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Vibrational Suspension of Two Cylinders in a Rotating Liquid-Filled Cavity with a Time-Varying Rotation Rate
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作者 Olga Vlasova 《Fluid Dynamics & Materials Processing》 EI 2024年第9期2127-2137,共11页
The dynamics of rotating hydrodynamic systems containing phase inclusions are interesting due to the related widespread occurrence in nature and technology.The influence of external force fields on rotating systems ca... The dynamics of rotating hydrodynamic systems containing phase inclusions are interesting due to the related widespread occurrence in nature and technology.The influence of external force fields on rotating systems can be used to control the dynamics of inclusions of various types.Controlling inclusions is of current interest for space technologies.In low gravity,even a slight vibration effect can lead to the appearance of a force acting on phase inclusions near a solid boundary.When vibrations are applied to multiphase hydrodynamic systems,the oscillating body intensively interacts with the fluid and introduces changes in the related flow structure.Asymmetries in the fluid flow lead to the appearance of an averaged force.As a result,the body is repelled from the cavity boundary and takes a position at a certain distance from it.The vibrationally-induced movement of phase inclusions in liquids can be used to improve various technological processes(for example,when degassing and cleaning liquids from solid inclusions,mixing various components,etc.).This study presents a relevant methodology to study the averaged vibrational force acting on a pair of free cylindrical bodies near the oscillating wall of a cavity.Attention is paid to the region of moderate and low dimensionless frequencies when the size of the inclusion is consistent with the thickness of the Stokes boundary layer.The dynamics of these bodies is considered in a horizontal cylindrical cavity with a fluid undergoing modulated rotation.The average lift force of a vibrational nature is measured by the method of quasi-stationary suspension of bodies whose density differs from the density of the liquid in a static centrifugal force field.The developed technique makes it possible to determine the dependence of the lift force on vibration parameters and the distance from the oscillating boundary at which solid inclusions are located.It is shown that in the region of moderate dimensionless frequencies,the average lift force acting on an inclusion near the boundary undergoing modulated rotation almost linearly depends on the dimensionless frequency. 展开更多
关键词 solid bodies rotational oscillations viscous fluid lift force
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Rotating magnetic field inhibits Aβ protein aggregation and alleviates cognitive impairment in Alzheimer’s disease mice
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作者 Ruo-Wen Guo Wen-Jing Xie +5 位作者 Biao Yu Chao Song Xin-Miao Ji Xin-Yu Wang Mei Zhang Xin Zhang 《Zoological Research》 SCIE CSCD 2024年第4期924-936,共13页
Amyloid beta(Aβ)monomers aggregate to form fibrils and amyloid plaques,which are critical mechanisms in the pathogenesis of Alzheimer’s disease(AD).Given the important role of Aβ1-42 aggregation in plaque formation... Amyloid beta(Aβ)monomers aggregate to form fibrils and amyloid plaques,which are critical mechanisms in the pathogenesis of Alzheimer’s disease(AD).Given the important role of Aβ1-42 aggregation in plaque formation,leading to brain lesions and cognitive impairment,numerous studies have aimed to reduce Aβaggregation and slow AD progression.The diphenylalanine(FF)sequence is critical for amyloid aggregation,and magnetic fields can affect peptide alignment due to the diamagnetic anisotropy of aromatic rings.In this study,we examined the effects of a moderate-intensity rotating magnetic field(RMF)on Aβaggregation and AD pathogenesis.Results indicated that the RMF directly inhibited Aβamyloid fibril formation and reduced Aβ-induced cytotoxicity in neural cells in vitro.Using the AD mouse model APP/PS1,RMF restored motor abilities to healthy control levels and significantly alleviated cognitive impairments,including exploration and spatial and non-spatial memory abilities.Tissue examinations demonstrated that RMF reduced amyloid plaque accumulation,attenuated microglial activation,and reduced oxidative stress in the APP/PS1 mouse brain.These findings suggest that RMF holds considerable potential as a non-invasive,high-penetration physical approach for AD treatment. 展开更多
关键词 lzheimer’s disease rotating magnetic field Amyloid-β Cognitive function Alzheimer’s disease animal models
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α-Synuclein pathology from the body to the brain:so many seeds so close to the central soil
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作者 Yunying Yang Zhentao Zhang 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第7期1463-1472,共10页
α-Synuclein is a protein that mainly exists in the presynaptic terminals.Abnormal folding and accumulation of α-synuclein are found in several neurodegenerative diseases,including Parkinson’s disease.Aggregated and... α-Synuclein is a protein that mainly exists in the presynaptic terminals.Abnormal folding and accumulation of α-synuclein are found in several neurodegenerative diseases,including Parkinson’s disease.Aggregated and highly phospho rylated a-synuclein constitutes the main component of Lewy bodies in the brain,the pathological hallmark of Parkinson s disease.For decades,much attention has been focused on the accumulation of α-synuclein in the brain parenchyma rather than considering Parkinson s disease as a systemic disease.Recent evidence demonstrates that,at least in some patients,the initial α-synuclein pathology originates in the peripheral organs and spreads to the brain.Injection of α-synuclein preformed fibrils into the gastrointestinal tra ct trigge rs the gutto-brain propagation of α-synuclein pathology.However,whether α-synuclein pathology can occur spontaneously in peripheral organs independent of exogenous α-synuclein preformed fibrils or pathological α-synuclein leakage from the central nervous system remains under investigation.In this review,we aimed to summarize the role of peripheral α-synuclein pathology in the pathogenesis of Parkinson’s disease.We also discuss the pathways by which α-synuclein pathology spreads from the body to the brain. 展开更多
关键词 aggregation autonomic nervous system barrier receptors body fluid circulation in situ generation Parkinson’s disease PHOsPHORYLATION propagation sYNUCLEINOPATHIEs Α-sYNUCLEIN α-synuclein fibrils
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Writing the Silenced Female Body, Scrutinizing the Grand Narrative of Colonization and Decolonization: The Body in Zoë Wicomb’s David’s Story
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作者 SHI Ju-hong LUO Wen-jie 《Journal of Literature and Art Studies》 2024年第7期576-583,共8页
David’s Story by Zoë Wicomb addresses the complexities of representing female suffering and the limitations of traditional historical narratives in capturing the experiences of marginalized bodies.It challenges ... David’s Story by Zoë Wicomb addresses the complexities of representing female suffering and the limitations of traditional historical narratives in capturing the experiences of marginalized bodies.It challenges the grand narratives of national history by emphasizing the indispensable role of women’s experiences.Through characters like Dulcie and Rachael,Wicomb portrays the female body as a site of resistance and resilience,highlighting the need for more nuanced and inclusive ways of documenting history.Underscoring the inexpressibility of trauma and the limitations of language and representation,the novel self-reflexively acknowledges its own aporia of completing the narrative,embodying the ongoing struggle to capture the full breadth of human experience. 展开更多
关键词 David’s story silenced female body caution against grand narrative
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Analysis of the Orbitation and Rotation of Celestial Bodies
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作者 Gabriel Barceló 《Journal of Applied Mathematics and Physics》 2023年第9期2765-2774,共10页
We have developed a structure of dynamic knowledge for non-inertial systems, the so-called Theory of Dynamic Interactions (TDI) as a part of non-inertial dynamic knowledge, which incorporates a causal demonstration of... We have developed a structure of dynamic knowledge for non-inertial systems, the so-called Theory of Dynamic Interactions (TDI) as a part of non-inertial dynamic knowledge, which incorporates a causal demonstration of phenomena accelerated by rotation, which would complement Classical Mechanics. We believe that the TDI mathematical model that we propose is of great conceptual importance. In addition, we think that it is not only necessary to understand the dynamics of rotating bodies, but also to understand the dynamics of the cosmos, with bodies that orbit and with constantly recurring movements, which make possible systems that have been in dynamic equilibrium for centuries and are not in a process of unlimited expansion. We even believe that this new dynamic theory allows us a better understanding of our universe, and the matter from which it is made. 展开更多
关键词 rotational Dynamics Dynamic Interactions Accelerated by rotation Dynamics of rotating Dynamics of the Cosmos Dynamic Equilibrium secular Dynamic Equilibrium Behavior of rotating Bodies Moments
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Generalized flyby trajectories around elongated minor celestial bodies as a rotating mass dipole 被引量:3
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作者 Xiangyuan Zeng Baodong Fang +1 位作者 Junfeng Li Yang Yu 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2016年第3期535-545,共11页
The aim of this paper is to understand the common characteristics of the generalized flyby trajectory around natural elongated bodies. Such flyby trajectories provide a short-term mechanism to clear away vicinal objec... The aim of this paper is to understand the common characteristics of the generalized flyby trajectory around natural elongated bodies. Such flyby trajectories provide a short-term mechanism to clear away vicinal objects or temporally capture ejecta into circling orbits. The gravitational potential of elongated bodies is described by a unified approximate model, i.e., the rotating mass dipole which is two point masses connected with a constant massless rod The energy power is used to illustrate the flyby effect in terms of the instantaneous orbital energy. The essential of the single flyby trajectory is studied analytically, and the relationship between the flyby trajectory and its Jacobi integral is also illustrated. Sample trajectories are given to show the variational trend of the energy increment with respect to differen orbital periapsides. The distribution of natural ejecting orbits is presented by varying the parameters of the approximate model. 展开更多
关键词 Generalized flyby trajectory Natural elongated body rotating mass dipole Natural ejecting orbits
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Multi-Barycenter Mechanics, N-Body Problem and Rotation of Galaxies and Stars
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作者 Honglai Zhu 《Journal of Applied Mathematics and Physics》 2023年第10期3251-3273,共23页
In the present paper, the establishment of a systematic multi-barycenter mechanics is based on the multi-particle mechanics. The new theory perfects the basic theoretical system of classical mechanics, which finds the... In the present paper, the establishment of a systematic multi-barycenter mechanics is based on the multi-particle mechanics. The new theory perfects the basic theoretical system of classical mechanics, which finds the law of mutual interaction between particle groups, reveals the limitations of Newton’s third law, discovers the principle of the intrinsic relationship between gravity and tidal force, reasonably interprets the origin and change laws for the rotation angular momentum of galaxies and stars and so on. By applying new theory, the multi-body problem can be transformed into a special two-body problem and for which an approximate solution method is proposed, the motion law of each particle can be roughly obtained. 展开更多
关键词 Multi-Barycenter Mechanics Translation Principle for a Vector system Variation Principle for a Vector Origin and Change Laws for the rotation Angular Momentum of Galaxies and stars Multi-body Problem
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The Development of Hi-Speed Punching System Using A Couple of Rotating Bodies
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作者 Shinichi Taya Keiichi Shimizu 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2002年第S1期116-117,共2页
Punched steel sheets (metal sheets or foils) as thi n as 0.1mm are quite useful in the field of filters and various precision instrume nts. Thus, we have to develop more accurate and speedy techniques for punching t h... Punched steel sheets (metal sheets or foils) as thi n as 0.1mm are quite useful in the field of filters and various precision instrume nts. Thus, we have to develop more accurate and speedy techniques for punching t hin sheets. The traditional punching method uses an up-down pressing motion of a punch or a die on a strip of metal. The efficiency of this method is determine d by the speed of the motion. In the case of punching a sequence of tiny holes w ith a few millimeters’ interval, the speed of feeding a strip of metal to the p unching machine cannot exceed only a couple of meters per minute. We have de veloped a new technique for punching tiny holes with a pair of rotating bodies i n order to increase the feeding speed up to 100 meters per minute. Our proposed technique is shown in Fig.1 where the female tool has a round blade and the male tool has an M-shape boss. In addition, the setting of two tools i s alternating. The interference between them cannot occur because the clearance between the front and the back edge of the male tool and the female tool in the rotating direction becomes infinite in this configuration. An appropriate cleara nce is given for the thickness of the sheet between the side edge of the male to ol and the female tool. The punching itself is done by shearing. The side edge o f the male tool does contact with the female tool, but they cannot be interferin g. Our technique has another advantage to the traditional up-down pressing mach ine where the stamped out chips are hard to be discharged. It is quite easy in o ur proposed technique. Fig.2, 3 show a sample of punched material [TPP116A,+39mm88mm,Y,PZ#]Fig.1 The configuration of the punching parts using the sequential punching system.[TPP116B,+43mm155mm,X,BP#]Fig.2 A sample of punched material using the continuous punch ing lineFig.3 A exterior picture of a piece of punched steel foil(coi l) using the continuous punching For our developed high speed punching system, it is shown for (1) the configurat ion of punching tool and the punching mechanism, (2) the influence of male shape on punched hole quality, (3) the outline of continuous punching system, (4) the relation between punching speed and accuracy of hole pitch and hole dimensi on, (5) the mechanical property of punched metal sheet and (6) capability of hig her punching. 展开更多
关键词 The Development of Hi-speed Punching system Using A Couple of rotating Bodies
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A novel binary effective medium model to describe the prepeak stressstrain relationship of combined bodies of rock-like material and rock 被引量:2
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作者 Tienan Wang Yue Zhai +2 位作者 Huan Gao Yubai Li Ruifeng Zhao 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第5期601-616,共16页
Combined bodies of rock-like material and rock are widely encountered in geotechnical engineering,such as tunnels and mines.The existing theoretical models describing the stress-strain relationship of a combined body ... Combined bodies of rock-like material and rock are widely encountered in geotechnical engineering,such as tunnels and mines.The existing theoretical models describing the stress-strain relationship of a combined body lack a binary feature.Based on effective medium theory,this paper presents the governing equation of the“elastic modulus”for combined and single bodies under triaxial compressive tests.A binary effective medium model is then established.Based on the compressive experiment of concretegranite combined bodies,the feasibility of determining the stress threshold based on crack axial strain is discussed,and the model is verified.The model is further extended to coal-rock combined bodies of more diverse types,and the variation laws of the compressive mechanical parameters are then discussed.The results show that the fitting accuracy of the model with the experimental curves of the concretegranite combined bodies and various types of coal-rock combined bodies are over 95%.The crack axial strain method can replace the crack volumetric strain method,which clarifies the physical meanings of the model parameters.The variation laws of matrix parameters and crack parameters are discussed in depth and are expected to be more widely used in geotechnical engineering. 展开更多
关键词 Combined body stress-strain relationship Hooke’s law Effective medium theory stress threshold determination
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Joint Detection of Serum Vitamin D,Body Mass Index,and Tumor Necrosis Factor Alpha for the Diagnosis of Crohn’s Disease 被引量:1
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作者 Ying ZHENG Jing-hong LI +7 位作者 Shan-ying LIAO Yi-ming FU Yan-jun ZHANG Jun-long LIN Xin-bin CHEN Wei-hong SHA Shi-xue DAI Wen-jun MA 《Current Medical Science》 SCIE CAS 2023年第3期496-504,共9页
Objective Vitamin D(VD)deficiency was reported to contribute to the progression of Crohn’s disease(CD)and affect the prognosis of CD patients.This study investigated the role of serum VD,body mass index(BMI),and tumo... Objective Vitamin D(VD)deficiency was reported to contribute to the progression of Crohn’s disease(CD)and affect the prognosis of CD patients.This study investigated the role of serum VD,body mass index(BMI),and tumor necrosis factor alpha(TNF-α)in the diagnosis of Crohn’s disease.Methods CD patients(n=76)and healthy subjects(n=76)were enrolled between May 2019 and December 2020.The serum 25-hydroxyvitamin D[25(OH)D]levels,BMI,and TNF-αlevels,together with other biochemical parameters,were assessed before treatment.The diagnostic efficacy of the single and joint detection of serum 25(OH)D,BMI,and TNF-αwas determined using receiver operating characteristic(ROC)curves.Results The levels of 25(OH)D,BMI,and nutritional indicators,including hemoglobin,total protein,albumin,and high-density lipoprotein cholesterol,were much lower,and the TNF-αlevels were much higher in the CD patients than in the healthy subjects(P<0.05 for all).The areas under the ROC curve for the single detection of 25(OH)D,BMI,and TNF-αwere 0.887,0.896,and 0.838,respectively,with the optimal cutoff values being 20.64 ng/mL,19.77 kg/m^(2),and 6.85 fmol/mL,respectively.The diagnostic efficacy of the joint detection of 25(OH)D,BMI,and TNF-αwas the highest,with an area under the ROC curve of 0.988(95%CI:0.968–1.000).Conclusion The joint detection of 25(OH)D,TNF-α,and BMI showed high sensitivity,specificity,and accuracy in CD diagnosis;thus,it would be effective for the diagnosis of CD in clinical practice. 展开更多
关键词 Crohn’s disease vitamin D body mass index tumor necrosis factor alpha
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Rotation of the Earth as a Triaxial Rigid Body 被引量:6
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作者 SHEN Wenbin CHEN Wei +1 位作者 WANG Wenjun LIANG Yiqiang 《Geo-Spatial Information Science》 2007年第2期85-90,共6页
The Earth is taken as a triaxial rigid body, which rotates freely in the Euclidian space. The starting equations are the Euler dynamic equations, with A smaller than B and B smaller than C. The Euler equations are sol... The Earth is taken as a triaxial rigid body, which rotates freely in the Euclidian space. The starting equations are the Euler dynamic equations, with A smaller than B and B smaller than C. The Euler equations are solved, and the numerical results are provided. In the calculations, the following parameters are used: (C-B)/A=0.003 273 53; (B-A)/C=0.000 021 96; (C-A)/B=0.003 295 49, and the mean angular velocity of the Earth's rotation, ω =0.000 072 921 15 rad/s. Calculations show that, besides the self-rotation of the Earth and the free Euler procession of its rotation, there exists the free nutation: the nutation angle, or the angle between the Earth's momentary rotation axis and the mean axis that periodically change with time. The free nutation is investigated. 展开更多
关键词 Earth's rotation triaxial rigid body problem variation of Eulerian angles
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Association between childhood obesity and gut microbiota:16S rRNA gene sequencing-based cohort study 被引量:1
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作者 Xu-Ming Li Qing Lv +2 位作者 Ya-Jun Chen Lu-Biao Yan Xin Xiong 《World Journal of Gastroenterology》 SCIE CAS 2024年第16期2249-2257,共9页
BACKGROUND This study aimed to identify characteristic gut genera in obese and normal-weight children(8-12 years old)using 16S rDNA sequencing.The research aimed to provide insights for mechanistic studies and prevent... BACKGROUND This study aimed to identify characteristic gut genera in obese and normal-weight children(8-12 years old)using 16S rDNA sequencing.The research aimed to provide insights for mechanistic studies and prevention strategies for childhood obesity.Thirty normal-weight and thirty age-and sex-matched obese children were included.Questionnaires and body measurements were collected,and fecal samples underwent 16S rDNA sequencing.Significant differences in body mass index(BMI)and body-fat percentage were observed between the groups.Analysis of gut microbiota diversity revealed lowerα-diversity in obese children.Differences in gut microbiota composition were found between the two groups.Prevotella and Firmicutes were more abundant in the obese group,while Bacteroides and Sanguibacteroides were more prevalent in the control group.AIM To identify the characteristic gut genera in obese and normal-weight children(8-12-year-old)using 16S rDNA sequencing,and provide a basis for subsequent mechanistic studies and prevention strategies for childhood obesity.METHODS Thirty each normal-weight,1:1 matched for age and sex,and obese children,with an obese status from 2020 to 2022,were included in the control and obese groups,respectively.Basic information was collected through questionnaires and body measurements were obtained from both obese and normal-weight children.Fecal samples were collected from both groups and subjected to 16S rDNA sequencing using an Illumina MiSeq sequencing platform for gut microbiota diversity analysis.RESULTS Significant differences in BMI and body-fat percentage were observed between the two groups.The Ace and Chao1 indices were significantly lower in the obese group than those in the control group,whereas differences were not significant in the Shannon and Simpson indices.Kruskal-Wallis tests indicated significant differences in unweighted and weighted UniFrac distances between the gut microbiota of normal-weight and obese children(P<0.01),suggesting substantial disparities in both the species and quantity of gut microbiota between the two groups.Prevotella,Firmicutes,Bacteroides,and Sanguibacteroides were more abundant in the obese and control groups,respectively.Heatmap results demonstrated significant differences in the gut microbiota composition between obese and normal-weight children.CONCLUSION Obese children exhibited lowerα-diversity in their gut microbiota than did the normal-weight children.Significant differences were observed in the composition of gut microbiota between obese and normal-weight children. 展开更多
关键词 Childhood obesity Gut microbiota 16s rDNA sequencing Diversity analysis Genus identification body mass index
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Colliding Bodies Optimization with Machine Learning Based Parkinson’s Disease Diagnosis
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作者 Ashit Kumar Dutta Nazik M.A.Zakari +1 位作者 Yasser Albagory Abdul Rahaman Wahab Sait 《Computer Systems Science & Engineering》 SCIE EI 2023年第3期2195-2207,共13页
Parkinson’s disease(PD)is one of the primary vital degenerative diseases that affect the Central Nervous System among elderly patients.It affect their quality of life drastically and millions of seniors are diagnosed... Parkinson’s disease(PD)is one of the primary vital degenerative diseases that affect the Central Nervous System among elderly patients.It affect their quality of life drastically and millions of seniors are diagnosed with PD every year worldwide.Several models have been presented earlier to detect the PD using various types of measurement data like speech,gait patterns,etc.Early identification of PD is important owing to the fact that the patient can offer important details which helps in slowing down the progress of PD.The recently-emerging Deep Learning(DL)models can leverage the past data to detect and classify PD.With this motivation,the current study develops a novel Colliding Bodies Optimization Algorithm with Optimal Kernel Extreme Learning Machine(CBO-OKELM)for diagnosis and classification of PD.The goal of the proposed CBO-OKELM technique is to identify whether PD exists or not.CBO-OKELM technique involves the design of Colliding Bodies Optimization-based Feature Selection(CBO-FS)technique for optimal subset of features.In addition,Water Strider Algorithm(WSA)with Kernel Extreme Learning Machine(KELM)model is also developed for the classification of PD.CBO algorithm is used to elect the optimal set of fea-tures whereas WSA is utilized for parameter tuning of KELM model which alto-gether helps in accomplishing the maximum PD diagnostic performance.The experimental analysis was conducted for CBO-OKELM technique against four benchmark datasets and the model portrayed better performance such as 95.68%,96.34%,92.49%,and 92.36%on Speech PD,Voice PD,Hand PD Mean-der,and Hand PD Spiral datasets respectively. 展开更多
关键词 Parkinson’s disease colliding bodies optimization algorithm feature selection metaheuristics classification kelm model
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Irregular surface seismic forward modeling by a body-fitted rotated–staggered-grid finite-difference method 被引量:4
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作者 Cheng Jing-Wang Fan Na +1 位作者 Zhang You-Yuan Lü Xiao-Chun 《Applied Geophysics》 SCIE CSCD 2018年第3期420-431,共12页
Finite-difference(FD) methods are widely used in seismic forward modeling owing to their computational efficiency but are not readily applicable to irregular topographies. Thus, several FD methods based on the transfo... Finite-difference(FD) methods are widely used in seismic forward modeling owing to their computational efficiency but are not readily applicable to irregular topographies. Thus, several FD methods based on the transformation to curvilinear coordinates using body-fitted grids have been proposed, e.g., stand staggered grid(SSG) with interpolation, nonstaggered grid, rotated staggered grid(RSG), and fully staggered. The FD based on the RSG is somewhat superior to others because it satisfies the spatial distribution of the wave equation without additional memory and computational requirements; furthermore, it is simpler to implement. We use the RSG FD method to transform the firstorder stress–velocity equation in the curvilinear coordinates system and introduce the highprecision adaptive, unilateral mimetic finite-difference(UMFD) method to process the freeboundary conditions of an irregular surface. The numerical results suggest that the precision of the solution is higher than that of the vacuum formalism. When the minimum wavelength is low, UMFD avoids the surface wave dispersion. We compare FD methods based on RSG, SEM, and nonstaggered grid and infer that all simulation results are consistent but the computational efficiency of the RSG FD method is higher than the rest. 展开更多
关键词 FINITE DIFFERENCE FORWARD modeling GRID staggered rotated body-fitted sURFACE free BOUNDARY
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基于线性密集台阵的2023年甘肃积石山M_(S)6.2地震断层低速带研究
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作者 吴柏辰 秦满忠 +3 位作者 郭晓 王亚红 孙点峰 温淑琳 《地震工程学报》 CSCD 北大核心 2024年第3期734-741,共8页
2023年12月18日,甘肃省积石山县发生M_(S)6.2逆冲型地震。该地震发生在祁连活动地块拉脊山北缘断裂带,在断裂两侧曾发生过20余次5级左右中强地震,地震活动频次高,因此研究拉脊山断裂带特征具有重要意义。根据拉脊山断裂走向和此次地震... 2023年12月18日,甘肃省积石山县发生M_(S)6.2逆冲型地震。该地震发生在祁连活动地块拉脊山北缘断裂带,在断裂两侧曾发生过20余次5级左右中强地震,地震活动频次高,因此研究拉脊山断裂带特征具有重要意义。根据拉脊山断裂走向和此次地震余震分布,在刘集乡布设一条线性密集台阵,利用不同方位的余震事件计算体波的走时延时和放大效应。结果表明,P波和S波分别存在6个采样点(约0.012 s)和15个采样点(约0.03 s)的走时延时,推断出台阵西侧存在一个约150 m宽近似垂直的断层低速带,且该结果与远震P波相似性系数矩阵结果一致。 展开更多
关键词 甘肃积石山M_(s)6.2地震 走时延时 体波放大效应 线性密集台阵 断层低速带
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Electromagnetic Field Created by Rotation of Celestial Bodies 被引量:1
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作者 Arkady Dolginov 《Journal of Modern Physics》 2016年第16期2418-2425,共8页
The observed correlation of the angular momenta L<sup>ik</sup> and magnetic moments μ<sub>lm</sub> of celestial bodies (the Sun, planets and stars) was discussed by many au... The observed correlation of the angular momenta L<sup>ik</sup> and magnetic moments μ<sub>lm</sub> of celestial bodies (the Sun, planets and stars) was discussed by many authors but without any explanation. In this paper, a possible explanation of this phenomenon is suggested. It is shown that the function  satisfies Maxwell equations and can be considered as a function which determines the electro-magnetic properties of rotating heavy bodies. The R<sub>iklm</sub> is the Riemann tensor, which determines the gravitational field of the body, r<sub>g</sub> is the gravitational radius of the body, and η is the constant which has to be determined by observations. The field Φ<sub>lm</sub> describes the observed  correlation. It explains the stability of magnetic field of white dwarfs and neutron stars despite the ohmic dissipation. The function Φ<sub>l0</sub><sub></sub> describes the electric field created by rotating heavy bodies. The presented theory does not contradict any existed experiments and observations. 展开更多
关键词 Electromagnetic Field rotating Celestial Bodies GRAVITATION
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DISTURBANCES TO A ROTATING FLUID WITH A SPHEREMOVING ALONG THE AXIS OF ROTATION
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作者 乐嘉春 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1998年第9期861-866,667,共7页
In this paper, the disturbances to a uniformly rotating ideal fluid with a sphere moving steadily along the axis of rotation are analysed by using linearization theory, the equations of disturbance pressure and distur... In this paper, the disturbances to a uniformly rotating ideal fluid with a sphere moving steadily along the axis of rotation are analysed by using linearization theory, the equations of disturbance pressure and disturbance stream function governing the stability of motion are derived based on the assumption that the flow is rotational symmetric. The equation of disturbance stream function is analysed with the method of normal modes, and the constraints on wave number and wave velocity of the nontrivial neutral disturbances are established and the exact expression of the neutral disturbances are obtained. The conclusion is drawn that there are three kinds of possible forms of neutral disturbances. 展开更多
关键词 rotating fluids motion of body small disturbances sTABILITY
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The GBR Hypothesis Revisited
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作者 Lewis Nash 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第2期800-809,共10页
The radical hypothesis concerning the physics of gravitational black-body radiation is placed on a more solid statistical mechanics foundation in this study. As the concepts and formalism in the former presentation ar... The radical hypothesis concerning the physics of gravitational black-body radiation is placed on a more solid statistical mechanics foundation in this study. As the concepts and formalism in the former presentation are only partially developed and furthermore, suffer from an unfortunate misstep regarding Hawking radiation and the hypothetical gravitational black-body temperature of a parcel or distribution of energy;this paper aims to fill in some of the theoretical gaps in the derivation of the Planck radiation formula for gravity (or non-Euclidean space-time), and there by provide a more complete and transparent quantum theory of thermal gravitational radiation. 展开更多
关键词 Gravitational Black body GRAVITONs Thermal Gravitational Radiation spiral Galaxy rotation Curves
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Remarks about External Forces Acting on Earth’s Rotation Axis
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作者 Monica Zoe Ciobanu 《World Journal of Mechanics》 2023年第2期73-77,共5页
It is well known that a variation in the direction of Earth’s rotation axis is a real astronomical phenomenon, named nutation. It is interesting if a variation of this axis can take place only in intensity, in the si... It is well known that a variation in the direction of Earth’s rotation axis is a real astronomical phenomenon, named nutation. It is interesting if a variation of this axis can take place only in intensity, in the simplest theoretical case of only two rigid body dynamics. This paper presents two positions of the Moon during its monthly orbit, where a sudden variation of Earth’s rotation axis in intensity can take place. The duration of this phenomenon is limited in time, maybe an instant or a day, and then a vortex can appear. 展开更多
关键词 NUTATION Variation in Intensity of Earth’s rotation Axis Chandler’s Wobble
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Astronomic background of global huge earthquakes at beginning of 21st century
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作者 Hu Hui Su You-Jin 《Applied Geophysics》 SCIE CSCD 2024年第3期423-432,616,共11页
Since the beginning of the 21st century,major earthquakes have frequently occurred worldwide.To explore the impact of astronomical factors on earthquakes,in this study,the statistical analysis method of correlation is... Since the beginning of the 21st century,major earthquakes have frequently occurred worldwide.To explore the impact of astronomical factors on earthquakes,in this study,the statistical analysis method of correlation is used to systematically analyze the effects of astronomical factors,such as solar activity,Earth’s rotation,lunar declination angle,celestial tidal force,and other phenomena on M≥8 global earthquakes at the beginning of the 21st century.With regard to solar activity,this study focuses on the analysis of the 11-year and century cycles of solar activity.The causal relationship of the Earth’s rotation is not obvious in this work and previous works;in contrast,the valley period of the solar activity century cycle may be an important astronomical factor leading to the frequent occurrence of global earthquakes at the beginning of the 21st century.This topic warrants further study. 展开更多
关键词 M≥8.0 earthquake astronomical factors solar activity Earth’s rotation lunar declination angle tidal force phenomena
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