共查询到20条相似文献,搜索用时 62 毫秒
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以间硝基苯胺为原料,经苯甲酰化、铁粉还原和羟乙基化等反应合成了3'-(双-2-羟乙基)氨基苯甲酰苯胺,并对反应的影响因素进行了讨论。 相似文献
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本文用气相色谱法对2-乙基-6-甲基-N-(1’-甲氧基-2’-甲氧乙基)苯胺进行定量分析。这种方法简单,快速,准确和实用,标准偏差为0.11,变异系数为0.11%,回收率为99.28 ̄100.61%。 相似文献
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回顾2007年,中国水泥工业走进了以大企业(集团)为主导的发展时代.有业内人士据此提出,2008年以大企业集团为主导的重组联合,新建为辅的发展态势仍是行业发展的主流. 相似文献
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《Ceramics International》2022,48(15):21201-21208
A2Mo3O12 (A-Al, Fe, Cr) have large negative thermal expansion (NTE) coefficients and structural stability but high phase-transition temperatures (PTTs). Herein, we prepared (Al1/3Fe1/3Cr1/3)2(Mo1/2W1/2)3O12 (AFCMW), and found it to have a low NTE coefficient and a low PTT. Furthermore, combination of AFCMW with (Co1/2Ni1/2)(Mo1/2W1/2)O4 (CNMW) afforded an AFCMW–CNMW composite with a low thermal expansion (LTE). We determined that the PTT reductions in A2Mo3O12 are largely due to the high-entropy effect resulting from the introduction of different ions into its A and M sites. Moreover, we found that the low LTE of the AFCMW–CNMW composite is attributable to the opposite thermal expansion behaviours of AFCMW and CNMW. We suggest that the suppressed thermal expansion during the phase transition process of the AFCMW–CNMW composite could be derived from the high-entropy effect resulting from its increased diversity of polyhedra, the influence of Co2+ and Ni2+ dopants, and CNMW-induced lattice distortion. 相似文献
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Cyclization Reactions of 1-[2-amino-1-cyano-2-thio-]ethenepyridinium Ylides 1-[2-Amino-1-cyano-2-thio-]ethene-pyridinium ylides 1 can be alkylated with methyliodide or α-haloesters and α-haloketones, respectively, to form 1-[2-alkyl(aryl)amino-1-cyano-2-methylthio-ethene-1]pyridinium iodides 2a-–e or 1-[2-alkyl(aryl)-amino-1-cyano-2-alkoxy(aryl)-carbonylmethylthio-ethene-1] pyridinium salts 3a–f . With the exception of 3a–b the compounds 3 or 1 react with haloketones to yield 1-[4-amino-2-alkyl-(aryl)amino-5-benzoyl-thiene-3]pyridinium salts 4a–m or 3-alkyl-4-aryl-2-(1-cyano-1-pyridinium)methylene-Δ4-thiazoline salts 5a–f . 相似文献
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1-甲胺基-1-甲硫基-2-硝基乙烯的合成 总被引:1,自引:1,他引:0
在高频共振研磨机中采用湿法研磨5 h制备了平均粒径为266 nm的微纳米碳酸钾。以微纳米碳酸钾为碱,硝基甲烷和异硫氰酸甲酯在无水乙醇中反应得到1-甲胺基-2-硝基乙烯硫醇钾,然后在水溶液中与硫酸二甲酯反应得到1-甲胺基-1-甲硫基-2-硝基乙烯。探讨了物料比、反应温度、反应时间对第1步反应的影响,优化后两步反应总收率为86%。化合物的结构通过FTIR和1HNMR进行了表征。 相似文献
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Danka Gobeljic Robert Dittmer Jürgen Rödel Vladimir V. Shvartsman Doru C. Lupascu 《Journal of the American Ceramic Society》2014,97(12):3904-3912
The stability of the field‐induced ferroelectric (FE) state was studied in relaxor lead‐free ceramics (1 ? y)[0.81Bi1/2Na1/2TiO3–0.19Bi1/2K1/2TiO3]–yBiZn1/2Ti1/2O3 both macroscopically and microscopically. A strong dc electric field results in the formation of a stable FE state with a large piezoelectric coefficient for compositions with a small amount of Bi(Zn1/2Ti1/2)O3, which are in the non‐ergodic relaxor state at room temperature. Increasing temperature promotes ergodic relaxor behavior, which is accompanied by the rapid destabilization of the induced state, that is, small relaxation times. Based on the obtained data, it is proposed that the depolarization is a two‐step process consisting of an initial realignment of the FE domains and their subsequent breakup into polar nanoregions. The ergodic relaxor behavior is also promoted by increasing the Bi(Zn1/2Ti1/2)O3 content. The related charge disorder results in an enhancement of random electric fields and consequently a stable FE state cannot be induced even at room temperature. 相似文献