The aim was to research fresh-keeping effects of natamycin on cold-pre- served grape. Red globe grapes were processed with compound coating liquid of chitosan with mass fraction at 1% and natamycin with mass fractions...The aim was to research fresh-keeping effects of natamycin on cold-pre- served grape. Red globe grapes were processed with compound coating liquid of chitosan with mass fraction at 1% and natamycin with mass fractions at 0.20% （T1）, 0.40% （T2） and 0.60% （T3）, respectively. Grapes processed with water （CK3） and 1% chitosan （CK2） were taken as control groups. Rotten rate, seed shattering rate, mass loss rate, respiratory intensity and related physiological quality in test and control groups were compared. The results indicated that respiratory intensity, mass loss rate, rotten rate and seed shattering rate in CK1 were all higher than those in CK2. In addition, T1, T2 and T3 were lower in the indices than CK1 and CK2, but still kept at a high level in fruit hardness. Furthermore, mass fractions of Vc and titratable acid declined more slowly in T1, T2 and T3, compared with CK1 and CK2. Natamycin better preserved grapes and prolonged storage period. In general, natamycin with mass fraction at 0.4% proved best in fresh-keeping.展开更多
风电功率预测对电力系统的安全稳定运行具有重要意义。针对多风电场的超短期概率预测问题,提出了一种基于Bagging混合策略和核密度估计(kernel density estimation,KDE)的稀疏向量自回归预测方法。首先通过时间序列分解和余项自举,生成...风电功率预测对电力系统的安全稳定运行具有重要意义。针对多风电场的超短期概率预测问题,提出了一种基于Bagging混合策略和核密度估计(kernel density estimation,KDE)的稀疏向量自回归预测方法。首先通过时间序列分解和余项自举,生成若干自举时间序列。对于每个时间序列,采用向量自回归(vector autoregression,VAR)模型进行预测。针对传统模型在风场数量较多时容易出现的过拟合问题,采用稀疏向量自回归模型,筛选最有效的回归系数,得到稀疏系数矩阵。每个时间序列训练的预测模型分别产生点预测结果,对于多重点预测结果,使用KDE方法产生概率密度的预测结果。在真实风电集群数据上,验证所提多场站概率预测方法的有效性,采用分位数得分评估概率预测精度。相关实验结果表明,该方法可以有效提高概率预测精度。展开更多
[Objective]The paper was to study the effects of nine kinds of household vase solutions on fresh-keeping effect of Lilium cut flowers.[Method]Using Lilium"Sorbonne"as the material,nine kinds of household vas...[Objective]The paper was to study the effects of nine kinds of household vase solutions on fresh-keeping effect of Lilium cut flowers.[Method]Using Lilium"Sorbonne"as the material,nine kinds of household vase solutions were prepared by edible white granulated sugar,white vinegar,akafen powder and vitamin C tablets,respectively.The morphological and physiological indexes of Lilium cut flowers,including vase life,ornamental grade,flower diameter,fresh weight of flower branches,water balance value,soluble protein content and MDA content of petals,were observed,and the effects of nine kinds of household vase solutions on fresh-keeping effect of Lilium cut flowers were studied.[Result]The household vase solution F8(20 g/L white granated sugar+1 packet/L acafen powder+2 tablets/L vitamin C tablets)had the best fresh-keeping effect on Lilium cut flowers,which was beneficial to prolong the vase life and improve the ornamental value of Lilium cut flowers.[Conclusion]The household vase solution of Lilium cut flowers is optimized,which is not only environmentally friendly but also convenient for ordinary families.展开更多
Using sucrose, citric acid and vitamin C as the basic liquid, different concentrations of 6-BA and B9 preservatives were added, and the carnation variety ＇ Master＇ was treated. The results showed that the formula of...Using sucrose, citric acid and vitamin C as the basic liquid, different concentrations of 6-BA and B9 preservatives were added, and the carnation variety ＇ Master＇ was treated. The results showed that the formula of 3% sucrose ＋ 50 mg/L citric acid ＋ 600 mg/L vitamin C ＋ 20 mg/L 6-BA could effectively maintain the water balance of the cut flower, prolong the vase life of the cut flower to 16.4 d, and maximize the flower diameter and the crown height.展开更多
This study considered and predicted blast-induced ground vibration(PPV)in open-pit mines using bagging and sibling techniques under the rigorous combination of machine learning algorithms.Accordingly,four machine lear...This study considered and predicted blast-induced ground vibration(PPV)in open-pit mines using bagging and sibling techniques under the rigorous combination of machine learning algorithms.Accordingly,four machine learning algorithms,including support vector regression(SVR),extra trees(ExTree),K-nearest neighbors(KNN),and decision tree regression(DTR),were used as the base models for the purposes of combination and PPV initial prediction.The bagging regressor(BA)was then applied to combine these base models with the efforts of variance reduction,overfitting elimination,and generating more robust predictive models,abbreviated as BA-ExTree,BAKNN,BA-SVR,and BA-DTR.It is emphasized that the ExTree model has not been considered for predicting blastinduced ground vibration before,and the bagging of ExTree is an innovation aiming to improve the accuracy of the inherently ExTree model,as well.In addition,two empirical models(i.e.,USBM and Ambraseys)were also treated and compared with the bagging models to gain a comprehensive assessment.With this aim,we collected 300 blasting events with different parameters at the Sin Quyen copper mine(Vietnam),and the produced PPV values were also measured.They were then compiled as the dataset to develop the PPV predictive models.The results revealed that the bagging models provided better performance than the empirical models,except for the BA-DTR model.Of those,the BA-ExTree is the best model with the highest accuracy(i.e.,88.8%).Whereas,the empirical models only provided the accuracy from 73.6%–76%.The details of comparisons and assessments were also presented in this study.展开更多
The vitamin C rich-kiwi fruit-the king of fruits-is good to taste but hard to store. Only a few countries can prevent mildew on the fruit stalk during the storage process. The fresh-keeping technology developed by the...The vitamin C rich-kiwi fruit-the king of fruits-is good to taste but hard to store. Only a few countries can prevent mildew on the fruit stalk during the storage process. The fresh-keeping technology developed by the Shaanxi Teachers University has enabled China to catch up with the advanced countries in this field.展开更多
文摘The aim was to research fresh-keeping effects of natamycin on cold-pre- served grape. Red globe grapes were processed with compound coating liquid of chitosan with mass fraction at 1% and natamycin with mass fractions at 0.20% （T1）, 0.40% （T2） and 0.60% （T3）, respectively. Grapes processed with water （CK3） and 1% chitosan （CK2） were taken as control groups. Rotten rate, seed shattering rate, mass loss rate, respiratory intensity and related physiological quality in test and control groups were compared. The results indicated that respiratory intensity, mass loss rate, rotten rate and seed shattering rate in CK1 were all higher than those in CK2. In addition, T1, T2 and T3 were lower in the indices than CK1 and CK2, but still kept at a high level in fruit hardness. Furthermore, mass fractions of Vc and titratable acid declined more slowly in T1, T2 and T3, compared with CK1 and CK2. Natamycin better preserved grapes and prolonged storage period. In general, natamycin with mass fraction at 0.4% proved best in fresh-keeping.
文摘风电功率预测对电力系统的安全稳定运行具有重要意义。针对多风电场的超短期概率预测问题,提出了一种基于Bagging混合策略和核密度估计(kernel density estimation,KDE)的稀疏向量自回归预测方法。首先通过时间序列分解和余项自举,生成若干自举时间序列。对于每个时间序列,采用向量自回归(vector autoregression,VAR)模型进行预测。针对传统模型在风场数量较多时容易出现的过拟合问题,采用稀疏向量自回归模型,筛选最有效的回归系数,得到稀疏系数矩阵。每个时间序列训练的预测模型分别产生点预测结果,对于多重点预测结果,使用KDE方法产生概率密度的预测结果。在真实风电集群数据上,验证所提多场站概率预测方法的有效性,采用分位数得分评估概率预测精度。相关实验结果表明,该方法可以有效提高概率预测精度。
文摘[Objective]The paper was to study the effects of nine kinds of household vase solutions on fresh-keeping effect of Lilium cut flowers.[Method]Using Lilium"Sorbonne"as the material,nine kinds of household vase solutions were prepared by edible white granulated sugar,white vinegar,akafen powder and vitamin C tablets,respectively.The morphological and physiological indexes of Lilium cut flowers,including vase life,ornamental grade,flower diameter,fresh weight of flower branches,water balance value,soluble protein content and MDA content of petals,were observed,and the effects of nine kinds of household vase solutions on fresh-keeping effect of Lilium cut flowers were studied.[Result]The household vase solution F8(20 g/L white granated sugar+1 packet/L acafen powder+2 tablets/L vitamin C tablets)had the best fresh-keeping effect on Lilium cut flowers,which was beneficial to prolong the vase life and improve the ornamental value of Lilium cut flowers.[Conclusion]The household vase solution of Lilium cut flowers is optimized,which is not only environmentally friendly but also convenient for ordinary families.
文摘Using sucrose, citric acid and vitamin C as the basic liquid, different concentrations of 6-BA and B9 preservatives were added, and the carnation variety ＇ Master＇ was treated. The results showed that the formula of 3% sucrose ＋ 50 mg/L citric acid ＋ 600 mg/L vitamin C ＋ 20 mg/L 6-BA could effectively maintain the water balance of the cut flower, prolong the vase life of the cut flower to 16.4 d, and maximize the flower diameter and the crown height.
基金funded by Vietnam National Foundation for Science and Tech-nology Development(NAFOSTED)under Grant No.105.99-2019.309.
文摘This study considered and predicted blast-induced ground vibration(PPV)in open-pit mines using bagging and sibling techniques under the rigorous combination of machine learning algorithms.Accordingly,four machine learning algorithms,including support vector regression(SVR),extra trees(ExTree),K-nearest neighbors(KNN),and decision tree regression(DTR),were used as the base models for the purposes of combination and PPV initial prediction.The bagging regressor(BA)was then applied to combine these base models with the efforts of variance reduction,overfitting elimination,and generating more robust predictive models,abbreviated as BA-ExTree,BAKNN,BA-SVR,and BA-DTR.It is emphasized that the ExTree model has not been considered for predicting blastinduced ground vibration before,and the bagging of ExTree is an innovation aiming to improve the accuracy of the inherently ExTree model,as well.In addition,two empirical models(i.e.,USBM and Ambraseys)were also treated and compared with the bagging models to gain a comprehensive assessment.With this aim,we collected 300 blasting events with different parameters at the Sin Quyen copper mine(Vietnam),and the produced PPV values were also measured.They were then compiled as the dataset to develop the PPV predictive models.The results revealed that the bagging models provided better performance than the empirical models,except for the BA-DTR model.Of those,the BA-ExTree is the best model with the highest accuracy(i.e.,88.8%).Whereas,the empirical models only provided the accuracy from 73.6%–76%.The details of comparisons and assessments were also presented in this study.
文摘The vitamin C rich-kiwi fruit-the king of fruits-is good to taste but hard to store. Only a few countries can prevent mildew on the fruit stalk during the storage process. The fresh-keeping technology developed by the Shaanxi Teachers University has enabled China to catch up with the advanced countries in this field.
