A new analytical method for the determination of urea-urease system based on biochemical reaction heat induced laser beam deflection is presented in this paper. With the method, the Michaelis constant (K-m) of urease ...A new analytical method for the determination of urea-urease system based on biochemical reaction heat induced laser beam deflection is presented in this paper. With the method, the Michaelis constant (K-m) of urease and apparent inhibition constant (K-i) of some metal ion inhibitors were measured respectively. This method was also used for the quantitative determination of metal ions with satisfactory result.展开更多
In this work we present the results of the optical evaluation of vibrations of a conventional concrete column with a metal frame.In a previous work[1]we reported the optical evaluation of a pure concrete column,withou...In this work we present the results of the optical evaluation of vibrations of a conventional concrete column with a metal frame.In a previous work[1]we reported the optical evaluation of a pure concrete column,without a metal framework.In this evaluation we expected to obtain a noticeably different result,but that was not the case,then the obtained results are surprisingly similar.From the LPD evaluations,the first 12 vibration resonances were found,which fit very well with the basic applied theory(the cantilever theory).Using known average values,we estimate the corresponding column effective length,obtaining an average value of 2.5 m.As in the former case of the concrete column,we find a discrepancy with respect to the length value,measurable from the ground(1.75 m),which can be explained again by the fact that the column and its base were built on inconsistent terrain.展开更多
Piezoelectric tip/tilt stages(PZT stages),which precisely and quickly control laser beam deflection,are widely used in laser communications.Most are driven by piezoelectric stack actuators(PSAs)and have high capacitan...Piezoelectric tip/tilt stages(PZT stages),which precisely and quickly control laser beam deflection,are widely used in laser communications.Most are driven by piezoelectric stack actuators(PSAs)and have high capacitance and power consumption.The negative voltage causes irreversible damage to PSAs.Therefore,negative voltage operation needs to be prohibited,which complicates manipulating the bidirectional deflection of the mirror.However,the aerospace field places higher requirements on power consumption and ease of operation,which makes the PZT stage require reduced power consumption and simple operation.This paper presents a high-performance bend-actuated PZT stage,which uses ceramic plates for driving,with a capacitance of only 26.4 nF/axis and a power of only 27 mW(at operating conditions of 1 mrad and 100 Hz).The sandwich structure allows for bi-directional voltage,which makes the operation easier.Two channels control two degrees of freedom(DOFs).A theoretical model suitable for bend-actuated structures is proposed.It is used to calculate the deflection angle and resonance frequency,and its validity is verified by finite element analysis.Experimental results show that it has a deflection angle of±2.97 mrad(x-axis),±3.24 mrad(y-axis)at 600 V p-p,an unloaded first-order resonance frequency of 1728 Hz,and a quasi-static hysteresis of only 7.5%,which is less than that of PSAs(>10%).With the constructed laser beam deflection system,a circular trajectory is realized,which has the potential for beam steering.展开更多
文摘A new analytical method for the determination of urea-urease system based on biochemical reaction heat induced laser beam deflection is presented in this paper. With the method, the Michaelis constant (K-m) of urease and apparent inhibition constant (K-i) of some metal ion inhibitors were measured respectively. This method was also used for the quantitative determination of metal ions with satisfactory result.
文摘In this work we present the results of the optical evaluation of vibrations of a conventional concrete column with a metal frame.In a previous work[1]we reported the optical evaluation of a pure concrete column,without a metal framework.In this evaluation we expected to obtain a noticeably different result,but that was not the case,then the obtained results are surprisingly similar.From the LPD evaluations,the first 12 vibration resonances were found,which fit very well with the basic applied theory(the cantilever theory).Using known average values,we estimate the corresponding column effective length,obtaining an average value of 2.5 m.As in the former case of the concrete column,we find a discrepancy with respect to the length value,measurable from the ground(1.75 m),which can be explained again by the fact that the column and its base were built on inconsistent terrain.
基金supported by the National Natural Science Foundation of China(Grant Nos.62227812,524B2053,52225501)the Postdoctoral Fellowship Program of CPSF(Grant No.GZB20240959)the Self-Planned Task of State Key Laboratory of Robotics and Systems(HIT)(Grant No.SKLRS202302C).
文摘Piezoelectric tip/tilt stages(PZT stages),which precisely and quickly control laser beam deflection,are widely used in laser communications.Most are driven by piezoelectric stack actuators(PSAs)and have high capacitance and power consumption.The negative voltage causes irreversible damage to PSAs.Therefore,negative voltage operation needs to be prohibited,which complicates manipulating the bidirectional deflection of the mirror.However,the aerospace field places higher requirements on power consumption and ease of operation,which makes the PZT stage require reduced power consumption and simple operation.This paper presents a high-performance bend-actuated PZT stage,which uses ceramic plates for driving,with a capacitance of only 26.4 nF/axis and a power of only 27 mW(at operating conditions of 1 mrad and 100 Hz).The sandwich structure allows for bi-directional voltage,which makes the operation easier.Two channels control two degrees of freedom(DOFs).A theoretical model suitable for bend-actuated structures is proposed.It is used to calculate the deflection angle and resonance frequency,and its validity is verified by finite element analysis.Experimental results show that it has a deflection angle of±2.97 mrad(x-axis),±3.24 mrad(y-axis)at 600 V p-p,an unloaded first-order resonance frequency of 1728 Hz,and a quasi-static hysteresis of only 7.5%,which is less than that of PSAs(>10%).With the constructed laser beam deflection system,a circular trajectory is realized,which has the potential for beam steering.
