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861.
862.
A second order nonlinear differential equation
相似文献
863.
864.
Intercalationchemistryoflayeredtransitionmetaldisulfideshasbeenextensivelystudiedinthepastyears[1].Ithasbeenestablishedthattheintercalationreactiondependsstronglyonelectronicstructureofthetransitionmetaldisulfides.Forinstance,variousguestmoleculeshavebe… 相似文献
865.
866.
镓在裸Si系和SiO2/Si系掺杂效应 总被引:3,自引:0,他引:3
Based on the diffusion action of gallium in silicon and SiO2 ,a diffusion model of gallium doping in bare silicon system and SiO_2/Si system is first presented in this paper ,the gallium doping effect in the two systems is analyzed theoretically. Experiments and applications have proved that the use of the open-tube gallium deffusion in SiO2/Si system can substantially improve diffusion quality and device characteristics . 相似文献
867.
X. Zhao Y. Itoh Y. Aoyagi T. Sugano K. Hirata Y. Kobayashi T. Ohdaira R. Suzuki T. Mikado 《Journal of Radioanalytical and Nuclear Chemistry》1996,211(1):31-38
Positron and positronium annihilation investigations were applied to nanocrystalline silicon (nc-Si) thin films, for the first time. The nc-Si thin films with average grain diameters of 3–5 nm show intense blue luminescence at room temperature. The nanometer-sized Si crystallites formed in amorphous Si (a-Si) matrix give rise to this luminescence. Very highS-parameters up to 0.62 were observed in the as-grown a-Si thin film suggesting positronium formation in the a-Si layer. The average lifetime of the positrons in the a-Si was determined to be about 520 ps. TheS-parameters dropped significantly to 0.53 by crystallization of the thin film at 800 °C for 10 seconds, which was almost the same to the value observed in bulk Si (100) substrate. Further crystallization from 60 seconds to 1 hour showed smaller change in theS-parameters than that from the a-Si to 10 seconds. The large change in theS-parameters due to the annealing might be caused by the formation of Si nanocrystallites in a-Si matrix suggesting that positron is a sensitive probe for structural investigations of the nc-Si materials. 相似文献
868.
Xingang Kong Jiarui Zhang Jianfeng Huang Jiayin Li Yi Qin Ting Zhao Qi Feng 《中国化学快报》2019,30(3):771-774
SnNb2O6 and Sn2Nb2O7 nanosheets were synthetized via microwave assisted hydrothermal method, and innovatively employed as anode materials for lithium-ion battery. Compared with Sn2Nb2O7 and the previously reported pure Sn-based anode materials, the SnNb2O6 electrode exhibited outstanding cycling performance. 相似文献
869.
A new fluorinated polystyrene bearing a p-sulbstiuted perfluoro[1-(2-fluorosulfonylethoxy)]ethyl group was synthesized via one-electron oxidation of polystyrene by perfluoro[2-(2-fluorosulfonylethoxy)]propionyl peroxide at different peroxide to polystyrene molar ratios.The yield of perfluoroalkylation decreases with the increase of the reactant molar ratio.The modified polymer has been characterized by various techniques:the ring pefluoro[1-(2-fluorosulfonylethoxy)]ethylation has been proved by FT-IR and ^19FNMR;the X-ray photoelectron spectra(XPS) show the maximum binding energy of F18,O18,C18(two kinds of carbon atoms,namely C-H and C-F)and S2p,respectively; desulfonylation of the fluorinated polystyrene appearing at 217℃ has been found by its thermogravimetric analysis (TGA).The determinations of contact angle,refractive index and glass transition temperature of the modified polymer have disclosed that when the contact angle increases with the increase of the molar ratio,the refractive index and glass transition temperature decrease.The polydispersity values indicate that the degradation of the polymer chains did not occur during the reaction. 相似文献
870.
Yu-Fen Zhao De-Qing Zhang Chu-Biao Xue Jia-Ning Zeng Gai-Jiao Ji 《Journal of mass spectrometry : JMS》1991,26(5):510-513
Positive ion fast atom bombardment mass spectrometry of N-diisopropyloxyphosphoryl dipeptides and tripeptides showed a novel cleavage pattern in that only the N-phosphoryl fragment ions gave intense peaks while the C-terminal series of ions was suppressed. The base peak was the N-phosphoryl imino ion responding to the N-terminal residue. These advantages are superior to those of other types of N-protecting groups. 相似文献
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