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分时段并行A/D转换精度理想量化数学模型 被引量:1
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作者 陶瓦 《重庆师范学院学报(自然科学版)》 1999年第2期66-72,共7页
给出信息的电压形式从模拟量到数字量精确转换所依赖的基础———A/D界面。揭示构成各类分时段并行A/D转换器量化界面基础性、共通性的各种要素性电路环节,对A/D量化界面电路进行全面整体数学抽象。在此基础上,给出分时段并... 给出信息的电压形式从模拟量到数字量精确转换所依赖的基础———A/D界面。揭示构成各类分时段并行A/D转换器量化界面基础性、共通性的各种要素性电路环节,对A/D量化界面电路进行全面整体数学抽象。在此基础上,给出分时段并行A/D转换精度理想量化数学模型,指明A/D界面电路全体相关因素的各种函数关系。 展开更多
关键词 量化数学模型 A/D转换精度 A/D转换器 A/D模块
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绿色建筑空调通风系统节能影响因素分析及验证 被引量:1
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作者 陈玮吉 《微型电脑应用》 2022年第6期205-208,共4页
针对绿色建筑领域耗材严重的问题,对绿色建筑空调通风系统节能影响因素进行分析。通过将影响室内温度的因素主要可以分成室内因素、建筑材料因素以及室外因素三种因素进行分类分析,采用间隙式空调运转模型减小空调运行时间,利用排气热... 针对绿色建筑领域耗材严重的问题,对绿色建筑空调通风系统节能影响因素进行分析。通过将影响室内温度的因素主要可以分成室内因素、建筑材料因素以及室外因素三种因素进行分类分析,采用间隙式空调运转模型减小空调运行时间,利用排气热回收技术对空气热能进行再利用,提高能量利用效率;并通过对外墙材料、室外影响因素以及室内与室外热传递模型进行分析,针对墙体热传导系数、窗墙比以及遮阳措施进行设计,有效地将空调工作状态和设定温度以数学模型量化表示,提高了宏观事物的微观分析能力。并对设计方案中多种影响因素进行对比分析,有效地选出最佳节能方案。通过对比实验,可以得出采用本研究设计的节能方案其整座建筑的能源消耗减少了50%以上。 展开更多
关键词 绿色建筑 热传递模型 数学模型量化 宏观事物 能源消耗
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Mathematical model for coupled reactive flow and solute transport during heap bioleaching of copper sulfide 被引量:5
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作者 尹升华 吴爱祥 +1 位作者 李希雯 王贻明 《Journal of Central South University》 SCIE EI CAS 2011年第5期1434-1440,共7页
Based on the momentum and mass conservation equations, a comprehensive model of heap bioleaching process is developed to investigate the interaction between chemical reactions, solution flow, gas flow, and solute tran... Based on the momentum and mass conservation equations, a comprehensive model of heap bioleaching process is developed to investigate the interaction between chemical reactions, solution flow, gas flow, and solute transport within the leaching system. The governing equations are solved numerically using the COMSOL Multiphysics software for the coupled reactive flow and solute transport at micro-scale, meso-scale and macro-scale levels. At or near the surface of ore particle, the acid concentration is relatively higher than that in the central area, while the concentration gradient decreases after 72 d of leaching. The flow simulation between ore particles by combining X-ray CT technology shows that the highest velocity in narrow pore reaches 0.375 m/s. The air velocity within the dump shows that the velocity near the top and side surface is relatively high, which leads to the high oxygen concentration in that area. The coupled heat transfer and liquid flow process shows that the solution can act as an effective remover from the heap, dropping the highest temperature from 60 to 38 ℃. The reagent transfer coupled with solution flow is also analyzed. The results obtained allow us to obtain a better understanding of the fundamental physical phenomenon of the bioleaching process. 展开更多
关键词 copper sulphide heap bioleaching leaching reaction solution flow solute transport
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Study on the Mathematical Model of Hydraulic Jump Atomization 被引量:2
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作者 张华 练继建 刘昉 《Transactions of Tianjin University》 EI CAS 2004年第1期71-76,共6页
An equation of atomization quantity from energy dissipation by hydraulic jump was derived from the dimensional analysis. By applying Gauss diffusion equation, the spray diffusion rule in valley was studied under the c... An equation of atomization quantity from energy dissipation by hydraulic jump was derived from the dimensional analysis. By applying Gauss diffusion equation, the spray diffusion rule in valley was studied under the condition of continuous linear source and random wind direction.By considering the spray rain switching process, coagulation, condensation and evaporation of droplets, the air temperature, air relative humidity, spray density and the rainfall intensity in the lower reaches of the linear source were calculated. The 3 D numerical simulation fitted well with prototype monitoring. Finally, the prediction of atomization influence on environments for Xiangjiaba Hydropower Station was conducted. 展开更多
关键词 energy dissipation by hydraulic jump ATOMIZATION numerical simulation
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Mathematic Model of Unsteady Penetration Mass Transfer in Randomly Packed Hollow Fiber Membrane Module 被引量:2
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作者 张秀莉 张泽廷 +1 位作者 张卫东 郝欣 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2004年第2期185-190,共6页
Based on the membrane-based absorption experiment of CO2 into water, shell-side flow distribution and mass transfer in a randomly packed hollow fiber module have been analyzed using subchannel model and unsteady penet... Based on the membrane-based absorption experiment of CO2 into water, shell-side flow distribution and mass transfer in a randomly packed hollow fiber module have been analyzed using subchannel model and unsteady penetration mass transfer theory. The cross section of module is subdivided into many small cells which contains only one hollow-fiber. The cross sectional area distribution of these cells is presented by the normal probability density distribution function. It has been obtained that there was a most serious non-ideal flow in shell side at moderate mean packing density, and the large amount of fluid flowed and transferred mass through a small number of large voids. Thus mass transfer process is dominated by the fluid through the larger void area. The mass transfer process in each cell is described by the unsteady penetration theory. The overall mass transfer coefficient equals to the probability addition of the mean mass transfer coefficient in each cell. The comparisons of the values calculated by the model established with the empirical correlations and the experimental data of this work have been done.The predicted overall mass transfer coefficients are in good agreement with experimental data. 展开更多
关键词 hollow fiber membrane module mass transfer membrane separation mathematic model
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Model-based optical metrology and visualization of 3-D complex objects 被引量:2
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作者 LIU Xiao-li LI A-meng +3 位作者 ZHAO Xiao-bo GAO Peng-dong TIAN Jin-dong PENG Xiang 《Optoelectronics Letters》 EI 2007年第2期115-118,共4页
This letter addresses several key issues in the process of model-based optical metrology, including three dimensional (3D) sensing, calibration, registration and fusion of range images, geometric representation, and v... This letter addresses several key issues in the process of model-based optical metrology, including three dimensional (3D) sensing, calibration, registration and fusion of range images, geometric representation, and visualization of reconstructed 3D model by taking into account the shape measurement of 3D complex structures,and some experimental results are presented. 展开更多
关键词 三维复杂目标 可视化 光学计量 数学模型 距离象 图象融合
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Evaluation of straightening capacity of plate roll straightener 被引量:1
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作者 王勇勤 刘志芳 严兴春 《Journal of Central South University》 SCIE EI CAS 2012年第9期2477-2481,共5页
Straightening machine is widely used for improving the quality of the defective mild steel plates.In general,the capacity of straightening machine is affected by material properties,the initial shape of the incoming p... Straightening machine is widely used for improving the quality of the defective mild steel plates.In general,the capacity of straightening machine is affected by material properties,the initial shape of the incoming plate and the plastic ratio.The mechanics model describing the capacity of the machine was developed.The deviation of the straightening capacity curves was studied.Then,the presented model was evaluated by comparative study to filed production data.Finally,the influences of overstretch,straightening speed,strengthening coefficient,elastic modulus,width of the plate on the straightening capacity were studied.It is convenient to determine whether the plate can be straightened or not by a series of straightening capacity curves.The straightening speed,width of the plate and elastic modulus of the material are more sensitive to the straightening capacity than the strengthening coefficient. 展开更多
关键词 plastic ratio straightening capacity strengthening factor PLATE
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Modeling of Solar Thermochemical Receiver
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作者 A. Torres R. Lugo +1 位作者 M. Salazar E. Bonilla 《Journal of Energy and Power Engineering》 2011年第11期1015-1020,共6页
This work provides information for an optimal design of a thermochemical storage system, through a proposed mathematical model that predicts the behavior of a solar fluidized bed receiver finding the temperature and c... This work provides information for an optimal design of a thermochemical storage system, through a proposed mathematical model that predicts the behavior of a solar fluidized bed receiver finding the temperature and concentration profiles in transient state. The mathematical model is developed for a fluidized bed solar reactor, taking into account dynamics conditions of heating and reaction. The heating was simulated for radiated flux with a normal distribution over lateral walls and with distributed flow conditions of the focal stain. The contraction and expansion effects of the bed were involved with a two dimensional distribution. The mathematical model of a solar fluidized bed reactor involves a reversible chemistry reaction of thermal dissociation of the zinc sulfate (ZnSO4), also the mathematical model is accomplished by a sensitivity study with regard to the gas inlet temperature and radiation flux. 展开更多
关键词 THERMOCHEMICAL fluidized bed solar reactor dissociation of the zinc sulfate.
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Comparison on Non-isothermal Oxidation between Spent Catalytic Cracking Catalysts and Coal
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作者 Men Xiujie Zhan Shuhong +2 位作者 Li Yanjun Wang Zijun Wang Xieqing (Research Institute of Petroleum Processing,SINOPEC,Beijing 100083) 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2010年第2期33-40,共8页
Oxidation of coke deposited on spent catalytic cracking catalysts was compared with that of coal and coal char via the non-isothermal oxidation means, i.e. the thermal-gravimetric analysis (TGA) and the differential... Oxidation of coke deposited on spent catalytic cracking catalysts was compared with that of coal and coal char via the non-isothermal oxidation means, i.e. the thermal-gravimetric analysis (TGA) and the differential thermal analysis (DTA). Oxidation kinetic parameters were further investigated by model-fitting methods. The test results showed that the oxidation of spent catalysts was a quite mild process, while coal and coal char experienced sharp weight loss during oxidation. The temperature for commencement and termination of oxidation increased in the following order: coal〈coal char〈spent catalysts, and the oxidation of the three tested materials displayed a self-catalytic nature, with their largest oxidation rate appearing at a weight percent of 24.96%, 34.21% and 57.93%, respectively. The oxidation of spent catalysts obeyed a random nucleation model for the first-order reaction, with Ea=206.13 kJ/mol and lgA=10.10, and the oxidation of coal could be a diffusion-controlled reaction mechanism, with Ea=161.61 kJ/mol and lgA=7.74, while the oxidation of coal char also obeyed a random nucleation model for the first-order reaction, with Ea= 149.36 k J/mol and lgA=7.89. 展开更多
关键词 spent catalysts COAL coal char non-isothermal oxidation TGA oxidation kinetics and mechanism
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No evidence for the evolution of mass density power-law index γ from strong gravitational lensing observation
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作者 Jing-Lei Cui Hai-Li Li Xin Zhang 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2017年第8期8-14,共7页
In this paper, we consider the singular isothermal sphere lensing model that has a spherically symmetric power-law mass dis- tribution ρtot(r) - r-γ. We investigate whether the mass density power-law index y is co... In this paper, we consider the singular isothermal sphere lensing model that has a spherically symmetric power-law mass dis- tribution ρtot(r) - r-γ. We investigate whether the mass density power-law index y is cosmologically evolutionary by using the strong gravitational lensing (SGL) observation, in combination with other cosmological observations. We also check whether the constraint result of y is affected by the cosmological model, by considering several simple dynamical dark energy models. We find that the constraint on y is mainly decided by the SGL observation and independent of the cosmological model, and we find no evidence for the evolution of y from the SGL observation. 展开更多
关键词 strong gravitational lensing mass density power-law index dynamical dark energy cosmological parameter estimation
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