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91.
Modular Self‐Assembling Peptide Platform with a Tunable Thermoresponsiveness via a Single Amino Acid Substitution 下载免费PDF全文
《Advanced functional materials》2018,28(35)
The introduction of a stimulus‐responsive property is an effective way to increase the applicability of functional materials in the field of nanobiotechnology. Herein, a peptide platform is devised for constructing elastin‐like peptide amphiphiles (ELPAs) that exhibit a temperature‐responsiveness that can be easily tuned via a single N‐terminal amino acid substitution at the final step of peptide synthesis. Due to the modular property of peptides, the platform based on a miniaturized elastin‐like peptide (MELP) can be conjugated with various bioactive peptide sequences in diverse macromolecular topologies. First, the MELP platform is coupled with a short linear RGD peptide. The ELPAs of the peptide conjugates exhibit rapid aggregation (coacervation) and retard disaggregation in response to heating and cooling, respectively. Second, the platform is grafted with an α‐helical guest peptide in a lariat‐type structure, which forms ELPAs that undergo faster disassembly than the ELPAs without the guest peptide in response to temperature increases. Interestingly, the critical temperatures for the thermoresponsive behaviors are commonly dependent on the hydrophobic and aromatic properties of the N‐terminal amino acid residues. These results suggest that this peptide platform possesses great potential for use in the development of smart materials in wide‐ranging applications related to temperature change. 相似文献
92.
One‐Step Construction of N,P‐Codoped Porous Carbon Sheets/CoP Hybrids with Enhanced Lithium and Potassium Storage 下载免费PDF全文
Jing Bai Baojuan Xi Hongzhi Mao Yue Lin Xiaojian Ma Jinkui Feng Shenglin Xiong 《Advanced materials (Deerfield Beach, Fla.)》2018,30(35)
Despite the desirable advancement in synthesizing transition‐metal phosphides (TMPs)‐based hybrid structures, most methods depend on foreign‐template‐based multistep procedures for tailoring the specific structure. Herein, a self‐template and recrystallization–self‐assembly strategy for the one‐step synthesis of core–shell‐like cobalt phosphide (CoP) nanoparticles embedded into nitrogen and phosphorus codoped porous carbon sheets (CoP?NPPCS), is first proposed. Relying on the unusual coordination ability of melamine with metal ions and the cooperative hydrogen bonding of melamine and phytic acid to form a 2D network, a self‐synthesized single precursor can be attained. Importantly, this approach can be easily expanded to synthesize other TMPs?NPPCS. Due to the unique compositional and structural characteristics, these CoP?NPPCSs manifest outstanding electrochemical performances as anode materials for both lithium‐ and potassium‐ion batteries. The unusual hybrid architecture, the high specific surface area, and porous features make the CoP?NPPCS attractive for other potential applications, such as supercapacitors and electrocatalysis. 相似文献
93.
Bhupendra Singh Nitika Devi Lakshya Mathur Rajesh K. Singh Aman Bhardwaj Sun-Ju Song Dirk Henkensmeier 《Ceramics International》2018,44(6):6170-6175
In the present work, we report a method of fabrication of dense 10 mol% Mg2+-doped cerium pyrophosphate-phosphate (Ce0.9Mg0.1P2O7-PmOn; CMP-P) composites by microwave heat-treatment of the preformed Ce0.9Mg0.1P2O7 substrates in the presence of phosphoric acid. The composite was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The microwave heating at 375 °C for 5 min resulted in the formation of dense CMP-P composites which retained most of the pyrophosphate phase. The electrical conductivity was extracted from the EIS data and for the CMP-P composite prepared by H3PO4 loading for 10 h and microwave heat-treatment for 5 min it was found to be >10?2 S m?1 in 100–250 °C range with a maximum of 0.062 S cm?1 at 190 °C, which was significant for its application as electrolyte in intermediate temperature fuel cells. 相似文献
94.
Bachir Bendjedia Nassim Rizoug Moussa Boukhnifer Farid Bouchafaa Mohamed Benbouzid 《International Journal of Hydrogen Energy》2018,43(25):11614-11628
Fuel cell electric vehicles (FCEVs) have some limitation which make them less competitor to thermal ones and delay their commercialization. The most important problems as the range, the durability and the cost depend directly on the energy storage problematic issues. In this context, this work presents an optimal sizing methodology for an Energy Storage System (ESS) composed by a fuel cell and an assistant source to supply a lightweight vehicle with 700 km driving range. Firstly, a comparative study between single and hybrid source is carried out to show the benefits of hybridization according to the range in terms of weight, cost and fuel consumption. Moreover, in order to improve the hybrid source characteristics, three technologies of the secondary source are tested and evaluated to be chosen for hybridization with fuel cell system purposes. Furthermore, the influence of three Energy Management Strategies (EMSs) on ESS sizing is studied where an optimal strategy provides the most favorable dimensions of the hybrid system. Simulation results give us the best technology needed for hybridization and allow us adopting the optimal management strategy to design the hybrid source. Finally, in order to show the influence of the driving cycles on the ESS design, a comparison study using the New European Driving Cycle “NEDC” and the Assessment and Reliability of Transport Emission Models Inventory Systems (ARTEMIS) confirms that there is a slow influence of the driving cycle on the ESS sizes. 相似文献
95.
L.P.A. Guerrero-Ortega A. Manzo-Robledo E. Ramírez-Meneses J. Mateos-Santiago L. Lartundo-Rojas V. Garibay-Febles 《International Journal of Hydrogen Energy》2018,43(12):6117-6130
Ni-rich PtNi bi-metallic catalyst and its counterpart free of nickel supported on carbon Vulcan have been synthesized by the impregnation methodology from Na2PtCl6 and Ni(C5H7O2)2 as precursors. The obtained materials Pt/C and PtNi/C were used as electrocatalysts for the methanol oxidation reaction (MOR) in acid conditions. Electrochemical evaluations demonstrated that the addition of Ni in the Pt-Vulcan matrix promotes an important increment in the faradic current during MOR of one order of magnitude, even though the platinum load is lower in the bi-metallic catalyst. These results suggest that the incorporation of nickel promotes some structural and electronic modifications that enhance a better reaction performance at the electrode interface. Morphological characterization using scanning electron microscopy and transmission electron microscopy with energy dispersive spectroscopy (SEM-TEM-EDS) showed Pt/C and PtNi/C catalysts have a particle size of 5.7 nm and 4.4 nm, respectively. X-ray diffraction (XRD) reveals the formation of Ni3Pt from the synthesis of PtNi catalysts. Additionally, X-ray photoelectron spectroscopy (XPS) confirmed the presence of Pt and Ni in their metallic-oxidation states on the carbon surface. 相似文献
96.
针对手工焊接汽车轮毂总成效率低下、焊接质量不稳定等问题及一种重载汽车轮毂总成的结构特点及焊接要求,设计了一种直角坐标型自动点焊机器人。阐述了自动点焊机器人本体的方案设计、控制系统应用等过程,并利用现场试验与工业性试验对自动点焊机器人的性能等进行了验证,为重载汽车轮毂总成的自动焊接提供了一种可供借鉴的方法。 相似文献
97.
Solvent‐Controlled Assembly of Aromatic Glutamic Dendrimers for Efficient Luminescent Color Conversion 下载免费PDF全文
《Advanced functional materials》2018,28(34)
A binary supramolecular system where self‐sorting and coassembly behavior can be switched by changing the solvent polarity is hereby reported. Glutamic dendron is separately conjugated with pyrene and naphthalimide luminophores through an alkyl spacer. The resulting structurally similar building units can self‐assemble into one‐dimensional micro/nanostructures with hexagonal and lamellar packing, respectively. Varying solvents from polar aqueous solution to nonpolar decane is evidenced to profoundly inverse the superchirality and switch self‐sorted assembly to coassembly of the two building blocks. The moisture sensitivity of the naphthalimide moiety is considered the primary driving force for the self‐sorting phenomenon in aqueous solution, resulting in inevitable hydration to repel its stacking with hydrophobic pyrene moiety. On the other hand, the naphthalimide unit can integrate segmentally with the pyrene unit in decane, greatly facilitating the nanofiber growth and supramolecular gel formation along with improved energy transfer efficiency between luminophores. As a result, the coassembly‐based thin films show efficient luminescent color conversion upon the UV light irradiation. This research presents a useful route for the fabrication of controllable solution‐processed light emitting devices from self‐assembled multicomponent systems. 相似文献
98.
Gerardo Valadez Huerta Johanan Álvarez Jordán Michael Dragon Keno Leites Stephan Kabelac 《International Journal of Hydrogen Energy》2018,43(34):16684-16693
Solid oxide fuel cell (SOFC) systems with anode off-gas recirculation (AGR) and diesel pre-reforming are advantageous because they can operate with the current fuel infrastructure. In the SchIBZ-project, the prototype of such a SOFC system for maritime applications has already been commissioned. In this first paper, we model the system devices to conduct an exergy analysis of this real SOFC plant and validate them with experimental values from experiments in laboratory scale. The results of our simulation agree well with the experimental values. The calculations with the validated results may be closer to the real thermodynamic behavior of such system components than previous literature. 相似文献
99.
Samira Chamyani Alireza Salehirad Nasrin Oroujzadeh Davod Sadeghi Fateh 《Ceramics International》2018,44(7):7754-7760
Due to importance and wide applications, CoCr2O4 ceramic pigment nanoparticles were synthesized via low-temperature solution combustion route by different fuels including ethylenediamine/oxalic acid, ethylenediamine/citric acid, oxalic acid/citric acid and ethylenediamine/oxalic acid/citric acid. Physicochemical properties of the synthesized samples were determined by different techniques such as fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectroscopy (EDX) and color/optical properties were evaluated based on CIELAB system by spectrophotometer. Moreover, thermodynamic considerations of combustion reactions for CoCr2O4 nanopigments formation in terms of calculated adiabatic flame temperature and enthalpy of combustion reaction were studied. The Comparison of results and data showed that cobalt chromite pigment nanoparticles synthesized by using ethylenediamine/citric acid and ethylenediamine/oxalic acid/citric acid fuels exhibited higher purity, smaller crystallite size and lower degree agglomeration. 相似文献
100.