"Strange Laser" PPT download

Description

"Strange Laser" PPT download

Part One: First Reading Perception

1. Background information

Laser is another major invention of mankind since the 20th century, after atomic energy, computers, and semiconductors. It is called the "fastest knife", "the most accurate ruler", "the brightest light" and "the strange laser" . It is about 10 billion times brighter than sunlight. The principle of lasers was discovered by the famous American physicist Einstein as early as 1916, but it was not until 1960 that a laser was successfully manufactured for the first time. Laser came into being in the context of theoretical preparation and urgent needs for production practice. As soon as it came out, it achieved unusually rapid development. The development of laser not only gave new life to ancient optical science and optical technology, but also led to The emergence of an entire new industry.

2. Word integration

(1) Difficult words

dizzy

Literal meaning ① (eyes) dimness; ② confusion, confusion.

Word expansion (dizziness) (dazzled by fame and fortune)

Application I suddenly felt dizzy and almost fell down.

burn

Meaning of the word ①burning; ②bright.

Expanded word (scorching) (burning) (insight)

The police used thunderous force to eradicate evil forces and were praised by the public.

(2) Polyphonetic characters

drill zuàn (diamond) zuān (drill into)

Application: Uncle Li has been drilling ( ) and drilling ( ) stone cutting technology recently.

(3) Important and difficult words

learn a lesson

【Significantly】Obviously eye-catching.

【Cultivation】Cultivation and careful management of (plants).

[Strange] Strange, surprising.

Synonyms: burn - burn silence - quiet strange - strange

Antonyms: special - general concentration - scattered temporary - permanent

3. Overall perception

Read the text and try to fill it in.

"Strange Laser" is an expository article. The author introduced to us (the characteristics of lasers and their wide application in modern life), allowing us to fully feel (the magic of lasers and appreciating the omnipotence of science and technology) between the lines, stimulating our enthusiasm for learning and loving science and The desire to explore the mysteries of science.

special statement

Find out which sentences in the article reflect the characteristics of laser, and try to find the corresponding sentences.

1) Laser is a new type of light, artificial light, which is different from the light emitted by the sun, electric lamps, etc. (paragraph 2)

2) If you use it to cut a steel plate with a thickness of several millimeters, you will see steel splashes flying around. With a slight sound, the steel plate will be divided into two, and the cutting seam will be thin and straight without deformation at all. (Paragraph 5)

3) Laser guns can not only seriously injure people's eyes, but also burn the human body. Laser cannons can be used to shoot down enemy aircraft; lasers are the fastest knives and can cut steel plates, drill holes in hard diamonds, etc. (Paragraph 10)

Paragraph to the effect

According to the story process and the author's emotional changes, the paragraphs can be divided as follows:

⑴ Always write down the characteristics of laser. (1)

⑵ Introduce the characteristics and uses of laser in detail. (2-9)

⑶ Further introduce other applications of laser. (10-11)

Strange laser PPT, part 2: read the text again

Read the text and think about the questions.

1. What rhetorical device is used at the beginning of the article? what's the effect?

Click: Ranking. The use of three "most" characters in a row enhances the momentum of the speech, emphasizing the high level and great capabilities of the laser, highlighting its unique role, leaving a deep impression on people, and paving the way for the following narrative.

2. What examples does the article cite when introducing laser as “the fastest knife”? Please summarize them separately.

Tips: three: (1) people use lasers to cut steel plates; (2) lasers are used to drill holes in diamonds; (3) doctors use lasers to operate. These few examples specifically illustrate that the laser is the “fastest knife.”

3. How to understand the meaning of the first five sentences in paragraph 8?

Instructions: "Stars dotted", "Galaxy shines", "bang, bang" sounds are heard from time to time, "red lights cut through the darkness and shoot into the sky", the visual and auditory impact accompanies us. Let's start with the application of laser - "laser rangefinder", and once again experience the characteristics of laser - it has strong directionality. It is precisely because of this characteristic that it has become the "most accurate ruler" in the world.

4. Why is laser said to be a "strange" light?

Tip: Because laser has strong directionality and is the brightest light, it is widely used in the military: laser guns can not only seriously injure people's eyes, but also burn the human body. Laser cannons can be used to shoot down enemy aircraft; lasers It is the fastest knife, it can cut steel plates, drill holes in hard diamonds, etc.; the laser is the most accurate ruler, it can accurately measure the distance between the earth and the moon; the laser can also "guide" construction and treat eye diseases. , helping agronomists breed new varieties. The powerful effects and wide range of applications of lasers make people feel strange and surprising, so lasers are said to be "strange" light.

Strange laser PPT, the third part: intensive reading of the text

In the text, the author uses many explanation methods to explain the characteristics of laser. Try to find these explanation methods and give corresponding examples.

Instructions: First draw the sentences used by the author to explain the method in the order of the text's narrative, then read it, and then combine the sentences of the text to understand it.

The author uses comparisons, numbers, examples, and analogies to illustrate.

1. to compare

(1) Laser is a new type of light, artificial light, which is different from the light emitted by the sun, electric lamps, etc.

2. Column numbers

Because it emits light in a concentrated direction, it emits particularly bright light. At its brightest, it is 10 billion times brighter than the sun!

3. Give examples

If you use it to cut a steel plate with a thickness of several millimeters, you will see steel flowers splashing everywhere. With a slight sound, the steel plate will be divided into two, and the cutting seam will be thin and straight without deformation at all.

4. Make an analogy

Every few seconds, the laser rangefinder generates a beam of laser light that hits the moon and then reflects from the moon to the earth. As we all know, a scud alone can travel 300,000 kilometers in one second. The laser light shot from the earth to the moon is reflected back to the earth in more than two seconds.

Strange laser PPT, part 4: interactive feedback

1. Mental enlightenment

Let me say

The magical laser is a product of the rapid development of science and technology. Its invention has provided great convenience to our production and life. The use of lasers for surgery, measurement data, and the emergence of laser TV show that lasers are closely related to human life. Technology is truly omnipotent! We also need to learn science, explore science, and use science to benefit mankind.

2. Imitation training

Please use examples to illustrate.

Original sentence of the text

When building railways and highways, using lasers to "guide" the construction can make the roads built accurately and straight.

Example: There are stone arch bridges almost everywhere in our country. These bridges come in many sizes and forms, and many are stunning masterpieces. The most famous among them are the Zhaozhou Bridge in Zhao County, Hebei Province, and the Marco Polo Bridge in Fengtai District, Beijing.

Method analysis: illustrate the characteristics of things by citing representative and appropriate examples.

3. Language accumulation

In class: scatter temporary burn infection significant special precise cultivation advent strange

Extracurricular: Famous quotes about science:

Science and technology are primary productive forces. ——Deng Xiaoping

The greatest advances in science are brought about by new and bold imaginations. ——Dewey

Science is the most important, beautiful and needed thing in people's lives. ——Chekhov

Strange laser PPT, part 5: practice in class

1. Read Pinyin and write words

ｽàｎ ｗｈ( )

2. Choose words to fill in the blanks.

accurate precise correct

1. Using a rangefinder made by laser, the distance between the earth and the moon measured is very ().

2. Mathematical operation requirements ( ), it is impossible to do this if you are careless.

3. The running posture must be ( ), otherwise you will not be able to run fast.

3. Fill in the blanks according to the text content.

People take advantage of the characteristics of laser and apply it in the military to develop ( ) and ( ); it is used in industry to cut steel plates; it can also be used in ( ), ( ) and ( ). It can be seen that the use of laser is very ( ).

Keywords: free download of the Chinese PPT courseware for the first volume of the fifth grade of the E-education edition, strange laser PPT download, .PPT format;

For more information about the "Strange Laser" PPT courseware, please click the "Strange Laser ppt" tab.

"Strange Laser" PPT:

"Strange Laser" PPT Part One Content: New Lesson Introduction What objects have you seen emitting light in your life? Electric lights and the sun, moonlight, lasers, strange lasers, strange: strange; special. (1) Check the pronunciation: j zn xun zhu tū gē distance temporarily ..

"Strange Laser" PPT courseware:

"Strange Laser" PPT courseware In this class we study "Strange Laser". After reading the topic, do you have any questions? It seems that the students are all sticking to this question and asking strange questions. What does strange mean? What is so magical about lasers? Let's quickly...

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Update Time: 2024-11-20

This template belongs to Chinese courseware E-education edition Chinese language for fifth grade, volume 1 industry PPT template

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