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121.
122.
本文对对酞内酰胺基苯甲酰氯的合成方法进行了研究,改进了溶剂的预处理方法,有效地消除了其中的有害杂质。 相似文献
123.
The combined synthesis and spectrometric characterization of 2,3,3'‐trichlorobiphenyl (PCB 20) and 3,3’,4‐trichlorobiphenyl (PCB 35) is described for the first time. By a combination of highly efficient column distillation and repeated recrystallizations it was possible to isolate the two products as reference materials with a purity exceeding 99%. X‐ray analysis of crystals of 2,3,3'‐trichlorobiphenyl positively identified the substitution pattern of the biphenyl moiety by chlorine atoms. The two phenyl rings are at an angle of 52°, while the relative disposition of the chlorine atoms on both rings is closer to anti than to syn. 相似文献
124.
农药人工抗原的合成直接影响制备抗体的质量,是建立农药分子特异性强、灵敏度高的免疫分析方法的关键。本文综述了国内外对于氨基甲酸酯类广泛使用的3种农药甲萘威、克百威、涕灭威人工抗原合成过程中的农药分子半抗原的设计原则、合成方法,人工抗原的设计、优选及影响因素等方面的研究进展。 相似文献
125.
Abstract The study on the sustainable utilization of water resources of Jinan city is a research hotspot in the urban sustainable development field. How to use a scientific and rational evaluation index system to analyze the sustainable utilization of water resources of Jinan city and then guide the development and utilization of water resources becomes particularly important. Based on the theory of sustainable development this study introduces the method, basic steps and evaluation indexes of the assessment of the development and utilization of water resources. By systemic analyzing the exploitation and utilization standards of water resources and economy and society in Jinan city, the evaluation and index system of sustainable utilization of water resources in Jinan city can be constructed and index weight can be confirmed, and then, the standard of sustainable utilization of water resources in different years can be analyzed comparably. Thus, the deficiency of lack of reflection of coordination extent in water resources development standard, society and economy in traditional evaluation method is settled efficiently. The paper takes the sustainable utilization of water resources of Qingdao City in 2008 as the standard to compare and assess the water resources utilization in Jinan City. The paper also collects data of water resources in Jinan City from 2001 to 2007. The result indicates that evaluation method is of feasibility and it is effective to the implementation of sustainable utilization strategy water resources in Jinan City. 相似文献
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127.
双功能螯合剂在放射性药物的研究、合成、应用,特别是在生物分子的放射性标记方面发挥着极为重要的作用.本文采用简易方法合成了MAMA双功能螯合剂前体,N-(2"-对甲氧苄巯乙基)-2-[(2'-对甲氧苄巯乙基)氨基]乙酰胺,并通过Uv-vis、IR、1HNMR、MS以及元素分析等对其结构组成进行了确证;同时,利用Gaussian 03W程序对其进行了结构优化描述,并计算了相应的分子能量.此外,对制备得到的前体进行了稳定化处理,将其转化为盐酸盐形式,并用IR、1HNMR等进行了检验,确定了此处理是合理可行的. 相似文献
128.
采用低温燃烧合成法制备了Ni掺杂TiO2光催化剂,通过紫外-可见漫反射光谱(UV-Vis DRS)、X射线粉末衍射(XRD)、激光散射、热重-差示扫描量热分析(TG-DSC)等方法对催化剂的光吸收特性、晶相组成、粒度分布、升温过程中化学变化等进行了表征,以亚甲基蓝为模型污染物考察了催化剂在可见光下的光催化活性.结果表明,相对P25而言,Ni掺杂TiO2的光吸收带边红移,当Ni/Ti原子比为0.4时,催化剂的带隙宽度为2.3eV,对应的吸收带边为564nm;催化剂晶型以锐钛矿TiO2为主,随Ni掺杂量增大,NiTiO3比例升高;催化剂粒径主要分布在50~150nm之间,占总量的96.9%;升温过程中催化剂在445.2℃发生晶型转化,出现锐钛矿和NiTiO3晶体.催化剂显示出较高的催化活性,在可见光作用150min后最高可使93.9%的亚甲基蓝分解,活性高于P25. 相似文献
129.
区域可持续发展战略规划的理论与方法研究 总被引:1,自引:0,他引:1
实施区域可持续发展战略规划是落实科学发展观的需要。结合广东省江门市可持续战略规划的实践,对可持续发展规划的概念、内涵、基本框架以及技术流程进行探讨。基本结论是:区域可持续发展战略规划应以“环境社会系统”全新的视角,回答一个区域该如何化解“三大供需矛盾”,消除“三大危机”,提高区域可持续发展能力的问题;对区域环境社会系统这类开放型复杂巨系统进行可持续发展战略决策,需采用专家经验与计算机建模相结合、反复试错、多元互动的综合集成方法。 相似文献
130.
Leaching of nitrate contributes to the deterioration of groundwater and can consequently have a negative influence on the quality of our drinking water. Critical threshold values for nitrogen leaching are established to preserve groundwater quality. A critical threshold value for nitrate leaching of 50 mg 1−1 (11.3 mg N 1−1), similar to the drinking water standard, serves as a threshold value for European countries. However, the temporal aggregation scale on which this threshold value should be considered is unknown. A well tested simulation model was used to evaluate the exceedance of the threshold value at different time aggregation levels, ranging from one day till 30 yr. For three different soil structure types within one soil type and a selected fertilisation regime, the aggregated nitrogen leaching over 30 yr was 11.4, 19.2 and 10.6 mg 1−1. Considering an aggregation level of one day, the critical threshold value of 11.3 mg N 1−1 was exceeded 2973, 5801 and 2556 times, respectively, for the three structure types during 30 yr. By considering other time aggregation levels, a clear relation resulted between time aggregation level and the number of time elements during which the critical level was exceeded. Results strongly indicate that a critical threshold value for leaching should include an associated time-aggregation level. 相似文献