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Assessment of the induced radioactivity in the treatment room of the heavy-ion medical machine in Wuwei using PHITS

Nuclear Science and Techniques 2023年第2期34卷 153-166页

作者： ying Luo Sheng‑Cong Huang Hui Zhang Hai‑Jun Mao Qiang Li zhong‑ying dai Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Science Lanzhou 730000China Key Laboratory of Basic Research on Heavy Ion Radiation Application in Medicine Lanzhou 730000China Lanzhou University Lanzhou 730000China

Carbon-ion radiotherapy(CIRT)offers unique physical and biological advantages over photon ***,some materials and devices in the CIRT treatment room become radioactive under bombardment by therapeutic carbon-ion beams due to nuclear reactions,thereby leading to possible radiation hazards to medical staff and additional and unwanted doses to *** study assessed the level of induced radioactivity in the treatment room of the Heavy-Ion Medical Machine(HIMM)in *** Carlo simulations using PHITS were performed for a conservative case under the conditions of maximum beam energy and intensity provided by the HIMM *** geometry and configuration of Treatment Room 2 of the HIMM facility in Wuwei were *** evaluated the activation of air,the phantom,and the components of the beamline,such as the primary collimator(PC),ridge filter(RF),and multileaf collimator(MLC).For air activation,we calculated the medical staff immersion external exposure and inhalation internal exposure caused by the corresponding *** phantom activation,we estimated the additional dose to the patient’s family members owing to secondary photons after *** addition,the exemption or non-exemption of the component material activation was *** results showed that external radiation caused by air activation was the main source of the annual effective dose at approximately 0.5 mSv/*** induced radioactivity exposure to family members of a patient after CIRT was approximately 40μSv,sufficiently lower than the public dose limit of 1 mSv/*** induced radioactivity of the PC,RF,and MLC was all above the exempt levels after the devices were retired,whereas the induced radioactivity of the RS and compensator could reach the exempt levels after one patient *** study indicated that medical staff engaged in CIRT should stay away from the high-dose-rate area of induced radioactivity along the beam direction,shorten the residence time in

关键词： activation approximate thereby

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Monte Carlo study of the neutron ambient dose equivalent at the heavy ion medical machine in Wuwei

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Nuclear Science and Techniques 2022年第9期33卷 111-125页

作者： Sheng-Cong Huang Hui Zhang Kai Bai ying Luo Hai-Jun Mao zhong-ying dai University of Chinese Academy of Sciences Beijing 100049China Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China

The use of carbon-ion radiotherapy(CIRT)is gradually *** to the generation of high-energy secondary neutrons during CIRT,its use presents new challenges in radiation ***,secondary neutron dose distributions must be explored and evaluated under clinical scenarios based on different treatment ***,neutron dose and energy spectrum measurements are often *** can be primarily attributed to the inherent limitations of most neutron detectors,such as their unsuitability for spectral measurements and inaccurate responses to neutrons with energies above 20 *** calculation methods based on probabilistic statistical theory are fast and convenient for neutron dose *** this study,external secondary neutron doses at the heavy ion medical machine in Wuwei,which is equipped with a passive beam delivery system,were calculated using the Monte Carlo *** dependence of neutron doses on various treatment parameters(incident carbon-ion beam energy,spatial location,field size,and spread-out Bragg peak(SOBP)width)was ***,the feasibility of applying an analytical model to predict the ambient dose equivalent was *** the combination involving an energy of 400 MeV=u and SOBP width of 6 cm,the ambient dose equivalent per therapeutic dose(H=D)at the isocenter was 79.87 mSv=Gy:The H=D value decreased rapidly with increasing spatial distance and slightly with increasing aperture size and SOBP *** H=D values derived from the Monte Carlo simulations were in good agreement with the results reported in the *** analytical model could be used to quickly predict the H=D value along the incidence direction of the beam with an error of less than 20%.Thus,our study contributes to the understanding of the relationship between neutron radiation and treatment configuration parameters,which establishes a basis for predicting non-therapeutic radiation doses in CIRT.

关键词： Carbon-ion radiotherapy Passive beam delivery Secondary neutrons Monte Carlo method

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Biohythane production from two-stage anaerobic digestion of food waste:A review

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Journal of Environmental Sciences 2024年第5期139卷 334-349页

作者： Xiaona An ying Xu Xiaohu dai State Key Laboratory of Pollution Control and Resource Reuse School of Environmental Science and EngineeringTongji UniversityShanghai 200092China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092China

The biotransformation of food waste(FW)to bioenergy has attracted considerable research attention as a means to address the energy crisis and waste disposal *** this end,a promising technique is two-stage anaerobic digestion(TSAD),in which the FW is transformed to biohythane,a gaseous mixture of biomethane and *** review summarises the main characteristics of FW and describes the basic principle of ***,the factors influencing the TSAD performance are identified,and an overview of the research status;economic aspects;and strategies such as pre-treatment,co-digestion,and regulation of microbial consortia to increase the biohythane yield from TSAD is ***,the challenges and future considerations associated with the treatment of FW by TSAD are *** paper can provide valuable reference for the improvement and widespread implementation of TSAD-based FW treatment.

关键词： Two-stage anaerobic digestion(TSAD) Food waste(FW) Methane production Hydrogen production

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Neighborhood predictors of short sleep duration and bedtime irregularity among children in the United States: results from the 2019-2020 National Surveyof Children's Health

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World Journal of Pediatrics 2024年第1期20卷 73-81页

作者： ying dai Jianghong Liu School of Nursing University of Pennsylvania418 Curie Blvd.Room 426Claire M.Fagin HallPhiladelphiaPA19104-6096USA

Background Environmental factors may contribute to short sleep duration and irregular bedtime in *** factors and children's sleep duration and bedtime regularity remain a less investigated *** aim of this study was to investigate the national and state-level proportions of children with short sleep duration and irregular bedtime and their neighborhood *** A total of 67,598 children whose parents completed the National Survey of Children's Health in 2019-2020 were included in the ***-weighted Poisson regression was used to explore the neighborhood predictors of children's short sleep duration and irregular *** The prevalence of short sleep duration and irregular bedtime among children in the United States(US)was 34.6%[95%confidence interval(CI)=33.8%-35.4%]and 16.4%(95%CI=15.6%-17.2%)in 2019-2020,*** neighborhoods,supportive neighborhoods,and neighborhoods with amenities were found to be protective factors against children's short sleep duration,with risk ratios ranging between 0.92 and 0.94,P<*** with detracting elements were associated with an increased risk of short sleep duration[risk ratio(RR)=1.06,95%CI=1.00-1.12]and irregular bedtime(RR=1.15,95%CI=1.03-1.28).Child race/ethnicity moderated the relationship between neighborhood with amenities and short *** Insufficient sleep duration and irregular bedtime were highly prevalent among US children.A favorable neighborhood environment can decrease children's risk of short sleep duration and irregular *** the neighborhood environment has implications for children's sleep health,especially for children from minority racial/ethnic groups.

关键词： Child National Survey of Children's Health Neighborhood.Sleep Social determinants of health

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Efficient and rapid capture of uranium(Ⅵ) in wastewater via multiamine modified β-cyclodextrin porous polymer

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Chinese Journal of Chemical Engineering 2024年第4期68卷 144-155页

作者： Xing zhong Yubin Tan Siyuan Wu Caixia Hu Kai Guo Yongchuan Wu Neng Yu Mingyang Ma ying dai School of Chemistry and Materials Science East China University of TechnologyNanchang 330013China

It is quite important to ensure the safety and sustainable development of nuclear energy for the treatment of radioactive wastewater. To treat radioactive wastewater efficiently and rapidly, two multi-amine β-cyclodextrin polymers(diethylenetriamine β-cyclodextrin polymer(DETA-TFCDP) and triethylenetetramine β-cyclodextrin polymer(TETA-TFCDP)) were prepared and applied to capture uranium. Results exhibited that DETA-TFCDP and TETA-TFCDP displayed the advantages of high adsorption amounts(612.2and 628.2 mg·g-1, respectively) and rapid adsorption rates, which can reach(88 ± 1)% of their equilibrium adsorption amounts in 10 min. Moreover, the adsorbent processes of DETA-TFCDP and TETATFCDP on uranium(Ⅵ) followed the Langmuir model and pseudo-second-order model, stating they were mainly chemisorption and self-endothermic. Besides, TETA-TFCDP also showed excellent selectivity in the presence of seven competing cations and could be effectively reused five times via Na2CO3as the desorption reagent. Meanwhile, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy illustrated that the enriched multi-amine groups and oxygen-containing functional groups on the surface of TETA-TFCDP were the main active sites for capturing uranium(Ⅵ). Hence, multi-amine β-cyclodextrin polymers are a highly efficient, rapid, and promising adsorbent for capturing uranium(Ⅵ)from radioactive wastewater.

关键词： Adsorption Waste water Pollution Uranium(VI) b-Cyclodextrin

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Multi-stream signals separation based on space-time-isomeric (SPATIO) array using metasurface antennas

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Science China(Information Sciences) 2024年第2期67卷 181-200页

作者： Yangming LOU Liang JIN Huiming WANG Zhou zhong Junyan dai PLA Strategic Support Force Information Engineering University School of Information and Communications Engineering Xi'an Jiaotong University 3. State Key Laboratory of Millimeter WavesSoutheast University

In spatial domain signal processing, it is necessary to equip more antennas at the receiver to improve spatial demultiplexing capability. However, increasing the number of antennas under restricted space will reduce antenna spacing and raise the channel correlation, making the number of signal streams spatially demultiplexed much smaller than that of antennas. This paper proposes a method to design a space-timeisomeric(SPATIO) array based on metasurface antennas under wireless multipath conditions. Each antenna in this array has a different pattern and varies independently with time, reducing the channel correlation by superposing multipath at distinct positions and moments. Based on the SPATIO array, we present an array parameter design scheme based on infinity norm minimization, which can maximize the received energy of each stream while separating multi-stream received signals. Simulation results illustrate the performance of the SPATIO array for multi-stream signal reception. Compared with conventional multiple-input multipleoutput arrays, the proposed array can reduce the bit error rate by one order of magnitude under the same simulation conditions.

关键词： multiple-input multiple-output metasurface antenna space-time-isomeric array multipath channel degree of freedom

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Securing Forwarding Layers from Eavesdropping Attacks Using Proactive Approaches

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Computers, Materials & Continua 2024年第4期79卷 563-580页

作者： Jiajun Yan ying Zhou Anchen dai Tao Wang School of Electronics and Communication Engineering Sun Yat-sen UniversityShenzhen518107China

As an emerging network paradigm,the software-defined network(SDN)finds extensive application in areas such as smart grids,the Internet of Things(IoT),and edge *** forwarding layer in software-defined networks is susceptible to eavesdropping *** hopping is amoving target defense(MTD)technology that is frequently employed to resist eavesdropping *** the traditional route hopping technology,both request and reply packets use the same hopping *** an eavesdropping attacker monitors the nodes along this path,the risk of 100%data leakage becomes *** this paper,we present an effective route hopping approach,called two-day different path(TDP),that turns communication paths into untraceable moving *** technology minimizes the probability of data leakage by transmitting request data and reply data through different ***,a brief introduction to the network model and attack model involved in this paper is ***,the algorithm and processingmethod of the TDP are ***,the paper proposes three differentmetrics tomeasure the effectiveness of the proposed ***,theoretical analysis and simulation results show that the TDP can effectively reduce the percentage of data exposure,decrease eavesdropping attack success probability,and improve the unpredictability of the path.

关键词： Route hopping moving target defense software-defined network two-way different path metrics

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Broadband Dual-Input Doherty Power Amplifier Design Based on a Simple Adaptive Power Dividing Ratio Function

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China Communications 2024年第5期21卷 97-112页

作者： dai Zhijiang zhong Kang Li Mingyu Pang Jingzhou Jin Yi School of Microelectronics and Communication Engineering Chongqing UniversityChongqing 400044China Xi’an Branch of China Academy of Space Technology Xi’an 710100China

In this paper,a simple adaptive power dividing function for the design of a dual-input Doherty power amplifier(DPA)is *** the presented approaches,the signal separation function(SSF)at different frequency points can be characterized by a *** in the practical test,the coefficients of SSF can be determined by measuring a small number of data points of input *** as other dualinput DPAs,the proposed approach can also achieve high output power and back-off efficiency in a broadband operation band by adjusting the power distribution ratio ***,a 1.5-2.5 GHz highefficiency dual-input Doherty power amplifier is implemented according to this *** test results show that the peak power is 48.6-49.7d Bm,and the 6-d B back-off efficiency is 51.0-67.0%,and the saturation efficiency is 52.4-74.6%.The digital predistortion correction is carried out at the frequency points of 1.8/2.1GHz,and the adjacent channel power ratio is lower than-54.5d *** and experiment results can verify the effectiveness and correctness of the proposed method.

关键词： broadband doherty power amplifier dualinput efficiency enhancement load modulation

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Asymmetric copolyimide membranes fabricated by nonsolvent-induced phase separation for He/CH_(4) and He/N_(2) separation

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Frontiers of Chemical Science and Engineering 2024年第4期18卷 97-106页

作者： ying Li Lu Wang Junyan Xie Yong dai Xuehong Gu Xuerui Wang State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical EngineeringNanjing Tech UniversityNanjing 211816China Quzhou Membrane Material Innovation Institute Quzhou 324000China

Membrane gas separation is considered an energy-saving technique to extract He from natural gas due to no phase change and room temperature ***,the membrane performance was strongly limited by the trade-off between permeance and ***,novel 4,4′-(hexafluoroisopropylidene)diphthalic anhydride(6FDA)-2,2′-bis(3-amino-4-hydroxyphenyl)hexafluoropropane(APAF)-5-amino-2-(4-aminobenzene)benzimidazole(BIA)asymmetric membranes with a thickness of 300 nm were successfully prepared by the non-solvent induced phase separation *** membrane performance was modulated by regulating dope solution compositions(e.g.,tetrahydrofuran and polymer concentration).The ideal He/CH_(4) selectivity was 124 and the optimized He permeance reached 87 GPU,beyond the current upper ***/CH_(4) selectivity was 75 and He permeance was 73 GPU for the binary mixture feed containing 0.2 mol%*** membrane showed good resistance to CO_(2) and C_(2)H_(6),which are the typical impurities in natural *** 6FDA-APAF-BIA membranes have good stability(>160 h),which can provide great potential in He extraction from natural gas.

关键词： He separation membrane natural gas copolyimide

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Revealing the stability origins of 596 days-humidity-stable semitransparentperovskite solar cells

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Journal of Energy Chemistry 2024年第7期94卷 208-216页

作者： Tian Chen ying Yang Congtan Zhu Weihuang Lin Qilin dai Xueyi Guo School of Metallurgy and Environment Central South UniversityChangsha 410083HunanChina Department of Chemistry Physics and Atmospheric SciencesJackson State UniversityJacksonMS 39217USA

Hybrid organic-inorganic perovskites(HOIPs)hold promise in the field of optoelectronics due to their excellent photoelectric conversion ***,the ion migration and hygroscopicity of these perovskite solar cells need to be ***,we presented semitransparent perovskite solar cells(ST-PSCs)using hole transport layer(HTL)combined with polyaniline(PANI)to stabilize HTL/perovskite interface,achieving a humidity durability(RH,50%-90%)for 596 days(14304 h)without ***,the decrease in hydrolysis products(LiF)showed the interaction between PANI with the addi-tives in HTL dramatically inhibited the water uptake and corrosion on MAPbI_(3),*** PANI modified samples had a higher I/Pb ratio and lower trap state density,which indicated the passivation effect of PANI on the uncoordinated Pb^(2+)and iodine ***,PANI successfully stabilized the interface and perovskite by inhibiting the formation of Pb^(0) and Au migration as long period *** work presented an interfacial design to develop HOiP in air with high humidity stability.

关键词： HTL/perovskite interface Polyaniline-passivation Humidity-degradation mechanism lon migration

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