大学物理实验教案-霍尔效应

relationship between Government and business. The two sessions, General Secretary of Pro, clear the word succinctly summarized the new relationship between Government and business, as pure politics, reshaping the political relationship specified in the direction. District leaders in handling political and business relations, engage in trading power for money, and finally stumbled, we a lesson, always keep in mind that Pro, clean practicing Pro, clear. Pro is to open a sincere engagement with private enterprise to help solve practical difficulties; Clear is to clarify the Division of power, exercised in accordance with, private entrepreneurs with innocent purity, not abusing power for personal gain, not to engage in trading power for money. Third, in order to maintain fairness and justice. Fairness and justice is the lifeline of the rule of law, is the best development environment. Currently, lax law enforcement and the judicial sector in our region also exist to varying degrees, law enforcement departments and individual window units power for personal gains and bribes, thick friends, relations, human cases, money cases in which seriously infringe on the legitimate rights and interests of enterprises and people. Especially some law enforcement and inspection for profit purposes, deliberately looking for corporate loopholes, found directly under the ticket does not give business improvement opportunities. We recruit a company doesnt easily, cultivating a business more difficult, never for personal gain, systematic harassment, card, last checked to check to get the enterprise collapsed. To guarantee the legitimate rights and interests. Always proceed from the overall situation of reform and development of services, fully consider the characteristics of production and management in non-public enterprises and social benefits, an accurate grasp of legal limits, protect the enthusiasm of entrepreneurs and practitioners in innovation and entrepreneurship, enhancing expectations and confidence. To promote strict enforcement. Strengthening law enforcement procedures, improve law enforcement performance evaluation, strengthening the supervision of law enforcement, exploration and practice of risk control mechanism of law enforcement to further standardize the social security, urban management, road traffic administrative law enforcement, effectively free, extensive law-enforcement and lax enforcement of law enforcement and other issues. To uphold justice. Justice is the last line of Defense to safeguard fairness and justice, to unequivocally support the courts and procuratorates independently exercise level . Judicial activities were rampant, must not be allowed to run, favors, money, must not be allowed to knowingly violate the miscarriage, violations of the legitimate rights and interests of the masses must not be allowed to abuse of power, to make forest mass can be felt in every judicial cases in equity and justice. Four to deepen grass-roots governance according to lawchain do long, and put scale big. To serve the development of enterprises. Duocuo simultaneously improving service efficiency, build better public services platform, enhance work efficiency, initiative to help businesses solve the project procedures, financing loans, issues such as land-use approval, reduce operating costs, business travel light and enhance the confidence to overcome all kinds of difficulties and the Foundation, real entrepreneurial passion play entrepreneurship, enhance the internal vitality and creativity. SI XING an construction, promoting the rule of law, tries to make the transformation of forest development XI General Secretary stressed, to reinvigorate Northeast China, optimized development environment is very important. Environment of rule of law most gather Moss, the most conducive to development. Improving the leading cadres using the method of thought and the rule of law Administration work, problem-solving, the ability to promote the development, is the key to promoting the rule of law. The law may affect the efficiency of out of the path of development will be more smooth, won development gains will be sustained, and end with greater efficiency. Leading cadres at all levels should take the lead in respect of law law, abide by, and actively foster Socialist culture, actively promoting the field of multi-level governance according to law, guide the masses and consciously abide by the law, failing to find law, solve the problem by law, in accordance with the law prevail. XXX administration by law of leading cadres do not exist on the rule of law, law enforcement, casual, and vow not to investors, the new scores and other turmoil. These important expositions on my district create good development environment with highly targeted and guidance, especially the General Secretary pointed out that the chaos in my area also exists to varying degrees, some even quite serious. Leading cadres at all levels must improve the development environment of rule of law as a fundamental task, adhere to the problem oriented, solid and solve the problems in the construction of rule of law, to rule the new effect for development environment improvements. To hold key minority. Leaders of this group, although few in number, but the effect is critical. If a local leaders take the lead right according to law, in accordance with the law, the local CPPCC fresh, pragmatic and efficient development environment. Conversely, if a local leaders of ignoring the law, impunity, not only the political environment will be destroyed, will have serious implications for the development environment. Now, some leading cadres lack of awareness on the importance of learning, that learn or not does not matter. Think efficiency is too low too much, act according to the procedure, than an executive order getting along with. In dealing with complex issues, often speak of settling and done; on the issue of handling letters and visits, like to spend money and buy stop and stable, but disregard the law administration, in accordance with the law, the rulechain do long, and put scale big. To serve the development of enterprises. Duocuo simultaneously improving service efficiency, build better public services platform, enhance work efficiency, initiative to help businesses solve the project procedures, financing loans, issues such as land-use approval, reduce operating costs, business travel light and enhance the confidence to overcome all kinds of difficulties and the Foundation, real entrepreneurial passion play entrepreneurship, enhance the internal vitality and creativity. SI XING an construction, promoting the rule of law, tries to make the transformation of forest development XI General Secretary stressed, to reinvigorate Northeast China, optimized development environment is very important. Environment of rule of law most gather Moss, the most conducive to development. Improving the leading cadres using the method of thought and the rule of law Administration work, problem-solving, the ability to promote the development, is the key to promoting the rule of law. The law may affect the efficiency of out of the path of development will be more smooth, won development gains will be sustained, and end with greater efficiency. Leading cadres at all levels should take the lead in respect of law law, abide by, and actively foster Socialist culture, actively promoting the field of multi-level governance according to law, guide the masses and consciously abide by the law, failing to find law, solve the problem by law, in accordance with the law prevail. XXX administration by law of leading cadres do not exist on the rule of law, law enforcement, casual, and vow not to investors, the new scores and other turmoil. These important expositions on my district create good development environment with highly targeted and guidance, especially the General Secretary pointed out that the chaos in my area also exists to varying degrees, some even quite serious. Leading cadres at all levels must improve the development environment of rule of law as a fundamental task, adhere to the problem oriented, solid and solve the problems in the construction of rule of law, to rule the new effect for development environment improvements. To hold key minority. Leaders of this group, although few in number, but the effect is critical. If a local leaders take the lead right according to law, in accordance with the law, the local CPPCC fresh, pragmatic and efficient development environment. Conversely, if a local leaders of ignoring the law, impunity, not only the political environment will be destroyed, will have serious implications for the development environment. Now, some leading cadres lack of awareness on the importance of learning, that learn or not does not matter. Think efficiency is too low too much, act according to the procedure, than an executive order getting along with. In dealing with complex issues, often speak of settling and done; on the issue of handling letters and visits, like to spend money and buy stop and stable, but disregard the law administration, in accordance with the law, the rule大学物理实验教案 实验名称霍尔效应教学时数4学时教学目的和要求1、了解霍尔效应原理。2、了解霍尔电势差V与霍尔元件工作电流之间的关系，了解霍尔电势差V与励磁电流之间的关系。3、学习用“对称交换测量法”消除负效应产生的系统误差。4、学习利用霍尔效应测量磁感应强度B的原理和方法。教学重点1、霍尔效应原理。2、对称交换测量法消除负效应产生的系统误差。3、用霍尔元件测量磁场的原理和方法。教学难点1、用霍尔元件测量磁场的原理和方法。2、霍尔电压测量时产生附加电压的消除方法教学内容1、真空中载流长直螺线管内部的磁感应强度为。2、 霍尔效应一通电薄条在电场垂直方向加一磁场，结果发现在电场与磁场都垂直的方向上会出现一个电场。 3 霍尔电压的测量 实际测量时所测的电压不是，还包括其它因素带来的附加电压：（1）不等势电压VO， （2）厄廷豪森效应VE，（3）能斯脱效应VN， （4）里记勒杜克效应VRL，我们可通过改变IS、B的方向的办法，使在不同的测量条件下抵消这些因素的影响。教学方法教师讲解教学内容，明确其重点和难点，然后实际演示操作要点。教学手段学生操作，随堂检查操作情况。根据学生的操作情况将容易犯错的问题做重点提示，学生可以根据操作中遇到的具体问题个别提问。时间分配第一次课讲授30分钟，学生操作70分钟，做霍尔效应。第二次课做测量螺线管磁场部分。板书设计实验目的、实验原理、测量关系式、数据处理提示。主要参考资料1、杨述武等，普通物理实验（第四版）M. 北京：高等教育出版社，2007.2、郑庚兴，大学物理实验M. 上海：上海科学技术文献出版社，2004.3、黄水平，大学物理实验M. 北京：机械工业出版社，2012.4、徐扬子，丁益民，大学物理实验M. 北京：科学出版社，2006.5、李蓉，基础物理实验教程M. 北京：北京师范大学出版社，2008.实验名称：霍尔效应实验目的：1、了解霍尔效应原理。2、了解霍尔电势差V与霍尔元件工作电流之间的关系，了解霍尔电势差V与励磁电流之间的关系。3、学习用“对称交换测量法”消除负效应产生的系统误差。4、学习利用霍尔效应测量磁感应强度B的原理和方法。实验仪器：TH-H霍尔效应实验仪 TH-H霍尔效应测试磁场测试仪实验原理：一、霍尔效应原理若将通有电流的导体置于磁场之中，磁场（沿z轴）垂直于电流（沿x轴）的方向，如图所示，则在导体中垂直于和的方向上出现一个横向电势差，这个现象称为霍尔效应。 ISEH+FB+-zyxACCAbd 这一效应对金属来说并不显著，但对半导体非常显著。利用霍尔效应可以测定载流子浓度、载流子迁移率等重要参数，是判断材料的导电类型和研究半导体材料的重要手段。还可以用霍尔效应测量直流或交流电路中的电流强度和功率，以及把直流电流转成交流电流并对它进行调制、放大。用霍尔效应制作的传感器广泛用于磁场、位置、位移、转速的测量。 霍尔电势差产生的本质，是当电流通过霍尔元件（假设为型，即导电的载流子是空穴。）时，空穴有一定的漂移速度v，垂直磁场对运动电荷产生一个洛仑兹力 （1）式中为载流子电荷。洛沦兹力使载流子产生横向的偏转，由于样品有边界，所以有些偏转的载流子将在边界积累起来，产生一个横向电场E，直到电场对载流子的作用力FE=qE与磁场作用的洛沦兹力相抵消为止，即 （2）这时载流子在样品中流动时将不偏转地通过霍尔元件，霍尔电势差就是由这个电场建立起来的。如果是型样品，即导电的载流子是电子，则横向电场与前者相反，所以型样品和型样品的霍尔电势差有不同的符号，据此可以判断霍尔元件的导电类型。设型样品的载流子浓度为，宽度为，厚度为。通过样品电流，则空穴的速度，代入（2）式有 （3）上式两边各乘以，便得到 （4）霍尔电压（、之间电压）与、的乘积成正比，与霍尔元件的厚度成反比，比例系数，称为霍尔系数。它是反映材料霍尔效应强弱的重要参数。 （5）在应用中一般写成 （6）比例系数，称为霍尔元件灵敏度，单位为mV/(mAT)。一般要求愈大愈好。与载流子浓度成反比，半导体内载流子浓度远比金属载流子浓度小，所以选用半导体材料作为霍尔元件。与片厚成反比，所以霍尔元件都做的很薄，一般只有0.2mm厚。由（4）式可以看出，知道了磁感应强度，只要分别测出传导电流及霍尔电势差，就可算出霍尔系数和霍尔元件灵敏度。二、由确定以下参数（1）由的符号（或霍尔电压的正负）判断样品的导电类型。判断的方法是按图所示的和的方向，若测得的0,（即电流流入端电势高于流出端的电势），则为正，样品属型，反之则为型。（2） 由求载流子浓度，即。应该指出，这个关系是假定所有载流子都具有相同的漂移速度得到的（严格一点，应考虑载流子的速度统计分布，在若磁场下应引入一个修正因子）。（3）结合电导率的测量，求载流子的迁移率。电导率可以通过图6-1所示的、（或、）电极进行测量。设、间的距离为，样品的横截面积为，流过样品的电流为。在零磁场下，若测得、间的电压为（ 即），可由下式求得。 （6-7）根据材料的电导率关系，即，或者，测出值即可求。式中为载流子的迁移率，即单位电场下载流子的运动速度。一般电子的迁移率比空穴迁移率大，所以霍尔元件多采用型材料。三、霍耳元件副效应的影响及其消除1霍耳元件的副效应在研究固体导电过程中，继霍耳效应之后不久又发现了厄廷豪森（Etinghausen）、能斯特（Nernst）和里纪勒杜克（Righi-Ledue）效应，它们都归属于热磁效应。 （1）厄廷豪森效应1887年厄廷豪森发现，由于载流子的速度不相等，它们在磁场的作用下，速度大的受到洛仑兹力大，绕大圆轨道运动；速度小的则绕小圆轨道运动，这样导致霍耳元件的一端较另一端具有较多的能量而形成一个横向的温度梯度。因而产生温差电效应，形成电势差，记为。其方向决定于和磁场B的方向，并可判断与始终同向（2）能斯特效应由于输入电流端引线的焊接点a、b处的电阻不相等，通电后发热程度不同，使a和b两端之间存在温度差，于是在a和b之间出现热扩散电流。在磁场的作用下，在c、e两端出现了横向电场，由此产生附加电势差，记为。其方向与无关，只随磁场方向而变。（3）里纪勒杜克效应由于热扩散电流的载流子的迁移率不同，类似于厄廷豪森效应中载流子速度不同一样，也将形成一个横向的温度梯度，以产生附加电势差，记为。其方向只与磁场方向有关，且与同向。2不等势电势差 不等势电势差是由于霍耳元件的材料本身不均匀，以及电压输入端引线在制作时不可能绝对对称地焊接在霍耳片的两侧所引起的，如图所示。因此，当电流流过霍耳元件时，在电极3、4之间也具有电势差，记为，其方向只随方向不同而改变，与磁场方向无关。3副效应的消除根据以上副效应产生的机理和特点，除外，其余的都可利用异号法消除其影响，因 图2 能斯特效应 图3 不等势电势差而需要分别改变和B的方向，测量四组不同的电势差，然后作适当的数据处理，而得到。取、测得取、测得取、测得取、测得消去、和得因，一般可忽略不计，所以 （7）本实验要利用霍尔效应测量长直螺线管轴线上的磁感应强度。实验内容1、 掌握仪器性能，连接测试仪与实验仪各组之间的连线（1）开关机前，测试仪的“IS调节”和“IM调节”旋钮均置零位（即逆时针旋到底）。（2）连接测试仪和实验仪之间各组的连线。2、绘VHIS曲线将测试仪的“功能切换”置VH，取IM=0.600A，分别取IS=0.50,1.00,1.50，2.00,2.50,3.00mA，依次测量+IS, +B；+IS,B；IS,B；IS, +B相应的VH,值。 3、测绘VHIM曲线保持IS值不变（取IS=2. 00mA），分别取IM=0.100,0.200，0.300，0.400,0.500，0.600A，依次测量+IS, +B；+IS,B；IS,B； IS, +B相应的VH值。 4、在零磁场下，取IS=0.20mA，测量实验数据记录与处理 2.0 KGS/A1、 1.2T0.500.71-0.630.66-0.720.681.001.44-1.361.35-1.451.41.502.16-2.032.02-2.182.092.002.88-2.212.69-2.872.662.503.59-3.383.40-3.583.483.004.30-4.054.06-4.314.18以为横坐标，为纵坐标作图，求斜率k霍尔系数为1.4*0.50/1.2=0.583判断导电类型载流子浓度75.2 2、0.1000.52-0.390.40-0.510.4450.2000.99-0.850.83-1.000.9170.3001.45-1.311.33-1.441.380.4001.92-1.781.79-1.931.850.5002.40-2.242.23-2.412.320.6002.87-2.702.71-2.882.79以为横坐标，为纵坐标作图，求斜率kK=3.893、电导率 载流子的迁移率参与本物业的竣工验收，并在物业移交接管时，与甲方办理物业管理书面交接手续；本物业交付使用后的质量标准.说课标就是要把课程标准中的课程目标（三维目标）作为本课题教学的指导思想和教学依据，从课程论的高度驾驭教材和指导教学设计。Grass-roots governance according to law is an important foundation for promoting the construction of rule of law, but also the most basic development environment. Despite my good social order in General, but there are law-abiding consciousness, social order is not standard, regardless of faith, Twining visit visit and other outstanding problems. We want to actively promote the field of multi-level governance according to law, promote the continuous improvement of the social environment. To promote universal compliance. Actively foster the rule of law culture, carry out law publicity and education on honesty and trustworthiness, guide the masses and consciously abide by the law, failing to find method, problem-solving method, method of gradually changing the world, he is not looking for but someone unspoken rules, formed all law law, abide by the good atmosphere. To strengthen the comprehensive management of public security. Deepening peace xingan construction, strongly against violence crime, mafia and serious criminal offences, to protect the legitimate rights and interests of citizens, legal persons, carry out criminal policy of temper justice with mercy, the maximum stimulating social vitality, and earnestly safeguard social harmony and stability. To resolve social conflicts by law. To further smooth channels of reporting social conditions and public opinion, improving regulation, arbitration, as well as dispute resolution mechanisms, implement fully the petitioners cases third-party hearings and supervising system of letters and calls, and to resolve the involved law lawsuit into the orbit of rule of law, vexatious, Twining visit visit, disturbing social order and other malicious extortion, resolutely crack down. Five, improving cadres Vitale, provide strong protection for forest development XI General Secretary stressed that the comprehensive revitalization in Northeast China, needs a high quality, solid style, cadres of the dare to play. Cadre cadres is a pledge, should want to do work and able to do good, enthusiasm is paramount. Treat party cadres, it is necessary to Strict management, and warm care, enable the broad masses of cadres work hard work, this is two parallel principles. In strict accordance with the standards of good cadres selection and appointment, the real officers, dare officers, those who want to play, good as excellent cadres at all levels of leadership in the past. At present, some leading cadres work initiative is not high, beyond political, idle, lazy governance governance, not as, slow, messy and a phenomenon still exist to varying degrees, affected and restricted economic and social development. We must mobilize the enthusiasm of cadres as an urgent task, adhere to combination of incentives and constraints, and adhere to the strict management and warm care, practical solution for the officers not to problem, motivate cadres and better lead the masses to an undertaking, the cadres and create the new achievement in a dare to play, good at shows as new. To identify the problem, accurate pulseof law to visit and contribute to make visits to the vexatious visits arrogance. On these issues, we need to have a proper understanding, should take the lead to establish a sense of fear of the law, strengthen the application of the rule of law and the rule of law work of thinking and take up responsibility for the construction of the rule of law. Put learning first. Premise is ignorant of the law, abide by the law. Leading cadres at all levels should take the lead in studying the Constitution and laws and regulations closely related to work assumed by, an accurate grasp of the basic position of our party to address the issue of the rule of law, known for the scale to do things, figure out how to use it right, what things do, what not to do, it can never legal literacy. To enhance the awareness of the rule of law. Firmly establish the supremacy of constitutional law, legal equality before the, right by the law makes the right to statutory, as we