计量科学与技术

Exploration of Ground Verification for Adaptability Research of Metrology Standards in Space

CHEN Aqin, LIU Min, DING Wei, JIN Haibin, WANG Wei

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0172

Abstract(14)

HTML (9)

PDF(0)

Abstract:
Space metrology is a technical management activity that ensures the uniformity, accuracy, and reliability of measurement units in outer space. This article takes the study of space metrology as the starting point, selects standard resistors and voltage benchmarks as the research objects, explores the ground test hardware platform for space application electrical standards, and designs a ground verification test platform. Through the analysis of the measurement uncertainty of the design platform, the measurement uncertainty can reach the level of 10⁻⁵, laying the foundation for the development of spatial metrology requirements. However, the system has only been validated for a certain range of physical resistance and specific voltage values, and further research is needed for ground verification systems of other electrical standards.

Measurement and Analysis of Graphene Layers Based on Raman Spectroscopy

LV Qingbin, LIANG Junmei, ZHAO Haibo, ZHAO Xiaoning, LIU Ran, WANG Bingyue

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0218

Abstract(41)

HTML (34)

PDF(2)

Abstract:
Graphene material layer control is one of the important indicators to achieve high-quality development of graphene. Accurately measuring the number of layers is the core for the research, development and application of graphene materials, and analyzing the number of layers for graphene materials has a significant impact on their product performance and applications., the necessity of graphene layer number measurement is first described, and then several existing methods for measuring graphene layers are summarized, including optical contrast method, Raman spectroscopy, atomic force microscopy, and high-resolution transmission electron microscopy. The number of layers of graphene samples prepared by mechanical exfoliation method is measured and analyzed based on Raman spectroscopy . Meanwhile, the randomly selected graphene samples are measured using Raman spectroscopy. By selecting the testing conditions, the signal value of Raman mode peak for blank substrate silicon is higher than 5000. Under the testing method, the characteristic peaks of silicon Raman modes containing graphene samples are measured, we also calculate the ratio of Raman peak heights between graphene containing samples and blank substrates. Compare this ratio with the theoretical value measured by Raman spectroscopy in the national standard to determine the number of layers for graphene samples. The test results show that the developed technique can measure the layer number of graphene film samples prepared by mechanical stripping method, and further provide a reference for detection analysis of the layer number of graphene materials.

Progress in Peptide Chemical Synthesis and its Metrology

ZHAO Yue, ZHAO Haibo, LENG Xiaojing, ZHAO Xiaoning, WANG Bingyue

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0215

Abstract(53)

HTML (42)

Abstract:
Peptides are an important class of organic molecules in life bodies, and they participate in life activities together with proteins. Peptides, which have strong biological activity and biological functions, have been widely used in new materials, biological medicine, food, cosmetics and other fields. And they have tremendous social and economic value. In recent years, the rapid development of peptide synthesis technology, especially the rapid development of peptide chemical synthesis method, has greatly accelerated the development and application of peptide products. In the face of more and more peptide products on the market, the market demand for biological activity analysis of peptide compounds is increasing. And at the same time, the standardization of quality control of peptide products is also put forward. As a science of measurement, metrology technology can ensure that the measurement results can be reproduced and traced, and plays a critical role in the development and production of peptides and the quality control of related products. Developing peptide/protein metrology, which focuses on the research to achieve the accuracy and consistency of biological measurement and to ensure the measurement results can be traced to the international system of Units (SI), is an urgent and arduous task for metrology workers. This paper comprehensively introduces the chemical synthesis strategies of peptides, along with the advantages and disadvantages of these strategies, and application values. Meanwhile, the development, application and challenges of peptide/protein metrology are also introduced. This article intends to provide a reference for the quality control of peptide/protein products.

Experimental Study of Wall Shear Stress Based on Double-Layer Hot Film

FU Zhengwei, ZHAO Longhui, ZHANG Qi, YANG Shuiwang, JIANG Yuxuan, CHEN Xiaoting

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0242

Abstract(95)

HTML (37)

Abstract:
The shear stress of fluid wall is a direct parameter to accurately study the frictional resistance of fluid flowing through solid wall, and is a key parameter to evaluate the performance of aircraft equipment and surface friction distribution. Accurate measurement of wall shear stress is of great significance to obtain the viscous resistance of aircraft and optimize the structure of aircraft.. Aiming at the verification of the wall shear stress measurement method based on double-layer hot film technology, a long pipeline air flow wall shear stress test platform was designed to verify the accuracy of the method to measure wall shear stress, and also to verify the stability and repeatability of the double-layer hot film sensor to measure wall shear stress under different temperature differences. At ΔT = 30℃, 40℃, 50℃ and 60℃, the maximum measured wall shear stress is 1.27 Pa, the relative synthetic uncertainty of wall shear stress measurement is 0.50%, and the relative error is less than 4%.

Utilization and Advancement in Reference Materials of Per- and Polyfluoroalkyl Substances

ZHU Xin, WEI Qi, SU Fuhai

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0181

Abstract(51)

HTML (61)

Abstract:
Per- and polyfluoroalkyl substances (PFAS) are a class of persistent organic pollutants, which are difficult to degrade, bioaccumulative, and have long-range transport properties. Therefore, China, America and the EU have taken a series of legal measures to regulate PFAS since 2023. Reference materials play an important role PFAS regulation and should be given sufficient attention. Currently, the PFAS reference materials system in China is deficient, because not only pure substances and standard solutions, but also isotopically labeled reference substances materials and matrix reference materials need to be further enriched and developed. In addition, this paper reviews the application of some PFAS reference materials in environmental analysis in the past five years, providing underutilized uses for reference materials for environmental analysis and monitoring work. Finally, some suggestions are provided for the construction of the PFAS reference materials system in China.

Comparative Analysis of Energy Spectrum Simulation for Medical Diagnostic X-Rays

XU Jun, HAO Wei, WANG Jiawei, ZHANG Zhicheng, DU Yusheng

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0206

Abstract(27)

HTML (19)

PDF(2)

Abstract:
In order to further understand the radiation characteristics of medical diagnostic X-rays and verify the feasibility of computer energy spectrum simulation, two Monte Carlo simulation programs, EGSnrc and MCNP5, were used to simulate the X-ray energy spectrum distribution under different tube voltages and different additional filter thicknesses, and the energy spectrum database of RQR series radiation qualities was established. The results show that the energy spectrum distribution of X-ray is affected by tube voltage and filter material. In daily practice, when the anode target Angle of the X-ray equipment has been determined, the accurate setting of the tube voltage, regular monitoring of the radiation quality changes, and the necessary adjustment of the additional filtration are necessary means to ensure the consistency of the measurement results of the medical diagnostic equipment. Comparing and analyzing the simulation results of the two software, the average energy difference is less than 2%. EGSnrc has the advantages of easy use, high simulation efficiency and convenient data processing in the process of simulation calculation.

Research and Implementation of a Fully Intelligent Pressure Gauge Calibration System

DENG Yulan, LIN Feizhen, LIN Yanbo, SUN Tao, HUANG Feng

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0233

Abstract(48)

HTML (29)

PDF(2)

Abstract:
To improve the calibration efficiency of pressure gauges and reduce reading errors, a fully intelligent pressure gauge calibration system has been developed. The system consists of an integrated AI recognition model, control software, and calibration devices, achieving full intelligence and automation of the pressure gauge calibration process. The recognition model of the system is an integrated AI model based on a deep learning network framework, integrating YOLO detection model, Paddle OCR model, text classifier, and adjacent angle reading algorithm. It can not only recognize the reading information of pointers in pressure gauge images, but also recognize basic information such as the manufacturer, production number, accuracy level, and unit of the pressure gauge; The control software is designed based on a multi-threaded and asynchronous communication structure, supporting simultaneous communication with multiple hardware of the calibration device, controlling the simultaneous calibration of multiple pressure gauges, and supporting the storage of calibration images and data for later review and traceability. It also supports synchronizing calibration results to the OA system and automatically printing calibration certificates. Through experimental verification, the results show that the system can accurately and reliably calibrate 1-6 pressure gauges simultaneously. Compared with manual calibration and other automated calibration systems, the system has a greater degree of intelligence, higher calibration efficiency, and smaller reading errors. It has practical application and promotion significance.

Research on the Calibration Method of PM_2.5/PM₁₀ Particle Automatic Monitoring Instrument Based on Gravimetric Method

ZHANG Wenge, LIU Wei, ZHAO Liang, CHEN Jinchang, ZHOU Huanhuan

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0179

Abstract(44)

HTML (32)

PDF(5)

Abstract:
To ensure the accuracy and reliability of PM_2.5/PM₁₀ monitoring data, the traceability method for the automatic PM_2.5/PM₁₀ particle automatic monitoring instrument based on the gravimetric method was studied. Parameters of common features and key technologies that affect the measurement accuracy of such instruments have been determined by analysing this type of structure and working principle. Based on introducing the functions, parameters, and influencing factors of key modules such as sampling unit, constant temperature and humidity module, weighing module, and filter membrane electrostatic removal module, we studied the corresponding calibration methods and extracted the corresponding measurement performance parameters, and specified the value of the parameter indicators. Finally the rationality of the values of measurement performance parameters and the feasibility of testing methods were further verified through experiments in which took monitoring instruments with high market share as samples. At the same time, the uncertainty evaluation method for the calibration results was provided by analysing the influencing factors of the calibration procedure. This study lays the foundation for further promoting the development of corresponding technical specifications and guiding the accuracy and effectiveness of calibration data for such instruments.

Research Progress of Fluid Viscosity Measurement Technologies

LI Youqiang, WANG Jun, FAN Xu, HOU Likai

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0212

Abstract(35)

HTML (36)

Abstract:
Viscosity is an important fluid characteristic that measures the magnitude of a fluid's viscosity coefficient. How to choose an appropriate viscosity measurement method is crucial for industrial production and scientific research and development. With the expansion of microfluidic applications in fields such as biomedicine, new energy and new materials, viscosity measurement methods for microfluidics are gradually emerging. To better meet people's needs for selecting viscosity measurement methods and to provide more comprehensive and advanced guidelines for relevant researchers, this article reviews the current status of fluid viscosity measurement technology and divides current viscosity measurement methods into two categories: traditional macroscopic fluid viscosity measurement methods and microfluidic viscosity measurement methods. For traditional macroscopic fluid measurement methods, this article reviews the related methods and devices such as rotational viscometers, oscillatory viscometers, falling viscometers, and ultrasonic viscometers, and introduces their structures, measurement principles, advantages and disadvantages, and current status. For microfluidic viscosity measurement methods, the article introduces several new types of methods and devices, including Micro Electro Mechanical System (MEMS)-based viscometers, optically based microfluidic viscometers, droplet-based microfluidic viscometers and paper-based microfluidic viscometers. The article explores their structural characteristics, measurement accuracy and principles, and compares them with traditional viscometers to highlight their respective advantages. The conclusion indicates that although traditional viscosity measurement devices are still the preferred choice for large-scale industrial production processes, new microfluidic viscometers are increasingly valued for their advantages, such as small sample size, high measurement efficiency, low cost and compact size. This review provides a valuable reference for selecting the most suitable viscosity measurement method for specific needs.

Calibration Reagent Research of Isothermal PCR Analyzer Based on Loop-mediated Isothermal Amplification Technology

CHEN Xian, WU Xiao, WANG Zhidong, GAO Yunhua

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0203

Abstract(25)

HTML (22)

PDF(3)

Abstract:
To meet the urgent calibration requirements of the isothermal polymerase chain reaction analyzer (PCR instrument) in the market, this paper developed the calibration reagent and standard system for isothermal PCR instruments based on loop-mediated isothermal amplification (LAMP) technology. The specific values and characteristic sequences of the fluorescence quantitative PCR instrument standard material (GBW(E)091100-091108) was utilized as the standard, and LAMP regular primers (F3, B3, FIP, BIP) and loop primers (LF, LB) were designed. The screening tests for optimum regular primers, loop primers and temperature testing were performed; besides, the performance of the calibration kit was investigated by examining its corresponding standard material concentration gradient range, sensitivity, and reproducibility, and then validated based on a commercial isothermal PCR instrument. The results showed that the optimum temperature of LAMP calibration kit is 65℃, the calibration concentration range covers 7 orders of magnitude (10⁰～10⁶ copies/μL), and the minimum detectable concentration can reach 10⁰ copies/μL, demonstrating the advantage of good repeatability. In conclusion, the developed isothermal PCR instruments calibration reagents based on the LAMP technology are suitable for the calibration test of isothermal PCR instruments, support the performance evaluation and market supervision of isothermal PCR instruments, and lay a foundation for the formulation and implementation of national calibration and verification standards for isothermal PCR instruments.

Research on the Spatio-Temporal Distribution and Influencing Factors of Carbon Emissions in China's Power Industry

LEI Shaobo, TONG Chenhua, XIAO Bin, FAN Haoyan

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0170

Abstract(67)

HTML (29)

PDF(3)

Abstract:
In 2020, China proposed the goal of peaking carbon emissions and achieving carbon neutrality. As a key industry, the power industry's carbon emission is an important factor in achieving carbon peaking and carbon neutrality. To analyze the characteristics and influencing factors of carbon emissions in China's power industry, traditional statistical methods are used to analyze the spatio-temporal data of carbon emissions, and the grey correlation analysis method is used to analyze the carbon emissions of different energy sources in the power industry. From the aspect of time data, the carbon emissions of China's power industry have been increasing year by year, and the growth rate continues to fluctuate; From the aspect of spatial data, the carbon emissions of the power industry in the Bohai Rim region have always been at a high level. The carbon emissions of the power industry in Inner Mongolia and Xinjiang are showing an upward trend, while the carbon emissions of the power industry in the Jiangsu-Zhejiang-Shanghai district are showing a downward trend; From the results of grey correlation analysis, it can be seen that the carbon emissions of raw coal, other petroleum products, coke oven gas, and other natural gas have a significant impact on the carbon emissions of the power industry.

Methodological Study of Carbon Emission Reduction for Coal Oxy-Fuel Combustion Power Generation Project

XIE Hui, LI Yanghai, XIONG Zhuo, WANG Pingping, ZHANG Junying, ZHAO Yongchun

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0038

Abstract(45)

HTML (19)

Abstract:
Coal oxy-fuel combustion technology is of great practical significance for efficient carbon reduction in coal-fired power generation. However, there is no clear accounting method for carbon emission reduction in coal oxy-fuel combustion generation project. This study refers to the norms of the Clean Development Mechanism (CDM) and the general ideas of greenhouse gas (GHG) emission reduction methodology, and establishes the accounting boundary by determining the baseline scenario. Then the author calculates the carbon emission according to the characteristics of the carbon emission in accordance with the two phases of stationary source combustion and flue gas desulphurization. After that, the author uses the methodology tools to demonstrate the additionality of the coal oxy-fuel combustion generation project, and the results show that the project activity still needs the support of the relevant carbon emission reduction and trading policies to be sustained, which is still far from the mature commercial operation. The project activity has additionality. Combing with the practical application scenario of the carbon flow and accounting methodology, it determines the main accounting process of carbon emission in the process of the project activity, and provides methodological support for the verification of carbon emission reduction in coal oxy-fuel combustion generation projects and the formulation of carbon trading policies. Finally, the methodology is applied to calculate the annual carbon emission reductions of up to one million tones generated by the retrofit of 2×300 MW coal-fired generating units with oxy-fuel combustion technology.

Research Progress on Different Catalytic Techniques for Carbon Dioxide Reduction Reaction

DING Chaomin, LI Ke, YAN Yong, WANG Defa, XIAO Zhe, LIU Fan, ZHANG Xin, LI Qi, GUO Xiaoyan, ZHANG Zhengdong

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0201

Abstract(156)

HTML (64)

PDF(15)

Abstract:
Elevated levels of carbon dioxide (CO₂), a typical greenhouse gas, are a major contributor to the global greenhouse effect. With China’s goals of “achieving carbon peak by 2030” and “achieving carbon neutrality by 2060”, how to efficiently convert CO₂ has become an important research direction for Chinese researchers. Carbon dioxide reduction reaction (CO₂RR) is a common means of converting CO₂ into carbon-based fuels and high-value-added products using photocatalytic, thermal catalytic, electrocatalytic, and biocatalytic technologies. However, the above technologies still suffer from low CO₂ conversion efficiency, low target product selectivity, and poor reaction stability. This paper is based on the reaction principles of different catalytic techniques, combined with the characteristics of the catalysts such as material or loading method. Recent research progress in the formation of products such as methanol, methane, and ethylene from carbon dioxide reduction is reviewed. The aim is to provide further guidance for carbon dioxide reduction and utilization.

Research on the Verification Method of Vehicle Horn Monitoring System

TANG Jiahao, ZHOU Changhua, LI Lin

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0165

Abstract(49)

HTML (23)

Abstract:
As an off-site law enforcement system, the vehicle horn monitoring system is an effective law enforcement means for the traffic police to investigate and punish the illegal vehicle horn behavior. Based on the principle of the sound source location algorithm of the vehicle horn monitoring system, the measurement error of sound pressure level, spatial resolution, positioning error, effective recognition area and time consistency of acousto-optic image of the verification items in the national verification regulations are measured respectively, by analyzing the location results of different sound sources at different frequencies and positions, the relevant rules of the sound pressure level measurement system are obtained The relationship between wavelength and resolution angle of spatial resolution at different frequencies.

Development and Application of an On-Line Gas Chromatograph with Micro Thermal Conductivity Detector for Natural Gas Energy Metering

LIN Junjie, DENG Fanfeng, ZHOU Li, XU Xiangdong, LI Zhiang, ZHANG Ting, XIAO Lian, WEI Dong, PAN Yi

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0078

Abstract(37)

HTML (36)

Abstract:
Micro-online gas chromatograph for natural gas energy measurement have been monopolized by foreign countries, it brings unfavorable impact on China's international natural gas trade. So developed localization substitution is of great significance. The research team has developed multiple key core devices for natural gas energy measurement, such as the micro chromatographic injection system and micro thermal conductivity detector, and also developed the chromatographic workstation for online energy value calculation. The research team also taking the lead in developing a reliable micro-online gas chromatograph for natural gas energy measurement with independent intellectual property rights in China. The experimental prototype machine has been applied in natural gas flow measurement station and hydrogen production plant using natural gas. The experimental prototype can analyze 11 components in natural gas such as N₂, CO₂, C₁～C₆, and the analysis cycle is 2.5 minutes. The detection limit of hexane is 80 μmol/mol, the resolution R of n-butane and Isobutane is less than 2.0, the repeatability test of n-butane is 0.3%, 4-hour instrument stability test is 0.07%. The experimental prototype has passed the long-term stability test for 6020 unit*hour, and meet the needs for natural gas energy measurement. Localized substitution has been achieved in the area of micro-online gas chromatograph and provided measurement technology support to achieve the strategic goal of "dual carbon", assisted the national natural gas energy security.

Research on Calibration System of Gas Detection Alarm Based on MCGS

CHENG Liping, ZHAO Jinshuang, LI Jian, HE Yuanyuan, XUE Yanming, WANG Haiyan

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0074

Abstract(50)

HTML (16)

PDF(2)

Abstract:
Most of the continuous on-line gas detection alarms are 4～20 mA analog electrical signal outputs, which have complex gas types, many manufacturers, various specifications and models, and complex wiring operation in the course of calibration. At present, no calibration system can effectively carry out the calibration of various 4～20 mA analog electrical signal output alarm, and the efficiency of calibration is extremely low. A calibration system based on embedded configuration software of MCGS is designed in this paper, which can automatically collect, intelligently process and judge the result of the electrical signals of several gas detection alarms at one time. The electric signals collected by the calibration system are accurate and reliable. In the ventilation test, the distribution of indication error among the channels is relatively concentrated, and the total variation trend of indication error is consistent between the data obtained from the automatic calculation of the system and the data measured by the method specified in the national verification regulation, the automatic calculation function of the system improves the work efficiency of gas detection alarm calibration.

Research and Design of a New Type of RF Voltmeter Calibrator

LIU Yiyang, LI Yong, CHEN Shuo, JIA Chao, CUI Xiaohai

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0089

Abstract(34)

HTML (27)

PDF(1)

Abstract:
RF voltage measurement plays a crucial role in scientific research and industry. High-frequency voltmeter calibrators are widely used in metering stations across the national metering system, undertaking numerous calibration tasks. This article introduces a newly developed intelligent RF voltmeter calibrator that offers several advantages, including a wide frequency bandwidth, high dynamic range, high accuracy, and automatic testing. It provides functions for basic error calibration and frequency additional error calibration, enabling automatic or semi-automatic calibration of various types of RF voltmeters and generating calibration certificates. The calibrator design focuses on two aspects: hardware and software. In the hardware design, a standard AC voltage source circuit is developed for basic error calibration. This circuit consists of an AC voltage generator module, a voltage amplification module, and a closed-loop feedback module, ensuring high-accuracy output. To achieve frequency additional error calibration, a new type of sensor chip and structure are designed to facilitate more accurate and convenient DC voltage calibration. The software design encompasses the measurement and control circuit control module, the data processing module, and the display module. These modules enable automatic value reading for feedback adjustment, range or frequency switching, value display, and subsequent data processing. The introduced RF voltmeter calibrator design is at the forefront in China, contributing to the innovation of domestic calibrators, reducing reliance on foreign instruments, and meeting the needs of domestic high-frequency voltmeter verification and calibration.

A High-Accuracy Measurement Method for Direction of Arrival of Millimeter-Wave Radar Based on Fast Iterative Adaptive Algorithm

YU Danyang, DU Lei

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0198

Abstract(84)

HTML (20)

PDF(13)

Abstract:
The Iterative Adaptive Algorithm (IAA) is a super-resolution algorithm widely applied for highly accurate measurement of the Direction of Arrival (DOA) in millimeter-wave radar. However, traditional IAA encounter challenges related to algorithmic complexity and computational delay, making them unsuitable for applications requiring real-time performance. Moreover, in order to reduce the angle estimation errors caused by the mismatch between the source locations and the grid dictionary, a common approach is to refine the grid. However, this further exacerbates the slow computation problem of the IAA. To tackle this problem, a Fast Iterative Adaptive Algorithm (FIAA) is proposed in this paper. The FIAA adopts a hierarchical grid refinement approach to iteratively measure source angles. Initially, a coarse grid division is implemented across the entire spatial domain and the potential areas of real source locations are identified by utilizing the IAA. Subsequently, within these potential regions, a refined grid division is executed, accompanied by updates to the signal direction matrix. Ultimately, the IAA, incorporating a regularized covariance matrix, is employed to attain highly accurate measurements of the signal source angles. Experimental results demonstrate that FIAA effectively circumvents scanning and computation in non-signal potential regions, the calculation time is reduced to at least 4% of the IAA, and the accuracy of the measurements are basically consistent with the IAA when the SNR is higher than 0dB. It is suitable for scenarios requiring high real-time performance and high-accuracy millimeter-wave radar DOA measurement.

Research on Ranging Calibration Method Based on Common Optical Path Approach

LIU Hongguang, ZHAO Lingzhe, SUN Quan, FAN Hua, WANG Wei, ZHENG Yelong, ZHAO Meirong

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0110

Abstract(48)

HTML (17)

PDF(1)

Abstract:
In the existing handheld laser rangefinder detection method, there were problems such as shortage of field baseline field and poor practicality of optical path folding method. Therefore, for the problem that it was difficult to establish the detection reference of the length of more than 50 m, a new rangefinder detection method tracing back to the total station was proposed. A highly operable detection device was designed to carry out the detection experiment of the hand-held laser rangefinder signaling error in the measurement section of 50 m-200 m. The experiments showed that the uncertainty of the range detection method based on the common optical path was 1.6 mm at 200 m, which met the requirements of JJG 966-2010 calibration specification for handheld laser rangefinders. Finally, the reliability of the measurement capability of the detection method was verified by comparison experiments. The research method is the first one in China to extend the measurement range of the measurement standard "Handheld Laser Rangefinder Calibration Device" from 50 m to 200 m under the condition of no baseline field, which has outstanding value of popularization and application.

Current situation of thyroid function test standardization

WU Meiran, HAN Liqiao, ZHANG Qiaoxuan

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0132

Abstract(73)

HTML (29)

PDF(8)

Abstract:
The clinical indicators for detecting thyroid function include triiodothyronine, thyroxine, free triiodothyronine, free thyroxine, thyroid stimulating hormone, thyroid peroxidase antibodies, anti-thyrotropin receptor antibody, and thyroglobulin antibodies. Thyroid illness diagnosis and therapy benefit from the standardization and consistency of thyroid function testing programs. At present, some small-molecule hormone items can already achieve standardization, but for protein detection items, due to the complexity of the measurement, there are still difficulties and challenges to achieving standardization. This article summarizes the detection methods of thyroid function examination indicators, the reasons that affect the comparability of results between different methods, and the standardization progress and problems of different detection items.

Research Of Ultra -High -Speed Signal Collection and Integrity Processing Technology

WANG Zhiyu, ZHANG Yue, ZHOU Keji, YANG Guanghong, XIAO Kaige

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0130

Abstract(159)

HTML (31)

PDF(11)

Abstract:
With the development of current electronic systems towards larger bandwidth, higher transmission rate and stronger computing power, the demand for platforms with corresponding ultra-high-speed signal acquisition capabilities is becoming more and more urgent. At the same time, with the corresponding platform, to achieve the whole process of signal integrity processing, monitoring, feedback evaluation and promote its optimization technology came into being, the synergistic development of these two aspects of the ability to promote the effective improvement and improvement of the industry in the field of high-speed processing technology, so as to promote the rapid development of China's ultra-high-speed sampling, storage, transmission and signal integrity related applications and upstream and downstream industry chain.Ultra -high -speed signal acquisition and signal integrity processing testing technology is based on the self -developed 80GSA sampling ADC chip as the core, using a large amount of software for data processing, and the test measurement, processing, and calculation precision can be greatly improved. In terms of complete processing, the conditioning circuit is the key component, and the retrospective algorithm as the core. The value data displayed by the value displayed is the result of the algorithm calculation.

Research Progress of Graphene Quantum Dots and Graphene Quantum Dots Reference Materials

LIU Ran, LV Qingbin, ZHAO Haibo, LIANG Liang, SHEN Shangyi, ZHAO Xiaoning

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0217

Abstract(104)

HTML (20)

PDF(10)

Abstract:
Graphene quantum dots refer to a new type of fluorescent carbon material with a transverse size of less than 30 nm and a layer number of less than 10 layers. Due to their unique characteristics and broad application prospects, graphene quantum dots have received extensive attention. In this paper, the unique structure, electrical and optical properties of graphene quantum dots are introduced, the main preparation methods of graphene quantum dots are summarized, and their applications in new energy, catalysis, sensing, biomedicine and environmental remediation are introduced in detail. Finally, the research progress of graphene quantum dots standard materials is briefly introduced. Future research on graphene quantum dots is mainly focused on improving the photoluminescent quantum yield and manufacturing output, as well as expanding the application range and preparing graphene quantum dot standard materials. With the progress of new material design concepts and the continuous development of quantum technology, graphene quantum dots and their standard materials are expected to show their unique advantages and application value in more fields.

Research on Characterization Method of Cardiac Troponin I by Hydrogen-Deuterium Exchange Mass Spectrometry

SUN Haofeng, MA Lingyun, LIU Jianyi, ZHANG Qi, SONG Dewei

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0166

Abstract(48)

HTML (33)

PDF(2)

Abstract:
Acute myocardial infarction (AMI) ranks first among the death factors in China, and is the top priority in the clinical prevention and treatment of cardiovascular diseases. Myocardial troponin I (cTnI), as the most reliable clinical index of evaluating myocardial injury, is currently the preferred biomarker and gold standard for the diagnosis of myocardial infarction. Immunology method is a common method of clinical detection AMI, many domestic and foreign diagnostic reagent suppliers can produce cTnI detection kit, but immune testing system from different manufacturers will produce different value results for the same sample, on the one hand, the commercial kits of different suppliers in sensitivity, specificity and selectivity, on the other hand is different kits used in different antibodies, identify antigen epitope region, antibody and serum cTnI sample binding ability differences, resulting in inconsistent results between different manufacturers, thus affect the accuracy of clinical diagnosis. The consistency and accuracy of the quantitative results are closely related to the structure of cTnI. However, due to the complexity of cTnI, the structural characterization of cTnI in the solution state is very challenging. Through experimental condition optimization and data processing parameters, the characterization method of cTnI HDX, based on hydrogen deuterium exchange-mass spectrometry (HDX-MS) technology, is established, and applied to the study of cTnI. Meanwhile, this method has good universality and can be easily extended to cTnI conformation transition study and the development of kinetic method, which lays the technical foundation for promoting the standardization of cTnI from the perspective of protein structure.

Analysis of the Structural-related Impurities Involved in 3,3',5-Triiodo-L-thyronine (T3) Purity Reference Material

XIAO Peng, SONG Dan, LI Hongmei

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0134

Abstract(67)

HTML (38)

PDF(8)

Abstract:
Research and development of 3,3',5-Triiodo-L-thyronine (T3) purity reference material is a way to establish the primary material for clinical measurement value traceability, which can provide more accurate and comparable evidence in thyroid disease diagnosis. In the mass balance quantitative approach, determining and analyzing those structural-related impurities is essential. Such investigation could also be an effective way to reduce the uncertainty of the standard value. First, nuclear magnetic resonance and high-resolution mass spectrometry analytical tools have been employed to validate the chemical structure of the reference material. Then, the structural-related impurities are separated and qualitatively analyzed by using reliable analytical technologies, including high-performance liquid chromatography, high-resolution mass spectrometry, and ion mobility spectrometry. The results indicated that there are three kinds of structural-related impurities involved in the T3 purity reference material (NIM-RM3239), which are Diiodo-L-thyronine, Chloro-diiodo-L-thyronine, and L-Thyroxine. The relative content of each impurity is greater than 0.1% in UV 220nm. Furthermore, the chiral isomer separation result indicated that no dextroisomer (D-T3) existed in NIM-RM3239. These analytical results can be utilized as the foundations in the mass balance approach, applied in developing T3 primary certified reference material.

Current Status of Serum Theophylline Standardization in Clinical Laboratories

DU Yuanyuan, ZHANG Qiaoxuan, HAN Liqiao

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0115

Abstract(95)

HTML (20)

PDF(7)

Abstract:
Theophylline is a widely used medication for treating asthma and chronic obstructive pulmonary disease (COPD). It’s essential to accurately monitor the blood concentration of theophylline, due to the significant inter-individual variability and its narrow therapeutic window. Currently, immunoassays, high-performance liquid chromatography (HPLC), and liquid chromatography-tandem mass spectrometry (LC-MS/MS) are commonly used as routine methods for measuring serum theophylline in clinical laboratories. However, there is significant difference among the measurement results of these methods. The reference measurement procedure for serum theophylline in the Joint Committee for Traceability in Laboratory Medicine (JCTLM) database is the isotope dilution gas chromatography-mass spectrometry (ID-GC/MS) method. The primary reference material was developed by the UK Laboratory of the Government Chemist (LGC) and China National Institute of Metrology (NIM). No secondary reference material with serum matrix was reported. To ensure the reliability and harmonization of measurement results, it is important to establish a comprehensive traceability chain for the standardization of serum theophylline.

Quantitative Analysis of Recombinant Human Serum Amyloid A by Isotope Dilution Mass Spectrometry

ZHANG Qi, JIANG Zelin, SONG Dewei

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0163

Abstract(88)

HTML (42)

PDF(7)

Abstract:
Serum amyloid A (SAA) is one of the four inflammation biomarkers in clinical diagnosis. At present, there is no SAA certified reference materials, which cannot achieve traceability and standardization in clinical SAA diagnosis. In this study, the recombinant human serum amyloid A expressed in E. coli was selected as the raw material, and it was qualitatively and quantitatively analysed to study the traceability method. The purity and molecular weight of SAA were analysed by gel electrophoresis, liquid chromatography and mass spectrometry. The results showed that the purity of SAA was >98%, and the molecular weight of 11820.09 Da was consistent with the theoretical value. An absolute quantification method of amino acid analysis-isotope dilution mass spectrometry for SAA was established. The content of phenylalanine, isoleucine and proline in the hydrolysed sample was determined at 8 h of hydrolysis, and the mass concentration of SAA solution was 9.32 µg/g (RSD = 0.91%). An absolute quantification method of signature peptide-isotope dilution mass spectrometry for SAA was established. Within the mass ratio of trypsin and SAA was 1:1 and digestion time was 8 h, the content of peptide EANYIGSDK, GPGGVWAAEAISDAR was detected by IDMS, and the mass concentration of SAA is calculated to 9.41 g/g (RSD = 0.49%). The results of the two methods were consistent by statistical test, and there was no significant difference shown. The quantitative results of this study are traceable to SI units, which lays a foundation for the development of SAA reference materials.

Uncertainty Evaluation of Determination of the Gross Alpha Radioactivity and Gross Beta Radioactivity in Drinking Water

GU Xinyi, GU Jun, CHENG Xiaohong

, Available online , doi: 10.12338/j.issn.2096-9015.2023.0277

Abstract(258)

HTML (110)

PDF(34)

Abstract:
To evaluate the uncertainty of determination of the gross alpha radioactivity and the gross beta radioactivity in drinking water by thick source method. According to GB/T 5750.13-2023 "Standard Examination Methods for Drinking Water Part 13 Radioactivity Index", the gross alpha radioactivity and beta radioactivity in drinking water are measured. The measurement repeatability was regarded as type A uncertainty, and the factors introduced by the residue mass, water sample volume, instrument detection efficiency, recovery rate, etc. were regarded as type B uncertainty. The measured gross alpha and beta radioactivity concentrations were 0.66 Bq/L and 0.48 Bq/L, the relative combined uncertainties were 6.0% and 5.7%, and the expanded uncertainties were 0.08 Bq/L and 0.06 Bq/L. Uncertainty introduced by the instrument count rate (n) is the main source of uncertainty and has the greatest influence. The measurement repeatability, the counting efficiency (ε) of standard powder source and radioactivity recovery rate (F) have greater influence. The influences of total mass of the water sample residue (W), mass of the water residue weighed to prepare the sample source (m) , and the volume (V) of the water sample are less and negligible.

The Development of Small Pulling Force Gauge Calibration Device

ZHANG Duoli, JIN Longxue, WU Yueming

, Available online , doi: 10.12338/j.issn.2096-9015.2021.0037

Abstract(437)

HTML (273)

PDF(53)

Abstract:
Point at present situation of measuring small pulling forcegauge inmetrological service,small pulling forcegauge calibration device was developed,so some matterswhensmallpulling forcegauge is measured usingWeight,for example ,heavy working intensity,unablezeroed and full scale range cannot be measured ,can be solved.

Measurement Comparison of Plasmid DNA Capability by Digital PCR

WANG Xia, NIU Chunyan, LIU Zheng, LU Lin, DONG Lianhua

, Available online , doi: 10.12338/j.issn.2096-9015.2021.0590

Abstract(586)

Abstract:
Digital PCR (dPCR) is an absolute quantitative technique of nucleic acid, which is widely used in transgenic and gene detection. In order to ensure the accuracy and reliability of digital PCR measurement results in China, 16 laboratories were tested using transgenic plasmid DNA samples. The comparison results showed that the difference between the ratio of foreign gene to internal copy number (<25%) to evaluate the measuring ability of the laboratories. The 16 laboratories were all within the acceptable range, and there was no significant difference among different digital PCR platforms. Due to the influence of plasmid conformation, the absolute copy number content of plasmid DNA measured in 7 laboratories was significantly lower than the reference value. It is suggested that when using digital PCR for quantitative measurement of plasmid DNA copy number, it should be confirmed whether the conformation of plasmid has an effect on amplification.

, Available online , doi: 10.12338/j.issn.2096-9015.2020.0166

Abstract(379)

HTML (84)

PDF(43)

Abstract:
In mmwave technology a low frequency is always multiplied to generate a much higher frequency. Phase noise will be also increased and phase noise test will be more important in mmwave band. It is limited with spectrum analyzer method because of some reasons. And phase noise analyzer can only cover up to 50 GHz in a single unit. After the basic introduction of phase noise test technology in mmwave band two external mixer method is provided. Result shows that with this method we can get a stable test result.

New Accepeted

DynamicMORE+

ScienceMORE+