优缺点

The available WRV models such as shadow price model, marginal opportunity cost model, reproduction model, income present value model and supply-demand price model are introduced, and their principle, applicability, merits and demerits are analysed. And then, this paper discusses various factors which may have influence on WRV. Finally, this paper establishes the fuzzy model of WRV.4. Based on the real situation of China, this paper deals with the problems of sustainable utilization of water resources.

指出现有的影子价格模型，边际机会成本价格模型，再生产模型，收益现值模型，供求定价模型等水资源价值模型各自的模型原理、适用性及其优缺点，然后在此基础上论述有关因素对水资源价值的影响，指出水资源价值的模糊属性，构建了水资源价值模糊数学模型。

One- dimensional photonic crystal omnidirectional reflector is a perfect mirror without the limits of metal mirror and multi- layer dielectric mirror.

在总结金属反射镜及多层介质反射镜的优缺点的基础上研究一维光子晶体全角度反射器件。

The status quo of the development of the high voltage high power conversion technology is summarized in chapter 1 and two interrelating technology developments - power switching devices and digital control technology, are introduced. In chapter 2, the topologies of multilevel converters and control schemes are summarized. Moreover, their advantages, disadvantages and application fields are also analyzed and compared.

本文首先在第一章中对高压大功率变流技术研究现状进行了回顾，并对与多电平变流技术紧密相关的电力电子功率器件、数字控制技术的发展情况做了介绍；第二章对目前多电平变流器的电路拓扑和控制策略进行了总结，并将各自的优缺点和应用场合加以分析、比较。

An up-to-date comprehensive review of the domestic and foreign research anddevelopment level of the micro-climate...

本文对国内外日光温室微气候及供热技术的研究状况和水平进行了综合评述，分析了各种研究方法的优缺点。

The research of micro-climate and heating technology in greenhouse is urgently needed at present.

本文对国内外日光温室微气候及供热技术的研究状况和水平进行了综合评述，分析了各种研究方法的优缺点。

Call it a microkernel or a hack to overcome braindamaged hardware: It demonstrates a concept, with its pros and cons -- a documented concept.

可称之为微内核或者对死脑筋的硬件的黑客行为：它展示了一个概念，一个书面的概念，和它优缺点。

In order to present a better knowledge about the geographical world, cartographers traditionally compile maps of different themes, times and scales.

本文分析了产生该问题的原因，多比例尺空间数据库的定义及相关性，回顾了多比例尺空间数据库建立的 3种模型以及其组织结构、管理方式和优缺点。

In this study, two models to fit soil three-variable characteristic surfaces of different soils were proposed based on the Brooks-Corey soil water retention curve model. Advantages, disadvantages and application conditions of the two were illuminated. In addition, soil three-variable surfaces measured for packed soil samples through centrifuging and controlling bulk density using paraffin material were used to verify the proposed models.

本文在Brooks-Corey土壤水分特征曲线模型的基础上，提出了两种描述土壤质量含水量、吸力和容重三变量关系的曲面模型，分析了模型的优缺点和适用条件，并采用离心机石蜡控容重法实测了四种质地填装土壤的三变量特征曲面。

The comparative analysis of different converters which could be used in the wind power conversion syst...

文中还对比分析了可能采用的各种变流器线路的优缺点。

Based on the analysis of advantages and disadvantages of all kinds of web caching protocols, a web caching content express scheme based on RCD algorithm is proposedd. We expect to integrate advantages of all algorithms, to improve the response time of network access and reduce the load of web server.

本文通过对各种网络缓存协议优缺点的分析，提出了一种基于RCD算法的网络缓存内容表达方案，希望综合各种算法之长，达到提高网络响应速度，减少服务器负载的作用。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。