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131.
Phosphorus-doped ZnO nanocombs with double-sided symmetry were prepared by a modified thermal-evaporation process using phosphorus pentoxide as the dopant source. Scanning electron microscopy and transmission electron microscopy reveal that the single-crystal teeth in the doped nanocombs grow along [0002] direction and that the formation of the tapered tip should be related to the lattice strain caused by the incorporation of phosphorous. Raman spectra further reveal the influence of phosphorus doping on the lattice dynamics of ZnO, and display the amphoteric nature of phosphorus dopant. The p-type doping is confirmed by the temperature-dependent photoluminescence spectra, and the acceptor binding energy is estimated to be about 165 meV. 相似文献
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133.
组合荷载下超大群桩受力变形模型试验研究 总被引:1,自引:0,他引:1
研究表皮生长因子(EGF)2,4,7,14d处理后鼠小肠所发生的生物力学重建. 通
过双轴试验(膨胀与轴向拉伸组合),用最小二乘法计算了近于在体状态下环向、纵向及交
叉向增量杨氏模量. 各组环向和纵向模量均不相等,即正常状态和EGF处理后的小肠是各向
异性的. 在EGF处理期间,各向的杨氏模量随时间变化(P<0.05). 在EGF处理的最
初7d中,环向模量减小,在处理14d后,又恢复到对照组的水平. 增量模量介
于17.4kPa与24.2kPa
之间. 纵向模量的值介于22.9kPa与32.4kPa之间,在处理4d后,比对照值显著增大(P<0.02).
交叉模量的值介于4.7kPa与6.6kPa之间,在最初EGF处理的4d中降低,此后增加并
于第7d达到最大值. 可以得出结论,肠壁的力学性质呈各向异性且在EGF处理期间会发生重建. 相似文献
134.
Judong You Jiangman Liu Donghua Chen Zhenghua Song 《Journal of Analytical Chemistry》2014,69(1):17-21
A green, rapid and sensitive flow injection procedure based on the inhibition of the chemiluminescence (CL) intensity from the luminol-myoglobin (Mb) system is proposed for the determination of matrine. The decrement of CL signal was linear with the logarithm of the matrine concentration over the range from 10 to 1000 ng/mL (R 2 = 0.9978) offering a detection limit of 3.5 ng/mL. At a flow rate of 2.0 mL/min, one analysis cycle, including sampling and washing, could be accomplished in 0.5 min with a relative standard deviation (RSD) of less than 5.0%. The sensitive flow injection method was successfully applied to the determination of matrine in pharmaceutical injection and human serum, with recoveries from 94.1 to 113.4% and RSDs of less than 5.0%. 相似文献
135.
Three‐step process improves crystal quality of Cu2ZnSnS4 absorber layer and efficiency of solar cell
Donghua Fan Junzhi Zhang Xianghu Wang Manqin Xu Shuai Xu 《Crystal Research and Technology》2015,50(8):613-620
Cu2ZnSnS4 (CZTS) films are fabricated using the three‐step process, including deposition, preheating and sulfurization of Cu–Zn–Sn (CZT) precursors. The effect of preheating temperature on structures, morphologies, and optical properties of CZTS films is investigated detailedly by X‐ray diffraction, Raman spectra, scanning electron microscopy, and UV spectrophotometer. It is found that the proper preheating temperature can improve the crystal quality of CZTS films. The prepared CZTS film by sulfurizing the preheated precursor at 300 °C presents high crystallinity, uniform surface morphology, and suitable optical properties. Compared with two‐step process, three‐step method can not only improve crystal quality of CZTS films but also decline sulfurization temperature. We also discuss the mechanism of improving the properties of CZTS absorber layer by the preheating route in detail. In addition, the experimental results also indicate that solar cell prepared by three‐step method displays higher conversion efficiency. 相似文献
136.
YUAN Ji-xin ** HU Mao-lin LI Ju-xia SONG Xin-yuan . College of Chemistry Chemical Engineering Donghua University Shanghai P. R. China . Department of Chemistry Wenzhou Normal College Wenzhou P.R.China 《高等学校化学研究》2005,21(1):21-23
IntroductionThe synthesis and characterization of the novelcomplexes with polycarboxylate groups are activefields currently due to their diverse intriguingstructures and potential properties as new materi-als[1_ 3 ] . 1 ,2 ,4,5 - Benzenetetracarboxylic acid( H4tcb) has a versatile coordination behavior sinceit can bridge metal centers in many modes,gener-ating various and sometimes surprising moleculararchitectures. Therefore,numerous complexeswith ligand H4TCB have been extensively stud-ied… 相似文献
137.
Jie Qiu Donghua Xu Junchai Zhao Yanhua Niu Zhigang Wang 《Journal of Polymer Science.Polymer Physics》2008,46(19):2100-2115
A semicrystalline ethylene‐hexene copolymer (PEH) was subjected to a simple thermal treatment procedure as follows: the sample was isothermally crystallized at a certain isothermal crystallization temperature from melt, and then was quenched in liquid nitrogen. Quintuple melting peaks could be observed in heating scan of the sample by using differential scanning calorimeter (DSC). Particularly, an intriguing endothermic peak (termed as Peak 0) was found to locate at about 45 °C. The multiple melting behaviors for this semicrystalline ethylene‐hexene copolymer were investigated in details by using DSC. Wide‐angle X‐ray diffraction (WAXD) technique was applied to examine the crystal forms to provide complementary information for interpreting the multiple melting behaviors. Convincing results indicated that Peak 0 was due to the melting of crystals formed at room temperature from the much highly branched ethylene sequences. Direct heating scans from isothermal crystallization temperature (Tc, 104–118 °C) were examined for comparison, which indicated that the multiple melting behaviors depended on isothermal crystallization temperature and time. A triple melting behavior could be observed after a relatively short isothermal crystallization time at a low Tc (104–112 °C), which could be attributed to a combination of melting of two coexistent lamellar stack populations with different lamellar thicknesses and the melting‐recrystallization‐remelting (mrr) event. A dual melting behavior could be observed for isothermal crystallization with both a long enough time at a low Tc and a short or long time at an intermediate Tc (114 °C), which was ascribed to two different crystal populations. At a high Tc (116–118 °C), crystallizable ethylene sequences were so few that only one single broad melting peak could be observed. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 2100–2115, 2008 相似文献
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