基于最小路径的应急系统响应可靠度的计算

为了分析突发事件应急系统可靠性,计算应急系统响应可靠度,首先分析一般应急系统的组成与结构,提出应急系统由硬件子系统、软件子系统、人子系统、人与硬件关系子系统和人与软件关系子系统组成,根据系统的最小路径推导得到应急系统响应可靠度的解析表达式,分析各个子系统的可靠度,得到对于特定的应急系统响应可靠度的解析表达式可以由最小路径直接得到的结论,为其他复杂系统的可靠度的计算提供依据。     

煤巷顶板沉积岩体钻进动力响应特性试验研究

为了探究煤巷顶板锚固孔钻进动力响应指标（钻速和转速）与顶板岩石物理特性（普氏系数）间的关系,采用实验室及数值试验研究方法对煤巷顶板沉积岩体进行模拟钻进。结果表明,锚固孔的钻进动力响应指标整体上均随顶板岩石普氏系数的增加而减小,大致呈负指数关系。实验室试验数据拟合曲线与数值模拟分析所得结果较为相似,但也存在一定的差别。据此可实现对顶板岩层的初步判别,对煤巷顶板锚杆支护参数的优化和冒顶事故的预防有重要的指导意义;为实验室研究岩石的钻进试验提供了一种可行的方法,也为岩石可钻性与顶板岩层探测仪器的深入研究提供了一定的参考价值。     

无锡太湖水源地藻类爆发应急管理与处置体系研究

本文通过对太湖蓝藻爆发事件的分析,揭示了我国水源地藻类爆发应急管理和处置体系存在预警、预案机制不完善,监测机制与预警机制脱节,公众信息系统不健全、公开透明程度欠缺等不足,并设计出一套水源地藻类爆发应急处理体系,包括监测检测、应急处理、长效治理和管理体系,以应对该类事件的再次发生。     

The effects of burial by sand on survival and growth of Pitcher’s thistle (Cirsium pitcheri) along lake huron

Greenhouse experiments were conducted to determine the effects of sand burial on survival and growth of seedlings ofCirsium pitcheri. In 1992–1993, seedlings were buried to depths of 0, 25, 50, 75, and 100% of their height while in 1993–1994, the seedlings were buried to depths of 0, 4 cm (single burial), 4 cm (repeated burial of 1 cm every 8 days), 8 cm (single burial) and 8 cm (repeated burial of 2 cm every 8 days). Several physiological traits, net photosynthetic rate, chlorophyll a∶b ratio, leaf area, number and length of leaves, number of internodes, amount of tillering, and biomass, were measured. The results showed that all seedlings died in the complete (100%) burial, 20% died in the 75% burial and none died in the 0, 25 and 50% burial treatments. Burial of seedlings to a depth of 25% stimulated their growth but 75% burial significantly decreased the total dry weight. Repeated burial treatments exhibited significantly greater stimulation of growth than single burial. Surviving seedlings grew through the sand deposit by elongating the stem and leaf petioles, increasing the number of nodes and the length of internodes. This elongation occurred at the expense of development of the root system indicating that available energy was re-allocated to above-ground parts.     

城市地表覆盖材料的热反应

本文对几种地表覆盖材料在具有“火炉”之称的山城重庆典型夏季气候条件下的热反应进行了实测研究，以期为生态城市设计提供有益的参考数据。     

Ecohydrological impact–assessment modeling: an example for terrestrial ecosystems in Noord-Holland, the Netherlands

In the Netherlands the increasing demand for ecohydrological models on a regional (provincial) scale has resulted in the development of an empirical statistical impact–assessment model for semi-natural terrestrial herbaceous ecosystems. This model, called ITORS, describes the relationship between plant species and site factors such as soil, groundwater and management. The model, developed for the region of Noord-Holland, is applied to support provincial policy on soil and water management. The empirical statistical approach required the collection of a large set of field data, describing the biotic and environmental variation of a variety of semi-natural terrestrial ecosystems in Noord-Holland. These data were used to calculate species response models with help of logistic regression, resulting in significant models for 130 out of 144 species. Significant species response models were incorporated in the computer program ITORS. With help of ITORS the effect of various management scenarios can be easily evaluated, which is demonstrated by an example. This revised version was published online in July 2006 with corrections to the Cover Date.     

Multiplicity-adjusted Inferences in Risk Assessment: Benchmark Analysis with Continuous Response Data

We develop and study multiplicity adjustments for low-dose inferences in environmental risk assessment. Application is intended for risk analysis studies where human, animal, or ecological data are used to set safe levels of a hazardous environmental agent. A modern method for making inferences in this setting is known as benchmark analysis, where attention centers on the dose at which a fixed benchmark level of risk is achieved. Both upper confidence limits on the risk and lower confidence limits on the “benchmark dose” are of interest. In practice, a number of possible benchmark risks may be under study; if so, corrections must be applied to adjust the limits for multiplicity. In this note, we discuss approaches for doing so with continuous, nonquantal response data.     

土壤微生物呼吸热适应性与微生物群落及多样性对全球气候变化响应研究

土壤微生物呼吸热适应性被认为是决定陆地生态系统对全球变暖反馈作用的潜在重要机制,可能显著改变未来的气候变化趋势,然而,土壤微生物群落结构变化如何引起土壤微生物呼吸热适应性的研究目前尚存争议.该文针对气候变化对土壤微生物呼吸的影响研究,梳理了当前对土壤微生物呼吸的热适应性是否存在的争议和不同观点与结论,综述了气候变化对土...     

土层地震反应分析的地面加速度峰值计算研究

针对不同的工程场地采用20组相互独立的基岩加速度时程作为输入地震波,对广东省307个项目的地震安全性评价中的662个地震钻孔剖面进行土层地震反应分析,用相对均方误差来定量评估所得到的地面加速度峰值离散值,发现地面加速度峰值的计算结果具有很大的离散性,最大相对均方误差为19%,平均相对均方误差为7.53%;地震基本烈度高的地区比地震基本烈度低的地区的相对均方误差大,场地类别差的比场地类别好的相对均方误差大;目前较为普遍地用1条或3条基岩加速度时程作为地震动输入是明显不够的,应适当地增加,对于高烈度地区和场地类别较差的场地更是如此,才能得到较为合理的地面加速度峰值。