不同重金属在烤烟中的累积分配特征研究

研究了重金属Hg、As、Pb在烤烟中的累积分布。结果表明：烤烟对Hg、As、Pb的耐受力较强；Hg抑制K326根系的生长，Pb、As对K326的生长有一定的促进作用。随着重金属浓度的增加，各部位重金属含量和烟株累积总量多呈增加趋势。在不同的处理下，3种重金属的含量在根系中最高；在相同的处理下，重金属在烟叶各部位的含量按大小顺序均为下部叶〉中部叶〉上部叶。随着处理浓度的增加，分配在根系中的重金属元素的比例不断增加，而在叶片中的分配比例不断降低；按重金属元素在叶片中的分配比例排序为Hg〉As〉Pb。     

粉煤灰开发应用新途径

简要介绍粉煤灰在综合利用方面的新用途。提出了把粉煤灰中的有效成分以及提取后的灰渣，进行综合开发及应用于生产的问题。     

A diagnostic experiment of the influence of CO2 on winter wheat

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生态安全弹性与生态安全"倒U"曲线

文章从生态安全的研究现状入手,根据生态系统和人类社会系统之间的主要关系,论述了生态安全弹性和安全"倒U"曲线理论.生态安全弹性能够反映安全系数、安全阈值、干扰程度三者的关系,由它来判断人类向生态系统索取自然资源的活动更具有预测性、可操作性,并能保证生态系统自身也处于可持续发展的良性状态.     

兔子宫内膜蛋白等电聚焦电泳载体两性电解质pH范围及比例的选择

兔子宫内膜蛋白是研究早期胚胎发育过程中胚泡附植机制的关键因素之一．为了对子宫内膜蛋白进行有效的分离，本研究探讨了用于等电聚焦电泳的载体两性电解质pH范围及其比例．研究结果表明：在只有pH3～9．5的情况下，蛋白质谱带主要分布于胶条碱性端1／3区域，酸性端无谱带；在载体两性电解质pH3-9．5：pH4～6=1：4的情况下，蛋白质谱带主要分布于胶条碱性端2／3部分；在载体两性电解质以pH3-9．5：pH4～6：pH6—9=1：4：1时，蛋白质谱带分布比较均匀，酸性端也有谱带分布．这说明在作子宫内膜蛋白的等电聚焦电泳时采用pH3～9．5：pH4～6：pH6～9=1：4：1比较理想．     

氢自养还原菌同步去除水中Cr(Ⅵ)和NO3-

本实验研究了序批式条件下Cr（Ⅵ）和NO₃^-浓度、pH值和H₂含量对于氢自养还原菌同步去除水中Cr（Ⅵ）和NO₃^-的性能及微生物群落的影响.结果表明：系统中存在氢气时,正常活性的氢自养还原菌可实现Cr（Ⅵ）的还原;Cr（Ⅵ）初始浓度不高于2000 μg/L时,Cr（Ⅵ）和NO₃^-的还原速率及氢自养还原菌的活性不会受到Cr（Ⅵ）初始浓度的影响;作为一种优先电子受体,NO₃^-会与Cr（Ⅵ）争夺电子,降低Cr（Ⅵ）的还原速率;氢自养还原菌同步还原Cr（Ⅵ）和NO₃^-的最佳pH值为7.0左右,酸性或碱性环境都会抑制Cr（Ⅵ）还原,且NO₂^-会随着pH值的升高逐渐积累;作为电子供体,H₂是还原Cr（Ⅵ）和NO₃^-的必要条件,但H₂足量后,过量提供H₂不能提高Cr（Ⅵ）和NO₃^-的还原速率.     

再加热步进炉仪表系统自动化节能改造

本文描述了采用SIEMENS S7 414-5H CPU和WINCC等自动化产品实现再加热步进炉的自动控制。网络拓扑结合了Profibus-DP冗余现场总线和以太网(TCP/IP),使用STEP7编程实现了双交叉PID,使用WINCC软件实现了各工艺子系统画面以及参数监控、报表打印等功能。实现了用户控温节能的目的。     

Exploring the internal and external wildlife gradients created by conservation fences

Spillover effects are an expansion of conservation benefits beyond protected areas through dispersal of species that reside within. They have been well documented in marine but not terrestrial systems. To understand the effects on wildlife created by conservation fences, we explored the internal and external gradients of activity in mammal, reptile, and bird species at a conservation reserve in arid Australia that is fenced to exclude invasive rabbits (Oryctolagus cuniculus), cats (Felis catus), and foxes (Vulpes vulpes). Two methods were used: counts of animal tracks along transects on sand dunes and captures at pitfall-trapping sites. In both cases, sites were spaced at different distances from the reserve fenceline inside and outside the reserve. We recorded a range of spillover, source-sink, step, and barrier effects that combined to create a zone within and around the reserve with fence-induced species-specific wildlife gradients. Two endemic rodents but none of the 4 mammal species reintroduced to the reserve showed positive spillover effects. Barrier effects, where activity was highest close to the fence, were recorded for the feral cat and native bettong (Bettongia lesueur), species that could not breach the fence. In comparison, some reptiles and native mammal species that could permeate the fence displayed source-sink effects; that is, their activity levels were reduced close to the fence likely due to constant emigration to the side with lower density. Activity of some reptiles was lowest at sites inside the reserve and gradually increased at outside sites with distance from the fence, a gradient likely related to trophic cascades triggered by predator exclusion. Our result shows that fenced reserves can create overlapping layers of species-specific gradients related to each species’ ability to permeate the fence and its varying susceptibility to threats. Managers should be aware that these gradients may extend for several kilometers either side of the fence and that not all contained species will increase in abundance. Creating wider conservation benefits may require increased fence permeability and threat reduction outside the fence.     

An adaptive plan for prioritizing road sections for fencing to reduce animal mortality

Mortality of animals on roads is a critical threat to many wildlife populations and is poised to increase strongly because of ongoing and planned road construction. If these new roads cannot be avoided, effective mitigation measures will be necessary to stop biodiversity decline. Fencing along roads effectively reduces roadkill and is often used in combination with wildlife passages. Because fencing the entire road is not always possible due to financial constraints, high-frequency roadkill areas are often identified to inform the placement of fencing. We devised an adaptive fence-implementation plan to prioritize road sections for fencing. In this framework, areas along roads of high, moderate, and low levels of animal mortality (respectively, roadkill hotspots, warmspots, and coldspots) are identified at multiple scales (i.e., in circles of different diameters [200–2000 m] in which mortality frequency is measured). Fence deployment is based on the relationship between the amount of fencing being added to the road, starting with the strongest roadkill hotspots, and potential reduction in road mortality (displayed in mortality-reduction graphs). We applied our approach to empirical and simulated spatial patterns of wildlife–vehicle collisions. The scale used for analysis affected the number and spatial extent of roadkill hot-, warm-, and coldspots. At fine scales (e.g., 200 m), more hotspots were identified than at coarse scales (e.g., 2000 m), but combined the fine-scale hotspots covered less road and less fencing was needed to reduce road mortality. However, many short fences may be less effective in practice due to a fence-end effect (i.e., animals moving around the fence more easily), resulting in a trade-off between few long and many short fences, which we call the FLOMS (few-long-or-many-short) fences trade-off. Thresholds in the mortality-reduction graphs occurred for some roadkill patterns, but not for others. Thresholds may be useful to consider when determining road-mitigation targets. The existence of thresholds at multiple scales and the FLOMS trade-off have important implications for biodiversity conservation.     

生物滴滤床净化二甲苯废气的性能研究

分别以大小两种拉西环作为生物滴滤床填料净化二甲苯废气,研究入口负荷、气体停留时间、营养液喷淋密度及营养液中氯化铵的质量浓度对生物滴滤床净化效果的影响.实验结果表明:随着入口负荷的增加,去除负荷也呈增加趋势,但二者并非线性关系.气体停留时间越长,去除效果越好.营养液中氯化铵的质量浓度对去除效果有显著影响,充足的氮源是高去除率的保证.在氮源充足的前提下,营养液喷淋密度对去除效果无显著影响.