离子对烷基化法在2,4-D和2,4,5-T残留分析中的应用

有机阴离子可以和长碳链的季胺盐阳离子结合生成可溶于高介电常数有机溶剂的离子对.在此溶剂中,它可以和某些卤代烃发生复分解反应,生成季铵盐阳离子的卤化物及有机阴离子的相应烷基化物,故称离子对烷基化反应.此反应条件温和,转化率高,被广泛地应用于酸性及其它含活泼氢的有机化合物的烷基衍生物合成中.在这类有机物的分析中也得到应用.但尚未见应用于农药及其降解物残留分析中的报道. 2,4-D,2,4,5-T是典型的酸性有机农药,广泛用作农田除草剂.在二者的残留分析中,通常用CH_2N_2、BF_3CH_3OH、(CH_3)_2SO_4将它们烷基化,然后用气相色谱加以分析.近几年也有人用多卤素取代醇的BCl_3络合物或五氟苄基溴化物同Na_2CO_3作为     

建设项目实施过程中的可行性研究与环境影响评价

作者根据多年的工作实践，分析了目前建设项目可行性研究与环境影响评价工作中存在的一些问题。提出了编写环境影响评价报告时如何有效地利用建设项目的可行性研究报告文本，以及在没有可行性研究报告的情况下怎样使环境影响评价报告能够准确地反映建设项目的环境问题，进而保证环境影响报告书的质量。总之，恰当处理这两者之间的关系，保证建设项目在建设期与运营期降低与防止建设项目对周边环境影响是本文的主要目的之一。     

Strategies of a bark beetle, Pityogenes bidentatus, in an olfactory landscape

 Volatiles from leaves or bark of nonhost birch (Betula pendula) and Norway spruce (Picea abies) dramatically reduced the attraction of the bark beetle, Pityogenes bidentatus (Coleoptera: Scolytidae), to their aggregation pheromone components (cis-verbenol and grandisol) in the field. In addition, odors from both the needles and bark of the host Scots pine (Pinus sylvestris) similarly inhibited attraction. Monoterpenes of pine and spruce (α-pinene, β-pinene, terpinolene, and 3-carene) as well as ethanol, chalcogran and some nonhost green leaf alcohols [(Z)-3-hexen-1-ol, (E)-2-hexen-1-ol, and 1-hexanol], also reduced catches. Collections of volatiles from the field-tested plant tissues indicated they released monoterpenes in amounts similar to the synthetics that inhibited responses. The various plant and insect sources of these inhibitory compounds indicate that P. bidentatus bark beetles have evolved several strategies to increase their fitness by avoiding nonhost and unsuitable host trees in a complex olfactory landscape. Received: 6 June 2000 / Accepted in revised form: 25 September 2000     

再论次生石英岩型非金属矿床

次生石英岩型非金属矿床明显受不同级别的火山构造控制,是中—酸性火山岩区一套很有特色的矿床组合;热源、水源、地层产状有机组合生成的环流热液是成矿的前提之一;成矿流体以重碳酸盐型、硫酸盐型为主,属中—低盐度热液;温度、pH值、fo_2等物理化学条件是矿床及矿种类刑的重要控制因素。本文在《次生石英岩容矿型非金属矿床系列的矿种、组合及其成矿作用特征》(1986)一文基础上,进一步总结这类矿床的成矿机理和地质地球化学模式。     

Dynamic fate modeling of γ-hexachlorocyclohexane in the lower reaches of the Liao River

A QWASI model dependent on temperature is parameterized to describe the long-term fate of persistent organic pollutants (POPs) in the Liao River. The model parameters, namely fugacity capacity, degradation rate, and transfer coefficient, are profoundly affected by temperature. This model is used to simulate the fate of γ-hexachlorocyclohexane (γ-HCH) in the lower reaches of the Liao River from 1998 to 2008. Modeling results show that γ-HCH fugacity capacities in air, water, and sediment increase as temperature decreases, and the transfer and transformation rate coefficients increase as temperature increases. The variations of transfer and transformation parameter D values depend on fugacity capacities, and transfer and transformation coefficients simultaneously. The performance of the model is evaluated by comparing the predicted and observed concentrations in the water and sediment of the Liao River. The predicted values agree well with the observed value in the order of magnitude, in most cases within the factor of 3. It is believed that the model is appropriate for simulating the long term fate of POPs in the Liao River. Translated from Environmental Science, 2006, 27(1): 121–125 [译自: 环境科学]     

Atmospheric particulate pollution of Lanzhou using magnetic measurements

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城市水业投资模式及BOT模式操作要点

水务行业特许经营在今后一定时间内是解决城市基础设施建设的主要手段之一.它能够解决城市基础设施投资资金短缺的问题;实现基础设施行业投资结构多元化,促进体制改革;引入竞争机制,提高服务质量;引入先进技术与科学的管理手段,提高经营管理效率.本文主要介绍了城市水业投资的模式及其适用条件,并以案例分析的方式讨论了BOT模式的操作要点.     

沉淀物和生物中U,Th和226Ra的联合测定

用放射化学法对U,Th,~(226)Ra等核素进行联合测定,国外已有不少报道,只是所用的分离方法和所测的介质不同而已。我国学者也做过一些这方面的工作。本工作建立了用三正辛胺-二甲苯萃取分离法对沉积物和生物样中U,Th和~(226)Ra的联合测定方法。 二、主要仪器与试剂     

硫代氨基甲酸盐提取工业废水中的锌离子

本文主要探索了金属离子络合剂———硫代氨基甲酸盐的合成制备 ,并通过其对锌离子的络合作用 ,以达到脱除金属离子的目的 .实验表明 ,由吗啡啉合成制得的硫代氨基甲酸盐 锌离子络合剂在酸性废水中 ,对锌离子具有良好的络合能力 .通过对废水中金属锌离子的脱除工艺条件的相应探索 ,发现在体系的pH =2～ 6范围内 ,硫代氨基甲酸盐对锌离子的脱除率均达99 %以上