strange incidence

The incident angle refers to the angle between the light ray and the normal line of the surface of the medium when it enters the surface of the medium, and the reflection angle refers to the angle between the light ray and the normal line of the surface of the medium when it is reflected from the surface of the medium. In the optical diagram, a straight line with an arrow is usually used to represent the light ray. The incident light ray is shot at the interface of the two media, and the straight line (that is, the normal line) is vertical to the interface through the incident point. The angle between the incident light ray and the normal line is the incident angle. The reflected light is the light reflected at the interface. The angle between the reflected light and the normal is the reflection angle. Moreover, according to the law of reflection, the reflection angle was equal to the incident angle. On the diagram, it was shown that these two angles were symmetrical with the normal line as the axis, and their sizes were equal. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

Starting from the principle that light always travels along the fastest path, Helen discovered that the angle of incidence was equal to the angle of reflection. When light travels to different substances, it will be reflected at the interface. The reflected light, the incident light, and the normal line are on the same plane. The reflected light and the incident light are separated on both sides of the normal line, and the reflection angle is equal to the incident angle. It can be summarized as "three lines are in the same plane, two lines are separated, and two angles are equal." This phenomenon was consistent with the law of reflection. Hiro of Alexandria in the 1st century AD first described the relevant content of the law of reflection. In 1823, fresnel introduced the quantitative law of the law of reflection and the law of refraction (fresnel formula). This law holds true when light is shot from one medium to another, such as light from air into water or glass into air. It is widely used in the field of light to explain the reflection of light and related optical phenomena. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

In high school biology, the calculation of the incidence rate of genetic diseases would be involved. For example, the incidence rate of a certain genetic disease = the number of individuals with a certain genetic disease/the total number of individuals investigated for a certain genetic disease. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

The high incidence of gastroesophagus reflex disease was mainly related to the following factors: 1. [Lifestyle and eating habits: The unhealthy lifestyle of modern people has increased the frequency of gastric and esophagus obstruction.] For example, drinking too much alcohol, eating too much, eating sweets (such as sweet potatoes, sweet porridge, and sugar water), spicy food, greasy food, acidic drinks, and sour food, smoking frequently, drinking a lot of strong tea, coffee, etc. These bad eating habits are all related to the occurrence of gastroesophagus reflex disease. In addition, bad eating habits such as lying flat after a meal and eating too much before going to bed could also easily cause the disease. 2. ** Age factor **: The occurrence rate of GED in people over 30 years old is higher than that in people under 30 years old, and the peak age is 50 - 69 years old. The elderly had decreased saliva secretion, decreased chemical clearance ability, and decreased resistance to damage caused by decreased blood flow in submural capillaries. The muscle relaxation and elasticity of the esophagus wall decreased, and the gate function of the lower esophagus and the junction between the esophagus and the esophagus was weakened or even almost zero. These physiological changes made it easier to get sick. 3. ** Drug factors **: Some drugs such as theylline, beta2-adrenoceptors, oral contraceptives, calcium channel blockades, indolergic antagonist, valium, and morphines are related to the occurrence of the disease. 4. ** Disease factors **: Some diseases, such as low intelligence, sequelae of stroke, Peptic Ulcer, and surgery of the stomach and gallbladder, are related to the occurrence of the disease. Some diseases can also cause excessive abdominal fluid to form in the abdominal cavity, causing the abdominal cavity pressure to increase and cause the disease. Hiatus Hernia (HH) often occurs in combination with gastroesophagus reflex disease, which can also aggravate the condition. 5. ** Changes in physiological structure **: Pregnant women are the high-risk group of people with gastric and esophagus reflex disease. On the one hand, the diet structure changes after pregnancy, the amount of food intake increases greatly, and the burden on the stomach increases. On the other hand, the pregnancy reaction during pregnancy, frequent vomiting, can easily cause the lower esophagus constrictor to relax and cause reflex. There are also changes in the body structure of pregnant women. As the fetus grows, the pressure in the abdominal cavity will gradually increase. After the stomach is squeezed, the pressure in the stomach will increase. When the pressure exceeds the pressure in the esophagus, there will be reflex. 6. ** Mental factors **: Mental factors can cause and aggravate the symptoms of gastric reflex. The risk of developing gastric reflex in mentally fragile people is 3.8 times higher than that of other people. 7. ** Obese factors **: Obese people (whose body weight is more than 20% of their ideal weight) have a significantly higher incidence of gastric-esophagus reflex disease than people of normal weight. Body mass index (Body Mass Index = weight (kg)/height (m) 2), waist circumference, and excessive weight will make individuals more susceptible to gastric-esophagus reflex disease, erosive reflex disease, and Barrett's esophagus. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

The following is a summary of some mathematical problems related to the angle of incidence and reflection: ** 1. Angular Calculation ** 1. ** Calculating the angle of incidence and reflection from the angle between the light ray and the flat mirror ** - For example, when the angle between a ray of light and a flat mirror is 60°, the angle of incidence and the angle of reflection are calculated. - The solution: The angle of incidence is the angle between the incident light and the normal. Since the angle between the incident light and the mirror is 60°, and the normal is normal to the mirror, the angle of incidence is 90° - 60° = 30°. Since the reflection angle was equal to the incident angle, the reflection angle was also 30°. - When the incident angle increases by 10°, find the angle between the incident ray and the reflected ray. - The original angle of incidence was 30°. After adding 10°, it became 40°. The angle of reflection also became 40 °. Then the angle between the incident ray and the reflected ray was 40°+40° = 80°. 2. ** Calculating the angles of incidence and reflection in a geometric figure (involving circles and other geometric figures)** - For example, in a glass sphere that is approximately a semicircle O, where A is the diameter, there is a chandelier at point C on the semicircle O, E F A B, C O A B, the middle point of E F is D, O A = 4, there is an incident light M H, a reflected light H N, HH M = HH N = 45°, tan COH is known, and the length of ON is found (this involves using the incident angle to determine the angle relationship, and then combining the properties of the geometric figure to solve the problem). - The solution to the problem was to cross point N and make NG Ox at point G. Let NG = 3k (k>0), then OG = 4k, ON = 5k, from Ox N = 45°, GH = NG = 3k, and then find the value of k according to the known conditions such as the radius of the circle, thus obtaining the length of ON. ** 2. Proof class (often combined with the law of reflection and the relationship between geometric figures)** 1. ** In a lamp with two mirrors, when AA-B-C, the incident angle is equal to the reflection angle (1 = 2, 3 = 4) to explain the problems related to the light entering the lamp. ** - [Solution: You need to prove the transmission path of light based on the angle of incidence equals the angle of reflection and the vertical relationship between mirrors.] ** 3. Similar triangle combined with the angle of incidence and the angle of reflection ** 1. ** For example, in the graph related to the glass sphere, finding the length of the line segment (such as the length of CD) involves proving the similarity between the two. Here, the condition that the incident angle is equal to the reflection angle may be an implicit angle equality relationship, which is used to determine the angle equality of the triangle, thus proving the similarity ** - Solution: By analyzing the parallel relationship, vertical relationship, etc. in the graph, combined with the angle of the incident angle being equal to the angle of reflection, find the conditions for the similarity of the triangle, and then find the length of the line segment according to the proportion of the corresponding side of the similar triangle. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>