计量科学与技术

Laser Multilateration Coordinate Measurement Systems and Development Status:A Review

ZHANG Qingyan, LI Jianshuang, MIAO Dongjing

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0100

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The laser multilateral coordinate measuring system has the characteristics of high coordinate measurement accuracy, which has attracted much attention from academic circles, industries and metrology institutions in various countries. However, since the accuracy of coordinate measurement in large spatial ranges is affected by various factors, and there is a lack of domestic standards related to the measurement and calibration of laser multilateral coordinate measurement systems, the development of laser multilateral coordinate measurement systems still faces many problems that need to be solved. This article focuses on the principle of laser multilateral measurement, system parameter self-calibration method, coordinate measurement traceability status and the formulation of related standards, measurement uncertainty assessment and analysis of influencing factors, the extension of laser multilateral coordinate measurement in the field of attitude measurement, and the application in the industrial field at home and abroad Extensive research and summary have been conducted on its practical applications. Among them, domestic and foreign researchers have made a variety of attempts to improve measurement accuracy, such as compensating environmental field interference, reducing ranging errors, improving system self-calibration accuracy, increasing the number of measurement stations, setting constraints, and researching the optimal layout of the system. At the same time, the establishment and improvement of relevant standards for domestic laser polygonal coordinate measurement system measurement, calibration and traceability can provide reference and basis for the manufacturing and assembly of large parts and components in industrial applications and the calibration and compensation of instruments. This article reviews the relevant literature on laser multilateral coordinate measurement systems in the field of large spatial range measurement, focusing on the principles of laser multilateral coordinate measurement, system parameter self-calibration methods, coordinate measurement uncertainty and applications, aiming to provide researchers with information on The development status and future development trends of laser multilateral coordinate measurement systems promote the development of coordinate measurement technology in large spatial ranges.

Establishment of standard reference data set for hazardous VOCs in ambient air

BAI Lu, LIU Zilong, LUO Yuqi, XIONG Xingchuang

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0061

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Currently, countries around the world are paying increasing attention to the management of harmful volatile organic compounds (VOCs) in the ambient air, and harmful VOCs data is gradually becoming an important data for atmospheric environmental monitoring and control, with a significant increase in data importance. The list and information of harmful VOCs in the standards, regulations, and policy documents issued by various countries for harmful VOCs are scattered, and there is no centralized search channel or file that can fully cover the harmful VOCs data published by various countries, making it difficult to comprehensively and effectively use harmful VOCs data and information. This article designs a technical route for establishing a dataset of harmful VOCs compounds and its establishment methods based on the chemical characteristics of harmful VOCs compounds, atmospheric environment monitoring and control, and the requirements for digital calibration certification and recognition of standard reference data. The establishment process is actually completed. The reference dataset for harmful VOCs established has become a standard dataset after self-assessment, data inspection, comparison between Chinese and American datasets, and expert review. This dataset has been publicly available on the official website of the National Metrology Science Data Center, providing important data resources such as authoritative maps of harmful VOCs for scientific research and the development of the environmental protection industry. It greatly enhances scientific research autonomy and has certain reference value for the governance and research of harmful VOCs. It also lays the foundation for subsequent digital calibration certification and recognition.

Research on Calibration Method of Portable Uric Acid Meters

CUI Hongen, YIN Geman, WU Liqing, YANG Zheng, YU Hairong, ZHOU Qian, ZHANG Kai

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0104

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The accuracy of portable uric acid analyzers has a direct impact on the daily monitoring of uric acid in patients with gout and hyperuricemia. In view of the lack of its calibration specifications, the calibration specifications are formulated. Based on the portable uric acid meter calibration device, the portable uric acid meter calibration method is proposed, the technical indicators are determined, and the calibration case is verified and the relevant influencing factors are analyzed. According to the calibration method, the verification results of the indication error and repeatability of the portable uric acid meter meet the technical requirements. The successful establishment of calibration method of portable uric acid meter can provide a useful reference for the preparation of the "Calibration Specification of Portable Uric Acid Meters", and promote the traceability and standardization of the measurement value of portable uric acid meter.

Research status of CO₂ detection methods

PENG Zhixiang, PAN Guanfu, WU Tong, XU Dinghua, QIU Lin, HANG Chenzhe

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0079

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CO₂ is an important greenhouse gas that poses a multifaceted hazard to the Earth's environment and human health. With the increase of industrialization, urbanization and energy consumption, the emission of greenhouse gases such as CO₂ in the atmosphere has continued to increase, raising concerns about global climate change. Therefore, the detection of CO₂ concentration has become crucial. Currently, there are two main types of carbon emission measurement methods which are testing method and the accounting method. The testing method has the advantages of high precision, real-time monitoring, more conducive to guiding the low-carbon transformation and operation of the unit comparing with the accounting method. This paper mainly introduces the existing main detection method of CO₂. It mainly includes chemical analysis methods and physical optical analysis method. Chemical analysis method mainly includes potentiometric titration method, chemical absorption method, gas-sensitive sensing technology, gas chromatography and mass spectrometry, etc. The physical optical analysis method includes cavity ring-down spectroscopy, off-axis integration cavity output spectrometry, non-dispersive infrared absorption spectrometry, fourier transform infrared spectroscopy and tunable diode laser absorption spectroscopy, etc. The traditional chemical analysis is more suitable for accurate detection of complex components, but usually not suitable for long period on-line detection. With the rapid development of computer technology and optical detection technology, the emerging physical optical detection technology gradually plays a greater advantage. The paper summarises and analyses the various detection methods that can help researcher to select suitable CO₂ detection methods and provide data support for related industries; it also can help develop high-sensitivity and high-precision CO₂ metrology and detection equipments, which can help to implement the dual-carbon policy and control the ambient air quality.

Calibration Method for Adjusting Components of Active Optical Telescope with Large Field of View

AN Qichang, WU Xiaoxia, ZHANG Jingxu, LI Hongwen

, Available online , doi: 10.12338/j.issn.2096-9015.2023.0260

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In order to better regulate the large field of view active optical telescope. Firstly, the basic principle of the calibration of the adjustment components in the telescope based on the internal and external measurement system is expounded. Secondly, error analysis was conducted on the calibration process of a large field of view active optical telescope. Afterwards, the feasibility of the differential field of view curvature sensing method for large field of view active optical telescopes was analyzed and experimentally studied. Finally, the principle of the detection method for moving components of a large field of view active optical telescope was verified through desktop experiments. In the end, the large-scale calibration process achieved non diffractive uniform beam splitting, overcoming the shortcomings of diffraction beam splitting with multiple stray fringes and small beam splitting angle. The accuracy of dispersion angle above 100° is better than 15 microns, and the angle accuracy is better than 3″. The accuracy of calibration based on wavefront sensing is better than 10 microns. This study can effectively improve the imaging quality of large aperture and large field of view telescopes.

Picosecond Level Research on Phase Difference Measurement between Signals of Multiple Frequencies

ZHANG Yang, LIN Pingwei, Ru Ning, Ma Yanning

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0072

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To meet the demand for high-precision timing signals in modern science, this paper proposes using the phase information of sine waves as a fine marker for timing signal measurement, which is expected to accurately synchronize timing signal errors to the picosecond level. The non-drifting multiplication signal of sine wave phase can be used to characterize the fine phase information within one cycle of a sine wave signal. The prerequisite for measuring the picosecond-level phase drift between different frequency signals is the calibration of the phase drift between the multiplication signal and the sine wave signal. Currently, there is no instrument that can measure the phase difference between different frequency signals with picosecond-level accuracy. This paper innovatively designs a picosecond-level accuracy measurement circuit for the phase difference of different frequency signals. It analyzes the influence of power dividers, amplifiers, mixers, filters, and attenuators used in the circuit on the signal phase. The circuit itself causes a time difference of no more than 3 ps for the measured phase difference, and the stability of the measurement results is in the range of E-13, proving that the accuracy and stability of the measurement circuit meet the requirements of picosecond-level high-precision measurement. This creates conditions for further calibrating the phase drift between signals and accurately characterizing the phase information of sine waves to achieve high-precision timing signal synchronization.

Measurement of Beam Parallelism of Photoelectric Autocollimator Based on Pentaprism

MA Juanjuan, XU Aihua, SONG Xiao, WU Jinfeng, ZENG Zhuo

, Available online , doi: 10.12338/j.issn.2096-9015.2023.0275

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In order to measure beam parallelism of photoelectric autocollimator precisely, a method based on pentaprism has been proposed in this paper. Using a pentaprism, the measurement optical path can be optimized. It helps reduce the influence of surface shape of the mirror required in the detection process. The error of non-parallel beam of photoelectric autocollimator has been quantitatively analyzed. And different methods of beam parallelism measurement are compared. Compared with the traditional measurement method, the pentaprism method is comparable to using a mirror with a curvature of 5×10^-5 m^-1, and the difference between the results is less than 0.1″. In addition, the repeatability using the pentaprism method can reach 0.1″. The pentaprism method reduces the system error and improves the measurement accuracy of the beam parallelism of the photoelectric autocollimator.

Research on key technology of calibration of Spirometer Syringes capacity

GUO Ligong, REN Litai, WANG Jintao, BAO Xuesong, TONG Lin, CHANG Xu

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0065

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To better realize the traceability of the Spirometer Syringes used in spirometry (hereinafter referred to as Syringes), the research on the method of calibrating the capacity of the Syringes and the development of the calibration device have been conducted. The volume V₂₀ of the Syringes at standard temperature is obtained by using the developed calibration device, which is calibrated on the negative pressure principle by measuring the mass of pure water inhaled into the weighing cylinder by the piston rod of the Syringes slowly withdrawn to generate negative pressure, as well as by measuring the temperature, humidity, and pressure of the atmosphere in the weighing cylinder and calibration cylinder at the beginning and end of the measurement. The volume of pure water drawn in is calculated as V₂₀₁, the volume of air at the beginning and end of the measurement is calculated by applying van der Waals' formula, and the difference in volume is calculated to obtain a correction value of ΔV for the volumetric measurement, and the sum of V₂₀₁ and ΔV is V₂₀. Volume measurements were carried out on Syringes with nominal capacities of 1 L and 3 L. The repeatability of the results of several sets of measurements was less than 0.06%, and the measurement uncertainty was less than 0.1% (k=2); the difference between the results of the volume measurements and those of the conventional static weighing method was within 0.05%, confirming that the measurements of the calibrated device were equivalent to those of the conventional static weighing method.. The calibration method and calibration device in this paper satisfy the requirements of carrying out capacity calibration for Syringes with a capacity measurement requirement of 0.05% repeatability and a tolerance of ±0.5%, and will also provide an important technical support for the preparation of the calibration specification for the volume of confined cavities.

Research on Quantity Value Correction Model of Liquid-Medium Piston Gauges

ZENG Lin, ZHOU Siqing, CHEN Yuefei

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0024

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The mass of the special weight is calculated with reference to the effective area of the zero-pressure piston, when calculating the mass of the large weight, only the deformation of the piston system caused by loading the large weight is considered, so the actual pressure measured by the piston gauge is less than the nominal pressure. Based on the basic principles of piston pressure gauge measurement and disseminate pressure, a quantity value correction model for liquid-medium piston gauges with a measurement upper limit of 25 MPa and above is derived. The relative pressure correction values of piston gauges with upper measurement limits of 60MPa and 250MPa show: The absolute value of the relative pressure correction value increases nearly linearly with the number of small weights loaded, but shows a nonlinear increase with a gradually weakening trend as the number of large weights loaded; The limit value of the relative pressure correction value is proportional to the pressure deformation coefficient and the upper limit of measurement of piston gauge; the influence of small weights on the relative pressure correction value is significantly greater than that of large weights, the relative pressure correction value of the pressure measurement point with the largest number of small weights loaded near the upper limit of the piston measurement reaches an extreme value, the relative pressure correction limit of the 250MPa piston is −5.17×10⁻⁵, which exceeds the maximum allowable error of the 0.005-level piston gauge; based on the limitation of the maximum tolerance of the mass of the special weight, the disseminate values of 25MPa piston gauges of grade 0.01 and above and 250MPa piston gauges of grade 0.02 and above must be corrected to ensure the accuracy of their pressure value transmission.

Research Progress on Error Factors and Technology of Ultrasonic Flow Meter

YU Jiayun, LOU Qiannan, DING Youting, WANG Zhaozheng, GU Yunqing

, Available online , doi: 10.12338/j.issn.2096-9015.2023.0336

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[Abstract]Ultrasonic flow meters show the advantages of high precision and instantaneous measurement in flow measurement, and have significant application potential, which is of great significance for safe oil and gas storage, low loss transportation and fair settlement. This paper analyzes the working mechanism of high-precision ultrasonic flow meter based on four flow calculation principles, namely, time difference method, frequency method, cross-correlation method and Doppler method, and reveals the influence of flow velocity and temperature on flow measurement accuracy from three perspectives of turbulence characteristics, instrument structure and environmental factors, and discusses the interference of meter geometry change on flow velocity field. This paper summarizes the error factors of ultrasonic flow meter and the technical methods to reduce the error, and provides ideas and guidance for the innovation of high-precision flow meter technology through research and prospect.

MSA Analysis and Research on Automatic Verification Assembly Line of Electric Energy Measurement Instruments

LI Liangbo, WANG Xue, LI Hairong, GUO Hai, ZHU Xinwang

, Available online , doi: 10.12338/j.issn.2096-9015.2023.0355

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The automatic verification assembly line of electric energy measurement instruments can experience performance degradation or even malfunctions during long-term online high load operation, leading to deviations in the test results of electric energy measurement errors. In order to accurately grasp the fluctuation pattern of the automatic verification assembly line measurement system of electric energy measurement instruments, determine the total variation from the measurement system and the differences in each variable, and improve the accuracy and reliability of the measurement system, an analysis plan for the assembly line measurement system was designed. On the basis of analyzing the structural characteristics and working principles of the assembly line, a new experimental scheme is proposed, and a measurement system analysis plan is formulated. Taking the automated calibration assembly line of low-voltage current transformers as an example, the repeatability and reproducibility, bias and linearity, and stability of the measurement system were analyzed. The analysis results show that the variation of the measurement system accounts for 1.67% of the total variation, the variation index% GR&R is 18.21%, the bias ratio is 5.4%, the linearity ratio is 8.7%, and there are 7 distinguishable categories. The measurement system has the required measurement ability and is in a conditional acceptance state. Further analysis of the sources of variation reveals that reproducibility is the main factor of variation, and there are significant differences in the consistency of measurement systems at different workstations. Finally, based on the analysis results of the measurement system, production site management, and operation and maintenance experience, suggestions for improving the measurement system are proposed.

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

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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.

Valuation Method for Milk Somatic Cell Count Reference Materials and the Uncertainty Evaluation

LIU Yingying, ZHOU Yuhu, WANG Ziquan

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0018

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A method based on microscopic imaging flow cytometry was established to measure the concentration of milk somatic cells in the standard substance for milk somatic cell count. This method labels milk somatic cells using the fluorescent dye Ethium Bromide, and the single cell multi parameter microscopic images provided by flow cytometry can effectively assist in identifying target cells in flow cytometry analysis, thereby providing the correctness and repeatability of the gate strategy. Through multiple measurements and analysis of milk somatic cell standard substance samples with different concentrations of somatic cells, it has been proven that this method has good indoor and daytime repeatability. A mathematical model for measuring the concentration of milk somatic cells in a standard substance for milk somatic cell count based on microscopic imaging flow cytometry technology was established. The analysis determined that the uncertainty of this measurement method mainly comes from measurement repeatability, sample pretreatment, reagent addition, gate operation, and measurement volume. Comprehensive evaluation, targeting the candidate V-grade (～1.0×10⁶/mL) of the standard substance for milk somatic cell count prepared in the study, the relative uncertainty of the measurement method for milk somatic cell concentration based on microscopic imaging flow cytometry is 4.84%.

Research on On-Line In-Situ Calibration Technology for Bogie Rolling Vibration Test Bench

XIAO Ke, BAI Wenqi, WANG Li, CHEN Hongjiang

, Available online , doi: 10.12338/j.issn.2096-9015.2023.0351

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As one of the key components of heavy-duty electric locomotives, the bogie is closely related to the operational and safety performance of heavy-duty electric locomotives. In the design and manufacturing process of bogies, there are problems such as ineffective traceability and insufficient detection methods in large-scale specialized testing devices such as bogie rolling vibration test benches. Moreover, during the testing process, the measurement results are inevitably affected by load effects, mechanical wave interference, locomotive vibration, wheel hub distortion, and other factors; The existing traceability methods for bogie values adopt offline calibration, ignoring the influence of factors such as actual installation position, electromagnetic interference, and environmental disturbance, making calibration data difficult to apply. The author analyzed the basic structure and working principle of the rolling vibration test bench for heavy-duty electric locomotive bogies, and summarized a series of technical indicators that can comprehensively and objectively reflect the measurement characteristics of the test bench. The calibration items and specific testing methods of the test bench were clarified, and the most critical performance indicator torque of the test bench was selected for measurement uncertainty analysis. Finally, three test benches developed by CRRC Zhuzhou Machinery Co., Ltd. were selected for experimental verification, proving that the calibration method of the discussed test benches is scientific and reasonable.

Research on the Calibration Method and Device of Ultrasonic Chordal Phantom Based on Intelligent Technology

QI Fang, WANG Tongyu, LIU Zhe, ZHU Weimin

, Available online , doi: 10.12338/j.issn.2096-9015.2023.0350

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This article studies the calibration method of ultrasonic chordal phantom, designed and developed a ultrasonic chord phantom calibration device based on intelligent technology. This device can collect the rotational speeds of the ultrasonic capstan and driven wheels of the chordal phantom through a dual channel laser velocimeter and input them into the analysis system for analysis and calculation, in order to calculate the chordal speed of the chordal phantom. And it can collect the line speeds of each point within the physiological waveform cycle and compare them with the standard physiological waveform line speeds in the database, in order to determine whether the physiological waveform curve at the setting speed meets the requirements. The experimental results indicate that compared to the existing detection methods for constant blood flow velocity, this method and device can not only conveniently and efficiently detect constant blood flow velocity, but also detect physiological waveforms intelligently, they solved the calibration and traceability problem of ultrasonic chordal phantom effectively.

Analysis and Extension of Validation Methods for SAR Measurement Systems

PANG Xinhua, ZHOU Xin, WU Tong, SHEN Qingfei, TANG Wei, LI Anxiang, MU Xiaotong, YANG Chao

, Available online , doi: 10.12338/j.issn.2096-9015.2023.0357

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Specific Absorption Rate (SAR), as a mandatory parameter for the personal safety of electromagnetic radiation involving wireless communication products, has new requirements for the validation of the measurement system as its measurement method and measurement system need to be updated due to the change of the device under test. Based on the in-depth understanding of the validation methods in the current standard, the validation methods of the three traditional validation steps, namely, Extrapolation routine verification, Probe linearity verification and others, are measured and analyzed through electromagnetic simulation and experimental measurements, and the validation methods are extended by combining with the new requirements of the new test. The measured results show the feasibility and stability of the extended verification method. Since the reference values are obtained by the self-developed method, the validation method can be extended and the validation configurations, such as the validation points, can be customized according to the needs. This provides technical support for the study of the validation method for new and domestic SAR measurement systems.

Study on the Impact of Cell Viability Detection and Processing on Drug Effect Evaluation

YANG Lulu, GONG Xiaoyun, ZENG Qingli, ZHANG Wenquan, XUE Zhichao, SHENTU Xuping

, Available online , doi: 10.12338/j.issn.2096-9015.2023.0358

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When conducting drug experiments on cells cultured in vitro, drug treatment can cause cell death, and different methods for detecting cell survival rates can have impacts on the experimental results. This experiment takes Hela cells as the experimental object, and treats the cells with different concentrations of cisplatin. The cell survival rates detected with or without floating cells in the old culture medium are compared. The experimental results indicated that using the CCK8 method to detect the cell survival rates of 96 well plates and 24 well plates, the cell survival rates of the experimental group without removing the old culture medium was higher than that of the experimental group removing the old culture medium. At a cisplatin concentration of 0.625 μM, there is a significant difference in cell survival rates between the experimental group with and without removing the old medium. In 6-well plates and 100 mm dishes, a cell counter was used to detect the floating cells in the cell culture medium after application of drugs, and the presence of viable cells in the floating cells in the medium was found. Therefore, the floating living cells in the culture medium will affect the experimental results of cell drug experiment.

Overview of the Interaction Between the Chemical Composition and the Main Physicochemical Properties of Diesel Fuel

DING Chaomin, ZHANG Zhengdong, DU Biao, WANG Guixuan, LIU Fan, LI Qi, LI Ke

, Available online , doi: 10.12338/j.issn.2096-9015.2023.0259

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In order to reduce the environmental pollution caused by the use of diesel fuel, and to promote the development of the automotive industry in the direction of more environmental protection and efficiency, China’s diesel quality has completed the upgrade from China Ⅳ to China Ⅵ, with increasingly stringent requirements on the physicochemical properties of diesel within the standards. The quality upgrade has a direct impact on the physicochemical properties of diesel fuel, which in turn is determined by its chemical composition. Therefore, investigating the relationship between the chemical composition and physicochemical properties of diesel fuel can help fuel producers to optimise diesel fuel formulations to meet higher quality requirements, and can also help users to choose diesel fuel products in accordance with their own needs in order to improve diesel fuel utilisation and reduce environmental pollution. This study reviews the intrinsic relationship between the chemical composition of diesel fuel and density, cetane number, lubricity, low temperature fluidity, sulfur-containing compounds, nitrogen-containing compounds and fatty acid methyl esters. This study provides a theoretical basis for diesel blending and quality upgrading, as well as a useful reference for sustainable energy development and environmental protection.

Research on Dynamic Characteristic Calibration Method of Resistance Strain Sensor

XU Aihua, DAI Guohong, HU Hongbo, ZENG Zhuo, XU Hao, LI Tiantian, XU Jianhua

, Available online , doi: 10.12338/j.issn.2096-9015.2023.0349

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There are many types and applications of resistance strain sensors, which are widely used in industries and fields such as bridges, tunnels, construction, aerospace, etc. They are often used to monitor their structures. Therefore, it is very important to evaluate the dynamic characteristics of resistance strain sensors reasonably. This article discusses and analyzes the characteristics of resistance strain sensors and the description of metrological characteristics in relevant domestic and foreign standards and specifications. In view of the current status of metrological calibration of resistance strain sensors, this paper discusses a method for calibrating the dynamic characteristics of resistance strain sensors using existing vibration measuring devices. This method is based on the existing vibration standard device, collecting vibration table signals and strain sensor signals through a dynamic signal analyzer, and analyzing the measurement signals to obtain dynamic sensitivity, completing the calibration of sensor dynamic characteristics. The feasibility and good repeatability of this method were verified through experiments. Finally, the data processing process was explained and the uncertainty of the dynamic sensitivity of the sensor was evaluated.

Research on Vibration Detection Method for Partial Discharge Faults in GIL

XU Aihua, HU Hongbo, ZANG Chunyan, LI Hairong, ZENG Zhuo, XU Hao, CUI Chenxi

, Available online , doi: 10.12338/j.issn.2096-9015.2023.0329

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During the production and transportation of GIL, internal defects may occur, leading to localized partial discharge faults during operation, accompanied by abnormal vibration and sound signals. When GIL malfunctions, it not only causes serious damage to the equipment itself, but also poses a threat to the stable operation of the power system. This paper studies a method for detecting partial discharge faults in GIL based on vibration signals, which can accurately identify specific units and locations of the faults. The paper analyzes the characteristics of vibration signals in GIL localized partial discharge fault states. By processing and identifying signals collected from simulated experiments and on-site tests, the identification method has been optimized, enabling accurate and effective determination of whether GIL has experienced localized partial discharge faults.

Research on the Funding Effectiveness of National Major Scientific Research Instrument Development Projects Based on Bibliometrics

LI Xiaomeng, SHANG Xueshen, FAN Wen, SUI Zhiwei, LI Dabo, WU Aihua, LIU Yulan, LIU Yitong

, Available online , doi: 10.12338/j.issn.2096-9015.2023.0274

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Scientific research instruments are the basic conditions and achievements of scientific and technological innovation. Under the situation of a new round of scientific and technological revolution and industrial reform, they have become the focus of scientific and technological innovation competition in the world, including China. Taking the scientific research output in the national major scientific research instrument development project (NMSRIDP) as the research object, this paper used bibliometric analysis to reveal the quantity, quality characteristics and internal laws of scientific papers from different dimensions, such as the output quantity, published journals, citation frequency, output institutions, etc. At the same time, combined with highly cited papers and hot papers, this paper analyzed the funding effectiveness of instrument development projects from 2011 to 2022 in terms of output, output influence, input-output ratio and other dimensions. It is expected to provide a basis for the performance evaluation of the achievements and outputs of science fund projects, and provide reference value for understanding the role of instrument fund in promoting the frontier breakthrough of basic research in China.

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

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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

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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

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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.

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