I have seen beautiful winter jasmine and red leaves in Xiangshan, but I have never seen such flowers as roses. Rose Zhen Hong, red as the blood of a soldier; Roses are so beautiful and intoxicating; Roses are really fragrant, and the fragrance attracts a few bees; I watched quietly, watching the delicate rose like a fairy, and I was intoxicated by it.
I have seen the magnificent sea and admired the artificial lake as a mirror, but I have never seen water like Huangshan. The water in Huangshan Mountain is really cold. My face is very cold, which is more comfortable than taking a cold bath in summer. The water in Huangshan Mountain is very clear, and you can see small fish playing in the water. The water in Huangshan Mountain is really urgent. I was so anxious to shoot on the rock that the water splashed. "Ah! Son, it's time to go up the mountain! " It just occurred to me that I should go up the mountain.
I have seen the fragrant cordate telosma and the graceful Chinese rose, but I prefer the strong and unyielding plum blossom, which is really white! Like snowflakes in winter; How beautiful these plum blossoms are! Like a dancing swan; Plum blossoms are so strong! Like a brave warrior, the indomitable spirit of Meihua has always inspired me to move forward.
2. Nanotechnology Nanometer is a unit of length, originally called nanometer, which is 10-9 meters (65438+ one billionth of a meter), that is, 10-6 mm (65438+ one millionth of a millimeter).
Nanoscience and technology, sometimes called nanotechnology, is to study the properties and applications of materials with structural dimensions ranging from 1 to 100 nm. Nano-effect means that nano-materials have strange or abnormal physical and chemical properties that traditional materials do not have. For example, copper, which was originally conductive, will only conduct electricity at a certain nano-scale limit, while silicon dioxide and crystals, which were originally insulated, will only begin to conduct electricity at a certain nano-scale limit.
This is because nano-materials have the characteristics of small particle size, large specific surface area, high surface energy and large proportion of surface atoms, and their three unique effects: surface effect, small size effect and macro quantum tunneling effect. For solid powder or fiber, when its one-dimensional size is less than 100nm, it can be called nano-material. For an ideal spherical particle, when the specific surface area is greater than 60m2/g, its diameter will be less than 100nm, which is nano-sized.
It is very important to study the specific surface area of nano-materials. Only when the specific surface area of nano-materials is detected by bet method can the results be true and reliable. At present, many instruments in China can only do direct comparison, and now they have been eliminated in China. At present, the multi-point bet method is used to measure the specific surface area at home and abroad, and the standards for measuring the specific surface area at home and abroad are based on the bet method. Please refer to China's national standard (GB/T19587-2004)-the method of measuring the specific surface area of solid matter by gas adsorption bet principle.
Detection of specific surface area is actually a time-consuming work. Due to the different adsorption capacity of samples, the testing of some samples may take a whole day. If the test process is not fully automated, the tester can't leave all the time. He should be highly concentrated, observe the dashboard and control the knob. A little carelessness will lead to the failure of the testing process and waste a lot of valuable time for testers. Only the truly automatic intelligent specific surface area tester products meet the international standards of the testing instrument industry. The international similar products are fully automatic, and the manually operated instruments have long been eliminated abroad.
The real automatic intelligent specific surface area analyzer liberates testers from repeated mechanical operations, greatly reduces their work intensity, is simple in training and improves work efficiency. The real automatic intelligent specific surface area tester greatly reduces the error caused by human operation and improves the testing accuracy.
F-sorb 2400 specific surface area tester is an instrument that can really realize the bet method (using direct comparison method). More importantly, f-sorb 2400 specific surface area tester is the only fully automatic and intelligent specific surface area testing equipment in China. The test results are highly consistent with international standards and have good stability. At the same time, human error is reduced and the accuracy of test results is improved. Edit the meaning of nanotechnology in this paragraph-1. The so-called nanotechnology refers to a brand-new technology to study the motion laws and characteristics of electrons, atoms and molecules in the scale of 0. 1~ 100 nanometers.
In the process of studying the composition of matter, scientists found that several or dozens of countable atoms or molecules isolated on the nanometer scale show many new characteristics, and the technology of manufacturing equipment with specific functions by using these characteristics is called nanotechnology. The main differences between nanotechnology and microelectronics are: nanotechnology studies the realization of specific functions of equipment by controlling single atoms and molecules, and it works by using the fluctuation of electrons; Microelectronics technology mainly realizes its function by controlling the population of electrons and works by using the particle nature of electrons.
The purpose of people's research and development of nanotechnology is to achieve effective control of the entire micro-world. Nanotechnology is a comprehensive subject with strong cross-cutting, and its research content involves the vast field of modern science and technology.
From 65438 to 0993, the International Steering Committee of Nanotechnology divided nanotechnology into six sub-disciplines: nanoelectronics, nanophysics, nanochemistry, nanobiology, nanofabrication and nanometrology. Among them, nano-physics and nano-chemistry are the theoretical basis of nano-technology, and nano-electronics is the most important content of nano-technology.
Edit the meaning of nanotechnology in this paragraph -2 nanotechnology nanotechnology is actually a technology that uses a single atom and molecule to make substances. Judging from the research so far, there are three concepts about nanotechnology.
The first is 1986, the molecular nanotechnology put forward by American scientist Dr. drexler in his book The Machine of Creation. According to this concept, we can make the machine of combining molecules practical, so that we can combine various molecules at will and make any molecular structure.
The nanotechnology of this concept has not made significant progress. The second concept defines nanotechnology as the limit of micromachining technology.
That is, the technology of artificially forming nano-scale structures through nano-precision "processing". This nano-scale processing technology also makes the miniaturization of semiconductors reach the limit.
Even if the existing technology continues to develop, it will eventually reach its limit in theory. This is because if the line width of the circuit is reduced, the insulation film forming the circuit will be extremely thin, which will destroy the insulation effect.
In addition, there are problems such as fever and trembling. In order to solve these problems, researchers are studying new nanotechnology.
The third concept is put forward from a biological point of view. It turns out that organisms have nano-scale structures in cells and biomembranes.
The so-called nanotechnology refers to a brand-new technology to study the motion laws and characteristics of electrons, atoms and molecules in the scale of 0. 1~ 100 nanometers. In the process of studying the composition of matter, scientists found that several or dozens of countable atoms or molecules isolated on the nanometer scale show many new characteristics, and the technology of manufacturing equipment with specific functions by using these characteristics is called nanotechnology.
Nanotechnology is a comprehensive subject with strong cross-cutting, and its research content involves the vast field of modern science and technology. Nanotechnology now includes nano-biology, nano-electronics, nano-materials, nano-mechanics, nano-chemistry and other disciplines.
From micro-technology including microelectronics to nano-technology, human beings are becoming more and more microscopic.
3. Composition on Nanotechnology (580) Nanotechnology, the latest technology of mankind! Nanotechnology, a brand-new term, appears in front of human beings, and people can use it in medicine and science.
Wait, it has made great contributions to mankind, and people can be proud of discovering it! Give a real example: spunlace, a local dialect, is an animal that can drink human blood very well, which makes people very scared! It was my sixth grade summer vacation. My brother and I went fishing in the river. My brother said he was very hot and wanted to go down and take a bath. I said, "well, be careful, find a shallow place to swim, and never find a deep place!" " "I know!" What he said.
After a while, I caught four fish and suddenly heard my brother calling for help! I guess he must have fallen into deep water. I didn't expect him to shout with his legs in shallow water. I thought he was playing me, only to hear him say, "I was stung by brother sting, and now it's on my leg." Ah.
! "I look at his legs, right? ! A bulging thing wriggled on my brother's leg, and I remembered that if I didn't get it out in time, my brother's blood would definitely be sucked dry by it! I hit my brother's leg hard with my hand to get it out, but the more I hit it, the more I went in. It's over. I fell on the grass. Suddenly, I remembered that there was a clinic nearby, so I picked up my brother and ran to the clinic at high speed. When I got there, the doctor said that this situation was very difficult, so I had to try to use nano-robots to force in and spit out water thorns.
After a while, the spunlace was finally expelled by the nano-robot, and the adventure was over. Through this incident, I learned two things: ① Never go to the river bend, dam pond and other places without an adult.
② Nanotechnology is so useful! Nanotechnology, the latest technology of mankind.
4. Ask for an article about nanotechnology. nanotechnology
Nanometer is a unit of length, originally called nanometer, which is -9 power meter (65438+ billionth meter) of 10. Nanoscience and technology, sometimes called nanotechnology, is to study the properties and applications of materials with structural dimensions ranging from 1 to 100 nm. As far as concrete matter is concerned, people often describe things as thin as hair as. In fact, human hair is generally 20-50 microns in diameter, not thin. A single bacterium is invisible to the naked eye, and the diameter measured by a microscope is 5 microns, which is not too fine. At the extreme, 1 nm is roughly equivalent to the diameter of 4 atoms. Nanotechnology includes the following four main aspects:
1. Nanomaterials: When a substance reaches the nanometer scale, which is about 1- 100 nanometer, the properties of the substance will suddenly change and special properties will appear. This kind of material with special properties different from the original atoms, molecules and macroscopic substances is called nano-material. If only nano-scale materials have no special properties, they cannot be called nano-materials. In the past, people only paid attention to atoms, molecules or cosmic space, and often ignored this intermediate field, which actually exists in nature in large quantities, but did not realize the performance of this scale range before. Japanese scientists were the first to truly recognize its characteristics and introduce the concept of nano. In 1970s, they prepared ultramicro ions by evaporation, and found that a kind of conductive copper-silver conductor lost its original properties after being made into nano-scale, neither conducting electricity nor conducting heat. The same is true of magnetic materials, such as iron-cobalt alloys. If the size is about 20-30 nanometers, the magnetic domain will become a single magnetic domain, and its magnetism will be 1000 times higher than the original. In the mid-1980s, people formally named this kind of materials as nanomaterials.
Nano-dynamics, mainly micro-machinery and micro-motor, or micro-electromechanical system, is applied to micro-sensors and actuators of belt-driven machinery, optical fiber communication systems, special electronic equipment, medical and diagnostic instruments, etc. It adopts a new technology similar to the design and manufacture of integrated appliances. The feature is that the parts are very small, the etching depth often needs tens to hundreds of microns, and the width error is very small. This process can also be used to manufacture three-phase motors, ultra-high-speed centrifuges or gyroscopes. In the research, micro-deformation and micro-friction at quasi-atomic scale should be detected accordingly. Although they have not really entered the nanometer scale at present, they have great potential scientific and economic value.
13. nano-biology and nano-pharmacology, such as fixing dna particles on mica surface with nano-sized colloidal gold, doing experiments on the interaction between biomolecules with interdigital electrodes on the surface of silica, double-layer planar biofilm of phospholipids and fatty acids, and fine structure of dna. With nanotechnology, you can also put parts or components into cells through self-assembly to form new materials. About half of the new drugs, even the fine powder of micron particles, are insoluble in water; However, if the particles are nanoscale (i.e. ultrafine particles), they can be dissolved in water.
Nano-electronics includes nano-electronic devices based on quantum effect, optical/electrical characteristics of nanostructures, characterization of nano-electronic materials, atomic manipulation and atomic assembly. The current trend of electronic technology requires devices and systems to be smaller, faster, colder and smaller, which means faster response. Being colder means that a single device consumes less power. But smaller is not infinite. Nanotechnology is the last frontier of builders, and its influence will be enormous.
1in April, 1998, Dr. Neil Ryan, the president's science and technology adviser, commented that if someone asked me which science and engineering field would have a breakthrough impact on the future, I would say that the start-up plan was to establish a nanotechnology challenge organization to fund interdisciplinary research and education teams, including long-term goal centers and networks. Some potential breakthroughs include:
The data of the entire Library of Congress is compressed into a device the size of a cube of sugar. This is achieved by increasing the storage capacity per unit surface by 65,438+0,000 times and expanding the storage capacity of large storage electronic equipment to the level of several megabytes. Materials and products are from small to large, that is, made up of an atom and a molecule. This method can save raw materials and reduce pollution. Production strength is 10 times that of steel, and the weight is only a small part of steel, so as to make various lighter and more fuel-efficient land, water and air vehicles. Through tiny transistors and memory chips, the speed and efficiency of computers have increased by millions of times, which has made today's Pentium? The processor is already slow. Using genes and drugs to deliver nano-scale mri contrast agent to find cancer cells or locate human tissues and organs, so as to remove the smallest pollutants in water and air, thus obtaining a cleaner environment and drinkable water. The energy efficiency of solar cells has been tripled.
5. Who has a composition about nanotechnology? In the past few years, we have witnessed the rapid development of science and technology in our great motherland, which makes me feel extremely proud to be a China native. I remember a long time ago, there was almost only one purpose of mobile phones, that is, making phone calls. But a few years ago, mobile phones have changed a lot, not only in appearance, but also in many uses. They can be used to take photos, have meetings, surf the Internet, send short messages and so on, which makes our life more convenient and makes me more aware of the power of technology. However, I am just a fledgling student. But I want to think about technology and the future from the perspective of a student.
From the dream of genetic engineering to the promise of nanotechnology to ensure that you don't have to wash clothes; From the warmth of artificial intelligence "give you a lovely robot dog" to the wonder of transgenic technology "let mice grow human ears", new technologies are constantly being born, and every discovery of new technologies will make people ecstatic, because these new technologies are gradually improving our lives and let us know ourselves better. In the near future, China completed the whole genome sequencing of SARS virus for the first time, which is recognized as the most harmful disease in the world at present. But why can't other countries finish it first, while our country has just finished it? Quite simply, this shows that our country is not behind others, nor worse than others. Looking back on our motherland's past, from a country that has just started reform and opening up to a big country with a leading scientific and technological level, our motherland has experienced many ups and downs and experienced many difficulties and bumps, but our motherland has survived because we firmly believe that science and technology can not only change our destiny, but also change our future.
For our generation, the general feeling given to the society is a strong sense of competition and sufficient motivation to learn. Popular science knowledge is the focus of our attention, Einstein, Hawking and Bill Gates are the stars in our minds, and computer science, modern physics and chemical kinetics are influencing us all the time. We have understood the importance and universality of science and technology.
Although the prospect of technology creating a new life is fascinating and fascinating. But in the final analysis, it depends on the concerted efforts of all of you, Qi Xin. As the backbone of the future construction of the motherland, the burden on our generation of young people is really not light, and new opportunities are always accompanied by risks and challenges. However, we will not give up easily. We swear to our predecessors with our youth that we will never live up to their hopes.
Looking back at the course of civilization, it is the light of science and technology that sweeps away the darkness of ignorance in human history, and it is the fire of science that ignites the burning hope in human hearts; Science and technology support civilization, science and technology create the future, and the future is in our hands. Let's become explorers of knowledge, let's roam on unknown roads, and let's use our creativity to make the world we live in a better place.