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Method for rapid warning and activity concentration estimates in online waterγ-spectrometry systems

Nuclear Science and Techniques 2024年第3期35卷 1-12页

作者： Meng Wang Yi Gu Mao-Lin Xiong Liang-Quan Ge qing-xian zhang Guo-Qiang Zeng Heng Lu Sheng-Liang Guo College of Nuclear Technology and Automation Engineering Chengdu University of TechnologyChengdu 610059China Applied Nuclear Technology in Geosciences Key Laboratory of Sichuan Province (Chengdu University of Technology)Chengdu 610059China Chengdu New Ray Technology Co.Ltd Chengdu 610052China

Onlineγ-spectrometry systems for inland waters,most of which extract samples in situ and in real time,are able to produce reliable activity concentration measurements for waterborne radionuclides only when they are distributed relatively uniformly and enter into a steady-state diffusion regime in the measurement *** protect residents’health and ensure the safety of the living environment,better timeliness is required for this measurement *** address this issue,this study established a mathematical model of the online waterγ-spectrometry system so that rapid warning and activity estimates can be obtained for water under non-steady-state(NSS)*** addition,the detection efficiency of the detector for radionuclides during the NSS diffusion process was determined by applying the computational fluid dynamics technique in conjunction with Monte Carlo *** this basis,a method was developed that allowed the online waterγ-spectrometry system to provide rapid warning and activity concentration estimates for radionuclides in *** analysis of the NSS-mode measurements of^(40)K radioactive solutions with different activity concentrations determined the optimum warning threshold and measurement time for producing accurate activity concentration estimates for *** experimental results show that the proposed NSS measurement method is able to give warning and yield accurate activity concentration estimates for radionuclides 55.42 and 69.42 min after the entry of a 10 Bq/L^(40)K radioactive solution into the measurement chamber,*** times are much shorter than the 90 min required by the conventional measurement ***,the NSS measurement method allows the measurement system to give rapid(within approximately 15 min)warning when the activity concentrations of some radionuclides reach their respective limits stipulated in the Guidelines for Drinking-water Quality of the WHO,suggesting that this method con

关键词： Water radioactivity monitoring Dynamic detection efficiency Rapid warning Activity estimation

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Evaluation of terrestrial radiation in the Chengdu Plain using 1/250,000-scale geochemical prospecting data

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Nuclear Science and Techniques 2017年第10期28卷 31-36页

作者： qing-xian zhang Jian-Kun Zhao Yi Gu Liang-Quan Ge Yuan-qing Huang Sichuan-Provincial Key Laboratory of Nuclear Technologyin Geosciences Chengdu University of TechnologyChengdu 610059China Sichuan Nuclear Geology Institute Chengdu 610061China

Based on the geochemical prospecting data, we have calculated the gamma absorbed dose rates in air 1 m above the ground surface in the Chengdu Plain, analyzed the relationship between the geological conditions and the distribution of the natural radionuclides, and preliminarily studied the influence of the geological conditions on the terrestrial radiation level in the Chengdu Plain. The result shows that the terrestrial radiation level in the Chengdu Plain is slightly lower than the average values of China and varies greatly according to the complex geological conditions.

关键词：成都平原地面辐射地球化学找矿评价天然放射性核素地质条件辐射水平普查数据

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Fine mapping and candidate gene prediction of the photoperiod and thermo-sensitive genic male sterile gene pms1(t) in rice

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2011年第6期12卷 436-447页

作者： Yuan-fei ZHOU xian-yin zhang qing-zhong XUE Department of Agronomy College of Agriculture and Biotechnology Zhejiang University Hangzhou 310029 China

Pei＇ai64S, an indica sterile variety with photoperiod and thermo-sensitive genic male sterile （PTGMS） genes, has been widely exploited for commercial seed production for ＂two-line＂ hybrid rice in China. One PTGMS gene from Pei＇ai64S, pmsl（t）, was mapped by a strategy of bulked-extreme and recessive-class approach with simple sequence repeat （SSR） and insert and deletion （In-Del） markers. Using linkage analysis for the F2 mapping population consisting of 320 completely male sterile individuals derived from a cross between Pei＇ai64S and 93-11 （indica restorer） lines, the pmsl（t） gene was delimited to the region between the RM21242 （0.2 cM） and YF11 （0.2 cM） markers on the short arm of chromosome 7. The interval containing the pmsl（t） locus, which was co-segregated with RM6776, is a 101.1 kb region based on the Nipponbare rice genome. Fourteen predicted loci were found in this region by the Institute for Genomic Research （TIGR） Genomic Annotation. Based on the function of the locus LOC_Os07g12130 by bioinformatics analysis, it is predicted to encode a protein containing a Myb-like DNA-binding domain, and may process the transcript with thermosensory response. The reverse transcription-polymerase chain reaction （RT-PCR） results revealed that the mRNA levels of LOC_Os07g12130 were altered in different photoperiod and temperature treatments. Thus, the LOC_Os07g12130 locus is the most likely candidate gene for pmsl（t）. These results may facilitate not only using the molecular marker assisted selection of PTGMS genes, but also cloning of the pmsl（t） gene itself.

关键词： Super hybrid rice pmsl(t) Photoperiod and thermo-sensitive male sterile gene Genetic mapping

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Quantitative energy-dispersive X-ray fluorescence analysis for unknown samples using full-spectrum least-squares regression

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Nuclear Science and Techniques 2019年第3期30卷 149-159页

作者： Yong-Li Liu qing-xian zhang Jian zhang Hai-Tao Bai Liang-Quan Ge The College of Applied Nuclear Technology and Automation Engineering Chengdu University of Technology

The full-spectrum least-squares(FSLS) method is introduced to perform quantitative energy-dispersive X-ray fluorescence analysis for unknown solid *** on the conventional least-squares principle, this spectrum evaluation method is able to obtain the background-corrected and interference-free net peaks, which is significant for quantization analyses. A variety of analytical parameters and functions to describe the features of the fluorescence spectra of pure elements are used and established, such as the mass absorption coefficient, the Gi factor, and fundamental fluorescence formulas. The FSLS iterative program was compiled in the C language. The content of each component should reach the convergence criterion at the end of the calculations. After a basic theory analysis and experimental preparation, 13 national standard soil samples were detected using a spectrometer to test the feasibility of using the algorithm. The results show that the calculated contents of Ti, Fe, Ni, Cu, and Zn have the same changing tendency as the corresponding standard content in the 13 reference samples. Accuracies of 0.35% and 14.03% are obtained, respectively, for Fe and Ti, whose standard concentrations are 8.82% and 0.578%, respectively. However, the calculated results of trace elements (only tens of lg/g) deviate from the standard values. This may be because of measurement accuracy and mutual effects between the elements.

关键词： Energy-dispersive X-ray fluorescence analysis Full-spectrum least-squares method Effective atomic number Mass attenuation coefficient Fundamental parameter method

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Design and preliminary test of tritiated water online detector system based on plastic scintillators

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Nuclear Science and Techniques 2022年第10期33卷 68-78页

作者： Chun-Hui Dong Kai-Yong Liao Rui-Yang Xu Hong-Wu Liu qing-xian zhang Chengdu University of Technology Chengdu 610059China

In this study,an online detector system based on plastic scintillators is designed to monitor the activity of tritiated water in the liquid effluents of nuclear power *** feasibility of the detector is verified via simulation on Geant4,and the optimal detector structure size is determined.A back-end electronics system is designed and an experimental measurement platform forβ-rays based on a ^(40)KCl solution is *** ^(40)KC solutions with different activities ranging from 10 to4500 Bq/L are measured,and 1300 V is determined as the optimal operating high voltage of the photomultiplier tubes.A linear fit is performed in 10-min counts,and the maximum linear goodness of fit(R^(2))achieved is ***-term stability measurements are performed for two detectors,one filled with air and the other with a ^(40)KCl solution exhibiting an activity of 2000 Bq/*** relative deviation of the counts of the detector system every 10 min is 0.998%when the ^(40)KCl solution is used,and the maximum Gaussian R^(2) of the counts is 0.9849.

关键词： Tritiated water Geant4 Plastic scintillator Electronics system

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The study of a neutron spectrum unfolding method based on particle swarm optimization combined with maximum likelihood expectation maximization

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Nuclear Science and Techniques 2023年第4期34卷 149-160页

作者： Hong-Fei Xiao qing-xian zhang He-Yi Tan Bin Shi Jun Chen Zhi-Qiang Cheng Jian zhang Rui Yang Applied Nuclear Technology in Geosciences Key Laboratory of Sichuan Province Chengdu University of TechnologyChengdu 610059China National Key Laboratory for Metrology and Calibration Techniques China Institute of Atomic EnergyBeijing 102413China

The neutron spectrum unfolding by Bonner sphere spectrometer(BSS) is considered a complex multidimensional model,which requires complex mathematical methods to solve the first kind of Fredholm integral equation. In order to solve the problem of the maximum likelihood expectation maximization(MLEM) algorithm which is easy to suffer the pitfalls of local optima and the particle swarm optimization(PSO) algorithm which is easy to get unreasonable flight direction and step length of particles, which leads to the invalid iteration and affect efficiency and accuracy, an improved PSO-MLEM algorithm, combined of PSO and MLEM algorithm, is proposed for neutron spectrum unfolding. The dynamic acceleration factor is used to balance the ability of global and local search, and improves the convergence speed and accuracy of the algorithm. Firstly, the Monte Carlo method was used to simulated the BSS to obtain the response function and count rates of BSS. In the simulation of count rate, four reference spectra from the IAEA Technical Report Series No. 403 were used as input parameters of the Monte Carlo method. The PSO-MLEM algorithm was used to unfold the neutron spectrum of the simulated data and was verified by the difference of the unfolded spectrum to the reference spectrum. Finally, the 252Cf neutron source was measured by BSS, and the PSO-MLEM algorithm was used to unfold the experimental neutron *** with maximum entropy deconvolution(MAXED), PSO and MLEM algorithm, the PSO-MLEM algorithm has fewer parameters and automatically adjusts the dynamic acceleration factor to solve the problem of local optima. The convergence speed of the PSO-MLEM algorithm is 1.4 times and 3.1 times that of the MLEM and PSO algorithms. Compared with PSO, MLEM and MAXED, the correlation coefficients of PSO-MLEM algorithm are increased by 33.1%, 33.5% and 1.9%, and the relative mean errors are decreased by 98.2%, 97.8% and 67.4%.

关键词： Particle swarm optimization Maximum likelihood expectation maximization Neutron spectrum unfolding Bonner spheres spectrometer Monte Carlo method

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Verification of a self-developed CFD-based multi-physics coupled code MPC-LBE for LBE-cooled reactor

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Nuclear Science and Techniques 2021年第5期32卷 84-100页

作者： Zhi-Xing Gu qing-xian zhang Yi Gu Liang-Quan Ge Guo-Qiang Zeng Mu-Hao zhang Bao-Jie Nie College of Nuclear Technology and Automation Engineering Chengdu University of TechnologyChengdu 610059China Sino-French Institute of Nuclear Engineering and Technology Sun Yat-Sen UniversityZhuhai 519082China

To perform an integral simulation of a pool-type reactor using CFD code,a multi-physics coupled code MPC-LBE for an LBE-cooled reactor was proposed by integrating a point kinetics model and a fuel pin heat transfer model into self-developed CFD *** code verification,a code-to-code comparison was employed to validate the CFD ***,a typical BT transient benchmark on the LBE-cooled XADS reactor was selected for verification in terms of the integral or system *** on the verification results,it was demonstrated that the MPC-LBE coupled code can perform thermal-hydraulics or safety analyses for analysis for processes involved in LBE-cooled pool-type reactors.

关键词： LBE-cooled pool-type reactor Computational fluid dynamics Multi-physics coupling code Safety analysis code Verification

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Communication Resource-Efficient Vehicle Platooning Control With Various Spacing Policies

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 362-376页

作者： Xiaohua Ge qing-Long Han xian-Ming zhang Derui Ding IEEE School of Science Computing and Engineering TechnologiesSwinburne University of TechnologyMelbourne VIC 3122Australia

Platooning represents one of the key features that connected automated vehicles may possess as it allows multiple automated vehicles to be maneuvered cooperatively with small headways on roads. However, a critical challenge in accomplishing automated vehicle platoons is to deal with the effects of intermittent and sporadic vehicle-to-vehicle data transmissions caused by limited wireless communication resources. This paper addresses the co-design problem of dynamic event-triggered communication scheduling and cooperative adaptive cruise control for a convoy of automated vehicles with diverse spacing policies. The central aim is to achieve automated vehicle platooning under various gap references with desired platoon stability and spacing performance requirements, while simultaneously improving communication efficiency. Toward this aim, a dynamic event-triggered scheduling mechanism is developed such that the intervehicle data transmissions are scheduled dynamically and efficiently over time. Then, a tractable co-design criterion on the existence of both the admissible event-driven cooperative adaptive cruise control law and the desired scheduling mechanism is derived. Finally, comparative simulation results are presented to substantiate the effectiveness and merits of the obtained results.

关键词： Automated vehicles constant time headway spacing constant spacing cooperative adaptive cruise control event-triggered communication vehicle platooning

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Early and delayed castrations confer a similar survival advantage in TRAMP mice

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Asian Journal of Andrology 2009年第3期11卷 291-297页

作者： Zai-xian zhang qing-Quan Xu Xiao-Bo Huang Ji-Chuan Zhu Xiao-Feng Wang Department of Urology Peking University People＇s Hospital Beijing 100044 China

The most appropriate time to introduce androgen deprivation therapy for prostate cancer remains controversial. Our aim was to evaluate the effects of early versus delayed surgical castration on prostate cancer progression and survival in the transgenic adenocarcinoma of the mouse prostate （TRAMP） model. TRAMP mice were randomly divided into three groups： the early castration group （on which castration was performed at the age of 4 weeks）, the delayed castration group （on which castration was performed when abdominal tumours could be palpated）, and the sham-castrated group. Mice were monitored daily throughout their lives until cancer-related death or the develop- ment of an obviously moribund appearance, at which time the individual mouse was killed. Androgen receptor expression in prostate tumours was also evaluated. The results shows that the average lifespan in early castration, delayed castration and sham-castrated groups were 54.1 weeks, 59.9 weeks and 39.1 weeks, respectively. Both early castration and delayed castration conferred a statistically significant survival advantage when compared with the sham-castrated group （P 〈 0.001）. However, the difference in lifespan between the early castration group and the delayed castration group was not statistically significant （P = 0.85）. The increase in lifespan in the TRAMP mice that received either early or delayed castration correlated with lower G/B value （genitourinary tract weight/body weight） at death than the sham-castrated mice. In conclusion, early and delayed castrations in TRAMP mice pro- longed survival to a similar extent. This finding may provide a guide for clinical practice in prostate cancer therapy.

关键词： castration prostate cancer survival TRAMP

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Accumulated-state-error-based event-triggered sampling scheme and its application to H∞ control of sampled-data systems

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Science China(Information Sciences) 2024年第6期67卷 328-341页

作者： xian-Ming zhang qing-Long HAN Bao-Lin zhang Xiaohua GE Dawei zhang School of Science Computingand Engineering TechnologiesSwinburne University of Technology College of Automation and Electronic Engineering Qingdao University of Science & Technology School of Mathematics Shandong University

This paper is concerned with event-triggered H∞control of sampled-data systems. Its novelties lie in three aspects:（i） A novel accumulated-state-error-based event-triggered scheme is introduced by comparing the integral of the state error from tk to t with the system state sampled at tk. This condition works well due to the fact that the so-called Zeno behaviour does not occur.（ii） A novel Lyapunov functional is constructed to establish a criterion to ensure some certain H∞performance of the closed-loop system. This Lyapunov functional is dependent on the integral of the state error involved in the event-triggered scheme.（iii） Under the event-triggered sampling scheme, suitable state-feedback controllers can be designed rather than be given a priori. Moreover, a self-triggered implementation of the proposed event-triggered sampling scheme is presented as well. Finally, a batch reactor model and an inverted pendulum system are given to demonstrate the effectiveness of the proposed method.

关键词： event-triggered sampling self-triggered implementation $H_\infty$ control looped-functional

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