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Decarbonising energy: The developing international activity in hydrogen technologies and fuel cells

Journal of Energy Chemistry 2020年第12期29卷 405-415页

作者： john meurig thomas Peter P.Edwards Peter J.Dobson Gari P.Owend Department of Materials Science&Metallurgy University of CambridgeCambridge CB30FSUK King Abdulaziz City for Science and Technology(KACST)-Oxford Centre of Excellence in Petrochemicals and Inorganic Chemistry Laboratory University of OxfordOxford OX13QRUK The Queen’s College University of OxfordOxford OX14AWUK Annwvyn Solutions(Independent Consultant) BromleyKent BR13DWUK

Hydrogen technologies and fuel cells offer an alternative and improved solution for a decarbonised energy *** cells are electrochemical converters;transforming hydrogen (or energy sources containing hydrogen) and oxygen directly into *** hydrogen fuel cell,invented in 1839,permits the generation of electrical energy with high efficiency through a non-combustion,electrochemical process and,importantly,without the emission ofits point of ***,despite numerous efforts to exploit the obvious attractions of hydrogen technologies and hydrogen fuel cells,various challenges have been encountered,some of which are reviewed ***,however,given the exigent need to urgently seek low-carbon paths for humankind’s energy future,numerous countries are advancing the deployment of hydrogen technologies and hydrogen fuel cells not only for transport,but also as a means of the storage of excess renewable energy from,for example,wind and solar ***,hydrogen is also being blended into the natural gas supplies used in domestic heating and targeted in the decarbonisation of critical,large-scale industrial processes such as steel *** briefly review specific examples in countries such as Japan,South Korea and the People’s Republic of China,as well as selected examples from Europe and North America in the utilization of hydrogen technologies and hydrogen fuel cells.

关键词： Decarbonisation Hydrogen Energy Hydrogen Economy Fuel cells Environment Sustainability

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Nanoscale electron tomography and atomic scale high-resolution electron microscopy of nanoparticles and nanoclusters:A short survey

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Progress in Natural Science:Materials International 2013年第3期23卷 222-234页

作者： john meurig thomas Paul A.Midgley Caterina Ducati Rowan K.Leary Department of Materials Science and Metallurgy University of CambridgePembroke StreetCambridgeCB2 3QZUK

The outstanding merits of scanning transmission electron tomography as a technique for the investigation of the internal structure and morphology of nanoparticle and nanocluster materials are summarized with the aid of numerous typical *** is made also to the significant advances that have arisen in probing ultrastructural characteristics of nanoscale solids using aberrationcorrected(AC) electron microscopy(EM).Information of a unique kind may be retrieved by combining the imaging and analytical power of ACEM.

关键词： Nanoclusters Nanoparticles Atomic structure Electron tomography Aberration-corrected electron microscopy

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非平衡态下水分子在分子筛ZSM-5上的吸附

非平衡态下水分子在分子筛ZSM-5上的吸附

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第十六届全国分子筛大会

作者：许名灿 Kenneth D.M.Harris john meurig thomas 同济大学材料科学与工程学院 School of Chemistry Cardiff University Department of Materials Science and Metallurgy University of Cambridge

＜正＞最近,我们发明了一种新原位固体核磁共振波谱方法。应用该方法,我们能够在体系达到平衡以前（在非平衡态下）即可以跟踪水分子在ZSM-5分子筛上的吸附过程,揭示前所未有的过程细节。实验结果表明,在低温下水分子在分子筛ZSM-5上吸...

＜正＞最近,我们发明了一种新原位固体核磁共振波谱方法。应用该方法,我们能够在体系达到平衡以前（在非平衡态下）即可以跟踪水分子在ZSM-5分子筛上的吸附过程,揭示前所未有的过程细节。实验结果表明,在低温下水分子在分子筛ZSM-5上吸附时,水分子吸附到B酸位,倾向于形成一定大小的团簇;而团簇的大小与性质与平衡分子筛骨架电荷的阳离子有关。对于固体

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Does defensive posture increase mimetic fidelity of caterpillars with eyespots to their putative snake models？

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Current Zoology 2014年第1期60卷 76-89页

作者： thomas john HOSSIE thomas N. SHERRATT Ottawa-Carleton Institute of Biology Carleton University 1125 Colonel By Drive Ottawa ON K1S 5B6 Canada Department of Biology Carleton University 1125 Colonel By Drive Ottawa ON K1S 5B6 Canada

Organisms often evolve behaviours that increase or reinforce the protection from predators afforded by their morpho- logical defences. For example, mimetic animals may adopt postures or locomotory behaviours that emulate a characteristic fea- ture of their model to increase predator deception. Caterpillars with eyespots are thought to mimic snakes, and when threatened many of these caterpillars adopt a posture that appears to enhance this resemblance. Herein we evaluate the quantitative strength of evidence of behavioural mimicry in the caterpillars of 14 species by comparing how closely a series of putative snake-mimicking caterpillars resemble snakes while at rest and when threatened. Specifically, we quantified the head morphology and eye position of a range of snake species, as well as the shape of the apparent head （i.e. anterior body segments） and position of eyespots in caterpillars resting or in their defensive posture. This allowed us to objectively examine evidence for an increased resemblance to either snakes generally, or to Viperidae snakes specifically, upon adopting the defensive posture. Widening the anterior body segments during the defensive posture typically made caterpillars appear more viper-like as opposed to more snake-like in general. Enhanced resemblance to vipers upon mounting the defensive posture was apparent only from the dorsal view. Laterally, caterpillars more closely resembled snakes in the resting posture and shifting to the defensive posture instead reduced mimetic fidelity, Overall we found evidence for behavioural mimicry in all 14 species examined. We highlight that objectively quantifying mimetic fidelity can help identify key features involved in deception .

关键词： Behaviour Geometr!c morphometrics Protective colouration Mimicry Morphology Vipers

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Dynamic Modeling, Testing, and Stability Analysis of an Ornithoptic Blimp

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Journal of Bionic Engineering 2011年第4期8卷 375-386页

作者： john Dietl thomas Herrmann Gregory Reich Ephrahim Garcia Sibley School of Mechanical and Aerospace Engineering Cornell University Ithaca New York USA Air Force Research Laboratory Wright-Patterson AFB OH 45433-7542 USA

In order to study omithopter flight and to improve a dynamic model of flapping propulsion, a series 0f tests are conducted on a flapping-wing blimp. The blimp is designed and constructed from mylar plastic and balsa wood as a test platform for aerodynamics and flight dynamics. The blimp, 2.3 meters long and 420 gram mass, is propelled by its flapping wings. Due to buoyancy the wings have no lift requirement so that the distinction between lift and propulsion can be analyzed in a flight platform at low flight speeds. The blimp is tested using a Vicon motion tracking system and various initial conditions are tested including accelerating flight from standstill, decelerating from an initial speed higher than its steady state, and from its steady-state speed but disturbed in pitch angle. Test results are used to estimate parameters in a coupled quasi-steady aerodynamics/Newtonian flight dynamics model. This model is then analyzed using Floquet theory to determine local dynamic modes and stability. It is concluded that the dynamic model adequately describes the vehicle＇s nonlinear behavior near the steady-state velocity and that the vehicle＇s linearized modes are akin to those of a fixed-wing aircraft.

关键词： omithopter blimp flight dynamics stability analysis

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Threshold logic based low-level vision sparse object features

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International Journal of Intelligent Computing and Cybernetics 2016年第4期9卷 314-324页

作者： Nitha thomas Joshin john Mathew Alex James Department of Research EnviewTrivandrumIndia ARS Traffic and Transport Technology TrivandrumIndia School of Engineering Nazarbayev UniversityAstanaKazakhstan

Purpose-The real-time generation of feature descriptors for object recognition is a challenging *** this research,the purpose of this paper is to provide a hardware friendly framework to generate sparse features that can be useful for key feature point selection,feature extraction,and descriptor *** inspiration is drawn from feature formation processes of the human brain,taking into account the sparse,modular,and hierarchical processing of visual ***/methodology/approach-A sparse set of neurons referred as active neurons determines the feature points necessary for high-level vision applications such as object recognition.A psycho-physical mechanism of human low-level vision relates edge detection to noticeable local spatial stimuli,representing this set of active neurons.A cognitive memory cell array-based implementation of low-level vision is *** of memory cell in edge detection are used for realizing human vision inspired feature selection and leading to feature vector construction for high-level vision ***-True parallel architecture and faster response of cognitive circuits avoid time costly and redundant feature extraction *** of proposed feature vector toward high-level computer vision applications is demonstrated using standard object recognition *** comparison against existing state-of-the-art object recognition features and methods shows an accuracy of 97,95,69 percent for Columbia Object Image Library-100,ALOI,and PASCAL VOC 2007 databases indicating an increase from benchmark methods by 5,3 and 10 percent,***/value-A hardware friendly low-level sparse edge feature processing system isproposed for recognizing *** edge features are developed based on threshold logic of neurons,and the sparse selection of the features applies a modular and hierarchical processing inspired from the human neural system.

关键词： Object recognition Object features Sparse features Threshold logic Low-level vision Active neurons Cognitive memory-cell array Edge detection Feature description

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Predation changes the shape of thermal performance curves for population growth rate

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Current Zoology 2016年第5期62卷 501-505页

作者： thomas M. LUHRING john P. DELONG School of Biological Sciences University of Nebraska Lincoln Nebraska 68588 USA

Ectotherms generally demonstrate nonlinear changes in performance （e.g., movement speed, indi- vidual growth, population growth） as a function of temperature that are characterized by thermal performance curves （TPC）. Predation risk elicits phenotypic and behavioral changes that likewise impact performance measures. We tested whether exposure to predation Orthocyclops modestus impacts the maximum population growth rate （rmax） TPC of the protist Paramecium aurelia. We fit predator and non-predator exposed P. aurelia population growth rates to a function previously shown to best describe Paramecium population growth rate TPC＇s （Lactin-2） and compared subse- quent parameter estimates between curves. For Paramecium exposed to predation risk, maximum population growth increased more rapidly as temperatures rose and decreased more rapidly as temperatures fell compared to the initial temperature. The area under each TPC curve remained ap- proximately the same, consistent with the idea of a trade-off in performance across temperatures. Our results indicate TPCs are flexible given variation in food web context and that trophic inter- actions may play an important role in shaping TPCs. Furthermore, this and other studies illustrate the need for a mechanistic model of TPCs with parameters tied to biologically meaningful properties.

关键词： paramecium phenotypic plasticity predation reaction norm temperature thermal performance curve.

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Comparing crystal structures with symmetry and geometry

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npj Computational Materials 2021年第1期7卷 1491-1501页

作者： john C.thomas Anirudh Raju Natarajan Anton Van der Ven Materials Department University of CaliforniaSanta BarbaraCAUSA

Measuring the similarity between two arbitrary crystal structures is a common challenge in crystallography and materials *** there are an infinite number of ways to mathematically relate two crystal structures,only a few are physically *** we introduce both a geometry-based and a symmetry-adapted similarity metric to compare crystal *** crystal symmetry and combinatorial optimization we describe an algorithm to arrive at the structural relationship that minimizes these similarity metrics across all possible maps between any pair of crystal *** approach makes it possible to(i)identify pairs of crystal structures that are identical,(ii)quantitatively measure the similarity between crystal structures,and(iii)find and rank structural transformation pathways between any pair of crystal *** discuss the advantages of using the symmetryadapted cost metric over the geometric ***,we show that all known structural transformation pathways between common crystal structures are recovered with the mapping *** methodology presented in this study will be of value to efforts that seek to catalogue crystal structures,identify structural transformation pathways or prune large first-principles datasets used to parameterize on-lattice Hamiltonians.

关键词： crystal symmetry similarity

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In-situ probing of thermal desorption of vapor molecules on a nanowire via work function variance

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Nano Research 2016年第11期9卷 3334-3345页

作者： Kovur Prashanthi john Eric Hawk Ryan McGee Ravi Gaikwad thomas Thundat Ingenuity Lab Department of Chemical and Materials Engineering University of Alberta Edmonton AB T6G 2V4 Canada

Nanowire sensors based on variations of their electrical properties show great potential for real-time, in situ monitoring of molecular adsorption and desorption. Although the molecular adsorption-induced change in the electronic work function is very sensitive, it does not have any specificity. However, the temperature dependency of the adsorption-induced work function variation can provide limited selectivity based on the desorption temperature. In this study, we report the in situ probing of molecular desorption by monitoring the work function variations of a single Pt nanowire as a function of temperature. The work function of a clean Pt nanowire shows a significant variation due to vapor adsorption at room temperature. Increasing the temperature of the nanowire results in a variation of the work function due to molecular desorption. Experimentally measured differential work function as a function of temperature shows desorption peaks at 36 and 44 ℃ for methanol and ethanol molecules respectively. Adsorption-induced variation of the Pt nanowire work function was further confirmed using ultraviolet photoelectron spectroscopy before and after exposure to methanol vapor. These results show that the molecular adsorption/desorption-induced variation of the work function and its temperature dependency can be used for developing nanoscale electro-calorimetric sensors.

关键词： Kelvin probe microscopy nanowires thermal desorption work function

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Isotretinoin for the treatment of nonobstructive azoospermia: a pilot study

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Asian Journal of Andrology 2021年第5期23卷 537-540页

作者： john K Amory Charles H Muller thomas J Walsh Department of Medicine University of WashingtonSeattleWA 98195USA Department of Urology University of WashingtonSeattleWA 98195USA

The treatment of men with infertility from azoospermia is *** some men with severe oligozoospermia improve sperm output during treatment with isotretinoin,we treated nine men with azoospermia with isotretinoin to determine if azoospermic men would also respond to isotretinoin *** of these men who had a previous negative testicular sperm extraction(TESE)was found to have an area of sperm production on a postisotretinoin testicular *** man achieved a pregnancy and a live birth of a healthy,term daughter after in vitro fertilization coupled with intracytoplasmic sperm injection(IVF/ICSI).A second subject had a positive TESE after treatment as *** study of isotretinoin therapy in men with azoospermia undergoing testicular sperm harvesting procedures is warranted.

关键词： treatment injection pregnancy

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