Atractylodes Chinensis(DC)Koidz is a perennial herb often used as a prescription medicine for influenza,to invigorate the spleen and remove dampness.The quality of the herb is determined by the quality of the seedling...Atractylodes Chinensis(DC)Koidz is a perennial herb often used as a prescription medicine for influenza,to invigorate the spleen and remove dampness.The quality of the herb is determined by the quality of the seedlings.The traditional A.chinensis seedling production technique has nonuniform seedlings and low mechanisation.The plug seedling technique was used to produce A.Chinensis seedlings.This study was conducted to determine the growth characteristics of A.Chinensis seedlings according to the cell size of plug trays and number of days after sowing.Plant height,stem diameter,rhizome diameter,number of leaves,leaf area,and shoot dry and fresh weight of A.Chinensis seedlings were significantly higher in the P32-D treatment than in the P72,P50,and P32 treatments,but not significantly different from the P28-D treatment 60 d after sowing.The P28-D treatment resulted in a considerable drop in rhizome fresh weight and healthy seedling index,both of which are key indicators for assessing seedling quality.Although the differences in Pn among treatments were not significantly different,Tr was considerably greater in A.Chinensis seedlings treated with P32-D and P28-D than in the other three treatments.The P32-D and P28-D treatments had considerably greater potential maximum photochemical efficiency of PSII,quantum yield of photosystem II,photochemical quenching and electron transport rate than the other three treatments.Root vitality of A.Chinensis seedlings was significantly stronger in the P32-D treatment than in the other four treatments,and it was 1.9 times higher than in the P28-D treatment.The soluble protein,soluble sugar,and starch contents of A.Chinensis seedlings were highest in the P32-D treatment,but the differences among treatments were not significant.LUE,EUE,PY and EY were significantly higher in the P32-D treatment than in the other four treatments,being 1.3,1.3,1.4 and 1.4 times higher than in P28-D,respectively.On the other hand,as for the change in the growth of A.Chinensis seedlings according to the number of days after sowing,the growth of shoots and rhizome was most vigorous at the 60 d after sowing,while the fresh weight of the rhizome,which can be considered as an indicator of root growth,increased steadily during the experiment but slowed down after 60 d.As a result,32-cell deepened plug trays and a seedling nursery for a period of 60-75 d are recommended for commercial cultivation of A.Chinensis seedlings.This will provide technical support for production in A.Chinensis seedling.展开更多
针对插电式混合动力汽车(plug-in hybrid electric vehicle,PHEV)复合电源系统存在的高频动态特性、计算量大和混杂特性等问题,提出一种双向DC/DC变换器的混杂自动机模型。通过分析PHEV复合电源系统的工作原理,根据拉格朗日力学理论,建...针对插电式混合动力汽车(plug-in hybrid electric vehicle,PHEV)复合电源系统存在的高频动态特性、计算量大和混杂特性等问题,提出一种双向DC/DC变换器的混杂自动机模型。通过分析PHEV复合电源系统的工作原理,根据拉格朗日力学理论,建立双向DC/DC变换器各工作模态的数学模型,再基于混杂自动机理论并结合离散化处理得到PHEV复合电源双向DC/DC变换器混杂自动机模型,并使用仿真实验对其进行验证。仿真结果表明:该模型计算量适中、跟踪精度高,能完整地描述系统的各个工作模态,兼顾了CCM模式和DCM模式,具有实际应用价值。展开更多
在交直流混合微电网中,若汇入直流母线中的功率瞬时值中含有纹波分量(如三相不平衡交流负荷、交直流微电网互联功率存在不平衡有功功率分量等),均会导致直流母线电压出现纹波分量,严重时会影响系统供电电能质量和可靠性。为此,提出基于...在交直流混合微电网中,若汇入直流母线中的功率瞬时值中含有纹波分量(如三相不平衡交流负荷、交直流微电网互联功率存在不平衡有功功率分量等),均会导致直流母线电压出现纹波分量,严重时会影响系统供电电能质量和可靠性。为此,提出基于直流有源滤波器(DC active power filter,DC-APF)的直流母线电压纹波抑制方法,主要由直流电压纹波抑制、直流有源滤波器输入端电容电压控制以及电流闭环控制3部分构成。阻抗分析方法表明所采用的控制参数设计方法能保证拟抑制纹波频率处直流有源电力滤波器输出阻抗远小于直流微电网中其余单元的输出阻抗,从而能消除或减小直流纹波电压。此外,基于所提方法,还可实现多直流有源滤波器即插即用与并联运行。最后在Matlab/Simulink中搭建了含直流型分布式电源、交直流双向DC-AC变流器、直流负荷以及两台直流有源电力滤波器的交直流混合微电网仿真模型,建立了相应的实验平台,数字仿真和实验结果均验证了所提方法的有效性。展开更多
基金supported by the earmarked fund for CARS(Grant No.CARS-21).
文摘Atractylodes Chinensis(DC)Koidz is a perennial herb often used as a prescription medicine for influenza,to invigorate the spleen and remove dampness.The quality of the herb is determined by the quality of the seedlings.The traditional A.chinensis seedling production technique has nonuniform seedlings and low mechanisation.The plug seedling technique was used to produce A.Chinensis seedlings.This study was conducted to determine the growth characteristics of A.Chinensis seedlings according to the cell size of plug trays and number of days after sowing.Plant height,stem diameter,rhizome diameter,number of leaves,leaf area,and shoot dry and fresh weight of A.Chinensis seedlings were significantly higher in the P32-D treatment than in the P72,P50,and P32 treatments,but not significantly different from the P28-D treatment 60 d after sowing.The P28-D treatment resulted in a considerable drop in rhizome fresh weight and healthy seedling index,both of which are key indicators for assessing seedling quality.Although the differences in Pn among treatments were not significantly different,Tr was considerably greater in A.Chinensis seedlings treated with P32-D and P28-D than in the other three treatments.The P32-D and P28-D treatments had considerably greater potential maximum photochemical efficiency of PSII,quantum yield of photosystem II,photochemical quenching and electron transport rate than the other three treatments.Root vitality of A.Chinensis seedlings was significantly stronger in the P32-D treatment than in the other four treatments,and it was 1.9 times higher than in the P28-D treatment.The soluble protein,soluble sugar,and starch contents of A.Chinensis seedlings were highest in the P32-D treatment,but the differences among treatments were not significant.LUE,EUE,PY and EY were significantly higher in the P32-D treatment than in the other four treatments,being 1.3,1.3,1.4 and 1.4 times higher than in P28-D,respectively.On the other hand,as for the change in the growth of A.Chinensis seedlings according to the number of days after sowing,the growth of shoots and rhizome was most vigorous at the 60 d after sowing,while the fresh weight of the rhizome,which can be considered as an indicator of root growth,increased steadily during the experiment but slowed down after 60 d.As a result,32-cell deepened plug trays and a seedling nursery for a period of 60-75 d are recommended for commercial cultivation of A.Chinensis seedlings.This will provide technical support for production in A.Chinensis seedling.
文摘针对插电式混合动力汽车(plug-in hybrid electric vehicle,PHEV)复合电源系统存在的高频动态特性、计算量大和混杂特性等问题,提出一种双向DC/DC变换器的混杂自动机模型。通过分析PHEV复合电源系统的工作原理,根据拉格朗日力学理论,建立双向DC/DC变换器各工作模态的数学模型,再基于混杂自动机理论并结合离散化处理得到PHEV复合电源双向DC/DC变换器混杂自动机模型,并使用仿真实验对其进行验证。仿真结果表明:该模型计算量适中、跟踪精度高,能完整地描述系统的各个工作模态,兼顾了CCM模式和DCM模式,具有实际应用价值。
文摘在交直流混合微电网中,若汇入直流母线中的功率瞬时值中含有纹波分量(如三相不平衡交流负荷、交直流微电网互联功率存在不平衡有功功率分量等),均会导致直流母线电压出现纹波分量,严重时会影响系统供电电能质量和可靠性。为此,提出基于直流有源滤波器(DC active power filter,DC-APF)的直流母线电压纹波抑制方法,主要由直流电压纹波抑制、直流有源滤波器输入端电容电压控制以及电流闭环控制3部分构成。阻抗分析方法表明所采用的控制参数设计方法能保证拟抑制纹波频率处直流有源电力滤波器输出阻抗远小于直流微电网中其余单元的输出阻抗,从而能消除或减小直流纹波电压。此外,基于所提方法,还可实现多直流有源滤波器即插即用与并联运行。最后在Matlab/Simulink中搭建了含直流型分布式电源、交直流双向DC-AC变流器、直流负荷以及两台直流有源电力滤波器的交直流混合微电网仿真模型,建立了相应的实验平台,数字仿真和实验结果均验证了所提方法的有效性。
