乌鲁木齐市硫酸盐化速率关键影响因子分析

对硫酸盐化速率与大气中污染物质浓度和气象因素的分析结果表明,硫酸盐化速率不仅取决于SO2的浓度,还与PM10显著相关,是因为PM10表面为SO2的催化氧化提供了载体。气压和空气相对湿度对硫酸盐化速率有积极的促进作用,空气中的气态H2O具有凝结污染物质的能力,而降水对污染物质的冲刷效应降低了硫酸盐化速率。影响硫酸盐化速率的是空气中气态H2O而非降水。气温通过影响逆温层和风速共同影响着污染物浓度的扩散和稀释,从而决定着硫酸盐化速率的增减。     

焦化苯初馏份蒸馏釜发生爆炸的原因探讨

通过对某企业的一起典型爆炸事故案例进行分析,找出其产生的原因,提出了预防措施。     

Colonial公司原油管道泄漏事故原因分析及启示

介绍了一起在美国南卡罗来纳州发生的原油管道泄漏事故，分析了事故的主要原因，并对我国原油管道的维护管理提出建议。     

考虑人因差错影响的结构可靠度计算方法

通过对单个或任意多个人因差错影响下构件截面失效概率计算方法的分析讨论,推导出在理想已知条件下的数学解析求解公式;在考虑人因差错对结构参数影响程度的空间离散化后,得出了相应的简化计算方法;并以一个单筋梁的正截面为例进行了失效概率计算和人因差错影响程度分析.在目前人因差错的发生及其影响规律的研究不完善、缺乏必要的数学模型的现实条件下,该方法对人因差错影响下构件截面失效概率的分析计算有一定的实用价值.     

Thoughts concerning the economic valuation of landscapes

The incorporation of economic thinking into the valuation of landscapes is still relatively new. It is an approach that yields valuable new insights and can help with prioritizing the use of scarce resources to improve and/or preserve landscapes. This paper explores and discusses the uses and limitations of economic valuation of landscapes from market failure, policy process, and theoretical and philosophical perspectives.     

公路交通事故黑点成因的对应分析法

为了便捷获取公路事故黑点的形成原因,应用对应分析构建立事故黑点成因分析模型。该模型设立事故样本和事故影响因素之间的列联表,将列联表中影响变量的状态呈现于二维对应分析散点图中,以直观简洁的形式描述事故样本与影响因素之间的对应关系。进而设定相关系数判定对应分析模型的收敛性,应用点子排除法剔除特殊影响变量,增强了分析结果的鲁棒性。通过G205事故黑点路段(K954+50-K954+900)的实例分析表明,运用对应分析法所建立的模型与算法可以获得公路事故黑点形成的主要和次要因素,准确确定直接原因与根本原因的对应关系。     

破片撞击LPG储罐失效数值模拟

在国内外液化气储罐失效的相关理论基础上,运用ANSYS和ANSYS LS-DYNA软件,对液化石油气储罐的失效过程中破片撞击的影响进行了数值模拟,为储罐的安全管理提供了指导.     

Using data linkage to assess the impact of motorized recreational vehicle-related injuries in Ohio

Problem

Motorized recreational vehicle (MRV)-related injuries can result in severe medical and financial consequences. The objective of this study was to describe the epidemiology, and clinical and financial impact of MRV-related injuries in Ohio.

Method

Probabilistically linked statewide Emergency Medical Services (EMS) and hospital (inpatient and emergency department) data for 2003 and 2004 were examined. Record pairs with a MRV-related E-code (E821-E823, E825) were included in this study.

Results

There were 2,893 patients with MRV-related injuries, who had linked EMS and hospital records, resulting in more than $15 million in hospital charges and 1,921 inpatient days of hospitalization. The male-to-female ratio was nearly 4:1, and 19% were younger than 16. Almost 82% of cases were not wearing a helmet; there was a trend of decreasing helmet use with increasing age. Mean (SE) inpatient hospital charges and length of stay (LOS) were $22,218 ($1,290) and 3.8 (0.2) days, respectively. The mean (SE) Injury Severity Score (ISS) for inpatients was 9.2 (0.4). Individuals injured on a street/highway were 3.20 times more likely to sustain an ISS ≥ 16 (95% CI: 1.03, 9.88; p = 0.044) and 3.05 times more likely to sustain a traumatic brain injury (TBI) (95% CI: 1.17, 7.94; p = 0.024) than those who were injured at a place designated for sport or recreation. Children aged 12 to 15 and young adults aged 16 to 25 were 2.47 and 2.14 times more likely, respectively, to sustain a TBI than adults aged 36 or older (aged 12 to 15: 95% CI: 1.13, 5.38; p = 0.024; aged 16 to 25: 95% CI: 1.26, 3.64; p = 0.005). Higher ISS was associated with both higher total charges (p < 0.001) and longer LOS (p < 0.001).

Discussion

This study demonstrates that MRV-related injuries are an important public health problem in Ohio, with a substantial clinical and financial impact.

Impact on Industry

Enactment and enforcement of statewide MRV safety legislation and training of MRV users offer valuable opportunities to prevent these costly injuries.     

内排压脚与边坡稳定性的关系

为了研究边坡角及边坡形状与边坡稳定性的关系,采用有限元软件ANSYS模拟了不同边坡角对应的稳定系数,以及不同平盘宽度和压脚高度所形成的等储备强度边坡的稳定系数。模拟中假设材料符合相关联的理想弹塑性本构关系,强度准则符合Drucker-Prager准则,用计算收敛性作为边坡稳定性的准则,用强度折减法得出边坡的稳定系数。为了形成等储备强度边坡,由下到上分步骤进行压脚。先在平面边坡最下台阶压脚,这样提高了边坡稳定系数,在边坡进入临界状态时,最下两台阶的塑性状态相同,则压脚停止;再在最下两台阶同时压脚,在边坡进入临界状态时,最下3个台阶的塑性状态相同,则压脚停止;以此类推,在最下边n个台阶同时压脚,在边坡进入临界状态时,压到与第n+1个台阶的塑性状态相同为止。结果表明,边坡总是从坡脚开始形成塑性区,在重力加载过程中,塑性区以弧形条带向坡顶扩展,形成滑带。最有效的内排压脚是从最下台阶开始形成等储备强度边坡的压脚。     

火灾探测报警系统失效风险评估

火灾探测报警系统的可靠程度,直接影响消防系统控制火灾蔓延和保护人民生命财产安全的能力,对系统进行失效风险评估是检验火灾探测报警系统可靠性的有效方法。先采用故障树分析法对火灾探测报警系统的失效风险进行分析,得出影响火灾探测报警系统失效的底事件;再利用模糊综合评价法和重要度算法得到各底事件的失效概率和权重,并给出火灾探测报警系统失效风险计算步骤;以沈阳航空航天大学图书馆火灾探测报警系统为例,评价该系统不失效的概率为0.795 0,不易失效的概率为0.144 1,较易失效的概率为0.0608,易失效的概率为0,然后根据模糊评价的最大隶属度原则,确定评估结果为该系统不失效。