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731.
A series of Eu3+-incorporated ETS-10 samples were successfully prepared based on the traditional ion exchange method. The relationship between photogenerated charge behaviors and luminescent properties has been investigated in detail. It has been demonstrated that as a result of the charge transfer from the titanate quantum wires to Eu3+ crystal field states, the host matrix ETS-10 functions as the sensitizer of Eu3+ to enhance the red luminescence, while Eu3+ cations contribute to the recombination of photogenerated charges. The behavior of photogenerated charges has significant impact on the luminescent properties of Eu3+-incorporated ETS-10 materials. 相似文献
732.
733.
Prof. Dr. Minghuey Shieh Chun‐Hsien Yu Yen‐Yi Chu Yu‐Wen Guo Chung‐Yi Huang Kai‐Jieah Hsing Pei‐Chi Chen Chung‐Feng Lee 《化学:亚洲杂志》2013,8(5):963-973
The reactions of E powder (E=S, Se) with a mixture of Cr(CO)6 and Mn2(CO)10 in concentrated solutions of KOH/MeOH produced two new mixed Cr? Mn? carbonyl clusters, [E2CrMn2(CO)9]2? (E=S, 1 ; Se, 2 ). Clusters 1 and 2 were isostructural with one another and each displayed a trigonal‐bipyramidal structure, with the CrMn2 triangle axially capped by two μ3‐E atoms. The analogous telluride cluster, [Te2CrMn2(CO)9]2? ( 3 ), was obtained from the ring‐closure of Te2Mn2 ring complex [Te2Mn2Cr2(CO)18]2? ( 4 ). Upon bubbling with CO, clusters 2 and 3 were readily converted into square‐pyramidal clusters, [E2CrMn2(CO)10]2? (E=Se, 5 ; Te, 6 ), accompanied with the cleavage of one Cr? Mn bond. According to SQUID analysis, cluster 6 was paramagnetic, with S=1 at room temperature; however, the Se analogue ( 5 ) was spectroscopically proposed to be diamagnetic, as verified by TD‐DFT calculations. Cluster 6 could be further carbonylated, with cleavage of the Mn? Mn bond to produce a new arachno‐cluster, [Te2CrMn2(CO)11]2? ( 7 ). The formation and structural isomers, as well as electrochemistry and UV/Vis absorption, of these clusters were also elucidated by DFT calculations. 相似文献
734.
Dong‐Cheng Hu Chao‐Hu Xiao Guo‐Zhe Guo Yun‐Xia Yang Jia‐Cheng Liu 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(4):356-359
A one‐dimensional AgI coordination complex, catena‐poly[[silver(I)‐μ‐{2‐[2‐(pyridin‐4‐yl)‐1H‐benzimidazol‐1‐ylmethyl]phenol‐κ2N2:N3}] perchlorate monohydrate], {[Ag(C19H15N3O)]ClO4·H2O}n, was synthesized by the reaction of 2‐[2‐(pyridin‐4‐yl)‐1H‐benzimidazol‐1‐ylmethyl]phenol (L) with silver perchlorate. In the complex, the L ligands are arranged alternately and link AgI cations through one benzimidazole N atom and the N atom of the pyridine ring, leading to an extended zigzag chain structure. In addition, the one‐dimensional chains are extended into a three‐dimensional supramolecular architecture via O—H...O hydrogen‐bond interactions and π–π stacking interactions. The complex exhibits photoluminescence in acetonitrile solution, with an emission maximum at 390 nm, and investigation of the thermal stability reveals that the network structure is stable up to 650 K. 相似文献
735.
Yuanyuan Guo Limin Chen Ding Ma Daiqi Ye Bichun Huang 《Journal of Energy Chemistry》2013,22(4):591-598
Activated carbon (AC) supported silver catalysts were prepared by incipient wetness impregnation method and their catalytic performance for CO preferential oxidation (PROX) in excess H2 was evaluated. Ag/AC catalysts, after reduction in H2 at low temperatures (≤200 °C) following heat treatment in He at 200 °C (He200H200), exhibited the best catalytic properties. Temperature-programmed desorption (TPD), X-ray diffraction (XRD) and temperature-programmed reduction (TPR) results indicated that silver oxides were produced during heat treatment in He at 200 °C which were reduced to metal silver nanoparticles in H2 at low temperatures (≤200 °C), simultaneously generating the adsorbed water/OH. CO conversion was enhanced 40% after water treatment following heat treatment in He at 600 °C. These results imply that the metal silver nanoparticles are the active species and the adsorbed water/OH has noticeable promotion effects on CO oxidation. However, the promotion effect is still limited compared to gold catalysts under the similar conditions, which may be the reason of low selectivity to CO oxidation in PROX over silver catalysts. The reported Ag/AC-S-He catalyst after He200H200 treatment displayed similar PROX of CO reaction properties to Ag/SiO2. This means that Ag/AC catalyst is also an efficient low-temperature CO oxidation catalyst. 相似文献
736.
Qi Guo Zhenhua Sun Man Gao Zhi Tan Bingsen Zhang Dang Sheng Su 《Journal of Energy Chemistry》2013,22(2):347-355
Vanadium pentoxide (V2O5) exhibits high theoretical capacities when used as a cathode in lithium ion batteries (LIBs), but its application is limited by its structural instability as well as its low lithium and electronic conductivities. A porous composite of V2O5-SnO2/carbon nanotubes (CNTs) was prepared by a hydrothermal method and followed by thermal treatment. The small particles of V2O5, their porous structure and the coexistence of SnO2 and CNTs can all facilitate the diffusion rates of the electrons and lithium ions. Electrochemical impedance spectra indicated higher ionic and electric conductivities, as compared to commercial V2O5. The V2O5-SnO2/CNTs composite gave a reversible discharge capacity of 198 mAh·g?1 at the voltage range of 2.05–4.0 V, measured at a current rate of 200 mA·g?1, while that of the commercial V2O5 was only 88 mAh·g?1, demonstrating that the porous V2O5-SnO2/CNTs composite is a promising candidate for high-performance lithium secondary batteries. 相似文献
737.
A novel fluorescent probe based on B,O-chelated dipyrromethene chromophore in far-visible and near-infrared spectral region (600–900 nm), boron chelated 8-(3,4-diaminophenyl)-3,5-bis(2-hydroxyphenyl)-4-bora-3a,4a-diaza-s-indancene (BOPB), has been first developed for nitric oxide (NO) imaging. BOPB, a turn-on fluorescent probe, can react with NO rapidly under physiological condition. The reaction product of BOPB with NO, BOPB-T, emits bright red fluorescence at 643 nm when excited at 622 nm. Meanwhile, BOPB-T displays high fluorescent quantum yield of 0.21 and good photostability. The selectivity for NO over other reactive oxygen/nitrogen species and ascorbic acid has been investigated and BOPB has good specificity for the detection of NO. MTT assay shows that the toxicity of BOPB (below 10 μM) to living cells can be neglected. Based on these investigations, BOPB has been used for NO imaging in Raw 264.7 cells and onion tissues. Meanwhile, mechanical injury to onion tissues results in a brighter fluorescence around the wound, which indicates that more NO has been produced in plant tissues in response to external stimuli. Our studies illustrate that BOPB has advantages of high sensitivity, low background interference and little photo damage on fluorescence imaging of NO. 相似文献
738.
739.
Bao-Min Wang Zhang Yuan Zhi-Qiang Guo Hai-Nan Ma Chuan Fook Lai 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2013,87(13):2253-2259
As a new nano-scale functional material, it is necessary to achieve a uniform distribution in the composites for gaining the CNFs’ excellent reinforcing effect. In this paper, CNFs were purified by the method of high temperature annealing treatment. Six surfactants, methylcellulose (MC), hydroxypropyl methylcellulose (HPMC), sodium dodecyl sulfate (SDS), dodecylamine (DDA), N, N-dimethyl formamide (DMF) and cetyltrimethyl ammonium bromide (CTAB) were used individually and combinatorially in a certain concentration to disperse the CNFs in aqueous solution. To achieve a good dispersion of the CNFs, a method utilizing ultrasonic processing was employed. The CNFs treated by the method of high temperature annealing treatment were characterized by differential thermal analysis (DTA) and thermogravimetry analysis (TGA), and the ultrasonication-driven dispersion of CNFs in aqueous solutions were monitored by UVvis spectroscopy and transmission electron microscopy (TEM). The experiments reveal that the method of high temperature annealing treatment purified the CNFs and the maximum achievable dispersion of CNFs corresponds to the maximum UV absorbance of the solution. All results show that the surfactants mixture of MC and SDS in a certain concentration of 0.4 and 2.0 g/L has the maximum dispersion effect on CNFs in aqueous solution, the optimum concentration ratio of MC, SDS, and CNFs was 2: 10: 1. 相似文献
740.
Treatment of cerium dioxide with small amounts of RuCl3. 3H2O allows the mild preparation of an efficient heterogeneous system for the dioxygen oxidation of various alcohols and aldehydes. 相似文献