排序方式: 共有21条查询结果,搜索用时 15 毫秒
11.
Summary
Parastizopus armaticeps andEremostibes opacus are two closely related desert tenebrionids which also live in close association, the former having biparental brood care and the latter cleptoparasitising the brood.E. opacus is unable to discriminate between the conspecific and host odour even in the absence of physical contact. Gas chromatographic analysis of headspace volatiles of resting animals showed almost complete qualitative and quantitative odour congruity between them. Comparison of these odour profiles with those of two other tenebrionids sharing the same ecological niche,Gonopus agrestis andHerpiscius sp. (damaralis?) showed that congruity was independent of common foodplant utilisation. It is also independent of common defensive gland secretions. Parallels between resting odour spectra, defensive secretion spectra and systematic status suggest that the origins of congruity lie in odour homology, by means of which the cleptoparasite was able to exploit its host. 相似文献
12.
Summary The production of volatile secondary plant substances during the evolution of terrestrial plants is reviewed in regard to the defensive systems of plants to microorganisms and herbivores. Plant volatiles can be produced by both anabolic and catabolic processes. Although attraction of pollinators is a well-studied phenomenon, functions of volatiles range from excretion of waste products to the production of compounds attracting natural enemies of herbivores. During the evolution of the angiosperms a diversity of volatiles were selected to defend generative parts against microorganisms. Many of these allomones were related to or even identical with sex pheromones of insects. As a result flowers of angiosperms became utilized as a mating site. Consequently insects visiting flowers became involved in pollination, facilitating the steps from anemophily to entomophily. The efficiency of entomophily was increased because of nutritional rewards.An evolutionary scenario for the impact of plant volatiles on insects is presented and the role of volatile allomones in the establishment of plant-insect relationships is emphasized by (1) their strong antimicrobial properties, (2) strategies to protect symbiotic microorganisms, (3) their function as repellents and deterrents, (4) the use of volatile allomones as kairomones. These facts speak for an adaptation of insects to plant physiology and a limited importance of phytophagous insects in selection pressure upon plants. Herbivorous insects have realized specific adaptations to be able to discriminate between complex odour blends, but the utilization of chemical groups among insect taxa is different.The main theories on plant chemical defence do not discuss the impact of volatiles on host plant selection and may be apt to revision when pheromones, allomones, kairomones and synomones are not taken into account. 相似文献
13.
14.
Floral scents are known as an olfactory signal for attracting pollinators, but why the flowers pollinated by highly specialised pollinators emit scents consisting of mixtures of many compounds and dominated by one or a few compounds is still poorly understood. We supposed that each (especially characteristic) chemical in floral scents may play a specific role in mediating pollinator behaviours and tested this supposition in a fig-fig wasp mutualism. Ficus curtipes is obligately pollinated by an undescribed Eupristina species. In the scent of F. curtipes receptive figs, over 50 compounds have been identified, and the scent is dominated by two compounds, 6-methyl-5-hepten-2-ol (OL) and 6-methyl-5-hepten-2-one (NE). We therefore tested the roles of the two major chemicals in mediating the pollinator behaviours. Our results show that OL and NE, respectively, act as a long-distance attractant and a fig-entry behaviour stimulant to the obligate pollinator wasp. Namely, OL attracts the wasps to the figs and NE guides the wasps into the figs. This finding on the work division of floral scent compounds partially explains the maintenance mechanism of the fig-fig wasp mutualism and the significance of the chemical diversity of floral scent in plant–pollinator interactions, especially in specialised pollination systems. 相似文献
15.
生物滤池净化城市生活垃圾BMT发酵恶臭气体的研究 总被引:5,自引:1,他引:4
针对城市生活垃圾BMT过程中的恶臭气体,以堆肥为填料,在现场进行了生物滤池处理研究,分别测定了臭气的成分、臭气中TVOC浓度变化的规律、滤池的净化效率、填料中有机质、全氮、全碳、全磷和pH等特征,以及填料菌落数的变化. SPME-CC-MS的分析结果表明,恶臭气体中的主要有机污染物包括苯系物、萜烯和烷烃;臭气中TVOC浓度在发酵初期较大,而后逐渐减少,变化范围为68.3×10-6~3.3×10-6(体积分数),滤池净化效率范围为31,5%~84,8%;在4个月的运行过程中,填料中有机质、总氮、总碳、总磷的含量基本上保持在比较稳定的数值,而水溶性总氮增加了53.7%.水溶性总磷减少了19.6%,填料的pH值在初始经历了一个升高阶段后稳定在7.8左右;填料中细菌和霉菌的数量呈上升趋势,而酵母菌和放线菌的数量呈下降趋势,分别为初始填料的3.1、3.4、0.04、0.07倍. 相似文献
16.
荆勇 《辽宁城乡环境科技》2013,(6):45-47
结合多年的研究成果和实践经验,针对城市垃圾填埋场目前运营方式及存在的恶臭污染问题进行了分析,重点对恶臭的发生与环境影响、恶臭污染水平的测试、相关规定与科学运用以及治理技术与对策方面的技术要点进行了总结,概述了点源、面源和渗滤液恶臭控制的合理途径和控制准则。 相似文献
17.
Marlon Brancher Martin Piringer Davide Franco Paulo Belli Filho Henrique De Melo Lisbo Günther Schauberger 《环境科学学报(英文版)》2019,31(5):11-24
In recent years, there has been a growing concern about potential impacts on public health and wellbeing due to exposure to environmental odour. Separation distances between odour-emitting sources and residential areas can be calculated using dispersion models, as a means of protecting the neighbourhood from odour annoyance. This study investigates the suitability of using one single year of meteorological input data to calculate reliable direction-dependent separation distances. Accordingly, we assessed and quantified the inter-annual variability of separation distances at two sites with different meteorological conditions, one in Brazil and the other in Austria. A 5-year dataset of hourly meteorological observations was used for each site. Two odour impact criteria set in current regulations were selected to explore their effect on the separation distances. The coefficient of variation was used as a statistical measure to characterise the amount of annual variation. Overall,for all scenarios, the separation distances had a low degree of inter-annual variability(mean coefficient of variation values from 8% to 21%). Reasonable agreements from year to year were therefore observed at the two sites under investigation, showing that one year of meteorological data is a good compromise to achieve reliable accuracy. This finding can provide a more cost-effective solution to calculate separation distances in the vicinity of odour sources. 相似文献
18.
Klaschka Ursula Kolossa-Gehring Marike 《Environmental science and pollution research international》2007,14(1):44-52
Goal, Scope and Background Fragrance preparations or perfumes are used in an increasing variety of applications, as for example washing, cleansing, personal
care products, consumer goods or in applications to modify indoor air. However, up to now, little is known to the general
or scientific public about their chemical identity and the use pattern of single substances, not even for high production
volume chemicals. Some toxicological data are published for a comparatively small number of substances with a focus on sensitisation
and dermal effects, while other effects are neglected. Information on ecotoxicity and environmental fate are rare, especially
for long-term exposure. Data for a detailed hazard and risk analysis are available in exceptional cases only. According to
the current legal situation, fragrance industry is self-regulated, which means that pre-market risk evaluation is not required
for most fragrances.
Odour and the ability to smell play a major role for wildlife for all taxonomic groups. Reproductive and social behaviour,
defence, communication and orientation depend on volatile compounds which can be identical to those used in fragrance preparations.
Our interdisciplinary approach leads to the question of whether and, if so, to what extent anthropogenic fragrances may influence
life and reproduction of organisms in the environment.
Main Features Information from literature on use, exposure and biological effects was combined to analyse the state of knowledge. Following
an overview of the amounts of fragrances used in different consumer products and their release into the environment, the roles
of odours in nature are shown for a selection of compounds. Existing regulation was analysed to describe the data basis for
environmental risk evaluation. Finally, recommendations for further action are derived from these findings.
Results Three main results were elaborated: First, fragrance substances are continuously discharged in large amounts into the environment,
especially via the waste water. Second, there are some indications of negative effects on human health or the environment,
although the data basis is very thin due to the self regulation of the fragrance industry and the regulatory situation of
fragrance substances. Third, many odoriferous substances used by man are identical to those which are signal substances of
environmental organisms at very low concentrations, thus giving rise to specific mode of actions in the ecosystem.
Recommendations For the adequate risk assessments of fragrances, test results on their unspecific as well as their specific effects as signal
substances are needed. This would imply prioritisation methods and development of useful test methods for specific endpoints
for appropriate risk assessments. Before a comprehensive testing and evaluation of results has been finished, a minimization
of exposure should be envisaged. Eco-labelling of products containing acceptable fragrance ingredients could be a first step
and provide consumers with the respective information. Transparency concerning the fragrance ingredients used and their biological
potency will help to build up confidence between producers and consumers.
Conclusions and Perspectives The interdisciplinary approach, bringing together chemical, biological, toxicological and ecotoxicological data with information
provided by manufacturers and with legal and consumer aspects, offers new insights into the field of fragrance substances
used in consumer products. The amounts and application fields of fragrance substances increases while fate and effects in
the environment are hardly known. The current legal situation is not suited to elucidate the effects of fragrances on human
health and the environment sufficiently, especially as it was shown that fragrances may play a considerable role in the ecosystem
on the behaviour of organisms. According to the precautionary principle, the lack of knowledge should best be tackled by reducing
exposure, especially for compounds such as fragrance substances where no ethical reasons object a substitution by less hazardous
chemicals.
ESS-Submission Editor: Dr. Thomas Knacker (th-knacker@ect.de) 相似文献
19.
广东金雁电工有限公司是我国生产铜漆包线电缆的十大企业之一,该厂对漆包线生产过程中所产生的以苯、甲苯、二甲苯等苯系物为主的有机废气采用"低温催化燃烧+植物提取液高能雾化吸收"的处理工艺,在常规低温催化燃烧有机废气的基础上,运用植物提取液超微气态分散的原理,强化吸收净化废气并消除燃烧臭味。经过治理,苯、甲苯、二甲苯排放浓度均低于DB 44/27—2001《广东省地方标准大气污染排放限值》污染源二级排放标准限值,并消除了臭味的影响。该工艺具有运行可靠、去除效率高、成本低廉、管理方便等优点,值得在国内同类废气治理中推广应用。 相似文献
20.