基于微型无人机遥感数据的城市水环境信息提取初探

近年来,黑臭水体整治已经成为各级政府的重要工作内容。为更好地开展黑臭水体筛查和监管工作,提出基于多旋翼无人机搭载多光谱相机的遥感监测方案,尝试采用影像特征变换结合面向对象分类方法提取黑臭水体的遥感信息。结果表明:(1)无人机影像上地物具有更加丰富的色彩和纹理;(2)与主成分变换和纹理分析方法相比,光谱指数对典型地物具有较好的判别能力;(3)采用标准最邻近分类法提取城市水环境信息,能够获得较高分类精度。     

Features of fatal injuries in older cyclists in vehicle–bicycle accidents in Japan

Objective: The purpose of this study was to identify and better understand the features of fatal injuries in cyclists aged 75 years and over involved in collisions with either hood- or van-type vehicles.

Methods: This study investigated the fatal injuries of cyclists aged 75 years old and over by analyzing accident data. We focused on the body regions to which the fatal injury occurred using vehicle–bicycle accident data from the Institute for Traffic Accident Research and Data Analysis (ITARDA) in Japan. Using data from 2009 to 2013, we examined the frequency of fatally injured body region by gender, age, and actual vehicle travel speed. We investigated any significant differences in distributions of fatal injuries by body region for cyclists aged 75 years and over using chi-square tests to compare with cyclists in other age groups. We also investigated the cause of fatal head injuries, such as impact with a road surface or vehicle.

Results: The results indicated that head injuries were the most common cause of fatalities among the study group. At low vehicle travel speeds for both hood- and van-type vehicles, fatalities were most likely to be the result of head impacts against the road surface.

The percentage of fatalities following hip injuries was significantly higher for cyclists aged 75 years and over than for those aged 65–74 or 13–59 in impacts with hood-type vehicles. It was also higher for women than men in the over-75 age group in impacts with these vehicles.

Conclusions: For cyclists aged 75 years and over, wearing a helmet may be helpful to prevent head injuries in vehicle-to-cyclist accidents. It may also be helpful to introduce some safety measures to prevent hip injuries, given the higher level of fatalities following hip injury among all cyclists aged 75 and over, particularly women.     

遥感技术在水生态环境管理的应用与前景

随着遥感数据源的不断丰富,遥感技术不断提高,可以解决越来越多的水环境问题。指出了当前水生态环境管理方面的主要需求,结合目前遥感技术的发展,对国内外的水环境遥感研究进展进行综述。以湖泊富营养化监测与评估、核电站温排水遥感监测及城市黑臭水体遥感监测为案例,具体阐述遥感在水环境管理中的应用方法及成效。未来水生态环境管理发展趋势将以水污染防治为主向水污染防治和水生态修复与保护并重发展。基于此趋势,提出遥感在水生态修复的应用潜力,利于更多地方部门积极有效应用遥感技术,解决水生态环境问题。     

城市黑臭水体的产生原因及治理对策

在我国经济发展势头如此迅猛的背景下,城市污染问题日益严重。城市黑臭水体对城市生态环境造成严重影响,如果不能及时进行治理,则会对原有水生态循环系统造成破坏,影响城市居民正常生活。本文首先对城市黑臭水体产生原因进行分析,然后提出有效的治理对策。     

基于虚拟碰撞试验分析燃料电池轿车车身结构的安全性

在燃料电池轿车的车身结构配合动力驱动系统的改进而不断改进的过程中,需要从碰撞安全性角度去分析结构方案的优劣.本文采用虚拟正面碰撞试验方法,研究经过改进后的燃料电池轿车的半承载式车身是否满足国家被动安全法规,并通过与第1代燃料电池轿车的整车碰撞模拟结果的对比,分析车身结构改进对正面碰撞安全性的影响,从而为进一步的结构改进提供有价值的建议.     

Physiologically based pharmacokinetic modeling of perfluoroalkyl substances in the human body

Currently, there are limited data on the levels of perfluoroalkyl substances other than perfluorooctane sulfonic acid and perfluorooctanoic acid in the human body. Most of this information has been extracted from biological monitoring of plasma while the occurrence of perfluoroalkyl substances in other human tissues is rarely studied. The objective of the present study was to develop a physiologically based pharmacokinetic model to assess the concentration of perfluoroalkyl substances in human tissues, based on an existing model previously validated for perfluorooctane sulfonic acid and perfluorooctanoic acid. Experimental data on concentrations of perfluoroalkyl substances in human tissues from individuals in Tarragona County (Catalonia, Spain) were used to estimate the values of some distribution and elimination parameters needed for the simulation. No significant correlations were found between these parameters and the chain lengths. The model was finally validated for five perfluoroalkyl substances.     

Development of a Computationally Efficient Full Human Body Finite Element Model

Introduction: A simplified and computationally efficient human body finite element model is presented. The model complements the Global Human Body Models Consortium (GHBMC) detailed 50th percentile occupant (M50-O) by providing kinematic and kinetic data with a significantly reduced run time using the same body habitus.

Methods: The simplified occupant model (M50-OS) was developed using the same source geometry as the M50-O. Though some meshed components were preserved, the total element count was reduced by remeshing, homogenizing, or in some cases omitting structures that are explicitly contained in the M50-O. Bones are included as rigid bodies, with the exception of the ribs, which are deformable but were remeshed to a coarser element density than the M50-O. Material models for all deformable components were drawn from the biomechanics literature. Kinematic joints were implemented at major articulations (shoulder, elbow, wrist, hip, knee, and ankle) with moment vs. angle relationships from the literature included for the knee and ankle. The brain of the detailed model was inserted within the skull of the simplified model, and kinematics and strain patterns are compared.

Results: The M50-OS model has 11 contacts and 354,000 elements; in contrast, the M50-O model has 447 contacts and 2.2 million elements. The model can be repositioned without requiring simulation. Thirteen validation and robustness simulations were completed. This included denuded rib compression at 7 discrete sites, 5 rigid body impacts, and one sled simulation. Denuded tests showed a good match to the experimental data of force vs. deflection slopes. The frontal rigid chest impact simulation produced a peak force and deflection within the corridor of 4.63 kN and 31.2%, respectively. Similar results vs. experimental data (peak forces of 5.19 and 8.71 kN) were found for an abdominal bar impact and lateral sled test, respectively. A lateral plate impact at 12 m/s exhibited a peak of roughly 20 kN (due to stiff foam used around the shoulder) but a more biofidelic response immediately afterward, plateauing at 9 kN at 12 ms. Results from a frontal sled simulation showed that reaction forces and kinematic trends matched experimental results well. The robustness test demonstrated that peak femur loads were nearly identical to the M50-O model. Use of the detailed model brain within the simplified model demonstrated a paradigm for using the M50-OS to leverage aspects of the M50-O. Strain patterns for the 2 models showed consistent patterns but greater strains in the detailed model, with deviations thought to be the result of slightly different kinematics between models. The M50-OS with the deformable skull and brain exhibited a run time 4.75 faster than the M50-O on the same hardware.

Conclusions: The simplified GHBMC model is intended to complement rather than replace the detailed M50-O model. It exhibited, on average, a 35-fold reduction in run time for a set of rigid impacts. The model can be used in a modular fashion with the M50-O and more broadly can be used as a platform for parametric studies or studies focused on specific body regions.     

Assessment of potential dermal and inhalation exposure of workers to the insecticide imidacloprid using whole-body dosimetry in China

In China, although improvements to the pesticide registration process have beenmade in last thirty years, no occupational exposure data are required to obtain a commercial license for a pesticide product. Consequently, notably little research has been conducted to establish an exposure assessment procedure in China. The present study monitored the potential dermal operator exposure from knapsack electric sprayer wheat field application of imidacloprid in Liaocheng City, Shandong Province and in Xinxiang City, Henan Province, China, using whole-body dosimetry. The potential inhalation exposure was determined using a personal air pump and XAD-2 sample tubes. The analytical method was developed and validated, including such performance parameters as limits of detection and quantification, linear range, recovery and precision. The total potential dermal and inhalation exposures were 14.20, 16.80, 15.39 and 20.78 mL/hr, respectively, for the four operators in Liaocheng and Xinxiang, corresponding to 0.02% to 0.03% of the applied volume of spray solution. In all trials, the lower part (thigh, lower leg) of the body was the most contaminated, accounting for approximately 76% to 88% of the total exposure. The inhalation exposure was less than 1% of the total exposure. Such factors as the application pattern, crop type, spray equipment, operator experience and climatic conditions have been used to explain the exposure distribution over the different parts of the body. As indicated by the calculated Margin of Exposure, the typical wheat treatment scenarios when a backpack sprayer was used are considered to be safe in terms of imidacloprid exposure.     

Relationship between musculoskeletal disorders and anthropometric indices among bus drivers in Zahedan city

Introduction. Most work-related musculoskeletal disorders (MSDs) are associated with improper postures and poorly designed workstations. This study is an attempt to examine the prevalence and severity of MSDs as well as anthropometric dimensions among city bus drivers. Methodology. This cross-sectional study was carried out on 60 male bus drivers. A body discomfort chart was used to evaluate MSDs. Spearman correlation was employed to examine the relationship between body size and the severity of discomfort. Results. Data analysis showed that discomfort reported in the lower back (33.3%), upper back (18.3%) and knee (15%) was severe and there was a direct and significant correlation between the body mass index and the severity of discomfort in the shoulder, arm and hip (p?p?Conclusion. The results of the study can be used to address ergonomic risk factors and reduce their associated disorders. The findings of the study can be used in training programs to educate drivers how to decrease the risk associated with work-related MSDs by adopting appropriate behavior strategies.     

肠道微生物对土壤中铜、锌、锰生物可给性的影响

为了更全面、准确地评价土壤中金属元素对人体的健康风险,研究土壤中金属元素在结肠阶段的生物可给性具有重要意义。通过采集我国一些地区的6种土壤,利用in vitro方法(PBET和SHIME联用)研究土壤中Cu、Zn、Mn在胃、小肠、结肠阶段的生物可给性。研究显示,土壤中Cu、Zn、Mn在胃阶段的生物可给性分别为23.8%~63.0%、21.2%~64.4%、11.7%~35.6%;从胃阶段到小肠阶段,土壤中Cu的生物可给性提高了0.4%~14.4%,而土壤中Zn在小肠阶段的生物可给性降低了6.7%~38.7%。结肠阶段,土壤中Cu、Zn、Mn的生物可给性分别为2.4%~12.9%、5.7%~18.7%、6.2%~18.9%,与小肠阶段相比,分别降低了21.7%~56.9%、0.4%~36.8%、4.5%~19.1%。结果表明,在肠道微生物存在的情况下,土壤中Cu、Zn、Mn在结肠阶段有较低的人体健康风险。