Question? Based on my own classroom teaching, this paper talks about what aspects can be started when writing teaching reflection.
As a habit of thinking, reflection is as common as eating and walking, because it is an instinctive behavior to sum up experience and work better. Especially as educators, we need sincere reflection. In order to understand reflection more deeply in essence, let's first understand "educational tact".
What problems should the sixth-grade class teacher pay attention to in education and teaching? We should pay attention to students' study and life. The sixth grade is a rebellious period, and the mood fluctuates greatly, so we should pay more attention.
Teachers reflect on the main links in the process of education and teaching from the Internet for reference only.
1 reflect on the teaching process
To understand the meaning of a problem is to get information from it in order to solve it. The process of reflecting and understanding the meaning of the problem is the process of thinking about how to obtain information. For example, what information was obtained and what information was missed. Why is this information missing, resulting in wrong or complicated answers?
Example 1. It is known that A and B are two imaginary roots of the equation x2+x+p=0, and |a-b|=3, then the value of the real number p is ().
A: -2 B: C:-D:
Narrow the difference between the initial state and the target state, according to Vieta theorem a+b=- 1 and AB = P | A-B | 2 = (a-b) 2 = (a+b) 2-4ab =1-4p = 9. The solution is p=-2. The reason for this missolution reflection is the omission of the known condition information of the topic. A and b are two imaginary roots of the equation x2+x+p=0. The reason why this information is omitted is that the above solution is disturbed by the concept of absolute value of real numbers and misuses |z|2=z2.
Example 2. It is known that A, B and C are three sides of △ABC, and their diagonal angles are A, B and C respectively, and aCosB=bCosA. With regard to two equations B (x2-1)+C (x2+1)-2ax = 0, it is proved that △ABC is an isosceles right triangle (65438).
By analyzing the solution process of this problem, starting from the condition aCosB=bCosA, it can be concluded that △ABC is an isosceles triangle by using cosine theorem. From the condition = 0, it can be deduced that △ABC is a right triangle. On the surface, this problem has been solved correctly. The first step is to prove "isosceles" and the second step is to prove "right angle", but compared with the derivation of "isosceles", it is less helpful to "right angle". Conversely, the "right angle" is deduced as "isosceles", that is, cosA and cosB are defined and given directly by acute triangle function without cosine theorem, and the length of solving problems is shortened by changing the order of solving problems. The change of the order of solving problems reflects the understanding of the essence of solving problems. One reason why reflection sometimes fails to go deep into the essence of the topic is that we ignore that "the conclusion of the topic is also known (suggestive) information"
2.2.2 Reflection on the process of thought formation
The idea of problem solving is to combine the information obtained when understanding the meaning of the problem with the information in the mind, process, reorganize and regenerate, so that the thinking is closer to the goal and the problem solving process is realized. Therefore, the formation process of reflective thinking is the reflection on information processing, reorganization and regeneration. For example, how to realize the transformation from the initial state to the target state, which way to choose, where is the key to solving the problem, and whether many steps can be replaced by general rules to improve the problem-solving viewpoint and thinking level. This requires us to pay attention to the reflection of knowledge points and the intersection of knowledge, and form a knowledge chain through reflection until a thinking chain is formed.
2.2. 1 Reflection on the intersection of different knowledge
Example 3. Given the long axis of the ellipse |A 1A2|=6, the focal length |F 1F2|=4, and the left focal point of the ellipse | F 1, make a straight line and the ellipse intersect at two points, m and n, and let ∠F2F 1M=, (0
Solution 1: Establish a rectangular coordinate system centered on the X axis and the origin, and the elliptic equation = 1. Let the linear equation where MN is located be y=k(x+2), and use the chord length formula |MN|= |x 1-x2|= to get k2=, and then get = or =
Solution 2: (Slight solution) Take the left focus F 1 as the pole and the straight line where the long axis is located as the polar axis, and establish the polar coordinate equation =, |F 1M|= 1=, |F2M|= 2= to get | Mn | =1+2.
Solution 3 (abbreviated solution) Let the radial angle equation of the line where MN is located be (t is radial angle), and substitute it into the elliptic equation | Mn | = t. 1-t2 | = = 2, = or =.
Solution 4: defined by an ellipse, let |F 1N|= d 1, |F 1M|= d2, and connect NF2 and NF 1 to get |NF2|=6-d 1, | nf2. (6-d 1) 2= d22+32+8 d2cos, and the solution is d 1=, d2=, (hereinafter abbreviated).
Reflecting on various solutions to this problem, the key to this problem is to express |MN|. Using the intersection of different knowledge points, different problem-solving ideas are produced.
The solution 1 can be directly solved by the formula of the distance between two points, which is complicated and can be simplified by Vieta's theorem.
Solution 2 and solution 3 think that distance can also be expressed by radial angle equation or polar coordinate equation. Solution 4 Find out |F 1N| F 1M| Using the method of equation thinking, directly find out the troubles, taking into account the over-focus of the straight line, using the definition of ellipse and cosine theorem. By reflecting on the intersection of different knowledge, we can communicate all aspects of knowledge, cultivate contact and transform dialectical thinking. Make thinking tend to be diversified and extend to different directions and levels, and improve students' problem-solving ability and broad thinking.
2.2.2 Reflection on different levels of mathematical thinking
K dunkel divided the thinking process of solving problems into three levels: general solution, functional solution and concrete solution. The implementation of these three levels can not be separated from the guidance of mathematical thought. Reflecting on different levels of mathematical thinking can sublimate experience and produce a leap in understanding, thus producing different problem-solving thinking.
Example 5. If the equation =x+b has no solution, find the range of the number b.
Solution 1 (the idea of combining numbers and shapes) transforms the equation into a bi-functional image position relationship. Let y=, y=x+b, in order to make the equation unsolvable, only the straight line and the hyperbola (the upper part) have no intersection point, and the value range of b (-∞,-1)∩[0, 1] is obvious from the figure.
Scheme 2 (classification discussion idea) Classification discussion determines the appropriate classification standard according to the requirements of the topic, then solves each classification category, classifies if necessary, and finally synthesizes the results. When classification is needed, it should not be repeated or omitted (omitted)
Example 6 f(x-3)=x2+2x+3 is known, and f(x) is found.
Solution 1: replace x=x+3-3 with variables, and generate x with x+3.
Solution 2: Set f(x)=ax2+bx+c by substitution coefficient method to get f(x-3), and compare the coefficients of similar items.
Solution 3: Matching method, f (x-3) = x2+2x+3 = (x-3) 2+8 (x-3)+18.
After inducing students to solve problems in teaching, being good at refining and reflecting mathematical thoughts from different levels is very beneficial to strengthening mathematical thoughts and improving problem-solving ability.
3.3 Reflection on the expression process of problem solving
The performance of solving problems is the implementation of the plan. Reflective problem-solving expression mainly reflects whether the operation is correct and the reasoning is rigorous. Reflect on which thinking circuits have been taken, whether it can reflect the beauty of simplicity by deleting complexity and simplifying, and at the same time cultivate the rigor and criticism of students' thinking.
Example 7 If (z-x) 2-4(x-y)(y-z)=0, it is proved that x, y and z become arithmetic progression.
Observing the equation, it is found that the discriminant is similar to the unary quadratic equation = b2-4ac = 0, so the equation (x-y)t2+(z-x)t+(y-z)=0 is constructed and this equation has equal roots. If the sum of the coefficients is 0, then 1 has two equal roots, and Vieta theorem t 1t2= = 1, that is, 2y=x+z ∴ x, y and z become arithmetic progression.
Reflecting on the above solutions, the reasoning is not rigorous enough. 1, b2-4ac=0 (*) and the equation ax2+bx+c=0 are not in one-to-one correspondence, for example, x2+bx+ac=0, 2ax2+bx+ =0, and their discriminant is (*). 2. Whether the constructed equation is a quadratic equation, [
What problems should be paid attention to in the process of purchasing cabinets! Several secrets of cabinet purchase
Look at the edge of the plate.
The edge sealing of high-quality cabinets is delicate, smooth and feels good. The sealing line is straight and the seam is fine. Professional manufacturers use linear edge banding machine to complete edge banding, decapitation, trimming, chamfering, polishing and other processes at one time, with uniform edge banding and stable pressure to ensure the most accurate size. Workshop-style small factory, use brush to glue, manually press and seal the edges, use grating knife to trim the edges, and use manual polishing machine to polish. Due to uneven pressure, many places are unstable, and toxic gases such as formaldehyde will also volatilize into the air.
Second, look at the kitchen cabinet connection.
Nowadays, panel furniture is assembled by three-in-one connectors, and the coordination and accuracy of hole positions will affect the structural stability of cabinets. Professional manufacturers use multi-row drills to complete multiple holes on the edge and surface of a plate at one time. These holes are positioning benchmarks, and the dimensional accuracy is guaranteed.
Third, look at the chopping block.
Cutting board is the first process of cabinet production. Large-scale specialized enterprises use electronic sawing machine, and input the machining size through computer, and the computer controls the accuracy of material selection size, so that several plates can be machined at a time. The device has the advantages of stable efficiency, high dimensional accuracy of the plate, tolerance in microns, and no stubble collapse at the edge of the plate.
Kanmenban
Door panels are the faces of cabinets, as important as people's faces. Door panels produced in small factories are prone to deformation due to improper treatment of substrate and surface technology. Fifth, look at the assembly effect of the whole set of cabinets
Any size error in the production process will be shown on the door panel. The door panels produced by professional factories are horizontal and vertical, and the gap between doors is even. However, the door panels produced by small factories will have uneven cracks and uneven gaps, big and small.
Look at the slide rail of the drawer
Although it is a small detail, it is an important part that affects the quality of cabinets. Due to the error between the hole position and the plate size, there is an error in the installation size of the slide rail, which leads to the drawer not being pulled smoothly or loose left and right. Pay attention to whether the gap in the drawer is even. When choosing cabinets, we should pay attention to the following points: good cabinets that can be bought.
1. Choosing a cabinet depends first on whether the cabinet enterprise has its own design team. Only with a good designer can new products appear in his cabinet style. This also represents the strength of the enterprise.
2. Secondly, we must have professional production experience in the furniture industry to ensure quality and understand the overall style of home. What we can't do is neither fish nor fowl. The imitation is too rubbish, and there is no idea of making it.
3. There must be big brand hardware accessories as the foundation. Otherwise, no matter how good the design, no matter how good the publicity, and no matter how rubbish the accessories are, the whole cabinet will be fragmented and problems will appear constantly, which will have a great impact on the life of the cabinet and cause harm to customers. The importance of small parts determines the survival path of this cabinet enterprise. Only by paying attention to details can we truly gain a foothold in this market.
4. The quality of cabinet products is not made by advertising, but by strength! For cabinets and door panels, we should also choose the right ones. Now many enterprises are outsourcing door panels, rather than processing and producing them themselves. It usually takes 30-40 days for consumers to order, which is also a waste of time in maintenance. Maintenance is a big difficulty. The cabinet must be selected, otherwise it won't take long for the cabinet to break down after several times of oil, smoke, water and heat. You must choose the right brand, which is durable.
Also, making cabinets is not just selling household appliances, but a whole set of home styles and design concepts. The overall style should be integrated and reflect the culture. A single electrical appliance brand is not the best. Electrical appliances and cabinets are heavier, and cabinets are far more than the choice of electrical appliances.
6. For franchisees, ordering, designing and installing cabinets is a process, but it has many meanings. Manufacturers need strength, agents need integrity, and there can be no OEM phenomenon in the middle. Now many enterprises are in a state of fishing in troubled waters. In order to expand the market, they repeatedly discounted profits, and then the materials and accessories in the cabinets were shoddy, which harmed consumers.
The thickness of cabinets, door panels, electrical appliances, hardware accessories, countertops, glass, plates, and the skills of installation masters are all very important. It is also a place where cabinet enterprises try their best to make profits. Jerry-building, shoddy, abuse of materials, the most hateful thing is that many agents represent well-known brands, but in the process of consumer ordering, they find small workshops to secretly process and sell them to customers, and the supply is sufficient.
7. The brand cabinet I admire more is the Oubang solid wood cabinet of Yibang Home, the sovereign enterprise of Shanghai Furniture Factory. Manufacturers do not need false advertisements, only rely on strength competition, take quality as the first priority and take a high-level route. All materials, accessories and electrical appliances are imported, and solid wood cabinets pay attention to a whole concept. In order to ensure the unity of product quality and style, Oubang produces door panels by itself, which can avoid the color difference and disharmony between door panels and cabinets. In addition, we should pay attention to the use of Roman columns, the collocation of solid wood frames, and even the use of solid wood range hoods. The solid wood in Oubang cabinets is mainly cherry, walnut, oak and maple. After many processes, the moisture content reaches the standard, and the product will not deform after sale 10 years. The cabinet is made of Austrian Eiger super E0 grade plate, which is the first case in China. As far as the top cabinet brands in developed countries are concerned, only a few super environmentally friendly materials are selected. The cost of solid wood is high, so the cost of solid wood cabinets will be higher than that of other cabinets. Generally, it costs tens of thousands or even hundreds of thousands of yuan to buy a set of cabinets with solid wood door panels, about 5,000-6,000 yuan per linear meter, which is about 30% higher than that of cabinets made of other materials and belongs to the top consumption of all door panel materials. These solid wood frames and doors are hand-carved, coupled with hand-painted and polished, it will look very retro, which is incomparable to general solid wood cabinets. It also has absolute advantages in solid wood range hoods and other solid wood components. And the product line is also very malleable. In addition to solid wood cabinet products, we have also developed a variety of dining tables and chairs, bathroom cabinets, dressing tables, bars and other products. When you arrive at Oubang's exhibition hall, you can basically choose all the furniture, saving time for customers, and you can also compare it yourself and choose your favorite and most suitable style. However, the product price is much higher than that of the panel cabinet, which is suitable for consumers with a certain economic foundation. Most importantly, Oubang has its own highly skilled design team. The layout and style of all products are completely independently designed. In order to avoid plagiarism in the same industry, Obon did not promote himself in the media. Instead, an exhibition hall with a building area exceeding 1200 square meters was built in the bustling downtown area of Shanghai. * * * people who buy cabinets go to the scene to comment.
At present, most consumers, especially ordinary consumers, still stay at the level of what materials are used for cabinets, but they have not paid enough attention to the environmental protection indicators of raw materials, the qualified rate of safety indicators, the qualified technology and the after-sales protection. The environmental protection of cabinets directly harms your health, and it is conceivable to be heated by lampblack and water.
A set of qualified cabinets shall have a service life of at least 10 years. At present, there is no strict definition of the level of domestic cabinet production enterprises. Five or six people can also build factories and process them on their behalf. So what brand can we talk about and how can we talk about product life? Our consumers are out of the game, and there is no clear concept about it.
At present, the development of domestic cabinet enterprises has not reached the real brand stage, and the top enterprises can only say that the market share is high, and there is still a certain distance from the real brand. This is like Volkswagen and BMW. The exhibition hall is bigger than BMW, but the brand concept is fundamentally different. The cabinet industry can only be called a real brand when the cabinet consumers' understanding and consumption of the brand reach the stage of understanding and consumption of the automobile brand.
What problems should be paid attention to during fan installation? First of all, we should pay attention to the placement of the fan, that is, whether the foundation and placement position of the fan are firm.
Secondly, the connection between the fan and the air duct and the tightness of installation should be adapted. There are also the grades of shock absorbers that must be added.
Finally, the maintenance of the fan, the place where the air outlet is installed with insect-proof net, and the diameter of the air outlet pipe can only be increased, but not decreased.
The above is provided by Shandong Luo Taifan.
What problems should be paid attention to in emergency evacuation drills?
First, the basic requirements of emergency evacuation drills:
1, stay calm, make a correct judgment and act quickly.
2. Learn to take care of yourself and beware of tripping and collision when evacuating.
3, obey the command, in accordance with the predetermined order, queue up to evacuate.
4, after arriving at a safe place, focus on the class as a unit, by the head teacher count, and report to the leadership.
Second, the teacher notes:
1, the class teacher should mobilize the students of this class to carry out emergency evacuation activities, explain the significance and requirements of the activities, and pay special attention to the possible situations and handling methods in the preset evacuation activities, so that students can attach importance to this activity ideologically and actively participate in the activities.
2. After hearing the evacuation signal, the class teacher and the class teacher should be in place quickly, carry out their duties and cooperate closely to evacuate both teachers and students.
4. During the drill, the class teacher and subject teacher leave together with the students, and pay attention to observe, find and deal with the problems existing in the drill, so as to better summarize.
Third, students should pay attention to:
1. Students who are unable to participate in the drill due to special diseases should inform the class teacher in advance to avoid participating.
2. Students participating in the drill are not allowed to wear high heels, long skirts, slippers, etc. So as not to fall.
3. After receiving the evacuation order, keep calm, obey the command, and act quickly when evacuating. It is forbidden to bump and push and pull others. When encountering obstacles, the students in front should find ways to quickly remove obstacles to ensure the smooth evacuation of the students behind.
4. If a student falls, one or two students behind him should quickly pick him up and continue to evacuate. Other students should gather around, don't watch and crowd, and don't push him up.
When counting the number of people, if you find that the number is uneven, don't go back to the original place to look for it. You should report to the teacher immediately, and the teacher will deal with it after reporting to the leader.
6. Pay attention to safety when evacuating in class, especially to prevent collision with desks and stools, causing injuries.
7. After each class is evacuated from the classroom, it can only be divided into two columns and evacuated according to the specified route. It is not allowed to change places side by side or at will. When evacuating, ask students not to run down stairs and corners, and slow down to prevent students from hitting the wall because of too fast speed.
In the process of observation and experiment, we should pay attention to which problem chemistry is a natural science based on experiments, and study the composition, structure, properties and changing laws of substances. In chemical knowledge, a lot of knowledge, such as chemical concepts, basic principles, properties of elemental compounds, etc., are obtained through chemical experiments. Therefore, in chemistry learning, we must learn to observe experiments correctly, and draw conclusions according to experimental phenomena on the basis of observation, so as to master chemistry knowledge. So, how to observe the experiment correctly and what should be paid attention to in the process of experimental observation?
First of all, we should make clear the purpose of the experiment and determine the focus of experimental observation.
The purpose of textbook experiment is to achieve a certain learning purpose, and the experimental purpose determines the focus of experimental observation. Only by clarifying the content of key observation and grasping the essential phenomenon can we observe and learn effectively. For example, junior high school chemistry sequence experiment designed several experiments to help students understand and master the changes of physical chemistry smoothly. Therefore, the focus of observation should be whether the substance has changed qualitatively before and after the reaction, so as to determine whether this change belongs to physical change or chemical change. For example, in the magnesium belt combustion experiment, the key point of observation is the essential difference between the burned magnesium products and the magnesium belt, and it is judged whether the reaction is a new substance, so as to judge whether the reaction belongs to a chemical change. We should not only pay attention to the non-essential phenomenon of "giving off dazzling light and releasing a lot of heat" during the experiment. Only in this way can we achieve the purpose of the experiment-to master the essence of physical changes and chemical changes.
Secondly, make clear the elements and procedures of observation and conduct experimental observation in an all-round and orderly way.
For experiments, especially some too complicated experiments, there are often many elements of experimental observation. In the process of experiment, we must observe in an all-round and orderly way to achieve the purpose of experimental teaching, so as to master chemical knowledge thoroughly and comprehensively.
So, how to observe chemical experiments in an orderly and comprehensive way? We can express it in the following table:
Observation program
Observation element
The first stage (before the experiment)
1, physical properties of reactants (such as color, state, smell, etc. );
2, reaction conditions (such as whether heating, electricity, etc. );
3. Reaction device (what is the reaction device, what are the characteristics of the device, etc.). );
4. Operation sequence (how to assemble the experimental device, how to add drugs in sequence, etc. );
5, others (such as drug dosage, experimental considerations, etc.). ).
The second stage (in the experiment)
Main phenomena in the reaction process (such as discoloration, gas generation, precipitation, luminescence, heat release, etc.). )
The third stage (after the experiment)
1. Is there any new substance generated?
2. Color, state, smell and solubility of new substances;
3, instrument split order
4, instrument layout, etc.
With the deepening of the experiment and the improvement of knowledge level, students are increasingly required to observe the experiment comprehensively and deeply and master the chemical knowledge comprehensively. If you can't observe the experiment comprehensively, it will often lead to various problems because of the one-sidedness of observation, such as the inability to obtain comprehensive knowledge. More seriously, in the specific operation of the experiment, it may lead to failure or danger. For example, when heating solid drugs, the mouth of the test tube inclines downward, resulting in the rupture of the test tube; In the experiment of reducing copper oxide with hydrogen, if we don't follow the order of introducing hydrogen for a period of time before the experiment and removing the alcohol lamp for a period of time after the experiment, it will inevitably lead to the failure and danger (explosion) of the experiment.
Third, coordinate various sensory organs.
The observation of experimental phenomena is often more than just eye observation. In many experiments, you need to use your hands, nose and other senses. For example, in the experiment of sulfur combustion in the first chapter, in addition to observing with eyes, you need to smell (the smell of sulfur dioxide) with your nose and touch (feeling the heating phenomenon by touching the gas container) with your hands. Only in this way can we fully obtain perceptual materials.
In addition, in the process of observing experimental phenomena, we should also overcome the following bad habits: 1, only pay attention to the phenomenon of * * * strong action and ignore other phenomena; 2. Because we can't concentrate highly, we ignore the fleeting phenomenon; 3. Only pay attention to the phenomena in the experimental process, but ignore the observation of the experimental operation sequence and device characteristics; 4. Observe without thinking.
What problems should be paid attention to in the process of unexpectedly selecting village heads? 1. Clear-headed, understand the responsibilities of the village head.
Need the support of the masses.
3. Calm down.
First of all, we must make a plan, which is related to the interests of the villagers in this village.
First, how to lead villagers to increase their income and how to develop characteristic industrial projects with local characteristics (for example, aquaculture, planting, handicrafts, or small farmhouse music, etc.). Do something beneficial to the villagers.
Second, we should set an example, have a sense of responsibility, and never covet small profits and destroy our image among the villagers.
Third, to develop in an all-round way, we must first change the external environment of the village, improve the original chaotic situation, and make things concrete.
Fourth, although village officials are small, there will be many things. People often say that sparrows are small and complete. It is not easy to do one thing well, nor is it easy for the village head. Only by doing things best can you show your influence among the villagers.