Reomtly, Coordinate bieasuring Machines （CMMs） are widely used to measure roundness errors. Roundness is calculated from a large number of points collected from the profiles of the parts. According to the Guide to t...Reomtly, Coordinate bieasuring Machines （CMMs） are widely used to measure roundness errors. Roundness is calculated from a large number of points collected from the profiles of the parts. According to the Guide to the Expression of Uncertainty in Measta- meat （GUM）, all measurement results must have a stated uncertainty associated the titan. However, no CMMs give the uncertainty value of the roundness, because no suitable measrement uncertainty calculation procedure exists. In the case of roundness raeasurement in coordinate metrology, this paper suggests the algorithms for the calculation of the measurement uncertainty of the roudness deviation based on the two mainly used association criteria, LSC and MZC. The calculation of the sensitivity coefficients for the uncertainty calculatiion can be done by autnatic differentiation, in order to avoid introducing additional emars by the traditional difference quotient approxima- tions. The proposed methods are exact and need input data only as the nrasured coordinates of the data points and their associated un- certainties.展开更多
High-precision sensing of vectorial forces has broad impact on both fundamental research and technological applications such as the examination of vacuum fluctuations and the detection of surface roughness of nanostru...High-precision sensing of vectorial forces has broad impact on both fundamental research and technological applications such as the examination of vacuum fluctuations and the detection of surface roughness of nanostructures.Recent years have witnessed much progress on sensing alternating electromagnetic forces for the rapidly advancing quantum technology-orders of magnitude improvement has been accomplished on the detection sensitivity with atomic sensors,whereas such high-precision measurements for static electromagnetic forces have rarely been demonstrated.Here,based on quantum atomic matter waves confined by a two-dimensional optical lattice,we perform precision measurement of static electromagnetic forces by imaging coherent wave mechanics in the reciprocal space.The lattice confinement causes a decoupling between real-space and reciprocal dynamics,and provides a rigid coordinate frame for calibrating the wavevector accumulation of the matter wave.With that we achieve a stateof-the-art sensitivity of 2.30(8)×10^(-26) N/√Hz.Long-term stabilities on the order of 10^(-28) N are observed in the two spatial components of a force,which allows probing atomic Van der Waals forces at one millimeter distance.As a further illustrative application,we use our atomic sensor to calibrate the control precision of an alternating electromagnetic force applied in the experiment.Future developments of this method hold promise for delivering unprecedented atom-based quantum force sensing technologies.展开更多
We developed a colorimetric assay to quantify clavulanic acid （CA） in culture broth of Streptomyces clavuligerus, to facilitate screening of a large number of S. clavuligerus mutants. The assay is based on a β-1act...We developed a colorimetric assay to quantify clavulanic acid （CA） in culture broth of Streptomyces clavuligerus, to facilitate screening of a large number of S. clavuligerus mutants. The assay is based on a β-1actamase-catalyzed reaction, in which the yellow substrate nitrocefin （λmax=390 nm） is converted to a red product （λmax=486 nm）. Since CA can irreversibly inhibit β-1actamase activity, the level of CA in a sample can be measured as a function of the A390]A486 ratio in the assay mixture. The sensitivity and detection window of the assay were determined to be 50 μg L -1 and 50 μg L to 10 mg L-1, respectively. The reliability of the assay was confirmed by comparing assay results with those obtained by HPLC. The assay was used to screen a pool of 65 S. clavuligerus mutants and was reliable for identifying CA over-producing mutants. Therefore, the assay saves time and labor in large-scale mutant screening and evaluation tasks. The detection window and the reliability of this assay are markedly better than those of previously reported CA assays. This assay method is suitable for high throughput screening of microbial samples and allows direct visual observation of CA levels on agar plates.展开更多
Phage contamination is a very serious and unavoidable problem in modem fermentation industry. It is necessary to develop sensitive and rapid phage detection methods for the early detection of phage contamination. In t...Phage contamination is a very serious and unavoidable problem in modem fermentation industry. It is necessary to develop sensitive and rapid phage detection methods for the early detection of phage contamination. In the present work, a real-time, rapid, specific and quantitative phage T4 detection method based on surface plasmon resonance （SPR） technique has been in- troduced. Escherichia coli was immobilized onto the preformed MPA self-assembled monolayer （SAM） through the widely used EDC/NHS cross-linking reaction as the recognition element. The bacteria immobilization was verified efficiently through the electrochemical measurements and fluorescence microscopy observations. The specific adsorption was much stronger than the non-specific adsorption of phage T4 binding to the biosensor surface modified by E. coli, and the latter could be neglected. The detection sensitivity reached 1×10^7 PFU/mL within 10 min. Within the experimental phage concentrations, the linear cor- relation between the SPR response and the phage concentration was good. The results suggest that the SPR technique is a po- tentially powerful tool for the phage or other virus detections, as a label-free, real-time, and rapid method.展开更多
In this work,we parallelly detected the specific binding between microarray targets including 12 different kinds of proteins and the probe solution containing five corresponding antibodies and quantitatively analyzed ...In this work,we parallelly detected the specific binding between microarray targets including 12 different kinds of proteins and the probe solution containing five corresponding antibodies and quantitatively analyzed the interactions between CDH13 and solution phase anti-CDH13 at six different probe concentrations by oblique-incidence reflectivity difference(OIRD)method in label-free format.The detection sensitivity reached 10 ng/mL.The experimental results indicate that the OIRD method is a promising and competing technique not only in research work but also in clinic.展开更多
基金supported by the National Natural Science Foundation of China(No.50705002,50627501)
文摘Reomtly, Coordinate bieasuring Machines （CMMs） are widely used to measure roundness errors. Roundness is calculated from a large number of points collected from the profiles of the parts. According to the Guide to the Expression of Uncertainty in Measta- meat （GUM）, all measurement results must have a stated uncertainty associated the titan. However, no CMMs give the uncertainty value of the roundness, because no suitable measrement uncertainty calculation procedure exists. In the case of roundness raeasurement in coordinate metrology, this paper suggests the algorithms for the calculation of the measurement uncertainty of the roudness deviation based on the two mainly used association criteria, LSC and MZC. The calculation of the sensitivity coefficients for the uncertainty calculatiion can be done by autnatic differentiation, in order to avoid introducing additional emars by the traditional difference quotient approxima- tions. The proposed methods are exact and need input data only as the nrasured coordinates of the data points and their associated un- certainties.
基金supported by the National Program on Key Basic Research Project of China (2018YFA0305601, 2021YFA07183012021YFA1400900)+4 种基金the National Natural Science Foundation of China (61727819, 11934002, and 11874073)Shanghai Municipal Science and Technology Major Project (2019SHZDZCX01)the Chinese Academy of Sciences Priority Research Program(XDB35020100)the Science and Technology Major Project of Shanxi (202101030201022)the Space Application System of China Manned Space Program
文摘High-precision sensing of vectorial forces has broad impact on both fundamental research and technological applications such as the examination of vacuum fluctuations and the detection of surface roughness of nanostructures.Recent years have witnessed much progress on sensing alternating electromagnetic forces for the rapidly advancing quantum technology-orders of magnitude improvement has been accomplished on the detection sensitivity with atomic sensors,whereas such high-precision measurements for static electromagnetic forces have rarely been demonstrated.Here,based on quantum atomic matter waves confined by a two-dimensional optical lattice,we perform precision measurement of static electromagnetic forces by imaging coherent wave mechanics in the reciprocal space.The lattice confinement causes a decoupling between real-space and reciprocal dynamics,and provides a rigid coordinate frame for calibrating the wavevector accumulation of the matter wave.With that we achieve a stateof-the-art sensitivity of 2.30(8)×10^(-26) N/√Hz.Long-term stabilities on the order of 10^(-28) N are observed in the two spatial components of a force,which allows probing atomic Van der Waals forces at one millimeter distance.As a further illustrative application,we use our atomic sensor to calibrate the control precision of an alternating electromagnetic force applied in the experiment.Future developments of this method hold promise for delivering unprecedented atom-based quantum force sensing technologies.
基金supported by the Young Scientists Fund (Grant No. 31000025) from the National Natural Science Foundation of ChinaNational High Technology Research and Development Program of China (Grant No. 2012AA021302)
文摘We developed a colorimetric assay to quantify clavulanic acid （CA） in culture broth of Streptomyces clavuligerus, to facilitate screening of a large number of S. clavuligerus mutants. The assay is based on a β-1actamase-catalyzed reaction, in which the yellow substrate nitrocefin （λmax=390 nm） is converted to a red product （λmax=486 nm）. Since CA can irreversibly inhibit β-1actamase activity, the level of CA in a sample can be measured as a function of the A390]A486 ratio in the assay mixture. The sensitivity and detection window of the assay were determined to be 50 μg L -1 and 50 μg L to 10 mg L-1, respectively. The reliability of the assay was confirmed by comparing assay results with those obtained by HPLC. The assay was used to screen a pool of 65 S. clavuligerus mutants and was reliable for identifying CA over-producing mutants. Therefore, the assay saves time and labor in large-scale mutant screening and evaluation tasks. The detection window and the reliability of this assay are markedly better than those of previously reported CA assays. This assay method is suitable for high throughput screening of microbial samples and allows direct visual observation of CA levels on agar plates.
基金support from the National Basic Research Program of China (2011CB933600)the National Natural Science Foundation of China (21077081,20921062)+1 种基金the Natural Science Foundation of Hubei Province (2010CDB01302)the Fundamental Research Funds for Central Universities (1103005 and 1101007)
文摘Phage contamination is a very serious and unavoidable problem in modem fermentation industry. It is necessary to develop sensitive and rapid phage detection methods for the early detection of phage contamination. In the present work, a real-time, rapid, specific and quantitative phage T4 detection method based on surface plasmon resonance （SPR） technique has been in- troduced. Escherichia coli was immobilized onto the preformed MPA self-assembled monolayer （SAM） through the widely used EDC/NHS cross-linking reaction as the recognition element. The bacteria immobilization was verified efficiently through the electrochemical measurements and fluorescence microscopy observations. The specific adsorption was much stronger than the non-specific adsorption of phage T4 binding to the biosensor surface modified by E. coli, and the latter could be neglected. The detection sensitivity reached 1×10^7 PFU/mL within 10 min. Within the experimental phage concentrations, the linear cor- relation between the SPR response and the phage concentration was good. The results suggest that the SPR technique is a po- tentially powerful tool for the phage or other virus detections, as a label-free, real-time, and rapid method.
基金supported by the National Basic Research Program of China(Grant No.2007CB935700)
文摘In this work,we parallelly detected the specific binding between microarray targets including 12 different kinds of proteins and the probe solution containing five corresponding antibodies and quantitatively analyzed the interactions between CDH13 and solution phase anti-CDH13 at six different probe concentrations by oblique-incidence reflectivity difference(OIRD)method in label-free format.The detection sensitivity reached 10 ng/mL.The experimental results indicate that the OIRD method is a promising and competing technique not only in research work but also in clinic.
