Modeling and Optimization of Solar Collector Design for the Improvement of Solar-Air Source Heat Pump Building Heating System

To enhance system stability,solar collectors have been integrated with air-source heat pumps.This integration facilitates the concurrent utilization of solar and air as energy sources for the system,leading to an improvement in the system’s heat generation coefficient,overall efficiency,and stability.In this study,we focus on a residential building located in Lhasa as the target for heating purposes.Initially,we simulate and analyze a solar-air source heat pump combined heating system.Subsequently,while ensuring the system meets user requirements,we examine the influence of solar collector installation angles and collector area on the performance of the solar-air source heat pump dual heating system.Through this analysis,we determine the optimal installation angle and collector area to optimize system performance.

班主任学历对初中学生认知能力的影响——基于CEPS数据的实证分析

本文使用中国教育追踪调查(CEPS)2014—2015年度数据和增值模型(Value-added Model),实证分析了班主任学历对学生认知能力的影响及其机制。研究发现:班主任学历能够显著提高学生的认知能力,班主任学历为全日制本科、研究生及以上对学生认知能力的影响比专科和成人本科强,其中以研究生及以上学历的影响作用最大。从影响机制来看,班主任学历的提高会增强其业务能力和管理能力,提升班主任的教学质量水平;高学历班主任的教学方式更加多样化,与学生交流更为密切,对学生更加负责任,越能提升学生的认知能力。异质性分析结果表明,班主任学历对女学生认知能力的提升作用比男学生更强;城市地区和中、低教龄班主任的学历对学生认知能力具有显著的提升作用,而农村地区和高教龄班主任的学历对学生认知能力的影响不显著。本文进一步探讨了这些差异背后的原因,为政府、学校教育部门提供相关的启示建议。