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81.
Guanghui Yue Jiandi Liu Jiangtao Han Donghui Qin Qiang Chen Jianxiong Shao 《催化学报》2018,39(12):1951-1959
An amorphous CoSnO3@rGO nanocomposite fabricated using a surfactant-assisted assembly method combined with thermal treatment served as a catalyst for non-aqueous lithium-oxygen (Li-O2) batteries. In contrast to the specific surface area of the bare CoSnO3 nanoboxes (104.3 m2 g–1), the specific surface area of the CoSnO3@rGO nanocomposite increased to approximately 195.8 m2 g–1 and the electronic conductivity also improved. The increased specific surface area provided more space for the deposition of Li2O2, while the improved electronic conductivity accelerated the decomposition of Li2O2. Compared to bare CoSnO3, the overpotential reduced by approximately 20 and 60 mV at current densities of 100 and 500 mA g?1 when CoSnO3@rGO was used as the catalyst. A Li-O2 battery using a CoSnO3@rGO nanocomposite as the cathode catalyst cycled indicated a superior cyclic stability of approximately 130 cycles at a current density of 200 mA g–1 with a limited capacity of 1000 mAh g–1, which is 25 cycles more than that of the bare amorphous CoSnO3 nanoboxes. 相似文献
82.
Guanghui Yuan Huafeng Jin Yanzi Jin Lizhou Wu 《Journal of Solid State Electrochemistry》2018,22(3):693-703
Lithium–sulfur (Li–S) battery is considered as a promising option for electrochemical energy storage applications because of its low-cost and high theoretical capacity. However, the practical application of Li–S battery is still hindered due to the poor electrical conductivity of S cathode and the high dissolution/shuttling of polysulfides in electrolyte. Herein, we report a novel physical and chemical entrapment strategy to address these two problems by designing a sulfur–MnO2@graphene (S–MnO2@GN) ternary hybrid material structure. The MnO2 particles with size of ~ 10 nm are anchored tightly on the wrinkled and twisted GN sheets to form a highly efficient sulfur host. Benefiting from the synergistic effects of GN and MnO2 in both improving the electronic conductivity and hindering polysulfides by physical and chemical adsorptions, this unique S–MnO2@GN composite exhibits excellent electrochemical performances. Reversible specific capacities of 1416, 1114, and 421 mA h g?1 are achieved at rates of 0.1, 0.2, and 3.2 C, respectively. After a 100 cycle stability test, S–MnO2@GN composite cathode could still maintain a reversible capacity of 825 mA h g?1. 相似文献
83.
Wang F Ye M Dong J Tian R Hu L Han G Jiang X Wu R Zou H 《Journal of separation science》2008,31(14):2589-2597
The postcolumn void volume, which is introduced by the connecting tubing and void ESI emitter in the nanoflow LC coupled with MS/MS system (microLC-MS/MS), is harmful for the analysis of peptides in shotgun proteome analysis. A new type of porous C12 monolithic ESI emitter was prepared to eliminate the disruption and mixing effects occurring in the connecting tubing and void emitter. It was demonstrated that the porous hydrophobic monolith inside the emitter played a key role in retaining the good peak profile, and the average peak capacity of the whole separation system increased 12.8% in contrast to commercially available void emitter. Then, the porous C12 monolithic emitter was applied in label-free quantitative proteome analysis of two standard protein mixtures that were spiked into the tryptic digest of mouse livers extract. Compared to commercially available void ESI emitter, the number of proteins with reliable results in quantification increased greatly. And the relative quantities of the four standard proteins were all determined with the relative error < or = 6.8%. However, quantitative information of only three standard proteins could be obtained when void emitter was used. 相似文献
84.
Guanghui Deng Yuanyuan Li Yu Zhou Jiang Wang Hualiang Jiang Hong Liu 《Tetrahedron》2008,64(46):10512-10516
The non-proteinogenic amino acid (2S)-2-amino-3,3-bis(4-fluorophenyl)propanoic acid [(S)-1] is a key intermediate required for the synthesis of Denagliptin (2a). Denagliptin is a dipeptidyl peptidase IV (DPP IV) inhibitor that is being developed for the treatment of type-2 diabetes mellitus. A diastereoselective, cost-efficient synthetic procedure for (S)-1 was developed by alkylating a Ni(II) glycine equivalent derived from (S)-2-[(N-benzylprolyl) amino] benzophenone [(S)-BPB]. The alkylated product was then decomposed to isolate the target amino acid (S)-1 (ee >99%) and ligand (S)-BPB, which can be reused in subsequent reactions. The enantiomer (R)-1 and racemate (rac)-1 were synthesized from their corresponding Ni(II) glycine equivalents. Denagliptin diastereomers (2), derived from the key intermediates (S)-1, (R)-1, and (rac)-1 were synthesized, and their dipeptidyl peptidase IV inhibitory activities were investigated. These findings are important in the design and synthesis of DPP IV inhibitors. 相似文献
85.
Guanghui Feng Dr. Shibin Wang Prof. Shenggang Li Ruipeng Ge Dr. Xuefei Feng Prof. Junwei Zhang Dr. Yanfang Song Dr. Xiao Dong Jiazhou Zhang Prof. Gaofeng Zeng Prof. Qiang Zhang Prof. Guijun Ma Dr. Yi-De Chuang Prof. Xixiang Zhang Prof. Jinghua Guo Prof. Yuhan Sun Prof. Wei Wei Prof. Wei Chen 《Angewandte Chemie (International ed. in English)》2023,62(15):e202218664
Using sunlight to produce valuable chemicals and fuels from carbon dioxide (CO2), i.e., artificial photosynthesis (AP) is a promising strategy to achieve solar energy storage and a negative carbon cycle. However, selective synthesis of C2 compounds with a high CO2 conversion rate remains challenging for current AP technologies. We performed CO2 photoelectroreduction over a graphene/silicon carbide (SiC) catalyst under simulated solar irradiation with ethanol (C2H5OH) selectivity of>99 % and a CO2 conversion rate of up to 17.1 mmol gcat−1 h−1 with sustained performance. Experimental and theoretical investigations indicated an optimal interfacial layer to facilitate the transfer of photogenerated electrons from the SiC substrate to the few-layer graphene overlayer, which also favored an efficient CO2 to C2H5OH conversion pathway. 相似文献
86.
87.
Simple Peptide‐Tuned Self‐Assembly of Photosensitizers towards Anticancer Photodynamic Therapy
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Dr. Kai Liu Dr. Ruirui Xing Dr. Qianli Zou Prof. Dr. Guanghui Ma Prof. Dr. Helmuth Möhwald Prof. Dr. Xuehai Yan 《Angewandte Chemie (International ed. in English)》2016,55(9):3036-3039
Peptide‐tuned self‐assembly of functional components offers a strategy towards improved properties and unique functions of materials, but the requirement of many different functions and a lack of understanding of complex structures present a high barrier for applications. Herein, we report a photosensitive drug delivery system for photodynamic therapy (PDT) by a simple dipeptide‐ or amphiphilic amino‐acid‐tuned self‐assembly of photosensitizers (PSs). The assembled nanodrugs exhibit multiple favorable therapeutic features, including tunable size, high loading efficiency, and on‐demand drug release responding to pH, surfactant, and enzyme stimuli, as well as preferable cellular uptake and biodistribution. These features result in greatly enhanced PDT efficacy in vitro and in vivo, leading to almost complete tumor eradication in mice receiving a single drug dose and a single exposure to light. 相似文献
88.
Analysis of pesticide residues in tobacco with online size exclusion chromatography with gas chromatography and tandem mass spectrometry
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Weiyun Guo Zhaoyang Bian Gangling Tang Deguo Wang Guanghui Li Jianlong Wang 《Journal of separation science》2016,39(14):2754-2759
An ultrasensitive method for the simultaneous analysis of pesticides residues in tobacco was developed with online size exclusion chromatography with gas chromatography and tandem mass spectrometry. Tobacco samples were extracted with the solvent mixture of cyclohexane and acetone (7:3, v/v) and centrifuged. Then, the supernatant liquors were injected directly into the online size exclusion chromatography with gas chromatography and tandem mass spectrometry without any other purification procedures after being filtered with a 0.22 μm organic phase filter. The matrix interferences were effectively removed and recoveries of most pesticides were in the range of 72–121%. Especially, for chlorothalonil, the analysis efficiency of this method was much more favorable than that of the general method, in which dispersive solid‐phase extraction was used as an additional purified procedure. In addition, the limits of quantitation of this method were from 1 to 50 μg/kg. Therefore, a rapid, cost‐effective, labor‐saving method was proposed in the present work, which was suitable for the analysis of 41 pesticide residues in tobacco. 相似文献
89.
90.
Finite element method to fluid–solid interaction problems with unbounded periodic interfaces
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Guanghui Hu Andreas Rathsfeld Tao Yin 《Numerical Methods for Partial Differential Equations》2016,32(1):5-35
Consider a time‐harmonic acoustic plane wave incident onto a doubly periodic (biperiodic) surface from above. The medium above the surface is supposed to be filled with a homogeneous compressible inviscid fluid of constant mass density, whereas the region below is occupied by an isotropic and linearly elastic solid body characterized by its Lamé constants. This article is concerned with a variational approach to the fluid–solid interaction problems with unbounded biperiodic Lipschitz interfaces between the domains of the acoustic and elastic waves. The existence of quasiperiodic solutions in Sobolev spaces is established at arbitrary frequency of incidence, while uniqueness is proved only for small frequencies or for all frequencies excluding a discrete set. A finite element scheme coupled with Dirichlet‐to‐Neumann mappings is proposed and the convergence analysis is performed. The Dirichlet‐to‐Neumann mappings are approximated by truncated Rayleigh series expansions. Finally, numerical tests in 2D are presented to confirm the convergence of solutions and the energy balance formula. In particular, the frequency spectrum of normally reflected signals is plotted for water–brass and water–brass–water interfaces. © 2015 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 32: 5–35, 2016 相似文献