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MOVES模型在城市交通碳减排评估中的应用
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作者 杨阳 张义 +2 位作者 王小平 贾志绚 贾文奇 《甘肃科学学报》 2024年第3期44-50,共7页
为准确评估城市道路交叉口信号优化的碳减排效果,在实际交通调查的基础上利用MOVES模型模拟信号优化后道路车辆污染物排放的变化,对交通管控的节能减排效应进行定量分析。结果表明:信号优化不仅能有效缓解交通拥堵,提高主干道交通流的速... 为准确评估城市道路交叉口信号优化的碳减排效果,在实际交通调查的基础上利用MOVES模型模拟信号优化后道路车辆污染物排放的变化,对交通管控的节能减排效应进行定量分析。结果表明:信号优化不仅能有效缓解交通拥堵,提高主干道交通流的速度,还能够不同程度降低不同污染物的排放总量,尤其是CO_(2)的排放量;虽然信号优化后不同污染物排放总量都在降低,但对于道路行驶的基数较小的车型,其污染物排放趋势有可能增加;不同污染物对信号优化的敏感性不同,因此减排效果不同,但相同车型的不同污染物的减排趋势相似。通过详细分析模型参数的本地化过程和排放结果,所研究的污染物排放测算方法更符合实际情况,可以为其他城市交通管控的减排效益研究提供参考,为城市的低碳绿色发展提供理论基础。 展开更多
关键词 碳减排评估 信号优化 MOVES模型 参数本地化 尾气排放
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Numerical analysis of moving train induced vibrations on tunnel,surrounding ground and structure 被引量:1
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作者 Swati Srivastav Sowmiya Chawla Swapnil Mishra 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2024年第1期179-192,共14页
This study is focused on the effect of vibration induced by moving trains in tunnels on the surrounding ground and structures.A three-dimensional finite element model is established for a one-track railway tunnel and ... This study is focused on the effect of vibration induced by moving trains in tunnels on the surrounding ground and structures.A three-dimensional finite element model is established for a one-track railway tunnel and an adjacent twelve-storey building frame by using commercial software Midas GTS-NX(2019)and Midas Gen.This study considered the moving load effect of a complete train,which varies with space as well as with time.The effect of factors such as train speed,overburden pressure on the tunnel and variation in soil properties are studied in the time domain.As a result,the variations in horizontal and vertical acceleration for two different sites,i.e.,the free ground surface(without structure)and the area containing the structure,are compared.Also,the displacement pattern of the raft foundation is plotted for different train velocities.At lower speeds,the heaving phenomenon is negligible,but as the speed increases,both the heaving and differential settlement increase in the foundation.This study demonstrates that the effect of moving train vibrations should be considered in the design of new nearby structures and proper ground improvement should be considered for existing structures. 展开更多
关键词 moving train load TUNNELS vibration effect finite element method(FEM) wave propagation
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Semi-analytical investigation of heat transfer in a porous convective radiative moving longitudinal fin exposed to magnetic field in the presence of a shape-dependent trihybrid nanofluid 被引量:1
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作者 C.G.PAVITHRA B.J.GIREESHA M.L.KEERTHI 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第1期197-216,共20页
The thermal examination of a non-integer-ordered mobile fin with a magnetism in the presence of a trihybrid nanofluid(Fe_3O_4-Au-Zn-blood) is carried out. Three types of nanoparticles, each having a different shape, a... The thermal examination of a non-integer-ordered mobile fin with a magnetism in the presence of a trihybrid nanofluid(Fe_3O_4-Au-Zn-blood) is carried out. Three types of nanoparticles, each having a different shape, are considered. These shapes include spherical(Fe_3O_4), cylindrical(Au), and platelet(Zn) configurations. The combination approach is utilized to evaluate the physical and thermal characteristics of the trihybrid and hybrid nanofluids, excluding the thermal conductivity and dynamic viscosity. These two properties are inferred by means of the interpolation method based on the volume fraction of nanoparticles. The governing equation is transformed into a dimensionless form, and the Adomian decomposition Sumudu transform method(ADSTM) is adopted to solve the conundrum of a moving fin immersed in a trihybrid nanofluid. The obtained results agree well with those numerical simulation results, indicating that this research is reliable. The influence of diverse factors on the thermal overview for varying noninteger values of γ is analyzed and presented in graphical representations. Furthermore, the fluctuations in the heat transfer concerning the pertinent parameters are studied. The results show that the heat flux in the presence of the combination of spherical, cylindrical, and platelet nanoparticles is higher than that in the presence of the combination of only spherical and cylindrical nanoparticles. The temperature at the fin tip increases by 0.705 759% when the value of the Peclet number increases by 400%, while decreases by 11.825 13% when the value of the Hartman number increases by 400%. 展开更多
关键词 convection radiation moving longitudinal fin Adomian decomposition Sumudu transform method(ADSTM) trihybrid nanofluid magnetic field
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Numerical analysis of geosynthetic-reinforced embankment performance under moving loads
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作者 Xuanming Ding Jinqiao Zhao +1 位作者 Qiang Ou Jianfei Liu 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第2期682-696,共15页
The performance of geosynthetic-reinforced embankments under traffic moving loads is always a hotspot in the geotechnical engineering field.A three-dimensional(3D)model of a geosynthetic-reinforced embankment without ... The performance of geosynthetic-reinforced embankments under traffic moving loads is always a hotspot in the geotechnical engineering field.A three-dimensional(3D)model of a geosynthetic-reinforced embankment without drainage consolidation was established using the finite element software ABAQUS.In this model,the traffic loads were simulated by two moving loads of rectangular pattern,and their amplitude,range,and moving speed were realized by a Fortran subroutine.The embankment fill was simulated by an equivalent linear viscoelastic model,which can reflect its viscoelasticity.The geogrid was simulated by the truss element,and the geocell was simulated by the membrane element.Infinite elements were utilized to weaken the boundary effect caused by the model geometry at the boundaries.Validation of the established numerical model was conducted by comparing the predicted deformations in the cross-section of the geosynthetic-reinforced embankment with those from the existing literature.On this basis,the dynamic stress and strain distribution in the pavement structure layer of the geosynthetic-reinforced embankment under a moving load was also analyzed.Finally,a parametric study was conducted to examine the influences of the different types of reinforcement,overload,and the moving load velocity on the geosynthetic-reinforced embankment. 展开更多
关键词 Geosynthetic-reinforced layer Numerical model moving load EMBANKMENT DEFORMATION Stress
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Efficient 2-D MUSIC algorithm for super-resolution moving target tracking based on an FMCW radar
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作者 Xuchong Yi Shuangxi Zhang Yuxuan Zhou 《Geodesy and Geodynamics》 EI CSCD 2024年第5期504-515,共12页
Frequency modulated continuous wave(FMCW)radar is an advantageous sensor scheme for target estimation and environmental perception.However,existing algorithms based on discrete Fourier transform(DFT),multiple signal c... Frequency modulated continuous wave(FMCW)radar is an advantageous sensor scheme for target estimation and environmental perception.However,existing algorithms based on discrete Fourier transform(DFT),multiple signal classification(MUSIC)and compressed sensing,etc.,cannot achieve both low complexity and high resolution simultaneously.This paper proposes an efficient 2-D MUSIC algorithm for super-resolution target estimation/tracking based on FMCW radar.Firstly,we enhance the efficiency of 2-D MUSIC azimuth-range spectrum estimation by incorporating 2-D DFT and multi-level resolution searching strategy.Secondly,we apply the gradient descent method to tightly integrate the spatial continuity of object motion into spectrum estimation when processing multi-epoch radar data,which improves the efficiency of continuous target tracking.These two approaches have improved the algorithm efficiency by nearly 2-4 orders of magnitude without losing accuracy and resolution.Simulation experiments are conducted to validate the effectiveness of the algorithm in both single-epoch estimation and multi-epoch tracking scenarios. 展开更多
关键词 2D-MUSIC FMCW radar moving target tracking SUPER-RESOLUTION Algorithm optimization
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Random vibration analysis of FGM plates subjected to moving load using a refined stochastic finite element method
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作者 Ngoc-Tu Do Trung Thanh Tran 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第4期42-56,共15页
The article introduces a finite element procedure using the bilinear quadrilateral element or four-node rectangular element(namely Q4 element) based on a refined first-order shear deformation theory(rFSDT) and Monte C... The article introduces a finite element procedure using the bilinear quadrilateral element or four-node rectangular element(namely Q4 element) based on a refined first-order shear deformation theory(rFSDT) and Monte Carlo simulation(MCS), so-called refined stochastic finite element method to investigate the random vibration of functionally graded material(FGM) plates subjected to the moving load.The advantage of the proposed method is to use r-FSDT to improve the accuracy of classical FSDT, satisfy the stress-free condition at the plate boundaries, and combine with MCS to analyze the vibration of the FGM plate when the parameter inputs are random quantities following a normal distribution. The obtained results show that the distribution characteristics of the vibration response of the FGM plate depend on the standard deviation of the input parameters and the velocity of the moving load.Furthermore, the numerical results in this study are expected to contribute to improving the understanding of FGM plates subjected to moving loads with uncertain input parameters. 展开更多
关键词 FGM moving load R-FSDT Q4 element Monte Carlo simulation Random vibration
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High-order Bragg forward scattering and frequency shift of low-frequency underwater acoustic field by moving rough sea surface
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作者 莫亚枭 张朝金 +2 位作者 鹿力成 孙启航 马力 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第3期459-470,共12页
Acoustic scattering modulation caused by an undulating sea surface on the space-time dimension seriously affects underwater detection and target recognition.Herein,underwater acoustic scattering modulation from a movi... Acoustic scattering modulation caused by an undulating sea surface on the space-time dimension seriously affects underwater detection and target recognition.Herein,underwater acoustic scattering modulation from a moving rough sea surface is studied based on integral equation and parabolic equation.And with the principles of grating and constructive interference,the mechanism of this acoustic scattering modulation is explained.The periodicity of the interference of moving rough sea surface will lead to the interference of the scattering field at a series of discrete angles,which will form comb-like and frequency-shift characteristics on the intensity and the frequency spectrum of the acoustic scattering field,respectively,which is a high-order Bragg scattering phenomenon.Unlike the conventional Doppler effect,the frequency shifts of the Bragg scattering phenomenon are multiples of the undulating sea surface frequency and are independent of the incident sound wave frequency.Therefore,even if a low-frequency underwater acoustic field is incident,it will produce obvious frequency shifts.Moreover,under the action of ideal sinusoidal waves,swells,fully grown wind waves,unsteady wind waves,or mixed waves,different moving rough sea surfaces create different acoustic scattering processes and possess different frequency shift characteristics.For the swell wave,which tends to be a single harmonic wave,the moving rough sea surface produces more obvious high-order scattering and frequency shifts.The same phenomena are observed on the sea surface under fully grown wind waves,however,the frequency shift slightly offsets the multiple peak frequencies of the wind wave spectrum.Comparing with the swell and fully-grown wind waves,the acoustic scattering and frequency shift are not obvious for the sea surface under unsteady wind waves. 展开更多
关键词 high-order Bragg scattering frequency shift low-frequency acoustic field moving rough sea surface
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Evaluation of Moving Grid Adjustment (MGA) Method in Field Variation Control
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作者 Jixiang Wu Johnie N. Jenkins Jack C. McCarty 《Open Journal of Statistics》 2024年第5期450-466,共17页
Spatial variation is often encountered when large scale field trials are conducted which can result in biased estimation or prediction of treatment (i.e. genotype) values. An effective removal of spatial variation is ... Spatial variation is often encountered when large scale field trials are conducted which can result in biased estimation or prediction of treatment (i.e. genotype) values. An effective removal of spatial variation is needed to ensure unbiased estimation or prediction and thus increase the accuracy of field data evaluation. A moving grid adjustment (MGA) method, which was proposed by Technow, was evaluated through Monte Carlo simulation for its statistical properties regarding field spatial variation control. Our simulation results showed that the MGA method can effectively account for field spatial variation if it does exist;however, this method will not change phenotype results if field spatial variation does not exist. The MGA method was applied to a large-scale cotton field trial data set with two representative agronomic traits: lint yield (strong field spatial pattern) and lint percentage (no field spatial pattern). The results suggested that the MGA method was able to effectively separate the spatial variation including blocking effects from random error variation for lint yield while the adjusted data remained almost identical to the original phenotypic data. With application of the MGA method, the estimated variance for residuals was significantly reduced (62.2% decrease) for lint yield while more genetic variation (29.7% increase) was detected compared to the original data analysis subject to the conventional randomized complete block design analysis. On the other hand, the results were almost identical for lint percentage with and without the application of the MGA method. Therefore, the MGA method can be a useful addition to enhance data analysis when field spatial pattern exists. 展开更多
关键词 Spatial Variation Linear Mixed Model Approach Experimental Design moving Grid Adjustment Crop Trial
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A High-Accuracy Curve Boundary Recognition Method Based on the Lattice Boltzmann Method and Immersed Moving Boundary Method
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作者 Jie-Di Weng Yong-Zheng Jiang +2 位作者 Long-Chao Chen Xu Zhang Guan-Yong Zhang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第9期2533-2557,共25页
Applying numerical simulation technology to investigate fluid-solid interaction involving complex curved bound-aries is vital in aircraft design,ocean,and construction engineering.However,current methods such as Latti... Applying numerical simulation technology to investigate fluid-solid interaction involving complex curved bound-aries is vital in aircraft design,ocean,and construction engineering.However,current methods such as Lattice Boltzmann(LBM)and the immersion boundary method based on solid ratio(IMB)have limitations in identifying custom curved boundaries.Meanwhile,IBM based on velocity correction(IBM-VC)suffers from inaccuracies and numerical instability.Therefore,this study introduces a high-accuracy curve boundary recognition method(IMB-CB),which identifies boundary nodes by moving the search box,and corrects the weighting function in LBM by calculating the solid ratio of the boundary nodes,achieving accurate recognition of custom curve boundaries.In addition,curve boundary image and dot methods are utilized to verify IMB-CB.The findings revealed that IMB-CB can accurately identify the boundary,showing an error of less than 1.8%with 500 lattices.Also,the flow in the custom curve boundary and aerodynamic characteristics of the NACA0012 airfoil are calculated and compared to IBM-VC.Results showed that IMB-CB yields lower lift and drag coefficient errors than IBM-VC,with a 1.45%drag coefficient error.In addition,the characteristic curve of IMB-CB is very stable,whereas that of IBM-VC is not.For the moving boundary problem,LBM-IMB-CB with discrete element method(DEM)is capable of accurately simulating the physical phenomena of multi-moving particle flow in complex curved pipelines.This research proposes a new curve boundary recognition method,which can significantly promote the stability and accuracy of fluid-solid interaction simulations and thus has huge applications in engineering. 展开更多
关键词 Fluid-solid interaction curve boundary recognition method Lattice Boltzmann method immersed moving boundary method
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Prediction and Output Estimation of Pattern Moving in Non-Newtonian Mechanical Systems Based on Probability Density Evolution
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作者 Cheng Han Zhengguang Xu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第4期515-536,共22页
A prediction framework based on the evolution of pattern motion probability density is proposed for the output prediction and estimation problem of non-Newtonian mechanical systems,assuming that the system satisfies t... A prediction framework based on the evolution of pattern motion probability density is proposed for the output prediction and estimation problem of non-Newtonian mechanical systems,assuming that the system satisfies the generalized Lipschitz condition.As a complex nonlinear system primarily governed by statistical laws rather than Newtonian mechanics,the output of non-Newtonian mechanics systems is difficult to describe through deterministic variables such as state variables,which poses difficulties in predicting and estimating the system’s output.In this article,the temporal variation of the system is described by constructing pattern category variables,which are non-deterministic variables.Since pattern category variables have statistical attributes but not operational attributes,operational attributes are assigned to them by posterior probability density,and a method for analyzing their motion laws using probability density evolution is proposed.Furthermore,a data-driven form of pattern motion probabilistic density evolution prediction method is designed by combining pseudo partial derivative(PPD),achieving prediction of the probability density satisfying the system’s output uncertainty.Based on this,the final prediction estimation of the system’s output value is realized by minimum variance unbiased estimation.Finally,a corresponding PPD estimation algorithm is designed using an extended state observer(ESO)to estimate the parameters to be estimated in the proposed prediction method.The effectiveness of the parameter estimation algorithm and prediction method is demonstrated through theoretical analysis,and the accuracy of the algorithm is verified by two numerical simulation examples. 展开更多
关键词 Non-newtonian mechanical systems prediction and estimation pattern moving probability density evolution pseudo partial derivative
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Qingdao Recommendations for the Protection and Return of Cultural Objects Removed from Colonial Contexts or Acquired by Other Unjustifiable or Unethical Means
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《China & The World Cultural Exchange》 2024年第7期27-30,共4页
The International Conference on the Protection and Return of Cultural Objects Removed from Colonial Contexts was held in Qingdao,China on June 20,2024.representatives from 28 countries and 2 international organization... The International Conference on the Protection and Return of Cultural Objects Removed from Colonial Contexts was held in Qingdao,China on June 20,2024.representatives from 28 countries and 2 international organizations attended the conference or shared ideas and communicated through video. 展开更多
关键词 communicate Qingdao moved
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Nonlinear dynamic modeling of planar moving Timoshenko beam considering non-rigid non-elastic axial effects
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作者 M.ABBASI GAVARI M.R.HOMAEINEZHAD 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第3期479-496,共18页
Due to the importance of vibration effects on the functional accuracy of mechanical systems,this research aims to develop a precise model of a nonlinearly vibrating single-link mobile flexible manipulator.The manipula... Due to the importance of vibration effects on the functional accuracy of mechanical systems,this research aims to develop a precise model of a nonlinearly vibrating single-link mobile flexible manipulator.The manipulator consists of an elastic arm,a rotary motor,and a rigid carrier,and undergoes general in-plane rigid body motion along with elastic transverse deformation.To accurately model the elastic behavior,Timoshenko’s beam theory is used to describe the flexible arm,which accounts for rotary inertia and shear deformation effects.By applying Newton’s second law,the nonlinear governing equations of motion for the manipulator are derived as a coupled system of ordinary differential equations(ODEs)and partial differential equations(PDEs).Then,the assumed mode method(AMM)is used to solve this nonlinear system of governing equations with appropriate shape functions.The assumed modes can be obtained after solving the characteristic equation of a Timoshenko beam with clamped boundary conditions at one end and an attached mass/inertia at the other.In addition,the effect of the transverse vibration of the inextensible arm on its axial behavior is investigated.Despite the axial rigidity,the effect makes the rigid body dynamics invalid for the axial behavior of the arm.Finally,numerical simulations are conducted to evaluate the performance of the developed model,and the results are compared with those obtained by the finite element approach.The comparison confirms the validity of the proposed dynamic model for the system.According to the mentioned features,this model can be reliable for investigating the system’s vibrational behavior and implementing vibration control algorithms. 展开更多
关键词 planar moving Timoshenko beam non-rigid non-elastic axial effect as-sumed mode method(AMM) nonlinear motion analysis
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Review on dynamic analysis of road pavements under moving vehicles and plane strain conditions
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作者 Edmond V.Muho Niki D.Beskou 《Journal of Road Engineering》 2024年第1期54-68,共15页
This paper reviews works on the dynamic analysis of flexible and rigid pavements under moving vehicles on the basis of continuum-based plane strain models and linear theories.The purpose of this review is to provide i... This paper reviews works on the dynamic analysis of flexible and rigid pavements under moving vehicles on the basis of continuum-based plane strain models and linear theories.The purpose of this review is to provide in-formation about the existing works on the subject,critically discuss them and make suggestions for further research.The reviewed papers are presented on the basis of the various models for pavement-vehicle systems and the various methods for dynamically analyzing these systems.Flexible pavements are modeled by a homogeneous or layered half-plane with isotropic or anisotropic and linear elastic,viscoelastic or poroelastic material behavior.Rigid pavements are modeled by a beam or plate on a homogeneous or layered half-plane with material properties like the ones for flexible pavements.The vehicles are modeled as concentrated or distributed over a finite area loads moving with constant or time dependent speed.The above pavement-vehicle models are dynamically analyzed by analytical,analytical/numerical or purely numerical methods working in the time or frequency domain.Representative examples are presented to illustrate the models and methods of analysis,demonstrate their merits and assess the effects of the various parameters on pavement response.The paper closes with con-clusions and suggestions for further research in the area.The significance of this research effort has to do with the presentation of the existing literature on the subject in a critical and easy to understand way with the aid of representative examples and the identification of new research areas. 展开更多
关键词 Flexible pavements Rigid pavements moving vehicles Plane strain models Dynamic analysis
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Investigation multi-target synergistic mechanism of Choerospondias axillaris in the treat of cerebral ischemia based on systems pharmacology and experimental verification
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作者 Yang Ma Min-Chun Chen +2 位作者 Zuo-Yan Zhang Kang-Kang Yan Yi Ding 《Natural Therapy Advances》 CAS 2024年第3期37-47,共11页
Background:Choerospondias axillaris(CA)is a traditional Mongolian medicine that has been proven to have a good therapeutic effect on cerebrovascular disease.Cerebral Ischemia(CI)is a severe and life-threatening cerebr... Background:Choerospondias axillaris(CA)is a traditional Mongolian medicine that has been proven to have a good therapeutic effect on cerebrovascular disease.Cerebral Ischemia(CI)is a severe and life-threatening cerebrovascular disease.However,the specific mechanism of action of CA in the treatment of CI is still unclear.Methods:In this study,the related targets and pathways of CA in the treatment of CI were first predicted by system pharmacology and then verified by relevant experiments.Results:The results showed that 12 active ingredients and 208 targets were selected.Further validation through protein-protein interaction(PPI)network analysis and active ingredients-target-pathway(A-T-P)network analysis has confirmed the pivotal roles of the main bioactive constituents,including quercetin,kaempferol,naringin,β-sitosterol,and gallic acid.These components exert their anti-ischemic effects by modulating key targets such as IL6,TNF,MAPK3,and CASP3,thereby regulating the PI3K-Akt,HIF-1,and MAPK signaling pathways,which are integral to processes like inflammation,apoptosis,and oxidative stress.More importantly,through experimental verification,this study confirmed our prediction that CAE significantly reduced neurological function scores,infarct volume,and the percentage of apoptosis neurons.Conclusion:This indicates that CA acts on CI through multi-target synergistic mechanism,and this study provides theoretical basis for the clinical application of CA. 展开更多
关键词 systems pharmacology Choerospondias axillaris cerebral ischemia multi-target synergistic mechanism middle cerebral artery occlusion
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Nanofluid Flow across aMoving Plate under Blasius-Rayleigh-Stokes(BRS)Variable Transport Fluid Characteristics
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作者 Hanumesh Vaidya Fateh Mebarek-Oudina +3 位作者 K.V.Prasad Rajashekhar Choudhari Neelufer Z.Basha Sangeeta Kalal 《Frontiers in Heat and Mass Transfer》 EI 2024年第1期65-78,共14页
This investigation aims to analyze the effects of heat transport characteristics in the unsteady flow of nanofluids over a moving plate caused by a moving slot factor.The BRS variable is utilized for the purpose of an... This investigation aims to analyze the effects of heat transport characteristics in the unsteady flow of nanofluids over a moving plate caused by a moving slot factor.The BRS variable is utilized for the purpose of analyzing these characteristics.The process of mathematical computation involves converting the governing partial differential equations into ordinary differential equations that have suitable similarity components.The Keller-Box technique is employed to solve the ordinary differential equations(ODEs)and derive the corresponding mathematical outcomes.Figures and tables present the relationship between growth characteristics and various parameters such as temperature,velocity,skin friction coefficient,concentration,Sherwood number,and Nusselt number.The results are assessed by comparing them to previous findings.The observation reveals that higher dimensionless reference temperature and variable values of the moving slot parameter have a suppressing effect on the velocity and temperature patterns of nanofluids.Higher values of the dimensionless reference temperature and moving slot parameter lead to enhancements in the Sherwood number,skin friction coefficient,and Nusselt number.The conductivity of the nanofluid is ultimately affected by these enhancements. 展开更多
关键词 Blasius-Rayleigh-Stokes stretching sheet variable viscosity boundary layer flow variable thermal conductivity moving slot
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A Method to Obtain the Moving Speed of Uncooperative Target Based on Only Two Measurements
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作者 Tao Yu 《Advances in Aerospace Science and Technology》 2024年第1期1-9,共9页
The existing research results show that a fixed single station must conduct three consecutive frequency shift measurements and obtain the target’s moving speed by constructing two frequency difference equations. This... The existing research results show that a fixed single station must conduct three consecutive frequency shift measurements and obtain the target’s moving speed by constructing two frequency difference equations. This article proposes a new method that requires only two consecutive measurements. While using the azimuth measurement to obtain the angular difference between two radial distances, it also conducts two consecutive Doppler frequency shift measurements at the same target azimuth. On the basis of this measurement, a frequency difference equation is first constructed and solved jointly with the Doppler frequency shift equation. By eliminating the velocity variable and using the measured angular difference to obtain the target’s lead angle, the target’s velocity can be solved by using the Doppler frequency shift equation again. The new method avoids the condition that the target must move equidistantly, which not only provides an achievable method for engineering applications but also lays a good foundation for further exploring the use of steady-state signals to achieve passive positioning. 展开更多
关键词 moving Speed Non-Cooperative Target Doppler Frequency Shift Frequency Difference Equation AZIMUTH Steady-State Signal Passive Location
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Research on Rotating Machinery Fault Diagnosis Based on Improved Multi-target Domain Adversarial Network
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作者 Haitao Wang Xiang Liu 《Instrumentation》 2024年第1期38-50,共13页
Aiming at the problems of low efficiency,poor anti-noise and robustness of transfer learning model in intelligent fault diagnosis of rotating machinery,a new method of intelligent fault diagnosis of rotating machinery... Aiming at the problems of low efficiency,poor anti-noise and robustness of transfer learning model in intelligent fault diagnosis of rotating machinery,a new method of intelligent fault diagnosis of rotating machinery based on single source and multi-target domain adversarial network model(WDMACN)and Gram Angle Product field(GAPF)was proposed.Firstly,the original one-dimensional vibration signal is preprocessed using GAPF to generate the image data including all time series.Secondly,the residual network is used to extract data features,and the features of the target domain without labels are pseudo-labeled,and the transferable features among the feature extractors are shared through the depth parameter,and the feature extractors of the multi-target domain are updated anatomically to generate the features that the discriminator cannot distinguish.The modelt through adversarial domain adaptation,thus achieving fault classification.Finally,a large number of validations were carried out on the bearing data set of Case Western Reserve University(CWRU)and the gear data.The results show that the proposed method can greatly improve the diagnostic efficiency of the model,and has good noise resistance and generalization. 展开更多
关键词 multi-target domain domain-adversarial neural networks transfer learning rotating machinery fault diagnosis
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基于MOVES的高速公路客运交通排放特性研究 被引量:2
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作者 李菊 何超 柏洋洋 《机电工程技术》 2023年第2期102-105,共4页
研究了高速公路客车污染物排放时空分布特性,为政府相关部门制定合理的交通管制措施提供理论支持,从而减轻客车排放对高速公路及周围环境造成的危害。以2021年云南省高速公路通行客车收费数据为基础,结合云南省客车技术特征、环境条件... 研究了高速公路客车污染物排放时空分布特性,为政府相关部门制定合理的交通管制措施提供理论支持,从而减轻客车排放对高速公路及周围环境造成的危害。以2021年云南省高速公路通行客车收费数据为基础,结合云南省客车技术特征、环境条件及燃油特性等参数对MOVES模型进行本土化修正,从而计算高速公路客车排放因子,结合车流量及行驶里程建立2021年云南省排放清单,并采取自下而上的方法和ArcGIS技术对排放清单进行时空分布分析。结果表明,各项污染物主要来源于客一。在时间分布上,在工作日期间客车污染物排放量在8时及18时左右出现双高峰结构,而非工作日期间,在14时到18时之间一直处于较高的排放水平;在空间分布上,污染物分布以昆明市为中心向四周扩散,离昆明市越远的地方,污染物排放分担率越小。 展开更多
关键词 高速公路 客车 排放清单 时空分布 MOVES模型
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Fecal microbial biomarkers combined with multi-target stool DNA test improve diagnostic accuracy for colorectal cancer 被引量:2
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作者 Jin-Qing Fan Wang-Fang Zhao +4 位作者 Qi-Wen Lu Fu-Rong Zha Le-Bin Lv Guo-Liang Ye Han-Lu Gao 《World Journal of Gastrointestinal Oncology》 SCIE 2023年第8期1424-1435,共12页
BACKGROUND Colorectal cancer(CRC)is a major global health burden.The current diagnostic tests have shortcomings of being invasive and low accuracy.AIM To explore the combination of intestinal microbiome composition an... BACKGROUND Colorectal cancer(CRC)is a major global health burden.The current diagnostic tests have shortcomings of being invasive and low accuracy.AIM To explore the combination of intestinal microbiome composition and multi-target stool DNA(MT-sDNA)test in the diagnosis of CRC.METHODS We assessed the performance of the MT-sDNA test based on a hospital clinical trial.The intestinal microbiota was tested using 16S rRNA gene sequencing.This case-control study enrolled 54 CRC patients and 51 healthy controls.We identified biomarkers of bacterial structure,analyzed the relationship between different tumor markers and the relative abundance of related flora components,and distinguished CRC patients from healthy subjects by the linear discriminant analysis effect size,redundancy analysis,and random forest analysis.RESULTS MT-sDNA was associated with Bacteroides.MT-sDNA and carcinoembryonic antigen(CEA)were positively correlated with the existence of Parabacteroides,and alpha-fetoprotein(AFP)was positively associated with Faecalibacterium and Megamonas.In the random forest model,the existence of Streptococcus,Escherichia,Chitinophaga,Parasutterella,Lachnospira,and Romboutsia can distinguish CRC from health controls.The diagnostic accuracy of MT-sDNA combined with the six genera and CEA in the diagnosis of CRC was 97.1%,with a sensitivity and specificity of 98.1%and 92.3%,respectively.CONCLUSION There is a positive correlation of MT-sDNA,CEA,and AFP with intestinal microbiome.Eight biomarkers including six genera of gut microbiota,MT-sDNA,and CEA showed a prominent sensitivity and specificity for CRC prediction,which could be used as a non-invasive method for improving the diagnostic accuracy for this malignancy. 展开更多
关键词 Gut microbiome Colorectal cancer Diagnostic model multi-target stool DNA test Tumor biomarker
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Joint target assignment and power allocation in the netted C-MIMO radar when tracking multi-targets in the presence of self-defense blanket jamming 被引量:1
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作者 Zhengjie Li Junwei Xie +1 位作者 Haowei Zhang Jiahao Xie 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第6期414-427,共14页
The netted radar system(NRS)has been proved to possess unique advantages in anti-jamming and improving target tracking performance.Effective resource management can greatly ensure the combat capability of the NRS.In t... The netted radar system(NRS)has been proved to possess unique advantages in anti-jamming and improving target tracking performance.Effective resource management can greatly ensure the combat capability of the NRS.In this paper,based on the netted collocated multiple input multiple output(CMIMO)radar,an effective joint target assignment and power allocation(JTAPA)strategy for tracking multi-targets under self-defense blanket jamming is proposed.An architecture based on the distributed fusion is used in the radar network to estimate target state parameters.By deriving the predicted conditional Cramer-Rao lower bound(PC-CRLB)based on the obtained state estimation information,the objective function is formulated.To maximize the worst case tracking accuracy,the proposed JTAPA strategy implements an online target assignment and power allocation of all active nodes,subject to some resource constraints.Since the formulated JTAPA is non-convex,we propose an efficient two-step solution strategy.In terms of the simulation results,the proposed algorithm can effectively improve tracking performance in the worst case. 展开更多
关键词 Netted radar system MIMO Target assignment Power allocation multi-targets tracking Self-defense blanket jamming
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