We demonstrate the feasibility of simultancous multi-probe detection for an optcal-resolution photoacoustic microscopy(OR-PAM)system.OR-P AM has elicited the attention of biomedical imaging researchers because of its ...We demonstrate the feasibility of simultancous multi-probe detection for an optcal-resolution photoacoustic microscopy(OR-PAM)system.OR-P AM has elicited the attention of biomedical imaging researchers because of its optical absorption contrast and high spatial resolution with great imaging depth.OR-PAM allows label-free and noninvasive imaging by maximizing the optical absorption of endogenous biomolecules.However,given the inadequate absoption of some biomolcules,detection sensitivity at the same incident intensity requires improvement.In this study,a modulated continuous wave with power density less than 3mW/cm^(2)(1/4 of the ANSI safety limit)excited the weak photoacoustic(PA)signals of biological cells.A microcavity traneducer is developed based on the bulk modulus of gas five orders of magnitude lower than that of solid;air pressure variation is inversely proportional to cavity volume at the same temperature increase.Considering that a PA wave expands in various directions,detecting PA signals from different positions and adding them together can increase detection sensitivity and signal-to-noise ratio.Therefore,we employ four detectors to acquire tiny PA signals simul-taneously.Experimental results show that the developed OR-PAM system allows the label-free imaging of cells with weak optical absorption.展开更多
In order to improve the interference rejection performance in the measurement of average ion velocity by multi-grid probe, an integral expression is proposed. The integral expression, differing from other expressions ...In order to improve the interference rejection performance in the measurement of average ion velocity by multi-grid probe, an integral expression is proposed. The integral expression, differing from other expressions for probe measurement, avoids the differential operation on the I-V characteristics of multi-grid probe measurement; and by this method, the ion average velocity can be figured out directly by the I-V characteristics of multi-grid probe measurement.展开更多
Scanning ion conductance microscopy（SICM） is an emerging non-destructive surface topography characterization apparatus with nanoscale resolution. However, the low regulating frequency of probe in most existing modul...Scanning ion conductance microscopy（SICM） is an emerging non-destructive surface topography characterization apparatus with nanoscale resolution. However, the low regulating frequency of probe in most existing modulated current based SICM systems increases the system noise, and has difficulty in imaging sample surface with steep height changes. In order to enable SICM to have the capability of imaging surfaces with steep height changes, a novel probe that can be used in the modulated current based bopping mode is designed. The design relies on two piezoelectric ceramics with different travels to separate position adjustment and probe frequency regulation in the Z direction. To fiarther improve the resonant frequency of the probe, the material and the key dimensions for each component of the probe are optimized based on the multi-objective optimization method and the finite element analysis. The optimal design has a resonant frequency of above 10 kHz. To validate the rationality of the designed probe, microstructured grating samples are imaged using the homebuilt modulated current based SICM system. The experimental results indicate that the designed high frequency probe can effectively reduce the spike noise by 26% in the average number of spike noise. The proposed design provides a feasible solution for improving the imaging quality of the existing SICM systems which normally use ordinary probes with relatively low regulating frequency.展开更多
针对光学元件研磨阶段传统单测头检测方法对机床导轨运动误差敏感,难以同时兼顾检测精度与在位测量效率的问题,提出一种适用于普通机床集成条件下的多测头非接触式面形检测方法,以实现光学元件研磨阶段的高精度在位检测。阐述由3个激光...针对光学元件研磨阶段传统单测头检测方法对机床导轨运动误差敏感,难以同时兼顾检测精度与在位测量效率的问题,提出一种适用于普通机床集成条件下的多测头非接触式面形检测方法,以实现光学元件研磨阶段的高精度在位检测。阐述由3个激光位移传感器组成的多测头系统的差分检测原理,通过三测头两两差分抑制机床导轨运动误差,并将位移差分量转换为被测面局部斜率信息,再基于Zernike多项式的斜率拟合与面形重建原理,利用最小二乘拟合由斜率场反演得到全口径面形。建立系统的几何仿真模型,采用蒙特卡罗法分析测头位置误差和姿态误差对面形重构结果的影响,进一步引入Sobol全局敏感度系数量化各误差源对均方根(Root Mean Square,RMS)误差的贡献,为系统装调公差分配和误差控制策略提供依据。最后,对一片口径为Φ400 mm、材料为单晶硅的研磨阶段平面反射镜进行实验验证,将本研究的检测结果与三坐标测量机(Coordinate Measuring Machine,CMM)的检测结果进行对比。实验结果表明,两种方法得到的峰谷值(Peak to Valley,PV)值绝对偏差为0.21μm,相对偏差为2.22%;RMS值绝对偏差为0.14μm,相对偏差为7.78%。所提方法可保持良好的测量一致性和稳定性,为光学元件研磨阶段的高精度面形检测提供了一种易于工程实现的解决方案。展开更多
A Cd-containing metal–organic framework（Cd L）, formula as {[Cd_3（L）_2（H_2O）_6] 1.5DMF}, has been synthesized under solvothermal condition by the reaction of 4,40,400-（methylsilanetriyl）tribenzoic acid（H_3L）...A Cd-containing metal–organic framework（Cd L）, formula as {[Cd_3（L）_2（H_2O）_6] 1.5DMF}, has been synthesized under solvothermal condition by the reaction of 4,40,400-（methylsilanetriyl）tribenzoic acid（H_3L） and Cd^（2＋）ion. Single-crystal X-ray diffraction reveals that Cd L displays a three-dimensional framework with 2-fold interpenetration and DMF molecules locate in the void space of the channels. A topological analysis of the framework indicates Cd Lisa 3,4-connected pto net. The photoluminescence properties of Cd L are systematically studied in detail. Impressively, Cd L shows excellent detection performance towards Fe^（3＋）ion and acetone in the sensing experiments, which undoubtedly demonstrates the great potential of Cd L as a highly selective multi-responsive luminescent sensor for the detection of organic solvents and metal ions.展开更多
Adenosine 5＇-triphosphate（ATP） not only participates in various physiological activities as the universal energy currency but also implicates in various pathological processes in living cells. Consequently,sensitiv...Adenosine 5＇-triphosphate（ATP） not only participates in various physiological activities as the universal energy currency but also implicates in various pathological processes in living cells. Consequently,sensitive and selective detection ATP in live cells, tissues, as well as environmental samples, are urgently demanded. Due to the simple and convenient operation, economy cost, high selectivity for analyte, well biocompatibility and low cytotoxicity, fluorescent sensors for monitoring ATP have aroused great attention of researchers. In recent years, a large number of fluorescent sensors for detecting ATP have developed. This manuscript summarized most of these sensors and the interaction-mechanism between ATP and sensors, mainly including electrostatic interaction, p-p interaction, covalent bonding or hydrogen bond, or combinations of them, and the advantages of each strategy were also generalized.Here, a viewpoint of classification was shown where the sensors were divided into five typed ones according to the structure of probes used.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.61178086)Science and Technology Program of Guangzhou,China(Grant No.2012J4300138)Foundation for Distinguished Young Talents in South China Normal University,China.(Grant No.2012KJ010).
文摘We demonstrate the feasibility of simultancous multi-probe detection for an optcal-resolution photoacoustic microscopy(OR-PAM)system.OR-P AM has elicited the attention of biomedical imaging researchers because of its optical absorption contrast and high spatial resolution with great imaging depth.OR-PAM allows label-free and noninvasive imaging by maximizing the optical absorption of endogenous biomolecules.However,given the inadequate absoption of some biomolcules,detection sensitivity at the same incident intensity requires improvement.In this study,a modulated continuous wave with power density less than 3mW/cm^(2)(1/4 of the ANSI safety limit)excited the weak photoacoustic(PA)signals of biological cells.A microcavity traneducer is developed based on the bulk modulus of gas five orders of magnitude lower than that of solid;air pressure variation is inversely proportional to cavity volume at the same temperature increase.Considering that a PA wave expands in various directions,detecting PA signals from different positions and adding them together can increase detection sensitivity and signal-to-noise ratio.Therefore,we employ four detectors to acquire tiny PA signals simul-taneously.Experimental results show that the developed OR-PAM system allows the label-free imaging of cells with weak optical absorption.
基金National Natural Science Foundation of China(No.50676026)
文摘In order to improve the interference rejection performance in the measurement of average ion velocity by multi-grid probe, an integral expression is proposed. The integral expression, differing from other expressions for probe measurement, avoids the differential operation on the I-V characteristics of multi-grid probe measurement; and by this method, the ion average velocity can be figured out directly by the I-V characteristics of multi-grid probe measurement.
基金Supported by National Natural Science Foundation of China(Grant No.51375363)
文摘Scanning ion conductance microscopy（SICM） is an emerging non-destructive surface topography characterization apparatus with nanoscale resolution. However, the low regulating frequency of probe in most existing modulated current based SICM systems increases the system noise, and has difficulty in imaging sample surface with steep height changes. In order to enable SICM to have the capability of imaging surfaces with steep height changes, a novel probe that can be used in the modulated current based bopping mode is designed. The design relies on two piezoelectric ceramics with different travels to separate position adjustment and probe frequency regulation in the Z direction. To fiarther improve the resonant frequency of the probe, the material and the key dimensions for each component of the probe are optimized based on the multi-objective optimization method and the finite element analysis. The optimal design has a resonant frequency of above 10 kHz. To validate the rationality of the designed probe, microstructured grating samples are imaged using the homebuilt modulated current based SICM system. The experimental results indicate that the designed high frequency probe can effectively reduce the spike noise by 26% in the average number of spike noise. The proposed design provides a feasible solution for improving the imaging quality of the existing SICM systems which normally use ordinary probes with relatively low regulating frequency.
文摘针对光学元件研磨阶段传统单测头检测方法对机床导轨运动误差敏感,难以同时兼顾检测精度与在位测量效率的问题,提出一种适用于普通机床集成条件下的多测头非接触式面形检测方法,以实现光学元件研磨阶段的高精度在位检测。阐述由3个激光位移传感器组成的多测头系统的差分检测原理,通过三测头两两差分抑制机床导轨运动误差,并将位移差分量转换为被测面局部斜率信息,再基于Zernike多项式的斜率拟合与面形重建原理,利用最小二乘拟合由斜率场反演得到全口径面形。建立系统的几何仿真模型,采用蒙特卡罗法分析测头位置误差和姿态误差对面形重构结果的影响,进一步引入Sobol全局敏感度系数量化各误差源对均方根(Root Mean Square,RMS)误差的贡献,为系统装调公差分配和误差控制策略提供依据。最后,对一片口径为Φ400 mm、材料为单晶硅的研磨阶段平面反射镜进行实验验证,将本研究的检测结果与三坐标测量机(Coordinate Measuring Machine,CMM)的检测结果进行对比。实验结果表明,两种方法得到的峰谷值(Peak to Valley,PV)值绝对偏差为0.21μm,相对偏差为2.22%;RMS值绝对偏差为0.14μm,相对偏差为7.78%。所提方法可保持良好的测量一致性和稳定性,为光学元件研磨阶段的高精度面形检测提供了一种易于工程实现的解决方案。
基金supported by National Natural Science Foundation of China (Nos. 21171162, 21471144)Jilin Province Youth Foundation (No. 20130522132JH)+1 种基金Jilin Province Natural Science Foundation (No. 20150101181JC)Changchun Science and Technology Plan (No. 2013059)
文摘A Cd-containing metal–organic framework（Cd L）, formula as {[Cd_3（L）_2（H_2O）_6] 1.5DMF}, has been synthesized under solvothermal condition by the reaction of 4,40,400-（methylsilanetriyl）tribenzoic acid（H_3L） and Cd^（2＋）ion. Single-crystal X-ray diffraction reveals that Cd L displays a three-dimensional framework with 2-fold interpenetration and DMF molecules locate in the void space of the channels. A topological analysis of the framework indicates Cd Lisa 3,4-connected pto net. The photoluminescence properties of Cd L are systematically studied in detail. Impressively, Cd L shows excellent detection performance towards Fe^（3＋）ion and acetone in the sensing experiments, which undoubtedly demonstrates the great potential of Cd L as a highly selective multi-responsive luminescent sensor for the detection of organic solvents and metal ions.
基金supported by the National Natural Science Foundation of China (Nos. 21676218, 21476185, 21472016, 21272030)the Fundamental Research Funds for the Central Universities (Nos. 2014YB027, 2452015447, 2452013py014)Shaanxi Province Science and Technology
文摘Adenosine 5＇-triphosphate（ATP） not only participates in various physiological activities as the universal energy currency but also implicates in various pathological processes in living cells. Consequently,sensitive and selective detection ATP in live cells, tissues, as well as environmental samples, are urgently demanded. Due to the simple and convenient operation, economy cost, high selectivity for analyte, well biocompatibility and low cytotoxicity, fluorescent sensors for monitoring ATP have aroused great attention of researchers. In recent years, a large number of fluorescent sensors for detecting ATP have developed. This manuscript summarized most of these sensors and the interaction-mechanism between ATP and sensors, mainly including electrostatic interaction, p-p interaction, covalent bonding or hydrogen bond, or combinations of them, and the advantages of each strategy were also generalized.Here, a viewpoint of classification was shown where the sensors were divided into five typed ones according to the structure of probes used.
