查询词典 systematic sampling

Methods: The survey were designed by stratified cluster sampling.

方法采取分层整群抽样的方法。

Methods Questionnaire survey was conducted with stratified cluster sampling.

方法采用分层整群抽样的方法，进行无记名问卷调查。

Methods:Random cluster sampling method was used.2 763 subjects were studied with a self-reported questionnaire.

采用整群随机抽样方法，对2763名学生通过自填问卷的方式进行了调查。

Methods With stratified cluster sampling method,1?

采取分层随机抽样方法，对沈阳市2所大学1？

Methods By cluster random sampling method,a total of 21 kindergarten children in Meizhou were taken.

方法采用整群随机抽样的方法，抽取梅州市21所幼儿园的全部在园儿童，采用自拟问卷和克氏行为量表进行调查和评定。

Methods Seventy-five stu-dents were recruited based on cluster sampling for this study.

目的 探讨健康教育对护理本科生艾滋病知识和态度的影响。

Methods A questionnaire investigation was carried out among pupils, parents and teachers by cluster sampling.

采用整群抽样对学生和家长教师进行问卷调查。

A structured questionnaire was administered to 1091 students who were selected by cluster sampling.

以问卷调查法针对33所原住民国小1250名学童为对象，有效问卷1091份。

Methods 1118 students in 4 senior high schools in Dongcheng District of Beijing were sampled by random cluster sampling.

方法采用整群随机抽样的方法，抽取北京市东城区4所中学的高中一、二、三年级各2个班，共1118名学生，用中学生心理健康诊断测验量表进行测评。

AVO analysis is suggested for solving to solve the difficulty in identification of thin alternating layers in exploration of oilfields. It can improve the current method that has no thickness variable in the formula of reflective and is limited by sampling rates in calculation of the coefficient in the time of domain. Using the relationship of stress and displacement on two interfaces, this paper derives the spectrum of reflective coefficient for any incidence angle and thiekness of thim layer based on the equation of seismic wave propagation in the frequency domain.

针对油气田开发中薄互层认识难的问题，提出从AVO分析解决困难，克服现有方法在反射系数公式中无厚度变量、时间域计算反射系数谱受采样率限制的不足，运用两个界面间位移与应力关系，从频率域地震波传播方程推导了任意入射角和薄层厚度下的反射系数谱。

"Second Life is remarkably easy to work with, and is very popular,"

"第二次生命是显着容易的工作，并且很受欢迎，"

For example, we usually assume that materials are homogeneous and isotropic and free of internal defects or flaws.

为了得到适合有限元分析的模型，我们必须经过如图2所示的简化步骤。