Background:Ampelopsis grossedentata,vine tea,which is the tea alternative beverages in China.In vine tea processing,a large amount of broken tea is produced,which has low commercial value.Methods:This study investigat...Background:Ampelopsis grossedentata,vine tea,which is the tea alternative beverages in China.In vine tea processing,a large amount of broken tea is produced,which has low commercial value.Methods:This study investigates the influence of different extraction methods(room temperature water extraction,boiling water extraction,ultrasonic-assisted room temperature water extraction,and ultrasonic-assisted boiling water extraction,referred to as room temperature water extraction(RE),boiling water extraction(BE),ultrasonic assistance at room temperature water extraction(URE),and ultrasonic assistance in boiling water extraction(UBE))on the yield,dihydromyricetin(DMY)content,free amino acid composition,volatile aroma components,and antioxidant properties of vine tea extracts.Results:A notable influence of extraction temperature on the yield of vine tea extracts(P<0.05),with BE yielding the highest at 43.13±0.26%,higher than that of RE(34.29±0.81%).Ultrasound-assisted extraction significantly increased the DMY content of the extracts(P<0.05),whereas DMY content in the RE extracts was 59.94±1.70%,that of URE reached 66.14±2.78%.Analysis revealed 17 amino acids,with L-serine and aspartic acid being the most abundant in the extracts,nevertheless ultrasound-assisted extraction reduced total free amino acid content.Gas chromatography-mass spectrometry analysis demonstrated an increase in the diversity and quantity of compounds in the vine tea water extracts obtained through ultrasonic-assisted extraction.Specifically,69 and 68 volatile compounds were found in URE and UBE extracts,which were higher than the number found in RE and BE extracts.In vitro,antioxidant activity assessments revealed varying antioxidant capacities among different extraction methods,with RE exhibiting the highest DPPH scavenging rate,URE leading in ABTS•+free radical scavenging,and BE demonstrating superior ferric ion reducing antioxidant activity.Conclusion:The findings suggest that extraction methods significantly influence the chemical composition and antioxidant properties of vine tea extracts.Ultrasonic-assisted extraction proved instrumental in elevating the DMY content in vine tea extracts,thereby enriching its flavor profile while maintaining its antioxidant properties.展开更多
当前各金融行业之间的联系日益密切,风险溢出进一步增强。在这一背景下,本文构建Vine-Copula模型,刻画银行业、保险业、基金业和证券业之间的风险相依关系,将上行广义Co Va R与下行广义Co Va R置于同一结构中,进一步研究当某一行业陷入...当前各金融行业之间的联系日益密切,风险溢出进一步增强。在这一背景下,本文构建Vine-Copula模型,刻画银行业、保险业、基金业和证券业之间的风险相依关系,将上行广义Co Va R与下行广义Co Va R置于同一结构中,进一步研究当某一行业陷入风险时对其他金融行业的风险溢出效应。实证结果显示,各金融行业均存在显著的正向风险溢出效应,上行风险溢出与下行风险溢出表现出非对称性。分行业而言,证券业对其他行业的风险溢出效应最强,银行业和基金业的风险溢出效应较为平稳,而保险业的风险溢出也处于较高水平,应当重点关注证券业与保险业之间的风险溢出效应。本文研究明晰了金融行业间的风险溢出效应,有助于对我国经济“三期叠加”阶段性特征进行科学理解与准确研判,为防范与化解重大金融风险提供参考依据。展开更多
可再生能源参与电力现货市场政策制定前,需度量可再生能源的市场风险。在可再生能源未深度参与电力现货背景下,直接采用传统方法对历史数据进行风险度量不可行。文章结合可再生能源有效出力和在险模型(Value at Risk,VaR)设计了可再生...可再生能源参与电力现货市场政策制定前,需度量可再生能源的市场风险。在可再生能源未深度参与电力现货背景下,直接采用传统方法对历史数据进行风险度量不可行。文章结合可再生能源有效出力和在险模型(Value at Risk,VaR)设计了可再生能源风险度量指标,通过风险场景匹配市场和机组出力数据。针对目前国内电力现货市场数据量少的问题,结合市场主体在电力现货市场中所能获得的数据进行市场因子筛选,通过Vine-Copula函数考虑多个市场因子间的相关性;改进了传统蒙特卡罗法收敛慢的缺陷,采用拟蒙特卡罗模拟法生成市场因子数据,根据拟合的映射关系生成电价水平数据。最后,文章基于南方(以广东起步)电力现货市场结算试运行的数据和海上风电与光伏的仿真出力,对所提出的模型进行算例分析,结果显示拟蒙特卡罗法收敛性更高,能满足模型中所有风险场景高频计算风险的需求。展开更多
The study aimed to evaluate the application of silage fermentation in storing vine tea residue.Dynamic of fermentationrelated product,chemical component and bacterial community of silage with or without Lactobacillus ...The study aimed to evaluate the application of silage fermentation in storing vine tea residue.Dynamic of fermentationrelated product,chemical component and bacterial community of silage with or without Lactobacillus plantarum F1inoculant were analyzed.The results showed that F1 treatment had a significant (P<0.05) impact on the lactic acid and ammoniacal nitrogen concentrations and pH value.Total phenols were well preserved in both treatments.After 30 days of ensiling,L.plantarum occupied the majority of Lactobacillus genus (more than 95%) in all silage samples.Spearman revealed a positive (P<0.01) correlation between lactic acid content and Lactobacillus.Overall,ensiling vine tea residue with L.plantarum can effectively preserve the nutritional attributes and total phenols,which offers a new insight into utilizing vine tea residue.展开更多
Vine decline disease (VDD) constitutes a menace to melons worldwide. Especially, the one caused by the fungus Monosporascus cannonballus. Thus, resistant plant material must be released to help growers. Hence, our goa...Vine decline disease (VDD) constitutes a menace to melons worldwide. Especially, the one caused by the fungus Monosporascus cannonballus. Thus, resistant plant material must be released to help growers. Hence, our goal was to develop resistant plant material to VDD. More than 600 melon accessions are expected to be tested for disease resistance in M. cannonballus infested soil in Weslaco, Texas, USA, to identify resistance to VDD, and other important traits. So far, at most 7 lines were found to be resistant to VDD and some of them were used to develop elite, muskmelon inbred lines by pedigree breeding following single or double backcrosses. These elite parents were crossed to each other to develop the hybrids M3 and M4. They were also tested in the same infested field in Weslaco. The hybrids were grown using standard commercial practices followed by growers and when their fruits were ready, their roots were sampled as well as scored for disease severity to estimate high and mid-parent heterosis Our results indicate the existence of heterosis regarding resistance to VDD. Thus, resistant plant material can be developed and selection for resistance can be accomplished.展开更多
This paper expounded the current situation and genetic mechanisms of short-vine watermelon breeding from the aspects of material sources,breeding process and genetic characteristics of F_1,hoping to provide a theoreti...This paper expounded the current situation and genetic mechanisms of short-vine watermelon breeding from the aspects of material sources,breeding process and genetic characteristics of F_1,hoping to provide a theoretical basis for short-vine watermelon breeding,and breeding materials for watermelon planting innovation,as well as new opportunities for high-quality and high-yield watermelon.展开更多
基金supported by the Key Research and Development Program of Hunan Province of China(No.2022NK2036)Xiangxi Prefecture Science and Technology Plan Project"School-Local Integration"Special Project(No.2022001)the scientific research project of Hunan Provincial Department of Education(No.22B0520).
文摘Background:Ampelopsis grossedentata,vine tea,which is the tea alternative beverages in China.In vine tea processing,a large amount of broken tea is produced,which has low commercial value.Methods:This study investigates the influence of different extraction methods(room temperature water extraction,boiling water extraction,ultrasonic-assisted room temperature water extraction,and ultrasonic-assisted boiling water extraction,referred to as room temperature water extraction(RE),boiling water extraction(BE),ultrasonic assistance at room temperature water extraction(URE),and ultrasonic assistance in boiling water extraction(UBE))on the yield,dihydromyricetin(DMY)content,free amino acid composition,volatile aroma components,and antioxidant properties of vine tea extracts.Results:A notable influence of extraction temperature on the yield of vine tea extracts(P<0.05),with BE yielding the highest at 43.13±0.26%,higher than that of RE(34.29±0.81%).Ultrasound-assisted extraction significantly increased the DMY content of the extracts(P<0.05),whereas DMY content in the RE extracts was 59.94±1.70%,that of URE reached 66.14±2.78%.Analysis revealed 17 amino acids,with L-serine and aspartic acid being the most abundant in the extracts,nevertheless ultrasound-assisted extraction reduced total free amino acid content.Gas chromatography-mass spectrometry analysis demonstrated an increase in the diversity and quantity of compounds in the vine tea water extracts obtained through ultrasonic-assisted extraction.Specifically,69 and 68 volatile compounds were found in URE and UBE extracts,which were higher than the number found in RE and BE extracts.In vitro,antioxidant activity assessments revealed varying antioxidant capacities among different extraction methods,with RE exhibiting the highest DPPH scavenging rate,URE leading in ABTS•+free radical scavenging,and BE demonstrating superior ferric ion reducing antioxidant activity.Conclusion:The findings suggest that extraction methods significantly influence the chemical composition and antioxidant properties of vine tea extracts.Ultrasonic-assisted extraction proved instrumental in elevating the DMY content in vine tea extracts,thereby enriching its flavor profile while maintaining its antioxidant properties.
文摘当前各金融行业之间的联系日益密切,风险溢出进一步增强。在这一背景下,本文构建Vine-Copula模型,刻画银行业、保险业、基金业和证券业之间的风险相依关系,将上行广义Co Va R与下行广义Co Va R置于同一结构中,进一步研究当某一行业陷入风险时对其他金融行业的风险溢出效应。实证结果显示,各金融行业均存在显著的正向风险溢出效应,上行风险溢出与下行风险溢出表现出非对称性。分行业而言,证券业对其他行业的风险溢出效应最强,银行业和基金业的风险溢出效应较为平稳,而保险业的风险溢出也处于较高水平,应当重点关注证券业与保险业之间的风险溢出效应。本文研究明晰了金融行业间的风险溢出效应,有助于对我国经济“三期叠加”阶段性特征进行科学理解与准确研判,为防范与化解重大金融风险提供参考依据。
文摘可再生能源参与电力现货市场政策制定前,需度量可再生能源的市场风险。在可再生能源未深度参与电力现货背景下,直接采用传统方法对历史数据进行风险度量不可行。文章结合可再生能源有效出力和在险模型(Value at Risk,VaR)设计了可再生能源风险度量指标,通过风险场景匹配市场和机组出力数据。针对目前国内电力现货市场数据量少的问题,结合市场主体在电力现货市场中所能获得的数据进行市场因子筛选,通过Vine-Copula函数考虑多个市场因子间的相关性;改进了传统蒙特卡罗法收敛慢的缺陷,采用拟蒙特卡罗模拟法生成市场因子数据,根据拟合的映射关系生成电价水平数据。最后,文章基于南方(以广东起步)电力现货市场结算试运行的数据和海上风电与光伏的仿真出力,对所提出的模型进行算例分析,结果显示拟蒙特卡罗法收敛性更高,能满足模型中所有风险场景高频计算风险的需求。
基金supported by the National Natural Science Foundation of China (32001402 and 32171686)。
文摘The study aimed to evaluate the application of silage fermentation in storing vine tea residue.Dynamic of fermentationrelated product,chemical component and bacterial community of silage with or without Lactobacillus plantarum F1inoculant were analyzed.The results showed that F1 treatment had a significant (P<0.05) impact on the lactic acid and ammoniacal nitrogen concentrations and pH value.Total phenols were well preserved in both treatments.After 30 days of ensiling,L.plantarum occupied the majority of Lactobacillus genus (more than 95%) in all silage samples.Spearman revealed a positive (P<0.01) correlation between lactic acid content and Lactobacillus.Overall,ensiling vine tea residue with L.plantarum can effectively preserve the nutritional attributes and total phenols,which offers a new insight into utilizing vine tea residue.
文摘Vine decline disease (VDD) constitutes a menace to melons worldwide. Especially, the one caused by the fungus Monosporascus cannonballus. Thus, resistant plant material must be released to help growers. Hence, our goal was to develop resistant plant material to VDD. More than 600 melon accessions are expected to be tested for disease resistance in M. cannonballus infested soil in Weslaco, Texas, USA, to identify resistance to VDD, and other important traits. So far, at most 7 lines were found to be resistant to VDD and some of them were used to develop elite, muskmelon inbred lines by pedigree breeding following single or double backcrosses. These elite parents were crossed to each other to develop the hybrids M3 and M4. They were also tested in the same infested field in Weslaco. The hybrids were grown using standard commercial practices followed by growers and when their fruits were ready, their roots were sampled as well as scored for disease severity to estimate high and mid-parent heterosis Our results indicate the existence of heterosis regarding resistance to VDD. Thus, resistant plant material can be developed and selection for resistance can be accomplished.
文摘This paper expounded the current situation and genetic mechanisms of short-vine watermelon breeding from the aspects of material sources,breeding process and genetic characteristics of F_1,hoping to provide a theoretical basis for short-vine watermelon breeding,and breeding materials for watermelon planting innovation,as well as new opportunities for high-quality and high-yield watermelon.
