期刊文献+
共找到42篇文章
< 1 2 3 >
每页显示 20 50 100
Development and Experimental Evaluation of a Steady-state Model for the Step-feed Biological Nitrogen Removal Process 被引量:7
1
作者 祝贵兵 彭永臻 +3 位作者 王淑莹 左金龙 王亚宜 郭建华 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2007年第3期411-417,共7页
In this article,a steady-state mathematical model was developed and experimentally evaluated to inves- tigate the effect of influent flow distribution and volume ratios of anoxic and aerobic zones in each stage on the... In this article,a steady-state mathematical model was developed and experimentally evaluated to inves- tigate the effect of influent flow distribution and volume ratios of anoxic and aerobic zones in each stage on the to- tal nitrogen concentration of the effluent in the step-feed biological nitrogen removal process.Unlike the previous modeling methods,this model can be used to calculate the removal rates of ammonia and nitrate in each stage and thereby predict the concentrations of ammonia,nitrate,and total nitrogen in the effluent.To verify the simulation results,pilot-scale experimental studies were carried out in a four-stage step feed process.Good correlations were achieved between the measured data and the simulation results,which proved the validity of the developed model. The sensitivity of the model predictions was analyzed.After verification of the validity,the step feed process was optimally operated for five months using the model and the criteria developed for the design and operation.During the pilot-scale experimental period,the effluent total nitrogen concentrations were all below 5mg·L -1 ,with more than 90%removal efficiency. 展开更多
关键词 activated siudge biological nitrogen removal OPTIMIZATION SIMULATION steady-state model step-feedprocess
下载PDF
Numerical modelling of non-ideal detonation in ANFO explosives applying Wood-Kirkwood theory coupled with EXPLO5 thermochemical code 被引量:4
2
作者 Barbara Stimac Vinko Skrlec +1 位作者 Mario Dobrilovic Muhamed Suceska 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2021年第5期1740-1752,共13页
Ammonium nitrate and fuel oil(ANFO)based explosive is a classic example of non-ideal high explosives.Its detonation is characterized by a strong dependence of detonation parameters on explosive charge diameter,presenc... Ammonium nitrate and fuel oil(ANFO)based explosive is a classic example of non-ideal high explosives.Its detonation is characterized by a strong dependence of detonation parameters on explosive charge diameter,presence and characteristics of confinement,as well as incomplete consumption of explosive at the sonic point.In this work we propose a detonation model based on the Wood-Kirkwood(WK)theory coupled with the thermochemical code EXPLO5 and supplemented with reaction rate models.Our objective is to analyze the validity of the model for highly non-ideal ANFO explosives,with emphasis on effect of reaction rate models.It was found that both single-step and two-step pressure-based models can be calibrated to reproduce experimental detonation velocity-charge radius data of ANFO at radii significantly above the failure radius(i.e.for D/D_(id)>~0.6).Single-step pressure-based model,with the pressure exponent equal to 1.4,proved to be the most accurate,even in the vicinity of the failure radius.The impact of the rate models is most evident on temporal(and spatial)distribution of flow parameters in detonation driving zone,especially when it comes to the conversion and width of detonation driving zone. 展开更多
关键词 ANFO non-ideal detonation Reaction rate model Numerical modelling EXPLO5
下载PDF
STEADY-STATE SOLUTIONS FOR A ONE-DIMENSIONAL NONISENTROPIC HYDRODYNAMIC MODEL WITH NON-CONSTANT LATTICE TEMPERATURE 被引量:1
3
作者 黎野平 《Acta Mathematica Scientia》 SCIE CSCD 2008年第3期479-488,共10页
A one-dimensional stationary nonisentropic hydrodynamic model for semiconductor devices with non-constant lattice temperature is studied. This model consists of the equations for the electron density, the electron cur... A one-dimensional stationary nonisentropic hydrodynamic model for semiconductor devices with non-constant lattice temperature is studied. This model consists of the equations for the electron density, the electron current density and electron temperature, coupled with the Poisson equation of the electrostatic potential in a bounded interval supplemented with proper boundary conditions. The existence and uniqueness of a strong subsonic steady-state solution with positive particle density and positive temperature is established. The proof is based on the fixed-point arguments, the Stampacchia truncation methods, and the basic energy estimates. 展开更多
关键词 steady-state nonisentropic hydrodynamic model SEMICONDUCTOR SUBSONIC
下载PDF
Steady-State Modeling of Heat Transfer on the Recovery System of Condensing Boiler
4
作者 Joachim Ntonda Frederic Lontsi Francois Njock Bayock 《Journal of Power and Energy Engineering》 2021年第7期29-40,共12页
<span style="font-family:Verdana;">The increase of energy production is very important nowadays. It is necessary to improve the performance and efficiency of heat production facilities. The objective i... <span style="font-family:Verdana;">The increase of energy production is very important nowadays. It is necessary to improve the performance and efficiency of heat production facilities. The objective is to reduce pollutant emissions and regulate investment costs. One </span><span style="font-family:Verdana;">of the </span><span style="font-family:Verdana;">solution</span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> is to control fuel and electricity consumption. </span><span style="font-family:Verdana;">This article develops a new model of simulation heat diffusion on the recovery system of condensing boiler. The method is based on the first and second thermodynamic systems. The Numerical discrete Model (NDM) was applied using MATLAB to simulate different characteristics of heat transfer in the recovery system. The result shows that the recovery unit can absorb the following temperatures;the range from 88°C to 90.7°C when the length of the tube is between respectively 110 and 111 m. the energy efficiency was between 0.55 and 0.57 which allowed confirming the model. This new model has some advantages such as;the use of an instantaneous calculation time. The heat recovered by the water tank can also serve as preheating different systems. One part of the heat recovered will be accumulated to be used as domestic hot water.</span> 展开更多
关键词 Heat Recovery steady-state Numerical Discrete model
下载PDF
Establishment of a humanized mouse model using steady-state peripheral blood-derived hematopoietic stem and progenitor cells facilitates screening of cancer-targeted T-cell repertoires
5
作者 Yulin Xu Wei Shan +8 位作者 Qian Luo Meng Zhang Dawei Huo Yijin Chen Honghu Li Yishan Ye Xiaohong Yu Yi Luo He Huang 《Cancer Innovation》 2024年第3期1-21,共21页
Background:Cancer-targeted T-cell receptor T(TCR-T)cells hold promise in treating cancers such as hematological malignancies and breast cancers.However,approaches to obtain cancer-reactive TCR-T cells have been unsucc... Background:Cancer-targeted T-cell receptor T(TCR-T)cells hold promise in treating cancers such as hematological malignancies and breast cancers.However,approaches to obtain cancer-reactive TCR-T cells have been unsuccessful.Methods:Here,we developed a novel strategy to screen for cancer-targeted TCR-T cells using a special humanized mouse model with person-specific immune fingerprints.Rare steady-state circulating hematopoietic stem and progenitor cells were expanded via three-dimensional culture of steady-state peripheral blood mononuclear cells,and then the expanded cells were applied to establish humanized mice.The human immune system was evaluated according to the kinetics of dendritic cells,monocytes,T-cell subsets,and cytokines.To fully stimulate the immune response and to obtain B-cell precursor NAML-6-and triple-negative breast cancer MDA-MB-231-targeted TCR-T cells,we used the inactivated cells above to treat humanized mice twice a day every 7 days.Then,human T cells were processed for TCRβ-chain(TRB)sequencing analysis.After the repertoires had been constructed,features such as the fraction,diversity,and immune signature were investigated.Results:The results demonstrated an increase in diversity and clonality of T cells after treatment.The preferential usage and features of TRBV,TRBJ,and the V–J combination were also changed.The stress also induced highly clonal Science and Technology,Grant/Award Number:2021C03010;Zhejiang Provincial Natural Science Foundation of China,Grant/Award Numbers:LTGY24H080003,LY21H080004 expansion.Tumor burden and survival analysis demonstrated that stress induction could significantly inhibit the growth of subsequently transfused live tumor cells and prolong the survival of the humanized mice.Conclusions:We constructed a personalized humanized mouse model to screen cancer-targeted TCR-T pools.Our platform provides an effective source of cancer-targeted TCR-T cells and allows for the design of patient-specific engineered T cells.It therefore has the potential to greatly benefit cancer treatment. 展开更多
关键词 cancer-targeted T-cell receptor T(TCR-T)cells circulating hematopoietic stem and progenitor cells(HSPCs) humanized mouse model steady-state peripheral blood T-cell receptorβ-chain(TRB) three-dimensional culture
原文传递
STEADY-STATE OPERATION ANALYSIS OF AN IDEAL HEAT INTEGRATED DISTILLATION COLUMN 被引量:1
6
作者 黄克谨 钱积新 +2 位作者 战德志 中岩勝 高松武一郎 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 1997年第4期43-54,共12页
A systematic approach for the steady-state operation analysis of chemical processes is pro-posed.The method affords the possibility of taking operation resilience into consideration during thestage of process design.I... A systematic approach for the steady-state operation analysis of chemical processes is pro-posed.The method affords the possibility of taking operation resilience into consideration during thestage of process design.It may serve the designer as an efficient means for the initial screening ofalternative design schemes.An ideal heat integrated distillation column(HIDiC),without any reboileror condenser attached,is studied throughout this work.It has been found that among the various va-riables concerned with the ideal HIDiC,feed thermal condition appears to be the only factor exertingsignificant influences on the interaction between the top and the bottom control loops.Maximuminteraction is expected when the feed thermal condition approaches 0.5.Total number of stages andheat transfer rate are essential to the system ability of disturbance rejection.Therefore,more stagesand higher heat transfer rate ought to be preferred.But,too many stages and higher heat transfer ratemay increase the load of the 展开更多
关键词 DISTILLATION model IDENTIFICATION steady-state design operation RESILIENCE PROCESS control
下载PDF
Functional Sustainability of a Flight Dynamics Control System for Stable Hovering Flight of an Unmanned Aerial Vehicle(UAV),such as in Agricultural Applications:Mathematical Modeling and Simulation
7
作者 Naji Mordi Naji Al-Dosary 《Journal of Agricultural Science and Technology(A)》 2023年第1期1-29,共29页
The simulation of a control system for the longitudinal axis of the rotary or fixed-wing unmanned aerial vehicles(UAVs)is demonstrated in this study.The control unit includes design considerations of two controllers t... The simulation of a control system for the longitudinal axis of the rotary or fixed-wing unmanned aerial vehicles(UAVs)is demonstrated in this study.The control unit includes design considerations of two controllers to provide robust stability,tracking of the proposed linear dynamics,an adequate set of proportional-integral-derivative(PID)controller gains,and a minimal cost function.The PID control and linear quadratic regulator(LQR)with or without full-state-observer were evaluated.An optimal control system is assumed to provide fast rise and settling time,minimize overshoot,and eliminate the steady-state error.The effectiveness of this approach was verified by a linear model of the UAV aircraft in the semi-dynamic simulation platform of Matlab/Simulink,in which the open-loop system was assessed in terms of flight robustness and reference tracking.The experimental results show that the proposed controllers effectively improve the configuration of the control system of the plant,maintain the sustainability of the dynamic flight model stability,and diminish the flight controller errors.The LQR provides robust stability,but it is not optimal in the transient phase of particular plant output.The PID control system can adjust the controller’s gains for optimal hovering(or stable slow flight)and is especially useful for the tracking system.Finally,comparing aircraft stability using PID and LQR controllers shows that the latter has less overshoot and a shorter settling time;in addition,all proposed controllers can be practically deployed as one UAV’s system,which can be handled as an exemplary model of the UAV flight management system. 展开更多
关键词 Agricultural applications cost function dynamic model PID&LQR controllers steady-state error UAV aircraft
下载PDF
A Pragmatic Approach for Assessing the Economic Performance of Model Predictive Control Systems and Its Industrial Application 被引量:12
8
作者 赵超 苏宏业 +1 位作者 古勇 褚建 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2009年第2期241-250,共10页
In this article,an approach for economic performance assessment of model predictive control(MPC) system is presented.The method builds on steady-state economic optimization techniques and uses the linear quadratic Gau... In this article,an approach for economic performance assessment of model predictive control(MPC) system is presented.The method builds on steady-state economic optimization techniques and uses the linear quadratic Gaussian(LQG) benchmark other than conventional minimum variance control(MVC) to estimate the potential of reduction in variance.The LQG control is a more practical performance benchmark compared to MVC for performance assessment since it considers input variance and output variance,and it thus provides a desired basis for determining the theoretical maximum economic benefit potential arising from variability reduction.Combining the LQG benchmark directly with benefit potential of MPC control system,both the economic benefit and the optimal operation condition can be obtained by solving the economic optimization problem.The proposed algorithm is illustrated by simulated example as well as application to economic performance assessment of an industrial model predictive control system. 展开更多
关键词 economic performance assessment model predictive control linear quadratic Gaussian benchmark steady-state model based optimization
下载PDF
A Model of Car-Following with Adaptive Headway 被引量:2
9
作者 李志鹏 刘允才 《Journal of Shanghai Jiaotong university(Science)》 EI 2006年第3期394-398,共5页
The performances of a well-known GHR car-following model was investigated by using numerical simulations in describing the acceleration and deceleration process induced by the motion of a leading car. It is shown that... The performances of a well-known GHR car-following model was investigated by using numerical simulations in describing the acceleration and deceleration process induced by the motion of a leading car. It is shown that in GHR model vehicle is allowed to run arbitrarily close together if their speed are identical,and it waves aside even though the separation is larger than its desired distance. Based on these investigations, a modified GHR model which features a new nonlinear term which attempts to adjust the inter-vehicle spacing to a certain desired value was proposed accordingly to overcome these deficiencies. In addition, the analysis of the additive nonlinear term and steady-state flow of the new model were studied to prove its rationality. 展开更多
关键词 car-following models inter-vehicle spacing traffic flow steady-state
下载PDF
Finite element modeling of convective pore-fluid flow in fluid-saturated porous rocks within upper crust:An overview 被引量:2
10
作者 ZHAO Chong-bin Bruce HOBBS Alison ORD 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第3期501-514,共14页
Convective pore-fluid flow (CPFF) plays a critical role in generating mineral deposits and oil reservoirs within the deep Earth. Therefore, theoretical understanding and numerical modeling of the thermodynamic process... Convective pore-fluid flow (CPFF) plays a critical role in generating mineral deposits and oil reservoirs within the deep Earth. Therefore, theoretical understanding and numerical modeling of the thermodynamic process that triggers and controls the CPFF are extremely important for the exploration of new mineral deposits and underground oil resources. From the viewpoint of science, the CPFF within the upper crust can be treated as a kind of thermodynamic instability problem of pore-fluid in fluid-saturated porous media. The key issue of dealing with this kind of problem is to assess whether a nonlinear thermodynamic system under consideration is supercritical. To overcome limitations of using theoretical analysis and experimental methods in dealing with the CPFF problems within the upper crust, finite element modeling has been broadly employed for solving this kind of problem over the past two decades. The main purpose of this paper is to overview recent developments and applications of finite element modeling associated with solving the CPFF problems in large length-scale geological systems of complicated geometries and complex material distributions. In particular, two kinds of commonly-used finite element modeling approaches, namely the steady-state and transient-state approaches, and their advantages/disadvantages are thoroughly presented and discussed. 展开更多
关键词 convective flow steady-state approach transient-state approach numerical modeling upper crust porous rock
下载PDF
Groundwater Flow Modeling for Qushtapa Plain Unconfined Aquifer in Southern Erbil Basin, Kurdistan Region, Iraq 被引量:2
11
作者 Shwan Seeyan 《Journal of Geoscience and Environment Protection》 2020年第3期116-132,共17页
Increasing population growth and water demand for various purposes such as irrigation, domestic and industrial production in many parts of the Kurdistan Region is causing deficit in fresh water and rising groundwater ... Increasing population growth and water demand for various purposes such as irrigation, domestic and industrial production in many parts of the Kurdistan Region is causing deficit in fresh water and rising groundwater dependence. Drilling many deep wells in the area unsystematically and continuously increased pumping water from groundwater reservoirs results in lowering of water table. Therefore, it is essential to assess the management of water resources. The study focuses on the groundwater modeling for the Qushtapa District plain area in particular under steady state flow conditions. The aquifer was simulated under unconfined condition and is represented by a single layer of 100 m thickness. MODPATH was used to measure contamination track lines and travel times. This approach involved the introduction of particles at sources of contaminants in the wells and the recharge area, then the identification of the path lines and the determination of the special distribution of contaminants through steady state flow conditions. The simulation of the groundwater head shows that the groundwater head starts from the northeastern part of the plain and decreases towards Lesser Zab River in the south of the plain from 420 m to 140 m above sea level. The modeled layer was calibrated under steady state conditions using hydraulic parameters obtained from observation and pumping wells. The calibrated model is effective in producing steady-state groundwater head distribution and good compliance with observed data. The standard error was estimated as 4.88 m, the normalized root mean square error is 8.3% and the residual mean is 15.79 m. The results of the forward tracking show the source of potential pollutants from the recharge area after different travel time, the particles released at the northern boundary travels to the center and the western part toward the pollution sources. The results of the backward tracking show that the particles located in the extraction wells moved toward the recharge area in the north and northeastern part of the study area. 展开更多
关键词 Unconfined AQUIFER GROUNDWATER model steady-state Flow Conditions Kurdistan REGION
下载PDF
Tire Dynamics Modeling Method Based on Rapid Test Method 被引量:1
12
作者 Dang Lu Lei Lu +2 位作者 Haidong Wu Wei Wang Manyi Lv 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2020年第6期228-237,共10页
Combined with the tire dynamics theoretical model,a rapid test method to obtain tire lateral and longitudinal both steady-state and transient characteristics only based on the tire quasi-steady-state test results is p... Combined with the tire dynamics theoretical model,a rapid test method to obtain tire lateral and longitudinal both steady-state and transient characteristics only based on the tire quasi-steady-state test results is proposed.For steady state data extraction,the test time of the rapid test method is half that of the conventional test method.For transient tire characteristics the rapid test method omits the traditional tire test totally.At the mean time the accuracy of the two method is much closed.The rapid test method is explained theoretically and the test process is designed.The key parameters of tire are extracted and the comparison is made between rapid test and traditional test method.The result show that the identification accuracy based on the rapid test method is almost equal to the accuracy of the conventional one.Then,the heat generated during the rapid test method and that generated during the conventional test are calculated separately.The comparison shows that the heat generated during the rapid test is much smaller than the heat generated during the conventional test process.This benefits to the reduction of tire wear and the consistency of test results.Finally,it can be concluded that the fast test method can efficiently,accurately and energy-efficiently measure the steady-state and transient characteristics of the tire. 展开更多
关键词 Tire dynamics modeling Rapid test method Tire steady-state and transient characteristics Identificationof tire characteristics parameterg
下载PDF
Adsorption of 2-naphthalenesulfonic acid/sulfuric acid/sulfurous acid from aqueous solution by iron-impregnated weakly basic resin:Equilibrium and model 被引量:1
13
作者 Changhai Li Dongmei Jia 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2016年第11期1522-1526,共5页
Commercial grade weakly basic resin D301 was impregnated with iron through a simple method using ferric chloride. Experiments for single, bisolute and trinary competitive adsorption were carried out to investigate the... Commercial grade weakly basic resin D301 was impregnated with iron through a simple method using ferric chloride. Experiments for single, bisolute and trinary competitive adsorption were carried out to investigate the adsorption behavior of 2-naphthalenesulfonic acid(NSA), sulfuric acid and sulfurous acid from their solution at 298 K onto the novel hybrid iron impregnated D301(Fe-D301). Adsorption affinity of NSA on Fe-D301 was found to be much higher than that of sulfuric acid, while adsorption affinity of sulfuric acid was slightly higher than that of sulfurous acid. The data of single-solute adsorption were fitted to the Langmuir model and the Freundlich adsorption model. The non-ideal competitive adsorbed model coupled with the single-solute adsorption models were used to predict the bisolute and trinary-solute competitive adsorption equilibria. The NICM coupled with the Langmuir model yields the favorable representation of the bisolute and trinary-solute competitive adsorption behavior. 展开更多
关键词 2-naphthalenesulfonic acid Hybrid iron impregnated D301 Adsorption non-ideal competitive adsorbed model model Equilibrium
下载PDF
Quantum entanglement dynamics based on composite quantum collision model
14
作者 Xiao-Ming Li Yong-Xu Chen +2 位作者 Yun-Jie Xia Qi Zhang Zhong-Xiao Man 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第6期82-89,共8页
By means of composite quantum collision models,we study the entanglement dynamics of a bipartite system,i.e.,two qubits S1 and S2 interacting directly with an intermediate auxiliary qubit SA,while SA is in turn couple... By means of composite quantum collision models,we study the entanglement dynamics of a bipartite system,i.e.,two qubits S1 and S2 interacting directly with an intermediate auxiliary qubit SA,while SA is in turn coupled to a thermal reservoir.We are concerned with how the intracollisions of the reservoir qubits influence the entanglement dynamics.We show that even if the system is initially in the separated state,their entanglement can be generated due to the interaction between the qubits.In the long-time limit,the steady-state entanglement can be generated depending on the initial state of S1 and S2 and the environment temperature.We also study the dynamics of tripartite entanglement of the three qubits S1,S2,and SA when they are initially prepared in the GHZ state and separated state,respectively.For the GHZ initial state,the tripartite entanglement can be maintained for a long time when the collision strength between the environment qubits is sufficiently large. 展开更多
关键词 entanglement dynamics steady-state entanglement collision model
下载PDF
Asymptotic analysis on weakly forced vibration of axially moving viscoelastic beam constituted by standard linear solid model
15
作者 王波 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2012年第6期817-828,共12页
The weakly forced vibration of an axially moving viscoelastic beam is inves- tigated. The viscoelastic material of the beam is constituted by the standard linear solid model with the material time derivative involved.... The weakly forced vibration of an axially moving viscoelastic beam is inves- tigated. The viscoelastic material of the beam is constituted by the standard linear solid model with the material time derivative involved. The nonlinear equations governing the transverse vibration are derived from the dynamical, constitutive, and geometrical relations. The method of multiple scales is used to determine the steady-state response. The modulation equation is derived from the solvability condition of eliminating secular terms. Closed-form expressions of the amplitude and existence condition of nontrivial steady-state response are derived from the modulation equation. The stability of non- trivial steady-state response is examined via the Routh-Hurwitz criterion. 展开更多
关键词 axially moving beam weakly forced vibration standard linear solid model method of multiple scales steady-state response
下载PDF
Construction of Earth's gravitational field model from CHAMP,GRACE and GOCE data 被引量:2
16
作者 Liu Xiaogang Wu Xiaoping 《Geodesy and Geodynamics》 2015年第4期292-298,共7页
The basic principle of spectral combination method is discussed,and the general expressions of the spectral weight and spectral combination of the united-processing of various types of gravimetric data are shown.What... The basic principle of spectral combination method is discussed,and the general expressions of the spectral weight and spectral combination of the united-processing of various types of gravimetric data are shown.What's more,based on degree error RMS of potential coefficients,the detailed expressions of spectral combination formulae and the corresponding spectral weights in the Earth's gravitational field model(EGM) determination using GOCE + GRACE and CHAMP + GRACE + GOCE are derived.The fundamental situation that ulux-champ2013 s,tongji-GRACE01,go-cons-gcf-2-tim-r5 constructed respectively by CHAMP,GRACE,GOCE data and go-cons-gcf-2-dir-r5 constructed by syncretic processing of GRACE,GOCE and LAGEOS data are explained briefly,the degree error RMS,cumulative geoid height error and cumulative gravity anomaly error of these models are calculated.A syncretic model constructed from CHAMP,GRACE and GOCE data,which is expressed by champ + grace + goce,is obtained based on spectral combination method.Experimentation results show that the precision of CHAMP data model is the lowest in satellite-only models,so it is not needed in the determination of syncretic models.The GRACE data model can improve the GOCE data model in medium-long wavelength,so the overall precision of syncretic model can be improved.Consequently,as many types of gravimetric data as possible should be combined together in the data processing in order to strengthen the quality and reliability with widening scope and improve the precision and spatial resolution of the computational results. 展开更多
关键词 Earth's gravitational field model(EGM) Challenging mini-satellite payload satellite (CHAMP)Gravity recovery and climate exper-iment satellite (GRACE)Gravity field and steady-state oceancirculation explorer satellite (GOCE)Spectral combination method Satellite gravimetry
下载PDF
Qualitative Analysis on a Reaction-Diffusion Prey-Predator Model and the Corresponding Steady-States 被引量:3
17
作者 Qunyi BIE Rui PENG 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2009年第2期207-220,共14页
The authors study a diffusive prey-predator model subject to the homogeneous Neumann boundary condition and give some qualitative descriptions of solutions to this reaction-diffusion system and its corresponding stead... The authors study a diffusive prey-predator model subject to the homogeneous Neumann boundary condition and give some qualitative descriptions of solutions to this reaction-diffusion system and its corresponding steady-state problem. The local and global stability of the positive constant steady-state are discussed, and then some results for non- existence of positive non-constant steady-states are derived. 展开更多
关键词 Prey-predator model steady-state Global stability NON-EXISTENCE
原文传递
NON-CONSTANT POSITIVE STEADY-STATES OF A PREDATOR-PREY-MUTUALIST MODEL 被引量:4
18
作者 CHENWENYAN WANGMINGXIN 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2004年第2期243-254,共12页
In this paper, the authors deal with the non-constant positive steady-states of a predator-prey-mutualist model with homogeneous Neumann boundary condition. They first give a priori estimates (positive upper and lower... In this paper, the authors deal with the non-constant positive steady-states of a predator-prey-mutualist model with homogeneous Neumann boundary condition. They first give a priori estimates (positive upper and lower bounds) of positive steady-states,and then study the non-existence, the global existence and bifurcation of non-constant positive steady-states as some parameters are varied. Finally the asymptotic behavior of such solutions as d3 →∞ is discussed. 展开更多
关键词 Predator-prey-mutualist model Non-constant positive steady-states BIFURCATION A priori estimates
原文传递
Studying the Effect of the Pre-Stimulation Paradigm on Steady-State Visual Evoked Potentials with Dynamic Models Based on the Zero-Pole Analytical Method 被引量:1
19
作者 Shangen Zhang Xu Han Xiaorong Gao 《Tsinghua Science and Technology》 SCIE EI CAS CSCD 2020年第3期435-446,共12页
This study explored methods for improving the performance of Steady-State Visual Evoked Potential(SSVEP)-based Brain-Computer Interfaces(BCI), and introduced a new analytical method to quantitatively analyze and refle... This study explored methods for improving the performance of Steady-State Visual Evoked Potential(SSVEP)-based Brain-Computer Interfaces(BCI), and introduced a new analytical method to quantitatively analyze and reflect the characteristics of SSVEP. We focused on the effect of the pre-stimulation paradigm on the SSVEP dynamic models and the dynamic response process of SSVEP, and performed a comparative analysis of three pre-stimulus paradigms(black, gray, and white). Four dynamic models with different orders(second-and third-order)and with and without a zero point were used to fit the SSVEP envelope. The zero-pole analytical method was adopted to conduct quantitative analysis on the dynamic models, and the response characteristics of SSVEP were represented by zero-pole distribution characteristics. The results of this study indicated that the pre-stimulation paradigm affects the characteristics of SSVEP, and the dynamic models had good fitting abilities with SSVEPs under various types of pre-stimulation. Furthermore, the zero-pole characteristics of the models effectively characterize the damping coefficient, oscillation period, and other SSVEP characteristics. The comparison of zeros and poles indicated that the gray pre-stimulation condition corresponds to a lower damping coefficient, thus showing its potential to improve the performance of SSVEP-BCIs. 展开更多
关键词 steady-state Visual Evoked Potential(SSVEP) dynamic model PRE-STIMULATION zero and pole analysis brain-computer interface
原文传递
Multi-port Network Modeling and Stability Analysis of VSC-MTDC Systems
20
作者 Shangning Tan Junliang Liu +2 位作者 Xiong Du Jingyuan Su Lijuan Fan 《Journal of Modern Power Systems and Clean Energy》 SCIE EI 2024年第5期1666-1677,共12页
The voltage source converter based multi-terminal high-voltage direct current(VSC-MTDC)system has attracted much attention because it can achieve the interconnection between AC grids.However,the initial phases and sho... The voltage source converter based multi-terminal high-voltage direct current(VSC-MTDC)system has attracted much attention because it can achieve the interconnection between AC grids.However,the initial phases and short-circuit ratios(SCRs)of the interconnected AC grids cause the steady-state phases(SSPs)of AC ports in the VSC-MTDC system to be different.This can lead to the issues such as mismatches in multiple converter reference frame systems,potentially causing inaccuracies in stability analysis when this phenomenon is disregarded.To address the aforementioned issues,a multi-port network model of the VSC-MTDC system,which considers the SSPs of the AC grids and AC ports,is derived by multiplying the port models of different subsystems(SSs).The proposed multi-port network model can accurately describe the transmission characteristics between the input and output ports of the system.Additionally,this model facilitates accurate analysis of the system stability.Furthermore,it identifies the key factors affecting the system stability.Ultimately,the accuracy of the proposed multi-port network model and the analysis of key factors are verified by time-domain simulations. 展开更多
关键词 Normalized sensitivity multi-port network model steady-state phase small-signal stability voltage source converter based multi-terminal high-voltage direct current(VSC-MTDC)
原文传递
上一页 1 2 3 下一页 到第
使用帮助 返回顶部