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排序方式: 共有7891条查询结果,搜索用时 46 毫秒
1.
Venhryn Yu. I. Popovych I. D. Serednytski A. S. Kolomys O. F. Luchechko A. P. Strelchuk V. V. 《Journal of Materials Science: Materials in Electronics》2022,33(14):10715-10722
Journal of Materials Science: Materials in Electronics - The ZnO and TiO2 nanopowders have been prepared by means of the pulsed laser reactive ablation of metallic (Zn, Ti) targets. The Structural,... 相似文献
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《Ceramics International》2022,48(9):12537-12548
Enhancing the electrical conductivity of electrode materials via a cationic substitution strategy was recognized as an effective way of improving the electrochemical performance of Li-ion batteries. Thus, LixCa1-xFe2O4 nanoparticles were synthesized via a facile inexpensive process at low temperature. XRD peaks refer to the formation of an orthorhombic structure with the Pnma space group. HR-TEM investigations reveal orthorhombic-like shape for pure CaFe2O4, nanoplatelet-like morphology for Li0.05Ca0.95Fe2O4 and irregular distorted crystals for Li0.1Ca0.9Fe2O4. Voids and pores in Li-doped CaFe2O4 were confirmed by FESEM and BET measurements. XPS spectra of O1s prove that Li-doped CaFe2O4 have higher conductivity due to the created lattice defects and oxygen species. Li-doped CaFe2O4 anodes exhibit great improvement in their initial discharge capacities ~1219 and 1606 mAhg?1 upon substitution of Ca with 5% and 10% Li, respectively. Furthermore, 10% Li-doped CaFe2O4 anode displays the highest Li-ions diffusion coefficient and exchange current density due to the enhanced Li+ ions mobility. Moreover, the DC activation energies for the LixCa1-xFe2O4 nanoparticles decreased with increasing Li content. 相似文献
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Golam Haider Krishna Sampathkumar Tim Verhagen Lukáš Nádvorník Farjana J. Sonia Václav Valeš Jan Sýkora Peter Kapusta Petr Němec Martin Hof Otakar Frank Yang-Fang Chen Jana Vejpravová Martin Kalbáč 《Advanced functional materials》2021,31(29):2102196
Recent advancements in isolation and stacking of layered van der Waals materials have created an unprecedented paradigm for demonstrating varieties of 2D quantum materials. Rationally designed van der Waals heterostructures composed of monolayer transition-metal dichalcogenides (TMDs) and few-layer hBN show several unique optoelectronic features driven by correlations. However, entangled superradiant excitonic species in such systems have not been observed before. In this report, it is demonstrated that strong suppression of phonon population at low temperature results in a formation of a coherent excitonic-dipoles ensemble in the heterostructure, and the collective oscillation of those dipoles stimulates a robust phase synchronized ultra-narrow band superradiant emission even at extremely low pumping intensity. Such emitters are in high demand for a multitude of applications, including fundamental research on many-body correlations and other state-of-the-art technologies. This timely demonstration paves the way for further exploration of ultralow-threshold quantum-emitting devices with unmatched design freedom and spectral tunability. 相似文献
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《Journal of the European Ceramic Society》2021,41(14):6983-6990
Ternary 0.552Pb(Ni1/3Nb2/3)O3-xPbZrO3-(0.448-x)PbTiO3 (PNN-PZ-PT) ceramics near the triple point compositions were fabricated by an improved two-step sintering method. The triple point composition 0.552PNN-0.135PZ-0.313PT ceramic has outstanding piezoelectric performance with piezoelectric coefficient d33 = 1200 pC/N. Its easy fabrication and low cost make this piezoelectric material an excellent candidate for high sensitivity sensors and ultrasonic transducers. The evolution of domain structures for ceramics with composition near the triple point provides deeper insight into the mechanism of ultrahigh piezoelectric properties of PNN-PZ-PT ceramics. 相似文献
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When a laser beam induces surface tension gradient at the free surface of a liquid, a weak surface depression is expected and has been observed. Here we report giant depression and rupture in “optothermocapillary fluids” under the illumination of laser and sunlight. Computational fluid dynamics models were developed to understand the surface deformation and provided desirable physical parameters of the fluid for maximum deformation. New optothermocapillary fluids were created by mixing transparent lamp oil with different candle dyes. They can be cut open by sunlight and be patterned to different shapes and sizes using an ordinary laser show projector or a common laser pointer. Laser driving and elevation of optothermocapillary fluids, in addition to the manipulation of different droplets on their surface, were demonstrated as an efficient controlling method and platform for optofluidic operations. The fundamental understanding of light-induced giant depression and creation of new optothermocapillary fluids encourage the fundamental research and applications of optofluidics. 相似文献
7.
The wearable intelligent electronic product similar to electronic skin has a great application prospect. However, flexible electronic with high performance pressure sensing functions are still facing great challenges. In this paper, the highly sensitive flexible electronic skin (FES) based on the PVDF/rGO/BaTiO3 composite thin film was fabricated using the near-field electrohydrodynamic direct-writing (NFEDW) method. The PVDF/rGO/BaTiO3 composite solution was directly written on flexible substrate by the NFEDW method to fabricate FES with micro/nano fiber structure, which has the function of sensing pressure with high sensitivity and fast response. The surface morphology and microstructure were characterized by SEM, AFM, and optical microscope in detail. The fabricated FES has high sensitivity (59 kPa−1) and faster response time (130 ms). FES has been successfully applied to the detection of human motion and subtle physiological signals. The experimental results show that FES has good stability and reliability. FES can recognize human motion, and it has a broad application prospect in the field of wearable devices. 相似文献
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Pavel Strunz Debashis Mukherji Přemysl Beran Ralph Gilles Lukas Karge Michael Hofmann Markus Hoelzel Joachim Rösler Gergely Farkas 《Metals and Materials International》2018,24(5):934-944
An addition of boron largely increases the ductility in polycrystalline high-temperature Co–Re alloys. Therefore, the effect of boron on the alloy structural characteristics is of high importance for the stability of the matrix at operational temperatures. Volume fractions of ε (hexagonal close-packed—hcp), γ (face-centered cubic—fcc) and σ (Cr2Re3 type) phases were measured at ambient and high temperatures (up to 1500 °C) for a boron-containing Co–17Re–23Cr alloy using neutron diffraction. The matrix phase undergoes an allotropic transformation from ε to γ structure at high temperatures, similar to pure cobalt and to the previously investigated, more complex Co–17Re–23Cr–1.2Ta–2.6C alloy. It was determined in this study that the transformation temperature depends on the boron content (0–1000 wt. ppm). Nevertheless, the transformation temperature did not change monotonically with the increase in the boron content but reached a minimum at approximately 200 ppm of boron. A probable reason is the interplay between the amount of boron in the matrix and the amount of σ phase, which binds hcp-stabilizing elements (Cr and Re). Moreover, borides were identified in alloys with high boron content. 相似文献