深基坑边坡支护信息化施工技术研究

运用位移监控信息、土体平衡原理、护壁桩支撑设计原理指导深基坑支护适应基坑深度变大的难题,具有施工方便、经济、安全的、工期短等特点,为在闹市区深基坑支护施工提供了经验.图1,表1,参7.     

Pillar building in the fiddler crab Uca beebei: evidence for a condition-dependent ornament

In the fiddler crab (Uca beebei) males build a small mud pillar next to their burrow which increases their attractiveness to females. Three hypotheses were tested to explain inter-male variation in pillar-building. (1) The benefits of pillar-building are density dependent. The experimental addition of vertical structures did not support this hypothesis as there was no change in the level of pillar-building. (2) There are two classes of males (pillar-builders and non-pillar-builders). This could either be due to an alternative mating strategy, or because pillar building is age or size-dependent. There was also no support for this hypothesis. (3) Pillar-building is an honest signal of male quality dependent on body condition. A food supplementation experiment was performed. Addition of food affected several aspects of male behaviour and resulted in a two fold increase in the number of pillars built between control and food treatments (P < 0.001). However, the percentage of males building pillars did not increase significantly. Pillar building in this species has been attributed to sensory exploitation. Our results indicate that a trait which may well have evolved through sensory exploitation also appears to be condition-dependent. We emphasise that showing that an ornament or behaviour is condition-dependent does not necessarily mean that it evolved through good gene processes. However, in terms of its current selective value, pillar building may be maintained through female choice because it acts as a signal of male condition.     

挥发性有机废气生物处理技术研究进展

随着现代工业的快速发展,带来的挥发性有机废气(VOCs)排放到大气中,逐渐增加的VOCs已成为当今关注的重要环境问题之一。生物净化VOCs具有易操作、维护方便、净化效率高、运行费用低、安全性高、无二次污染等优点而备受世界各国的广泛关注。VOCs废气生物处理技术原理是将有机污染物在微生物作用下转换为无害或者低害的物质,而微生物则起到了至关重要的作用。综述了生物滤池、生物滴滤、生物洗涤3种净化工艺的原理和研究进展,将3种反应器优缺点进行了对比;最后论述了该技术当前存在问题及发展趋势。     

CuNiIn 微动磨损涂层失效机理研究

目的系统研究CuNiIn和CuInO_2的晶体结构、体模量、剪切模量、杨氏模量、泊松系数、韧性、热膨胀系数、残余应力等物理参量,阐明CuNiIn涂层中生成的其他复合化合物—CuInO_2对CuNiIn机械性能的影响作用机制。方法采用基于密度泛函理论的第一原理,弹性常数采用应力-应变方案,体模量、剪切模量、杨氏模量采用Voigt-Reuss-Hill方法计算。结果CuNiIn和CuInO_2均为机械稳定结构,CuNiIn和CuInO_2的体模量、剪切模量、杨氏模量、泊松系数分别为118.2GPa,13.7GPa,39.6GPa,0.44和119.0GPa,36.8GPa,100.1GPa,0.36。化合物CuInO_2的机械模量较CuNiIn高,韧性较差,热膨胀系数较低,涂层的残余应力较高。结论喷涂工艺不适,或CuNiIn涂层服役过程中生成的CuInO_2对微动磨损CuNiIn涂层服役性能有不利影响。     

Ecological knowledge and North Sea environmental policies

In an analysis of North Sea eutrophication science and policies, focusing on the period 1980–2005, it was investigated how scientific information was used in policy-making. The analysis focused on the central assumptions of the rational policy-making model, i.e. that scientific information can be used to formulate decisions, based upon objective scientific information (rational decision-making), and secondly, can support implementing these decisions (rational management). In general terms, the following was concluded:

• •More knowledge has increased rather than reduced uncertainty;
• •In order to handle the problem of dealing with complexity and uncertainty at the political level, a simplification of facts has occurred, in this case focusing on nutrients as the main cause of the problem, at the same time excluding other possible causes;
• •Both the limited scientific view (i.e. the nutrient view) and the exaggeration of the seriousness of the problem (impacts, scope) have been used as an authoritative basis for the justification of political decisions. Both were not supported by the majority of the scientific community;
• •New scientific knowledge, not in support of existing policies, has been excluded from the policy process;
• •The science–policy interface, mainly consisting of “civil-servant scientists”, that emerged and increased its influence over the period of investigation, has been the central element in the simplification and exclusion process.

The main lesson learned is that work at the interface of science and policy must be subject to democratic principles, i.e. be transparent and involving all parties with a stake in the issue under consideration.     

Evaluating impacts of forage fish abundance on marine predators

Forage fish—small, low trophic level, pelagic fish such as herrings, sardines, and anchovies—are important prey species in marine ecosystems and also support large commercial fisheries. In many parts of the world, forage fish fisheries are managed using precautionary principles that target catch limits below the maximum sustainable yield. However, there are increasing calls to further limit forage fish catch to safeguard their fish, seabird, and marine mammal predators. The effectiveness of these extra-precautionary regulations, which assume that increasing prey abundance increases predator productivity, are under debate. In this study, we used prey-linked population models to measure the influence of forage fish abundance on the population growth rates of 45 marine predator populations representing 32 fish, seabird, and mammal species from 5 regions around the world. We used simulated data to confirm the ability of the statistical model to accurately detect prey influences under varying levels of influence strength and process variability. Our results indicate that predator productivity was rarely influenced by the abundance of their forage fish prey. Only 6 predator populations (13% of the total) were positively influenced by increasing prey abundance and the model exhibited high power to detect prey influences when they existed. These results suggest that additional limitation of forage fish harvest to levels well below sustainable yields would rarely result in detectable increases in marine predator populations.     

基于可能-概率测度转换的危险品运输风险分析

为解决不确定环境下的风险分析问题,针对危险货物运输中风险参数具有不确定性、随机性和模糊性的特点,建立基于概率测度-可能性测度转换原则和模糊逻辑的危险货物运输风险分析方法。首先对具有模糊性的参数直接建立模糊数,对具有随机性的参数建立随机数;接着依据概率测度向可能性测度转换的最优原则,将随机数转换为模糊数;然后根据模糊运算法则进行风险计算和分析。最后通过一个算例验证了模型和算法的有效性。结果表明,提出的方法能处理随机和模糊环境下的风险分析问题,能为风险分析尽可能多地保留不确定性信息,尽可能少地丢失有用信息。     

Effect of Information Availability on Assessment and Designation of Species at Risk

Abstract: Information required to evaluate the extent to which species are at risk of extinction is usually limited and characterized as highly uncertain. In this context, we define information availability as the presence or absence of information used to determine the value of an ecological variable. We examined which of three hypothetical approaches best matched how levels of risk are assigned to species: (1) precautionary approach in which analysts designate levels of risk regardless of the amount of information available, (2) worst‐case approach in which analysts assign the maximum level of risk possible from the criteria, and (3) insurance approach in which analysts assign poorly known species to a high‐risk category when little information is available. We used the quantitative assessment criteria of the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) as a case study. We created a binary (0/1) matrix of all 2.4192 × 10⁷ logical combinations of available information for the 14 ecological variables included in the quantitative criteria. We processed each combination of information availability represented in the matrix with a computer algorithm designed to emulate COSEWIC decision‐making rules. Low information availability was associated with a relatively high frequency of not being able to assign a candidate taxon to a risk category, which does not follow the precautionary principle. Information availability and the level of risk assigned to species were directly related, which is associated with the worst‐case approach, and counter to the insurance approach. Our results suggest that information availability can have a major effect on the level of risk assigned to a species. We recommend a conscious determination of whether such effects are desired, and we recommend the development of methods to explicitly characterize and incorporate information availability and other sources of uncertainty in decision‐making processes.     

典型云南高原湖泊叶绿素a与影响因子的定量关系及对比分析

湖泊富营养化的影响因子涉及水文、物化、生物等多方面,具有复合性和非线性特征,定量化其与影响因素间的相关关系有助于识别影响湖泊营养状态的关键因子,可以用较低的成本、较短的时间达到理想的控制效果.云南高原湖泊具有易发生富营养化的自然和气候特征,对其富营养化发生条件及影响因子的分析可为科学的控制决策提供参考.本文选取云南滇池、程海、抚仙湖和异龙湖4个高原湖泊,比较湖泊自然特征与流域社会经济条件的异同;构建包括绝对主成分多元线性回归分析(APCS-MLR)、结构方程模型(SEM)及人工神经网络模型(ANN)的综合分析方法,重点关注并确定浮游初级生产力的代表指标(叶绿素a,Chla)与相关影响因子间的定量相关关系.研究发现:14个湖泊中,对Chla浓度变化影响最大的均为理化因子,但在各湖中该影响的正、负性及不同理化因子的贡献权重有较大差异;2流域污染源构成的不同在一定程度上影响了入湖的氮、磷负荷,使4个湖泊表现出不同的营养盐限制性特征;3流域面积、湖泊形态及湖体水动力条件影响着营养盐在湖体中的迁移转换,造成4个湖泊富营养化的差异性特征;4对Chla与影响因子间因果关联的识别须结合深入的机理过程分析.     

草海湿地生态系统健康评价

贵州省威宁草海是贵州最大的天然高原淡水湖泊,同时也是我国亚热带高原湿地生态系统的典型代表,成为中国西南地区迁徙水禽的重要越冬地和停歇地。但草海湿地生态系统由于人类活动加剧引起的其功能作用会削弱、生物多样性会降低、水体富营养化等生态环境问题多方面的影响导致其表现出明显的生态脆弱性,尤其是在其生态系统的生态环境方面表现尤为突出。如果草海受到多方面的影响不及时加以制止和消除,将直接威胁着草海湿地生态系统的稳定。本文首先从湿地的生态特征、功能和社会经济环境三个方面的30个主要影响草海生态健康的因子进行分析,并对每个因子的健康状况进行调查、分析说明。其次,利用模糊综合评价模型中的层次分析法对草海生态健康影响的30个主要因子进行了整合分析,并对草海现在的健康状况应用平均加权原则进行了评估。最后,针对草海目前的健康状况,对草海今后的防治提出了相关建议。