计量科学与技术

Developing a Verification Method for Electronic Police Systems in Monitoring Illegal Vehicle Spacing

ZENG Weixian, TANG Hao, LIN Wenhui, YIN Lan, DENG Qiuxi, LING Fu, XIA Yihong

2023, 67(10): 3-7, 53. doi: 10.12338/j.issn.2096-9015.2023.0265

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Abstract:
This paper addresses the heightened risk of rear-end collisions associated with insufficient vehicle spacing during high-speed driving. In response, traffic authorities have introduced an electronic police system equipped with cameras to identify vehicles failing to maintain a safe following distance. Despite the system's technological advancements, China currently lacks specialized measurement and testing equipment for its calibration and maintenance. This study proposes a novel laser-based device, integrating a laser rangefinder and a speedometer, to accurately determine the distance between vehicles and their speed. The data, including distance, speed, and time, are displayed on an LED screen installed in the test vehicle. This information is captured by the electronic police system to assess discrepancies between the LED display and the system's measurements. The device aims to offer robust evidence for law enforcement and encourage safer driving practices, thereby enhancing road safety.

Development of a Deep Learning-Based Self-Calibrating Radar Speed Measurement System

ZHANG Zhuo, TANG Hao, LUO Gao, PENG Zheng, YAO Wu, LING Fu, ZENG Weixian, LUO Bin, YE Yulong

2023, 67(10): 8-18, 76. doi: 10.12338/j.issn.2096-9015.2023.0323

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Radar speedometers, crucial in vehicular speed measurement, encounter challenges in maintaining accuracy over extended periods. This study introduces a self-calibrating radar speed measurement system employing a convolutional neural network (CNN) to enhance data accuracy and reliability. We present an economical neural network-based speed measurement system that utilizes digital image processing and YOLO v7 object detection neural network for target vehicle extraction. Additionally, a dedicated CNN for speed calculation is designed and trained using a custom dataset. The network's parameters are optimized through data ablation experiments. Experimental validation confirms the system's capability to measure vehicle speed with high accuracy and stability. The developed CNN for speed calculation effectively identifies potential radar errors and excludes anomalous data, thus facilitating the radar's automatic calibration. This feature ensures long-term precision of the speed measurement equipment, significantly improving the reliability and sustainability of speed measurement operations.

Exploring and Applying Dual Infrared Laser Technology for Tunnel Traffic Speed Measurement

TANG Hao, ZENG Weixian, LIN Wenhui, YIN Lan, YAO Wu, PENG Zheng, YANG Kun, WANG Feilong

2023, 67(10): 19-24. doi: 10.12338/j.issn.2096-9015.2023.0295

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Tunnels, as vital components of transportation infrastructure, not only enhance traffic efficiency but also pose significant challenges in terms of frequent traffic accidents. This study delves into the peculiarities of the tunnel traffic environment to understand the high incidence of accidents, particularly in the context of high-speed rear-end collisions. Addressing the limitations of Doppler radar speedometers in tunnels, we introduce a speed measurement system based on dual infrared laser technology, specifically designed to overcome the difficulties of speed measurement in such environments. This system, featuring a dual infrared laser setup, has demonstrated excellent performance on open roads and superior capabilities within tunnel settings. Field tests and comparisons with conventional speed measurement methods have validated the effectiveness of the dual infrared laser speedometer in tunnels. However, enhancements in monitoring efficiency, particularly under high traffic conditions, are still necessary. Overall, this research presents a novel technological approach to tunnel traffic monitoring, offering significant innovations for improving traffic safety and efficiency. Future efforts should aim at further increasing monitoring efficiency to accommodate more complex and dense traffic scenarios, thereby advancing the comprehensive progress of tunnel traffic management systems.

Advancements in Interval Distance Measurement Using UAV Technology

TANG Hao, LIN Wenhui, YIN Lan, DENG Qiuxi, XIA Yihong, LUO Gao, DENG Qiqi, HU Xiangcheng, ZENG Weixian

2023, 67(10): 25-29, 61. doi: 10.12338/j.issn.2096-9015.2023.0238

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The absence of national metrological verification regulations by the State Administration for Market Regulation presents a significant challenge in assessing the accuracy of interval velocity measurement systems. A pivotal aspect of this challenge is the precise measurement of interval distances, essential for validating interval speed measurement systems for motor vehicles. This study leverages Unmanned Aerial Vehicle (UAV) technology combined with oblique photogrammetry to achieve high-precision data collection and analysis of road information. Utilizing the Dijkstra algorithm, we calculated the shortest driving distances within intervals. Our research underscores the integration of modern data processing tools to innovate and enhance precision in road modeling and measurement. The findings are expected to substantially improve the accuracy and fairness of speeding monitoring, offering robust support for police traffic enforcement and advancing road safety and traffic order.

Development of Certified Reference Material for Forchlorfenuron Residue in Cucumber Powder

YANG Mengrui, SHI Haochuan, XU Qi, CHEN Wenwen, ZHANG Liyuan, ZHOU Jian, WANG Min

2023, 67(10): 30-36. doi: 10.12338/j.issn.2096-9015.2023.0318

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Matrix certified reference materials (CRMs) play a crucial role in validating analytical methods and ensuring quality control. To enhance the accuracy and reliability of risk assessments for plant growth regulators, we have developed a certified reference material (CRM) for forchlorfenuron in cucumber powder, thereby improving the measurement quality of forchlorfenuron residues in cucumbers. The CRM was prepared through processes including pulping, drug-adding, homogenization, freeze-drying, grinding, sieving, mixing, and encapsulation. The liquid chromatography-tandem isotope dilution mass spectrometry (ID-LC/MS/MS) method was optimized and established for the quantification of the CRM. The certified value of forchlorfenuron in cucumber powder was determined to be 14.7 mg/kg with an expanded uncertainty of 2.7 mg/kg (k=2). Furthermore, the homogeneity of the material was assessed, along with its long-term stability at −20°C over nine months and short-term stability at 40°C over nine days. The study comprehensively evaluated uncertainties introduced by characterization, homogeneity, and stability assessments.

Preparation of Rimantadine Hydrochloride Purity Certified Reference Material

LI Fukai, WANG Min, ZHOU Jian, YANG Mengrui, WANG Tongtong, LI Liang

2023, 67(10): 37-45. doi: 10.12338/j.issn.2096-9015.2023.0317

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The development of a rimantadine hydrochloride purity certified reference material (CRM) (GBW 10262) was carried out using two independent methods: the mass balance (MB) method and quantitative nuclear magnetic resonance (qNMR) spectroscopy. Critical aspects of the CRM development process, including homogeneity, stability, calibration, and uncertainty, were systematically investigated. The purity of rimantadine hydrochloride CRM, as determined by both methods, was found to be 99.7%±0.3% (k=2). The CRM demonstrated excellent homogeneity, maintaining long-term stability for 20 months, and short-term stability for seven days at 50°C. The study also involved a thorough assessment of uncertainty sources, including characterization, stability, and homogeneity. The rimantadine hydrochloride CRM will support activities such as instrument calibration, method validation, and quality and safety risk monitoring.

Development of a Certified Reference Material for Fumonisin B₁ Purity

GUO Wenbo, MENG Jiajia, NIU Xueke, WANG Xinyi, NIE Dongxia, ZHAO Zhihui, HAN Zheng

2023, 67(10): 46-53. doi: 10.12338/j.issn.2096-9015.2023.0284

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To enhance the accuracy, reliability, and traceability of agricultural product quality safety testing, a certified reference material (CRM) for fumonisin B₁ (FB₁) purity was developed. The CRM candidate, obtained through laboratory purification of FB₁, was qualitatively identified using mass spectrometry, infrared spectroscopy, and nuclear magnetic resonance spectroscopy. The purity of the candidate was quantified using both mass balance and quantitative nuclear magnetic resonance methods. The mass balance method included area normalization, the Karl Fischer method, gas chromatography-tandem mass spectrometry, and inductively coupled plasma mass spectrometry to determine the main component, moisture, volatile and non-volatile impurity contents. Furthermore, homogeneity tests and stability studies were conducted, along with systematic uncertainty evaluations. The results indicated that the FB₁ CRM has a purity value of 99.1% with an extended uncertainty of 0.3% (k=2), exhibiting good homogeneity and fulfilling a 12-month stability requirement. The developed FB₁ CRM, certified as a national secondary standard material (GBW (E) 100550), is suitable for qualitative and quantitative detection, method evaluation, and establishing a traceability system for FB₁ in agricultural products

Development of Aflatoxin B₁ Certified Reference Material in Peanut Oil

LI Peng, LI Li, YE Jin, WU Yu, WANG Songxue

2023, 67(10): 54-61. doi: 10.12338/j.issn.2096-9015.2023.0320

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To fulfill the requirements of food safety monitoring in China, a certified reference material (CRM) for aflatoxin B₁ (AFB₁) analysis in peanut oil was developed. This CRM was derived from naturally contaminated positive samples, undergoing processes such as blending, nitrogen purging, and packaging. Homogeneity of the CRM candidate was assessed using High-Performance Liquid Chromatography with Fluorescence Detection (HPLC-FLD), while its stability was evaluated using High-Performance Liquid Chromatography - Isotope Dilution Mass Spectrometry (HPLC-ID-MS/MS). Value assignment was performed through collaborative laboratory efforts utilizing both HPLC-FLD and HPLC-ID-MS/MS. The results indicated that the CRM meets technical specifications, displaying excellent homogeneity and stability for 16 months at −18 ℃. The certified value of AFB₁ is 15.6 μg/kg with an expanded uncertainty of 1.6 μg/kg (k = 2). The uncertainty assessment encompassed factors from homogeneity, stability, and value assignment. The developed CRM for AFB₁ in peanut oil, certified as GBW(E) 100604, fulfills the urgent need for traceable standards in edible oil AFB₁ measurement and ensures accurate and reliable results.

Development of Reference Material for Calcium and Phosphorus in Chicken Formula Feed

YAN Hua, XU Siyuan, HU Shen, ZHANG Zhenhao, JIA Zheng, FAN Xia

2023, 67(10): 62-69. doi: 10.12338/j.issn.2096-9015.2023.0324

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To address the needs of food safety monitoring, a certified reference material (CRM) for calcium and phosphorus in chicken formula feed was developed. The CRM underwent sample pretreatment using microwave digestion, followed by quantification of calcium and phosphorus content using an inductively coupled plasma optical emission spectrometer (ICP-OES). The homogeneity and stability of the CRM were systematically analyzed, and uncertainties were evaluated. The results demonstrate that the CRM exhibits excellent homogeneity and stability, with certified values of 1.221% for calcium and 0.687% for phosphorus, and expanded uncertainties of 0.117% and 0.091% (k=2), respectively. The CRM can be stored for 16 months at −18 ℃. This development fulfills the requirements for feed quality and safety monitoring and provides essential technical support for calibration, quality control, and method validation in the analysis of calcium and phosphorus in formulated feed samples.

Progress in Tumor Gene Mutation Detection Methods and Development of Reference Materials

WANG Shangjun, HUANG Bei, XIA Xue, YAN Ru, XU Jieru

2023, 67(10): 70-76. doi: 10.12338/j.issn.2096-9015.2023.0251

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Malignant tumors represent a major cause of global mortality, posing a significant threat to human health. In China, the incidence of malignant tumors is increasing, creating a challenging situation for cancer prevention and control. Tumor mutation gene detection technologies offer a scientific foundation for early screening, diagnosis, and treatment, thereby significantly improving cancer survival rates. In China, various approved tumor mutation gene detection kits provide critical support for cancer control efforts. Nucleic acid reference materials play a vital role in ensuring the accuracy and traceability of test results. This paper discusses common methods for detecting tumor gene mutations, reviews certified detection kits available in China, and analyzes the current status of nucleic acid reference materials, both domestically and internationally. The aim is to inform the development and use of reference materials for tumor gene mutations and to promote their application in precision medicine diagnostics.

2023 Vol. 67, No. 10

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