Scientific English Writing

Section Ⅳ

Ex. 2 Ex. 2

II. 19. This rule can be used for all integers, II. 19. This rule can be used for all integers, both both positive and negativepositive and negative..

27. Impedance in an ac circuit plays the same role 27. Impedance in an ac circuit plays the same role that resistancethat resistance does does in a dc circuit. in a dc circuit.

28. Two parallel wires 28. Two parallel wires a distance of a distance of δ apartδ apart carry carry the current the current ii..

Ex.3Ex.3

II. 7. This facilitates II. 7. This facilitates their usetheir use in circuit analysis. in circuit analysis.

10. Here we must use wires 10. Here we must use wires one thousandth the one thousandth the diameter of a silk threaddiameter of a silk thread..

14. AC can be changed into DC, 14. AC can be changed into DC, a process called a process called rectificationrectification..

16. 16. An instrument for measuring currentAn instrument for measuring current, voltage , voltage and resistance, the multi-meter is widely used in and resistance, the multi-meter is widely used in the work having connection with electricity.the work having connection with electricity.

19. This curve shows the fall 19. This curve shows the fall in in conductivity conductivity with with increasing temperature.increasing temperature.

IV. 1. The second law of motion provides IV. 1. The second law of motion provides a a method formethod for measuring shat is called the “inertial measuring shat is called the “inertial mass” of a body. mass” of a body. All one needs to doAll one needs to do is to apply is to apply the same force in turn to a standard of mass and the same force in turn to a standard of mass and to an unknown mass and then to compare their to an unknown mass and then to compare their accelerations, accelerations, something that can be done something that can be done anywhere in the universe with the same resultsanywhere in the universe with the same results. . No matter where we are, we can always No matter where we are, we can always tell a tell a wooden ball from a lead ballwooden ball from a lead ball of the same size by of the same size by throwing them.throwing them.

2.2. **: male, born in 1938, professor, and advisor for **: male, born in 1938, professor, and advisor for doctoral students. He graduated from the Xi’an Milidoctoral students. He graduated from the Xi’an Military Telecommunications Engineering Institute in 1tary Telecommunications Engineering Institute in 1964 and remained there as a faculty member. He has 964 and remained there as a faculty member. He has long been engaged in the teaching and research in thlong been engaged in the teaching and research in the field of radar. e field of radar. Through close cooperation withThrough close cooperation with quit quite a few radar research institutes and enterprises, he e a few radar research institutes and enterprises, he has has successively undertaken or taken charge ofsuccessively undertaken or taken charge of mor more than twenty national defence key e than twenty national defence key preliminary resepreliminary research projectsarch projects and engineering projects and engineering projects with many pwith many practical achievementsractical achievements, most of which have been , most of which have been poppopularized and appliedularized and applied, or used to , or used to equip the armed forequip the armed forcesces, thus , thus making contributions tomaking contributions to the development o the development of radar technology in China.f radar technology in China.

Independent work 3

1 、人体是由大大小小无数结构构成的。 (using an adjective phrase to express the underlined part)

2 、这台计算机的速度由于它使用了继电器而受到了限制。（ using a prepositional phrase to express the underlined part ）

3 、他们使用了与卡车同宽的一些厚木板。（ using a noun phrase to express the underlined part ）

The human body is made up of numerous structures large and small. This computer was limited in speed by its use of relays.

They used plants the width of the truck.

4. 如果这关系式成立的话，我们就会得到一个负的电流，这种情况是不可能的。

5. 色谱法（ chromatography ）是一种非常有效的分离方法，它已得到了广泛的应用。

6. 一块 15m 长的厚木板放在相距 8m 的两个支座上。

If this relation were to hold, we would get a negative current, an impossible situation.

A very effective separation method, chromatography is widely used.

A plant 15-meter-long is put on 2 supports 8 meters apart.

SECTION Ⅱ Parenthesis, negation, and comparison

I. Parenthetic clauses (1) in the main clause Nuclear fission, it has been claimed, will be a

cheap, clean and almost inexhaustible source of power.

Potential energy, it is true, might not affect the sense of touch in the same way as kinetic energy would.

(2) in the sub-clause Ohm’s law has a few forms which it will be foun

d are very useful.

One of the major problems which faced me in writing this book was ‘digesting' the vast literature on computer-aided library systems and presenting it in what I hope is a clear and concise manner.

(3) say=let us say

Well-grounded students can absorb Chapters 4 and 5 in say three weeks. A resistor of say 100 ohms may be connected across the capacitor.

II. Negation

This parameter does not change during all time intervals.

Eq.(5) cannot be satisfied for all values of x.

普通的窗户均承受不了如此大的力。

None of the ordinary windows can withstand so large a force.

这些学生对那些电路均不熟悉。

Summary

1. Partial negation

all [both, every] + not

2. Full negation

no [none of the …, neither ]+ n.

Both books are not suitable.

这两台设备的质量都不好。

Ⅲ. Comparison

Equation (8-10) contains much more than a mere description of how the gain saturates.

The real forecast must take account far more climate factors.

(1)The way to express the idea of “… 得多”

much/ far /considerably/significantly

+ comparative degree

Computers are becoming ever smaller.

increasingly + positive degree

Electronic devices are getting increasingly complicated.

(2) The ways to express the idea of “ 越来越…”

ever + ~er

That cable is as long as three kilometers.

Efficiencies of as much as 99% are achieved in large transformers 。

月亮离地球的距离远达 24 万英里。

(3) The ways to express the idea of “… 达（到）”

as + adj. + as + quantity

** Such books are as political as educational.

** These energy bands are actually composed of a multitude of individual energy levels, as many as there are atoms in the crystal.

(4) The ways to express the idea of “… 越… , 就越…”

物体运动的越快，其具有的动能越大。

The faster the body moves, the greater kinetic energy it will possess.

** That person is more brave than wise.

He is more proud than vain.

** Bamboo is used for more than building.

This voltage is more than enough to saturate transistor Q4.

** The beauty of Huangshan Mountain is more than I can express.

Such insult was more than I could stand.

Assignment:

P.39 Ex. 4 II-1, 4, 8, 9, 17, 18

optional IV-1, 2, 3