查询词典 stratified sample

Methods 7 282 children aged 2 to 5 years were selected by stratified sampling from twelve software.

分层随机抽取我国12个省市7 282名2～5岁儿童作为研究对象。

Methods Students from 6 high schools in Hangzhou were selected by stratified sampling.

中学生的学习成绩是社会、学校、家庭关注的主要问题。

Methods With stratified clustered sampling method, 375 college students were chosen to complete the questionnaire.

采用分层随机抽样方法，在杭州市的大学中抽取大学生375名进行问卷调查。

Methods Study subjects were selected through stratified sampling and data were collected through questionnaire and physical examination.

方法］采用分层整群抽样的方法获取研究样本，采用问卷调查和体检相结合的方法收集相关信息。

Methods Based on stratified sampling, 363 medical facilities were selected to conduct the survey.

采取分层抽样方法在全国范围内抽取363家医疗机构开展调查。

Methods (1) Randomized stratified clustered sampling method was used.

(1)采用分层整群随机抽样法，收集徐州市

Methods A self-developed questionnaire was used to investigate 2600 old persons selected in 26 provinces by stratified sampling.

方法在26省按照城乡和男女分层抽样，对2600名老年人进行问卷调查，并对有效的2414份问卷进行数据统计学处理。

Stratified random sampling was used to recruit 553 participants, and response rate was 70.5%.

取样方式为分层随机抽样，共发出553份，回收390份，回收率70.5%。

Methods The Knowledge of occupational hazard and prevention in different enterprises was investigated by stratified random sampling.

方法采用整群抽样的方法对不同行业的外资企业农民工进行职业病危害因素认知及其防护知识的问卷调查和统计分析。

In this paper, 236 SMEs of different types of ownership and from different industries are investigated using a stratified sampling method.

本文采用分层抽样方法，对236家不同所有制、具有行业代表性的中小企业展开了问卷调查。

This paper designs the communication system of radio telescope FAST.

针对500m口径球面射电望远镜FAST分布式控制系统的特点完成了其通信系统的设计。

Political sheep's step-by-step a large number of fossils unearthed in the county soil Ma Ali after rural village in the middle of sallow pelitic siltstone.

步氏和政羊化石大量出土于广河县阿力麻土乡后山村，产于灰黄色泥质粉砂岩中。