变换

A 3kW prototype converter is built to verify the effectiveness of the improved converter and the best scheme for the blocking capacitor, and the experimental results are also included in this paper.

本文将改进型零电压全桥变换器应用于高压直流二次电源DC／DC变换器中，研制出一台3kW工程样机，并给出实验结果。

In this paper, principle and technique of volume holographic storage are presented such as volume grating formation, Bragg diffraction, and horizontal angle selectivity.

本论文介绍了体全息存储原理及技术，包括体光栅的形成和布拉格衍射、衍射效率、水平角度选择性，还介绍了相干光学信息处理系统、Vander Lugt 滤波器的形成过程，给出了多重匹配滤波器相关的运算过程，最后介绍了子波变换的定义以及光学子波变换。

Comparing the synchronous rectifier to normal circuit by calculating the efficiency indicates that forestay is much better on efficiency and thermal performance. A simple circuit with good consistency, high efficiency, high reliability and low cost is presented in this paper. The feasibility is proved by emulating with computer.

通过分析已有的集中解决隔离型变换器输出带预偏置电压启动的解决方案，提出了一种全新的一致性好、成本低、效率高、简单和可靠性高的解决隔离变换器输出有预偏置电压的启动问题的电路，通过仿真验证了其可行性。

It has been showed that the quantum PCII can be still valid for the general case Jacobi J 1, which is different from quantum Noether theorem. The equivalence between quantum canonical equation and PCII is deflved at the quantum level. The comparisons of these results in quantum level with those in classical theories are discussed in detail. The relationship of canonical transformation with quantum PCII is obtained.

结果表明，当变换的Jacobi行列式不为1时，量子PC积分不变量仍然存在，从而把PC积分不变量推广到了最一般情形；在量子水平上，证明了量子正则方程与该积分不变量之间的等价性；比较了经典与量子PC积分不变量以及PC积分不变量与Noether定理；给出正则变换与量子PC积分不变量间的关系。

In this article,byJordan-Winger transformation,the weakly dimerized spin-1/2 anti-ferromagneticchain is transformed into quantum sine-Gordon model in the continuum limit.Onthe fundament of self-consistent field the usual field variable and canonical momen-tum are rescaled by using the Bogoliubov transformation.

我们利用Jordan-winger变换，在连续表象把量子二聚化spin-1/2反铁磁链哈密顿变换至sine-Gordon方程，在自洽场理论的框架内利用Bogoliubov变化重新标度了常规场变量和动量，有效地解决了远红外发散问题，自洽地得到了基态能和激发谱。

The main jobs of the paper are as follows, Multi-scale decomposition and reconstruction of wavelet transform is utilized to filter the noise of negative-pressure-wave, which is brought by leakage. With the capacity to detect the signal singularity quickly and accurately, wavelet transform was used to catch the break point of pressure signal. Accordingly, the work improved the location accuracy.

主要研究工作有：利用小波变换的多分辨率分解和重构技术，对采集到的管道泄漏产生的负压波信号进行消噪处理，并对几个影响消噪质量的关键因素及其选取方法进行了分析；再利用小波变换技术对信号奇异点的快速、准确的识别能力，对经消噪后的负压波信号进行奇异点捕捉，从而实现更精确的单条燃气管道泄漏定位。

This paper combines with pipeline delivery of our countrys actual conditions and other methods of detection and location. To the leakage characteristic of the fault to the long-distance natural gas pipeline, a method is raised, which is on the basis of wavelet and negative-pressure-wave to detect the leakage and locate. Jobs in this paper are as follows:Multi-resolution decomposition and reconstruction of wavelet transform is utilized to filter the noises, which the leakage brings the noises of negative-pressure-wave. The research is worked in the wavelet and wavelet packet filter. The wavelet transform have a fast and accurate recognition capability to signal singularity. This paper chooses wavelet technology to catch the break point of pressure signal.

本文结合我国管道输送的实际情况和目前现有的各种泄漏检测与定位方法，针对天然气长输管线泄漏故障的特点，提出了基于小波分析和负压波相结合的方法检测泄漏并定位，其中主要进行了以下几个方面的工作：利用小波变换的多分辨率分解和重构技术，对采集到的管道发生泄漏时产生的负压波信号进行降噪处理，并对小波及小波包优化的降噪效果进行对比性研究；利用小波变换技术对信号奇异点的快速、准确的识别能力，捕捉负压波信号的突变点，从而判断是否有泄漏发生。

Because the temperature along the pipeline is not a constant, it changes the velocity of the negative-pressure-wave; the Romberg algorithm of numeric integral and the searching for algorithm are emloyed to locate the leakage.Multi-scale decomposition and reconstruction of wavelet transform is applied to filter the noise of negative-pressure-wave, which was brought by leakage. With the capacity to detect the signal singularity fast and accurately, wavelet transform was used to catch the break point of pressure signal. The work improved the accuracy of Δt in location formula, and the location accuracy is improved.

利用小波变换的多分辨分析和重构技术，对采集到的管道发生泄漏时产生的负压波信号进行了消噪处理；并利用小波变换技术对信号奇异点快速、准确的识别能力，对经过消噪处理后的负压波信号进行了奇异点捕捉，准确确定了定位公式中上、下游站点采集到的负压波奇异点的时间差△t，从而提高了定位的精度。

A novel matrix transformation, Multiple Cayley Transformation, and its application to the power system small signal stability analysis is presented.

提出了一种新型矩阵变换——多重Cayley变换方法，并将其用于电力系统小干扰稳定性分析。

What this text to study is according to an detection by the transformation of HOUGH, some round characteristics value will bi found, like the round radius and the center of a circle.

本文所要研究的是基于HOUGH变换的圆检测，即通过HOUGH变换提取出被检测圆的一些特征值，如圆的半径及圆心所在的坐标。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。