Environmental conditions influence egg color of reed warblers <Emphasis Type="Italic">Acrocephalus scirpaceus</Emphasis> and their parasite,the common cuckoo <Emphasis Type="Italic">Cuculus canorus</Emphasis>

The outer layer of the eggshell in birds is in many cases covered by pigments that are assumed to be genetically determined traits with a negligible environmental component. To test the hypothesis that spring environmental conditions (i.e., temperature and rainfall) may affect bird egg pigmentation, we measured by spectrophotometry and photography egg coloration and spottiness on reed warbler (Acrocephalus scirpaceus L.) clutches parasitized by the common cuckoo (Cuculus canorus L.) collected over a period of 24 years and preserved in the Zoological Museum, Copenhagen, Denmark. In addition, we investigated whether spring environmental conditions may influence the coevolutionary relationship between the cuckoo and its host via changes in cuckoo–host egg matching. Generalized mixed models revealed that reed warbler eggs were more brilliant in those springs with a higher rainfall and tended to be bluer and greener in springs with a lower relative temperature. On the other hand, cuckoo eggs were bluer and greener in springs with a higher rainfall. Cuckoo–host egg matching in blue-greenness and spottiness was better in springs with a higher rainfall. These results provide support for the existence of an environmental component on bird egg coloration and suggest that environmental factors may potentially affect the outcome of important features of the arms race between cuckoos and reed warblers.     

ANALYSIS OF NITROGEN MANAGEMENT STRATEGIES USING EPIC1

ABSTRACT: This paper illustrates a method of using a hydrologic/water quality model to analyze alternative management practices and recommend best management practices (BMPs) to reduce nitrate-nitrogen (NO₃^--N) leaching losses. The study area for this research is Tipton, an agriculturally intensive area in southwest Oklahoma. We used Erosion Productivity Impact Calculator (EPIC), a field-scale hydrologic/water quality model, to analyze alternative agricultural management practices. The model was first validated using observed data from a cotton demonstration experiment conducted in the Tipton area. Following that, EPIC was used to simulate fertilizer response curves for cotton and wheat crops under irrigated and dryland conditions. From the fertilizer response functions (N-uptake and N-leaching), we established an optimum fertilizer application rate for each crop. Individual crop performances were then simulated at optimum fertilizer application rates and crop rotations for the Tipton area, which were selected based on three criteria: (a) minimum amount of NO₃^--N leached, (b) minimum concentration of NO₃^--N leached, and (c) maximum utilization of NO₃^--M. Further we illustrate that by considering residual N from alfalfa as a credit to the following crop and crediting NO₃^--N present in the irrigation water, it is possible to reduce further NO₃^--N loss without affecting crop yield.     

冲压模CAE技术及软件选型方法

综述了国内外常用冲压模具CAE分析软件的内容和种类 ,从实用角度讨论了CAE系统应用中诸如规划、软件选型、人员培训、应用推广等问题 ,对其选型和实施方法作了重点介绍     

HKB—1型磁化率仪研制及计算机联机的实现

本文介绍了一种新研制的磁化率仪,它可测定自然界中大多数物质(良导体除外)的初始磁化率,特别适合于岩石的磁化率及其各向异性(AMS)测量。仪器工作磁场300A/m,频率920Hz,样机总磁化率测量灵敏度达到 2×10~(-12)m~3,读数采用数字显示方式并具有自动锁定功能。与计算机的联机采用了标准EIARS-232C串行接口,因此具有良好的通用性。在软件的控制下,计算机可自动完成测量数据的采集、计算处理、座标转换以及成图或存贮等工作,AMS参数的测量效率得到很大提高。     

AnnAGNPS模型在潋水河流域产水、产沙的模拟评价

日益严重的土壤侵蚀造成了土地退化、水体污染等一系列的环境和生态问题,利用基于过程的数学模型已成为流域土壤侵蚀状况定量评价和控制的有效方法.利用美国农业部开发的流域尺度AnnAGNPS模型,设计了基于地形特征的cell离散方案,在多种地理数据采集和参数化的基础上,对江西兴国潋水河流域1991～2005年的径流、产沙过程进行了分布式计算机模拟.在对产水量进行径流滤波分析的基础上,分别对模型模拟的地表径流和产沙量进行了校正和验证.地表径流模拟结果多年平均相对误差为11.8%,确定性系数R2为0.94,产沙量模拟结果的多年平均相对误差为19.71%,确定性系数R2为0.77.表明AnnAGNPS能较好地模拟潋水流域年、月尺度的地表径流和产沙过程.地下径流模拟结果误差较大,其原因和地下径流模拟模块在潋水流域的适用性有待进一步研究检验.对潋水流域土壤侵蚀定量分析表明,潋水流域的年平均侵蚀模数为1 150.29.t(km2.a)-1,属于轻度侵蚀等级,流域内侵蚀较严重的区域集中分布于居民地附近和公路沿线,其水土流失与人类活动有很大关系.     

飞行器控制系统数据综合关键技术研究

控制系统数据综合是导弹等飞行器实现低成本和小型化的有效途径.文中提出基于双处理器结构的飞行控制系统任务计算机系统结构,并对数据综合过程中的时间同步、时间管理等关键技术问题,采取初始同步和周期同步相结合的方式,对任务运行同步误差进行了修正,在时间同步的基础上,将控制链条按照资源占用情况进行分解,并对各功能模块进行统筹、分时调度,实现了双机并行处理.     

废水处理中pH值计算机模糊控制系统的设计

酸碱中和是化工废水处理中的一个重要环节。本ｐＨ值控制系统采用ＰＩＤ控制和模糊控制并列转换形式,当系统的偏差较小时,采用ＰＩＤ法进行流程控制;而当系统的偏差较大时,采用计算机模糊控制。介绍ｐＨ值计算机模糊控制系统设计原理与模糊控制器的实现,包括模糊化处理、模糊规则库的建立、模糊计算和反模糊化处理。在废水处理工艺流程中采用该控制方法可获得高效、稳定的控制效果。     

生物裂解效应对污泥脱水减量的作用研究

从市政污水处理厂活性污泥中筛选培养出噬菌型细菌,并通过噬菌型细菌的富集与投加,探讨其对市政污泥生物裂解预处理的有效性及其所受环境影响因素与作用规律.研究结果显示,市政污泥中存在具有污泥裂解作用的广谱性噬菌型细菌,宿主菌的投加量可影响噬菌型细菌的富集浓度,但培养基营养物组成浓度对噬菌型细菌的生长增殖无明显影响.当筛选出的噬菌型细菌以10⁶ pfu/mL（污泥）与中性市政污泥在室温下共存培养24h即可有效裂解污泥细胞,污泥比阻与污泥体积较未投加任何菌剂的参照污泥降低了36%和15%.并可导致胞内营养物的释放,污泥液相中总氮与总磷浓度较参照污泥分别上升了245%和242%,溶解性COD与总COD比值（SCOD/TCOD）则提高了195%,但生物裂解作用效果并不与裂解时间始终保持正相关性,最佳污泥生物裂解时间为24h.     

宝钢特种设备计算机管理系统的研究与应用

简述了宝钢特种设备安全管理理念,提出了宝钢特种设备计算机管理系统的总体思路,并对该系统的应用作了一定描述。     

机房安全监控系统软件浅析

计算机机房的安全监控软件可分为本地监控软件和远程监控软件两大类,分别就目前这两类软件的特点及其发展趋势做了比较和分析,为用户选择安全监控软件提供了参考和建议。