The isotherm,mechanism and kinetics of carbon tetrachloride(CT) adsorption by polyacrylonitrile-based activated carbon fiber(PAN-ACF) were investigated in batch reactors and a continuous flow reactor,and the regenerat...The isotherm,mechanism and kinetics of carbon tetrachloride(CT) adsorption by polyacrylonitrile-based activated carbon fiber(PAN-ACF) were investigated in batch reactors and a continuous flow reactor,and the regeneration of PAN-ACF was also studied.Freundlich and Dubinin-Radushkevich(D-R) adsorption equations can well describe the adsorption isotherm.CT is mainly adsorbed on the exterior surface of PAN-ACF with low boundary layer effect and rate-controlling step of intra-particle diffusion.The adsorption dynamics in the batch reactor well fits with the pseudo-first-order model,and the breakthrough curves in the continuous flow reactor can be well described by the Yoon-Nelson model.The ACF can be recycled through thermal regeneration,whereas the adsorption capacity decreases from 7.87 to 4.98 mg/g after the fourth regeneration.78%-94%of CT can be removed from the wastewater of a fluorine chemical plant on a pilot scale,which confirms the efficacy of ACF under industrial conditions.The results indicate that PAN-ACF is applicable to CT removal from wastewater.展开更多
In order to meet the precision requirements and tracking performance of the continuous rotary motor electro-hydraulic servo system under unknown strong non-linear and uncertain strong disturbance factors,such as dynam...In order to meet the precision requirements and tracking performance of the continuous rotary motor electro-hydraulic servo system under unknown strong non-linear and uncertain strong disturbance factors,such as dynamic uncertainty and parameter perturbation,an improved active disturbance rejection control(ADRC)strategy was proposed.The state space model of the fifth order closed-loop system was established based on the principle of valve-controlled hydraulic motor.Then the three parts of ADRC were improved by parameter perturbation and external disturbance;the fast tracking differentiator was introduced into linear and non-linear combinations;the nonlinear state error feedback was proposed using synovial control;the extended state observer was determined by nonlinear compensation.In addition,the grey wolf algorithm was used to set the parameters of the three parts.The simulation and experimental results show that the improved ADRC can realize the system frequency 12 Hz when the tracking accuracy and response speed meet the requirements of double ten indexes,which lay foundation for the motor application.展开更多
该研究利用缺磷胁迫调控螺旋藻高效固碳生产功能性葡聚糖;采用红外光谱、单糖组成分析、核磁共振氢谱、凝胶渗透色谱和动态光散射等方法对不同培养时间(第6天和第8天)下获得的葡聚糖进行结构表征,并评估其膳食纤维含量、消化特性和体外...该研究利用缺磷胁迫调控螺旋藻高效固碳生产功能性葡聚糖;采用红外光谱、单糖组成分析、核磁共振氢谱、凝胶渗透色谱和动态光散射等方法对不同培养时间(第6天和第8天)下获得的葡聚糖进行结构表征,并评估其膳食纤维含量、消化特性和体外免疫活性。相比于正常P(+P)条件,缺磷(-P)胁迫使螺旋藻的CO_(2)固定效率提高36.8%,达到0.53 g CO_(2)/(L·d),α-葡聚糖的含量和产量分别提升至38.9%和0.99 g/L。-P第6天获得的葡聚糖(G6)主要由89.38%的葡萄糖组成,是一种带有α-1→6分支的α-1→4葡聚糖,分支度为5.82%。G6含有大(HMW)、中(MMW)、小(LMW)3种不同分子质量葡聚糖组分,重均分子质量依次是9461.7、4152.5、2388.2 kDa,对应的分子链构象依次是刚性棒状、球状和高度分支化结构。-P第8天获得的葡聚糖(G8)与G6结构和组成类似,但其分支度更高,分子体积更大,且HMW组分比G6具有更紧密的结构,而MMW和LMW的结构更为松散。G6和G8比麦芽糊精具有更低的快消化成分,而膳食纤维分别是麦芽糊精的26倍和12倍。G6和G8均可诱导巨噬细胞RAW264.7的NO、TNF-α和IL-6分泌,其中G6相比G8具有更好的免疫增强效果。-P可以作为螺旋藻高效固碳的调控策略,其调控下产生的α-葡聚糖具有开发成为具有免疫调节活性且含有益生元的慢消化功能性食品的潜力。展开更多
提出并验证了一种基于可调有源双耦合器环级联复合腔(Active dual-coupler ring based compound-cavity,ADCR-CC)滤波器的2μm波段单纵模(Single-longitudinal-mode,SLM)铥钬共掺光纤激光器。将具有可调滤波带宽和透射率的ADCR-CC滤波...提出并验证了一种基于可调有源双耦合器环级联复合腔(Active dual-coupler ring based compound-cavity,ADCR-CC)滤波器的2μm波段单纵模(Single-longitudinal-mode,SLM)铥钬共掺光纤激光器。将具有可调滤波带宽和透射率的ADCR-CC滤波器与光纤布拉格光栅(Fiber Bragg grating,FBG)结合,实现了SLM激光输出。当主腔和复合腔的泵浦功率分别为1.8 W和1.1 W时,测得的激光器输出波长为2048.510 nm,光信噪比高达83.08 dB,90 min内的最大光谱中心波长和光谱峰值功率波动分别为0.006 nm和0.19 dB,激光器输出功率为50.03 mW。使用等强度悬臂梁对FBG引入应变调节,SLM激光可在1.45 nm范围内实现波长的可调谐输出。展开更多
基金Project(2004C33068) supported by the Science and Technology Programs of Zhejiang Province,ChinaProject(20100933B17) supported by the Social Development and Science Research Program of Hangzhou,China
文摘The isotherm,mechanism and kinetics of carbon tetrachloride(CT) adsorption by polyacrylonitrile-based activated carbon fiber(PAN-ACF) were investigated in batch reactors and a continuous flow reactor,and the regeneration of PAN-ACF was also studied.Freundlich and Dubinin-Radushkevich(D-R) adsorption equations can well describe the adsorption isotherm.CT is mainly adsorbed on the exterior surface of PAN-ACF with low boundary layer effect and rate-controlling step of intra-particle diffusion.The adsorption dynamics in the batch reactor well fits with the pseudo-first-order model,and the breakthrough curves in the continuous flow reactor can be well described by the Yoon-Nelson model.The ACF can be recycled through thermal regeneration,whereas the adsorption capacity decreases from 7.87 to 4.98 mg/g after the fourth regeneration.78%-94%of CT can be removed from the wastewater of a fluorine chemical plant on a pilot scale,which confirms the efficacy of ACF under industrial conditions.The results indicate that PAN-ACF is applicable to CT removal from wastewater.
基金Project(51975164)supported by the National Natural Science Foundation of ChinaProject(2019-KYYWF-0205)supported by the Fundamental Research Foundation for Universities of Heilongjiang Province,China。
文摘In order to meet the precision requirements and tracking performance of the continuous rotary motor electro-hydraulic servo system under unknown strong non-linear and uncertain strong disturbance factors,such as dynamic uncertainty and parameter perturbation,an improved active disturbance rejection control(ADRC)strategy was proposed.The state space model of the fifth order closed-loop system was established based on the principle of valve-controlled hydraulic motor.Then the three parts of ADRC were improved by parameter perturbation and external disturbance;the fast tracking differentiator was introduced into linear and non-linear combinations;the nonlinear state error feedback was proposed using synovial control;the extended state observer was determined by nonlinear compensation.In addition,the grey wolf algorithm was used to set the parameters of the three parts.The simulation and experimental results show that the improved ADRC can realize the system frequency 12 Hz when the tracking accuracy and response speed meet the requirements of double ten indexes,which lay foundation for the motor application.
文摘该研究利用缺磷胁迫调控螺旋藻高效固碳生产功能性葡聚糖;采用红外光谱、单糖组成分析、核磁共振氢谱、凝胶渗透色谱和动态光散射等方法对不同培养时间(第6天和第8天)下获得的葡聚糖进行结构表征,并评估其膳食纤维含量、消化特性和体外免疫活性。相比于正常P(+P)条件,缺磷(-P)胁迫使螺旋藻的CO_(2)固定效率提高36.8%,达到0.53 g CO_(2)/(L·d),α-葡聚糖的含量和产量分别提升至38.9%和0.99 g/L。-P第6天获得的葡聚糖(G6)主要由89.38%的葡萄糖组成,是一种带有α-1→6分支的α-1→4葡聚糖,分支度为5.82%。G6含有大(HMW)、中(MMW)、小(LMW)3种不同分子质量葡聚糖组分,重均分子质量依次是9461.7、4152.5、2388.2 kDa,对应的分子链构象依次是刚性棒状、球状和高度分支化结构。-P第8天获得的葡聚糖(G8)与G6结构和组成类似,但其分支度更高,分子体积更大,且HMW组分比G6具有更紧密的结构,而MMW和LMW的结构更为松散。G6和G8比麦芽糊精具有更低的快消化成分,而膳食纤维分别是麦芽糊精的26倍和12倍。G6和G8均可诱导巨噬细胞RAW264.7的NO、TNF-α和IL-6分泌,其中G6相比G8具有更好的免疫增强效果。-P可以作为螺旋藻高效固碳的调控策略,其调控下产生的α-葡聚糖具有开发成为具有免疫调节活性且含有益生元的慢消化功能性食品的潜力。
