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Shortening the delivery time of proton therapy by real-time co.pensation method with raster scanning

Nuclear Science and Techniques 2022年第6期33卷 62-74页

作者： Xiang-Shang Sun Yong-Jiang Li Jun-Ya Liu Wen-Tao Liao Chao Wu Yue-Hu Pu shanghai institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of sciences Beijing 100049China shanghai APACTRON Particle Equipment co. LtdShanghai 201800China shanghai Advanced research institute Chinese Academy of SciencesShanghai 201210China Medical Equipment Innovation research Center West China HospitalSichuan UniversityChengdu 610041China

Among the various scanning techniques, spot and raster scanning are the most frequently adopted. Raster scanning turns off the beam only when each isoenergy slice irradiation is co.pleted. This feature intrinsically solves the leakage dose and frequent beam-switching problems enco.ntered during spot scanning. However, to shorten the delivery time of raster scanning, a sophisticated dose co.trol strategy is required to guarantee dose *** this study, a real-time co.pensation method with raster scanning for synchrotron systems was designed. It is characterized by a small spot-spacing planning strategy and real-time subtraction of the transient number of particles delivered between two planning-spot positions from the planned number of particles of the subsequent raster *** efficacy of the co.pensation method was demonstrated by performing accurate raster scanning simulations with an in-house simulation co.e and accurate final dose evaluations with a co.mercial treatment planning *** the similar dose evaluation criteria under a practical high scanning speed, co.pared with the spot scanning method, the total delivery time of the co.pensated raster scanning method was significantly shortened by 53.3% in the case of irradiating a cubical target and by 28.8% in a pelvic case. Therefore, it can be co.cluded that real-time co.pensated raster scanning with a fast scanning co.figuration can significantly shorten the delivery time co.pared to that of spot scanning. It is important to reduce the pressure on patients caused by prolonged immobilization and to improve patient throughput capacity at particle therapy centers.

关键词： Proton therapy Raster scanning Delivery time Scanning simulation

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Influence of Turbulence Schmidt Number on Exit Temperature Distribution of an Annular Gas Turbine co.bustor using Flamelet Generated Manifold

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Journal of Thermal Science 2020年第1期29卷 58-68页

作者： WANG Weihao YANG Songlin GAO Chuang HUANG Weiguang shanghai Advanced research institute Chinese Academy of SciencesShanghai 201210China University of Chinese Academy of sciences Beijing 100049China School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China Helan Turbines co. LtdShanghai 201815China

The Reynolds analogy co.cept has been used in almost all turbulent reacting flow RANS(Reynoldsaveraged Navier–Stokes)simulations,where the turbulence scalar transfers in flow fields are calculated based on the modeled turbulence momentum *** co.cept,applied to a lean premixed co.bustion system,was assessed in this paper in terms of exit temperature *** of the isotropic assumption involved in this analogy,the prediction in some flow co.dition,such as jet cross flow mixing,would be *** this study,using Flamelet Generated Manifold as reaction model,some of the numerical results,obtained from an annular co.bustor co.figuration with the turbulent Schmidt number varying from 0.85 to 0.2,were presented and co.pared with a benchmark atmospheric test *** was found that the Schmidt numberσt in mean mass fraction f transport equation had significant effect on dilution air mixing *** mixing between dilution air and reaction products from the primary zone obviously improved asσt decreased on the co.bustor exit ***,the sensitivity ofσt in three turbulence models including Realizable k-ε,SST(Shear Stress Transport)and RSM(Reynolds Stress Model)has been co.pared as *** the calculation method of eddy visco.ity was different within these three models,RSM was proved to be less sensitive than another two models and can guarantee the best prediction of mixing process *** the other hand,the results of dilution air mixing were almost independent of Schmidt number Sct in progress variable c transport *** study suggested that for accurate prediction of co.bustor exit temperature distribution in steady state reacting flow simulation,the turbulent Schmidt number in steady state simulation should be modified to cater to dilution air mixing process.

关键词： gas turbine co.bustor flamelet-generated manifold turbulent Schmidt Number Reynolds Stress Model Reynolds analogy

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Real-time measurement of the fast axis angle of a quarter-wave plate based on simultaneous phase shifting technique

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Chinese Optics Letters 2008年第8期6卷 568-571页

作者：杨坤曾爱军王向朝王华唐锋 shanghai institute of Optics and Fine Mechanics Chinese Academy of Sciences shanghai Hengyi Optics and Fine Mechanics co. Ltd.

Real-time measurement of the fast axis angle of a quarter-wave plate based on simultaneous phase shifting technique is presented. The simultaneous phase shifting function is realized by an orthogonal grating, a diaphragm, an analyzer array, and a 4-quadrant detector. The intensities of the light beams from the four analyzers with different azimuths are measured simultaneously. The fast axis angle of the quarter-wave plate is obtained through the four light intensity values. In this method, rotating elements are not required, so real-time measurement is achieved.

关键词： Electromagnetic waves

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Preliminary Systematic Study of the Temperature Effect on the K—Cs—Sb Photocathode Performance Based on the K and Cs co.Evaporation

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Chinese Physics Letters 2020年第1期37卷 6-9页

作者： Xu-Dong Li Zeng-Gong Jiang Qiang Gu Ming-Hua Zhao Li Guo shanghai Advanced research institute Chinese Academy of SciencesShanghai 201210 shanghai institute of Applied Physics Chinese Academy of SciencesShanghai 201800

It is very important to increase the quantum efficiency(QE)and prolong the lifetime of the photocathode in a variety of *** have succeeded in preparing a high QE cesium potassium antimonide(K-Cs-Sb)photocathode by K and Cs co.evaporation in the photocathode preparation *** order to better understand the effect of the substrate(photocathode)temperature on the photocathode performance,the photocathode preparation,photocathode performance degradation,photocathode performance reco.ery and photocathode removal are studied in detail.

关键词： preparing preparation lifetime

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Analysis and evaluation of electromagnetic vibration and noise in permanent magnet synchronous motor with rotor step skewing

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Science China(Technological sciences) 2019年第5期62卷 839-848页

作者： DONG QiChao LIU XinTian QI HongZhong SUN Chao WANG YanSong School of Mechanical and Automotive Engineering Shanghai University of Engineering Science Guangzhou Automobile group co. LTD Automotive Engineering Institute

In this paper, a multi-physics simulation model capable of electromagnetic noise prediction is established, and the effectiveness of the established simulation model in predicting and evaluating electromagnetic noise is verified. Based on the verified motor model, a rotor step skewing model which can affect electromagnetic noise is proposed, and the influence of the skewing angle on electromagnetic noise is investigated in detail. By studying the spectral characteristics of the low-order radial magnetic force which has a great influence on electromagnetic noise, the distribution of electromagnetic noise characteristics of the permanent magnet synchronous motor(PMSM) with or without the rotor step skewing is co.pared and analyzed. Therefore, it lays a technological foundation for predicting and suppressing the electromagnetic vibration noise of electric vehicle(EV) driving motor in the electromagnetic design.

关键词： PMSM electromagnetic noise step skewing multi-physics simulation model spectrum analysis

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The ignored emission of volatile organic co.pounds from iron ore sinter process

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Journal of Environmental sciences 2019年第3期31卷 282-290页

作者： Juexiu Li Xiaoping He Bing Pei Xianwei Li Diwen Ying Yalin Wang Jinping Jia School of Environmental Science and Engineering Shanghai Jiao Tong University Iron-Making Plant Taiyuan Iron & Steel (Group) Co. Ltd. (TISCO) shanghai Environmental Monitoring Center Central research institute (Technology Center) China Baowu Steel Group Corporation shanghai institute of Pollution co.trol and Eco.ogical Security

Iron ore sintering is a major source of gaseous and particulate pollutants emission in iron smelt plant. The aim of present study is to characterize the volatile organic co.pounds(VOCs) emission profiles from iron ore sintering process. Both sinter pot test and sinter simulation experiment were co.ducted and co.pared. Out results showed that sinter process produced large quantity of VOCs together with NOxand SO_2. VOCs and NO were produced simultaneously in sinter pot test from 3 to 24 min after ignition, flowed by SO_2 production from 15 min to the end of sintering. Total VOCs(TVOC) co.centration in sinter flue gas was affected by the co.l and co.e ratio in sinter raw material. The maximum TVOC co.centration was 34.5 ppm when using 100% co.l as fuel. Sinter simulation experiments found that the number of VOCs species and their co.centrations were found by sinter temperature. The largest VOCs species varieties were obtained at 500 °C. Benzene, toluene,xylene and ethylbenzene were major VOCs in sinter flue gas based on the results from both simulation test and sinter pot. It thus demonstrated that in addition to NO_x, SO_2 and metal oxide particles, sinter flue gas also co.tained significant amount of VOCs whose environmental impact cannot be ignored. Based on our work, it is timely needed to establish a new VOC emission standard for sinter flue gas and develop advanced techniques to simultaneously eliminate multi-pollutants in iron ore sinter process.

关键词： Iron ore sinter VOCs Flue gas Emission

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Soil Microstructure Evolution and Macro Deformation Mechanism for co.trolling co.struction Disturbance in shanghai Soft Soil

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Journal of shanghai Jiaotong university(Science) 2016年第6期21卷 713-718页

作者：贾坚谢小林杨科 Architectural Design & research institute of Tongji University (group) co. Ltd. Shanghai 200092 China Deparment of GeotechnicalEngineering Tongji University shanghai 200092 China

Abundant practical evidences have indicated that the soil progressively loses its structural co.figuration under co.struction disturbance and this can result in long-term macro *** fundamental understanding of soil microstructure evolution subject to co.struction disturbance is necessary for co.trolling disturbance in excavation projects and minimizing ground *** microstructure of shanghai soft soil is investigated in this *** laboratory isotropic co.pression tests are respectively performed on the virgin soil and the reco.structed shanghai soft soil to investigate the macro deformation of soil under *** element method model is used to study the micro particle level responses of soil under *** laboratory tests and numerical simulations provide theoretical basis for co.struction disturbance mitigation to ensure safety and stability of excavation projects.

关键词： shanghai soft soil soil disturbance microstructure soil deformation degree of disturbance

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co.tinuous time sigma delta ADC design and non-idealities analysis

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Journal of Semico.ductors 2011年第12期32卷 128-133页

作者：袁俊张钊锋吴俊王超陈珍海钱文荣杨银堂 School of Microelectronics Xidian University shanghai Advanced research institute Chinese Academy of Sciences Marvell Technology group Ltd.

A wide bandwidth co.tinuous time sigma delta ADC is implemented in 130 nm CMOS. A detailed nonidealities analysis （excess loop delay, clock jitter, finite gain and GBW, co.parator offset and DAC mismatch） is performed developed in Matlab/Simulink. This design is targeted for wide bandwidth applications such as video or wireless base-stations. A third-order co.tinuous time sigma delta modulator co.prises a third-order RC operational- amplifier-based loop filter and 3-bit internal quantizer operated at 512 MHz clock frequency. The sigma delta ADC achieves 60 dB SNR and 59.3 dB SNDR over a 16-MHz signal band at an OSR of 16. The power co.sumption of the CT sigma delta modulator is 22 mW from the 1.2-V supply.

关键词： ADC co.tinuous time sigma delta ADC low power design sigma delta modulation

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DATA co.TEXT MODEL IN THE PRO-CESS INTEGRATION FRAMEWORK

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Chinese Journal of Mechanical Engineering 2008年第2期21卷 104-107页

作者： ZHAO Bo YAN Yan NING Ruxin LI Shiyun School of Mechanical and Vehicular Engineering Beijing Institute of Technology Beijing 100081 China shanghai Hudong-zhonghua Shipbuilding （group） co. Shanghai 200129 China

Process integration is the important aspect of product development process. The recent researches focus on project management, workflow management and process modeling. Based on the analysis of the process, product development process is divided into three levels acco.ding to different grains from macrosco.y to microco.m. Our research co.centrate on the workflow and the free-grained design process. Acco.ding to the need of representing the data and the relationships among them for process integration, co.text model is introduced, and its characters are analyzed. The tree-like structure of inheritance among co.text model＇s classes is illustrated; The relationships of reference among them are also explained. Then, extensible markup language （XML） file is used to depict these classes. A four-tier framework of process integration has been established, in which model-view-co.troller pattern is designed to realize the separation between co.text model and its various views. The integration of applications is applied by the encapsulation of enterprise＇s business logic as distributed services. The prototype system for the design of air filter is applied in an institute.

关键词： co.text model Process integration Extensible markup language(XML) Model-view-co.troller(MVC) Service

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Reformatted method for two-dimensional detector arrays measurement data in proton pencil beam scanning

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Nuclear Science and Techniques 2021年第6期32卷 83-93页

作者： Meng-Ya Guo Xiu-Fang Li Jie Wang Qi Liu Xiu-Zhen Deng Man-Zhou Zhang Li-Ren Shen Yue-Hu Pu Zhi-Ling Chen shanghai institute of Applied Physics Chinese Academy of SciencesBeijing 100049China University of Chinese Academy of sciences shanghai APACTRON Particle Equipment co.Ltd Shanghai 201800China shanghai Advanced research institute Chinese Academy of SciencesShanghai 201210China

The spatial resolution of a co.mercial two-dimensional(2D)ionization chamber(IC)array is limited by the size of the individual detector and the center-to-center distance between *** dose distributions with areas of steep dose gradients,inter-detector dose values are derived by the interpolation of nearby detector readings in the co.ventional mathematical interpolation of 2D IC array *** may introduce significant errors,particularly in proton spot scanning *** this study,by co.bining logfile-based reco.structed dose values and detector measurements with the Laplacian pyramid image blending method,a novel method is proposed to obtain a reformatted dose distribution that provides an improved estimation of the delivered dose distribution with high spatial ***,the similarity between the measured original data and the downsampled logfilebased reco.structed dose is regarded as the co.fidence of the reformatted dose ***,we quantify the performance benefits of this new approach by directly co.paring the reformatted dose distributions with 2D IC array detector mathematically interpolated measurements and original low-resolution *** result shows that this new method is better than the mathematical interpolation and achieves gamma pass rates similar to those of the original low-resolution *** reformatted dose distributions generally yield a co.fidence exceeding 95%.

关键词： 2D ion chamber array detectors Laplacian pyramid image blending High-resolution reformatted methods Pencil beam scanning Proton therapy

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