腐殖质对二氧化锰引起的五氯酚转化反应的影响

研究了在二氧化锰催化引起的五氯酚的转化反应中,腐殖质前身化合物的加入对五氯酚去除率的影响,并以p-coumaricacid为代表研究了体系pH值、反应时间、二氧化锰的质量浓度以及腐殖质前生物的浓度和分子结构对去除率的影响。结果表明,反应的最佳pH值范围是4～4.70,去除率在80%左右。五氯酚在24h内去除速率较快,去除率达到75%左右;反应到168h,去除速率趋于0,去除率达到80%左右。相同条件下,无p-coumaricacid的对照体系中,对应的反应时间内去除率仅分别为20%和25%左右。五氯酚的去除率还随二氧化锰质量浓度和p-coumaricacid浓度的增加而增大。当二氧化锰的质量浓度由0增加到100g·L-1时,去除率由0增大为95%;而当p-coumaricacid的浓度由0增加到1mmol·L-1时,去除率由25%增大到100%左右。此外,不同腐殖质前身物的分子结构和浓度对去除率分别起到了提高、不明显改变和降低的作用。     

屋顶绿化生态系统箱的研制

调查发现广州市屋顶自然生长的维管植物有49科109属128种,植物种类较多的科为菊科、禾本科、桑科、景天科、茜草科和鸭跖草科;屋顶自然生长的植物种类数量与环境受污染程度成反比,而与周围植物的多少成正比;屋顶自然生长的植物由于长期适应屋顶的极端环境,形成了的一些独特的生态生物学特征。基于上述结果配置相应的植物组合,设计适于屋顶绿化的生态系统箱、配制相应土壤并进行技术集成,观测其生长和隔热效应。同时进行空白对照、黑网荫蓬对照、生态隔热层对照、普通土壤种植区对比试验,发现生态隔热层和生态系统箱具有成本低、易维持、隔热好、景观美的效果。     

4种中草药的超临界CO2萃取物对霉菌的抑制效果

利用气相扩散法、固相扩散法、平板法研究了荷叶、艾叶、佩兰、细辛4种中草药的超临界CO2萃取物对霉菌的抑制作用和最低抑制浓度(MIC).结果表明,4种中草药的超临界CO2萃取物对单一或混合霉菌均有较强的抑制作用,荷叶和细辛的MIC<1.56g/L,佩兰的MIC<0.63g/L,艾叶的MIC<0.2g/L.表3参11     

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.     

异常环境电磁场对生物影响的研究进展

物理学的研究表明,在地球的大气环境中存在一个巨大的电场,大气电离层的电势约为360 kV,地球表面的电势约为130 kV;地球又是一个大磁球,地球表面磁场的磁感应强度约为10~-5T,地球上生物就是在这样的环境电磁场中繁衍和进化.然而,在现代社会中,随着电力和电子信息技术的飞速发     

湿地冷湿效应初探

对湿地周围不同距离农田的近地面气温、湿度、地温以及典型湿地地温的测定表明 ,湿地冷湿效应与湿地植被及其积水深度有关。在所选择的 3种湿地植被中 ,漂筏苔草积水最深 ,冷湿效应最大 ,其次为毛果苔草 ,小叶章最小。不同距离农田的近地面气温和湿度变化不同 ,随距离增加 ,温度增大 ,湿度减小。这种变化主要是由湿地的局部冷湿作用造成的。农田地温平均值高出小叶章湿地 4℃之多 ,高出漂筏苔草湿地近 5℃ ,表明湿地的制冷作用很明显     

湘黄鸡马立克氏病(MD)临床免疫方法及效果研究

通过本次临床试验得出；湘黄鸡马立克氏病(MD)的免疫以CVI988 HVT苗或Rispens CVI988苗为最佳效果，可使该病的临床发病率分别控制在1．33％和1．67％以下，致瘤率为34％左右．用中药进行预防达不到免疫的效果．所以认为用血清I型疫苗是目前衡阳地区湘黄鸡马立克氏病(MD)的唯一有效的免疫方法．     

封育次生马尾松(Pinus massoniana)林优势种群竞争密度效应

以退化红壤区封山育林植被恢复过程中优势种群马尾松为研究对象,研究不同恢复阶段马尾松种群竞争密度效应,并提出一个适用性更强的竞争密度效应模型.研究表明,退化红壤区植被恢复过程中优势种群马尾松竞争密度效应明显,优势种群平均胸径(D)、平均胸高断面积(S)、平均单株材积(V)、林分蓄积量 (M)与种群密度 (ρ)的竞争密度关系密切,达到极显著水平(α<0. 01);新竞争密度效应模型较前人模型描述C-D效应效果更理想,可在森林竞争密度效应研究中应用. 表 4参 19     

Social cohesion and foraging decrease with group size in fallow deer (Dama dama)

We studied the impact of group size on foraging behaviour and level of movement synchronisation among female herdmates of a fallow deer population in Central Italy. Both proportion of foraging events and movement synchronisation decreased with increasing group size. The proportion of foraging events was higher for animals on the edge of the group than for deer in the centre of the group; hence, there appears to be a trade-off between protection against predators and foraging interference, both of which decrease from the centre to the periphery of the group. This is the first time this type of behaviour has been recorded for wild ungulates. As expected, we also found that the movement of peripheral animals was less synchronised than that of central animals. Consequently, peripheral animals may lose contact with their herdmates and split off the group. We conclude that social inequalities may lead to conflicting requirements among group members and instability of large groups. Movement synchronisation (as a function of group size) appears to interact with habitat openness to produce variations of group size (which appear to be adaptive for individuals) as an emergent property of these aggregations.