A stratified sample method of scattering source for time - dependent monte carlo transport 非定常粒子输运蒙特卡罗散射源分层抽样方法
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Methods centers of disease prevention and control in three parts of china had been sampled by two - stage stratified sampling method to investigate the fulfillment degree of quality and quantity of the treatment management of hypertension patients in community and its influencing factors 方法运用分层抽样、问卷调查的方法，获得社区高血压患者治疗规范管理的数量完成程度和质量达标程度及相应难点。
