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61.
Xinye Yang Xiaohui Wang Ming Huang Shaopeng Zhang Longtu Li 《Journal of Sol-Gel Science and Technology》2014,69(1):61-66
0.65CaTiO3–0.35Sm0.9Nd0.1AlO3 (CTSA) ceramic nanopowders were synthesized via sol–gel method using the ethylene diamine tetraacetic acid as a chelating agent. Thermal analysis, Fourier transform infrared spectroscopy and X-ray diffraction were used to character the decomposition of precursor and phase transformation process of derived oxide powders. Single phase and well-crystallized 0.65CaTiO3–0.35Sm0.9Nd0.1AlO3 powders with particle size of 30–40 nm were obtained by calcination at 800 °C. Dense ceramic was successfully obtained from the ultrafine powders sintered at 1,325 °C, almost 100 °C lower than 1,415 °C required for conventional powders. Compared with those prepared by conventional solid-state method, the CTSA ceramics derived from sol to gel process sintered at a lower temperature showed better microwave dielectric properties of εr ~ 39, Q × f over 50,000 GHz and small τf ~ ?7.1 ppm/K. 相似文献
62.
Rujie Wang Xiaoming Yan Xuemei Wu Gaohong He Lin Du Zhengwen Hu Ming Tan 《Journal of Polymer Science.Polymer Physics》2014,52(16):1107-1117
Modification of proton conductive channels (PCCs) in Nafion has been achieved with the assistance of 3, 4‐dimethylbenzaldehyde (DMBA). During annealing, ionic clusters develop from small isolated spheres (1.72 nm) to wide continuous channels (5.15 nm), and the crystallinity of Nafion/DMBA membranes is also improved from 17% to 32% as shown by X‐ray diffraction. Molecular dynamic simulation reveals that hydrogen bonding and hydrophobic interaction between DMBA and Nafion work synergistically to achieve better phase separation. The morphology–property relationship shows that, versus various PCCs width, the corresponding proton conductivities vary greatly from 0.079 to 0.139 S/cm at 80 °C. By carefully tuning the width of PCCs, the proton conductivity shows an improvement of 22–34% as compared with pristine Nafion. A significant enhancement on the maximum power density is achieved for the membrane electrode assembly on Nafion/DMBA‐8h (as high as 1018 mW/cm?2), yielding an enhancement of 39% on pristine Nafion‐8h (730 mW/cm?2). © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 52, 1107–1117 相似文献
63.
64.
Determination of selected polychlorinated biphenyls in soil and earthworm (Eisenia fetida) using a QuEChERS‐based method and gas chromatography with tandem MS 下载免费PDF全文
Zeying He Lu Wang Yi Peng Ming Luo Wenwen Wang Xiaowei Liu 《Journal of separation science》2015,38(21):3766-3773
Soil and earthworms are important objects in soil pollution assessment and environmental behavior and toxicity study for polychlorinated biphenyls. Accelerated solvent extraction and solid‐phase extraction are generally required for the extraction and clean‐up of polychlorinated biphenyls in soil and earthworm, which are tedious and time‐consuming. In this work, a modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) procedure combined with gas chromatography and triple quadrupole mass spectrometry was developed for the determination of 20 selected polychlorinated biphenyl congeners in soil and earthworm. Different extraction times, solvents, and clean‐up adsorbents were compared and optimized. The average recoveries from spiked soils ranged between 70 and 120% with satisfactory relative standard deviations for all the polychlorinated biphenyls. In earthworm, the recoveries of polychlorinated biphenyls 180, 183, and 189 were relatively low (< 70% in some spiking levels) compared to that of the other polychlorinated biphenyls. The limits of quantification were in the range of 0.01–0.05 ng/g. The method was successfully applied to the analysis of 66 agricultural soils. To our knowledge, a combined method based on QuEChERS for the determination of polychlorinated biphenyls in soil and earthworms has not been published before. The procedure proved to be simple, sensitive, efficient, and environmentally friendly. 相似文献
65.
66.
Synthesis of Nanoporous Ni‐Co Mixed Oxides by Thermal Decomposition of Metal‐Cyanide Coordination Polymers 下载免费PDF全文
Mohamed B. Zakaria Dr. Ming Hu Dr. Malay Pramanik Dr. Cuiling Li Dr. Jing Tang Prof. Ali Aldalbahi Prof. Saad M. Alshehri Dr. Victor Malgras Prof. Yusuke Yamauchi 《化学:亚洲杂志》2015,10(7):1541-1545
A straightforward strategy to prepare nanoporous metal oxides with well‐defined shapes is highly desirable. Through thermal treatment and a proper selection of metal‐cyanide coordination polymers, nanoporous nickel‐cobalt mixed oxides with different shapes (i.e., flakes and cubes) can be easily prepared. Our nanoporous materials demonstrate high electrocatalytic activity for oxygen evolution reaction. 相似文献
67.
A Nanoscale Multiresponsive Luminescent Sensor Based on a Terbium(III) Metal–Organic Framework 下载免费PDF全文
Dr. Song Dang Dr. Ting Wang Dr. Feiyan Yi Dr. Qinghui Liu Dr. Weiting Yang Prof. Zhong‐Ming Sun 《化学:亚洲杂志》2015,10(8):1703-1709
A nanoscale terbium‐containing metal–organic framework ( nTbL ), with a layer‐like structure and [H2NMe2]+ cations located in the framework channels, was synthesized under hydrothermal conditions. The structure of the as‐prepared sample was systematically confirmed by powder XRD and elemental analysis; the morphology was characterized by field‐emission SEM and TEM. The photoluminescence studies revealed that rod‐like nTbL exhibited bright‐green emission, corresponding to 5D4→7FJ (J=6–3) transitions of the Tb3+ ion under excitation. Further sensing measurements revealed that as‐prepared nTbL could be utilized as a multiresponsive luminescent sensor, which showed significant and exclusive detection ability for Fe3+ ions and phenylmethanol. These results highlight the practical applications of lanthanide‐containing metal–organic frameworks as fluorescent probes. 相似文献
68.
Ming Chen Lingzhi Li Han Nie Jiaqi Tong Lulin Yan Bin Xu Jing Zhi Sun Wenjing Tian Zujin Zhao Anjun Qin Ben Zhong Tang 《Chemical science》2015,6(3):1932-1937
Research on aggregation-induced emission (AIE) has been a hot topic. Due to enthusiastic efforts by many researchers, hundreds of AIE luminogens (AIEgens) have been generated which were mainly based on archetypal silole, tetraphenylethene, distyrylanthracene, triphenylethene, and tetraphenyl-1,4-butadiene, etc. To enlarge the family of AIEgens and to enrich their functions, new AIEgens are in high demand. In this work, we report a new kind of AIEgen based on tetraphenylpyrazine (TPP), which could be readily prepared under mild reaction conditions. Furthermore, we show that the TPP derivatives possess a good thermal stability and their emission could be fine-tuned by varying the substituents on their phenyl rings. It is anticipated that TPP derivatives could serve as a new type of widely utilized AIEgen, based on their facile preparation, good thermo-, photo- and chemostabilities, and efficient emission. 相似文献
69.
Qiu‐Ying Huang Ming‐Yang Su Xiang‐Ru Meng 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(6):474-478
The combination of N‐heterocyclic and multicarboxylate ligands is a good choice for the construction of metal–organic frameworks. In the title coordination polymer, poly[bis{μ2‐1‐[(1H‐benzimidazol‐2‐yl)methyl]‐1H‐tetrazole‐κ2N3:N4}(μ4‐butanedioato‐κ4O1:O1′:O4:O4′)(μ2‐butanedioato‐κ2O1:O4)dicadmium], [Cd(C4H4O4)(C9H8N6)]n, each CdII ion exhibits an irregular octahedral CdO4N2 coordination geometry and is coordinated by four O atoms from three carboxylate groups of three succinate (butanedioate) ligands and two N atoms from two 1‐[(1H‐benzimidazol‐2‐yl)methyl]‐1H‐tetrazole (bimt) ligands. CdII ions are connected by two kinds of crystallographically independent succinate ligands to generate a two‐dimensional layered structure with bimt ligands located on each side of the layer. Adjacent layers are further connected by hydrogen bonding, leading to a three‐dimensional supramolecular architecture in the solid state. Thermogravimetric analysis of the title polymer shows that it is stable up to 529 K and then loses weight from 529 to 918 K, corresponding to the decomposition of the bimt ligands and succinate groups. The polymer exhibits a strong fluorescence emission in the solid state at room temperature. 相似文献
70.
Shao‐Ming Ying Jing‐Jing Ru Wu‐Kui Luo 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(7):618-622
Metal–organic frameworks (MOFs) have potentially useful applications and an intriguing variety of architectures and topologies. Two homochiral coordination polymers have been synthesized by the hydrothermal method, namely poly[(μ‐N‐benzyl‐L‐phenylalaninato‐κ4O,O′:O,N)(μ‐formato‐κ2O:O′)zinc(II)], [Zn(C16H16NO2)(HCOO)]n, (1), and poly[(μ‐N‐benzyl‐L‐leucinato‐κ4O,O′:O,N)(μ‐formato‐κ2O:O′)zinc(II)], [Zn(C13H18NO2)(HCOO)]n, (2), and studied by single‐crystal X‐ray diffraction, elemental analyses, IR spectroscopy and fluorescence spectroscopy. Compounds (1) and (2) each have a two‐dimensional layer structure, with the benzyl or isobutyl groups of the ligands directed towards the interlayer interface. Photoluminescence investigations show that both (1) and (2) display a strong emission in the blue region. 相似文献