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Hybrid simulation of q=1 high-order harmonics driven by passing energetic particles in tokamak plasmas
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作者 刘胜 任珍珍 +3 位作者 汪卫华 申伟 杨锦宏 宁洪伟 《Plasma Science and Technology》 SCIE EI CAS CSCD 2023年第12期31-39,共9页
High-order harmonics q(ψ_(s))=1 energetic particle modes(EPMs)have been observed in toroidal plasmas experiments with neutral beam injection.To investigate these phenomena,linear properties and nonlinear dynamics of ... High-order harmonics q(ψ_(s))=1 energetic particle modes(EPMs)have been observed in toroidal plasmas experiments with neutral beam injection.To investigate these phenomena,linear properties and nonlinear dynamics of these EPMs driven by passing energetic particles(EPs)are studied via the global hybrid kinetic-magnetohydrodynamic code M3D-K.Simulation results demonstrate that passing EPs'effects on high mode-number harmonics(q(ψ_(s))=m/n=2/2,3/3,4/4)instability are more obvious than the q(ψ_(s))=1/1 mode,especially when q-profile is sufficiently flat in the core region.Furthermore,the effects of the pitch angleΛ_0 and beam ion pressure P_(hot)/P_(total)on the features of high n components are also analyzed specifically.It is found that there exists only one resonant condition for these EPMs.In the nonlinear phase,these high mode-number harmonics can induce significant energetic ions redistribution and chirping up phenomena,which differs from the classical fishbone excited by passing EPs.These discoveries are conducive to better apprehend the underlying physical mechanisms of the highorder harmonics driven by passing EPs. 展开更多
关键词 high-order harmonics passing energetic particles wave-particle resonance TOKAMAK
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Non-Stationary and Resonant Passage of a System: A High-Frequency Cutoff Noise
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作者 Xiaoyang Shi 《Journal of Modern Physics》 2023年第10期1323-1332,共10页
We study non-equilibrium behaviors of a particle subjected to a high-frequency cutoff noise in terms of generalized Langevin equation, where the spectrum of internal noise is considered to be of the generalized Debye ... We study non-equilibrium behaviors of a particle subjected to a high-frequency cutoff noise in terms of generalized Langevin equation, where the spectrum of internal noise is considered to be of the generalized Debye form. A closed solution is impossible even if the equation is linear, because the Laplace transform of the memory kernel is a multi-value function. We use a numerical method to calculate the velocity correlation function of a force-free particle and the probability of a particle passing over the top of an inverse harmonic potential. We indicate the nonergodicity of the second type, i.e., the auto-correlation function of the velocity approaches to non-stationary at large times. Applied to the barrier passage problem, we find and analyse a resonant phenomenon that the dependence of the cutoff frequency is nonmonotonic when the initial directional velocity of the particle is less than the critical value, the latter is determined by the passing probability equal to 0.5. 展开更多
关键词 Nonergodicity Generalized Debye Noise Resonance passing
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Microstructure Distribution Characteristics of High-Strength Aluminum Alloy Thin-Walled Tubes during Multi-Passes Hot Power Backward Spinning Process
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作者 Yuan Tian Ranyang Zhang +1 位作者 Gangyao Zhao Zhenghua Guo 《Journal of Materials Science and Chemical Engineering》 2023年第7期114-121,共8页
The microstructure of the thin-walled tubes with high-strength aluminum alloy determines their final forming quality and performance. This type of tube can be manufactured by multi-pass hot power backward spinning pro... The microstructure of the thin-walled tubes with high-strength aluminum alloy determines their final forming quality and performance. This type of tube can be manufactured by multi-pass hot power backward spinning process as it can eliminate casting defects, refine microstructure and improve the plasticity of the tube. To analyze the microstructure distribution characteristics of the tube during the spinning process, a 3D coupled thermo-mechanical FE model coupled with the microstructure evolution model of the process was established under the ABAQUS environment. The microstructure evolution characteristics and laws of the tube for the whole spinning process were analyzed. The results show that the dynamic recrystallization is mainly produced in the spinning deformation zone and root area of the tube. In the first pass, the dynamic recrystallization phenomenon is not obvious in the tube. With the pass increasing, the trend of dynamic recrystallization volume percentage gradually increases and extends from the outer surface of the tube to the inner surface. The fine-grained area shows the states of concentration, dispersion, and re-concentration as the pass number increases. . 展开更多
关键词 Cast high-Strength Aluminum Alloy Tube Multi-pass Hot Power Backward Spinning FE Simulation Microstructure Evolution
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两组不同中医体质安氏Ⅱ^(1)错(牙合)患者运用PASS技术矫正前后牙颌相关指标及体质的变化
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作者 杨超 房慧岭 王迅 《中国美容医学》 CAS 2024年第5期144-148,共5页
目的:比较平和质与阴虚质安氏Ⅱ1错(牙合)患者运用PASS矫正技术治疗后牙颌及体质相关指标的变化。方法:选择2019年2月-2023年2月来笔者医院口腔科就诊的安氏Ⅱ类1分类患者为研究对象,通过体质分型选择平和质(10例)与阴虚质(10例)错(牙合... 目的:比较平和质与阴虚质安氏Ⅱ1错(牙合)患者运用PASS矫正技术治疗后牙颌及体质相关指标的变化。方法:选择2019年2月-2023年2月来笔者医院口腔科就诊的安氏Ⅱ类1分类患者为研究对象,通过体质分型选择平和质(10例)与阴虚质(10例)错(牙合)患者运用PASS矫正技术进行治疗,比较两组患者矫正时托槽的脱落情况,矫正前后面型、牙颌及体质的改变。结果:平和质组患者托槽的脱落率明显小于阴虚质组(P<0.05);两种体质患者运用PASS矫正技术治疗前后的头影测量结果差异有统计学意义(P<0.05);矫正结束半年后,阴虚质较平和质患者的体质发生了明显改善(P<0.05)。结论:相较于阴虚体质错(牙合)患者,平和质体质错(牙合)患者在托槽脱落情况及矫正结束后体质的转归方面具有明显优势,因此不同体质对于错(牙合)畸形的矫正具有一定的指导意义。 展开更多
关键词 中医体质 安氏Ⅱ类1分类 pass矫正技术 错(牙合)畸形 正畸
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Cholesky分解的单Pass随机算法
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作者 刘雪翠 《理论数学》 2024年第1期87-93,共7页
对于大规模数据矩阵,数据的读取成本远高于算法本身的成本;对存储在磁盘外部的流型数据,往往只有一次读取数据的机会。而以往的Cholesky分解的随机算法都至少需要读取输入数据两次,难以满足实际应用中的低成本需求。本文基于矩阵分解的... 对于大规模数据矩阵,数据的读取成本远高于算法本身的成本;对存储在磁盘外部的流型数据,往往只有一次读取数据的机会。而以往的Cholesky分解的随机算法都至少需要读取输入数据两次,难以满足实际应用中的低成本需求。本文基于矩阵分解的单pass随机算法研究,提出了Cholesky分解的单pass随机算法,并给出了该算法的误差上界,最后通过数值实验验证了该算法的可行性以及有效性。 展开更多
关键词 CHOLESKY分解 矩阵分解 pass随机算法
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Turbo Message Passing Based Burst Interference Cancellation for Data Detection in Massive MIMO-OFDM Systems
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作者 Wenjun Jiang Zhihao Ou +1 位作者 Xiaojun Yuan Li Wang 《China Communications》 SCIE CSCD 2024年第2期143-154,共12页
This paper investigates the fundamental data detection problem with burst interference in massive multiple-input multiple-output orthogonal frequency division multiplexing(MIMO-OFDM) systems. In particular, burst inte... This paper investigates the fundamental data detection problem with burst interference in massive multiple-input multiple-output orthogonal frequency division multiplexing(MIMO-OFDM) systems. In particular, burst interference may occur only on data symbols but not on pilot symbols, which means that interference information cannot be premeasured. To cancel the burst interference, we first revisit the uplink multi-user system and develop a matrixform system model, where the covariance pattern and the low-rank property of the interference matrix is discussed. Then, we propose a turbo message passing based burst interference cancellation(TMP-BIC) algorithm to solve the data detection problem, where the constellation information of target data is fully exploited to refine its estimate. Furthermore, in the TMP-BIC algorithm, we design one module to cope with the interference matrix by exploiting its lowrank property. Numerical results demonstrate that the proposed algorithm can effectively mitigate the adverse effects of burst interference and approach the interference-free bound. 展开更多
关键词 burst interference cancellation data detection massive multiple-input multiple-output(MIMO) message passing orthogonal frequency division multiplexing(OFDM)
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The Research on the Battle of Yanmen Pass
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作者 XING Cheng 《Journal of Literature and Art Studies》 2024年第2期151-154,共4页
During the war between Liao Dynasty(907-1125)and Northern Song Dynasty(960-1127),there was a classic battle that happened in Yanmen Pass(located in today’s Dai County,Xinzhou,Shanxi Province,China).It was a well know... During the war between Liao Dynasty(907-1125)and Northern Song Dynasty(960-1127),there was a classic battle that happened in Yanmen Pass(located in today’s Dai County,Xinzhou,Shanxi Province,China).It was a well known battle of ancient China because a commander of the Song army named Yang Ye(?-986)was really famous in both classical Chinese fictions and Chinese war history.He is the early protagonist of a famous Chinese classic fiction named The Romance of the Yang family’s generals(written in the 16th century,Ming Dynasty of China).The story of his family also appears in other novels.Besides,in history,he was a general who was active in the early stages of the war between Liao Dynasty and Northern Song Dynasty.The battle of Yanmen Pass(980)was one of the most important battles of Yang’s military career.His combat style especially his cavalry tactic can be summarized through researching this battle. 展开更多
关键词 Northern Song Dynasty Yanmen pass Yang Ye Liao Dynasty cavalry tactic
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基于Pass平台的人事薪资管理系统设计与实现
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作者 邹细云 周霞丽 +1 位作者 李林霖 邹团营 《科技与创新》 2024年第21期59-61,共3页
设计了基于Pass平台的人事薪资管理系统。详细讨论了系统的功能和特点、用户需求分析、法规合规性要求、系统架构设计、功能模块实现、性能测试和部署、安全性和稳定性。系统具备员工信息管理、薪资计算、绩效评估等功能,并在Pass平台... 设计了基于Pass平台的人事薪资管理系统。详细讨论了系统的功能和特点、用户需求分析、法规合规性要求、系统架构设计、功能模块实现、性能测试和部署、安全性和稳定性。系统具备员工信息管理、薪资计算、绩效评估等功能,并在Pass平台上构建,以实现灵活性、可用性、安全性和成本效益的平衡。性能测试确保系统在高负荷下表现良好,而系统的安全性和稳定性措施可确保数据安全和系统稳定运行。部署和维护计划则保证了系统的长期可维护性和稳定性。综合研究将有助于提高人事薪资管理的效率和可靠性,为企业提供全面的管理解决方案。 展开更多
关键词 人力资源管理 薪资计算 pass平台 自动化
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水电站110kV开关站PASS开关设备运行维护要点
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作者 焦剑伟 《电力设备管理》 2024年第14期187-189,共3页
高压开关站是水电站的主要组成部分,主要作用是接受和分配水轮发电机组发出的电能,经升压后向电网或负荷点供电的高压配电装置的场所。本文结合张掖黑河龙首二级水电站110kV PASS开关设备多年的运行维护检修,从设备运行的每个部位的正... 高压开关站是水电站的主要组成部分,主要作用是接受和分配水轮发电机组发出的电能,经升压后向电网或负荷点供电的高压配电装置的场所。本文结合张掖黑河龙首二级水电站110kV PASS开关设备多年的运行维护检修,从设备运行的每个部位的正常运行要求进行总结,提出了PASS开关设备正常运行必须满足的设备运行条件要求,为工程运行总结和提供了一定的成功经验。 展开更多
关键词 pass开关设备 开关站 维护
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Application Effect of Blended Education Strategy Based on the Learning Pass Platform in Phase III Cardiac Rehabilitation of Patients with Coronary Artery Disease
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作者 Shanshan Cui Guihua Xue +4 位作者 Xuelan Yan Hua Zhang Fang Wang Yan Xu Xuefei Li 《Journal of Contemporary Educational Research》 2024年第2期91-97,共7页
Objective:To explore the application effect of the blended education strategy based on the Learning Pass platform in the phase III cardiac rehabilitation of patients with coronary artery disease.Methods:90 patients di... Objective:To explore the application effect of the blended education strategy based on the Learning Pass platform in the phase III cardiac rehabilitation of patients with coronary artery disease.Methods:90 patients diagnosed with coronary artery disease in the Department of Cardiology of our hospital from January 2019 to January 2021 were selected and divided into the control group and the experimental group according to the method of randomized numerical table,with 45 cases in each group.Both the experimental group and the control group received pre-discharge cardiac rehabilitation education by conventional means.The control group received education and supervision information via WeChat after discharge,while the experimental group joined the Learning Pass platform to receive online and offline hybrid education and supervision,with online as the mainstay and offline as a supplement.The disease cognitive level,self-management skills,quality of life,medication adherence,and emotional status of the two groups were compared.Results:The disease cognitive levels in the experimental group were significantly higher than those of the control group(P<0.05);the scores of the experimental group in terms of quality of life,self-management skills,and medication adherence were significantly higher than those of the control group(P<0.05);and the scores of anxiety and depression in the experimental group were significantly lower than those of the control group(P<0.05).Conclusion:The blended education strategy based on the Learning Pass platform has a significant application effect in phase III cardiac rehabilitation of patients with coronary artery disease.It can improve patients’disease cognitive level,self-management skills,and quality of life,and provide a basis for improving patients’prognosis. 展开更多
关键词 Learning pass platform Blended education Coronary artery disease Cardiac rehabilitation
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聆听极致的纯A类之声 PASS XP-22/XA200.8 前后级放大器
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作者 小路(图/文) 《视听前线》 2024年第8期36-40,共5页
在音响媒体领域工作,总免不了引来朋友们的羡慕目光,皆因我们能够近距离接触并体验各类音响产品,特别是那些价值高达数十万的高端器材。这不,最近又与一套高端音响不期而遇,它主要由美国PASS放大器与英国ATC音箱组成。其产品由国内享有... 在音响媒体领域工作,总免不了引来朋友们的羡慕目光,皆因我们能够近距离接触并体验各类音响产品,特别是那些价值高达数十万的高端器材。这不,最近又与一套高端音响不期而遇,它主要由美国PASS放大器与英国ATC音箱组成。其产品由国内享有盛誉的音响代理商一一力高音响引进,我有幸在其试音室内亲身体验了这套总价上百万的音响系统。 展开更多
关键词 音响产品 音响系统 pass 放大器 亲身体验 代理商
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基于LLVM Pass的复杂嵌套循环自动并行化框架 被引量:1
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作者 马春燕 吕炳旭 +1 位作者 叶许姣 张雨 《软件学报》 EI CSCD 北大核心 2023年第7期3022-3042,共21页
随着多核处理器的普及应用,针对嵌入式遗留系统中串行代码的自动并行化方法是研究热点.其中,针对具有非完美嵌套结构、非仿射依赖关系特征的复杂嵌套循环的自动并行化方法存在技术挑战.提出了一种基于LLVMPass的复杂嵌套循环的自动并行... 随着多核处理器的普及应用,针对嵌入式遗留系统中串行代码的自动并行化方法是研究热点.其中,针对具有非完美嵌套结构、非仿射依赖关系特征的复杂嵌套循环的自动并行化方法存在技术挑战.提出了一种基于LLVMPass的复杂嵌套循环的自动并行化框架(CNLPF).首先,提出了一种复杂嵌套循环的表示模型,即循环结构树,并将嵌套循环的正则区域自动转换为循环结构树表示;然后,对循环结构树进行数据依赖分析,构建循环内和循环间的依赖关系;最后,基于OpenMP共享内存的编程模型生成并行的循环程序.针对SPEC2006数据集中包含近500个复杂嵌套循环的6个程序案例,分别对其进行复杂嵌套循环占比统计和并行性能加速测试.结果表明,提出的自动并行化框架可以处理LLVMPolly无法优化的复杂嵌套循环,增强了LLVM的并行编译优化能力,且该方法结合Polly的组合优化,比单独采用Polly优化的加速效果提升了9%-43%. 展开更多
关键词 复杂嵌套循环 自动并行化 LLVM pass 依赖分析
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认知加工如何影响语言学业成绩:基于PASS模型的分析
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作者 陈瑾 焦江丽 陈得军 《基础教育》 北大核心 2023年第1期80-88,共9页
为探讨基础认知加工能力如何影响小学阶段语言学业成绩,研究采用DN:CAS认知评估系统对小学3-6年级共168名儿童的计划、注意、同时性和继时性加工过程进行评估。结果显示:计划分别通过注意、同时性加工和“注意→同时性加工”的多重中介... 为探讨基础认知加工能力如何影响小学阶段语言学业成绩,研究采用DN:CAS认知评估系统对小学3-6年级共168名儿童的计划、注意、同时性和继时性加工过程进行评估。结果显示:计划分别通过注意、同时性加工和“注意→同时性加工”的多重中介作用预测语文成绩;计划通过注意、继时性加工平行中介作用于英语成绩。另外,增加学业成绩的影响路径后,计划、注意和同时性加工通过语文学业成绩影响英语学业成绩。结果表明进行与计划、注意和编码策略相关的认知技能教学和课程设计,将有助于儿童语言类课程学业成绩的提高。另外,语文学业成绩对儿童英语学业成绩发展有重要意义。 展开更多
关键词 pass认知理论 DN:CAS认知评估系统 语文学业成绩 英语学业成绩
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基于PASS理论的方步运动方案在卒中后认知障碍患者中的应用 被引量:2
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作者 汪梦月 蒋园园 +2 位作者 于林杰 姜叶琳 彭田田 《护理学杂志》 CSCD 北大核心 2023年第5期106-109,共4页
目的观察基于PASS理论构建的方步运动方案对卒中后认知障碍患者认知功能、平衡功能、跌倒风险的影响。方法将卒中后认知障碍患者随机分为观察组41例,对照组39例。对照组实施常规专科护理、康复训练和认知训练,观察组在对照组基础上采取... 目的观察基于PASS理论构建的方步运动方案对卒中后认知障碍患者认知功能、平衡功能、跌倒风险的影响。方法将卒中后认知障碍患者随机分为观察组41例,对照组39例。对照组实施常规专科护理、康复训练和认知训练,观察组在对照组基础上采取基于PASS理论构建的方步运动方案干预,比较两组干预效果。结果干预1个月、3个月、6个月后,观察组蒙特利尔认知评估量表评分、Berg平衡量表评分显著高于对照组,Morse跌倒评估量表评分显著低于对照组(均P<0.05)。结论基于PASS理论构建的方步运动方案能够改善卒中后认知障碍患者的认知功能、平衡能力,降低患者跌倒风险。 展开更多
关键词 脑卒中 卒中后认知障碍 认知训练 pass理论 方步运动 跌倒风险 平衡能力 康复护理
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Aerodynamic performances and vehicle dynamic response of high-speed trains passing each other 被引量:7
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作者 Yinghui ZHAO Jiye ZHANG +1 位作者 Tian LI Weihua ZHANG 《Journal of Modern Transportation》 2012年第1期36-43,共8页
Based on the aerodynamics and vehicle dynamics, the aerodynamic performances and vehicle dynamic characteristics of two high-speed trains passing each other on the ground, embankment and bridge are studied. Firstly, a... Based on the aerodynamics and vehicle dynamics, the aerodynamic performances and vehicle dynamic characteristics of two high-speed trains passing each other on the ground, embankment and bridge are studied. Firstly, a train aerodynamic model and a vehicle dynamic model are established. Through the simulation of the two models, the pressure waves, aerodynamic forces, and vehicle dynamic responses are obtained. Then, the pressure waves and aero- dynamic forces on different foundations are compared. The results show that the variation trends of pressure wave and aerodynamic forces of trains passing each other on different foundations are almost similar. The peak-to-peak differ- ences in pressure wave and aerodynamic force are below 4% and 3% in three cases in open air. Besides, the differences of security indexes, including coefficient of derailment, wheel unloading rate, the wheelset lateral force, and the wheel- rail vertical force, are below 2% among the three cases; the differences of comfort indexes, including the lateral acceleration and the vertical acceleration, are also below 2%. It is concluded that the dynamic performances of trains pass- ing each other are influenced little by different foundations in open air. 展开更多
关键词 trains passing each other FOUNDATIONS pressure wave AERODYNAMICS vehicle dynamics
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Study on Electromagnetic Transient Condition of EMU Passing by Phase-separation with Electric Load in High-speed Railway 被引量:1
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作者 Xiaoxu Guo Jianzhong Wei +2 位作者 Long Xu Shibin Gao Zhengqing Han 《Energy and Power Engineering》 2013年第4期1061-1068,共8页
Aiming at the complex electromagnetic transient process of EMU passing by phase-separation with electric load in high-speed railway, mechanism of overvoltage caused by switching off, overvoltage caused by switching on... Aiming at the complex electromagnetic transient process of EMU passing by phase-separation with electric load in high-speed railway, mechanism of overvoltage caused by switching off, overvoltage caused by switching on and impact current is analyzed systematically in this article. π-type equivalent circuit of feeding section is put forward in the analysis of overvoltage mechanism. Overvoltage and overcurrent model of passing by phase-separation with electric load are also built. Correctness of mechanism was validated by simulation. In addition, the methods to solve the influence on substations, transformers and protection devices in this process are put forward, which provides a new idea on passing by phase-separation with electric load technology. 展开更多
关键词 passING by PHASE-SEPARATION with Electric Load ELECTROMAGNETIC Transient Process OVERVOLTAGE Impact Current Traction Power Supply System
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Influence of adiabatic response of passing energetic ions on high-frequency fishbone
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作者 Haozhe KONG Feng WANG Jizhong SUN 《Plasma Science and Technology》 SCIE EI CAS CSCD 2022年第9期24-30,共7页
Adiabatic response effects on high-frequency flshbone instability driven by passing energetic ions are studied.With flnite orbit width effects,the adiabatic contributionδW_(hf)is derived analytically for purely passi... Adiabatic response effects on high-frequency flshbone instability driven by passing energetic ions are studied.With flnite orbit width effects,the adiabatic contributionδW_(hf)is derived analytically for purely passing energetic ions.By approximating the adiabatic contribution to the flrst order of the reverse aspect ratioε,we derive one of its analytic expressions,which is expected to be more accurate than that in a previous work(Graves J P 2004 Phys.Rev.Lett.92185003).For high-frequency flshbone instability,nonadiabatic response is usually dominant over adiabatic response,but under certain circumstances the latter plays an important role,comparable to the former.With a more generalized distribution function by introducing Gaussian-type factors representing their pitch and radial dependences and using a slowing-down equilibrium distribution for the energy of energetic ions,numerical analysis indicates that the adiabatic contribution is conducive to stabilization of the mode and causes a decrease in mode frequency.In addition,we flnd that the adiabatic contribution has a weak stabilizing effect on the flshbone instability when the flnite orbit width effect is taken into account.We further analyze the dependence of the adiabatic contribution on the characteristic parameters of the distribution function.When the neutral beam has either a larger deviation from the plasma axis or a larger radial proflle,the adiabatic contribution has a more evident effect on the flshbone instability.When the neutral beam has a relatively small critical energy,the adiabatic contribution has a greater effect on the mode instability. 展开更多
关键词 flshbone passing particle adiabatic response TOKAMAK
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Vector Approximate Message Passing with Sparse Bayesian Learning for Gaussian Mixture Prior 被引量:2
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作者 Chengyao Ruan Zaichen Zhang +3 位作者 Hao Jiang Jian Dang Liang Wu Hongming Zhang 《China Communications》 SCIE CSCD 2023年第5期57-69,共13页
Compressed sensing(CS)aims for seeking appropriate algorithms to recover a sparse vector from noisy linear observations.Currently,various Bayesian-based algorithms such as sparse Bayesian learning(SBL)and approximate ... Compressed sensing(CS)aims for seeking appropriate algorithms to recover a sparse vector from noisy linear observations.Currently,various Bayesian-based algorithms such as sparse Bayesian learning(SBL)and approximate message passing(AMP)based algorithms have been proposed.For SBL,it has accurate performance with robustness while its computational complexity is high due to matrix inversion.For AMP,its performance is guaranteed by the severe restriction of the measurement matrix,which limits its application in solving CS problem.To overcome the drawbacks of the above algorithms,in this paper,we present a low complexity algorithm for the single linear model that incorporates the vector AMP(VAMP)into the SBL structure with expectation maximization(EM).Specifically,we apply the variance auto-tuning into the VAMP to implement the E step in SBL,which decrease the iterations that require to converge compared with VAMP-EM algorithm when using a Gaussian mixture(GM)prior.Simulation results show that the proposed algorithm has better performance with high robustness under various cases of difficult measurement matrices. 展开更多
关键词 sparse Bayesian learning approximate message passing compressed sensing expectation propagation
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The Project “Study on Technology for Manufacture of High-Spheroidicity FCC Catalysts” Passed SINOPEC's Appraisal
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《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2015年第1期23-23,共1页
On January 7, 2015 the project "Study on the technology formanufacture of high-spheroidicity FCC catalysts "undertakenby the SINOPEC Research Institute of Petroleum Processing(RIPP) has passed the technical apprai... On January 7, 2015 the project "Study on the technology formanufacture of high-spheroidicity FCC catalysts "undertakenby the SINOPEC Research Institute of Petroleum Processing(RIPP) has passed the technical appraisal organized by theScience and Technology Division of the Sinopec Corp. 展开更多
关键词 FCC The Project passed SINOPEC’s Appraisal Study on Technology for Manufacture of high-Spheroidicity FCC Catalysts
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Assessment of Monitor Units and Gamma Pass Rate for 6 MV and Flattening Filter Free (FFF) Beams in Volumetric Modulated Arc Therapy (VMAT)
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作者 Kwame Anokye Amoabeng Anne Beate Langeland Marthinsen +4 位作者 Francis Hasford Samuel Nii Adu Tagoe Evelyn Anaafi Mark Pokoo-Aikins Theresa Bebaaku Dery 《International Journal of Medical Physics, Clinical Engineering and Radiation Oncology》 2023年第1期1-8,共8页
Background: In linear accelerators, the treatment field’s uniform intensity is achieved by including a flattening filter in the beam. However, to produce more conformal dose distributions, contemporary radiotherapy p... Background: In linear accelerators, the treatment field’s uniform intensity is achieved by including a flattening filter in the beam. However, to produce more conformal dose distributions, contemporary radiotherapy practice now frequently uses fluence and aperture modifying techniques, such as volumetric modulated arc therapy. In these circumstances, the flattening filter in the beam manufacturing process is no longer required. It is therefore necessary to compare the monitor units of 6 MV and flattening filter free plans and how it influences the gamma pass rates to determine which is best for treating cervical cancer with pelvic lymph node metastasis. Methods: VMAT plans for fifteen patients with cervical cancer with pathological pelvic lymph node metastasis were included in this study. Each patient had two VMAT plans using conventional 6 MV beam with flattening filter and one with flattening filter free beam (FFF). The VMAT plans were made using two arcs, and then recalculated to give the planned dose distribution to the detectors in a Delta4 phantom. The VMAT plans were irradiated on the Delta4 phantom using an Elekta linear accelerator (6 MV). Results: The mean monitor unit for the 6 MV plans was 506.3 MU and a standard deviation of 48.6 while that of the FFF plans had a mean MU of 701.5 with a standard deviation of 87.6. The total monitor units (MUs) for the FFF plans were significantly greater than the 6 MV plans (p = 6.1 × 10<sup>-5</sup>). Conclusion: Flattening filter free (FFF) plans require more numbers of monitor units in comparison to conventional 6 MV filtered beams for external radiation of cervical cancer with pelvic lymph nodes involvement. 展开更多
关键词 Monitor Units Gamma pass Rate Flattening Filter Free Multileaf Collimator
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