零比零的

The converter can be improved just by exchanging the position of the resonant inductance and the transformer such that the transformer is connected with the lagging leg. The improved converter has several advantages over its counterpart, e.g., the clamping diodes conduct only once in a switching period, and the resonant inductance current is smaller in zero state, leading to a higher efficiency and reduced duty cycle loss. The operation principle of the improved converter and the comparison with the original converter are analyzed in this paper. The effect of the blocking capacitor in series with the transformer or resonant inductance is discussed, and a best scheme is determined.The improved converter is adopted to design the DC/DC converter of secondary power supply in HVDC power system.

本文将谐振电感和变压器交换位置，使变压器与滞后桥臂相连，这样箝位二极管在一个开关周期中只导通一次，同时零状态时谐振电感电流较小，有利于提高变换效率和减小占空比丢失，本文分析改进后变换器的工作原理，并与改进前的变换器进行对比，讨论隔直电容在不同位置对变换器工作的影响，确定一种最佳工程方案。

By 1 Grey Fox 0——2——3"; they are not now found here; and in his ledger, Feb, 7th, 1743, Hezekiah Stratton has credit "by 1/2 a Catt skin 0——1——4+; of course, a wild-cat, for Stratton was a sergeant in the old French war, and would not have got credit for hunting less noble game.

斯特拉登贷款"半张猫皮，零元一角四分半"；这当然是山猫皮，因为从前法兰西之战的时候，斯特拉登做过军曹，当然不会拿比山猫还不如的东西来贷款的。

My pockets were sagging with the weight of it. I hauled it all out and counted it carefully. There was exactly 2,875 francs and 35 centimes. More than I had thought.

我的衣袋都被钱的重量拉得坠下来了，我把它全掏出来细细数了一遍，一共是两干八百七十五法郎零三十五生丁，比我预计的还多。

Policy makers have contributed to that excess demand by keeping bank deposit rates near zero, which has made property a better outlet for household savings for the past two decades.

通过将银行存款利率保持在接近于零的水平，决策者们一直在对房地产的过量需求起着推波助澜作用。过去20年中，房地产投资一直是比储蓄更好的一种家庭财产保值出路。

At last, the influence of modulation index and zero-vector distribution variable on the modulation signal and output voltage harmonic characteristics of the three-phase inverter is investigated.

对SVPWM常规算法和快速算法进行了综合分析，并给出了其数字化实现方法；针对不同的零矢量分配因子和不同的调制比，对三相SVPWM逆变器的调制信号及其输出电压谐波特性进行了比较分析。

A tariff cut comparable to that in panel A would have yielded less, but since it would include the revenue from the higher new tariff, it might still be larger than the gain in panel A. In contrast, if the new tariff were zero in this case, then again area f would be added to the country's net gain.

一个降低关税相媲美，在面板一个会取得更少，但是，因为它将包括收入更高的新关税，它可能仍然比获得小组在形成鲜明对比的是，如果新关税是零，在这种情况下，然后再把区域外将加入到这个国家的净收益。

When we do the math, we discover that an averagely decent streamliner with a drag coefficient of .3 can go farther than 1021 km in 24 hours on only 110 watts of human power (enough effort to go 15 kph or 9 mph on a mountain bike).

当我们这样做数学，我们发现，一个平均体面streamliner的风阻系数在0.3可以做得比一千零二十一公里在24小时内就只有110瓦的人力（足够的努力去15公里或9英里每小时在山地自行车）。

The model of fiber-optic Fabry-Perot interferometer was established when ideal or unideal optical source was applied. Through simulating interferometric signal by computer under the condition of nonmonochromatic light, the symmetry of fringes deteriorated, the fluctuating domain of fringes became small as the ratio of cavity length to coherence length increasing.

推导了光源在理想情况和非理想情况下的光纤Fabry-Perot干涉模型，通过计算机模拟了干涉信号，指出在非单色光源下，干涉条纹失去周期性，随着腔长相干长度比增加干涉条纹的变化幅度减小，最后演化成一条直线，条纹的可见度也慢慢趋近于零。

The effect of cell temperature,gas humidification temperature,pressure and reactant gas flow rate on the performance of PEM fuel cell was studied by experimetal methods.Some characteristics of the law with interdigitated flow fields from the cell polarization curves were obtained.

PEM燃料电池是21世纪最具希望的汽车动力源，它以其操作温度低比能量高、响应速度快、启动速度快和零环境污染等固有优势，可以广泛的作为便携式、移动式和大型固定式设备的动力源。

This quarter is located in CBD of Fortune Center, Block A sale, the average selling offer Grade A office space increased slightly sequentially to reach 2107 U.S. dollars / sq m building.

本季度位于生物多样性公约的财富中心A座销售，平均销售提供甲级写字楼比上季度略有增加，达到二千一百零七美元/平方米的建设。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。