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Virtual source approach for maximizing resolution in high-penetration gamma-ray imaging

Matter and Radiation at Extremes 2024年第3期9卷 19-30页

作者： Yuchi Wu Shaoyi Wang Bin Zhu Yonghong Yan Minghai Yu Gang Li Xiaohui Zhang Yue Yang Fang Tan Feng Lu Bi Bi xiaoqin mao Zhonghai Wang Zongqing Zhao Jingqin Su Weimin Zhou Yuqiu Gu National Key Laboratory of Plasma Physics Laser Fusion Research CenterCAEPMianyangSichuan 621900China College of Physics Sichuan UniversityChengdu 610065China

High-energy gamma-ray radiography has exceptional penetration ability and has become an indispensable nondestructive testing(NDT)tool in various *** high-energy photons,point projection radiography is almost the only feasible imaging method,and its spatial resolution is primarily constrained by the size of the gamma-ray *** conventional industrial applications,gamma-ray sources are commonly based on electron beams driven by accelerators,utilizing the process of bremsstrahlung *** size of the gamma-ray source is dependent on the dimensional characteristics of the electron *** research has been conducted on various advanced accelerator technologies that have the potential to greatly improve spatial resolution in *** our investigation of laser-driven gamma-ray sources,a spatial resolution of about 90μm is achieved when the areal density of the penetrated object is 120 g/cm^(2).A virtual source approach is proposed to optimize the size of the gamma-ray source used for imaging,with the aim of maximizing spatial *** this virtual source approach,the gamma ray can be considered as being emitted from a virtual source within the convertor,where the equivalent gamma-ray source size in imaging is much smaller than the actual emission *** the basis of Monte Carlo simulations,we derive a set of evaluation formulas for virtual source scale and gamma-ray emission *** optimal conditions,the virtual source size can be as small as 15μm,which can significantly improve the spatial resolution of high-penetration imaging to less than 50μm.

关键词： resolution approach utilizing

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健瘘方热敷联合阿司匹林肠溶片对尿毒症自体动静脉内瘘成形术后患者内瘘功能的影响

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河北中医 2024年第4期46卷 578-582页

作者：毛晓琴鲁毅张晓玲四川省射洪市中医院肾病科四川射洪629200

目的观察健瘘方热敷联合阿司匹林肠溶片对尿毒症自体动静脉内瘘成形术(AVF)后患者内瘘功能的影响。方法选择2019年7月至2021年7月收治的80例尿毒症AVF后患者为研究对象,按照随机数字表法分为2组,对照组40例予阿司匹林肠溶片治疗,治疗组4... 详细信息

目的观察健瘘方热敷联合阿司匹林肠溶片对尿毒症自体动静脉内瘘成形术(AVF)后患者内瘘功能的影响。方法选择2019年7月至2021年7月收治的80例尿毒症AVF后患者为研究对象,按照随机数字表法分为2组,对照组40例予阿司匹林肠溶片治疗,治疗组40例在对照组基础上联合健瘘方热敷治疗。2组均治疗1个月比较2组治疗前及治疗1、2、3、4周内瘘血流量、内瘘内径及血管内皮功能指标[包括内皮素-1(ET-1)及一氧化氮(NO)]水平变化情况,比较2组治疗期间血管弹性、血管杂音、内瘘通畅率及并发症发生情况,2组治疗结束后均随访1年,统计内瘘失功或再造情况。结果与本组治疗前比较,2组治疗1、2、3、4周内瘘血流量及内瘘内径均增加(P<0.05),且治疗组治疗1、2、3、4周内瘘血流量及内瘘内径均大于对照组(P<0.05)。与本组治疗前比较,2组治疗1、2、3、4周血管内皮功能指标ET-1水平均降低(P<0.05),NO水平均升高(P<0.05),且治疗组治疗1、2、3、4周ET-1水平低于对照组(P<0.05),NO水平高于对照组(P<0.05)。治疗组血管弹性好率92.50%(37/40),血管杂音弱率90.00%(36/40)),对照组血管弹性好率70.00%(28/40),血管杂音弱率72.50%(29/40),治疗组血管弹性好率高于对照组(P<0.05),血管杂音弱率高于对照组(P<0.05)。治疗组内瘘通畅率92.50%(37/40),对照组内瘘通畅率72.50%(29/40),治疗组内漏通畅率高于对照组(P<0.05)。治疗组并发症总发生率2.50%(1/40),对照组并发症总发生率20.00%(8/40),治疗组并发症总发生率低于对照组(P<0.05)。治疗组随访1年内瘘失功或再造率5.00%(2/40),对照组随访1年内瘘失功或再造率25.00%(10/40),治疗组随访1年内瘘失功或再造率低于对照组(P<0.05)。结论健瘘方热敷联合阿司匹林肠溶片治疗尿毒症AVF后患者疗效确切,可有效改善患者内瘘内径,增加动静脉内瘘血流量,增加血管弹性,减少血管杂音,维持内瘘通畅,减少并发症的发生,且远期疗效可靠,其作用机制可能与改善血管内皮细胞功能,预防血栓形成有关。

关键词：尿毒症动静脉吻合阿司匹林中药疗法

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融合课程思政的大学物理实验学生创新能力培养路径实践

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物理通报 2024年第7期 8-11页

作者：王本阳毛晓芹刘一李岩王新顺哈尔滨工业大学(威海)理学院山东威海264209

为了解决学生缺乏独立思考、教学模式固定等“痛点”问题,大学物理实验课建立了以思想政治教育为指导,以解决具体问题为导向,以各种教学平台和课后自主实验为载体,以教师分层次、个性化的引导为途径,以提高学生的创新能力和科学素养为目... 详细信息

为了解决学生缺乏独立思考、教学模式固定等“痛点”问题,大学物理实验课建立了以思想政治教育为指导,以解决具体问题为导向,以各种教学平台和课后自主实验为载体,以教师分层次、个性化的引导为途径,以提高学生的创新能力和科学素养为目标,学生在开放式的教学模式下进行深度学习的新的教育培养模式.该模式以问题为导向引导创新,课内课外相融合逐步创新,以思政教育为引领,激发创新,使学生的知识、能力和素养得到全方位的锻炼.在此教学模式下,学生发表科研论文5篇,获得物理科技创新类竞赛国家级奖励10余项和省部级奖励50余项,教学成效显著.

关键词：思政教育创新能力以问题为导向科学素养教学模式

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Simulation and evaluation study of atmospheric aerosol nonsphericity as a function of particle size

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Particuology 2024年第7期90卷 281-291页

作者： Qianjun mao Xin Nie School of Urban Construction Wuhan University of Science and TechnologyWuhan430065China College of New Energy and Materials Northeast Petroleum UniversityDaqing163318China

Aerosol nonsphericity causes great uncertainty in radiative forcing assessments and climate *** considerable studies have attempted to quantify this uncertainty,the relationship between aerosol nonsphericity and particle size is usually not considered,thus reducing the accuracy of the *** this study,a coupled inversion algorithm combining an improved stochastic particle swarm optimization algorithm and angular light scattering is used for the nonparametric estimation of aerosol nonsphericity variation with particle size,and the optimal sample selection method is employed to screen the *** on the verification of inversion accuracy,the variation of aerosol aspect ratio with particle size based on the ellipsoidal model in global regions has been obtained from Aerosol Robotic Network(AERONET)data,and the effect of nonsphericity on radiative forcing and dry deposition has been *** results show that the aspect ratio increases with particle size in all regions,with the maximum ranging from 1.4 to 1.8 in the desert,reflecting the differences in aerosol composition at different particle *** radiation calculations,considering aerosol nonsphericity makes the aerosol cooling effect weaker and surface radiative fluxes increase,but hardly changes the aerosol absorption,with maximum differences of 9.22%and 22.12%at the bottom and top of the atmosphere,***,the differences in radiative forcing between aspect ratios as a function of particle size and not varying with particle size are not significant,averaging less than 2%.Besides,the aspect ratio not varying with particle size underestimates the deposition velocity of small particles and overestimates that of large particles compared to that as a function of particle size,with maximum differences of 7%and 4%,respectively.

关键词： Aerosol nonsphericity Inversion Aspect ratio Radiative forcing Dry deposition velocity

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Proof of Two Supercongruences of Truncated Hypergeometric Series_(4)F_(3)

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Acta Mathematica Sinica,English Series 2024年第4期40卷 1015-1028页

作者： Guo Shuai mao Department of Mathematics Nanjing University of Information Science and TechnologyNanjing 210044P.R.China

In this paper,we prove two supercongruences conjectured by Z.-*** via the Wilf-Zeilberger *** of them is,for any prime p>3,4F3[7/6 1/2 1/2 1/2 1/6 1 1]-1/8]-1/2≡p(-2/p)+p^(3)/4(2/p)Ep-3 (mod p^(4))where(·/p)stands f... 详细信息

关键词： Supercongruence truncated hypergeometric series Wilf–Zeilberger method Euler numbers Legendre symbol

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恩替卡韦治疗慢性乙型肝炎病毒携带者近期疗效观察

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中华肝脏病杂志 2014年第12期22卷 900-903页

作者：颜成果姚云清毛晓琴重庆医科大学附属第一医院感染科 400016

目的观察恩替卡韦治疗慢性HBV携带者的近期疗效与安全性,探讨慢性HBV携带者抗病毒治疗的临床意义. 方法慢性HBV携带者47例,慢性乙型肝炎患者46例,诊断均符合“慢性乙型肝炎防治指南（2010年版）”.两组患者均给予恩替卡韦分散片0.5 m... 详细信息

目的观察恩替卡韦治疗慢性HBV携带者的近期疗效与安全性,探讨慢性HBV携带者抗病毒治疗的临床意义. 方法慢性HBV携带者47例,慢性乙型肝炎患者46例,诊断均符合“慢性乙型肝炎防治指南（2010年版）”.两组患者均给予恩替卡韦分散片0.5 mg/d口服治疗,观察两组患者治疗第4、12、24、48周血清学应答率、生物化学应答率与突破率的差异,并观察药物相关不良事件发生率.数据均使用SPSS17.0统计分析软件进行,分别采用t检验和x2检验.结果第4、12、24、48周完全病毒学应答率：慢性HBV携带者组分别为14.9％、51.1％、76.6％和97.9％;慢性乙型肝炎患者组分别为,17.4％、63.0％、89.1％和100.0％,两组间各时间点比较,差异均无统计学意义.第4、12、24、48周部分病毒学应答率：慢性HBV携带者组分别为42.6％、57.4％、85.0％和100.0％;慢性乙型肝炎患者组分别为47.8％、65.2％、89.1％和100.0％,两组间各时间点比较,差异均无统计学意义.第4、12、24、48周HBeAg阴转率：慢性HBV携带者组分别为0、2.1％、4.3％和8.5％;慢性乙型肝炎患者组分别为4.4％、8.7％、13.0％和21.7％,两组间各时间点比较,差异均无统计学意义.第4、12、24、48周HBeAg血清学转换率：慢性HBV携带者组分别为0、0、2.1％和6.4％;慢性乙型肝炎患者组分别为0、4.4％、10.9％和17.4％,两组间各时间点比较,差异均无统计学意义.HBsAg阴转率与血清学转换率,两组各观察时段均为0.慢性乙型肝炎患者组第4、12、24、48周ALT复常率分别为26.1％、65.2％、91.3％和97.8％.两组患者均无病毒学突破和生物化学突破病例.两组患者均未观察到肾毒性、骨髓抑制、横纹肌溶解或其他药物相关不良事件.结论采用恩替卡韦分散片治疗慢性HBV携带者近期疗效好、安全.

关键词：肝炎,乙型,慢性治疗恩替卡韦慢性乙型肝炎病毒携带者

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Dynamic steric confinement effect expands the frontier of Cu-catalyzed asymmetric propargylic aminations

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Science China Chemistry 2024年第10期67卷 3181-3183页

作者： Peng Chen mao-mao Zhang Wen-Jing Xiao Liang-Qiu Lu Engineering Research Center of Photoenergy Utilization for Pollution Control and Carbon Reduction Ministry of EducationCollege of ChemistryCentral China Normal University Wuhan Institute of Photochemistry and Technology State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical Physics (LICP)Chinese Academy of Sciences School of Chemistry and Chemical Engineering Henan Normal University

Chiral α-tertiary amines and related azacycles are commonly found in many natural products, pharmaceuticals and agrochemicals [1]. Copper-catalyzed asymmetric propargylic amination(APA) reactions have been established as a reliable method to access enantio-enriched propargylic amines,largely due to the seminal contribution of Nishibayashi et al.[2] and van Maarseveen et al. [3] in 2008.

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Heat Storage Performance of PCM in a Novel Vertical Pointer-Shaped Finned Latent Heat Tank

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Journal of Thermal Science 2024年第2期33卷 422-434页

作者： mao Qianjun ZHU Yuanyuan LI Tao School of Urban Construction Wuhan University of Science and TechnologyWuhan430065China

The heat storage performance of latent heat storage systems is not good due to the poor thermal conductivity of phase change *** this paper,a new type of pointer-shaped fins combining rectangular and triangular fins has been employed to numerically simulate the melting process in the heat storage tank,and the fin geometry parameter effects on heat storage performance have been *** results indicate that compared with the bare tube and the rectangular finned tank,the melting time of the phase change material in the pointer-shaped finned tank is reduced by 64.2%and 15.1%,*** closer the tip of the triangular fin is to the hot wall,the better the heat transfer *** optimal height of the triangular fin is about 8 *** the number of fins from 4 to 6 and from 6 to 8 reduces the melting time by 16.0%and 16.7%***,increasing the number of fins from 8 to 10 only reduces the melting time by 8.4%.When the fin dimensionless length is increased from 0.3 to 0.5 and from 0.5 to 0.7,the melting time is shortened by 17.5%and 13.0%.But the melting time is only reduced by 2.9%when the dimensionless fin length is increased from 0.7 to *** optimising the design of the thermal storage system,the results can provide a reference value.

关键词： thermal energy storage phase change material pointer-shaped fins heat storage performance

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Equilibrium Strategy of the Pursuit-Evasion Game in Three-Dimensional Space

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 446-458页

作者： Nuo Chen Linjing Li Wenji mao School of Artificial Intelligence University of Chinese Academy of SciencesBeijing 100049 Institute of Automation Chinese Academy of SciencesBeijing 100190China

The pursuit-evasion game models the strategic interaction among players, attracting attention in many realistic scenarios, such as missile guidance, unmanned aerial vehicles, and target defense. Existing studies mainly concentrate on the cooperative pursuit of multiple players in two-dimensional pursuit-evasion games. However, these approaches can hardly be applied to practical situations where players usually move in three-dimensional space with a three-degree-of-freedom control. In this paper,we make the first attempt to investigate the equilibrium strategy of the realistic pursuit-evasion game, in which the pursuer follows a three-degree-of-freedom control, and the evader moves freely. First, we describe the pursuer's three-degree-of-freedom control and the evader's relative coordinate. We then rigorously derive the equilibrium strategy by solving the retrogressive path equation according to the Hamilton-Jacobi-Bellman-Isaacs(HJBI) method, which divides the pursuit-evasion process into the navigation and acceleration phases. Besides, we analyze the maximum allowable speed for the pursuer to capture the evader successfully and provide the strategy with which the evader can escape when the pursuer's speed exceeds the threshold. We further conduct comparison tests with various unilateral deviations to verify that the proposed strategy forms a Nash equilibrium.

关键词： Differential game equilibrium strategy pursuit-evasion game threedegree-of-freedom control

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First Passage Density of Brownian Motion with Two-sided Piecewise Linear Boundaries

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Acta Mathematica Sinica,English Series 2024年第6期40卷 1505-1520页

作者： Zhen YU mao Zai TIAN Center for Applied Statistics School of StatisticsRenmin University of ChinaBeijing 100872P.R.China School of Mathematics and Data Science Changji UniversityChangji 831100P.R.China

The first passage time has many applications in fields like finance,econometrics,statistics,and ***,explicit formulas for the first passage density have only been obtained for a few *** paper derives an explicit formula for the first passage density of Brownian motion with twosided piecewise continuous boundaries which may have some points of *** are used to obtain a simplified formula for estimating the first passage ***,the results are also generalized to the case of two-sided general nonlinear *** can be easily carried out with Monte Carlo method and it is demonstrated for several typical two-sided boundaries that the proposed approximation method offers a highly accurate approximation of first passage density.

关键词： Boundary non-crossing probability first density passage density two-sided piecewise continuous boundaries Brownian motion

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