可变化

In the design of the power supply, the main circuit topology frame uses full-bridge series resonant switching and parallel load connection, in which, four MOSFETs are adopted as the power switches, and by four pulses which UC3879 produces, high frequency operation and fast response are realized. In addition, the MOSFET in the switching power supply has no hard turn-on or turn-off situation in transition, thus the disturbance to the power system is avoided. Especially,by the use of high frequency transformer, PQ50/50, the switching power system can provide the steady discharge current without any amperite.

此开关电源采用全桥软开关技术、串联谐振并联输出，四个MOSFET管为主控制开关元件，通过脉冲产生电路UC3879产生的四路相关脉冲实现了高频交替开关，同时能快速响应输出的各种变化；避免了开关管的硬开关，提高了转换效率，另外通过采用高频变压器PQ50/50隔离了原副边，减小了高次谐波对电网干扰；无需镇流电阻也可实现气体稳定放电。

This kind of technology can flex the application of optical amplifier so that a same adaptive amplifier can be used as a pre-amplifier, a boost amplifier as well as a line amplifier.

在光标记交换系统中，可满足由于路由切换导致的光功率损耗大范围动态变化的应用需求。

Based on the latest achievements of the mechanism of peradaptation to myocardium ischemia and pharmacodic preadaptation up to date, observations were made on 80 patients of acute myocardial infarction to assess the enzymatic dynamics of myocardium, symptoms after myocardial infarction occurred like cardiac rhythm abnormality, anginapectoris, heart failure, cardiogenic shock, reinfarct and the mortality in the hospital. The results indicated that peradaptation to myocardium ischemia is of significance in protecting myocardium, reducing the areas of infarction, abating the cardiac insufficiency after infarction and reducing the abnormality of heart rhythm and significantly ameliorating the prognosis.

本研究结合现代医学对心肌缺血预适应机制及药理性预适应作用的最新研究成果和动向，通过临床观察80例急性心肌梗死患者的心肌酶学变化，心律失常、梗死后心绞痛、心力衰竭、心源性休克、再次梗死等心肌梗死后并发症和住院病死率，证实缺血预适应具有保护心肌，缩小梗死范围，减轻梗死后心功能不全及减少心律失常的作用，可明显改善心肌梗死病人的预后。

For a long time, it is believed that security price reflects information completely, future price is unpredictable, and no investor can earn premium returns basing on the information.

学术界在很长的一段时间里都认为市场是有效的，证券价格总是能充分体现可获信息变化的影响，未来的价格是不可预测的，任何投资者都不能在某时刻依据已有的信息来获得超额回报。

It might be, on this one day, that there was an expression unseen before, nor, indeed, vivid enough to be detected now; unless some preternaturally gifted observer should have first read the heart, have afterwards sought a corresponding development in the countenance mien.

这一天，她脸上或许有一种前所未见的表情，不过此时 www.8 tt t8.Com 尚未清晰可察；除非有一个具备超自然秉赋的观察者能够 SSBBww 首先洞悉她的内心，然后8t t t8.com 才会在她的表情和举止上找到相应的变化。

Emphasis on the primacy of research, but also a changing definition of what constitutes an acceptable research paper.

将过去一个半世纪英国地质学领域的出版物做一下比较，就会发现不仅对科研的主导地位的强调不断攀升，而且一篇可接受的科研论文所包含的内容的定义也有所变化。

Based on the equations, the contact spots on the face gear are simulated and analyses are conducted on the rule of the principal curvature of the contact points on the pinion and the face gear as well as the rule of the maximum press stress of the contact areas on the face gear.

根据布希涅斯克问题的求解方法，给出了传动中面齿轮上接触区域的椭圆长、短半径、中心最大变形量、最大压应力以及载荷分布的方程，分析了接触中心最大压应力的变化规律，实现了接触斑点的可视化仿真。

According to the transition probability matrix combining with stand original distribution, the change of stand structure in fifteen years was modeled.

根据转移概率参数和进界生长参数可以得到落叶松的转移概率矩阵，结合其初始分布可模拟15年后林分的结构变化。

The study results indicated that serum IL-6 can be used as a pramater for evaluating the effect of therapy and prognosis of the disease,and is of clinical significance in prognostication of hyperthyroidism reccurence.

结论提示检测血清IL-6水平变化可作为甲亢患者治疗效果及预后判断的一项指标，并对甲亢复发的预测有一定的临床意义。

In the SD rats with acute liver failure, the different levels of serum endotoxin are existed and the level of cell factors diversification inflammation progressional reactions can be induced, and SMD can regulate the level of cell factors to treat the disease.

急性肝衰竭状态下，可存在不同程度的内毒素血症，并引起细胞因子水平变化的炎症级联反应，生脉散通过调节细胞因子水平起到治疗作用。

She gently rebuff ed him, but agreed that they could be friends

她婉言拒绝了，但同意作为朋友相处。

If in the penal farm, you were sure to be criticized.

要是在劳改农场，你等着挨绳子吧！