Orientation in captive migratory and sedentary Australian silvereyes <Emphasis Type="Italic">Zosterops lateralis</Emphasis> (Zosteropidae)

The orientation of two closely related subspecies of Australian silvereye Zosterops lateralis was studied in captivity over 14 months. Migratory silvereyes Z. lateralis lateralis showed significant directional preferences during the spring and autumn migration periods and also displayed orientated behaviour during the breeding period. In contrast, the non-migratory subspecies Z. lateralis familiaris did not display any significant directional preferences at any time. This is the first time that the orientation behaviour of a migratory and non-migratory subspecies has been compared over the duration of an annual cycle, both during and outside the migratory periods. The results suggest that migratory silvereyes possess an endogenous program determining the timing and direction of autumn and spring migration and that this program is unique to the migratory subspecies. This is also the first comparison of this nature on southern hemisphere birds and demonstrates that the migratory behaviour of southern hemisphere migrants may be more similar to that of northern hemisphere migrants than previously thought.Submitted to Behavioral Ecology and Sociobiology: 23 Jan 2006.     

Modelling asymmetrically distributed circular data using the wrapped skew-normal distribution

We consider problems of inference for the wrapped skew-normal distribution on the circle. A centered parametrization of the distribution is introduced, and simulation used to compare the performance of method of moments and maximum likelihood estimation for its parameters. Maximum likelihood estimation is shown, in general, to be superior. The operating characteristics of two moment based tests, for wrapped normal and wrapped half-normal parent populations, respectively, are also explored. The former test is easy to apply, maintains the nominal significance level well and is generally highly powerful. The latter test does not hold the nominal significance level so well, although it is very powerful against negatively skew alternatives. Likelihood based tests for the two distributions are also discussed. A real data set from the ornithological literature is used to illustrate the application of the developed methodology and its extension to finite mixture modelling. Received: September 2003/ Revised: April 2005     

Differential predator escape performance contributes to a latitudinal sex ratio cline in a migratory shorebird

Sexual segregation outside the mating season is common in vertebrates, and has been attributed to sexual differences in predator escape performance in ungulates and fish, but not in birds. Here, we tested the hypothesis that sex- and latitude-specific predator escape performance underlies the differential nonbreeding distribution of western sandpipers (Calidris mauri), a migratory shorebird. Females overwinter further south along the American Pacific coast, creating a latitudinal cline in sex ratio. Escape performance is reduced with increasing body mass, and birds generally carry less fat further south. Western sandpipers with poor escape performance were therefore predicted to prefer southern sites to reduce the risk of mortality posed by predators. Data from four nonbreeding latitudes showed that wing loading, used as an index of escape performance, was overall higher for females, and that it decreased with latitude in both sexes. Within latitudes, wing loading was lower at smaller, and presumably more dangerous, sites. Flight response to a predatory attack was longer in the south. Mortality risk offers a novel and candidate explanation for differential distribution patterns in western sandpipers and possibly other avian migrants.     

垃圾焚烧重金属迁移特性及其影响因素

综述了城市固体垃圾(MSW)焚烧过程中的Hg、Cd、Pb、Cu、Zn、As和Cr等几种主要重金属污染源在焚烧过程中的迁移特性及其主要影响因素。将重金属在焚烧过程中的迁变归结为:蒸发、气相和表面反应、冷凝成核团聚和飞灰吸附等4个主要过程;而垃圾中重金属的初始浓度、原始垃圾的基体盐分(如A l、S i和K、Na等的存在形式)、垃圾中的C l(PVC和NaC l)和S的含量、垃圾的含水量以及焚烧过程中的运行参数(温度、滞留时间、氧化-还原气氛)等都会对焚烧过程的迁移规律产生影响。     

中性含氮化合物的演化及地化意义

通过对生油岩样品中的中性氮系列化合物含量和组成变化的系统研究 ,指出了含氮化合物的热演化规律和形成机制 ,含氮化合物是沉积有机质成岩演化的产物 ,其含量和组成明显受控于有机质成熟度 ;认为 1- / 4-甲基咔唑、苯并 [a]咔唑 /苯并 [c]咔唑等比值可作为成熟度参数。     

利用静电旋风除尘器捕集亚微米粒子的研究

利用高场强静电旋风除尘器捕集柴油机排放的亚微米粒子,通过实验证实了,静电旋风除尘器可以有效捕集亚微米粒子。提出了对于该静电旋风除尘器,粒子的有效驱进速度与进口风速的关系式,这对于发展捕集亚微米粒子的静电旋风除尘器具有一定的参考价值。为控制柴油机的颗粒物排放提供了一个新的思路。     

土地荒漠化与我国生态移民政策研究

生态移民是把生态环境脆弱地区的人口有计划、有组织地异地搬迁安置，从而达到人口、资源、环境和经济社会的协调发展，是我国实施环境保护基本国策的重要措施之一。通过研究我国的生态移民政策及其实施现状，在分析目前存在的困难和问题的基础上，提出实施生态移民工程所要完善研究的内容和政策措施，以期能够保证我国生态移民工作的顺利推进。     

盐间非砂岩低渗透油藏中原油运移动力学分析

独特的江汉盆地潜江凹陷潜江组盐间非砂岩油藏生储同层 ,盐岩封盖条件极佳 ,但储集层渗透能力极低 ,油气运移条件差。目前的众多证据表明 ,就是在渗透能力如此低下的盐间层中 ,非断裂区的原油也顺层发生了一定规模的运移。在压实作用、流体热增压、有机质生烃生气增压以及毛细管压差等应力作用下 ,盐间原油得以从烃源岩层中排除 ,并在低渗透的盐间层运移主干道中顺层侧向 (或断裂区垂向穿层 )从生烃次洼向构造高部位等低势区聚集。从动力学的角度证明了盐间非砂岩低渗透油藏中原油顺层运移的可能性 ,并指出了盐间石油的运移方向和有利聚集区。     

水环境中重金属的存在形态和迁移转化规律综述

本文综述水环境中重金属的存在形态和污染特征以及迁移转化规律的研究概况。水体中重病态民的存在形态了子交换态，碳酸盐结合态、铁氧结合态、有机质和硫化物结合态和残渣态，重金属形态和生物效应有关，对重金属在水体中迁移和转化规律及其过程的动力学水质模型的建立进行了论述。     

A simulation analysis of the migration and transformation of pollutants contained in landfill leachate

A dynamic composite model for a soil-water system that can be used to simulate the movement of leachate from a landfill. The composite model includes nine sub-models that trace water movement and the migration and transformation of five pollutants(organic N, NE4^- ,NO3^- , NO2^-, and Cl^ - ) in saturated and unsaturated soil. The model to simulate the movement of leachate from a landfill in Laogang Town,Shanghai City was used. In this application, the values for the model parameters were oblained by performing a laboratory simulation experimentof water movement and pollutant migration and transformation in soil columns. Soil and leachate obtained from the landfill site and its vicinitywere used in the laboratory experiments. The model was then used to simulate leachate movement and pollutant activity during the ten-year period when the landfill was in operation and in the twenty-year period following its closure. The simulation results revealed that the leachate migrated into the groundwater at the rate of 90-100 meters per year. This model can be applied in the design of future landfills in China for the purpose of assessing and forecasting leachate plumes.