级联放大

There are multiple cell signaling cascades, some of which are beneficial or compensatory and others deleterious.

人体心血管系统有许多细胞信号级联放大系统，其中一些是有益的，一些是代偿的，而其它则是有害的。

It was found greater expression of NRP2-1 and NRP2-2 in pituitary, ovary, uterus and oviduct of ruttish Erhualian than corresponding tissues of ruttish Duroc, which suggested enhancing expression of NRP2 was favorable to increasing litter size. But the difference of NRP2 expression was not significant between two breeds, which suggested the key phase that NRP2 affected litter size was not oestrum probably, or NRP2 could enlarge cell signals and finally affect litter size ascribe that it was the receptor of nerve axon guidance factors.

NRP2-1和NRP2-2在发情期二花脸卵巢、子宫、输卵管中的表达量均大于杜洛克相应组织的表达量，推测NRP2表达水平高可能有利于提高产仔数，但两品种间表达差异不明显，推测NRP2影响产仔数的关键阶段可能不是猪的发情期；另外，NRP2 是神经轴突介导因子的受体，这些神经轴突转导的信号往往有级联放大的功能，虽然NRP2-1和NRP2-2在二花脸和杜洛克卵巢、子宫、输卵管中的表达差异不大，但二花脸有可能通过神经系统转导信号的级联放大最终引起一些效应激素或蛋白的急剧增加，从而提高排卵率或产仔数。

Seeded amplification of colored conical emission and two-dimensional multicolored transverse arrays as well as simultaneously up-converted parametric amplification have been demonstrated using spectral synthesis to obtain sub-fs pulses.

基于分子调制过程，文章作者提出并发展了一系列亚飞秒脉冲产生和操控的技术；围绕频谱合成方案，利用级联二阶非线性效应，实现了多色圆锥辐射注入放大和二维多色阵列及其参量上转换放大；同时，还开展了基于飞秒振荡器及外腔增强技术的高重复频率高次谐波产生与输出耦合的相关研究。

Exercises 1. Translate the following into Chinese.

很多实际应用系统中的放大电路都通过级联多级放大器来提高放大倍数。

The former stimulates the cells and transfer the signals into the cells through the ligation with receptors on the cell membrane. The latter, a derivative of nucleotide, causes a cytotoxic effect to suppress thymidylate synthetase activity, and, therefore, to damnify RNA and DNA synthesis.

前者通过与细胞表面的受体结合，把胞外刺激传递到胞内，诱导免疫受体介导的信号级联放大作用，引起一系列免疫效应；后者是是小分子的核苷酸衍生物，可直接进入细胞内，通过抑制胸苷酸合成酶及损伤RNA、DNA等对基因转录和核苷酸代谢产生影响，最后产生细胞毒效应。

started with the analysis of characteristic parameter of the successive detection logarithmic amplifier,mainly discusses the main factor affecting its transfer characteristic by mathematics reasoning to its transfer function,studies the correlative relations of the single stair′s plus,the series with the dynamic range and the logarithmic precision by matlab and matrixx simulation.so two pieces of conclusion have been reached:one is on condition that the dynamic range is limited,the more the series that is used and the single stair′s plus is less,the higher the logarithmic precision is.the other is that using the double amplifier chain can enhance the logarithm starting point,so its stability is improved.and the conclusion has been applied to the practical circuit′s analysis of the tacan beaconing receiver.

摘 要：从分析连续检波式对数放大器的特性参数入手，对其传输函数进行了数学推导，重点讨论了影响其传输特性的主要因素，通过matlab和matrixx仿真，研究了输入动态范围与级联级数、单级增益和对数精度的相互关系，得出了两点结论：一是在限定动态范围的前提下采用的级数越多其单级增益越小而精度就会越高，二是采用双放大链结构可以提高对数起点，从而提高其稳定性。最后将结论应用于塔康信标接收机实际电路的分析中。关键词：对数放大器；连续检波；塔康信标；对数精度

Cascade Amplification Successively using two or more amplification systems.

级联放大逐次使用两个或多个放大系统。

In order to study the characteristics of pulse amplification in multi-stage cascade ytterbium-doped fiber amplifiers,the three-stage high-gain pulse fiber amplifier with all-fiber structure was experimentally studied based on the master oscillator power amplifier technology.

为了探讨多级级联掺镱光纤放大器的脉冲放大特性，采用主振功率放大技术，实验研究了3级级联、全光纤结构的高增益脉冲激光放大器。

They interact,induce cascade amplification effect by activating a series of cell signals,lead to inter-attraction between tumor cells and neural fibers,appear the perineural invasion phenomenon.

肿瘤周围存在通过自分泌和旁分泌方式而来的神经生长因子及受体，它们相互作用，通过激活一系列分子信号途径引起级联放大效应，导致肿瘤细胞和神经纤维相互吸引而产生神经侵袭现象。

Retinal ischemia is a common cause of visual impairment and blindness . At the cellular level , ischemic retinal injury consists of a self-reinforcing destructive cascade involving neuronal depolarisation , calcium influx and oxidative stress initiated by energy failure and increased glutamatergic stimulati on .

视网膜缺血是一常见的引起视觉损害和致盲的原因，在细胞水平上，缺血性视网膜损伤由一系列自我加强破坏性的级联放大反应组成的，包括神经元去极化，钙流入和起源于能量缺少和谷氨酸刺激的氧化应激反应。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。