DSpace community: 尖端材料科學學士學位學程

Bimetallic nanoalloys planted on super-hydrophilic carbon nanocages featuring tip-intensified hydrogen evolution electrocatalysis

title: Bimetallic nanoalloys planted on super-hydrophilic carbon nanocages featuring tip-intensified hydrogen evolution electrocatalysis abstract: The insufficient availability and activity of interfacial water remain a major challenge for alkaline hydrogen evolution reaction (HER). Here, we propose an “on-site disruption and near-site compensation” strategy to reform the interfacial water hydrogen bonding network via deliberate cation penetration and catalyst support engineering. This concept is validated using tip-like bimetallic RuNi nanoalloys planted on super-hydrophilic and high-curvature carbon nanocages (RuNi/NC). Theoretical simulations suggest that tip-induced localized concentration of hydrated K+ facilitates optimization of interfacial water dynamics and intermediate adsorption. In situ synchrotron X-ray spectroscopy endorses an H* spillover-bridged Volmer‒Tafel mechanism synergistically relayed between Ru and Ni. Consequently, RuNi/NC exhibits low overpotential of 12 mV and high durability of 1600 h at 10 mA cm‒2 for alkaline HER, and demonstrates high performance in both water electrolysis and chlor-alkali electrolysis. This strategy offers a microscopic perspective on catalyst design for manipulation of the local interfacial water structure toward enhanced HER kinetics.

Surmounting scaling relationship on Cu-base diatomic catalysts by geminal-site-induced synergistic effect for high-selectivity CO2 electrochemical reduction to CO

title: Surmounting scaling relationship on Cu-base diatomic catalysts by geminal-site-induced synergistic effect for high-selectivity CO2 electrochemical reduction to CO abstract: Cu-based nanomaterials are regarded as the most promising alternatives for catalyzing electrochemical CO2 reduction reactions (ECO2RR). However, its development is impeded by the low selectivity. Improving the selectivity of ECO2RR plays a key role in the commercialized progress of Cu-based nanomaterials. Herein, we screened out the most potential diatomic site from representative Cu-based diatomic catalysts (DACs) and their responsive single-atomic catalysts through theoretical calculations and experiments. The theoretical calculations revealed that the synergistic effect between the diatomic sites in Cu-Mn and Cu-Fe DACs can assist them to break through the limit of scaling relationship and realize the high-selectivity ECO2RR to CO. This was verified by the electrochemical measurements that the as-synthesized nitrogen-doped carbon-supported Cu-Mn and Cu-Fe DACs (Cu-Mn/NC and Cu-Fe/NC) delivered high Faraday efficiency of CO (FECO >90 %) at a wide potential range. Furthermore, the Cu-Mn/NC displayed remarkable mass activity of 1760 A g−1, which is about 27.3 times of a Cu single-atom catalyst, and catalytic stability that goes through a 30-h electrolytic process without current attenuation at −0.6 V. Our work suggests that this synergistic effect can be used as a viable and general strategy to design DACs with high-selectivity ECO2RR for desired products.

Interrogation of 3d Transition Bimetallic Nanocrystal Nucleation and Growth Using In Situ Electron Microscope and Synchrotron X-ray Techniques

title: Interrogation of 3d Transition Bimetallic Nanocrystal Nucleation and Growth Using In Situ Electron Microscope and Synchrotron X-ray Techniques abstract: Understanding the nucleation and growth mechanism of 3d transition bimetallic nanocrystals (NCs) is crucial to developing NCs with tailored nanostructures and properties. However, it remains a significant challenge due to the complexity of 3d bimetallic NCs formation and their sensitivity to oxygen. Here, by combining in situ electron microscopy and synchrotron X-ray techniques, we elucidate the nucleation and growth pathways of Fe–Ni NCs. Interestingly, the formation of Fe–Ni NCs emerges from the assimilation of Fe into Ni clusters together with the reduction of Fe–Ni oxides. Subsequently, these NCs undergo solid-state phase transitions, resulting in two distinct solid solutions, ultimately dominated by γ-Fe3Ni2. Furthermore, we deconvolve the interplays between local coordination and electronic state concerning the growth temperature. We directly visualize the oxidation-state distributions of Fe and Ni at the nanoscale and investigate their changes. This work may reshape and enhance the understanding of nucleation and growth in atomic crystallization.

WS2 Moiré Superlattices Supporting Au Nanoclusters and Isolated Ru to Boost Hydrogen Production

title: WS2 Moiré Superlattices Supporting Au Nanoclusters and Isolated Ru to Boost Hydrogen Production abstract: Maximizing the catalytic activity of single-atom and nanocluster catalysts through the modulation of the interaction between these components and the corresponding supports is crucial but challenging. Herein, guided by theoretical calculations, a nanoporous bilayer WS2 Moiré superlattices (MSLs) supported Au nanoclusters (NCs) adjacent to Ru single atoms (SAs) (Ru1/Aun-2LWS2) is developed for alkaline hydrogen evolution reaction (HER) for the first time. Theoretical analysis suggests that the induced robust electronic metal–support interaction effect in Ru1/Aun-2LWS2 is prone to promote the charge redistribution among Ru SAs, Au NCs, and WS2 MSLs support, which is beneficial to reduce the energy barrier for water adsorption and thus promoting the subsequent H2 formation. As feedback, the well-designed Ru1/Aun-2LWS2 electrocatalyst exhibits outstanding HER performance with high activity (η10 = 19 mV), low Tafel slope (35 mV dec−1), and excellent long-term stability. Further, in situ, experimental studies reveal that the reconstruction of Ru SAs/NCs with S vacancies in Ru1/Aun-2LWS2 structure acts as the main catalytically active center, while high-valence Au NCs are responsible for activating and stabilizing Ru sites to prevent the dissolution and deactivation of active sites. This work offers guidelines for the rational design of high-performance atomic-scale electrocatalysts.

Defect-Rich SnO2 Nanofiber as an Oxygen-Defect-Driven Photoenergy Shield against UV Light Cell Damage

title: Defect-Rich SnO2 Nanofiber as an Oxygen-Defect-Driven Photoenergy Shield against UV Light Cell Damage abstract: Usually, most studies focus on toxic gas and photosensors by using electrospinning and metal oxide polycrystalline SnO2 nanofibers (PNFs), while fewer studies discuss cell–material interactions and photoelectric effect. In this work, the controllable surface morphology and oxygen defect (VO) structure properties were provided to show the opportunity of metal oxide PNFs to convert photoenergy into bio-energy for bio-material applications. Using the photobiomodulation effect of defect-rich polycrystalline SnO2 nanofibers (PNFs) is the main idea to modulate the cell–material interactions, such as adhesion, growth direction, and reactive oxygen species (ROS) density. The VO structures, including out-of-plane oxygen defects (op-VO), bridge oxygen defects (b-VO), and in-plane oxygen defects (ip-VO), were studied using synchrotron analysis to investigate the electron transfer between the VO structures and conduction bands. These intragrain VO structures can be treated as generation-recombination centers, which can convert various photoenergies (365–520 nm) into different current levels that form distinct surface potential levels; this is referred to as the photoelectric effect. PNF conductivity was enhanced 53.6-fold by enlarging the grain size (410 nm2) by increasing the annealing temperature, which can improve the photoelectric effect. In vitro removal of reactive oxygen species (ROS) can be achieved by using the photoelectric effect of PNFs. Also, the viability and shape of human bone marrow mesenchymal stem cells (hMSCs-BM) were also influenced significantly by the photobiomodulation effect. The cell damage and survival rate can be prevented and enhanced by using PNFs; metal oxide nanofibers are no longer only environmental sensors but can also be a bio-material to convert the photoenergy into bio-energy for biomedical science applications.

Ferromagnetism at Room Temperature in 2D Iron Nanolaminated MAX Phases

title: Ferromagnetism at Room Temperature in 2D Iron Nanolaminated MAX Phases

Encaging Co nanoparticle in atomic CoN4-dispersed graphite nanopocket evokes high oxygen reduction activity for flexible Zn-air battery

title: Encaging Co nanoparticle in atomic CoN4-dispersed graphite nanopocket evokes high oxygen reduction activity for flexible Zn-air battery abstract: Rational design of oxygen reduction reaction (ORR) electrocatalysts with indestructible active sites for high-performance Zn-air batteries (ZABs) remains a significant challenge. Herein, we achieve an innovative active site design by encaging Co nanoparticles within the Co−N4 atomic sites-dispersed graphite nanopocket (CoSAs-NPs/NC), leading to outstanding alkaline ORR activity and stability, and consequently ultra-high power density of 193.8 mW cm–2 and specific capacity of 819.1 mAh gZn–1 at 10 mA cm–2 of a primary ZAB assembled, along with impressive power density of 73.4 mW cm–2 and charging/discharging stability up to 110 cycles of a flexible solid-state ZAB. Theoretical calculations unveil the enhanced ORR kinetics can be traced to the significantly optimized local electronic structure of Co−N4 sites with upshifted d-band center and reduced energy barrier of rate-limiting step by the encaged Co nanoparticle. This study showcases a creative conformational design for guiding the construction of valid synergy in hybridized metal/single-atom catalysts.

Strain-Controlled Intermetallic PtZn Nanoparticles via N-Doping Propel Highly Efficient Oxygen Reduction Electrocatalysis

title: Strain-Controlled Intermetallic PtZn Nanoparticles via N-Doping Propel Highly Efficient Oxygen Reduction Electrocatalysis abstract: Targeting high-performance yet cost-effective Pt-based catalysts with low Pt usage and high Pt utilization remains a big challenge in the oxygen reduction reaction (ORR) electrocatalysis. In this work, we demonstrate delicate engineering of strain control via N-doping in ordered PtZn intermetallic nanoparticles supported on N-doped carbon (PtZnN/NC). Benefiting from the ameliorated compressive strain and consequently greatly optimized electronic structures, PtZnN/NC displays ultrahigh ORR activity and durability in both acidic and alkaline media, with respective high mass activities of 297.5 and 80.7 A gPt–1 at 0.9 VRHE, exceeding those of benchmark Pt/C by 8.3- and 2.8-folds. Theoretical calculations reveal that the N-doping effectively lowers the d-band center of PtZnN, resulting in loose binding of *OH on the PtZnN surface, which facilitates the potential-determining step with a reduced energy barrier. This work successfully offers strategic guidance for strain equilibration in alloys via N-doping toward the rational design of advanced electrocatalysts.

Interfacial defects for high-performance photoelectrochemical properties of core-shell BiVO4 ZnO nanodendrite: X-ray Spectro-Microscopic Investigation

title: Interfacial defects for high-performance photoelectrochemical properties of core-shell BiVO4 ZnO nanodendrite: X-ray Spectro-Microscopic Investigation

Evolution of Superconductivity in K2-xFe4+ySe5: X-ray Absorption and Emission Spectroscopic Studies

title: Evolution of Superconductivity in K2-xFe4+ySe5: X-ray Absorption and Emission Spectroscopic Studies

Role of Interfacial Defects in Photoelectrochemical Properties of BiVO4 Coated on ZnO Nanodendrites: X-ray Spectroscopic and Microscopic Investigation

title: Role of Interfacial Defects in Photoelectrochemical Properties of BiVO4 Coated on ZnO Nanodendrites: X-ray Spectroscopic and Microscopic Investigation abstract: Synchrotron-based X-ray spectroscopic and microscopic techniques are used to identify the origin of enhancement of the photoelectrochemical (PEC) properties of BiVO4 (BVO) that is coated on ZnO nanodendrites (hereafter referred to as BVO/ZnO). The atomic and electronic structures of core–shell BVO/ZnO nanodendrites have been well-characterized, and the heterojunction has been determined to favor the migration of charge carriers under the PEC condition. The variation of charge density between ZnO and BVO in core–shell BVO/ZnO nanodendrites with many unpaired O 2p-derived states at the interface forms interfacial oxygen defects and yields a band gap of approximately 2.6 eV in BVO/ZnO nanocomposites. Atomic structural distortions at the interface of BVO/ZnO nanodendrites, which support the fact that there are many interfacial oxygen defects, affect the O 2p–V 3d hybridization and reduce the crystal field energy 10Dq ∼2.1 eV. Such an interfacial atomic/electronic structure and band gap modulation increase the efficiency of absorption of solar light and electron–hole separation. This study provides evidence that the interfacial oxygen defects act as a trapping center and are critical for the charge transfer, retarding electron–hole recombination, and high absorption of visible light, which can result in favorable PEC properties of a nanostructured core–shell BVO/ZnO heterojunction. Insights into the local atomic and electronic structures of the BVO/ZnO heterojunction support the fabrication of semiconductor heterojunctions with optimal compositions and an optimal interface, which are sought to maximize solar light utilization and the transportation of charge carriers for PEC water splitting and related applications.

Bandgap Shrinkage and Charge Transfer in 2D Layered SnS2 Doped with V for Photocatalytic Efficiency Improvement

title: Bandgap Shrinkage and Charge Transfer in 2D Layered SnS2 Doped with V for Photocatalytic Efficiency Improvement abstract: Effects of electronic and atomic structures of V-doped 2D layered SnS2 are studied using X-ray spectroscopy for the development of photocatalytic/photovoltaic applications. Extended X-ray absorption fine structure measurements at V K-edge reveal the presence of VO and VS bonds which form the intercalation of tetrahedral OVS sites in the van der Waals (vdW) gap of SnS2 layers. X-ray absorption near-edge structure (XANES) reveals not only valence state of V dopant in SnS2 is ≈4+ but also the charge transfer (CT) from V to ligands, supported by V Lα,β resonant inelastic X-ray scattering. These results suggest V doping produces extra interlayer covalent interactions and additional conducting channels, which increase the electronic conductivity and CT. This gives rapid transport of photo-excited electrons and effective carrier separation in layered SnS2. Additionally, valence-band photoemission spectra and S K-edge XANES indicate that the density of states near/at valence-band maximum is shifted to lower binding energy in V-doped SnS2 compare to pristine SnS2 and exhibits band gap shrinkage. These findings support first-principles density functional theory calculations of the interstitially tetrahedral OVS site intercalated in the vdW gap, highlighting the CT from V to ligands in V-doped SnS2.

Design of Ru-Ni diatomic sites for efficient alkaline hydrogen oxidation

title: Design of Ru-Ni diatomic sites for efficient alkaline hydrogen oxidation abstract: Anion exchange membrane fuel cells are limited by the slow kinetics of alkaline hydrogen oxidation reaction (HOR). Here, we establish HOR catalytic activities of single-atom and diatomic sites as a function of *H and *OH binding energies to screen the optimal active sites for the HOR. As a result, the Ru-Ni diatomic one is identified as the best active center. Guided by the theoretical finding, we subsequently synthesize a catalyst with Ru-Ni diatomic sites supported on N-doped porous carbon, which exhibits excellent catalytic activity, CO tolerance, and stability for alkaline HOR and is also superior to single-site counterparts. In situ scanning electrochemical microscopy study validates the HOR activity resulting from the Ru-Ni diatomic sites. Furthermore, in situ x-ray absorption spectroscopy and computational studies unveil a synergistic interaction between Ru and Ni to promote the molecular H2 dissociation and strengthen OH adsorption at the diatomic sites, and thus enhance the kinetics of HOR.

A single-atom library for guided monometallic and high-entropy designs

title: A single-atom library for guided monometallic and high-entropy designs

Temperature‐Dependent Structures of Single‐Atom Catalysts

title: Temperature‐Dependent Structures of Single‐Atom Catalysts abstract: Single-atom catalysts (SACs) have the unique coordination environment and electronic structure due to the quantum size effect, which plays an essential role in facilitating catalytic reactions. However, due to the limited understanding of the formation mechanism of single atoms, achieving the modulation of the local atomic structure of SACs is still difficult and challenging. Herein, we have prepared a series of Ni SACs loaded on nitrogen-doped carbon substrates with different parameters using a dissolution-and-carbonization method to systematically investigate the effect of temperature on the structure of the SACs. The results of characterization and electrochemical measurements are analyzed to reveal the uniform law between temperature and the metal loading, bond length, coordination number, valence state and CO2 reduction performance, showing the feasibility of controlling the structure of SACs through temperature to regulate the catalytic performance. This is important for the understanding of catalytic reaction mechanisms and the design of efficient catalysts.

Disordered Au Nanoclusters for Efficient Ammonia Electrosynthesis

title: Disordered Au Nanoclusters for Efficient Ammonia Electrosynthesis abstract: The electrochemical nitrogen (N2) reduction reaction (N2RR) under mild conditions is a promising and environmentally friendly alternative to the traditional Haber-Bosch process with high energy consumption and greenhouse emission for the synthesis of ammonia (NH3), but high-yielding production is rendered challenging by the strong nonpolar N≡N bond in N2 molecules, which hinders their dissociation or activation. In this study, disordered Au nanoclusters anchored on two-dimensional ultrathin Ti3C2Tx MXene nanosheets are explored as highly active and selective electrocatalysts for efficient N2-to-NH3 conversion, exhibiting exceptional activity with an NH3 yield rate of 88.3±1.7 μg h−1 mgcat.−1 and a faradaic efficiency of 9.3±0.4 %. A combination of in situ near-ambient pressure X-ray photoelectron spectroscopy and operando X-ray absorption fine structure spectroscopy is employed to unveil the uniqueness of this catalyst for N2RR. The disordered structure is found to serve as the active site for N2 chemisorption and activation during the N2RR process.

Chemically coupling SnO2 quantum dots and MXene for efficient CO2 electroreduction to formate and Zn–CO2 battery

title: Chemically coupling SnO2 quantum dots and MXene for efficient CO2 electroreduction to formate and Zn–CO2 battery abstract: Electrochemical conversion of CO2 into formate is a promising strategy for mitigating the energy and environmental crisis, but simultaneously achieving high selectivity and activity of electrocatalysts remains challenging. Here, we report low-dimensional SnO2 quantum dots chemically coupled with ultrathin Ti3C2Tx MXene nanosheets (SnO2/MXene) that boost the CO2 conversion. The coupling structure is well visualized and verified by high-resolution electron tomography together with nanoscale scanning transmission X-ray microscopy and ptychography imaging. The catalyst achieves a large partial current density of −57.8 mA cm−2 and high Faradaic efficiency of 94% for formate formation. Additionally, the SnO2/MXene cathode shows excellent Zn–CO2 battery performance, with a maximum power density of 4.28 mW cm−2, an open-circuit voltage of 0.83 V, and superior rechargeability of 60 h. In situ X-ray absorption spectroscopy analysis and first-principles calculations reveal that this remarkable performance is attributed to the unique and stable structure of the SnO2/MXene, which can significantly reduce the reaction energy of CO2 hydrogenation to formate by increasing the surface coverage of adsorbed hydrogen.

In situ TEM investigation of indium oxide/titanium oxide nanowire heterostructures growth through solid state reactions

title: In situ TEM investigation of indium oxide/titanium oxide nanowire heterostructures growth through solid state reactions abstract: Heterostructured TiO2/In2O3 nanowires have been extensively applied in various photonic devices; their performance is highly related to the microstructures, which has not been, however, clearly understood; thus, it is important to investigate the microstructural evolution of the material during processing. In this work, the crystallinity and microstructure of TiO2/In2O3 nanowires were successfully controlled with the variation of annealing temperatures via solid-state reactions. The dynamic phase transformation process was demonstrated by in situ transmission electron microscope (TEM). Moreover, the elemental information at different states was identified by energy dispersive spectroscopy (EDS). It is found that different annealing temperatures would contribute to different solid-state reactions and nanowire heterostructures. Additionally, photoresponse studies show characteristics enhancement for such nanoheterostructures. This study provides the knowledge of the fundamental science in kinetics of heterostructured nanostructures, which benefits the improvement of the performance for future photonic applications.

蛋黃油脫色脫味之製備方法

title: 蛋黃油脫色脫味之製備方法 abstract: 本發明提供一種蛋黃油脫色脫味之製備方法，其至少包含下列步驟：提供粗製蛋黃油；提供第一乙醚溶液，將第一乙醚溶液加入粗製蛋黃油中，經第一攪拌製程，產生第一蛋黃油混合液；提供活性碳，將活性碳加入第一蛋黃油混合液，經第二攪拌製程，再移除活性碳後，產生第二蛋黃油混合液；提供第二乙醚溶液與蒸餾水，將第二乙醚溶液與蒸餾水加入第二蛋黃油混合液，經第三攪拌製程，產生第三蛋黃油混合液；以及將第三蛋黃油混合液用蒸餾製程移除蒸餾水、部分第一乙醚溶液與部分第二乙醚溶液後，再用真空製程將剩餘第一乙醚溶液與剩餘第二乙醚溶液移除後，產生脫色脫味之蛋黃油。
description: 專利證號：I741469

微針元件的製造方法

title: 微針元件的製造方法 abstract: 一種微針元件的製造方法，係包括以下步驟：目標組織基本資訊取得步驟、微針模板取得步驟、微針材料添加步驟、微針半成品取得步驟以及微針元件取得步驟。內層組織分佈資訊係應用光學相干涉斷層掃描技術取得。微針模板係依據皮膚表面曲率資訊以及內層組織分佈資訊取得。微針模板具有複數區域以及複數模孔，該些模孔的孔徑及孔深中的至少一者是由內層組織分佈資訊所決定，該些區域的曲率半徑是由皮膚表面曲率資訊所決定。所述的微針元件的製造方法可適用於製造針體為混合型微針以及針筒型微針的態樣。
description: 專利證號：I741732

利用X光光譜來探討超導體K2-xFe4+ySe5及電荷密度波單晶材料Sr3Ir4Sn13之電子與原子結構研究

title: 利用X光光譜來探討超導體K2-xFe4+ySe5及電荷密度波單晶材料Sr3Ir4Sn13之電子與原子結構研究 abstract: In this thesis, the X-ray Absorption Near Edge Structure (XANES), Extended X-Ray Absorption Fine Structure (EXAFS), X-Ray Emission Spectroscopy (XES) and Resonant Inelastic X-Ray Scattering (RIXS) have been investigated the following two topics. In the first part, the superconductor, SC, (K1.9Fe4.2Se5) and non-superconductor, NS, (K2Fe4Se5) samples have been synthesized by quenching from various temperatures, 820 0C (SC-820 and NS-820) and 750 0C (SC-750 and NS-750). Fe K-edge EXAFS show enhanced Fe vacancy disorder in SC samples as compared to the NS samples, suggesting the Fe vacancy disorder strongly associated with the superconductor. The RR factor analysis by using Fe Lα, β-edge RIXS spectra, the SC-sample revealed the lower magnetic spin state, suggesting increasing in the low spin state enhance the superconducting behavior. Fe L3,2-edge and Se K-edge XANES suggested that the lower charge transfer effect from Fe 3d to Se 4p state in SC-group, which resulted in the lower spin state in SC-sample. These observations clearly elucidate that the spin state of Fe atom, charge transfer effect and Fe vacancy disorder are closely associated with the superconducting behavior in K2-xFe4+ySe5. In the second part, the evolution of a series of satellite peaks below the anomalous resistivity transition (T*~147 K) have been observed in Sr3Ir4Sn13 (SIS) single crystal by using X-ray scattering experiment, indicating the formation of possible charge density wave (CDW) in the (110) plane, and consistent with Sn K-edge EXAFS results. XANES spectra at the Ir L3-edge and Sn K-edge demonstrated that the Ir 5d states are closely related to the anomalous resistivity transition, rather than the Sn 5p state. Accordingly, a close relationship exists between local electronic and atomic structures and the CDW-phase in the SIS. 本文利用X光吸收近邊結構(XANES)、延伸Ｘ光吸收精細結構(EXAFS)、X光發射能譜 (XES)和非彈性共振X光散射能譜術(RIXS)來研究以下兩個主題。在第一部分，利用製程中不同的冷卻溫度(820 0C和750 0C)來合成，不同的超導體K1.9Fe4.2Se5 (SC-820和SC-750)與非超導體K2Fe4Se5 (NS-820和NS-750)。Fe K-edge EXAFS證明在超導的樣品(SC)中的鐵缺陷亂度比非超導樣品(NS)較大，藉此說明鐵缺陷的亂度與超導有很大的關係。利用Fe Lα, β-edge RIXS 來分析RR factor，發現到超導樣品(SC)具有較低的磁自旋態，說明較多的低自旋態可以增加超導之特性。在Fe L3,2-edge 和 Se K-edge XANES中，發現在超導的樣品中(SC)，由Fe 3d到Se 4p的電荷轉換現象較微弱，此即導致超導樣品(SC)有較低磁自旋態之原因之一。這些現象說明了在K2-xFe4+ySe5中鐵的自旋態、電荷轉移、鐵缺陷亂度與超導特性有強烈的關係。在第二部分中，利用X光散射實驗發現到當Sr3Ir4Sn13 (SIS)單晶溫度低於不規則的電阻轉變T<147 K (T*)時，會演化出一系列的衛星峰，說明了當溫度低於T*時，電荷密度波(CDW)可能形成在(110)平面且此結果也與EXAFS結果相吻合。在Ir L3 -edge 和 Sn K-edge XANES中，證實在溫度接近T*時，不規則的電阻變化與Ir 5d態有強烈的關係而並非與Sn 5p態有關。根據以上的結果，在SIS單晶中局域性的電子、原子結構和CDW有著密不可分的關係。

Enhancement in the Detection Ability of Metal Oxide Sensors Using Defect‐Rich Polycrystalline Nanofiber Devices

title: Enhancement in the Detection Ability of Metal Oxide Sensors Using Defect‐Rich Polycrystalline Nanofiber Devices abstract: The development of SnO2 and TiO2 polycrystalline nanofiber devices (PNFDs) has been widely researched as a method of protecting humans from household air pollution. PNFDs have three significant advantages. The nanofibers before the annealing process are polymer‐rich materials, which can be used as particulate material (PM) filters. The multiporous nanofibers fabricated by the annealing process have numerous defects that can serve as generation‐recombination centers for electron–hole pairs, enabling the PNFDs to serve as multiple‐wavelength light (from 365 to 940 nm) detectors. Lastly, the numerous surface/interface defects can drastically enhance the toxic gas detection ability. The toxic gas detection range of PNFDs for CO(g) and NO(g) is from 400 to 50 ppm and 400 to 50 ppb, respectively. Quick response times and recovery properties are key parameters for commercial applications. The recovery time of NO(g) detection can be improved from 1 ks to 40 s and the PNFD operating temperature lowered to 50 °C. These results indicate that SnO2 and TiO2 PNFDs have good potential for commercialization and use as toxic gas and photon sensors in daily lives.

The effect of turbulent viscous shear stress on red blood cell hemolysis

title: The effect of turbulent viscous shear stress on red blood cell hemolysis abstract: Non-physiologic turbulent flow occurs in medical cardiovascular devices resulting in hemodynamic stresses that may damage red blood cells (RBC) and cause hemolysis. Hemolysis was previously thought to result from Reynolds shear stress (RSS) in turbulent flows. A more recent hypothesis suggests that turbulent viscous shear stresses (TVSS) at spatial scales similar in size to RBCs are related to their damage. We applied two-dimensional digital particle image velocimetry to measure the flow field of a free-submerged axisymmetric jet that was utilized to hemolyze porcine RBCs in selected locations. Assuming a dynamic equilibrium for the sub-grid scale (SGS) energy flux between the resolved and the sub-grid scales, the SGS energy flux was calculated from the strain rate tensor computed from the resolved velocity fields. The SGS stress was determined by the Smagorinsky model, from which the turbulence dissipation rate and then TVSS were estimated. Our results showed the hemolytic threshold of the Reynolds stresses was up to 517 Pa, and the TVSSs were at least an order of magnitude less than the RSS. The results provide further insight into the relationship between turbulence and RBC damage.