2022年八年级物理下册知识点归纳 2.pdf
thrift of excellent traditional and style lack deep of understandi ng, one-sided think in now of good situation Xia, economic smooth more fast developme nt, and reform made major progress, and people living significantly improve, and social the career made new progress, no necessary always hard has, no awareness to Chi na also has many poverty area, and also has many poverty population of exists, more living improve has, more need keep hard of style. Three is not strictly honest. Total thought units is a water sector, clean self-disci pline away from himself too far, no real processing good living of improve and hard, and thrift excellent traditional of relationship, no effective do comply with Constitution and party of regulations must from I do up, no right mercy good bitter Le, and wealth of relationship, no right awareness to in comply with Constitution and party of regulations aspe cts everyone has accountability. Four, future dire ction and improvement measures 1, belief and faith, strengthen party spirit. One is to firmly establish the noble ideals of struggle for the ideals of communism, communist struggle for life, ready to sacrifice everything for the party and the pe ople. Second is to continuously improve the quality and standard of political, conscientiously study Deng Xiaopi ng theory and three represents important thought an d the scientific Outlook on devel opment, implement the partys basic program for the primary stage of socialism, adhere to the correct political orientation, maintain highly consistent with the CPC Central Committee, is good at theories of socialism with Chinese characteristics to analyze and solve problems. Third, strengthening the party spirit and the world transformation, perseverance of the party Constitution, relive Party vows to establish correct world Outlook , Outlook on life and the world, practically embodies ideals and beliefs into action, combine lofty ideals and practical activities, transforming the objective world, actively participate in the great practice of building socialism with Chinese characteristics. 2, keep the pur pose in concept, changing the style of work. First, keep in mind that the purpose of serving, adhere to assumi ng power for the people, keep in mind the people and care about people, and the joys and sorrows of the masses, .According to city discipline, and municipal organization Department requirements, today we hel d implement implementation independent Commission agai nst corruption guidelines effective strengthening led cadres style construction topic democratic life, main task is close contact thought, and work actual, control check district Standi ng Committee team and t he personal in implementation independe nt Commission against corruption guidelines S hang exists of problem, in-depth carried out criticism and self-critical, further clear rectification direction and measures, effective enhance d clean politics of consciousness and i nitiative, firm set good of ruling image. Before the meeting, the way we take surveys solicited a views, combed, related o team buildingroject work, cadre s, cadres selection and other aspe cts of a total of 19, further defined the direction of rectification, enhancing the pertinence and effectiveness of democratic life. Good for this meeting, we reque sted the Standing Committee of the municipal party Committee, municipal Secretary General Tang We njin, the City Commission for disci pline inspection Standing Committee Yang Xu, Jiang Jixue, Deputy Director of the personnel office, and other leading comrades present guidance allows us to warm applause for their welcome a nd thanks! Below, I first District Committee member of the 20XX team annual democratic meeting implementation of the corrective measures, as well as member of the team and of my own report guidelines for the implementation of the independent Commission against corruption statement invited leaders and comrades criticism. First, annual party on the 20XX team, Member of democratic life action plan implementation year 20XX, district democratic meeting a member of the team on study and practice the scientific Outlook on development theme, find a project supporting strong enough, the industry well enough, urban construction management level needs to be improved, livelihood improvement needs to be strengthened, district team itself, such as the five aspects. Year of 20XX, we find out the problems mentione d above, based on actual Shunqi ng construction and development, conscientiously sum up improvements, achieving significant development results and effectiveness of their work. (A) highlight the project handl e, maintain high growth of investment. Adhere to the strategy as a Foundation, carrying out projects to promote increased stamina important. One is to increa se the intensity of projects towards. Actively seek national and pr ovincial policy support, superior special transfer payments, a variety of additional income will top 700 million Yuan, a number of key infrastructur e projects, livelihood projects, industrial projects into the cage. Second, increasing the pr oject attracts. T his year a total of 23 signed a major project, of which 14 billion project, Chi na Metallurgical group, vanke group, Guangdong hengda group, Taiwan Ruentex group, on the RI group, Shenzhen Kaisa, jifeng agricultural machinery, Mercedes-Benz, Audi 4S store and other large enterprises and proje cts have settled in Shunqing. Third, strengthen pr oject construction. Annual implementation focus project 39 a, fixed assets investment total will breakthrough 12 billion yuan, created district yilai history high, Sout h door dam, and five in shop old city transformation, and Ying Chi na industrial conce ntrated district construction, and city main road construction, and Northeast steam Trade Center, and m odern farmers industry Park, and vocational education city, and low rental, and also room construction, and features blocks build, and farmers market transformation, and rural version Street transformation, focus engineering speed up implementation, effectiveness obviously. Expected to be achi eved this year, area-wi de GDP 17 billion八年级物理下册知识点归纳第六章电压电阻一、电压（一）电压的作用1电压是形成电流的原因：电压使电路中的自由电荷定向移动形成了电流。电源是提供电压的装置。2电路中获得持续电流的条件：电路中有电源（或电路两端有电压）；电路是连通的。3在理解电流、电压的概念时，通过观察水流、水压的模拟实验帮助我们认识问题，这里使用了科学研究方法“类比法”（二）电压的单位1国际单位： V 常用单位： kV 、mV 、 V 换算关系： 1Kv1000V 1V1000mV 1mV1000V 2记住一些电压值：一节干电池15V 一节蓄电池2V 家庭电压220V 安全电压不高于 36V（三）电压测量：1仪器：电压表，符号：2读数时，看清接线柱上标的量程，每大格、每小格电压值3使用规则：两要、一不电压表要并联在电路中。电流从电压表的“正接线柱”流入，“负接线柱”流出。否则指针会反偏。被测电压不要超过电压表的最大量程。 危害：被测电压超过电压表的最大量程时，不仅测不出电压值，电压表的指针还会被打弯甚至烧坏电压表。 选择量程：实验室用电压表有两个量程，03V和 015V。测量时，先选大量程，用开关试触，若被测电压在 3V15V可测量，若被测电压小于3V则换用小的量程，若被测电压大于15V则换用更大量程的电压表。（四）电流表、电压表的比较电流表电压表异符号连接串联并联直接连接电源不能能量程06A 3A3V 15V每大格02A 1A1V 5V每小格002A 0 1A01V 0 5V内阻很小，几乎为零相当于短路很大相当于开路同调零；读数时看清量程和每大（小）格；正接线柱流入，负接线柱流出；不能超过最大测量值。（五）利用电流表、电压表判断电路故障精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 1 页，共 9 页thrift of excellent traditional and style lack deep of understandi ng, one-sided think in now of good situation Xia, economic smooth more fast development, and reform made major progress, and people living significantly improve, and social the career made new progress, no necessary always hard has, no aw areness to Chi na also has many poverty area, and also has many poverty population of exists, more living improve has, more need keep hard of style. Three is not strictly honest. Total thought units is a water sector, clean self-disci pline away from himself too far, no real processing good living of improve and hard, and thrift excellent traditional of relationship, no effective do comply with Constitution and party of regulations must from I do up, no right mercy good bitter Le, and wealth of relationship, no right awareness to in comply with Constitution and party of regulations aspe cts everyone has accountability. Four, future dire ction and improvement measures 1, belief and faith, strengthen party spirit. One is to firmly establish the noble ideals of struggle for the ideals of communism, communist struggle for life, ready to sacrifice everything for the party and the pe ople. Second is to continuously improve the quality and standard of political, conscientiously study Deng Xiaopi ng theory and three represents important thought and the scientific Outlook on devel opment, implement the partys basic program for the primary stage of socialism, adhere to the correct political orientation, maintain highly consistent with the CPC Central Committee, is good at theories of socialism with Chinese characteristics to analyze and solve problems. Third, strengthening the party spirit and the world transformation, perseverance of the party Constitution, relive Party vows to establish correct world Outlook , Outlook on life and the world, practically embodies ideals and beliefs into action, combine lofty ideals and practical activities, transforming the objective world, actively participate in the great practice of building socialism with Chinese characteristics. 2, keep the pur pose in concept, changing the style of work. First, keep in mind that the purpose of serving, adhere to assumi ng power for the people, keep in mind the people and care about people, and the joys and sorrowof the masses, . According to city discipline, and municipal organization Department requirements, today we hel d implement implementation independent Commission agai nst corruption guidelines effective strengthening led cadres style construction topic democratic life, main task is close contact thought, and work actual, control check district Standi ng Committee team and the personal i n implementation independe nt Commission against corruption guidelines S hang exists of problem, in-depth carried out criticism and self-critical, further clear rectification direction and measures, effective enhance d clean politics of consciousness and i nitiative, firm set good of ruling image. Before the meeting, the way we take surveys solicited a views, combed, related to team buildingroject work, cadre s, cadres selection and other aspe cts of a total of 19, further defined the direction of rectification, enhancing the pertinence and effectiveness of democratic life. Good for this meeting, we reque sted the Standing Committee of the municipal party Committee, municipal Secretary General Tang We njin, the City Commission for disci pline inspection Standing Committee Yang Xu, Jiang Jixue, Deputy Director of the personnel office, and other leading comrades present guidance allows us to warm applause for their welcome a nd thanks! Below, I first District Committee member of the 20XX team annual democratic meeting implementation of the corrective measures, as well as member of the team and of my own report guidelines for the implementation of the independent Commission against corrupti on statement invited leaders and comrades criticism. First, annual party on the 20XX team, Member of democratic life action plan implementation year 20XX, district democratic meeting a member of the team on study and practice the scientific Outlook on developme nt theme, find a project supporting strong enough, the industry well enough, urban construction management level needs to be improved, livelihood improvement needs to be strengthened, district team itself, such as the five aspects. Year of 20XX, we find out the problems mentione d above, based on actual Shunqi ng construction and development, conscientiously sum up improvements, achieving significant development results and effectiveness of their work. (A) highlight the project handl e, maintain high growth of investment. Adhere to the strategy as a Foundation, carrying out projects to promote increased stamina important. One is to increa se the intensity of projects towards. Actively seek national and pr ovincial policy support, superior special transfer payments, a variety of additional income will top 700 million Yuan, a number of key infrastructur e projects, livelihood projects, industrial projects into the cage. Second, increasing the pr oject attracts. T his year a total of 23 signed a major project, of which 14 billion project, Chi na Metallurgical group, vanke group, Guangdong hengda group, Taiwan Ruentex group, on the RI group, Shenzhen Kaisa, jifeng agricultural machinery, Mercedes-Benz, Audi 4S store and other large enterprises and proje cts have settled in Shunqing. Third, strengthen pr oject construction. Annual implementation focus project 39 a, fixed assets investment total will breakthrough 12 billion yuan, created district yilai history high, Sout h door dam, and five in shop old city transformation, and Ying Chi na industrial conce ntrated district construction, and city main road construction, and Northeast steam Trade Center, and m odern farmers industry Park, and vocational education city, and low rental, and also room construction, and features blocks build, and farmers market transformation, and rural version Street transformation, focus engineering speed up implementation, effectiveness obviously. Expected to be achi eved this year, area-wi de GDP 17 billion2 1电流表示数正常而电压表无示数：“电流表示数正常”表明主电路为通路，“电压表无示数”表明无电流通过电压表，则故障原因可能是：电压表损坏；电压表接触不良；与电压表并联的用电器短路。2电压表有示数而电流表无示数“电压表有示数”表明电路中有电流通过，“电流表无示数”说明没有或几乎没有电流流过电流表，则故障原因可能是： 电流表短路； 和电压表并联的用电器开路，此时电流表所在电路中串联了大电阻（电压表内阻） 使电流太小，电流表无明显示数。3电流表电压表均无示数“两表均无示数”表明无电流通过两表，除了两表同时短路外，最大的可能是主电路断路导致无电流。二、电阻（一）定义及符号: 电阻表示导体对电流阻碍作用的大小符号： R。（二）单位1国际单位：欧姆。规定：如果导体两端的电压是1V，通过导体的电流是1A，这段导体的电阻是1。2常用单位：千欧、兆欧。3换算： 1M =1000K1K=10004了解一些电阻值：手电筒的小灯泡，灯丝的电阻为几欧到十几欧。日常用的白炽灯，灯丝的电阻为几百欧到几千欧。 实验室用的铜线， 电阻小于百分之几欧。电流表的内阻为零点几欧。电压表的内阻为几千欧左右。（三）影响因素1实验原理：在电压不变的情况下，通过电流的变化来研究导体电阻的变化。（也可以用串联在电路中小灯泡亮度的变化来研究导体电阻的变化）2 实验方法：控制变量法。3结论：导体的电阻是导体本身的一种性质，它的大小决定于导体的材料、长度和横截面积，还与温度有关。4结论理解：导体电阻的大小由导体本身的材料、长度、横截面积决定。与是否接入电路、与外加电压及通过电流大小等外界因素均无关，所以导体的电阻是导体本身的一种性质。结论可总结成公式R= L/S ，其中叫电阻率，与导体的材料有关。记住：银铜铝，锰铜镍隔。假如架设一条输电线路，一般选铝导线，因为在相同条件下，铝的电阻小，减小了输电线的电能损失；而且铝导线相对来说价格便宜。（四）分类1 定值电阻：电路符号：。2可变电阻（变阻器）：电路符号。滑动变阻器：构造：瓷筒、线圈、滑片、金属棒、接线柱。结构示意图：。变阻原理：通过改变接入电路中的电阻线的长度来改变电阻。使用方法：选、串、接、调。根据铭牌选择合适的滑动变阻器；串联在电路中；接法：“一上一下”；接入电路前应将电阻调到最大。铭牌：某滑动变阻器标有“501.5A ”字样， 50表示滑动变阻器的最大阻值为50或变阻范围为050。 15A表示滑动变阻器允许通过的最大电流为1.5A 精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 2 页，共 9 页作用：通过改变电路中的电阻，逐渐改变电路中的电流和部分电路两端的电压；保护电路。应用：电位器优缺点：能够逐渐改变连入电路的电阻，但不能表示连入电路的阻值。注意：滑动变阻器的铭牌，告诉了我们滑片放在两端及中点时，变阻器连入电路的电阻；分析因变阻器滑片的变化引起的动态电路问题，关键搞清哪段电阻丝连入电路，再分析滑片的滑动导致变阻器的阻值如何变化。第七章欧姆定律一、欧姆定律1探究电流与电压、电阻的关系提出问题：电流与电压电阻有什么定量关系？制定计划，设计实验：要研究电流与电压、电阻的关系，采用的研究方法是：控制变量法。即：保持电阻不变，改变电压研究电流随电压的变化关系；保持电压不变，改变电阻研究电流随电阻的变化关系。进行实验，收集数据信息：（会进行表格设计）分析论证： （分析实验数据寻找数据间的关系， 从中找出物理量间的关系， 这是探究物理规律的常用方法。 ）得出结论：在电阻一定的情况下，导体中的电流与加在导体两端的电压成正比；在电压不变的情况下，导体中的电流与导体的电阻成反比。2欧姆定律的内容：导体中的电流，跟导体两端的电压成正比，跟导体的电阻成反比。3数学表达式I=U/R 。4说明：适用条件：纯电阻电路（即用电器工作时，消耗的电能完全转化为内能）； I 、U、R对应同一导体或同一段电路，不同时刻、不同导体或不同段电路三者不能混用，应加角码区别。三者单位依次是A、V、；同一导体（即R不变），则I 与 U成正比同一电源（即U不变），则I 与 R成反比。RU/I 是电阻的量度式，它表示导体的电阻可由U/I 给出，即R与 U、I 的比值有关，但R与外加电压U和通过电流I 等因素无关。二、伏安法测电阻1定义： 用电压表和电流表分别测出电路中某一导体两端的电压和通过的电流就可以根据欧姆定律算出这个导体的电阻
