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Characteristics of Emission Non-nulling Pulsars Through Simulation

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Research in Astronomy and Astrophysics 2024年第4期24卷 91-102页

作者： Rai yuen Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Xinjiang Key Laboratory of Radio Astrophysics Chinese Academy of SciencesUrumqi 830011China Key Laboratory of Radio Astronomy Chinese Academy of SciencesNanjing 210008China SIfA School of PhysicsUniversity of SydneySydneyNSW2006Australia

We investigate the population and several properties of radio pulsars whose emission does not null(non-nulling)through simulation of a large pulsar sample.Emission from a pulsar is identified as non-nulling if(i)the emission does not cease across the whole pulse profile,and(ii)the emission is detectable.For(i),we adopt a model for switching in the plasma charge density,and emission persists if the charge density is non-zero.For(ii),we assume that detectable emission originates from source points where it is emitted tangentially to the magnetic field-line and parallel to the line-of-sight.We find that pulsars exhibiting non-nulling emission possess obliquity angles with an average of 42°.5,and almost half the samples maintain a duty cycle between 0.05 and 0.2.Furthermore,the pulsar population is not fixed but dependent on the obliquity angle,with the population peaking at 20°.In addition,three evolutionary phases are identified in the pulsar population as the obliquity angle evolves,with the majority of samples having an obliquity angle between 20°and 65°.Our results also suggest that emission from a pulsar may evolve between nulling and non-nulling during its lifetime.

关键词： radiation mechanisms:non thermal stars:neutron (stars:)pulsars:general

Targeting calcium signaling in Alzheimer’s disease: challenges and promising therapeutic avenues

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Neural Regeneration Research 2024年第3期19卷 501-502页

作者： LinLin Song yongPei Tang Betty yuen Kwan Law Neher’s Biophysics Laboratory for Innovative Drug Discovery State Key Laboratory of Quality Research in Chinese MedicineMacao University of Science and TechnologyMacao Special Administration RegionChina

The critical role of calcium dyshomeostasis in the pathogenesis of Alzheimer’s disease(AD):AD is a progressive neurodegenerative disease characterized by cognitive decline,memory impairment,and behavioral changes.With an estimated 50 million people being affected worldwide,the incidence of AD is constantly increasing globally.The hallmark of AD is the accumulation of amyloid-beta protein(Aβ)in the form of amyloid plaques and hyperphosphorylated tau protein in the form of neurofibrillary tangles.however,increasing evidence suggests that calcium ion(Ca2+)dysregulation also plays a crucial role in the pathogenesis of AD(Calvo-Rodriguez and Bacskai,2021).As a key second messenger,Ca2+regulates a wide range of cellular processes,including the release of neurotransmitters,gene expression,and cell death.Ca^(2+)also regulates the activity of Calcium/calmodulin-dependent protein kinase II,which is critical for synaptic plasticity,learning,and memory(Kaushik et al.,2022).Alternation in the Ca^(2+)signal is an early event in the pathogenesis of AD,which can lead to synaptic dysfunction,neuronal loss,and cognitive impairment.

关键词： Alzheimer homeostasis globally

Asymptotics for the joint tail probability of bidimensional randomly weighted sums with applications to insurance

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Science China Mathematics 2024年第1期67卷 163-186页

作者： yang yang Shaoying Chen Kam Chuen yuen School of Statistics and Data Science Nanjing Audit UniversityNanjing 211815China Department of Statistics and Actuarial Science The University of Hong KongHong Kong 999077China

This paper studies the joint tail behavior of two randomly weighted sums∑_(i=1)^(m)Θ_(i)X_(i)and∑_(j=1)^(n)θ_(j)y_(j)for some m,n∈N∪{∞},in which the primary random variables{X_(i);i∈N}and{y_(i);i∈N},respectively,are real-valued,dependent and heavy-tailed,while the random weights{Θi,θi;i∈N}are nonnegative and arbitrarily dependent,but the three sequences{X_(i);i∈N},{y_(i);i∈N}and{Θ_(i),θ_(i);i∈N}are mutually independent.Under two types of weak dependence assumptions on the heavy-tailed primary random variables and some mild moment conditions on the random weights,we establish some(uniformly)asymptotic formulas for the joint tail probability of the two randomly weighted sums,expressing the insensitivity with respect to the underlying weak dependence structures.As applications,we consider both discrete-time and continuous-time insurance risk models,and obtain some asymptotic results for ruin probabilities.

关键词： asymptotic joint tail behavior randomly weighted sum heavy-tailed distribution dependence insurance risk model

Response Evaluation Using Contrast-Enhanced Ultrasound for Unresectable Advanced hepatocellular Carcinoma Treated With Tyrosine Kinase Inhibitors Plus Anti-PD-1 Antibody Therapy

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Spreadsheet quality assurance:a literature review

Ultrasound in Medicine and Biology 2024年第1期50卷 142-149页

作者： Zhao C.-K. Guan X. Pu y.-y. Zhou B.-y. Wang L.-F. Sun y.-K. yin h.-h. Xia h.-S. Wang X. han h. Xu h.-X. Department of Ultrasound Zhongshan Hospital Institute of Ultrasound in Medicine and Engineering Fudan University Shanghai China Shanghai Institute of Medical Imaging Shanghai China Central Laboratory and Department of Medical Ultrasound Sichuan Academy of Medical Sciences Sichuan Provincial People's Hospital University of Electronic Science and Technology of China Chengdu China

Objective: The aim of the work described here was to evaluate the role of contrast-enhanced ultrasound (CEUS) in response evaluation for unresectable advanced hepatocellular carcinoma (hCC) treated with tyrosine kinase inhibitors (TKIs) plus anti-programmed cell death protein-1 (PD-1) antibody therapy. Methods: A prospective cohort of consecutive patients with hCC who received combined TKI/anti-PD-1 antibody treatment for unresectable hCC between January 2022 and October 2022 was included in this study. The patients underwent unenhanced ultrasound (US) and CEUS examinations before treatment and at follow-up. Changes in the largest diameters of the target tumor on unenhanced US and the largest diameters of the enhancing target tumors on CEUS were evaluated. Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 with unenhanced US and magnetic resonance imaging/computed tomography (MRI/CT) and modified RECIST (mRECIST) with CEUS and CEMRI/CT were used to assess treatment response. Results: A total of 24 hCC patients (23 men and 1 woman; mean age: 56.5 ± 8.5 y; Barcelona Clinic Liver Cancer stage C, 62.5%; 29 intrahepatic target tumors) were studied. Calculations of degree of necrosis in the target tumors revealed no significant differences between CEUS and CEMRI/CT (44.5 ± 36.2% vs. 45.3 ± 36.8%, p = 0.862). As for the differentiation of responders from non-responders, the agreement between RECIST version 1.1 of unenhanced US and mRECIST-CEUS was poor (κ coefficient = 0.233). Meanwhile, there was a high degree of concordance between mRECIST-CEUS and mRECIST-CEMRI/CT (κ coefficient = 0.812). Conclusion: CEUS proved to be superior to baseline US and is comparable to CEMRI/CT in defining treatment outcome for combined TKI/anti-PD-1 antibody therapy. © 2023 World Federation for Ultrasound in Medicine & Biology

关键词： Anti-angiogenic therapy Anti-PD-1 antibody Contrast-enhanced ultrasound hepatocellular carcinoma

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Frontiers of Computer Science 2024年第2期18卷 61-82页

作者： Pak-Lok POON Man Fai LAU yuen Tak yU Sau-Fun TANG School of Engineering and Technology Central Queensland UniversityMelbourne 3000Australia Department of Computing Technologies Swinburne University of TechnologyHawthorn 3122Australia Department of Computer Science City University of Hong KongHong Kong SAR 999077China The Royal Victorian Eye and Ear hospital East Melbourne 3002Australia

Spreadsheets are very common for information processing to support decision making by both professional developers and non-technical end users.Moreover,business intelligence and artificial intelligence are increasingly popular in the industry nowadays,where spreadsheets have been used as,or integrated into,intelligent or expert systems in various application domains.however,it has been repeatedly reported that faults often exist in operational spreadsheets,which could severely compromise the quality of conclusions and decisions based on the spreadsheets.With a view to systematically examining this problem via survey of existing work,we have conducted a comprehensive literature review on the quality issues and related techniques of spreadsheets over a 35.5-year period(from January 1987 to June 2022)for target journals and a 10.5-year period(from January 2012 to June 2022)for target conferences.Among other findings,two major ones are:(a)Spreadsheet quality is best addressed throughout the whole spreadsheet life cycle,rather than just focusing on a few specific stages of the life cycle.(b)Relatively more studies focus on spreadsheet testing and debugging(related to fault detection and removal)when compared with spreadsheet specification,modeling,and design(related to development).As prevention is better than cure,more research should be performed on the early stages of the spreadsheet life cycle.Enlightened by our comprehensive review,we have identified the major research gaps as well as highlighted key research directions for future work in the area.

关键词： decision support system end-user computing end-user programming Excel spreadsheet

Construction of 2D/2D Ti_(3)C_(2)T_(x)MXene/CdS heterojunction with photothermal effect for efficient photocatalytic hydrogen production

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Journal of Materials Science & Technology 2024年第4期171卷 1-9页

作者： T.y.huang Z.yang S.y.yang Z.h.Dai y.J.Liu J.h.Liao G.y.Zhong Z.J.Xie y.P.Fang S.S.Zhang Key Laboratory for Biobased Materials and Energy of Ministry of Education Guangdong Laboratory for Lingnan Modern AgricultureCollege of Materials and EnergySouth China Agricultural UniversityGuangzhou 510643China School of Physics and Optoelectronics South China University of TechnologyGuangzhou 510640China School of Chemical Engineering and Energy Technology Guangdong Provincial Key Laboratory of Distributed Energy SystemsDongguan University of TechnologyDongguan 523808China

The insensitivity of semiconductors to visible and infrared light is a key constraint on the utilization of light energy in photocatalytic reactions.Constructing photocatalysts with full-spectrum absorption through surface engineering is an effective approach to fully harnessing light energy in semiconductor materials.herein,a novel stable Ti_(3)C_(2)T_(x)MXene/CdS heterojunction catalyst is obtained by in-situ epitaxial growth of two-dimensional(2D)CdS nanosheets on 2D MXene interface via a solvothermal method.The exceptional light absorption properties of MXene confer outstanding full-spectrum driven photocat-alytic hydrogen evolution capability upon the heterogeneous catalyst.The unique 2D/2D structure effectively mitigated the recombination of photogenerated carriers,enhancing the photocatalytic performance of the catalyst.Moreover,the composite catalyst exhibits a significantly higher surface temperature of 80.4℃under visible light irradiation at an intensity of 0.1 W/cm^(2),which is 1.84 times higher than that of CdS.Under irradiation of visible and near infrared light,the composite catalyst with photothermal ef-fect demonstrates a remarkable hydrogen evolution rate of 65.4 mmol g^(-1)h^(-1),which is 7.2 times higher than that of CdS catalyst.This study introduces a novel approach for constructing full-spectrum absorption catalysts and expands the application of the photothermal effect in photocatalytic hydrogen evolution research.

关键词： Two-dimensional structure heterostructure Photothermal effect Photocatalyst hydrogen evolution

high-resolution multi-scale air pollution system:Evaluation of modelling performance and emission control strategies

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Journal of Environmental Sciences 2024年第3期137卷 65-81页

作者： Diogo Lopes Joana Ferreira Sandra Rafael Ka In hoi Xin Li yuan Liu Ka-Veng yuen Kai Meng Mok Ana Isabel Miranda Department of Environment and Planning&CESAM University of AveiroAveiroPortugal Department of Civil&Environmental Engineering Faculty of Science and TechnologyUniversity of MacaoMacao SARChina

A high percentage of the world's population lives in areas where air pollutant concentrations exceed the World health Organization guidelines.This work aims to develop and test,a high-resolution multi-scale air pollution modelling system by integrating a set of adequate tools.This system is able to provide detailed air pollutant concentrations in urban areas and support air quality management strategies through a better identification of different atmospheric processes.It also allows furthering the design and assessment of air pollution control measures for a specific area.To evaluate its performance and suitability,the system was applied to the Macao Special Administrative Region(SAR),China,one of the most densely populated areas on earth,during a winter period when this area is affected by high levels of Particulate Matter(PM).Although the developed system tends to underestimate the PM concentrations,it revealed a good performance in reproducing the temporal and spatial air pollution patterns.Several exceedances of the Chinese air quality standards were calculated and high population exposure to PM pollution was estimated.The tested urban atmospheric emission reduction scenarios have shown air quality improvements,indicating that emission reduction measures at urban level should focus on the domestic sector.however,it is crucial to implement joint pollution prevention strategies with neighbouring regions to improve the air quality in Macao SAR.The approach developed in this work can support policymakers in defining new strategies to reduce atmospheric pollution in urban areas.

关键词： Urban areas high-resolution emission inventory Particulate matter Population exposure

Rational design of AgGaS/ZnS/ZnS quantum dots with a near-unity photoluminescence quantum yield via double shelling scheme

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Journal of Materials Science & Technology 2024年第2期169卷 235-242页

作者： h.X.Lu h.Liu Z.Z.Fu y.y.Chen h.Q.Dai Z.hu W.L.Zhang R.Q.Guo Institute for Electric Light Sources School of Information Science and TechnologyFudan UniversityShanghai 200433China Institute of Future Lighting Academy for Engineering and TechnologyFudan UniversityShanghai 200433China yiwu Research Institute of Fudan University YiwuZhejiang 322000China Zhongshan-Fudan Joint Innovation Center Zhongshan 528437China

In this study,a two-step method was used to synthesize highly luminescent AgGaS/ZnS/ZnS quantum dots(QDs).In the first step,an inner ZnS shell was formed via a one-pot method,which resulted in a smaller lattice mismatch between the AgGaS core and the outer ZnS shell,thereby facilitating the formation of a thick outer shell.After the two-step shelling process,the synthesized AgGaS/ZnS/ZnS QDs showed an excellent photoluminescence quantum yield(PLQy)of 96.4%with a peak wavelength of 508 nm,repre-senting the highest PLQy reported thus far for AgGaS QDs.Furthermore,the effect of halogen ions in Zn precursors on the shelling process was investigated.It was proposed that the capacity of halogen ions to coordinate with the QDs influenced the balance between Zn cation diffusion and ZnS shelling reaction.Specifically,the ZnS shelling reaction was dominant when ZnCl_(2)was employed,while Zn cation diffusion was the dominant process under the I^(−)-rich environment.This work provides insights into the interfacial restructuring during the ZnS shelling and offers a clear map for the tailored synthesis of core/shell QDs.

关键词： AgGaS Quantum dots Photoluminescence Core/shell Alloyed core/shell interface

Single Fe atom-anchored manganese dioxide for efficient removal of volatile organic compounds in refrigerator

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Nano Research 2024年第5期17卷 3927-3933页

作者： yiwen Wang Jun Zhang yongfei Zhang yu Zhang Zhe Wang Jing Wang yuen Wu Department of Endocrinology the First Affiliated Hospital of USTCDivision of Life Science and MedicineUniversity of Science and Technology of ChinaHefei 230001China School of Chemistry and Materials Science University of Science and Technology of ChinaHefei 230026China hefei hualing Co. LtdHefei 230088China Linkway Technology Co. LtdResearch Institute of Single Atom Catalysts Industry TechnologyNanning 530000China

The efficient and rapid removal of volatile organic compounds(VOCs)holds significant importance for ensuring food quality and human health,particularly within the low-temperature confined spaces in refrigerators.however,achieving effective VOCs degradation under such conditions poses challenges in terms of activating inert bonds and facilitating mass transfer.In this study,we propose a novel solution by designing a cleaner module that incorporates 1.07%single Fe atom-anchored manganese dioxide catalysts(FeSAs-MnO_(2)).The combination of single Fe atoms and defect-rich MnO_(2) substrate efficiently activates molecular oxygen,leading to enhanced generation of highly reactive oxygen species(ROS).Non-thermal plasma(NTP)and circulating fan are introduced to facilitate the regeneration of catalytic activity and improve mass transfer.The FeSAs-MnO_(2) cleaner module demonstrates exceptional performance in trimethylamine(TMA)removal,achieving a conversion efficiency of 98.9%for 9 ppm within just 9 min.Furthermore,accelerated aging tests predict an extended service life of up to 45 years for the FeSAs-MnO_(2) cleaner module,surpassing the expected lifespan of refrigerators significantly.

关键词： single atom catalysts volatile organic compounds(VOCs) trimethylamine(TMA) non-thermal plasma(NTP) refrigerator