A high-throughput sample introduction system for chip-based microfluidic analysis was developed. The sampling system was composed of a capillary sampling probe attached to the microchip channel and an array of horizon...A high-throughput sample introduction system for chip-based microfluidic analysis was developed. The sampling system was composed of a capillary sampling probe attached to the microchip channel and an array of horizontally positioned micro-sample vials with slits fabricated on the bottom of each vial for pass-through of the sampling probe. The micro-sample vials array was fixed on a homebuilt platform capable of moving linearly under computer control. Sample introduction was performed by linearly moving the array of vials,allowing the probe inlet to sequentially enter the solutions in the vials through the slits. The use of a slotted vial array in the sample introduction system allowed convenient and rapid sample change with low sample volume in 10\+\{-9\} L range and high sampling frequency without requiring mechanical valves and pumps. The system was applied to achieve continuously automated sample change in a chip-based flow injection analysis system with absorption detection by using a liquid-core waveguide capillary flow-cell. High sampling throughput of 600 h -1 was obtained in this system with a sample consumption of only 4.3 nL for each cycle.展开更多
In this work, two novel approaches were developed for miniaturized liquid-liquid(L-L) extraction on microfluidic chips, based on a stopped-flow extraction technique. In the first approach, trapped droplets extraction ...In this work, two novel approaches were developed for miniaturized liquid-liquid(L-L) extraction on microfluidic chips, based on a stopped-flow extraction technique. In the first approach, trapped droplets extraction mode, organic solvent droplets of a few hundred 10 -12 L were trapped within micro recesses fabricated in the channel walls of microfluidic chips, and analytes in aqueous streams flowing over the droplets were transferred into them, affecting a preconcentration. In the second approach, a stable interface between stationary organic phase and continuously flowed aqueous phase was formed by stopping the flow of organic phase. Analytes were transferred from the aqueous phase into the organic phase on the interface. Enrichment factors exceeding 1 000 and 300 were achieved with a preconcentration period of 20 min with sample consumption lower than 10 μL for trapped droplets and stopped-flow microextraction. In situ laser induced fluorescence detection of the concentrated analyte was performed following the preconcentration.展开更多
针对BTT导弹飞行控制系统的自适应鲁棒控制问题,基于反馈线性化控制和自适应RBF(radical base function)神经网络控制系统设计方法,设计了高精度鲁棒飞行控制器。提出在线权值修正算法,使RBF神经网络能实现对飞行控制系统动态逆误差的...针对BTT导弹飞行控制系统的自适应鲁棒控制问题,基于反馈线性化控制和自适应RBF(radical base function)神经网络控制系统设计方法,设计了高精度鲁棒飞行控制器。提出在线权值修正算法,使RBF神经网络能实现对飞行控制系统动态逆误差的在线逼近,进而实现对系统不确定性和外界扰动的实时补偿。通过数值仿真,对所设计的飞行控制器进行了有效性验证。仿真结果表明,相比仅采用反馈线性化控制的飞行控制器,文中提出的飞行控制器能较好地跟踪期望的指令角度信息,鲁棒性能更优。展开更多
文摘A high-throughput sample introduction system for chip-based microfluidic analysis was developed. The sampling system was composed of a capillary sampling probe attached to the microchip channel and an array of horizontally positioned micro-sample vials with slits fabricated on the bottom of each vial for pass-through of the sampling probe. The micro-sample vials array was fixed on a homebuilt platform capable of moving linearly under computer control. Sample introduction was performed by linearly moving the array of vials,allowing the probe inlet to sequentially enter the solutions in the vials through the slits. The use of a slotted vial array in the sample introduction system allowed convenient and rapid sample change with low sample volume in 10\+\{-9\} L range and high sampling frequency without requiring mechanical valves and pumps. The system was applied to achieve continuously automated sample change in a chip-based flow injection analysis system with absorption detection by using a liquid-core waveguide capillary flow-cell. High sampling throughput of 600 h -1 was obtained in this system with a sample consumption of only 4.3 nL for each cycle.
文摘In this work, two novel approaches were developed for miniaturized liquid-liquid(L-L) extraction on microfluidic chips, based on a stopped-flow extraction technique. In the first approach, trapped droplets extraction mode, organic solvent droplets of a few hundred 10 -12 L were trapped within micro recesses fabricated in the channel walls of microfluidic chips, and analytes in aqueous streams flowing over the droplets were transferred into them, affecting a preconcentration. In the second approach, a stable interface between stationary organic phase and continuously flowed aqueous phase was formed by stopping the flow of organic phase. Analytes were transferred from the aqueous phase into the organic phase on the interface. Enrichment factors exceeding 1 000 and 300 were achieved with a preconcentration period of 20 min with sample consumption lower than 10 μL for trapped droplets and stopped-flow microextraction. In situ laser induced fluorescence detection of the concentrated analyte was performed following the preconcentration.
文摘针对BTT导弹飞行控制系统的自适应鲁棒控制问题,基于反馈线性化控制和自适应RBF(radical base function)神经网络控制系统设计方法,设计了高精度鲁棒飞行控制器。提出在线权值修正算法,使RBF神经网络能实现对飞行控制系统动态逆误差的在线逼近,进而实现对系统不确定性和外界扰动的实时补偿。通过数值仿真,对所设计的飞行控制器进行了有效性验证。仿真结果表明,相比仅采用反馈线性化控制的飞行控制器,文中提出的飞行控制器能较好地跟踪期望的指令角度信息,鲁棒性能更优。
