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991.
Potentiodynamic sweep and electrochemical impedance spectroscopy measurements were applied to investigate the effects of both temperature and acetic acid (HAc) on the anodic and cathodic reactions in CO2 corrosion of P110 steel in 3.5% NaCl solution. The temperatures were controlled at 30 and 60 °C. The concentrations of HAc were controlled at 0, 1000, 3000 and 5000 ppm. In this work, the corrosion parameters of polarization curves, such as corrosion potential (Ecorr), corrosion current density (icorr), and anodic and cathodic branch slopes (ba and bc), are presented and discussed in detail. In addition, the equivalent circuit models and ZsimpWin software were utilized to discuss the Nyquist plots. The plots showed that the Ecorr values shifted in the positive direction as the HAc concentration increased. The icorr values increased with the increase in HAc concentration, indicating that HAc could accelerate the corrosion. The impedance spectra measured at 30 and 60 °C have different time constants and characterization. The coverage fraction θ and the thickness L of corrosion film are two most important controlled variables that influence and control the CO2 corrosion mechanisms. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
992.
Wenlong Yin Dajiang Mei Jiyong Yao Peizhen Fu Yicheng Wu 《Journal of solid state chemistry》2010,183(11):2544-2551
Two new ternary bismuth chalcogenides, Bi3In4S10 and Bi14.7In11.3S38, were synthesized from the reactions of binary sulfides via a two-step flux technique. Single-crystal X-ray diffraction analyses indicate that Bi3In4S10 crystallizes in the non-centrosymmetric space group Pm and Bi14.7In11.3S38 crystallizes in the centrosymmetric space group P21/m. Both compounds adopt three-dimensional frameworks. A distinct structural feature in the two structures is the presence of chains of Bi atoms with alternating short Bi-Bi bonds of around 3.1 Å and longer distances of around 4.6 Å. The optical band gaps of 1.42(2) eV for Bi3In4S10 and 1.45(2) eV for Bi14.7In11.3S38 were deduced from the diffuse reflectance spectra. 相似文献
993.
A series of novel helicid derivatives containing 3,4-dihydropyrimidin-2(1H)-one and 3,4-dihydropyrimidine2(1H)-thione moiety (3a–3f and 4a–4f) were synthesized starting from helicid. The structure of the new compounds were characterized by 1H NMR, IR and HR-MS spectra. The sedative-hypnotic activities of the target compounds were evaluated using the test of spontaneous
locomotor activity in mice. All of the derivatives produced moderate to high activities; in particular, compound 4a presented the most potent sedative-hypnotic effect in comparison to the other derivatives, and derivatives 3a, 3c, 3d, 3e and 3f also showed potent activities. 相似文献
994.
Utilizing all forms of sugars derived from lignocellulosic biomass via various pretreatment and hydrolysis process is a primary criterion for selecting a microorganism to produce biofuels and biochemicals. A broad carbon spectra and potential inhibitors such as furan, phenol compounds and weak acids are two major obstacles that limited the application of dilute-acid hydrolysate of lignocellulosics in lactic acid fermentation. Two strains of bacteria isolated from sour cabbage, S3F4 (Lactobacillus brevis) and XS1T3-4 (Lactobacillus plantrum), exhibited the ability to utilize various sugars present in dilute-acid hydrolysate of biomass. The S3F4 strain also showed strong resistance to potential fermentation inhibitors such as ferulic acid and furfural. Fermentation in flasks by this strain resulted in 39.1 g/l of lactic acid from dilute acid hydrolysates of corncobs that had initial total sugar concentration of 56.9 g/l (xylose, 46.4 g/l; glucose, 4.0 g/l; arabinose, 6.5 g/l). The hydrolysate of corncobs was readily utilized by S3F4 without detoxification, and the lactic acid concentration obtained in this study was higher compared to other reports. 相似文献
995.
Limiao Li Xiaoming Yin Shuang Liu Yanguo Wang Libao Chen Taihong Wang 《Electrochemistry communications》2010,12(10):1383-1386
Porous SnO2 nanotubes were prepared via electrospinning followed by calcination in air. As anode materials for lithium ion batteries, the porous nanotubes delivered a high discharge capacity of 807 mAh g? 1 after 50 cycles. Even after cycled at high rates, the electrode still retained a high fraction of its theoretical capacity. Such excellent performances of porous SnO2 nanotubes could be attributed to the porous and hollow structure which facilitated liquid electrolyte diffusion into the bulk materials and buffered large volume changes during lithium ions insertion/extraction. Furthermore, the nanoparticles of nanotubes provided the shorter diffusion length for lithium ions insertion which benefited in retaining the structural stability and good rate performance. Our results demonstrated that this simple method could be extended for the synthesis of porous metal oxide nanotubes with high performances in the applications of lithium ion batteries and other fields. 相似文献
996.
Guang-jin Wang Yun-zhi Gao Zhen-bo Wang Chun-yu Du Ge-ping Yin 《Electrochemistry communications》2010,12(8):1070-1073
Here, we report the development of a new membrane electrode assembly (MEA) structure for passive direct borohydride fuel cells (DBFCs). The anode of this type of MEA includes upper and lower parts for the electro-oxidation of borohydride and hydrogen, respectively. In comparison to conventional MEAs, the maximum power of this MEA is increased by 28.1%, and the anode polarization is decreased due to the current contribution of hydrogen electro-oxidation. The hydrogen generated from borohydride hydrolysis can be oxidized inside the cell, and the fuel coulombic efficiency reaches 100%. Therefore, high fuel utilization and cell safety can be obtained by employing this novel MEA in DBFCs. 相似文献
997.
Quanpeng Chen Shiyun Ai Hai Fan Jun Cai Qiang Ma Xiangbin Zhu Huanshun Yin 《Journal of Solid State Electrochemistry》2010,14(9):1681-1688
A novel and sensitive biosensor was developed for the determination of nitrite. Firstly, multi-walled carbon nanotubes–poly(amidoamine)–chitosan
(MWNT–PAMAM–Chit) nanocomposite along with the incorporation of DNA was used to modify the glassy carbon electrode. Then the
immobilization of Cyt c was accomplished using electrochemical deposition method by consecutive cyclic voltammetry (CV) scanning in a neutral Cyt
c solution. CV behaviors of the modified electrodes showed that the MWNT–PAMAM–Chit nanocomposite is a good platform for the
immobilization of DNA and Cyt c in order, at the same time, an excellent promoter for the electron transfer between Cyt c and the electrode. At high potential, the immobilized Cyt c could be further oxidized into highly reactive Cyt c π-cation by two-step electrochemical oxidation, which could oxidize NO2
− into NO3
− in the solution. Therefore, a nitrite biosensor based on the biocatalytic oxidation of the immobilized Cyt c was fabricated, which showed a fast response to nitrite (less than 5 s). The linear range of 0.2–80 μM and a detection limit
of 0.03 μM was obtained. Finally, the application in food analysis using sausage as testing samples was also investigated. 相似文献
998.
D. W. Zhang X. D. Li S. Chen F. Tao Z. Sun X. J. Yin S. M. Huang 《Journal of Solid State Electrochemistry》2010,14(9):1541-1546
Double-walled carbon nanotubes (DWCNTs) have been studied for counter-electrode application in dye-sensitized solar cells
(DSCs). Mesoporous TiO2 films are prepared from the commercial TiO2 nanopowders by screen-printing technique on optically
transparent-conducting glasses. A metal-free organic dye (indoline dye D102) is used as a sensitizer. DWCNTs are applied to
substitute for platinum as counter-electrode materials. Morphological and electrochemical properties of the formed counter
electrodes are investigated by scanning electronic microscopy and electrochemical impedance spectroscopy, respectively. The
electronic and ionic processes in platinum and DWCNT-based DSCs are analyzed and discussed. The catalytic activity and DSC
performance of DWCNTs and Pt are compared. A conversion efficiency of 6.07% has been obtained for DWCNT counter-electrode
DSCs. This efficiency is comparable to that of platinum counter-electrode-based devices. 相似文献
999.
纳米技术和纳米医学的研究在生物医学、疾病诊断和治疗方面显示出了巨大的应用潜力. 有机荧光分子基检测技术已被广泛的用作造影和信号转换的工具用以测定痕量的分析物. 然而, 有机荧光分子基团的降解、光漂白作用使得其荧光的稳定性受到影响, 从而限制了它们在复杂的生理环境中的应用. 无机纳米粒子因其形状、尺寸和组成的不同而具有独特且稳定的光、电、磁及催化性能, 可用作新型的生物纳米造影材料, 能很好的解决造影检测技术所面临的难题. 并且, 纳米造影材料的表面修饰则可以提高它们的在生理条件下的稳定性和靶向生物活性分子的能力. 相似文献
1000.
Shu‐Hui Yin Yufang Liu Wei Zhang Ming‐Xing Guo Peng Song 《Journal of computational chemistry》2010,31(10):2056-2062
In this work, the time‐dependent density functional theory (TDDFT) method was carried out to investigate the hydrogen‐bonded intramolecular charge‐transfer excited state of 2‐(4′‐N,N‐dimethylaminophenyl)imidazo[4,5‐b]pyridine (DMAPIP) in methanol (MeOH) solvent. All the geometric conformations of the ground state and locally excited (LE) state and the twisted intramolecular charge‐transfer (TICT) state for isolated DMAPIP and its hydrogen‐bonded complexes have been optimized. At the same time, the absorption and fluorescence spectra of DMAPIP and the hydrogen‐bonded complexes in different electronic states are also calculated. We theoretically demonstrated for the first time that the intermolecular hydrogen bond formed between DMAPIP and MeOH can induce the formation of the TICT state for DMAPIP in MeOH solvent. Therefore, the two components at 414 and 506 nm observed in the fluorescence spectra of DMAPIP in MeOH solvent were reassigned in this work. The fluorescence peak at 414 nm is confirmed to be the LE state. Furthermore, the red‐shifted shoulder at 506 nm should be originated from the hydrogen‐bonded TICT excited state. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010 相似文献