General food contamination incident is to eat into the contaminated food at the same time or successive onset of people, although the performance can be different, can not tell whether the poisoning or discomfort do not know how to deal with it can be dialed to the local Poison Control Center to get help, where the experts will be provided free of charge to prevent poisoning and first aid guidance and help, but also provide special antidote drugs and poisonous substances Specialty antidotes and toxicology services are also available. In most cases, it can be dealt with at home under the guidance of the experts of the poison control center by inducing vomiting, taking adsorbent drugs, resting, etc. or with the help of friends and relatives, but in serious cases, the experts will guide you to a professional unit for treatment.
Fingerprint test
Principle: Iodine sublimates into iodine vapor when heated. The iodine vapor dissolves in finger oils and other secretions, and forms a brown fingerprint impression.
Supplies: test tube, rubber stopper, medicine spoon, alcohol lamp, scissors, white paper, iodine.
Steps: 1. Take a piece of clean, smooth white paper, cut it into strips about 4 cm long and no wider than the diameter of the test tube, and press a few fingerprints on the strips with your fingers. 2. 2. Using a medicine spoon, take a grain of iodine about the size of a sesame seed and place it in a test tube. Suspend the strip of paper in the test tube (be careful not to put the fingerprints on the wall of the tube) and put a rubber stopper on it. 3. 3. Slightly heat the test tube with iodine above the flame of an alcohol lamp, stop heating as soon as iodine vapor is produced, and observe the fingerprints on the paper strip.
Some new ways to make hydrogen course
Teaching Materials Institute Liang Yinghao
In recent years, scientists from various countries have developed some new ways to make hydrogen, scientists in China have also experimented with some new ways to make hydrogen, and now part of these new methods are introduced as follows: ceramic reaction with water to make hydrogen scientists at Tokyo Institute of Technology in Japan in the 300 ℃, so that ceramics and water reaction to make hydrogen. and water reaction to produce hydrogen. They are in the argon and nitrogen gas flow, the carbon of nickel ferrite (CNF) heated to 300 ℃, and then with a syringe needle to the CNF on the injection of water, so that the water with the hot CNF contact, on the production of hydrogen. The ferrite can be used repeatedly because the CNF returns to an inactive state after the water decomposes. In each reaction, an average of 2 cubic centimeters to 3 cubic centimeters of hydrogen is produced per gram of CNF. Enzymatic hydrogen production from microorganisms Glucose deoxygenase. Glucose deoxygenase is extracted from Lactobacillus thermophilus at Oak Cen National Laboratory, USA. Lactobacillus thermophilus was first discovered in low-temperature dry-distillation cinders from mines in the United States. Glucose deoxygenase is able to extract hydrogen from glucose with the help of nicotinamide adenine dinucleotide phosphate (NADP). In the process of making hydrogen, NADP strips one hydrogen atom from glucose, turning the remaining material into a solution of hydrogen atoms. Hydrogen Production from Bacteria Many primitive lower organisms can also give off hydrogen during their metabolism. For example, many bacteria can release hydrogen under certain conditions. In Japan, a bacterium called "Trichoderma erythropolis" has been found to be an excellent hydrogen producer. In a glass vessel, with starch as raw material, mixed with some other nutrients made of culture solution, you can cultivate this bacteria. For every 5 millimeters of starch nutrient solution consumed, 25 milliliters of hydrogen can be produced.
Producing hydrogen from green algae
Scientists have found a new way to make green algae produce hydrogen on demand. Scientists at the University of California at Berkeley say that green algae, which are among the oldest plants known to man, have developed through evolution the ability to live in two very different environments. When green algae live in normal air and sunlight, it photosynthesizes like any other plant. Photosynthesis uses sunlight, water and carbon dioxide to produce oxygen and the chemicals plants need to sustain life. However, when the green algae lacks sulfur, a key nutrient, and is placed in an anaerobic environment, it returns to another way of living in order to survive, in this case producing hydrogen. Scientists say that a one-liter culture of green algae can produce 3 milliliters of hydrogen per hour, but the researchers believe that the green algae could be at least 100 times more efficient at producing hydrogen.
Artificial snowfall
Since ancient times, the heavens have been known to snow when they are happy and not when they are not. Is there any way to make God snow according to the needs of mankind, let it snow on snow? There is a way, this is artificial snowfall. Water vapor in the sky to become rain and snow down must have two conditions, one is there must be a certain degree of water vapor saturation (mainly related to temperature), the other is there must be a condensation nucleus. Therefore, artificial snowfall must first have clouds in the sky, and without clouds, it is as difficult as a woman without rice to cook, so it cannot snow. The cloud that can make snow, Zou 0 ℃ below the "cold cloud". In cold clouds, there are small water droplets condensed by water vapor and small snow crystals condensed by water vapor. However, they are very small and light, if there are no conditions for further growth, they can only be suspended in the air like smoke and dust, and it is difficult to fall down. We can often see in the winter, a large chunk of clouds, just do not see the snowflakes floating down, because the composition of these clouds of snow crystals is too small to overcome the buoyancy of the air, precipitation capacity is very poor. If the clouds in the spray some particulate matter to promote the snow crystal quickly grow to be able to overcome the buoyancy of the air to land down, which is the work of artificial snowfall.
What kind of material can be sprayed to promote the rapid growth of snow crystals? In the early days, people showed their ingenuity to use many interesting methods. These methods are: arson on the ground burning, put a lot of smoke and dust into the sky; attack the clouds with cannons; the use of kites flying high in the clouds, and then in the kite on the electricity, flash discharge flowers; take the airplane into the clouds spray liquid water droplets and dust particles. However, the results of all these methods were very unsatisfactory. It was not until 1946 that it was discovered that putting very small particles of dry ice into cold clouds could form millions of snow crystals. On January 3 of that year, someone in an airplane sprinkled crushed dry ice particles onto the top of a high cumulus cloud with a temperature of -20 degrees Celsius, and snow was found to fall from this cloud.
The dry ice described here is not ice frozen by water, but a solid state of carbon dioxide, much like compacted snow in winter. The temperature of dry ice is very low, below -78.5℃. The dry ice crystals are sprayed in the cold cloud like a goddess scattering flowers, and each carbon dioxide crystal becomes a cold center, which prompts the water vapor, small water droplets and small snow crystals in the cold cloud to gather around it very quickly, and condense into larger snowflakes to land down. How do you disperse these condensation nuclei into the clouds? Most modern people use artillery, where chemicals are loaded into cannonballs and fired into the clouds from the cannon. However, this method of spraying is not uniform, and there is a large waste of medicines, which increases the cost of artificial snowfall. Others put them in clay rockets and let the rockets fly into the clouds to spray them.
Pesticide contamination of food poisoning
People eating pesticide residues in the food will appear poisoning symptoms and the severity of the symptoms depends on the type of pesticide and the amount of pesticides into the body to determine. Not all pesticide contamination of food poisoning, if the pollution is light, people eat into the amount of small can not appear obvious symptoms, but often have a headache, dizziness, weakness, nausea, poor mental performance, when the pesticide contamination is heavy, the amount of pesticides into the body more pesticides can be obvious discomfort, such as fatigue, vomiting, diarrhea, muscle tremors, panic and other manifestations. In severe cases, generalized convulsions, coma, heart failure and other manifestations can occur, which can cause death. The performance of poisoning also depends on the type of poison, residual pesticide poisoning caused by the main varieties of pesticides are: methamidophos, parathion (1605), methyl parathion, methomyl, oxalic acid, furadan and so on.
Pollution of human odor
The metabolites of the human body **** there are more than 400 kinds of substances. There are 149 species excreted by breath, 229 species in urine, 196 species in feces, 151 species in sweat, 271 species excreted through the skin, and so on. Carbon dioxide, carbon monoxide, hydrocarbons, acetone, benzene, methane, aldehydes, etc., are found in excreta. In the case of air circulation, the pollutants will spread rapidly and feel no smell. If the room, the cabin of the car and boat people, poor ventilation, it will be "human odor" full.
How to remove pesticide residues on vegetables
Family to remove pesticide residues on vegetables and fruits on the following simple methods:
Soak and wash method: vegetables contaminated with pesticide varieties of organophosphorus insecticides, organophosphorus insecticides are difficult to dissolve in water, this method only removes some of the contaminated pesticides. But the water washing is to remove other dirt on vegetables and fruits and remove residual pesticide base method. Mainly used for leafy vegetables, such as spinach, broccoli, leek flowers, lettuce, cabbage and so on. Generally first rinse off the surface dirt with water, and then soak in water, soak not less than 10 minutes. Fruit and vegetable detergent can increase the dissolution of pesticides, so soak can add a small amount of fruit and vegetable detergent. Rinse with running water 2-3 times after soaking.
Peeling method: vegetables and fruits surface pesticide amount is relatively more, so peeling is a better way to remove residual pesticides. Can be used for apples, pears, kiwis, cucumbers, carrots, winter squash, pumpkins, zucchini, eggplants, radishes and so on. When handling, it is necessary to prevent the mixing of peeled vegetables and fruits and re-contamination.
Storage method: pesticides in the environment over time can slowly decompose into harmless substances. So for easy preservation of fruits and vegetables can be stored for a certain period of time, less pesticide residues. Applicable to apples, kiwis, winter melon and other non-perishable species. Usually stored for more than 15 days. It is also recommended not to consume freshly picked unpeeled fruits immediately.
Heating method: carbamate insecticides decompose faster as the temperature rises. So for some other methods difficult to deal with vegetables and fruits can be heated to remove some of the pesticides. Commonly used in celery, spinach, cabbage, cabbage, peppers, cauliflower, beans and so on. First wash the surface dirt with water, put it into boiling water for 2-5 minutes and fish it out, then rinse it with water 1-2 times.
What are minerals
Mankind can't live without minerals in all aspects of clothing, food, housing and transportation. For example, the various materials needed to build a house, the gemstones you wear with you, and the salt you eat every day all come from minerals. What are minerals?
A substance can only be called a mineral if it has the following conditions:
1) Minerals are natural compounds or monomers formed by various geological processes, such as volcanism. They can be solid (e.g., quartz, diamond), liquid (e.g., natural mercury), gaseous (e.g., water vapor from volcanic jets), or colloidal (e.g., opal).
2) Minerals have a certain chemical composition. Such as diamond composition for the single carbon (C), quartz for the silicon dioxide (SiO2), but the natural mineral composition is not completely pure, often contains a small number of impurities.
3) Minerals also have a certain crystal structure, their atoms are regularly arranged. For example, the crystal arrangement of quartz is silicon ions on each of the four corners of the top with an oxygen ion to form tetrahedrons, these tetrahedrons are connected to each other to the corner of the top in three-dimensional space to form a shelf structure.
If there is sufficient space for growth, solid minerals have a certain form. For example, diamond forms octahedral, quartz often forms columns, often with transverse lines on the surface of the columns. When there is no growth space, their inherent form can not be expressed.
4) Minerals have more stable physical properties. For example, galena is steel gray, very bright metallic luster, opaque, and its powder (streak) is black and softer (can be scratched by a knife).
Graphite powder "flying" out of the diamond
The mention of diamonds, people will be associated with brilliant, sparkling scenarios, it with the owner's activities and radiant. But because of its high price, most people can only be deterred. Nonetheless, people still yearn for diamonds. Do you know what a diamond is? Its chemical composition is carbon (C), natural diamonds are made of diamonds that have been faceted before they can be called "diamonds". Natural diamonds are very rare, the world's weight greater than 1,000 carats (1 gram = 5 carats) of diamonds only 2, 400 carats of diamonds more than only a number of grains, our country has so far found the largest diamond weighing 158.786 carats, which is the "Changling Diamond". Rarity is precious, just because the natural diamond can be used as "diamond" is very rare, people want to "artificial" diamond to replace it, which naturally thought of the diamond's "twin" brother - graphite. brother - graphite.
The chemical composition of diamond and graphite is carbon (C), which is called "isotope". From this kind of name can know that they have the same "quality", but "shape" or "sex" is different, and there is a world of difference, diamond is currently the hardest material, while graphite is the softest The diamond is by far the hardest substance, while graphite is one of the softest.
The difference in hardness between graphite and diamond is so great that people still want to use synthetic methods to obtain diamond, because graphite (carbon) is abundant in nature. But it is not so easy to make the carbon in graphite into carbon arranged like diamond. Graphite at 50,000-60,000 atmospheres ((5-6) × 103MPa) and 1000 to 2000 degrees Celsius high temperature, and then use metal iron, cobalt, nickel and so on as a catalyst, can make graphite into diamond.
At present, more than ten countries in the world (including China) have synthesized diamond. But this kind of diamond because the particle is very fine, the main use is to do abrasive, used for cutting and geological, oil drilling with drill bits. Currently, 80% of the world's diamond consumption of synthetic diamond is mainly used in industry, and its output is also far more than that of natural diamond.
The initial synthesized diamond particles are black, 0.5mm in size, weighing about 0.1 carat (diamond used for gemstones generally cannot be less than 0.1 carat minimum). Now China's development of large particles of diamond up to 3mm or more, the United States, Japan and other countries have made more than 6.1 carat diamond. We say that diamond has been "flying" from graphite, gem-level artificial diamond will also be supplied to the market in the near future.
"World Water Day"
March 22, 1999 was the seventh "World Water Day" and the first day of the new "China Water Week". The Agriculture Committee of the National People's Congress (NPC), the Environment and Resources Committee and the Ministry of Water Resources jointly held a commemorative symposium in Beijing to call on the whole society to pay more attention to the problem of China's water resources. Water is an irreplaceable resource on which human beings depend for their survival and development, and is increasingly becoming a constraint on the sustainable development of the global economy and society. In order to arouse public attention to water issues around the world, the forty-seventh session of the United Nations General Assembly in 1993 will be March 22 each year as the "World Water Day".
The theme of this year's World Water Day is "Everyone Lives Downstream", which aims to remind people that when developing and utilizing water resources, the interests of downstream residents should be taken into account. As China drew more and more water from the Yellow River to meet the needs of its growing economy, the river began to struggle to meet its water supply needs more than 25 years ago, and in 1972 a dramatic drop in its water level caused it to dry up before reaching the sea for the first time in China's long history. That year the Yellow River was cut off for 15 days and intermittently for the next 10 years. since 1985, the Yellow River has been cut off year after year for longer and longer periods of time. in 1996, the Yellow River was cut off for 133 days. in 1997, due to a drought, the Yellow River was cut off for 226 days, and for a long time that year, the river failed to reach the province of Shandong, the last province that the Yellow River flows through out to sea.
In addition, increasing water pollution can also cause water shortages. Pollution occurs when harmful substances in the water exceed the self-purification capacity of the water body. These harmful substances include pesticides, heavy metals and their compounds and other toxic substances, organic and inorganic chemical substances, disease-causing microorganisms, oil substances, plant nutrients, a variety of waste and radioactive substances. The sources of water pollution are mainly untreated industrial wastewater, domestic wastewater and hospital sewage.
Water pollution is extremely harmful to human health. Pathogenic microorganisms and viruses in sewage can cause the spread of infectious diseases. Toxic substances in the water can make human and animal poisoning, some highly toxic substances can be within a few minutes to make the water creatures and drinking water death, this situation is still relatively easy to find. The most dangerous is the pollution of mercury, cadmium, chromium, aluminum and other metal compounds, they enter the human body caused by chronic poisoning, once found can not be curbed. According to a survey by the World Health Organization (WHO), 70% of the world's population cannot drink safe and hygienic drinking water. Now the world every year 15 million children under the age of 5 die, the cause of death is mostly related to drinking water. According to the United Nations, 25,000 people in the world get sick every day due to drinking polluted water or die due to lack of water.
Discovery of acid rain
The modern industrial revolution began with the steam engine, which burned coal in boilers to produce steam to power machines; and then coal-fired power plants proliferated, burning ever-increasing amounts of coal. Unfortunately, coal contains impurity sulfur, about one percent, in the combustion will emit acidic gas SO2; combustion of high temperature can still prompt combustion air part of the chemical change, oxygen and nitrogen synthesis, but also emit acidic gas NOx. they are in the air for the rain and snow wash, dissolved, rain became acid rain; these acidic gases become rain in the impurity of sulfate, nitrate, and ammonium ions. 1872 England Scientist Smith analyzed the Renton City, rainwater composition, found that it is acidic, and rural rain containing ammonium carbonate, acidic; suburban rain containing ammonium sulfate, slightly acidic; urban rain containing sulfuric acid or acidic sulfate, acidic. So Smith first introduced the term "acid rain" in his book "Air and Rainfall: The Beginnings of Chemical Climatology"
Hygienic Drinking Water and Chemistry
Water that has been boiled for a long time on a stove, and water that has been boiled repeatedly in an electric water heater. This kind of water is boiled for too long, and the water contains mostly non-playing substances, such as calcium, magnesium and other heavy metal components and nitrites. Drinking this water for a long time, will interfere with the gastrointestinal function, temporary diarrhea, bloating; toxic nitrites, but also cause hypoxia, severe coma and convulsions, and even death
People drink tap water, are chlorinated disinfection and sterilization processed. Chlorine treated water can be separated from 13 harmful substances, including halogenated hydrocarbons, chloroform also has a carcinogenic, teratogenic effect. When the water temperature reaches 90 ℃, halogenated hydrocarbon content from the original 53 micrograms per kilogram rose to 177 micrograms, more than 2 times the national drinking water health standards. Experts pointed out that drinking unboiled water, the possibility of bladder cancer, rectal cancer increased by 21% -38%. When the water temperature reaches 100 ℃, these two harmful substances will evaporate with the vapor and greatly reduced, such as continue to boil for 3 minutes, it is safe to drink.
Acid rain
Simply put, acid rain is acidic rain.
What is acid? Pure water is neutral and has no flavor; lemonade, orange juice has a sour taste, vinegar has a larger sour taste, they are weak acids; baking soda water has a slightly astringent alkaline, while caustic soda water is astringent, alkaline taste is larger, they are alkaline. Scientists found that the size of the acidic flavor and hydrogen ion concentration in aqueous solution; and alkaline flavor and hydroxyl ion concentration in aqueous solution; and then established an indicator: the negative of the logarithm of the concentration of hydrogen ions, called the pH value. Thus, pure water has a pH of 7; the more acidic it is, the lower the pH; the more alkaline it is, the higher the pH. Uncontaminated rain and snow is neutral, pH value of nearly 7; when it is saturated with carbon dioxide in the atmosphere, slightly acidic, pH value of 5.65. by the presence of acidic gases in the atmosphere pollution, pH value of less than 5.65 of the rain is called acid rain; pH value of less than 5.65 of the snow is called acid snow; in the high altitude or mountains (such as Emei Mountain) on the diffuse fog, pH value of less than 5.65 when called acid fog.
The modern industrial revolution, starting from the steam engine, boilers burning coal, produce steam, promote the machine; and then thermal power plants starring, the number of coal-fired increasing dramatically. Unfortunately, coal contains impurity sulfur, about one percent, in the combustion will emit acidic gas SO2; combustion of high temperature can still prompt combustion air part of the chemical change, oxygen and nitrogen synthesis, but also emit acidic gas NOx. they are in the air for the rain and snow wash, dissolve, rain became acid rain; these acidic gases become rain impurities sulfate, nitrate and ammonium ions. 1872 British Scientist Smith analyzed the composition of the rain in the city of Renton, found that it is acidic, and rural rain containing ammonium carbonate, acidity is not large; suburban rain containing ammonium sulfate, slightly acidic; urban rain containing sulfuric acid or acidic sulfate, acidic.
A drop of life in the water
A drop of water, crystal clear, the naked eye looks, there is nothing inside, put it under the microscope, hey, it is really unique! Behold, there are like the flash of the "strap", like a long, thin "big pin", flat "disk", and even like a delicate "iron anchor! "...... It's a sight for sore eyes. What is this? This is plankton. Plankton body is short, most only a few thousandths of a centimeter to a few centimeters, the naked eye is invisible. Their swimming skills are not high, some will not swim, just go with the flow. But don't look down on these small people, they can reproduce very well! If in the right environment, an individual plankton, let it develop, a few days work can fill the entire body of water! Even by a variety of natural conditions, the number of its still considerable very much, they can be called the water of the "big family".
Without sunlight, phytoplankton cannot survive, so they mostly live in the sunny surface of the water.
Although the individual phytoplankton is so small and insignificant, it is the original food producer in the water, without them, I'm afraid the big life in the water can not survive. Plankton is the main bait for fish, but also part of the human food source. China's coastal working people have long used the tide to catch larger plankton such as krill, prawns, etc., but due to various conditions, can not be captured in large quantities. In the future, through further research and practice, better grasp of the distribution of zooplankton, and constantly improve the fishing technology, the zooplankton as a direct source of food for human beings is very promising.
Things are divided into two. Plankton is of great economic significance, but not all plankton are beneficial. Some plankton are harmful to fish. Like blue-green algae, ichthyobacteria, etc., in the hot weather, a large number of breeding, so that the water quality is bad, will seriously affect the normal life of fish and other aquatic organisms, and even make the fish mass death. 1946-1947, the Gulf of Mexico on the reproduction of many toxic phytoplankton, resulting in the death of a large number of fish. The sea water emitted a foul odor, seriously hindering people's breathing. This phenomenon has occurred to varying degrees along the coast of our country. 1972 autumn, the East China Sea surface had a large number of floating a yellowish-brown dirt, and with a foul smell, fishermen called it "stinking water", which is caused by the massive reproduction of chlamydospermum.
The use of plankton favorable side, to prevent the harmful side, and turn harm into benefit, is to improve the productivity of the water body is an important measure.
Carbon monoxide
CO is inhaled through the respiratory tract. Inhaled CO enters the bloodstream through the alveoli and immediately combines with hemoglobin to form carboxyhemoglobin, leading to hypoxemia and causing tissue hypoxia. The central nervous system is the most sensitive to hypoxia, so it is the first to be affected. Common manifestations include mental disorders, aphasia and blindness. It is necessary to move the patient away from the scene of poisoning to a ventilated place, loosen the collar, pay attention to keep warm, and observe the consciousness state closely. Timely and effective oxygenation is the most important treatment principle for acute CO poisoning. Apply hyperbaric oxygen therapy to rapidly correct tissue hypoxia.