A rapid method to determine glutamic acid (Glu) in cerebrospinal fluid (CSF) by capillaryelectrophoresis with high frequency conductivity detection (contactless conductivity detection) wasdescribed. The CSF sample was...A rapid method to determine glutamic acid (Glu) in cerebrospinal fluid (CSF) by capillaryelectrophoresis with high frequency conductivity detection (contactless conductivity detection) wasdescribed. The CSF sample was pretreated with silver cation resin to remove high concentration ofCl- ions in CSF. The separation was achieved in the buffer solution of 10 mmol/L Tris and 8mmol/L boric acid at the separation voltage of 20.0 kV. Glu showed linear response in the range of5.0×10-6 to 6.0×10-3 mol/L, the limit of detection was 1.0×10-6 mol/L. The method was used foranalysis Glu in CSF satisfactorily with a recovery of 97.8-98.8%.展开更多
Ba0.95Ce0.9Y0.1O3－α solid electrolyte was prepared by high temperature solid state reaction. The electrochemical oxygen permeation (oxygen pumping) rates and oxide ion transport number in this electrolyte were detec...Ba0.95Ce0.9Y0.1O3－α solid electrolyte was prepared by high temperature solid state reaction. The electrochemical oxygen permeation (oxygen pumping) rates and oxide ion transport number in this electrolyte were detected in the temperature of 600～ 1000℃ . It was found that this electrolyte exhibited the oxide ion conduction with the oxide ion transport number of 0.3～ 0.5.展开更多
Effective control of terahertz radiation requires fast and efficient modulators with a large modulation depth-a challenge that is often tackled by using metamaterials.Metamaterial-based active modulators can be create...Effective control of terahertz radiation requires fast and efficient modulators with a large modulation depth-a challenge that is often tackled by using metamaterials.Metamaterial-based active modulators can be created by placing graphene as a tuneable element shunting regions of high electric field confinement in metamaterials.However,in this common approach,the graphene is used as a variable resistor,and the modulation is achieved by resistive damping of the resonance.In combination with the finite conductivity of graphene due to its gapless nature,achieving 100%modulation depth using this approach remains challenging.Here,we embed nanoscale graphene capacitors within the gaps of the metamaterial resonators,and thus switch from a resistive damping to a capacitive tuning of the resonance.We further expand the optical modulation range by device excitation from its substrate side.As a result,we demonstrate terahertz modulators with over four orders of magnitude modulation depth(45.7 dB at 1.68 THz and 40.1 dB at 2.15 THz),and a reconfiguration speed of 30 MHz.These tuneable capacitance modulators are electrically controlled solid-state devices enabling unity modulation with graphene conductivities below 0.7 mS.The demonstrated approach can be applied to enhance modulation performance of any metamaterial-based modulator with a 2D electron gas.Our results open up new frontiers in the area of terahertz communications,real-time imaging,and wave-optical analogue computing.展开更多
基金This project was supported by the Guangdong Provincial Foundation of Natural Science(021808)
文摘A rapid method to determine glutamic acid (Glu) in cerebrospinal fluid (CSF) by capillaryelectrophoresis with high frequency conductivity detection (contactless conductivity detection) wasdescribed. The CSF sample was pretreated with silver cation resin to remove high concentration ofCl- ions in CSF. The separation was achieved in the buffer solution of 10 mmol/L Tris and 8mmol/L boric acid at the separation voltage of 20.0 kV. Glu showed linear response in the range of5.0×10-6 to 6.0×10-3 mol/L, the limit of detection was 1.0×10-6 mol/L. The method was used foranalysis Glu in CSF satisfactorily with a recovery of 97.8-98.8%.
文摘Ba0.95Ce0.9Y0.1O3－α solid electrolyte was prepared by high temperature solid state reaction. The electrochemical oxygen permeation (oxygen pumping) rates and oxide ion transport number in this electrolyte were detected in the temperature of 600～ 1000℃ . It was found that this electrolyte exhibited the oxide ion conduction with the oxide ion transport number of 0.3～ 0.5.
基金supported by the UK Engineering and Physical Sciences Research Council(EPSRC)grant EP/S023046/1 for the EPSRC Centre for Doctoral Training in Sensor Technologies for a Healthy and Sustainable Futurefunding from the HyperTerahertz grant,no.EP/P021859/1the TeraCom grant,no.EP/W028921/1。
文摘Effective control of terahertz radiation requires fast and efficient modulators with a large modulation depth-a challenge that is often tackled by using metamaterials.Metamaterial-based active modulators can be created by placing graphene as a tuneable element shunting regions of high electric field confinement in metamaterials.However,in this common approach,the graphene is used as a variable resistor,and the modulation is achieved by resistive damping of the resonance.In combination with the finite conductivity of graphene due to its gapless nature,achieving 100%modulation depth using this approach remains challenging.Here,we embed nanoscale graphene capacitors within the gaps of the metamaterial resonators,and thus switch from a resistive damping to a capacitive tuning of the resonance.We further expand the optical modulation range by device excitation from its substrate side.As a result,we demonstrate terahertz modulators with over four orders of magnitude modulation depth(45.7 dB at 1.68 THz and 40.1 dB at 2.15 THz),and a reconfiguration speed of 30 MHz.These tuneable capacitance modulators are electrically controlled solid-state devices enabling unity modulation with graphene conductivities below 0.7 mS.The demonstrated approach can be applied to enhance modulation performance of any metamaterial-based modulator with a 2D electron gas.Our results open up new frontiers in the area of terahertz communications,real-time imaging,and wave-optical analogue computing.
