大學生magnet

Ⅰ 中國 超漂亮 清晰 美少女 收藏（哇靠 第一畫面 還真 大學生 美女呢 ）高清完整版下載地址有么感謝哈

中國 超漂亮 清晰 美少女 收藏（哇靠 第一畫面 還真 大學生 美女呢 ）高清內完整版下載地址：

Ⅱ 求2010年中國大學生物理競賽題目答案

2010年的是：競賽題目（英文）
1. Electromagnetic cannon
A solenoid can be used to fire a small ball. A capacitor is used to energize the solenoid coil. Build a device with a capacitor charged to a maximum 50V. Investigate the relevant parameters and maximize the speed of the ball.
2. Brilliant pattern
Suspend a water drop at the lower end of a vertical pipe. Illuminate the drop using a laser pointer and observe the pattern created on a screen. Study and explain the structure of the pattern.
3. Steel balls
Colliding two large steel balls with a thin sheet of material (e.g. paper) in between may 「burn」 a hole in the sheet. Investigate this effect for various materials.
4. Soap film
Create a soap film in a circular wire loop. The soap film deforms when a charged body is placed next to it. Investigate how the shape of the soap film depends on the position and nature of the charge.
5. Grid
A plastic grid covers the open end of a cylindrical vessel containing water. The grid is covered and the vessel is turned upside down. What is the maximal size of holes in the grid so that water does not flow out when the cover is removed?
6. Ice
A wire with weights attached to each end is placed across a block of ice. The wire may pass through the ice without cutting it. Investigate the phenomenon.
7. Two flasks
Two similar flasks (one is empty, one contains water) are each connected by flexible pipes to a lower water reservoir. The flasks are heated to 100°C and this temperature is held for some time. Heating is stopped and as the flasks cool down, water is drawn up the tubes. Investigate and describe in which tube the water goes up faster and in which the final height is greater. How does this effect depend on the time of heating?
8. Liquid light guide
A transparent vessel is filled with a liquid (e.g. water). A jet flows out of the vessel. A light source is placed so that a horizontal beam enters the liquid jet (see picture). Under what conditions does the jet operate like a light guide?
9. Sticky water
When a horizontal cylinder is placed in a vertical stream of water, the stream can follow the cylinder』s circumference along the bottom and continue up the other side before it detaches. Explain this phenomenon and investigate the relevant parameters.
10. Calm surface
When wind blows across a water surface, waves can be observed. If the water is covered by an oil layer, the waves on the water surface will diminish. Investigate the phenomenon.
11. Sand
Dry sand is rather soft to walk on when compared to damp sand. However sand containing a significant amount of water becomes soft again. Investigate the parameters that affect the softness of sand.
12. Wet towels
When a wet towel is flicked, it may create a cracking sound like a whip. Investigate the effect. Why does a wet towel crack louder than a dry one?
13. Shrieking rod
A metal rod is held between two fingers and hit. Investigate how the sound proced depends on the position of holding and hitting the rod?
14. Magnetic spring
Two magnets are arranged on top of each other such that one of them is fixed and the other one can move vertically. Investigate oscillations of the magnet.
15. Paper anemometer
When thin strips of paper are placed in an air flow, a noise may be heard. Investigate how the velocity of the air flow can be deced from this noise?
16. Rotating spring
A helical spring is rotated about one of its ends around a vertical axis. Investigate the expansion of the spring with and without an additional mass attached to its free end.
17. Kelvin』s dropper
Construct Kelvin』s dropper. Measure the highest voltage it can proce. Investigate its dependence on relevant parameters.
競賽題目（中文）
（此版本的譯文某些地方可能有出入，如果你發現有哪些地方譯得不對請及時指出）
1.電磁炮
螺線管可以用來發射一個小球體。使用電容器為螺線管提供能量。以一個以50V為最大電壓的電容器製作一個裝置。探究球體速度的界限和如何是球體速度達到上限。
2.完美圖像
一滴水懸掛在縱向水管的出口處，用一束激光去照射，觀察屏上呈現的圖像。研究並解釋圖像的結構。
3鋼球
用兩個巨大的鋼球在一個軟材料薄片（例如一張紙）處碰撞，會在這片材料上「燒」出一個洞。研究這種效應在不同材料上的體現。
4.肥皂膜
在一個圓形的水槽中製造一個肥皂膜。當把一個帶電物體放在旁邊時會使肥皂膜變形。探究該物體帶電的方位和電性如何影響上述效應。
5.格柵
一個塑料格柵蓋在一個盛有水的圓柱形容器頂部。在格柵上面蓋上蓋子，把容器倒置過來。在蓋子移開時水不會落下來的前提下，格柵的最大孔徑是多少？
6.冰塊
一個兩邊掛有重物的金屬線被橫置在一個冰塊上，金屬線可能會自動地從冰塊中穿過。探究這一現象。
7.兩個燒瓶
兩個相同的燒瓶（一個是空的，另一個盛有水）分別連接著一根通向一個低處蓄水池的軟導管。兩個燒瓶都被加熱到100攝氏度並保持在此溫度一段時間。當加熱停止，燒瓶正在冷卻時，水從導管中被吸了上去。探究在哪一個燒瓶中水會較快的被吸上去，哪一個中的水位最高。加熱的時間如何影響這一效應。
8.液體導光（讓光線在水流里全反射）
一個透明的圓柱形容器裝滿了一種液體（例如水），一束水流從容器中流出來。放置一個光源，使光束水平地射入液體流。探究在何種情況下這束水流可以像光纖一樣。
9.粘稠的水
當把一個豎直的圓柱體被放置在一束豎直流下的水流之中，這束水流在掉下來之前可以沿圓柱體的圓形底面流到另一端。解釋這種現象並探究相關參數。
10.平靜的水面
當風吹過水面時，會產生明顯的波紋，如果水面被一層油膜蓋住，水面的波紋就會減小。探究這一現象。
11.沙子
相比於濕的沙子，在乾燥的沙子上面行走感覺更柔軟，然而，含有大量水分的沙子會重新變得柔軟。探究影響沙子柔軟程度的相關因素。
12.濕毛巾
如果拍動一條濕毛巾（我猜應該是用濕毛巾去抽打一個堅硬物體），會產生像用鞭子抽打一樣的劈啪聲。探究這一現象。為什麼濕毛巾會比干毛巾發出更響亮的聲音。
13.尖叫的棒子
用兩個手指拿起一個鐵棒，並（用某種方式）敲打它。探究手指所拿的位置和敲擊的位置如何影響發出的聲響。
14.磁體彈簧
兩塊磁體，一個放在另一個的上邊。這樣其中一個（下面那個）就被固定住，另一個可以豎直的移動，探究這塊磁體的振動。
15.紙質風速計
當把一個薄紙條放在流動的空氣中時，可能會聽到一種聲音。探究如何依據這種聲音推斷風速。
16.轉動的彈簧
一個螺旋的彈簧，一端被固定著，圍繞著一個豎直的軸轉動，探究彈簧自由端掛重物和不掛重物時彈簧的伸長。
17.開爾文滴管
（豎直放置的磁流體發電器，開爾文滴管的具體構造最好還是去考證一下）
製造一個開爾文滴管，測量它能產生的最大電壓，探究它所依賴的相關因素。