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Ru@RuO2 Core-Shell Nanorods: A Highly Active and Stable Bifunctional Catalyst for Oxygen Evolution and Hydrogen Evolution Reactions

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Energy & Environmental Materials 2019年第3期2卷 201-208页

作者： Rongzhong jiang Dat t.tran jiangtian Li Deryn Chu Sensors and Electron Devices Directorate U.S.Army Research Laboratory2800 Powder Mill RoadAdelphiMD 20783-1197USA

Ru@RuO2 core-shell nanorods were successfully synthesized by heat-treating Ru nanorods with air oxidation through an accurate control of the temperature and time. the structure, composition, dimension, and adsorption property of the core-shell nanorods were well characterized with XRD and tEM. the catalytic activity and stability were electrochemically evaluated with a rotating disk electrode, a rotating ring-disk electrode, and chronopotentiometric methods. the Ru@RuO2 nanorods reveal excellent bifunctional catalytic activity and robust stability for both oxygen evolution reaction(OER) and hydrogen evolution reaction(HER). the overpotentials for OER and HER are 320 m V and 137 m V at the current density of10 m A cm-2, respectively. the catalytic activity of Ru@RuO2 nanorods for OER is 6.5 times higher than that of the state-of-the-art catalyst IrO2 according to the catalytic current density measured at 1.60 V(versus RHE).the catalytic activity of Ru@RuO2 nanorods for HER is comparable to 40%Pt/C by comparing the catalytic current densities at à0.2 V.

关键词： bifunctional catalyst core-shell hydrogen evolution reaction oxygen evolution reaction Ru@RuO2

Ferrofluid moving thin films for active flow control

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Chinese journal of Aeronautics 2021年第5期34卷 115-119页

作者： Francisco j.ARIAS Department of Fluid Mechanics Polytechnic University of CataloniaESEIAATC/Colom 1108222 BarcelonaSpain

Ferrofluid moving thin films and their possible significance with regard to active flow control for lift and attack angle enhancement are *** this strategy,a very thin film of ferrofluid is strongly attached at the wall of the wing by a normal magnetic field from below and pumped tangentially along the *** a simplified physical model and from the available experimental data on moving walls,the expected lift enhancement and effect on the attack angle were *** research and design is required in order to explore the possibilities in the use of ferrofluid moving thin films.

关键词： Active flow control Boundary layer separation Ferrofluid

Peptide-based targeting of immunosuppressive cells in cancer

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Bioactive Materials 2020年第1期5卷 92-101页

作者： Noah t.trac Eun ji Chung Department of Biomedical Engineering University of Southern CaliforniaLos AngelesCAUSA Department of Chemical Engineering and Materials Science University of Southern CaliforniaLos AngelesCAUSA Division of Nephrology and Hypertension Keck School of MedicineUniversity of Southern CaliforniaLos AngelesCAUSA Department of Vascular Surgery Keck School of MedicineUniversity of Southern CaliforniaLos AngelesCAUSA Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research University of Southern CaliforniaLos AngelesCAUSA Norris Comprehensive Cancer Center Keck School of MedicineUniversity of Southern CaliforniaLos AngelesCAUSA

Cancer progression is marked by the infiltration of immunosuppressive cells,such as tumor-associated macrophages(tAMs),regulatory t lymphocytes(tregs),and myeloid-derived suppressor cells(MDSCs).these cells play a key role in abrogating the cytotoxic t lymphocyte-mediated(CtL)immune response,allowing tumor growth to proceed ***,targeting these immunosuppressive cells through the use of peptides and peptide-based nanomedicine has shown promising *** we review the origins and functions of immunosuppressive cells in cancer progression,peptide-based systems used in their targeting,and explore future avenues of research regarding cancer *** success of these studies demonstrates the importance of the tumor immune microenvironment in the propagation of cancer and the potential of peptide-based nanomaterials as immunomodulatory agents.

关键词： Immunosuppression tumor microenvironment Peptide Nanoparticle

Water transport to the core–mantle boundary

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National Science Review 2021年第4期8卷 13-16页

作者： Michael j.Walter Earth and Planets Laboratory Carnegie Institution for Science

Water can have remarkable effects when exposed to rocks at high pressures and temperatures. It can form new minerals with unique properties and often profoundly affects the physical, transport and rheological properti... 详细信息

关键词： StABILItY H2O

Review on Hydrogen Embrittlement of Press-hardened Steels for Automotive Applications

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Acta Metallurgica Sinica(English Letters) 2023年第7期36卷 1123-1143页

作者： Z.Wang Q.Lu Z.H.Cao H.Chen M.X.Huang j.F.Wang General Motors China Science Lab Shanghai201206China Department of Mechanical Engineering The University of Hong KongPokfulam RoadHong Kong999077China Key Laboratory for Advanced Materials of Ministry of Education School of Materials Science and EngineeringTsinghua UniversityBeijing100084China

Press-hardened steel(PHS)with an ultimate tensile strength(UtS)of 1500 MPa has been widely used in automotive body-in-white in the last two decades,due to its ultra-high strength and excellent formability that is achieved by hot stamping ***,the application of PHS with UtS exceeding 1500 MPa in automotive industry could be deferred due to the increased risk of hydrogen *** reduce this kind of risk,recent research efforts have been focused on various ways to optimize the microstructure of *** present review intends to summarize these efforts,to highlight present solutions to address hydrogen embrittlement,and to shed light on directions for future *** influence of microstructure on the hydrogen embrittlement of PHS has been discussed in terms of both the steel substrate and the surface *** substrate part covers the influence of martensite,carbides,inclusions,and retained austenite,while the surface part covers decarburization and oxidation,pre-coating,and trimming.

关键词： Hot stamping Press-hardened steels Coating-free Hydrogen embrittlement Fracture Al-Si coating

An Estimate of the Shadow Price of Water in the Southern Ogallala Aquifer

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journal of Water Resource and Protection 2017年第3期9卷 289-304页

作者： ryan B. Williams Rashid Al-Hmoud Eduardo Segarra Donna Mitchell Department of Agricultural and Applied Economics Texas Tech University Lubbock TX. USA Department of Economics and Geography Texas Tech University Lubbock TX USA

In this paper, we attempt to quantify the shadow price of an additional inch of groundwater resource left in situ for the Southern Ogallala Aquifer. Previous authors have shown the degree to which the optimal resource extraction path may diverge from the competitive extraction path based upon varying assumptions. We utilize high-quality data over an unconfined groundwater resource to evaluate the validity of these results. We find that the size of the existing groundwater resource is sufficiently small to result in a divergence between the competitive and socially optimal solutions. We are also able to confirm that the model responds to changes in the parameters in a manner consistent with previous research. Finally, we arrive at a marginal user cost for an additional acre-inch of water which is relatively low, but reasonable given uncertainty about future technological improvements.

关键词： Groundwater Resource Extraction Hotelling Rule Shadow Price

Re nanoclusters anchored on nanosheet supports: Formation of Re-O-matrix bonding and evaluation as all-pH-range hydrogen evolution reaction (HER) electrocatalysts

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journal of Energy Chemistry 2022年第6期31卷 185-193,I0006页

作者： Shiyu Xu Hao Li jeongbok Lee N.Clament Sagaya Selvam Baotao Kang jin Yong Lee Pil j.Yoo School of Chemical Engineering Sungkyunkwan UniversitySuwon 16419Republic of Korea Department of Chemistry Sungkyunkwan UniversitySuwon 16419Republic of Korea

Although the water splitting-based generation of hydrogen as an energy carrier can help to mitigate the global problems of energy shortage and climate change,the practical implementation of this strategy is hindered by the absence of inexpensive high-performance electrocatalysts for the hydrogen evolution reaction (HER).Re-based HER electrocatalysts exhibit predictable high performance within the entire pH range but suffer from arduous formation (i.e.,vulnerability to oxidation) and uncontrollable aggregation,which strongly discourages the maximisation of active site exposure required for activity *** overcome these limitations,we herein hydrothermally synthesise Re nanoclusters uniformly distributed on nanosheet supports,such as reduced graphene oxide nanosheets (Re NCs@rGO),revealing that this hybrid features abundant exposed active sites and high oxidation *** obtained electrocatalysts were elaborately characterized by microscopic and spectroscopic ***,density functional theory calculations confirm the optimised synthesis of Re NCs@rGO and indicate the crucial role of Re–O–C junction formation in securing *** effective suppression of Re nanocluster detachment/dissolution under HER conditions endows Re NCs@rGO with high electron conductivity and electrochemical stability,resulting in a durability superior to that of commercial Pt/C and an activity similar to that of this *** a result,Re NCs@rGO exhibited remarkably small HER overpotentials of 110,130,and 93 m V to deliver a current density of 10 mA cm^(-2) in 0.5 M H_(2)SO_(4),1 M PBS,and 1 M KOH,***,Re NCs@rGO is a promising alternative to conventional Pt-group-metal catalysts and should find applications in next-generation high-performance water splitting systems.

关键词： Hydrogen evolution reaction(HER) Hydrothermal synthesis Re nanoclusters Nanosheet supports Electrocatalysts

towards standardizing retinal optical coherence tomography angiography:a review

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Light(Science & Applications) 2022年第4期11卷 520-541页

作者： Danuta M.Sampson Adam M.Dubis Fred K.Chen Robert j.Zawadzki David D.Sampson Surrey Biophotonics Centre for VisionSpeech and Signal Processing and School of Biosciences and MedicineThe University of SurreyGuildford GU27XHUK NIHR Biomedical Research Centre at Moorflelds Eye Hospital NHS trust and UCL Institute of Ophthalmology London EC1V 2PDUK. Centre for Ophthalmology and Visual Science(incorporating Lions Eye Institute) The University of Western AustraliaNedlandsWestern Australia 6009Australia. Department of Ophthalmology Royal Perth HospitalPerthWestern Australia 6000Australia. Ophthalmology Department of SurgeryUniversity of MelbourneMelbourneVictoria 3002Australia. Department of Ophthalmology&Vision Science University of California DavisSacramentoCA 95817USA. Surrey Biophotonics Advanced Technology InstituteSchool of Physics and School of Biosciences and MedicineUniversity of SurreyGuildfordSurrey GU27XHUK

the visualization and assessment of retinal microvasculature are important in the study,diagnosis,monitoring,and guidance of treatment of ocular and systemic *** the introduction of optical coherence tomography angiography(OCtA),it has become possible to visualize the retinal microvasculature volumetrically and without a contrast *** lab-based and commercial clinical instruments,imaging protocols and data analysis methods and metrics,have been applied,often inconsistently,resulting in a confusing picture that represents a major barrier to progress in applying OCtA to reduce the burden of *** data and software sharing,and cross-comparison and pooling of data from different studies are *** inabilities have impeded building the large databases of annotated OCtA images of healthy and diseased retinas that are necessary to study and define characteristics of specific *** paper addresses the steps needed to standardize OCtA imaging of the human retina to address these *** review of the OCtA literature,we identify issues and inconsistencies and propose minimum standards for imaging protocols,data analysis methods,metrics,reporting of findings,and clinical practice and,where this is not possible,we identify areas that require further *** hope that this paper will encourage the unification of imaging protocols in OCtA,promote transparency in the process of data collection,analysis,and reporting,and facilitate increasing the impact of OCtA on retinal healthcare delivery and life science investigations.

关键词： transparency steps inconsistent

Cs_(3)Bi_(2)l_(9)-hydroxyapatite composite waste forms for cesium and iodine immobilization

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journal of Advanced Ceramics 2022年第5期11卷 712-728页

作者： Kun YANG Yachun WANG junhua SHEN Spencer M.SCOtt Brian j.RILEY john D.VIENNA jie LIAN Department of Mechanical Aerospaceand Nuclear EngineeringRensselaer Polytechnic InstituteTroyUSA Department of Materials Science&Engineering Rensselaer Polytechnic InstituteTroyUSA Savannah River National Laboratory AikenUSA Pacific Northwest National Laboratory RichlandUSA

Perovskite-based ceramic composites were developed as potential waste form materials for immobilizing cesium(Cs)and iodine(I)with high waste loadings and chemical *** perovskite Cs_(3)Bi_(2)I_(9)has high Cs(22 wt%)and I(58 wt%)content,and thus can be used as a potential host phase to immobilize these critical *** this work,the perovskite Cs_(3)Bi_(2)I_(9)phase was synthesized by a cost effective solution-based approach,and was embedded into a highly durable hydroxyapatite matrix by spark plasma sintering to form dense ceramic composite waste *** chemical durabilities of the monolithic Cs_(3)Bi_(2)I_(9)and Cs_(3)Bi_(2)I_(9)-hydroxyapatite composite pellets were investigated by static and semi-dynamic leaching tests,*** and I are incongruently released from the matrix for both pure Cs_(3)Bi_(2)I_(9)and composite *** normalized Cs release rate is faster than that of I,which can be explained by the difference in the strengths between Cs-I and Bi-I bonds as well as the formation of insoluble micrometer-sized BiOI *** activation energies of elemental releases based on dissolution and diffusion-controlled mechanisms are determined with significantly higher energy barriers for dissolution from the composite versus that of the monolithic Cs_(3)Bi_(2)I_(9).the ceramic-based composite waste forms exhibit excellent chemical durabilities and waste loadings,commensurate with the state-of-the-art glass-bonded perovskite composites for I and Cs immobilization.

关键词： cesium(Cs) iodine(Ⅰ) perovskite nuclear waste hydroxyapatite