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221.
222.
Crystal structure of meso‐substituted pyrazolyl porphyrin complexes and their highly active catalyst for oxidation of alkylbenzenes 下载免费PDF全文
During the past few years, a great deal of effort has been devoted to the anchoring of catalytic oxidation. In this work, three new catalysts CuPp, MnPp and ZnPp by solvothermal methods with 5, 10, 15, 20‐tetrakis(4‐N‐pyrazolyl)‐phenyl porphyrin (H2Pp) and the corresponding metal salts have been synthesized and structurally characterized. The single crystal structures determined by X‐ray diffraction show the bond distances of M‐N in porphyrin cores determined the conformation of porphyrin rings. We explored the catalytic activity of CoPp, CuPp, MnPp and ZnPp for oxidation of alkylbenzenes. The experimental results display these products exhibit high catalytic activities and selectivities for oxidation of ethylbenzene to acetophenone, and can be reused by filtration without appreciable decrease in catalytic activity and selectivity. 相似文献
223.
Liwei Zhang Guiqiang Du Yewen Zhang 《Applied Physics A: Materials Science & Processing》2012,109(4):851-856
We present a theoretical investigation into the energy transport and transient wave propagation in metamaterial tunneling structures consisting of ??-negative (ENG) and ??-negative (MNG) materials. It is proved that a conjugated matched ENG/MNG bilayer and a (zero-index-material doped) photonic crystal heterostructure can work as a sub-wavelength resonator at tunneling frequency. The tunneling modes need a certain time to achieve the steady state and the charge up characteristic time increases (nearly) exponentially with the thickness of the structures. Under the steady state, the wave in the single-negative-material structures is not evanescent, but a hybrid of a traveling wave and a reactive standing wave. The phase difference between the electric field and the magnetic field varies with the position and time. The investigation of transient wave propagation in the metamaterial tunneling structures will help us to understand the interaction process between wave and metamaterial and to design special functional apparatus. 相似文献
224.
Weishi Du Yaokang Lv Hongliang Lu Zaihua Chen Dominic S. Wright Cheng Zhang 《中国化学快报》2017,28(12):2285-2289
An efficient and cost-effective strategy to modificate the surface of active carbon (AC), form a 3D-conductive network, and therefore improve the electrochemical performance of AC based supercapacitor was developed. 相似文献
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226.
Nonlinear Dynamics - The chemical synapses in a neural network are known to be modulated by the neuronal firing activities through the spike-timing-dependent plasticity (STDP) rule. In this paper,... 相似文献
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228.
Meng Liu Dr. Hao Fan Dr. Ou Zhuo Xiao Du Longqi Yang Prof. Peng Wang Lijun Yang Prof. Qiang Wu Prof. Xizhang Wang Prof. Zheng Hu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(15):3843-3848
Molybdenum disulfide (MoS2) is an intensively studied anode material for lithium-ion batteries (LIBs) owing to its high theoretical capacity, but it is still confronted by severe challenges of unsatisfactory rate capability and cycle life. Herein, few-layer MoS2 nanosheets, vertically grown on hierarchical carbon nanocages (hCNC) by a facile hydrothermal method, introduce pseudocapacitive lithium storage owing to the highly exposed MoS2 basal planes, enhanced conductivity, and facilitated electrolyte access arising from good hybridization with hCNC. Thus, the optimized MoS2/hCNC exhibits reversible capacities of 1670 mAh g−1 at 0.1 A g−1 after 50 cycles, 621 mAh g−1 at 5.0 A g−1 after 500 cycles, and 196 mAh g−1 at 50 A g−1 after 2500 cycles, which are among the best for MoS2-based anode materials. The specific power and specific energy, which can reach 16.1 kW and 252.8 Wh after 3000 cycles, respectively, indicate great potential in high-power and long-life LIBs. These findings suggest a promising strategy for exploring advanced anode materials with high reversible capacity, high-rate capability, and long-term recyclability. 相似文献
229.
Comparison of the effects of K4Fe(CN)6 and K3Fe(CN)6 on TICT dual fluorescence of sodium p-dimethylaminobenzoate (SDMAB) in cetyltrimethyl ammonium chloride (CTAC) micelle yields a conclusion that the presence of a magnetic effect un favors the TICT process, which is verified by inserting the sample in a stationary magnetic field of 100G in which a decrease in the relative quantum yield of TICT state is observed. 相似文献
230.
Kristina D. Radosavljević Jelena D. Lović Dušan Ž. Mijin Slobodan D. Petrović Milka B. Jadranin Aleksandar R. Mladenović Milka L. Avramov Ivić 《Chemical Papers》2017,71(7):1217-1224
The electrodegradation of azithromycin was studied by its indirect oxidation using dimensionally stable Ti/RuO2 anode as catalyst in the electrolyte containing methanol, 0.05 M NaHCO3, sodium chloride and deionized water. The optimal conditions for galvanostatic electrodegradation for the azithromycin concentration of 0.472 mg cm?3 were found to be NaCl concentration of 7 mg cm?3 and the applied current of 300 mA. The differential pulse voltammetry using glassy carbon electrode was performed for the first time in the above-mentioned content of electrolyte for the nine concentration of azithromycin (0.075–0.675 mg cm?3) giving the limits of azithromycin detection and of quantification as: LOD 0.044 mg cm?3 and LOQ 0.145 mg cm?3. The calibration curve was constructed enabling the electrolyte analysis during its electrodegradation process. The electrolyte was analyzed by high-performance liquid chromatography and electrospray ionization time-of-flight mass spectrometry. The electrooxidation products were identified and after 180 min there was no azithromycin in the electrolyte while TOC analysis showed that 79% of azithromycin was mineralized. The proposed degradation scheme is presented. 相似文献