英语词汇多义关系的衍生机制

<正>英语词汇中存在很多多义词,即一个词具有两个或两个以上的义项,而且各个义项之间存在着意义的关联。多义词同形不同义,其不同的意义容易被学习者混淆,因此,多义词教学是英语教学研究的一个重要话题。本文将探讨一词多义的形成过程。一、概念化概念化是人类对纷繁复杂的客观世界进行分类的一种高级认知活动,以理解周身生     

维护环境权与落实科学发展观

环境权益由“环境”和“权益”两个词构成,其中环境是一个多义的概念,一般意义上的环境是指围绕着中心存在物的存在的总和,即围绕某个中心事物的外部空间、条件和状况。我国环境保护法关于环境的定义,是指影响人类生存和发展的各种天然的和经过人工改造的自然因素的总体,     

英语同义表达法与英语学习

本文通过对英语同义表达法(Engligh Paraphurasing)的介绍,阐明了英语同义表达法在英语学习中的重要作用。借助词、词组和句法的变化来实现英语的同义表达,对于使学生准确掌握所学英语词、词组的意义,养成用英语思维和交流的习惯有着重要的意义。     

英语同义表达法与英语学习

本通过对英语同义表达法(English Paraphrasing)的介绍，阐明了英语同义表达法在英语学习中的重要作用。借助词、词组和句法的变化来实现英语的同义表达，对于使学生准确掌握所学英语词、词组的意义，养成用英语思维和交流的习惯有着重要的意义。     

基于隐喻机制形成的网络新词的意义建构

文章运用认知语言学的概念整合理论,对基于隐喻机制形成的网络新词进行穷尽性考察。基于封闭语料分析发现,通过隐喻机制形成的网络新词主要借助语音隐喻、非拟人隐喻和拟人隐喻等方式串联概念整合网络的多个空间,并最终完成新的意义建构。     

对初中英语阅读教学的思考

英语可以说是人类共同的语言,是全世界的普通话。随着国际间交流的日渐频繁,英语的运用也凸显其重要性和普遍性。新课程理念下的初中英语教学,倡导大阅读理念,让学生在阅读中体验成长。英语作为一门语言学科,理应遵循这一教学理念。因此,在初中英语教学改革中,应通过大量的英语阅读训练,培养学生对英语知识的理解和运用能力,培养学生的语感,提高学生的猜词等能力,尤其是与生活紧密相关的信息,更是教学的重点,可以综合提高学生的英语素养。     

英语认知称谓名词特点及其社会成因初探

虽然认知称谓名词跨语种的研究具有极高的学术价值,但是社会语言学历史上对它们的研究实属凤毛麟角。本文试图通过定量分析的研究方法对英语中的认知称谓名词的特点做出详细分析,并尝试性探讨英语认知称谓名词的社会成因。     

历史的转折点——纪念斯德哥尔摩人类环境会议十周年

(一) 一九七二年六月在斯德哥尔摩召开的“人类环境会议”十周年了。联合国环境理事会通过决议隆重纪念这一会议,并号召世界各国开展纪念活动。十年,在人类历史上是短暂一瞬,但是就人类对环境的认识和态度而言,这十年却是一个新的里程碑。 (二) 十年来,在维护和改善人类环境方面,做了大量工作,取得了多方面的成就。从认识和管理的角度看,我以为下述三点是重要的。第一,对环境整体性的认识。“环境”一词,对多数人来说本是陌生的,现在竟成了一个常用语,但这个词的含义却是在不断充实和变化的。在一个很长时间里,环境问题主要是指工     

如何激发中学生学习英语的兴趣

<正>作为一名有十多年教学经验的教师,笔者经常很无奈地看到这些现象:某学生数学成绩非常好,英语成绩却是一般,甚至很糟糕;某学生面对几十分甚至十几分的英语成绩自我解嘲地说:我是中国人,何必学外文;某学生很苦恼地对教师说,自己知道学习英语是多么的重要,可不知怎么的就是提不起兴趣……这些现象只说明一个问题,学生经过了几年的英语学习已经没有了学习英语的热情和兴趣。我觉得,初中阶段的英语教学有一个最重要的任务     

运用隐喻故事帮助幼儿改正不合理行为的研究

能帮助幼儿改正不合理行为的隐喻故事需要具备两个条件:一是隐喻故事与幼儿的生活世界之间要形成一种对称关系,二是隐喻故事中要蕴藏着帮助幼儿解决问题的方案。在听隐喻故事时,幼儿会借助于自己的想象力,反复思考、重新组织故事,并借用故事中的情节和隐喻来理解自己的生活,故事中蕴藏的道理和解决方案也就成为幼儿摆脱生活困境的方案,幼儿在听故事的过程中不知不觉地改正了不合理行为。     

Toxic effects of acetochlor, methamidophos and their combination on nifH gene in soil

Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis （DGGE） and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity （both in gene richness and diversity index values） and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor （50 mg/kg） recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos （150 mg/kg） caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos （250 mg/kg） produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes （bands） responded differently to the impact of agrochemicals： four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.     

Arsenic uptake by arbuscular mycorrhizal maize （Zea mays L.） grown in an arsenic-contaminated soil with added phosphorus

The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.     

Degradation of metabolites accumulated of benzo[a]pyrene by coupling Penicillium Chrysogenum with KMnO4

Several main metabolites of benzo[a]pyrene （BaP） formed by Penicillium chrysogenum, Benzo[a]pyrene-1,6-quinone （BP 1,6- quinone）, trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene （BP 7,8-diol）, 3-hydroxybenzo[a]pyrene （3-OHBP）, were identified by high-performance liquid chromatography （HPLC）. The three metabolites were liable to be accumulated and were hardly further metabolized because of their toxicity to microorganisms. However, their further degradation was essential for the complete degradation of BaP. To enhance their degradation, two methods, degradation by coupling Penicillium chrysogenum with KMnO4 and degradation only by Penicillium chrysogenum, were compared; Meanwhile, the parameters of degradation in the superior method were optimized. The results showed that （1） the method of coupling Penicillium chrysogenum with KMnO4 was better and was the first method to be used in the degradation of BaP and its metabolites; （2） the metabolite, BP 1,6-quinone was the most liable to be accumulated in pure cultures; （3） the effect of degradation was the best when the concentration of KMnO4 in the cultures was 0.01% （w/v）, concentration of the three compounds was 5 mg/L and pH was 6.2. Based on the experimental results, a novel concept with regard to the bioremediation of BaP-contaminated environment was discussed, considering the influence on environmental toxicity of the accumulated metabolites.     

Impact of atrazine and nitrogen fertilizers on the sorption of chlorotoluron in soil and model sorbents

Sorption of chlorotoluron in ammonium sulfate, urea and atrazine multi-solutes system was investigated by batch experiments. The results showed application of nitrogen fertilizers to the soil could affect the behavior of chlorotoluron. At the same concentration of N, sorption of chlorotoluron decreased as the concentration of atrazine increased on the day 0 and 6 in soil, respectively. The sorption of chlorotoluron increased from 0 to 6 d when soils were preincubated with deionized water, ammonium sulfate and urea solution for 6 d. That indicated incubation time was one of the most important factors for the sorption of chlorotoluron in nitrogen fertilizers treatments. The individual sorption isotherms of chlorotoluron in rubbery polymer and silica were strictly linear in single solute system, but there were competition sorption between pesticides or between pesticides and nitrogen fertilizers. That indicated the sorption taken place by concurrent solid-phase dissolution mechanism and sorption on the interface of water-organic matter or water-mineral matter.     

Distribution and ecological effect of mercury in Laogang landfill, Shanghai, China

Laogang landfill near Shanghai is the largest landfill in China, and receives about 10000 t of daily garbage per day, Samples of topsoil and plants were analyzed to evaluate mercury pollution from the landfill. For topsoil samples, there were significant correlations among total mercury （HgT）, combinative mercury （Hgc） and gaseous mercury （HgG）, and content of total organic carbon （TOC）, but, no significantly relationship was found between Hg content and filling time. Hg content changes in vertical profiles with time showed that the average Hgv of profiles 1992, 1996, and 2000 was similar, but their average HgG was quite different. HgT was significantly correlated with Hgc in profile 1992 and 2000, and Hgv was significantly correlated with Hg6 in profile 1996. HgG/Hgv ratio in profile samples decreased in the order of （HgG,/HgT）1992〉（HgG/HgT）1996〉〉（HgG/HgT）2000. A simple outline of Hg release in landfill could be drawn： with increasing of filling time, degradation undergoes different biodegradation, accordingly, gaseous mercury goes through small, more, and small proportion to total mercury. Distribution of Hg in plants was inhomogeneous, following the order of leaf〉root〉stem. The highest value of leaf may be associated with higher atmospheric Hg from landfill. Ligneous plants （e.g. Phyllostachys glanca, Prunus salicina and Ligustrum lucidum） are capable of enriching more Hg than herbaceous plants.     

EDTA-enhanced phytoremediation of lead contaminated soil by Bidens maximowicziana

Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils.Bidens maximowicziana is a new Pb hyperaccumulator,which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb.The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues.The Pb distribution order in the B. maximowicziana was:leaf>stem>root.The effect of amendments on phytoremediation was also studied.The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application.Compared with CK(control check),EDTA application promoted translocation of Pb to overground parts of the plant.The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg.This research demonstrated that B.maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil,especially,combination with EDTA.     

Potential of plant polyphenol oxidases in the decolorization and removal of textile and non-textile dyes

In this study an effort has been made to use plant polyphenol oxidases; potato （Solanum tuberosum） and brinjal （Solanum melongena）, for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.     

Decomposition of alachlor by ozonation and its mechanism

Decomposition and corresponding mechanism of alachlor, an endocrine disruptor in water by ozonation were investigated. Results showed that alachlor could not be completely mineralized by ozone alone. Many intermediates and final products were formed during the process, including aromatic compounds, aliphatic carboxylic acids, and inorganic ions. In evoluting these products, some of them with weak polarity were qualitatively identified by GC-MS. The information of inorganic ions suggested that the dechlorination was the first and the fastest step in the ozonation of alachlor.     

Enzymatic oxidation of aqueous pentachlorophenol

The influence of the nonionic surfactant Tween 80 on pentachlorophenol （PCP） oxidation catalyzed by horseradish peroxidase was studied. The surfactant was tested at concentrations below and above its critical micelle concentration （CMC）. Enhancement of PCP removal was observed at sub-CMCs. The presence of Tween 80 in the reaction mixture reduced enzyme inactivation which occurred through a combination of free radical attack and sorption by precipitated products. A simple first-order model was able to simulate time profiles for enzyme inactivation in the presence or absence of Tween 80. At supra-CMCs, the surfactant caused noticeable reductions in PCP removal, presumably through micelle partitioning of PCP which precluded the hydrophobic PCP molecule from interacting with the enzyme.     

Removal of heavy metals from sewage sludge by low costing chemical method and recycling in agriculture

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