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991.
992.
Pengzuo Chen Kun Xu Zhiwei Fang Yun Tong Junchi Wu Xiuli Lu Xu Peng Hui Ding Changzheng Wu Yi Xie 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(49):14923-14927
Designing highly efficient electrocatalysts for oxygen evolution reaction (OER) plays a key role in the development of various renewable energy storage and conversion devices. In this work, we developed metallic Co4N porous nanowire arrays directly grown on flexible substrates as highly active OER electrocatalysts for the first time. Benefiting from the collaborative advantages of metallic character, 1D porous nanowire arrays, and unique 3D electrode configuration, surface oxidation activated Co4N porous nanowire arrays/carbon cloth achieved an extremely small overpotential of 257 mV at a current density of 10 mA cm−2, and a low Tafel slope of 44 mV dec−1 in an alkaline medium, which is the best OER performance among reported Co‐based electrocatalysts to date. Moreover, in‐depth mechanistic investigations demonstrate the active phases are the metallic Co4N core inside with a thin cobalt oxides/hydroxides shell during the OER process. Our finding introduces a new concept to explore the design of high‐efficiency OER electrocatalysts. 相似文献
993.
Monte Carlo simulation of full energy spectrum of electrons emitted from silicon in Auger electron spectroscopy 下载免费PDF全文
N. Cao B. Da Y. Ming S. F. Mao K. Goto Z. J. Ding 《Surface and interface analysis : SIA》2015,47(1):113-119
A Monte Carlo simulation including surface excitation, Auger electron‐ and secondary electron production has been performed to calculate the energy spectrum of electrons emitted from silicon in Auger electron spectroscopy (AES), covering the full energy range from the elastic peak down to the true‐secondary‐electron peak. The work aims to provide a more comprehensive understanding of the experimental AES spectrum by integrating the up‐to‐date knowledge of electron scattering and electronic excitation near the solid surface region. The Monte Carlo simulation model of beam–sample interaction includes the atomic ionization and relaxation for Auger electron production with Casnati's ionization cross section, surface plasmon excitation and bulk plasmon excitation as well as other bulk electronic excitation for inelastic scattering of electrons (including primary electrons, Auger electrons and secondary electrons) through a dielectric functional approach, cascade secondary electron production in electron inelastic scattering events, and electron elastic scattering with use of Mott's cross section. The simulated energy spectrum for Si sample describes very well the experimental AES EN(E) spectrum measured with a cylindrical mirror analyzer for primary energies ranging from 500 eV to 3000 eV. Surface excitation is found to affect strongly the loss peak shape and the intensities of the elastic peak and Auger peak, and weakly the low energy backscattering background, but it has less effect to high energy backscattering background and the Auger electron peak shape. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
994.
995.
In this paper, we presented a novel, rapid and highly sensitive sensor for glutathione (GSH), cysteine (Cys) and histidine (His) based on the recovered fluorescence of the carbon quantum dots (CQDs)–Hg(II) system. The CQDs were synthesized by microwave-assisted approach in one pot according to our previous report. The fluorescence of CQDs could be quenched in the presence of Hg(II) due to the coordination occurring between Hg(II) and functional groups on the surface of CQDs. Subsequently, the fluorescence of the CQDs–Hg(II) system was recovered gradually with the addition of GSH, Cys or His due to their stronger affinity with Hg(II). A good linear relationship was obtained from 0.10 to 20 μmol L−1 for GSH, from 0.20 to 45 μmol L−1 for Cys and from 0.50 to 60 μmol L−1 for His, respectively. This method has been successfully applied to the trace detection of GSH, Cys or His in human serum samples with satisfactory results. The proposed method was simple in design and fast in operation, which demonstrated great potential in bio-sensing fields. 相似文献
996.
Yanhua Huang Yuzhi WangQi Pan Ying WangXueqin Ding Kaijia XuNa Li Qian Wen 《Analytica chimica acta》2015
Four kinds of green deep eutectic solvents (DESs) based on choline chloride (ChCl) have been synthesized and coated on the surface of magnetic graphene oxide (Fe3O4@GO) to form Fe3O4@GO-DES for the magnetic solid-phase extraction of protein. X-ray diffraction (XRD), vibrating sample magnetometer (VSM), Fourier transform infrared spectrometry (FTIR), field emission scanning electron microscopy (FESEM) and thermal gravimetric analysis (TGA) were employed to characterize Fe3O4@GO-DES, and the results indicated the successful preparation of Fe3O4@GO-DES. The UV–vis spectrophotometer was used to measure the concentration of protein after extraction. Single factor experiments proved that the extraction amount was influenced by the types of DESs, solution temperature, solution ionic strength, extraction time, protein concentration and the amount of Fe3O4@GO-DES. Comparison of Fe3O4@GO and Fe3O4@GO-DES was carried out by extracting bovine serum albumin, ovalbumin, bovine hemoglobin and lysozyme. The experimental results showed that the proposed Fe3O4@GO-DES performs better than Fe3O4@GO in the extraction of acidic protein. Desorption of protein was carried out by eluting the solid extractant with 0.005 mol L−1 Na2HPO4 contained 1 mol L−1 NaCl. The obtained elution efficiency was about 90.9%. Attributed to the convenient magnetic separation, the solid extractant could be easily recycled. 相似文献
997.
998.
Xiude Hua Liangliang Zhou Lu Feng Yuan Ding Haiyan Shi Limin Wang Shirley J. Gee Bruce D. Hammock Minghua Wang 《Analytica chimica acta》2015
Twenty-three phage-displayed peptides that specifically bind to an anti-benzothiostrobin monoclonal antibody (mAb) in the absence or presence of benzothiostrobin were isolated from a cyclic 8-residue peptide phage library. Competitive and noncompetitive phage enzyme linked immunosorbent assays (ELISAs) for benzothiostrobin were developed by using a clone C3-3 specific to the benzothiostrobin-free mAb and a clone N6-18 specific to the benzothiostrobin immunocomplex, respectively. Under the optimal conditions, the half maximal inhibition concentration (IC50) of the competitive phage ELISA and the concentration of analyte producing 50% saturation of the signal (SC50) of the noncompetitive phage ELISA for benzothiostrobin were 0.94 and 2.27 ng mL−1, respectively. The noncompetitive phage ELISA showed higher selectivity compared to the competitive. Recoveries of the competitive and the noncompetitive phage ELISAs for benzothiostrobin in cucumber, tomato, pear and rice samples were 67.6–119.6% and 70.4–125.0%, respectively. The amounts of benzothiostrobin in the containing incurred residues samples detected by the two types of phage ELISAs were significantly correlated with that detected by high-performance liquid chromatography (HPLC). 相似文献
999.
The Aerobic Oxidation and C=C Bond Cleavage of Styrenes Catalyzed by Cerium(IV) Ammonium Nitrate (CAN) 下载免费PDF全文
Lei Yu Yaping Huang Zengbing Bai Bingchun Zhu Kehong Ding Tian Chen Yuanhua Ding Yuguang Wang 《中国化学会会志》2015,62(6):479-482
The CAN‐catalyzed aerobic oxidation severed the C=C bond selectively through the single electron transfer mechanism, giving a green method to decompose olefins. Compared with the literature reported examples, this method required simple catalyst, cheap, abundant and clean oxidant and was very safe to operate due to the mild conditions. 相似文献
1000.
以部分脱铝的Beta分子筛为母体,采用同晶置换法将Sn植入骨架制备双功能[Sn,Al]-Beta分子筛,并应用于葡萄糖一步催化生成5-羟甲基糠醛(5-HMF)反应中.样品中Sn与Al的含量通过酸洗的浓度和酸洗的时间以及SnCl4处理的时间来控制.由于骨架中有与Al相关为B酸位,和Sn相关的L酸位,[Sn,Al]-Beta可作为一种双功能的固体酸催化剂.优化了[Sn,Al]-Beta催化葡萄糖一步催化生成5-HMF的反应参数,在最优Sn/Al比条件下,葡萄糖转化率为60.0%,5-HMF选择性为62.1%. 相似文献