Objective To observe the clinical efficacy of opposing needling for the treatment of migraine with the symptom of hyperactivity of liver yang type and its effect on NO level in plasma of patients. Methods Atotal of 60...Objective To observe the clinical efficacy of opposing needling for the treatment of migraine with the symptom of hyperactivity of liver yang type and its effect on NO level in plasma of patients. Methods Atotal of 60 migraine patients with the symptom of hyperactivity of liver yang who met the inclusive criteria were randomly divided into a opposing needling group （group A） and a routine acupuncture group （group B） by using SPSS 15.0 software according to the registration order with 30 patients in each group. Patients in group A were treated with opposing needling. Taich6ng （太冲 LR 3）, Zhongzhu （中渚 TE 3）, ZOlfnqi （足临泣 GB 41） and QiOxu （丘墟 GB 40） in the uninjured side were selected. After deqi, reducing method was used. Then Taixi （太溪 KI 3） in the uninjured side was selected. After deqi, rein forcing method was used. Needles were retained for 30 rain. Patients in group B were treated with routine acupuncture. Local Ash point, Sishncong （ 四神聪EX-HN1）, Yifeng （翳风 TE 17）, Fengchi （风池 GB 20）, Sizhukong （丝竹空 TE 23）, Shuaigu （率谷GB 8）, Hegu （合谷 LI 4） and LiEque （列缺 LU 7） were selected. After puncturing, reducing method was used routinely and needles were retained for 30 rain. After 2 weeks treatment, migraine specific quality of life questionnaire （MSQ）, visual analogue scale （VAS） and nitric oxide （NO） level in plasma of patients in two groups were observed. Results After treatment, the MSQ, VAS and NO of two groups were significantly improved compared with those before treatment. After treatment, score of MSQ functional limitation was 73.41±10.22 in group A and 60.95 ± 10.15 in group B; the score of MSQ dysfunction was 86.11 ±8.22 in group A and 75.45±8.34 in group B; score of MSQ emotion was 80.51±10.16 in group A and 75.01± 10.20 in group B. The improvements of group A were superior to those of group B, and the differences were all statistically significant （all P〈0.05）. After treatment, the VAS score was 0.93 ± 1.25 in group A and 2.17± 1.70 in group B. The improvement of group A was superior to that of group B, and the difference was statistically significant （P〈0.05）. After treatment, blood plasma NO level was （42.15 ± 16.15） μmol/L in group A and （62.76±15.17） μmol/L in group B. The improvement of group A was superior to that of group B, and the difference was statistically significant （P〈0.05）. Overall response rate was 86.7% （26/30） in group A and 53.3% （16/30） in group B, and the difference between two groups was statistically significant （P〈0.05）. Conclusion Opposing needling is an effective method for the treatment of migraine with the symptom of hyperactivity of liver yong. Its mechanism is to regulate the generation of NO in migraine patients, and improve the relaxation and contraction of cerebral vascular smooth muscle, so as to adjust the cerebral circulation.展开更多
This paper focuses on the usage of the forward-facing cavity and opposing jet combinatorial configuration as the thermal protection system （TPS） for hypersonic vehicles. A hemispherecone nose-tip with the combinator...This paper focuses on the usage of the forward-facing cavity and opposing jet combinatorial configuration as the thermal protection system （TPS） for hypersonic vehicles. A hemispherecone nose-tip with the combinatorial configuration is investigated numerically in hypersonic free stream. Some numerical results are validated by experiments. The flow field parameters, aerodynamic force and surface heat flux distribution are obtained. The influence of the opposing jet stagnation pressure on cooling efficiency of the combinatorial TPS is discussed. The detailed numerical results show that the aerodynamic heating is reduced remarkably by the combinatorial system. The recirculation region plays a pivotal role for the reduction of heat flux. The larger the stagnation pressure of opposing jet is, the more the heating reduction is. This kind of combinatorial system is suitable to be the TPS for the high-speed vehicles which need long-range and long time flight.展开更多
Implementation of an opposing jet in design of a hypersonic blunt body significantly modifies the external flowfield and yields a considerable reduction in the aerodynamic drag.This study aims to investigate the effec...Implementation of an opposing jet in design of a hypersonic blunt body significantly modifies the external flowfield and yields a considerable reduction in the aerodynamic drag.This study aims to investigate the effects of flowfield modeling parameters of injection and freestream on the flow structure and aerodynamics of a blunt body with an opposing jet in hypersonic flow.Reynolds-Averaged Navier-Stokes(RANS)equations with a Shear Stress Transport(SST)turbulence model are employed to simulate the intricate jet flow interaction.Through utilizing a Non-Intrusive Polynomial Chaos(NIPC)method to construct surrogates,a functional relation is established between input modeling parameters and output flowfield and aerodynamic quantities in concern.Sobol indices in sensitivity analysis are introduced to represent the relative contribution of each parameter.It is found that variations in modeling parameters produce large variations in the flow structure and aerodynamics.The jet-to-freestream total-pressure ratio,jet Mach number,and freestream Mach number are the major contributors to variation in surface pressure,demonstrating an evident location-dependent behavior.The penetration length of injection,reattachment angle of the shear layer,and aerodynamic drag are also most sensitive to the three crucial parameters above.In comparison,the contributions of freestream temperature,freestream density,and jet total temperature are nearly negligible.展开更多
In this paper, a Non-Ablative Thermal Protection System(NATPS) with the spiked body and the opposing jet combined configuration is proposed to reduce the aerodynamic heating of the hypersonic vehicle, and the coupled ...In this paper, a Non-Ablative Thermal Protection System(NATPS) with the spiked body and the opposing jet combined configuration is proposed to reduce the aerodynamic heating of the hypersonic vehicle, and the coupled fluid-thermal numerical analysis is performed to study the thermal control performance of the NATPS. The results show that the spiked body pushes the bow shock away from the protected structure and thus reduces the shock intensity and the wall heat flux. In addition, the low temperature gas of the opposing jet separates the high temperature gas behind the shock from the nose cone of the spiked body, ensuring the non-ablative property of the spiked body. Therefore, the NATPS reduces the aerodynamic heating by the reconfiguration of the flow field, and the thermal control efficiency of the system is better than the Thermal Protection System(TPS) with the single spiked body and the single opposing jet. The influencing factors of the NATPS are analyzed. Both increasing the length of the spiked body and reducing the total temperature of the opposing jet can improve the thermal control performance of the NATPS and the nonablative property of the spiked body. However, increasing the heat conductivity coefficient of the spiked body can enhance benefit the non-ablative property of the spiked body, but has little influence on the thermal control performance of the NATPS.展开更多
The three-dimensional Navier Stokes equation and the k-ε viscous model are used to simulate the attack angle characteristics of a hemisphere nose-tip with an opposing jet thermal protection system in supersonic flow ...The three-dimensional Navier Stokes equation and the k-ε viscous model are used to simulate the attack angle characteristics of a hemisphere nose-tip with an opposing jet thermal protection system in supersonic flow conditions. The numerical method is validated by the relevant experiment. The flow field parameters, aerodynamic forces, and surface heat flux distributions for attack angles of 0°, 2°, 5°, 7°, and 10° are obtained. The detailed numerical results show that the cruise attack angle has a great influence on the flow field parameters, aerodynamic force, and surface heat flux distribution of the supersonic vehicle nose-tip with an opposing jet thermal protection system. When the attack angle reaches 10°, the heat flux on the windward generatrix is close to the maximal heat flux on the wall surface of the nose-tip without thermal protection system, thus the thermal protection has failed.展开更多
Experimental and numerical studies are carried out to validate the potential of opposing Plasma Synthetic Jet(PSJ)for drag reduction for a hemisphere.Firstly,flow field changes of opposing PSJ are analyzed by comparin...Experimental and numerical studies are carried out to validate the potential of opposing Plasma Synthetic Jet(PSJ)for drag reduction for a hemisphere.Firstly,flow field changes of opposing PSJ are analyzed by comparing the experimental schlieren images and simulation results in a supersonic free stream of Mach number 3.As PSJ is a kind of unsteady pulsed jet,the shock standoff distance increases initially and then decreases under the control of PSJ,which corresponds to the change of the strength of PSJ.Accordingly,the amount of drag reduction of the hemisphere increases initially and then decreases.It is found that there is a short period of“drag rise”during the formation of PSJ before the drag reduction,which is induced by the generation of normal shock waves and the area difference of the cavity wall of PSJ Actuator(PSJA).Secondly,the effects of five parameters,including exit diameter,discharge energy of PSJA,Mach number,static pressure of incoming flow and angle of attack,on drag reduction of opposing PSJ were studied in detail by using numerical method.It is found that the Maximum Pressure Ratio(MPR)has a significant impact on the average drag reduction for a configuration-determined PSJA.For the configuration selected in this study,the flow field of opposing PSJ shows typical Short Penetration Mode(SPM)in a control cycle of PSJ when the MPR is less than 0.89.However,the flow field shows typical Long Penetration Mode(LPM)at some time when the MPR is bigger than 0.89.Relatively better drag reduction is achieved in this case.展开更多
Flying condition with angle of attack is inevitable in a hypersonic vehicle,and it may influence the thermal protection system(TPS)performance of opposing jet and its combinations.A 3D Navier–Stokes equation and shea...Flying condition with angle of attack is inevitable in a hypersonic vehicle,and it may influence the thermal protection system(TPS)performance of opposing jet and its combinations.A 3D Navier–Stokes equation and shear stress transfer(SST)k-ωmodel with compressible correction are employed to simulate the angle of attack characteristics of a blunt body with opposing jet and platelet transpiration TPS.The flowfield and heat flux transfer for angles of attack 0°,3°,6°with jet pressure ratio PR=0.1 and 0°,6°,12°with PR=0.2 are obtained.Numerical results show that the flowfield is no longer symmetrical with the effect of the angle of attack.The flowfield and heat transfer in windward and leeward performed adversely.The recompression shock wave in windward is strengthened,which increases local temperature and strengthens heat transfer.The opposing jet fails in thermal protection when the angle of attack reaches critical value;however,the critical angle of attack can be promoted by increasing PR.Finally,the transpiration gas can strengthen the cooling efficiency of windward,thereby,increasing the critical angle of attack.展开更多
The relationship between the opposing left-turn conflict and the traffic participants was analyzed in this study. Based on the traffic conflict technology, the image data were collected in a real traffic situation. Th...The relationship between the opposing left-turn conflict and the traffic participants was analyzed in this study. Based on the traffic conflict technology, the image data were collected in a real traffic situation. The relationship was investigated under two different conditions. The number of opposing left-turn conflicts was positively correlated with the number of left-turn vehicles while the ratio of left-turn vehicles to opposing vehicles was less than 1, and showed a positive correlation with the number of opposing-through vehicles when the ratio of left-turn vehicles to opposing vehi- cles was more than 1. In other words, the opposing left-turn risk was positively correlated with the number of the minor traffic participants, which had a negative effect on the whole traffic system op- eration.展开更多
198 cases of cerebral infarction diagnosed clinically.by means of CT scan wereselected, and the therapeutic effects obtained with the methods of opposing and non-opposing needlingwere compared, The primary points incl...198 cases of cerebral infarction diagnosed clinically.by means of CT scan wereselected, and the therapeutic effects obtained with the methods of opposing and non-opposing needlingwere compared, The primary points included Head-Linqi(GB 15) and Zhengying(GB 17) (penetra-tion needling), Fengchi(GB 20), Neiguan (PC 6), qnd Yinlingquan (SP 9). While the supplemen-tary points were Jiquan (HT 1 ), Xiaohai (SI 8), Huantiao (GB 30), Yinmen (BL 37), Sanyinjiao(SP 6), and Taixi (KI 3). It was found that the radical cure rate in the group treated with opposingneedling was 57%, while that in the group with non-opposipg needling was 34%. The difference oftherapeutic effects between the two groups was of statistical significance (P【0.01 ). It indicates thatopposing needling is superior to non-opposing needling in elevating cure rates and reducing sequelae.展开更多
The opposing jet technique has the potential to provide superior aerothermal protection for long-term high-speed flight in the atmosphere.However,the single-hole opposing jet has certain limitations,including a high r...The opposing jet technique has the potential to provide superior aerothermal protection for long-term high-speed flight in the atmosphere.However,the single-hole opposing jet has certain limitations,including a high requirement for jet injection pressure and inadequate maneuverability.To overcome this,a novel multi-hole opposing jet concept has been proposed,comprising a primary hole located at the stagnation point and multiple secondary holes located downstream.The findings indicated that a secondary hole positioned inside the primary jet recirculation vortex can inhibit primary jet flow reattachment and mitigate peak reattachment heat flux.A smaller secondary hole could impede the lift-off effect of the downstream vortex,facilitating efficient heat reduction at various jet injection pressures.The side-by-side and staggered multi-hole opposing jet configurations were established,which demonstrated an efficacy in reducing the peak heat flux by 11.7%statistically compared to a single-hole injection at the same mass flow rate.When an incoming angle of attack was presented,the multi-lhole arrangement exhibited a flurther peak heat flux reduction of 12.2%by statistical analysis.The results underscore the effectiveness of multi-hole configurations with low-pressure injection in reducing heat and enhancing maneuverability,while demonstrating stronger engineering applicability than traditional combined thermal protection systems without structural compromises or flow instability risks.展开更多
Opposed multi-burner(OMB)gasification technology is the first large-scale gasification technology developed in China with completely independent intellectual property rights.It has been widely used around the world,in...Opposed multi-burner(OMB)gasification technology is the first large-scale gasification technology developed in China with completely independent intellectual property rights.It has been widely used around the world,involving synthetic ammonia,methanol,ethylene glycol,coal liquefaction,hydrogen production and other fields.This paper summarizes the research and development process of OMB gasification technology from the perspective of the cold model experiment and process simulation,pilotscale study and industrial demonstration.The latest progress of fundamental research in nozzle atomization and dispersion,mixing enhancement of impinging flow,multiscale reaction of different carbonaceous feedstocks,spectral characteristic of impinging flame and particle characteristics inside gasifier,and comprehensive gasification model are reviewed.The latest industrial application progress of ultralarge-scale OMB gasifier and radiant syngas cooler(RSC)combined with quenching chamber OMB gasifier are introduced,and the prospects for the future technical development are proposed as well.展开更多
基金Supported by Traditional Chinese Medicine Bureau of Guangdong Province,project number:20141240
文摘Objective To observe the clinical efficacy of opposing needling for the treatment of migraine with the symptom of hyperactivity of liver yang type and its effect on NO level in plasma of patients. Methods Atotal of 60 migraine patients with the symptom of hyperactivity of liver yang who met the inclusive criteria were randomly divided into a opposing needling group （group A） and a routine acupuncture group （group B） by using SPSS 15.0 software according to the registration order with 30 patients in each group. Patients in group A were treated with opposing needling. Taich6ng （太冲 LR 3）, Zhongzhu （中渚 TE 3）, ZOlfnqi （足临泣 GB 41） and QiOxu （丘墟 GB 40） in the uninjured side were selected. After deqi, reducing method was used. Then Taixi （太溪 KI 3） in the uninjured side was selected. After deqi, rein forcing method was used. Needles were retained for 30 rain. Patients in group B were treated with routine acupuncture. Local Ash point, Sishncong （ 四神聪EX-HN1）, Yifeng （翳风 TE 17）, Fengchi （风池 GB 20）, Sizhukong （丝竹空 TE 23）, Shuaigu （率谷GB 8）, Hegu （合谷 LI 4） and LiEque （列缺 LU 7） were selected. After puncturing, reducing method was used routinely and needles were retained for 30 rain. After 2 weeks treatment, migraine specific quality of life questionnaire （MSQ）, visual analogue scale （VAS） and nitric oxide （NO） level in plasma of patients in two groups were observed. Results After treatment, the MSQ, VAS and NO of two groups were significantly improved compared with those before treatment. After treatment, score of MSQ functional limitation was 73.41±10.22 in group A and 60.95 ± 10.15 in group B; the score of MSQ dysfunction was 86.11 ±8.22 in group A and 75.45±8.34 in group B; score of MSQ emotion was 80.51±10.16 in group A and 75.01± 10.20 in group B. The improvements of group A were superior to those of group B, and the differences were all statistically significant （all P〈0.05）. After treatment, the VAS score was 0.93 ± 1.25 in group A and 2.17± 1.70 in group B. The improvement of group A was superior to that of group B, and the difference was statistically significant （P〈0.05）. After treatment, blood plasma NO level was （42.15 ± 16.15） μmol/L in group A and （62.76±15.17） μmol/L in group B. The improvement of group A was superior to that of group B, and the difference was statistically significant （P〈0.05）. Overall response rate was 86.7% （26/30） in group A and 53.3% （16/30） in group B, and the difference between two groups was statistically significant （P〈0.05）. Conclusion Opposing needling is an effective method for the treatment of migraine with the symptom of hyperactivity of liver yong. Its mechanism is to regulate the generation of NO in migraine patients, and improve the relaxation and contraction of cerebral vascular smooth muscle, so as to adjust the cerebral circulation.
基金co-supported by National Natural Science Foundation of China (No. 90916018)Research Fund for the Doctoral Program of Higher Education of China (No.200899980006)
文摘This paper focuses on the usage of the forward-facing cavity and opposing jet combinatorial configuration as the thermal protection system （TPS） for hypersonic vehicles. A hemispherecone nose-tip with the combinatorial configuration is investigated numerically in hypersonic free stream. Some numerical results are validated by experiments. The flow field parameters, aerodynamic force and surface heat flux distribution are obtained. The influence of the opposing jet stagnation pressure on cooling efficiency of the combinatorial TPS is discussed. The detailed numerical results show that the aerodynamic heating is reduced remarkably by the combinatorial system. The recirculation region plays a pivotal role for the reduction of heat flux. The larger the stagnation pressure of opposing jet is, the more the heating reduction is. This kind of combinatorial system is suitable to be the TPS for the high-speed vehicles which need long-range and long time flight.
文摘Implementation of an opposing jet in design of a hypersonic blunt body significantly modifies the external flowfield and yields a considerable reduction in the aerodynamic drag.This study aims to investigate the effects of flowfield modeling parameters of injection and freestream on the flow structure and aerodynamics of a blunt body with an opposing jet in hypersonic flow.Reynolds-Averaged Navier-Stokes(RANS)equations with a Shear Stress Transport(SST)turbulence model are employed to simulate the intricate jet flow interaction.Through utilizing a Non-Intrusive Polynomial Chaos(NIPC)method to construct surrogates,a functional relation is established between input modeling parameters and output flowfield and aerodynamic quantities in concern.Sobol indices in sensitivity analysis are introduced to represent the relative contribution of each parameter.It is found that variations in modeling parameters produce large variations in the flow structure and aerodynamics.The jet-to-freestream total-pressure ratio,jet Mach number,and freestream Mach number are the major contributors to variation in surface pressure,demonstrating an evident location-dependent behavior.The penetration length of injection,reattachment angle of the shear layer,and aerodynamic drag are also most sensitive to the three crucial parameters above.In comparison,the contributions of freestream temperature,freestream density,and jet total temperature are nearly negligible.
基金supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘In this paper, a Non-Ablative Thermal Protection System(NATPS) with the spiked body and the opposing jet combined configuration is proposed to reduce the aerodynamic heating of the hypersonic vehicle, and the coupled fluid-thermal numerical analysis is performed to study the thermal control performance of the NATPS. The results show that the spiked body pushes the bow shock away from the protected structure and thus reduces the shock intensity and the wall heat flux. In addition, the low temperature gas of the opposing jet separates the high temperature gas behind the shock from the nose cone of the spiked body, ensuring the non-ablative property of the spiked body. Therefore, the NATPS reduces the aerodynamic heating by the reconfiguration of the flow field, and the thermal control efficiency of the system is better than the Thermal Protection System(TPS) with the single spiked body and the single opposing jet. The influencing factors of the NATPS are analyzed. Both increasing the length of the spiked body and reducing the total temperature of the opposing jet can improve the thermal control performance of the NATPS and the nonablative property of the spiked body. However, increasing the heat conductivity coefficient of the spiked body can enhance benefit the non-ablative property of the spiked body, but has little influence on the thermal control performance of the NATPS.
基金Project supported by the National Natural Science Foundation of China (Grant No. 90916018)the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 200899980006)the Natural Science Foundation of Hunan Province,China(Grant No. 09JJ3109)
文摘The three-dimensional Navier Stokes equation and the k-ε viscous model are used to simulate the attack angle characteristics of a hemisphere nose-tip with an opposing jet thermal protection system in supersonic flow conditions. The numerical method is validated by the relevant experiment. The flow field parameters, aerodynamic forces, and surface heat flux distributions for attack angles of 0°, 2°, 5°, 7°, and 10° are obtained. The detailed numerical results show that the cruise attack angle has a great influence on the flow field parameters, aerodynamic force, and surface heat flux distribution of the supersonic vehicle nose-tip with an opposing jet thermal protection system. When the attack angle reaches 10°, the heat flux on the windward generatrix is close to the maximal heat flux on the wall surface of the nose-tip without thermal protection system, thus the thermal protection has failed.
基金co-supported by the National Natural Science Foundation of China(Nos.52075538,12002377,11872374)the Natural Science Foundation of Hunan Province,China(Nos.2020JJ5670,2020JJ2031)+1 种基金the research program of National University of Defense Technology(No.ZK18-03-11)China Postdoctoral Science Foundation(No.2019M652754)。
文摘Experimental and numerical studies are carried out to validate the potential of opposing Plasma Synthetic Jet(PSJ)for drag reduction for a hemisphere.Firstly,flow field changes of opposing PSJ are analyzed by comparing the experimental schlieren images and simulation results in a supersonic free stream of Mach number 3.As PSJ is a kind of unsteady pulsed jet,the shock standoff distance increases initially and then decreases under the control of PSJ,which corresponds to the change of the strength of PSJ.Accordingly,the amount of drag reduction of the hemisphere increases initially and then decreases.It is found that there is a short period of“drag rise”during the formation of PSJ before the drag reduction,which is induced by the generation of normal shock waves and the area difference of the cavity wall of PSJ Actuator(PSJA).Secondly,the effects of five parameters,including exit diameter,discharge energy of PSJA,Mach number,static pressure of incoming flow and angle of attack,on drag reduction of opposing PSJ were studied in detail by using numerical method.It is found that the Maximum Pressure Ratio(MPR)has a significant impact on the average drag reduction for a configuration-determined PSJA.For the configuration selected in this study,the flow field of opposing PSJ shows typical Short Penetration Mode(SPM)in a control cycle of PSJ when the MPR is less than 0.89.However,the flow field shows typical Long Penetration Mode(LPM)at some time when the MPR is bigger than 0.89.Relatively better drag reduction is achieved in this case.
文摘Flying condition with angle of attack is inevitable in a hypersonic vehicle,and it may influence the thermal protection system(TPS)performance of opposing jet and its combinations.A 3D Navier–Stokes equation and shear stress transfer(SST)k-ωmodel with compressible correction are employed to simulate the angle of attack characteristics of a blunt body with opposing jet and platelet transpiration TPS.The flowfield and heat flux transfer for angles of attack 0°,3°,6°with jet pressure ratio PR=0.1 and 0°,6°,12°with PR=0.2 are obtained.Numerical results show that the flowfield is no longer symmetrical with the effect of the angle of attack.The flowfield and heat transfer in windward and leeward performed adversely.The recompression shock wave in windward is strengthened,which increases local temperature and strengthens heat transfer.The opposing jet fails in thermal protection when the angle of attack reaches critical value;however,the critical angle of attack can be promoted by increasing PR.Finally,the transpiration gas can strengthen the cooling efficiency of windward,thereby,increasing the critical angle of attack.
基金Supported by the Programme of Introducing Talents of Discipline to Universities (B12022)
文摘The relationship between the opposing left-turn conflict and the traffic participants was analyzed in this study. Based on the traffic conflict technology, the image data were collected in a real traffic situation. The relationship was investigated under two different conditions. The number of opposing left-turn conflicts was positively correlated with the number of left-turn vehicles while the ratio of left-turn vehicles to opposing vehicles was less than 1, and showed a positive correlation with the number of opposing-through vehicles when the ratio of left-turn vehicles to opposing vehi- cles was more than 1. In other words, the opposing left-turn risk was positively correlated with the number of the minor traffic participants, which had a negative effect on the whole traffic system op- eration.
文摘198 cases of cerebral infarction diagnosed clinically.by means of CT scan wereselected, and the therapeutic effects obtained with the methods of opposing and non-opposing needlingwere compared, The primary points included Head-Linqi(GB 15) and Zhengying(GB 17) (penetra-tion needling), Fengchi(GB 20), Neiguan (PC 6), qnd Yinlingquan (SP 9). While the supplemen-tary points were Jiquan (HT 1 ), Xiaohai (SI 8), Huantiao (GB 30), Yinmen (BL 37), Sanyinjiao(SP 6), and Taixi (KI 3). It was found that the radical cure rate in the group treated with opposingneedling was 57%, while that in the group with non-opposipg needling was 34%. The difference oftherapeutic effects between the two groups was of statistical significance (P【0.01 ). It indicates thatopposing needling is superior to non-opposing needling in elevating cure rates and reducing sequelae.
基金supported by Tsinghua University Initiative Scientific Research Program。
文摘The opposing jet technique has the potential to provide superior aerothermal protection for long-term high-speed flight in the atmosphere.However,the single-hole opposing jet has certain limitations,including a high requirement for jet injection pressure and inadequate maneuverability.To overcome this,a novel multi-hole opposing jet concept has been proposed,comprising a primary hole located at the stagnation point and multiple secondary holes located downstream.The findings indicated that a secondary hole positioned inside the primary jet recirculation vortex can inhibit primary jet flow reattachment and mitigate peak reattachment heat flux.A smaller secondary hole could impede the lift-off effect of the downstream vortex,facilitating efficient heat reduction at various jet injection pressures.The side-by-side and staggered multi-hole opposing jet configurations were established,which demonstrated an efficacy in reducing the peak heat flux by 11.7%statistically compared to a single-hole injection at the same mass flow rate.When an incoming angle of attack was presented,the multi-lhole arrangement exhibited a flurther peak heat flux reduction of 12.2%by statistical analysis.The results underscore the effectiveness of multi-hole configurations with low-pressure injection in reducing heat and enhancing maneuverability,while demonstrating stronger engineering applicability than traditional combined thermal protection systems without structural compromises or flow instability risks.
基金supported by the National Natural Science Foundation of China(21776086,21761132034)。
文摘Opposed multi-burner(OMB)gasification technology is the first large-scale gasification technology developed in China with completely independent intellectual property rights.It has been widely used around the world,involving synthetic ammonia,methanol,ethylene glycol,coal liquefaction,hydrogen production and other fields.This paper summarizes the research and development process of OMB gasification technology from the perspective of the cold model experiment and process simulation,pilotscale study and industrial demonstration.The latest progress of fundamental research in nozzle atomization and dispersion,mixing enhancement of impinging flow,multiscale reaction of different carbonaceous feedstocks,spectral characteristic of impinging flame and particle characteristics inside gasifier,and comprehensive gasification model are reviewed.The latest industrial application progress of ultralarge-scale OMB gasifier and radiant syngas cooler(RSC)combined with quenching chamber OMB gasifier are introduced,and the prospects for the future technical development are proposed as well.
