英语翻译好像是关于生物的However,when actively driving biological materia

英语翻译
好像是关于生物的
However,when actively driving biological materials it is important to understand their
dispersive behavior.A great deal of work has been done in this area by H.P.Schwan who
examined the permittivity and conductivity of tissue and cell suspensions.His work
showed that there are three distinct regions of dispersion which must be considered when
measuring the impedance characteristics of biological materials.At low frequencies (50 to
200 Hz) the counter-ion cloud surrounding the surface of the cellular membrane becomes
polarized,resulting in what is called the a-dispersion.From approximately 60 kHz to 5
MHz the cell membrane becomes electrically charged (through intra- and extra-cellular
pathways) causing what is known as the b-dispersion.At much higher frequencies
(1 GHz),the dispersive behavior of water causes the measured permittivity to change
(g-dispersion) [Schwan,1988].In each case,the permittivity of the material changed by up
to 2 orders of magnitude while the conductivity remained fairly constant (except during
the g-dispersion where the conductivity increased by 2 orders of magnitude).
For measurement of changes in membrane resistance (due to modulation of ionic
channel conduction) of cultured cells,all of these dispersive effects may not be important.
2
Assuming a membrane capacitance of approximately 0.01 pF/μm ,the capacitive
2
impedance is 16 TW*μm *Hz.This impedance was compared to the range of possible
2
membrane resistances (1 MW to 100 GW*μm ) in Figure 2.10.From this figure it can be
seen that the capacitive impedance of the membrane always dominates the overall
impedance for frequencies above 10 MHz.Thus,the g-dispersion need not be considered
when measuring conductance changes in cellular membranes.However,depending on the
actual membrane resistance of the sample,it is possible that both the a- and b-dispersions
need be considered.These effects would be evidenced by a changing capacitive
component of the measured cellular impedance as the measurement frequency was varied.
As will be described in Chapter 5,the impedance measurement system developed for this
work operated between 100 Hz and 100 kHz; the extremes coincide with the end of the
a-dispersion and the beginning of the b-dispersion respectively.It was hoped that this
configuration would limit the impact of dispersive behavior on the measurements.

然而,当积极推动生物材料,重要的是了解他们的
分散的行为.大量的工作已经做了在这一领域,惠普施婉谁
审查了介电常数和电导率的组织和细胞悬液.他的工作
表明,有三种截然不同的地区分散时必须考虑
测量阻抗特性的生物材料.低频（ 50 〜
200赫兹）的反离子云周围表面的细胞膜成为
两极化,导致所谓的一个分散.大约从60千赫至5
兆赫细胞膜成为带电（通过内和细胞外
途径）造成所谓的B -分散.以更高的频率
（ 1 GHz ）的,分散的行为造成的水的测量介电常数改变
（克分散） [施婉,1988 ] .在每种情况下,介电常数的材料改变了
到2个数量级,而电导率相当稳定（除在
国分散的电导率提高了2个数量级） .
用于测量的变化,膜电阻（由于调制离子
频道传导）对培养的细胞,所有这些分散的影响可能不很重要.
2
假设膜电容约0.01电容/微米,电容
2
阻抗为16 μm的荃湾* *赫兹.这阻抗相对于各种可能的
2
膜电阻（ 1万千瓦至100万千瓦*微米）在图2.10 .从这一数字可以
可见,电容阻抗膜始终占主导地位的总体
阻抗频率超过10兆赫.因此,八国集团的分散不必考虑
测量电导变化细胞膜.然而,这取决于
实际膜电阻的样品,很可能都在A和B分散
需要加以考虑.这些影响将是证明了一个不断变化的电容
组成部分,作为衡量细胞阻抗的测量频率各不相同.
至于将第5章所述,阻抗测量系统开发的这一
工作运行100赫兹和100千赫;极端配合结束
1 ,分散和开始的B -分散分别.人们希望,这
配置将限制的影响,分散行为的测量.