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On the basis of a great deal of information, several general problem on land sarface process parametrization for a global circulation model and its history of development are described. The Bucket model, EARTH, ISBA and SiSPAT models are respectively expounded, and the situation of studies on land surface process parametrization is summarized. China is a participating country of the international geosphere-biosphere program and the study on circulation of global energy and moisture, and has put forward some valuable soil-vegetation-atmosphere models for land surface process parametrization. which results in effective studies on vegetation indexes.
在大量资料基础上,叙述了大气环流模式陆面过程参数化方案的一般问题及其发展历程,分别阐述了水桶模式、EARTH模式、ISBA模式和SiSPAT模式;总结了在陆面过程参数化方面的研究状况,我国参与了国际地圈生物圈计划和全球能量与水分循环的研究,特别是在陆面过程的参数化研究方面,提出了一些有价值的土壤—植物—大气模式,对植被指数进行了有成效的研究。
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Biodiversity is one of the front areas of current biological research. The mechanisms of the formation, spatial distribution pattern, conservation and utilization of biodiversity have been an important area of biological and environmental research. In this study, through analyses of data about plant diversity, animal diversity, geographic factors, climatic factors, and energy factors by use of GIS software, statistic software and ecology software, the mainland of China was divided into 241 small districts of 2° by 2°. The environmental factors in each district were analyzed and isopleth maps of environmental elements were depicted.
生物多样性是当今生物学研究的热点问题之一,生物多样性的形成机制和分布格局以及保护利用问题一直是生物学和环境科学所研究的重要内容,本文由此出发,以中国陆地为研究区域,通过植物多样性数据、动物多样性数据、地理因子、气候因子、能量因子等资料,利用MAPGIS、MAPINFO等GIS软件,SPSS、DPS等统计学软件以及CANOCO等生态学软件,将中国陆地划分为241个小区,分析了各区内的环境特点,统计了各区内生物多样性的数量,并绘出环境因子等值线图,中国陆地种子植物科、属、种,裸子植物种、蕨类植物种、兽类、鸟类、爬行类、两栖类种数的等值线分布图,对中国陆地植物、动物多样性现状、分布格局及与环境因子的关系进行了研究。
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May 22, 2003 Montelukast effectively treats vernal keratoconjunctivitis associated with asthma, according to the results of a small trial published in the May issue of the Archives of Ophthalmology . Based on these findings, the investigators now recommend randomized trials.
2003年5月22日—发表于5月号Archives of Ophthalmology的小型研究报告指出,Montelukast 可以有效地治疗与气喘有关的春季型角膜结膜炎,根据这些研究结果,研究人员建议,继续进行随机化的试验以确认研究结果。
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The thesis contains five chapters. The first chapter summarizes the development and research of switched reluctance drive, discusses the main research direction, and explains the main work in this paper. In chapter 2, hardware system which includes the design of power converter and various control circuit is discussed. TMS320LF2407 DSP is used to design the hardware circuits of SRM control system, and design details including the current detection, position sensing, fault protection, speed detecting, keyboard and display etc. are provided. Because of the full use of the abundant peripheral resources of DSP, it comes to the aim simplifying the circuit structure and heightening the reliability. In chapter 3, the application of neural network on SRM control system is introduced, a new the application of neural network and the method of sampling is proposed and a simulation system based on Matlab/Simulink is established. Chapter 4 discusses the routine designing issue. Because the modularized programming method is adopted, and multi-interrupt processing technique is used, operation efficiency of the control software is highly raised. At last, the foregoing SRM control system is tested. Speed adjustment is realized, and other targets on the research and design of SRM control system are reached, which establishes a good foundation for further research.
本文共分五章,第一章概述了开关磁阻电机调速系统(Switched Reluctance Drive,简称SRD)及其发展和研究现状,论述了其主要研究方向,并说明了本文的主要工作;接下来的一章主要讨论了SRM的硬件系统,主要包括功率变换器的设计和各种控制电路的设计,本文以TMS320LF2407为核心设计了开关磁阻电机控制系统硬件电路,给出了包括电流检测、位置检测、故障保护、测速电路及键盘和显示电路等部分电路的详细设计,充分利用了DSP的丰富外设资源,达到了简化电路结构、提高运行可靠性的目的;第三章介绍了人工神经网络在开关磁阻电机控制系统中的应用,提出了一种新的应用方式(利用GPFN神经网络调节PI参数)以及如何采取样本,搭建了基于Matlab/Simulink的仿真系统;在第四章中,讨论了开关磁阻电机控制软件的设计,采用模块化编程方法,采用基于多中断的控制程序,提高了控制软件的效率;最后,对所设计的开关磁阻电机控制系统进行了实验,实现了电机调速,达到了开关磁阻电机控制系统研究和设计的预期目标,为更近一步研究打下了基础。
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The discrete velocity ordinate method in the kinetic theory of gases is developed and applied to discretize the correspo
借助非定常时间分裂法和无波动无自由参数的NND耗散格式,建立直接求解微观分子速度分布函数的有限差分数值格式;研究并发展可用于离散速度坐标点选取和离散速度空间宏观取矩的高斯─埃尔米特无穷积分方法、等均间隔的牛顿─柯斯复合积分法、以勒让德多项式的根为积分结点的高斯─勒让德数值积分法,并应用于不同马赫数绕流模拟;通过对不同流域一维激波管问题、二维圆柱绕流问题和三维球体绕流的计算研究,并将计算结果与其他途径得到的研究结果诸如DSMC模拟值、N-S解及有关实验数据进行比较分析,创建了一套能有效模拟稀薄流到连续流不同流域气体流动问题简化的统一数值算法研究框架
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Based on the hydrodynamic theory of dense gas-solid flow and the kinetic theory of dense gases proposed by Chapman and Cowling, the kinetic theory of cohesive particles flow and constitutive equations of cohesive particles are established.
目前科学家们对粘附性颗粒的流态化研究主要集中于实验研究,数值模拟研究做的比较少,特别是对传统的双流体模型,如何进一步改进完善,以适应粘附性颗粒的气固两相流动的研究,成为当务之急。
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This thesis try to discuss what kind of knowledge-diffusion model and knowledge-integration model would easily success in different innovation type from knowledge-based theory. The research methodology is case study of quality method and research target is knowledge intensive industry. The research has interviewed eight managers and concluded four case. Finally, we have some conclusion below
本研究尝试从知识基础论的角度出发来探讨在不同的创新类型之间,应采用何种的知识流通模式与知识整合机制较容易成功,研究方法采用质性研究之个案访谈法,研究对象为知识密集产业,总共访谈了八位高阶主管,并将之整理成四个个案,经由分析归纳后得到以下几点结论。
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On the basis of summarizing scientific goals of lunar exploration and analyzing distribution characteristics of landing sites, the authors chose three craters of Copernicus, Kepler, and Aristarchus in KREEP rock distribution area as candidate landing sites.
克里普岩对于研究月球的起源和演化有重要意义,但由于该岩石被玄武岩所覆盖,难以利用轨道探测器开展全面深入的研究。撞击坑是研究月表以下物质成分的窗口,在克里普岩区选择条件合适的撞击坑开展软着陆探测有助于对克里普岩的深入研究。
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In the introduction part, the theories and experimental researches into false memory were first reviewed. And some recent laboratorial research were introduced. Then, in the conclusion section, the research illustrated the purpose of this research.
本研究在引言部分首先对错误记忆的理论和实验进行了回顾,然后对当前的一些研究作了说明,最后阐明了本研究的研究目的。
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The conversion boundary of self-incompatibility was researched by sowing by stage. Sunshine of day and temperature was studied critically by investigating leafage and researching traits indoors. The results showed that the daily minimum temperature was the principal factor of affinity conversion and the affinity conversion boundary was 16.5~18.1℃.HE97 was primarily regard as self-incompatible line in this research. The method was by inbreeding and sib HE97, Half the silk of HE97 and Zheng58. Inbreeding and cross have been done simultaneously. The extending condition of pollen tube was observed by dying the silk after pollinating 4 hours. The individuals with pollen tube were observed having seeds, while the individuals without pollen tube were observed having few seeds or no seeds. So this study regard HE97 as sporophytic self-incompatibility .The planting ration of female parent HE97 and male parent 87-1 was 4:1.The nature cross-pollination was studied by the theory of endosperm xenity, the study show that the setting percentage of HE97 was 625%, in which the seed in self was 70% and the seed in hybrid was 30%. This was consistent with the study of silk anatomy structure, then come to the same conclusion: compatible pollen germination and fertilization can stimulate the self-incompatible pollen germination and fertilization in the same corn cob.
通过分期播种,进行了光温敏自交不亲和材料HE97亲和性转换区间的研究,依据田间跟踪调查叶龄及室内考种研究了HE97亲和性转换区间的光温临界值,结果表明:1日最低温度是影响HE97自交不亲和性的主要原因,亲和性转换区间在16.5℃~18.1℃之间。2通过HE97自交和姊妹交以及将HE97与郑58作为双亲,各自的花丝一分为二,分别正反交,授粉后4个小时分别取其花丝进行固定、染色,观察花粉管的伸长情况,根据结实率与花粉管伸长的对应关系,结果发现观察到花粉管的对应植株收获到了种子,而没有观察到花粉管的对应植株结实率极低或没有结实,本研究把HE97初步划为孢子体自交不亲和类型。3以HE97为母本,87-1为父本,按4母:1父行比,通过花粉直感效应研究天然异交率,结果母本HE97结实良好(62%),其中自交粒占70%,异交粒占30%,结合花丝切片观察表明,亲和花粉的萌发及受精会导致落在同一果穗柱头上不亲和花粉的萌发不再受抑制。
- 推荐网络例句
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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。
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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!
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Several theories about reigniting and extinguishing of the arc have been refered.
本文综合考虑了几种电弧重燃和熄灭理论。