Cost effective patterning based on scanning probe nanolithography(SPL)has the potential for electronic and optical nano-device manufacturing and other nanotechnological applications.One of the fundamental advantages o...Cost effective patterning based on scanning probe nanolithography(SPL)has the potential for electronic and optical nano-device manufacturing and other nanotechnological applications.One of the fundamental advantages of SPL is its capability for patterning and imaging employing the same probe.This is achieved with self-sensing and self-actuating cantilevers,also known as‘active'cantilevers.Here we used active cantilevers to demonstrate a novel path towards single digit nanoscale patterning by employing a low energy(<100 eV)electron exposure to thin films of molecular resist.By tuning the electron energies to the lithographically relevant chemical resist transformations,the interaction volumes can be highly localized.This method allows for greater control over spatially confined lithography and enhances sensitivity.We found that at low electron energies,the exposure in ambient conditions required approximately 10 electrons per single calixarene molecule to induce a crosslinking event.The sensitivity was 80-times greater than a classical electron beam exposure at 30 keV.By operating the electro-exposure process in ambient conditions a novel lithographic reaction scheme based on a direct ablation of resist material(positive tone)is presented.展开更多
Objective The detection of RNA single nucleotide polymorphism(SNP)is of great importance due to their association with protein expression related to various diseases and drug responses.At present,splintR ligase-assist...Objective The detection of RNA single nucleotide polymorphism(SNP)is of great importance due to their association with protein expression related to various diseases and drug responses.At present,splintR ligase-assisted methods are important approaches for RNA direct detection,but its specificity will be limited when the fidelity of ligases is not ideal.The aim of this study was to create a method to improve the specificity of splintR ligase for RNA detection.Methods In this study,a dualcompetitive-padlock-probe(DCPLP)assay without the need for additional enzymes or reactions is proposed to improve specificity of splintR ligase ligation.To verify the method,we employed dual competitive padlock probe-mediated rolling circle amplification(DCPLP-RCA)to genotype the CYP2C9 gene.Results The specificity was well improved through the competition and strand displacement of dual padlock probe,with an 83.26%reduction in nonspecific signal.By detecting synthetic RNA samples,the method demonstrated a dynamic detection range of 10 pmol/L-1 nmol/L.Furthermore,clinical samples were applied to the method to evaluate its performance,and the genotyping results were consistent with those obtained using the qPCR method.Conclusion This study has successfully established a highly specific direct RNA SNP detection method,and provided a novel avenue for accurate identification of various types of RNAs.展开更多
In this work, we construct electrodes of brass to produce plasma by arc discharge and is characterized by using a movableLangmuir single probe. It is a simple way to measure plasma parameters such as electron temperat...In this work, we construct electrodes of brass to produce plasma by arc discharge and is characterized by using a movableLangmuir single probe. It is a simple way to measure plasma parameters such as electron temperature, electron density and iondensity. A movable Langmuir single probe technique has a reference point since it is biased with reference to any one electrode ofthe plasma producing system. The values obtained are at atmospheric pressure. The plasma thus produced in laboratory has variousapplications which include gaseous discharge, plasma torch, sputtering, laser produced plasma as well as tokamak plasma.展开更多
To identify flow patterns in horizontal gas-liquid flows,a single-wire capacitance probe was used for voltage output for the first time.Regardless of the measurement accuracy of water layer height,the statistic parame...To identify flow patterns in horizontal gas-liquid flows,a single-wire capacitance probe was used for voltage output for the first time.Regardless of the measurement accuracy of water layer height,the statistic parameters of the voltage-time traces were compared within the same sampling time of 5s under different flow patterns,including maximum,minimum,range,and average.The results show that most of flow pattens were accurately identified except for some transition lines.展开更多
The principle and accuracy of 3-D coordinates acquisition using one single camera and the Aided Measuring Probe(AMP) are discussed in this paper. Using one single camera and one AMP which has several embedded targets ...The principle and accuracy of 3-D coordinates acquisition using one single camera and the Aided Measuring Probe(AMP) are discussed in this paper. Using one single camera and one AMP which has several embedded targets and one tip with known coordinates, the single camera′s orientation and location can be calculated. After orientation, the global coordinate system is obtained. During measurement, the camera is fixed firstly, then the AMP is held and the feature point is touched.The camera is triggered lastly. The position and orientation of the AMP are therefore calculated from the size and position of its image on the sensor. Since the tip point of AMP has known relation with the embedded targets, the feature point can be measured. Tests show that the accuracy of length measurement is 0.2 mm and accuracy for flatness measurement in XSY-plane is 0.1 mm.展开更多
Based on the traditional measurement theory of transient plane source (TPS) technique, single-side TPS method is proposed for measuring the thermal conductivity of single specimen. The problem of transient heat conduc...Based on the traditional measurement theory of transient plane source (TPS) technique, single-side TPS method is proposed for measuring the thermal conductivity of single specimen. The problem of transient heat conduction in a semi-infinite boundary condition is studied and the theoretical formula of single-side TPS method is deduced. During the measurement, the influence of the probe heat capacity on the results is analyzed and the corresponding mathematical compensation model is established, and a series of experiments on different materials are conducted by hot disk probe at normal temperature and pressure. The results show that the relative error with the single-side TPS method is less than 5% and the relative standard deviation is no greater than 3%. This method has high accuracy and good reproducibility, which provides a feasible measuring method for single material that does not meet the requirements of the standard TPS theory.展开更多
A nuclear microprobe with high spatial resolution and high analyti- cal sensitivity was applied to analyze atmospheric aerosol at five monitoring sites in Shanghai city. Meantime, a new pattern recognition technique, ...A nuclear microprobe with high spatial resolution and high analyti- cal sensitivity was applied to analyze atmospheric aerosol at five monitoring sites in Shanghai city. Meantime, a new pattern recognition technique, which used the micro PIXE spectrum of a single aerosol particle as its fingerprint, was developed to identify the origin of the particle. The results showed that the major contributors to the at- mosphere pollution were soil dust (31.6%), building dust (30.8%), and the next were vehicle exhaust (13.7%), metallurgic industry excrements (5.6%), oil combustion (5%) and coal combustion (2.3%). Besides these, about 10% of the particles could not be identified. Based on the cluster analysis of these particles, they could be divided into eight groups. By inference, they might belong to some sub-pollution sources from soil dust, building dust and metallurgic industry excrements. Moreover, some new pollution sources from tyres and chemical plants were also revealed.展开更多
实现土壤失水过程的原位监测,对红壤区水土资源管理、自然灾害预警及防灾减灾具有重要意义。热脉冲法是目前土壤水热特性原位测量的常用方法,但红壤土失水时极易产生裂缝,单探针热脉冲法能否准确测定失水过程目前尚不清楚。通过室内模...实现土壤失水过程的原位监测,对红壤区水土资源管理、自然灾害预警及防灾减灾具有重要意义。热脉冲法是目前土壤水热特性原位测量的常用方法,但红壤土失水时极易产生裂缝,单探针热脉冲法能否准确测定失水过程目前尚不清楚。通过室内模拟土壤从饱和到干燥的连续失水过程,用时域反射法(TDR)作为标准对照,验证热脉冲方法测定土壤失水过程的准确性,并评估土壤裂缝产生后对单探针热脉冲法的影响。结果表明:随着土壤失水,土壤热导率K值由1.8 W/(m·K)减小到1.1 W/(m·K),热扩散率α值由1.0×10^(-8)m^(2)/s增加到3.0×10-8 m 2/s,比热容C值由1.8×108 J/(kg·K)减小到0.4×10^(8)J/(kg·K);接触热导率H值随着土壤失水具有台阶状变化特征,与土壤含水率变化速率的转折相吻合;与TDR测定结果相比,MAE和RMSE值分别为1.66和1.94 cm 3/cm^(3),R^(2)值为0.96;单探针热脉冲法能提供可靠的红壤土失水过程测定结果,且H值的变化能指征土壤裂隙的产生,可为土壤干湿循环过程、边坡和堤坝稳定性的动态监测提供技术和理论支撑。展开更多
单分子荧光原位杂交(single-molecule fluorescence in situ hybridization,smFISH)技术是一种通过用偶联荧光基团的寡核苷酸探针,对固定细胞或组织中单个mRNA分子进行成像的方法。smFISH可对RNA进行定位、定量,以此对目标转录本进行实...单分子荧光原位杂交(single-molecule fluorescence in situ hybridization,smFISH)技术是一种通过用偶联荧光基团的寡核苷酸探针,对固定细胞或组织中单个mRNA分子进行成像的方法。smFISH可对RNA进行定位、定量,以此对目标转录本进行实时研究。sm FISH适用于细胞、组织切片等多种类型生物样本。近年来,多种基于基础smFISH的改进技术被发明,进一步促进了该技术的实际应用。smFISH良好的RNA单分子可视化能力,使得其在发育生物学、神经生物学及肿瘤生物学等基础生物学科中得到了广泛的应用。本文综述了smFISH技术基本原理、smFISH技术的局限性、smFISH衍生技术方法、smFISH在不同生物学科中的应用进展,并对smFISH技术的发展前景做出展望。展开更多
To establish a rapid, accurate and economical real-time PCR assay system based on TaqMan probe technology for the detection of genetic variations of single nucleotide polymorphisms （SNPs） in myestatin （MSTN） gene,...To establish a rapid, accurate and economical real-time PCR assay system based on TaqMan probe technology for the detection of genetic variations of single nucleotide polymorphisms （SNPs） in myestatin （MSTN） gene, a pair of TaqMan probes were designed on the polymorphism loci of MSTN gene and used in PCR reaction system for SNP genotyping. Meanwhile, an association study was performed between MSTN genotypes and growth traits of Tan sheep, including birth weight, weaning weight, 3-month weight, and 6-month weight. The results showed that rs417816017 locus of MSTN gene in Tan sheep had two genotypes ： YY and XY. The individuals with genotype XY had a growth advantage over the ones with genotype YY. The results indicate that TaqMan probe-based real-time PCR assay can be used to detect the genotype of MSTN gene, which will provide candidate genes for breeding of Tan sheep.展开更多
A probe-hole field emission microscope system,controlled by the Apple Ⅱ computer,has been developed and operated successfully for measuring the work function of a single crystalplane.The detection screen,the phototub...A probe-hole field emission microscope system,controlled by the Apple Ⅱ computer,has been developed and operated successfully for measuring the work function of a single crystalplane.The detection screen,the phototube and the amplifier are combined for measuring theprobe-hole current.The combination is calibrated and the calibrated data are used in the com-puter program.The high voltage on the viewing screen is adjusted by using a D/A converter.The total current and the probe-hole current are acquired by using an A/D converter.A programin BASIC is used for processing all data and the Fowler-Nordheim plot parameters are given.Work functions of single crystal planes can then be calculated;as examples,the work functionson the clean W(100)and W(111)planes are measured to be 4.67 eV and 4.45 eV,respectively.展开更多
文摘Cost effective patterning based on scanning probe nanolithography(SPL)has the potential for electronic and optical nano-device manufacturing and other nanotechnological applications.One of the fundamental advantages of SPL is its capability for patterning and imaging employing the same probe.This is achieved with self-sensing and self-actuating cantilevers,also known as‘active'cantilevers.Here we used active cantilevers to demonstrate a novel path towards single digit nanoscale patterning by employing a low energy(<100 eV)electron exposure to thin films of molecular resist.By tuning the electron energies to the lithographically relevant chemical resist transformations,the interaction volumes can be highly localized.This method allows for greater control over spatially confined lithography and enhances sensitivity.We found that at low electron energies,the exposure in ambient conditions required approximately 10 electrons per single calixarene molecule to induce a crosslinking event.The sensitivity was 80-times greater than a classical electron beam exposure at 30 keV.By operating the electro-exposure process in ambient conditions a novel lithographic reaction scheme based on a direct ablation of resist material(positive tone)is presented.
文摘Objective The detection of RNA single nucleotide polymorphism(SNP)is of great importance due to their association with protein expression related to various diseases and drug responses.At present,splintR ligase-assisted methods are important approaches for RNA direct detection,but its specificity will be limited when the fidelity of ligases is not ideal.The aim of this study was to create a method to improve the specificity of splintR ligase for RNA detection.Methods In this study,a dualcompetitive-padlock-probe(DCPLP)assay without the need for additional enzymes or reactions is proposed to improve specificity of splintR ligase ligation.To verify the method,we employed dual competitive padlock probe-mediated rolling circle amplification(DCPLP-RCA)to genotype the CYP2C9 gene.Results The specificity was well improved through the competition and strand displacement of dual padlock probe,with an 83.26%reduction in nonspecific signal.By detecting synthetic RNA samples,the method demonstrated a dynamic detection range of 10 pmol/L-1 nmol/L.Furthermore,clinical samples were applied to the method to evaluate its performance,and the genotyping results were consistent with those obtained using the qPCR method.Conclusion This study has successfully established a highly specific direct RNA SNP detection method,and provided a novel avenue for accurate identification of various types of RNAs.
文摘In this work, we construct electrodes of brass to produce plasma by arc discharge and is characterized by using a movableLangmuir single probe. It is a simple way to measure plasma parameters such as electron temperature, electron density and iondensity. A movable Langmuir single probe technique has a reference point since it is biased with reference to any one electrode ofthe plasma producing system. The values obtained are at atmospheric pressure. The plasma thus produced in laboratory has variousapplications which include gaseous discharge, plasma torch, sputtering, laser produced plasma as well as tokamak plasma.
基金Supported by Postdoctoral Foundation of P R China(Grant No:20080440619)
文摘To identify flow patterns in horizontal gas-liquid flows,a single-wire capacitance probe was used for voltage output for the first time.Regardless of the measurement accuracy of water layer height,the statistic parameters of the voltage-time traces were compared within the same sampling time of 5s under different flow patterns,including maximum,minimum,range,and average.The results show that most of flow pattens were accurately identified except for some transition lines.
文摘The principle and accuracy of 3-D coordinates acquisition using one single camera and the Aided Measuring Probe(AMP) are discussed in this paper. Using one single camera and one AMP which has several embedded targets and one tip with known coordinates, the single camera′s orientation and location can be calculated. After orientation, the global coordinate system is obtained. During measurement, the camera is fixed firstly, then the AMP is held and the feature point is touched.The camera is triggered lastly. The position and orientation of the AMP are therefore calculated from the size and position of its image on the sensor. Since the tip point of AMP has known relation with the embedded targets, the feature point can be measured. Tests show that the accuracy of length measurement is 0.2 mm and accuracy for flatness measurement in XSY-plane is 0.1 mm.
文摘Based on the traditional measurement theory of transient plane source (TPS) technique, single-side TPS method is proposed for measuring the thermal conductivity of single specimen. The problem of transient heat conduction in a semi-infinite boundary condition is studied and the theoretical formula of single-side TPS method is deduced. During the measurement, the influence of the probe heat capacity on the results is analyzed and the corresponding mathematical compensation model is established, and a series of experiments on different materials are conducted by hot disk probe at normal temperature and pressure. The results show that the relative error with the single-side TPS method is less than 5% and the relative standard deviation is no greater than 3%. This method has high accuracy and good reproducibility, which provides a feasible measuring method for single material that does not meet the requirements of the standard TPS theory.
基金Supported by National Natural Science Foundation of China (11030042)
文摘A nuclear microprobe with high spatial resolution and high analyti- cal sensitivity was applied to analyze atmospheric aerosol at five monitoring sites in Shanghai city. Meantime, a new pattern recognition technique, which used the micro PIXE spectrum of a single aerosol particle as its fingerprint, was developed to identify the origin of the particle. The results showed that the major contributors to the at- mosphere pollution were soil dust (31.6%), building dust (30.8%), and the next were vehicle exhaust (13.7%), metallurgic industry excrements (5.6%), oil combustion (5%) and coal combustion (2.3%). Besides these, about 10% of the particles could not be identified. Based on the cluster analysis of these particles, they could be divided into eight groups. By inference, they might belong to some sub-pollution sources from soil dust, building dust and metallurgic industry excrements. Moreover, some new pollution sources from tyres and chemical plants were also revealed.
文摘实现土壤失水过程的原位监测,对红壤区水土资源管理、自然灾害预警及防灾减灾具有重要意义。热脉冲法是目前土壤水热特性原位测量的常用方法,但红壤土失水时极易产生裂缝,单探针热脉冲法能否准确测定失水过程目前尚不清楚。通过室内模拟土壤从饱和到干燥的连续失水过程,用时域反射法(TDR)作为标准对照,验证热脉冲方法测定土壤失水过程的准确性,并评估土壤裂缝产生后对单探针热脉冲法的影响。结果表明:随着土壤失水,土壤热导率K值由1.8 W/(m·K)减小到1.1 W/(m·K),热扩散率α值由1.0×10^(-8)m^(2)/s增加到3.0×10-8 m 2/s,比热容C值由1.8×108 J/(kg·K)减小到0.4×10^(8)J/(kg·K);接触热导率H值随着土壤失水具有台阶状变化特征,与土壤含水率变化速率的转折相吻合;与TDR测定结果相比,MAE和RMSE值分别为1.66和1.94 cm 3/cm^(3),R^(2)值为0.96;单探针热脉冲法能提供可靠的红壤土失水过程测定结果,且H值的变化能指征土壤裂隙的产生,可为土壤干湿循环过程、边坡和堤坝稳定性的动态监测提供技术和理论支撑。
基金Supported by Special Fund for Science and Technology Development of Ningxia Hui Autonomous Region(2012ZDN1001)Domestic Animal Germplasm Resources Sharing Platform Project(2005DKA21101)
文摘To establish a rapid, accurate and economical real-time PCR assay system based on TaqMan probe technology for the detection of genetic variations of single nucleotide polymorphisms （SNPs） in myestatin （MSTN） gene, a pair of TaqMan probes were designed on the polymorphism loci of MSTN gene and used in PCR reaction system for SNP genotyping. Meanwhile, an association study was performed between MSTN genotypes and growth traits of Tan sheep, including birth weight, weaning weight, 3-month weight, and 6-month weight. The results showed that rs417816017 locus of MSTN gene in Tan sheep had two genotypes ： YY and XY. The individuals with genotype XY had a growth advantage over the ones with genotype YY. The results indicate that TaqMan probe-based real-time PCR assay can be used to detect the genotype of MSTN gene, which will provide candidate genes for breeding of Tan sheep.
基金Subject Supported by the Natural Science Fund of China.
文摘A probe-hole field emission microscope system,controlled by the Apple Ⅱ computer,has been developed and operated successfully for measuring the work function of a single crystalplane.The detection screen,the phototube and the amplifier are combined for measuring theprobe-hole current.The combination is calibrated and the calibrated data are used in the com-puter program.The high voltage on the viewing screen is adjusted by using a D/A converter.The total current and the probe-hole current are acquired by using an A/D converter.A programin BASIC is used for processing all data and the Fowler-Nordheim plot parameters are given.Work functions of single crystal planes can then be calculated;as examples,the work functionson the clean W(100)and W(111)planes are measured to be 4.67 eV and 4.45 eV,respectively.
