Climatic and Biotic Stochasticity: Disparate Causes of Convergent Demographies in Rare, Sympatric Plants

Abstract:  Species with known demographies may be used as proxies, or approximate models, to predict vital rates and ecological properties of target species that either have not been studied or are species for which data may be difficult to obtain. These extrapolations assume that model and target species with similar properties respond in the same ways to the same ecological factors, that they have similar population dynamics, and that the similarity of vital rates reflects analogous responses to the same factors. I used two rare, sympatric annual plants (sand gilia [ Gilia tenuiflora arenaria ] and Monterey spineflower [ Chorizanthe pungens pungens ]) to test these assumptions experimentally. The vital rates of these species are similar and strongly correlated with rainfall, and I added water and/or prevented herbivore access to experimental plots. Their survival and reproduction were driven by different, largely stochastic factors and processes: sand gilia by herbivory and Monterey spineflower by rainfall. Because the causal agents and processes generating similar demographic patterns were species specific, these results demonstrate, both theoretically and empirically, that it is critical to identify the ecological processes generating observed effects and that experimental manipulations are usually needed to determine causal mechanisms. Without such evidence to identify mechanisms, extrapolations among species may lead to counterproductive management and conservation practices.     

基于激光快速成形技术的快速工/模具制造

概括了基于激光快速成形技术的快速工/模具制造的两种方法——间接法和直接法,对两种工/模具制造技术作了较具体的介绍,并分析了其特点.     

保护北疆铁路,建设良好的生态环境,促进博州经济发展

保护和改善生态环境,是确保北疆铁路畅通无阻与发展博尔塔拉州国民经济的重要环节,就此,本文根据资料进行了讨论并提出了相应措施。     

生物过滤系统处理恶臭技术

介绍了可生物降解的恶臭气体种类、来源，生物过滤系统的历史与研究现状，生物过滤系统的设计与运行操作，填料的开发与选择。生物过滤系统是处理恶息的有效工艺，在我国有广泛的应用前景。     

分光光度法在化学需氧量快速测定中的应用研究

通过实验研究，建立起化学需氧量（ＣＯＤ）分光光度快速测定方法．回流时间由原来的２ｈ缩短为１５ｍｉｎ，并用分光光度法代替碘量法进行测定．该法与标准法相比，具有操作简便、测定快速等优点．该法对实际水样进行没定，测定结果与标准法相比，无显著性差异     

5B—1型COD快速测定仪测试污水中COD

本文通过对废水中ＣＯＤ的两种分析方法的对比实验， 结果表明： 用仪器法测废水中的ＣＯＤ， 方法简便， 节约能耗， 数据准确， 比用普通的化学法更为实用， 适合于大批量的废水检测。     

物化法处理制罐生产废水

根据调查研究制罐（铝质易拉罐）生产废水的来源、水质及水量，提出了“酸化破乳、中和、混凝沉淀、过滤、活性炭吸附”的处理工艺。利用实验室试验结果，在某制罐厂建成一座处理规模为４００ｍ３／ｄ的废水处理站。废水经处理后，各项指标均符合排放标准。     

高压线下袋装砂井的施工

在公路软基处理过程中，如公路上空有高压线穿越，则往往因高压线下净空不够使袋装砂井无法施工，采用其它处理方式时，往往导致处理费用大幅上升。本文介绍了套管接驳的方式施工装砂井的工艺，经济可行，可供同行借鉴。     

用二氧化氯直接处理印染废水的试验

用二氧化氯直接氧化处理含疏水性染料的印染废水（ＣＯＤ３６０ｍｇ／ｌ，色度２５６倍），经ＰＥ精密过滤器过滤，出水水质为ＣＯＤ６４ｍｇ／ｌ，色度４倍。     

适度处理污水回用于循环水系统的工业化应用

通过对镇海炼化适度处理污水回用于循环水系统工艺的介绍，提出运行中存在的问题及建议，为目前国内各炼油厂炼油污水回用提供参考和借鉴。