TNT当量法预测某石化设备爆炸后果评价

以烃化反应器为模拟发生泄漏事故源,泄漏的物料形成爆炸性气体,发生爆炸事故,采用TNT当量法预测爆炸事故后果,通过公式,计算出因爆炸冲击波导致肺出血而引起死亡的概率为0.5的半径.     

NO参与铝诱导蚕豆保卫细胞死亡的调控

铝(Al)是地壳中含量最丰富的金属元素,是酸性土壤中导致植物生长抑制和作物产量下降的一个主要因素,但铝毒性作用机制尚不清楚.本文以蚕豆叶表皮为材料,研究铝胁迫对气孔保卫细胞活性的影响,探讨NO在铝诱导细胞死亡中的作用.结果表明,一定浓度的A1Cl3可诱导气孔保卫细胞活性降低,部分细胞死亡,且随着铝浓度的增高细胞死亡率增高.死细胞呈现核固缩、核崩解、凋亡小体等典型凋亡特征,且凋亡抑制剂Z-Asp-CH2-DCB能阻止AlCl3诱发的细胞死亡.用NO清除剂c-PTIO、NO合酶抑制剂L-NAME或硝酸还原酶抑制剂NaN3降低铝处理组胞内NO后,细胞死亡率显著降低,胞内ROS、Ca2+水平同期降低;NaN3还能降低铝处理组中具有程序性死亡特征的细胞比率.用ROS清除剂AsA清除铝处理组胞内ROS后,细胞死亡率显著降低,胞内Ca2+和NO水平亦显著降低;铝处理液中加入Ca2+通道抑制剂LaCl3后,细胞死亡率低于铝单独处理组,胞内ROS和NO水平无明显改变.研究结果表明,铝胁迫引起的胞内NO合成增加通过Ca2+信号途径介导了保卫细胞的程序性死亡.     

An Avoidable Tragedy at the Sea Cliff (Rincon) Oil Field

Three men were killed and four others were injured during a well drill operation on Hobson Well C-10A in the Sea Cliff Oil Field (also known as Rincon Oil Field), in Ventura County, California, United States, on August 10, 1994, as a result of errors made by the work supervisors at the site. The oil field was under management by Vintage Petroleum, Ltd., which was sued for negligence by the families of the deceased and injured. The coroner's autopsy examination concluded that the cause of the deaths was due to the inhalation of the toxic gas carbon monoxide (CO). This gas was assumed to have been released from the firing of high-energy guns (HEGs) using carbon-rich explosive pentaerythritol tetranitrate (PETN) in an oxygen-depleted environment, during a fracking operation by Schlumberger Corporation on Well C-10A. The author of this article was appointed as an expert witness by Schlumberger to evaluate if the coroner's conclusion was correct. A series of chemical analytical analyses were conducted on the vapor phase of samples, in addition to dissolved components in water from Well C-10A and two adjacent wells. Stable isotope analyses were also conducted on hydrogen (H₂), methane (CH₄), nitrogen (N₂), CO, and water (H₂O) 3 weeks after the accident, as well as on four additional occasions from September to December 1994. Control test analyses were performed on the products from HEG firings, using the same explosives as those used in the perforation of Well C-10A in control chambers at a Schlumberger facility in Houston, Texas. The conclusion reached was that the dominant products of PETN detonations are H₂, CH₄, CO, and N₂. However, the isotope ratios (D/H and ¹³C/¹²C) of methane in the control experiments were different in Well C-10A, following the detonation on August 10, 1994, than those resulting from controlled PETN explosions. The conclusion reached in this study was that the fracking of the well at a depth of around 2,150 ft had increased the permeability of the sediment layers in the Padres Zone at that depth to allow the rapid release of a large quantity of natural gas, primarily CH₄, which supersaturated the water in the well. This event caused the formation of a large bubble, which ballooned out of the well to the surface, displacing air in the location where the men were working, and thus causing asphyxiation, which resulted in the death of the three men. The judge accepted this interpretation.     

Study of urban population attitudes towards various wastewater reuse options: Israel as a case study

This paper summarizes the findings of a survey (256 participants) conducted to determine the attitude of the Israeli urban public towards various urban water reuse options. Israel is known for its long and successful agricultural water reuse scheme, but to date no large-scale urban reuse projects have been implemented. The survey included 21 reuse options, which were clustered into three reuse categories, namely: low, medium, and high contact levels. Results show that a high proportion of the participants supported medium contact reuse options such as sidewalk landscaping (95%), domestic WC flushing (85%) and firefighting (96%). Higher contact reuse options such as domestic laundry (38%), preserved food (13%), and potable aquifer recharge (11%) found much lesser support. Less than expected support was found for low contact reuse options with 86% for field crop irrigation, 62% for aquifer recharge for agricultural irrigation, and as low as 49% for orchard irrigation. This low support is surprising, since all three options have been practiced on a large scale for over three decades in Israel without any adverse effects to the public. No correlation was found between any biographical characteristic examined (education, gender, income, marital status, having young children, and age) and support for medium contact options. For the medium contact options, the results suggest that perceived financial gain (individual and/or communal) and positive public opinion enhances support, while perceived health effects negatively affects the degree of support. Technology, trust in authorities and awareness of water and environmental issues were found to not have a significant effect on support for medium contact reuse options. Analyzing the four possible reasons for support given by participants who identified themselves as supporters of wastewater reuse revealed that the most important reason for support was "water saving", followed by "minimization of importing water from abroad". These were followed by "infrastructure cost saving" together with "environmental improvement".     

Time perspective balance and team adaptation in dynamic task contexts

The concept of time perspective balance has attracted increased attention from scholars in the past decade, reflected in published evidence suggesting positive outcomes ranging from enhanced mood to life satisfaction for those individuals possessing balance among their past, present, and future time perspectives, and assumedly able to shift their time perspective to match situational demands. In this paper, we consider the notion of time perspective balance in an organizational setting within which much consequential adaptation often occurs—the team environment—and explore different configurations of time perspective balance in teams facing dynamic task contexts. Drawing from work on situational awareness, we first consider the mechanism by which time perspective balance likely influences individual adaptation in dynamic task-focused situations. Next, we postulate what types of team configurations—ones with more balanced time perspective uniformity or ones with more time perspective variety—might be more appropriate in dynamic contexts given key team conditions. We illustrate our analysis with examples from healthcare team settings and offer ideas for future research.     

探究城市污水处理项目的环境影响评价

水作为人类赖以生存的主要能源物质,随着社会综合水平的提高,各行业对水资源的需求越是急切。而现阶段城市中大量污水给环境带来很多不利影响,环保公司针对城市污水处理不断在技术上进行突破、完善,将智能化节能技术运用到城市污水处理中,使设备、资源得到充分利用,为人们用水条件带来更加充沛、丰富的保障与支持。为有效处理城市污水,争取在城市污水处理发挥更大作用,带动城市环境可持续发展。     

面向北京冬奥会的态势感知与指挥体系研究*

为全面掌控北京冬奥会运行情况,结合冬奥会概况构建具有全局全过程态势感知能力与指挥体系的运行保障系统。系统阐述冬奥会指挥体系构建的出发点、特点和要求,分析冬奥会态势感知构建基础框架,包括所需数据类型、层级体系和态势汇总共享技术要求。研究表明:体系充分考虑冬奥会及城市运行特点,是冬奥会顺利举办的重要保障,可为冬奥会提供系统构建指导,并为未来大型活动与城市运行态势感知体系构建提供理论支持。     

山海关区农村生态环境状况及保护对策

从山海关区农村生态环境现状出发,客观分析了农村生态环境存在的水体污染、土壤污染、水土流失等问题,以及影响农村生态环境的主要因素,如污水和垃圾的无组织排放、化肥和农药的不合理使用、基础设施差、监管缺位等,提出应从环保体制、环保意识、基础设施建设、自然资源保护、污染防治、强化监管等方面采取切实可行的措施,保护农村生态环境。     

汶川灾区居民环境意识现状与提升对策研究——以龙门山镇为例

以彭州市龙门山镇为例,实地调查、问卷调查与访谈相结合,从知识、态度和行为三个角度对灾后公众环境意识状况进行研究。当地居民环境知识水平普遍较低;对环境问题关注度较高,环境态度较好;环境行为差异较大。职业、性别、年龄和文化程度对环境意识影响主要体现在环境知识方面而对环保态度和环保行为影响不大。旅游业受地震破坏严重,灾后物资紧缺,环境教育应结合实际,针对学生、村民、公务员等不同人群分别采取对应措施。