科技英语写作练习答案.docx

1、科技英语写作练习答案科技英语写作练习答案练习一一、1、an(人们对这课题的兴趣越来越浓。2、a (功率额定值是电阻器不会引起温度太大的上升而能安全地耗散的最大率。3、an(其主要的缺点是增加了噪声。4、The; a(该设备的成功设计需要详细地了解性能指标。5、the; a; a(在氢原子的布尔模型中,一个电子绕一个质子以半径为R的圆周转。6、the(频率的单位是赫兹。7、a; a; an; the(如果在电路的两端加上电压的话,就会有电流在电路中流动。8、/; /(图5-1画出了Oersted的实验。9、an(这里我们应该使用一个18伏的电池。10、A; a; a(机器是能够传递力来完成某一确

2、定目的的一种设备。11、The; /(水压机将在第14章加以考虑。12、The; the; the(研究处于运动中的流体,是力学中较为困难的分支之一,因为可能出现的现象是多种多样的。13、the; the /(我们容易确定参数的值。14、/; the(根据式(2-1,我们得到以下的关系式。15、an(在这里必须使用一根S形管子。16、the; /(作者工作在位于阿林顿的得克萨斯大学。17、an(这是一只R位的变换器。18、An(这里必须使用一个“异”或门电路。XOR = Exclusive OR二、1. This is an h parameter.2. We turn now to a di

3、scussion of local area networks.3. The Bainbridge mass spectrometer is as important an instrument as the optical spectrometer.4. It is necessary to find out how long a time is required for an electron to travel the this length of the wire.5. The density of a substance is its mass per unit volume.6.

4、The radius of the earth is 6.37106 m.7. The These two parameters are the same.8. An increase in pressure always causes a decrease in volume.9. Fig. (2-5 shows what is expressed by Eq. (2-2.10. The unit of inductance is the henry.11. Too large an input signal can cause nonlinear distortion.12. Using

5、the definition of slope, we can derive the equation which represents a straight line.13. The expression f (x+h-f (x is frequently used in the study of calculus.14. An equation which can be written in the following form is known as a linear equation in one unknown.15. In a computer, the tendency is t

6、o operate at as high a clock rate as possible.16. Tin does not have as high a melting point as lead (does.17. This average velocity is half the final velocity.18. Electricity can be easily changed into other forms of energy.19. In 1831, Joseph Henry in the United States discovered the phenomenon of

7、electromagnetic induction.20. A computer consists of several parts units.三、Chemistry is based upon concepts that require the measurement of such quantities as length, volume, mass, and temperature. These measurements are quantitative; that is, they have numbers associated with them. In this section,

8、 we will consider some of the simple instruments used in quantitative measurements. We will also look at the units used to express these measured quantities.四、1. The UASMA protocol employs a unique frame structure.2. Performance analysis of an M-ary spread spectrum receiver using biorthogonal cyclic

9、 codes3. Finally, a broad stepped impedance transformer is designed by this method.4. Dynamic analysis and evaluation of the security of a proactive secret sharing system5. With the state-transition diagram, the security probability of the system is obtained.6. The approach can be applied to the one

10、-dimensional potential barrierwith an arbitrary profile.7. We propose a numerical method based on Newtons iterative method.练习二一、1. Ordinary transformers are not ideal, and therefore power losses occur in them.2. This material attracts iron objects and can even magnetize them.3. This circuit consists

11、 of a battery, an inductor and a capacitor.4. Compute the electric fields at points a, b, and c.5. This satellite is used for communications between the United States and Great Britain, France and Italy.6. Matter is anything like air, water or wood.7. Assume that losses in the coil are zero, that C

12、= 500F, and that the ripple is 20 percent.8. It is found more convenient to adopt the point of view that a moving charge sets up a magnetic field, and that this field exerts a force on another charge moving through it.9. Chapters 6, 7, and 8 deal with what is called the electronic brain.10. Students

13、 may learn that mathematics is the language for scientific ideas, that science is a source of mathematical ideas, and that mathematics can furnish brilliant answers to important scientific problems.二、1. The current in the circuit is one half the short-circuit current of the source.2. The internal re

14、sistance of this kind of storage battery is only a few thousandths of an ohm.3. Its error is six parts in 1012.4. This computer stores four times more information than that one (does.5. The mass of the moon is 1/80 that of the earth.6. The demand for this kind of equipment in the near future will be

15、 20 times what it is.7. The voltage across this component is a few tenths of a volt.8. Now its internal pressure is one third what it was.三、The concept of temperature is familiar to all of us. This is because our bodies are so sensitive to temperature differences. When we pick up a piece of ice, we

16、feel cold because its temperature is lower than that of our hand. After drinking a cup of cof fee, we may refer to it as hot, lukewarm, or atrocious. In the first two cases, at least, we are describing the extent to which its temperature exceeds ours.四、1. The voltage across this capacitor is a few h

17、undredths of a volt.2. This object is five times heavier than that one is.3. Unless otherwise stated, it is assumed that silicon transistors are used and that ICBO can be neglected.4. This circuit has the advantages of simple structure and easy adjustment.5. Figs. 1, 2, and 3 show this process.6. Fo

18、r further information, consult references 3, 5, 9.7. The interior point is a minimum rather than a maximum, given that the return functions are convex, and that the Hessian determinant is positive. 练习三一、1. This type of computer has many advantages over that type.2. We must solve this equation for th

19、e loop current.3. Of these five new chapters, the first one deals with the basic principles of negative feedback.4. This section introduces presents the concept of force.5. This parameter varies changes with temperature.6. The current and voltage in this circuit differ in phase by 90o. The phases of

20、 the current and voltage in this circuit differ by 90o.7. Sound waves travel in all directions.8. By analyzing By the analysis of the parameters of the instrument, we can understand its performance.9. This is a sufficient and necessary condition for solving the solution of the equation.10. We will f

21、ind out its average velocity over this distance.11. We measure force in newtons.12. This paper introduces a new method for measuring this parameter. 二、1. For x1, there is no solution to this equation this equation has no solution.2. Upon On substituting substitution of these values into to the equat

22、ion, it was found that v is equal to the velocity of light.3. In their study of electricity, physicists defined the parameter.4. This circuit is similar in operation to that of Fig. 1-10.5. In our discussion of this subject, we shall restrict our attention to its basic principles.6. We describe the

23、interactions among charges with the help of the concept of electric field.7. This is due in part to the earths rotation.8. Upon On application of proper external force, the body will start to move.9. This computer is very small in size.10. These waves travel only in one direction.三、The common dry ce

24、ll used in flashlights is constructed as shown in Fig. 2-28. The positive electrode is a carbon rod and the negative one is a zinc can. The cell is called dry because its electrolyte is a moist paste. If it were actually dry, ions in the electrolyte could not move about and no current could be produ

25、ced. In the operation of the cell, zinc atoms become zinc ions by losing electrons.四、1. This paper presents a new method for the recognition of radar targets.2. The influence of the moving state of the target on the tracking accuracy of the EKF is great.3. This new method has many advantages over th

26、ose available.4. This newly designed instrument is good in quality is of good quality.5. Another comsat was launched on the morning of the 8th of October.6. V oltage is measured in volts.7. This experiment started at 8 oclock last night.8. They will leave for Beijing to attend an international confe

27、rence on mobile communication.练习四一、1. The answer (key to this problem looks (appears correct.2. This coefficient remains to be determined.3. The two equations below will be often (frequently used in later chapters.4. Here we use two metal balls 10 cm apart.5. This paper contains (has nothing new. Th

28、ere is nothing new in this paper.6. The force acts perpendicular to the surface of the table.7. This rule can be used for can apply to all integers, both positive and negative.8. A neutron has a mass slightly larger than that of a proton. has a slightly mass than a proton.9. Electrons are the smalle

29、st particles present in ordinary matter.10. All the textbooks available discuss this problem.11. Accurate in operation and high in speed, computers have found wide applications.12. The input goes negative and while the output stays constant.13. These rays seem to come from the image.14. Impedance in

30、 an ac-circuit plays the same role that resistance does ina dc-circuit.15. Two parallel wires a dist ance (ofapart carry the current i.16. The equations here are of great importance.17. We shall use a cable 10 meters long.18. The problem now is how to measure the voltage across this component.19. Th

31、ese data will be sent to the computing center 2 kilometers away.20. Upon rearranging the equation above, we have get, obtain the following expression.21. That statement sounds quite reasonable.22. Electrons can pass relatively unimpeded through metals.23. The body collides with other bodies nearby.2

32、4. These charges can interact with other charges present.25. Forces can be transmitted without contact, contrary to the common belief.26. There is no root larger than 1 unity.27. This coefficient is typically 0.35.28. The charge is moving parallel to the electric field.二、The density of a substance is the ratio of its mass to its vo