Solution and quenching heat treatments are generally carried out in a roller hearth furnace for large-scale thick aluminum alloy plates.However,the asymmetric or uneven spray water flow rate is inevitable under indust...Solution and quenching heat treatments are generally carried out in a roller hearth furnace for large-scale thick aluminum alloy plates.However,the asymmetric or uneven spray water flow rate is inevitable under industrial production conditions,which leads to an asymmetric residual stress distribution.The spray quenching treatment was conducted on self-designed spray equipment,and the residual stress along the thickness direction was measured by a layer removal method based on deflections.Under the asymmetric spray quenching condition,the subsurface stress of the high-flow rate surface was lower than that of the low-flow rate surface,and the difference between the two subsurface stresses increased with the increase in the difference in water flow rates.The subsurface stress underneath the surface with a water flow rate of 0.60 m^(3)/h was 15.38 MPa less than that of 0.15 m^(3)/h.The simulated residual stress by finite element(FE)method of the high heat transfer coefficient(HTC)surface was less than that of the low HTC surface,which is consistent with the experimental results.The FE model can be used to analyze the strain and stress evolution and predict the quenched stress magnitude and distribution.展开更多
[Objectives] To optimize the ethyl acetate impurity removal method for extracting and isolating mangiferin from mango leaves,and provide raw materials and technical support for development and use of mangiferin relate...[Objectives] To optimize the ethyl acetate impurity removal method for extracting and isolating mangiferin from mango leaves,and provide raw materials and technical support for development and use of mangiferin related products. [Methods]Five steps( material crushing→ ethyl acetate impurity removing → concentrated extract washing → extracting with methanol → crystallization and precipitation) were used.The single factor experiment and L9( 34) orthogonal experiment was carried out to optimize the process parameters including extraction time,ultrasonic power,extraction times,and extraction temperature.[Results] The optimum process of ethyl acetate impurity removal method for extracting and isolating mangiferin from mango leaves was as follows: the mango leaves were crushed and sieved; 3 m L/g of ethyl acetate was added,sealed and soaked for 4 h,ultrasonically shaken for 20 min( 50℃,350 W),filtered at room temperature,filtered with 100 mesh sieve,and extracted three times; added 100% methanol to the residue at 3 m L/g,extract by ultrasonic vibration for 20 min( 350 W,55℃)for four times,filtered with 100 mesh sieve when it was still hot; mixed the extract of each time,condensed by vacuum decompression to get the extract; added 100% methanol at 4 m L/g,mixed and washed for 5 min at room temperature,placed for 10 min,filtered with 100 mesh sieve,washed 3 times repeatedly,and dried the filter residue at 60℃ to obtain the crude mangiferin; added 100% methanol at 4 m L/g,mixed and washed at 50℃ for 5 min,placed at 6℃ for 8 h,dried the filter residue at 60℃,and repeatedly crystallized two times. According to the above process,crude and pure mangiferin products could be obtained,the purity of mangiferin of the crude product was higher than 64. 00%,the total recovery rate was 83. 90%,and the purity of mangiferin of the pure product was higher than 98. 00%,and the total recovery rate was about 66. 40%. [Conclusions] The optimized ethyl acetate impurity removal method is easy in operation,low in cost,and high in efficiency for extracting and isolating mangiferin,and can be applied for actual production of mangiferin.展开更多
A new velocity determination algorithm with combination of remove and restore method, outliers detection method and Chebyshev fitting method with redundant observations is proposed. An optimal selection of number of s...A new velocity determination algorithm with combination of remove and restore method, outliers detection method and Chebyshev fitting method with redundant observations is proposed. An optimal selection of number of sampling points is given. The result shows that, when the number of sampling points is 19, the three-dimension (3D) interpolation precision of velocity is superior to 0.1 mm/s, which is above 3 times better than that of Chebyshev fitting method with redundant observations and far better than those of the conventional interpolation methods.展开更多
According to autopsy reports,patients who died from COVID-19 had a lot of mucus in the lung that obstructed the airways,reduced the effect of mechanical ventilation,and even led to pulmonary failure.Traditional Chines...According to autopsy reports,patients who died from COVID-19 had a lot of mucus in the lung that obstructed the airways,reduced the effect of mechanical ventilation,and even led to pulmonary failure.Traditional Chinese medicine literature mentions that"Inability to remove phlegm impair s the lung,which leads to death."Hence one of the most urgent problems to be solved is to remove phlegm from the small airways.This article elaborates ten methods to remove phlegm for clinical reference.展开更多
According to autopsy reports,patients who died from COVID‑19 had a lot of mucus in the lung that obstructed the airways,reduced the effect of mechanical ventilation,and even led to pulmonary failure.Traditional Chines...According to autopsy reports,patients who died from COVID‑19 had a lot of mucus in the lung that obstructed the airways,reduced the effect of mechanical ventilation,and even led to pulmonary failure.Traditional Chinese medicine literature mentions that“Inability to remove phlegm impairs the lung,which leads to death.”Hence one of the most urgent problems to be solved is to remove phlegm from the small airways.This article elaborates ten methods to remove phlegm for clinical reference.展开更多
According to the original works of an ancient Chinese medicine book"Treatise on Spleen and Stomach"(Detailed Analysis of Spleen and Stomach Diseases;1249 C.E.)written by Li Dongyuan(1180-1251 C.E),and relate...According to the original works of an ancient Chinese medicine book"Treatise on Spleen and Stomach"(Detailed Analysis of Spleen and Stomach Diseases;1249 C.E.)written by Li Dongyuan(1180-1251 C.E),and related explanations of later physicians,the efficacy and application of Ginseng(Ginseng Radix et Rhizoma)in related prescriptions were investigated from the aspects of dosage,usage and treatment methods.Ginseng appeared in 27 named prescriptions,including 20 decoctions,4 pill and 3 powder.In terms of dosage and usage,the common dosage of Ginseng is five points,mainly decoction.Most of the processing methods are"Fuju"(Bite up the medicine with your mouth so it can be taken.)and decoction with water.In terms of treatment methods,Ginseng is used in the sweet temperature and heat removing method and Nourishes Qi and Eliminates Evils Method(build your body to cure disease)in Li Dongyuan's"Treatise on Spleen and Stomach".Explaining Sweet Temperature Heat Removal Method(Use sweet and warm medicines to treat Qi-deficiency fever or Blood-deficiency fever;there are many reasons for fever,and cold and cooling medicines with heat-clearing effect are generally used for treatment.Use bitter cold medicine,so as not to consume the body's Yang.)takes Buzhong Yiqi Decoction(BYD)as an example,and explaining the Nourishes Qi and Eliminates Evils Method takes Mahuang-renshen-shaoyao decoction as an example.At the same time,"Treatise on Spleen and Stomach"matured in the Jin and Yuan Dynasties(1115-1368 C.E.).Its system of weights and measures,terminology and medical theory are quite different from those of modern Chinese medicine.Therefore,when researching the dosage,usage and treatment methods of Ginseng,we will explore the controversial points,and explain them by using modern Chinese medicine theory,so as to guide the clinical medication more accurately.展开更多
Based on the field hyperspectral data from the analytical spectral devices (ASD) spectrometer, we characterized the spectral properties of rice canopies infested with brown spot disease and selected spectral regions...Based on the field hyperspectral data from the analytical spectral devices (ASD) spectrometer, we characterized the spectral properties of rice canopies infested with brown spot disease and selected spectral regions and bands sensitive to four severity degrees (severe, moderate, light, and healthy). The results show that the curves' variation on the original and the first- and second-order de- rivative curves are greatly different, but the spectral difference in the near-infrared region is the most obvious for each level. Specifically, the peaks are located at 822, 738, and 793 nm, while the valleys are located at 402, 570, and 753 run, respectively. The sensitive regions are between 430-520, 530-550, and 650-710 nm, and the bands are 498, 539, and 673 nm in the sensitivity analysis, while they are in the ranges of 401-530, 550-730 as well as at 498 nm and 678 nm in the continuum removal.展开更多
基金financially supported by the National Key Research and Development Program of China(No.2020YFF0218200)。
文摘Solution and quenching heat treatments are generally carried out in a roller hearth furnace for large-scale thick aluminum alloy plates.However,the asymmetric or uneven spray water flow rate is inevitable under industrial production conditions,which leads to an asymmetric residual stress distribution.The spray quenching treatment was conducted on self-designed spray equipment,and the residual stress along the thickness direction was measured by a layer removal method based on deflections.Under the asymmetric spray quenching condition,the subsurface stress of the high-flow rate surface was lower than that of the low-flow rate surface,and the difference between the two subsurface stresses increased with the increase in the difference in water flow rates.The subsurface stress underneath the surface with a water flow rate of 0.60 m^(3)/h was 15.38 MPa less than that of 0.15 m^(3)/h.The simulated residual stress by finite element(FE)method of the high heat transfer coefficient(HTC)surface was less than that of the low HTC surface,which is consistent with the experimental results.The FE model can be used to analyze the strain and stress evolution and predict the quenched stress magnitude and distribution.
基金Supported by Key Technological Innovation Project of Sichuan Province,China(2016XM120)
文摘[Objectives] To optimize the ethyl acetate impurity removal method for extracting and isolating mangiferin from mango leaves,and provide raw materials and technical support for development and use of mangiferin related products. [Methods]Five steps( material crushing→ ethyl acetate impurity removing → concentrated extract washing → extracting with methanol → crystallization and precipitation) were used.The single factor experiment and L9( 34) orthogonal experiment was carried out to optimize the process parameters including extraction time,ultrasonic power,extraction times,and extraction temperature.[Results] The optimum process of ethyl acetate impurity removal method for extracting and isolating mangiferin from mango leaves was as follows: the mango leaves were crushed and sieved; 3 m L/g of ethyl acetate was added,sealed and soaked for 4 h,ultrasonically shaken for 20 min( 50℃,350 W),filtered at room temperature,filtered with 100 mesh sieve,and extracted three times; added 100% methanol to the residue at 3 m L/g,extract by ultrasonic vibration for 20 min( 350 W,55℃)for four times,filtered with 100 mesh sieve when it was still hot; mixed the extract of each time,condensed by vacuum decompression to get the extract; added 100% methanol at 4 m L/g,mixed and washed for 5 min at room temperature,placed for 10 min,filtered with 100 mesh sieve,washed 3 times repeatedly,and dried the filter residue at 60℃ to obtain the crude mangiferin; added 100% methanol at 4 m L/g,mixed and washed at 50℃ for 5 min,placed at 6℃ for 8 h,dried the filter residue at 60℃,and repeatedly crystallized two times. According to the above process,crude and pure mangiferin products could be obtained,the purity of mangiferin of the crude product was higher than 64. 00%,the total recovery rate was 83. 90%,and the purity of mangiferin of the pure product was higher than 98. 00%,and the total recovery rate was about 66. 40%. [Conclusions] The optimized ethyl acetate impurity removal method is easy in operation,low in cost,and high in efficiency for extracting and isolating mangiferin,and can be applied for actual production of mangiferin.
基金supported by the National Natural Science Foundation of China(41174008)the Open Foundation of State Key Laboratory of Geodesy and Earth’s Dynamics(SKLGED2013-4-2-EZ)the Foundation for the Author of National Excellent Doctoral Dissertation of China(2007B51)
文摘A new velocity determination algorithm with combination of remove and restore method, outliers detection method and Chebyshev fitting method with redundant observations is proposed. An optimal selection of number of sampling points is given. The result shows that, when the number of sampling points is 19, the three-dimension (3D) interpolation precision of velocity is superior to 0.1 mm/s, which is above 3 times better than that of Chebyshev fitting method with redundant observations and far better than those of the conventional interpolation methods.
文摘According to autopsy reports,patients who died from COVID-19 had a lot of mucus in the lung that obstructed the airways,reduced the effect of mechanical ventilation,and even led to pulmonary failure.Traditional Chinese medicine literature mentions that"Inability to remove phlegm impair s the lung,which leads to death."Hence one of the most urgent problems to be solved is to remove phlegm from the small airways.This article elaborates ten methods to remove phlegm for clinical reference.
文摘According to autopsy reports,patients who died from COVID‑19 had a lot of mucus in the lung that obstructed the airways,reduced the effect of mechanical ventilation,and even led to pulmonary failure.Traditional Chinese medicine literature mentions that“Inability to remove phlegm impairs the lung,which leads to death.”Hence one of the most urgent problems to be solved is to remove phlegm from the small airways.This article elaborates ten methods to remove phlegm for clinical reference.
文摘According to the original works of an ancient Chinese medicine book"Treatise on Spleen and Stomach"(Detailed Analysis of Spleen and Stomach Diseases;1249 C.E.)written by Li Dongyuan(1180-1251 C.E),and related explanations of later physicians,the efficacy and application of Ginseng(Ginseng Radix et Rhizoma)in related prescriptions were investigated from the aspects of dosage,usage and treatment methods.Ginseng appeared in 27 named prescriptions,including 20 decoctions,4 pill and 3 powder.In terms of dosage and usage,the common dosage of Ginseng is five points,mainly decoction.Most of the processing methods are"Fuju"(Bite up the medicine with your mouth so it can be taken.)and decoction with water.In terms of treatment methods,Ginseng is used in the sweet temperature and heat removing method and Nourishes Qi and Eliminates Evils Method(build your body to cure disease)in Li Dongyuan's"Treatise on Spleen and Stomach".Explaining Sweet Temperature Heat Removal Method(Use sweet and warm medicines to treat Qi-deficiency fever or Blood-deficiency fever;there are many reasons for fever,and cold and cooling medicines with heat-clearing effect are generally used for treatment.Use bitter cold medicine,so as not to consume the body's Yang.)takes Buzhong Yiqi Decoction(BYD)as an example,and explaining the Nourishes Qi and Eliminates Evils Method takes Mahuang-renshen-shaoyao decoction as an example.At the same time,"Treatise on Spleen and Stomach"matured in the Jin and Yuan Dynasties(1115-1368 C.E.).Its system of weights and measures,terminology and medical theory are quite different from those of modern Chinese medicine.Therefore,when researching the dosage,usage and treatment methods of Ginseng,we will explore the controversial points,and explain them by using modern Chinese medicine theory,so as to guide the clinical medication more accurately.
基金Supported by the National Natural Science Foundation of China (41071276 and 41101395)China Postdoctoral Science Foundation (20110490317)Postdoctoral Science Foundation of Beijing Academy of Agriculture and Forestry Sciences (2011)
文摘Based on the field hyperspectral data from the analytical spectral devices (ASD) spectrometer, we characterized the spectral properties of rice canopies infested with brown spot disease and selected spectral regions and bands sensitive to four severity degrees (severe, moderate, light, and healthy). The results show that the curves' variation on the original and the first- and second-order de- rivative curves are greatly different, but the spectral difference in the near-infrared region is the most obvious for each level. Specifically, the peaks are located at 822, 738, and 793 nm, while the valleys are located at 402, 570, and 753 run, respectively. The sensitive regions are between 430-520, 530-550, and 650-710 nm, and the bands are 498, 539, and 673 nm in the sensitivity analysis, while they are in the ranges of 401-530, 550-730 as well as at 498 nm and 678 nm in the continuum removal.