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Artificial neural network algorithm for pulse shape discrimination in 2πα and 2πβ particle surface emission rate measurements

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Nuclear Science and Techniques 2023年第10期34卷 91-102页

作者： yuan-qiao li Bao-Ji Zhu Yang Lv Heng Zhu Min lin Ke-Sheng Chen li-Jun Xu China Institute of Atomic Energy Beijing 102413China National Key Laboratory for Metrology and Calibration Techniques Beijing 102413China

To enhance the accuracy of 2πα and 2πβ particle surface emission rate measurements and address the identification issues of nuclides in conventional methods, this study introduces two artificial neural network(ANN) algorithms: back-propagation(BP) and genetic algorithm-based back-propagation(GA-BP). These algorithms classify pulse signals from distinct α and β particles. Their discrimination efficacy is assessed by simulating standard pulse signals and those produced by contaminated sources, mixing α and β particles within the detector. This study initially showcases energy spectrum measurement outcomes, subsequently tests the ANNs on the measurement and validation datasets, and contrasts the pulse shape discrimination efficacy of both algorithms. Experimental findings reveal that the proportional counter's energy resolution is not ideal, thus rendering energy analysis insufficient for distinguishing between 2πα and 2πβ particles. The BP neural network realizes approximately 99% accuracy for 2πα particles and approximately 95% for 2πβ particles, thus surpassing the GA-BP's performance. Additionally, the results suggest enhancing β particle discrimination accuracy by increasing the digital acquisition card's threshold lower limit. This study offers an advanced solution for the 2πα and 2πβ surface emission rate measurement method, presenting superior adaptability and scalability over conventional techniques.

关键词： Pulse shape discrimination Artificial neural networks Alpha and beta sources Multi-wire proportional counter Surface emission rate

Monte Carlo method for evaluation of surface emission rate measurement uncertainty

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Nuclear Science and Techniques 2024年第7期35卷 126-136页

作者： yuan-qiao li Min lin li-Jun Xu Rui Luo Yu-He Zhang Qian-Xi Ni Yun-Tao liu China Institute of Atomic Energy Beijing102413China National Key Laboratory for Metrology and Calibration Techniques Beijing102413China Department of Radiation Oncology Hunan Cancer HospitalChangsha410031China The Affiliated Cancer Hospital of Xiangya School of Medicine Central South UniversityChangsha410031China

The aim of this study is to evaluate the uncertainty of 2πα and 2πβ surface emission rates using the windowless multiwire proportional counter *** study used the Monte Carlo method (MCM) to validate the conventional Guide to the Expression of Uncertainty in Measurement (GUM) method.A dead time measurement model for the two-source method was established based on the characteristics of a single-channel measurement system,and the voltage threshold correction factor measurement function was indirectly obtained by fitting the threshold correction *** uncertainty in the surface emission rate was calculated using the GUM method and the law of propagation of *** MCM provided clear definitions for each input quantity and its uncertainty distribution,and the simulation training was realized with a complete and complex mathematical *** results of the surface emission rate uncertainty evaluation for four radioactive plane sources using both methods showed the uncertainty’s consistency E_(n)lidation tool for GUM results.

关键词： Surface emission rate Monte Carlo method Metrology Probability distribution function Dead time Low-energy loss correction Least-squares method

Implantation of an S-ICD in a Patient with a DDD Pacemaker and Congenitally Corrected Transposition of the Great Arteries

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Cardiovascular Innovations and Applications 2021年第1期5卷 207-212页

作者： Yu Zhang Wen-Long Dai Can-Can lin qiao-yuan li Cheng-Jun Guo Department of Cardiology Beijing Anzhen HospitalCapital Medical UniversityBeijingChina

Subcutaneous implantable cardioverter-defi brillator(S-ICD)therapy has become a viable alternative to conventional transvenous ICD *** with congenitally corrected transposition of the great arteries(ccTGA)have a high risk of sudden cardiac death due to malignant *** interaction between the S-ICD system and the transvenous pacemaker system is not fully *** report a case of S-ICD implantation in a patient with ccTGA and a DDD *** patient was a 30-year-old man with a previously placed pacemaker with diagnoses of congenital heart disease,ccTGA(SLL),left atrioventricular valve insuffi ciency,and third-degree atrioventricular *** presented with an out-of-hospital cardiac arrest,and an S-ICD was implanted to prevent sudden cardiac *** brillation checks were performed *** tested the compatibility of the DDD pacemaker with the S-ICD and found that there was no interference between *** conclusion,an S-ICD system is a reasonable and safe option in patients with ccTGA.

关键词： Subcutaneous implantable cardioverter-defi brillator congenitally corrected transposition of the great arteries pacemaker

Comparison of His-purkinje bundle pacing and right ventricular inflow tract septal pacing in the elderly

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Journal of Geriatric Cardiology 2020年第6期17卷 351-358页

作者： Chun-Shan LU Wen-Long DAI Dong-Ping FANG Peng HAO Dong-Fang HE qiao-yuan li Xu liU Can-Can liN Cheng-Jun GUO Department of Cardiology Beijing Anzhen HospitalCapital Medical UniversityBeijing Institute of HeartLung and Blood Vessel DiseasesBeijingChina

Objective To compare the short-term clinical effect and electrical parameters of His-purkinje bundle pacing(HPBP) and right ventricular inflow tract septal pacing(RVIP) in the elderly. Methods Between April 2017 and September 2019, sixty patients with indications for permanent cardiac pacing and resynchronization therapy in Beijing Anzhen Hospital were divided into the HPBP and RVIP groups, and were analyzed. A ventricular pacing lead was implanted in left ventricular septal sites with left bundle potentials or His potentials in the HPBP group. The lead was placed in right ventricular inflow tract septal sites close to distal His-bundle regions without potentials from the His-purkinje conduction system in the RVIP group. Lead impedance, R wave amplitude, pacing thresholds, QRS duration, left ventricular ejection fraction(LVEF), and left ventricular end-diastolic diameter(LVEDD), mitral regurgitation area reflux, QTc, T wave directivity, Tp-e and Tp-e/QT ratio were compared between the HPBP and RVIP groups during the procedure and the short-month follow-up. Results No significant differences were found in lead impedance, R wave amplitude, QRS duration, LVEF, LVEDD, mitral regurgitation area reflux, QTc, T wave directivity, Tp-e and Tp-e/QT ratio between the HPBP and RVIP groups. However, the pacing threshold was significantly lower in the HPBP group than in the RVIP group(0.7 ± 0.2 vs. 0.9 ± 0.3 V, P = 0.02). Conclusions The efficacy and electrical parameters of HPBP is comparable with RVIP during the procedure and the short-term follow-up.

关键词： Bundle branch block His-purkinje bundle pacing Pacemaker Right ventricular inflow tract

青藏高原草地植被物候变化及其对气候变化的响应

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中国草地学报 2021年第9期43卷 32-43页

作者：袁巧丽杨建黄河水利职业技术学院水利工程学院河南开封475004 西南民族大学青藏高原研究院四川成都610225

基于NDVI、草地类型和地面实测数据,辅以Sen趋势分析、变异系数(Cv)及偏相关分析法,探索青藏高原2000~2019年草地植被物候时空变化特征及其对气候变化的响应。结果表明:(1)空间分布上表现为从西北向东南,草地生长季始期(SOS)呈提前趋势... 详细信息

基于NDVI、草地类型和地面实测数据,辅以Sen趋势分析、变异系数(Cv)及偏相关分析法,探索青藏高原2000~2019年草地植被物候时空变化特征及其对气候变化的响应。结果表明:(1)空间分布上表现为从西北向东南,草地生长季始期(SOS)呈提前趋势、生长季末期(EOS)呈推迟趋势、生长季长度(LOS)逐渐变长。其中,SOS集中在5月上旬到6月下旬(130~170d),60.50%的面积上表现为显著提前趋势,提前速率为0.5~2.0d/a。EOS集中在9月上旬到10月上旬(250~280d),62.85%的面积上呈推迟趋势。LOS持续在110~160d,呈变长趋势的面积占研究区总面积的65.98%。(2)海拔低于3100m区域的草地SOS随海拔升高以1.9d/100m的速率逐渐提前,海拔高于3300m的区域,草地SOS随海拔升高而逐渐推迟。EOS随海拔上升呈逐渐推迟趋势,LOS随海拔上升呈缩短趋势。(3)SOS与年平均气温和年总降水量表现出显著的正相关关系。气温和降水与EOS主要以负相关关系为主,但空间差异较大。LOS与降水以负相关关系为主,与气温以正相关关系为主。以上研究结果为青藏高原草地物候监测提供参考。

关键词：草地植被物候时空特征植被分区青藏高原

Co/Co_(7)Fe_(3)heterostructures with controllable alloying degree on carbon spheres as bifunctional electrocatalyst forrechargeable zinc-air batteries

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 476-487页

作者： Junkang Chen Yongyue Zhuang Yanxin qiao Yu Zhang Aihua yuan Hu Zhou School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China School of Environmental and Chemical Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China

Exploring efficient and nonprecious metal electrocatalysts of oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is crucial for developing rechargeable zinc-air batteries(ZABs).Herein,an alloying-degree control strategy was employed to fabricate nitrogen-doped carbon sphere(NCS)decorated with dual-phase Co/Co_(7)Fe_(3)heterojunctions(CoFe@NCS).The phase composition of materials has been adjusted by controlling the alloying *** optimal CoFe_(0.08)@NCS electrocatalyst displays a half-wave potential of 0.80 V for ORR and an overpotential of 283 mV at 10 mA·cm^(-2)for OER in an alkaline *** intriguing bifunctional electrocatalytic activity and durability is attributed to the hierarchically porous structure and interfacial electron coupling of highly-active Co_(7)Fe_(3)alloy and metallic Co *** the CoFe_(0.08)@NCS material is used as air-cathode catalyst of rechargeable liquid-state zinc-air battery(ZAB),the device shows a high peak power-density(157 mW·cm^(-2))and maintains a stable voltage gap over 150 h,outperforming those of the benchmark(Pt/C+RuO_(2))-based *** particular,the as-fabricated solid-state flexible ZAB delivers a reliable compatibility under different bending *** work provides a promising strategy to develop metal/alloy-based electrocatalysts for the application in renewable energy conversion technologies.

关键词： bifunctional electrocatalysts oxygen reduction reaction oxygen evolution reaction zinc-air battery metal/alloy carbon sphere

Impact of Bubbles on Mechanical Performances in a Borosilicate Glass

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Journal of Wuhan University of Technology(Materials Science) 2025年第1期40卷 25-29页

作者： li Chengxing li Dongfeng MA Shilong qiao Ang ZHENG Qingshuang China Helicopter Research and Development Institute Jingdezhen 333001China State Key Laboratory of Silicate Materials for Ar-chitectures Wuhan University of TechnologyWuhan 430070China

To analyze the impact of bubbles on the mechanical behavior of glasses,by controlling the refining time,we prepared three borosilicate glasses with the same composition and different *** the analysis software integrated within the optical microscope,the diameter and number of the bubbles on the surface of three borosilicate glasses were *** the hardness and crack initiation resistance(CR),we built the relationship between the porosity and the mechanical performance of these borosilicate glasses.

关键词： bubbles oxide glass hardness creak initiation resistance

Correlation between the rock mass properties and maximum horizontal stress:A case study of overcoring stress measurements

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 39-48页

作者： Peng li Meifeng Cai Shengjun Miao yuan li Yu Wang Key Laboratory of Ministry of Education for Efficient Mining and Safety of Metal Mines University of Science and Technology BeijingBeijing 100083China State Key Laboratory of Coal Resources and Safe Mining China University of Mining and TechnologyXuzhou 221116China

Understanding the mechanical properties of the lithologies is crucial to accurately determine the horizontal stress *** investigate the correlation between the rock mass properties and maximum horizontal stress,the three-dimensional(3D)stress tensors at 89 measuring points determined using an improved overcoring technique in nine mines in China were adopted,a newly defined characteristic parameter C_(ERP)was proposed as an indicator for evaluating the structural properties of rock masses,and a fuzzy relation matrix was established using the information distribution *** results indicate that both the vertical stress and horizontal stress exhibit a good linear growth relationship with *** is no remarkable correlation between the elastic modulus,Poisson's ratio and depth,and the distribution of data points is scattered and ***,there is no obvious relationship between the rock quality designation(RQD)and *** maximum horizontal stress σ_(H) is a function of rock properties,showing a certain linear relationship with the C_(ERP)at the same *** addition,the overall change trend of σ_(H) determined by the established fuzzy identification method is to increase with the increase of C_(ERP).The fuzzy identification method also demonstrates a relatively detailed local relationship betweenσ_H and C_(ERP),and the predicted curve rises in a fluctuating way,which is in accord well with the measured stress data.

关键词： overcoring stress measurements elastic modulus Poisson's ratio rock quality designation maximum horizontal stress fuzzy identification

Nanoindentation Size Effect on Type 316 Stainless Steel

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Journal of Wuhan University of Technology(Materials Science) 2004年第B10期19卷 30-33页

作者：姚远 University of Science and Technology Beijing

Nanoindentation size effect was investigated under very low loads on type 316 stainless steel. Nanoindentation measurements were carried out on the samples surfaces with a Berkovich pyramidal diamond indenter applying loads in the range of 25-1000μN. Simultaneously, AFM images of the sample surface were recorded before and after indentation process .For type 316 stainless steel, the indentation size effect was found. The results were discussed in the terms of the model of geometrically necessary dislocations proposed to interpret the indentation size *** can be seen that the square of the nanohardness, H 2, vs the inverse of indentation depth, 1/h, is linearly dependent on the indented depth in the range of 25-150nm,which is a good qualitative agreement with the predictions of the model. However, for shallow indents, the slope of the line severely *** possible mechanisms for this change were proposed.

关键词： nanoindentation indentation size effect type 316 stainless steel