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太阳对气候的影响机制不仅仅是总辐射能量——“太阳变率与地球气候”研讨会评介
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作者 董仕 肖子牛 《气象科技进展》 2013年第3期73-74,共2页
探索过去1万年地球气候的变化和太阳可能存在的联系,对过去、现在的太阳和太阳变率进行了总结,点出了在不同时间尺度下太阳和气候的关系,以及太阳和气候关系的相关机制。
关键词 地球气候 变率 相对平均差 太阳 恒星 辐射能量 研讨会
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Correlation between welding and hardening parameters of friction stir welded joints of 2017 aluminum alloy 被引量:1
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作者 Hassen BOUZAIENE Mohamed-Ali REZGUI +1 位作者 Mahfoudh AYADI Ali ZGHAL 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第5期1064-1072,共9页
An experimental study was undertaken to express the hardening Swift law according to friction stir welding (FSW) aluminum alloy 2017. Tensile tests of welded joints were run in accordance with face centered composit... An experimental study was undertaken to express the hardening Swift law according to friction stir welding (FSW) aluminum alloy 2017. Tensile tests of welded joints were run in accordance with face centered composite design. Two types of identified models based on least square method and response surface method were used to assess the contribution of FSW independent factors on the hardening parameters. These models were introduced into finite-element code "Abaqus" to simulate tensile tests of welded joints. The relative average deviation criterion, between the experimental data and the numerical simulations of tension-elongation of tensile tests, shows good agreement between the experimental results and the predicted hardening models. These results can be used to perform multi-criteria optimization for carrying out specific welds or conducting numerical simulation of plastic deformation of forming process of FSW parts such as hydroforming, bending and forging. 展开更多
关键词 friction stir welding response surface methodology face centered central composite design HARDENING simulation relative average deviation criterion
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Numerical simulation of the hydrodynamics within octagonal tanks in recirculating aquaculture systems 被引量:16
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作者 柳瑶 刘宝良 +2 位作者 雷霁霖 关长涛 黄滨 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2017年第4期912-920,共9页
A three-dimensional numerical model was established to simulate the hydrodynamics within an octagonal tank of a recirculating aquaculture system. The realizable k-e turbulence model was applied to describe the flow, t... A three-dimensional numerical model was established to simulate the hydrodynamics within an octagonal tank of a recirculating aquaculture system. The realizable k-e turbulence model was applied to describe the flow, the discrete phase model (DPM) was applied to generate particle trajectories, and the governing equations are solved using the finite volume method. To validate this model, the numerical results were compared with data obtained from a full-scale physical model. The results show that: (1) the realizable k-e model applied for turbulence modeling describes well the flow pattern in octagonal tanks, giving an average relative error of velocities between simulated and measured values of 18% from contour maps of velocity magnitudes; (2) the DPM was applied to obtain particle trajectories and to simulate the rate of particle removal from the tank. The average relative error of the removal rates between simulated and measured values was 11%. The DPM can be used to assess the self-cleaning capability of an octagonal tank; (3) a comprehensive account of the hydrodynamics within an octagonal tank can be assessed from simulations. The velocity distribution was uniform with an average velocity of 15 cm/s; the velocity reached 0.8 m/s near the inlet pipe, which can result in energy losses and cause wall abrasion; the velocity in tank corners was more than 15 cm/s, which suggests good water mixing, and there was no particle sedimentation. The percentage of particle removal for octagonal tanks was 90% with the exception of a little accumulation of 〈5 mm particle in the area between the inlet pipe and the wall. This study demonstrated a consistent numerical model of the hydrodynamics within octagonal tanks that can be further used in their design and optimization as well as promote the wide use of computational fluid dynamics in aquaculture engineering. 展开更多
关键词 recirculating aquaculture systems octagonal tanks hydrodynamic simulation rate of particle removal
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Function chain neural network prediction on heat transfer performance of oscillating heat pipe based on grey relational analysis 被引量:12
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作者 鄂加强 李玉强 龚金科 《Journal of Central South University》 SCIE EI CAS 2011年第5期1733-1737,共5页
As for the factors affecting the heat transfer performance of complex and nonlinear oscillating heat pipe (OHP),grey relational analysis (GRA) was used to deal with the relationship between heat transfer rate of a loo... As for the factors affecting the heat transfer performance of complex and nonlinear oscillating heat pipe (OHP),grey relational analysis (GRA) was used to deal with the relationship between heat transfer rate of a looped copper-water OHP and charging ratio,inner diameter,inclination angel,heat input,number of turns,and the main influencing factors were defined.Then,forecasting model was obtained by using main influencing factors (such as charging ratio,interior diameter,and inclination angel) as the inputs of function chain neural network.The results show that the relative average error between the predicted and actual value is 4%,which illustrates that the function chain neural network can be applied to predict the performance of OHP accurately. 展开更多
关键词 oscillating heat pipe grey relational analysis fimction chain neural network heat transfer
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Online model identification of lithium-ion battery for electric vehicles 被引量:3
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作者 胡晓松 孙逢春 邹渊 《Journal of Central South University》 SCIE EI CAS 2011年第5期1525-1531,共7页
In order to characterize the voltage behavior of a lithium-ion battery for on-board electric vehicle battery management and control applications,a battery model with a moderate complexity was established.The battery o... In order to characterize the voltage behavior of a lithium-ion battery for on-board electric vehicle battery management and control applications,a battery model with a moderate complexity was established.The battery open circuit voltage (OCV) as a function of state of charge (SOC) was depicted by the Nernst equation.An equivalent circuit network was adopted to describe the polarization effect of the lithium-ion battery.A linear identifiable formulation of the battery model was derived by discretizing the frequent-domain description of the battery model.The recursive least square algorithm with forgetting was applied to implement the on-line parameter calibration.The validation results show that the on-line calibrated model can accurately predict the dynamic voltage behavior of the lithium-ion battery.The maximum and mean relative errors are 1.666% and 0.01%,respectively,in a hybrid pulse test,while 1.933% and 0.062%,respectively,in a transient power test.The on-line parameter calibration method thereby can ensure that the model possesses an acceptable robustness to varied battery loading profiles. 展开更多
关键词 battery model on-line parameter identification lithium-ion battery electric vehicle
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Kinetic study of alkaline protease 894 for the hydrolysis of the pearl oyster Pinctada martensii 被引量:1
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作者 陈忻 陈华 +2 位作者 蔡冰娜 刘清钦 孙恢礼 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2013年第3期591-597,共7页
A new enzyme (alkaline protease 894) obtained from the marine extremophile Flavobacterium yellowsea (YS-80-122) has exhibited strong substrate-binding and catalytic activity, even at low temperature, but the character... A new enzyme (alkaline protease 894) obtained from the marine extremophile Flavobacterium yellowsea (YS-80-122) has exhibited strong substrate-binding and catalytic activity, even at low temperature, but the characteristics of the hydrolysis with this enzyme are still unclear. The pearl oyster Pinctada martensii was used in this study as the raw material to illustrate the kinetic properties of protease 894. After investigating the intrinsic relationship between the degree of hydrolysis and several factors, including initial reaction pH, temperature, substrate concentration, enzyme concentration, and hydrolysis time, the kinetics model was established. This study showed that the optimal conditions for the enzymatic hydrolysis were an initial reaction pH of 5.0, temperature of 30°C, substrate concentration of 10% (w/v), enzyme concentration of 2 500 U/g, and hydrolysis time of 160 min. The kinetic characteristics of the protease for the hydrolysis of P. martensii were obtained. The inactivation constant was found to be 15.16/min, and the average relative error between the derived kinetics model and the actual measurement was only 3.04%, which indicated a high degree of fitness. Therefore, this study provides a basis for the investigation of the concrete kinetic characteristics of the new protease, which has potential applications in the food industry. 展开更多
关键词 alkaline protease 894 Pinctada martensii kinetics model inactivation constant proteolysis rate degree of hydrolysis
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CFD Simulation of Flow and Mass Transfer in Structured Packing Distillation Columns 被引量:3
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作者 陈江波 刘春江 +1 位作者 袁希钢 余国琮 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2009年第3期381-388,共8页
Detailed investigation of flow behavior in structured packing distillation columns is of great importance in accurate prediction of process efficiency and development of more efficient and optimal equipment internals.... Detailed investigation of flow behavior in structured packing distillation columns is of great importance in accurate prediction of process efficiency and development of more efficient and optimal equipment internals. In this study, a three-dimensional two-phase flow model based on VOF method for simulating the hydrodynamics and mass-transfer behavior in a typical representative unit of the structured packing is developed. In the proposed model, the c 2 - ε c model is used for the closure of turbulent mass transfer equation. By solving the proposed model, the velocity distribution, phase fraction profile and concentration field are obtained. Using these data, the total liquid holdup, the wetted area and the separation efficiency [height equivalent to a theoretical plate (HETP)] are estimated. For testing the model validation, the simulated HETPs are compared with our previous experimental data obtained in a 150 mm-diameter column containing Mellapak 350Y operating at the pressures of 0.6-1.8 MPa. The compari-son shows that they are in satisfactory agreement, with an average absolute deviation (AAD) of 25.4%. 展开更多
关键词 structured packing two-phase flow model mass transfer height equivalent to a theoretical plate
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Flow stress behavior and constitutive modeling of 20MnNiMo low carbon alloy 被引量:1
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作者 王梦寒 王根田 王瑞 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第8期1863-1872,共10页
The hot deformation behavior of 20 Mn Ni Mo low carbon alloy was investigated by isothermal compression tests over wide ranges of temperature(1223-1523 K) and strain rate(0.01-10 s^(-1)). According to the experimental... The hot deformation behavior of 20 Mn Ni Mo low carbon alloy was investigated by isothermal compression tests over wide ranges of temperature(1223-1523 K) and strain rate(0.01-10 s^(-1)). According to the experimental true stress-true strain data, the constitutive relationships were comparatively studied based on the Arrhenius-type model, Johnson-Cook(JC) model and artificial neural network(ANN), respectively. Furthermore, the predictability of the developed models was evaluated by calculating the correlation coefficient(R) and mean absolute relative error(AARE). The results indicate that the flow stress behavior of 20 Mn NiM o low carbon alloy is significantly influenced by the strain rate and deformation temperature. Compared with the Arrhenius-type model and Johnson-Cook(JC) model, the ANN model is more efficient and has much higher accuracy in describing the flow stress behavior during hot compressing deformation for 20 Mn Ni Mo low carbon alloy. 展开更多
关键词 pressure vessel steel flow stress behavior constitutive model Arrhenius model Johnson-Cook model
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Salting-out effect of ionic liquids on isobaric vapor-liquid equilibrium of acetonitrile-water system
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作者 方静 赵蕊 +2 位作者 王辉 李春利 刘婧 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第8期1369-1373,共5页
This paper presents the vapor–liquid equilibrium(VLE) data of acetonitrile–water system containing ionic liquids(ILs) at atmospheric pressure(101.3 k Pa). Since ionic liquids dissociate into anions and cations, the ... This paper presents the vapor–liquid equilibrium(VLE) data of acetonitrile–water system containing ionic liquids(ILs) at atmospheric pressure(101.3 k Pa). Since ionic liquids dissociate into anions and cations, the VLE data for the acetonitrile + water + ILs systems are correlated by salt effect models, Furter model and improved Furter model. The overall average relative deviation of Furter model and improved Furter model is 5.43% and 4.68%, respectively. Thus the salt effect models are applicable for the correlation of IL containing systems. The salting-out effect theory can be used to explain the change of relative volatility of acetonitrile–water system. 展开更多
关键词 Salting-out effect Vapor–liquid equilibrium Separation Ionic liquid Acetonitrile
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Estimation of Partition Coefficients of Fe-S Protein Models: Se Substitutions in Fe4S4Cysn
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作者 Francisco Torrens Gloria Castellano 《Journal of Chemistry and Chemical Engineering》 2012年第10期867-877,共11页
The SCAP method allows a semiquantitative estimation of the partitioning of many solutes between numerous pairs of solvents. The organic solvent-water partition coefficients P are calculated. For FeaS4Cysn, the organi... The SCAP method allows a semiquantitative estimation of the partitioning of many solutes between numerous pairs of solvents. The organic solvent-water partition coefficients P are calculated. For FeaS4Cysn, the organic solvent-water partition coefficients for l-octanol Po, cyclohexane Pch and chloroform Pcf decay 4.46, 6.25 and 4.60 log units per Cys, respectively. The Po is of the same order of magnitude as CDHI (conformationally dependent hydrophobic index) calculations and Pch-cf as computations performed with a method by Leo and Hansch. The logPo-ch-cf mean relative errors are 17%, 25% and-17%, which represent mean and unsigned relative errors of -3% and 20%. On varying the number of Cys, the structures show hydrophobic moments indicative of amphipathic compounds. For Se substitutions in Fe4SeaCys,, Po-ch-cf drop 4.52, 6.30 and 4.66 exponents per Cys. With the reference calculations, Po-ch-cf decay 4.03, 4.80 and 5.76 exponents per Cys. For FeaS4 mSemCys4, the calculated similar partition coefficients and hydrophobic moments, and lower distance in dendrogram suggest a role of Fe-Se clusters in physiological processes. The analysis is extended to lysozyme and its secondary structures. 展开更多
关键词 Solvation parameter model partition coefficient hydrophobic moment iron-sulphur protein mixed-valence non-integeroxidation number.
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Properties of A=7-9 Drip-Line Nuclei in RMF Theory
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作者 WANG Cheng-Bin DONG Tie-Kuang +1 位作者 REN Zhong-Zhou ZHU Zhi-Yuan 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第5期895-898,共4页
The relativistic mean-field (RMF) theory is used to calculate the properties of A =7-9 drip-line nuclei ^7Li, ^7;9Be, ^8;9B, and ^9C. Systematic deviations between experimental and theoretical binding energies are f... The relativistic mean-field (RMF) theory is used to calculate the properties of A =7-9 drip-line nuclei ^7Li, ^7;9Be, ^8;9B, and ^9C. Systematic deviations between experimental and theoretical binding energies are found. Possible reasons of these systematic deviations are discussed in terms of pairing energy. The root-mean-square (rms) radii of matter distributions for these nuclei agree with the experimental data quite well. The one-proton halo structure in ^8B is reproduced well, and the two-proton halo in ^9C is predicted. The calculations show that the RMF theory is valid in studying the properties of light drip-line nuclei. 展开更多
关键词 RMF method drip-line nuclei nuclear structure
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Location Refinement and Power Coverage Analysis Based on Distributed Antenna
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作者 赵晓楠 侯春萍 +2 位作者 汪清 陈华 浦亮洲 《Transactions of Tianjin University》 EI CAS 2016年第1期7-10,共4页
To establish wireless channel suitable for the cabin environment, the power coverage was investigated with distributed antenna system and centralized antenna system based on the actual measurement of channel impulse r... To establish wireless channel suitable for the cabin environment, the power coverage was investigated with distributed antenna system and centralized antenna system based on the actual measurement of channel impulse response. The results indicated that the distributed antenna system has more uniform power coverage than the centralized antenna system. The average relative errors of receiving power of both antennas were calculated. The optimal position of the centralized antenna was obtained by Gaussian function refinement, making the system achieve a better transmission power with the same coverage effect, and providing a reference for antenna location in the future real communication in the cabin. 展开更多
关键词 CABIN distributed antenna power coverage
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Study on Residual Oil HDS Process with Mechanism Model and ANN Model
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作者 Ma Chengguo Weng Huixin (Research Center of Petroleum Processing, ECUST, Shanghai 200237) 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2009年第1期39-43,共5页
Based on the Residual Oil Hydrodesulfurization Treatment Unit (S-RHT), the n-order reaction kinetic model for residual oil HDS reactions and artificial neural network (ANN) model were developed to determine the sulfur... Based on the Residual Oil Hydrodesulfurization Treatment Unit (S-RHT), the n-order reaction kinetic model for residual oil HDS reactions and artificial neural network (ANN) model were developed to determine the sulfur content of hydrogenated residual oil. The established ANN model covered 4 input variables, 1 output variable and 1 hidden layer with 15 neurons. The comparison between the results of two models was listed. The results showed that the predicted mean relative errors of the two models with three different sample data were less than 5% and both the two models had good predictive precision and extrapolative feature for the HDS process. The mean relative error of 5 sets of testing data of the ANN model was 1.62%—3.23%, all of which were smaller than that of the common mechanism model (3.47%— 4.13%). It showed that the ANN model was better than the mechanism model both in terms of fitting results and fitting difficulty. The models could be easily applied in practice and could also provide a reference for the further research of residual oil HDS process. 展开更多
关键词 residual oil hydrodesulfurization (HDS) mechanism model artificial neural network (ANN) model
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HIGH-RESOLUTION NUMERICAL SIMULATION OF WIND ENERGY RESOURCE IN HAINAN PROVINCE AND ITS OFFSHORE WATERS
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作者 邢旭煌 朱蓉 +1 位作者 翟盘茂 俞卫 《Journal of Tropical Meteorology》 SCIE 2010年第3期292-298,共7页
With high resolution (1 kin), the distribution of wind energy resources in Hainan province and over its offshore waters is numerically simulated by using the Wind Energy Simulation Toolkit (WEST) model developed b... With high resolution (1 kin), the distribution of wind energy resources in Hainan province and over its offshore waters is numerically simulated by using the Wind Energy Simulation Toolkit (WEST) model developed by Meteorological Research Branch of Environment Canada. Compared with observations from eight coastal anemometric towers and 18 existing stations in the province, the simulations show good reproduction of the real distribution of wind resources in Hainan and over its offshore waters, with the relative error of annual mean wind speed being no more than 9% at the 70-m level. Moreover, based on the simulated results of WEST grids that are closest to where the eight wind towers are located, the annual mean wind speeds are further estimated by using the Danish software Wasp (Wind Atlas Analysis and Application Program). The estimated results are then compared with the observations from the towers. It shows that the relative error is also less than 9%. Therefore, WEST and WEST+WAsP will be useful tools for the assessment of wind energy resources in high resolution and selection of wind farm sites in Hainan province and over its offshore waters. 展开更多
关键词 wind energy resources Wind Energy Simulation Toolkit (WEST) wind speed high resolution numerical simulation
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Pattern design and realization for calibrating near infrared camera in surgical navigation 被引量:1
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作者 温小艳 刘素娟 +1 位作者 杨荣骞 王志刚 《Optoelectronics Letters》 EI 2012年第6期409-413,共5页
A calibration board composed of 8×8 near-infrared surface-mounted diodes(NIR-SMDs)(940 nm)is designed.Meanwhile,a common binocular measurement system with the average error less than 0.1320 mm is used to obtain t... A calibration board composed of 8×8 near-infrared surface-mounted diodes(NIR-SMDs)(940 nm)is designed.Meanwhile,a common binocular measurement system with the average error less than 0.1320 mm is used to obtain the geometric information of this board.A calibration method with the designed pattern is performed to obtain the parameters of the near-infrared camera(NIRC).In the experiment,the average relative errors of focal length and principal point are 0.244%and 0.735%,respectively.The mean of image residuals is less than 0.01 pixel.The error of three-dimensional(3D)measurement is less than 0.3 mm.All those results indicate that the designed calibration board is suitable and accurate for calibrating NIRC. 展开更多
关键词 Infrared devices
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Design and realization of random measurement scheme for compressed sensing 被引量:3
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作者 解成俊 徐林 《Optoelectronics Letters》 EI 2012年第1期60-62,共3页
Design and realization of random measurement scheme for compressed sensing (CS) are presented in this paper, and lower limits of the measurement number are achieved when the precise reconstruction is realized. Four ... Design and realization of random measurement scheme for compressed sensing (CS) are presented in this paper, and lower limits of the measurement number are achieved when the precise reconstruction is realized. Four kinds of random measurement matrices are designed according to the constraint conditions of random measurement. The performance is tested employing the algorithm of stagewise orthogonal matching pursuit (STOMP). Results of the experiment show that lower limits of the measurement number are much better than the results described in Refs.[ 13-15]. When the ratios of measurement to sparsity are 3.8 and 4.0, the mean relative errors of the reconstructed signals are 8.57 × 10^-13 and 2.43 × 10^-14, respectively, which confh-rns that the random measurement scheme of this paper is very effective. 展开更多
关键词 MEASUREMENTS Signal reconstruction
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Simultaneous determination of brilliant blue and indigotine by derivative fluorescence spectrometry combined with WT-RBFNN 被引量:1
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作者 马超群 陈国庆 +3 位作者 高淑梅 陈超 史院平 谷玲 《Optoelectronics Letters》 EI 2011年第2期158-160,共3页
The mixed solutions of brilliant blue and indigotine are prepared and the fluorescence spectra of them are experimentally measured. The serious overlapping spectra of brilliant blue and indigotine are solved by means ... The mixed solutions of brilliant blue and indigotine are prepared and the fluorescence spectra of them are experimentally measured. The serious overlapping spectra of brilliant blue and indigotine are solved by means of the first-derivative fluorescence spectrometry. The wavelet coefficients, obtained by compressing the spectral data using wavelet transformation (WT), are taken as inputs to establish the radial basis function neural network (RBFNN). The neural network model can realize simultaneous determination of brilliant bFue and indigotine, and the mean relative errors of both compounds are 1.84% and 1.26%, respectively 展开更多
关键词 Data compression FLUORESCENCE Fluorescence spectroscopy METADATA Radial basis function networks SPECTROMETRY Wavelet transforms
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PARAMETER IDENTIFICATION AND TERMINAL STEADY-STATE OPTIMIZATION FOR S SYSTEM IN MICROBIAL CONTINUOUS FERMENTATION 被引量:1
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作者 XIAOFANG LI RONGNING QU 《International Journal of Biomathematics》 2012年第2期73-83,共11页
In this paper, we propose a special S system to describe the process of continuous glycerol fermentation to 1,3-propanediol by Klebsiella pneurnoniae. Some properties of solution for S system are discussed. Moreover, ... In this paper, we propose a special S system to describe the process of continuous glycerol fermentation to 1,3-propanediol by Klebsiella pneurnoniae. Some properties of solution for S system are discussed. Moreover, in order to identify the values of parameters such that S system can simulate the fermentation as exactly as possible, we develop a param- eter identification model, and prove the identifiability of parameters. Numerical results show that the average relative error between computational value and experimental data is 20.0875% lower than 24.4225% in previous work, which demonstrates that S system is better in describing continuous fermentation. Finally, we present a terminal steady- state optimization model with state constraints. Optimization results show that the maximum volume yields of 1,3-propanediol at terminal moment increased from 114.3 to 124.911 mmol L-1 h-1. The results provide reference for the commercial production of 1,3-propanediol. 展开更多
关键词 S system continuous culture parameter identification steady optimization.
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