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981.
Ken Tan Zhenwei Wang Weiweng Chen Zongwen Hu Benjamin P. Oldroyd 《Die Naturwissenschaften》2013,100(3):245-248
An ‘I see you’ (ISY) prey–predator signal can co-evolve when such a signal benefits both prey and predator. The prey benefits if, by producing the signal, the predator is likely to break off an attack. The predator benefits if it is informed by the signal that the prey is aware of its presence and can break off what is likely to be an unsuccessful and potentially costly hunt. Because the signal and response co-evolve in two species, the behaviour underlying an ISY signal is expected to have a strong genetic component and cannot be entirely learned. An example of an ISY signal is the ‘shimmering’ behaviour performed by Asian hive bee workers in the presence of their predator Vespa velutina. To test the prediction that bee–hornet signalling is heritable, we let honey bee workers of two species emerge in an incubator so that they had never been exposed to V. velutina. In Apis cerana, the shimmering response developed 48 h post-emergence, was strong after 72 h and increased further over 2 weeks. In contrast, A. mellifera, which has evolved in the absence of Asian hornets, did not produce the shimmering signal. In control tests, A. cerana workers exposed to a non-threatening butterfly did not respond with the shimmering signal. 相似文献
982.
预氧化技术是随着油田污水处理的需要发展起来的一种新技术。预氧化的目的就是把二价铁离子转化为三价铁,并在后期通过添加化学药剂沉淀出来,从而提高水质稳定性,降低后续处理过程的结垢现象。目前采用的预氧化技术主要有两种:化学预氧化和电化学预氧化。详细介绍预氧化技术,并通过与传统工艺技术的对比总结了预氧化技术的特点;分析了两种预氧化技术的异同;并通过这两种技术在油田的实际应用情况对它们的应用水质、运行管理、加药情况等方面进行了对比研究,总结了两种技术的优缺点及适用水质,并对该技术以后的推广应用提出相应建议。 相似文献
983.
环境监管能力是环境保护工作开展的重要支撑和保障,"十一五"以来环境监管能力建设取得显著成效。面对未来日趋严峻的环保形势,"十二五"期间国家环境监管能力建设需求尤为突出。本文从"十二五"环境监管能力建设的阶段特点和需求出发,明确以加强顶层设计、强化协调推进、强调集成效应原则的基本思路,研究提出环境监管各领域建设的重点。 相似文献
984.
Biochar is extensively used as an effective soil amendment for environmental remediation.In addition to its strong contaminant sorption capability, biochar also plays an important role in chemical transformation of contaminant due to its inherent redox-active moieties.However, the transformation efficiency of inorganic contaminants is generally very limited when the direct adsorption of contaminants on biochar is inefficient. The present study demonstrates the role of Fe ion as an electron shuttle to enhance Cr(Ⅵ) reduction by biochars. Batch experiments were conducted to examine the effects of Fe(Ⅲ) levels,pyrolysis temperature of biochar, initial solution pH, and biochar dosage on the efficiency of Cr(Ⅵ) removal. Results showed a significant enhancement in Cr(Ⅵ) reduction with an increase in Fe(Ⅲ) concentration and a decrease of initial pH. Biochar produced at higher pyrolysis temperatures(e.g., 700°C) favored Cr(Ⅵ) removal, especially in the presence of Fe(Ⅲ), while a higher biochar dosage proved unfavorable likely due to the agglomeration or precipitation of biochar. Speciation analysis of Fe and Cr elements on the surface of biochar and in the solution further confirmed the role of Fe ion as an electron shuttle between biochar and Cr(Ⅵ). The present findings provide a potential strategy for the advanced treatment of Cr(Ⅵ) at low concentrations as well as an insight into the environmental fate of Cr(Ⅵ) and other micro-pollutants in soil or aqueous compartments containing Fe and natural or engineered carbonaceous materials. 相似文献
985.
Lijun Hao Wei Chen Lei Li Jianwei Tan Xin Wang Hang Yin Yan Ding Yunshan Ge 《环境科学学报(英文版)》2017,29(5):109-117
An instantaneous emission model was developed to model and predict the real driving emissions of the low-speed vehicles. The emission database used in the model was measured by using portable emission measurement system (PEMS) under actual traffic conditions in the rural area, and the characteristics of the emission data were determined in relation to the driving kinematics (speed and acceleration) of the low-speed vehicle. The input of the emission model is driving cycle, and the model requires instantaneous vehicle speed and acceleration levels as input variables and uses them to interpolate the pollutant emission rate maps to calculate the transient pollutant emission rates, which will be accumulated to calculate the total emissions released during the whole driving cycle. And the vehicle fuel consumption was determined through the carbon balance method. The model predicted the emissions and fuel consumption of an in-use low-speed vehicle type model, which agreed well with the measured data. 相似文献
986.
987.
在气升式循环反应器处理污水中,对炉渣、焦炭和塑料颗粒进行载体试验比较,认为炉渣和焦炭可作为所选择的生物膜载体。 相似文献
988.
Ken T Hepburn HR Radloff SE Yusheng Y Yiqiu L Danyin Z Neumann P 《Die Naturwissenschaften》2005,92(10):492-495
Defensiveness of honeybee colonies of Apis cerana and Apis mellifera (actively balling the wasps but reduction of foraging) against predatory wasps, Vespa velutina, and false wasps was assessed. There were significantly more worker bees in balls of the former than latter. Core temperatures
in a ball around a live wasp of A. cerana were significantly higher than those of A. mellifera, and also significantly more when exposed to false wasps. Core temperatures of bee balls exposed to false wasps were significantly
lower than those exposed to V. velutina for both A. cerana and for A. mellifera. The lethal thermal limits for V. velutina, A. cerana and A. mellifera were significantly different, so that both species of honeybees have a thermal safety factor in heat-killing such wasp predators.
During wasps attacks at the hives measured at 3, 6 and 12 min, the numbers of Apis cerana cerana and Apis cerana indica bees continuing to forage were significantly reduced with increased wasp attack time. Tropical lowland A. c. indica reduced foraging rates significantly more than the highland A. c. cerana bees; but, there was no significant effect on foraging by A. mellifera. The latency to recovery of honeybee foraging was significantly greater the longer the duration of wasp attacks. The results
show remarkable thermal fine-tuning in a co-evolving predator–prey relationship. 相似文献
989.
Dr. J. A. M. A. Tan J. S. H. Tay L. I. Lin S. K. Y. Kham J. N. Chia T. M. Chin Norkamar Bt. Adb. Aziz H. B. Wong 《黑龙江环境通报》1994,14(11):1077-1082
β-Thalassaemia major patients have chronic anaemia and since 3–4 per cent of Singaporeans carry the β-gene, prenatal diagnosis is essential. We evaluated the amplification refractory mutation system (ARMS) technique as a routine test for prenatal diagnosis of β-major. Six mutations along the β-gene were studied—41–42 (-TCTT), IVSII #654 (C-T), 17β (A-T), – 28 TATA (A-G), IVSI #5 (G-C), and IVSI #1 (G-T). Our results indicate that prenatal diagnosis using these mutations can be offered to 90 per cent (35/39) of our Chinese couples and 54·6 per cent (12/22) of our Malay couples at risk. Confirmation of ARMS results was carried out using allele-specific oligonucleotide hybridization. Prenatal diagnosis using ARMS was successfully carried out in nine cases which included a set of triplets and twins. The triplets were diagnosed with the β-trait carrying the 41–42 mutation. The couple with twins possessed the #654 mutation and one twin was diagnosed with the β-trait and the other with #654 homozygosity. Genomic sequencing of the undefined mutations in the Chinese couples revealed rarer mutations at − 29 and an ATG-AGG base substitution at the initiation codon for translation. In the Malay couples, genomic sequencing detected mutations at codon 15 (TGG-TAG) and codon 26 (GAG-AAG). We conclude that ARMS with its direct detection of amplified products by gel electrophoresis provides an accurate, rapid, and simpler method for our β-thalassaemia prenatal diagnosis programme in Singapore. 相似文献
990.
稳定同位素在污染物溯源与示踪中的应用 总被引:5,自引:0,他引:5
由于稳定同位素在特定污染源中组成确定,且具有分析结果精确可靠、在污染物迁移与转化过程中不发生显著变化的特点,故已被广泛应用于环境污染事件的仲裁、环境污染物的来源分析与示踪研究中。介绍了稳定同位素分馏对于来源分析的影响以及稳定同位素技术在污染物溯源与示踪中识别大气多环芳烃来源、推测环境中硫和铅的来源、考察甲基叔丁基醚来源与降解过程等方面的应用进展。 相似文献