碱催化脱氯技术处理氯代新POPs研究及示范工程

以硫丹作为氯代新POPs的代表,通过实验室小试研究,探讨反应温度、NaOH和石蜡油投加量对硫丹在NaOH/石蜡油碱催化反应体系中的去除和脱氯效率(RE和DE)的影响,并寻找出最优条件,开展示范工程研究.实验室小试结果表明,反应温度、NaOH投加量和石蜡油投加量对硫丹脱氯效率的影响要大于对其去除率的影响.当温度为250℃,硫丹和NaOH及石蜡油的质量比为1:3:6和1:3:10时,反应3h后,硫丹去除率和脱氯效率分别达到99.99%和99%以上.采用硫丹和得克隆两种氯代有机物开展示范工程研究,中试设备处理能力达到15kg/批次,在250~300℃下反应3~10h后,对硫丹和得克隆的去除效率均达到99.9%以上,表明硫丹和得克隆被有效分解.示范工程的成功实施为我国履行斯德哥尔摩公约提供技术支持.     

兰州市南北两山不同生境红砂种群数量动态研究

对兰州市南北两山不同生境天然分布的红砂种群进行数量动态研究,通过径级结构回归年龄结构,编制静态生命表,绘制生存函数曲线,计算动态指数及谱分析,结果表明:不同生境红砂种群均表现为幼龄个体多,中老龄个体少,种群在Ⅲ龄级时死亡率最高,随着年龄增加,死亡率有所降低,Ⅶ、Ⅷ龄级由于生理衰老死亡率上升,种群存活曲线均接近于Deevey-Ⅲ型,年龄结构均接近增长型,增长潜力阴坡山下(5.90%)>阳坡山下(5.62%)>阴坡山上(4.77%)>阳坡山上(3.79%),并存在明显的周期性,红砂种群的数量动态变化整体上受其生命周期中生物学特性的控制;由于坡向及海拔差异带来的环境异质性,阴坡山下红砂种群整体生长最佳,阴坡山上和阳坡山下次之,而阳坡山上的红砂种群危险系数最大,受环境和种内压力共同作用显著,应适当抚育,从而促进种群持续发育。     

ENSG-30000-125可调频高声强声波吹灰器除垢机理分析

目前国内燃煤电厂湿法烟气脱硫装置常因为GGH堵塞而被迫停运,为了解决这个问题,介绍了一种利用高声强声波吹灰器结合高压水冲洗,彻底解决GGH结垢堵塞的方法,并对高声强声波吹灰器的除垢机理进行了分析,认为高强声波的推拉作用可使换热器表面的硬垢因声致疲劳而松动、脱落,同时,降低灰垢在换热器表面的附着力。另外,针对强声波对GGH的机械作用力进行了平衡分析,认为在强声波环境下GGH运行是安全的。     

Modelling environmental stochasticity in adult survival for a long-lived species

Stochastic matrix population models are often used to help guide the management of animal populations. For a long-lived species, environmental stochasticity in adult survival will play an important role in determining outcomes from the model. One of the most common methods for modelling such stochasticity is to randomly select the value of adult survival for each year from a distribution with a specified mean and standard deviation. We consider four distributions that can provide realistic models for stochasticity in adult survival. For values of the mean and standard deviation that cover the range we would expect for long-lived species, all four distributions have similar shapes, with small differences in their skewness and kurtosis. This suggests that many of the outcomes from a population model will be insensitive to the choice of distribution, assuming that distribution provides a realistic model for environmental stochasticity in adult survival. For a generic age-structured model, the estimate of the long-run stochastic growth rate is almost identical for the four distributions, across this range of values for the mean and standard deviation. Model outcomes based on short-term projections, such as the probability of a decline over a 20-year period, are more sensitive to the choice of distribution.     

Generation time and the maximum growth rate for populations with age-specific fecundities and unknown juvenile survival

In age-classified population models where all parameters are known, the generation time and growth rate are calculated in a straightforward manner. For many populations, some parameters, such as juvenile survival, are difficult to estimate accurately. In a simplified population model where fecundity and survival are constant from the onset of breeding, it is known that generation time may be calculated given only adult survival, age at first reproduction, and the population growth rate. However, the assumption of constant fecundity from the onset of breeding does not hold for many populations. An extended population model allows calculation of generation time with the additional knowledge of the ratio of age-specific fecundities compared to a maximum fecundity rate. When these relative fecundities are unknown, an ad hoc adjustment to the simplified model performs well.When the study population is in an ideal environment, the optimal generation time and maximum growth rate are linked, and both may be approximated knowing only adult survival, age at first reproduction, and the relative fecundities. The maximum growth rate has important conservation implications, and calculating it correctly is therefore important. Improper use of the simplified population model to calculate the maximum growth rate, combined with a simple decision rule, leads to an average overharvest of 36%, and >60% for three of six bird species studied, compared to the full population model. By comparison, using the approximation from the extended or adjusted models results in average overharvests of only 8% (extended model) and 5% (adjusted model), and <50% for all six species (either model).     

Choosing classes for size projection matrix models

Projection matrix models are intensely used in ecology to model the dynamics of structured populations. When dealing with size-structured populations, there is no satisfactory algorithm to partition size into discrete classes. We show that the Vandermeer-Moloney algorithm for choosing classes is inconsistent with the Usher model, and systematically selects the finest classes. Considering that the matrix model is a discrete approximation of a continuous model, we define an approximation error as the sum of a distribution error (the difference between the discrete distribution and its continuous counterpart), and a sample error. The optimal partition of size into classes is the one that minimizes the approximation error. This method for choosing classes also shows that the choice of the class width cannot be disconnected from the choice of the time step. When applied to 520 trees of Dicorynia guianensis in French Guiana, this algorithm identified 8 classes of 11.4 cm in width, which is in agreement with the empirical choice of foresters.     

Roads,Interrupted Dispersal,and Genetic Diversity in Timber Rattlesnakes

Abstract: Anthropogenic habitat modification often creates barriers to animal movement, transforming formerly contiguous habitat into a patchwork of habitat islands with low connectivity. Roadways are a feature of most landscapes that can act as barriers or filters to migration among local populations. Even small and recently constructed roads can have a significant impact on population genetic structure of some species, but not others. We developed a research approach that combines fine‐scale molecular genetics with behavioral and ecological data to understand the impacts of roads on population structure and connectivity. We used microsatellite markers to characterize genetic variation within and among populations of timber rattlesnakes (Crotalus horridus) occupying communal hibernacula (dens) in regions bisected by roadways. We examined the impact of roads on seasonal migration, genetic diversity, and gene flow among populations. Snakes in hibernacula isolated by roads had significantly lower genetic diversity and higher genetic differentiation than snakes in hibernacula in contiguous habitat. Genetic‐assignment analyses revealed that interruption to seasonal migration was the mechanism underlying these patterns. Our results underscore the sizeable impact of roads on this species, despite their relatively recent construction at our study sites (7 to 10 generations of rattlesnakes), the utility of population genetics for studies of road ecology, and the need for mitigating effects of roads.     

关中-天水经济区人口-经济-生态协调发展研究

在经济迅速发展的背景下,我国人口、经济和生态的矛盾日益突出。选择关中-天水经济区为研究对象,基于变异系数的协调函数模型对其人口-经济-生态协调度进行了测算。结果表明：1）1999—2008年,关中-天水经济区各地市人口-经济-生态协调度整体呈现上升的趋势,总体由失调状态转向勉强协调,其中天水市呈直线上升趋势,咸阳、宝鸡、铜川3市的协调度在波动中有所增加,西安市变化幅度不大;2）人口、经济、生态3个子系统的变化都会影响到整个系统的变化,西安市生态子系统协调度的下降,制约了整个系统的协调发展;3）协调度在空间上表现为关中-天水经济区中部地市的协调度较高,渭南和天水市的协调度始终处于该地区的较低水平。     

水安全智能识别模型的建立及应用

通过人口迁移算法优化投影寻踪模型,提出了一种新的水安全智能识别模型。与遗传算法优化的投影模型相对比,人口迁移算法的自身优势有效地避免了网络早熟现象及寻找全局最优解的困扰。从水安全的评价结果来看,用人口迁移算法优化投影寻踪是可行的,并显示出优越性。人口迁移算法为求解投影寻踪模型的非线性约束提供了新的优化方法,并为水安全评价工作提供了新的智能识别模型。