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In a unique research cooperation between Stratasys, Education, R&D departments and MIT’s Self-Assembly Lab, a new process is being developed, known as 4D Printing.
The 4D printing concept, which allows materials to “self-assemble (自行组装)” into 3D structures, was initially proposed by Massachusetts Institute of Technology faculty member Skylar Tibbits. Tibbits and his team combined a strand (缕) of plastic with a layer made out of “smart” material that could self-assemble in water. They advanced this concept by creating materials that can change into several different complicated shapes, though this kind of material remains the bottleneck of 4D technology.
To many people that are just starting to get used to the idea of 3D printers, the name 4D is causing confusion because they cannot understand where this fourth “dimension” coming from. 4D technology shares many of the same principles of 3D printing and is essentially still about creating a new, 3D structure out of certain component; however, Tibbits states the fourth dimension at work here comes from concept of the fourth dimension of time. The difference between these 3D and 4D creations is that these new forms have the ability to transform and adapt over time.
4D printing works through self-assembly — a system where “disordered elements form an “ordered” structure via an interaction. With these 4D printed materials, these disordered materials are strands or sheets of specially designed materials. Environmental changes then stimulate (刺激）a response from them so that they form a preprogrammed shape.
The idea of having adaptable technology that only relies on energy and non-human interactions raises some interesting questions about where 4D printing can be used and the practical applications in dangerous environments. This could mean improved infrastructures in extreme conditions, leading to a reduced need for workers to put themselves at risk, but the potential goes even further than that. The technology promises exciting new possibilities for a variety of applications. A solar panel or similar product could be produced in a flat shape onto which functional devices can be easily installed. It could then be changed to a compact shape for packing and shipping. After arriving at its destination, the product could be stimulated to form a different shape that serves its function. Also it could be used to build furniture, bikes, cars and even buildings. As with many of the ideas being put forward, it is easy to go a step too far into the extreme, but this just shows the potential of 4D in comparison to 3D.
The next stage for the research is to move from printing single strands to sheets and eventually whole structures. And water need not be the process’ s only energy source.
62. Which of the following displays the fourth dimension of 4D printing?
A. 4D printing creates a new, 3D structure out of certain component.
B. 4D technology reduces need for workers to put themselves at risk.
C. 4D technology can be used in many more fields than 3D printing.
D. 4D printed materials reshape themselves with conditions changing.
63. The major problem concerning the development of 4D printing lies in__________.
A. producing essential 4D printers
B. creating proper smart materials
C. providing a suitable environment
D. promoting practical applications
64. What does the passage lead you to believe?
A. 4D printing will take the place of 3D printing in the near future.
B. Most aspects of our daily life can be affected by 4D printing.
C. 4D printing will benefit humans by saving labor somehow.
D. Smart materials can be transformed into other types of material.
65. It can be inferred from the passage that__________.
A. electricity is not used in 4D technology
B. 4D printing has been applied in industry
C. more potential of 4D is to be discovered
D. smart materials can change in a random way
D
Dear Textual Healing,
I would be very interested in your recommendations for any books to help me through a difficult time of my life. At 57, f am feeling a bit lost. I have a wonderful, loving husband and bright, caring teenage daughter but I am lonely and have lost my spark for life.
I have always taken care of everyone and managed a career, but, after the death of my father this summer, my difficulties as a child in a terribly abnormal family have come back to me regularly. / have become unfocused and often alone while my husband is away frequently on business and my daughter busy with school and friends.
I am seeking the help of a therapist and taking care of myself but I would love to read something to help me “get my groove (理想状况）back” and reengage with life.
PC
Dear PC,
From the letter you’ve given us about your life, it’s no wonder you’re feeling a little lost. But before prescribing titles to help you get your groove back, I’d recommend taking a journey into Rebecca Solnit’s non-fiction book, A Field Guide to Getting Lost, which is packed with the wisdom of everyone from Pat Barker to Thoreau and Keats.
The word lost is rooted in the Old Norse “los”, meaning the disbanding of an army. “This origin suggests soldiers falling out of formation to go home, ceasing fighting with the wide world. I worry now that many people never disband their armies, never go beyond what they know,” Solnit writes. So instead of fearing that lost feeling, try seeing its potential for discovery. Explorers, remember, are always lost simply because they’re forever someplace new.
“Leave the door open for the unknown, the door into the dark,” Solnit advises. “That’s where the most important things come from, where you yourself came from, and where you will go.”
For something that asks a little less of the reader while still giving plenty in return, try a dose (―剂）of Anne Tyler, the beloved creator of numerous heroes whose serious conditions will move anyone who finds themselves in a midlife difficult situation. One such character is 53-year-old Rebecca Davitch, the heroine of Back When We Were Grownups. Like you, she’s combined marriage and motherhood with a career but suddenly finds herself feeling lonely in her own home. Could it be, she wonders, that she’s “turned into the wrong person"? Don't be fooled by the way this novel ambles along — as Rebecca revisits youthful ambitions and the college boyfriend she abandoned, it asks some heart-rending questions before arriving at a place of graceful, joyous acceptance.
Along similar lines, I'm also going to recommend The Unlikely Pilgrimage of Harold Fry by Rachel Joyce. Its hero is 65 when he learns that a former colleague sick. On his way to post her a note, he decides instead to visit her— on foot, from his home in deepest Devon to England's northernmost town, more than 600 miles away. You don’t manage that without focus! It’s a journey to a holy place that will take him 87 days to complete, during which he considers his childhood, marriage and relationship with his son, and becomes an accidental media sensation (轰动). By the time he reaches his destination, you’ll feel anything but tired.
Finally, Ruth Ozeki’s novel A Tale for the Time Being will charm the missing spark back into your life. Combining the diary of a sad Tokyo teenager with the story of the middle-aged novelist who finds it, washed ashore on a remote island off the coast of British Columbia, it’s a beautiful illustration of how our lives touch — and are touched by — others in ways we mightn't even be aware of. This Man Booker Prize finalist has plenty to teach about Zen Buddhism, and unless you happen to live in one of its settings, it provides a bracing change of scene, too.
One other suggestion: books, as we all know, make great companions but that doesn't mean they can’t be enjoyed in the company of others. If you find yourself home alone, why not slip one into your back pack and head out to a favourite café.
66. What has mainly led to PC’s negative attitude to life?
A. The lack of helpful books.
B. The blow of her father’s death.
C. The contrast between her devotion to others and her being ignored.
D. The contrast between her easy life and her family members busy life.
67. By mentioning the origin of the word lost, Textual Healing implies that__________.
A. PC should extend her knowledge by reading more
B. PC should stop struggling with anyone around her
C. PC had better try to avoid going someplace new
D. PC oughtn’t to be trapped in her present situation
68. Who clarifies the idea in his/her work that people are socially related?
A. Rebecca Solnit. B. Anne Tyler.
C. Rachel Joyce. D. Ruth 0zeki.
69. The character Rebecca Davitch is mentioned by Textual Healing because her experience is__________.
A. typical B. persuasive C. enjoyable D. extraordinary
70. Which of the following can be the proper title?
A. Which books will cure loneliness?
B. How can you get rid of loneliness?
C. Here are good examples for you
D. Books will keep you busy and healthy
