We report a simple, vacuum-compatible fiber attach process for in situ study of grating-coupled photonic devices. The robustness of this technique is demonstrated on grating-coupled waveguides exposed to multiple X-ra...
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ISBN:
(纸本)9798350369311
We report a simple, vacuum-compatible fiber attach process for in situ study of grating-coupled photonic devices. The robustness of this technique is demonstrated on grating-coupled waveguides exposed to multiple X-ray irradiations for aerospace studies.
Recent advances in machine learning (ML) are expediting materials discovery and design. One significant challenge facing ML for materials is the expansive combinatorial space of potential materials formed by diverse c...
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Recent advances in machine learning (ML) are expediting materials discovery and design. One significant challenge facing ML for materials is the expansive combinatorial space of potential materials formed by diverse constituents and their flexible configurations. This complexity is particularly evident in molecular mixtures, a frequently explored space for materials, such as battery electrolytes. Owing to the complex structures of molecules and the sequence-independent nature of mixtures, conventional ML methods have difficulties in modeling such systems. Here, we present MolSets, a specialized ML model for molecular mixtures, to overcome the difficulties. Representing individual molecules as graphs and their mixture as a set, MolSets leverages a graph neural network and the deep sets architecture to extract information at the molecular level and aggregate it at the mixture level, thus addressing local complexity while retaining global flexibility. We demonstrate the efficacy of MolSets in predicting the conductivity of lithium battery electrolytes and highlight its benefits in the virtual screening of the combinatorial chemical space.
Recent discoveries of high-Tc superconducting hydrides at high pressure have opened up new possibilities for improving the superconducting transition temperature (Tc) using hydrogenation. Here, a unique thermodynamic ...
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Recent discoveries of high-Tc superconducting hydrides at high pressure have opened up new possibilities for improving the superconducting transition temperature (Tc) using hydrogenation. Here, a unique thermodynamic approach is developed based on the concept of rapid thermal annealing and is adopted to study the hydrogenation effect on the superconducting properties of Nb/Pd bilayer films. Below 300∘C annealing temperatures, the Tc is enhanced from 8.77 to 9.06 K and is correlated with the compression of the Nb unit cell. A weak lattice expansion occurs at higher annealing temperatures, and the Tc is gradually suppressed. Furthermore, the rapid thermal hydrogenation affects the Tc differently depending on the substrate on which the Nb/Pd bilayers are grown. For the c-cut Al2O3 substrate, the Tc reduction starts at 250∘C, while for the r-cut Al2O3, this occurs at 350∘C. We associate these features with the elastic behavior of Nb film upon hydrogenation. A proposed model shows that the increase of Tc could be caused by the compressive stress related to the rapid nucleation of hydrides or the removal of impurities. Our discoveries provide insights into how superconductivity can be manipulated by rapid thermal hydrogenation.
This paper reports the use of microwave-assisted hydrothermal and precipitation approaches to prepare a composite from a polyethylene glycol (PEG − 10000) surfactant-assisted dispersion of p-Ag2O particles in conjunct...
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Electrostatic adhesion, also known as electro-adhesion, has been employed in many robotic devices for dynamic adhesion and shows fast switching between adhesive/non-adhesive states on demand. However, a well-known cha...
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Catalysis is pivotal in the production of green hydrogen through water splitting to meet the goal of carbon neutrality. Hematite (Fe2O3) is an excellent catalyst and benchmarked photoanode materials in photoelectroche...
Catalysis is pivotal in the production of green hydrogen through water splitting to meet the goal of carbon neutrality. Hematite (Fe2O3) is an excellent catalyst and benchmarked photoanode materials in photoelectrochemical water splitting. Among the metal dopants, aluminum (Al) substitution in hematite is found intrinsically. In this study, we investigate Al doped nanostructured hematite as a photoanode material and a catalyst in water oxidation mechanism using density functional theory+ U methodology. We have found that Al doping in hematite monolayer leads to unfavorable increase in theoretical overpotential value by 0.19 V. To improve the efficiency of oxygen evolution reaction, we consider heterostructuring of Al doped nanostructured hematite with pristine graphene and nitrogen (N) doped graphene as an underlayer material. Nitrogen doped graphene underlayer leads to the lowest overpotential value of 0.54 V compared to Al doped hematite catalyst (0.96 V) and graphene-Al doped hematite catalyst (0.63 V). The work function is notably reduced after nitrogen doping by 1.41 eV and 1.12 eV as compared to graphene-Al doped hematite and Al doped hematite, respectively. Charge density difference and Bader charge analysis confirm that nitrogen doped graphene underlayer induces delocalized charge density and lowers the activity of the surface states in the *O intermediate. Nitrogen doped graphene-Al doped hematite heterostructure has nearly zero band gap and has the highest cumulative probability of charge transport at photoanode’s surface. Our theoretical study provides mechanistic insights into improving the catalytic efficiency of Al doped nanostructured hematite by heterostructuring with pristine and N doped graphene.
CsSnI3 is widely studied as an environmentally friendly Pb-free perovskite material for optoelectronic device applications. To further improve material and device performance, it is important to understand the surface...
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Sn-based perovskites as low-toxicity materials are actively studied for optoelectronic applications. However, their performance is limited by p-type self-doping, which can be suppressed by substitutional doping on the...
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Ammonia is a key feedstock of fertilizers for farming and convenient hydrogen carrier as an emerging clean fuel,but industrial ammonium production process,Haber-Bosch reaction,is an energy-intensive process,consuming...
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Ammonia is a key feedstock of fertilizers for farming and convenient hydrogen carrier as an emerging clean fuel,but industrial ammonium production process,Haber-Bosch reaction,is an energy-intensive process,consuming 1%–2%of global energy and producing 3%global *** nitrogen reduction reaction(NRR)is one of the most promising routes to realize highly efficient NH3 production under ambient ***,up to now,few precious-metal-free electrocatalysts with desirable catalytic performance have been *** this work,Mo2C nanodots anchored on three-dimensional ultrathin macroporous carbon(Mo2C@3DUM-C)framework is developed toward significantly enhanced nitrogen reduction *** to the special structural design of 3D ultrathin macroporous carbon and highly active and stable Mo2C toward N2 electrochemical reduction,the Mo2C@3DUM-C framework exhibits a high Faradaic efficiency of 9.5%for NH3 production at−0.20 V and the yield rate reaches 30.4µg h−1 mgMo2C−*** electrochemical characterizations reveal the enhanced electron transfer and increased electrochemical surface area in the 3D macroporous carbon ***,the Mo2C@3DUM-C electrocatalysts hold high catalytic stability after long-term NRR *** temperature-dependent yield rate of NH3 demonstrates that the activation energy of nitrogen reduction on the employed catalyst was calculated to be 28.1 kJ mol−*** proposed earth-abundant Mo2C@3DUM-C demonstrates an alternative insight into developing efficient and stable nitrogen fixation catalysts in acids as alternatives to noble metal catalysts.
The current treatment approach for lower back pain caused by intervertebral disc (IVD) degeneration involves the use of PEEK (polyether ether ketone) polymer or titanium alloy based spinal cages to replace the degener...
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ISBN:
(数字)9784991191176
ISBN:
(纸本)9798350385908
The current treatment approach for lower back pain caused by intervertebral disc (IVD) degeneration involves the use of PEEK (polyether ether ketone) polymer or titanium alloy based spinal cages to replace the degenerated IVD. However, this method not only restricts the natural mobility of the vertebrae but also fails to mimic the structure and function of the human IVD with a single material. Additionally, the use of high-hardness materials may lead to vertebral settling, further contributing to lower back pain. Therefore, this study is dedicated to utilizing high-biocompatibility polymer (PEEK and Polydimethylsiloxane (PDMS)) composites to create an artificial IVD closely mimics the real intervertebral disc. Through adjusting the manufacture parameters, the proportion of PEEK and PDMS, and the porosity we were able to achieve the elastic modulus that is close to those of humans' IVD. Furthermore, the dual-layer structure can better replicate the functions and structure of human intervertebral disc then spinal cage.
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