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Normalized glandular dose coefficients for digital breast tomosynthesis using detailed Chinese breast models

Nuclear Science and Techniques 2024年第5期35卷 42-59页

作者： Jia-Hao Wang Rui qiu An-Kang Hu ye-qi liu Zhen Wu Hui Zhang Jun-li li Department of Engineering Physics Tsinghua UniversityBeijing 100084China Key Laboratory of Particle and Radiation Imaging Ministry of EducationTsinghua UniversityBeijing 100084China Joint Institute of Tsinghua University Nuctech Company Limited BeijingBeijing 100084China

The rise in breast cancer diagnoses among Chinese women has necessitated the use of X-ray breast screening,which carries a radiation *** study aimed to provide a dosimetry protocol for the Chinese female population to replace the traditional standard that utilizes simplified breast models,for the accurate estimation of the mean glandular dose of a patient undergoing digital breast tomosynthesis(DBT).The first set of detailed Chinese female breast models and representative breast parameters was *** backscatter radiation and computational efficiency,we improved the combination of these models and the Chinese reference adult female whole-body voxel *** acquisition for four commercial DBT systems that are widely employed in China was simulated using the Monte Carlo method to obtain the normalized glandular dose coefficients of DBT(D_(gN)^(DBT))and the glandular depth dose(D_(g)^(dep)(z))for different breast characteristics and X-ray *** calculated a series of D_(gN)^(DBT) values for breasts with different percentage mass glandularities(5%,25%,50%,75%,and 100%)and compressed breast thicknesses(2,3,4,5,6,and 7 cm)at various tube potentials(25,28,30,32,35,and 49 kV)and target/filter combinations(W/Rh,W/Al,Mo/Mo,Rh/Rh,and Rh/Ag).The parameter dependence of the breast characteristics and beam conditions on D_(gN)^(DBT) in detailed breast models was *** D_(gN)^(DBT) results were 14.6-51.0%lower than those of the traditional dosimetry standard in *** difference in D_(gN)^(DBT) was mainly due to a decrease in the depth of the main energy deposition area caused by the glandular distribution along the depth *** results obtained in this study may be used to improve breast dosimetry in China and provide more detailed information on risk assessment during DBT.

关键词： Digital breast tomosynthesis Normalized glandular dose coefficients Detailed breast model Monte Carlo simulation

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The Orthogonal Bases of Exponential Functions Based on Moran-Sierpinski Measures

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Acta Mathematica Sinica,English Series 2024年第7期40卷 1804-1824页

作者： qi Rong DENG Xing Gang HE Ming Tian li Yuan ling ye School of Mathematics and Statistics Center for Applied Mathematics of Fujian Province&Key Laboratory of Analytical Mathematics and Applications(Ministry of Education)Fujian Normal UniversityFuzhou350117P.R.China School of Mathematics and Statistics Key Lab NAA-MOE and Hubei Key Lab-Math.Sci.Central China Normal UniversityWuhan430079P.R.China School of Mathematical Sciences&South China Research Center for Applied Mathematics and Interdisciplinary Studies South China Normal UniversityGuangzhou510631P.R.China

Let An∈M2(ℤ)be integral matrices such that the infinite convolution of Dirac measures with equal weightsμ{A_(n),n≥1}δA_(1)^(-1)D*δA_(1)^(-1)A_(2)^(-2)D*…is a probability measure with compact support,where D={(0,0)^(t),(1,0)^(t),(0,1)^(t)}is the Sierpinski *** prove that there exists a setΛ⊂ℝ2 such that the family{e2πi〈λ,x〉:λ∈Λ} is an orthonormal basis of L^(2)(μ{A_(n),n≥1})if and only if 1/3(1,-1)A_(n)∈Z^(2)for n≥2 under some metric conditions on A_(n).

关键词： Moran-Sierpinski measures orthonormal basis of exponential functions self-affine measures spectral measures

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Synergistic effects of multiscale TiC and dual-phase structure on tensile properties of particle-reinforced steel

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Journal of Iron and Steel Research International 2024年第5期31卷 1232-1245页

作者： ye Jia Xiang-tao Deng qi Wang Cheng-ru li Hao Wu Zhao-dong Wang State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang110819LiaoningChina

The conventional melting methods were used to obtain in situ TiC particle-reinforced dual-phase steel,followed by hot rolling and heat treatment *** aim was to investigate the effect of TiC particles on the fracture behavior of dual-phase steel at different annealing temperatures,by analyzing the microstructure and tensile behavior of the multiscale TiC particle-reinforced dual-phase *** results showed that TiC particles precipitated in the as-cast microstructure of dual-phase steel were distributed along the grain *** hot rolling,the grain boundary-like morphology of the micron-sized TiC particles was disrupted,and the particles became more refined and evenly distributed in the *** tensile tests revealed that the strength of the TiC particle-reinforced dual-phase steel increased with increasing martensite content,while the elongation *** results were similar to those of conventional *** addition of 1 vol.%multiscale TiC particles improved the strength of the dual-phase steel but did not affect elongation of the *** and holes were primarily concentrated around the TiC particles rather than at the interface of martensite and *** main causes of crack sprouting were TiC particle interface cracking and TiC particle internal ***,the study demonstrated the potential of multiscale TiC particle-reinforced dual-phase steel as a strong and tough *** refined distribution of TiC particles in the matrix improved the strength of the material without compromising its *** results also highlighted the importance of careful selection of reinforcement particles to avoid detrimental effects on the fracture behavior of the material.

关键词： TiC particle Dual-phase structure TiC-reinforced dual-phase steel Tension Fracture behavior

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Buckling optimization of curvilinear fiber-reinforced composite structures using a parametric level set method

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Frontiers of Mechanical Engineering 2024年第1期19卷 149-160页

作者： ye TIAN Tielin SHI qi XIA State Key Laboratory of Intelligent Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China

Owing to their excellent performance and large design space,curvilinear fiber-reinforced composite structures have gained considerable attention in engineering fields such as aerospace and *** addition to the stiffness and strength of such structures,their stability also needs to be taken into account in the *** study proposes a level-set-based optimization framework for maximizing the buckling load of curvilinear fiber-reinforced composite *** the proposed method,the contours of the level set function are used to represent fiber *** a composite laminate with a certain number of layers,one level set function is defined by radial basis functions and expansion coefficients for each ***,the fiber angle at an arbitrary point is the tangent orientation of the contour through this *** the finite element of buckling,the stiffness and geometry matrices of an element are related to the fiber angle at the element *** study considers the parallelism constraint for fiber *** the sensitivity calculation of the objective and constraint functions,the method of moving asymptotes is utilized to iteratively update all the expansion coefficients regarded as design *** numerical examples under different boundary conditions are given to validate the proposed *** show that the optimized curved fiber paths tend to be parallel and equidistant regardless of whether the composite laminates contain holes or ***,the buckling resistance of the final design is significantly improved.

关键词： buckling optimization curvilinear fiber composite structure level set method manufacturing constraint

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A new liquid membrane diffusion model for characterizing the adsorption kinetics of europium by using a continuous measurement of adsorption platform

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Nuclear Science and Techniques 2024年第1期35卷 59-72页

作者： Hao-qi Yu Tao Yu Jian-Hua ye State Key Laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang 330013China CGN Cangnan Nuclear Power Co. Ltd.Cangnan 325800China Jiangxi Province Key Laboratory of Polymer Micro/Nano Manufacturing and Devices East China University of TechnologyNanchang 330013China School of Nuclear Science and Engineering East China University of TechnologyNanchang 330013China

To explore the kinetic adsorption under continuous and nonequilibrium states, an integration of continuous measurement and adsorption platform kinetics method was proposed, which was initially called the ICM-AP kinetics method, and a corresponding kinetic adsorption experimental method was developed. Adsorption experiments of europium(Eu) on Ca-bentonite,Na-bentonite, and the D231 cation exchange resin were performed using the ICM-AP kinetics method and continuous measurements. Because the kinetic experimental results observed in this study were different from those of traditional batch adsorption data, pseudo-first-order or pseudo-second-order kinetic models were unsuitable for fitting the experimental ***, a liquid membrane diffusion(LMD) model was developed based on the assumption of simultaneous adsorption/desorption to discuss the mechanism of kinetic adsorption. The kinetic adsorption mechanism was also studied by using *** results indicated that the proposed adsorption model can fit the experimental data more suitably, and the adsorption/desorption behaviors of Eu on bentonite and the D231 resin were simultaneously observed, suggesting that the adsorption kinetics of Eu(Ⅲ) was mainly dominated by hydrated Eu(Ⅲ) ions on the liquid membrane.

关键词： ICM-AP method LMD model Adsorption mechanism Eu(Ⅲ)

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Achieving high carrier mobility and low lattice thermal conductivity in GeTe-based alloys by cationic/anionic co-doping

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Rare Metals 2024年第6期43卷 2784-2795页

作者： Xiao-qiang Wang Xiao-Quan Hu Jun-Yan lin Chu-Bin li Xiao-Tong Yu qi-Yong Chen li-li Xi qi-Shuo Yang Han li Ji-ye Zhang Shuan-Kui li Kai Guo School of Physics and Materials Science Guangzhou UniversityGuangzhou 510006China Research Center for Advanced Information Materials(CAIM) Huangpu Research&Graduate School of Guangzhou UniversitySino-Singapore Guangzhou Knowledge CityGuangzhou510555China School of Materials Science and Engineering Shanghai UniversityShanghai 200444China Materials Genome Institute Shanghai UniversityShanghai 200444China School of Mechanical and Mining Engineering University of QueenslandBrisbaneQLD 4072Australia Key Laboratory of Si-Based Information Materials&Devices and Integrated Circuits Design Department of Education of Guangdong ProvinceGuangzhou 510006China

TheⅣ-Ⅵcompound GeTe is considered as a promising alternative to the toxic PbTe for high-efficiency mid-temperature thermoelectric ***,pristine GeTe suffers from a high concentration of Ge vacancies,resulting in an excessively high hole concentration(>1×10^(21)cm^(-3)),which greatly limits its thermoelectric *** address this issue,CuBiTe_(2)alloying is introduced to increase the formation energy of Ge vacancies in GeTe,thereby inhibiting the high carrier *** carrier scattering caused by the electronegativity difference between different elements is suppressed due to the similar electronegativity of Cu and Ge atoms.A relatively high hole mobility is obtained,which ultimately leads to a high power ***,by introducing Se as an alloying element at the anionic site in GeTe,dense point defects with mass/strainfield fluctuations are *** contributes to the strengthening of phonon scattering,thereby reducing the lattice thermal conductivity from 1.44 W·m^(-1)·K^(-1)for pristine GeTe to 0.28 W·m^(-1)·K^(-1)for Ge_(0.95)Cu_(0.05)Bi_(0.05)Te_(0.9)Se_(0.15)compound at 623 K.

关键词： GeTe Carrier mobility CuBiTe_(2)alloying Lattice thermal conductivity Thermoelectric properties

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Investigations of Water Flow Behaviors Induced by Local Temperature Variations through a Single Rough Fracture for the Enhanced Geothermal Systems

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Journal of Thermal Science 2024年第3期33卷 1055-1064页

作者： li Jiawei ye lin Department of Energy and Power Engineering Tsinghua UniversityBeijing100084China School of Power and Energy Northwestern Polytechnical UniversityXi’an710072China

In recent years,Enhanced Geothermal System(EGS)technologies have been applied to the geothermal resources production in the Hot Dry Rock(HDR).The core of EGS technologies is to adopt hydraulic fracturing in the reservoir to create a connected network of discrete fractures with the consideration of water as a working fluid for hydraulic fracturing and heat *** paper investigates the characteristics of water flow behaviors through a single rough fracture under different temperature and pressure conditions.A single fracture model with rough fracture surfaces is constructed and then characterized,and influences of the anisotropic factor on the average tortuosity and frictional resistance coefficient of water flow through a single fracture with rough surfaces have been compared and *** consideration of other impacting factors(temperature,pressure,fracture roughness),the impact of mass flow rate has also been *** simulation results present that changes of average tortuosity for water flow through a single rough facture are mainly affected by *** can be observed that higher temperature leads to larger average tortuosity but the frictional resistance coefficient shows an opposite *** for pressure conditions,it is found that effects of pressure on average tortuosity and frictional resistance coefficient is very small,which can be neglected under high pressure ***,the average tortuosity shows a progressively linear relationship with the mass flow *** the contrary,the frictional resistance coefficient has a negative relationship with the mass flow *** is revealed that when the mass flow rate reaches a critical point,the influences of temperature on the frictional resistance coefficient will be *** of single rough fractures with different anisotropic factors show that values of average tortuosity and frictional resistance coefficient have positive relationships with the increase

关键词： single rough fracture tortuosity frictional resistance enhanced geothermal system

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Global precipitation change during the Holocene:a combination of records and simulations

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Frontiers of Earth Science 2024年第1期18卷 112-126页

作者： Wangting ye Yu li Key Laboratory of Western China᾽s Environmental Systems(Ministry of Education) College of Earth and Environmental SciencesCenter for Hydrologic Cycle and Water Resources in Arid RegionLanzhou UniversityLanzhou 730000China

Precipitation can shape our climate both in the present and the *** though we have made significant advances in studying the mechanisms of millennial-scale climate changes through high-resolution records,we still cannot quantitatively characterize the global spatiotemporal precipitation variations within the ***,we developed a new approach to integrating data from 349 globally distributed records and climate models to reconstruct regional and global precipitation patterns over the last 12000 *** results reveal that precipitation reconstructions can be divided into monsoon-driven and westerly driven *** results suggest that an arid climate was experienced in the late glacial and early Holocene epoch(~12−7.4 cal ka BP),attaining a middle Holocene optimum(~7.4−3.5 cal ka BP),and drier after the middle *** to our reconstructions,the global precipitation reconstruction increased from the early Holocene until 3.8 cal ka BP and then subsequently *** addition,our reconstructions better reproduce the low-frequency events and extreme precipitation at the millennial scale in the hemispheres,but the performance of the reconstructions in the equatorial Pacific and the Southern Hemisphere of Africa and the Americas is *** resolution of the record and the simulation capability of the climate model remain important means to improve our understanding of past climate change.

关键词： Holocene equatorial glacial

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Electrospun nanofibrous membranes with antimicrobial activity for air filtration

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Chinese Chemical Letters 2024年第10期35卷 147-157页

作者： Guangyao Wang Zhitong Xu ye qi Yueguang Fang Guiling Ning Junwei ye State Key Laboratory of Fine Chemicals and School of Chemical Engineering Dalian University of TechnologyDalian 116012China Engineering Laboratory of Boric and Magnesic Functional Material Preparative and Applied Technology Dalian 116024China

Air pollution,including airborne pathogens and particulate matter(PM),has become a prominent issue affecting human health and *** air filtration materials do not meet the requirements for efficient PM capture or do not instantly kill pathogens,leading to increased risk of direct/indirect contact transmission and infection due to the accumulation of pathogens during *** nanofibrous membranes have emerged as a promising platform due to their rich porous structure,finer fiber diameters,good internal connectivity,and the ability to easily incorporate active chemicals for antimicrobial *** this review,antimicrobial mechanisms of nanofibrous membranes for air filtration and PM capture mechanisms of nanofibers were firstly investigated,and various types of electrospun nanofibrous membranes with different antimicrobial agents for efficient air filtration were described in detail,including organic antimicrobial agents,inorganic antimicrobial agents and metal-organic *** hope this work could provide a better practical insight for designing novel electrospun nanofibrous membranes with antimicrobial efficacy for efficient air filtration.

关键词： Electrospinning Nanofibrous membrane Antimicrobial Particulate matter Airfiltration

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Modeling Carbon and Water Budgets in the Lushi Basin with Biome-BGC

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Chinese Journal of Population,Resources and Environment 2005年第2期3卷 27-34页

作者： Dong Wenjuan, qi ye, li Huimin, Zhou Dajie, Shi Duanhua& Sun liyingSchool of Environment, Beijing Normal University, Beijing 100875, China School of Environment Beijing Normal University Beijing 100875 China

In this article, annual evapotranspiration(ET) and net primary productivity (NPP) of fourtypes of vegetation were estimated for the Lushi basin,a subbasin of the yellow River in China. These fourvegetation types include: deciduous broadleaf forest,evergreen needle leaf forest, dwarf shrub and ***-BGC--a biogeochemical process model wasused to calculate annual ET and NPP for eachvegetation type in the study area from 1954 to *** microclimate data of 47 years monitored byLushi meteorological station was extrapolated tocover the basin using MT-CliM, a mountainmicroclimate simulator. The output files of MT-CliM were used to feed Biome-BGC. We usedaverage ecophysiological values of each type ofvegetation supplied by Numerical TerradynamicSimulation Group (NTSG) in the University ofMontana as input ecophysiological constants *** estimates of daily NPP in early July and annualET on these four biome groups were comparedrespectively with field measurements and other *** gross primary production (GPP) of evergreenneedle leaf forest measurements were very close tothe output of Biome-BGC, but measurements ofbroadleaf forest and dwarf shrub were much smallerthan the simulation result. Simulated annual ET andNPP had a significant correlation with precipitation,indicating precipitation is the major environmentalfactor affecting ET and NPP in the study *** also is the key climatic factor for theinterannual ET and NPP variations.

关键词： Carbon and water budgets Biome-BGC the Lushi basin evapotranspiration netprimary productivity (NPP) gross primaryproduction (GPP)

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