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221.
设计合成了一种缺电性的刚性棒状超分子单体,在葫芦脲(CB[8])存在下,它与富电性的柔性单体受CB[8]包结增强的供体-受体作用驱动在水中共组装形成"刚-柔"(rod-coil)型超分子共聚物.运用核磁共振滴定实验、紫外-可见光谱、二维扩散排序核磁共振谱(DOSY)、动态光散射(DLS)以及透射电子显微镜(TEM)等对超分子聚合物的形成及其结构进行了证实和表征,并发现该超分子共聚物在低浓度下采取伸展的线形构象,当浓度增加到一定程度后其线形骨架发生卷曲,转变为颗粒状团聚结构. 相似文献
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223.
采用高效液相色谱-串联质谱法测定生鲜乳中三聚氰胺残留量。样品经乙腈溶液超声提取,过Waters Oasis MCX固相萃取小柱净化,50℃氮气吹干,再用1.0mL乙腈溶解后供高效液相色谱-串联质谱分析。以Waters Hilic色谱柱(100 mm×2.1 mm,3μm)为固定相,用乙腈-5mmol·L-1乙酸铵(95+5)溶液洗脱,采用电喷雾正离子模式多反应监测,内标法定量。三聚氰胺的质量浓度在10.0μg·L-1以内呈线性,检出限(3S/N)为0.5μg·kg-1。取空白样品在3个标准加入水平下进行回收和精密度试验,回收率在99.8%~103%之间,测定值的相对标准偏差(n=10)在1.9%~3.2%之间。 相似文献
224.
Jun Jianga Jian Zhanga Feng Gua Wei Shaoa Chunzhong Lia Mengkai Lub a Key Laboratory for Ultrafine Materials of Ministry of Education School of Materials Science Engineering East China University of Science Technology Shanghai China b State Key Laboratory of Crystal Materials Sh ong University Jinan China 《中国颗粒学报》2011,(3)
For better performance of dye sensitized solar cells(DSSCs) ,a bilayer structured electrode was constructed by employing a mesoporous anatase TiO2 overlayer above a commercial P25 TiO2 nanoparticles underlayer. The mesoporous anatase TiO2,prepared through a facile surfactant-assisted sol-gel process,possessed large pore size and well inter-connected network structure,both beneficial for dye adsorption and electron transfer. The dye adsorption capability of the mesoporous TiO2 was nearly twice that of the P2... 相似文献
225.
AbstractThe viscosity of neat ionic liquids is very important for their application in organic synthesis as a solvent because most of the neat ionic liquids are very viscous, which would result in the less efficient mass transfer of reactants. In the present study, a series of novel dihydro-[1,2,4]triazolo[1,5-a]pyrimidines were prepared using a low viscous and acid-functionalized ionic liquid. Our results showed that new ionic liquid can act as a green solvent and acid catalyst due to low viscosity and acid functionality. The products were simply extracted and the ionic liquid was retrieved several times without reducing its catalytic efficiency. The current application of TMDPS in the one-pot multicomponent reactions as dual solvent-catalyst highlights the importance of low viscous acid-functionalized ionic liquids in organic synthesis, and we hope that further research will be conducted in the future to finding other applications of TMDPS with promising results. 相似文献
226.
An assembly of Keggin polyoxomolybdate and organic substrate(Hbipy)3[PMo12O40](1,bipy=2,2’-bipyridine) was synthesized and characterized by elemental analysis,infrared spectrum,and single-crystal X-ray analysis.The ligand bipy of compound 1 was generated by a decarboxylation coupling reaction of H2pdc(H2pdc=pyridine-2,6-dicarboxylic acid) in situ under hydrothermal reaction conditions and the control experiments illustrate that La(NO3)3 or Ce(NO3)3,which does not appear in the final structure,is necessary for the decarboxylation coupling reaction.Moreover,compound 1 displays strong photoluminescence property in the solid state at room temperature. 相似文献
227.
Qing-Xiang Guan De-Ya Sun Ji-Hua Liu Wei Li Qin Meng Cong Geng Jian-Yuan Yin 《中国化学快报》2013,24(6):524-526
Bioassay-guided fractionation of the acid hydrolysate of total ginsenosides of Panax ginseng C.A.Meyer (Araliaceae) led to the isolation of a novel ginsengenin(1).The structure of 1 was determined as (20S,22S)-dammar-22,25-epoxy-3β,12β,20-triol by extensive spectroscopy and single-crystal X-ray diffraction analyses.The cytotoxicity of 1 was further tested against SWl 116,HCTl 16,and A549 cells by the MTT method,with IC50 values in the range of 2.96-30.9μmol/L. 相似文献
228.
Barbara Cosimelli Gabrio RoncucciDonata Dei Lia FantettiFiammetta Ferroni Micaela RicciDomenico Spinelli 《Tetrahedron》2003,59(50):10025-10030
The synthesis of new unsymmetrical substituted zinc phthalocyanines derivatives has been described; moreover the photodynamic activity of some compounds tested against Candida albicans has been reported. 相似文献
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230.
Runde W Brodnax LF Goff GS Peper SM Taw FL Scott BL 《Chemical communications (Cambridge, England)》2007,(17):1728-1729
Single crystals of Na(8)Pu(2)(O(2))(2)(CO(3))(6) x 12H(2)O, exhibiting bridging mu(2),eta(2)-O(2) ligands in unprecedented Pu(IV) dimeric units, were obtained at ambient temperature from an aqueous Pu(IV) peroxide carbonate solution. 相似文献