层次分析法在工业污水处理厂收水体制选择中的应用

该文基于适应于工业污水处理厂(工业废水量≥50%)的收水体制,利用层次分析法(AHP)建立4层14指标2方案的综合评价体系,并通过构造判断矩阵及一致性检验得到各指标的权重值。在此基础上,利用专家打分法建立指标评价标准和量化方法,并选择采用合流制和分流制收水体制的工业污水处理厂各8家,分别建立来水复杂程度、处理效果和投资费用之间的相关函数,从而为通过来水复杂程度选择收水体制提供理论依据和实践指导。     

How does agricultural intensification modulate changes in plant community composition?

Agricultural intensification, at local and landscape scales, has caused a decrease in plant diversity and changes in species composition in cereal fields. To better understand the role of landscape complexity and farming systems in shaping plant assemblages, it is of interest to focus on functional traits rather than on floristic composition, which may help to highlight trends in vegetation patterns. We analysed the relative abundance of various functional attributes (different life forms, growth forms, wind-pollinated species and wind-dispersed species) at three contrasted field positions (boundary, edge and centre) of 29 organic and 29 conventional cereal fields distributed in 15 agrarian localities of NE Spain. Agricultural intensification affected the biological attributes of the vegetation in dryland Mediterranean cereal fields; local factors (farming system and position) had a more prominent role in affecting plant functional composition than the surrounding landscape. Local factors were important for life form distribution, growth form and pollination type, whereas landscape complexity mainly affected the proportion of wind-dispersed species. Therefore, depending on the objective of the study, it is important to select functional attributes sensitive to the different scales of agricultural intensification, especially because landscape complexity and land-use intensity are commonly related.     

Bird community responses to cattle stocking rates in a Pacific Northwest bunchgrass prairie

In 2006-2010, effects of four different cattle stocking rates (0, 14.4, 28.8, and 43.2 animal unit months) were compared, representing 0%, 20%, 32%, and 46% utilization of vegetation by domestic livestock, on vegetation structure (as indexed by visual obstruction), and songbird population and apparent nest density, community composition, and diversity in a Pacific Northwest bunchgrass prairie in northeastern Oregon, USA. Overall paddock-level visual obstruction decreased and structural heterogeneity increased with increasing stocking rates, and those effects carried over 1 year after grazing had ceased. Most species were able to locate nesting sites regardless of differences in visual obstruction, except western meadowlark and vesper sparrow, for which obstruction was lower in paddocks with higher stocking rates. Apparent nest density for grasshopper sparrows was negatively affected by higher stocking rates. Grazing effects on absolute songbird population density were restricted to negative effects of higher stocking rates on savannah sparrows, but this relationship was not observed until 1 year after grazing had ceased. Songbird community composition differed between control and heavily-grazed paddocks, driven by an increase in the proportion of horned larks and a decrease in the proportion of savannah sparrows in heavily-grazed paddocks from pre-treatment to post-treatment years. Bird diversity indices were unaffected by stocking rate. Negative effects of high stocking rates on densities of two species and the absence of any clear positive effect for the other three species suggest high stocking rates as applied in this experiment may not provide suitable habitat for all grassland songbirds. The absence of negative responses of density to low and moderate stocking rates suggests these grazing regimes generally provided suitable habitat for all species.     

Organisational behaviour and strategies in the adoption of certified management systems: an analysis of the Spanish hotel industry

While the literature over the last ten years has dealt with the implementation of quality, environmental and other management systems in terms of the interest aroused and results obtained, little has been written about organisational behaviour and the extent to which such standards have been adopted in the service sector. The present article explores these variables in the hotel industry, based on information collected from 403 hotels. The empirical analysis conducted evinces significant differences in behaviour and penetration between the service and manufacturing sectors, as well as between the implementation of management systems and the introduction of other business practices in the hotel industry. The results shed light on the importance of implementing certified management systems for conducting the hotel business.     

窖水中微生物降解污染物的关键细菌

为探究以氮、磷及有机物污染为主要特征的、窖水中参与污染物降解的关键细菌及它们之间潜在的相关关系,基于16S rRNA的微生物组学截面数据,分析了窖水中细菌群落结构与功能及其与水质因子间的相关性,并通过微生物物种的同现或相关种间作用推断模型,构建了7个微生物菌属间的共现性关联网络.结果表明,窖水中存在具有相对特定生态功能的细菌,进行着诸多活跃的与新陈代谢功能基因相关的代谢活动;窖水微生物类群共现性关联网络中大部分节点的菌属营互利共生类型的生态关系;Lacibacter、Arthrobacter、Candidatus Protochlamydia、Methylocaldum、Sulfuritalea、Mycobacterium、Aquirestis、Rhodobacter、Methylotenera等菌属拥有较高的点度中心度;较强的互作关系发生在Sulfuritalea-Rhodobacter、Azospirillum-Rhodobacter、Methylocaldum-Rhodobacter、Arthrobacter-Rhodobacter、Rhodoplanes-Rhodobacter、Candidatus Protochlamydia-Rhodobacter、Methylotenera-Rhodobacter、Rhodobacter-Aquirestis、Mycobacterium-Rhodobacter、PlanctomycesCandidatus Solibacter、Planctomyces-Legionella、Hymenobacter-Adhaeribacter、Luteolibacter-Crenothrix之间.综合分析节点微生物相关性、点度中心度及菌属间的互作强度,认为Rhodobacter、Methylocaldum、Methylotenera、Acinetobacter、Novosphingobium、Planctomyces、Hymenobacter、Luteolibacter为参与窖水污染物微生物降解的关键细菌,Rhodobacter为关键细菌的代表属.研究结果加深了对窖水中污染物微生物降解机制的认识.     

战场电磁环境复杂度与战术通信性能的相关性研究

目的为提升战场电磁环境环境复杂度评估的客观性,基于电磁环境与通信性能的相关性提出一种电磁环境复杂度评估方法。方法该方法以层次分析法和混合加权理论为基础,以典型通信系统为例,建立语音通信和数据通信设备性能和电磁环境复杂度等级的映射,并据此建立通信网系性能和电磁环境复杂度的等级映射,从目标层、准则层、指标层给出五级量化指标体系。结果在50 km×50 km典型地域中,上述评估方法给出了10部高频和10部超高频通信设备组成的通信网络各单链路通信质量,分别为Ⅳ、Ⅳ、Ⅰ、Ⅳ、Ⅲ、Ⅱ、Ⅳ、Ⅴ、Ⅳ、Ⅲ、Ⅱ、Ⅱ、Ⅲ、Ⅴ、Ⅱ、Ⅰ、Ⅴ、Ⅳ、Ⅴ、Ⅴ,并在此基础上评估了整个网系的通信质量等级和整个通信网系面临的电磁环境复杂度(Ⅳ)。结论上述研究验证了方法的可行性,同时证实了同一环境下不同设备所受的电磁环境影响具有个体差异性,整体通信网系的受影响程度有别于单一设备。研究结果可为通信网系的电磁环境适应性试验、电磁干扰效应评估等研究提供基础和有益的参考。     

Yolk testosterone organizes behavior and male plumage coloration in house sparrows (<Emphasis Type="Italic">Passer domesticus</Emphasis>)

Vertebrate eggs contain maternal steroid hormones in their yolks; and in avian species the concentration of these steroids vary within and among clutches. The organizational actions of these variable doses of maternal steroids in the avian egg, analogous to those regulating the development of sexually dimorphic traits, are little explored. In this study, we examined the organizational effects of yolk testosterone in the house sparrow, Passer domesticus, a sexually dichromatic passerine bird in which males are characterized by the presence of a throat patch or badge of black feathers that varies in size among males. We injected a physiological dose of testosterone or vehicle into eggs in the field, removed nestlings, and hand-raised them in the laboratory. At 5 months of age, we investigated treatment effects on plumage and behavior. Males that hatched from testosterone-injected eggs developed a larger badge than males that hatched from vehicle-injected (control) eggs. However, testosterone did not induce the expression of a badge in females. In staged dyadic encounters, both males and females hatched from testosterone-injected eggs were more successful at obtaining and defending a food source than individuals of the same sex hatched from control eggs. The results suggest that variable concentrations of maternal testosterone in the eggs of the house sparrow organize the expression of a plumage trait in males and behavior in both sexes.Communicated by J. Graves     

Chaotic dynamics in a multispecies community

Environmental and Ecological Statistics - It is shown that community dynamics is neither haphazard nor completely directed. This is quite clear from our examination of a concrete example where...     

PREDICTING CHANGE IN NON-LINEAR SYSTEMS

Complex systems are characterizedby surprising switches to new behaviours. Evaluating and predicting these changes demands anunderstanding of the behaviour of the whole system. The combined ecosystem-climate system shows chaoticor pseudorandom behaviour, stochastic or trulyrandom behaviour, as well as simple bifurcation andsemi-stability. Semistability involves the suddenchange from a destabilized attractor to a newstable attractor which may occur after an apparentlyunpredictable time delay. We present some recentresults for analyzing time series data and for usingsimulations of non-linear models to predict these changes.     

基于统计复杂度的分数阶欠阻尼双稳系统的随机共振研究

目的研究Gaussian白噪声作用下分数阶欠阻尼双稳系统的随机共振现象。方法采用统计复杂度方法探究分数阶导数、余弦信号的幅值及频率、阻尼系数等参数对分数阶系统随机共振效应的影响。结果当这些参数变化时,分数阶系统的统计复杂度曲线和标准Shannon熵曲线会产生不同的变化趋势,且在分数阶导数q=0.3时,系统最易发生随机共振现象。此外,当信号振幅增加至0.2时,可以增强随机共振效应;相反,信号频率增大至0.07时,可以削弱此现象。结论这些因素可以有效地调节分数阶双稳系统的随机共振现象。