查询词典 sampling methods

Methods Decorated houses within 6 months in Changchun were selected with the method of cluster radom sampling.

目的 探讨室内装修空气污染的主要污染物、污染程度及对人群健康的影响。

Methods Decorated houses within 6 months in Changchun were selected with the method of cluster radom sampling.

采用随机整群抽样的方法，在长春市选择装修6个月内的住户，监测甲醛、氨和总挥发性有机物的

Methods Decorated houses within 6 months in Changchun were selected with the method of cluster radom sampling.To examine densities of formaldehyde,ammonia,total volatile organic compounds and complete questionaire.

采用随机整群抽样的方法，在长春市选择装修6个月内的住户，监测甲醛、氨和总挥发性有机物的浓度，同时进行问卷调查。

Methods Radom cluster sampling was used to choose 5 nursery schools,all 301 preschool children of low class were investigation object, and micronutrient measures such as serum zinc, iron, calcium and serum vitamin A were carried out.

随机整群抽取深圳市5家托幼机构，中、小班全体学龄前儿童3 0 1名为调查对象，进行血清锌、铁、钙、血清维生素A等微量营养素测量。

Methods: The examination was performed according to methods of food hygienic analysis GB/T5009. 37-2003 and the freeze test in methods for examination of adulterate food.

依据GB/T5009.37-2003食用植物油卫生标准的分析方法和《食品掺伪监测方法》中的冷冻试验法进行检验。

Being completely new methods , Rough Classifiers , Neutral Classifiers , and analysis of Extension Information have provided non-classical set analytic methods , and have filled the gap of traditional mathematic analytic methods .

特别提出了粗糙分类方法、软分类方法、发散性方法和蕴含性方法等崭新的数据挖掘方法，为建立动态的分析型信息系统提供了基于非经典集合的分析方法，弥补了经典数学分析方法的不足。

The most common and most widely studied methods of all analytical approximation methods for nonlinear differential equations are the perturbation methods.

非线性振动由于其振动方程的特点，到现在还没有通用的解析求解方法，只能根据系统的特点采用一些特殊的方法来求解。

In this thesis,based on the DFT+NEGF first-principles method,we construct a lead-molecule-lead sandwich system with single benzene-based molecule to investigate the relationship between the structure and properties of the molecular devices and the factors that influence properties of the molecular devices.Our computational investigations on these molecular devices are primarily concentrated on the effect of contact geometry between molecules and electrodes,the effect of side groups,the effect of different torsion angle between two phenyl rings and the effect of external electric field.This thesis consists of five chapters:In Chapter one,we mainly introduce the research background and development of the molecular electronics,including the experimental fabrication of molecular electronic components and theoretical simulation methods.Afterwards we discuss the questions that need to be solved in this area.Finally,the main contents of this thesis are listed.In Chapter two,we introduce the theoretical methods used in this thesis, including the main first-principles calculation methods,i.e.,the Density-Functionmethod and nonequilibrium Green\'s function.

本论文拟采用密度泛函理论和非平衡格林函数相结合的第一性原理计算方法，选取苯基小分子作为研究对象，构建了金属电极/有机小分子/金属电极三明治结构体系，系统地研究了苯基分子器件结构的改变与分子电输运性质之间的关系以及影响分子器件电输运性质的相关因素，其中重点研究了分子与电极间可能的接触结构改变、官能团、分子间的扭转角以及外电场对苯基分子电输运性质的影响，本论文主要包括以下五个章节的内容：第一章为综述部分，主要介绍了分子电子学产生的背景、分子器件的研究意义、当前研究分子器件的实验和主要理论方法，以及目前在研究分子器件中存在的一些问题，最后给出了本论文的主要研究内容和技术路线。

Based on the three dimensional surface data of the face and skull, methods of geometric analysis on them are presented through these parameters with their numerical calculating methods under the landmarks of the anthropologist and anthropometrist are proposed,which is the foundation of the statistical model that will be used in the field; 4Geometric analysis methods that based on the approximation coefficients of spherical harmonic functions are proposed.

以三维面皮和颅骨数据为基础，分别给出了基于公安法医学标志点和人体测量学标志点的几何分析主要途径和方法，确定了几何分析的主要参量，并给出了相关的计算方法，为建立颅面统计模型奠定基础； 4基于球面调和函数的颅面形态学的几何分析方法。

To give the definition of the mass concrete and to concrete\'s cracks together with practical meanings of control ,and give a brief review on the research in the field at home and abroad, at last, methods to control temperature crack of the mass concrete from several aspects such as design measures,concrets material, construction schedules.etc are summed up; To explain the physical mechanics of the concrete and computing methods-Difference Method and Finite Element Method, and illustrate the application of their specific methods repectively;Several temperature factors that can influence the temperature stress of mass concrete baseplate are analyzed. The influence degree of temperature factor can be got through the ANSYS simulation computation the control of temperature can control the temperature stress, consequently control the temperature crack of mass concert baseplate; through the influence of the crack resistance ability of mass concrete baseplate which takes the reinforcement as a part is analyzed. By ANSYS simulation, the best suited volume ratio of reinforcement is found out, at same time the layout of reinforcement with the same volume ratio can also affect the resistance ability of mass concrete baseplate. Sum up of above analysis, anti-crack function of steel bar in early mass concrete baseplate is obvious, so it\'s necessary to consider beneficial effect of construction steel bar in research of temperature control on mass concrete baseplate.

本文先容了大体积混凝土及混凝土裂缝的基本概念，对国内外在这个领域里的研究现状作了扼要叙述，并从结构设计、混凝土材质、施工措施等方面总结了大体积混凝土温度裂缝控制的方法及防止措施；阐述了混凝土的基本物理力学性能，总结了大体积混凝土温度计算的方法——差分法和有限元法，并分别举例说明其具体应用的方法；分析了影响大体积混凝土底板温度应力的几种温度因素，利用ANSYS模拟计算，得出了每种因素的影响程度，通过分析提出了在这几种温度影响因素下如何通过控制温度以达到控制温度应力从而来控制裂缝的具体建议；针对大体积混凝土基础底板中配筋的不同对混凝土底板抗裂能力的影响不同，利用ANSYS进行模拟分析，得出底板中最合适的体积配筋率，同时分析了在相同体积配筋率下钢筋的具体布置对大体积混凝土基础底板抗裂能力的影响，分析表明，配置钢筋对混凝土结构的开裂阻止作用明显，在研究大体积混凝土温度裂缝题目时，要考虑钢筋在其中的有利作用。

Pachomius manual labour was organized as an essential part of the monastic life; and since it is a principle of the monks as distinguished from the mendicants, that the body shall be self-supporting, external work of one sort or another has been an inevitable part of the life ever since.

根据圣pachomius体力劳动组织作为一个重要组成部分寺院生活；以来，这是一个原则的和尚，作为有别于乞丐，该机构应自支撑，对外工作的这种或那种已一个必然的一部分，生活至今。

In order to study the effects of parametrical rolling on the ship movement and tilts, in allusion to ship's navigating in regular following waves, the equation of ship rolling motion is transformed into normal Mathieu equation by proper variable replacement when strong parametrical excitation in restoring moment varied according to sine or cosine wave.

为研究参数横摇对船舶运动和倾覆的影响，通过对船在规则波上随浪航行时，恢复力矩中出现的1个以正余弦规律变化的强参数激励项进行适当的变量置换，将船舶的横摇运动方程转换成标准形式的Mathieu方程。