Get stuck into chemistry with these fascinating guides.
An Elementary Guide to the Periodic Table
by Gill Arbuthnott (Bloomsbury Children's Books)
There are lots of funny stories, fascinating facts and interesting explanations packed into this book, which aims to provide a good introduction to the periodic table. As well as plenty of information, there are lots of eye-catching diagrams and illustrations.
Exploring the Elements
by Isabel Thomas. Illustrated by Sara Gillingham (Phaidon Press)
This beautifully designed book provides an introductory guide to the chemical elements ——where they are found, their properties and the remark able ways we've learned to use them. Smart and stylish, the book even comes with an illustrated periodic table.
The Elements in the Room
by Mike Barfield. Illustrated by Lauren Humphrey (Laurence King)
As the candidate for lots of awards, this entertaining book invites you to join detective Sherlock Ohms as he tries to solve the mystery of how absolutely everything came to exist. This is a fun way to learn about the basics of chemical elements, from aluminum to zinc.
The Periodic Table Book
by Darling Kindersley, Ltd
If you are just starting your chemistry learning, look no further than this comprehensive visual encyclopedia, which is packed with stunning photographs. It covers all the basics of chemistry, with information about the different elements, and you'll also learn about some of the famous scientists who discovered them.
The tornado came without any sign——the sky was blue and the sun had been out. My husband Jimmy ran upstairs to find me in our third-floor bedroom. No sooner had we found coverage of the tornado than it was on top of us. The bones of the house shook, and the power went out. The wind began to roar through the house. We had three flights of steps to navigate to get to the relative safety of the first floor. Because the closet down there was installed underneath a brick staircase, it seemed like the most solid place in our house to wait things out.
I didn't know how or if we would make it down the steps. It felt as if there were no floor underneath me as the wind lifted me off my feet. I gripped the handrail (扶手) and tried to move forward, but this intense pressure held me in place. In those seconds of stillness, I could hear everything around me rattling.
As we reached the last flight of steps, our front door blew out. Pieces of glass that looked like broken ice flew everywhere. Suddenly, a three-foot-long tree branch whipped through the door frame. It flew over our heads, missing us by inches. Had we been one step up, it would have gone through us and caused serious injuries. The back wall of the house followed suit and tore off into the darkness outside.
Instantly I reached the closet, Jimmy pushed me (down to the closet floor, but he couldn't get inside himself because of the wind. I gripped Jimmy's arm as the tornado sucked the door open and tried to bring Jimmy with it. My knees were full of glass, but at that moment, I felt no pain. If I had let go, Jimmy would have flown right out and into the bay. "Hold on! Hold on!" he yelled. But there was nothing in this closet to hold on to.
All of a sudden, Jimmy lifted off his feet like people in tornadoes do in the movies. I thought he was gone. And then everything stopped. He landed on his feet. At those first quiet moments, I couldn't believe it was over. Jimmy said he'd go outside to check. "No, "I said. "Don't leave me. "
Our neighbor says the storm lasted four minutes. At that time, four of the twelve houses in our community were completely destroyed. Of the houses left standing, ours suffered the most damage. However, none of us were severely injured.
Every year thousands of people come to the city of Pamplona, in north-eastern Spain, for the opportunity to run for their lives as six fighting bulls are released to charge through the town. There are injuries and deaths every year, but the event is of interest to many people. A paper just published in Science describes the insight the event offers into the psychology of panicked crowds.
That is a useful topic to explore. Architects, civil engineers and urban planners must try to work out how people will behave in the event of a disaster like a fire, a flood or a terrorist attack so they can design their creations to avoid potentially deadly collisions. Unfortunately, solid information is hard to come by. Daniel Parisi, the paper's lead author, realized that the Pamplona bull-runs offered the perfect natural experiment.
Dr Parisi and his team went to two different rooftop locations in Pamplona in July 2019, and filmed the runners as the animals were released. Later in the lab, they calculated the speed of the runners, the density (密度) of the crowd, the probability of a runner tripping and falling and the relationship between runner-group density and speed.
Perhaps unsurprisingly, the researchers found that runners picked up speed when the bulls drew near. Less expected was the finding, that the speed of individual runners augmented with the density of the crowd, which was contrary to a long-held assumption in architectural and urban-design circles that people will slow their pace as group density goes up, in order to lower the risk of a collision, which could lead to a fall and, perhaps, injury or death.
It seems that, in the heat of the moment, people pay little attention to the danger of colliding with each other and even accelerate. The responsibility therefore falls upon urban designers to work out how best to plan the construction of future tunnels, bridges and other passages that restrict flow. The only option may well be to make them broad enough.
Asparagus (芦笋) is a very odd vegetable. It can grow up to 2cm in an hour. Cut a field one afternoon, return the next morning, and with almost frightening speed it will be back. Whereas other vegetables spend time producing leaves, asparagus grows as single spears (嫩茎), making it superbly suited to robotic pickers.
In late June a small white object slowly makes its way along a field of asparagus in Gloucester-shire. When it passes over a group of spears it pauses, whirr then clunks: the asparagus has been sliced. This robot called Sprout is being developed by a London start up called Muddy Machines. It is more inflexible on wheels than Ex Ma-china android. However, John Chinn, Britain's largest asparagus producer, regards it with enthusiasm. For him, he says, it could be "fantastic".
The world is suffering from a shortage of seasonal workers. Last summer Mr. Chinn needed 1, 300 workers. He got around 800. Trying to find labour is, for a farmer, "the thing that stops you sleeping". The shortage of workers is particularly acute in Britain, where Brexit (英国脱欧) has been spoiling harvests as well as growth.
Now, it is a time to innovate. Moravec's paradox (莫拉维克悖论)states that computers find things simple that humans find hard——and vice versa. Differential calculus (微分学)? Not a problem. Telling the difference between a ripe strawberry and a stone? Really hard. Harvesting is especially ripe for robotic puzzlement. Leaves confuse them; bumps puzzle them; colour prevents them. In 2015, Joe Jones, a robotics whose inventions include the Roomba, a vacuum cleaner, was considering new areas to explore, and started to make a list of which crops a robot might be able to pick most easily. He considered different variables (变量) that "would make it easy for a robot to handle", then scored each crop out of 12. "And what crop, "he wrote on his blog, "came out on top?"
In the fields of Gloucester shire is the answer. Sprout crawls forward; pauses. Another whirr, whoosh, clunk. It is an original model, but Mr. Chinn is optimistic. His dream would be to see a herd of 100 in his fields next year. He needs them. The stress is now so bad that "If we can't find a solution, we'll all give up soon."
Memory allows the brain to store and retrieve (检索) information when required. Our short-term memory can hold a small amount of information fora short time, Our memory is amazing, but why do we still forget things
It's possible we don't always store information in our memory effectively, maybe because we are in a rush or we consider it irrelevant at the time. If you don't have these connections, then it can be easier to forget. Luis Villazon says "It is also possible that memories decline over time. As they have not been revisited, their biological 'trace becomes weak. "It's true that if you don't perform a task for a long period of time, it can be difficult to recall how to do it. This could be because, just like in a computer, our memory is full, or that our short-term memory is easier to access.
Have you ever gone into a room to fetch something only to forget what you wanted when you got there? This is called 'The Doorway Effect'. Psychologist Tom Stafford explains that" this occurs because we change both the physical and mental environments, moving to a different room and thinking about different things. "
So, if you have a mind like a sieve (筛子), it could be because you have too much on your mind. Generally, beyond our 50s our brains tend to shrink in volume and our memory begins to decline. That's when we're at more risk of getting Alzheimer's disease.
A. so we can remember much knowledge at a stroke.
B. But sometimes even our short-term memory can let us down.
C. But we do need to keep our memory sharp by continually using it.
D. Put simply, we are metaphorically trying to spin too many plates at the same time.
E. while our long-term memory can hold an unlimited amount of information for a long time.
F. It would waste our cognitive (认知的) resources if we remembered every detail of the world around us.
G. When we do store information, we often make connections with other things, which helps us recall it later.
Having worked in a bank for ten years, I determined to go beyond a nine-to-five job. Scanning advertisements, I learned a1company was to hire consultants. Excited, I made a(n)2with a branch president. That day, it went so well that I was 3 he would hire me on the spot. 4, he told me to come back for 12 more5with his top salespeople!
Over the next five months, every one of them6me from working as a consultant in finance. The more they attacked my dream, the more my stomach7. I, though nervous, realized I would have to "fake it till I make it."
8, the last interview with the president came. "You've got the job! But you must take an exam and pass it without one point lost on the first9!"he announced.
I nearly choked at the prospect of taking a leap of faith into the unknown. However, attracted by this great risk I had never had, I10hard and said, "I'll take it. "At last, when the scores were displayed, I let out a loud sigh of 11.
My experience12the truth of Thoreau's words: "If one advances13in the direction of his dreams and14to live the life he had imagined, he will encounter success15in common hours.
In June, the world's biggest trial of a four-day work week kicked off in the UK. More than 3, 300 workers, based throughout the UK and(represent) more than 30 sectors of the UK economy, began receiving 100% of the pay for 80% of the time. Similar programs(choose) as a solution to the low-productivity in the workplace by several countries up to now, including the United Arab Emirates, Belgium, etc.
The campaign is aimed at enhancing employees' willingness(adjust) the work-life balance and stimulating higher work(efficient). For many workers, Mondays —or, more typically, Fridays —are transformed into something other thanregular workday. It may be as simple as making it a day of no meetings, which allows employees to catch up on projects they haven't finished, or as (extend) as a company wide move to a 32-hour week. For some companies, the four-day work week is a new recruiting tool that sides with a younger generation laying great emphasiswork-life balance. Besides， the ongoing pandemic (流行病) (speed) up the four-day trend currently.
carried out in some sectors, this work mode is by no means the mainstream, with potential negative effects. When Japan cut down working hours from 48 to 40 per week in the late 1980s and 1990s, their hardworking residents(remarkable)watched more TV and spent more time on personal grooming (仪容).
内容包括∶
1）栏目介绍
2）稿件内容
3）稿件长度约300词
4）交稿日期12月25日前。
注意∶
1）写作词数应为80左右
2）可以适当增加细节，以使行文连贯；
3）文章开头和结尾已给出，不计入总词数。
Dear Mary,
……
Yours,
Li Hua
Sue and Johnsy had their art studio in Greenwich Village. In November, an unknown disease struck this village and Johnsy was seriously sick with it. The doctor took Sue aside and claimed, "She has one chance in ten. And that chance is for her to want to live. "
Sue came into Johnsy's room, only to find Johnsy's eyes were open, but they weren't watching her. Instead, she stared out the window and counted backwards: "Ten, nine, eight, seven…"
"What are you counting, dear?" asked Sue. "They're falling faster now, "replied Johnsy. "Three days ago there were almost a hundred. But now there are only five left. When the last one falls, I must go, too. Didn't the doctor tell you?"
"Oh, I never heard of such nonsense. Now, try to take some broth (肉汤),and let yourself relax," quickly replied Sue. But Johnsy's mind was made up. "I don't want any broth. I just want to see the last leaf fall. "
"Try to sleep," said Sue. Then she went to fetch her neighbour Mr Behrman, a failed painter, to be a model for her drawing. In 40 years he had never produced the masterpiece he longed to paint. Sue told him about Johnsy's longing to slip away like the leaves. Behrman cried with disbelief, "Such a foolish idea! This is not a place in which Miss Johnsy shall lie sick. Someday I will create a masterpiece, and we shall all go away. "
Behrman and Sue looked out of the window at the vine (藤蔓)and noticed that there was just one remaining leaf. Then they looked at each other for a moment without speaking as if thinking of something artistic. What's more, a cold rain was falling, mixed with snow.
The next morning, Johnsy woke and asked for the curtains to be opened. One leaf remained on the vine, bravely holding on in the wind and rain. ''It will fall today, for sure. And I will die with it. "
That day in the afternoon, the doctor came, not for Johnsy, but for Mr Behrman, who was found lying in bed helplessly with pain, his shoes and clothing wet through and icy cold, and some brushes, paints, a lantern and a ladder on the ground.
The following day, Johnsy commanded that the curtain be raised again.
……
After Behrman's funeral, Sue came to Johnsy who was sipping her soup, and said, "I have 201 something to tell you."
