技术与人文、自然的对话-华科大脉冲强磁场实验楼设计

该文介绍了华中科技大学脉冲强磁场实验楼的设计,此项目设计致力于给科研人员提供良好的交流环境,针对高新技术产业的特点,着重考虑两个方面的内容：一是营造自然、亲切的工作环境;二是建构多向度、复合化的交流平台。     

对轴压力作用下带有椭圆形开孔的圆柱形壳体屈曲的数值和试验研究

在圆柱形壳体的设计中,开孔对于其承载能力及屈曲性能的影响非常大。采用有限元方法对具有不同尺寸开孔的薄壁钢圆柱形壳进行模拟和分析,分析了开孔的位置、长度与直径比值（L／D）和直径与厚度比值（D／t）对圆柱形壳届曲和后屈曲性能的影响。采用INSTRON 8802液压系统对一些构件进行屈曲试验,并将试验结果与数值计算结果进行对比发现,两者具有非常好的一致性。最后,基于试验和数值分析结果,提出计算这类结构屈曲荷载的公式。     

常温热管散热器试验研究与分析

本文采用实验方法对一台新型热管散热器进行了变工况性能测试研究。人工环境实验室的空气处理机组模拟环境温度(即冷侧进风温度),用电加热装置调节散热器热侧(热管蒸发段)空气进口温度。冷侧进风温度在5℃～41℃范围调节,热侧进风温度在20℃～55℃范围调节,得出散热功率与冷热侧进风温差有关而与进出风温度范围无关;对充液率分别为35%和25%热管散热器进行变工况实验研究,得出了热管散热器充液率25%时性能优于充液率35%时性能等结论。     

闽江大跨越塔岩石锚杆基础设计与真型试验研究

针对福建山区线路工程特点,结合正在建设的闽江大跨越线路工程,选择3个典型的岩石锚杆基础试验点对中等风化、强风化岩石地质条件下岩石锚杆的直锚基础和单锚基础进行设计和真型试验研究,验证设计理论正确性和应用可行性。     

预应力对PC梁动静刚度影响的试验研究

通过对偏心距不同的两片直线钢束梁和一片曲线钢束梁进行试验,研究预应力对不同钢束位置和形态对实验梁的动刚度和静刚度的影响.发现预应力对钢束通过截面形心的P1梁的频率影响最小,对存在偏心距的直线钢束梁P2的挠度影响最大.     

房屋建筑节能施工技术的探讨

随着经济的发展、时代的进步,城市建设规模不断扩大。建筑耗能十分严重,为国家和社会带来了能源、资源负担,同时,也影响了企业的经济效益。减少建筑能耗,提高资源、能源的利用效率,为国家和社会节省更多的能源资源,已经成为建筑企业所面临的一大挑战。     

成绵乐客运专线双块式无砟轨道施工技术研究

近几年来,双块式无砟轨道施工程度越来越高,客专及高铁施工对于双块式无砟轨道施工提出了更高的要求。本文旨在以成绵乐客运专线双块式无砟轨道为例,分析双块式无砟轨道施工技术,为我国在双块式无砟轨道施工技术方面的进一步提升提供参考。     

Effect of flow rate and lead/copper pipe sequence on lead release from service lines

A pilot experiment examined lead leaching from four representative configurations of service lines including: (1) 100% lead (Pb), (2) 100% copper (Cu), (3) 50% Pb upstream of 50% Cu, and (4) 50% Pb-downstream of 50% Cu using a range of flow rates. The cumulative mass of lead release indicated that a typical partial replacement configuration (50% lead downstream of copper) did not provide a net reduction in lead when compared to 100% lead pipe (85 mg for 50% Pb-downstream versus 83 mg for 100%-Pb) due to galvanic and deposition corrosion. The partially replaced service line configuration also had a much greater likelihood of producing water with "spikes" of lead particulates at higher flow rates, while tending to produce lower levels of lead at very low flow rates. After the first 214 days the galvanic current between copper and lead was only reduced by 34%, proving that galvanic impacts can be highly persistent even in water with optimized corrosion control by dosing of zinc orthophosphate. Finally, this experiment raises concern about the low flow rates used during some prior home sampling events, which may underestimate exposure to lead during normal water use, especially when galvanic Pb:Cu connections are present.     

Onset of mucosal, dermal, and general symptoms in relation to biomarkers and exposures in the dwelling: a cohort study from 1992 to 2002

We examined the associations between biomarkers of allergy and inflammation, indoor environment in dwellings, and incidence and remission of symptoms included in the sick building syndrome (SBS) and changes in the home environment of 452 adults who were followed from 1992 to 2002 within the Uppsala part of the European Community Respiratory Health Survey (ECRHS). The 10-year incidence (onset) of general, mucosal, and dermal symptoms was 8.5%, 12.7%, and 6.8%, respectively. Dampness or indoor molds at baseline was a predictor of incidence of general (relative risk [RR] = 1.98), mucosal (RR = 2.28), and dermal symptoms (RR = 1.91). Women had higher incidence of general (RR = 1.74) and mucosal symptoms (RR = 1.71). Indoor painting increased the incidence of general symptoms (RR = 1.62). Bronchial responsiveness (BR), eosinophil counts in blood, total IgE and eosinophilic cationic protein (ECP) in serum at baseline were predictors of incidence of SBS. At follow-up, BR, total IgE, and C-reactive protein (CRP ) were associated with increased incidence of SBS. Moreover, subjects with doctor-diagnosed asthma at baseline had a higher incidence of general (RR = 1.65) and mucosal symptoms (RR = 1.97). In conclusion, female gender, dampness or indoor molds, indoor painting, and biomarkers of allergy and inflammation were associated with a higher incidence of SBS symptoms, in particular mucosal symptoms. PRACTICAL IMPLICATIONS: The focus in Sweden on indoor environment issues over the last few decades has resulted in improvements in dwellings, and reduced tobacco smoking, which could be beneficial for public health. Reducing dampness and molds in the dwelling place is another important way of reducing occurrence of SBS symptoms in the general adult population. The association between the incidence of SBS symptoms and clinical biomarkers of allergy and inflammation suggests a common etiology between inflammatory diseases, including asthma, rhinitis, and SBS. Lastly, good agreement between self-reported and clinically diagnosed atopy indicates that questionnaire data on atopy can be used in epidemiological studies.