Florida red bay (Persea borbonia) leaf extracts deter oviposition of a sympatric generalist herbivore, Papilio glaucus (Lepidoptera: Papilionidae)

Summary. The ability to perceive and respond to phytochemicals that reliably indicate poor suitability of a potential host plant confers a selective advantage to ovipositing female swallowtail butterflies. Papilio glaucus females are generalists that nonetheless do not oviposit on red bay (Persea borbonia: Lauraceae). Red bay is toxic to P. glaucus neonates but is commonly found in habitats alongside their principal host plant, Magnolia virginiana, in central Florida. The hypothesis that deterrent compounds present in the leaves of red bay mediate its rejection by P. glaucus was evaluated in our study. Florida populations of P. glaucus did not oviposit on host leaves sprayed with the methanol extract of red bay foliage, although they accepted solvent-treated and untreated tulip tree leaves in 3 choice bioassays. Additionally, tulip tree leaves sprayed with methanolic extracts of red bay also deterred oviposition by P. glaucus females from Ohio, Kentucky and Pennsylvania, although these populations do not naturally encounter red bay. Clearly, deterrent compounds found within this non-host are the basis of its rejection by populations of P. glaucus and such recognition is fundamental to the species, not just a reflection of local adaptations. Received 2 April 1999; accepted 11 June 1999.     

红壤中交换性铝调控条件的研究Ⅱ.有机质和CaCO_3对交换性铝的影响

研究了有机质和ＣａＣＯ３。对发育于花岗岩和第四纪红色粘土母质上的红壤的交换性铝的影响。结果表明,在用Ｈ２Ｏ２去除土壤中的有机质后,交换性铝的含量随有机质的降低而降低,但降低的速度不均匀,由慢到快似有一个“突跃”。而在向土壤中添加有机质的研究结果则表明,交换性铝的含量随有机质的增加而增加;在增加的过程中由快到慢,达到极点后,有机质含量再增加,交换性铝反而下降。在相同的土壤环境中,由于作物品种不同,施用等量的ＣａＣＯ３（或石灰粉）对土壤交换性铝的含量及作物产量的影响不同,而且差异显著。     

施用石灰对酸性土壤中氧化亚氮形成的影响

对酸性红壤施用石灰和N2O生成之间的关系进行了探讨。结果表明,在好气条件下,石灰的施用与NH4＋氧化过程中N2O的产生量之间的关系不明显。但随着石灰施用量的增加,厌气条件下NO3－还原过程中N2O的积累量明显增加了,这与施用石灰后土壤pH升高而提高了硝酸还原酶活性有关。试验还表明,尽管在厌气条件下土壤pH较高有利于NO3－还原成NO2－,但当缺乏有效碳源时,NO2－向N2O的进一步还原受到限制,易发生NO2－的积累。     

Metrics for quantifying how much different threats contribute to red lists of species and ecosystems

Red lists are a crucial tool for the management of threatened species and ecosystems. Among the information red lists provide, the threats affecting the listed species or ecosystem, such as pollution or hunting, are of special relevance. This information can be used to quantify the relative contribution of different threat factors to biodiversity loss by disaggregating the cumulative extinction risk across species into components that can be attributed to certain threats. We devised and compared 3 metrics that accomplish this and may be used as indicators. The first metric calculates the portion of the temporal change in red list index (RLI) values that is caused by each threat. The second metric attributes the deviation of an RLI value from its reference value to different threats. The third metric uses extinction probabilities that are inferred from red list categories to estimate the contribution of a threat to the expected loss of species or ecosystems within 50 years. We used data from Norwegian Red Lists to test and evaluate these metrics. The first metric captured only a minor portion of the biodiversity loss caused by threats because it ignores species whose red list category does not change. Management authorities will often be interested in the contribution of a given threat to the total deviation from the optimal state. This was measured by the remaining metrics. The second metric was best suited for comparisons across countries or taxonomic groups. The third metric conveyed the same information but uses numbers of species or ecosystem as its unit, which is likely more intuitive to lay people and may be preferred when communicating with stakeholders or the general public.     

铁炭微电解-微波激发无极紫外光处理活性红195染料模拟废水

以NaClO为氧化剂,采用铁炭微电解-微波激发无极紫外光协同作用处理活性红195染料模拟废水。实验的优化工艺条件为：当NaClO加入量为9mL／L,用铁炭微电解～微波激发无极紫外光协同作用处理质量浓度为400mg／L的活性红195染料模拟废水50min时,废水脱色率达97％,COD去除率达82％。     

联合法赤泥的特性及其对水溶液中Pb(Ⅱ)的去除

赤泥作为氧化铝冶炼过程中排出的一般工业固废,具有数量大、碱性强、粒径小、孔隙结构丰富等特征。采用XRF、XRD、SEM/EDX等分析手段,研究了赤泥的化学组成、矿物结构、粒度、比表面积、表面形貌、酸中和能力等特性。通过批实验观测了赤泥对水溶液中Pb(Ⅱ)的去除效果,并对Pb(Ⅱ)初始浓度、pH等影响因子对去除效果的影响展开了分析。结果表明,赤泥的主要化学成分为CaO、SiO₂、Al₂O₃和Fe₂O₃,平均比表面积为43.8 m²·g⁻¹;赤泥有很强的酸中和能力,对硝酸的中和能力约为1.875 mol·kg⁻¹。初始pH=4,且过程中不控制pH时,反应在10 min之内达到平衡,去除率为98%~100%,赤泥对Pb(Ⅱ)的去除能力可达到25.9 mg·g⁻¹。当pH=4时,赤泥对水溶液中Pb(Ⅱ)的去除反应在90~120 min时达到平衡,去除率为10%~45%,当初始浓度为1~100 mg·L⁻¹时,Pb(Ⅱ)初始浓度越高,Pb(Ⅱ)去除能力越强,去除率越低。当pH为7和10时,Pb(Ⅱ)去除率分别为92%和98%,残留Pb(Ⅱ)浓度小于污水综合排放标准中第一类污染物最高允许排放浓度1.0 mg·L⁻¹。通过分析可知,赤泥对Pb(Ⅱ)的去除符合拟二级动力学模型,吸附机理主要为化学吸附。     

Comparative studies of the Fe3+/2+-UV, H2O2-UV, TiO2-UV/vis systems for the decolorization of a textile dye X-3B in water

The degradation of a common textile dye, Reactive-brilliant red X-3B, by several advanced oxidation technologies was studied in an air-saturated aqueous solution. The dye was resistant to the UV illumination (wavelength λ  320 nm), but was decolorized when one of Fe³⁺, H₂O₂ and TiO₂ components was present. The decolorization rate was observed to be quite different for each system, and the relative order evaluated under comparable conditions followed the order of Fe²⁺–H₂O₂–UV  Fe²⁺–H₂O₂ > Fe³⁺–H₂O₂–UV > Fe³⁺–H₂O₂ > Fe³⁺–TiO₂–UV > TiO₂–UV > Fe³⁺–UV > TiO₂–visible light (λ  450 nm) > H₂O₂–UV > Fe²⁺–UV. The mechanism for each process is discussed, and linked together for understanding the observed differences in reactivity.     

剩余污泥对活性黑和酸性大红混合染料的吸附

以剩余污泥为吸附剂,研究其对混合染料废水中活性黑KN-B和酸性大红G的吸附行为,考察了吸附动力学、吸附等温线、离子浓度、废水pH,以及染料质量比对吸附的影响。结果表明,污泥对RB KN-B和AR G的混合染料吸附迅速,时间可以控制在30 min;RB KN-B的吸附量是AR G的2.4~2.5倍;其吸附过程可以用假二级动力学方程进行描述和预测。Langmuir方程可以较好地描述污泥对RB KN-B和AR G的吸附,而混合染料MD的吸附更符合Freundlich方程。污泥对RB KN-B的吸附量在pH<11范围内比较稳定;AR G则在pH ≤ 2时吸附量较高,pH 2~4之间吸附量急剧下降,pH 4~11之间吸附量相对稳定;混合染料中染料所占比例对单个染料去除率影响较小,但对混合染料总的去除率影响较大。     

活性炭负载CuO催化过硫酸盐去除活性艳红X-3B染料

利用活性炭吸附法及基于SO4-·的高级氧化技术,以活性炭和过渡金属氧化物CuO为催化剂,催化过硫酸盐产生SO4-·降解活性艳红X-3B染料。结果表明,活性炭负载CuO催化过硫酸盐可有效去除活性艳红X-3B,色度去除率达90%以上,显著优于活性炭(21.53%)、过硫酸盐(46.88%)、活性炭催化过硫酸盐(53.67%)(P<0.05)。活性艳红X-3B的催化降解效果受CuO负载量、pH、过硫酸盐投加量、温度的影响。单因素法研究表明,各因素最佳条件为:负载量活性炭与CuO质量比为1:5,投加量0.2 g,pH为3,过硫酸钠投加量0.2 g,反应温度40℃,活性艳红X-3B的色度去除率分别达到91.34%、95.57%、98.54%和98.81%,COD去除率分别为82.73%、88.89%、87.60%和93.46%。     

改性棉铃壳对水中刚果红的吸附性能

通过甲醇酯化制备改性棉铃壳吸附剂,利用红外光谱仪、扫描电镜等表征了改性前后棉铃壳表面结构和官能团变化情况,考察了改性棉铃壳投加量、刚果红初始浓度和溶液pH等因素对改性棉铃壳吸附水中刚果红的性能影响,并通过实验分析了改性棉铃壳对水中刚果红吸附动力学。结果表明,改性后棉铃壳表面官能团明显改变,表面光滑、致密。改性棉铃壳对刚果红的吸附效果较未改性棉铃壳明显提高,增加刚果红初始浓度和吸附时间可以增加改性棉铃壳对刚果红的吸附量。在溶液pH为6、吸附剂投加量为20 g·L-1,吸附时间为120 min时,刚果红的去除率可达79.1%。改性棉铃壳对刚果红的吸附过程符合Lagergren准二级动力学模型,吸附过程属于化学吸附,吸收速率受表面扩散和颗粒内扩散控制。