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The burden of upper motor neuron involvement is correlated with the bilateral limb involvement interval in patients with amyotrophic lateral sclerosis:a retrospective observational study
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作者 Jieying Wu Shan Ye +2 位作者 Xiangyi Liu Yingsheng Xu Dongsheng Fan 《Neural Regeneration Research》 SCIE CAS 2025年第5期1505-1512,共8页
Amyotrophic lateral sclerosis is a rare neurodegenerative disease characterized by the involvement of both upper and lower motor neurons.Early bilateral limb involvement significantly affects patients'daily lives ... Amyotrophic lateral sclerosis is a rare neurodegenerative disease characterized by the involvement of both upper and lower motor neurons.Early bilateral limb involvement significantly affects patients'daily lives and may lead them to be confined to bed.However,the effect of upper and lower motor neuron impairment and other risk factors on bilateral limb involvement is unclear.To address this issue,we retrospectively collected data from 586 amyotrophic lateral sclerosis patients with limb onset diagnosed at Peking University Third Hospital between January 2020 and May 2022.A univariate analysis revealed no significant differences in the time intervals of spread in different directions between individuals with upper motor neuron-dominant amyotrophic lateral sclerosis and those with classic amyotrophic lateral sclerosis.We used causal directed acyclic graphs for risk factor determination and Cox proportional hazards models to investigate the association between the duration of bilateral limb involvement and clinical baseline characteristics in amyotrophic lateral sclerosis patients.Multiple factor analyses revealed that higher upper motor neuron scores(hazard ratio[HR]=1.05,95%confidence interval[CI]=1.01–1.09,P=0.018),onset in the left limb(HR=0.72,95%CI=0.58–0.89,P=0.002),and a horizontal pattern of progression(HR=0.46,95%CI=0.37–0.58,P<0.001)were risk factors for a shorter interval until bilateral limb involvement.The results demonstrated that a greater degree of upper motor neuron involvement might cause contralateral limb involvement to progress more quickly in limb-onset amyotrophic lateral sclerosis patients.These findings may improve the management of amyotrophic lateral sclerosis patients with limb onset and the prediction of patient prognosis. 展开更多
关键词 amyotrophic lateral sclerosis bilateral limb involvement Cox proportional hazards regression model horizontal spread restricted cubic spline analysis time interval upper motor neuron vertical spread
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Electrothermal Model Based Remaining Charging Time Prediction of Lithium-Ion Batteries against Wide Temperature Range
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作者 Rui Xiong Zian Zhao +2 位作者 Cheng Chen Xinggang Li Weixiang Shen 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第2期330-339,共10页
Battery remaining charging time(RCT)prediction can facilitate charging management and alleviate mileage anxiety for electric vehicles(EVs).Also,it is of great significance to improve EV users’experience.However,the R... Battery remaining charging time(RCT)prediction can facilitate charging management and alleviate mileage anxiety for electric vehicles(EVs).Also,it is of great significance to improve EV users’experience.However,the RCT for a lithiumion battery pack in EVs changes with temperature and other battery parameters.This study proposes an electrothermal model-based method to accurately predict battery RCT.Firstly,a characteristic battery cell is adopted to represent the battery pack,thus an equivalent circuit model(ECM)of the characteristic battery cell is established to describe the electrical behaviors of a battery pack.Secondly,an equivalent thermal model(ETM)of the battery pack is developed by considering the influence of ambient temperature,thermal management,and battery connectors in the battery pack to calculate the temperature which is then fed back to the ECM to realize electrothermal coupling.Finally,the RCT prediction method is proposed based on the electrothermal model and validated in the wide temperature range from-20℃to 45℃.The experimental results show that the prediction error of the RCT in the whole temperature range is less than 1.5%. 展开更多
关键词 Electric vehicles Lithium-ion batteries Remaining charging time Electrothermal model
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Microbial Growth and Decay: A Commented Review of the Model
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作者 Alberto Schiraldi 《Advances in Microbiology》 CAS 2024年第1期1-10,共10页
The paper reviews previous publications and reports some comments about a semi empirical model of the growth and decay process of a planktonic microbial culture. After summarizing and reshaping some fundamental mathem... The paper reviews previous publications and reports some comments about a semi empirical model of the growth and decay process of a planktonic microbial culture. After summarizing and reshaping some fundamental mathematical expressions, the paper highlights the reasons for the choice of a suitable time origin that makes the parameters of the model self-consistent. Besides the potential applications to predictive microbiology studies and to effects of bactericidal drugs, the model allows a suitable proxy of the fitness of the microbial culture, which can be of interest for the studies on the evolution across some thousand generations of a Long Term Evolution Experiment. 展开更多
关键词 Microbial Cultures model Time Scale Growth and Decay EVOLUTION
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Analytical and NumericalMethods to Study the MFPT and SR of a Stochastic Tumor-Immune Model
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作者 Ying Zhang Wei Li +1 位作者 Guidong Yang Snezana Kirin 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第3期2177-2199,共23页
The Mean First-Passage Time (MFPT) and Stochastic Resonance (SR) of a stochastic tumor-immune model withnoise perturbation are discussed in this paper. Firstly, considering environmental perturbation, Gaussian whiteno... The Mean First-Passage Time (MFPT) and Stochastic Resonance (SR) of a stochastic tumor-immune model withnoise perturbation are discussed in this paper. Firstly, considering environmental perturbation, Gaussian whitenoise and Gaussian colored noise are introduced into a tumor growth model under immune surveillance. Asfollows, the long-time evolution of the tumor characterized by the Stationary Probability Density (SPD) and MFPTis obtained in theory on the basis of the Approximated Fokker-Planck Equation (AFPE). Herein the recurrenceof the tumor from the extinction state to the tumor-present state is more concerned in this paper. A moreefficient algorithmof Back-Propagation Neural Network (BPNN) is utilized in order to testify the correction of thetheoretical SPDandMFPT.With the existence of aweak signal, the functional relationship between Signal-to-NoiseRatio (SNR), noise intensities and correlation time is also studied. Numerical results show that both multiplicativeGaussian colored noise and additive Gaussian white noise can promote the extinction of the tumors, and themultiplicative Gaussian colored noise can lead to the resonance-like peak on MFPT curves, while the increasingintensity of the additiveGaussian white noise results in theminimum of MFPT. In addition, the correlation timesare negatively correlated with MFPT. As for the SNR, we find the intensities of both the Gaussian white noise andthe Gaussian colored noise, as well as their correlation intensity can induce SR. Especially, SNR is monotonouslyincreased in the case ofGaussian white noisewith the change of the correlation time.At last, the optimal parametersin BPNN structure are analyzed for MFPT from three aspects: the penalty factors, the number of neural networklayers and the number of nodes in each layer. 展开更多
关键词 Stochastic tumor-immune model mean first-passage time stochastic resonance signal-to-noise ratio back-propagation neural network
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Multi-Time Scale Operation and Simulation Strategy of the Park Based on Model Predictive Control
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作者 Jun Zhao Chaoying Yang +1 位作者 Ran Li Jinge Song 《Energy Engineering》 EI 2024年第3期747-767,共21页
Due to the impact of source-load prediction power errors and uncertainties,the actual operation of the park will have a wide range of fluctuations compared with the expected state,resulting in its inability to achieve... Due to the impact of source-load prediction power errors and uncertainties,the actual operation of the park will have a wide range of fluctuations compared with the expected state,resulting in its inability to achieve the expected economy.This paper constructs an operating simulation model of the park power grid operation considering demand response and proposes a multi-time scale operating simulation method that combines day-ahead optimization and model predictive control(MPC).In the day-ahead stage,an operating simulation plan that comprehensively considers the user’s side comfort and operating costs is proposed with a long-term time scale of 15 min.In order to cope with power fluctuations of photovoltaic,wind turbine and conventional load,MPC is used to track and roll correct the day-ahead operating simulation plan in the intra-day stage to meet the actual operating operation status of the park.Finally,the validity and economy of the operating simulation strategy are verified through the analysis of arithmetic examples. 展开更多
关键词 Demand response model predictive control multiple time scales operating simulation
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Refinement of the Proposed Gamma-Ray Burst Time Delay Model
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作者 Godson Fortune Abbey Joseph Simfukwe +3 位作者 Prospery Christopher Simpemba Saul Paul Phiri Alok Srivastava Golden Gadzirayi Nyambuya 《International Journal of Astronomy and Astrophysics》 2024年第2期120-147,共28页
This paper is the second instalment in our study of the observed time delay in the arrival times of radio photons emanating from Gamma Ray Bursts (GRBs). The mundane assumption in contemporary physics as to the cause ... This paper is the second instalment in our study of the observed time delay in the arrival times of radio photons emanating from Gamma Ray Bursts (GRBs). The mundane assumption in contemporary physics as to the cause of these pondersome time delays is that they are a result of the photon being endowed with a non-zero mass. While we do not rule out the possibility of a non-zero mass for the photon, our working assumption is that the major cause of these time delays may very well be that these photons are travelling in a rarefied cosmic plasma in which the medium’s electrons interact with the electric component of the Photon, thus generating tiny currents that lead to dispersion, hence, a frequency-dependent speed of Light (FDSL). In the present instalment, we “improve” on the model presented in the first instalment by dropping the assumption that the resultant pairs of these radio photons leave the shock front simultaneously. The new assumption of a non-simultaneous— albeit systematic—emission of these photon pairs allows us to obtain a much more convincing and stronger correlation in the time delay. This new correlation allows us to build a unified model for the four GRBs in our sample using a relative distance correction mechanism. The new unified model allows us to obtain as our most significant result a value for the frequency equivalence of the interstellar medium (ISM)’s conductance ν* ~ 1.500 ± 0.009 Hzand also an independent distance measure to the GRBs where we obtain for our four GRB samples an average distance of: ~69.40 ± 0.10, 40.00 ± 0.00, 58.40 ± 0.40, and 86.00 ± 1.00 Mpc, for GRB 030329, 980425, 000418 and 021004 respectively. 展开更多
关键词 Gamma-Ray Bursts (GRB) Photon Mass PLASMA Time Delay Fireball model
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Prediction and Analysis of O_3 based on the ARIMA Model 被引量:2
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作者 李双金 杨宁 +2 位作者 闫奕琪 曹旭东 冀德刚 《Agricultural Science & Technology》 CAS 2015年第10期2146-2148,共3页
The research conducted prediction on changes of atmosphere pollution during July 9, 2014-July 22, 2014 with SPSS based on monitored data of O3 in 13 successive weeks from 6 sites in Baoding City and demonstrated predi... The research conducted prediction on changes of atmosphere pollution during July 9, 2014-July 22, 2014 with SPSS based on monitored data of O3 in 13 successive weeks from 6 sites in Baoding City and demonstrated prediction effect of ARIMA model is good by Ljung-Box Q-test and R2, and the model can be used for prediction on future atmosphere pollutant changes. 展开更多
关键词 Air quality Analysis of time series SPSS ARIMA model
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The Additive-multiplicative Hazards Model for Multiple Type of Recurrent Gap Times
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作者 Zhang Qi-xian Liu Ji-cai +1 位作者 Guan Qiang Wang De-hui 《Communications in Mathematical Research》 CSCD 2015年第2期97-107,共11页
Recurrent event gap times data frequently arise in biomedical studies and often more than one type of event is of interest. To evaluate the effects of covariates on the marginal recurrent event hazards functions, ther... Recurrent event gap times data frequently arise in biomedical studies and often more than one type of event is of interest. To evaluate the effects of covariates on the marginal recurrent event hazards functions, there exist two types of hazards models: the multiplicative hazards model and the additive hazards model. In the paper, we propose a more flexible additive-multiplicative hazards model for multiple type of recurrent gap times data, wherein some covariates are assumed to be additive while others are multiplicative. An estimating equation approach is presented to estimate the regression parameters. We establish asymptotic properties of the proposed estimators. 展开更多
关键词 additive-multiplicative hazards model estimating equation gap time multiple recurrent event data semi-parametric regression model
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Impacts of Increasing Model Resolutions and Shortening Forecast Lead Times on QPFs in South China During the Rainy Season
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作者 张旭斌 李静珊 +4 位作者 罗亚丽 宝兴华 陈靖扬 肖辉 文秋实 《Journal of Tropical Meteorology》 SCIE 2023年第3期277-300,共24页
This study investigated the impacts of increasing model resolutions and shortening forecast lead times on the quantitative precipitation forecast(QPF)for heavy-rainfall events over south China during the rainy seasons... This study investigated the impacts of increasing model resolutions and shortening forecast lead times on the quantitative precipitation forecast(QPF)for heavy-rainfall events over south China during the rainy seasons in 2013-2020.The control experiment,where the analysis-forecast cycles run with model resolutions of about 3 km,was compared to a lower-resolution experiment with model resolutions of about 9 km,and a longer-term experiment activated 12 hours earlier.Rainfall forecasting in the presummer rainy season was significantly improved by improving model resolutions,with more improvements in cases with stronger synoptic-scale forcings.This is partially attributed to the improved initial conditions(ICs)and subsequent forecasts for low-level jets(LLJs).Forecasts of heavy rainfall induced by landfalling tropical cyclones(TCs)benefited from increasing model resolutions in the first 6 hours.Forecast improvements in rainfall due to shortening forecast lead times were more significant at earlier(1-6 h)and later(7-12 h)lead times for cases with stronger and weaker synoptic-scale forcings,respectively,due to the area-and case-dependent improvements in ICs for nonprecipitation variables.Specifically,significant improvements mainly presented over the northern South China Sea for low-level onshore wind of weak-forcing cases but over south China for LLJs of strong-forcing cases during the presummer rainy season,and over south China for all the nonprecipitation variables above the surface during the TC season.However,some disadvantages of higher-resolution and shorter-term forecasts in QPFs highlight the importance of developing ensemble forecasting with proper IC perturbations,which include the complementary advantages of lower-resolution and longer-term forecasts. 展开更多
关键词 south China QPF model resolution forecast lead time
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Mathematical model for precursor gas residence time in isothermal CVD process of C/C composites
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作者 于澍 郑洲顺 +1 位作者 张福勤 蔡永强 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第8期1833-1839,共7页
In the chemical vapor deposition(CVD) process of C/C composites,the dynamics and mechanism of precursor gas flowing behavior were analyzed mathematically,in which the precursor gas was infiltrated by the pressure di... In the chemical vapor deposition(CVD) process of C/C composites,the dynamics and mechanism of precursor gas flowing behavior were analyzed mathematically,in which the precursor gas was infiltrated by the pressure difference of the gas flowing through felt.Differential equations were educed which characterized the relations among the pressure inside the felt,the pressure outside the felt of the precursor gas and the porosity of the felt as a function of CVD duration.The gas residence time during the infiltration process through the felt was obtained from the differential equations.The numerical verification is in good agreement with the practical process,indicating the good reliability of the current mathematical model. 展开更多
关键词 chemical vapor deposition residence time mathematical model
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The Operation Model of Pig Supply Chain Based on Temporal and Spatial Perspectives
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作者 高阔 甘筱青 《Agricultural Science & Technology》 CAS 2014年第9期1624-1628,共5页
This paper constructed pig supply chain based on theoretical study and practical research, then analyzed the operation model of pig supply chain from tem- poral and spatial perspectives. The results showed that from t... This paper constructed pig supply chain based on theoretical study and practical research, then analyzed the operation model of pig supply chain from tem- poral and spatial perspectives. The results showed that from the spatial perspective, pig supply chain had five models of operation, such as vertical integration pig sup- ply chain, quasi-vertical integration pig supply chain (tightly-knit pig supply chain), semi-tightly pig supply chain, loosely-organized pig supply chain and market-oriented pig supply chain. In contrast, from temporal aspect, pig supply chain experiences the pure market transaction, contract form, cooperatives, vertical integration and hori- zontal integration model of operation; the future pig supply chain model in China might be the longitudinal transverse group alliance pig supply chain, namely, the upper vertical integration or quasi-vertical integration (leading processing enterprise + farmer) and down horizontal integration (leading processing enterprises + logistics company + sales), and it would be a kind of competition among interest groups by division of cooperation. 展开更多
关键词 Pig supply chain Operation model TIME SPACE
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Seed germination response of the invasive Haloxylon persicum in Tunisia
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作者 Hanen FARHAT Khouloud KRICHEN +1 位作者 Khouloud ZAGOUB Mohamed CHAIEB 《Journal of Arid Land》 SCIE CSCD 2024年第12期1744-1759,共16页
Biological invasion represents a major worldwide threat to native biodiversity and environmental stability.Haloxylon persicum was introduced to Tunisia(North Africa)with Saharan bioclimate in 1969 to fix sandy dunes.S... Biological invasion represents a major worldwide threat to native biodiversity and environmental stability.Haloxylon persicum was introduced to Tunisia(North Africa)with Saharan bioclimate in 1969 to fix sandy dunes.Since then,it has gained significant interest for its potential to colonize,proliferate,and become naturalized in Tunisia.Hence,understanding the seed germination response of H.persicum to abiotic conditions,including temperature,water stress,and salt stress,is crucial for predicting its future spread and adopting effective control strategies.Our work investigated the germination behavior of this invasive plant species by incubation at temperatures from 10.0℃ to 35.0℃ and at various osmotic potentials(-2.00,-1.60,-1.00,-0.50,and 0.00 MPa)of polyethylene glycol-6000(PEG6000,indicating water stress)and sodium chloride(NaCl,indicating salt stress)solutions.Results showed remarkable correlations among the seed functional traits of H.persicum,indicating adaptive responses to local environmental constraints.The maximum germination rate was recorded at 25.0℃ with a rate of 0.39/d.Using the thermal time model,the base temperature was recorded at 8.4℃,the optimal temperature was 25.5℃,and the ceiling temperature was found at 58.3℃.Besides,based on the hydrotime model,the base water potential showed lower values of -7.74 and -10.90 MPa at the optimal temperatures of 25.0℃ and 30.0℃,respectively.Also,the species was found to have excellent tolerance to drought(water stress)compared to salt stress,which has implications for its potential growth into new habitats under climate change.Combining ecological and physiological approaches,this work elucidates the invasive potential of H.persicum and contributes to the protection of species distribution in Tunisian ecosystems. 展开更多
关键词 Haloxylon persicum seed germination osmotic potentials seed functional traits hydrotime model thermal time model Tunisian Saharan bioclimate
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Intrinsic Spin Angular Momentum of Electron Relation to the Discrete Indivisible Quantum of Time Kshana or Moment
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作者 Shesharao M. Wanjerkhede 《Journal of Modern Physics》 2024年第9期1337-1352,共16页
The frequency of any periodic event can be defined in terms of units of Time. Planck constructed a unit of time called the Plank time from other physical constants. Vyasa defined a natural unit of time, kshana, or mom... The frequency of any periodic event can be defined in terms of units of Time. Planck constructed a unit of time called the Plank time from other physical constants. Vyasa defined a natural unit of time, kshana, or moment based on the motion of a fundamental particle. It is the time taken by an elementary particle, to change its direction from east to north. According to Vyasa, kshana is discrete, exceedingly small, indivisible, and is a constant time quantum. When the intrinsic spin angular momentum of an electron was related to the angular momentum of a simple thin circular plate, spherical shell, and solid sphere model of an electron, we found that the value of kshana in seconds was equal to ten to a power of minus twenty-one second. The disc model for the spinning electron provides an accurate value of the number of kshanas per second as determined previously and compared with other spinning models of electrons. These results indicate that the disk-like model of spinning electrons is the correct model for electrons. Vyasa’s definition of kshana opens the possibility of a new foundation for the theory of physical time, and perspectives in theoretical and philosophical research. 展开更多
关键词 Natural Time Unit Quantum Time Kshana Plank Time Intrinsic Angular Momentum Thin Disc model Compton Wavelength
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Motivation in Foreign Language Learning: Applying the Time Continuum Model of Motivation in FLL
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作者 符晓 《海外英语》 2010年第8X期378-380,共3页
The research is: by using Wdolkowski's Time Continuum Model throughout a lesson plan enables the teacher to increase students'motivation and help them move closer to success in a learning environment. This res... The research is: by using Wdolkowski's Time Continuum Model throughout a lesson plan enables the teacher to increase students'motivation and help them move closer to success in a learning environment. This research supports the theory that instruction is a network of interactions between the teacher and learner that promotes a successful learning experience. It identifies a three-part learning sequence-a beginning, middle and an end. Each part has two of six key motivational factors that when applied correctly by the teacher will maximize the success and continued motivation of the learner. 展开更多
关键词 MOTIVATION TIME CONTINUUM model
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Effect of Time Step Size and Turbulence Model on the Open Water Hydrodynamic Performance Prediction of Contra-Rotating Propellers 被引量:15
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作者 王展智 熊鹰 《China Ocean Engineering》 SCIE EI CSCD 2013年第2期193-204,共12页
A growing interest has been devoted to the contra-rotating propellers (CRPs) due to their high propulsive efficiency, torque balance, low fuel consumption, low cavitations, low noise performance and low hull vibrati... A growing interest has been devoted to the contra-rotating propellers (CRPs) due to their high propulsive efficiency, torque balance, low fuel consumption, low cavitations, low noise performance and low hull vibration. Compared with the single-screw system, it is more difficult for the open water performance prediction because forward and aft propellers interact with each other and generate a more complicated flow field around the CRPs system. The current work focuses on the open water performance prediction of contra-rotating propellers by RANS and sliding mesh method considering the effect of computational time step size and turbulence model. The validation study has been performed on two sets of contra-rotating propellers developed by David W Taylor Naval Ship R & D center. Compared with the experimental data, it shows that RANS with sliding mesh method and SST k-ω turbulence model has a good precision in the open water performance prediction of contra-rotating propellers, and small time step size can improve the level of accuracy for CRPs with the same blade number of forward and aft propellers, while a relatively large time step size is a better choice for CRPs with different blade numbers. 展开更多
关键词 contra-rotating propeller open water performance RANS time step size turbulence model
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A Regional Air-Sea Coupled Model and Its Application over East Asia in the Summer of 2000 被引量:8
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作者 房永杰 张耀存 +1 位作者 汤剑平 任雪娟 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2010年第3期583-593,共11页
A regional air-sea coupled model, comprising the Regional Integrated Environment Model System (RIEMS) and the Princeton Ocean Model (POM) was developed to simulate summer climate features over East Asia in 2000. T... A regional air-sea coupled model, comprising the Regional Integrated Environment Model System (RIEMS) and the Princeton Ocean Model (POM) was developed to simulate summer climate features over East Asia in 2000. The sensitivity of the model's behavior to the coupling time interval (CTI), the causes of the sea surface temperature (SST) biases, and the role of air-sea interaction in the simulation of precipitation over China are investigated. Results show that the coupled model can basically produce the spatial pattern of SST, precipitation, and surface air temperature (SAT) with five different CTIs respectively. Also, using a CTI of 3, 6 or 12 hours tended to produce more successful simulations than if using 1 and 24 hours. Further analysis indicates that both a higher and lower coupling frequency result in larger model biases in air-sea heat flux exchanges, which might be responsible for the sensitivity of the coupled model's behavior to the CTI. Sensitivity experiments indicate that SST biases between the coupled and uncoupled POM occurring over the China coastal waters were due to the mismatch of the surface heat fluxes produced by the RIEMS with those required by the POM. In the coupled run, the air-sea feedbacks reduced the biases in surface heat fluxes, compared with the uncoupled RIEMS, consequently resulted in changes in thermal contrast over land and sea and led to a precipitation increase over South China and a decrease over North China. These results agree well observations in the summer of 2000. 展开更多
关键词 REGIONAL air-sea coupled model coupling time interval air-sea interactions East Asian climate
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Modeling of Fluid Turbulence Modification Using Two-time-scale Dissipation Models and Accounting for the Particle Wake Effect 被引量:3
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作者 于勇 周力行 王保国 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2006年第3X期314-320,共7页
Presently developed two-phase turbulence models under-predict the gas turbulent fluctuation, because their turbulence modification models cannot fully reflect the effect of particles. In this paper, a two-time-scale d... Presently developed two-phase turbulence models under-predict the gas turbulent fluctuation, because their turbulence modification models cannot fully reflect the effect of particles. In this paper, a two-time-scale dis- sipation model of turbulence modification, developed for the two-phase velocity correlation and for the dissipation rate of gas turbulent kinetic energy, is proposed and used to simulate sudden-expansion and swirling gas-particle flows. The proposed two-time scale model gives better results than the single-time scale model. Besides, a gas tur- bulence augmentation model accounting for the finite-size particle wake effect in the gas Reynolds stress equation is proposed. The proposed turbulence modification models are used to simulate two-phase pipe flows. It can prop- erly predict both turbulence reduction and turbulence enhancement for a certain size of particles observed in ex- periments. 展开更多
关键词 TURBULENCE MODIFICATION two time scale DISSIPATION model WAKE effect
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Comparison of four models for end-stage liver disease in evaluating the prognosis of cirrhosis 被引量:13
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作者 Ming Jiang Fei Liu +2 位作者 Wu-Jun Xiong Lan Zhong Xi-Mei Chen 《World Journal of Gastroenterology》 SCIE CAS CSCD 2008年第42期6546-6550,共5页
AIM: To investigate the prognostic value of the model for end-stage liver disease (MELD) and three new MELD-based models combination with serum sodium in decompensated cirrhosis patients-the MELD with the incorpora... AIM: To investigate the prognostic value of the model for end-stage liver disease (MELD) and three new MELD-based models combination with serum sodium in decompensated cirrhosis patients-the MELD with the incorporation of serum sodium (MELD-Na), the integrated MELD (iMELD), and the MELD to sodium (MESO) index. METHODS: A total of 166 patients with decompensated cirrhosis were enrolled into the study. MELD, MELD- Na, iMELD and MESO scores were calculated for each patient following the original formula on the first day of admission. All patients were followed up at least 1 year. The predictive prognosis related with the four models was determined by the area under the receiver operating characteristic curve (AUC) of the four parameters. Kaplan-Meier survival curves were made using the cut-offs identified by means of receiver operating characteristic (ROC). RESULTS: Out of 166 patients, 38 patients with significantly higher MELD-Na (28.84 ± 2.43 vs 14.72 ± 0.60), iMELD (49.04 ± 1.72 vs 35.52 ± 0.67), MESO scores (1.59 ± 0.82 vs 0.99 ± 0.42) compared to the survivors died within 3 mo (P 〈 0.001). Of 166 patients, 75 with markedly higher MELD-Na (23.01 ± 1.51 vs 13.78 ± 0.69), iMELD (44.06 ± 1.19 vs 34.12 ± 0.69), MESO scores (1.37 ± 0.70 vs 0.93 ± 0.40) than the survivors died within 1 year (P 〈 0.001). At 3 mo of enrollment, the iMELD had the highest AUC (0.841), and was followed by the MELD-Na (0.766), MESO (0.723), all larger than MELD (0.773); At year, the iMELD still had the highest AUC (0.783), the difference between the iMELD and MELD was statistically significant (P 〈 0.05). Survival curves showed that the three new models were all clearly discriminated the patients who survived or died in short-term as well as intermediate-term (P 〈 0.001). CONCLUSION: Three new models, changed with serum sodium (MELD-Na, iMELD, MESO) can exactly predict the prognosis of patients with decompensated cirrhosis for short and intermediate period, and may enhance the prognostic accuracy of MELD. The iMELD is better prognostic model for outcome prediction in patients with decompensated cirrhosis. 展开更多
关键词 CIRRHOSIS model for end-stage liver disease Serum sodium PROGNOSIS Survival time
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A continuum traffic flow model with the consideration of coupling effect for two-lane freeways 被引量:3
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作者 D.-H. Sun G.-H. Peng +1 位作者 L.-P. Fu H.-P. He 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2011年第2期228-236,共9页
A new higher-order continuum model is proposed by considering the coupling and lane changing effects of the vehicles on two adjacent lanes. A stability analysis of the proposed model provides the conditions that ensur... A new higher-order continuum model is proposed by considering the coupling and lane changing effects of the vehicles on two adjacent lanes. A stability analysis of the proposed model provides the conditions that ensure its linear stability. Issues related to lane changing, shock waves and rarefaction waves, local clustering and phase transition are also investigated with numerical experiments. The simulation results show that the proposed model is capable of providing explanations to some particular traffic phenomena commonly observable in real traffic flows. 展开更多
关键词 Two-lane traffic Two delay time scales model Numerical simulation Coupling effect Phase transition
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A mathematical model of a P53 oscillation network triggered by DNA damage 被引量:3
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作者 夏俊峰 贾亚 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第4期112-116,共5页
Taking the interaction between a DNA damage repair module, an ATM module, and a P53--MDM2 oscillation module into account, this paper presents a mathematical model of a P53 oscillation network triggered by a DNA damag... Taking the interaction between a DNA damage repair module, an ATM module, and a P53--MDM2 oscillation module into account, this paper presents a mathematical model of a P53 oscillation network triggered by a DNA damage signal in individual cells. The effects of the DNA damage signal and the delay time of P53-induced MDM2 expression on the behaviours of the P53 oscillation network are studied. In the oscillatory state of the P53--MDM2 oscillator, it is found that the pulse number of P53--P oscillation increases with the increase of the initial DNA damage signal, whereas the amplitude and the period of P53--P oscillation are fixed for different initial DNA damage signals, and the period numbers of P53--P oscillations decrease with the increase of time delay of MDM2 expression induced by P53. These theoretical predictions are consistent with previous experimental results. The combined negative feedback of P53--MDM2 with the time delay of P53-induced MDM2 expression causes oscillation behaviour in the P53 network. 展开更多
关键词 P53 oscillation network DNA damage signal time delay kinetic model
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