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971.
Yong Liu Yuchun Song Yaohui You Xiaojing Fu Jing Wen Xiaogang Zheng 《Journal of Saudi Chemical Society》2018,22(4):439-448
Spinel structure nickel ferrite (NiFe2O4) doped graphitic carbon nitride (g-C3N4) photocatalyst NiFe2O4/g-C3N4 was synthesized by the coprecipitation route to enhance the photocatalytic activity for the visible-light driven degradation of methyl orange. The NiFe2O4 doping content is responsible for the microstructure and photocatalytic activity of NiFe2O4/g-C3N4 samples. Compared with pure NiFe2O4 and g-C3N4, the 2-NiFe2O4/g-C3N4 composite with NiFe2O4 doping of 2.0 wt% exhibited excellent photocatalytic activity and superior stability after five runs for degrading methyl orange under visible light irradiation. The catalytic activity of 2-NiFe2O4/g-C3N4 sample produced using the coprecipitation route was higher than those of conventional 2-NiFe2O4/g-C3N4 bulks prepared by the impregnation approach. The prepared samples for the photocatalytic degradation of methyl orange followed pseudo-first-order reaction kinetics. It’s ascribed to the synergistic effect between NiFe2O4 and g-C3N4, which can inhibit the recombination of photoexcited electron-hole pairs, accelerate photoproduced charges separation, and enhance the visible light absorption. 相似文献
972.
Brønsted Acid Enabled Nickel‐Catalyzed Hydroalkenylation of Aldehydes with Styrene and its Derivatives
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Xing‐Wang Han Tao Zhang Yan‐Long Zheng Wei‐Wei Yao Jiang‐Fei Li You‐Ge Pu Prof. Dr. Mengchun Ye Qi‐Lin Zhou 《Angewandte Chemie (International ed. in English)》2018,57(18):5068-5071
A Brønsted acid enabled nickel‐catalyzed hydroalkenylation of aldehydes and styrene derivatives has been developed. The Brønsted acid acts as a proton shuttle to transfer a proton from the alkene to the aldehyde, thereby leading to an economical and byproduct‐free coupling. A series of synthetically useful allylic alcohols were obtained through one‐step reactions from readily available styrene derivatives and aliphatic aldehydes in up to 88 % yield and with high linear selectivity. 相似文献
973.
建立了液相色谱-串联质谱(LC-MS/MS)检测人尿中去氨加压素的方法。样品经Waters C_(18)固相萃取净化,Phenomenex Onyx Monolothic C_(18)色谱柱分离,以10 mmol/L甲酸铵水溶液(用甲酸调至p H 3.5)-乙腈作为流动相进行梯度洗脱,流速为0.4 m L/min,串联质谱正离子模式电离(ESI~+),多反应监测模式(MRM)检测。收集8名志愿者在服用单次单剂量去氨加压素后留取3 d内全部尿液样本,使用建立的方法进行检测并绘制代谢曲线。结果表明:尿中去氨加压素的检出限为0.2μg/L;线性范围为0.5~20μg/L,相关系数(r~2)大于0.997;在低、中、高3个加标浓度下,回收率均高于59%,日内及日间精密度均小于10%,基质效应在20%以内。8名志愿者的阳性尿中去氨加压素浓度峰值在服药后70~150 min之间,最高浓度为0.2~2.4μg/L,检测窗口期最长可至服药后13 h左右。该法对于尿中去氨加压素具有特异性,能显著降低实验时间和成本,完全满足世界反兴奋剂组织对该药物的检测要求。该实验考察了服药后阳性尿中去氨加压素的浓度变化,研究了去氨加压素在人体内的消除情况。 相似文献
974.
Baonan Jia Pengfei Lu Jie Zhang Zhixing Peng Binbin Yan You Wang Gang-Ding Peng 《Journal of Cluster Science》2018,29(5):861-865
We report silica fiber with trivalent bismuth (Bi3+) in first-principles calculations. The influences of members of “Si–O–Si” rings are considered to study atomic structures, frontier molecular orbital and optical properties of Bi-doped optical fiber. Our results reveal that the luminescence of Bi3+-doped optical fiber is the result of a combination of Bi3+ ions and silica matrix. Different ring structures affect the luminescence properties, which explained why Bi3+-doped silica fiber usually cover a broad spectral range from the UV to visible light. 相似文献
975.
Stereodivergent Synthesis of Tetrahydrofuroindoles through Pd‐Catalyzed Asymmetric Dearomative Formal [3+2] Cycloaddition
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Qiang Cheng Dr. Fang Zhang Yue Cai Prof. Dr. Yin‐Long Guo Prof. Dr. Shu‐Li You 《Angewandte Chemie (International ed. in English)》2018,57(8):2134-2138
A stereodivergent synthesis of tetrahydrofuroindoles through palladium‐catalyzed asymmetric dearomative formal [3+2] cycloaddition of nitroindoles with epoxybutenes was developed. The polarity of the solvent was found to play a key role in the diastereoselectivity. In toluene, good to excellent yields (70–99 %), diastereoselectivity (87/13‐>95/5 d.r.), and enantioselectivity (85/15–94/6 e.r.) were obtained, regardless of the properties of the substituents on nitroindoles. In acetonitrile, tetrahydrofuroindoles of a different diastereoisomer were produced with good to excellent yields (75–98 %) and stereoselectivity (78/22–93/7 d.r., 93/7–99/1 e.r.). Mechanistic studies were conducted to illustrate the origin of the diastereodivergency. The kinetic experiments indicate that the rate‐determining step of this reaction is different in different solvents. ESI‐MS experiments also support the existence of key palladium complex intermediates and the catalytic cycle of the reaction. 相似文献
976.
Fuel‐Free Bio‐photoelectrochemical Cells Based on a Water/Oxygen Circulation System with a Ni:FeOOH/BiVO4 Photoanode
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He Zhang You Yu Lingling Zhang Prof. Shaojun Dong 《Angewandte Chemie (International ed. in English)》2018,57(6):1547-1551
A bio‐photoelectrochemical cell (BPEC) based on a fuel‐free self‐circulation water–oxygen–water system was fabricated. It consists of Ni:FeOOH modified n‐type bismuth vanadate (BiVO4) photoanode and laccase catalyzed biocathode. In this BPEC, irradiation of the photoanode generates photocurrent for photo‐oxidation of water to oxygen, which is reduced to water again at the laccase biocathode. Of note, the by‐products of two electrode reactions could continue to be reacted, which means the H2O and O2 molecules are retained in an infinite loop of water–oxygen–water without any sacrificial chemical components. As a result, the assembled fuel‐free BPEC exhibits good performance with an open‐circuit potential of 0.97 V and a maximum power density of 205 μW cm?2 at 0.44 V. This BPEC based on a self‐circulation system offers a fuel‐free model to enhance multiple energy conversion and application in reality. 相似文献
977.
Dr. Alam Venugopal Narendra Kumar Yinghao Li Shuli Yin Chunjie Li Dr. Hairong Xue Dr. You Xu Prof. Xiaonian Li Dr. Hongjing Wang Prof. Liang Wang 《化学:亚洲杂志》2018,13(16):2093-2100
Tailoring metal oxide nanostructures with mesoporous architectures is vital to improve their electrocatalytic performance. Herein, we demonstrate the synthesis of 2D mesoporous Co3O4 (meso‐Co3O4) nanobundles with uniform shape and size by employing a hard‐template method. In this study, the incipient wetness impregnation technique has been chosen for loading metal precursor into the silica hard template (SBA‐15). The results reveal that the concentration of a saturated precursor solution plays a vital role in mesostructured ordering, as well as the size and shape of the final meso‐Co3O4 product. The optimized precursor concentration allows us to synthesize ordered meso‐Co3O4 with four to seven nanowires in each particle. The meso‐Co3O4 structure exhibits excellent electrocatalytic activity for both glucose and water oxidation reactions. 相似文献
978.
Yang You Hao Huang Song Xia Zijian Cai Panyiming Liu Chengming Wang Ran Long Li Song Yujie Xiong 《中国科学:化学(英文版)》2018,(9)
Supports are commonly implemented in the industrial application of heterogeneous catalysts to improve the stability and recyclability of catalysts.The supported catalysts often show the enhanced activity and selectivity in various catalytic reactions.However,the specific contributions of electronic and steric effects to a catalytic system often remain elusive due to the lack of well-defined model systems.In this work,two types of uniform Pd nanocrystals covered by{111}facets in tetrahedral and octahedral shapes,respectively,are synthesized with identical chemical environment and loaded on Ti O_2supports to form hybrid structures(Pd{111}-Ti O_2)towards the application of formic acid decomposition.Our observation suggests that the polarization effect at the interface of Pd-Ti O_2enhances its activity in formic acid decomposition.Moreover,the Pd tetrahedrons-Ti O_2hybrid structure whose Pd{111}-Ti O_2interface possesses a larger angle shows higher catalytic activity,owing to the reduced steric effect as compared to Pd octahedrons-Ti O_2.This study reveals the nature of interface effects in formic acid decomposition,and provides a guidance for the related catalyst design. 相似文献
979.
Dan Wei Jing Sun You Yang Chengheng Wu Suping Chen Zhenzhen Guo Hongsong Fan Xingdong Zhang 《Materials Today Chemistry》2018
The majority of tissues within human body are constituted of designated structures to enable specific functions. Much effort has been done to engineer artificial fabric cell-laden scaffolds which are widely used for a great diversity of linear tissue constructs. For this purpose, collagen microfibers are of great concern among diverse materials while the control of cell-laden fiber formation and orientated structure is still unsolvable. Here, we developed a novel microfluidic-based strategy for continuous fabrication and assembly of three-dimensional (3D) cell-laden oriented collagen hydrogel microfibers. Inspired by the flow-introduced shear force in a microfluidic chip, collagen hydrogel microfibers obtained the oriented fabric structure which could guide rat pheochromocytoma cells (PC12) oriented spreading and enhance relative cellular functional expression. Rat aortic endothelial cells (RAOECs) were introduced to construct a co-cultured microfiber model, which further facilitated the functional expression of neural cells due to the synergistic effect of both vascularized-like cells and neural-like cells. Moreover, the ability of assembling collagen microfibers into larger constructs will benefit a variety of applications in tissue engineering and biomedical research. 相似文献
980.
L. Kong S. Chunyu S. He Y. You Q. Zhang Y. Cai S. Yang W. Huang Y. Gu A. He X. Yang X. Li Y. Wang X. Cheng W. Xie 《Applied physics. B, Lasers and optics》1996,62(6):619-622
We have obtained results for converting focused laser radiation to X-ray line emissions in laser-heated NaF and Cu plasmas. These plasmas were used as the pump source for studying the phenomena of inner-shell photoionization of Zn-like ionic states. Soft X-ray emissions from transitions of 3d
94s
2 3d
104p in Cu-like Pd and Ag ions were observed. 相似文献