大学英语自学教程（下）电子版
upon that composes a musical work, day after day, in painstaking fashion. Most composers since Beethoven's day belong to this second type.
The third type of composer I can only call, for lack of a better name, the traditionalist type. Men like Palestrina and Bach belong in this category. They both are characteristic of the kind of composer who is born in a particular period of musical history, when a certain musical style is about to reach its fullest development. It is a question at such a time of creating music in a well-known and accepted style and doing it in a way that is better than anyone has done it before you.
The traditionalist type of composer begins with a pattern rather than with a theme. The creative act with Palestrina is not the thematic conception so much as the personal treatment of a well-established pattern. And even Bach, who composed forty-eight of the most various and inspired themes in his Well Tempered Clavichord, knew in advance the general formal mold that they were to fill. It goes without saying that we are not living in a traditionalist period nowadays. One might add, for the sake of completeness, a fourth type of composer -- the pioneer type: men like Gesualdo in the seventeenth century, Moussorgsky and Berlioz in the nineteenth, Debussy and Edgar Varese in the twentieth. It is difficult to summarize the composing methods of so diversified a group. One can safely say that their approach to composition is the opposite of the traditionalist type. They clearly oppose conventional solutions of musical problems. Inmany ways, their attitude is experimental ?they seek to add new harmonies, new sonorities, new formal principles. The pioneer type was the characteristic one at the turn of the seventeenth century and also at the beginning of the twentieth century, but it is much less evident today.
06-A. Improving Industrial Efficiency through Robotics
Robots, becoming increasingly prevalent in factories and industrial plants throughout the developed world, are programmed and engineered to perform industrial tasks without human intervention.
Most of today's robots are employed in the automotive industry, where they are programmed to take over such jobs as welding and spray painting automobile and truck bodies. They also load and unload hot, heavy metal forms used in machines casting automobile and truck frames. Robots, already taking over human tasks in the automotive field, are beginning to be seen, although to a lesser degree, in other industries as well. There they build electric motors, small appliances, pocket calculators, and even watches. The robots used in nuclear power plants handle the radioactive materials, preventing human personnel from being exposed to radiation. These are the robots responsible for the reduction in job-related injuries in this new industry. What makes a robot a robot and not just another kind of automatic machine? Robots differ from automatic machines in that after completion of one specific task, they can be reprogrammed by a computer to do another one. As an example, a robot doing spot welding one month can be reprogrammed and switched to spray painting the next. Automatic machines, on the other hand,
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are not capable of many different uses; they are built to perform only one task.
The next generation of robots will be able to see objects, will have a sense of touch, and will make critical decisions. Engineers skilled in microelectronics and computer technology are developing artificial vision for robots. With the ability to \one specific class of objects out of a stack of different kinds of materials. One robot vision system uses electronic digital cameras containing many rows of light-sensitive materials. When light from an object such as a machine part strikes the camera, the sensitive materials measure the intensity of light and convert the light rays into a range of numbers. The numbers are part of a grayscale system in which brightness is measured in a range of values. One scale ranges from 0 to 15, and another from 0 to 255. The 0 is represented by black. The highest number is white. The numbers in between represent different shades of gray. The computer then makes the calculations and converts the numbers into a picture that shows an image of the object in question. It is not yet known whether robots will one day have vision as good as human vision. Technicians believe they will, but only after years of development.
Engineers working on other advances are designing and experimenting with new types of metal hands and fingers, giving robots a sense of touch. Other engineers are writing new programs allowing robots to make decisions such as whether. to discard defective parts in finished products. To do this, the robot will also have to be capable of identifying those defective parts. These future robots, assembled with a sense of touch and the ability to see and make decisions, will have plenty of work to do. They can be used to explore for minerals on the ocean floor or in deep areas of mines too dangerous for humans to enter. They will work as gas station attendants, firemen, housekeepers, and security personnel. Anyone wanting to understand the industry of the future will have to know about robotics.
06-B. Predicting Earthquakes
Can earthquakes be predicted? Scientists are working on programs to predict where and when an earthquake will occur. They hope to develop an early warning system that can be used to forecast earthquakes so that lives can be saved.
Earthquakes are the most dangerous and deadly of all natural events. They occur in many parts of the world. Giant earthquakes have been recorded in Iran, China, Guatemala, Chile, India, and Alaska. Two of the biggest earthquakes that were ever recorded took place in China and Alaska. These earthquakes measured about 8.5 on the Richter Scale. The Richter Scale was devised by Charles Richter in 1935, and compares the energy level of earthquakes. An earthquake that measures a 2 on the scale can be felt hut causes little damage. One that measures 4.5 on the scale can cause slight damage, and an earthquake that has a reading of over 7 can cause major damage. It is important to note that a reading of 4 indicates an earthquake ten times as strong as one with a reading of 3.Scientists want to be able to predict those earthquakes that have a reading of over 4 on the Richter Scale.
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How do earthquakes occur? Earthquakes are caused by the shifting of rocks along cracks, or faults, in the earth's crust. The fault is produced when rocks near each other are pulled in different directions. The best-known fault in North America is the San Andreasfault in the state of California in the United States.
The nations that are actively involved in earthquake prediction programs include Japan, China, Russia, and the United States. These countries have set up seismic networks in areas of their countries where earthquakes are known to occur. These networks are on the alert for warning signs that show the weakening of rock layers that can precede an earthquake. Many kinds of seismic instruments are used by the networks to monitor the movements of the earth's crust. The scientists also check water in deep wells. They watch for changes in the water level and temperature that are associated with movement along faults.
Scientists in China, Russia, and the United States measure radon in ground water. Radon is a gas that comes from the radioactive decay of radium in rocks. The gas flows through the ground and dissolves in underground streams and wells. Scientists speculate that the amount of radon increases in the ground when rocks layers shift, exposing new rock, and thus more radon. Chinese and Russian scientists have reported that in places where stress is building up, the radon levels of the water build up too. When the radon levels of the water subside and drop back to normal readings, an earthquake may occur. United States scientists have also placed radon monitoring stations in earthquake zones, particularly California. However, all the scientists agree that more data is necessary to prove that radon levels in water are associated with the possible birth of an earthquake.
Earthquake prediction is still a young science. Everyone agrees that earthquakes cannot be predicted with any reliability. Scientists have only a partial understanding of the physical processes that cause earthquakes. Much more research has to be done. New and more up-to-date methods have to be found for collecting earthquake data and analyzing it. However, scientists have had some success in predicting earthquakes. Several small earthquakes were predicted in New York State, in the eastern part of the United States. Chinese scientists predicted a major one in Haicheng in 1975, and Russian scientists predicted a major one in Garm in 1978. While this is a small start, it is still a beginning.
07-A. Leisure and Leadership
Observations and research findings indicate that people in advanced industrial societies are increasingly concerned with opportunities for leisure and what they can do in their leisure time. The importance people attach to paid holidays and the rapid development of services for mass entertainment and recreation are signs of this increasing concern.
The term \of life\is difficult to define. It covers a very wide scope such as living environment, health, employment, food, family life, friends, education, material possessions, leisure and recreation, and so on. Generally speaking, the quality of life, especially as seen by the individual, is meaningful in terms of the degree to which these various areas of life are
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available or provide satisfaction to the individual.
As activity carried out as one thinks fit during one's spare time, leisure has the following functions: relaxation, recreation and entertainment, and personal development. The importance of thesevaries according to the nature of one's job and one's life-style. Thus, people who need to exert much energy in their work will find relaxation most desirable in leisure. Those with a better education and in professional occupations may tend more to seek recreation and personal development (e.g., cultivation of skills and hobbies) in leisure.
The specific use of leisure varies from individual to individual. Even the same leisure activity may be used differently by different individuals. Thus, the following are possible uses of television watching, a popular leisure activity: a change of experience to provide \the stress and strain of work; to learn more about what is happening in one's environment; to provide an opportunity for understanding oneself by comparing other people抯 life experiences as portrayed in the programmes.
In an urban society in which highly structured, fast-paced and stressful work looms large in life, experiences of a different nature, be it television watching or bird-watching, can lead to a self-renewal and a more \
Since leisure is basically self-determined, one is able to take to one's interests and preferences and get involved in an activity in ways that will bring enjoyment and satisfaction.
Our likes and dislikes, tastes and preferences that underlie our choices of such activities as reading books, going to the cinema, camping, or certain cultural pursuits, are all related to social contexts and learning experiences. We acquire interests in a variety of things and subjects from our families, schools, jobs, and the mass media. Basically, such attitudes amount to a recognition that leisure is an important area of life and a belief that leisure can and should be put to good use.
Professional workers in recreation services, too, will find that to impart positive leisure attitudes to the general public is essential for motivating them to use their leisure in creative and satisfying ways. Hence, it can be argued that the people with whom we come into contact in these various contexts are all likely to have exerted some influence in shaping our attitudes, interests and even skills relevant to how we handle leisure. Influence of this kind is a form of leadership.
Parents, teachers in schools, work associates and communicators in or using the mass media are all capable of arousing our potential interests. For example, the degree to which and the ways in which a school encourages participation in games, sports and cultural pursuits are likely to contribute to the shaping of leisure attitudes on the part of the students.
Schools usually set as their educational objective the attainment of a balanced development of the person. The more seriously this is sought, the more likely positive attitudes towards leisure as well as academic work will be encouraged.
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