展望未来外文文献翻译、中英文翻译

外文资料

（一）A look into the future

With a little imagination, it is not difficult to conjure up visions

of future developments in high technology, in whatever direction one cares

to look. The following two examples illustrate how advances may take place

both by novel applications and refinements of old technologies and by

development of new ones.

(1) Molecular electronics

Lithography and thin-film technology are the key technologies that

have made possible the continuing and relentless reduction in the size

of integrated circuits, to increase both packing density and operational

speed. Miniaturization has been achieved by engineering downwards from

the macro to the micro scale. By simple extrapolation it will take

approximately two decades for electronic switches to be reduced to

molecular dimensions. The impact of molecular biology and genetic

engineering has thus provided a stimulus to attempt to engineer upwards,

starting with the concept that single molecules, each acting as an

electronic device in their own right, might be assembled using

biotechnology, to form molecular electronic devices or even biochip

computers.

Advances in molecular electronics by downward engineering from the

macro to the micro scale are taking place over a wide front. One fruitful

approach is by way of the Langmure-Biodgett(LB) film using a method first

described by Blodgett(1935). A multi-layer LB structure consists of a

sequence of organic monolayers made by repeatedly dipping a substrate into

a trough containing the monolayer floating on a liquid (usually water),

one layer being added at a time. The classical film forming materials were

the fatty acids such as stearic acid and their salts. The late 1950s saw

the first widespread and commercially important application of LB films

in the field of X-ray spectroscopy (e.g,Henke 1964,1965). The important

properties of the films that were exploited in this application were the

uniform thickness of each film, i.e. one molecule thick, and the range

of thickness, say from 5to 15nm, which were available by changing the

composition of the film material. Stacks of fifty or more films were formed

on plane of curved substrates to form two-dimensional diffraction

gratings for measuring the characteristic X-ray wavelengths of the

elements of low atomic number for analytical purposes in instruments such

as the electron probe of X-ray micro-analyzer.

(2) Scanning tunneling engineering

It was stated that observational techniques such as microscopy do mot,

at least for the purposes of this article, fall within the domain of

nanotechnology. However,it is now becoming apparent that scanning

tunneling microscopy(STM) may provide the basis of a new technology, which

we shall call scanning tunneling engineering.

In the STM, a sharp stylus is positioned within a nanometre of the

surface of the sample under investigation. A small voltage applied between

the sample and the stylus will cause a current to foow through the thin

intervening insulating medium(,vacum, oxide layer). This is the

tunneling electron current which is exponentially dependent on the

sample-tip gap. If the sample is scanned in a planr parallel to ies surface

and if the tunneling current is kept cnstant by adjusting the height of

the stylus to maintain a constant gap, then the displacement of the stylus

provides an accurate representation of the surface topographyu of the

sample. It is relevant to the applications that will be discussed that

individual atoms are easily resolved by the STM,that the stylus tip may

be as small as a single atom and that the tip can be positioned with

sub-atomic dimensional accuracy with the aid of a piezoelectric

transducer.

The STM tip has demonstrated its ability to draw fine lines, which

exhibit nanometre-sized struture, and hence may provide a new tool for

nanometre mode of action was not properly understood,but

it was suspected that under the influence of the tip a conducting carbon

line had been drawn as the result of polymerizing a hydrocarbon film, the

process being assisted by the catalytic activity of the tungsten tip. By

extrapolating their results the authors believed that it would be possible

to deposit fine conducting lines on an insulating film. The tip would

operate in a gaseous environment that contained the metal atoms in such

a form that they could either be pre-adsorbed on the film and then be

liberated from their ligands or they would form free radicals at the

location of the tip and be transferred to the film by appropriate

adjustment of the tip voltage.

Feynman proposed that machine tools be used to make smaller machine

tools which in turn would make still smaller ones, and so on all the way

down to the atomic level. These machine tools would then operate via

computer control in the nanometre domain, using high resolution electron

microscopy for observation and control. STM technology has

short-cricuired this rather cumbrous concept,but the potential

applications and benefits remain.

展望未来

不论在什么方面展望，想象未来高科技发展是很容易的。以下两个例子阐述

了通过旧技术的改进和新技术采用可以使科技取得新的进展。

（ 1 ）分子电子学

光刻和薄膜技术是关键技术，有可能持续和缩小集成电路的规模， 为了增

加包装密度和运行速度。小型化已取得了从宏观到微观规模的向下工程。由简单

外推法，将会采取将近两个几十年来通过电子转换来减少分子尺寸。分子生物学

和基因工程的影响提供了一个刺激，从而使工程师向上思考，开始将单分子概念，

瓦赫代理作为一个电子装置来思考，这样可能会使生物技术形成分子电子器件或

甚至生物芯片的电脑。

分子电子学优势从宏观到微观的各个领域都在体现。一个卓有成效的方法，

是透过该langmure - biodgett （磅）电影使用的一种方法由blodgett所描述

的（ 1935年）来实现 。多层磅的结构组成一个序列的有机单分子膜通过多次

浸渍，包含漂浮在液体中的单层（通常是水） ， 一层在同一时间补充。经典电

影形成的材料都是不饱和脂肪酸，如硬脂酸及其盐类。 50年代后期看到的第一

广泛和具有重要商业价值的应用LB膜在该领域的X射线光谱（例如， henke

1964,1965 ） 。薄膜的重要性能被剥削，在这方面应用统一的厚度，即一个分

子厚，厚度的范围从5to 15nm ，其中可通过改变薄膜材料的组成。成堆的五十

或以上的薄膜上形成的平面基板弯曲，形成两个空间为衍射光栅测量特征，低原

子序数的各项要素的X射线波长为分析目的，如电子探针X射线微型分析器。

（ 2 ）扫描隧道工程

据指出，观测技术，如显微镜不能属于该域的纳米技术，至少为本条的目的。

不过，它现在正成为明显的扫描隧道显微镜（ STM ）可提供的基础上的新技术，

我们应响应扫描隧道工程。

在扫描隧道显微镜，一个尖锐的笔是定位在正在调查中的一个纳米的表面样

本。一个小电压应用之间的样本及笔会造成电流通过干预薄绝缘介质（ 例如，

空气 ，真空，氧化层） 。这是隧道电子电流指数依赖于样本尖端的差距。如果

样本在一个平面平行它的表面进行扫描，如果隧道电流是通过笔不断调整高度以

维持恒定的差距，那么，位移笔提供了一个准确的该样本的代表性表面地势。这

是将讨论的有关应用个别原子由扫描隧道显微镜很容易解决，手写笔的秘诀可作

为小型单一的原子，并可以随着压电换能器的帮助与分原子尺寸精度定位。

该STM针尖已表明，它有能力制定罚款线，展示纳米大小的结构，因而可能

为纳米石版印刷术提供一个新的工具.这种模式的运行是不正确的理解，但作为

聚合烃电影的结果尖端导电碳线已造成的影响是值得怀疑的，这一进程正在协助

催化活性的钨针尖。通过推测其结果，作者认为进行线对绝缘膜将有可能被罚款。

在气体环境下尖端会经营，载有金属原子这样的形式，它们可以预先吸附于电影，

然后从解放他们的或他们会形成自由基的尖端位置和由提示的电压适当的调整

转移向电影。

费曼提出机床被用来制造较小的机床，这反过来又会使其仍然较小，所以对

所有的方式到原子水平。在纳米领域这些机床会通过计算机控制操作，用高分辨

电子显微学来观察和控制。扫描隧道显微镜技术短期电路这个颇为繁复的概念，

但潜在的应用和效益仍然存在。