比较原理

The train of thought is by the principle of systematic analysis and comparison it researches the strategy of many countries practicing classified management of forestry, Under the direction of the theory of forestry division of labor in the process of forestry changing approaches its fundamental theories, searches for its achievement, sums up its experience and lessons so as to be used by our country.

研究的思路是：运用系统分析和系统比较的原理，对在从传统林业向现代林业转变的过程中，世界上的一些国家以林业分工论为指导，实行林业分类经营的战略进行研究，探讨其基本理论，总结其经验与教训，为我国实行分类经营提出可借鉴的依据。

In this paper, the principle of push-pull forward converter is analyzed in detail, three secondary-side rectifier topologies are studies contrastively and the advantages and disadvantages are compared.

本文详细分析了推挽正激变换器的工作原理，对比研究了该变换器的三种次级整流结构，比较了各自的优缺点。

Lu J. Acoustic computer tomgraphic pyrometry for two-dimensional measurement of gases taking into account the effect of refraction of sound wave paths .

田丰，孙小平，邓福军，邵富群，王福利。声学法电站锅炉温度场重建算法的研究与比较。量子电子学报， 2003， 20(5)： 607～612薛飞，黄国权，李晓东等。CCD计测量燃烧室截面温度场的原理研究。

The thermometry principle and application of infrared thermometer are analyzed,and the comparison of the performance between pyrophotometer and infrared thermometer is made.

分析了红外测温仪的测温原理和应用，比较了光学高温计和红外测温仪的性能。

The characteristics of FIFO, double-port RAM and ping-pang cache structure were compared. The principle and features of ping-pang cache structure were discussed, and a real ping-pang cache structure was also given which consisted of high-speed, large capacity SRAM and FPGA. For a video processing system, this ping-pang cache structure is easy to interface with AD, DA and DSP.

文中比较了FIFO、双口RAM、乒乓缓存结构三种数据缓存电路的优缺点，讨论了乒乓缓冲控制器的结构和原理，并以高速、大容量的SRAM 以及FPGA器件为基础，设计了一种适应于高速DSP图像处理系统的乒乓缓存结构，其特点是速度快、所需器件少，易于与DSP器件接口。

Section two elaborates the structure of a simple model on static yield curve of zero-coupon bond. According to the difference of constitution principle, the dissertation divides the numerous static models into direct ones and indirect ones. On the basis of setting forth the different constitution thoughts of two methods, it compares the merits, shortcomings, and the application scopes of the two methods. Spline model is the most common indirect method, and is the study emphasis of this section, especially its three key approaches that are defining the rank of function, the subinterval number to be divided, and knot of each subinterval, which are fully elaborated in the dissertation.

第二节阐述了现行静态零息票债券收益率曲线简单模型的构造，根据构造原理的不同，论文把众多静态模型划分为直接法和间接法两大类，在简述两种方法各自不同的构造思想的基础上，对两种方法的优缺点及适应范围进行了比较；分段样条函数模型作为最常用的间接法，是本节研究的重点，尤其是对它的三个关键环节：确定函数的阶数、确定所分的段数、确定各段的分解点，论文更是给予了充分的论述。

The Kalina cycle which uses ammonia-water mixture as the working-medium, has the characteristics of lower vaporization temperature and non-isothermal heat absorption. Therefore, the Kalina cycle is used in low temperature waste heat recovery based on introduction of operating principle. The primary parameters of Kalina and Rankine cycle are optimized by mean of genetic algorithm respectively, and the net output power of the two cycles is compared on the same condition.

卡林纳循环采用氨水混合物作为工质，具有气化温度低和非等温吸热的特点，因此，在简要介绍其工作原理的基础上将其应用于中低温余热回收，采用遗传算法对卡林纳循环和常规朗肯循环的主要参数进行了优化，在相同的余热条件下，比较了卡林纳循环和常规朗肯循环的净输出功率。

Pulse Width Modulation technique is one of the most important contents in the digital current control. Two PWM algorithms–Asymmetric Regular Sampling PWM and Space Vector PWM, is described. in detail, and then a fast algorithm of Space Vector PWM is got by combining the advantages of the two algorithm.

脉宽调制技术是数字电流控制中的核心内容，文中详细分析了非对称式规则采样法和空间矢量法两种PWM调制方法的原理和计算方法，在对这两种方法比较的基础上，介绍了一种空间矢量PWM的快速算法。

By comparing the theoretical and measured results, we find that the rectangular cavity perturbation method has relative high precision in complex permittivity.

详细介绍了矩形谐振腔微扰法的基本原理；通过对比标准物质的测量结果发现，矩形谐振腔微扰法测量复介电常数具有比较高的测量精度，且使用样品少。

Summarized are the suspending principle, technology characteristic and applicable range of repellence and attraction maglevvehicle. Analyzed as a emphases are the drive technology characteristic and performance compare of long－stator and short－stator linear synchronization motor driving for maglevvehicle

综述了斥力型和吸力型磁浮列车的悬浮原理、技术特征及适用范围，重点分析了两种不同的磁浮列车驱动方式——长定子线性同步电机驱动及短定子线性同步电机驱动的技术特征和性能比较。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。