检索结果-南通市图书馆

characteristics of Emission Non-nulling Pulsars Through Simulation

在线全文

学校读者我要写书评

暂无评论

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 *** 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 ***(i),we adopt a model for switching in the plasma charge density,and emission persists if the charge density is ***(ii),we assume that detectable emission originates from source points where it is emitted tangentially to the magnetic field-line and parallel to the *** 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 ***,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

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

在线全文

学校读者我要写书评

暂无评论

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 *** 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 *** 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

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

在线全文

学校读者我要写书评

暂无评论

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 *** an estimated 50 million people being affected worldwide,the incidence of AD is constantly increasing *** 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 ***,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 ***^(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

Spreadsheet quality assurance:a literature review

在线全文

学校读者我要写书评

暂无评论

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 ***,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 ***,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 *** 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 *** 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 *** 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

Large-scale manufacturing of functional single-atom ink for convenient glucose sensing

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第8期17卷 7256-7263页

作者： Muyu Yan Xiaofei Zhu can Xiong Xiao Han Zhenggang Xue yuen Wu Department of Endocrinology Institute of Endocrine and Metabolic DiseasesThe First Affiliated Hospital of USTCDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefei 230001China Deep Space Exploration Laboratory University of Science and Technology of ChinaHefei 230026China NEST Laboratory Department of PhysicsDepartment of ChemistryCollege of ScienceShanghai UniversityShanghai 200444China center of Advanced Nanocatalysis(cAN) Department of Applied ChemistryUniversity of Science and Technology of ChinaHefei 230026China

Printing techniques hold great potential in the manufacture of electronics such as sensors,micro-supercapacitors,and flexible ***,developing large-scale functional conductive inks with appropriate rheological properties and active components still remains a ***,through optimizing the formulations of ink,iron single sites supported N-doped carbon black(Fe_(1)-Nc)inks can serve as both conductive electrodes and high-reactive catalysts to realize convenient glucose detection,which pronouncedly reduces the dosage of enzyme and simplifies the sensors *** detail,utilizing in-situ pyrolysis method,Fe_(1)-Nc single-atom catalysts(SAcs)are prepared in bulk(dekagram-level).The batched Fe_(1)-Nc SAcs materials can be uniformly mixed with modulated ink to realize the screen printing with high resolution and ***,the whole scalable preparation and ink-functional process can be extended to various metals(including co,Ni,cu,and Mn).The introduction of highly active Fe_(1)-Nc sites reduces the amount of enzyme used in glucose detection by at least 50%,contributing to the cost reduction of *** strategy in harnessing the SAcs onto the carbon inks thus provides a broad prospect for the low-cost and large-scale printing of sensitive sensing devices.

关键词： large-scale manufacturing single-atom inks screen printing glucose sensing low enzyme dosage

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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 ***,achieving effective VOcs degradation under such conditions poses challenges in terms of activating inert bonds and facilitating mass *** 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 *** 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 ***,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

Near-field channel estimation for extremely large-scale Terahertz communications

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science china(Information Sciences) 2024年第9期67卷 213-228页

作者： Songjie YANG Yizhou PENG Wanting LYU Ya LI Hongjun HE Zhongpei ZHANG chau yuen National key Laboratory of Wireless communications University of Electronic Science and Technology of China Future Research Laboratory China Mobile Research Institute School of Electrical and Electronics Engineering Nanyang Technological University

Future Terahertz communications exhibit significant potential in accommodating ultra-high-rate services. Employing extremely large-scale array antennas is a key approach to realize this potential, as they can harness substantial beamforming gains to overcome the severe path loss and leverage the electromagnetic advantages in the near field. This paper proposes novel estimation methods designed to enhance efficiency in Terahertz widely-spaced multi-subarray(WSMS) systems. Initially, we introduce three sparse channel representation methods: polar-domain representation(PD-R), multi-angular-domain representation(MADR), and two-dimensional polar-angular-domain representation(2D-PAD-R). Each method is meticulously developed for near-field WSMS channels, capitalizing on their sparsity characteristics. Building on this,we propose four estimation frameworks using the sparse recovery theory: polar-domain estimation(PD-E),multi-angular-domain estimation(MAD-E), two-stage polar-angular-domain estimation(TS-PAD-E), and two-dimensional polar-angular-domain estimation(2D-PAD-E). Particularly, 2D-PAD-E, integrating a 2D dictionary process, and TS-PAD-E, with its sequential approach to angle and distance estimation, stand out as particularly effective for near-field angle-distance estimation, enabling decoupled calculation of these parameters. Overall, these frameworks provide versatile and efficient solutions for WSMS channel estimation,balancing low complexity with high-performance outcomes. Additionally, they represent a fresh perspective on near-field signal processing.

关键词： Terahertz communications near field channel estimation widely-spaced multi-subarray sparse recovery

A nerve-like self-healable conductive wire

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

National Science Review 2024年第6期11卷 89-90页

作者： Xuemei Fu Benjamin c.k.Tee Department of Materials Science and Engineering National University of Singapore Institute for Health Innovation and Technology National University of Singapore

In wearables and robotics, it is often required to deploy electronic devices at different spatially distributed locations for multi-functionality [1–3]. Thus, conductive wires for efficient interconnection of various electronic devices are ***, in practical applications, the frequent motion of wearers and robots will result in high-strain deformations of these wires, which could cause irreparable damage.

关键词：

Shear behavior and off-fault damage of saw-cut smooth and tension-induced rough joints in granite

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1216-1230页

作者： Fanzhen Meng Feili Wang Louis Ngai yuen Wong Jie Song Muzi Li chuanqing Zhang Liming Zhang college of Science Qingdao University of TechnologyQingdao266033China Department of Earth Sciences The University of Hong KongPokfulamHong KongChina State key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China cooperative Innovation center of Engineering construction and Safety Shandong Peninsula Blue Economic Zone Qingdao266033China

The damage of rock joints or fractures upon shear includes the surface damage occurring at the contact asperities and the damage beneath the shear surface within the host *** latter is commonly known as off-fault damage and has been much less investigated than the surface *** main contribution of this study is to compare the results of direct shear tests conducted on saw-cut planar joints and tension-induced rough granite joints under normal stresses ranging from 1 MPa to 50 *** shear-induced off-fault damages are quantified and compared with the optical microscope *** results clearly show that the planar joints slip stably under all the normal stresses except under 50 MPa,where some local fractures and regular stick-slip occur towards the end of the *** post-peak stress drop and stick-slip occur for all the rough *** residual shear strength envelopes for the rough joints and the peak shear strength envelope for the planar joints almost *** root mean square(RMS)of asperity height for the rough joints decreases while it increases for the planar joint after shear,and a larger normal stress usually leads to a more significant decrease or increase in ***,the extent of off-fault damage(or damage zone)increases with normal stress for both planar and rough joints,and it is restricted to a very thin layer with limited micro-cracks beneath the planar joint *** comparison,the thickness of the damage zone for the rough joints is about an order of magnitude larger than that of the planar joints,and the coalesced micro-cracks are generally inclined to the shear direction with acute *** findings obtained in this study contribute to a better understanding on the frictional behavior and damage characteristics of rock joints or fractures with different roughness.

关键词： Planar joint Rough joint Shear behavior Off-fault damage Micro-cracks