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An Analysis of the Hoarse Speech Signals by the Three Mass Model of Vocal Cords *
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作者 程启明 陈雪丽 万德钧 《Journal of Southeast University(English Edition)》 EI CAS 1998年第1期81-85,共5页
A three mass model of vocal cords as well as mathematical expression of the model are discussed. Different kinds of typical hoarse speech due to laryngeal diseases are simulated on microcomputer and the effects of di... A three mass model of vocal cords as well as mathematical expression of the model are discussed. Different kinds of typical hoarse speech due to laryngeal diseases are simulated on microcomputer and the effects of different pathological factors of vocal cords on model parameters are studied. Some typical spectrum distribution of the simulated speech signals are given. Moreover, hoarse speech signals of some typical cases are analyzed by the methods of digital signal processing, including FFT, LPC, Cepstrum technique, Pseudocolor encoding, etc. The experiment results show that the three mass model analysis of vocal cords is an efficient method for analysis of hoarse speech signals. 展开更多
关键词 hoarse speech signal three mass model of vocal cords laryngeal diseases
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Effects of confinement on rock mass modulus:A synthetic rock mass modelling(SRM) study 被引量:10
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作者 I.Vazaios K.Farahmand +1 位作者 N.Vlachopoulos M.S.Diederichs 《Journal of Rock Mechanics and Geotechnical Engineering》 CSCD 2018年第3期436-456,共21页
The main objective of this paper is to examine the influence of the applied confining stress on the rock mass modulus of moderately jointed rocks(well interlocked undisturbed rock mass with blocks formed by three or ... The main objective of this paper is to examine the influence of the applied confining stress on the rock mass modulus of moderately jointed rocks(well interlocked undisturbed rock mass with blocks formed by three or less intersecting joints). A synthetic rock mass modelling(SRM) approach is employed to determine the mechanical properties of the rock mass. In this approach, the intact body of rock is represented by the discrete element method(DEM)-Voronoi grains with the ability of simulating the initiation and propagation of microcracks within the intact part of the model. The geometry of the preexisting joints is generated by employing discrete fracture network(DFN) modelling based on field joint data collected from the Brockville Tunnel using LiDAR scanning. The geometrical characteristics of the simulated joints at a representative sample size are first validated against the field data, and then used to measure the rock quality designation(RQD), joint spacing, areal fracture intensity(P21), and block volumes. These geometrical quantities are used to quantitatively determine a representative range of the geological strength index(GSI). The results show that estimating the GSI using the RQD tends to make a closer estimate of the degree of blockiness that leads to GSI values corresponding to those obtained from direct visual observations of the rock mass conditions in the field. The use of joint spacing and block volume in order to quantify the GSI value range for the studied rock mass suggests a lower range compared to that evaluated in situ. Based on numerical modelling results and laboratory data of rock testing reported in the literature, a semi-empirical equation is proposed that relates the rock mass modulus to confinement as a function of the areal fracture intensity and joint stiffness. 展开更多
关键词 Synthetic rock mass modelling (SRM) Discrete fracture network (DFN) Rock mass modulus Geological strength index (GSI) CONFINEMENT
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Analytically determining frequency and amplitude of spontaneous alpha oscillation in Jansen's neural mass model using the describing function method 被引量:1
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作者 Yao Xu Chun-Hui Zhang +1 位作者 Ernst Niebur Jun-Song Wang 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第4期551-558,共8页
Spontaneous alpha oscillations are a ubiquitous phenomenon in the brain and play a key role in neural information processing and various cognitive functions.Jansen's neural mass model(NMM) was initially proposed to... Spontaneous alpha oscillations are a ubiquitous phenomenon in the brain and play a key role in neural information processing and various cognitive functions.Jansen's neural mass model(NMM) was initially proposed to study the origin of alpha oscillations.Most of previous studies of the spontaneous alpha oscillations in the NMM were conducted using numerical methods.In this study,we aim to propose an analytical approach using the describing function method to elucidate the spontaneous alpha oscillation mechanism in the NMM.First,the sigmoid nonlinear function in the NMM is approximated by its describing function,allowing us to reformulate the NMM and derive its standard form composed of one nonlinear part and one linear part.Second,by conducting a theoretical analysis,we can assess whether or not the spontaneous alpha oscillation would occur in the NMM and,furthermore,accurately determine its amplitude and frequency.The results reveal analytically that the interaction between linearity and nonlinearity of the NMM plays a key role in generating the spontaneous alpha oscillations.Furthermore,strong nonlinearity and large linear strength are required to generate the spontaneous alpha oscillations. 展开更多
关键词 neural mass model spontaneous alpha oscillation describing function
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A novel observer design method for neural mass models
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作者 刘仙 苗东凯 +1 位作者 高庆 徐式蕴 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第9期68-72,共5页
Neural mass models can simulate the generation of electroencephalography(EEG) signals with different rhythms,and therefore the observation of the states of these models plays a significant role in brain research. Th... Neural mass models can simulate the generation of electroencephalography(EEG) signals with different rhythms,and therefore the observation of the states of these models plays a significant role in brain research. The structure of neural mass models is special in that they can be expressed as Lurie systems. The developed techniques in Lurie system theory are applicable to these models. We here provide a new observer design method for neural mass models by transforming these models and the corresponding error systems into nonlinear systems with Lurie form. The purpose is to establish appropriate conditions which ensure the convergence of the estimation error. The effectiveness of the proposed method is illustrated by numerical simulations. 展开更多
关键词 observer design neural mass model Lurie system theory
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Electron Shape Calculated for the Dual-Charge Dual-Mass Model
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作者 Arlen Young 《Journal of Modern Physics》 CAS 2023年第3期198-207,共10页
A model for the internal structure of the electron using classical physics equations has been previously published by the author. The model employs both positive and negative charges and positive and negative masses. ... A model for the internal structure of the electron using classical physics equations has been previously published by the author. The model employs both positive and negative charges and positive and negative masses. The internal attributes of the electron structure were calculated for both ring and spherical shapes. Further examination of the model reveals an instability for the ring shape. The spherical shape appears to be stable, but relies on tensile or compressive forces of the electron material for stability. The model is modified in this document to eliminate the dependency on material forces. Uniform stability is provided solely by balancing electrical and centrifugal forces. This stability is achieved by slightly elongating the sphere along the spin axis to create a prolate ellipsoid. The semi-major axis of the ellipsoid is the spin axis of the electron, and is calculated to be 1.20% longer than the semi-minor axis, which is the radius of the equator. Although the shape deviates slightly from a perfect sphere, the electric dipole moment is zero. In the author’s previously published document, the attributes of the internal components of the electron, such as charge and mass, were calculated and expressed as ratios to the classically measured values for the composite electron. It is interesting to note that all of these ratios are nearly the same as the inverse of the Fine Structure Constant, with differences of less than 15%. The electron model assumed that the outer surface charge was fixed and uniform. By allowing the charge to be mobile and the shape to have a particular ellipticity, it is shown that the calculated charge and mass ratios for the model can be exactly equal to the Fine Structure Constant and the Constant plus one. The electron radius predicted by the model is 15% greater than the Classical Electron Radius. 展开更多
关键词 Electron Shape Classical Electron model Dual-Charge Dual-mass model Electron Radius Negative mass Electron mass Inconsistency Electron Charge Inconsistency Fine Structure Constant
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Multiscale Hierarchical Digital Rock Mass Models and Numerical Testing on Mechanical and Hydaulic Properties of Rock Mass 被引量:1
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作者 Xiaoli Liu~1,Sijing Wang~2,Enzhi Wang~1 1.State Key Laboratory of Hydroscience and Engineering,Tsinghua University,Beijing 100084,China. 2.Institute of Geology and Geophysics of the Chinese Academy of Sciences,Beijing 100029,China 《地学前缘》 EI CAS CSCD 北大核心 2009年第S1期188-188,共1页
Underground space utilization and exploration is an irreversible trend for promoting sustainable development especially in megacities.Geotechnical engineering safety is always one of the most important issues in all p... Underground space utilization and exploration is an irreversible trend for promoting sustainable development especially in megacities.Geotechnical engineering safety is always one of the most important issues in all phases,including planning,design, construction and operation,of the underground project.Engineering geological and hydro-geological characteristics of the foundation rock mass 展开更多
关键词 multiscale HIERARCHICAL DIGITAL ROCK mass modelS numerical test underground space evaluation of ROCK mass quality
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A Global Weizsacker mass model with relativistic mean field shell correction 被引量:2
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作者 W.Zhang Z.Y.Li +1 位作者 W.Gao T.T.Sun 《Chinese Physics C》 SCIE CAS CSCD 2022年第10期163-169,共7页
A relativistic Weizsacker mass model is proposed based on the single-particle levels and ground state deformations obtained in axial deformed relativistic mean field theory.The density functional of relativistic mean ... A relativistic Weizsacker mass model is proposed based on the single-particle levels and ground state deformations obtained in axial deformed relativistic mean field theory.The density functional of relativistic mean field theory is chosen as DD-LZ1,which can partially remove spurious shell closures.Compared with the fourth Weizsacker-Skyrme mass model,the proposed model provides shell correction energies that exhibit wide spreading,and the root-mean-square mass deviation is 1.353 MeV.Further improvement is in progress. 展开更多
关键词 mass model relativistic mean field macroscopic-microscopic model
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Statistical errors in Weizscker-Skyrme mass model
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作者 刘敏 高宇 王宁 《Chinese Physics C》 SCIE CAS CSCD 2017年第11期71-76,共6页
The statistical uncertainties of 13 model parameters in the Weizscker-Skyrme(WS*) mass model are investigated for the first time with an efficient approach,and the propagated errors in the predicted masses are esti... The statistical uncertainties of 13 model parameters in the Weizscker-Skyrme(WS*) mass model are investigated for the first time with an efficient approach,and the propagated errors in the predicted masses are estimated.The discrepancies between the predicted masses and the experimental data,including the new data in AME 2016,are almost all smaller than the model errors.For neutron-rich heavy nuclei,the model errors increase considerably,and go up to a few MeV when the nucleus approaches the neutron drip line.The most sensitive model parameter which causes the largest statistical error is analyzed for all bound nuclei.We find that the two coefficients of symmetry energy term significantly influence the mass predictions of extremely neutron-rich nuclei,and the deformation energy coefficients play a key role for well-deformed nuclei around the β-stability line. 展开更多
关键词 nuclear mass model statistical error neutron-rich nuclei symmetry energy Weizsaecker-Skyrme
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Phenomenology of colored radiative neutrino mass model and its implications on cosmic-ray observations
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作者 Ran Ding Zhi-Long Han +1 位作者 Li Huang Yi Liao 《Chinese Physics C》 SCIE CAS CSCD 2018年第10期1-18,共18页
We extend the colored Zee-Babu model with a gauged U(1)B-L symmetry, and a scalar singlet dark matter (DM) candidate S. The spontaneous breaking of U(1)B-L leaves a residual Z2 symmetry that stabilizes the DM, a... We extend the colored Zee-Babu model with a gauged U(1)B-L symmetry, and a scalar singlet dark matter (DM) candidate S. The spontaneous breaking of U(1)B-L leaves a residual Z2 symmetry that stabilizes the DM, and generates a tiny neutrino mass at the two-loop level with the color seesaw mechanism. After investigating the DM and flavor phenomenology of this model systematically, we further focus on its imprint on two cosmic-ray anomalies: The Fermi-LAT gamma-ray excess at the Galactic Center (GCE), and the PeV ultra-high energy (UHE) neutrino events at the IceCube. We found that the Fermi-LAT GCE spectrum can be well-fitted by DM annihilation into a pair of on-shell singlet Higgs mediators while being compatible with the constraints from the relic density, direct detections, and dwarf spheroidal galaxies, in the Milky Way. Although the UHE neutrino events at the IceCube could be accounted for by the resonance production of a TeV-scale leptoquark, the relevant Yukawa couplings have been severely limited by the current low-energy flavor experiments. We subsequently derive the IceCube limits on the Yukawa couplings by employing its latest six-year data. 展开更多
关键词 neutrino mass models gamma-ray excess at galactic center IceCube neutrinos dark matter
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Mass Transfer Modeling in Pervaporation Based on Multi-fields Synergy Theory 被引量:6
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作者 雷震 吴莹莹 +1 位作者 路士庆 杨伯伦 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2008年第1期79-83,共5页
Toprovide a theoretical basis for optimizing the pervaporation procedure, a mass transfer model for pervaporation for binary mixtures was developed basedon the multi-fields synergy theory. This model used the mechanis... Toprovide a theoretical basis for optimizing the pervaporation procedure, a mass transfer model for pervaporation for binary mixtures was developed basedon the multi-fields synergy theory. This model used the mechanism of sorption-diffusion-desorption and introduced a diffusion coefficient, which was dependent on the feed concentration and temperature. Regarding the strong coupling effect in the mass transfer, the concentration distribution in membrane was predicted using the Flory-Huggins thermodynamic theory. The batch experiments and other experiments with constant composition-were conducted-using a modified chitosan pervaporatioffmembrane to separate tert-butyl alcohol (TBA)-water mixtures. The parameters of the mass transfer model were obtained from the flux of the experiments with a constant composition and the activity coefficients available through phase equilibrium equation, using the Willson equation in the feed side and the Flory-Huggins thermodynamic theory within the membrane The simulation results of the experiments .are in good agreement with the results, of the experiments. 展开更多
关键词 pervaporatlon MEMBRANE mass transter model multi-fields synergy theory coupling effect
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Basic characteristics of nuclear landscape by improved Weizs?cker-Skyrmetype nuclear mass model 被引量:4
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作者 Na-Na Ma Hai-Fei Zhang +1 位作者 Xiao-Jun Bao Hong-Fei Zhang 《Chinese Physics C》 SCIE CAS CSCD 2019年第4期114-129,共16页
Atomic Mass Evaluation(AME2016) has replenished the latest nuclear binding energy data. Other physical observables, such as the separated energies, decay energies, and the pairing gaps, were evaluated based on the new... Atomic Mass Evaluation(AME2016) has replenished the latest nuclear binding energy data. Other physical observables, such as the separated energies, decay energies, and the pairing gaps, were evaluated based on the new mass table. An improved Weizs?cker-Skyrme-type(WS-type) nuclear mass model with only 13 parameters was presented, including the correction from two combinatorial radial basis functions(RBFs), where shell and pairing effects are simultaneously dealt with using a Strutinsky-like method. The RBFs code had 2267 updated experimental binding energies as inputs, and their correspondent root-mean square(rms) deviations dropped to 149 keV. For the training of other mass models by RBFs correction, rms deviations are clustered between 100 keV to 200 keV. Compared with other experimental quantities, the rms deviations calculated within the improved WS-type model falls between 100 keV and 250 keV. We extrapolate the binding energies to 12435 nuclei, which covers the ranges 8 ≤ Z ≤ 128 and 8 ≤ N ≤ 251 in the framework of the WS-type model with RBFs correction. Simultaneously, the ground state deformations β_(2,4,6) and all parts in the WS-type mass formula are presented in this paper. Finally, we tabulated all calculated characteristics within the improved formula and linked them to https://github.com/lukeronger/Nuclear Data-LZU: nuclear binding energies, one-nucleon and two-nucleon separation energies(S_(n,p,2n,2p)), and β-decay energies( Q_α and Q_(β-,β+,EC)), and the pairing gap ?_n and ?_p. 展开更多
关键词 mass model radial basis functions BINDING ENERGY SEPARATED ENERGY DECAY ENERGY PAIRING gap
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Full Dynamic Model for Liquid Sloshing Simulation in Cylindrical Tank Shape
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作者 Omar Noui Mohamed Bouazara Marc J. Richard 《World Journal of Mechanics》 2024年第4期55-72,共18页
This study presents a comprehensive full dynamic model designed for simulating liquid sloshing behavior within cylindrical tank structures. The model employs a discretization approach, representing the liquid as a net... This study presents a comprehensive full dynamic model designed for simulating liquid sloshing behavior within cylindrical tank structures. The model employs a discretization approach, representing the liquid as a network of interconnected spring-damper-mass systems. Key aspects include the adaptation of liquid discretization techniques to cylindrical lateral cross-sections and the calculation of stiffness and damping coefficients. External forces, simulating various vehicle maneuvers, are also integrated into the model. The resulting system of equations is solved using Maple Software with the Runge-Kutta-Fehlberg method. This model enables accurate prediction of liquid displacement and pressure forces, offering valuable insights for tank design and fluid dynamics applications. Ongoing refinement aims to broaden its applicability across different liquid types and tank geometries. 展开更多
关键词 Fluid-Structure Interaction Equivalent Mechanical model Liquid Discretization Spring-mass model Spring-mass Network Liquid Simulation
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Forecasting conductivities of LiBOB-EC/DEC electrolytes by the mass triangle model 被引量:1
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作者 Jia-yuan Huang Bi-tao Yu Fu-shen Li Wei-hua Qiu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2009年第4期463-467,共5页
Conductivities of lithium bis(oxalato)borate (LiBOB)-ethyl carbonate (EC)/diethyl carbonaten (DEC) electrolytes at 25℃ and 50℃ were studied. The electrolyte component with the highest conductivity at each te... Conductivities of lithium bis(oxalato)borate (LiBOB)-ethyl carbonate (EC)/diethyl carbonaten (DEC) electrolytes at 25℃ and 50℃ were studied. The electrolyte component with the highest conductivity at each temperature was obtained through changing the concentration of LiBOB and the ratio of EC/DEC. The mass triangle model was applied to calculate the conductivity of Li- BOB-EC/DEC ternary system at 25℃ and 50℃. The results show that the calculated and experimental results have reached a good agreement. Therefore, it is expected that the experimental work can be vastly reduced by introducing the mass triangle model. 展开更多
关键词 lithium bis(oxalato)borate (LiBOB) ELECTROLYTE CONDUCTIVITY mass triangle model
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Distinct element modelling of fracture plan control in continuum and jointed rock mass in presplitting method of surface mining 被引量:4
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作者 Sharafisafa Mansour Aliabadian Zeinab +1 位作者 Alizadeh Rezvan Mortazavi Ali 《International Journal of Mining Science and Technology》 SCIE EI 2014年第6期871-881,共11页
Controlled blasting techniques are used to control overbreak and to aid in the stability of the remaining rock formation. Presplitting is one of the most common methods which is used in many open pit mining and surfac... Controlled blasting techniques are used to control overbreak and to aid in the stability of the remaining rock formation. Presplitting is one of the most common methods which is used in many open pit mining and surface blast design. The purpose of presplitting is to form a fracture plane across which the radial cracks from the production blast cannot travel. The purpose of this study is to investigate of effect of presplitting on the generation of a smooth wall in continuum and jointed rock mass. The 2D distinct element code was used to simulate the presplitting in a rock slope. The blast load history as a function of time was applied to the inner wall of each blasthole. Important parameters that were considered in the analysis were stress tensor and fracturing pattern. The blast loading magnitude and blasthole spacing and jointing pattern were found to be very significant in the final results. 展开更多
关键词 Controlled blasting Presplitting method Continuum and jointed rock mass Distinct element modelling
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New lumped-mass-stick model based on modal characteristics of structures: development and application to a nuclear containment building 被引量:8
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作者 Hwasung Roh Huseok Lee Jong Seh Lee 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2013年第2期307-317,共11页
In this study, a new lumped-mass-stick model (LMSM) is developed based on the modal characteristics of a structure such as eigenvalues and eigenvectors. The simplified model, named the "frequency adaptive lumped-ma... In this study, a new lumped-mass-stick model (LMSM) is developed based on the modal characteristics of a structure such as eigenvalues and eigenvectors. The simplified model, named the "frequency adaptive lumped-massstick model," hasonly a small number of stick elements and nodes to provide the same natural frequencies of the structure and is applied to a nuclear containment building. To investigate the numerical performance of the LMSM, a time history analysis is carried out on both the LMSM and the finite element model (FEM) for a nuclear containment building. A comparison of the results shows that the dynamic responses of the LMSM in terms of displacement and acceleration are almost identical to those of the FEM. In addition, the results in terms of floor response spectra at certain elevations are also in good agreement. 展开更多
关键词 new lumped-mass-stick model frequency adaptive nuclear containment buildings seismic response floor response spectrum
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Source Apportionment of Ambient PM_(10) in the Urban Area of Longyan City,China:a Comparative Study Based on Chemical Mass Balance Model and Factor Analysis Method 被引量:1
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作者 QIU Li-min LIU Miao +2 位作者 WANG Ju ZHANG Sheng-nan FANG Chun-sheng 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2012年第2期204-208,共5页
In order to identify the day and night pollution sources of PM10 in ambient air in Longyan City,the authors analyzed the elemental composition of respirable particulate matters in the day and night ambient air samples... In order to identify the day and night pollution sources of PM10 in ambient air in Longyan City,the authors analyzed the elemental composition of respirable particulate matters in the day and night ambient air samples and various pollution sources which were collected in January 2010 in Longyan with inductivity coupled plasma-mass spectrometry(ICP-MS).Then chemical mass balance(CMB) model and factor analysis(FA) method were applied to comparatively study the inorganic components in the sources and receptor samples.The results of factor analysis show that the major sources were road dust,waste incineration and mixed sources which contained automobile exhaust,soil dust/secondary dust and coal dust during the daytime in Longyan City,China.There are two major sources of pollution which are soil dust and mixture sources of automobile exhaust and secondary dust during the night in Longyan.The results of CMB show that the major sources are secondary dust,automobile exhaust and road dust during the daytime in Longyan.The major sources are secondary dust,soil dust and automobile exhaust during the night in Longyan.The results of the two methods are similar to each other and the results will guide us to plan to control the PM10 pollution sources in Longyan. 展开更多
关键词 Factor analysis(FA) method Chemical mass balance(CMB) model Source apportionment Atmospheric particle PM10
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Dynamic Behavior and Deformation Analysis of the Fish Cage System Using Mass-Spring Model 被引量:4
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作者 Chun Woo LEE Jihoon LEE Subong PARK 《China Ocean Engineering》 SCIE EI CSCD 2015年第3期311-324,共14页
Fish cage systems are influenced by various oceanic conditions, and the movements and deformation of the system by the external forces can affect the safety of the system itself, as well as the species of fish being c... Fish cage systems are influenced by various oceanic conditions, and the movements and deformation of the system by the external forces can affect the safety of the system itself, as well as the species of fish being cultivated. Structural durability of the system against environmental factors has been major concern for the marine aquaculture system. In this research, a mathematical model and a simulation method were presented for analyzing the performance of the large-scale fish cage system influenced by current and waves. The cage system consisted of netting, mooring ropes, floats, sinkers and floating collar. All the elements were modeled by use of the mass-spring model. The structures were divided into finite elements and mass points were placed at the mid-point of each element, and mass points were connected by springs without mass. Each mass point was applied to external and internal forces, and total force was calculated in every integration step. The computation method was applied to the dynamic simulation of the actual fish cage systems rigged with synthetic fiber and copper wire simultaneously influenced by current and waves. Here, we also tried to find a relevant ratio between buoyancy and sinking force of the fish cages. The simulation results provide improved understanding of the behavior of the structure and valuable information concerning optimum ratio of the buoyancy to sinking force according to current speeds. 展开更多
关键词 fish cage mathematical model aquaculture computer simulation mass-spring model
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Model test study of frost heaving pressures in tunnels excavated in fractured rock mass in cold regions 被引量:2
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作者 Bing Sun 《Research in Cold and Arid Regions》 2010年第5期405-410,共6页
Based on the similarity theory, taking the horseshoe, city-gate and round linings as examples, the value and distribution regularities of normal frost heaving pressures (hereinafter as frost heaving pressures) in tu... Based on the similarity theory, taking the horseshoe, city-gate and round linings as examples, the value and distribution regularities of normal frost heaving pressures (hereinafter as frost heaving pressures) in tunnels excavated in fractured rock mass in cold regions under different constraints and freezing depths were studied by a test model. It was found that the larger the frozen depth, the larger the frost heaving pressure, and the stronger the top constraint, the larger the frost heaving pressure. For the horseshoe lining and city-gate lining, the top constraint has a greater effect on the frost heaving pressures on the arch and the inverted arch. For the round lining, the influences of the top constraint on the frost heaving pressure in all linings are almost the same. The frost heaving pressure is maximum on the city-gate lining and minimal on the round lining. The largest frost heaving pressure all occur near the foot of the inverted arch for the three kinds of lining. Thus, the test data basically coincide with the observed in situ data. 展开更多
关键词 tunnel in cold region fractured rock mass frost heaving pressure model test
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Mass Balance Modeling for Electric Arc Furnace and Ladle Furnace System in Steelmaking Facility in Turkey 被引量:5
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作者 smail Ekmeki Ya ar Yetisken nal ■amdali 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2007年第5期1-6,55,共7页
In the electric arc furnace (EAF) steel production processes, scrap steel is principally used as a raw material instead of iron ore. In the steelmaking process with EAF, scrap is first melted in the furnace and then... In the electric arc furnace (EAF) steel production processes, scrap steel is principally used as a raw material instead of iron ore. In the steelmaking process with EAF, scrap is first melted in the furnace and then the desired chemical composition of the steel can be obtained in a special furnace such as ladle furnace (LF). This kind of furnace process is used for the secondary refining of alloy steel. LF furnace offers strong heating fluxes and enables precise temperature control, thereby allowing for the addition of desired amounts of various alloying elements. It also provides outstanding desulfurization at high-temperature treatment by reducing molten steel fluxes and removing deoxidation products. Elemental analysis with mass balance modeling is important to know the precise amount of required alloys for the LF input with respect to scrap composition. In present study, chemical reactions with mass conservation law in EAF and LF were modeled altogether as a whole system and chemical compositions of the final steel alloy output can be obtained precisely according to different scrap compositions, alloying elements ratios, and other input amounts. Besides, it was found that the mass efficiency for iron element in the system is 95.93%. These efficiencies are calculated for all input elements as 8. 45% for C, 30.31% for Si, 46.36% for Mn, 30.64% for P, 41.96% for S, and 69.79% for Cr, etc. These efficiencies provide valuable ideas about the amount of the input materials that are vanished or combusted for 100 kg of each of the input materials in the EAF and LF system. 展开更多
关键词 electric arc furnace ladle furnace system modeling mass balance STEELMAKING liquid steel
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Gas–liquid mass transfer and flow phenomena in the Peirce–Smith converter: a water model study 被引量:5
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作者 Xing Zhao Hong-liang Zhao +1 位作者 Li-feng Zhang Li-qiang Yang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2018年第1期37-44,共8页
A water model with a geometric similarity ratio of 1:5 was developed to investigate the gas-liquid mass transfer and flow charac- teristics in a Peirce-Smith converter. A gas mixture of CO2 and Ar was injected into a... A water model with a geometric similarity ratio of 1:5 was developed to investigate the gas-liquid mass transfer and flow charac- teristics in a Peirce-Smith converter. A gas mixture of CO2 and Ar was injected into a NaOH solution bath. The flow field, volumetric mass transfer coefficient per unit volume (Ak/V; where A is the contact area between phases, V is the volume, and k is the mass transfer coeffi- cient), and gas utilization ratio (t/) were then measured at different gas flow rates and blow angles. The results showed that the flow field could be divided into five regions, i.e., injection, strong loop, weak loop, splashing, and dead zone. Whereas the Ak/V of the bath increased and then decreased with increasing gas flow rate, and n steadily increased. When the converter was rotated clockwise, both Ak/F and t/increased. However, the flow condition deteriorated when the gas flow rate and blow angle were drastically increased. Therefore, these para- meters must be controlled to optimal conditions. In the proposed model, the optimal gas flow rate and blow angle were 7.5 m3.h-1 and 10°, respectively. 展开更多
关键词 Peirce-Smith converter water model mass transfer flow phenomena volumetric mass transfer coefficient
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