千米深井大倾角煤层综放采场矿压显现实测研究

针对开滦赵各庄矿3237深部大倾角综放工作面的矿压显现和围岩活动规律进行了全面的实测研究,通过多种观测手段和研究方法,获得了大量的观测数据,初步掌握了大采深大倾角厚煤层条件下综放开采工作面矿压显现的基本规律与顶板的运移特征,得出了大采深与大倾角回采巷道变形与支承压力的分布特征.     

煤矿工业电视系统的设计

阐述了煤矿工业电视系统的原理及结构 ,描述了系统各部分的设计及选型 ,尤其是视频传输的光纤部分 ,着重讲解了煤矿工业电视系统的要点 ,指出了施工中应注意的问题。实际运行证明 ,该系统设计合理 ,发挥了其应有的作用     

基于ADμC841单片机的防爆软起动控制系统

本文设计了一种基于ADμC841单片机的软起动器控制系统,着重介绍了系统原理及软硬件设计。经检验与实际运行表明,本系统技术先进,效果良好。     

斜结构奇异值及其在实参数不确定性导弹鲁棒稳定性评估中的应用

针对结构奇异值(?)存在计算量大、下界不易计算等问题,提出基于斜结构奇异值的评估方法。将系统频率看作1个实不确定参数,构建不确定系统的状态空间表达式,将某一频率范围内各频点对应的结构奇异值计算问题转化为单个的斜结构奇异值计算,给出2种算法分别计算斜结构奇异值的上下界,并对实参数不确定性导弹的鲁棒稳定性评估对所提方法的准确性和实用性进行验证。结果表明:该方法是一种高效且准确的鲁棒稳定性评估方法,适用于工程应用。     

广义m法及在基坑支护结构计算中的应用

在基础设计中有熟悉的文克尔弹性地基模型,在桩水平力计算及支护设计中有m法,如考虑多层土层复杂情况,m法则无法求解,本文将此类问题归入广义m法,利用两结点Hermite单元形函数推导其刚度矩阵。此法便于编制计算机程序,已用于弹性地基梁、桩水平力计算、支护结构三维有限元结构计算     

薄壁高墩连续梁移动模架法设计与施工

介绍了扬中夹江二桥引桥40 m跨等高预应力混凝土连续梁的设计与施工情况,重点介绍了移动模架造桥机在薄壁高墩连续梁结构中的成功应用,指出该工程使用的移动模架造桥机具有承载力大、滑移方便等优点,确保了施工进度,值得推广应用。     

The relationship between particulate air pollution and emergency hospital visits for hypertension in Beijing, China

Background

A number of epidemiological studies have examined the adverse effect of air pollution on mortality and morbidity. Also, several studies have investigated the associations between air pollution and specific-cause diseases including arrhythmia, myocardial infarction, and heart failure. However, little is known about the relationship between air pollution and the onset of hypertension.

Objective

To explore the risk effect of particulate matter air pollution on the emergency hospital visits (EHVs) for hypertension in Beijing, China.

Methods

We gathered data on daily EHVs for hypertension, fine particulate matter less than 2.5 μm in aerodynamic diameter (PM_2.5), particulate matter less than 10 μm in aerodynamic diameter (PM₁₀), sulfur dioxide, and nitrogen dioxide in Beijing, China during 2007. A time-stratified case-crossover design with distributed lag model was used to evaluate associations between ambient air pollutants and hypertension. Daily mean temperature and relative humidity were controlled in all models.

Results

There were 1,491 EHVs for hypertension during the study period. In single pollutant models, an increase in 10 μg/m³ in PM_2.5 and PM₁₀ was associated with EHVs for hypertension with odds ratios (overall effect of five days) of 1.084 (95% confidence interval (CI): 1.028, 1.139) and 1.060% (95% CI: 1.020, 1.101), respectively.

Conclusion

Elevated levels of ambient particulate matters are associated with an increase in EHVs for hypertension in Beijing, China.     

浅谈中小户型的设计

针对有关方面提出的“90m^2及以下住房比重要达到新建项目的70％，中小户型将成为市场的主流”这一实际问题，介绍了小面积住宅套型设计的历史，并通过对住宅使用空间的分析，探讨了中小户型的设计原理和方法，进而解决了小面积住宅套型设计的一些问题，说明中小户型住宅一般说来是可行的。     

Is the association between temperature and mortality modified by age, gender and socio-economic status?

Background

A number of studies have examined the relationship between high ambient temperature and mortality. Recently, concern has arisen about whether this relationship is modified by socio-demographic factors. However, data for this type of study is relatively scarce in subtropical/tropical regions where people are well accustomed to warm temperatures.

Objective

To investigate whether the relationship between daily mean temperature and daily all-cause mortality is modified by age, gender and socio-economic status (SES) in Brisbane, Australia.

Methods

We obtained daily mean temperature and all-cause mortality data for Brisbane, Australia during 1996-2004. A generalised additive model was fitted to assess the percentage increase in all deaths with every one degree increment above the threshold temperature. Different age, gender and SES groups were included in the model as categorical variables and their modification effects were estimated separately.

Results

A total of 53,316 non-external deaths were included during the study period. There was a clear increasing trend in the harmful effect of high temperature on mortality with age. The effect estimate among women was more than 20 times that among men. We did not find an SES effect on the percent increase associated with temperature.

Conclusions

The effects of high temperature on all deaths were modified by age and gender but not by SES in Brisbane, Australia.