生活中的物理现象

生活中的物理现象 随着科技的发展，社会的进步，物理已渗入到人类生活的各个领域。 例如，光是找找汽车中的光学知识就有以下几点: 1( 汽车驾驶室外面的观后镜是一个凸镜 利用凸镜对光线的发散作用和成正立、缩小、虚像的特点，使看到的实物小，观察范围更大，而保证行车安全。 2( 汽车头灯里的反射镜是一个凹镜 它是利用凹镜能把放在其焦点上的光源发出的光反射成为平行光射出的性质做成的。 3( 汽车头灯总要装有横竖条纹的玻璃灯罩 汽车头灯由灯泡、反射镜和灯前玻璃罩组成。根据透镜和棱镜的知识，汽车头灯玻璃罩相当于一个透镜和棱镜的组合体。在夜晚行车时，司机不仅要看清前方路面的情况，还要还要看清路边持人、路标、岔路口等。透镜和棱镜对光线有折射作用，所以灯罩通过折射，根据实际需要将光分散到需要的方向上，使光均匀柔和地照亮汽车前进的道路和路边的景物，同时这种散光灯罩还能使一部分光微向上折射，以便照明路标和里程碑，从而确保行车安全。 4( 轿车上装有茶色玻璃后，行人很难看清车中人的面孔 茶色玻璃能反射一部分光，还会吸收一部分光，这样透进车内的光线较弱。要看清乘客的面孔，必须要从面孔反射足够强的光透射到玻璃外面。由于车内光线较弱，没有足够的光透射出来，所以很难看清乘客的面孔。 5( 除大型客车外，绝大多数汽车的前窗都是倾斜的 当汽车的前窗玻璃倾斜时，车内乘客经玻璃反射成的像在国的前上方，而路上的行人是不可能出现在上方的空中的，这样就将车内乘客的像与路上行人分离开来，司机就不会出现错觉。大型客车较大，前窗离地面要比小汽车高得多，即使前窗竖直装，像是与窗同高的，而路上的行人不可能出现在这个高度，所以司机也不会将乘客在窗外的像与路上的行人相混淆。 再如下面一个例子: 五香茶鸡蛋是人们爱吃的，尤其是趁热吃味道更美。细心的人会发现，鸡蛋刚从滚开的卤汁里取出来的时候，如果你急于剥壳吃蛋，就难免连壳带“肉”一起剥下来。要解决这个问，有一个诀窍，就是把刚出锅的鸡蛋先放在凉水中浸一会，然后再剥，蛋壳就容易剥下来。 一般的物质(少数几种例外)，都具有热胀冷缩的特性。可是，不同的物质受热或冷却的时候，伸缩的速度和幅度各不相同。一般说来，密度小的物质，要比密度大的物质容易发生伸缩，伸缩的幅度也大，传热快的物质，要比传热慢的物质容易伸缩。鸡蛋是硬的蛋壳和软的蛋白、蛋黄组成的，它们的伸缩情况是不一样的。在温度变化不大，或变化比较缓慢均匀的情况下，还显不出什么;一旦温度剧烈变化，蛋壳和蛋白的伸缩步调就不一致了。把煮得滚烫的鸡蛋立即浸入冷水里，蛋壳温度降低，很快收缩，而蛋白仍然是原来的温度，还没有收缩，这时就有一小部分蛋白被蛋壳压挤到蛋的空头处。随后蛋白又因为温度降低而逐渐收缩，而这时蛋壳的收缩已经很缓慢了，这样就使蛋白与蛋壳脱离开来，因此，剥起来就不会连壳带“肉”一起下来了。 明白了这个道理，对我们很有用处。凡需要经受较大温度变化的东西，如果它们是用两种不同材料合在一起做的，那么在选择材料的时候，就必须考虑它们的热膨胀性质，两者越接近越好。工程师在房屋和桥梁时，都广泛采用钢筋混凝土，就是因为钢材和混凝土的膨胀程度几乎完全一样，尽管春夏秋冬的温度不同，也不会产生有害的作用力，所以钢筋混凝土的建筑十分坚固。 另外，有些电器元件却是用两种热膨胀性质差别很大的金属制成的。例如，铜片的热膨胀比铁片大，把铜片和铁片钉在一起的双金属片，在同样情况下受热，就会因膨胀程度不同而发生弯曲。利用这一性质制成了许多自动控制装置和仪。日光灯的“启动器”里就有小巧的双金属片，它随着温度的变化，能够自动屈伸，起到自动开启日光灯的作用。 culture and entertainment venues, fitness centers, has a good ecological environment, job security measures), these requirements are very straightforward, specific standards, also has a clear direction, more easily by a superior examination. Poverty assessment is to look at the per capita net income of the poor end of 2015 standards is ... ... Yuan, higher standards is poverty. Superior acceptance to entrust a third party institution from HouseImplementation. After acceptance, also through spot checks, visits, telephone surveys looking activities. This means that our achievements have been recognized by the poor for poverty alleviation through acceptance, which we put forward higher requirements for poverty eradication. Therefore, the County Office for poverty alleviation to evaluation efforts in this regard. To implement the grid management model, integrating poverty alleviation into grid management, and "make a heart" activity combined package of leading cadres implement monitoring systems for poverty alleviation, each poor households identified a package cost. In this regard, you can design a form, indicating the poor basic causes, current income, poverty, support measures, implementation of support measures, through helping ' income, annual revenue. From now on, protection officers working households, household-by-place. When the examination, which the poor don't have time to get out of poverty, and holding people accountable. Third, on environmental protection in construction of ecological civilization is the focus on one of the six battle this year. Xian Wei proposed to build "green mountains and beautiful, happy and harmonious" new ... ... Target, which is the basis of environmental protection. Do well environmental protection work, we keep the side of the mountains, nor to the masses to create a suitable for residential and business suitable for swimming and raising living and working environment. Last year, we got good grades the environmental work, atmospheric index ranked 4th in the city to obtain eco-compensationaccording to project needs, in accordance with the "channel, use the same, and use" principle, the implementation of project planning, funding and manpower arrangements, avoiding duplication of inputs and waste of resources, effective integration of poverty relief funds ... Here to remind everyone that bundle integration-related funds, aims to concentrate financial resources for big undertakings. Authorities do not think that has less autonomy, pursuing the deregulation of work. This year on the amount of funds on fighting for the departments concerned to increase over the previous year ... and ... respectively. In this regard, the financial Department to dispatch in a timely manner, analyses relevant departments strive for. (E) to implement the poverty assessment responsibilities. Of village-level evaluation is very clear, that is, "five-ten" ("five-way" path, power, through water, through radio, television, information; " Ten "the hanlaobaoshou fields, rich projects, Office kitchen, health services, sanitation system, pre-school education, 这样的例子举不胜举，物理是一门实用性很强的科学，与工农业生产、日常生活有着极为密切的联系。物理规律本身就是对自然现象的总结和抽象。 谈到物理学，有些同学觉得很难;谈到物理探究，有同学觉得深不可测;谈到物理学家，有同学更是感到他们都不是凡人。诚然，成为物理学家的人的确屈指可数，但只要勤于观察，善于思考，勇于实践，敢于创新，从生活走向物理，你就会发现:其实，物理就在身边。正如马克思说的:“科学就是实验的科学，科学就在于用理性的去整理感性材料”。物理不但是我们的一门学科，更重要的，它还是一门科学。 物理学存在于物理学家的身边。勤于观察的意大利物理学家伽利略，在比萨大教堂做礼拜时，悬挂在教堂半空中的铜吊灯的摆动引起了他极大的兴趣，后来反复观察，反复研究，发明了摆的等时性;勇于实践的美国物理学家富兰克林，为认清“天神发怒”的本质，在一个电闪雷鸣、风雨交加的日子，冒着生命危险，利用司空见惯的风筝将“上帝之火”请下凡，由此发明了避雷针;敢于创新的英国科学家亨利?阿察尔去邮局办事。当时身旁有位外地人拿出一大版新邮票，准备裁下一枚贴在信封上，苦于没有小刀。找阿察尔借，阿察尔也没有。这位外地人灵机一动，取下西服领带上的别针，在邮票的四周整整齐齐地刺了一圈小孔，然后，很利落地撕下邮票。外地人走了，却给阿察尔留下了一串深深的思考，并由此发明了邮票打孔机，有齿纹的邮票也随之诞生了;古希腊阿基米德发现阿基米德原理;德国物理学家伦琴发现X射线;„„研究身边的琐事并有大成就的物理学家的事例不胜枚举。 物理学也存在于同学们身边。学了测量的初步知识，同学们纷纷做起了软尺。有位同学别出心裁，用透明胶把制好的牛皮纸软尺包扎好，这样更牢固。然后，用大大卷泡泡糖的包装盒作为软尺的外壳，在盒的中心利用铁丝做一摇柄中心轴，软尺的末端固定在轴上，这样一个可以收拾并反复使用的卷尺诞生了。同时，这位同学受软尺自作的启示，用实验解决了一道习题:用软尺测量物体长度时，若把软尺拉长些，测量值是偏大还是偏小,他做了这样一个模拟实验:在白纸上画一条直线，标上刻度，然后用透明胶粘贴，再扯下来，便做成了“软尺”，用“软尺”不仅找到了上题的答案，而且还清楚地看到分度值变大了，知其然，并知其所以然;学了电学的有关知识后，同学们对蚯蚓能承受的最大电压进行了探究:当给它加上1.5V的电压时，蚯蚓迅速分泌粘液，且奋力挣扎，从瓶内跳出瓶外。当给它加上3V的电压时，蚯蚓被电为两截;有同学在测量“2.4V、0.5A”的小灯泡的功率，并研究其发光情况时，不满足于给灯泡加上2.4V的电压，而是用自己早已准备好的小灯泡做破坏性实验，不断加大灯泡两端的电压，直至电压高达9V、灯泡灯丝烧断，才停止探究;有同学在学习蒸发的知识时，不厌其烦地座在桌旁观察相同的两滴水(其中一滴水滩开)，进行聚精会神地观察，然后进行、对比，得出影响蒸发的因素;„„同学们捕捉身边的琐事进行探究的事例屡见不鲜。 身边的事物是取之不尽的，对与现实生活联系很紧密的物理学科来说，更是时时会用到的，用身边的事例去解释和总结物理规律，学生听起来熟悉，接受起来也就容易了。只要时时留意，经常总结，就会不断发现有利于物理教学的事物，丰富我们的课堂，活跃教学气氛，简化概念和规律。新课标告诉我们“义务教育阶段的物理课程应贴近学生生活，符合学生认知特点，激发并保持学生的学习兴趣，通过探索物理现象，揭示隐藏其中的物理规律，并将其应用于生产生活实际，培养学生终身的探索乐趣、良好的思维习惯和初步的科学实践能力。” 今天，人类所有的令人惊叹不已的科学技术成就，如克隆羊、因特网、核电站、航空技术等，无不是建立在早年的科学家们对身边琐事进行观察并研究的基础上的。在学习中，同学们要树立科学意识，大处着眼，小处着手，经历观察、思考、实践、创新等活动，逐步掌握科学的学习方法，训练科学的思维方式，不久你就会拥有科学家的头脑，为自己今后惊叹不已的发展，为今后美好的生活打下扎实的基础。 culture and entertainment venues, fitness centers, has a good ecological environment, job security measures), these requirements are very straightforward, specific standards, also has a clear direction, more easily by a superior examination. Poverty assessment is to look at the per capita net income of the poor end of 2015 standards is ... ... Yuan, higher standards is poverty. Superior acceptance to entrust a third party institution from HouseImplementation. After acceptance, also through spot checks, visits, telephone surveys looking activities. This means that our achievements have been recognized by the poor for poverty alleviation through acceptance, which we put forward higher requirements for poverty eradication. Therefore, the County Office for poverty alleviation to evaluation efforts in this regard. To implement the grid management model, integrating poverty alleviation into grid management, and "make a heart" activity combined package of leading cadres implement monitoring systems for poverty alleviation, each poor households identified a package cost. In this regard, you can design a form, indicating the poor basic causes, current income, poverty, support measures, implementation of support measures, through helping ' income, annual revenue. From now on, protection officers working households, household-by-place. When the examination, which the poor don't have time to get out of poverty, and holding people accountable. Third, on environmental protection in construction of ecological civilization is the focus on one of the six battle this year. Xian Wei proposed to build "green mountains and beautiful, happy and harmonious" new ... ... Target, which is the basis of environmental protection. Do well environmental protection work, we keep the side of the mountains, nor to the masses to create a suitable for residential and business suitable for swimming and raising living and working environment. Last year, we got good grades the environmental work, atmospheric index ranked 4th in the city to obtain eco-compensationaccording to project needs, in accordance with the "channel, use the same, and use" principle, the implementation of project planning, funding and manpower arrangements, avoiding duplication of inputs and waste of resources, effective integration of poverty relief funds ... Here to remind everyone that bundle integration-related funds, aims to concentrate financial resources for big undertakings. Authorities do not think that has less autonomy, pursuing the deregulation of work. This year on the amount of funds on fighting for the departments concerned to increase over the previous year ... and ... respectively. In this regard, the financial Department to dispatch in a timely manner, analyses relevant departments strive for. (E) to implement the poverty assessment responsibilities. Of village-level evaluation is very clear, that is, "five-ten" ("five-way" path, power, through water, through radio, television, information; " Ten "the hanlaobaoshou fields, rich projects, Office kitchen, health services, sanitation system, pre-school education, 身边有趣的物理现象 1 、挂在壁墙上的石英钟，当电池的电能耗尽而停止走动时，其秒针往往停在刻度盘上“ 9 ”的位置。这是由于秒针在“ 9 ”位置处受到重力矩的阻碍作用最大。 2 、有时自来水管在邻近的水龙头放水时，偶尔发生阵阵的响声。这是由于水从水龙头冲出时引起水管共振的缘故 . 3 、对着电视画面拍照，应关闭照相机闪光灯和室内照明灯，这样照出的照片画面更清晰。因为闪光灯和照明灯在电视屏上的反射光会干扰电视画面的透射光( 4 、冰冻的猪肉在水中比在同温度的空气中解冻得快。烧烫的铁钉放入水中比在同温度的空气中冷却得快。装有滚烫的开水的杯子浸入水中比在同温度的空气中冷却得快。这些现象都表明:水的热传递性比空气好。 5 、锅内盛有冷水时，锅底外表面附着的水滴在火焰上较长时间才能被烧干，且直到烧干也不沸腾，这是由于水滴、锅和锅内的水三者保持热传导，温度大致相同，只要锅内的水未沸腾，水滴也不会沸腾，水滴在火焰上靠蒸发而渐渐地被烧干。 6 、走样的镜子，人距镜越远越走样(因为镜里的像是由镜后镀银面的反射形成的，镀银面不平或玻璃厚薄不均匀都会产生走样。走样的镜子，人距镜越远，由光放大原理，镀银面的反射光到达的位置偏离正常位置就越大，镜子就越走样( 7 、天然气炉的喷气嘴侧面有几个与外界相通的小孔，但天然气不会从侧面小孔喷出， 只从喷口喷出 . 这是由于喷嘴处天然气的气流速度大，根据流体力学原理，流速大，压强小，气流表面压强小于侧面孔外的大气压强，所以天然气不会以喷管侧面小孔喷出。 8 、将气球吹大后，用手捏住吹口，然后突然放手，气球内气流喷出，气球因反冲而运动。可以看见气球运动的路线曲折多变。这有两个原因:一是吹大的气球各处厚薄不均匀，张力不均匀，使气球放气时各处收缩不均匀而摆动，从而运动方向不断变化;二是气球在收缩过程中形状不断变化，因而在运动过程中气球表面处的气流速度也在不断变化，根据流体力学原理，流速大，压强小，所以气球表面处受空气的压力也在不断变化，气球因此而摆动，从而运动方向就不断变化。 9 、吊扇在正常转动时悬挂点受的拉力比未转动时要小，转速越大，拉力减小越多(这是因为吊扇转动时空气对吊扇叶片有向上的反作用力(转速越大，此反作用力越大( 10 、电炉“燃烧”是电能转化为内能，不需要氧气，氧气只能使电炉丝氧化而缩短其使用寿命。 11 、从高处落下的薄纸片，即使无风，纸片下落的路线也曲折多变。这是由于纸片各部分凸凹不同，形状备异，因而在下落过程中，其表面各处的气流速度不同，根据流体力学原理，流速大，压强小，致使纸片上各处受空气作用力不均匀，且随纸片运动情况的变化而变化，所以纸片不断翻滚，曲折下落。 为什么灌满水的瓶子不易破, 有两个相同的玻璃瓶，一个空着，一个灌满了水，同时从相同的高度落到地面上，哪个瓶子容易破, 一般说重的瓶子容易破。可是，当瓶子灌满水后，瓶子里的水还有另外一个作用，能减少瓶子的形变，反而使瓶子不容易破了。 玻璃瓶破裂，大多是由于形变引起的。空瓶子落地，地对瓶子产生一个压力，瓶子从外向里形变，终于破裂。瓶子装满水，由于水是不可压缩的，从而减少了形变，使得瓶子不易破裂。瓶子里装满水，再拧紧瓶盖，就更不容易摔破了。 有趣的共振现象 唐朝的时候，洛阳的一座寺院里出了一件怪事。寺院的房间里有一口铜铸的磬，没人敲它，常常自己“嗡嗡”地响起来，这里是什么原因呢, 原来，这口磬和饭堂的一口大钟，它们在发声时，每秒种的振动次数——频率正好相同。每当小和尚敲响culture and entertainment venues, fitness centers, has a good ecological environment, job security measures), these requirements are very straightforward, specific standards, also has a clear direction, more easily by a superior examination. Poverty assessment is to look at the per capita net income of the poor end of 2015 standards is ... ... Yuan, higher standards is poverty. Superior acceptance to entrust a third party institution from HouseImplementation. After acceptance, also through spot checks, visits, telephone surveys looking activities. This means that our achievements have been recognized by the poor for poverty alleviation through acceptance, which we put forward higher requirements for poverty eradication. Therefore, the County Office for poverty alleviation to evaluation efforts in this regard. To implement the grid management model, integrating poverty alleviation into grid management, and "make a heart" activity combined package of leading cadres implement monitoring systems for poverty alleviation, each poor households identified a package cost. In this regard, you can design a form, indicating the poor basic causes, current income, poverty, support measures, implementation of support measures, through helping ' income, annual revenue. From now on, protection officers working households, household-by-place. When the examination, which the poor don't have time to get out of poverty, and holding people accountable. Third, on environmental protection in construction of ecological civilization is the focus on one of the six battle this year. Xian Wei proposed to build "green mountains and beautiful, happy and harmonious" new ... ... Target, which is the basis of environmental protection. Do well environmental protection work, we keep the side of the mountains, nor to the masses to create a suitable for residential and business suitable for swimming and raising living and working environment. Last year, we got good grades the environmental work, atmospheric index ranked 4th in the city to obtain eco-compensationaccording to project needs, in accordance with the "channel, use the same, and use" principle, the implementation of project planning, funding and manpower arrangements, avoiding duplication of inputs and waste of resources, effective integration of poverty relief funds ... Here to remind everyone that bundle integration-related funds, aims to concentrate financial resources for big undertakings. Authorities do not think that has less autonomy, pursuing the deregulation of work. This year on the amount of funds on fighting for the departments concerned to increase over the previous year ... and ... respectively. In this regard, the financial Department to dispatch in a timely manner, analyses relevant departments strive for. (E) to implement the poverty assessment responsibilities. Of village-level evaluation is very clear, that is, "five-ten" ("five-way" path, power, through water, through radio, television, information; " Ten "the hanlaobaoshou fields, rich projects, Office kitchen, health services, sanitation system, pre-school education, 大钟时，大钟的振动使得周围的空气也随着振动起来，当声波传到老和尚房内的磬上时，由于磬的频率跟声波频率相同，磬也跟着振动起来。发出了“嗡嗡”的响声。这就是发生振动的共振现象，也叫共鸣。 你注意过吧，胡琴的下端都有一个不小的“肚子”——蒙上蛇皮的竹筒。当你兴致勃勃地拉起胡琴时，琴弦的振动通过蛇皮会引起“肚子”中空气的共鸣，使发出来的琴声不仅响亮，而且音乐丰满，悠扬动听。人们把这种“肚子”叫做共鸣箱。你瞧，扬琴、琵琶、提琴、钢琴等乐器，不都有各种形状，大小不一的共鸣箱吗, 除了共鸣箱之外，人们利用共振现象来做的好事还不少呢。 建筑工人在造房子的时候，不论是浇灌混凝土的墙壁或地板，为了提高质量，总是一面灌混凝土，一面用振荡器进行震荡，使混凝土由于振荡更紧密、结实。 大街上的行人，车辆的喧闹声，机器的隆隆声——这些连绵不断的噪声不仅影响人们正常生活，还会损害人的听力。有一种共振性的消声器，是由开有许多小孔的孔板和空腔所构成。当传来的噪声频率与共振器的固有频率相同时，就会跟小孔内空气柱产生剧烈共振。这样，声音能在共振时转变为热能，使相当一部分噪声被“吞吃”掉。 此外，粉碎机，测振仪，电振泵等，也都是利用共振现象进行工作的。 但在某些情况下，共振现象也可能造成危害。例如:当军队过桥的时候，整齐的步伐能产生振动。如果它的频率接近于桥梁的固有频率，就可能使桥梁共振，以致到了断裂的程度。因此，部队过桥要用便步。 在我国西北一带，山头终年积雪。每当春暖花开，山上冰雪融化，雪层会离开原来的地方滑动。往往一次偶然的大吼声，厚厚的雪层就会因为共振而崩塌下来，因此规定攀登雪山的勘察队员，登山队员不能大声说话。 我们要将共振充分运用到各个科学领域，还要防止共振现象给生活、工作、环境带来危害。这就需要我们不断去研究、探索。 有关啤酒的奥秘 啤酒是一种新型饮料，它既能清凉解渴，裨益身体，又能使人振奋精神。但是当你喝啤酒时，是否留意过以下几个问题, 1(为什么打开室温下放置已久的啤酒瓶时，会冒出一股冷气呢, 原来，啤酒瓶内密封有一部分高压CO2气体，其温度与室温相同，当酒瓶一开，瓶内的气体迅速膨胀，来不及和外界交换热量，由热力学第一定律可知，瓶子里的气体克服外界的气压作功从而减少了内能，导致气体的压强减少，温度下降。因此，就感到一股冷气从瓶中冒出。 如果打开前摇动了啤酒瓶(瓶内温度升高，气压增大，再打开瓶子，大量CO2急速冒出同时会夹带着啤酒喷洒溢出。在电视上常见这样一些庆祝胜利的场面:取得自行车比赛冠军的选手，身着黄色领骑衫，手拿大瓶的啤酒瓶，强烈摇动，啤酒象喷泉一样从瓶口喷出，酒花泡沫在空中飞溅，也是这个原因。有时，啤酒在运输中，由于路面不平，啤酒在瓶中翻腾，温度升高，气压增大，有时甚至能使啤酒瓶发生爆炸。 2(啤酒倒入杯中后，为什么有许多气泡上升，以致液面上形成大量泡沫, 原来，啤酒里溶解有二氧化碳，在杯底、杯壁表面有缺陷或者有尘埃的地方存在容纳有空气的气穴，为二氧化碳的析出提供了一个液面。啤酒里的CO2进入这些气穴而形成气泡，由于CO2比啤酒轻，在浮力的作用下气泡离开杯壁，随着CO2不断进入气泡，使气泡体积渐渐变大，浮力变大气泡上升，最终气泡飘浮到液面，形成泡沫。又由于重力和气泡内部表面张力相互作用下，气泡壁厚度变薄且在泡沫翻腾着上升中破裂。 3(向杯中慢慢倾倒啤酒的时候，常常可以看到:啤酒不是在重力的作用下直接从瓶口竖直注入杯子的，culture and entertainment venues, fitness centers, has a good ecological environment, job security measures), these requirements are very straightforward, specific standards, also has a clear direction, more easily by a superior examination. Poverty assessment is to look at the per capita net income of the poor end of 2015 standards is ... ... Yuan, higher standards is poverty. Superior acceptance to entrust a third party institution from HouseImplementation. After acceptance, also through spot checks, visits, telephone surveys looking activities. This means that our achievements have been recognized by the poor for poverty alleviation through acceptance, which we put forward higher requirements for poverty eradication. Therefore, the County Office for poverty alleviation to evaluation efforts in this regard. To implement the grid management model, integrating poverty alleviation into grid management, and "make a heart" activity combined package of leading cadres implement monitoring systems for poverty alleviation, each poor households identified a package cost. In this regard, you can design a form, indicating the poor basic causes, current income, poverty, support measures, implementation of support measures, through helping ' income, annual revenue. From now on, protection officers working households, household-by-place. When the examination, which the poor don't have time to get out of poverty, and holding people accountable. Third, on environmental protection in construction of ecological civilization is the focus on one of the six battle this year. Xian Wei proposed to build "green mountains and beautiful, happy and harmonious" new ... ... Target, which is the basis of environmental protection. Do well environmental protection work, we keep the side of the mountains, nor to the masses to create a suitable for residential and business suitable for swimming and raising living and working environment. Last year, we got good grades the environmental work, atmospheric index ranked 4th in the city to obtain eco-compensationaccording to project needs, in accordance with the "channel, use the same, and use" principle, the implementation of project planning, funding and manpower arrangements, avoiding duplication of inputs and waste of resources, effective integration of poverty relief funds ... Here to remind everyone that bundle integration-related funds, aims to concentrate financial resources for big undertakings. Authorities do not think that has less autonomy, pursuing the deregulation of work. This year on the amount of funds on fighting for the departments concerned to increase over the previous year ... and ... respectively. In this regard, the financial Department to dispatch in a timely manner, analyses relevant departments strive for. (E) to implement the poverty assessment responsibilities. Of village-level evaluation is very clear, that is, "five-ten" ("five-way" path, power, through water, through radio, television, information; " Ten "the hanlaobaoshou fields, rich projects, Office kitchen, health services, sanitation system, pre-school education, 而是绕过瓶口，沿瓶子的外壁下流一段之后才注入杯子的，为什么会发生这种现象呢, 原来，对于液体来说，流过的轨迹半径越小，流速越大。啤酒瓶的瓶口细小，啤酒流过时，速度变大，由伯努利原理可以知道，瓶口的压力最小，当其值小于外界的气压时，大气压迫使啤酒沿瓶外壁下走，沿瓶壁所流的距离与液体的表面张力及流体的粘性有关，当外界有小的扰动，啤酒方脱离瓶壁注入杯子。倒油时，这种现象会更明显，所以厨房里的油瓶外面，经常是油腻腻的。 “泥娃撒尿”与气体定律 "泥娃"是由泥沙烧制而成的貌似幼童的棕色陶质玩具，由于其近似泥土之色彩，故有泥娃之称。另外经正确操作后，会使其从脐部之下向外喷水，犹如孩童撒尿，故又有"小尿人儿"之称。 观其"撒尿"，颇有情趣，深得儿童所喜爱。那么"泥娃"缘何会"撒尿"呢,究其原因，是巧妙地利用了气体性质的三个定律，现分析如下: 一(等压灌水(盖?吕萨克定律)要想使"泥娃"撒尿，就必须让其先喝水(灌水)。如何让它喝水是首先要解决的问题。图是"泥娃"的结构原理图。从图可知，它是一个中空的腔体，其脐下有一个针孔大小的开口经由前腔壁上的通道与腔内相连。由于孔径大小尚不足半毫米，直接由此灌水是不行的，必须设法使腔内气体向外排出些，再让腔内气体收缩后，靠外界大气压力将水压入腔内，实现灌水。具体做法是:将"泥娃"没入热水中，水温应高于当时的环境温度T0。当"泥娃"没入热水中后，便可看到从其脐下的开口(下称喷水口)往外冒气泡，待腔体与热水的温度相同(达到热平衡)时，排气停止，为灌水做好准备。当排气停止时，用手指堵住喷水口，迅速将"泥娃"从热水中捞出，并放入冷水中移去堵喷水口的手指，冷水就会自然地从喷水口灌入腔体了。当腔内气体温度与冷水温度T0相同时(再次达到热平衡)，灌水过程结束。这一过程为气体等压冷却过程。符合盖?吕萨克定律。因在灌水开始的瞬间，水已将喷水口堵住，腔内气体的质量就一定了。此时腔内气体的体积为V1，温度为T，压强为p0(大气压强)。经时间t后，气体温度与冷水温度相同，体积为V2，由盖吕萨克定律可求出V2,T0V1/T，由于T0,T，则V2,V1，可见，气体体积收缩，冷水乘虚而入是自然的了。 二(等容升压，储能过程(查里定律)灌水结束后，用手指堵住喷水口，将泥娃再次按入热水中加热。当初，由于喷水口被手指堵住，水不能外流，腔内气体体积也就恒定了，其压强、温度仍与外界的压强p0、温度T0相同。随着加热的进行，腔内气体与热水又达热平衡时，其温度变为T，压强为p，由查里定律得p,Tp0/T0 ，因T,T0，则p,p0。可见腔内气体温度上升后，压强增大了。 三(等温膨胀过程，喷水(玻意耳定律)当等容升压过程结束后，就可将"泥娃"从热水中拿出，使其居正立位，移去按压喷水口的手指，便立刻可看到水从喷水口喷出。随着腔内水量的减少，气体体积膨胀，压力自然减小，喷水射程也逐渐减小，待腔内压强和外界压强p0相等时，喷水结束。由于喷水过程极为短暂，仅几秒钟，腔 体温度尚未下降，则气体温度也基本恒定，可近似地认为是等温膨胀过程，遵从波意耳定律。由此可求出V2,pV1/p0 ，由于p,p0，则V2,V1。气体膨胀了，将水挤出是自然的。 纵观"泥娃撒尿"之全过程，每一部分过程都是极好地运用了气体的相关性质，不失为气体三定律应用之典范。我们还可用p—V图，形象地将各过程表示出来，如图所示。图中，状态I到状态II是等压收缩——灌水过程;状态II到状态III为等容升压——储能过程;状态III到状态I为等温膨胀——喷水过程。还有诸如"佛降雨"、"龟嬉水"之类的玩具，与"泥娃撒尿"原理相似，只不过腔体造型不同而已。 culture and entertainment venues, fitness centers, has a good ecological environment, job security measures), these requirements are very straightforward, specific standards, also has a clear direction, more easily by a superior examination. Poverty assessment is to look at the per capita net income of the poor end of 2015 standards is ... ... Yuan, higher standards is poverty. Superior acceptance to entrust a third party institution from HouseImplementation. After acceptance, also through spot checks, visits, telephone surveys looking activities. This means that our achievements have been recognized by the poor for poverty alleviation through acceptance, which we put forward higher requirements for poverty eradication. Therefore, the County Office for poverty alleviation to evaluation efforts in this regard. To implement the grid management model, integrating poverty alleviation into grid management, and "make a heart" activity combined package of leading cadres implement monitoring systems for poverty alleviation, each poor households identified a package cost. In this regard, you can design a form, indicating the poor basic causes, current income, poverty, support measures, implementation of support measures, through helping ' income, annual revenue. From now on, protection officers working households, household-by-place. When the examination, which the poor don't have time to get out of poverty, and holding people accountable. Third, on environmental protection in construction of ecological civilization is the focus on one of the six battle this year. Xian Wei proposed to build "green mountains and beautiful, happy and harmonious" new ... ... Target, which is the basis of environmental protection. Do well environmental protection work, we keep the side of the mountains, nor to the masses to create a suitable for residential and business suitable for swimming and raising living and working environment. Last year, we got good grades the environmental work, atmospheric index ranked 4th in the city to obtain eco-compensationaccording to project needs, in accordance with the "channel, use the same, and use" principle, the implementation of project planning, funding and manpower arrangements, avoiding duplication of inputs and waste of resources, effective integration of poverty relief funds ... Here to remind everyone that bundle integration-related funds, aims to concentrate financial resources for big undertakings. Authorities do not think that has less autonomy, pursuing the deregulation of work. This year on the amount of funds on fighting for the departments concerned to increase over the previous year ... and ... respectively. In this regard, the financial Department to dispatch in a timely manner, analyses relevant departments strive for. (E) to implement the poverty assessment responsibilities. Of village-level evaluation is very clear, that is, "five-ten" ("five-way" path, power, through water, through radio, television, information; " Ten "the hanlaobaoshou fields, rich projects, Office kitchen, health services, sanitation system, pre-school education, 物理学在厨房中的应用 我们在厨房里，若留心看一下其中的炉灶、器皿以及做饭、炒菜中出现的一些现象，定会发现很多处要用到物理知识。 一、热凉粥或冷饭时，锅内发出”扑嘟、扑嘟”的声音，并不断冒出气泡来，但一尝，粥或饭并不热，这是为什么, 把凉粥或饭烧热与烧开水是不一样的。虽然水是热的不良身体，对热的传导速度很慢，但水具有很好的流动性。当锅底的水受热时，它就要膨胀，密度减小就上浮，周围的凉水就流过来填补，通过这种对流，就把锅底的热不断地传递到水的各部分而使水变热。而凉粥或饭，既流动性差又不易传导热。所以，当锅底的粥或饭吸热后，温度就很快上升，但却不能很快地向上或四周流动，大量的热就集中在锅底而将锅底的粥烧焦。因热很难传到粥的上面，所以上面的粥依然是凉的。加热凉粥或饭时，要在锅里多加一些水，使粥变稀，增强它的流动性。此外，还要勤搅拌，强制进行对流，这样可将粥进行均匀加热。 二、用砂锅煮肉或烧汤时，当汤水沸腾后从炉子上拿下来，则汤水仍会继续沸腾一段时间，而铁、铝锅却没这种现象，这是为什么, 因为砂锅是陶土烧制成的，而非金属的比热比金属大得多，传热能力比金属差得多。当砂锅在炉子上加热时，锅外层的温度大大超过100?，内层温度略高于100?。此时，锅吸收了很多热量，储存了很多热能。将砂锅从炉子上拿下来后，远高于100?的锅的外层就继续向内层传递热量，使锅内的汤水仍达到100?而能继续沸腾一段时间，铁、铝锅就不会出现这种现象(其原因请同学们自己分析)。 三、炒肉中的“见面熟”。逢年过节，人们总要炒上几个肉菜，那么怎样爆炒肉片呢, 若将肉片直接放入热油锅里去爆炒，则瘦肉纤维中所含的水分就要急剧蒸发，致使肉片变得干硬，甚至于会将肉炒焦炒糊，大大失去鲜味。为把肉片爆炒得好吃，师傅们往往预先将肉片拌入适量的淀粉，则肉片放到热油锅里后，附着在肉片外的淀粉糊中的水分蒸发，而肉片里的水分难以蒸发，仍保持了原来肉的鲜嫩，还减少了营养的损失，肉又熟得快即“见面熟”。用这种方法炒的肉片，既鲜嫩味美，又营养丰富。 四、冻肉解冻用什么方法最好,从冰箱里取出冻肉、冻鸡，如何将其解冻呢, 用接近0?的冷水最好。因为冻肉温度是在0?以下，若放在热水里解冻，冻肉从热水中吸收热量，其外层迅速解冻而使温度很快升到0?以上，此的肉层之间便有了空隙，传递热的本领也就下降，使内部的冻肉不易再吸热解冻而形成硬核。若将冻肉放在冷水中，则因冻肉、冻鸡吸热而使冷水温度很快降到0?且部分水还会结冰。因1克水结成冰可放出80卡热量(而1克水降低1?只放出1卡热量)，放出的如此之多的热量被冻肉吸收后，使肉外层的温度较快升高，而内层又容易吸收热量，这样，整块肉的温度也就较快升到0?。如此反复几次，冻肉就可解冻。从营养角度分析，这种均匀缓慢升温的方法也是科学的 culture and entertainment venues, fitness centers, has a good ecological environment, job security measures), these requirements are very straightforward, specific standards, also has a clear direction, more easily by a superior examination. Poverty assessment is to look at the per capita net income of the poor end of 2015 standards is ... ... Yuan, higher standards is poverty. Superior acceptance to entrust a third party institution from HouseImplementation. After acceptance, also through spot checks, visits, telephone surveys looking activities. This means that our achievements have been recognized by the poor for poverty alleviation through acceptance, which we put forward higher requirements for poverty eradication. Therefore, the County Office for poverty alleviation to evaluation efforts in this regard. To implement the grid management model, integrating poverty alleviation into grid management, and "make a heart" activity combined package of leading cadres implement monitoring systems for poverty alleviation, each poor households identified a package cost. In this regard, you can design a form, indicating the poor basic causes, current income, poverty, support measures, implementation of support measures, through helping ' income, annual revenue. From now on, protection officers working households, household-by-place. When the examination, which the poor don't have time to get out of poverty, and holding people accountable. Third, on environmental protection in construction of ecological civilization is the focus on one of the six battle this year. Xian Wei proposed to build "green mountains and beautiful, happy and harmonious" new ... ... Target, which is the basis of environmental protection. Do well environmental protection work, we keep the side of the mountains, nor to the masses to create a suitable for residential and business suitable for swimming and raising living and working environment. Last year, we got good grades the environmental work, atmospheric index ranked 4th in the city to obtain eco-compensationaccording to project needs, in accordance with the "channel, use the same, and use" principle, the implementation of project planning, funding and manpower arrangements, avoiding duplication of inputs and waste of resources, effective integration of poverty relief funds ... Here to remind everyone that bundle integration-related funds, aims to concentrate financial resources for big undertakings. Authorities do not think that has less autonomy, pursuing the deregulation of work. This year on the amount of funds on fighting for the departments concerned to increase over the previous year ... and ... respectively. In this regard, the financial Department to dispatch in a timely manner, analyses relevant departments strive for. (E) to implement the poverty assessment responsibilities. Of village-level evaluation is very clear, that is, "five-ten" ("five-way" path, power, through water, through radio, television, information; " Ten "the hanlaobaoshou fields, rich projects, Office kitchen, health services, sanitation system, pre-school education,