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91.
柯起龙 《环境与可持续发展》2015,(4)
为了研究电吸附水处理技术(EST)对污水悬浮物的去除效果,本文采用电吸附水处理技术对生活污水中悬浮物进行处理分析,结果表明电吸附水处理系统对悬浮物的去除效果较好,去除率达到74.07%,而电吸附模块本身对悬浮物去除率仅为14.29%,氯离子、进水中悬浮物的浓度及进水中的硬度值均对悬浮物去除效率没有影响。因此,电吸附水处理技术可作为污水处理的一种新型有效方法。 相似文献
92.
Edouard Lavergne Isabelle Calvès Anne Leila Meistertzheim Grégory Charrier Uwe Zajonz Jean Laroche 《Marine Biology》2014,161(5):1113-1126
Temporarily open/closed estuaries (TOCEs) are major ecosystems of the Indian Ocean coastal zones. Their functioning is tightly linked to climatic events such as monsoons and storms, and their mouth can close up for prolonged and variable periods of time, thus limiting their connectivity with the marine environment. Two types of genetic markers (i.e., mitochondrial cytochrome c oxidase I (COI) gene and microsatellites) were used to assess the genetic structure of 288 individuals of Terapon jarbua, a widely distributed fish species in the wider Gulf of Aden. Firstly, the hypothesis of panmixia was tested. Then, alternative hypotheses were investigated to explain the population genetic structure of T. jarbua: could it be shaped by (1) regional biogeographic barriers (i.e., Socotra Island vs. mainland Yemen) and/or (2) the particular functioning of TOCEs in relation to the species life cycle and particular physical ocean parameters? On one hand, the polymorphism of the COI inferred (1) a high haplotype diversity and a reduced nucleotide diversity over the whole data set and (2) a “star-like” shape of the haplotype network, thus suggesting a population expansion after local extinctions during the Pleistocene glaciations. On a second hand, the genotyping of eight microsatellites showed a significant genetic differentiation between T. jarbua populations in the wider Gulf of Aden (F ST = 0.035, p < 0.01), and thus, the panmixia hypothesis was rejected. Analyses of molecular variance results did not show any significant structure between Socotra Island and mainland Yemen and thus did not support the role of biogeographic barriers in structuring T. jarbua populations. Significant multi-locus deficits in heterozygotes at particular locations displaying high levels of F IS were recorded. It was suggested that a possible Wahlund effect took place in those TOCEs which could gather several cohorts of larvae stemming from different marine subpopulations over the sampled area. The present study emphasized the uniqueness of each TOCE as a potential reservoir of biodiversity and the urgent need for a better conservation program of those estuaries in the region, in order to avoid habitat fragmentation and permanent closure of those nursery areas by human activities. 相似文献
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94.
Kirsten Halsnæs Amit Garg John Christensen Helene Ystanes Føyn Maryna Karavai Emilio La Rovere Matthew Bramley Xianli Zhu Catherine Mitchell Joyashree Roy Kanako Tanaka Hidefumi Katayama Carlos Mena Imoh Obioh Igor Bashmakov Stanford Mwakasonda Myong-Kyoon Lee Marlene Vinluan Yu Joe Huang Laura Segafredo 《Mitigation and Adaptation Strategies for Global Change》2014,19(1):45-71
The aim of this paper is to assess how policy goals in relation to the promotion of green growth, energy security, pollution control and greenhouse gas (GHG) emissions reductions have been aligned in policies that have been implemented in selected countries during the last decades as a basis for discussing how a multi objective policy paradigm can contribute to future climate change mitigation. The paper includes country case studies from Brazil, Canada, China, the European Union (EU), India, Japan, Mexico, Nigeria, South Africa, South Korea and the United States covering renewable energy options, industry, transportation, the residential sector and cross-sectoral policies. These countries and regions together contribute more than two thirds of global GHG emissions. The paper finds that policies that are nationally driven and that have multiple objectives, including climate-change mitigation, have been widely applied for decades in both developing countries and industrialised countries. Many of these policies have a long history, and adjustments have taken place based on experience and cost effectiveness concerns. Various energy and climate-change policy goals have worked together in these countries, and in practice a mix of policies reflecting specific priorities and contexts have been pursued. In this way, climate-change mitigation has been aligned with other policy objectives and integrated into broader policy packages, though in many cases specific attention has not been given to the achievement of large GHG emission reductions. Based on these experiences with policy implementation, the paper highlights a number of key coordination and design issues that are pertinent to the successful joint implementation of several energy and climate-change policy goals. 相似文献
95.
Sam M. Jones Jelle S. van Zweden Christoph Grüter Cristiano Menezes Denise A. Alves Patrícia Nunes-Silva Tomer Czaczkes Vera L. Imperatriz-Fonseca Francis L. W. Ratnieks 《Behavioral ecology and sociobiology》2012,66(1):1-12
Recent research has shown that entrance guards of the stingless bee Tetragonisca angustula make less errors in distinguishing nestmates from non-nestmates than all other bee species studied to date, but how they
achieve this is unknown. We performed four experiments to investigate nestmate recognition by entrance guards in T. angustula. We first investigated the effect of colony odours on acceptance. Nestmates that acquired odour from non-nestmate workers
were 63% more likely to be rejected while the acceptance rate of non-nestmates treated with nestmate odour increased by only
7%. We further hypothesised that guards standing on the wax entrance tube might use the tube as an odour referent. However,
our findings showed that there was no difference in the acceptance of non-nestmates by guards standing on their own colony’s
entrance tube versus the non-nestmate’s entrance tube. Moreover, treatment of bees with nestmate and non-nestmate resin or
wax had a negative effect on acceptance rates of up to 65%, regardless of the origin of the wax or resin. The role of resin
as a source of recognition cues was further investigated by unidirectionally transferring resin stores between colonies. Acceptance
rates of nestmates declined by 37% for hives that donated resin, contrasting with resin donor hives where acceptance of non-nestmates
increased by 21%. Overall, our results confirm the accuracy of nestmate recognition in T. angustula and reject the hypothesis that this high level of accuracy is due to the use of the wax entrance tubes as a referent for
colony odour. Our findings also suggest that odours directly acquired from resin serve no primary function as nestmate recognition
cues. The lack of consistency among colonies plus the complex results of the third and fourth experiments highlight the need
for further research on the role of nest materials and cuticular profiles in understanding nestmate recognition in T. angustula. 相似文献
96.
Cannibalistic tendencies are well known in spiders and may be a significant factor influencing population size. The wolf
spider, Pardosa agrestis, is the dominant non-web-building spider in a wide range of central European agricultural habitats. Preliminary field observations
indicated an extended reproductive period, which results in a very wide size distribution of juvenile instars. We hypothesised
that if cannibalism is enhanced by differences in size, especially during periods when prey is scarce, these populations might
be susceptible to cannibalism in an ecologically significant way. Laboratory studies were conducted on juvenile P. agrestis in arenas. We analysed the following specific aspects of cannibalism: (1) the effect of the weight ratio between the opponents;
(2) the effect of weight per se, and (3) the role of hunger level in determining cannibalistic tendencies of spiders. The
role of weight and hunger were analysed in separate experiments, in both cases by controlling for the other variable. The
results showed that cannibalism was strongly positively correlated with both weight ratio and hunger, but absolute size/age
of an individual could not predict the occurrence of a cannibalistic event. These experiments generated the plausible hypothesis
that cannibalism might be an important phenomenon in the regulation of real populations, which should be tested specifically
in future field experiments.
Received: 15 December 1997 / Accepted after revision: 10 October 1998 相似文献
97.
As the use of ultrasonography has become a routine procedure in the care of pregnant women, fetal congenital malformations have been frequently diagnosed prenatally. During a 4-year period abdominal wall defects (AWD) were diagnosed in 14 cases, five were gastroschises and nine were omphaloceles, seven females and seven males. Concomitant malformations were present in one case of gastroschisis and in five cases of omphalocele. Eleven AWD's were diagnosed in the second trimester and six pregnancies were interrupted. Eight children with AWD were born; two boys with omphalocele and one girl and one boy with gastroschisis are still alive. Alpha-fetoprotein was determined in amniotic fluid in 11 cases and also in maternal serum prior to the amniocentesis in eight cases. Chromosomal investigations were performed in 13 cases, 11 on amniotic fluid cells and two on lymphocytes from a blood sample made postnatally. Two abnormal karyotypes, 47,XX + 18 were found. 相似文献
98.
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100.
于2012年4月沿大九湖湿地平均分布10个采样点,各采集0~10、10~20以及20~30 cm浅层土壤,采用GC-MS对大九湖湿地浅层土壤中USEPA 16种优控多环芳烃(PAHs)进行分析,对其分布、组成、来源进行了详细的讨论,并对高山湿地PAHs污染标志物进行了浅析.结果表明,研究区0~10、10~20、20~30cm浅层土壤中∑16PAHs含量分别为48.55~984.73、14.36~806.47、12.84~1191.53 ng·g-1,均值分别为302.94、142.98、208.68 ng·g-1;7种致癌单体多环芳烃含量范围分别为21.20~844.29、2.96~592.06、0.66~964.70 ng·g-1,均值分别为197.25、93.16、147.16 ng·g-1,分别占总PAHs的65.12%、65.13%、69.08%;泥炭区PAHs含量明显高于非泥炭区,且已达到重度污染程度;PAHs组成以4、5、6环为主;结合IcdP/(IcdP+BghiP)及Pyr/BaP比值分析,推测大九湖湿地浅层土壤中PAHs主要来源于化石燃料及木材的燃烧,近年来旅游车辆的进入对PAHs的贡献较大;对浅层土壤中各单体PAH与PAHs总含量进行回归分析表明、苯并(b)荧蒽、茚(1,2,3cd)并芘、苯并(a)蒽作为泥炭地PAHs标志性化合物,用来评价PAHs的污染程度. 相似文献