Gardening can be a very relaxing hobby for many people and this wonderful experience is not just for adults. Children are interested in gardening as well, if given the chance to explore nature and science in this way. Gardening can bring joy to both children and their parents alike, especially when the experience is shared together.

    The time that is spent gardening together builds precious memories within their hearts and minds for years to come. When you are gardening with your children, try to give them their own special area. Keep their area in the center of the best soil and light, as you want to make sure of a successful gardening experience.

    Plastic tools easily break and are difficult to use in the dirt, so when you are gardening with your children, give them real tools to use if possible. Even offering to let them use your tools is a way to admit the worth of the work they are doing. It is also important to talk with your children about the whole process of gardening, from planting to the harvest. They need to understand how things work and the importance of what they are doing.

    Show off the children's gardening work by taking friends and visitors for a walking tour through the garden and point out the children's particular spot. When you give attention to the children's work, this is a great motivation（动机） for children to continue wanting to be involved. Do not force children to take part when they are in a bad mood or if they are becoming bored. Instead, allow them to do something different, like building a scarecrow(稻草人)! This makes the gardening experience even more interesting. As you work together side by side with your children, you will encourage a love of the land in them, as well as creating lasting memories of time spent with you.

    A world-famous Canadian author, Margaret Atwood, has created the world's first long-distance signing device(装置), the LongPen.

    After many tiring……from city to city, Atwood thought there must be a better way to do them . She hired some technical experts and started her own company in 2004. Together they designed the LongPen. Here's how it works: The author writes a personal message and signature on a computer tablet(手写板) using a special pen. On the receiving end, in another city, a robotic arm fitted with a regular pen signs the book. The author and fan can talk with each other via webcams(网络摄像机) and computer screens。

    Work on the LongPen began in Atwood's basement(地下室). At first, they had no idea it would be as hard as it turned out to be. The device went through several versions, including one that actually had smoke coming out of it. The investing finally completed, teat runs w ere made in Ottawa, and the LongPen was officially launched at the 2006 London Book Fair. From here , Atwood conducted two transatlantic book signings of her latest book for fans in Toronto and New York City.

    The LongPen produces a unique signature each time because it copies the movement of the author in real time. It has several other potential applications. It could increase credit card security and allow people to sign contracts from another province. The video exchange between signer and receiver can be recorded on DVD for proof when legal documents are used.

     “It's really fun”, said the owner of a bookstore, who was present for one of the test runs. “Obviously you can't shake hands with the author but there are chances for a connection that you don't get from a regular book signing..

    The response to the invention has not been all favorable. Atwood has received criticism from authors who think she is trying to end book tours. But she said, “It will be possible to go to places that you never got sent to before because the publishers couldn't  afford it.”

    We all know the feeling: looking at the computer screen, pretending to be interested in our homework, even though we really feel bored. But such feelings may soon be at an end, says Dr. Harry Witchel, head of the Essex Medical School. He believes that computers of the future will notice when people feel bored and even take action to stopit.

    Before you get concerned, the machine won't be reading your mind. It will be observing the many movements you make while using a computer. It's not interested in the big movements needed to use the machine — like moving a mouse or touching a screen — but small, barely noticeable movements like closing your eyes, moving in your seat or rubbing your face. Witchel calls these “boredom movements" and says they show how interested the person is in what they are reading or watching. The higher the interest level, the less movement!

    To test his theory, Witchel invited 27 people to perform various computer-based tasks. The activities ranged from playing online games (an interesting task) to reading documents like government laws that most people would find boring.

A special video camera followed the participants' movements as they completed each task. Just as the researcher expected, the “boredom movements" greatly decreased, by as much as 42%，when the subjects were very interested in what they were reading or seeing.

    Fortunately, Dr Witchel isn't planning to use his results to create machines that report students who are not paying attention at school. Instead, he wants “movement sensing” technology to be built into future computers in order to improve students' computer-based learning experience.

    The scientist says that by measuring the students' interest level as they work, educators will be able to adjust their materials in real-time to keep students focused. Witchel also believes that the technology can provide filmmakers with honest audience opinions and in the future, help to develop more intelligent robots.

    There are several ways you can find out about the countries and places you wish to visit. You can talk to friends who have traveled to the places, you can go and see a colour film about them, or you can read a travel book.

    It seems that there are three kinds of travel books. The first are those that give a person al, subjective(主观的) idea of travels which their writer has got himself. These books can be useful if the writers share their traveling experiences with others. The second kind are those books which give objective(客观的) information of things to be done and seen. If a cultured person has written such a book about the facts of a place, then it is more useful. The third kind are those books which are called “a guide” to some place or other. If they are good, they will describe and explain the place in detail. Like the first kind, they can be interesting and exciting, but their main purpose is to help the reader plan his travel in the most practical way. Whatever kind of travel book you choose, you must make sure that the book does not describe everything as interesting, exciting or fantastic. You must also keep an open eyes on its date of publication(出版) because travel is very practical matter and many things change quickly in the 21st century. Finally, you should make sure that it's easy to find the useful information for you travel.

    Throughout much of human history, man has been the measure of many, if not all, things. Lengths were divided up into feet and smaller units from the human hand. Other measures were equally characteristic. Mediterranean traders for centuries used the weight of grains of wheat to define (定义) their units of mass. The Romans used libra, forerunner of the pound, by referring to the weight of a carob (角豆树) seed.

    The sizes of similarly named units could also differ. The king's foot, used in France for nearly 1, 000 years after its introduction by Charlemagne in around 790 AD, was, at 32.5cm, around a centimeter shorter than the Belgic foot, used in England until 1300.Greek, Egyptian and Babylonian versions of water in a fixed container varied from one another by a few kilos, Nor was there agreement on such things within countries. In France, where there was no unified (统一的) measurement system at the national level, the situation was particularly terrible. The lieue (former measure of distance), for example, varied from just over 3 km in the north to nearly 6 km in the south.

    Although John Wilkins, an Englishman, first put forward a decimal system (十进制) of measurement in 1668, it was the French who in 1799 made it law. The Système International d'Unités (SI, or the metric system, as it is better known) developed from it and became the official measurement in all countries except Myanmar, Liberia and the United States. Now the International Bureau of Weights and Measures in Paris is set to give the metric system its biggest shake-up yet.

    At a meeting in Versailles, France, on November 16th, 2018, the world's measurement bodies are almost certain to approve a decision that will mean four out of the seven base SI units, including the kilogram, will follow the other three, including the metre, in being redefined in terms of the values of physical constants (物理常数).Each of the chosen constants has been measured incredibly precisely, which would mean that from May 20^th 2019 the constants will themselves be fixed at their current values for ever. Any laboratory in the world will then be able to measure, for example, the mass of an object as precisely as the accuracy of their equipment will allow.

With the summer heat becoming increasingly unbearable over the years due to climate change,the cooling load in the summertime has also been on the rise.Insulation(隔热) is currently the main solution for blocking heat from entering a building,but by applying an additional material that can delay heat penetration(渗透),it can prevent the indoor temperature from rising and in turn lower the cooling load of the building.

A research team in Korea has developed a new material for building walls that can help reduce the penetration of heat from the outside.The team directed by Dr.Sarng Woo Karng from KIST revealed that they have successfully done it through building walls by applying a phase change material(PCM).One of the most common types is paraffin oil,which is used to make candles.

A solid PCM absorbs heat as it transforms into a liquid phase,so by using a case to hold it when it is in a liquid phase without causing any leakage(渗漏),it is possible to apply them to a building wall to block heat from entering inside.

The problem,however,is that the PCM turns into liquid starting from the outermost layer,and the parts that are hot move upward,while the parts that are still relatively cool move downward.Thus,while the upper part may have completely melted,the lower part will have not,and as a result,heat will penetrate into the building through the area where the PCM is in a liquid phase.In the end,the PCM becomes ineffective in controlling the indoor temperature and is rendered useless.

Dr.Karng's team addressed the non-uniform phase change with bubble injections.Injecting bubbles into the bottom part of the PCM enabled uniform circulation(流动)of the PCM in a liquid phase.Dr.Karng said,"We expect that the insulating wall using the PCM bubble generator used in this study will contribute to reducing the amount of energy used to heat or cool a building.Insulation techniques using the PCM help reduce heat penetration,in combination with the building insulating material,and it can also be used as the outer walls of zero-energy buildings."