[rumor]

　　◎ Our reporter Chen Xi

　　In October, "all technology and hard work" became the hottest "stalk". The emergence of this hot spot has aroused people’s attention to food safety, and related rumors have also been widely spread, such as "sugar substitutes can be eaten openly" and "only zero addition is a good soy sauce" … … Rumors about the COVID-19 epidemic still appear from time to time, such as "scanning the code when going out in public places can avoid becoming a secret contact". In addition, the previous drought in some parts of China made the rumor that "precipitation can be artificially increased as long as there are clouds" spread widely.

　　Today, the reporter of Science and Technology Daily will take stock of the rumors that appeared in October one by one to help you clear the fog and find the truth.

　　Can sugar substitutes be eaten open?

　　Truth: Eating a lot of sugar substitutes also poses health risks.

　　With the approach of winter, people’s time for outdoor sports gradually decreases. Many people began to worry about insufficient calorie consumption, so they paid special attention to controlling calorie intake. Sugar substitute drinks and snacks marked "Zero Sugar" and "Zero Card" seem to contain no calories. Some people think that sugar substitute is healthy, so they don’t have to bear the "sweet burden" and can eat it openly. So, is this really the case?

　　"This view is wrong. Sugar substitutes should also be eaten reasonably, and there are also health risks when ingested in large quantities." Zheng Yunliang, director of Tianjin Institute of Modern Health Technology, said.

　　According to the data, sugar substitute refers to alternative sweeteners, which belong to food additives, and there are three main categories — — Natural sweeteners, sugar alcohols and artificial sweeteners. At present, most sugar substitutes on the market use artificial sweeteners, such as aspartame. This kind of sweetener does not exist in nature, but is synthesized by chemistry.

　　"From the perspective of energy production, sugar substitutes can be divided into nutritional and non-nutritional types. Almost all the decomposition products of non-nutritive sugar substitutes in human body do not contain glucose and do not directly participate in insulin secretion. Therefore, only in theory, non-nutritive sugar substitutes will not cause an increase in blood sugar. " Zheng Yunliang said.

　　However, this does not mean that we can eat sugar substitutes openly.

　　"The sweetness of sugar substitutes can stimulate appetite, and excessive intake may cause diarrhea, which may also increase the burden on the kidneys." Zheng Yunliang further said that with the progress of science and the deepening of research, most scientific research results show that artificial sweeteners may have pathogenic risks.

　　For example, on September 7, 2022, the British Medical Journal published a large-scale research result from France. This study shows that using artificial sweeteners instead of sugar in food or drink is not beneficial to the cardiovascular and cerebrovascular health of the whole population. Cell magazine also published a related study, which found that the intake of artificial sweeteners was related to the changes of intestinal microbiota and the increase of blood sugar.

　　Therefore, Zheng Yunliang suggested that consumers should try to choose foods containing natural sweeteners when choosing sugar substitutes, such as erythritol, stevioside, momordica grosvenori glycoside, sweet tea glycoside and so on.

　　"It is safe to eat food or drinks instead of sugar occasionally, so you don’t have to be overly nervous. The public should scientifically understand and eat sugar substitutes and improve their health through scientific and reasonable diet and exercise. " Zheng Yunliang said.

　　Can you avoid becoming a secret connector by scanning the code when you go out in public places?

　　Truth: Repeated code scanning will be considered as entering the place many times.

　　As a normal prevention and control measure of epidemic situation in COVID-19, scanning code before entering public places has been integrated into people’s daily life. However, a "special reminder" appeared in the WeChat circle of friends a few days ago: after scanning the code into a public place, scan the code again when leaving, and big data will "think" that you have gone out; If an infected person enters the site again, big data can "prove" that you and the infected person do not overlap in contact time, and you can avoid becoming close contacts.

　　In this regard, relevant departments in Shanghai, Shandong, Sichuan, Zhejiang, Fujian, Inner Mongolia, Liaoning and other places have all rumored. Experts from Dongying Big Data Center said that "place code" is a special two-dimensional code given to a place, which is used to identify the location, name and other information of the place and plays an important role in epidemic prevention and control in COVID-19. When someone scans the "place code", it can only show that they have been to the place. Using big data means can’t distinguish whether the person is in the "entry" or "departure" state.

　　In addition, relevant experts said that scanning the code twice may be considered as entering the place twice, which will not achieve the effect mentioned in the rumor, but will increase the workload of the flow control personnel and indirectly affect the epidemic prevention and control work. Experts reminded that the public only need to scan the code when entering the place, and there is no need to scan the code after going out. If the relevant staff find that the risk of infection of the code scanner is high, they will inform the code scanner in time and take prompt measures to avoid the spread of the virus.

　　Only zero addition is good soy sauce?

　　Truth: The quality of soy sauce depends on many factors.

　　Not long ago, the "additive" storm of a brand of soy sauce caused many consumers to talk about the color change of additives, so many people took the absence of additives as the standard for evaluating the quality of soy sauce.

　　"This statement is not entirely correct." Zheng Yunliang said that the so-called zero-added soy sauce is soy sauce with special color, fragrance and taste made by microbial fermentation without adding any monosodium glutamate or food additives. However, the quality of soy sauce depends on many factors, and zero addition is only one of them.

　　"First of all, the soy sauce listed should meet the relevant national standards." Zheng Yunliang introduced that China’s "National Standard for Food Safety Soy Sauce" (GB 2717-2018) stipulates that soy sauce is a liquid condiment with special color, fragrance and taste made from soybeans and/or defatted soybeans, wheat and/or wheat flour and/or wheat bran as the main raw materials through microbial fermentation. Soy sauce manufacturers shall have a complete fermentation and brewing process, and shall not use raw materials such as acid hydrolyzed vegetable protein seasoning liquid to produce soy sauce.

　　Soy sauce that meets the relevant national standards has reached the "passing line", but it is not high quality.

　　"Soluble solids, chloride, total nitrogen, total acid and reducing sugar in soy sauce are important quality evaluation indicators, which can affect the quality of soy sauce." Zheng Yunliang introduced that the umami taste of soy sauce depends on the content of amino acid nitrogen. Generally speaking, the higher the content of amino acid nitrogen, the higher the grade and the better the quality of soy sauce.

　　At the same time, as a traditional fermented condiment in China, the flavor of soy sauce is also an important quality index. The differences in koji varieties and technological processes of different soy sauces will make them have great differences in flavor.

　　According to related technical literature, 230 nonvolatile compounds were detected in soy sauce, including 90 peptides, 49 organic acids, 27 amino acids and their derivatives, 28 sugars, 11 sugar alcohols, 6 biogenic amines, 4 nucleotides and 16 other compounds, which determined the acidity, sweetness and concentration of soy sauce.

　　In addition, Zheng Yunliang reminded that consumers should also have a rational understanding of additives and not be overly superstitious about zero-added food.

　　"In soy sauce processing, the most commonly used food additives are sodium benzoate, disodium inosinate and disodium guanylate. Rational use of food additives can prevent bacterial growth, moderately extend the shelf life, and make soy sauce more cost-effective. " Zheng Yunliang said.

　　In fact, instead of paying attention to food additives, consumers should pay more attention to the sodium content in soy sauce.

　　"In every 100ml of soy sauce, the sodium content is about 6g, and the recommended intake of sodium is only 2g/day. Related studies have shown that excessive intake of sodium may lead to cardiovascular diseases such as hypertension and arteriosclerosis. " Zheng Yunliang reminded.

　　As long as there are clouds, it can artificially increase rainfall?

　　Truth: Certain conditions are needed, and the key is to have the right cloud.

　　Since this summer, the drought in the eastern part of southwest China, the south of the Yangtze River and the northern part of South China has continued to develop, and it has suffered from drought in summer and autumn. The water levels of Poyang Lake and Dongting Lake all hit record lows, and some lakes even became "deserts" and "grasslands". At the same time, there is a question on the internet: as long as there are clouds, artificial precipitation can be carried out. Why not carry out artificial precipitation enhancement in these arid areas?

　　In this regard, Wang Zhaoyu, director of the Tianjin Office of Weather Modification, said that artificial precipitation enhancement is not artificial rainfall, and "turning clouds into rain" requires certain conditions.

　　Artificial precipitation enhancement is to influence the microphysical process of clouds through artificial intervention under appropriate weather conditions, so as to increase the ground precipitation.

　　"The way of artificial intervention is mainly by sowing catalysts into the cloud. Generally speaking, the catalysts sown in the northern region are mostly silver iodide, while dry ice and liquid nitrogen are commonly used as artificial precipitation enhancement catalysts in the southern region. In addition to catalysts, there are ways of manual intervention, such as emitting femtosecond laser and charged particles to the cloud. " Wang Zhaoyu said that no matter which way is used, the ultimate goal is to form condensation nuclei, promote water vapor condensation, and finally form precipitation.

　　However, a clever woman can’t cook without rice. In this process, the most crucial thing is — — There should be a cloud that meets the conditions of artificial precipitation enhancement. Such a cloud needs to have a certain thickness, height and temperature, and at the same time, the water vapor in the cloud should be abundant and just in the updraft area.

　　Wang Zhaoyu explained that the medium and low clouds with a temperature of MINUS 10 to 0 degrees Celsius, a thickness of about 2,000 meters and a height of less than 6,000 meters are suitable for artificial precipitation enhancement. Such warm clouds are full of small water droplets, which float in the air and cannot fall down under the support of updraft, forming clouds; With the help of the catalyst, increasing the concentration of condensation nuclei in the cloud can make small water droplets collide more and more into large water droplets, and then form precipitation.

First, preface: 229 yuan! Give consideration to design and performance

In recent years, the popularity of the Internet is really staggering. Not only wireless network, but also the development of home fixed network is almost by leaps and bounds.

When I was in middle school, I still used dial-up Internet access at home. At that time, it took me an hour and a half to download Crossing the Fire Line with less than 1GB. Look at today, even the average family, the broadband speed is above 100M, and it can be satisfied to have 300M or 500M m.

At the same time, the speed-up and fee-reduction of fixed-line network has promoted the development of router industry. Nowadays, almost all mobile phone manufacturers are involved in the router industry, among which Xiaomi router is the largest and the earliest one.

When I was in college a few years ago, I used a certain route of Xiaomi in my dormitory. However, although Xiaomi mobile phone was very hot at that time, the attention of router accessories was not very high because the Mijia ecological chain had not yet appeared.

Today, the author took a look at an online mall. Xiaomi has sold more than 1 million routers, and the sales of other routers are also hundreds of thousands.

With such a large volume and so many years of technical accumulation, Xiaomi is no longer constrained by the traditional router development model, and some recent routing products basically bring some creativity and new ideas in function or appearance.

For example, Xiaomi Routing Mesh released at the beginning of this year can realize 3-channel hybrid networking of 2.4G WiFi, 5G WiFi and power line. Another example is Xiaomi Router HD, which is designed with all-metal body and equipped with 1TB HD streaming media hard disk.

Of course, due to the positioning of these two products, the price is not acceptable to all consumers (1299 yuan /999 yuan). Perhaps it is in view of this situation that the product we want to evaluate today — — Xiaomi router AC2100.

It is worth noting that its price is only 229 yuan, so what will happen to Xiaomi router AC2100? Let’s start today’s evaluation.

Second, appearance: minimalist cylindrical design, ventilation and super heat dissipation.

↑ ↑ ↑ Xiaomi routing AC2100 packaging box

↑ ↑ ↑ The specific information of the router is printed on the box.

↑ ↑ ↑ Xiaomi routing AC2100 fuselage front, using a minimalist design.

If you look closely, you can see that there are two indicator lights at the lower slot, namely the network status light and the system indicator light.

The black cylindrical shape gives people a heavy feeling, but it feels completely different in the hand. The whole plastic material makes its actual weight only 620 grams. Because there is a gap inside the router, the shell of the router will hear the empty echo when it is knocked.

↑ ↑ ↑On the back of the router, from top to bottom, there are four network cable sockets, power interface and reset key respectively.

There is only a minimalist Xiaomi Logo on the top of the router, and there is a circle of cooling holes on the periphery.

The cooling holes at the bottom echo with the top to form a chimney-type heat dissipation, and the heat dissipation efficiency will be higher by going straight up and down. In addition, the gray circle at the center is non-slip rubber.

↑ ↑ ↑ Fuselage details

Xiaomi routing AC2100 also comes with a gigabit network cable, which is very conscience.

↑ ↑ ↑ The standard power adapter of the router has an output of 12V/1A.

Third, signal strength: 200㎡ super-large space full coverage.

Xiaomi router AC2100 does not display the two signal bands of 2.4GHz and 5GHz by default like most routers now, but displays them separately. (as shown below)

After the router network is set up, it will provide two frequency bands, 2.4GHz and 5GHz, and mobile phones can be connected separately.

The advantage of this is that the two do not interfere with each other. When connected to 2.4GHz, the wall penetration performance is better and the coverage is farther; When connecting the 5GHz band, under the 802.11ac technology, the interference will be smaller and the speed will be higher, which is suitable for watching high-definition videos and playing large games.

If you are used to the combined display of 2.4GHz and 5GHz, the dual-frequency terminal can automatically select the optimal frequency band, and this function can be turned on in the Wed management background.

— — Signal strength test

In daily use of wireless routers, we pay most attention to the signal strength, which directly determines the user’s experience.

We usually use Wi-Fi at home. Under normal circumstances, the signal strength is 60dBm to 80dBm, which can meet the daily use of surfing the Internet and browsing video music. It can be stable above 60dBm, and there are few jams when playing games.

When large files need to be transferred, the requirements are slightly higher, and the dBm value should be above 40.

We tested the signal strength of Xiaomi routing AC2100 this time, which imitated the daily home environment. The wireless router was placed next to the TV in the living room, and three rooms with different distances were selected as test locations.

Here, the author chooses a house of about 100 square meters and a Xiaomi MIX3 as the Wi-Fi signal testing equipment.

↑ ↑ ↑ Schematic diagram of house type, with points A, B and C as test positions.

Let’s look at the test results:

The above picture shows the signal strength measured by Xiaomi MIX3 at positions A, B and C respectively.

The average signal strength of test point A is -23dBm, and the WiFi connection rate is stable.

The average signal strength at point B is -48dBm, and the signal is weakened by one grid.

The average signal strength at point C is -68dBm, and there is one grid of WiFi signal.

Judging from the test data of the above three points, the test range of 100㎡ in the author’s home is obviously not enough. After all, Xiaomi AC2100 mainly focuses on the large apartment of 200㎡!

After that, the author chose the further elevator D. At this time, the mobile phone began to choose to connect to the 2.4GHz band. Under the 2.4GHz network, the average signal strength measured here is acceptable, which is -70dBm, but the average delay is over 300ms, so it is absolutely impossible to play games at this distance.

— — Transmission rate test

For a router, in addition to signal strength and coverage, transmission rate is also an important link that has to be considered.

In order to have a deeper understanding of the transmission rate of Xiaomi routing AC2100, the author still tests under the same test link and conditions.

The test software is "Speedtest", which is a professional APP for testing the signal transmission speed on mobile phones. It can detect and calculate the download speed and upload speed.

From the test results of our 300M Unicom broadband, the actual download speed reached 332Mbps and the upload speed reached 33.4Mbps without partition, and the best performance of my home routing was basically the same.

At point C, which separates the two walls, its download speed can still be maintained at 169Mbps.

Judging from the actual test results, Xiaomi routing AC2100′ s wall penetration ability and network effect are satisfactory. According to the official data, Xiaomi Routing AC2100 can connect up to 128 devices, so in addition to family use, small and micro enterprises with more members can fully meet the demand.

V. Power consumption test: the peak value does not exceed 5W, and the power consumption lasts for ten days!

Although the power consumption of routers can’t be compared with that of household appliances, we hardly choose to turn it off in daily life, and the accumulated power consumption can’t be underestimated.

We tested the Xiaomi routing AC2100 with a power consumption tester. When four mobile phones are connected, the power consumption of Xiaomi routing AC2100 is about 4.7W.

According to the full-load power conversion of 4.7W, it takes 213 hours, or about 9 days, for Xiaomi to consume one degree of electricity through AC2100. That is to say, under the condition of full load for 24 hours, 1 degree of electricity can be used for nearly 10 days.

Sixth, summary: 100 yuan to 1,000 yuan high school low price full coverage.

All students who have used Xiaomi routing know that one of the advantages of Xiaomi routing is the linkage with Xiaomi smart home devices.

We have also said that many people, even if they are not Xiaomi mobile phone users, must have used the products of Mijia Eco-chain more or less. Just like the author, unconsciously, there are not only Mijia electric toothbrush at home, but also Mijia weighing scale, smart desk lamp, and so on.

Usually, mobile phones are often used to manipulate these devices. In the past few days, when using Xiaomi to route AC2100, the author also found a very useful small function, that is, when modifying the WiFi password through Xiaomi WIFI APP, the router will automatically synchronize to Xiaomi smart home devices at home. Although this function sounds simple, it is absolutely necessary for students who have multiple Xiaomi smart devices at home.

Xiaomi routing AC2100 also has some practical functions, such as Netease UU accelerator, anti-rubbing network, red envelope Wi-Fi, etc. We have seen most of them before, so I won’t repeat them here.

— — finally

When evaluating millet products, especially non-mobile phone products, we can’t avoid the price.

The price of Xiaomi router AC2100 is 229 yuan, and its positioning is closer to that of Xiaomi router Pro(449 yuan), both of which are advanced routers with high cost performance, taking into account avant-garde design and good performance.

The significance of the sale of Xiaomi router AC2100 is that Xiaomi router has completed the full coverage of high, medium and low prices from less than 100 yuan to more than 1,000 yuan.

If you want to choose an entry-level router, 59 yuan Xiaomi router 4C and 99 yuan Xiaomi router 4A can be selected.

If you have a big room at home, you can choose 999 yuan Xiaomi router Mesh or 1299 yuan Xiaomi router HD, with exquisite shell and super performance. Friends who have special needs for network storage will definitely like it.

　　China Meteorological Network News At 10: 00 on June 11, the Central Meteorological Observatory continued to issue a blue rainstorm warning. It is estimated that there will be heavy rainstorms in southern Jiangnan, central, eastern and southern South China, southeastern and western Yunnan, and Taiwan Province from 14: 00 on the 11th to 14: 00 on the 12th, including heavy rainstorms (100-150 mm) in parts of southwestern Jiangxi, central and southern Fujian, southeastern Guangxi, central and western Guangdong, and southern Taiwan Province. These local areas are accompanied by strong convective weather such as short-term thunderstorms and strong winds.

　　The meteorological department suggested that the government and relevant departments should do a good job in emergency prevention of rainstorm according to their duties, and all departments should strengthen information communication and emergency linkage; Do a good job in the drainage of cities and farmland, and pay attention to prevent possible disasters such as flash floods, landslides and mudslides; Cut off the outdoor power supply in dangerous areas and suspend outdoor work; The public should take measures to deal with the rainstorm and make reasonable arrangements for travel, production and life.　　

(Source: Editor of Central Meteorological Observatory: Li Wenqin)

　　

　　

　　　　

　　[Meteorological Science Popularization]

　　Rainstorm and its prevention and response

　　Heavy rain refers to rain with high precipitation intensity, which is often formed in cumulonimbus clouds. According to meteorological regulations, rain with an hourly rainfall of more than 16 mm, or a continuous rainfall of more than 30 mm for 12 hours and a 24-hour rainfall of 50 mm or more is called "rainstorm". According to its precipitation intensity, it is divided into three grades, that is, the 24-hour precipitation is 50-99.9 mm, which is called "rainstorm", the 100-249.9 mm is called "heavy rainstorm" and the 250 mm is called "extraordinary rainstorm". However, due to the different characteristics of precipitation and topography, the standards of rainstorm and flood in different places are also different. In business practice, rainstorm can be divided into local rainstorm, regional rainstorm, large-scale rainstorm and extra-large rainstorm according to the scope of occurrence and influence.

　　The local rainstorm lasts only a few hours or dozens of hours, and generally affects tens to thousands of square kilometers, causing less harm. However, when the rainfall intensity is extremely high, it can also cause serious casualties and property losses.

　　Regional rainstorm generally lasts for 3 ~ 7 days, and the influence range can reach 100 ~ 200,000 square kilometers or more. The disaster situation is average, but sometimes it may cause serious regional rainstorm and flood disaster due to the extremely strong rainfall intensity.

　　Extra-large-scale rainstorm lasts the longest, and it is generally a combination of continuous rainstorms in many areas. The rainfall can last intermittently for about 1 ~ 3 months, and the rain belt can be maintained for a long time. Torrential rain is a kind of disastrous weather, which often causes floods and serious soil erosion, leading to major economic losses such as engineering accidents, dike breaches and crop flooding. Especially for some low-lying and closed terrain areas, rainwater can not be quickly vented, resulting in farmland water accumulation and soil moisture over-saturation, which will cause more disasters.

　　How does the city "Rain Island" avoid waterlogging?

　　　　At present, China is at the peak of urbanization, population and wealth are constantly concentrated in cities, and the area of cities is getting bigger and bigger. Urban waterlogging not only brings inconvenience to people’s travel and life, but also may cause some secondary disasters. How to carry out scientific planning and design to ensure people’s travel and property safety?

　　Urban "Rain Island Effect" and "Turbid Island Effect"

　　Urban waterlogging refers to the phenomenon of waterlogging disaster in cities due to heavy precipitation or continuous precipitation exceeding urban drainage capacity. The amount of precipitation in a city depends firstly on the atmospheric circulation and secondly on the environmental conditions of the city itself.

　　Modern urban waterlogging has two characteristics: first, the universality of urban waterlogging exists in many cities in China. Secondly, the incidence of waterlogging is high in some specific places in the city, such as overpasses; With the construction of modern cities, underpasses, railway bridges and highway bridges crossing the street also occur frequently. In addition, in recent years, the phenomenon that precipitation in many cities is obviously greater than that in the surrounding suburbs has become more and more prominent.

　　High-rise buildings in cities are compared to "reinforced concrete forests", and with the increasing density of "forests", air conditioners and automobile exhaust increase the heat, forming a hot air flow over cities. The thicker the hot air flow, the more likely it is to cause precipitation. At the same time, the concentrated buildings in the city reduce the wind speed, and the weather system such as strong rain belt stays over the city longer than the empty suburbs, and the total precipitation increases, which is called the "rain island effect". The "rain island effect" mainly appears in flood season and rainstorm, and the frequency and intensity of urban rainstorm are higher than those in surrounding areas, which is easy to form flood disasters.

　　The concentration of industry, the large number of vehicles and the dense population in the city lead to the turbidity of polluted gases and dust in the air much higher than that in the surrounding areas, forming the urban "turbidity island effect". The influence of urban "turbid island effect" on rainfall is as follows: dust and other turbid substances are the most needed condensation nuclei for water vapor in clouds to change into rainfall. The more condensation nuclei there are over the city, the easier it is for water vapor to condense here and cause precipitation, thus increasing rainfall.

　　Generally speaking, the factors affecting urban waterlogging mainly include three aspects. One is rainfall, especially heavy rainfall. When the frequency and intensity of rainstorm in cities are higher than those in surrounding areas, it is easier to form flood disasters. The second is topography. It is not easy to form stagnant water in areas with relatively high terrain, but it is easy to form waterlogging in areas with relatively low terrain, which is also the reason why a large amount of stagnant water is easy to appear in overpasses and underground passages. Third, the urban drainage system is not perfect. In some cities, there are many "debts" in the drainage network, the pipes are aging and the drainage standards are relatively low. In addition, a large number of hard pavements, such as asphalt pavement and cement pavement, have poor permeability and are easy to cause water accumulation.

　　　How to effectively deal with the super-standard rainstorm

　　Unexpected events such as super-standard rainstorm will pose a great threat to urban waterlogging. Xie Yingxia, director of the Institute of Engineering Planning and Design of China Urban Planning and Design Institute, believes that combining engineering measures with non-engineering measures is an effective way to deal with the super-standard rainstorm, and it should be comprehensively considered from the aspects of economy and environment. First of all, for hard engineering measures, the standards should be appropriate and the emergency rescue system should be improved. When planning and designing, we should implement the construction contents, such as where to build reservoirs, where to divert floods, where to build pumping stations and where to build gates. Secondly, for soft non-engineering measures, it is necessary to strengthen the construction of emergency system and ensure its normal operation. In recent years, foreign countries have used ecological methods to improve the conditions of rainwater system, such as using permeable bricks to pave sidewalks, increasing permeable layers and reducing hard pavement. Storage regulation is also one of the main measures they usually take.

　　In addition, considering the environment, it is necessary to build an eco-city to meet the scientific development of the city. It is a good idea to beautify the city and store water and prevent waterlogging, such as increasing green space, reducing runoff, and using permeable bricks in sidewalks, squares and other areas. At the same time, planning and design methods that are economical, environmentally friendly and timely drainage are also needed to be strongly advocated.　　

　　So, how to carry out scientific planning and design to deal with urban waterlogging? Xie Yingxia said: First, we should update our concepts and pay attention to the problem of urban drainage; Second, it is necessary to introduce urban drainage planning and design standards as soon as possible, clarify the different drainage standards of different cities, and rationally arrange drainage facilities; Third, we should rationally choose urban construction land; Fourth, rational planning, scientific management, and targeted drainage planning; Fifth, we should take precautions against excessive rain, and reduce the loss of waterlogging by strengthening meteorological forecast and improving emergency management system; Sixth, we should gradually improve the construction standard of drainage system; Seventh, we must formulate good drainage measures. According to the local topography, the measures of flood interception, diversion and storage are studied; Eighth, we should pay attention to taking non-engineering measures, and it is strictly forbidden to occupy shed covers on both sides of the river, fill ditches and build land, and block the river bed. River ditches should be dredged in time to ensure smooth drainage.

"The blue sky is clear and clear", "Look at the picturesque mountains and clear waters, listen to the birds chirping and singing" and "White clouds are floating in the blue sky" … catchy lyrics describe people’s common beauty. However, in some places, such beautiful scenery is rare, and problems such as frequent smog weather, black and smelly water bodies and garbage siege are still the pain of people’s skin.

The Opinions of the State Council, the Central Committee of the Communist Party of China on Strengthening Ecological Environmental Protection in an All-round Way and Resolutely Fighting Pollution Prevention and Control (hereinafter referred to as "Opinions") published on the 24th made arrangements for comprehensively strengthening ecological environmental protection and resolutely fighting pollution prevention and control.

The target indicators maintain continuity, but also put forward new requirements, which are closely combined with the feelings of the people.

Since the 18th National Congress of the Communist Party of China, China has resolutely declared war on pollution, and successively implemented three major action plans to prevent and control air, water and soil pollution, thus solving a number of major environmental problems. On the whole, the quality of ecological environment has been improving steadily, but the effect is not stable.

China is in a period of rapid industrialization, informationization, urbanization and agricultural modernization. Li Ganjie, Minister of the Ministry of Ecology and Environment, said that the environmental problems in developed countries in the past 200 years have been concentrated in the rapid development of China for more than 30 years. The old environmental problems have not been solved yet, and new environmental problems are coming one after another.

"China’s environmental capacity is limited, the environmental carrying capacity has reached or approached the upper limit, the ecosystem is fragile, and the ecological environment with heavy pollution, great losses and high risks has not been fundamentally reversed." Wu Shunze, director of the Research Center for Environment and Economic Policy of the Ministry of Ecology and Environment, said that the compressed, complex and cumulative environmental problems accumulated over the years could not be cured in just a few years.

China’s ecological civilization construction and ecological environment protection are facing unprecedented challenges and historical opportunities. Li Ganjie said that China’s economy has changed from high-speed growth to high-quality development, green recycling and low-carbon development have been further promoted, and the macroeconomic environment is more favorable. In addition, the development and accumulation of 40 years of reform and opening up have provided a solid material, technical and talent foundation for solving ecological and environmental problems, and the dividend of ecological civilization system reform has been gradually released, which has added a strong impetus to ecological and environmental protection. China’s ecological and environmental protection has entered a stage of not owing new accounts but paying off old ones.

Xu Bijiu, Inspector General of the State Environmental Protection Supervision Office, introduced that the Opinions mainly take 2020 as the time node, taking into account 2035 and the middle of this century, and set targets from three levels: quality, total amount and risk. The Opinions set specific targets by 2020. For example, the concentration of fine particles in cities at or above the prefecture level has dropped by more than 18% compared with 2015, and the ratio of days with excellent air quality in cities at or above the prefecture level has reached more than 80%; The proportion of Class I-III surface water bodies in China is over 70%, and the proportion of inferior Class V water bodies is controlled within 5%. The red line area of ecological protection accounts for about 25%; The forest coverage rate reached more than 23.04%.

"These targets and indicators are scientific decisions made by the central authorities after overall consideration, maintaining continuity and putting forward new requirements, which are closely integrated with the feelings of ordinary people." Xu Bijiu said that by speeding up the construction of an ecological civilization system, the spatial pattern, industrial structure, production mode and lifestyle of resource conservation and ecological environment protection will be generally formed by 2035, the quality of ecological environment will be fundamentally improved, and the goal of a beautiful China will be basically achieved. By the middle of this century, ecological civilization will be improved in an all-round way and the national governance system and governance capacity in the field of ecological environment will be modernized.

Focus on key areas, seize the weak links, and fight three major defense battles and seven major landmark battles.

Focusing on key areas, the Opinions clearly require that three major battles (blue sky, clear water and pure land) and seven major landmark battles (winning the blue sky battle, fighting diesel truck pollution control, water source protection, black and odorous water treatment, Yangtze River protection and restoration, comprehensive management of Bohai Sea, and agricultural and rural pollution control) should be well fought, and solid results have been achieved.

"Resolutely winning the blue sky defense war is the top priority of the battle against pollution." Xu Bijiu said that the "Three-year Action Plan to Win the Blue Sky Defence War" will be issued and implemented in the near future. The general idea of winning the blue sky defense war is "four fours": highlighting four key points, optimizing four major structures, strengthening four supports and realizing four obvious.

Highlighting four key points, namely, the key pollution prevention factor is PM2.5, the key areas are Beijing-Tianjin-Hebei and its surrounding areas, the Yangtze River Delta and the Fenwei Plain, the key period is autumn and winter, and the key industries and fields are steel, thermal power, building materials and other industries, as well as "scattered pollution" enterprises, loose coal, diesel trucks, dust and other fields. Optimize the four major structures, that is, optimize the industrial structure, energy structure, transportation structure and land use structure. Strengthen the four supports, that is, strengthen environmental protection law enforcement supervision, regional joint defense and control, scientific and technological innovation and publicity and guidance. To achieve the "Four Nothings" is to further significantly reduce the concentration of PM2.5, significantly reduce the days of heavy pollution, significantly improve the ambient air quality, and significantly enhance people’s blue sky happiness.

Efforts will be made to fight the battle for clear water, ensure the safety of drinking water, and basically eliminate urban black and odorous water bodies. "To fight the battle for clear water, we will emphasize the protection of water and the treatment of poor water, ensure the safety of people’s drinking water, and keep the bottom line of water environment quality." Xu Bijiu said that in tackling key problems, both emission reduction and capacity expansion were emphasized. Grasp the rectification of three major types of pollution sources: industry, agriculture and life, and greatly reduce pollutant emissions; Grasping the renovation of water ecosystem with one hand, effectively expanding the capacity of water body to accept pollution and self-purification.

Solidly promote the defense of pure land, with the focus on preventing and controlling environmental risks. "Focusing on the goal of improving soil environmental quality and preventing and controlling environmental risks, laying a foundation, building a system and keeping the bottom line." Xu Bijiu said that it is necessary to fully implement the action plan for soil pollution prevention and control, take measures such as promoting the safe use of contaminated farmland, strictly controlling the use of construction land, accelerating the classified disposal of garbage, and completely prohibiting the entry of foreign garbage, highlighting key areas, industries and pollutants, and effectively controlling the soil environmental risks of agricultural land and urban construction land, so that ordinary people can eat and live with peace of mind.

All localities and departments should keep a close eye on the target, ensure the completion, and not let a region and a river basin fall behind.

Eco-environmental problems have been formed for a long time, and it takes a long process to solve them fundamentally. Xu Bijiu said that it is necessary to combine far and near, not only concentrate on fighting tough battles, but also make overall plans, pay attention to source prevention, expand capacity and strengthen security.

Source prevention is the fundamental policy to solve ecological and environmental problems. "To promote the formation of a green development mode and lifestyle, this is an important part of the tough battle and an important guarantee. The discharge of pollutants has dropped significantly from the source, and the quality of the ecological environment can be significantly improved." Xu Bijiu said that it is necessary to promote the development of green and low-carbon economic cycle, promote the overall conservation of energy resources, and at the same time guide the public to live a green life. Through the green change of lifestyle, it will force the green transformation of production methods.

Ecological protection and pollution prevention are inseparable and interactive. The "Opinions" require that the red line of ecological protection should be delineated and strictly observed, and the area accounting for about 25% of the national land space should be included in the red line of ecological protection according to the principle of ensuring all the protection and all the planning; Resolutely investigate and deal with ecological damage. Before the end of 2018, local governments at or above the county level will comprehensively investigate illegal and illegal activities such as occupying ecological space and destroying natural relics; Establish a system of nature reserves, and by 2020, integrate and set up a number of national parks, and basically establish relevant laws and regulations and management systems for nature reserves.

Perfecting the ecological environment supervision system, economic policy system, rule of law system, capacity guarantee system and social action system is an important guarantee for fighting the battle against pollution. The "Opinions" require improving the ecological environment supervision system and strengthening the unified supervision of ecological protection and restoration and pollution prevention and control; To improve the economic policy system for eco-environmental protection, capital investment should be tilted to the tough battle for pollution prevention and control, and the investment should be matched with the tough task. The central and local governments should increase investment in eco-environmental protection, gradually establish a normalized and stable financial capital investment mechanism, give full play to the role of market mechanism, and incite more social capital to enter the field of eco-environmental protection.

The "Opinions" clarify that the secretary of the provincial party committee, the secretary of the municipal party committee, the secretary of the county party committee, the governor, the mayor and the county magistrate take overall responsibility for the ecological environment protection work and the quality of the ecological environment in their respective administrative areas; Formulate the assessment methods for the effectiveness of the provincial party committees, people’s congresses, governments and relevant departments of the central and state organs, and the assessment results will serve as an important basis for the comprehensive assessment, reward and punishment, appointment and dismissal of leading bodies and leading cadres of local party committees, people’s congresses, governments and relevant departments of the central and state organs.

"All localities and departments should keep an eye on the target, fight on the wall chart, ensure the completion, and consolidate and improve the places with fast progress and good results; Where progress is slow and the effect is poor, it is necessary to catch up and ensure that one region and one basin are not left behind. " Xu Bijiu said. (Reporter Yan Jiangze)