Once a piece of fruit or a vegetable is picked, it starts to go bad. One common way to slow or stop that is to remove water from the foods. The process—dehydration (脱水)—typically uses heat, which can destroy their nutrients (营养). Now, researchers have come up with a new way, and it may help make dried fruit and vegetables more nutritious.
A common way to dry fruit and vegetables is to blow hot air across them. “But there’s another way to get air moving, and it doesn’t need a fan or heat,” says Kamran Iranshahi. He’s a mechanical engineer. Called “ionic wind (离子风)”, this technique had never seemed ready for being used widely. So Iranshahi’s team began improving the process.
In earlier research, the fruit and vegetables to be dried rested on a metal plate. As airflow never reached the underside of the foods, those pieces dried rather slowly. Iranshahi’s team has just replaced the plate with a metal mesh (网孔). That seemingly small change appears to have made a big difference. Using it, the team has not only cut the drying time, but in the latest test it also has dropped the energy use by more than 85 percent!
“People considered the hot air drying process as good enough for many years. But now, more and more people are worried about the health of their foods, so the popularity of drying foods with air moved by a fan or heat has waned,” says Vijaya Raghavan. He’s a mechanical engineer at McGill University in Montreal, Canada. “This team’s impressive invention”, he says, “may now make it easier to offer healthy and tasty dried foods.”
The new version of ionic wind could be more energy efficient, Iranshahi says. So far, few studies have tested the nutrient content of produce dried with ionic wind. However, Iranshahi notes, the new technique should destroy fewer nutrients than heat-based methods, and his team will focus on that in future studies.
1. What can we say about the work of Iranshahi’s team?| A．It causes a waste of resources. |
| B．It saves much time and energy. |
| C．It is costly for using high technology. |
| D．It changes the previous design completely. |
| A．Worked. | B．Begun. | C．Weakened. | D．Grown. |
| A．Satisfied. | B．Worried. | C．Doubtful. | D．Surprised. |
| A．Iranshahi is proud of his team’s achievements. |
| B．Heat-based methods of drying foods will be given up. |
| C．Iranshahi’s team will keep working on getting healthy dried foods. |
| D．The drying method with ionic wind has attracted public attention. |
相似题推荐
【推荐1】Making a transition away from fossil fuels and towards low-carbon energy is the only way to keep our planet safe and habitable for future generations. That transition has thankfully begun, but it has a vast distance to go. And the kinds of changes that are needed cost money. Development of new technology has always required investment.
This applies to the generation of renewable energy, and to the countless lifestyle changes that follow from the shift away from coal, oil and gas. Electric cars and other transport are one example. Packaging to replace plastic is another. Resources are also required to protect societies from the harms caused by the global heating that has already happened, and to help them adjust to altered conditions.
A new report presented at the Cop27 UN climate summit says that about S2tn (£1.75tn) a year will be needed by 2030 if developing countries are to make the necessary changes. One of the authors, Nicholas Stern, pointed to a crucial role for the World Bank as well as western governments in redirecting finance and reducing the cost of capital for investors (banks typically charge higher interest on investments in poor countries, due to predicted risks).
The promise made in 2009 of S100bn worth of climate finance annually from rich countries to poorer ones has been broken. But developing countries have succeeded in getting loss and damage on to the formal Cop agenda (议程) for the first time. So far, five European countries have agreed to contribute to a fund to help weak countries manage global beating’s destructive effects. These commitments are welcome, but insufficient.
Carbon emissions, and the dangerously warming planet they have led to, are the byproduct of the way that the rich world developed. Since industrialisation, we have burned our way to wealth. Thankfully, we now know that there are alternatives to this destructive patter. Renewable energy, along with social change aimed at limiting some forms of consumption, is at the heart of this prospectus (会议章程).
1. What does the underlined word “This” refer to in paragraph 2?| A．Transition | B．Investment |
| C．New technology | D．Low-carbon energy |
| A．Disapproving | B．Suspicious | C．Unconcerned | D．Unsatisfactory |
| A．By limiting our consumption. |
| B．By developing the byproducts. |
| C．By changing the destructive pattern. |
| D．By holding the Cop27 UN climate Summit. |
| A．A green transition requires funding. |
| B．The rich world must do more in the transition. |
| C．Rich countries are to blame for carbon emissions. |
| D．Development of new technology is urgently-needed. |
【推荐2】When robots and humans interact in the same environment, it is important for them to move in techniques that monitor an environment, predict the future actions of humans, identify secure track for a robot and control its movements accordingly.
Predicting human behavior and movements, however, can be incredibly challenging. Determining the future movements of a robot, on the other hand, could be far easier. If human users could anticipate the movements of robots and the effects these will have on the surrounding environment, they should then be able to easily adapt their actions in order to avoid accidents.
With this in mind, researchers at Kyushu University in Japan recently created a near-future perception system named Previewed Reality that allows human users to forecast future changes in their environment, which could then inform their decisions and guide their actions. This system compiles (编译) a data-set containing information about the position of objects, humans and robots within the same environment, to then produce simulations (模拟) of events that could take place in the near future. These simulations are presented to human users via Virtual Reality (VR) or Augmented Reality (AR) headsets.
To collect information about the position of different objects, robots, and humans in the same environment, the researchers used a number of strategically placed sensors, including optical trackers that monitored the movements of objects or robots, and a RGB-D camera which mainly tracked human actions. The data gathered by the sensors was then fed to a motion planner and a dynamics simulator. Combining these two system components allowed the researchers to forecast changes in a given environment and synthesize (合成) images of events that are likely to occur in the near future, from the viewpoint of a specific human. Human users could then view these synthesized images simply through a VR headset or an AR display.
“This system provides human-friendly communication between a human and a robotic system.” the researchers explained. In their next studies, they plan to expand and simplify the perception system, for instance by creating a lighter and more affordable version that can operate on smart phones or other portable devices.
1. Why did the researchers develop the system?| A．To predict future changes in human behavior. |
| B．To record developments in the field of robotics. |
| C．To enhance safety of human-robot interactions. |
| D．To make good use of virtual reality technology. |
| A．It simulates near-future events via VR headsets. |
| B．It enables human users to perceive future events. |
| C．It guides robots to track humans’ movements easily. |
| D．It helps determine the position information of objects. |
| A．The functions of the system components. | B．The dynamic way to synthesize images. |
| C．The inner structure of Previewed Reality. | D．The working procedure of Previewed Reality. |
| A．Promote the new version through advertising. |
| B．Trial this perception system with smart phones. |
| C．Make the system accessible on portable devices. |
| D．Apply some new techniques to robotic systems. |
【推荐3】Larger brain size linked to longer life in deer
The size of a female animals’ brain may determine whether they live longer and have more healthy offspring (后代), according to new research led by the University of Cambridge.
The study, published in the Royal Society Open Science journal, shows that female red deer with larger brains live longer and have more surviving offspring than those with smaller brains. Brain size is passed down through the generations. This is the first extensive study of individual differences in brain size in wild mammals and draws on data comparing seven generations of deer.
Across species of mammals, brain size varies widely. This is thought to be a consequence of specific differences in the benefits and costs of a larger brain. Mammals with larger brains may, for example, have greater cognitive abilities that enable them to adapt better to environmental changes or they may have longer lifespans (寿命) . But there may also be disadvantages: for instance, larger brains require more energy, so individuals that possess them may show reduced fertility (繁殖力).
The researchers, based at the University of Cambridge’s Zoology Department and Edinburgh University’s Institute of Evolutionary Biology, wanted to test if they could find more direct genetic or non-genetic evidence of the costs and benefits of large brain size by comparing the longevity (长寿) and survival of individuals of the same species with different sized brains. Using the skulls of 1,314 wild red deer whose life histories and breeding success had been monitored in the course of a long-term study on the Isle of Rum, they found that females with larger endocranial volumes (脑腔容量) lived longer and produced more surviving offspring in the course of their lives.
Lead author Dr Corina Logan, a Gates Cambridge Scholar, says, “The reasons for the association between brain size and longevity are not known, but other studies have suggested that larger brains are a consequence of the longer-lived species having longer developmental periods in which the brain can grow. These hypotheses (假设) were generated from cross-species correlations; however, testing such hypotheses requires investigations at the within-species level, which is what we did.”
Dr Logan adds, “We found that some of the cross-species predictions about brain size held for female red deer, and that none of the predictions were supported in male red deer. This indicates that each sex likely experiences its own set of trade-offs (权衡，协调) with regard to brain size.” The study also showed that females’ relative endocranial volume is smaller than that of males, despite evidence of selection for larger brains in females.
Professor Tim Clutton-Brock, who set up the Rum Red Deer study with Fiona Guinness in 1972 and initiated the work on brain size, points out, “The reason that this kind of study has not been conducted before is that it requires long term records of a large number of individuals across multiple generations and data of this kind are still rare in wild animals.”
1. What does the new research about brain size reveal?| A．Large-brain red deer tend to be more reproductive. |
| B．Large-brain female deer survive small-brain male deer. |
| C．Brain size causes individual differences in some mammals. |
| D．Brain size has been increasing from generation to generation. |
| A．mammals can develop different adaptive abilities |
| B．a larger brain has its advantages and disadvantages |
| C．different mammals are born with different lifespans |
| D．brain size is affected by genetic or non-genetic factors |
| A．The cause and effect needs to be further investigated. |
| B．Brain size absolutely determines animals’ longevity. |
| C．Longer-lived species allow brains to grow to a large size. |
| D．The cross-species assumptions apply to red deer of both sexes. |
| A．Researchers can’t possibly reach a conclusion about the reason. |
| B．Researchers are not patient enough to keep long term records. |
| C．Such research has been thoroughly conducted on wild animals before. |
| D．Such research will witness great difficulty in the long-term process. |
【推荐1】A huge 42 percent of marriages in the UK end in divorce, the highest rate in Europe. What is happening in the UK to cause such a phenomenon? Many consider the family to be the basic building block of society. If marriages and families are falling apart, is the UK society also falling apart? Is the UKs cultural identity breaking down? The UK of today is one of the most multicultural countries on earth. There are exotic sights and sounds on the street corners of every British city. British cuisine is now one of the most diverse around. Everyone speaks with a different accent.
Is such diversity a good thing? Well, it makes the UK a very exciting place to live in. There are new ideas everywhere. There is great freedom to be who you want to be, and most people will not criticize you for who you are. Yet such freedom seems to come at a cost. Some British people regard ethnic minorities (少数民族) as coming to the UK to steal jobs. When the economy does badly, this feeling increases as unemployment rates rise. So, it could be argued that the breakdown of marriages in the UK is in some part because of the pressures put upon families by wider problems in British society. Many people become stressed when those problems arise, and that can then make their family life unhappy as well.
Another possible reason for the high divorce rate might be that marriage no longer has the same value or meaning for British people as it once did. Church attendance in the UK has been falling for the last 50 years, suggesting fewer people consider marriage a holy thing. Since 1991, there has been a drop of 50 percent in people getting married in church rather than a register office.
Then there is the financial side. In the past, married couples paid lower government taxes than single people. That tax incentive (激励) policy, which used to reduce a couples tax by up to 500 in a year, has now disappeared, making the cost to keep a marriage higher.
However, the 42 percent UK divorce rate isn’t the highest rate in the past forty years! Meanwhile, some measures are being taken to strengthen marriage in the UK by the government.
1. According to the text, all the following account for the high divorce rate except .| A．Desire for freedom. | B．Social problems. |
| C．Change of values. | D．Financial pressures. |
| A．amazing | B．foreign |
| C．local | D．familiar |
| A．Cultural diversity has brought people freedom to criticize others. |
| B．The rising of the divorce rate indicates the society is falling apart. |
| C．The tax incentive policy once contributed to steady families to some degree. |
| D．More British people would get married in the church rather than in a register office. |
| A．Pessimistic. | B．Unconcerned. | C．Doubtful. | D．Optimistic. |
(1) women are helped more than men;
(2) men help more than women;
(3) attractive women are helped more than unattractive women.
Other factors relate to the number of people in the area, whether the person is thought to be in trouble through their own fault, and whether a person sees himself as being able to help.
According to Adrian Furnham, Professor of University College, London, there are three reasons why we tend to stand by doing nothing:
(1) “Shifting of responsibility”— the more people there are, the less likely help is to be given. Each person excuses himself by thinking someone else will help, so that the more “other people’ there are, the greater the total shifting of responsibility.
(2) “Fear of making a mistake” — situations are often not clear. People think that those involved in an accident may know each other or it may be a joke, so a fear of embarrassment makes them keep themselves to themselves.
(3) “Fear of the consequences if attention is turned on you, and the person is violent.”
Laurie Taylor, Professor of Sociology at London University, says: “In the experiments I’ve seen on intervention (介入), much depends on the neighborhood or setting. There is a silence on public transport which is hard to break. We are embarrassed to draw attention to something that is happening, while in a football match, people get involved, and a fight would easily follow.”
Psychotherapist Alan Dupuy identifies the importance of the individual: “The British as a whole have some difficulty intervening, but there are exceptional individuals in every group who are prepared to intervene, regardless of their own safety: These would be people with a strong moral code or religious ideals.”
1. Which of the following statements is true according to the passage?| A．Pretty women are more likely to be helped. |
| B．People on a bus are more likely to stop a crime. |
| C．Religious people are more likely to look on. |
| D．Criminals are more likely to harm women. |
| A．Sex. | B．Nationality. | C．Profession. | D．Setting. |
| A．When one is in trouble, people think it’s his own fault. |
| B．In a football match, people get involved in a fight. |
| C．Seeing a murder, people feel sorry that it should have happened. |
| D．On hearing a cry for help, people keep themselves to themselves. |
| A．to explain why bystanders behave as they do |
| B．to urge people to stand out when in need |
| C．to criticize the selfishness of bystanders |
| D．to analyze the weakness of human nature |
【推荐3】“I’ve never met a human worth cloning,” says cloning expert Mark Westhusin from his lab at Texas A&M University. “It’s a stupid endeavor.” That’s an interesting choice of adjective, coming from a man who has spent millions of dollars trying to clone a 13-year-old dog named Missy. So far, he and his team have not succeeded, though they have cloned two cows and expect to clone a cat soon. They just might succeed in cloning Missy this spring -------or perhaps not for another 5 years. It seems the reproductive system of man’s best friend is one of the mysteries of modern science.
Westhusin’s experience with cloning animals leaves him upset by all this talk of human cloning. In three years of work on the Missy project, using hundreds upon hundreds of dog’s eggs, the A&M team has produced only a dozen or so embryos carrying Missy’s DNA. None have survived the transfer to a surrogate (代孕的) mother. The wastage of eggs and the many spontaneously aborted fetuses (胎) may be acceptable when you’re dealing with cats or bulls, he argues, but not with humans. “Cloning is incredibly inefficient, and also dangerous,” he says.
Even so, dog cloning is a commercial opportunity, with a nice research payoff. Ever since Dolly the sheep was cloned in 1997, Westhusin’s phone has been ringing with people calling in hopes of making an exact copy of their cats and dogs, cattle and horses. “A lot of people want to clone pets, especially if the price is right,” says Westhusin. Cost is no obstacle for Missy’s mysterious billionaire owner; he’s put up $3.7 million so far to fund A&M’s research.
Contrary to some media reports, Missy is not dead. The owner wants a twin to carry on Missy’s fine qualities after she does die. The prototype is, by all accounts, athletic, good-natured and supersmart. Missy’s master does not expect an exact copy of her. He knows her clone may not have her temperament. In a statement of purpose, Missy’s owner and the A&M team say they are “both looking forward to studying the ways that her clones differ from Missy.”
Besides cloning a great dog, the project may contribute insight into the old question of nature vs. nurture. It could also lead to the cloning of special rescue dogs and many endangered animals.
However, Westhusin is cautious about his work. He knows that even if he gets a dog pregnant, the offspring, should they survive, will face the problems shown at birth by other cloned animals: abnormalities like immature lungs and heart and weight problems. “Why would you ever want to clone humans,” Westhusin asks, “when we’re not even close to getting it worked out in animals yet?”
1. By “stupid endeavor”, Westhusin means to say that ________.| A．animal cloning is not worth the effort at all |
| B．animal cloning is absolutely impractical |
| C．human cloning should be done selectively |
| D．human cloning is a foolish undertaking |
| A．study the possibility of cloning humans |
| B．search for ways to modify its temperament |
| C．examine the reproductive system of the dog species |
| D．find out the differences between Missy and its clones |
| A．Few private cloning companies could afford it. |
| B．Few people have realized its significance. |
| C．An exact copy of a cat or bull can be made. |
| D．It is becoming a prosperous industry. |
| A．Mr. Westhusin is going to clone a dog soon. |
| B．scientists are pessimistic about human cloning. |
| C．human reproductive system has not been understood. |
| D．rich people are only interested in cloning animals. |
