980 resultados para Sl 19


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合成了具有磁铅石结构的Sr1-xLaxNiAl11O19系列催化剂,并用XRD、UV-DRS、H2-O2滴定及Py-IR等方法对其体相及表面性质进行了表征.结果表明,La3+离子能够同晶取代Sr2+离子进入催化剂晶格内部;随着La3+含量增加,催化剂的结晶度提高,从而降低了镍的还原性,并使金属镍在表面上的分散度略有提高;在SrNiAl11O19中掺入La3+离子,能够抑制晶体沿c轴方向的生长,提高其比表面积;同时La3+离子对Sr2+离子的调变,减少了表面的酸中心数目

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对具有磁铅石结构的Sr1-xLaxNiAl11O19对甲烷与二氧化碳重整反应的催化活性、积炭量和稳定性进行了研究.不同还原温度下催化剂的XRD和催化活性的实验结果表明,金属镍是CH4+CO2重整反应的活性组分,金属镍含量越大,反应活性越高.反应后催化剂积炭量的分析结果说明,在相同镍含量和分散度的情况下,La3+离子对Sr2+离子调变,可以降低催化剂的表面酸性,提高催化剂的抗积炭能力.LaNiAl11O19是一种具有较好催化活性、稳定性和抗积炭性能的催化剂.

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合成了六铝酸盐SrNiAl11O19并用XRD、UVDRS、TGDTA和TEM等技术对其进行了表征。在750℃于SrNiAl11O19上进行的甲烷与二氧化碳重整反应表明,这类催化剂较Ni/SrAl12O19具有较大活性和低积碳能力,在催化反应过程中可有效地抑制Ni颗粒的增大。

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采用XRD、UV-DRS、H2-O2滴定、TPR、吡啶吸附红外光谱等技术,研究了La2O3助剂对La2O3-Ni/SrAl12O19催化剂的还原性、表面酸性、金属镍的分散度和抗烧结能力,以及对催化甲烷与二氧化碳重整制取合成气反应性能的影响.结果表明,在负载型的镍催化剂中,添加La2O3助剂,能够削弱金属组分与载体之间的相互作用,降低催化剂的还原性,提高金属镍在催化剂表面的分散度和在反应过程中的抗烧结能力,降低催化剂表面酸性.关联甲烷与二氧化碳重整反应活性的结果,发现影响负载型镍催化剂的反应活性、稳定性和积炭性质的主要因素是金属镍的分散状态,而不是催化剂表面酸性.La2O3主要是通过改变镍的分散度来影响催化甲烷与二氧化碳重整反应活性的.

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It is found that in the fast atom bombardment (FAB) mass spectra R-alpha-phenylethylamine and S-alpha-phenylethylamine can be clearly distinguished by S-1,1'-binaphthyl-2, 2'-diylhydrogenphosphate (S-BNP), Mixture of R-alpha-phenylethylamine and S-alpha-phenylethylamine also be tested and the relative abundance of the characteristic ion of mixture is related to the composition of the mixtute. We have therefore proposed a possible method to determine the optical purity of alpha-phenylethylamine.

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质谱中的立体化学效应(19)──对映异构的α-苯乙胺光学纯度质谱测定吴忆南,涂亚平,潘远江,陈耀祖(浙江大学化学系,杭州,310027,兰州大学应用有机化学国家重点实验室)崔勐,宋凤瑞,刘淑莹(中国科学院长春应用化学研究所)关键词对映体,光学纯度,质...

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一种新的聚工二烯型表面活性剂LYF经液体聚了二烯磺化方法制备而得,并应用于液膜分离研究之中。发现无论内水相是酸性还是碱性,由该表面活性剂制得的W/O型乳状液在稳定性、溶胀率和破乳诸方面均具有令人满意的综合性能。为深入了解液膜的稳定性,我们测定了处于两种水相间的双分子膜的强度。发现由LYF所形成的双分子膜具有最大的膜强值,优于聚异丁烯型的表面活性剂ECA4360和EM301.

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本文用差示扫描量热(DSC)、热重(TG)和红外光谱法研究了标题配合物(简记为C_9M)的热稳定性和固—固相变.讨论了中心金属离子对热稳定性和相变的影响.发现其热稳定性依C_9Co>C_9Mn>C_9Zn>C_9Cu降低.固—固相变数目、相变温度和相变的有序—无序效应主要取决于中心金属离子的种类。Zn组配合物总相变的无序效应比Cu组高,在高温相为完全无序相。C_9Zn配合物低温相变(285K)主要来源于链间相互作用和堆积态的有序—无序变化.高温相为“链熔化”态.

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由吉林省长春地区采集40例健康成人心肌样品,用荧光分光光度法测定硒,用催化极谱法测定钼,用高频感耦等离子体发射光谱法测定铝、硼、钡、钙、镉、钴、铬、铜、铁、钾、镁、锰、钠、磷、锶、钛和锌的含量。取90%可信限,通过计算确定了健康成人心肌19种元素的正常值范围。

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Growth hormone (GH), prolactin (PRL) and somatolactin (SL) were purified simultaneously under alkaline condition (pH 9.0) from pituitary glands of sea perch (Lateolabrax japonicas) by a two-step procedure involving gel filtration on Sephadex G-100 and reverse-phase high-performance liquid chromatography (rpHPLC). At each step of purification, fractions were monitored by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and by immunoblotting with chum salmon GH. PRL and SL antisera. The yields of sea perch GH, PRL and SL were 4.2, 1.0 and 0.28 mg/g wet tissue, respectively. The molecular weights of 19,200 and 20,370 Da were estimated by SDS-PAGE for sea perch GH and PRL, respectively. Two forms of sea perch SL were found: one (28,400 Da) is probably glycosylated, while the other one (23,200 Da) is believed to be deglycosylated. GH bioactivity was examined by an in vivo assay. Intraperitoneal injection of sea perch GH at a dose of 0.01 and 0.1 mug/g body weight at 7-day intervals resulted in a significant increase in body weight and length of juvenile rainbow trout. The complete sea-perch GH amino acid sequence of 187 residues was determined by sequencing fragments cleaved by chemicals and enzymes. Alignment of sea-perch GH with those of other fish GHs revealed that sea-perch GH is most similar to advanced marine fish, such as tuna, gilthead sea bream, yellowfin porgy, red sea bream, bonito and yellow tail with 98.4, 96.2%, 95.7%, 95.2%, 94.1% and 91% sequence identity, respectively. Sea-perch GH has low identity to Atlantic cod (76.5%), hardtail (73.3%), flounder (68.4%), chum salmon (66.3%), carp (54%) and blue shark (38%). Partial amino-acid sequences of 127 of sea-perch PRL and the N-terminal of 16 amino-acid sequence of sea-perch SL have been determined. The data show that sea-perch PRL has a slightly higher sequence identity with tilapia PRL( 73.2%) than with chum salmon PRL(70%) in this 127 amino-acid sequence. (C) 2001 Elsevier Science B.V. All rights reserved.

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2010

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2010