percent from last year,according to organizers.
文摘Background:Crohn’s disease,described by Dr.Burrill Crohn and his colleagues in 1932,continues to be of great research and clinical interest.It was initially perceived as a distinct condition and it has evolved since into a complex disease,with debates still going regarding its classification and etiology.Even though more that 80 years of research have passed,numerous significant questions regarding the disease’s causes and best possible treatment strategies still remain.Methods:This article reviews both historical and contemporary perspectives on Crohn’s disease,including its initial description,the research developments that happened in the years to follow,as well as the way it is regarded nowadays.It refers to notable contributions from medical figures,such as Dr.Crohn and his colleagues,examines related advances made in medical research and mentions the challenges and the treatment strategies that are still being discussed.Results:This article highlights the evolution of Crohn’s disease from a distinct condition to a more heterogeneous one.Furthermore,it refers to advancements made in medical research,such as the identification of CARD15(NOD2)gene mutations and the role of dysbiosis,and it examines current therapeutic approaches.Conclusion:Even though significant progress has been made since the initial description of Chron’s disease,there is no definitive cure,even though it has been determined that genetic and environmental factors are of great importance.The ongoing research could possibly lead to future discoveries and therefore aid in the discovery of efficient management and treatment of Crohn’s disease.
