Male-produced anti-sex pheromone in a plant bug

In plant bugs (Miridae), females produce sex pheromones in the metathoracic scent gland, which in most other true bugs (Heteroptera) is responsible for chemical defense. The possibility that the metathoracic gland secretion of male plant bugs plays a role other than defense has been largely overlooked. Here we show that in a pine-inhabiting mirid, Phytocoris difficilis Knight, hexyl butyrate and (E)-2-hexenyl butyrate are abundantly produced only in males; we demonstrate that these metathoracic gland compounds elicit strong antennal responses in conspecific males, and that these butyrates totally interrupt attraction of males to the female-produced sex pheromone. Our results suggest that in at least some plant bugs the male metathoracic scent gland esters have a natural communicative function as anti-sex pheromones, probably to interrupt further mating attempts by other males.     

“两控区”内燃煤火电厂烟气脱硫成本的转移

运用环境经济学、环境法学方面的知识研究了如何解决“两控区”内燃煤火电厂的烟气脱硫成本问题．结果表明,只要电能消费者消费了酸雨和SO₂污染控制区内燃煤火电厂的火电,就应最终承担燃煤火电厂的烟气脱硫成本电能消费者的负担标准为火电厂依靠经济上可实现的最佳可得控制技术生产单位电能所耗费的平均脱硫成本费用;烟气脱硫成本转移的最佳时间和方式为电网经营者把平均脱硫成本分摊给电能消费者,收取电费后再补贴给火电厂．     

A new find of a Middle Pleistocene mandible from Bilzingsleben, Germany

 The Middle Pleistocene site at Bilzingsleben is being excavated by the Forschungsstelle Bilzingsleben, FSU Jena. It is a living floor with structures of settlement and a great number of Lower Palaeolithic cultural remains. So far, 28 human skull fragments have been discovered, which can be reconstructed into two individual skulls. Recently, the right mandible has also been discovered (Bilzingsleben E7). Morphological comparisons indicate that there is a great similarity to the mandibles of HI and BI of Sinanthropus. A strong likeness to Arago II and XIII was also discovered. There are various different archaic features which assign the Bilzingsleben mandible and the two skulls to the advanced Homo erectus. Received: 16 March 2000 / Accepted in revised form: 30 March 2000     

污水处理厂中微塑料的去除效能与全流程分析——以北京某下沉式三级污水处理厂为例

污水处理厂排放是微塑料进入自然环境的重要途径之一,本研究对北京某下沉式三级污水处理厂八个工艺单元中微塑料的赋存特征和去除效能进行全流程分析.研究表明该厂赋存微塑料主要形态为纤维,主要成分为聚丙烯、聚酯和聚乙烯,尺寸≤500μm的微塑料影响最为显著.该厂对微塑料的整体去除率为91.7％,主要依靠沉淀和截留过滤去除.双层平...     

Removal of multicomponent VOCs in off-gases from an oil refining wastewater treatment plant by a compost-based biofilter system

Waste gases from oil refining wastewater treatment plants are often characterized by the presence of multicomponent and various concentrations of compounds. An evaluation of the performance and feasibility of removing multicomponent volatile organic compounds (VOCs) in off-gases from oil refining wastewater treatment plants was conducted in a pilot-scale compost-based biofilter system. This system consists of two identical biofilters packed with compost and polyethylene (PE). This paper investigates the effects of various concentrations of nonmethane hydrocarbon (NMHC) and empty bed residence time (EBRT) on the removal efficiency of NMHC. Based on the experimental results and practical applications, an EBRT of 66 s was applied to the biofilter system. The removal efficiencies of NMHC were within the range of 47%–100%. At an EBRT of 66 s, the average removal efficiency of benzene, toluene, and xylene were more than 99%, 99%, and 100%, respectively. The results demonstrated that multicomponent VOCs in off-gases from the oil refining wastewater treatment plant could be successfully removed in the biofilter system, which may provide useful information concerning the design criteria and operation of full-scale biofilters.     

Keratin decomposition by trogid beetles: evidence from a feeding experiment and stable isotope analysis

The decomposition of vertebrate carcasses is an important ecosystem function. Soft tissues of dead vertebrates are rapidly decomposed by diverse animals. However, decomposition of hard tissues such as hairs and feathers is much slower because only a few animals can digest keratin, a protein that is concentrated in hairs and feathers. Although beetles of the family Trogidae are considered keratin feeders, their ecological function has rarely been explored. Here, we investigated the keratin-decomposition function of trogid beetles in heron-breeding colonies where keratin was frequently supplied as feathers. Three trogid species were collected from the colonies and observed feeding on heron feathers under laboratory conditions. We also measured the nitrogen (δ¹⁵N) and carbon (δ¹³C) stable isotope ratios of two trogid species that were maintained on a constant diet (feathers from one heron individual) during 70 days under laboratory conditions. We compared the isotopic signatures of the trogids with the feathers to investigate isotopic shifts from the feathers to the consumers for δ¹⁵N and δ¹³C. We used mixing models (MixSIR and SIAR) to estimate the main diets of individual field-collected trogid beetles. The analysis indicated that heron feathers were more important as food for trogid beetles than were soft tissues under field conditions. Together, the feeding experiment and stable isotope analysis provided strong evidence of keratin decomposition by trogid beetles.     

Kinetics of phenol and m-cresol biodegradation by an indigenous mixed microbial culture isolated from a sewage treatment plant

An acclimatized mixed microbial culture, predominantly Pseudomonas sp., was enriched from a sewage treatment plant, and its potential to simultaneously degrade mixtures of phenol and m-cresol was investigated during its growth in batch shake flasks. A 22 full factorial design with the two substrates at two di erent levels and di erent initial concentration ranges (low and high), was employed to carry out the biodegradation experiments. The substrates phenol and m-cresol were completely utilized within 21 h when present at low concentrations of 100 mg/L for each, and at high concentration of 600 mg/L for each, a maximum time of 187 h was observed for their removal. The biodegradation results also showed that the presence of phenol in low concentration range (100–300 mg/L) did not inhibit m-cresol biodegradation. Whereas the presence of m-cresol inhibited phenol biodegradation by the culture. Moreover, irrespective of the concentrations used, phenol was degraded preferentially and earlier than m-cresol. A sum kinetics model was used to describe the variation in the substrate specific degradation rates, which gave a high coe cient of determination value (R2 > 0.98) at the low concentration range of the substrates. From the estimated interaction parameter values obtained from this model, the inhibitory e ect of phenol on m-cresol degradation by the culture was found to be more pronounced compared to that of m-cresol on phenol. This study showed a good potential of the indigenous mixed culture in degrading mixed substrate of phenolics.     

某电镀厂污泥酸浸除杂提磷试验

探讨了武汉某工业园电镀厂污泥酸浸、除杂提磷的工艺及条件。当H2SO4（浓度为72％）用量为4mL/g污泥,在液固比为5：1,常温搅拌浸出时间为1h,用碱液调节浸出液pH为4后沉淀1h,过滤,磷的浸出率为86％,铁的沉淀率达到94．2％,除铁后的浸出液进一步用NH4HCO3净化,并制取磷铵产品,总养分（N＋P2O5）为52％。产品达到国家合格品的标准。     

生物质气化发电厂洗焦废水生物处理的中试研究

为使生物质气化发电厂的洗涤废水得到有效的循环使用,在以废陶瓷片作为填料的生物膜反应器中,接种优势菌,对经过物化预处理的生物质气化洗涤废水进行处理,着重考察了不同工艺条件下,生物膜反应器对废水的处理效果.采用缺氧20h,好氧10h的处理工艺,可有效降低该废水的COD,当进水COD为584～923mg·L-1时,出水COD达到118 5～230 2mg L-1,COD的平均下降率为78 6%.     

Metal bioaccumulation in plant leaves from an industrious area and the Botanical Garden in Beijing

The concentrations of Fe, Mn, AI, Zn, Pb, Ni, Cr, and As were measured in soils and leaves from 21 plant species growing on hills near the Beijing Steel Factory(BSF) and 17 plant species in the Beijing Botanical Garden(BBG). The results showed that soils from BSF were Zn contaminated according to the threshold of natural background of China. There was a metal contamination of the soils by Ni,and Cr in BSF comparing with those in BBG. The comparison between concentrations of metals in leaves from both sites indicated that, in general, accumulation of metals in the leaves of the same species was significantly different between the two sites. Even within the same locality each species accumulation of metals was significantly variable. The study aimed to screen landscape plants for the capacity to clean-up toxic metals in soils, and developed an overall metal accumulation index(MAI) for leaves and then categorized the MAI that can be applied broadly in the selection of species in polluted areas. To do this, the spectrum of MAI values were divided into four classes: strongly accumulated(SA or grade I), moderately accumulated(MA or grade II), intermediately accumulated( IA or grade III), and weakly accumulated(WA or grade IV). The results showed that elemental association between Fe, AI, Ni, and As was generally highly correlated with each other in the sampling sites. This may suggest their common biochemical characteristics. Generally, those species containing strong and moderate accumulation in both sites are considered including Vitex negundo, Broussonetia papyrifera, Ulmus pumila, and Rubia cordifolia. At BSF and other industrial sites with a similar ecosystem, strong and moderate accumulation species include Sophora japonica, Ampelopsis aconitifolia var. glabra, Platycladus orientalis, Wikstroemia chamaedaphne, Cleistogenes squarrosa, Grewia biloba, and in BBG, in addition Setaria viddis, Cotinus coggygria, Lespedeza flodbunda, Rhamnus parvifolia, Lespedeza tomentosa.     

Predation and aggressiveness in host plant protection: a generalization using ants from the genus Azteca

In studying the ant genus Azteca, a Neotropical group of arboreal species, we aimed to determine the extent to which the ants use predation and/or aggressiveness to protect their host plants from defoliating insects. We compared a territorially dominant, carton-nester, Azteca chartifex, and three plant-ant species. Azteca alfari and Azteca ovaticeps are associated with the myrmecophyte Cecropia (Cecropiaceae) and their colonies shelter in its hollow branches; whereas Azteca bequaerti is associated with Tococa guianensis (Melastomataceae) and its colonies shelter in leaf pouches situated at the base of the laminas. Whereas A. bequaerti workers react to the vibrations transmitted by the lamina when an alien insect lands on a leaf making it unnecessary for them to patrol their plant, the workers of the three other species rather discover prey by contact. The workers of all four species use a predatory behaviour involving spread-eagling alien insects after recruiting nestmates at short range, and, in some cases, at long range. Because A. alfari and A. ovaticeps discard part of the insects they kill, we deduced that the workers' predatory behaviour and territorial aggressiveness combine in the biotic defence of their host tree.     

围填海造地环境成本评估:以胶州湾为例

海岸带环境资源由于其稀缺和有用性,是有价值的.围填海造地,使海岸带环境向经济过程提供某些服务功能减退,表现为价值损失或环境成本.本文以胶州湾海域为例,以意愿调查法评估胶州湾围填海造地的环境成本,运用Tobit模型估算居民对于围填海造地的环境功能退化进行恢复的支付意愿及影响因素,得出胶州湾围填海造地的环境成本为56元/m...     

污染场地土壤重金属的生物可给性及毒性研究

近年来,生物可给性被用于评估场地土壤污染健康风险,然而不同场地类型重金属生物可给性差别巨大,生物可给态重金属的人体健康危害效应仍然鲜见报道.本研究以浙江温岭某电子拆解厂为研究区,分析比较了5个场地土壤（S1-S5）中Zn、Cu、Cd、Pb的生物可给性并探究生物可给态重金属对人小肠上皮细胞的毒性效应机制.结果表明,场地土壤Cd和Cu污染较为严重,含量分别为4.84,438.52mg/kg.4种重金属在胃阶段生物可给性范围分别为2.10%~48.28%、4.84%~33.73%、16.04%~42.81%、1.81%~15.71%,小肠阶段为2.05%~36.91%、13.17%~22.23%、10.19%~23.10%、0.60%~2.69%,可见胃阶段的生物可给性低于小肠阶段.对于肠相生物可给态重金属暴露人体肠道上皮细胞后,除样点S4外,细胞活力均显著性下降.此外,样点S3和S5土壤提取液对超氧化物歧化酶活力影响较小,但显著抑制过氧化氢酶活力,并且该样点对DNA产生损伤.通过研究电子拆解厂土壤生物可给性以及其毒性效应,以为我国场地土壤重金属健康风险评估提供科学依据.     

城市污水处理厂的挥发性恶臭有机物组成及来源

采用GDX-502采样管和二次热解吸与GC-MSD联用仪研究广州一个典型城市污水处理厂不同污水处理单元和周边环境空气中挥发性恶臭有机物(MVOC)的组成和含量,通过对源排放特征、分子标志物和大气化学活性分析,建立该污水处理厂的MVOC源成分谱.结果表明,该污水处理厂检出烷烃、卤代烃、烯烃、芳香烃、含氧有机物和硫醚等6类40种挥发性有机物(VOC),其中34种为MVOC成分,各处理单元排放的MVOC含量占其VOC总量的95%以上;苯系物、2-丁酮、乙酸乙酯、乙酸丁酯和甲硫醚等为该污水处理厂重要的MVOC分子标志物,其中苯系物的含量最高,占源排放MVOC总量的75.89%;经归一化和重整的MVOC源成分谱与环境受体点的MVOC组成之间具有显著相关性.     

Physico-chemical study by two aircraft of a plume from a coal-fired power plant

During the experimental field program that was conducted in October 1985 ton study the physics and chemistry of the Le Havre power plant plume, joints flights were performed with two aircraft from EDF and KEMA. The two episodes with very different meteorological conditions were investigated. The first episode was characterized by fairly constant wind speed and direction with altitude, low solar irradiation and neutral vertical dispersion conditions. The second episode was characterized by low wind speed and changing wind direction, high solar irradiation and stable vertical dispersion conditions. During the latter episode, the concentrations of emitted gases, SO₂ and NO_x remained high, even at several tens of km downwind of the stock. Increased SO₄^2- and NO₃^- concentrations were detected in the power plant plume. In addition, important photochemical activity took p-lace in the plume of a nearby industrial area. The former episode showed more significantly vertical dilution and oxidation of NO but did not reveal any contribution of the power plant plume to aerosol formation.     

Kinetics of phenol and m-cresol biodegradation by an indigenous mixed microbial culture isolated from a sewage treatment plant

An acclimatized mixed microbial culture, predominantly Pseudomonas sp., was enriched from a sewage treatment plant, and its potential to simultaneously degrade mixtures of phenol and m-cresol was investigated during its growth in batch shake flasks. A 2² full factorial design with the two substrates at two different levels and different initial concentration ranges (low and high), was employed to carry out the biodegradation experiments. The substrates phenol and m-cresol were completely utilized within 21 h when present at low concentrations of 100 mg/L for each, and at high concentration of 600 mg/L for each, a maximum time of 187 h was observed for their removal. The biodegradation results also showed that the presence of phenol in low concentration range (100–300 mg/L) did not inhibit m-cresol biodegradation. Whereas the presence of m-cresol inhibited phenol biodegradation by the culture. Moreover, irrespective of the concentrations used, phenol was degraded preferentially and earlier than m-cresol. A sum kinetics model was used to describe the variation in the substrate specific degradation rates, which gave a high coefficient of determination value (R² > 0.98) at the low concentration range of the substrates. From the estimated interaction parameter values obtained from this model, the inhibitory effect of phenol on m-cresol degradation by the culture was found to be more pronounced compared to that of m-cresol on phenol. This study showed a good potential of the indigenous mixed culture in degrading mixed substrate of phenolics.