[Objective] The aim of this study was to find a better method to exactly quantify the residual polycyclic aromatic hydrocarbons(PAHs)in the long-term contaminated soil in the field so as to provide basis for the rem...[Objective] The aim of this study was to find a better method to exactly quantify the residual polycyclic aromatic hydrocarbons(PAHs)in the long-term contaminated soil in the field so as to provide basis for the remediation for PAHs contaminated soil.[Method]The comparisons of soxhlet extraction,ultrasonic extraction and shaking extraction were studied in the agricultural soil irrigated with oil sewage over a long period of time.[Result]The total PAHs extracted by soxhlet extraction were the highest(6 873.7 μg/kg),followed by shaking extraction(6 698.8 μg/kg)and ultrasonic extraction(5 737.6 μg/kg).Among these methods,the highest extracted 4 and 6 rings PAHs were in the soxhlet extraction,the highest extracted 2 and 5 rings PAHs were in the shaking extraction,and the highest extracted 3 rings PAHs were in the ultrasonic extraction.[Conclusion]This study had provided basis for the selection of the assessment method of residual PAHs in the field soil.展开更多
[ Objective] The aim was to establish the method of extracting genomic DNA from sheep blood clot on the basis of the improvement of method for extracting genomic DNA from tissues. [Method]The genomic DNA with complete...[ Objective] The aim was to establish the method of extracting genomic DNA from sheep blood clot on the basis of the improvement of method for extracting genomic DNA from tissues. [Method]The genomic DNA with complete primary structure and high purity was obtained from the sheep blood clot after the steps of cutting the sheep blood clot with ophthalmic scissors, cell lysis with tissue DNA extracts and digested by proteinase K, extracting with phenol/chloroform and precipitating with ethanol were performed. [ Result] The concentration of the extracted DNA was 159.90 ±0.70 ng/μl and the ratio of the A260/A280 was 1.80 +0.01. The sheep microsatellite locus of BM203 was amplified by using the extracted DNA from the sheep blood clot as template of PCR, and the PCR result was perfect. [Conclusion]This method is simple and feasible, the quantity and quality of the extracted DNA can satisfy the demands for the subsequent researches. It is worth to extending and using for reference.展开更多
[Objective] The aim was to study the flavonoid content of Fagopyrum megaspartanium leaves by water bath and ultrasonic extractions.[Method] By using water bath extraction and ultrasonic extraction,the total flavonoid ...[Objective] The aim was to study the flavonoid content of Fagopyrum megaspartanium leaves by water bath and ultrasonic extractions.[Method] By using water bath extraction and ultrasonic extraction,the total flavonoid content in buckwheat leaves was measured with UV spectrophotometer.[Result] The optimum wavelength for determination of the content of flavonoid extracted from buckwheat leaves was 420 nm;the content of total flavonoid extracted by ultrasonic extraction and water bath extraction from buckwheat were 5.26% and 5.40% respectively;and the average total flavonoid content by water bath extraction was significantly higher than that by ultrasonic extraction.[Conclusion] The result is significant for the improvement of flavonoid content measurement of buckwheat.展开更多
[Objective] The extraction efficiency of soluble nitrogen in common moun- tain red soil under different conditions was analyzed to provide experimental refer- ences for the extraction of soil soluble nitrogen. [Method...[Objective] The extraction efficiency of soluble nitrogen in common moun- tain red soil under different conditions was analyzed to provide experimental refer- ences for the extraction of soil soluble nitrogen. [Method] The fresh soil and air-dried soil, which were the common mountain red soil under evergreen broad-leaved forest vegetation, were used as the experimental materials. The 2 mol/L KCI and 0.5 mol/L K2SO4 were used as the extractants to extract the soil soluble nitrogen with the extractant-to-soil volume ratio at 4:1, 6:1 and 10:1, respectively, to examine the extrac- tion efficiency of soluble nitrogen in the experimental soil with different extraction conditions. [Result] Compared with K2SO4, the NH4+-N extracted by KCI was better in quantity and stability; while only at high extractant-to-soil volume ratio could K2SO4 fully extract the soil NH4+-N. The 2 extractants showed small difference in extracting NO3--N, but at low extractant-to-soil volume ratio, the stability of NO3--N extracted by KCI was higher than that extracted by K2SO4. The properties of NO2- -N extracted by the 2 extractants were very similar. As for soil SON extraction, there was small dif- ference between the 2 extractants. However, the SON extracted by KCI was fewer in quantity than that by K2SO4, but had higher stability, and the extracted SON amount of the 2 extractants showed significant correlation. The extractant-to-soil ratio had little effect on MBN extraction using K2SO4, but the effect was significant when using KCI to extract MBN. The difference between the extraction efficiency of KCI and K^SO4 in extracting fresh soils was greater than that in extracting air-dried soil; therefore, the extractants should be carefully selected in soluble nitrogen extraction from fresh soil. [Conclusion] The results lay the experimental foundation for improving the extraction efficiency of soil soluble nitrogen and increasing the comparability of measurement results.展开更多
For calibrating the laser plane to implement 3D shape measurement, an algorithm for extracting the laser stripe with sub-pixel accuracy is proposed. The proposed algorithm mainly consists of two stages: two-side edge...For calibrating the laser plane to implement 3D shape measurement, an algorithm for extracting the laser stripe with sub-pixel accuracy is proposed. The proposed algorithm mainly consists of two stages: two-side edge detection and center line extraction. First, the two-side edge of laser stripe is detected using the principal component angle-based progressive probabilistic Hough transform and its width is calculated through the distance between these two edges. Secondly, the center line of laser strip is extracted with 2D Taylor expansion at a sub-pixel level and the laser plane is calibrated with the 3D reconstructed coordinates from the extracted 2D sub-pixel ones. Experimental results demonstrate that the proposed method can not only extract the laser stripe at a high speed, nearly average 78 ms/frame, but also calibrate the coplanar laser stripes at a low error, limited to 0.3 mm. The proposed algorithm can satisfy the system requirement of two-side edge detection and center line extraction, and rapid speed, high precision, as well as strong anti-jamming.展开更多
This paper reports the rationale and methods of DNA extraction and purification from nine species of Compositae and four commercial drugs of corresponding plant Elephantopus scaber. The comparison of three methods: Cs...This paper reports the rationale and methods of DNA extraction and purification from nine species of Compositae and four commercial drugs of corresponding plant Elephantopus scaber. The comparison of three methods: CsCl gradient, CTAB/CsCl gradient and CTAB miniprep extraction by yield, purity and factors affecting PCR was carried out. In conclusion, CTAB miniprep method provides a rapid, effective, economic approach for isolating genomic DNA for Chinese drug identification by genomic fingerprints.展开更多
[Objective] This paper aims to study a new method of extracting pumpkin polysaccharide from pumpkin. Single factor experiments were conducted to examine the effects of extracting time,temperature,the solid-liquid rati...[Objective] This paper aims to study a new method of extracting pumpkin polysaccharide from pumpkin. Single factor experiments were conducted to examine the effects of extracting time,temperature,the solid-liquid ratio and pH value on the extraction yield of polysaccharide from pumpkin. [Method] The best enzyme ratio and extraction conditions for complex enzymes extraction were determined through orthogonal tests. Scavenging ·OH and O-2 activities of pumpkin polysaccharides were also investigated by salicylic acid and improved self-oxidation of o-pheno methods respectively. [Results] The results showed that the biggest extraction yield of polysaccharide from pumpkin can be got when adding 1% cellulose enzyme,1.5% pectinase,1.0% papain and Na2HPO4-citric acid buffer solution (pH was 4.6),and oscillating for 30 min under water at 40 ℃ with the solid-liquid ratio of 1:30. In addition,pumpkin polysaccharides had a strong activity of eliminating ·OH,but very weak activity to scavenge O-2. [Conclusion] This study provided basic data for research and application of Pumpkin polysaccharide.展开更多
The study employed ERP technique to explore whether the affordance derivation can facilitate semantic access in comprehending Chinese puns. ERPs were measured while participants read the pun sentences containing dual ...The study employed ERP technique to explore whether the affordance derivation can facilitate semantic access in comprehending Chinese puns. ERPs were measured while participants read the pun sentences containing dual meanings and made a judgement about the following probes and statements. The results showed that highly related probes in pun sentences elicited a smaller N400 and a larger LPC than moderately related probes in pun sentences. As for the comparison of sentence types, both highly and moderately related probes in pun sentences produce a smaller N400 and a larger LPC than those in control sentences. These results indicate that in the early stage of pun comprehension, semantic access to the literal meaning is easier through affordance derivation because of meaning dominance and frequency. In the late stage of integration, however,the intended meaning of puns can be facilitated and accessed through its privilege of affordance derivation activated by pun words in a pun context because of the priming context and its underlying intention. The study has discovered empirically that it is the affordance derivation,which connects the context and the dual meanings indicated by the pun words, that contributes to the different time courses and dynamic underlying neurocognitive mechanisms in comprehending puns in Chinese.展开更多
With the rapid development of the machining and manufacturing industry,welding has been widely used in forming connections of structural parts.At present,manual methods are often used for welding and quality inspectio...With the rapid development of the machining and manufacturing industry,welding has been widely used in forming connections of structural parts.At present,manual methods are often used for welding and quality inspection,with low efficiency and unstable product quality.Due to the requirements of visual inspection of weld feature size,a visual inspection system for weld feature size based on line structured light(LSL)is designed and built in this paper.An adaptive light stripe sub-pixel center extraction algorithm and a feature point extraction algorithm for welding light stripe are proposed.The experiment results show that the detection error of the weld width is 0.216 mm,the detection error of the remaining height is 0.035 mm,the single measurement costs 109 ms,and the inspection stability and repeatability of the system is 1%.Our approach can meet the online detection requirements of practical applications.展开更多
[ Objective] To optimize the ultrasonic-assisted extraction process of chlorogenic acid from sunflower meal. [ Method] Based on the sin-gle-factor test, the extraction factors of ethanol concentration, extraction temp...[ Objective] To optimize the ultrasonic-assisted extraction process of chlorogenic acid from sunflower meal. [ Method] Based on the sin-gle-factor test, the extraction factors of ethanol concentration, extraction temperature and extraction time were optimized using the response surface methodology with the extraction rate of chlorogenic acid as the response value. [ Result] The optimum extraction conditions of chlorogenic acid from sunflower meal were 57% of ethanol concentration, 39 min of extraction time, 53 ~C of extraction temperature, 100 W of ultrasonic power, 1 : 14 ( g/ ml) of solid-liquid ratio and one time of extraction. Under these conditions, the extraction rate of chlorogenic acid was 2.25%. [ Conclusion] Ultra-sonic assisted extraction method has high extraction rate but short time, the study provides a theoretical basis for the industrialized production of chlorogenic acid in sunflower meal.展开更多
method of extracting astaxanthin from Phaffia rhodozyma with various solvents after acid washing was investigated. The extraction efficiency was distinctly increased after acid washing of P. rhodozyma cells. When the ...method of extracting astaxanthin from Phaffia rhodozyma with various solvents after acid washing was investigated. The extraction efficiency was distinctly increased after acid washing of P. rhodozyma cells. When the concentration of HCl was 0.4 mol.L^-1, the highest extraction efficiency of astaxanthin was achieved which was about three times higher than the control. Acetone or benzene as single polar or non-polar solvent was the most ef- fective solvent in our research. With a combination of isopropanol and n-hexane (volume ratio of 2 : 1), the maxi- mal extraction efficiency was achieved, approximately 60% higher than that obtained with a single solvent. The liquid-solid ratio and the extracting time were also optimized. Under the optimum extraction conditions, the extraction yield of astaxanthin exceeded 98%.展开更多
[Objective] The aim was to study the optimum extraction process of polysaccharide from chrysanthemum.[Method] By dint of orthogonal and single-factor experiments,the influences of microwave efficiency,extraction time,...[Objective] The aim was to study the optimum extraction process of polysaccharide from chrysanthemum.[Method] By dint of orthogonal and single-factor experiments,the influences of microwave efficiency,extraction time,and liquid ratio on the extraction rate of polysaccharides from chrysanthemum were studied.The optimum operation condition by microwave extraction method was determined and was compared with that by traditional extraction method.[Result] The optimum extraction conditions were:800 W,1:15(solid-liquid ratio),and 15 min.The polysaccharides extraction yield under such optimum condition was 5.59%.The extraction yield of impregnation was generally about 2.73%.[Conclusion] Compared with the traditional extraction method,the microwave extraction was simple,convenient,energy saving,and efficient,and was suitable for industrial extraction of polysaccharide.展开更多
The visual inspection is an economical and effective method for welding. For measuring the feature sizes of grooves,a method based on line structured light is presented. Firstly,an adaptive algorithm to extract the su...The visual inspection is an economical and effective method for welding. For measuring the feature sizes of grooves,a method based on line structured light is presented. Firstly,an adaptive algorithm to extract the subpixel centerline of structured light stripes is introduced to deal with the uneven width and grayscale distributions of laser stripes,which is based on the quadratic weighted grayscale centroid. By means of region-of-interest(ROI)division and image difference,an image preprocessing algorithm is developed for filtering noise and improving image quality. Furthermore,to acquire geometrical dimensions of various grooves and groove types precisely,the subpixel feature point extraction algorithm of grooves is designed. Finally, experimental results of feature size measuring show that the absolute error of measurement is 0.031—0.176 mm,and the relative error of measurement is 0.2%—3.6%.展开更多
[ Objective ] To optimize the ultrasonic extraction technology of cottonseed oil by response surface methodology. [ Method ] Based on the single factor experiment, the response surface method with three factors at thr...[ Objective ] To optimize the ultrasonic extraction technology of cottonseed oil by response surface methodology. [ Method ] Based on the single factor experiment, the response surface method with three factors at three levels was adopted according to the principle of central composite design, The optimum extraction conditions of extraction duration, liquid-solid ratio and temperature were determined by regression analysis. [ Re- salt] The best ultrasonic extraction conditions of cottonseed oil were 35 min of extraction duration, 38 ℃ of extraction temperature and 56:6 of liquid-solid ratio. Under these conditions, the extraction rate of cottonseed oil could reach up to 45.81%, with a relative error of 0.13% from the theoreti-cal value of 45.94%. [ Conclusion] The method optimized the extraction technology and laid foundation for the further research of cottonseed oil. Key words Cottonseed oil; Ultrasonic extraction; Response surface method; China展开更多
基金Supported by Important Direction Project of Knowledge Innovation Program in Chinese Academy of Science(KZCX2-YW-446)~~
文摘[Objective] The aim of this study was to find a better method to exactly quantify the residual polycyclic aromatic hydrocarbons(PAHs)in the long-term contaminated soil in the field so as to provide basis for the remediation for PAHs contaminated soil.[Method]The comparisons of soxhlet extraction,ultrasonic extraction and shaking extraction were studied in the agricultural soil irrigated with oil sewage over a long period of time.[Result]The total PAHs extracted by soxhlet extraction were the highest(6 873.7 μg/kg),followed by shaking extraction(6 698.8 μg/kg)and ultrasonic extraction(5 737.6 μg/kg).Among these methods,the highest extracted 4 and 6 rings PAHs were in the soxhlet extraction,the highest extracted 2 and 5 rings PAHs were in the shaking extraction,and the highest extracted 3 rings PAHs were in the ultrasonic extraction.[Conclusion]This study had provided basis for the selection of the assessment method of residual PAHs in the field soil.
基金Supported by Natural Science Foundation of Shanxi Province(2007011081 )Returning Brains Project in Shanxi Province(2007066 )Agricultural Science and Technology Achievement Transformation Fund Project(2008GB2A300032)~~
文摘[ Objective] The aim was to establish the method of extracting genomic DNA from sheep blood clot on the basis of the improvement of method for extracting genomic DNA from tissues. [Method]The genomic DNA with complete primary structure and high purity was obtained from the sheep blood clot after the steps of cutting the sheep blood clot with ophthalmic scissors, cell lysis with tissue DNA extracts and digested by proteinase K, extracting with phenol/chloroform and precipitating with ethanol were performed. [ Result] The concentration of the extracted DNA was 159.90 ±0.70 ng/μl and the ratio of the A260/A280 was 1.80 +0.01. The sheep microsatellite locus of BM203 was amplified by using the extracted DNA from the sheep blood clot as template of PCR, and the PCR result was perfect. [Conclusion]This method is simple and feasible, the quantity and quality of the extracted DNA can satisfy the demands for the subsequent researches. It is worth to extending and using for reference.
基金Supported by National Key Technology Research and Development Program(2006BAD02B06)National Natural Science Foundation of China(31060207)+1 种基金Agricultural Research Project of Guizhou Province[NY(2010)3094]Special Program of Plant and Animal Breeding of Guizhou Province[No.(2010)023]~~
文摘[Objective] The aim was to study the flavonoid content of Fagopyrum megaspartanium leaves by water bath and ultrasonic extractions.[Method] By using water bath extraction and ultrasonic extraction,the total flavonoid content in buckwheat leaves was measured with UV spectrophotometer.[Result] The optimum wavelength for determination of the content of flavonoid extracted from buckwheat leaves was 420 nm;the content of total flavonoid extracted by ultrasonic extraction and water bath extraction from buckwheat were 5.26% and 5.40% respectively;and the average total flavonoid content by water bath extraction was significantly higher than that by ultrasonic extraction.[Conclusion] The result is significant for the improvement of flavonoid content measurement of buckwheat.
基金Supported by the National Natural Science Foundation of China (40901115,31070548,31170578)the Foundation of Fujian Province (2009J01207)~~
文摘[Objective] The extraction efficiency of soluble nitrogen in common moun- tain red soil under different conditions was analyzed to provide experimental refer- ences for the extraction of soil soluble nitrogen. [Method] The fresh soil and air-dried soil, which were the common mountain red soil under evergreen broad-leaved forest vegetation, were used as the experimental materials. The 2 mol/L KCI and 0.5 mol/L K2SO4 were used as the extractants to extract the soil soluble nitrogen with the extractant-to-soil volume ratio at 4:1, 6:1 and 10:1, respectively, to examine the extrac- tion efficiency of soluble nitrogen in the experimental soil with different extraction conditions. [Result] Compared with K2SO4, the NH4+-N extracted by KCI was better in quantity and stability; while only at high extractant-to-soil volume ratio could K2SO4 fully extract the soil NH4+-N. The 2 extractants showed small difference in extracting NO3--N, but at low extractant-to-soil volume ratio, the stability of NO3--N extracted by KCI was higher than that extracted by K2SO4. The properties of NO2- -N extracted by the 2 extractants were very similar. As for soil SON extraction, there was small dif- ference between the 2 extractants. However, the SON extracted by KCI was fewer in quantity than that by K2SO4, but had higher stability, and the extracted SON amount of the 2 extractants showed significant correlation. The extractant-to-soil ratio had little effect on MBN extraction using K2SO4, but the effect was significant when using KCI to extract MBN. The difference between the extraction efficiency of KCI and K^SO4 in extracting fresh soils was greater than that in extracting air-dried soil; therefore, the extractants should be carefully selected in soluble nitrogen extraction from fresh soil. [Conclusion] The results lay the experimental foundation for improving the extraction efficiency of soil soluble nitrogen and increasing the comparability of measurement results.
基金The National Natural Science Foundation of China(No.50805023)the Science and Technology Support Program of Jiangsu Province(No.BE2008081)+1 种基金the Research and Innovation Project for College Graduates of Jiangsu Province(No.CXZZ13_0086)Scientific Research Foundation of Graduate School of Southeast University(No.YBJJ1401)
文摘For calibrating the laser plane to implement 3D shape measurement, an algorithm for extracting the laser stripe with sub-pixel accuracy is proposed. The proposed algorithm mainly consists of two stages: two-side edge detection and center line extraction. First, the two-side edge of laser stripe is detected using the principal component angle-based progressive probabilistic Hough transform and its width is calculated through the distance between these two edges. Secondly, the center line of laser strip is extracted with 2D Taylor expansion at a sub-pixel level and the laser plane is calibrated with the 3D reconstructed coordinates from the extracted 2D sub-pixel ones. Experimental results demonstrate that the proposed method can not only extract the laser stripe at a high speed, nearly average 78 ms/frame, but also calibrate the coplanar laser stripes at a low error, limited to 0.3 mm. The proposed algorithm can satisfy the system requirement of two-side edge detection and center line extraction, and rapid speed, high precision, as well as strong anti-jamming.
文摘This paper reports the rationale and methods of DNA extraction and purification from nine species of Compositae and four commercial drugs of corresponding plant Elephantopus scaber. The comparison of three methods: CsCl gradient, CTAB/CsCl gradient and CTAB miniprep extraction by yield, purity and factors affecting PCR was carried out. In conclusion, CTAB miniprep method provides a rapid, effective, economic approach for isolating genomic DNA for Chinese drug identification by genomic fingerprints.
基金Supported by the Key Scientific and Technological Project of Henan Province (102102110157)the Scientific Research Found Project of Henan University of Urban Construction (2010JZD008)~~
文摘[Objective] This paper aims to study a new method of extracting pumpkin polysaccharide from pumpkin. Single factor experiments were conducted to examine the effects of extracting time,temperature,the solid-liquid ratio and pH value on the extraction yield of polysaccharide from pumpkin. [Method] The best enzyme ratio and extraction conditions for complex enzymes extraction were determined through orthogonal tests. Scavenging ·OH and O-2 activities of pumpkin polysaccharides were also investigated by salicylic acid and improved self-oxidation of o-pheno methods respectively. [Results] The results showed that the biggest extraction yield of polysaccharide from pumpkin can be got when adding 1% cellulose enzyme,1.5% pectinase,1.0% papain and Na2HPO4-citric acid buffer solution (pH was 4.6),and oscillating for 30 min under water at 40 ℃ with the solid-liquid ratio of 1:30. In addition,pumpkin polysaccharides had a strong activity of eliminating ·OH,but very weak activity to scavenge O-2. [Conclusion] This study provided basic data for research and application of Pumpkin polysaccharide.
基金supported by the Key Program of the National Social Science Foundation of China (Grant No. 19AYY011)the Major Scientific Program of Shanghai International Studies University (Grant No. 2018114027)。
文摘The study employed ERP technique to explore whether the affordance derivation can facilitate semantic access in comprehending Chinese puns. ERPs were measured while participants read the pun sentences containing dual meanings and made a judgement about the following probes and statements. The results showed that highly related probes in pun sentences elicited a smaller N400 and a larger LPC than moderately related probes in pun sentences. As for the comparison of sentence types, both highly and moderately related probes in pun sentences produce a smaller N400 and a larger LPC than those in control sentences. These results indicate that in the early stage of pun comprehension, semantic access to the literal meaning is easier through affordance derivation because of meaning dominance and frequency. In the late stage of integration, however,the intended meaning of puns can be facilitated and accessed through its privilege of affordance derivation activated by pun words in a pun context because of the priming context and its underlying intention. The study has discovered empirically that it is the affordance derivation,which connects the context and the dual meanings indicated by the pun words, that contributes to the different time courses and dynamic underlying neurocognitive mechanisms in comprehending puns in Chinese.
基金supported by the National Natural Science Foundation of China(No. 51975293)the Aeronautical Science Foundation of China(No. 2019ZD052010)
文摘With the rapid development of the machining and manufacturing industry,welding has been widely used in forming connections of structural parts.At present,manual methods are often used for welding and quality inspection,with low efficiency and unstable product quality.Due to the requirements of visual inspection of weld feature size,a visual inspection system for weld feature size based on line structured light(LSL)is designed and built in this paper.An adaptive light stripe sub-pixel center extraction algorithm and a feature point extraction algorithm for welding light stripe are proposed.The experiment results show that the detection error of the weld width is 0.216 mm,the detection error of the remaining height is 0.035 mm,the single measurement costs 109 ms,and the inspection stability and repeatability of the system is 1%.Our approach can meet the online detection requirements of practical applications.
基金Supported by the Science and Technology Program of Jilin Education Department during the"Eleventh-Five Year Plan" (Jilin[2010]No.206)
文摘[ Objective] To optimize the ultrasonic-assisted extraction process of chlorogenic acid from sunflower meal. [ Method] Based on the sin-gle-factor test, the extraction factors of ethanol concentration, extraction temperature and extraction time were optimized using the response surface methodology with the extraction rate of chlorogenic acid as the response value. [ Result] The optimum extraction conditions of chlorogenic acid from sunflower meal were 57% of ethanol concentration, 39 min of extraction time, 53 ~C of extraction temperature, 100 W of ultrasonic power, 1 : 14 ( g/ ml) of solid-liquid ratio and one time of extraction. Under these conditions, the extraction rate of chlorogenic acid was 2.25%. [ Conclusion] Ultra-sonic assisted extraction method has high extraction rate but short time, the study provides a theoretical basis for the industrialized production of chlorogenic acid in sunflower meal.
基金Supported by the Fundamental Research Funds for the Central Universities (FRF-AS-10-001B) and the National Natural Science Foundation of China (11071013).
文摘method of extracting astaxanthin from Phaffia rhodozyma with various solvents after acid washing was investigated. The extraction efficiency was distinctly increased after acid washing of P. rhodozyma cells. When the concentration of HCl was 0.4 mol.L^-1, the highest extraction efficiency of astaxanthin was achieved which was about three times higher than the control. Acetone or benzene as single polar or non-polar solvent was the most ef- fective solvent in our research. With a combination of isopropanol and n-hexane (volume ratio of 2 : 1), the maxi- mal extraction efficiency was achieved, approximately 60% higher than that obtained with a single solvent. The liquid-solid ratio and the extracting time were also optimized. Under the optimum extraction conditions, the extraction yield of astaxanthin exceeded 98%.
基金Supported by Doctoral Initial Funding of Henan University of TCM(BSJJ2009-34)
文摘[Objective] The aim was to study the optimum extraction process of polysaccharide from chrysanthemum.[Method] By dint of orthogonal and single-factor experiments,the influences of microwave efficiency,extraction time,and liquid ratio on the extraction rate of polysaccharides from chrysanthemum were studied.The optimum operation condition by microwave extraction method was determined and was compared with that by traditional extraction method.[Result] The optimum extraction conditions were:800 W,1:15(solid-liquid ratio),and 15 min.The polysaccharides extraction yield under such optimum condition was 5.59%.The extraction yield of impregnation was generally about 2.73%.[Conclusion] Compared with the traditional extraction method,the microwave extraction was simple,convenient,energy saving,and efficient,and was suitable for industrial extraction of polysaccharide.
基金supported by the National Natural Science Foundation of China(No. 51975293)the Aeronautical Science Foundation of China (No. 2019ZD052010)。
文摘The visual inspection is an economical and effective method for welding. For measuring the feature sizes of grooves,a method based on line structured light is presented. Firstly,an adaptive algorithm to extract the subpixel centerline of structured light stripes is introduced to deal with the uneven width and grayscale distributions of laser stripes,which is based on the quadratic weighted grayscale centroid. By means of region-of-interest(ROI)division and image difference,an image preprocessing algorithm is developed for filtering noise and improving image quality. Furthermore,to acquire geometrical dimensions of various grooves and groove types precisely,the subpixel feature point extraction algorithm of grooves is designed. Finally, experimental results of feature size measuring show that the absolute error of measurement is 0.031—0.176 mm,and the relative error of measurement is 0.2%—3.6%.
文摘[ Objective ] To optimize the ultrasonic extraction technology of cottonseed oil by response surface methodology. [ Method ] Based on the single factor experiment, the response surface method with three factors at three levels was adopted according to the principle of central composite design, The optimum extraction conditions of extraction duration, liquid-solid ratio and temperature were determined by regression analysis. [ Re- salt] The best ultrasonic extraction conditions of cottonseed oil were 35 min of extraction duration, 38 ℃ of extraction temperature and 56:6 of liquid-solid ratio. Under these conditions, the extraction rate of cottonseed oil could reach up to 45.81%, with a relative error of 0.13% from the theoreti-cal value of 45.94%. [ Conclusion] The method optimized the extraction technology and laid foundation for the further research of cottonseed oil. Key words Cottonseed oil; Ultrasonic extraction; Response surface method; China