共查询到19条相似文献,搜索用时 46 毫秒
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含氮六节芳杂环及其氨基衍生物是基础有机化学中杂环章节的主要内容之一,但一般教科书中对此部分内容叙述过于简单。为此,本文拟从有机碱的共轭酸的pKa入手,扼要的对其氨基取代对吡啶及其它含氮芳杂环化合物碱性的影响,以及氨基取代吡啶的结构作一阐述。 相似文献
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根据煤中氮的存在形式,提炼出11种具有不同杂化方式及含氮量的有机环状化合物.应用密度泛函理论(DFT)模拟方法对甲烷在这11种含氮化合物上的吸附模型进行结构优化,并结合吸附能、电荷分布及静电势能面的分析,从微观角度考察了甲烷与这些化合物之间的相互作用.计算结果表明:甲烷与含氮化合物的相互作用能在3.81-6.82kJ·mol-1范围内,且通过氢键和静电力相互作用;当化合物中氮的杂化方式为sp2时,其与甲烷的作用能大于sp3杂化方式的;当化合物中的氮含量增加时,可以提供更多的甲烷吸附位点. 相似文献
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本文应用电负性均衡原理,建立了一种标度氢氧化物碱性强弱的方法.对大量氢氧化物的计算结果表明,碱性标度(B)的大小与氢氧化物的实际碱性强弱的顺序基本一致,因此,氢氧化物碱性标度(B)的建立将有助于半定量比较氢氧化物的碱性强弱。 相似文献
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Reduction of Organic Compounds with Thiourea Dioxide II. The Reduction of Organic Nitrogen Compounds
Reduction of nitrobenzene with thiourea dioxide gave aniline and hydrazobenzene depending on the concentration of sodium hydroxide. Azobenzene and azoxybenzene were found to offer hydrazobenzene as the final product by the same reagent. 相似文献
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本文测定了23种有机含氮物。在强紫外光辐射下,应用4%K2S2O8为氧化剂,经酸、碱两步光解,除N-N键形成游离氮外,其它键型氮均在25分钟内定量分解。实验中精简了KO3的还原步骤。对天然水和污水的分析均有较好的效果。 相似文献
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《Analytical letters》2012,45(15):2949-2958
Abstract The effect of metal ions on TiO2 mediated photocatalytic oxidation for the determination of dissolved organic nitrogen compounds is investigated. Ethylenediaminetetraaceticacid was chosen as a model molecule for DON compounds. At pH 2, 5, 7, and 10 aqueous EDTA solutions were irradiated at 254 nm in the presence of Fe2+, Cu2+, Zn2+, Ni2+ or Co2+ ions. The sum of produced nitrate, nitrite, and ammonium ion concentrations gave the total oxidation recovery. At low pH, the photocatalytic oxidation recoveries of Fe‐EDTA, Ni‐EDTA, and Co‐EDTA were significantly lower than the photocatalytic degradation of EDTA. The presence of free Fe2+, Ni2+, and Co2+ ions decreased the photocatalytic oxidation recovery. The [NH4 +]/[NO3 ?] ratio was higher for Cu‐EDTA. 相似文献
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Assoc. Prof. Haoli Zhou Fei Tao Quan Liu Chunxin Zong Wenchao Yang Assoc. Prof. Xingzhong Cao Prof. Wanqin Jin Prof. Nanping Xu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(21):5849-5853
Microporous polymer membranes continue to receive tremendous attention for energy-efficient gas separation processes owing to their high separation performances. A new network microporous polyamide membrane with good molecular-sieving performance for the separation of N2 from a volatile organic compound (VOC) mixture is described. Triple-substituted triptycene was used as the main monomer to form a fisherman's net-shaped polymer, which readily forms a composite membrane by solution casting. This membrane exhibited outstanding separation performance and good stability for the molecular-sieving separation of N2 over VOCs such as cyclohexane. The rejection rate of the membrane reached 99.2 % with 2098 Barrer N2 permeability at 24 °C under 4 kPa. This approach promotes development of microporous membranes for separation of condensable gases. 相似文献
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应用Vario EL Ⅲ型元素分析仪研究了高氟和全氟有机化合物中碳、氢、氮的测定方法.为克服氟对碳、氮测定的干扰,在燃烧管的高温区填加固体MgO及Ag2WO4混合物作为催化氧化剂.这一措施还可同时消除卤素及硫的干扰.在分析全氟有机化合物时,则将WO3及V2O5作为催化氧化剂直接加入于试样中并包裹于"锡舟"中进行燃烧和碳、氢、氮的测定. 相似文献
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用离子色谱法测定丙烯中痕量碱性氮化物 总被引:2,自引:0,他引:2
采用化学反应浓缩技术,将丙烯中痕量碱性氮化物转变为水溶性的阳离子,用离子色谱法进行测定。该法准确度高,操作简便,可测定丙烯中10^9g/L的碱性氮化物,也可用于炼油厂及其它环境气氛中碱性氮化物的测定。 相似文献