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monte carlo simulation of reflection effects of multi-element materials on gamma rays

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Nuclear Science and Techniques 2021年第1期32卷 85-94页

作者： Ying-Hong Zuo Jin-Hui Zhu Peng Shang Northwest Institute of Nuclear Technology Xi’an 710024China

To study the effects of the gamma reflection of multi-element materials,gamma ray transport models of single-element materials,such as iron and lead,and multielement materials,such as polyethylene and ordinary concrete,were established in this *** among the albedo factors of the gamma photons and energies and average energy of the reflected gamma rays by material type,material thickness,incident gamma energy,and incidence angle of gamma rays were obtained by monte carlo *** results show that the albedo factors of single-element and multi-element materials increase rapidly with an increase in the material *** the thickness of the material increases to a certain value,the albedo factors do not increase further but rather tend to the saturation *** saturation values for the albedo factors of the gamma photons,and energies and the reflection thickness are related not only to the type of material but also to the incident gamma energy and incidence angle of the gamma *** a given incident gamma energy,which is between 0.2 and 2.5 MeV,the smaller the effective atomic number of the multi-element material is,the higher the saturation values of the albedo factors *** larger the incidence angle of the gamma ray is,the greater the saturation value of the gamma albedo factor,saturation reflection thickness,and average saturation energy of the reflected gamma photons are.

关键词： Multi-element materials Gamma albedo factor Effective atomic number monte carlo simulation

monte carlo simulation of neutron sensitivity of microfission chamber in neutron flux measurement

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Nuclear Science and Techniques 2022年第6期33卷 128-138页

作者： Ze-Peng Wu Xin-Biao Jiang Wen-Shou Zhang Chun-Lei Su Yong-Gang Zhang-Sun Li-Hong Bao State Key Laboratory of simulation and Effect for Intense Pulse Radiation Northwest Institute of Nuclear TechnologyXi’an 710024China

Microfission chambers loaded with highly enriched fissile materials are widely used for measuring power in reactors. The neutron sensitivity of the microfission chamber is a key parameter that determines the accuracy of the power measurement. To evaluate the performance of the FC4A microfission chamber, in this work, we introduced an accurate and validated model of the microfission chamber, a performed monte carlo simulation of the neutron sensitivity of the microfission chamber with GEANT4 code, and conducted an irradiation experiment on the neutron irradiation effect platform #3 of the Xi’an Pulsed Reactor. We compared the simulated sensitivity with the experimental results, which showed that the sensitivity obtained from the simulation was in good agreement with the experimental results. In addition, we studied the impact of the design parameters of the fission chamber on the calculated neutron sensitivity of the microfission chamber.

关键词： Microfission chamber Neutron sensitivity monte carlo simulation GEANT4

monte carlo simulation of the exposure factor

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Chinese Physics B 2009年第6期18卷 2217-2222页

作者：张涛刘义保杨波吴和喜顾金虎 Key Laboratory of Nuclear Resources and Environment (East China Institute of Technology) Ministry of Education School of Nuclear Engineering and Technology East China Institute of Technology

In this paper, we simulate the exposure factor by a simple model of a flee-air ionization chamber with the monte carlo programme Geant4. Special emphasis is placed on the discussion of the exposure factor related to parameters of the chamber model. The reason for the variation in exposure factor with incident ray energy is also analysed in terms of reaction cross section for different types of reactions. The obtained results indicate that our simulation is accurate in the calculation of the exposure factor and can serve as a reference in designing air ionization chambers.

关键词： exposure factor Geant4 monte carlo simulation free-air ionization chamber

monte carlo simulation-Based Robust Workflow Scheduling for Spot Instances in Cloud Environments

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Tsinghua Science and Technology 2024年第1期29卷 112-126页

作者： Quanwang Wu Jianzhao Fang Jie Zeng Junhao Wen Fengji Luo College of Computer Science Chongqing UniversityChongqing 400044China National Experimental Teaching Demonstration Center Chongqing UniversityChongqing 400044China College of Big Data and Software Engineering Chongqing UniversityChongqing 400044China School of Civil Engineering The University of SydneySydney 2006Australia

When deploying workflows in cloud environments,the use of Spot Instances(SIs)is intriguing as they are much cheaper than on-demand ***,Sls are volatile and may be revoked at any time,which results in a more challenging scheduling problem involving execution interruption and hence hinders the successful handling of conventional cloud workflow scheduling *** some scheduling methods for Sls have been proposed,most of them are no more applicable to the latest Sls,as they have evolved by eliminating bidding and simplifying the pricing *** study focuses on how to minimize the execution cost with a deadline constraint when deploying a workflow on volatile Sls in cloud *** on monte carlo simulation and list scheduling,a stochastic scheduling method called MCLS is devised to optimize a utility function introduced for this *** the monte carlo simulation framework,MCLS employs sampled task execution time to build solutions via deadline distribution and list scheduling,and then returns the most robust solution from all the candidates with a specific evaluation mechanism and selection *** results show that the performance of MCLS is more competitive comparedwithtraditionalalgorithms.

关键词： constrained optimization monte carlo simulation robustness Spot Instances(Sls) workflow scheduling

monte carlo simulation of ramified aggregates on hetero-substrates

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Chinese Physics B 2009年第5期18卷 1947-1954页

作者：钱昌吉李洪钟瑞罗孟波叶高翔 Department of Physics Wenzhou University Department of Physics Zhejiang University

We have studied the aggregation of particles on a hetero-substrate consisting of two different substrates A and B with finite surface barriers EAB and EBA between the AB and BA boundaries, respectively. With the diffusion energy limited aggregation （DELA） model, we find that the number of clusters and the mean radius of gyration of the clusters are dependent on the surface barriers EAB and EBA. For the case with a constant of EBA, a series of minima are summarized as EAB ：（E0 - kBAEBA）/kAB with kAB and kBA being two integers, for main minima （kBA = kAB = 1） and two local minima （kBA = kAB and kBA = kAB ＋ 1） between two neighbouring main minima.

关键词： diffusion energy limited aggregation hetero-substrate monte carlo simulation cluster

monte carlo simulation of Laser-Ablated Particle Splitting Dynamic in a Low Pressure Inert Gas

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Plasma Science and Technology 2016年第6期18卷 641-646页

作者：丁学成张子才梁伟华褚立志邓泽超王英龙 College of Physics Science and Technology Hebei University

A monte carlo simulation method with an instantaneous density dependent meanfree-path of the ablated particles and the Ar gas is developed for investigating the transport dynamics of the laser-ablated particles in a low pressure inert *** ablated-particle density and velocity distributions are *** force distributions acting on the ablated particles are *** influence of the substrate on the ablated-particle velocity distribution and the force distribution acting on the ablated particles are *** monte carlo simulation results approximately agree with the experimental data at the pressure of 8 Pa to 17 *** is helpful to investigate the gas phase nucleation and growth mechanism of nanoparticles.

关键词： ablated particles monte carlo simulation transport dynamic instantaneous mean-free-path low pressure

monte carlo simulation on Layered Polymeric Films

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Chinese Journal of Polymer Science 2014年第5期32卷 595-602页

作者： Ru Xia Xiang-song Wu 陈鹏 Jia-sheng Qian Xiao-shuang Feng Anhui Province Key Laboratory of Environment-friendly Polymer Materials School of Chemistry and Chemical Engineering Anhui University Eco-Efficient Product & Process Laboratory (E2P2L) UMI 3464 Research & Innovation Center in Shanghai (RICS) Solvay(China) Co. Ltd.

Thin films of polymer blends composed of alternating copolymer, diblock copolymer and/or homopolymer are studied using monte carlo simulation. A multilayer morphology is observed in the film, that is, the blended polymers assemble into individual domains arranged from interior to the surfaces of the film. The coexisting components residing throughout the neighboring domains in the film make no distinguishable interface between any neighboring domains. By this means, it forms a vertical composition gradient in the polymeric film. Being different from layer-by-layer deposition of polyelectrolyte or hydrogen bonding approach etc., the layered structure in this study is formed by polymer blending in one step. Alternating copolymers are found to be essential components to form vertical composition gradient （layered structure） in thin films.

关键词： monte carlo simulation Polymer blends Alternating copolymer Layered structure.

monte carlo simulation of sequential structure control of AN-MA-IA aqueous copolymerization by different operation modes

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Chinese Journal of Chemical Engineering 2022年第6期35卷 231-242页

作者： Tong Qin Zhenhao Xi Ling Zhao Weikang Yuan State Key Laboratory of Chemical Engineering East China University of Science and TechnologyShanghai 200237China College of Chemistry and Chemical Engineering Xinjiang UniversityUrumqi 830046China

The regulation of polyacrylonitrile(PAN)copolymer composition and sequence structure is the precondition for producing high-quality carbon fiber high *** this work,the sequential structure control of acrylonitrile(AN),methyl acrylate(MA)and itaconic acid(IA)aqueous copolymerization was investigated by monte carlo(MC)*** parameters used in monte carlo were optimized via machine learning(ML)and genetic algorithms(GA)using the experimental data from batch *** results reveal that it is difficult to control the aqueous copolymerization to obtain PAN copolymer with uniform sequence structure by batch polymerization with one-time *** contrary,it is found that the PAN copolymer with uniform composition and sequence structure can be obtained by adjusting IA feeding quantity in each reactor of a train of five ***,the results obtained in this work can provide valuable information for the understanding and optimization of AN copolymerization process to obtain high-quality PAN copolymer precursor.

关键词： Polyacrylonitrile monte carlo simulation Machine learning Genetic algorithms Sequence structure Operation method

monte carlo simulation based thinning and calculating method for noninvasive blood glucose sensing by near-infrared spectroscopy

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Journal of Innovative Optical Health Sciences 2017年第2期10卷 40-51页

作者： Congcong Ma Jia Qin Qi Zhang Junsheng Lu Kexin Xu Jingying Jiang Tianjin Key Laboratory of Biomedical Detecting Techniques and Instruments College of Precision Instruments B Opto-electronics Engineering Tianjin University(TU) 92#Weijin Road Nankai DistrictTianjin 300072P.R.China San Francisco OphthalmologyUniversity of Caliorrnia 480 North Civic Drive 106 Walnut CreekCalifornia 94596United States State Key Laboratory of Precision Measuring Technology and Instruments College of Precision Instruments Opto-electronics Engineering Tianjin University(TU)92#Weijin Road Nankai District Tianjin 300072P.R.China

Previous results show that the floating reference theory(FRT)is an effective tool to reduce the infuence of interference factors on noninvasive blood glucose sensing by near infrared spectros-copy(NIRS).It is the key to measure the floating reference point(FRP)precisely for the application of *** carlo(MC)simulation has been introduced to quantitatively in-vestigate the effects of positioning errors and light source drifts on measuring *** this article,thinning and calculating method(TCM)is proposed to quantify the positioning ***-while,the normalization process(NP)is developed to significantly reduce the error induced by light source *** results according to TCM show that 7 purm deviations in positioning can generate about 10.63%relative error in *** is more noticeable that 1%fluctuation in light source intensity may lead to 12.21%relative ***,the proposed NP model can effectively reduce the error caused by light source ***,the measurement system for FRPs must meet that the positioning error is less than 7 purm,and the light source drift is kept within 1%.Furthermore,an improvement for measurement system is proposed in order to take advantage of the NP model.

关键词： Thinning and calculating method monte carlo simulation noninvasive blood glucose sensing foating reference theory positioning error light source drift.