气垫导轨实验减小误差的几点体会

本文在实践及数据测试基础上,分析了气垫导轨实验减小系统误差的问题。     

土壤和建筑材料表面氡析出率对室内氡浓度的影响

采用监测数据可靠的RAD7测氡仪,选择深圳市某平房为研究对象,检测到平房周围为土壤氡低背景区,且土壤表面氡析出率较大,约为房间内水泥地板的2倍,说明土壤是室内氡的最大来源;而水泥地板表面氡析出率较瓷砖地板大,约为瓷砖地板的4倍。铺有水泥地板的房间室内氡浓度大于铺有瓷砖地板的房间,这是由于水泥地板表面氡析出率较大。因此,为了减少室内氡浓度,应该尽可能选择表面氡析出率低的材料铺设地板,并保持开窗通风。     

Pathways of China's PM2.5 air quality 2015–2060 in the context of carbon neutrality

Clean air policies in China have substantially reduced particulate matter (PM_2.5) air pollution in recent years, primarily by curbing end-of-pipe emissions. However, reaching the level of the World Health Organization (WHO) guidelines may instead depend upon the air quality co-benefits of ambitious climate action. Here, we assess pathways of Chinese PM_2.5 air quality from 2015 to 2060 under a combination of scenarios that link global and Chinese climate mitigation pathways (i.e. global 2°C- and 1.5°C-pathways, National Determined Contributions (NDC) pledges and carbon neutrality goals) to local clean air policies. We find that China can achieve both its near-term climate goals (peak emissions) and PM_2.5 air quality annual standard (35 μg/m³) by 2030 by fulfilling its NDC pledges and continuing air pollution control policies. However, the benefits of end-of-pipe control reductions are mostly exhausted by 2030, and reducing PM_2.5 exposure of the majority of the Chinese population to below 10 μg/m³ by 2060 will likely require more ambitious climate mitigation efforts such as China''s carbon neutrality goals and global 1.5°C-pathways. Our results thus highlight that China''s carbon neutrality goals will play a critical role in reducing air pollution exposure to the level of the WHO guidelines and protecting public health.     

浅谈气步枪比赛中的节奏

通过对上海市天山中学部分运动员参加上海市第十二届运动会气枪比赛前后经过的回顾和分析,认为气步枪比赛中存在的一个节奏现象是影响运动员技术水平和心理状态的重要因素,也就是最终影响成绩的重要因素.     

Risk,affect, and policy support: public perception of air pollution in China

Air pollution is a critical environmental problem that has spurred great public concern in China. This study examines how issue salience, environmental value, risk perception, and affective response influence information seeking, objective knowledge, and policy support related to this issue. The recent release of a controversial environmental documentary on Chinese social media, Under the Dome, also prompted us to explore the impact of exposure to this documentary on Chinese social media users’ information seeking and policy support related to air pollution. Results showed that risk perception and negative affect influenced information seeking and policy support both directly and indirectly. Also, exposure to the documentary moderated the effects of key variables on information seeking and policy support. However, contrary to our expectations, no significant relationship was found between information seeking and objective knowledge. Theoretical and practical implications of these findings were discussed.     

演进与变革:留学生与近代中国军事航空

近代以来，随着飞机广泛运用于军事领域，中国逐渐意识到其在未来战争中的巨大作用，从1909年始到1949年的41年间，多次选派留学生赴英、美、苏、法等国家学习先进的军事航空技术和飞机制造技术。这些军事留学生回国后，积极主持或参与中国飞机的研制工作，试制成功中国最早的水上飞机、仿苏E-16驱逐机、运输机等，促进了中国军事航空工业的发展；积极组建雷达部队、重型轰炸部队、空中照相侦察部队，增加了空军新兵种，在抗日战争中名噪一时；担任空军高级将领，充当空军基层训练教育的骨干，担任军事航空学校的高级职务，成为空军教育与训练的核心力量。他们的杰出工作，不仅开启了近代中国的军事航空事业．同时为中国军事航空事业的演进与变革作出了重要贡献。     

空气座柔性夹具系统设计及应用

空气座多品种、批量生产时,存在产品精度不易控制、生产效率不高等问题,通过产品结构分析,设计出一套柔性夹具系统,使用该系统夹持,可以提高产品精度和生产效率,同时实现生产与教学过程紧密结合,加深学生对实际工作过程的理解与掌握。     

基于DASP软件新风换气机的试验模态分析

研究了新风换气机的动态特性,以改善新风设备工作时的振动噪声,对XHBX-D2TH型号的新风换气机进行了试验模态研究,得到了新风机结构的8阶模态固有频率、阻尼比和模态振型等参数,为进行有限元模态仿真分析,振动、噪声分析与结构优化创造了条件.     

主动进气格栅技术研究

随着主动进气格栅技术在汽车上的逐步使用,主动进气格栅的技术优势逐步体现,文章阐述了主动进气格栅对整车行驶阻力的优化和整车热控制的相关影响,并以线性回归模型的方法对主动进气格栅的标定方法进行了初步探索。     

室内空气质量对人体健康的影响

室内空气污染对健康的影响是人类百多年来不断研究和探索的目标之一。本文分析了室内空气污染对人体健康的主要危害、基本原因和主要评价指标，简要综述了近5年在室内空气污染与健康领域，国内外的主要研究方向和内容。对我国室内环境与健康研究的基本思路和存在问题进行了初步探讨，并提出今后国内应在准确评价人群室内空气污染的暴露量、人群健康效应暴露-反应关系的定量评价、室内环境对人体舒适度和工作效率的影响机理、室内污染健康效应综合评价的方法学等几个主要科学问题方面深入地进行研究探讨。