共查询到19条相似文献,搜索用时 78 毫秒
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还原偶氮比色法分析硝基苯,分析结果受锌渣和慢速滤纸吸附系统误差的影响,结果偏低.用苯胺作标准,可去除硝基苯前处理还原中吸附产生的系统误差,提高硝基苯分析结果的可比性、准确性. 相似文献
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硒催化下CO/H2O还原硝基苯制苯胺 总被引:10,自引:1,他引:10
采用硒作催化剂,不使用任何助催化剂,用CO/H2O对硝基苯进行还原得到了苯胺.考察了反应时间、CO压力、反应温度、水量、硒粉用量和溶剂等因素对反应的影响.以四氢呋喃作溶剂,在n(H2O)/n(PhNO2)=10,n(Se)/n(PhNO2)=0.02,p(CO)=4MPa,θ=160℃,t=3h时,硝基苯转化率可达到98.2%,生成苯胺的选择性为100%. 相似文献
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以乙酰丙酮(1)的电氧化偶联产物3,4-二乙酰基-2,5-己二酮(2)为原料,在酸性介质中与取代苯胺(3a ̄3g)作用,得到1,4-二羰基的缩合产物2,5-二甲基-3,4-二乙酰基-1-芳基吡咯(4a ̄4g)。在相似的条件下,2与水合肼作用,则得到1,3-二羰基的缩合产物3,3',5,5'-四甲基-1,1'-二氢-4,4'-联吡唑(5)。 相似文献
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水合肼还原重量法测定银 总被引:1,自引:0,他引:1
样品经过硝酸分解后,用过量的氨水分离铅、铁、铝等金属离子,用EDTA掩蔽铜、锌和其他残留的金属离子,用水合肼作还原剂,将银还原成单质沉淀,过滤,洗涤,灼烧,恒重。该方法用于实际样品测定,结果与其他方法测定值一致,误差均在允许范围内;分别对银含量为2.54%和10.00%的样品重复测定12次,相对标准偏差(RSD)分别为1.50%和0.64%,此方法适用于1%以上银含量的测定。 相似文献
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Six diaryl acylhydrazine compounds were synthesized in normal temperature with self-made acyl-diazene compounds as raw materials and NH_2NH_2·H_2O as reducer.The products were confirmed by means of elemental analysis,IR and~1H NMR.In the results of IR,there were two N-H absorption at approximately 3200 and 3400 cm~(-1).However,the absorptions of N=N in raw materials disappeared.In the results of 1H NMR,the N-H chemical shifts couldn't be found.Meanwhile,two N-H chemical shifts were detected about from 8.46 to 11.38,respectively.The results of products' elemental analysis were consistent with the theoretical values.The yields of those six products were about from 84% to 93%. 相似文献
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用水合肼还原的Ru/AC氨合成催化剂的制备 总被引:6,自引:0,他引:6
用RuCl3水溶液浸渍BET比表面积为1020m2/g的椰壳活性炭(AC)载体,制备了钌含量为6%的Ru/AC氨合成催化剂.在添加助剂前,分别用水合肼水溶液、水合肼蒸气和H2还原催化剂,然后分别浸渍Ba(NO3)2和KOH.催化剂中的Ru∶K∶Ba摩尔比为1∶3∶0.3.用N2物理吸附、XPS和CO化学吸附等方法对催化剂进行了表征.结果表明,用不同还原方法制备的催化剂上的钌以不同的化学状态存在,它的活性与其比表面积和金属钌的分散度相关.用水合肼水溶液还原的催化剂S1中的钌在大气气氛下以金属态存在,它的BET比表面积和金属分散度较大,低温低压下催化活性最高.以水合肼蒸气还原的催化剂S2中的钌在大气气氛下以RuO3形态存在,它的BET比表面积和金属分散度小,催化活性最低.用H2还原的催化剂S3中的钌在大气气氛下以RuO2形态存在,其BET比表面积和金属分散度与S1催化剂相当,催化活性也与S1相近. 相似文献
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Abakumov O. O. Bychko I. B. Trypolskii A. I. 《Theoretical and Experimental Chemistry》2021,57(4):289-296
Theoretical and Experimental Chemistry - The composition of functional groups, morphology, defect structure, and surface fractal dimension DS of reduced graphene oxide (RGO) synthesized by... 相似文献
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Qi Xun SHI Rong Wen LU Zhu Xia ZHANG De Feng ZHAO 《中国化学快报》2006,17(8):1045-1047
The sulphur-containing aromatic amines are an important class of compounds frequently used as key intermediates in the synthesis of pharmaceutical products1,2, dyestuffs3-6 and polymers7. The usual methods for preparing sulphur-containing aromatic amines … 相似文献
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A method is presented to analyze quantitatively the degree of congenericity of claimed compounds in patent applications. The approach successfully differentiates patents exemplified with highly congeneric compounds of a structurally compact and well defined chemical series from patents containing a more diverse set of compounds around a more vaguely described patent claim. An application to 750 common patents available in SureChEMBL, SureChEMBLccs and ChEMBL is presented and the congenericity of patent compounds in those different sources discussed. 相似文献
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以可再生生物质资源莽草酸为原料, 在经酯化和2-碘酰基苯甲酸(IBX)氧化制得3-脱氢莽草酸甲酯的基础上, 研究了在不同反应溶剂中和不同反应温度下, 3-脱氢莽草酸甲酯分别与水合肼、 乙酰肼、 苯肼和乙酰胺选择性地得到非芳构化、 部分芳构化和芳构化产物的反应. 该方法具有选择性高、 操作简单和条件温和等优点, 为可再生非粮生物质资源莽草酸的利用提供了一种新的思路. 相似文献