分层抽样

Methods 3944 persons were selected by systematic sampling in 3 districts.

采取分层随机整群抽样的方法，于2006年10月和2007年9月进行2次调查，以示范路上沧浪区、金阊区、高新区的33个单位、10个社区居民，共计3 944人作为调查对象。2007年9月，以非示范路上某区采取同样方法抽取居民809人进行问卷调查。

All subjects in the sample of 600 individuals were selected by a stratified systematic random sampling method and interviewed by trained interviewers.

本研究采横断面研究方法，以苗栗县所有65岁以上老年人作为研究母群体，采分层随机抽样的方法，共得到600位样本，其中男性302人，女性298人。

Their weight, height, blood pressure and vital capacity were calculated.

采用分层随机整群抽样法选择张家口市7～12周岁3 043名儿童，分别测定身高、体重、血压和肺活量，计算体质量指数和肺活量指数。

Methods:The randomly group sampling,parallet comparison and dilamination methods are used in this study.166 cases (10 falling off) was observed on giving priority to diferent treatment of yiqi yangyin,wenbu spleen and kindey,qingre jiedu and evaluate the change of different quantity arrangement of CD4~+T lymphocyte cell of different treatment of TCM on HIV asymptomatic carriers.

采用随机整群抽样、平行对照、分层研究的方法，分别以益气养阴法、温补脾肾法和清热解毒法为主对166例(脱落10例)感染者进行干预，观察中医不同治法对感染者不同层次CD4~+T淋巴细胞的变化。

2Chlorine residual of indirected system are decreasing are sampling efficiency of stratification and stage are good.

2有效余氯量经水池、水塔后数值会降低，且分层分段抽样效率皆良好。

Results The rates of awareness about avian influenza and its infection sources were 99.0% and 83.8%,respectively;The rates of awareness about route of transmission of contact transmission,airborne infection,dungwatermouth and insect vector were 78.5%,71.2%,54.5%,70.2%,respectively;There were 45.5% people who thought all people could be infected easily by avian influenza virus;79.1% people thought fever was clinical situation of avian influenza,and that was 52.9% for nose running,cough,pharyngalgia.

采用分层整群随机抽样方法抽取顺义区禽流感高危险职业从业人员191名，进行禽流感有关知识、信念和行为的问卷调查。

objective to investigate the weight control behav iors and the related factors to middle school students, and to provide bases forpreventing health-risk behaviors.methodsquestionnaire surv ey was conducted among a cluster strati fied sample of 4 542 middle school students of grade one in junior middle schooland grade two in senior middle school.

目的 了解广州市中学生减肥行为现状及其影响因素，为预防中学生健康危险行为的发生提供依据。方法按随机分层整群抽样方法，抽取广州市4所中学初一到高二5个年级共4 542名中学生进行问卷调查；通过家长问卷收集学生的家庭背景资料，分析减肥行为与家庭因素的关系。

Methods Multi-stage stratified random sampling was used, and the combination of centralizing investigation and enter-household investigation were used to collect data.

方法采用多阶段分层随机抽样的方法确定调查样本，以集中调查和入户调查相结合的方式收集数据。

The sample populations were choused from an educational university in middle Taiwan. Students are all enrolled in the second semester, 2005. The total populations are 4443. Stratified random sample approaching the populations and 896 samples were gathered.

本研究以中部地区某国立大学94学年度第2学期在学的大学生共4443人为研究母群体，采分层随机抽样的方法取得样本数共计896人。

MethodsDescriptive analysis was conducted among 818 medicos, who were sampled by stratified cluster sampling, and the model was established.

采用分层整群抽样的方法，对某医科大学818名医学生心理健康状况的一般情况进行描述性分析，并拟合结构方程模型。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失