147 resultados para minutes 15


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本文应用取代基参数(SCS)方法处了15个EV共聚物的~(12)C NMR谱.它们是:(1)乙烯-α-烯烃共聚物,即乙烯-丙烯共聚物.乙烯-丁烯-1共聚物,乙烯-4-甲基-1-戊烯共聚物,乙烯-己烯-1共聚物和乙烯-辛烯-1共聚物;(2)乙烯-含氧乙烯基共聚物,即乙烯-甲基丙烯酸N,N-二甲基胺乙酯共聚物,乙烯-丙烯酸甲酯共聚物.乙烯-丙烯酸共聚物,乙烯-乙酸乙烯酯,乙烯-乙烯醇,乙烯-氧化碳共聚物(ECO)(?)乙烯-卤代乙烯共聚物及其它EV共聚物,即乙烯-氯化乙烯共聚物(包含氯化聚乙烯),乙烯-溴化乙烯共聚物,乙烯-苯乙烯共聚物(包含氢化丁二烯-苯乙烯共聚物)和乙烯-丙烯腈共聚物、得到了15种取代基的SCS参数.

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合成了一种Schiff碱型双冠醚N,N’-对苯二甲亚基双(4’-氨基苯并-15-冠-5)及其稀土硝酸盐的固体配合物,通过元素分析、摩尔电导、IR、UV、1HNMR和热分析等对其性质作了表征与比较。

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[La(NO3)(3)(OH2)(2)(OHMe)(bipy).15-crown-5 is monoclinic, P2(1)/n, with a = 11.239(6), b = 19.302(7), c = 14.458(8) Angstrom, beta = 92.47(5)degrees, and D-calc = 1.63 g cm(-3) for Z = 4. In the complex, two nitrogen atoms (from bipy) and nine oxygen atom

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5,10,15,20-四(对-山嵛酸乙酯-α-氧代苯基)卟啉LB膜结构研究王海水,曾广赋,谷淑珍,席时权(中国科学院长春应用化学研究所长春130022)利用LB膜技术将分子组装成有序的分子单层或多层体系,研究膜内分子间相互作用和分子的结构,对了解结构...

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对卟啉类化合物LB膜的结构、电性质和气敏性的研究已见报道。本文利用膜天平和UV-Vis分光光度计研究了标题化合物在气-液界面上的成膜特性、分子间相互作用和LB膜的结构。5,10,15,20-四(对-乙酯苯基)卟啉(TPEPP)由5,10,15,20-四(对-氰苯基)卟啉和乙醇酯化得到。元素分析测定值与计算值相符。λ(CHCl_3,nm):421,515,550,590,645;ν(KBr压

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仲碳伯胺N_(1923)萃取铈(Ⅳ)的~1H,~(15)N-NMR研究表明,在萃取铈(Ⅳ)时也同时萃取H_2O和H_2SO_4进入有机相,当铈(Ⅳ)浓度较高时,铈(Ⅳ)与N_(1923)生成配合物。

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本文研究了火焰原子吸收,石墨炉原子吸收,结合基体改进剂和平台技术,测定了人参中Pb、Ca、Co、Ni、Cr、Ba、K、Na、Cd、Mg、Fe、Cu、Zu、Mn、Sr等十五个微量元素,结果满意。

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本文利用 Pr~(3+)离子在 Pr_xLa_(1-x)P_5O_(14)晶体中的光谱性质和能级,在考虑~3P_o-~1D_2和~3H_4-~3H_6,~1D_2-~1D_4和~3H_4-~3F_4两个能级对交叉弛豫的情况下,详细研究了 Pr~(3+)离子的荧光动力学过程,给出了~3P_o,~1D_2和~1G_4能级的荧光发射规律。

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稀土冠醚络合物的组成和稳定性不但与稀土离子直径和冠醚孔径是否匹配,而且也和阴离子及合成用的溶剂有关.因15-冠-5(简写15C5)的孔径(2.2?)和大部分稀土离子直径相近.因此它们的络合物是研究孔径匹配关系的理想模型. Bunzli在乙腈中合成了大部分镧系硝酸盐15C5络合物,轻镧系(La-Gd)生成1:1无水络合物,重镧系(Tb-Lu)为含1—3分子水的1:1络合物.我们在无水丙酮中制备

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In addition to 10 known compounds (7-16), one new brominated diterpene, 10-hydroxykahukuene B (1), two new sesquiterpenes, 9-deoxyelatol (2) and isodactyloxene A (3), one new brominated C-15-acetogenin, laurenmariallene (4), and two new naturally occurring halogenated sesquiterpenes (5 and 6) that were previously obtained as intemediates in a biomimetic synthetic study of rhodolaureol and rhodolauradiol have been isolated and identified from the organic extract of the marine red alga Laurencia mariannensis. The structures of these compounds were established by spectroscopic methods. The antibacterial and antifungal activities of new compounds 1-4 were evaluated.

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Four new halogenated nonterpenoid C-15-acetogenins, 4:7,6:13-bisepoxy-9,10-diol-1,12-dibromopentadeca-1,2-diene (1, laurendecumallene A), 4:7,6:12-bisepoxy-9,10-diol-1,13-dibromopentadeca-1,2-diene (2, laurendecumallene 13), (3Z)-6:10,7:13-bisepoxy-12-bromo-9-hydroperoxylpentadeca-3-en-1-yne (3, laurendecumenyne A), and (3Z)-6:10,9:13-bisepoxy-12-bromo-7-chloropentadeca-3-en-1-yne (4, laurendecumenyne 13), together with one known halogenated C-15-acetogenin elatenyne (5) were isolated and identified from the organic extract of the marine red alga Laurencia decumbens. Their structures and relative stereochemistry were established by means of spectroscopic analysis including UV, IR, high-resolution electrospray ionization mass spectrometry (HRESIMS), and ID and 2D NMR techniques. All these metabolites were submitted for the cytotoxic assay against tumor cell line A549 (human lung adenocarcinoma), but all of them were found inactive (IC50 > 10 mu g/mL).

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Seven parguerane diterpenes: 15-bromo-2,7,19-triacetoxyparguer-9(11)-en-16-ol (1), 15-bromo-2,7,16,19-tetraacetoxyparguer-9(11)-ene (2), 15-bromo-2,19-diacetoxyparguer-9(11)-en-7,16-diol (3), 15-bromo-2,16,19-triacetoxyparguer-9(11)-en-7-ol (4), 15bromo-2,16-diacetoxyparguer-9(11)-en-7-ol (5), 15-bromoparguer-9(11)-en-16-ol (6), 15-bromoparguer-7-en-16-ol (7), two polyether triterpenes: thyrsiferol (8) and thyrsiferyl 23-acetate (9), and one C15-acetogenin, neolaurallene (10), were isolated from a sample of marine red alga Laurencia saitoi collected off the coast of Yantai. Their structures were established by detailed NMR spectroscopic analysis and comparison with literature data.

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new brominated C-15-acetogenin, namely, laurenidificin, was isolated from the marine red alga Laurencia nidifica. Its structure was determined on the basis of spectroscopic methods. (C) 2010 Bin Gui Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

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红毛菜(Bangia Lyngb.)属于红藻门,与紫菜属同属红毛菜科,其味道和营养都优于紫菜。目前红毛菜栽培产业已在我国福建莆田展开,但栽培技术还有待提高。海藻栽培技术的发展和成熟依赖于对其生长发育过程的认识。本研究针对红毛菜发育过程及相关光合生理展开,并初步探讨了一采自山西娘子关泉淡水红毛菜群体(FWB)的系统地位。 色素突变标记的壳孢子萌发特征表明最初两次分裂产生的4细胞决定了完整植株的形态建成。成熟植株,为雌雄异体。雌性生殖器果胞的标志性分化结构为原始受精丝,环境因子是促发原始受精丝发展的外部因素,其膨大程度随受精的延迟而增大。原孢子是主要的无性生殖孢子类型,在不良环境中,藻体也会形成内生孢子或休眠包囊,或者藻体断裂后重新形成完整的植株。 红毛菜的生长发育很大程度上受环境因子的控制。高温不利于配子体的发育,15-20 ºC比较适宜。红毛菜无性繁殖的最适温度-光照组合为20 ºC-8 h,有性繁殖为15 ºC-12h。 不同发育阶段,PSII实际光合效率(Y(II))与细胞的健康状况以及光合器官完整性及其在细胞内的分布有关,而与细胞的类型关系不大。健康的假根细胞、已分化未成熟的精子以及果孢子细胞均具有很高的Y(II)。色素体由中间位变为围周位,中央大液泡(营养藻丝)和大小纤维囊泡(成熟孢子与精子)的产生,使得细胞Y(II)降低。刚放散的壳孢子Y(II)很低,说明在壳孢子由贝壳基质释放到自由水体过程,光合作用受到一定程度抑制;而2h后,Y(II)开始恢复,rbcL的转录水平非常高,为孢子的萌发储备物质和能量需求。 在失水和低盐胁迫下,藻体均维持较高的Y(II)。干出处理至藻体重量不再变化,复水后Y(II)可回复初始水平。海生红毛菜在100%淡水培养基中(约20ºC)培养7天后,部分雄性藻体依然活着。从而体现了红毛菜位居高潮带的生理优势。 FWB终生行无性繁殖,藻体形态与发生以及染色体数目(4条)与海生群体没有区别。而rbcL-rbcS Spacer序列显示,红毛菜海生群体(无性和有性)具有完全相同的序列,而FWB与它们有5bp差异,但是与欧洲、北美地区的淡水群体仅1bp不同,初步说明所有淡水红毛菜群体具有共同的原始起源。