检索结果-南通市图书馆

商业周刊（中文版） 2024年第15期 26-27页

作者： Saritha rai Marissa Newman 逸思(译) 不详

经以色列监管机构批准,一家人工智能初创公司将与一家大型银行联合推出一款可提供选股建议的聊天机器人,尽管其他国家政府已发出警告,认为人工智能若被广泛应用于投资领域,可能会危及金融市场的稳定。

关键词：初创公司大型银行聊天机器人人工智能金融市场选股监管机构放松监管

Improving the performance of conventional base isolation systems by an external variable negative stiffness device under near-fault and long-period ground motions

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2020年第4期19卷 985-1003页

作者： sandhya Nepal Masato Saitoh Graduate School of Science and Engineering Saitama University255 Shimo-OkuboSakura-kuSaitamaJapan

Recent studies have shown that base-isolated objects with long fundamental natural periods are highly influenced by long-period earthquakes. These long-period waves result in large displacements for isolators, possibly leading to exceedance of the allowable displacement limits. Conventional isolation systems, in general, fail to resist such large displacements. This has prompted the need to modify conventional base isolation systems. The current work focuses on the development of an external device, comprising a unit of negative and positive springs, for improving the performance of conventional base isolation systems. This unit accelerates the change in the stiffness of the isolation system where the stiffness of the positive spring varies linearly in terms of the displacement response of the isolated objects. The target objects of the present study are small structures such as computer servers, sensitive instruments and machinery. Numerical studies show that the increase in the damping of the system and the slope of the linear function is effective in reducing the displacement response. An optimal range of damping values and slope, satisfying the stability condition and the allowable limits of both displacement and acceleration responses when the system is subjected to near-fault and long-period ground motions simultaneously, is proposed.

关键词： base isolation near-fault earthquakes long-period earthquakes negative stiffness variable stiffness

脉冲星J2313+4253的周期性消零和奇偶调制特性的研究

在线全文

学校读者我要写书评

暂无评论

中国科学：物理学、力学、天文学 2024年第4期54卷 185-198页

作者：陈建玲温志刚王洪光王娜袁建平 rai Yuen 闫文明韩伟李永宏王金鹏项斌斌运城学院物理与电子工程系运城044000 中国科学院新疆天文台乌鲁木齐830011 广州大学天体物理中心广州510006 新疆大学机电工程学院乌鲁木齐830017

脉冲星子脉冲的强度调制特征对揭示脉冲星辐射过程和磁层几何具有重要意义.前人研究表明,PSR J2313+4253的单脉冲序列具有44倍和2倍自转周期的强度调制.其中2倍周期的调制周期被称为奇偶性调制,其物理起源并不清晰.本文利用佳木斯66 m... 详细信息

脉冲星子脉冲的强度调制特征对揭示脉冲星辐射过程和磁层几何具有重要意义.前人研究表明,PSR J2313+4253的单脉冲序列具有44倍和2倍自转周期的强度调制.其中2倍周期的调制周期被称为奇偶性调制,其物理起源并不清晰.本文利用佳木斯66 m射电望远镜的观测数据,对脉冲星J2313+4253在2250 MHz的单脉冲辐射特性进行了详细研究.通过相位分离涨落谱(LRFS)、谐频分离的涨落谱(HRFS)和二维涨落谱(2DFS)的分析方法,发现PSR J2313+4253的奇偶性调制来自于其短周期子脉冲漂移,并且调制现象展现出了时间依赖性.分析表明,旋转木马模型下,奇偶性调制可能起源于脉冲星火花放电过程中,辐射区子辐射束间边界不清晰而发生的混叠效应.

关键词：脉冲星单脉冲消零

The meridional circulation of the Sun: Observations, theory and connections with the solar dynamo

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2021年第3期64卷 46-72页

作者： Arnab rai Choudhuri Department of Physics Indian Institute of ScienceBangalore560012India

The meridional circulation of the Sun, which is observed to be poleward at the surface, should have a return flow at some depth. Since large-scale flows like the differential rotation and the meridional circulation are driven by turbulent stresses in the convection zone, these flows are expected to remain confined within this zone. Current observational(based on helioseismology)and theoretical(based on dynamo theory) evidences point towards an equatorward return flow of the meridional circulation at the bottom of the convection zone. Assuming the mean values of various quantities averaged over turbulence to be axisymmetric,we study the large-scale flows in solar-like stars on the basis of a 2D mean field theory. Turbulent stresses in a rotating star can transport angular momentum, setting up a differential rotation. The meridional circulation arises from a slight imbalance between two terms which try to drive it in opposite directions: a thermal wind term(arising out of the higher efficiency of convective heat transport in the polar regions) and a centrifugal term(arising out of the differential rotation). To make these terms comparable,the poles of the Sun should be slightly hotter than the equator. We discuss the important role played by the meridional circulation in the flux transport dynamo model. The poloidal field generated by the Babcock-Leighton process at the surface is advected poleward, whereas the toroidal field produced at the bottom of the convection zone is advected equatorward. The fluctuations in the meridional circulation(with coherence time of about 30-40 yr) help in explaining many aspects of the irregularities in the solar cycle. Finally, we discuss how the Lorentz force of the dynamo-generated magnetic field can cause periodic variations in the large-scale flows with the solar cycle.

关键词： astrophysical plasma solar physics Sun:solar magnetism Sun:helioseismology fluid flow:rotational

Evolution of heart transplant donor characteristics in the 21st century: A United States single center’s experience

在线全文

学校读者我要写书评

暂无评论

World Journal of Transplantation 2024年第3期14卷 22-29页

作者： Alexander M Spring Christiana Gjelaj Shivank Madan Snehal R Patel Omar Saeed sandhya Murthy Yogita Rochlani Daniel B Sims Sasha Vukelic Stephen J Forest Jamil F Borgi Daniel J Goldstein Ulrich P Jorde Montefiore-Einstein Center for Heart and Vascular Care Montefiore Medical CenterAlbert Einstein College of MedicineBronxNY 10467United States Division of Cardiothoracic Surgery Tulane UniversityNew OrleansLA 70112United States

Despite a record setting number of heart transplants performed annually,the national donor shortage continues to plague transplant teams across the United *** we describe the barriers to adaptation of numerous“non-traditional”orthotopic heart transplant donor characteristics including donors with hepatitis C virus,those meeting criteria for donation after cardiac death,donors with coronavirus disease 19 infection,donors with the human immunodeficiency virus,and grafts with left ventricular systolic *** center’s objective was to increase our transplant volume by expanding our donor pool from“traditional”donors to these“non-traditional”*** detail how medical advances such as certain laboratory studies,pharmacologic interventions,and organ care systems have allowed our center to expand the donor pool thereby increasing transplantation volume without adverse effects on outcomes.

关键词： Orthotopic heart transplantation Hepatitis C virus COVID-19 Left ventricular systolic dysfunction Human immunodeficiency virus Donation after cardiac death

Knowledge and attitude on childhood cancer survivorship among healthcare trainees:a multicentre study from India

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Family Medicine and Community Health 2024年第S2期12卷 34-43页

作者： Amritesh Grewal Bhavik Bansal Chetanya Mittal Hardik Gupta Archana Sasi Prasanth Ganesan Aashima Dabas Puneet Sahi Lakshmi Ramamoorthy Hmar Thiak Lalthanthuami Jaikumar Ramamoorthy Arwachi Sindhu Suyash Arora Anumeha Bhukya Muthumani Hepzibah Kanchana Devi Karthick Krishnamurthy Sanjeet K rai Nikhil Mehta Komal Antil Sameer Bakhshi Shuvadeep Ganguly Medical Student All India Institute of Medical SciencesNew DelhiDelhiIndia Department of Medical Oncology Dr.B.R.A.Institute Rotary Cancer HospitalAll India Institute of Medical SciencesNew DelhiDelhiIndia Department of Medical Oncology Jawaharlal Institute of Postgraduate Medical Education and ResearchPuducherryPuducherryIndia Department of Pediatrics Lok Nayak HospitalNew DelhiDelhiIndia Department of Pediatrics Maulana Azad Medical CollegeNew DelhiDelhiIndia College of Nursing Jawaharlal Institute of Postgraduate Medical Education and ResearchPuducherryPuducherryIndia Department of Pediatrics Jawaharlal Institute of Postgraduate Medical Education and ResearchPuducherryPuducherryIndia Medical Student Maulana Azad Medical CollegeNew DelhiDelhiIndia Department of Surgical Disciplines All India Institute of Medical SciencesNew DelhiDelhiIndia Department of Dermatology and Venereology All India Institute of Medical SciencesNew DelhiDelhiIndia College of Nursing All India Institute of Medical SciencesNew DelhiDelhiIndia

Background The proportion of childhood cancer survivors(CCS)in low/middle-income countries(LMICs)is *** often develop several physical and psycho-social long-term adverse effects,with unique healthcare *** healthcare providers(primary care physicians(PCPs)),especially in LMICs,are often not equipped to handle survivorship *** study aimed to assess knowledge,and attitude among trainee healthcare providers concerning major issues of paediatric survivorship *** A multi-centre,cross-sectional,questionnaire-based study was conducted among nursing and medical undergraduate students,and postgraduate medical residents across three tertiary-care teaching hospitals in India—All India Institute of Medical Sciences,New Delhi;Jawaharlal Institute of Postgraduate Medical Education and Research,Puducherry;and Maulana Azad Medical College,New Delhi.A questionnaire with total of 24 questions(14 knowledge-based and 10 attitude-based)was finalised after validation by expert review and *** major domains covered in the questionnaire included knowledge and attitude regarding long-term adverse effects and psychosocial,employment-related issues faced by the *** was administered to the study participants *** knowledge-based questions had true/false responses(scored as 0 or 1 if incorrect or correct,respectively).Attitude-based questions were scored as 5-point Likert *** Total 898 responses were collected(median age:21 years,64%(576/898)female).Among the respondents,44%were undergraduate medical students,42%were nursing students and 14%were postgraduate medical *** mean(SD)of knowledge score was 8.72(2.04)(out of 14).On multivariable analysis,only discipline of training predicted knowledge scores regarding survivorship *** medical residents(9.08)as well as undergraduate medical students(8.85),had significantly higher mean knowledge scores than nursing students(8.47)(p=0.004).Two questions were

关键词： centre handle false

Starspots, stellar cycles and stellar flares： Lessons from solar dynamo models

维普期刊数据库评论

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(Physics,Mechanics & Astronomy) 2017年第1期60卷 1-16页

作者： Amab rai Choudhuri Department of Physics Indian Institute of Science Bangalore 560012 India

In this review, we discuss whether the present solar dynamo models can be extrapolated to explain various aspects of stellar activity. We begin with a summary of the following kinds of data for solar-like stars:(i) data pertaining to stellar cycles from Ca H/K emission over many years;(ii) X-ray data indicating hot coronal activity;(iii) starspot data(especially about giant polar spots); and(iv) data pertaining to stellar superflares. Then we describe the current status of solar dynamo modelling—giving an introduction to the flux transport dynamo model, the currently favoured model for the solar cycle. While an extrapolation of this model to solar-like stars can explain some aspects of observational data, some other aspects of the data still remain to be theoretically explained. It is not clear right now whether we need a different kind of dynamo mechanism for stars having giant starspots or producing very strong superflares.

关键词： sunspots solar dynamo solar cycle stellar dynamo, stellar activity

Detection of Alzheimer’s disease onset using MRI and PET neuroimaging:longitudinal data analysis and machine learning

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2023年第10期18卷 2134-2140页

作者： Iroshan Aberathne Don Kulasiri sandhya Samarasinghe Centre for Advanced Computational Solutions(C-fACS) Lincoln UniversityChristchurchNew Zealand

The scientists are dedicated to studying the detection of Alzheimer’s disease onset to find a cure, or at the very least, medication that can slow the progression of the disease. This article explores the effectiveness of longitudinal data analysis, artificial intelligence, and machine learning approaches based on magnetic resonance imaging and positron emission tomography neuroimaging modalities for progression estimation and the detection of Alzheimer’s disease onset. The significance of feature extraction in highly complex neuroimaging data, identification of vulnerable brain regions, and the determination of the threshold values for plaques, tangles, and neurodegeneration of these regions will extensively be evaluated. Developing automated methods to improve the aforementioned research areas would enable specialists to determine the progression of the disease and find the link between the biomarkers and more accurate detection of Alzheimer’s disease onset.

关键词： deep learning image processing linear mixed effect model neuroimaging neuroimaging data sources onset of Alzheimer’s disease detection pattern recognition

Functional repertoire of protein kinases and phosphatases in synaptic plasticity and associated neurological disorders

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2021年第6期16卷 1150-1157页

作者： Raheel Khan Don Kulasiri sandhya Samarasinghe Centre for Advanced Computational Solutions(C-fACS) Lincoln UniversityChristchurchNew Zealand Department of Molecular Biosciences Lincoln UniversityChristchurchNew Zealand

Protein phosphorylation and dephosphorylation are two essential and vital cellular mechanisms that regulate many receptors and enzymes through kinases and ***^2+- dependent kinases and phosphatases are responsible for controlling neuronal processing;balance is achieved through *** molecular mechanisms of learning and memory,kinases generally modulate positively while phosphatases modulate *** review outlines some of the critical physiological and structural aspects of kinases and phosphatases involved in maintaining postsynaptic structural *** also explores the link between neuronal disorders and the deregulation of phosphatases and kinases.

关键词： Alzheimer’s disease autism spectrum disorder CaMKII calcineurin longterm depression long-term potentiation protein kinase A protein phosphatase 1 protein dephosphorylation protein phosphorylation

Modeling protein-protein interactions in axon initial segment to understand their potential impact on action potential initiation

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2021年第4期16卷 700-706页

作者： Piyush Bhardwaj Don Kulasiri sandhya Samarasinghe Centre of Advanced Computational Solutions(C-fACS) Lincoln UniversityChristchurchNew Zealand Department of Molecular Biosciences Lincoln UniversityChristchurchNew Zealand

The axon initial segment(AIS)region is crucial for action potential initiation due to the presence of high-density AIS protein voltage-gated sodium channels(Nav).Nav channels comprise several serine residues responsible for the recruitment of Nav channels into the structure of AIS through interactions with ankyrin-G(AnkG).In this study,a series of computational experiments are performed to understand the role of AIS proteins casein kinase 2 and AnkG on Nav channel recruitment into the *** computational simulation results using Virtual cell software indicate that Nav channels with all serine sites available for phosphorylation bind to AnkG with strong *** the low initial concentration of AnkG and casein kinase 2,the concentration of Nav channels reduces significantly,suggesting the importance of casein kinase 2 and AnkG in the recruitment of Nav channels.

关键词： Alzheimer’s disease ankyrin-G axon initial segment casein kinase-2 microtubules voltage-gated potassium channel voltage-gated sodium channel