Radon observation is an important measurement item of seismic precursor network observation.The radon detector calibration is a key technical link for ensuring radon observation accuracy.At present,the radon detector ...Radon observation is an important measurement item of seismic precursor network observation.The radon detector calibration is a key technical link for ensuring radon observation accuracy.At present,the radon detector calibration in seismic systems in China is faced with a series of bottleneck problems,such as aging and scrap,acquisition difficulties,high supervision costs,and transportation limitations of radon sources.As a result,a large number of radon detectors cannot be accurately calibrated regularly,seriously affecting the accuracy and reliability of radon observation data in China.To solve this problem,a new calibration method for radon detectors was established.The advantage of this method is that the dangerous radioactive substance,i.e.,the radon source,can be avoided,but only“standard instruments”and water samples with certain dissolved radon concentrations can be used to realize radon detector calibration.This method avoids the risk of radioactive leakage and solves the current widespread difficulties and bottleneck of radon detector calibration in seismic systems in China.The comparison experiment with the traditional calibration method shows that the error of the calibration coefficient obtained by the new method is less than 5%compared with that by the traditional method,which meets the requirements of seismic observation systems,confirming the reliability of the new method.This new method can completely replace the traditional calibration method of using a radon source in seismic systems.展开更多
Carbonaceous materials in seismic fault zones may considerably influence seismic fault slip;however,the formation mechanism of carbonaceous materials remains unclear.In this study,we proposed a novel hypothesis for th...Carbonaceous materials in seismic fault zones may considerably influence seismic fault slip;however,the formation mechanism of carbonaceous materials remains unclear.In this study,we proposed a novel hypothesis for the formation of carbonaceous materials in fault gouge.Thus,we conducted a CO_(2) hydrogenation experiment in a high-temperature reactor at a co-seismic temperature,with fault gouge formed during the Wenchuan earthquake as the catalyst.Our experimental results demonstrate that carbonaceous materials in fault zones are formed on the fault gouge during the chemical reaction process,suggesting that the carbonaceous materials are possibly generated from the catalytic hydrogenation of CO_(2),followed by thermal cracking of its products.The results of this study provide a theoretical basis for understanding fault behavior and earthquake physics.展开更多
Heat waves associated with global warming and extreme climates would arouse serious consequences on nitrogen(N)cycle.However,the responses of the functional guilds to different temperatures,especially high temperature...Heat waves associated with global warming and extreme climates would arouse serious consequences on nitrogen(N)cycle.However,the responses of the functional guilds to different temperatures,especially high temperature and the cascading effect on N_(2)O emissions remain unclear.An incubation study was conducted to examine the effect of different temperatures(20°C,30°C,and 40°C)and fertilizer types(urea and manure)on N_(2)O-producers and N_(2)O-reducers,as well as the efficacy of dicyandiamide(DCD)on N_(2)O emissions in a vegetable soil.Results showed that ammonia oxidizers and nirS-type denitrifiers were well adapted to high temperature(40°C)with manure application,while the fungal nirK-denitrifiers had better tolerance with urea application.The nosZ clade I microbes had a strong adaptability to various temperatures regardless of fertilization type,while the growth of nosZ clade II group microbes in non-fertilized soil(control)were significantly inhibited at higher temperature.The N_(2)O emissions were significantly decreased with increasing temperature and DCD application(up to 60%,even at 40°C).Under high temperature conditions,fungal denitrifiers play a significant role in N-limited soils(non-fertilized)while nirS-type denitrifiers was more important in fertilized soils in N_(2)O emissions,which should be specially targeted when mitigating N_(2)O emissions under global warming climate.展开更多
Conversion of major ginsenosides into minor ginsenosides improves its pharmacological effects.This study managed to convert major ginsenosides into minor ginsenoside Rg3 and compound K(CK)by optimizing acidolysis cond...Conversion of major ginsenosides into minor ginsenosides improves its pharmacological effects.This study managed to convert major ginsenosides into minor ginsenoside Rg3 and compound K(CK)by optimizing acidolysis conditions(pH,incubation temperatures and time)and evaluated the effects of the whey protein isolate(WPI)/Tween 80 ratio on the physicochemical properties of ginsenoside nanoemulsions.The optimal conditions for acidolysis are incubation at 110℃ for 3 h at a pH of 2.0,whereafter the yield of ginsenoside Rg3 and CK was 2.16 mg/g and 2.80 mg/g,respectively.For the ginsenoside nanoemulsions with 0.5%WPI as emulsifier,as Tween 80 increased from 0.1%to 0.5%,the mean droplet diameter gradually decreased from~740 nm to~310 nm.Accordingly,the encapsulation efficiency of Rg3 and CK increased by 8.36%and 9.03%,respectively,and the centrifugal stability constant increased by 49.82%.These results showed that nanoemulsion prepared with 0.5%WPI and 0.5%Tween 80 exhibited higher encapsulation efficiency and physicochemical stability.In addition,ginsenoside nanoemulsion prepared with 0.5%WPI and 0.5%Tween 80 showed great industrial applicability during freeze-thaw cycles,heat treatments and storage.Generally,the incorporation of Tween 80 as a co-emulsifier improved the encapsulation efficiency and physicochemical stability of WPI-stabilized ginsenoside nanoemulsions,which may improve its bioaccessibility,by stabilizing ginsenoside emulsions during further processing,such as during thermal pasteurization and microencapsulation.展开更多
基金supported by the National Natural Science Foundation of China Study on the Key Technology of Non-radium Source Radon Chamber(No.42274235).
文摘Radon observation is an important measurement item of seismic precursor network observation.The radon detector calibration is a key technical link for ensuring radon observation accuracy.At present,the radon detector calibration in seismic systems in China is faced with a series of bottleneck problems,such as aging and scrap,acquisition difficulties,high supervision costs,and transportation limitations of radon sources.As a result,a large number of radon detectors cannot be accurately calibrated regularly,seriously affecting the accuracy and reliability of radon observation data in China.To solve this problem,a new calibration method for radon detectors was established.The advantage of this method is that the dangerous radioactive substance,i.e.,the radon source,can be avoided,but only“standard instruments”and water samples with certain dissolved radon concentrations can be used to realize radon detector calibration.This method avoids the risk of radioactive leakage and solves the current widespread difficulties and bottleneck of radon detector calibration in seismic systems in China.The comparison experiment with the traditional calibration method shows that the error of the calibration coefficient obtained by the new method is less than 5%compared with that by the traditional method,which meets the requirements of seismic observation systems,confirming the reliability of the new method.This new method can completely replace the traditional calibration method of using a radon source in seismic systems.
文摘Carbonaceous materials in seismic fault zones may considerably influence seismic fault slip;however,the formation mechanism of carbonaceous materials remains unclear.In this study,we proposed a novel hypothesis for the formation of carbonaceous materials in fault gouge.Thus,we conducted a CO_(2) hydrogenation experiment in a high-temperature reactor at a co-seismic temperature,with fault gouge formed during the Wenchuan earthquake as the catalyst.Our experimental results demonstrate that carbonaceous materials in fault zones are formed on the fault gouge during the chemical reaction process,suggesting that the carbonaceous materials are possibly generated from the catalytic hydrogenation of CO_(2),followed by thermal cracking of its products.The results of this study provide a theoretical basis for understanding fault behavior and earthquake physics.
基金funded by the National Key Research and Development Program of China(2022YFD1900602)Provincial Key Research and Development Program of Zhejiang(2022C02046)+2 种基金Zhejiang Provincial Natural Science Foundation of China(LR23D010002)the National Natural Science Foundation of China(42107316)the Natural Science Foundation of Shandong Province(ZR202102260221).
文摘Heat waves associated with global warming and extreme climates would arouse serious consequences on nitrogen(N)cycle.However,the responses of the functional guilds to different temperatures,especially high temperature and the cascading effect on N_(2)O emissions remain unclear.An incubation study was conducted to examine the effect of different temperatures(20°C,30°C,and 40°C)and fertilizer types(urea and manure)on N_(2)O-producers and N_(2)O-reducers,as well as the efficacy of dicyandiamide(DCD)on N_(2)O emissions in a vegetable soil.Results showed that ammonia oxidizers and nirS-type denitrifiers were well adapted to high temperature(40°C)with manure application,while the fungal nirK-denitrifiers had better tolerance with urea application.The nosZ clade I microbes had a strong adaptability to various temperatures regardless of fertilization type,while the growth of nosZ clade II group microbes in non-fertilized soil(control)were significantly inhibited at higher temperature.The N_(2)O emissions were significantly decreased with increasing temperature and DCD application(up to 60%,even at 40°C).Under high temperature conditions,fungal denitrifiers play a significant role in N-limited soils(non-fertilized)while nirS-type denitrifiers was more important in fertilized soils in N_(2)O emissions,which should be specially targeted when mitigating N_(2)O emissions under global warming climate.
基金supported by the National Natural Science Foundation of China(No.32101864)the Natural Science Foundation of Jiangsu Province(BK20210457)Standard Foods(China)Co.,Ltd.
文摘Conversion of major ginsenosides into minor ginsenosides improves its pharmacological effects.This study managed to convert major ginsenosides into minor ginsenoside Rg3 and compound K(CK)by optimizing acidolysis conditions(pH,incubation temperatures and time)and evaluated the effects of the whey protein isolate(WPI)/Tween 80 ratio on the physicochemical properties of ginsenoside nanoemulsions.The optimal conditions for acidolysis are incubation at 110℃ for 3 h at a pH of 2.0,whereafter the yield of ginsenoside Rg3 and CK was 2.16 mg/g and 2.80 mg/g,respectively.For the ginsenoside nanoemulsions with 0.5%WPI as emulsifier,as Tween 80 increased from 0.1%to 0.5%,the mean droplet diameter gradually decreased from~740 nm to~310 nm.Accordingly,the encapsulation efficiency of Rg3 and CK increased by 8.36%and 9.03%,respectively,and the centrifugal stability constant increased by 49.82%.These results showed that nanoemulsion prepared with 0.5%WPI and 0.5%Tween 80 exhibited higher encapsulation efficiency and physicochemical stability.In addition,ginsenoside nanoemulsion prepared with 0.5%WPI and 0.5%Tween 80 showed great industrial applicability during freeze-thaw cycles,heat treatments and storage.Generally,the incorporation of Tween 80 as a co-emulsifier improved the encapsulation efficiency and physicochemical stability of WPI-stabilized ginsenoside nanoemulsions,which may improve its bioaccessibility,by stabilizing ginsenoside emulsions during further processing,such as during thermal pasteurization and microencapsulation.
