Longing for a trip

Not a big fan of traveling, but since there has been too little excitement in my life for the past few months. A trip seems attractive suddenly. It should be fun!

A Crossbow

An ancient Chinese crossbow, an arrow-throwing weapon consisting of a bow fixed transversely upon a stock which contains a groove to guide the arrow, a cylindrical catch, the nut, for catching and holding the bow string, and a trigger to release it, is braced with an arrow set in the groove with the string fitted into its notch, at rest. When the trigger is pressed, the nut, which is joined to the trigger, rotates by the same acute angle as the trigger around a wooden shaft transversely fixed into the stock. Simultaneously, the maximum static friction between the string and the nut surface declines with the surface’s inclination. When the tension in the string exceeds the maximum static friction, it causes the string to shrink and slide over the nut surface. The surface and string temperature measurably increase due to friction. The arrow experiences a propulsive force from the string and begins to accelerate along the groove. During the arrow’s rectilinear motion, its acceleration declines as the tension in the string decreases, while the bow prod is transmogrified slightly after being released from the string’s pulling force. At the moment the string becomes perpendicular to the symmetrical axis of the crossbow, the arrow notch departs from the string, whose vibration instantaneously causes a significant sound, while the arrow attains its maximum horizontal velocity and continues sliding along the groove. Then the arrow slightly decelerates as the result of the frontal atmospheric resistance and the friction drag between the surfaces of the groove and the arrow, which also causes the surface temperature and the atmospheric temperature to slightly rise. When the arrow departs from the groove, it begins to vertically accelerate, while horizontally decelerating because of atmospheric resistance. During flight, the arrow shaft slightly quivers and rotates about its own axis while the fletching produces considerable air resistance to prevent rotation. The motion of the arrow causes turbulent motion of the atmospheric gases, causing a measurable yet faint sound.

 

Riddle…

When asked this riddle, 80% of kindergarten kids got the answer, compared to 17% of Stanford University seniors.
 
What is greater than God, more evil than the devil, the poor have it, the rich need it, and if you eat it, you’ll die?

Answer: Nothing.

 

A zipper

A zipper is mainly comprised of two parts: a slide, which is a collection of wedges, and a zipper track, constituted of dozens of teeth, which combines a hook and a hollow each. As the slide moves up the zipper track, the two teeth strips enter at a specific angle. As the strips move through the slide, the slide’s inclined edges push the teeth toward each other. The strips are offset from each other, so each hollow settles onto a hook in sequence. To work properly, each tooth should be exactly the same size and shape and they all must be perfectly positioned on the track, which makes the interlocking teeth difficult to separate.

 

The Review of My Laptop

My laptop is a Samsung X05 notebook computer, which is a mechanism which is generally comprised of a 14.1” XGA TFT LCD panel and a keyboard with a touching panel beside it. With a mass of 2.0 kilograms and a thickness of 2.5 centimeters, the most significant feature of my computer is its excellent portability.

 

There are two ways to provide the computer with electricity, standard battery and AC adaptor, which are both effective. With electricity supply is ready, the LCD latch, which is located in the middle of the computer edge, should be unlocked before opening LCD panel. By pressing the power button, the computer will be turned on. After the process of loading software and checking hardware, the desktop of operation system that has been installed in the computer is shown on the screen, after which I can begin my work on the computer.

 

Different icons indicate various programs that are available for different application, which makes it very convenient for me to run any frequently used programs by double-clicking the icons. According to the different categories of programs, their functions vary greatly. Typically, word processing program, Internet browser and multimedia player are relatively more frequently used. Besides, other application programs may be installed and used to meet different specifications. It is essential to shut down the computer through operation system and it is suggested not to press power button to turn off the computer directly, as it may cause loss of data that has not been saved and has a negative effect on the computer’s hardware.

 

Digital cameras & Film-based cameras

The most significant difference between digital cameras and film-based cameras is that there is no film in digital cameras to record images. Instead, semiconductor devices, such as CCD and CMOS image sensors, which convert light into electrons, are employed to perform the same function. Different from conventional film-based cameras, which depend on chemical and mechanical process, digital cameras record images in the form of digital data, which is processed by a built-in computer. Consequently, digital cameras are superior to film-based ones in terms of capacity, as they store enormous amounts of pictures on rewritable internal memory cards and expandable cards, while film-based ones are limited by the maximum length of films. Besides, digital cameras facilitate the process of uploading pictures onto websites and editing them with programs. The night vision function of digital cameras, which film ones don’t have, makes it possible to take a picture without a flash in dimly lighted environment. There is a tendency that the volume of digital cameras is becoming increasingly small, which provides much flexibility in some specific occasions, while the minimum volume of film cameras is not expected to become smaller than that of films in them. Pictures taken by film cameras are of measurably higher quality than those taken by digital cameras on average. As resolution of digital cameras, the primary factor contributing to digital camera image quality, being improved rapidly, it is controversial whether the quality of digital pictures will surpass that of film ones. Moreover, with rewritable memory material applied in digital cameras instead of one-off films composed of harmful chemical elements, digital cameras are more environment-friendly than conventional ones.

 

Forming the Habit

When you are free, do you read?

 

A survey was made to find some information about reading habit among Tsinghua University students.

According to our survey, 40 percent of the students choose reading, while 60 percent choose not to, and about half of the students have not formed the habit of regular reading.

 

So here comes a serious question: how should we form a good reading habit?

 

20 percent of the students hold the view that a good early home education is the key to put kids on the path of reading, while 60 percent insist that the motivation of reading comes from the desire for learning and finding interesting things.

 

It is clear that interest plays a significant role in the process of forming reading habit. Therefore, if we want to help teenagers read more and better, their curiosity and creativity should be encouraged.

 

On the other hand, a good reading atmosphere at home is also of great importance. The reason is simple, we are all inevitably partly influenced by the people surrounding us, and home education, especially early home education, appears to be the most significant as it comes at the early stage of habit-forming in our lives, which makes it an indispensable constituent part of education.

 

Apparently, when adults read, they not only educate themselves, but also set their children good examples as well. So what are we waiting for? Pick up an interesting book and enjoy yourself!