【推荐1】To address the plastic pollution troubling the world’s seas and waterways, Cornell University chemists have developed a new polymer (聚合物) that can degrade (降解) when exposed to ultraviolet (紫外线的) radiation, according to the research published in the Journal of the American Chemical Society.

“We have created a new plastic that has the mechanical properties required by commercial fishing gear. If it eventually gets lost in the water environment, this material can degrade on a realistic time scale,” said lead researcher Bryce Lipinski, professor of chemistry and chemical biology at Cornell University. “This material could reduce persistent plastic accumulation in the environment.”

Commercial fishing contributes to about half of all floating plastic waste that ends up in the oceans. Fishing nets and ropes are primarily made from three kinds of polymers, none of which easily degrade. “While research of degradable plastics has received much attention in recent years,” Lipinski said, “obtaining a material with the mechanical strength comparable to commercial plastic remains a difficult challenge.”

Coates and his research team have spent the past 15 years developing the new plastic called isotactic polypropylene oxide, or iPPO. While its original discovery was in 1949, the mechanical strength of this material was unknown before this recent work. The high isotacticity and polymer chain length of their material makes it different from previous plastics and provides its mechanical strength.

Lipinski noted that while iPPO is stable in ordinary use, it eventually breaks down when exposed to UV light. The change in the plastic’s composition is evident in the laboratory, but “visually, it may not appear to have changed much during the process,” he said, “The rate of degradation is light intensity-dependent, but under their laboratory conditions, the polymer chain lengths degraded to a quarter of their original length after 30 days of exposure.”

Lipinski and other scientists want no trace of the polymer to be left in the environment. He notes there is precedent for the biodegradation of small chains of iPPO which could effectively make it disappear and ongoing efforts aim to prove this.

【推荐1】Linda Evans was my best friend — like the sister I never had. We did everything together: taking piano lessons, going to the movies, swimming, and horseback riding.

When I was 13, my family moved away. Linda and I kept in touch through letters, and we saw each other on special time — like my wedding(婚礼) and Linda’s. Soon we were busy with children and moving to new homes, and we wrote less often. One day a card that I sent came back, stamped “Address Unknown.” I had no idea how to find Linda.

Over the years, I missed Linda very much. I wanted to share the happiness of my children and then grandchildren with her. And I needed to share my sadness when my brother and then my mother died. There was an empty place in my heart that only a friend like Linda could fill.

One day I was reading a newspaper when I noticed a photo of a young woman who looked very much like Linda and whose last name was Wagmans — Linda’s married name. “There must be thousands of Wagmans,” I thought, but I still wrote to her.

She called as soon as she got my letter. “Mrs. Tobin!” she said excitedly, “Linda Evans Wagmans is my mother.” Minutes later I heard a voice that I knew very much, even after 40 years, then we laughed and cried and caught up on each other’s lives. Now the empty place in my heart is filled. And there’s one thing that Linda and I know for sure: We won’t lose each other again.

【推荐2】When I was in the seventh grade, I volunteered about thirty to forty hours a week during the summer at a local hospital in my town. Most of the time I spent there was with Mr. Gillespie, who never had any visitors. Nobody seemed to care about his condition.

I spent many days there holding his hand and talking to him, helping with anything that needed to be done. He became a close friend of mine, even though he responded with only an occasional squeeze of my hand. Mr. Gillespie was in a coma (昏迷).

I left for a week to vacation with my parents, and when I came back, he was gone. I didn’t have the nerve to ask any of the nurses where he was, for fear they might tell me he had died. So with many questions unanswered, I continued to volunteer there through my eighth-grade year.

One day several years later, when I was at the gas station I noticed a familiar face. When I realized who it was, my eyes filled with tears. He was alive! I asked him if he was Mr. Gillespie. With an uncertain look on his faces, he replied yes. I explained how I knew him. His eyes welled up with tears, and he gave me the warmest hug I had ever received.

He began to tell me how, as he lay there comatose, he could hear me talking to him and could feel me holding his hand the whole time. He thought it was an angel, not a person, who was there with him. Mr. Gillespie firmly believed that it was my voice and touch that had kept him alive.

Although I haven’t seen him since, he fills my heart with joy every day. I know that I made a difference between his life and his death. More important, he has made a tremendous difference in my life. I will never forget him and what he did for me: he made me an angel.

【推荐2】One Sunday, Nicholas, a teenager, went skiing at Sugarloaf Mountain in Maine. In the early afternoon, when he was planning to go home, a fierce snowstorm swept the area. Unable to see far, he accidentally turned off the path. Before he knew it, Nicholas was lost, all alone! He didn’t have food, water or a phone. He was getting colder by the minute.

Nicholas had no idea where he was. He tried not to panic. He thought about all the survival shows he had watched on TV. It was time to put the tips he had learned to use.

He decided to stop skiing. There would be a better chance of someone finding him if he stayed put. The first thing he did was to seek shelter from the freezing wind and snow. If he didn’t, his body temperature would get very low, which could quickly kill him. Using his skis, Nicholas built a snow cave. He gathered a huge mass of snow and dug a hole in the middle. Then he piled branches on top of himself, like a blanket, to stay as warm as he could.

By that evening, Nicholas was really hungry. He ate snow and drank water from a nearby stream so that his body wouldn’t lose too much water. Not knowing how much longer he could last, Nicholas huddled (蜷缩) in his cave and slept.

The next day, Nicholas went out to look for help, but he couldn’t find anyone. He had to follow his tracks and return to the snow cave. On Tuesday, Nicholas went out again to seek help. He had walked for about a mile when a volunteer searcher found him. Having been stuck in the snow for two days, Nicholas was saved.

Had it not been for TV, Nicholas might not have survived this snowstorm. He had often watched Bear Grylls’ survival show Man vs.Wild. That’s where he learned the tips that saved his life. When Bear heard about Nicholas’ amazing deeds, he was super impressed that Nicholas had made it since he knew better than anyone how hard Nicholas had to work to stay alive.

【推荐3】I received a private message on Facebook. It began harmlessly enough: “Hey, girl. Wanted to invite you to join my next challenge group — we'll be focusing on fitting in 30 minutes of exercise and balanced nutrition.”

It was all becoming too much. Facebook was running my life, not me. But what killed Facebook for me was when I posted a photo, and five minutes later my son asked me how many “likes” it had got. His question was a wake-up call. “Likes” are signs of acceptance and approval(认可). I had forgotten that acceptance and approval need to come from within and had unknowingly set him a bad example.

Before Facebook, surfing the Internet was an occasional distraction and I spent a lot more time reading books and magazines. I checked in with friends through texts, emails and phone calls. To recreate the simplicity (质朴) of those days and set a healthier example for my son, I deactivated my Facebook account.

I'd been in the habit of checking Facebook many times a day, so I had to come up with some new habits. I carried a novel and a crossword puzzle book around with me. I rediscovered knitting (针织). I started taking yoga classes.

I started to remember a few things. My body is fine just the way it is. I have friends who will help me out when I'm in trouble, and I will help them out. I do my best to be a good mother, and our son is happy and healthy. We are very lucky to be able to afford two vacations a year. I stopped looking at the world through my cellphone. I felt completely present in the moment. The break left me feeling better about myself, my family, my home and my life.

After a few weeks, I returned to Facebook. Now I look at the photos of my friends' kids growing up and treasure how social media allows me to keep in touch with family far and wide. I look in on a daily basis, but no longer with the desire constantly to post updates. It is not an addiction any more.