Master painter Zhang Daqian (1899-1983) was well known for having a large number of friends and students. Among them, painter Li Qiujun was special.

    They got to know each other through Li's elder brother, who was one of Zhang's best friends.

    They admired each other's artistic talent and became confidants, which resulted in a romantic relationship.

    In 1948, Zhang produced Spring Clouds Amid Autumn Landscape, a mountain-and-water ink painting featuring gongbi (meticulous brushwork), as a gift for Li's 50th birthday.

    A year later, Zhang permanently departed from the mainland, and traveled and exhibited around the world before settling down in Taipei in 1976.

    After leaving the mainland, he often said that he missed Li, who died in Shanghai in 1973.

    Spring Clouds Amid Autumn Landscape will be auctioned in Hong Kong on Oct 4.

    The painting not only marks a friendship between the two painters, but it deserves special attention because it shows Zhang at the top of his game as he sought to master the mountain-and-water style, according to C.K. Cheung, head of Sotheby's Chinese painting department.

    Sotheby's will auction the work at its major autumn sale, which runs from Oct 1 to 5.

    Cheung says the painting's composition and Zhang's attention to details reflect his incorporation of traditional touches, especially from Song Dynasty (960-1279) paintings, while also developing his own style.

    The bike-sharing companies that are powering a transportation revolution in China's urban centers are not like those in the rest of the world. Their bikes have no docking ports or assigned zones for parking. Instead, riders open their smartphone apps, hop on, and start riding. So easy!

    In 2015, Ofo, China's bike-share pioneer, launched its first fleet of bicycles in Beijing. The bikes' bright yellow frames were soon met by the orange-rimmed（镶边）, basket-equipped models launched by Mobike, Ofo's main competitor today. In little over a year, the two companies have had a huge impact on revitalizing (重振) cycling in China, particularly among young people.

    Ofo placed 1 million bicycles across 35 cities and registered 15 million users in its first years, while Mobike has now gained more than 10 million unique users and bicycles in 21 cities. Inspired by their success, at least 10 other companies have jumped into the market, launching their own app-powered, brightly colored bikes in quick succession. But Mobike and Ofo are far ahead of them.

    The two industry leaders each take a different marketing method to a similar product. The Mobike app uses GPS to display bikes' locations to users. They can use the map to reserve a bike and walk over to it. A scan of the bike's QR code (二维码) unlocks the bike, and when users manually（手动地） lock the bike at the end of their trip, the app records the trip's end and the bike will pop back up on the map as available. Equipped with this wireless technology, Mobikes cost between 1,000 and 3,000 yuan. Rides cost 1 yuan for an hour or a half hour, depending on whether a user chooses a “Lite” or regular bike, and the deposit (押金) required to the service is 299 yuan.

Ofo, meanwhile, is devoted not just to producing its own bikes, which have slim yellow bodies and cost about 250 yuan, but also to connecting existing bikes to its network—-- a philosophy that begins with the practice of 2000 bikes offered to a campus bike-share program. The 2000 bikes were the first generation of Ofo. Yet the majority of the company's bikes are currently ones that have been specially manufactured and fitted with their lock system. Unlike Mobike,Ofo bikes themselves are offline: their locations are tracked through users' cell phones. Users find a free bike, enter the license plate number into their app, and receive the bike unlock code. When they have reached their destination, they end the ride on the app and manually lock the bike. Rides cost 1 yuan for an hour and the deposit is 99 yuan.

    There is one type of illness in the world that has a severe effect on more people than anything else and is very deadly. If untreated, this illness could affect everything you do. What is this illness? Depression. Serious depression requires professional treatment. Self-induced depression is something each of us can change.

    Everyone's circumstances are different, but the causes of self-induced depression are common: low self-esteem, hurtful thinking and a bad attitude.

    So how can we change the way we think, feel, and have a cheerful attitude?

    First we must look at ourselves, truly and honestly examining our motives for what we wish to accomplish. If you are dissatisfied because you feel you haven't or can't do anything, then one step is needed—to set goals.

    Always start your goals relatively small and easy to attain. Think of them as sand; one grain may be insignificant(微不足道的) but as a group they form the beach. Once you have set and attained small goals for yourself, move on to slightly larger, more challenging goals.It takes not just setting goals but positive thinking. How can we obtain this?

    There are a number of factors that can make us think negatively and one of those is diet.In my opinion, a person who eats a lot of take-out and fast food is feeding their body junk. Start by eating better foods which give the body much NEEDED minerals. If your physical body is happy, it's much easier for your mental body or “thinking ability” to be happy.

    Next, exercise. Half an hour a day is recommended for positive well-being. Then think about good memories you had, or generally think of things that make you smile. Remember, everything you wear costs money but to wear a smile is free. A smile can be the difference between an average day and a great day.

    If you follow these steps, positive change is on the way.

    We would like to wish all our readers a wonderful winter break. Our January magazine is now in the shops and available digitally. We're looking forward to sharing more adventures and discoveries with you in 2018, including:

    At a crossroads in the Atlantic

    As the population of Ascension Island rises up to mark the 200th anniversary of British rule, Fred Pearce wonders what the future might have in store for this strange part of land.

    Photostory: On the road again

    A selection of images from an exhibition opening this month at the Royal Geographical Society go hand in hand with M. Aurel Stein's early 20th century photographs of the Silk Road.

    Dossier: Going underground

    Mark Rowe discusses the role that carbon storage can play in the global effort to reduce carbon dioxide emission (排放).

    Net loss

    Kit Gillet reports from the Gulf of Thailand, whose fisheries (渔场) have been almost destroyed by the commercialization of the Thai fishing industry.

    And don't forget...a round-up of the latest geographical and climate science news; a hot spot focus on Turkey; advice on taking photographs in Antarctica; an interview with Lucien Castaing-Taylor, professor of visual arts at Harvard; plus lots, lots more...

    Buy your copy now, click here and save up to 35% or call+44

    One of the most important things in the world is friendship. In order to have friends, you have to be a friend. But how can you be a good friend at school？

Listen﹣Listen when they are talking. Don't say anything unless they ask you a question. Sometimes it's not necessary for you to have anything to say; they just need someone to talk to about their feelings.

    Help them﹣If your friend is ever in need of something, be there to help them. You should try to put them first, but make sure you don't do everything they want you to do. Try to take an extra pencil or pen with you to classes in case they forget one. Have a little extra money in your pocket in case they forget something they need.

    Be there for them﹣Be there for your friends to help make them feel better in hard times. Marilyn Monroe, a famous U.S. actor, once said, "I often make mistakes. Sometimes I am out of control, but if you can't stay with me at my worst, you are sure not to deserve to be with me at my best." Always remember this! If you don't want to stay with your friends when they're in hard times, then you don't deserve to be with them when they're having a good time!

    Make plans﹣Try to make plans with your friends. Go shopping, go for ice cream, have a party, go to a movie and so on. Take time to know each other even better by doing something you both enjoy. By planning things together, you both can have a good time. And you'll remember these things when you're all old!

    Happy birthday! Do birthdays really make people happy? Of course they do. Birthdays celebrate the day we were born. Besides, that extra candle on the cake suggests another year of growth and maturity (成熟)— or so we hope. We all like to imagine that we're getting wiser and not just older. Most of us enjoy seeing the miracle(奇迹) of growth in others, as well. For instance, seeing our children develop and learn new things makes us feel proud. For Americans, like people in most cultures, growing up is a wonderful process(过程). But growing old? That's a different story.

    Growing old is not exactly pleasant for people in youth-oriented(以年轻人为中心) American culture. Most Americans like to look young,act young and feel young. As the old saying goes, "You're as young as you feel." Older people joke about how many years young they are, rather than how many years old. People in some countries value the aged as a source of experience and wisdom. But Americans seem to favor those that are young, or at least "young at heart."

    Many older Americans find the "golden years" to be anything but golden. Economically, "senior citizens" often struggle just to get by. Retirement(退休) at age 65 brings a sharp decrease in personal income. Social security(安全) benefits usually cannot make up the difference. Older people may suffer from poor nutrition(营养), medical care and housing. Some even experience age discrimination. In 1987, American sociologist Pat Moore dressed up like an older person and wandered city streets. She was often treated rudely — even cheated and robbed. However, dressed as a young person, she received much more respect.

    Unfortunately, the elderly population in America is increasing fast. Why? People are living longer. Fewer babies are being born. And middle-aged "baby boomers" are rapidly entering the groups of the elderly. America may soon be a place where wrinkles(皱纹) are "in". Marketing experts are already noticing this growing group of consumers.