考虑群组行为的楼梯瓶颈处行人流模拟

为探究楼梯瓶颈处群组行为对行人流通行效率的影响,基于校园内的观测试验获取群组运动参数,采用Anylogic仿真平台建立考虑群组行为特征的楼梯瓶颈处人员运动模型,根据不同的群组运动参数、楼梯几何参数和障碍物布置方式对行人流通行时间与密度分布的影响开展数值模拟。结果表明:较大的群组比例和群组规模均会延长行人流通行时间,增加通行过程中的拥堵持续时间;在链状构型下,群组通行效率较高,而并排构型对人员通行造成的负面影响最大;在有群组和无群组情况下,楼梯位置变化会产生相反的通行效果;平行放置障碍物可以有效降低人群密度,提高群组行人流的通行效率。     

10kt/a甲醇合成精制装置安全性评估与消防设计

甲醇合成精制装置一旦发生泄漏事故,将会对厂内甚至相邻地区的人员生命、机械设备及环境造成严重威胁。为了有效预防事故的发生,通过ALOHA化学品泄漏扩散模拟软件对甲醇合成精制装置进行危险性辨识和评价。结果表明,热辐射危害是池火灾、BLEVE火球的主要危害;BLEVE火球和中毒事故危害范围较广:在BLEVE火球的热辐射中暴露60 s造成死亡的距离均超过100 m,泄漏孔径达5cm时毒气的体积分数达ERPG-3值的距离达326 m。因此,消防设计是甲醇精制装置安全系统设计的重要组成部分。根据《石油化工企业设计防火规范》及相关消防标准规范对该甲醇合成精制车间进行相应的消防系统设计,并用Auto CAD专业绘图软件绘制消防设施的布置图,为施工单位提供依据,从而提高甲醇合成精制装置的安全性,减少人员伤亡事故的发生。     

拉萨高原环境点型感烟探测器工程参数调整研究

气压对燃烧过程影响显著,常压环境下的火灾探测器标准不适用于高原环境.以高原环境下的点型感烟火灾探测器为研究对象,根据合肥及拉萨两地的国标探测器正庚烷标准火测试对比试验,研究高原环境对火灾烟气及点型离子、光电感烟探测器响应规律的影响.结果表明,对于相同火源,光电感烟探测器在高原环境下的响应明显弱于常压环境,而离子感烟感测器所受影响相对较小.依据试验结果,提出高原环境下点型感烟探测器的工程参数调整建议.     

Species-specific attraction to pheromonal analogues in orchid bees

Male orchid bees (Euglossini) collect fragrances from flowers and other natural sources, a behaviour that has shaped the euglossine pollination syndrome. Males store such chemicals in hind leg pouches and later expose them during courtship display. In the present study, we show that complex bouquets of two sympatric species of Eulaema, E. meriana and E. bombiformis, are chemically distinct. When exposed during bioassays at display perches individual hind leg extracts rapidly and consistently attracted other males of the correct species, even if derived from males of disparate localities (French Guiana and Panama). Conspecific males as well as females of E. bombiformis arrived at natural perch sites only from downwind, and two copulations were observed. Our findings demonstrate that acquired odours mediate exclusive attraction within species and support the idea that such fragrances are pheromone analogues. Their role in acquiring matings and during male–male interaction is discussed.     

Influence of pedestrian age and gender on spatial and temporal distribution of pedestrian crashes

Objectives: Every year, about 1.24 million people are killed in traffic crashes worldwide and more than 22% of these deaths are pedestrians. Therefore, pedestrian safety has become a significant traffic safety issue worldwide. In order to develop effective and targeted safety programs, the location- and time-specific influences on vehicle–pedestrian crashes must be assessed. The main purpose of this research is to explore the influence of pedestrian age and gender on the temporal and spatial distribution of vehicle–pedestrian crashes to identify the hotspots and hot times.

Methods: Data for all vehicle–pedestrian crashes on public roadways in the Melbourne metropolitan area from 2004 to 2013 are used in this research. Spatial autocorrelation is applied in examining the vehicle–pedestrian crashes in geographic information systems (GIS) to identify any dependency between time and location of these crashes. Spider plots and kernel density estimation (KDE) are then used to determine the temporal and spatial patterns of vehicle–pedestrian crashes for different age groups and genders.

Results: Temporal analysis shows that pedestrian age has a significant influence on the temporal distribution of vehicle–pedestrian crashes. Furthermore, men and women have different crash patterns. In addition, results of the spatial analysis shows that areas with high risk of vehicle–pedestrian crashes can vary during different times of the day for different age groups and genders. For example, for those between ages 18 and 65, most vehicle–pedestrian crashes occur in the central business district (CBD) during the day, but between 7:00 p.m. and 6:00 a.m., crashes among this age group occur mostly around hotels, clubs, and bars.

Conclusions: This research reveals that temporal and spatial distributions of vehicle–pedestrian crashes vary for different pedestrian age groups and genders. Therefore, specific safety measures should be in place during high crash times at different locations for different age groups and genders to increase the effectiveness of the countermeasures in preventing and reducing vehicle–pedestrian crashes.     

Influence of ATD versus PMHS reference sensor inputs on computational brain response in frontal impacts to advanced combat helmet (ACH)

ABSTRACT

Objective: This study analyzed the influence of reference sensor inputs from anthropomorphic test devices (ATDs) versus postmortem human subjects (PMHSs) on simulations of frontal blunt impacts to the advanced combat helmet (ACH).

Methods: A rigid-arm pendulum was used to generate frontal impacts to ACHs mounted on ATDs and PMHS. An appropriately sized ACH was selected according to standard fitting guidelines. The National Operating Committee on Standards for Athletic Equipment (NOCSAE) head was selected for ATD tests due to shape features that enabled a realistic helmet fit. A custom procedure was used to mount a reference sensor internally near the center of gravity (CG) of the PMHS. Reference sensor data from the head CG were used as inputs for the Simulated Injury Monitor (SIMon). Brain responses were assessed with the cumulative strain damage measure set at 10%, or CSDM(10).

Results: Compared to ATD tests, PMHS tests produced 18.7% higher peak linear accelerations and 5.2% higher peak angular velocities. Average times to peak for linear accelerations were relatively similar between ATDs (5.5?ms) and PMHSs (5.8?ms). However, times to peak for angular velocities were higher by a factor of up to 3.4 for PMHSs compared to ATDs. Values for were also higher by a factor of up to 13.1 when PMHS inputs were used for SIMon.

Conclusions: The preliminary findings of this work indicate that small differences in ATD versus PMHS head kinematics could lead to large differences in strain-derived brain injury metrics such as CSDM.     

利用Hach仪器开发低浓度COD的测试方法

利用Hach仪器开发了0 mg/L～150 mg/L COD的测试方法.采用反应器消解,比色法测定,配制的消解液能保证样品消解过程中浓硫酸和催化剂的含量与国标法相当,通过150 mg/L COD样品消解结束后重铬酸根离子半电池反应的电位折中确定重铬酸钾浓度.校准曲线线性关系良好,方法检出限为7 mg/L,与国标法作比较,结果表明两种方法可替换使用.     

磁絮凝污水处理装置的设计及实验验证

为了优化设计装置内部的结构,分别使用Fe3O4磁块和NdFeB磁块制作了2台简易装置进行实验。在实验中由于装置的结构和磁系会影响絮凝的过程,因此将磁盘厚度减到了33 mm,提高了单位时间内流体通过磁盘的流量。在实用可行方面,设计了高效率的絮体助卸装置;2块外磁盘只受单边磁力作用因而对其结构做了加强设计;并且设计了独特的磁盘位置调整机构,以便在实验中调整磁盘间距;装置使用变频调速控制能够及时调整磁盘的转速,从而保证分离的效果。在实际实验中验证了该装置的处理效果,经过处理的水体能达到国家三类水质标准。     

试压堵塞器在降低井控安全风险中的应用

文章结合大港油田井下作业现场特点,通过研究井控装置FZ18-35防喷器在试压过程中存在的"原试压堵塞器不适合350型采油树井口四通"的具体问题,改进研制适合FZ18-35防喷器与350型采油树井口四通配套的ST18-35试压堵塞器来解决井控装置的现场试压问题,确保现场井控装置的完好,有效降低井控风险以及井喷事故污染环境的风险。     

测量设备管理系统的开发与应用

阐述了开发测量设备管理系统的必要性。依据用户需求分析,提出了测量设备管理系统的设计思路,并介绍了公共管理子系统、资产管理子系统、档案管理子系统、系统管理子系统、查询／统计／报表生成子系统,以及计量管理子系统中各模块的功能。运行实践表明,使用该系统提高了环境监测管理水平。