{"questions":[{"id":"ch06-s018","type":"multi","chapter":6,"level":"重点","ability":"应用","difficulty":4,"stem":"关于机构运动简图及其绘制,下列说法正确的有(  )。","options":["它是用规定符号和运动尺寸表示机构运动特性的简化图形","只要外形画得逼真,即使构件数目与运动副类型和实际情况不符也可以使用","绘制时应先分析机构运动,确定构件数目、运动副类型及其相对位置","机架在简图中用规定符号表示,并作为其他构件运动的参考","构件与运动副的位置应按比例确定,因此要测量必要的运动尺寸"],"answer":[0,2,3,4],"explanation":"机构运动简图的作用是反映机构的运动关系,所以必须准确表达构件数目、运动副类型和相对位置,并按比例画出运动尺寸,机架要作为参考系用规定符号标出。第二项把它当成外观示意图,构件与运动副画错会使图形失去运动分析的价值,因此是错误的。","tags":["机构运动简图","符号与比例"]},{"id":"ch06-s019","type":"judge","chapter":6,"level":"一般","ability":"识记","difficulty":1,"stem":"判断:机械工程只关注机器的制造与装配过程,与产品设计中功能、结构和使用方式的确定无关。","options":["正确","错误"],"answer":[1],"explanation":"错误。机械工程以力学、材料、机构等知识为基础,研究机械系统的组成、运动与制造,为产品提供实现功能所需的运动方案和结构方案。设计师在确定功能、结构和使用方式时,必须考虑机械工程所提供的可能性和约束条件,因此说二者无关是不成立的。","tags":["机械工程的作用","机械工程与设计"]},{"id":"ch06-s020","type":"judge","chapter":6,"level":"一般","ability":"识记","difficulty":1,"stem":"判断:系统论认为系统的整体功能等于各组成部分功能的简单相加,因此只要提高每个零件的性能,整机性能就会同步提高。","options":["正确","错误"],"answer":[1],"explanation":"错误。整体性原理恰恰强调整体不等于各部分的简单相加:各要素按一定结构组合后会产生新的整体功能,配合不当还可能使整体性能低于各部分之和。整机性能取决于各组成部分及其相互关系的合理匹配,不能只靠提高单个零件的性能来实现。","tags":["系统论","整体性"]},{"id":"ch06-s021","type":"judge","chapter":6,"level":"重点","ability":"识记","difficulty":2,"stem":"判断:机构一般由机架、主动件、从动件和传动件组成,其中主动件的运动规律已知,机架则是相对静止并起支承作用的构件。","options":["正确","错误"],"answer":[0],"explanation":"正确。主动件又称原动件,是机构中运动规律由外部给定的构件;其余由主动件带动的运动构件称为从动件,在中间传递运动和力的称为传动件;机架相对静止,起支承作用,并作为研究各构件运动的参考系。只有明确了这些组成部分,才能分析机构的运动关系并绘制运动简图。","tags":["机构的组成","主动件"]},{"id":"ch06-s022","type":"judge","chapter":6,"level":"次重点","ability":"理解","difficulty":2,"stem":"判断:机器中的每一个零件都单独构成一个构件,构件不可能由多个零件组合而成。","options":["正确","错误"],"answer":[1],"explanation":"错误。构件的划分依据是运动,凡相互之间没有相对运动、共同参与同一运动的零件,都可以刚性连接成一个构件,例如连杆体、连杆盖和螺栓共同组成连杆构件;而一个零件单独参与运动时也就是一个构件。所以构件与零件可能一一对应,也可能一个构件包含多个零件。","tags":["构件","零件"]},{"id":"ch06-s023","type":"judge","chapter":6,"level":"重点","ability":"理解","difficulty":3,"stem":"判断:机构运动的实质,是通过构件之间的相对运动来传递运动和力,从而实现预期的运动形式。","options":["正确","错误"],"answer":[0],"explanation":"正确。机构各构件之间通过运动副保持接触,主动件运动时带动其他构件产生确定的相对运动,运动和力便沿着构件逐次传递,最终使从动件获得预期的运动形式。因此分析机构的关键不是外形和结构细节,而是构件数目、运动副类型以及各构件之间的相对运动关系。","tags":["机构运动的实质","相对运动"]},{"id":"ch06-s024","type":"blank","chapter":6,"level":"一般","ability":"识记","difficulty":1,"stem":"系统论认为,系统是由若干相互联系、相互作用的______组成的具有特定功能的有机整体,其核心思想是系统的______。","answer":["要素|部分","整体性|整体观念"],"explanation":"系统论把研究对象看作由若干要素按一定结构组成的有机整体,要素之间相互联系、相互作用,并与环境交换物质、能量和信息。它的核心思想是整体性,即整体功能不等于各要素功能的简单相加,因此认识和设计产品时应从整体出发,处理好要素之间的关系。","tags":["系统论","整体性"]},{"id":"ch06-s025","type":"blank","chapter":6,"level":"次重点","ability":"理解","difficulty":2,"stem":"机器按功能通常由动力部分、______部分和执行部分组成,为使机器按预定要求准确工作,现代机器还常设有______与检测部分。","answer":["传动","控制"],"explanation":"动力部分即原动机,把其他形式的能量转换为机械能,提供运动和动力;传动部分把运动和动力传递给执行部分,并可改变运动形式或运动速度;执行部分直接完成有用功,实现机器的使用功能;控制与检测部分则检测机器的运行状态并发出调节指令。四部分分工配合,构成完整的机器系统。","tags":["机器的解析","机器的组成"]},{"id":"ch06-s026","type":"blank","chapter":6,"level":"次重点","ability":"理解","difficulty":2,"stem":"两构件直接接触并能产生一定相对运动的可动连接称为______,按接触形式可分为低副和高副;运动副对构件相对运动所加的限制称为______。","answer":["运动副","约束"],"explanation":"运动副既保证两构件保持接触,又限制其部分相对运动,因此必然对构件施加约束。面接触的低副(转动副、移动副)限制两个自由度,点接触或线接触的高副(齿轮副、凸轮副)只限制一个自由度,这是两类运动副最基本的区别,也直接影响机构运动的可能范围。","tags":["运动副","约束与自由度"]},{"id":"ch06-s027","type":"blank","chapter":6,"level":"重点","ability":"应用","difficulty":3,"stem":"绘制机构运动简图时,两构件组成的转动副通常用______表示,移动副用______表示,两个齿轮啮合组成的齿轮副用一对______表示。","answer":["小圆圈|圆圈","滑块与导路|滑块和导路|滑块","节圆|相切的节圆"],"explanation":"机构运动简图用统一的规定符号表示运动副:转动副画成小圆圈,圆心即转动中心;移动副画成滑块与导路;齿轮副用一对相切的节圆表示;凸轮副则画出凸轮轮廓与从动件接触部分的形状。符号统一后,图形才能被准确识读,并用于机构的运动分析和方案比较。","tags":["机构运动简图","图例符号"]},{"id":"ch06-s028","type":"blank","chapter":6,"level":"重点","ability":"应用","difficulty":4,"stem":"绘制机构运动简图的一般步骤是:先分析机构的组成与运动情况,确定构件数目和运动副的______;再选择恰当的______,测量与运动有关的尺寸;最后按比例用规定符号绘图并标注。","answer":["类型","视图平面|投影面|视图"],"explanation":"机构运动简图只反映运动关系,所以第一步要把实际机构抽象为构件与运动副的组合,弄清运动副的类型;第二步选择与多数构件运动平面平行的视图平面,使机构的运动关系显示得最清楚;然后测量各运动副之间的相对位置等运动尺寸,按比例用规定符号作图,并省略与运动无关的零件和结构形状。","tags":["机构运动简图","绘制步骤"]},{"id":"ch06-s029","type":"term","chapter":6,"level":"重点","ability":"识记","difficulty":3,"stem":"解释概念:运动副","answer":["两构件直接接触并能产生一定相对运动的可动连接,称为运动副。","按接触形式不同,运动副分为低副和高副:以面接触的转动副、移动副为低副,以点接触或线接触的齿轮副、凸轮副为高副。","运动副对构件的相对运动起限制作用,这种限制称为约束,约束的数目直接影响构件保留的自由度。"],"explanation":"作答时应写出三个要点:一是“直接接触并能产生一定相对运动”这一核心含义,二是按接触形式划分低副与高副,三是运动副必然带来约束并影响构件的自由度,举例说明转动副、移动副与齿轮副、凸轮副更为完整。","tags":["运动副","低副与高副"]},{"id":"ch06-s030","type":"term","chapter":6,"level":"重点","ability":"理解","difficulty":4,"stem":"解释概念:机构运动简图","answer":["用规定的符号和与运动有关的尺寸,表示机构各构件之间运动关系(构件数目、运动副类型及其相对位置)的简化图形。","绘制时忽略与运动无关的结构形状和零件,如键、销、弹簧以及机架的具体外形。","它是进行机构运动分析和方案比较的基本依据,要求图形所表达的运动关系与机构实际情况一致。"],"explanation":"答题要抓住“规定符号”“运动尺寸”“反映运动关系”“简化”四个关键。它不追求外形逼真,而要求准确表达构件数目、运动副类型与相对位置,因此必须按比例绘制,并可以作为机构运动分析和不同机构方案比较的基本图样。","tags":["机构运动简图","运动分析"]},{"id":"ch06-s031","type":"short","chapter":6,"level":"重点","ability":"应用","difficulty":4,"stem":"简述绘制机构运动简图的一般步骤及注意事项。","answer":["分析机构的组成与运动情况,分清机架、主动件、从动件和各运动副,确定构件数目与运动副类型。","选择视图平面,一般取与多数构件运动平面平行的平面,使机构的运动关系显示清楚。","测量与运动有关的尺寸,即各运动副之间的相对位置,并选取适当的比例尺。","用规定符号按比例绘出各构件和运动副,标注构件编号,机架按约定符号表示。","忽略键、销、弹簧等与运动无关的零件和结构形状,保证图形与机构的实际运动关系一致。"],"explanation":"本题属应用层次,答题宜按“分析机构—选择视图平面—测量运动尺寸—按规定符号按比例作图—标注”的顺序展开,并强调只保留与运动有关的构件、运动副和尺寸,图形必须与机构的实际运动关系一致,不能为了美观而改变构件的相对位置。","tags":["机构运动简图","绘制步骤"]},{"id":"ch06-s032","type":"short","chapter":6,"level":"次重点","ability":"理解","difficulty":3,"stem":"简述机器的共同特征,并说明机器、机构与机械三者的区别和联系。","answer":["机器的共同特征:由人为的实物组合而成;各部分之间具有确定的相对运动;能转换或传递能量;能完成有用的机械功。","机构由若干构件组成,用于传递运动和力、实现预期的运动形式,它只具备前两项特征,不强调能量转换与完成有用功。","机器通常包含一个或多个机构,是在机构的基础上还能转换或传递能量、完成有用功的整体。","机械是机器与机构的总称,是二者的统称用语,不能与机器或机构等同使用。"],"explanation":"本题应把“共同特征”与“三者关系”分开作答。区别的关键在于:机构侧重传递运动和力、实现预期运动形式,机器还必须能转换或传递能量、完成有用功,因而机器往往由若干机构组成;联系在于机械是机器和机构的总称,机构是机器的重要组成部分。","tags":["机器的共同特征","机器与机构"]},{"id":"ch07-s001","type":"single","chapter":7,"level":"一般","ability":"识记","difficulty":1,"stem":"铰链四杆机构按照两个连架杆运动形式的不同,其三种基本形式是(  )。","options":["双曲柄机构、双摇杆机构、曲柄滑块机构","曲柄滑块机构、导杆机构、双摇杆机构","曲柄摇杆机构、双曲柄机构、双摇杆机构","曲柄摇杆机构、偏心轮机构、双曲柄机构"],"answer":[2],"explanation":"在铰链四杆机构中,与机架相连的两杆称为连架杆,能整周回转的为曲柄,只能在小于一周的范围内摆动的为摇杆。按两连架杆是曲柄还是摇杆组合,得到曲柄摇杆机构、双曲柄机构和双摇杆机构三种基本形式。曲柄滑块、导杆、偏心轮等都是在基本形式基础上演化而来的,不属于三种基本形式。","tags":["平面四连杆机构","基本形式"]},{"id":"ch07-s002","type":"single","chapter":7,"level":"一般","ability":"理解","difficulty":4,"stem":"某铰链四杆机构各杆长度为AB=30mm、BC=90mm、CD=70mm、AD=100mm,若取AD为机架,则该机构为(  )。","options":["曲柄摇杆机构,其中AB为摇杆","双摇杆机构","双曲柄机构","曲柄摇杆机构,其中AB为曲柄"],"answer":[3],"explanation":"最短杆AB=30mm与最长杆AD=100mm之和为130mm,小于其余两杆之和90+70=160mm,满足杆长条件。此时最短杆AB是连架杆,取AD为机架后AB能整周回转成为曲柄,另一连架杆CD只能摆动,故为曲柄摇杆机构且AB为曲柄。取最短杆为机架才得双曲柄机构,取最短杆为连杆才得双摇杆机构。","tags":["曲柄存在条件","曲柄摇杆机构"]},{"id":"ch07-s003","type":"multi","chapter":7,"level":"一般","ability":"识记","difficulty":2,"stem":"平面四连杆机构在生产中得到广泛应用,其优点有(  )。","options":["能实现多种运动形式,可把连续转动变为往复摆动或往复移动","各构件之间为面接触的低副,单位面积压力小、磨损小、承载能力大","构件形状简单,容易加工制造,也容易获得较高的制造精度","能精确实现任意给定的复杂运动规律和运动轨迹"],"answer":[0,1,2],"explanation":"四连杆机构以转动副、移动副等低副连接,接触面为面接触,压强小、磨损小、承载能力大;构件多为杆件,形状简单、便于加工制造,通过改变各杆尺寸和机架位置可获得多种运动形式,因此应用广泛。但它一般只能近似实现给定的运动规律,难以精确实现复杂的运动轨迹,故第四项错误。","tags":["平面四连杆机构","优缺点"]},{"id":"ch07-s004","type":"judge","chapter":7,"level":"重点","ability":"理解","difficulty":2,"stem":"判断:在平面四连杆机构中,当从动件与连杆共线时,机构的传动角为零,该位置称为死点位置,此时驱动力对从动件回转中心的力矩为零。","options":["正确","错误"],"answer":[0],"explanation":"正确。死点位置出现在从动件与连杆共线的位置,此时压力角为90°、传动角为0°,连杆作用于从动件的力通过从动件的回转中心,不能产生使从动件转动的有效力矩,机构出现卡死现象。死点对传动不利,但也可以被主动利用,如夹紧机构和飞机起落架。","tags":["死点位置","传动角"]},{"id":"ch07-s005","type":"single","chapter":7,"level":"一般","ability":"理解","difficulty":3,"stem":"在满足杆长条件的铰链四杆机构中,若取最短杆为机架,则该机构为(  )。","options":["双摇杆机构","曲柄滑块机构","曲柄摇杆机构","双曲柄机构"],"answer":[3],"explanation":"满足杆长条件即最短杆与最长杆长度之和小于或等于其余两杆长度之和时,最短杆上的两个转动副都能整周回转。取最短杆为机架,两个连架杆都能整周回转而成为曲柄,故为双曲柄机构;取最短杆的相邻杆为机架得曲柄摇杆机构,取最短杆为连杆得双摇杆机构。曲柄滑块机构须把转动副演化为移动副,与此条件无关。","tags":["曲柄存在条件","双曲柄机构"]},{"id":"ch07-s006","type":"single","chapter":7,"level":"重点","ability":"理解","difficulty":3,"stem":"关于平面四连杆机构的压力角和传动角,下列说法正确的是(  )。","options":["压力角是从动件受力方向与其受力点速度方向所夹的锐角,传动角是压力角的余角,传动角越大则传力性能越好","传动角越大,机构的传力性能越差,设计时应使传动角尽量小","传动角是从动件受力方向与其受力点速度方向所夹的锐角,压力角越大则传力性能越好","压力角和传动角只影响机构的外形尺寸,与传力性能无关"],"answer":[0],"explanation":"压力角是力的作用线与受力点速度方向所夹的锐角,传动角与压力角互为余角。传动角越大,力在速度方向上的有效分量越大,传力越省力、效率越高,因此设计时要求机构的最小传动角不小于许用值。曲柄摇杆机构的最小传动角出现在曲柄与机架两次共线位置之一。其余选项把两个角的定义或影响弄反了。","tags":["压力角","传动角"]},{"id":"ch07-s007","type":"blank","chapter":7,"level":"重点","ability":"识记","difficulty":2,"stem":"平面四连杆机构的设计通常可归结为三类基本问题:按给定______的位置设计、按给定两连架杆______位置设计,以及按给定行程速比系数K设计。","answer":["连杆","对应"],"explanation":"前两类问题的目标都是使机构能依次占据预定的位置:前者要求连杆通过若干给定位置,后者要求两连架杆的转角满足给定的对应关系;第三类问题以满足急回运动要求为目标,需要用到行程速比系数K与极位夹角的关系,通常还要给出摇杆摆角等条件。","tags":["设计内容","四连杆机构设计"]},{"id":"ch07-s008","type":"term","chapter":7,"level":"一般","ability":"识记","difficulty":3,"stem":"解释概念:铰链四杆机构的曲柄存在条件(格拉肖夫条件)","answer":["铰链四杆机构中,最短杆与最长杆的长度之和小于或等于其余两杆长度之和。","在此前提下,取最短杆的相邻杆为机架时得到曲柄摇杆机构,取最短杆为机架时得到双曲柄机构,取最短杆为连杆时得到双摇杆机构。","若不满足上述杆长条件,则机构中不存在曲柄,无论取哪个构件为机架,都只能得到双摇杆机构。"],"explanation":"答题要抓住杆长之和这一条件,并说明它与机架选择共同决定机构类型:满足条件时最短杆具备整周回转的能力,选取不同构件为机架便得到三种不同形式;不满足条件时两连架杆都只能摆动,只能得到双摇杆机构。","tags":["曲柄存在条件","格拉肖夫条件"]},{"id":"ch07-s009","type":"short","chapter":7,"level":"重点","ability":"应用","difficulty":4,"stem":"简述平面四连杆机构死点位置产生的原因,并说明工程中如何利用和避免死点。","answer":["产生原因:当从动件与连杆共线时,机构的压力角为90°、传动角为0°,连杆作用于从动件的力通过其回转中心,有效力矩为零,机构不能运动,该位置即死点位置。","利用:夹紧机构利用死点使工件夹紧后不会因反力而松脱;飞机起落架放下到位后利用死点保持可靠的支撑状态;锁紧、定位机构也常利用死点实现自锁。","避免:在从动件上安装飞轮,利用飞轮的惯性使机构冲过死点位置。","避免:采用多组相同机构错列布置,使各组的死点位置相互错开,保证整机连续运转。"],"explanation":"本题属应用层次,答题应分两部分:先说明死点的力学原因,即从动件与连杆共线、传动角为零、有效力矩为零;再分别举出利用死点的实例和避免死点的措施。只描述现象而不解释原因,或只写出一种措施,回答都不完整。","tags":["死点位置","机构设计"]},{"id":"ch07-s010","type":"single","chapter":7,"level":"一般","ability":"识记","difficulty":1,"stem":"曲柄滑块机构是由铰链四杆机构演化而来的,其演化方式是(  )。","options":["选取不同构件为机架,把连杆变为机架","增加一个齿轮,靠齿轮与齿条的啮合实现直线移动","改变运动副的类型,将其中一个转动副演化为移动副","扩大转动副的尺寸,把曲柄演化为偏心轮"],"answer":[2],"explanation":"在铰链四杆机构中,把其中一个转动副的销轴与轴孔结构改为滑块与导路,即把转动副演化为移动副,就得到曲柄滑块机构,它能把曲柄的连续转动变为滑块的往复移动,广泛用于冲床、内燃机等。扩大转动副尺寸得到的是偏心轮机构,选不同构件为机架得到的是导杆等机构,齿轮齿条属于另一种高副机构。","tags":["曲柄滑块机构","机构演化"]},{"id":"ch07-s011","type":"single","chapter":7,"level":"重点","ability":"应用","difficulty":4,"stem":"某曲柄摇杆机构的行程速比系数K=1.4,则其极位夹角θ等于(  )。","options":["30°","36°","20°","25.7°"],"answer":[0],"explanation":"极位夹角与行程速比系数的关系为K=(180°+θ)/(180°−θ),由此解得θ=180°×(K−1)/(K+1)=180°×0.4/2.4=30°。极位夹角为零时K=1,机构没有急回特性;极位夹角越大则K越大,急回特性越显著。其余几个角度代入该关系式都得不到K=1.4。","tags":["行程速比系数","极位夹角"]},{"id":"ch07-s012","type":"judge","chapter":7,"level":"一般","ability":"理解","difficulty":3,"stem":"判断:对于不满足曲柄存在条件的铰链四杆机构,无论取哪个构件为机架,两个连架杆都只能在一定范围内摆动,都是双摇杆机构。","options":["正确","错误"],"answer":[0],"explanation":"正确。铰链四杆机构的形式既取决于各杆的相对长度,也取决于机架的选择。当最短杆与最长杆的长度之和大于其余两杆长度之和时,机构中不存在能整周回转的曲柄,此时无论取哪个构件为机架,两个连架杆都只能摆动,故都属于双摇杆机构。","tags":["双摇杆机构","曲柄存在条件"]},{"id":"ch07-s013","type":"blank","chapter":7,"level":"重点","ability":"理解","difficulty":3,"stem":"在平面四连杆机构中,当从动件与______共线时,机构的传动角等于______,该位置称为死点位置。","answer":["连杆","0°|零度|0"],"explanation":"死点是由从动件与连杆共线造成的,此时压力角为90°、传动角为0°,连杆传给从动件的力通过其回转中心,不能产生有效力矩。工程上可通过加装飞轮利用惯性、或者采用多组机构错列布置等方法使机构通过死点,也可以主动利用死点实现夹紧与支撑。","tags":["死点位置","传动角"]},{"id":"ch07-s014","type":"multi","chapter":7,"level":"重点","ability":"识记","difficulty":2,"stem":"平面四连杆机构的设计内容(基本问题)通常包括(  )。","options":["按给定连杆的几个位置设计四连杆机构","按给定两连架杆的对应位置设计四连杆机构","按给定的构件质量与材料牌号设计四连杆机构","按给定的行程速比系数K及摇杆摆角等条件设计四连杆机构"],"answer":[0,1,3],"explanation":"四连杆机构的设计一般归结为三类基本问题:按给定连杆位置设计、按给定两连架杆对应位置设计、按给定行程速比系数K设计。前两类用于保证机构能够占据预定的位置,第三类用于满足急回运动要求。构件的质量与材料牌号属于结构设计内容,不是连杆机构设计的基本问题。","tags":["设计内容","四连杆机构设计"]},{"id":"ch07-s015","type":"judge","chapter":7,"level":"重点","ability":"理解","difficulty":3,"stem":"判断:平面四连杆机构的极位夹角越大,行程速比系数K越大,急回特性越显著;当极位夹角为零时K=1,机构没有急回特性。","options":["正确","错误"],"answer":[0],"explanation":"正确。由K=(180°+θ)/(180°−θ)可知,K随极位夹角θ的增大而增大,K越大说明返回行程的平均速度比工作行程越快,急回特性越显著;当极位夹角为零时K=1,往返行程的平均速度相等,机构没有急回特性,对心曲柄滑块机构就属于这种情况。","tags":["急回特性","极位夹角"]},{"id":"ch07-s016","type":"single","chapter":7,"level":"一般","ability":"理解","difficulty":3,"stem":"平面四连杆机构在应用中也有缺点,下列属于其缺点的是(  )。","options":["难以精确实现给定的复杂运动规律,惯性力不易平衡,高速时振动较大","只能传递整周转动,不能把连续转动变为往复摆动","必须依靠摩擦力传递动力,过载时必然打滑","各构件之间都是高副接触,磨损快、寿命短"],"answer":[0],"explanation":"四连杆机构一般只能近似实现给定的运动规律,难以精确实现复杂的运动轨迹;同时惯性力不易完全平衡,高速时会产生较大的振动与冲击。曲柄摇杆机构本身就能把连续转动变为往复摆动,第二项与事实相反;依靠摩擦力传动是带传动的特点;四连杆机构各构件之间为低副接触,磨损小,第四项错误。","tags":["平面四连杆机构","优缺点"]},{"id":"ch07-s017","type":"single","chapter":7,"level":"重点","ability":"识记","difficulty":1,"stem":"机器中位于原动机与工作机之间,用来传递运动和动力并实现转速变换的部分称为(  )。","options":["传动系统","控制系统","动力系统","执行系统"],"answer":[0],"explanation":"机器一般由动力系统、传动系统、执行系统和控制系统等组成。传动系统位于原动机与工作机之间,基本任务是传递运动和动力,并改变运动速度与运动形式、分配动力;动力系统即原动机,负责提供动力;执行系统直接完成生产任务;控制系统控制各部分的动作。","tags":["传动系统","机械传动"]},{"id":"ch07-s018","type":"multi","chapter":7,"level":"重点","ability":"识记","difficulty":2,"stem":"机械传动系统的作用主要有(  )。","options":["把原动机的运动和动力传递给工作机","改变运动速度,实现减速、增速或变速","改变运动形式,如把转动变为往复移动或摆动","代替原动机,直接为工作机提供动力"],"answer":[0,1,2],"explanation":"传动系统介于原动机与工作机之间,其基本作用是传递运动和动力,并根据工作需要进行减速、增速或变速,同时可以把一种运动形式转换为另一种运动形式,还可以分配动力、实现离合与换向。动力由原动机提供,传动系统只能传递而不能产生动力,故第四项错误。","tags":["传动系统","传动系统设计"]},{"id":"ch07-s019","type":"term","chapter":7,"level":"重点","ability":"识记","difficulty":1,"stem":"解释概念:传动比","answer":["传动比是传动系统中主动轮(主动轴)的转速与从动轮(从动轴)的转速之比,即i=n₁/n₂。","在齿轮传动中,传动比等于从动轮齿数与主动轮齿数之比,即i=z₂/z₁。","传动比大于1时为减速传动,小于1时为增速传动,它反映传动系统改变转速的能力。"],"explanation":"名词解释应写清定义式i=n₁/n₂,说明它表示主动轮转速与从动轮转速之比;在齿轮传动中由轮齿啮合关系可得i=z₂/z₁;并指出传动比大于1为减速传动、小于1为增速传动。传动比是传动系统设计中最基本的参数之一。","tags":["传动比","传动系统"]},{"id":"ch07-s020","type":"single","chapter":7,"level":"重点","ability":"识记","difficulty":1,"stem":"在齿轮传动中,适用于两轴相互垂直相交场合的是(  )。","options":["蜗杆传动","直齿圆柱齿轮传动","斜齿圆柱齿轮传动","锥齿轮传动"],"answer":[3],"explanation":"锥齿轮的轮齿分布在圆锥面上,用于两轴相互垂直相交的传动。直齿圆柱齿轮和斜齿圆柱齿轮都用于两轴平行的传动;蜗杆传动虽然两轴在空间相互垂直,但属于垂直交错而不相交,且传动比大、效率较低,不符合本题所说的相交要求。","tags":["齿轮传动","锥齿轮"]},{"id":"ch07-s021","type":"blank","chapter":7,"level":"重点","ability":"识记","difficulty":1,"stem":"在标准直齿圆柱齿轮中,决定轮齿大小和强度的主要参数是______;其分度圆直径d与模数m、齿数z的关系为d=______。","answer":["模数","mz|m·z|m×z"],"explanation":"模数m是齿距p与圆周率π的比值,是齿轮几何尺寸计算的基本参数,模数越大则轮齿越大、抗弯能力越强。分度圆是齿轮尺寸计算的基准圆,其直径d=mz,齿距p=πm,分度圆上的压力角取标准值。","tags":["齿轮传动","模数"]},{"id":"ch07-s022","type":"single","chapter":7,"level":"重点","ability":"应用","difficulty":4,"stem":"一对外啮合直齿圆柱齿轮,主动轮齿数z₁=20,从动轮齿数z₂=60,主动轮转速n₁=1200r/min,则从动轮转速n₂为(  )。","options":["360r/min","400r/min","300r/min","600r/min"],"answer":[1],"explanation":"齿轮传动的传动比i=n₁/n₂=z₂/z₁=60/20=3,即主动轮转3圈从动轮转1圈,属于减速传动,故n₂=n₁/i=1200/3=400r/min。齿轮靠轮齿啮合传动,转速与齿数成反比,传动比准确。其余数值对应错误的传动比取值,或把齿数比取反。","tags":["齿轮传动","传动比"]},{"id":"ch07-s023","type":"multi","chapter":7,"level":"重点","ability":"识记","difficulty":2,"stem":"关于齿轮传动,下列说法正确的有(  )。","options":["靠轮齿啮合传动,瞬时传动比恒定,传动比准确可靠","传递功率和圆周速度的范围大,效率高、寿命长","结构紧凑,特别适用于两轴中心距很大的场合","制造和安装精度要求较高,因此成本较高"],"answer":[0,1,3],"explanation":"齿轮传动靠轮齿啮合,能保证恒定的瞬时传动比;其传递功率可从很小到很大,圆周速度范围宽,效率高、工作可靠、寿命长,且结构紧凑。但齿轮加工需要专用机床和刀具,制造与安装精度要求高、成本较高,并且不适用于两轴中心距很大的场合,故第三项错误。","tags":["齿轮传动","传动特点"]},{"id":"ch07-s024","type":"judge","chapter":7,"level":"重点","ability":"识记","difficulty":1,"stem":"判断:齿轮传动中,主动轮转速与从动轮转速之比称为传动比,它等于从动轮齿数与主动轮齿数之比。","options":["正确","错误"],"answer":[0],"explanation":"正确。传动比是主动轮转速与从动轮转速之比,即i=n₁/n₂。齿轮传动中两轮轮齿逐齿啮合,转速与齿数成反比,故i=n₁/n₂=z₂/z₁,并可由n₂=n₁·z₁/z₂求出从动轮转速。传动比大于1表示减速传动,小于1表示增速传动。","tags":["传动比","齿轮传动"]},{"id":"ch07-s025","type":"blank","chapter":7,"level":"重点","ability":"应用","difficulty":4,"stem":"某传动系统中,电动机转速为1440r/min,经一对齿轮减速后输出,已知主动轮齿数z₁=20,从动轮齿数z₂=80,则该齿轮传动的传动比i=______,输出轴的转速为______r/min。","answer":["4","360"],"explanation":"齿轮传动的传动比i=z₂/z₁=80/20=4,属于减速传动;输出轴转速n₂=n₁/i=1440/4=360r/min。计算时要注意传动比是主动轮转速与从动轮转速之比,等于从动轮齿数与主动轮齿数之比,不要把齿数比写反,也不要误用增速关系。","tags":["传动比","传动系统设计"]},{"id":"ch07-s026","type":"single","chapter":7,"level":"重点","ability":"理解","difficulty":3,"stem":"带传动工作时,由于带是弹性体,紧边与松边拉力不同,带与带轮之间会产生(  ),使从动轮圆周速度低于主动轮,传动比不准确。","options":["打滑","弹性滑动","疲劳破坏","离心拉力"],"answer":[1],"explanation":"弹性滑动是紧边与松边拉力差引起带的弹性变形量不同而造成的带与带轮之间的微量相对滑动,它是带传动固有的、不可避免的现象,使从动轮圆周速度略低于主动轮,传动比不准确。打滑由过载引起,是可以避免的,并能起到过载保护作用;疲劳破坏和离心拉力都不是题述原因。","tags":["带传动","弹性滑动"]},{"id":"ch07-s027","type":"judge","chapter":7,"level":"重点","ability":"理解","difficulty":2,"stem":"判断:带传动中的打滑是由过载引起的,它会使传动不能正常工作,但在一定程度上能起到保护其他零件的作用。","options":["正确","错误"],"answer":[0],"explanation":"正确。打滑是载荷超过带与带轮之间的极限摩擦力时,带在带轮上发生的全面相对滑动,属于过载引起的失效形式,正常工作时应当避免;但打滑使传动中断,可防止电动机等零件因过载而损坏,这正是带传动具有过载保护作用的原因。打滑与不可避免的弹性滑动不同。","tags":["带传动","打滑"]},{"id":"ch07-s028","type":"blank","chapter":7,"level":"重点","ability":"理解","difficulty":2,"stem":"带传动依靠带与带轮之间的______传递运动和动力;由于带受力后产生______,从动轮的圆周速度低于主动轮,因此带传动的传动比不准确。","answer":["摩擦力","弹性滑动"],"explanation":"带传动属于摩擦传动,靠带与带轮接触面间的摩擦力传递运动和动力,因此安装时必须把带张紧,使带产生初拉力。由于紧边与松边拉力不同,带在两轮上产生不同的弹性变形,引起弹性滑动,使从动轮圆周速度略低于主动轮,传动比不准确,这是带传动固有的现象。","tags":["带传动","摩擦力"]},{"id":"ch07-s029","type":"single","chapter":7,"level":"重点","ability":"理解","difficulty":2,"stem":"与带传动相比,链传动的主要特点是(  )。","options":["传动比不准确,只适用于两轴中心距很小的场合","瞬时传动比绝对恒定,传动中不会产生冲击和噪声","属于啮合传动,平均传动比准确,能在较大功率、较低速度下工作","属于摩擦传动,过载时可以打滑,起安全保护作用"],"answer":[2],"explanation":"链传动靠链与链轮的啮合传递运动和动力,属于啮合传动,平均传动比准确,传递功率较大、效率较高,能在低速、重载、高温及油污等恶劣环境中工作,常用于两轴中心距较大的场合。打滑是带传动的特点;由于多边形效应,链传动的瞬时速度和瞬时传动比存在波动,会产生冲击和噪声,故其余选项错误。","tags":["链传动","传动特点"]},{"id":"ch07-s030","type":"single","chapter":7,"level":"重点","ability":"识记","difficulty":2,"stem":"关于蜗杆传动,下列说法正确的是(  )。","options":["承载能力很低,只能用于传递很小的功率","传动比大、结构紧凑、传动平稳,在一定条件下可以实现自锁","适用于两轴平行、中心距很大的场合","传动效率很高,通常高于齿轮传动"],"answer":[1],"explanation":"蜗杆传动用于两轴垂直交错、传动比要求较大的场合,具有传动比大、结构紧凑、传动平稳、噪声小等优点,在一定条件下还能实现自锁,常用于起重等装置。但蜗杆与蜗轮齿面间相对滑动速度大、摩擦损失大,效率明显低于齿轮传动;它适用于垂直交错轴而非平行轴,且能传递较大功率,故其余选项错误。","tags":["蜗杆传动","齿轮传动"]},{"id":"ch07-s031","type":"single","chapter":7,"level":"重点","ability":"应用","difficulty":3,"stem":"某产品需在相距较远、轴线平行的两轴之间传递运动,要求结构简单、成本较低,并希望在过载时能起到保护作用,宜优先选用(  )。","options":["齿轮传动","带传动","链传动","蜗杆传动"],"answer":[1],"explanation":"带传动适用于两轴中心距较大的场合,结构简单、成本较低,且过载时带在带轮上打滑,可防止其他零件损坏,符合题设要求。齿轮传动结构紧凑,一般用于中心距较小的场合,且没有过载保护作用;链传动虽可用于较大中心距,但不会打滑,无过载保护作用;蜗杆传动适用于两轴垂直交错且传动比大的场合,效率较低。","tags":["带传动","传动类型选用"]},{"id":"ch07-s032","type":"multi","chapter":7,"level":"重点","ability":"应用","difficulty":4,"stem":"关于机械传动类型的选用,下列说法合理的有(  )。","options":["两轴中心距较大且要求有过载保护时,可选用带传动","要求传动比准确、结构紧凑、传递功率较大时,可选用齿轮传动","两轴中心距较大、要求平均传动比准确且工作环境温度较高时,可选用链传动","两轴平行且中心距很大时,应优先选用齿轮传动"],"answer":[0,1,2],"explanation":"三种传动各有适用范围:带传动适用于中心距较大并要求过载保护的场合;齿轮传动传动比准确、结构紧凑、效率高、功率与速度范围大,但一般用于中心距较小的场合;链传动兼有两者的长处,平均传动比准确,能在高温、油污等恶劣环境和较大中心距下工作。中心距很大时不宜选用齿轮传动,故第四项错误。","tags":["传动类型选用","机械设计"]},{"id":"ch07-s033","type":"term","chapter":7,"level":"重点","ability":"理解","difficulty":3,"stem":"解释概念:死点位置","answer":["在平面四连杆机构中,当从动件与连杆共线时,机构的压力角为90°、传动角为0°,该位置称为死点位置。","此时连杆传递给从动件的力通过从动件的回转中心,不能产生使从动件转动的力矩,机构无法继续运动。","死点对传动不利,可借助从动件的惯性(加装飞轮)或采用多组机构错列布置等方法通过;也可以主动利用,如夹紧机构、飞机起落架等。"],"explanation":"回答应包含三个要点:死点的成因,即从动件与连杆共线、传动角为零;死点的后果,即有效力矩为零、机构卡死;以及工程上的两种处理方式,即利用与避免。只答机构不能运动而不指出共线这一几何条件,回答不完整。","tags":["死点位置","四连杆机构"]},{"id":"ch07-s034","type":"short","chapter":7,"level":"重点","ability":"应用","difficulty":4,"stem":"试比较齿轮传动、带传动和链传动的主要特点,并说明选用传动类型时应考虑的主要因素。","answer":["齿轮传动:靠轮齿啮合,瞬时传动比恒定、传动比准确,结构紧凑,效率高、寿命长,功率和速度范围大;但制造与安装精度要求高、成本较高,不宜用于两轴中心距很大的场合。","带传动:靠摩擦力传动,传动平稳、能缓冲吸振、噪声小,结构简单、成本低,适用于两轴中心距较大的场合,过载时打滑可起保护作用;但存在弹性滑动、传动比不准确,外廓尺寸较大,带寿命较短,不宜用于高温、易燃等场合。","链传动:靠链与链轮啮合传动,平均传动比准确,传递功率较大、效率较高,能在高温、油污等恶劣环境和较大中心距下工作;但瞬时传动比有波动,有冲击和噪声,需要注意润滑与维护。","选用时应考虑:传动比大小及其准确性要求、传递功率与转速、两轴中心距与相对位置、传动效率与寿命、工作环境、安装维护条件和成本等。"],"explanation":"本题属应用层次,应先概括三种传动的工作原理与优缺点,再从传动比准确性、功率与速度范围、中心距、效率与寿命、环境适应性、成本与维护等方面归纳选型依据。只罗列特点而不作比较,或者缺少选型依据,都会影响得分。","tags":["齿轮传动","带传动与链传动"]},{"id":"ch08-s001","type":"single","chapter":8,"level":"次重点","ability":"识记","difficulty":1,"stem":"按包装在流通过程中所起的作用(功能)分类,包装通常分为(  )。","options":["硬包装和软包装","纸包装、塑料包装、金属包装和玻璃包装","盒、袋、瓶、罐、管和泡罩","运输包装和销售包装"],"answer":[3],"explanation":"按包装在流通中的作用划分,包装分为运输包装和销售包装:前者以保护产品、方便装卸运输与储存为主要目的,后者以介绍产品、吸引消费者、方便使用为主要目的。纸、塑料、金属、玻璃是按材料划分,盒、袋、瓶、罐等是按形态划分,硬包装与软包装是按包装的刚性程度划分。","tags":["包装分类","运输包装与销售包装"]},{"id":"ch08-s002","type":"single","chapter":8,"level":"次重点","ability":"识记","difficulty":1,"stem":"按包装形态分类,把产品封合在透明塑料薄片成型的泡罩与纸板底板之间,兼有保护和展示作用的包装形式是(  )。","options":["罐","管","泡罩","袋"],"answer":[2],"explanation":"泡罩包装又称泡壳包装,用透明塑料薄片加热成型出容纳产品的泡罩,再与涂有胶粘剂的纸板或塑料底板封合,产品清晰可见、便于展示,同时具有一定的保护作用。罐、管、袋是与泡罩并列的其他包装形态,成型方式、封合方式和使用场合都不相同。","tags":["包装形态","泡罩包装"]},{"id":"ch08-s003","type":"single","chapter":8,"level":"次重点","ability":"理解","difficulty":2,"stem":"与销售包装相比,运输包装最核心的功能是(  )。","options":["直接向消费者说明产品的使用方法","提高产品的零售价格","在装卸、运输和储存过程中保护产品、方便流通","通过装潢设计吸引消费者购买"],"answer":[2],"explanation":"运输包装以保护产品、方便装卸运输与储存为主要目的,通常强调强度、堆码、防震、防潮等性能,并附有必要的运输标志;销售包装直接面对消费者,重在展示、说明与促销。两类功能可以由同一件包装兼顾,但运输包装的核心仍是保护产品与方便流通。","tags":["运输包装","包装功能"]},{"id":"ch08-s004","type":"single","chapter":8,"level":"次重点","ability":"识记","difficulty":1,"stem":"在满足保护、储运和使用要求的前提下,尽量减少包装材料用量、降低包装成本,体现了包装结构设计要求的(  )。","options":["节省材料","便于回收","便于储运","保护产品"],"answer":[0],"explanation":"包装结构设计既要保护产品,又要便于储运、便于展示与使用,还要节省材料并便于回收。题干强调在保证功能的前提下减少用料、降低成本,属于“节省材料”这一要求;合理选择材料、优化结构展开与排料是常用的实现途径。","tags":["包装结构设计要求","节省材料"]},{"id":"ch08-s005","type":"single","chapter":8,"level":"次重点","ability":"理解","difficulty":2,"stem":"为保护易碎或精密产品,在包装内设置缓冲结构的主要作用是(  )。","options":["增加包装总重量以稳定重心","便于产品在货架上立式陈列","降低包装材料的成本","吸收和分散冲击、振动能量,减小产品受到的冲击"],"answer":[3],"explanation":"产品在装卸和运输中会受到冲击与振动,缓冲结构通过瓦楞纸衬垫、泡沫、蜂窝纸板等材料的变形来吸收和分散能量,延长作用时间、减小加速度峰值,从而保护产品。它并不以增重、陈列或降低成本为目的,相反会增加一定的包装体积与费用。","tags":["缓冲结构","运输包装"]},{"id":"ch08-s006","type":"single","chapter":8,"level":"次重点","ability":"理解","difficulty":2,"stem":"盒盖与盒体相互独立、盒盖由上向下罩住盒体的盒型是(  )。","options":["天地盖盒","摇盖盒","抽屉盒","异型盒"],"answer":[0],"explanation":"天地盖盒由盒盖(天)与盒体(地)两部分组成,盒盖罩合在盒体上,多用于礼品、鞋类等产品的销售包装,用料较多但开启方便、外观完整。摇盖盒的盒盖与盒体一侧相连并可翻转开合;抽屉盒由盒套与可水平抽出的内盒组成;异型盒是非矩形轮廓的特殊盒型。","tags":["包装结构形式","天地盖盒"]},{"id":"ch08-s007","type":"single","chapter":8,"level":"次重点","ability":"识记","difficulty":2,"stem":"折叠纸盒设计与制造中,把立体盒型展开成平面图形所得到的图样称为(  )。","options":["轴测图","展开图","装配图","剖视图"],"answer":[1],"explanation":"展开图是把立体盒型按纸板厚度与折叠关系铺展成平面后绘制的图样,图上要标明裁切线(刀口线)与折痕线,是制作刀模、进行印刷和模切的依据。装配图、剖视图、轴测图属于机械制图的表达方式,不用于表达纸盒由平面到立体的成型关系。","tags":["折叠纸盒","展开图"]},{"id":"ch08-s008","type":"single","chapter":8,"level":"次重点","ability":"理解","difficulty":3,"stem":"折叠纸盒成型时不需要使用胶粘剂,而是依靠纸板裁切出的插舌与锁口相互咬合,这种方式称为(  )。","options":["锁合","焊接","铆接","粘合"],"answer":[0],"explanation":"锁合又称自锁,利用纸板上裁切出的插舌、锁口、卡榫相互勾挂卡紧,使盒体或盒底自行固定,不需施胶即可成型,便于用户拆开、压平,也有利于包装废弃后的分类回收;粘合依靠胶粘剂把搭接部位粘牢,连接强度较高但需要糊盒设备,拆解与回收相对不便。","tags":["纸盒结构","锁合与粘合"]},{"id":"ch08-s009","type":"single","chapter":8,"level":"重点","ability":"识记","difficulty":1,"stem":"使多个相同或形状相近的器物能够上下嵌套在一起、空置时显著减少占用空间的结构是(  )。","options":["易拆装结构","伸缩结构","折叠结构","套叠结构"],"answer":[3],"explanation":"套叠结构利用器物外形轮廓尺寸的递减或锥度,使一件器物能部分进入另一件之内,空置时若干件可以叠成一摞,节省堆放、储存和运输空间,常见于套叠椅、套叠凳、塑料周转箱和各类容器。其余几种结构分别依靠折合、滑动和拆装来改变占用空间。","tags":["套叠结构","收纳结构"]},{"id":"ch08-s010","type":"single","chapter":8,"level":"重点","ability":"理解","difficulty":2,"stem":"拉杆箱的拉杆通过管件之间的相对滑动改变长度,便于拖拉和收存,这属于收纳结构中的(  )。","options":["伸缩结构","柔性结构","套叠结构","折叠结构"],"answer":[0],"explanation":"伸缩结构依靠截面尺寸不同的零件相互套接并沿轴向相对滑动,从而改变长度或高度,收拢后占用空间小、展开后能够定位使用,拉杆箱拉杆、伸缩杆、可调高度支架都属于此类。它改变的是构件的长度尺寸,与折叠的角位移、套叠的空间嵌套、柔性材料的变形都不相同。","tags":["伸缩结构","拉杆箱"]},{"id":"ch08-s011","type":"multi","chapter":8,"level":"次重点","ability":"识记","difficulty":3,"stem":"下列关于包装分类的说法,正确的有(  )。","options":["按包装形态可分为盒、袋、瓶、罐、管、泡罩等","按包装在流通中的作用可分为运输包装和销售包装","按包装材料可分为纸、塑料、金属、玻璃、复合材料等","运输包装直接面向消费者,销售包装主要面向仓储和运输","同一件产品的包装可以同时兼顾运输包装和销售包装的功能"],"answer":[0,1,2,4],"explanation":"包装可按形态、功能、材料等不同角度分类:形态上常见盒、袋、瓶、罐、管、泡罩,功能上分为运输包装与销售包装,材料上分为纸、塑料、金属、玻璃、复合材料等。第四项把两类包装的服务对象说反了,运输包装面向仓储运输环节,销售包装面向消费者;两类功能也可由同一件包装兼顾。","tags":["包装分类","包装材料"]},{"id":"ch08-s012","type":"multi","chapter":8,"level":"次重点","ability":"识记","difficulty":3,"stem":"下列各项中,属于包装结构设计要求的有(  )。","options":["保护产品,使产品在流通过程中不损坏、不变质","便于储存、装卸和运输,提高流通效率","便于展示与使用,方便开启、取用和再封合","节省材料、便于回收,并符合法规和标准化尺寸要求","包装结构越复杂、用料越多,保护效果必然越好"],"answer":[0,1,2,3],"explanation":"包装结构设计的基本要求包括保护产品、便于储运、便于展示与使用、节省材料、便于回收,以及符合法规与标准化尺寸要求,这些要求往往需要综合权衡。第五项把“结构复杂”“用料多”等同于“保护效果好”,忽视了缓冲原理、材料性能以及成本与环保方面的约束,是明显的误解。","tags":["包装结构设计要求","标准化尺寸"]},{"id":"ch08-s013","type":"multi","chapter":8,"level":"重点","ability":"理解","difficulty":4,"stem":"关于产品收纳结构的基本类型,下列说法正确的有(  )。","options":["套叠结构依靠外形尺寸的递减或锥度实现嵌套,如套叠椅、周转箱","折叠结构借助铰链或折痕使构件折合,如折叠桌、折叠箱","易拆装结构用可重复装拆的连接件把产品分成若干部件,如平板包装家具","伸缩结构依靠零件间的相对滑动改变长度或高度,如拉杆箱拉杆","柔性结构以织物、薄膜等软性材料为主体,因材料柔软而不必考虑连接与耐久问题"],"answer":[0,1,2,3],"explanation":"套叠、折叠、易拆装、伸缩、柔性是产品收纳结构的五种基本类型,共同目标是缩小空置或运输状态下的体积。前四项的描述与其原理、典型产品相符;第五项错误,柔性结构虽然靠材料变形收拢,但缝制、铆合、尼龙搭扣等连接方式以及反复使用引起的磨损与老化同样必须考虑。","tags":["收纳结构类型","柔性结构"]},{"id":"ch08-s014","type":"multi","chapter":8,"level":"重点","ability":"理解","difficulty":4,"stem":"设计可折叠、可套叠或可拆装的产品时,应注意的问题有(  )。","options":["合理选择连接方式,兼顾连接强度、刚度与拆装便利性","铰链、导轨、卡扣等活动部件的配合精度影响开合手感与使用寿命","收拢状态应能稳定保持,展开状态应具有足够的强度与刚度","反复折叠、滑动会使材料产生疲劳与磨损,需要通过结构设计和材料选择提高耐久性","为便于活动,应取消一切限位和导向结构,让部件自由晃动"],"answer":[0,1,2,3],"explanation":"收纳类结构的设计要点集中在连接与运动部位:连接方式决定强度与拆装便利性;铰链、导轨、卡扣的精度决定使用手感与寿命;反复变形会引起材料疲劳,需通过圆角过渡、合理壁厚和耐磨材料提高耐久性;同时要保证收拢稳定、展开可靠。取消限位与导向会使产品松晃、定位不准,反而降低可靠性。","tags":["收纳结构设计要点","材料疲劳"]},{"id":"ch08-s015","type":"judge","chapter":8,"level":"次重点","ability":"识记","difficulty":1,"stem":"判断:销售包装除保护产品外,还承担着介绍产品、吸引消费者和方便使用的功能。","options":["正确","错误"],"answer":[0],"explanation":"正确。销售包装随产品一起进入零售环节,直接面向消费者,除必要的保护作用外,还要通过造型、装潢和文字说明传递产品信息、吸引购买,并便于开启、取用、携带与再封合。保护产品是各类包装的共同要求,而展示与促销是销售包装区别于运输包装的突出功能。","tags":["销售包装","包装功能"]},{"id":"ch08-s016","type":"judge","chapter":8,"level":"次重点","ability":"理解","difficulty":3,"stem":"判断:包装结构设计只要保证产品在运输中不被损坏,不必考虑包装废弃后的回收和标准化尺寸问题。","options":["正确","错误"],"answer":[1],"explanation":"错误。保护产品只是包装结构设计的要求之一,设计时还要兼顾便于储运、便于展示与使用、节省材料、便于回收以及符合法规和标准化尺寸等要求。忽视回收会造成资源浪费和环境负担;忽视标准化尺寸则会影响托盘、集装箱和货架的装载效率,反而增加流通成本。","tags":["包装结构设计要求","便于回收"]},{"id":"ch08-s017","type":"judge","chapter":8,"level":"重点","ability":"理解","difficulty":2,"stem":"判断:套叠结构只适用于容器类产品,家具不能采用这种结构。","options":["正确","错误"],"answer":[1],"explanation":"错误。套叠结构依靠外形尺寸的递减与锥度实现相互嵌套,适用范围并不限于容器。套叠椅、套叠凳就是典型例子:椅面与椅腿做成略带锥度的曲面,若干把椅子可以前后叠放成一摞,空置时大幅节省堆放与运输空间。判断某种结构是否适用,应看产品形态能否形成嵌套关系,而不是看产品类别。","tags":["套叠结构","套叠椅"]},{"id":"ch08-s018","type":"judge","chapter":8,"level":"重点","ability":"理解","difficulty":2,"stem":"判断:柔性结构以织物、薄膜等软性材料为主体,靠材料自身变形实现收拢,其承重与保护能力一般不如刚性结构。","options":["正确","错误"],"answer":[0],"explanation":"正确。软性收纳袋、折叠式织物储物箱等柔性收纳产品收拢后可以压平或卷起,重量轻、携带方便、适应性强,但材料模量低、形状保持能力差,承重能力和对内部物品的刚性保护不如金属、木材等刚性结构,因此多用于衣物、玩具等轻软物品的收纳。","tags":["柔性结构","收纳结构"]},{"id":"ch08-s019","type":"blank","chapter":8,"level":"次重点","ability":"识记","difficulty":2,"stem":"按包装在流通中的作用分类,包装可分为______和______;按包装形态分类,常见形式有盒、袋、瓶、罐、管和______等。","answer":["运输包装","销售包装","泡罩|泡罩包装"],"explanation":"这是包装最常用的两种分类角度。按作用(功能)分为运输包装和销售包装,前者重在保护产品与方便流通,后者重在展示与促销;按形态分为盒、袋、瓶、罐、管、泡罩等,其中泡罩包装由透明塑料薄片成型的泡罩与纸板底板封合而成,展示性好、用料较省。","tags":["包装分类","包装形态"]},{"id":"ch08-s020","type":"blank","chapter":8,"level":"次重点","ability":"识记","difficulty":1,"stem":"包装结构设计应满足保护产品、便于储运、便于展示与使用、______、便于回收以及符合法规和______尺寸等要求。","answer":["节省材料","标准化"],"explanation":"包装结构设计的要求是一个整体:既要在流通过程中保护产品、便于储存与运输,又要便于展示和使用;同时要在满足功能的前提下节省材料、降低成本,并便于包装废弃后的回收处理。此外,包装的外形与尺寸还应符合相关法规和标准化尺寸要求,以便与托盘、集装箱、货架等配合。","tags":["包装结构设计要求","标准化尺寸"]},{"id":"ch08-s021","type":"blank","chapter":8,"level":"重点","ability":"识记","difficulty":3,"stem":"产品收纳结构的基本类型有套叠结构、______结构、易拆装结构、______结构和柔性结构;其中易拆装结构常见于______包装的家具。","answer":["折叠","伸缩","平板|平板式"],"explanation":"套叠、折叠、易拆装、伸缩、柔性五种结构从不同途径缩小产品空置或运输时的体积。易拆装结构用可重复装拆的连接件把家具分成板件和五金件,以平板状态包装运输,用户可按说明自行组装,既节省包装与运输空间,又便于搬运和更换损坏的部件。","tags":["收纳结构类型","易拆装结构"]},{"id":"ch08-s022","type":"term","chapter":8,"level":"重点","ability":"理解","difficulty":3,"stem":"解释概念:套叠结构","answer":["指利用器物外形轮廓尺寸的递减或带有锥度,使一件器物能部分嵌入另一件之内、多件可以相互嵌套的收纳结构。","其优点是空置时可将多件叠成一摞,大幅节省堆放、储存和运输空间,取放也比较方便。","典型产品有套叠椅、套叠凳、塑料周转箱以及各类可叠放的容器。"],"explanation":"回答时应说明三点:一是结构原理,即依靠尺寸递减与锥度形成嵌套关系;二是优点,即空置时体积小、便于堆放和运输;三是典型产品。还应注意它与伸缩结构的区别,套叠靠空间嵌套,伸缩靠零件相对滑动改变长度。","tags":["套叠结构","收纳结构"]},{"id":"ch08-s023","type":"term","chapter":8,"level":"重点","ability":"理解","difficulty":4,"stem":"解释概念:折叠结构","answer":["指通过铰链、转轴或纸板、塑料的折痕,使构件能够相对转动折合,从而在收拢状态缩小体积的收纳结构。","其优点是收拢后占用空间小,便于携带、储存和运输,展开后即可形成可用的支撑或容纳空间。","典型产品有折叠桌、折叠椅、折叠箱和折叠式包装箱。","设计时要保证展开状态具有足够的强度与刚度,并通过限位、锁定机构防止使用中自行折合。"],"explanation":"要点包括三个方面:依靠铰链或折痕实现折合的原理;收拢体积小、便于储运的优点;折叠桌、折叠箱等典型产品。答题时最好补充设计注意事项,即展开后必须可靠锁定并具有足够刚度,避免使用时晃动或突然折合造成事故。","tags":["折叠结构","铰链"]},{"id":"ch08-s024","type":"short","chapter":8,"level":"重点","ability":"理解","difficulty":4,"stem":"简述产品收纳结构的常见类型,并说明设计这类结构时应注意的主要问题。","answer":["套叠结构:利用外形尺寸递减或锥度使器物相互嵌套,空置时叠成一摞,如套叠椅、周转箱。","折叠结构:借助铰链或折痕使构件折合,收拢后体积小,如折叠桌、折叠箱。","易拆装结构:用可重复装拆的连接件把产品分成若干部件,便于平板包装、运输和更换部件,如平板包装家具。","伸缩结构:依靠零件相对滑动改变长度或高度,如拉杆箱拉杆、伸缩杆。","柔性结构:以织物、薄膜等软性材料为主体,靠材料变形收拢,如软性收纳袋。","设计要点:合理选择连接方式以及铰链、导轨、卡扣等活动部件;保证展开状态有足够的强度与刚度、收拢状态稳定可靠;注意反复变形引起的材料疲劳与磨损,提高耐久性和使用寿命。"],"explanation":"本题属综合理解题,作答分两部分:先按五种类型分别说明原理、优点与典型产品,再归纳设计要点。设计要点应围绕连接方式、活动部件的精度与寿命、收拢与展开两种状态的可靠性,以及材料疲劳与耐久性展开,做到条理清楚、例证具体。","tags":["收纳结构","设计要点"]},{"id":"ch09-s001","type":"single","chapter":9,"level":"一般","ability":"识记","difficulty":1,"stem":"绿色能源主要是指(  )。","options":["颜色呈绿色的能源","价格最低廉的能源","对生态环境友好的能源,污染物与温室气体排放少,可再生或可循环利用","只能用于农业生产的能源"],"answer":[2],"explanation":"绿色能源也称清洁能源,强调的是环境友好属性:在其开发与利用过程中对生态环境影响小,污染物和温室气体排放少,并且大多可以再生或循环利用。它并不是按颜色、价格或使用行业来划分的概念,故其余选项都是望文生义的理解。","tags":["绿色能源","概念"]},{"id":"ch09-s002","type":"single","chapter":9,"level":"次重点","ability":"识记","difficulty":2,"stem":"太阳能热水器所实现的能量转换过程是(  )。","options":["化学能转换为热能","电能转换为热能","光能直接转换为电能","光能转换为热能"],"answer":[3],"explanation":"太阳能热水器依靠集热器吸收太阳辐射,把光能转换为热能并传递给水,属于太阳能的光热转换利用。光能直接转换为电能是光伏电池的光电转换,化学能转换为热能是燃料燃烧的过程,电能转换为热能则是电热水器的工作方式。","tags":["太阳能","光热转换"]},{"id":"ch09-s003","type":"single","chapter":9,"level":"次重点","ability":"识记","difficulty":2,"stem":"光伏电池实现光电转换所依据的物理效应是(  )。","options":["热电效应","光电效应","压电效应","电磁感应效应"],"answer":[1],"explanation":"光伏电池由半导体材料制成,当太阳光照射到半导体 PN 结上时产生光电效应,直接形成电动势和电流,把光能转换为电能。电磁感应是发电机的工作原理,热电效应用于温差发电,压电效应用于受力发电和传感器,均与光伏发电原理不同。","tags":["光伏电池","光电转换","光电效应"]},{"id":"ch09-s004","type":"single","chapter":9,"level":"次重点","ability":"识记","difficulty":2,"stem":"燃料电池工作时,其能量转换的基本方式是(  )。","options":["燃料与氧化剂在电极上发生电化学反应,把化学能直接转换为电能","燃料燃烧产生高温高压气体推动汽轮机做功","先把燃料燃烧的热能转换为机械能,再带动发电机发电","依靠太阳光照射半导体材料直接产生电流"],"answer":[0],"explanation":"燃料电池把燃料(如氢)和氧化剂(如氧)分别送入阳极和阴极,在电极与电解质的作用下发生电化学反应,把化学能直接转换为电能,中间不经过燃烧和机械做功环节,因而不受卡诺循环效率的限制,能量转换效率较高。","tags":["燃料电池","工作原理"]},{"id":"ch09-s005","type":"single","chapter":9,"level":"次重点","ability":"理解","difficulty":2,"stem":"燃料电池发电时,氢与氧发生电化学反应的生成物是(  )。","options":["二氧化硫和水","一氧化碳和氢气","水","二氧化碳和水"],"answer":[2],"explanation":"氢燃料电池中,氢在阳极失去电子生成氢离子,氧在阴极得到电子,二者结合生成水,因此其突出优点是排放物只有水,基本不产生二氧化碳、硫化物和颗粒物等污染物。二氧化碳是含碳燃料燃烧的产物,与氢氧反应的生成物无关。","tags":["燃料电池","氢能","零排放"]},{"id":"ch09-s006","type":"single","chapter":9,"level":"次重点","ability":"理解","difficulty":3,"stem":"关于风能的特点,下列表述正确的是(  )。","options":["风能的利用需要消耗大量燃料","风能能量密度较低且具有间歇性和随机性,需要配合储能或其他电源使用","风能十分稳定,可以像火电一样按需调节出力","风力发电不受地理环境与季节变化的影响"],"answer":[1],"explanation":"风能是清洁的可再生能源,风力发电不需要消耗燃料,但其能量密度低,风速和风向随季节、天气与地形不断变化,具有明显的间歇性和随机性,因此常需与储能装置或其他电源配合,才能保证供电的连续与稳定。","tags":["风能","特点","间歇性"]},{"id":"ch09-s007","type":"single","chapter":9,"level":"一般","ability":"识记","difficulty":2,"stem":"下列不属于生物质能利用方式的是(  )。","options":["电解水制取氢气","生物质热化学气化制取可燃气","有机废弃物经厌氧发酵制取沼气","秸秆等生物质直接燃烧供热"],"answer":[0],"explanation":"生物质能的利用方式包括直接燃烧、厌氧发酵制沼气、热化学气化、以及制取生物乙醇和生物柴油等。电解水制氢是以电能为输入、以水为原料的制氢技术,其能量来源是电能而非生物质,因此不属于生物质能的利用方式。","tags":["生物质能","利用方式"]},{"id":"ch09-s008","type":"single","chapter":9,"level":"一般","ability":"识记","difficulty":2,"stem":"超级电容最突出的性能特点是(  )。","options":["能量密度高,可替代蓄电池长期供电","功率密度高,充放电速度快,循环寿命长","单位质量的成本低于所有其他储能器件","只能用于交流电路"],"answer":[1],"explanation":"超级电容依靠电极与电解质界面形成的双电层储存电荷,充放电过程中不发生剧烈的化学反应,因此功率密度高、充放电速度快、循环寿命长。但它的能量密度低于蓄电池,难以单独承担长时间供电任务,通常与电池配合使用。","tags":["超级电容","特点","功率密度"]},{"id":"ch09-s009","type":"single","chapter":9,"level":"次重点","ability":"理解","difficulty":2,"stem":"太阳能光热发电的基本工作过程是(  )。","options":["利用光伏电池把太阳光直接转换为电能","用聚光装置把太阳辐射汇聚起来加热工质,产生蒸汽推动汽轮发电机组发电","利用太阳光照射半导体材料产生温差电动势","利用太阳光的热量直接驱动风力发电机"],"answer":[1],"explanation":"太阳能光热发电先用反射镜等聚光装置把太阳辐射汇聚到吸热器上,加热水或其他工质产生高温蒸汽,再推动汽轮发电机组发电,属于“光—热—功—电”的转换路径。第一项属于光伏发电,二者原理和系统构成都不同。","tags":["太阳能","光热发电"]},{"id":"ch09-s010","type":"single","chapter":9,"level":"次重点","ability":"理解","difficulty":3,"stem":"光伏发电系统的组成部件中,把光伏电池输出的直流电转换为交流电的装置是(  )。","options":["蓄电池","支架","逆变器","控制器"],"answer":[2],"explanation":"光伏电池输出的是直流电,而多数用电设备和电网需要交流电,因此系统中需用逆变器完成直流到交流的变换。蓄电池用于储存电能,控制器用于管理充放电过程、防止过充过放,支架用于支撑和调整光伏组件的安装角度。","tags":["光伏发电","逆变器","系统组成"]},{"id":"ch09-s011","type":"multi","chapter":9,"level":"一般","ability":"应用","difficulty":3,"stem":"下列属于可再生能源的有(  )。","options":["太阳能","生物质能","风能","煤和石油等化石能源"],"answer":[0,1,2],"explanation":"可再生能源指在自然界可以不断再生、持续利用的能源,太阳能、风能、生物质能以及水能等都属于这一类,其共同特点是对环境影响较小、可以持续获得。煤和石油是地质时期长期演化形成的化石能源,储量有限、不可再生,燃烧时还排放大量污染物和温室气体。","tags":["可再生能源","绿色能源","化石能源"]},{"id":"ch09-s012","type":"multi","chapter":9,"level":"次重点","ability":"应用","difficulty":3,"stem":"关于燃料电池的特点,下列说法正确的有(  )。","options":["能量转换效率较高,不受卡诺循环的限制","造价低、燃料储存方便,已经可以全面替代内燃机","能量密度较高,适合用于电动汽车和便携式电源","没有机械转动部件,运行噪声低,启动较快"],"answer":[0,2,3],"explanation":"燃料电池把化学能直接转换为电能,效率高且不受卡诺循环限制;没有机械转动部件,噪声与振动小、启动快;能量密度较高,适用于电动汽车和便携式电源。但其造价仍然较高,氢的制取、储存与运输也存在困难,目前尚不能全面替代内燃机。","tags":["燃料电池","特点","应用前景"]},{"id":"ch09-s013","type":"multi","chapter":9,"level":"次重点","ability":"理解","difficulty":3,"stem":"太阳能的应用前景主要体现在(  )。","options":["太阳能热水与供暖等光热利用在生活和生产中广泛普及","太阳能发电完全不受昼夜和天气影响,可独立稳定供电","光伏发电的成本不断下降,应用规模持续扩大,分布式光伏与建筑一体化成为重要发展方向","太阳能资源分布广泛,可就地开发利用,适合偏远地区供电"],"answer":[0,2,3],"explanation":"太阳能资源分布广泛、清洁可再生,可就地开发,适合偏远地区供电;随着技术进步和规模扩大,光伏发电成本持续下降,分布式光伏与建筑一体化以及太阳能热水、供暖等光热利用加快普及。但太阳能受昼夜、季节和天气影响明显,具有间歇性,通常需要储能或与其他电源配合使用。","tags":["太阳能","应用前景","分布式光伏"]},{"id":"ch09-s014","type":"multi","chapter":9,"level":"一般","ability":"理解","difficulty":3,"stem":"下列属于生物质能利用方式的有(  )。","options":["热化学气化制取可燃气,或制取生物乙醇、生物柴油等液体燃料","厌氧发酵制取沼气","直接燃烧供热或发电","利用核裂变释放的能量发电"],"answer":[0,1,2],"explanation":"生物质能是植物、动物及微生物等有机体通过光合作用形成的能量,其利用方式包括直接燃烧供热或发电、厌氧发酵制取沼气、热化学气化制取可燃气,以及制取生物乙醇和生物柴油等液体燃料。核裂变发电利用的是核能,与生物质能无关,故不属于生物质能的利用方式。","tags":["生物质能","利用方式","生物燃料"]},{"id":"ch09-s015","type":"judge","chapter":9,"level":"一般","ability":"理解","difficulty":2,"stem":"判断:太阳能热水器利用的是光热转换,光伏电池利用的是光电转换,二者是太阳能利用的两条不同技术路径。","options":["正确","错误"],"answer":[0],"explanation":"正确。太阳能利用主要分为光热转换和光电转换两类:太阳能热水器、太阳能供暖与光热发电通过集热器或聚光装置把光能转换为热能;光伏电池则利用光电效应把光能直接转换为电能,二者原理不同,可以分别使用也可以组合成光热光伏复合系统。","tags":["太阳能","光热转换","光电转换"]},{"id":"ch09-s016","type":"judge","chapter":9,"level":"次重点","ability":"理解","difficulty":2,"stem":"判断:燃料电池把化学能直接转换为电能,不需要经过燃烧和机械做功过程,因此其能量转换效率较高,且排放物主要是水,对环境影响小。","options":["正确","错误"],"answer":[0],"explanation":"正确。燃料电池通过电极上的电化学反应把燃料的化学能直接转换为电能,省去了燃烧和机械做功等中间环节,不受卡诺循环效率的限制,转换效率较高;以氢为燃料时生成物只有水,几乎不排放污染物和温室气体,被称为清洁高效的发电装置。","tags":["燃料电池","效率","清洁排放"]},{"id":"ch09-s017","type":"judge","chapter":9,"level":"一般","ability":"识记","difficulty":1,"stem":"判断:风能是清洁的可再生能源,风力发电不消耗燃料,也不排放污染物和温室气体。","options":["正确","错误"],"answer":[0],"explanation":"正确。风能来源于太阳辐射造成的大气运动,可以持续再生,风力发电把风的动能转换为电能,运行过程中不需要消耗燃料,也不排放污染物和温室气体,因此被广泛视为绿色能源。需要注意的是,风能存在间歇性和随机性,需要与其他电源配合。","tags":["风能","清洁能源"]},{"id":"ch09-s018","type":"judge","chapter":9,"level":"一般","ability":"理解","difficulty":2,"stem":"判断:超级电容的能量密度高于蓄电池,因此可以完全取代蓄电池为电动汽车提供长距离行驶所需的能量。","options":["正确","错误"],"answer":[1],"explanation":"错误。超级电容的长处是功率密度高、充放电速度快、循环寿命长,但能量密度低于蓄电池,单位质量或单位体积所能储存的能量有限,无法单独支撑长距离行驶。通常做法是把超级电容与蓄电池组成混合储能系统,前者承担加速与制动能量回收时的峰值功率,后者提供持续的续航能量。","tags":["超级电容","能量密度","互补关系"]},{"id":"ch09-s019","type":"blank","chapter":9,"level":"一般","ability":"识记","difficulty":2,"stem":"绿色能源也称______能源,是指在其开发与利用过程中对生态环境影响小、污染物和温室气体排放少,并且大多可以______利用的能源。","answer":["清洁","再生|循环"],"explanation":"绿色能源通常与清洁能源、可再生能源并称,其核心含义有两点:一是环境友好,开发与利用过程中对生态影响小、污染排放少;二是可持续,太阳能、风能、生物质能等可以在自然界不断再生,因此能够长期稳定地供给。","tags":["绿色能源","概念","可再生能源"]},{"id":"ch09-s020","type":"blank","chapter":9,"level":"次重点","ability":"理解","difficulty":3,"stem":"太阳能利用主要有两条技术路径:太阳能热水器、太阳能供暖等属于______转换利用,光伏电池发电属于______转换利用。","answer":["光热|光—热|光-热","光电|光—电|光-电"],"explanation":"光热转换通过集热器或聚光装置吸收太阳辐射并转化为热能,用于热水、供暖以及光热发电;光电转换利用半导体材料的光电效应把太阳光直接转换为电能,是光伏发电的基础。两条路径原理不同,可单独应用,也可组成光热光伏复合系统。","tags":["太阳能","光热转换","光电转换"]},{"id":"ch09-s021","type":"blank","chapter":9,"level":"次重点","ability":"识记","difficulty":2,"stem":"燃料电池工作时,燃料在______极发生氧化反应失去电子,氧化剂在______极得到电子,以氢为燃料时的生成物只有水。","answer":["阳","阴"],"explanation":"燃料电池由阳极、阴极和电解质等部分组成。燃料(如氢)送入阳极,在电极作用下失去电子被氧化;氧化剂(如空气中的氧)送入阴极,得到电子被还原;电子经外电路流动形成电流,氢离子与氧结合生成水,从而实现化学能向电能的直接转换。","tags":["燃料电池","电极反应"]},{"id":"ch09-s022","type":"blank","chapter":9,"level":"次重点","ability":"识记","difficulty":2,"stem":"风力发电机组把风的______能转换为机械能,再带动发电机转换为______能。","answer":["动","电"],"explanation":"风力发电的能量转换过程是:流动的空气推动风轮叶片旋转,把风的动能转换为风轮轴的机械能,风轮再通过传动系统带动发电机旋转,把机械能转换为电能,最后经变流、升压后送入电网或供本地使用。","tags":["风能","风力发电","能量转换"]},{"id":"ch09-s023","type":"term","chapter":9,"level":"一般","ability":"识记","difficulty":2,"stem":"解释概念:绿色能源","answer":["绿色能源又称清洁能源,是指在其开发利用过程中对生态环境影响小、污染物与温室气体排放少的能源。","它包括太阳能、风能、生物质能、水能等可再生能源,也包括部分通过技术手段实现清洁利用的能源形式。","发展绿色能源是缓解化石能源短缺、减少环境污染和实现可持续发展的重要途径。"],"explanation":"作答时要抓住三个要点:一是环境友好的核心含义,即污染排放少、生态影响小;二是所包含的主要能源种类,以可再生能源为主体;三是发展绿色能源的意义,包括优化能源结构、减少污染排放和支撑可持续发展。","tags":["绿色能源","概念","可持续发展"]},{"id":"ch09-s024","type":"term","chapter":9,"level":"次重点","ability":"识记","difficulty":2,"stem":"解释概念:燃料电池","answer":["燃料电池是一种把燃料与氧化剂发生电化学反应所产生的化学能直接转换为电能的发电装置。","它由阳极、阴极、电解质和外部电路等组成,燃料在阳极被氧化、氧化剂在阴极被还原,电子经外电路流动形成电流。","燃料电池能量转换效率高、噪声低、启动快、能量密度较高,以氢为燃料时排放物只有水,但存在成本高和储氢困难等问题。"],"explanation":"答题要点包括:一是装置性质,即把化学能直接转换为电能的发电装置;二是工作方式,燃料与氧化剂分别在两极发生氧化和还原反应;三是主要优缺点,效率高、噪声低、排放清洁,同时成本较高、燃料储存困难。","tags":["燃料电池","概念","特点"]},{"id":"ch09-s025","type":"short","chapter":9,"level":"次重点","ability":"理解","difficulty":3,"stem":"简述太阳能热利用与太阳能光电利用的主要形式,并说明二者各自的特点与局限。","answer":["太阳能热利用是先把太阳辐射转换为热能再加以使用,主要形式有太阳能热水器、太阳能采暖与制冷、太阳能光热发电等。","太阳能光电利用是依靠光伏电池的光电效应把太阳光直接转换为电能,其形式包括独立光伏系统、并网光伏电站和分布式光伏等,系统中需配置逆变器、控制器与蓄电池等部件。","光热利用的技术相对成熟、成本较低,但主要用于供热和发电,用途较窄;光电利用用途广泛、便于分散布置,但转换效率通常在百分之十几到二十几,且受昼夜、季节和天气影响明显,需要储能装置或与其他电源配合。"],"explanation":"本题应分别说明两条路径的转换原理、典型应用形式,并从技术成熟度、成本、用途范围和供电稳定性等方面比较其特点与局限。要点明确、层次清楚即可得分,不必展开具体的技术参数。","tags":["太阳能","光热利用","光电利用"]},{"id":"ch09-s026","type":"short","chapter":9,"level":"一般","ability":"理解","difficulty":3,"stem":"简述超级电容的特点及其与蓄电池的互补关系。","answer":["功率密度高,可以在短时间内释放或吸收很大的功率,适合提供峰值功率。","充放电速度快,充电时间短,能够在制动或下坡时快速回收能量。","循环寿命长,充放电次数远多于普通蓄电池,维护工作量小,工作温度范围较宽。","能量密度低于蓄电池,单独使用时续航能力有限,因此常与蓄电池组成混合储能系统。","在混合储能系统中,超级电容承担启动、加速和制动能量回收时的峰值功率,蓄电池提供持续稳定的能量,二者互补可延长电池寿命并提高系统效率。"],"explanation":"作答时先列出超级电容功率密度高、充放电快、循环寿命长、能量密度偏低的性能特点,再说明它与蓄电池的分工:超级电容负责短时高峰值功率,蓄电池负责持续供能,二者组合能够兼顾动力性与续航能力。","tags":["超级电容","特点","混合储能"]},{"id":"ch10-s001","type":"single","chapter":10,"level":"一般","ability":"识记","difficulty":1,"stem":"电子元器件发展的最早阶段所使用的核心器件是(  )。","options":["真空电子管","半导体晶体管","集成电路","大规模集成电路"],"answer":[0],"explanation":"电子元器件的发展大体经历电子管、晶体管、集成电路、大规模集成电路四个阶段。真空电子管体积大、耗电多、寿命短,是最早的电子有源器件。其余三项都是电子管之后才出现的,因此选第一项。","tags":["电子元件发展","电子管"]},{"id":"ch10-s002","type":"single","chapter":10,"level":"一般","ability":"识记","difficulty":1,"stem":"与真空电子管相比,半导体晶体管最突出的优势是(  )。","options":["可以直接放大交流信号而电子管不能","体积小、功耗低、寿命长、可靠性高,便于大量集成","不需要任何电源即可工作","只能用于大功率电能变换场合"],"answer":[1],"explanation":"晶体管用半导体材料实现电子管的功能,体积、重量、功耗都大幅下降,寿命与可靠性明显提高,且易于批量制造与集成,由此取代了电子管。电子管同样能放大信号,故第一项不成立;晶体管必须供电,也不是只用于大功率场合。","tags":["半导体元器件","晶体管"]},{"id":"ch10-s003","type":"single","chapter":10,"level":"一般","ability":"理解","difficulty":3,"stem":"与分立元件电路相比,集成电路最本质的特征是(  )。","options":["把多个电子元器件及其连线在同一基片上制作成一个不可分割的整体","把多个电阻简单地粘接在同一块塑料板上","把电路的体积放大以便于维修","用导线把若干独立元件捆扎成一个模块"],"answer":[0],"explanation":"集成电路是在半导体基片上用微电子工艺同时制作晶体管、电阻、电容等元件及它们之间的连线,使电路成为一个整体,因而体积小、重量轻、可靠性高、便于大批量生产。其余选项都是表面上的组合,并未形成一体化结构。","tags":["集成电路","集成化"]},{"id":"ch10-s004","type":"single","chapter":10,"level":"一般","ability":"识记","difficulty":1,"stem":"在电路图中,代表“储存电荷、隔断直流而让交流通过”的元件符号,对应的实物是(  )。","options":["二极管","电阻器","电感器","电容器"],"answer":[3],"explanation":"电容器由两片导体中间夹绝缘介质构成,能储存电荷,具有隔直流、通交流的特性,常用于耦合、旁路与滤波。电阻器限制电流,电感器储存磁场能量并对交流呈感抗,二极管具有单向导电性,均不符合题意,因此选电容器。","tags":["电容器","元器件识别"]},{"id":"ch10-s005","type":"single","chapter":10,"level":"一般","ability":"识记","difficulty":3,"stem":"在电子设备中,把温度、压力、光照等被测量转换为电信号输出的元器件称为(  )。","options":["稳压器","传感器","变压器","整流器"],"answer":[1],"explanation":"传感器是感受规定的被测量并按照一定规律把它转换成可用电信号输出的器件或装置,如热敏电阻、压敏元件、光敏元件等。整流器把交流变为直流,变压器改变交流电压,稳压器稳定输出电压,它们都不承担非电量到电量的转换功能。","tags":["传感器","元器件识别"]},{"id":"ch10-s006","type":"single","chapter":10,"level":"一般","ability":"识记","difficulty":2,"stem":"关于印制电路板的基材,下列说法正确的是(  )。","options":["常用基材是纯铜板,本身就是导体","常用基材是铝箔,用于导电而不用于支撑","常用基材是导电橡胶,靠自身导电连接各元件","常用基材由树脂与玻璃纤维布等增强材料复合而成,起绝缘与支撑作用"],"answer":[3],"explanation":"印制板的基材以树脂为粘结剂、以玻璃纤维布等为增强材料复合而成,具有绝缘性能和一定机械强度,用来支撑元器件与铜箔线路。纯铜、铝箔都是导体,不能作为绝缘基材;导电橡胶也不能充当印制板的支撑基体。","tags":["基材","印制板构成"]},{"id":"ch10-s007","type":"single","chapter":10,"level":"次重点","ability":"理解","difficulty":2,"stem":"属于表面贴装技术典型工艺特征的工序是(  )。","options":["用螺钉把元器件压紧在印制板上实现电气连接","用导电胶把元器件粘在塑料外壳内壁上","把元器件引脚逐个人工穿过通孔再逐个点焊","在焊盘上涂布焊膏,贴放片式元器件后整体加热使焊膏熔化完成连接"],"answer":[3],"explanation":"表面贴装技术的一般流程是印刷焊膏、贴装片式元器件、再流焊使焊膏熔化形成焊点,无需穿孔。逐个人工穿孔点焊属于通孔插装手工焊接,螺钉压紧与导电胶粘接都不能形成可靠的电气连接,也不是电子装配的常规做法。","tags":["表面贴装技术","焊膏"]},{"id":"ch10-s008","type":"single","chapter":10,"level":"次重点","ability":"应用","difficulty":3,"stem":"设计一台便携式音频播放器时,从内部布局角度考虑,比较合理的做法是(  )。","options":["把电池与音频放大电路紧贴叠放以节省空间","把质量较大的电池尽量布置在靠近手持部位的一侧并降低重心,同时避开对信号敏感的音频线路","把按键全部布置在机身背面以保持正面平整","把充电与耳机接口集中布置在机身同一转角,便于共用同一块开孔区域"],"answer":[1],"explanation":"手持产品的电池质量占比大,靠近手持部位并降低重心可改善握持与受力,远离音频敏感线路可减少干扰。电池与放大电路紧贴会引入噪声并造成热量集中;按键置于背面不便操作与辨识;充电与耳机接口挤在同一转角会削弱该处结构强度,也限制插头同时使用。","tags":["内部布局","产品改良设计"]},{"id":"ch10-s009","type":"single","chapter":10,"level":"一般","ability":"应用","difficulty":3,"stem":"某产品内部既有发热量较大的功率电路,又有对干扰敏感的传感器信号电路,下列布置方案中最合理的是(  )。","options":["两类电路交叉穿插布置,以充分利用板面空间","两类电路分区布置并保持一定距离,功率器件靠近散热面,敏感线路尽量短且远离干扰源","把传感器紧贴功率器件安装,使两者温度一致以便补偿","把两类电路的引线捆扎在一起走线,使外观整齐"],"answer":[1],"explanation":"功率电路是热源和干扰源,敏感电路是受扰对象,二者应分区隔离:功率器件靠近壳体散热面或散热片便于导热,传感器线路要短、走向合理并远离大电流回路。交叉穿插、紧贴安装与捆扎并行都会同时引入热干扰和电磁干扰,使信号失真。","tags":["电磁干扰","内部布局"]},{"id":"ch10-s010","type":"multi","chapter":10,"level":"一般","ability":"识记","difficulty":2,"stem":"电子元器件封装形式的选用关系到产品的装配方式与体积,下列属于常见封装形式的有(  )。","options":["直插式封装","表面贴装封装","球栅阵列封装","片式电阻的水泥涂层颜色"],"answer":[0,1,2],"explanation":"直插式封装(DIP)、表面贴装封装(SMD)和球栅阵列封装(BGA)都是通行的封装形式,区别在于引脚或焊盘的引出与安装方式。片式电阻表面的涂层颜色只是外观标记,用来辅助识别阻值,并不是封装形式的类别,故第四项不选。","tags":["封装形式","封装认知"]},{"id":"ch10-s011","type":"multi","chapter":10,"level":"一般","ability":"识记","difficulty":2,"stem":"电子线路的认知包括对电路图样的识读,常见的电路图样有(  )。","options":["用规定符号表示元器件及其连接关系的原理图","用图形符号表示元器件位置与印制导线的印制板图","表示元器件在整机上安装位置的装配图","记录产品外壳注塑工艺参数的工艺卡"],"answer":[0,1,2],"explanation":"原理图表达电路的工作原理与连接关系,印制板图表达元器件在板上的位置与铜箔走线,装配图表达整机安装关系;此外还有概括系统组成与信号流向的方框图。注塑工艺参数卡片属于成型工艺文件,与电子线路图样的识读无关,故第四项不选。","tags":["电子线路","电路图样"]},{"id":"ch10-s012","type":"multi","chapter":10,"level":"次重点","ability":"理解","difficulty":2,"stem":"关于印制电路的新技术和发展方向,下列说法正确的有(  )。","options":["高密度互连技术通过更细的导线与更小的孔提高板面布线密度","柔性电路板以可弯曲的基材制成,能适应三维安装空间","把电阻、电容等元件制作在印制板内部形成埋入式元件","印制电路技术已停止演进,目前各类电子产品仍普遍使用单面通孔插装印制板"],"answer":[0,1,2],"explanation":"印制电路正朝着高密度互连、柔性化、元件埋入化和三维立体化方向发展,以适应电子产品轻薄短小与多功能集成的需要:更细的导线与更小的孔提高布线密度,柔性基材适应三维安装空间,元件可埋入板内形成埋入式元件。第四项说法错误,单面通孔插装板属于早期形态,如今多层板、柔性板与表面贴装技术已成为主流。","tags":["印制电路新技术","高密度互连"]},{"id":"ch10-s013","type":"judge","chapter":10,"level":"一般","ability":"识记","difficulty":2,"stem":"判断:从电子管到晶体管、再到集成电路和大规模集成电路,电子元器件总体上沿着体积减小、集成度提高、功耗降低的方向发展。","options":["正确","错误"],"answer":[0],"explanation":"正确。电子管体积大、耗电多、寿命短;晶体管以半导体器件取代电子管,体积与功耗大幅下降;集成电路把众多元件集成在同一基片上;大规模集成电路进一步提高了集成度。这条脉络反映了元器件与电子产品不断小型化、高可靠化的进程。","tags":["电子元件发展","集成度"]},{"id":"ch10-s014","type":"judge","chapter":10,"level":"一般","ability":"理解","difficulty":2,"stem":"判断:印制电路板既是元器件之间的电气连接通道,同时又是安装和支撑元器件的结构基础。","options":["正确","错误"],"answer":[0],"explanation":"正确。印制板的铜箔线路在元器件之间传递电信号与电能,基材则提供绝缘支撑和机械强度,使元器件能够按既定位置可靠装配,并承受振动、跌落等机械载荷。正是这种“电气互连加结构支撑”的双重作用,使它成为电子产品的核心部件。","tags":["印刷电路板","电气互连"]},{"id":"ch10-s015","type":"judge","chapter":10,"level":"次重点","ability":"理解","difficulty":2,"stem":"判断:无铅焊料的采用主要是为了减少铅对环境和人体的危害,但往往需要适当提高焊接温度并改善工艺控制。","options":["正确","错误"],"answer":[0],"explanation":"正确。传统锡铅焊料中的铅具有毒性,废弃电子产品中的铅会污染环境,因此推广无铅焊料是电子制造的重要方向。无铅焊料的熔点通常较高、润湿性相对较差,需要适当提高焊接温度、优化温度曲线并加强工艺控制,才能保证焊点质量。","tags":["无铅焊接","焊接工艺"]},{"id":"ch10-s016","type":"blank","chapter":10,"level":"一般","ability":"识记","difficulty":1,"stem":"电子元器件的发展大体经历了电子管、______、集成电路和______四个阶段。","answer":["晶体管","大规模集成电路"],"explanation":"电子管是最早的有源器件,其后被半导体晶体管取代;集成电路把众多元件制作在同一基片上;大规模集成电路进一步提高集成度。四个阶段反映了电子产品持续小型化、轻量化与高可靠化的进程。","tags":["电子元件发展","半导体元器件"]},{"id":"ch10-s017","type":"blank","chapter":10,"level":"次重点","ability":"识记","difficulty":2,"stem":"印制电路板一般由______、铜箔层、阻焊层和______等构成,其中后者用于印制元器件位号与极性标识。","answer":["基材|基板|基材层","丝印层"],"explanation":"基材以树脂和玻璃纤维布等复合而成,提供绝缘与机械支撑;铜箔层经蚀刻形成导电线路;阻焊层保护线路并防止焊接时相邻线路搭连;丝印层印出元器件位号、轮廓和极性标记,方便装配、检查与维修。","tags":["印制板构成","基材"]},{"id":"ch10-s018","type":"blank","chapter":10,"level":"一般","ability":"识记","difficulty":3,"stem":"电子产品的焊接工艺中,把元器件引脚穿过印制板通孔后进行的批量焊接常采用______;而表面贴装元器件则主要采用______。","answer":["波峰焊","回流焊|再流焊"],"explanation":"波峰焊依靠泵送形成的焊料波峰,让插装后的印制板通过波峰一次完成通孔焊点的焊接,适合批量生产。表面贴装元器件则先涂布焊膏、贴放元件,再经回流焊使焊膏熔化形成焊点,两种工艺分别对应通孔插装与表面贴装。","tags":["波峰焊","回流焊"]},{"id":"ch10-s019","type":"term","chapter":10,"level":"一般","ability":"识记","difficulty":3,"stem":"解释概念:表面贴装技术(SMT)","answer":["是一种将片式或扁平封装的元器件直接贴放并焊接在印制板表面焊盘上的电子装配技术。","其典型流程为涂布焊膏、贴放元器件、通过回流焊使焊膏熔化形成焊点,无需在印制板上穿孔插装。","其优点是元器件与焊盘占用面积小、装配密度高、便于自动化生产,是实现电子产品小型化、轻量化的重要工艺基础。"],"explanation":"作答应抓住三点:安装方式是贴焊在板面而非穿孔;主要工序是涂布焊膏、贴装、回流焊;意义在于提高装配密度并支持产品小型化与自动化生产。","tags":["表面贴装技术","SMT"]},{"id":"ch10-s020","type":"term","chapter":10,"level":"一般","ability":"识记","difficulty":2,"stem":"解释概念:印制电路板","answer":["是以绝缘基材和附着其上的铜箔导线为主体,用于安装和连接电子元器件的电子部件。","铜箔经蚀刻形成导电线路与焊盘,实现元器件之间以及电路与外部接口的电气连接;基材提供绝缘、支撑与机械承载作用。","按导电层数可分为单面板、双面板和多层板,采用可弯曲基材的称柔性板,可按布线密度与安装空间选用。"],"explanation":"作答应说明三点:由绝缘基材与铜箔线路构成;同时承担电气互连与结构支撑两种功能;可按导电层数分为单面板、双面板、多层板以及柔性板。","tags":["印制电路板","印制板构成"]},{"id":"ch10-s021","type":"short","chapter":10,"level":"次重点","ability":"应用","difficulty":4,"stem":"简述从产品造型与结构角度对电子产品进行改良设计的基本思路。","answer":["形态与结构上采用模块化设计,把功能划分成可独立拆装的模块,便于装配、维修与升级,并为外观件的分件与配色提供依据。","围绕发热问题安排结构与造型,为发热器件设置散热片、通风孔与风道,使开孔位置与朝向既利于对流散热又不破坏整体形态。","按人的操作习惯布置操作面,把常用按键、显示区域和主要接口安排在便于观察与触及的位置,并明确标识、留出手指操作空间。","在壳体接合面、按键与接口处采取密封、防尘防水与防跌落措施,提高产品在真实使用环境中的可靠性与耐用性。","通过外观件工艺与材料选择提升质感与耐用性,如免喷涂、耐磨纹理、咬花处理,同时兼顾批量生产与成本控制。","统筹内部堆叠关系,使质量较大的部件靠近手持或支撑部位以降低重心,并把强干扰电路与敏感电路分区布置。"],"explanation":"本题属应用层次,宜从模块化、散热结构、人机操作面、防护与耐用性、外观件工艺、内部堆叠六个方面作答,每个方面都落到具体的造型或结构处理办法,避免空谈美观。","tags":["产品改良设计","造型与结构"]},{"id":"ch10-s022","type":"short","chapter":10,"level":"一般","ability":"理解","difficulty":4,"stem":"简述印制电路板的基本构成及各部分的主要作用。","answer":["基材:由树脂和玻璃纤维布等增强材料复合而成,起绝缘、支撑与机械承载作用。","铜箔层:经蚀刻形成导电线路与焊盘,实现元器件之间以及电路与外部接口的电气连接。","阻焊层:覆盖在铜箔线路上的绝缘保护层,只露出焊盘,防止焊接时相邻线路搭连并保护线路不被氧化与损伤。","丝印层:印出元器件位号、轮廓与极性标记,供装配、检测与维修人员识别。","按导电层数可分为单面板、双面板和多层板,采用可弯曲基材的则为柔性板,可根据产品的布线密度与安装空间选用。"],"explanation":"作答时应按基材、铜箔层、阻焊层、丝印层逐一说明作用,并补充单面、双面、多层与柔性板的分类,体现对印制板构成与选用的完整认识。","tags":["印制板构成","印刷电路板"]},{"id":"ch11-s001","type":"single","chapter":11,"level":"一般","ability":"识记","difficulty":1,"stem":"在电子产品的研发流程中,最早进行、决定后续工作方向的环节是(  )。","options":["大批量量产与市场推广","小批量试产与工艺验证","需求分析与可行性研究","样机制作与性能测试"],"answer":[2],"explanation":"电子产品研发一般按“需求分析、方案设计、样机试制、试产验证、量产上市”的顺序推进,需求分析与可行性研究处于最前端,用来明确功能指标、使用条件与成本约束,为后续方案确定依据。其余三项都是需求确定之后才开展的工作。","tags":["研发流程","需求分析"]},{"id":"ch11-s002","type":"single","chapter":11,"level":"一般","ability":"识记","difficulty":2,"stem":"电子产品的结构设计一般不包括(  )。","options":["散热、屏蔽与防护措施的布置","产品广告文案与销售渠道的策划","零部件之间的连接与装配关系设计","外壳与支撑件的形态、壁厚与强度设计"],"answer":[1],"explanation":"结构设计解决“产品由哪些零件组成、如何连接与装配、能否可靠工作”的问题,包含外壳、支撑、连接、装配、公差、散热、屏蔽与防护等内容。广告文案与销售渠道属于市场推广范畴,与产品的结构与装配无关,故不属于结构设计内容。","tags":["结构设计","研发流程"]},{"id":"ch11-s003","type":"single","chapter":11,"level":"次重点","ability":"理解","difficulty":3,"stem":"下列现象中,属于热传导的是(  )。","options":["靠发热体发出的红外线把热量传给远处物体","热量沿着金属外壳从高温端逐渐传向低温端","暖气片附近的空气受热上升形成循环","太阳的热量穿过空间传到地面"],"answer":[1],"explanation":"热传导依靠物质内部微粒的相互作用传递热量,发生在有温差的同一物体或直接接触的物体之间,金属外壳内部的热量传递即是如此。空气受热流动属于对流;太阳能穿过空间以及红外线传热都属于辐射,不需要介质。","tags":["传热方式","热传导"]},{"id":"ch11-s004","type":"single","chapter":11,"level":"次重点","ability":"识记","difficulty":3,"stem":"利用工质的相变并在两端温差驱动下实现高效传热的散热器件是(  )。","options":["散热片","均热板","导热硅脂","热管"],"answer":[3],"explanation":"热管是内部封有工质、靠蒸发与冷凝循环把热量从一端输送到另一端的器件,传热能力远高于同尺寸的金属实体。散热片靠扩大散热面积并对流散热,均热板主要把热量在平面内铺开,导热硅脂用于填充接触缝隙降低热阻。","tags":["热管","散热方式"]}]}