路面预防性养护时机确定方法探讨

介绍了路面预防性养护时机的确定方法 :应用行驶质量指数或破坏指数、基于时间或路况、效益费用评估、生命周期费用分析、决策树或决策矩阵、评分排序方法进行路面预防性养护时机的确定 ;挖掘了目前路面预防性养护时机选取方法中存在的不足。根据路面破坏的复杂性以及目前路面预防性养护时机选取方法的不足 ,提出应对措施 ,路面预防性养护时机研究应该在一个多标准、基于路面性能的基础上进行 ;在路面结构性能良好的情况下 ,基于预防性养护的路面功能性能衰变是进行路面预防性养护时机研究的关键     

灾害间接经济损失的计量

本文研究了三种灾害间接经济损失的计量，即间接停减产损失、中间投入积压增加损失和投资溢价损失。利用了城市投入──产出表所表达的产业关联关系估计了由于生产的联锁性造成灾害的进一步损失。并用上海市的实际数据对地震的间接经济损失作了预测计量。     

罐区气体泄漏PHOENICS数值模拟研究

基于紊流模式理论,在考虑重力影响的基础上,建立储气罐区气体泄漏扩散数学模型,并采用计算流体力学软件PHOENICS(双曲性,抛物性或椭圆型数值求解综合编码)对该数学模型进行数值求解。在油气安全综合平台上,通过选用二氧化碳作为泄漏物,红外二氧化碳传感器采集来的实验数据与PHOENICS模拟数据进行比较,发现误差较小。同时表明,借用该软件模拟储气罐区气体泄漏的扩散问题是可行的。运用该法也能为气体泄漏、火灾方面的研究提供一条便利的捷径。研究结果还可以为液化气与毒气罐区气体泄漏事故应急处理提供参考依据,同时对罐区浓度探测点位置的安放也有重要指导意义。     

Rapid,recurring, structured survey versus bioblitz for generating biodiversity data and analysis with a multispecies abundance model

A bioblitz inexpensively and quickly generates biodiversity data, but bioblitzes are often conducted with haphazard, unreplicated sampling. Results tend to be taxonomically, geographically, or temporally biased, lack metadata, and consist of lists of observed taxa that do not enable further analyses or correction for imperfect detection. A rapid, recurring, structured survey (RRSS) uses a structured sampling design and temporal and spatial replication to survey randomly selected sites on a conservation property. We participated in a loosely structured bioblitz and a subsequent RRSS at Big Canoe Creek Nature Preserve in Springville (St. Clair County), Alabama (USA) to compare observed richness derived from the 2 survey approaches. The RRSS data structure enabled us to fit models that accounted for imperfect detection to estimate abundances, occupancy probabilities, and habitat associations. The loosely structured bioblitz data could not be used in such models. We present a new integrated multispecies abundance model that we applied to avian RRSS data. Our model extension enables estimation for the community, employs data augmentation to estimate the number of undetected species, and incorporates covariates. The RRSS generated a more comprehensive and less biased list of observed taxonomic richness than the loosely structured bioblitz (e.g., 73 vs. 45 bird species and 104 vs. 63 insect families from the RRSS vs. loosely structured bioblitz, respectively). Models fit to the RRSS data identified seasonal patterns in avian community composition and allowed for estimation of habitat–occupancy relationships for insect taxa. The RRSS protocol has potential for broad transferability as a standardized, quick, and inexpensive way to inventory biodiversity and estimate ecological parameters while providing an outreach opportunity.     

利用粉煤灰输送与贮存系统处置粘胶纤维污水场污泥的研究

通过对粘胶纤维污水场的中和脱锌污泥、二沉池剩余污泥和煤灰水混合体的沉降性能实验,证实其固液分离性能良好;吸附与渗透实验取得了粉煤灰、亚粘土对锌、汞的吸附等温线和地下水影响预测所需的参数;并分析了灰泥混合流体对电厂原输灰系统和环境的影响。研究结果表明：利用粉煤灰输送与贮存系统处置粘胶纤维污水场污泥的处理工艺在技术上可行,操作简单、运行可靠、投资少,每年可节省污泥处理费用40.5万元。外排污染物达到国家排放标准。     

石油化工企业环境风险评价的方法研究

首次提出并采用安全检查表与层次分析相结合的石油化工企业环境风险评价方法,对我国运转中的一套丙烯腈系列装置进行系统风险评价和健康风险评价,建立了丙烯腈系列装置安全风险评价层次结构体系,开发了风险评价事故数据库软件。通过评价找出事故隐患,发现氰氢酸是导致职工慢性中毒的主要因素。评价结果表明,事故记录的准确性和事故档案保存的完好性对于评价至关重要。     

聚乙烯醇固定化混合细菌细胞对印染废水脱色的研究

应用聚乙烯醇(PVA)为载体固定化混合细菌细胞以PVA浓度为12％(w/v),细胞浓度为2％(w/v)最好,pH对固定化操作过程影响不大。固定化细胞对印染废水的脱色活性与其自然细胞相似,最适温度为30—40℃,最适pH为7.0;在pH 6.0—8.0温度25—40℃范围内都具有较高的脱色活性,以及好的热稳定性;在连续一个月的印染废水脱色试验中,停留时间小于3.0h,脱色率均可维持在70—80％。     

Practical safety management for small or medium enterprises

The article is intended for those who are not safety professionals but are responsible for safety management in a small or medium enterprise (SME) of the process industry. It assumes that a SME is loosely coupled and of low complexity and has a small number of major hazards present in it. The article describes Elementary Safety Management (ESM) as a combination of activities that maintain openness to safety impulses with Elementary Risk Control (ERC). ERC uses four milestones and three rules to get to the necessary and sufficient selection of control measures, which will achieve an acceptable level of risk. To make the ESM scheme as simple as possible, the term causal event is used, which is derived from the term causal factor. Practical Safety Management (PrSM) adds to the ESM the knowledge and skills that a person, who is supposed to design and implement a safety management system, needs. The PrSM procedure is developed to identify optimum controls. The procedure recognizes the unavoidable role of commitment to safety, respects the role of hazard identification, and integrates prospective and retrospective analyses and current knowledge of safety management systems. Examples of application of the procedure are given in the article.     

Dynamics of explosion venting in a compartment with methane-air mixtures

A series of experiments on explosion venting of methane-air mixtures are performed to scrutinize the pressure evolution as well as the flame dynamics and morphology at various vent conditions. Specifically, a premixed flame is ignited at the center of a polycarbonate cylindrical compartment, with three various vent areas considered (with negligible vent relief pressure). As expected, the highest maximum pressure is observed in the case of the smallest vent area. For all three cases, the pressure evolution experiences two major peaks, associated with the instants (i) when the maximum flame front surface area in the chamber is reached and (ii) when an external explosion occurs due to venting of unburned gases, respectively. For the fuel-rich mixtures, a flashback is observed subsequent to the external explosion, constituting the key outcome of the present work. The flame tip velocities show two general trends, namely, exponential acceleration towards the vent, while a flame propagates towards the blocked side of the compartment with no acceleration, which is important to know in the fire/explosion safety applications.     

Informal mining in Mongolia: livelihood change and continuity in the rangelands

Change has been the leitmotif of Mongolia in recent years as the country rides on the back of a mining boom, but enormous upheavals tear apart Mongolian economic, political and social fabrics. Yet, Mongolian imagination continues to be imbued with the idea of nomadic herders, the quintessential pasture and rangeland dwellers of the steppes. The conflicting visions raise the question: “How is the livelihood of Mongolia’s nomadic herders responding to the diverse changes ushered in by the post-socialist economic reforms?” This paper investigates this question in the context of the growing artisanal and small-scale mining, which is described as informal mining, and argues that the Mongolian nomads are continually (re)adjusting their livelihoods through informal mining to cope with the variety of transitions triggered off by processes put in place by state policies. It argues that the nomadic herders are not only responding to climate change or poverty, but are also stepping up to seek a share of the mineral resource wealth that the state is promising to the international investors. The aim of the paper is to offer an alternative interpretation of the commodity rush by erstwhile rural-based nomadic herders of Mongolia, and to link their involvement in informal mining with global debates of political economy.