2013年成都地区一次秸秆焚烧特征及成因分析

2013年9月14~17日成都及周边地区出现了一次秸秆焚烧空气污染过程,成都、德阳受污染影响较严重,乐山、眉山影响相对较轻。基于空气污染指数API,结合雷达消光系数反演图、在线气团后向轨迹及探空斜温图分析本次空气污染过程,主要是由成都城区以南地区秸秆焚烧及区域边界层辐射逆温等不利扩散气象条件共同造成的。     

基于需求与供给理论的甘肃省人口土地承载力研究

从供给和需求平衡的经济学视角,运用生态能值分析的研究方法,对2006年-2012年甘肃省农业土地人口承载力进行了实证研究.发现中国取消农业税政策提高了农民生产积极性,同时发现近年来甘肃省农业土地能值供给无法满足人口能值需求,但供需差距在缩小,预计未来十数年内随着农业产业化生产及农业科技的提高,甘肃省将实现农业土地产出和人口能值需求的自给自足.     

A Simulation Study on the Efficacy of Advanced Belt Restraints to Mitigate the Effects of Obesity for Rear-Seat Occupant Protection in Frontal Crashes

Objective: Recent field data analyses have shown that the safety advantages of rear seats relative to the front seats have decreased in newer vehicles. Separately, the risks of certain injuries have been found to be higher for obese occupants. The objective of this study is to investigate the effects of advanced belt features on the protection of rear-seat occupants with a range of body mass index (BMI) in frontal crashes.

Methods: Whole-body finite element human models with 4 BMI levels (25, 30, 35, and 40 kg/m²) developed previously were used in this study. A total of 52 frontal crash simulations were conducted, including 4 simulations with a standard rear-seat, 3-point belt and 48 simulations with advanced belt features. The parameters varied in the simulations included BMI, load limit, anchor pretensioner, and lap belt routing relative to the pelvis. The injury measurements analyzed in this study included head and hip excursions, normalized chest deflection, and torso angle (defined as the angle between the hip–shoulder line and the vertical direction). Analyses of covariance were used to test the significance (P <.05) of the results.

Results: Higher BMI was associated with greater head and hip excursions and larger normalized chest deflection. Higher belt routing increased the hip excursion and torso angle, which indicates a higher submarining risk, whereas the anchor pretensioner reduced hip excursion and torso angle. Lower load limits decreased the normalized chest deflection but increased the head excursion. Normalized chest deflection had a positive correlation with maximum torso angle. Occupants with higher BMI have to use higher load limits to reach head excursions similar to those in lower BMI occupants.

Discussion and Conclusion: The simulation results suggest that optimizing load limiter and adding pretensioner(s) can reduce injury risks associated with obesity, but conflicting effects on head and chest injuries were observed. This study demonstrated the feasibility and importance of using human models to investigate protection for occupants with various BMI levels. A seat belt system capable of adapting to occupant size and body shape will improve protection for obese occupants in rear seats.     

磁性吸附材料的制备及其在污水处理中的应用

磁性吸附材料是利用多种物理化学作用来处理水体中的无机污染物和有机污染物,其具有的磁性便于与污水分离,有利于集中处理污染物,具有快速、高效、可重复利用等优点。从Fe3O4磁性颗粒和纳米磁性粒子出发,对磁性吸附材料的制备以及其在污水处理中的应用研究进展进行综述,并对磁性吸附材料今后的研究方向进行展望。     

云南省环境空气质量数据传输系统的建设与发展

叙述了云南省空气质量监测、数据传输及发布的历史,空气监测子站的现状,及云南省空气联网实时发布数据传输系统的建设情况、进度安排和效益等。     

Influence of soil physical properties and vegetation coverage at different slope aspects in a reclaimed dump

Vegetation coverage is an important parameter for affecting soil erosion and the physical and chemical properties of soil. To analyze the mutual influence between vegetation coverage and soil quality at different slope aspects in a reclaimed dump, fitting analyses were built between the normalized difference vegetation index and soil physical properties at each slope aspect. Twenty six quadrats were sampled in slope-platform alternate mode. Each quadrat was 10 m × 10 m. Vegetation index and soil physical properties were measured and calculated. Through curve fitting analysis, the results showed that soil bulk density has a negative correlation with the vegetation index on shady and half shady slopes, sunny slopes, and half sunny slopes. Soil porosity has a positive correlation with the vegetation index on shady and half shady slopes, sunny slope, and half sunny slope. The soil mass water content has a concave function relationship with the vegetation index on shady and half shady slopes and has a quadratic function relationship with the vegetation index on sunny and half sunny slopes, with the parabola moving upwards. The soil gravel content has a linear relationship with the vegetation index on shady and half shady slopes, and the image has a negative slope with a quadratic function relationship to the vegetation index on sunny slope and half sunny slope, with the parabola moving downwards. Due to differences among hydrothermal conditions, the relationship between vegetation coverage and soil quality indicators at different slope aspects is different; therefore, reasonable improvement of soil quality indicators on sunny and half sunny slopes could help plants to grow. These findings feed into a reference document that sets out how vegetation and soil quality may be improved in mining areas.

     

Effectiveness of temporary traffic control measures in highway work zones

In the United States, hundreds of people lose their lives each year and many more are injured due to vehicle crashes in the work zones. Over the years, temporary traffic control (TCC) measures have been developed and deployed in work zones. To continuously improve the safety, there is a need to identify the traffic control deficiencies in work zones by evaluating the effectiveness of existing TTC measures based on the real crash cases. In this study, researchers evaluated the effectiveness of several commonly used TTC methods using logistic regression techniques and various significance test methods including likelihood ratio test, score test, and Wald test. These TTC methods included flagger/officer, stop sign/signal, flasher, no passing zone control, and pavement center/edge lines. A total of 655 severe crashes in Kansas highway work zones between January 2003 and December 2004 were used for the evaluation, which included 29 fatal crashes and 626 injury crashes. Results indicated that flagger, flasher, and pavement center/edge lines were effective in reducing the probability of causing fatalities when severe crashes occurred. In addition, using these devices could prevent some common human errors, such as “disregarded traffic control”, “inattentive driving”, “followed too closely”, and “exceeded speed limit or too fast for condition”, from causing severe crashes.