4节蓄电池串联智能充电器的设计

本文针对4节蓄电池串联充电时容易出现过充或欠充现象,设计了一种带均衡功能的智能充电器,同时对充电过程中的电池电压和充电电流提出了新的检测思路;并根据锂电池的充电特性曲线设计了充电器的软件.该充电器具有均衡作用,充电效率高.     

智能型镍镉充电器系统的设计

蓄电池被广泛的应用于工业和家用电子设备中,由于蓄电池的成本低,可以多次循环充电使用,符合国家节能环保的要求。市面上的镍镉充电器种类繁多,好的充电器可以延长电池的寿命,不好的充电器在充电工程中可以使电池发热,甚至出现过冲现象,会使充电池有爆炸的危险。市面上的充电多以检测电池温度和充电时间来确定电池是否充满。而现在研究的充电器除了以上检测功能以外,通过加入了电池的负压检测,来检测电池是否已经充满。充电器可以充6~15节电池,充电器通过MCU检测电池状态来控制外部硬件,形成一个闭环控制系统。     

HEV再生制动时电池快速充电模糊控制策略

为了提高混合动力汽车(HEV)再生制动时蓄电池的充电效率,保证蓄电池的使用安全,在分析蓄电池充电过程热交换模型的基础上,建立了电池开路电压-内阻模型与充电效率间的数学关系.然后,基于马斯定律,设计了适用于HEV再生制动时电池快速充电模糊控制算法.在Mat1ab环境下搭建了闭环控制系统仿真模型,通过建模与仿真计算出HEV在不同控制策略下的电能回收率.结果表明在相同制动情况下,设计的快速充电模糊控制策略与限流充电控制策略相比,电能回收率增加了8.41％.     

电动车用智能型快速充电器的研制

基于 PIC单片机和 DC/DC功率变换器 ,研制成功了智能控制型快速充电器。文章对新型的充电方案作了阐述 ,提出了充电器的硬件电路和控制软件的设计方案。该充电器成本低 ,性能可靠 ,能正确地监控和测量蓄电池状态。经检验测试和用户试用 ,充电效果较好 ,效率高 ,充电方案新颖。该充电方案对充分发挥蓄电池的功效 ,提高对蓄电池的充电速度 ,减少充电损耗 ,延长蓄电池的使用寿命具有重要意义     

基于CAN总线的车载充电器研制

根据CAN总线协议,设计了单片机的接口电路及车载智能充电器．充电器与整车ECU构成一个闭环的电池充电控制管理系统,根据ECU的命令和策略对电池充电．充电器主要由SH8F516CPU、CAN总线接口电路、主充电电路等组成．利用数字PID算法实现对充电电流和电压的调节．介绍了充电器总体软件设计流程,针对某引进混合动力车ECU的应用,给出了该充电器的充电电流电压准确度．实际充电过程和使用证明：基于CAN总线的车载充电器具有更好的适应性,能与各种车辆配套,在ECU的控制下能对不同类型和性能的电池充电．     

基于AVR单片机的太阳能路灯照明系统设计

结合蓄电池的充电方法和特性,设计了基于ATmega 48单片机为核心的太阳能路灯照明系统,包括太阳能电池、蓄电池、充电电路、驱动电路和指示电路等,通过单片机软件算法编程科学地控制功率开关管的导通与关断,对蓄电池的充放电和路灯加以控制,科学地采用不同百分比的PWM对蓄电池进行充电,依据不同的需求选择不同工作模式进行供电照明。     

脉冲电池充电器电路

脉冲电池充电器以周期方式为电池充电。一般来说,此类充电器包括电压检测电路、控制电路和驱动器电路。电压检测电路检测电池的电压,控制电路确定如何根据所检测到的电池电压对电池进行充电,驱动器电路提供对电池充电所需的电流,并利用开关式电流源实现周     

基于MPPT的太阳能充电控制器的设计

本文设计了一种具有MPPT功能的光伏发电充电控制器。通过单片机检测蓄电池充电电压、充电电流的大小,自动切换充电器的工作状态,有效地提高了蓄电池的寿命。在光照条件不足时,蓄电池的电压,电流未超出给定值,开启MPPT功能,保证整个系统最大效率的充电。经matlab仿真,该设计具有可行性。     

带温度补偿电路的铅酸蓄电池充电器

许多电器和电子设备常用可多次充电的蓄电池作为电源,其中以镍镉电池为理想,但价格昂贵,且充电电流必须恒定。而与镍镉电池相比,容量相同,铅酸蓄电池要经济得多。 为保证铅酸蓄电池完全充电,一般应采用“浮充”充电方式。图1为铅酸蓄电池充电器的     

矿用铅酸蓄电池高频智能快充充电器控制系统研究

针对矿用铅酸蓄电池充电器,研究了一款高频智能快充充电器的控制系统,由多环节功率变换单元组成,能量双向流动。在分析其工作原理的基础上,基于DSP给出了系统的硬件电路、软件实现方案及电路结构,采用移相PWM控制算法,实现了变电流智能快速充电放电方法。实验表明了该充电器控制系统设计的可行性和正确性,可自动匹配最佳充电放电曲线,实现了快速充电放电,性能指标优越,可以在行业内推广应用。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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Brief Introduction to “Journal of Jilin University( Science Edition) ”

<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has