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An improved ISR-WV rumor propagation model based on multichannels with time delay and pulse vaccination 被引量:1
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作者 董雅芳 霍良安 +1 位作者 谢笑笑 李明 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第7期234-248,共15页
The rapid development of the Internet has broadened the channels of dissemination of information,it has also led to the rapid and widespread propagation of rumors,which can have a serious negative impact socially.In t... The rapid development of the Internet has broadened the channels of dissemination of information,it has also led to the rapid and widespread propagation of rumors,which can have a serious negative impact socially.In this paper,an improved ISR-WV rumor propagation model integrating multichannels is proposed by considering the system’s time delay,and the influence of different channels of propagation on the dynamic process is further analyzed.Moreover,the basic reproduction number R0,rumor-free equilibrium,and rumor-prevailing equilibrium,as well as their stability,are deduced.Then,an optimal control problem with pulse vaccination is designed.Finally,the validity of the model and theoretical results is verified by numerical simulations and a practical application.The results show that the rumor propagation threshold R0 is more sensitive to the rate of the propagation of the information base channel.The shorter the thinking timeτ_(1)required for the ignorant to react after obtaining the information,the larger the final scale of propagation.Under this condition,the time delayτ_(2)spent by a spreader in producing a video is negatively related to the final scale of the propagation;conversely,a longerτ_(1)implies that the person tends to more cognizant,which can suppress the spread of rumors.Under this condition,τ_(2)has little effect on the final scale of propagation.In addition,the results also prove that timely implementation of the pulse vaccination control strategy of popular science education can effectively control the propagation of rumors and reduce their negative impact. 展开更多
关键词 rumor propagation propagation channels pulse vaccination control time delay information base
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Assessment of the Recent Hydromorphological Features of Nokoue Lake and Its Channels (South-East Benin)
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作者 Tètchodiwèï Julie-Billard Yonouwinhi Gérard Alfred Franck Assiom d’Almeida +1 位作者 Felix Kofi Abagale Akuemaho Virgile Onésime Akowanou 《Open Journal of Modern Hydrology》 CAS 2024年第1期33-55,共23页
Based on 2022 and 2023 hydrometric data and satellite images (Sentinel 2022, SPOT 2010), this study aims to present the Nokoué Lake and its channels’ re-cent hydromorphological characteristics. Integrating flow,... Based on 2022 and 2023 hydrometric data and satellite images (Sentinel 2022, SPOT 2010), this study aims to present the Nokoué Lake and its channels’ re-cent hydromorphological characteristics. Integrating flow, tributary morphology, and topography data determined specific power values along the axes studied. The values obtained range from 2.69 to 12.92 W/m2 for Ouémé River and 2.46 to 10.99 W/m2 for Sô River. The resulting water erosion on banks and bottoms is of linear, areolar, or gully and claw types. Lake bathymetry varies from -0.5 to -2.6 m (low flow period) and -1 to -4 m;in the Ouémé, Sô, and Totchè rivers, it varies from -5 m to -7 m, reaching -10 m at the Cotonou channel entrance (flood period). Bathymetric profiles reveal varied “U”, “V” and “Intermediate” bottom morphologies, influenced by erosion/sedimentation processes and human activities. The flow facies identified are lentic in the northern tributaries and lotic in the Cotonou and Totchè canals. Spatial analysis identified nine (09) thematic classes. In 2022, the surface area of the water body has increased from 274 km2 at low water to 280 km2 at high water, whereas in 2010 (a recent year of exceptional flooding), the surface area was 270 km2 at low water and 277 km2 at high water. Significant changes in land use are observed between 2010 and 2022. The floodplain area decreased slightly, from 421 km2 in 2010 (year of exceptional flooding) to 419 km2 in 2022. The evolution of land use shows a progressive expansion of the urban environment to the detriment of the natural environment. In the medium to long term, this trend could threaten the hydromorphological balance and even the existence of this important lagoon ecosystem. 展开更多
关键词 Nokoué Lake Ouémé River sô River Cotonou channel HYDROMORPHOLOGY
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ATP-sensitive potassium channels:novel potential roles in Parkinson's disease
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作者 曾洁 王刚 陈生弟 《Neuroscience Bulletin》 SCIE CAS CSCD 2007年第6期370-376,共7页
The ATP-sensitive potassium(KATP)channels which extensively distribute in diverse tissues(e.g.vascular smooth muscle,cardiac cells,and pancreas)are well-established for characteristics like vasodilatation,myocardi... The ATP-sensitive potassium(KATP)channels which extensively distribute in diverse tissues(e.g.vascular smooth muscle,cardiac cells,and pancreas)are well-established for characteristics like vasodilatation,myocardial protection against ischemia,and insulin secretion.The aim of this review is to get insight into the novel roles of KATPchannels in Parkinson's disease(PD),with consideration of the specificities KATPchannels in the central nervous system(CNS), such as the control of neuronal excitability,action potential,mitochondrial function and neurotransmitter release. 展开更多
关键词 ATP-sensitive potassium(KATP)channels Parkinson's disease
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Calcium channel blockers and Alzheimer's disease 被引量:2
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作者 Yi Tan Yulin Deng Hong Qing 《Neural Regeneration Research》 SCIE CAS CSCD 2012年第2期137-140,共4页
Alzheimer's disease is characterized by two pathological hallmarks: amyloid plaques and neurofibrillary tangles. In addition, calcium homeostasis is disrupted in the course of human aging Recent research shows that ... Alzheimer's disease is characterized by two pathological hallmarks: amyloid plaques and neurofibrillary tangles. In addition, calcium homeostasis is disrupted in the course of human aging Recent research shows that dense plaques can cause functional alteration of calcium signals in mice with Alzheimer's disease. Calcium channel blockers are effective therapeutics for treating Alzheimer's disease. This review provides an overview of the current research of calcium channel blockers involved in Alzheimer's disease theraov. 展开更多
关键词 Alzheimer's disease caic-ium channel calcium homeostasis Alzheimer's diseasepathogenesis Β-AMYLOID calcium channel blocker
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Approximate Private Quantum Channels on Fermionic Gaussian Systems 被引量:1
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作者 Kabgyun Jeong 《Journal of Quantum Information Science》 2021年第1期1-12,共12页
The private quantum channel (PQC) maps any quantum state to the maximally mixed state for the discrete as well as the bosonic Gaussian quantum systems, and it has fundamental meaning on the quantum cryptographic tasks... The private quantum channel (PQC) maps any quantum state to the maximally mixed state for the discrete as well as the bosonic Gaussian quantum systems, and it has fundamental meaning on the quantum cryptographic tasks and the quantum channel capacity problems. In this paper, we primally introduce a notion of approximate private quantum channel (<em>ε</em>-PQC) on <em>fermionic</em> Gaussian systems (<em>i.e.</em>, <em>ε</em>-FPQC), and construct its explicit form of the fermionic (Gaussian) private quantum channel. First of all, we suggest a general structure for <em>ε</em>-FPQC on the fermionic Gaussian systems with respect to the Schatten <em>p</em>-norm class, and then we give an explicit proof of the statement in the trace norm case. In addition, we study that the cardinality of a set of fermionic unitary operators agrees on the <em>ε</em>-FPQC condition in the trace norm case. This result may give birth to intuition on the construction of emerging fermionic Gaussian quantum communication or computing systems. 展开更多
关键词 Fermionic Private Quantum channel Approximate FPQC Isotropic Measure ε-Net Analysis McDiarmid’s Inequality
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Reduction of signal reflection along through silicon via channel in high-speed three-dimensional integration circuit 被引量:1
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作者 刘晓贤 朱樟明 +2 位作者 杨银堂 王凤娟 丁瑞雪 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第3期583-590,共8页
The through silicon via (TSV) technology has proven to be the critical enabler to realize a three-dimensional (3D) gigscale system with higher performance but shorter interconnect length. However, the received dig... The through silicon via (TSV) technology has proven to be the critical enabler to realize a three-dimensional (3D) gigscale system with higher performance but shorter interconnect length. However, the received digital signal after trans- mission through a TSV channel, composed of redistribution layers (RDLs), TSVs, and bumps, is degraded at a high data-rate due to the non-idealities of the channel. We propose the Chebyshev multisection transformers to reduce the signal reflec- tion of TSV channel when operating frequency goes up to 20 GHz, by which signal reflection coefficient ($11) and signal transmission coefficient ($21) are improved remarkably by 150% and 73.3%, respectively. Both the time delay and power dissipation are also reduced by 4% and 13.3%, respectively. The resistance-inductance-conductance-capacitance (RLGC) elements of the TSV channel are iterated from scattering (S)-parameters, and the proposed method of weakening the signal reflection is verified using high frequency simulator structure (HFSS) simulation software by Ansoft. 展开更多
关键词 three-dimensional integrated circuit through silicon via channel signal reflection s-PARAMETERs
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Ergodic stationary distribution of a stochastic rumor propagation model with general incidence function
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作者 Yuhuai Zhang Jianjun Zhu 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第6期145-154,共10页
In daily lives,when emergencies occur,rumors will spread widely on the internet.However,it is quite difficult for the netizens to distinguish the truth of the information.The main reasons are the uncertainty of netiz... In daily lives,when emergencies occur,rumors will spread widely on the internet.However,it is quite difficult for the netizens to distinguish the truth of the information.The main reasons are the uncertainty of netizens’behavior and attitude,which make the transmission rates of these information among social network groups be not fixed.In this paper,we propose a stochastic rumor propagation model with general incidence function.The model can be described by a stochastic differential equation.Applying the Khasminskii method via a suitable construction of Lyapunov function,we first prove the existence of a unique solution for the stochastic model with probability one.Then we show the existence of a unique ergodic stationary distribution of the rumor model,which exhibits the ergodicity.We also provide some numerical simulations to support our theoretical results.The numerical results give us some possible methods to control rumor propagation.Firstly,increasing noise intensity can effectively reduce rumor propagation when R_(0)>1That is,after rumors spread widely on social network platforms,government intervention and authoritative media coverage will interfere with netizens’opinions,thus reducing the degree of rumor propagation.Secondly,speed up the rumor refutation,intensify efforts to refute rumors,and improve the scientific quality of netizen(i.e.,increase the value ofβand decrease the value ofαandγ),which can effectively curb the rumor propagation. 展开更多
关键词 rumor propagation model general incidence function It?’s formula ergodic stationary distribution
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Research progress on the correlation between ion channel and excitability of striatum neurons in Parkinson's disease
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作者 Yuan-Yuan Ma Zhi-Bin Chen +1 位作者 Tan Wang Chang Zhou 《Journal of Hainan Medical University》 2021年第21期65-68,共4页
Parkinson's disease(PD)is a neurodegenerative disorder due to gradual loss of dopaminergic neurons in the substantia nigra in the midbrain,however the pathogenesis is unclear.There is a correlation between the exc... Parkinson's disease(PD)is a neurodegenerative disorder due to gradual loss of dopaminergic neurons in the substantia nigra in the midbrain,however the pathogenesis is unclear.There is a correlation between the excitability of striatal neurons and PD.Ion channels are important to maintain membrane potential and regulate excitability of neurons,while ionic mechanisms for modulation of neurons excitability are not fully understood.This article reviews the relationship between ion channels and excitability of striatal neurons in PD and ion channel changes in the pathogenesis of PD.In order to find new targets to treatment PD by intervening ion channels. 展开更多
关键词 Parkinson’s disease sodium leak channel non-selective protein Voltage-dependent K%PLUs%channel Voltage-gated calcium channel Neuronal excitability
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Investigation of nanofluid flow in a vertical channel considering polynomial boundary conditions by Akbari-Ganji’s method
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作者 M.Fallah Najafabadi H.TalebiRostami +1 位作者 Kh.Hosseinzadeh D.D.Ganji 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2022年第4期257-266,共10页
In this research,a vertical channel containing a laminar and fully developed nanofluid flow is investigated.The channel surface’s boundary conditions for temperature and volume fraction functions are considered qth-o... In this research,a vertical channel containing a laminar and fully developed nanofluid flow is investigated.The channel surface’s boundary conditions for temperature and volume fraction functions are considered qth-order polynomials.The equations related to this problem have been extracted and then solved by the AGM and validated through the Runge-Kutta numerical method and another similar study.In the study,the effect of parameters,including Grashof number,Brownian motion parameter,etc.,on the motion,velocity,temperature,and volume fraction of nanofluids have been analyzed.The results demonstrate that increasing the Gr number by 100%will increase the velocity profile function by 78%and decrease the temperature and fraction profiles by 20.87%and 120.75%.Moreover,rising the Brownian motion parameter in five different sizes(0.1,0.2,0.3,0.4,and 0.5)causes lesser velocity,about 24.3%at first and 4.35%at the last level,and a maximum 52.86%increase for temperature and a 24.32%rise for ψ occurs when N b rises from 0.1 to 0.2.For all N_(t) values,at least 55.44%,18.69%,for F(η),andΩ(η),and 20.23%rise for ψ(η)function is observed.Furthermore,enlarging the N r parameter from 0.25 to 0.1 leads F(η)to rise by 199.7%,fluid dimensionless temperature,and dimensional volume fraction to decrease by 18%and 92.3%.In the end,a greater value of q means a more powerful energy source,amplifying all velocity,temperature,and volume fraction functions.The main novelty of this research is the combined convection qth-order polynomials boundary condition applied to the channel walls.Moreover,The AMG semi-analytical method is used as a novel method to solve the governing equations. 展开更多
关键词 Akbari-Ganji’s method NANOFLUID Vertical channel Combined convection Polynomial boundary condition
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Melastatin-related transient receptor potential 2 channel in Aβ_(42)-induced neuroinflammation: implications to Alzheimer's disease mechanism and development of therapeutics
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作者 Linyu Wei Sharifah Alawieyah Syed Mortadza Lin-Hua Jiang 《Neural Regeneration Research》 SCIE CAS CSCD 2018年第3期419-420,共2页
Alzheimer’s disease (AD) is an age-related eurodegenerative disease that represents the most common cause of dementia among the elderly people. With the increasingly aging population, AD has presented an overwhelmi... Alzheimer’s disease (AD) is an age-related eurodegenerative disease that represents the most common cause of dementia among the elderly people. With the increasingly aging population, AD has presented an overwhelming healthcare challenge to modern society; the World Alzheimer Report 2015 has estimated that 46.8 million people worldwide lived with dementia in 2015 and this number will rise to 74.7 million in 2030 and that the total cost of dementia was 818 billion in US$ in 2015 and will reach two trillion in 2030. Post-mortem studies have identified two histopathological hallmarks in the brains of AD patients; extracellular senile plaque with elevated deposition of amyloid β (Aβ) peptides, and intracellular neurofibrillary tangle composed of hyper-phosphorylated microtubule-associated protein tau.Etiologically, progressive neuronal loss within the cerebral cortex and hippocampus regions of the brain leads to irreversible decline in, and eventually complete loss of, memory and other cognitive functions that afflict AD patients. The widely-accepted amyloid cascade hypothesis for AD pathogenesis holds that accumulation and aggregation of neurotoxic Aβ peptides, due to imbalance of their generation and clearance as a result of changes in genetic makeup, aging and/or exposure to environmental risk factors, is a major and early trigger of AD. This hypothesis has continuously gained support by preclinical and clinical studies (Selkoe and Hardy, 2016). However, the intensive and costly drug discovery efforts over the past decades based on such a hypothesis have proved extremely frustrating in developing effective therapeutics to treat or slow down the progress of AD, highlighting the need for more research to improve our understanding towards the cellular and molecular mechanisms by which Aβ peptides bring about neurotoxicity and cognitive dysfunction. 展开更多
关键词 induced neuroinflammation Melastatin-related transient receptor potential 2 channel in A implications to Alzheimer’s disease mechanism and development of therapeutics
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The Channel Characteristics Analysis of Two River Types in Lee's Ferry Area
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作者 Feng Moyang David Elliot Wang Lu 《Meteorological and Environmental Research》 CAS 2016年第2期52-54,57,共4页
Discovery showed that some of the rivers in Lee's Ferry area run on bedrocks while some are on the alluvium,based on geomorphology,the different kinds of channel characteristics can influence whether these rivers run... Discovery showed that some of the rivers in Lee's Ferry area run on bedrocks while some are on the alluvium,based on geomorphology,the different kinds of channel characteristics can influence whether these rivers run on bed rock or alluvium. By analyzing the velocity,discharge,width and depth,hydraulic radius and comparing the different channel characteristics of rivers in other areas with Lee's Ferry,it is observed that the channel discharge,velocity and the hydraulic radius play an important role in controlling the transport-limited river and these factors can be inferred to be correct even for all the river channels in Arizona. 展开更多
关键词 channel characteristic Lee's Ferry Controlling factor
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Hall Effects on Unsteady MHD Three Dimensional Flow through a Porous Medium in a Rotating Parallel Plate Channel with Effect of Inclined Magnetic Field
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作者 P. Sulochana 《American Journal of Computational Mathematics》 2014年第5期396-405,共10页
In this paper, we make an initial value investigation of the unsteady flow of incompressible viscous fluid between two rigid non-conducting rotating parallel plates bounded by a porous medium under the influence of a ... In this paper, we make an initial value investigation of the unsteady flow of incompressible viscous fluid between two rigid non-conducting rotating parallel plates bounded by a porous medium under the influence of a uniform magnetic field of strength H0 inclined at an angle of inclination α with normal to the boundaries taking hall current into account. The perturbations are created by a constant pressure gradient along the plates in addition to the non-torsional oscillations of the upper plate while the lower plate is at rest. The flow in the porous medium is governed by the Brinkman’s equations. The exact solution of the velocity in the porous medium consists of steady state and transient state. The time required for the transient state to decay is evaluated in detail and the ultimate quasi-steady state solution has been derived analytically. Its behaviour is computationally discussed with reference to the various governing parameters. The shear stresses on the boundaries are also obtained analytically and their behaviour is computationally discussed. 展开更多
关键词 HALL Effects UNsTEADY ROTATING FLOWs Three-Dimensional FLOWs Parallel Plate channels INCOMPREssIBLE VIsCOUs Fluids Brinkman’s Model
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Expansion of Financial Channel for the Construction of China's Highways
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作者 Yao Kai, General Office of the Ministry of Communications 《China's Foreign Trade》 1997年第2期6-7,共2页
China’s highways started at a low level in facilities. In 1949, the total mileage of the whole coun-try’s highways was only 80,000 km, with a density of 0.001 km/sq km. Following the founding of New China, especiall... China’s highways started at a low level in facilities. In 1949, the total mileage of the whole coun-try’s highways was only 80,000 km, with a density of 0.001 km/sq km. Following the founding of New China, especially since the 1980s, great changes have taken place in the facilities of China’s highways. By the end of 1995, the 展开更多
关键词 Expansion of Financial channel for the Construction of China’s Highways
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Numerical Simulation of Asymmetric Merging Flow in a Rectangular Channel
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作者 Abuzar Abid Siddiqui 《World Journal of Mechanics》 2016年第4期118-130,共13页
The steady, asymmetric and two-dimensional flow of viscous, incompressible and Newtonian fluid through a rectangular channel with splitter plate parallel to walls is investigated numerically. Earlier, the position of ... The steady, asymmetric and two-dimensional flow of viscous, incompressible and Newtonian fluid through a rectangular channel with splitter plate parallel to walls is investigated numerically. Earlier, the position of the splitter plate was taken as a centreline of channel but here it is considered its different positions which cause the asymmetric behaviour of the flow field. The geometric parameter that controls the position of splitter is defined as splitter position parameter a. The plane Poiseuille flow is considered far from upstream and downstream of the splitter. This flow-problem is solved numerically by a numerical scheme comprising a fourth order method, followed by a special finite-method. This numerical scheme transforms the governing equations to system of finite-difference equations, which are solved by point S.O.R. iterative method. In addition, the results obtained are further refined and upgraded by Richardson Extrapolation method. The calculations are carried out for the ranges -1 α R < 10<sup>5</sup>. The results are compared with existing literature regarding the symmetric case (when a = 0) for velocity, vorticity and skin friction distributions. The comparison is very favourable. Moreover, the notable thing is that the decay of vorticity to its downstream value takes place over an increasingly longer scale of x as R increases for symmetric case but it is not so for asymmetric one. 展开更多
关键词 Parallel Walls Rectangular channel with Parallel splitter special Finite-Difference Method s. O. R. and Richardson Extrapolation Methods
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UWB Channel Modeling Improvement in Indoor Line-of-Sight (LOS) Environments
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作者 Vahid Tabataba Vakili Dariush Abbasi-Moghadam Mostafa Yahyaabadi 《International Journal of Communications, Network and System Sciences》 2010年第11期870-876,共7页
Channel measurement and modeling is an important issue when designing ultra wideband (UWB) communication systems. A Precise model of the channel response is inevitable for designing an ultra wideband telecommunication... Channel measurement and modeling is an important issue when designing ultra wideband (UWB) communication systems. A Precise model of the channel response is inevitable for designing an ultra wideband telecommunication system. In this article signal propagation in indoor environment and LOS condition is evaluated and the appropriate model of this scenario is presented. Parameters such as the power delay profile, mean excess delay, delay spread, “NP10dB” are analyzed and simulated. Based on analysis results, the proposed model is presented. This model is based on Two-cluster approach but its average power delay profile is described with power function and cluster time of arrival is modeled by the modified exponential distribution. Finally UWB channel parameters of proposed model, Saleh and Valenzuela (S-V) and Two-cluster models are compared. Measurement and simulation results show that considerable improvement for mean excess delay, delay spread and “NP10dB” of proposed model comparing with S-V and Two-cluster model, this means the channel is better described, which mean the channel is described more precisely. 展开更多
关键词 channel Modeling s-V Model Power DELAY PROFILE Ultra WIDEBAND
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An Assisted Diagnosis of Alzheimer’s Disease Incorporating Attention Mechanisms Med-3D Transfer Modeling
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作者 Yanmei Li Jinghong Tang +3 位作者 Weiwu Ding Jian Luo Naveed Ahmad Rajesh Kumar 《Computers, Materials & Continua》 SCIE EI 2024年第1期713-733,共21页
Alzheimer’s disease(AD)is a complex,progressive neurodegenerative disorder.The subtle and insidious onset of its pathogenesis makes early detection of a formidable challenge in both contemporary neuroscience and clin... Alzheimer’s disease(AD)is a complex,progressive neurodegenerative disorder.The subtle and insidious onset of its pathogenesis makes early detection of a formidable challenge in both contemporary neuroscience and clinical practice.In this study,we introduce an advanced diagnostic methodology rooted in theMed-3D transfermodel and enhanced with an attention mechanism.We aim to improve the precision of AD diagnosis and facilitate its early identification.Initially,we employ a spatial normalization technique to address challenges like clarity degradation and unsaturation,which are commonly observed in imaging datasets.Subsequently,an attention mechanism is incorporated to selectively focus on the salient features within the imaging data.Building upon this foundation,we present the novelMed-3D transfermodel,designed to further elucidate and amplify the intricate features associated withADpathogenesis.Our proposedmodel has demonstrated promising results,achieving a classification accuracy of 92%.To emphasize the robustness and practicality of our approach,we introduce an adaptive‘hot-updating’auxiliary diagnostic system.This system not only enables continuous model training and optimization but also provides a dynamic platform to meet the real-time diagnostic and therapeutic demands of AD. 展开更多
关键词 Alzheimer’s disease channel attention Med-3D hot update
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Experimental Base of an Innovation S-Channel to Reduce MHD Pressure Drop
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作者 Zengyu Xu Chuanjie Pan +2 位作者 Xiujie Zhang Xuru Duan Yong Liu 《World Journal of Nuclear Science and Technology》 2012年第1期29-35,共7页
Consequent on MHD geometry sensibility phenomena was measured in an accident case;the more detail experiments have been conducted at the liquid metal experimental loop upgrade facility (LMEL-U). The experimental resul... Consequent on MHD geometry sensibility phenomena was measured in an accident case;the more detail experiments have been conducted at the liquid metal experimental loop upgrade facility (LMEL-U). The experimental results indicate that MHD pressure drop can be greatly reduced in the special designed ducts. Base on the experimental data, an innovation channel concept (tentatively called as the secondary flow channel, short in “S-channel”) is addressed as a reducing MHD pressure drop channel for the application of a liquid metal blanket system in fusion reactor. It may be a dawn for solving MHD pressure drop key issue of liquid metal blanket system. 展开更多
关键词 Liquid Metal BLANKET MHD Effect Pressure DROP s-channel
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一种非常紧凑的掩码AES的硬件设计与实现
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作者 隋谦 周佳运 +4 位作者 祝一豪 苏杨 许森 王伟嘉 《密码学报(中英文)》 CSCD 北大核心 2024年第3期662-680,共19页
差分能量分析作为一种强大的侧信道攻击手段,已经严重威胁到密码算法硬件实现的安全性,目前防护此类攻击最有效的方法就是对密码算法进行掩码处理.在AES算法中只有S盒是非线性的,因此如何安全高效地实现S盒一直是密码学领域的研究热点之... 差分能量分析作为一种强大的侧信道攻击手段,已经严重威胁到密码算法硬件实现的安全性,目前防护此类攻击最有效的方法就是对密码算法进行掩码处理.在AES算法中只有S盒是非线性的,因此如何安全高效地实现S盒一直是密码学领域的研究热点之一.本文在De Meyer等人研究工作的基础上,提出了一种具有已知最小面积的掩码S盒的串行化实现方案.先将用于零值处理的Kronecker Delta函数串行化,接着通过共享一个8位乘法器模块用于求逆以及布尔掩码和乘法掩码之间的转换,最后加上仿射变换以最小的面积代价实现了S盒.本文将S盒应用于AES算法,并且提供了掩码AES的串行化实现方案,同时给出了该方案的面积下限,在此基础上,对S盒及AES算法的部分结构进行调整,为未来的工作提供了一系列权衡面积和延迟的手段.实验表明,在可比的随机数成本下,本文S盒的一阶掩码和二阶掩码实现以一定延迟为代价将面积分别降低了48%和70%, AES算法的一阶掩码和二阶掩码实现分别降低10%和21%,并且随着安全阶数的增大,本文实现方案对面积的优化幅度会进一步提高.最后,在实验中通过对从SAKURA-G板上获取的轨迹执行固定与随机的Welch T测试来验证实现的安全性,对于AES算法的一阶掩码和二阶掩码实现分别采集了多达50万条曲线,没有发现泄漏点. 展开更多
关键词 s 掩码 AEs 侧信道攻击 电路面积
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构建双通道路径增强iCOF/Bi_(2)O_(3)S型异质结在纯水体系中光催化合成H_(2)O_(2)性能
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作者 夏阳 张康延 +2 位作者 杨恒 史利娟 易群 《物理化学学报》 SCIE CAS CSCD 北大核心 2024年第11期53-54,共2页
太阳能光催化技术是一种绿色、经济、可持续的制备H_(2)O_(2)方法,被认为是取代传统蒽醌法最有前景的策略。然而,由于有限的光捕获能力、快速的光生载流子复合以及氧化还原能力不足等问题,单一组分光催化剂表现出温和的光催化活性。并且... 太阳能光催化技术是一种绿色、经济、可持续的制备H_(2)O_(2)方法,被认为是取代传统蒽醌法最有前景的策略。然而,由于有限的光捕获能力、快速的光生载流子复合以及氧化还原能力不足等问题,单一组分光催化剂表现出温和的光催化活性。并且,在光催化合成H_(2)O_(2)反应系统中需要额外添加牺牲剂。在这项研究中,我们通过光沉积法将Bi_(2)O_(3)(BO)纳米颗粒负载于离子型有机共价框架材料(iCOF)纳米纤维上,构建一种S型异质结用于双通道路径光催化合成H_(2)O_(2)。在纯水体系中,在iCOF表面负载10 wt%BO时,复合催化剂iCOF/BO10表现出最高的H_(2)O_(2)产率,达到了9.76 mmol·g^(-1)·h^(-1)(在420 nm处的量子效率为5.5%)。这一性能分别是纯iCOF的2.2倍,纯BO的5.6倍。原位表征技术(包括原位X射线光电子能谱、DFT理论计算、活性物种捕获实验以及原位漫反射红外傅里叶变换光谱)揭示该S型异质结不仅能促进光生载流子的分离和增强光吸收能力,而且能实现氧化还原能力最大化,使得反应体系同时通过间接2e^(-)氧气还原反应和4e^(-)水氧化反应双通道路径产生H_(2)O_(2)。此外,4e^(-)水氧化反应生成的O_(2)能够通过间接2e^(-)氧气还原反应加快H_(2)O_(2)生成的反应动力学,实现光催化H_(2)O_(2)的全合成。该项工作为开发新颖催化剂实现高效光催化合成H2O_(2)提供了独特的见解。 展开更多
关键词 光催化 s型异质结 H_(2)O_(2)合成 无牺牲剂 双通道路径
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基于高阶多道同步挤压广义S变换的多属性融合储层预测技术研究及应用
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作者 赵慧言 高欢 +2 位作者 严海滔 文冉 宋修艳 《海相油气地质》 CSCD 北大核心 2024年第2期207-214,共8页
时频域地震精细解释建立在高分辨率时频分析算法的基础上。为适应高精度勘探开发的要求,在多道同步挤压广义S变换(MSGST)的基础上,提出了高阶多道同步挤压广义S变换(HMSGST),进一步聚焦时频分辨率,提高储层预测的精准性。通过理论信号... 时频域地震精细解释建立在高分辨率时频分析算法的基础上。为适应高精度勘探开发的要求,在多道同步挤压广义S变换(MSGST)的基础上,提出了高阶多道同步挤压广义S变换(HMSGST),进一步聚焦时频分辨率,提高储层预测的精准性。通过理论信号、理论加噪信号对比6种时频算法的计算结果,验证了HMSGST具有高时频分辨率,对复杂信号具有更好的刻画能力。以某三维工区海相砂岩为例,基于HMSGST在时频域沿主要油气储层(T2层)提取时间切片,开展频率衰减梯度、分频相干等属性分析以增强对短轴河道、次级断裂等目标的识别能力和烃类检测能力,进一步结合曲率属性开展RGB多属性融合精细雕刻。对于不同工区、不同地质条件的地震数据,需要进行HMSGST的参数分析,适合的参数是达到更为准确的计算结果的前提。 展开更多
关键词 时频分析 高阶多道同步挤压广义s变换 时频分辨率 多属性融合 储层预测
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