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991.
Neves Junior Alex Dweck Jo Filho Romildo Dias Toledo Ellis Brian Li Victor 《Journal of Thermal Analysis and Calorimetry》2019,135(1):97-109
Journal of Thermal Analysis and Calorimetry - The present study has evaluated the rheological behavior of an oil-based (5W50) hybrid nanofluid [magnesium oxide (65%)–multi-walled carbon... 相似文献
992.
Tassilo M. F. Restle Christian Sedlmeier Holger Kirchhain Wilhelm Klein Gabriele Raudaschl‐Sieber Volker L. Deringer Leo van Wüllen Hubert A. Gasteiger Thomas F. Fssler 《Angewandte Chemie (International ed. in English)》2020,59(14):5665-5674
Solid electrolyte materials are crucial for the development of high‐energy‐density all‐solid‐state batteries (ASSB) using a nonflammable electrolyte. In order to retain a low lithium‐ion transfer resistance, fast lithium ion conducting solid electrolytes are required. We report on the novel superionic conductor Li9AlP4 which is easily synthesised from the elements via ball‐milling and subsequent annealing at moderate temperatures and which is characterized by single‐crystal and powder X‐ray diffraction. This representative of the novel compound class of lithium phosphidoaluminates has, as an undoped material, a remarkable fast ionic conductivity of 3 mS cm?1 and a low activation energy of 29 kJ mol?1 as determined by impedance spectroscopy. Temperature‐dependent 7Li NMR spectroscopy supports the fast lithium motion. In addition, Li9AlP4 combines a very high lithium content with a very low theoretical density of 1.703 g cm?3. The distribution of the Li atoms over the diverse crystallographic positions between the [AlP4]9? tetrahedra is analyzed by means of DFT calculations. 相似文献
993.
Qian Han Dr. Fei Tao Yan Xu Hao Su Dr. Facui Yang Dr. Volker Körstgens Prof. Peter Müller-Buschbaum Prof. Peng Yang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(45):20367-20375
A promising route to the synthesis of protein-mimetic materials that are capable of strong mechanics and complex functions is provided by intermolecular β-sheet stacking. An understanding of the assembly mechanism on β-sheet stacking at molecular-level and the related influencing factors determine the potential to design polymorphs of such biomaterials towards broad applications. Herein, we quantitatively reveal the air/water interface (AWI) parameters regulating the transformation from crowding amorphous aggregates to ordered phase and show that the polymorph diversity of β-sheet stacking is regulated by the chain relaxation-crystallization mechanism. An amorphous macroscale amyloid-like nanofilm is formed at the AWI, in which unfolded protein chains are aligned in a short-range manner to form randomly packed β-sheets. The subsequent biopolymer chain relaxation-crystallization to form nanocrystals is further triggered by removing the limitations of energy and space at the AWI. 相似文献
994.
Dr. Kelvin Li Dr. Darryl Fong Dr. Eric Meichsner Prof. Alex Adronov 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(16):5057-5073
Highly efficient reactions that enable the assembly of molecules into complex structures have driven extensive progress in synthetic chemistry. In particular, reactions that occur under mild conditions and in benign solvents, while producing no by-products and rapidly reach completion are attracting significant attention. Amongst these, the strain-promoted azide–alkyne cycloaddition, involving various cyclooctyne derivatives reacting with azide-bearing molecules, has gained extensive popularity in organic synthesis and bioorthogonal chemistry. This reaction has also recently gained momentum in polymer chemistry, where it has been used to decorate, link, crosslink, and even prepare polymer chains. This survey highlights key achievements in the use of this reaction to produce a variety of polymeric constructs for disparate applications. 相似文献
995.
996.
You Chen Titov Alex Kim Baek Hyun Orazem Mark E. 《Journal of Solid State Electrochemistry》2020,24(11):3083-3090
Electrochemical impedance spectroscopy is used to study red and green quantum-dot light-emitting diodes devices. The high-frequency loop is interpreted in terms of the thickness, dielectric constant, and resistivity distribution of the hole-injection layer. The analysis employed the device capacitance obtained from a measurement model analysis, the film thickness measured by scanning electron microscopy, and an interpretation of the impedance based on a power-law model. Impedance measurements performed on hole-transport–only devices yielded results that were consistent with the interpretation of the high-frequency capacitive loop in terms of the properties of the hole-injection layer.
相似文献997.
Mauren Estupian-Amaya Carlos Alberto Fuenmayor Alex Lpez-Crdoba 《Molecules (Basel, Switzerland)》2020,25(23)
Andean blueberry (Vaccinium meridionale Swartz) fruits are an underutilized source of anthocyanins and other valuable bioactive phytochemicals. The purpose of this work was to obtain Andean blueberry juice powders via freeze-drying processing and evaluate the effect of maltodextrin as a drying aid on their physicochemical, technological, microstructural, and bioactive characteristics. Andean blueberry juices were mixed with variable proportions of maltodextrin (20–50%); freeze-dried; and characterized in terms of their tristimulus color, Fourier transform infrared spectra (FTIR), moisture content, water activity, morphology, water solubility, flow properties, total polyphenols and anthocyanins content, and DPPH•-scavenging capacity. The powders obtained presented suitable characteristics in terms of their water activity (<0.5), solubility (>90%), and bioactive compound recovery (>70% for total phenolics, and >60% for total monomeric anthocyanins), with antioxidant activities up to 4 mg equivalent of gallic acid/g of dry matter. Although an increased content of maltodextrin resulted in lower concentrations of phytochemicals, as expected, it also favored an increased % recovery (over 90% of total phenolics at the highest maltodextrin proportion) and improved their flow properties. Freeze-dried juice powders are a potential alternative for the stabilization and value addition of this fruit as a new source of functionality for processed foods. 相似文献
998.
Jan Burke CecilF. Hess Volker Kebbel 《Particle & Particle Systems Characterization》2003,20(3):183-192
We present a measurement technique that is capable of simultaneously determining sizes and positions of multiple transparent droplets in a plane from scattered light features. The technique is largely independent of particle intensity and mutual obscuration. Reflected and refracted light from the droplets in a pulsed laser sheet is recorded holographically to yield the smallest possible probe volume and the largest possible number density. Larger droplets are best analyzed at the image plane; in this case, the droplets appear as two spots (glare points), whose separation is proportional to the droplet diameter. Smaller droplets are easier to analyze at an out‐of‐focus plane, where their images appear as fringe patterns whose spatial frequency is related to droplet size. Photographic techniques allow only one of these planes to be chosen and are therefore not suitable for multidisperse sprays. Optical holography allows to analyze arbitrary depths, but often suffers from low sensitivity and long analysis times. With digital holography, the spray images are captured digitally by a CCD camera and reconstructed numerically; as in optical holography, the particle reconstruction plane can be freely chosen a posteriori to optimize the measurement. We discuss the issues raised by the transition from holographic film to a CCD sensor as the recording medium, and demonstrate the capabilities of the digital technique. 相似文献
999.
Athelstan L.J. Beckwith David H. Roberts Carl H. Schiesser Alex Wallner 《Tetrahedron letters》1985,26(28):3349-3352
Treatment of the trienyl bromide (2) with tributylgermane affords the two stereo-isomers of 4-methyl--tricyclo[6,3,0,02,6] undecane 9 (27%) and related tricyclic compounds by processes involving three consecutive radical ring closures 相似文献
1000.