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FIB Secondary Etching Method for Fabrication of Fine CNT Forest Metamaterials

Nano-Micro Letters 2017年第4期9卷 73-80页

作者： adam.Pander Akimitsu Hatta Hiroshi Furuta Department of Electronic and Photonic Systems Engineering Kochi University of TechnologyTosayamadaKamiKochi 782-8502Japan Center for Nanotechnology Research InstituteKochi University of TechnologyTosayamadaKamiKochi 782-8502Japan

Anisotropic materials, like carbon nanotubes(CNTs), are the perfect substitutes to overcome the limitations of conventional metamaterials; however, the successful fabrication of CNT forest metamaterial structures is still very challenging. In this study, a new method utilizing a focused ion beam(FIB) with additional secondary etching is presented, which can obtain uniform and fine patterning of CNT forest nanostructures for metamaterials and ranging in sizes from hundreds of nanometers to several micrometers. The influence of the FIB processing parameters on the morphology of the catalyst surface and the growth of the CNT forest was investigated, including the removal of redeposited material,decreasing the average surface roughness(from 0.45 to 0.15 nm), and a decrease in the thickness of the Fe *** results showed that the combination of FIB patterning and secondary etching enabled the growth of highly aligned, highdensity CNT forest metamaterials. The improvement in the quality of single-walled CNTs(SWNTs), defined by the very high G/D peak ratio intensity of 10.47, demonstrated successful fine patterning of CNT forest for the first time. With a FIB patterning depth of 10 nm and a secondary etching of 0.5 nm, a minimum size of 150 nm of CNT forest metamaterials was achieved. The development of the FIB secondary etching method enabled for the first time, the fabrication of SWNT forest metamaterials for the optical and infrared regime, for future applications, e.g., in superlenses, antennas,or thermal metamaterials.

关键词： Carbon nanotubes Metamaterial FIB patterning Secondary etching method Chemical vapor deposition

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Apoptosis and DNA damage in human spermatozoa

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Asian Journal of Andrology 2011年第1期13卷 36-42页

作者： R John Aitken adam.J Koppers ARC Centre of Excellence in Biotechnology and Development Priority Research Centre in Reproductive Science Discipline of Biological Sciences School of Environmental and Life Sciences University of Newcastle Callaghan NSW 2308 Australia Department of Anatomy and Developmental Biology School of Biomedical Sciences Monash University Clayton VIC 3800 Australia

DNA damage is frequently encountered in spermatozoa of subfertile males and is correlated with a range of adverse clinical outcomes including impaired fertilization, disrupted preimplantation embryonic development, increased rates of miscarriage and an enhanced risk of disease in the progeny. The etiology of DNA fragmentation in human spermatozoa is closely correlated with the appearance of oxidative base adducts and evidence of impaired spermiogenesis. We hypothesize that oxidative stress impedes spermiogenesis, resulting in the generation of spermatozoa with poorly remodelled chromatin. These defective cells have a tendency to default to an apeptotic pathway associated with motility loss, caspase activation, phosphatidylserine exteriorization and the activation of free radical generation by the mitochondria. The latter induces lipid peroxidation and oxidative DNA damage, which then leads to DNA fragmentation and cell death. The physical architecture of spermatozoa prevents any nucleases activated as a result of this apoptotic process from gaining access to the nuclear DNA and inducing its fragmentation. It is for this reason that a majority of the DNA damage encountered in human spermatozoa seems to be oxidative. Given the important role that oxidative stress seems to have in the etiology of DNA damage, there should be an important role for antioxidants in the treatment of this condition. If oxidative DNA damage in spermatozoa is providing a sensitive readout of systemic oxidative stress, the implications of these findings could stretch beyond our immediate goal of trying to minimize DNA damage in spermatozoa as a prelude to assisted conception therapy.

关键词： apoptosis DNA damage oxidative stress spermatozoa

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Crystal Structure of Arabidopsis thaliana Dawdle Forkhead-Associated Domain Reveals a Conserved Phospho-Threonine Recognition Cleft for Dicer-Like 1 Binding

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Molecular Plant 2013年第4期6卷 1290-1300页

作者： Satoru Machida Y.adam.Yuan Department of Biological Sciences and Centre for Bioimaging Sciences National University of Singapore 14 Science Drive 4 Singapore 117543 Singapore Temasek Lifesciences Laboratory National University of Singapore 1 Research Link Singapore 117604 Singapore Mechanobiology Institute National University of Singapore T-lab Building 5A Engineering Drive 1 Singapore 117411 Singapore

Dawdle （DDL） is a microRNA processing protein essential for the development of Arabidopsis. DDL contains a putative nuclear localization signal at its amino-terminus and forkhead-associated （FHA） domain at the carboxyl-termi- nus. Here, we report the crystal structure of the FHA domain of Arabidopsis Dawdle, determined by multiple-wavelength anomalous dispersion method at 1.7-A resolution. DDL FHA structure displays a seven-stranded 13-sandwich architec- ture that contains a unique structural motif comprising two long anti-parallel strands. Strikingly, crystal packing of the DDL FHA domain reveals that a glutamate residue from the symmetry-related DDL FHA domain, a structural mimic of the phospho-threonine, is specifically recognized by the structurally conserved phospho-threonine binding cleft. Consistently with the structural observations, co-immuno-precipitation experiments performed in Nicotiana benthami- ana show that the DDL FHA domain co-immuno-precipitates with DCL1 fragments containing the predicted pThr＋3（lle/ Val/Leu/Asp） motif. Taken together, we count the recognition of the target residue by the canonical binding cleft of the DDL FHA domain as the key molecular event to instate FHA domain-mediated protein-protein interaction in plant miRNA processing.

关键词： Arabidopsis DCL1 Arabidopsis DDL forkhead-associated domain phospho-threonine microRNA processing.

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Multi-regional observations and validation of the M_(3)ocean tide

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Science China Earth Sciences 2023年第10期66卷 2265-2277页

作者： adam.Thomas DEVLIN Jiayi PAN Déborah IDIER School of Geography and Environment Jiangxi Normal UniversityNanchang330022China Cooperative Institute for Marine and Atmospheric Research School of Ocean and Earth Science and TechnologyUniversity of Hawai’i at MānoaHonoluluHI96822USA Department of Oceanography University of Hawai’i at MānoaHonoluluHI96822USA The Chinese University of Hong Kong Hong Kong999077China Key Laboratory of Poyang Lake Wetland and Watershed Research of Ministry of Education Nanchang330022China BRGM Orléans45060France

Improved determinations of the oft-ignored third-degree ocean tides can yield better accuracy for tidal predictions,numerical model solutions,and *** only a small part of tidal range,these components can be larger at certain coastal locations due to shelf resonances and other ***,we discuss observations of the M3lunar terdiurnal tide using 9-year windowed tidal harmonic analyses at 157 tide gauges compares to a global assimilation model(TPXO9v5a),with a focus on the Western Pacific and the European ***9v5a does well in estimating the observed M_(3)amplitudes and phase lags in most regions,though determinations in coastal zones and in morphologically complex areas are coarse and often *** also employ a shallow-water model(MARS)on the European Shelf,which can yield localized improvement over *** five subregions of the European Shelf,regional root-mean-squared-errors(RMSEs)are lower(and thus a better fit)at three locations for TPXO for amplitudes,and three for phase lags,with MARS simulations being a better fit in the other *** also show that some locations have experienced significant long-term increases and/or decreases in the M_(3)amplitude over time,likely related to resonance changes under sea level rise(SLR)which can modulate the oceanic response to astronomical *** hypothesis is explored for Europe using the MARS model by applying various sea level rise scenarios,showing that the directionality(positive or negative)of the long-term changes in M_(3)amplitudes over time match the model results for more than half of our validation stations.

关键词： Third-degree tides M_(3)tide Altimetry Numerical simulation Sea level rise

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Determination of the Influence of c-BN+h-BN Coating Structure on Brittleness

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材料热处理学报 2004年第05B期25卷 888-893页

作者： Maciej Kupczyk adam.Lejwoda Przemyslaw Cieszkowski Przemyslaw Libuda Poznan University of Technology Institute of Mechanical Engineering Poznan PolandPoznan University of Technology Institute of Mechanical Engineering Poznan PolandPoznan University of Technology Institute of Mechanical Engineering Poznan PolandPoznan University of Technology Institute of Mechanical Engineering Poznan Poland

In the article is presented the brittleness study of boron nitride coatings deposited on cutting edges made of cemented carbides by the pulse-plasma method (PPD). Influences of the structure (density, pores, microcracks) of coating material on the brittleness and on selected technological parameters of boron nitride formation by PPD method particularly taking into account discharge voltage on brittleness are shown. Differences between values of both ai(300) and "1(5oo) coefficients characterized susceptibility to coatings cracking of investigated coating manufactured using different values of discharge voltage were defined. Results of an investigations have been confirmed usefulness of Palmqvist’s method for measurement of coating susceptibility to brittle cracking.

关键词：耐磨覆层 PVD 脆性氮化硼涂层

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Studies on thermally grown oxide as an interface between plasma-sprayed coatings and a nickel-based superalloy substrate

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International Journal of Minerals,Metallurgy and Materials 2017年第6期24卷 681-690页

作者： adam.Khan Mahaboob Basha Sundarrajan Srinivasan Natarajan Srinivasan Department of Mechanical Engineering Centre for Surface Engineering Kalasalingam University Krishnankoil 626126 Tamil Nadu India Department of Metallurgical and Materials Engineering National Institute of Technology Tiruchirapalli 620015 Tamil Nadu India Centre of Excellence in Corrosion and Surface Engineering (CECASE) National Institute of Technology Tiruchirapalli 620015 Tamil Nadu India

A thermally grown oxide layer formed by hot corrosion was investigated as an interface between plasma-sprayed coatings and a nickel-based superalloy substrate. The hot corrosion mechanism of NiCr–Cr_2O_3 and Al_2O_3–40wt% TiO_2(A40T) plasma coated Inconel 617 was evaluated. The experiments were carried out at 1000°C using a combination of Na_2SO_4, NaCl, and V_2O_5 salts to simulate the conditions of a gas turbine in a marine environment. The hot corrosion results revealed the spallation and dissolution of oxides upon prolonged exposure. Optical images and scanning electron micrographs of the exposed samples revealed the formation of oxide scale and provided details of its morphology in NiCr–Cr_2O_3 coated samples. Microstructure characterization of A40T coatings demonstrated a thermally grown oxide(TGO) layer at 1000°C. Increasing the thickness of the TGO layer decreased the corrosion resistance. The elemental analysis and image mapping revealed the migration of active elements from the substrate and coatings toward the corrosive environment.

关键词： corrosion coatings superalloy oxides

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Improvements in seismic event locations in a deep western U.S. coal mine using tomographic velocity models and an evolutionary search algorithm

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Mining Science and Technology 2009年第5期19卷 599-603页

作者： LURKA adam.SWANSON Peter Central Mining Institute NIOSH/Spokane Research Laboratory

Methods of improving seismic event locations were investigated as part of a research study aimed at reducing ground control safety hazards. Seismic event waveforms collected with a 23-station three-dimensional sensor array during longwall coal mining provide the data set used in the analyses. A spatially variable seismic velocity model is constructed using seismic event sources in a passive tomographic method. The resulting three-dimensional velocity model is used to relocate seismic event positions. An evolutionary optimization algorithm is implemented and used in both the velocity model development and in seeking improved event location solutions. Results obtained using the different velocity models are compared. The combination of the tomographic velocity model development and evolutionary search algorithm provides improvement to the event locations.

关键词： seismic event location tomographic velocity model an evolutionary search algorithm

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Latest developments on the mechanism of action of membrane disrupting peptides

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Biophysics Reports 2021年第3期7卷 173-184页

作者： Sara Pandidan adam.Mechler La Trobe Institute for Molecular Science La Trobe University

Antimicrobial peptides(AMPs) are integral components of the innate immune defence system of all complex organisms including plants, insects, and mammals. They have wide range of antibacterial, antifungal, antiviral, and even anticancer activities, therefore AMPs are attractive candidates for developing novel therapeutic approaches. Cationic α-helical membrane disrupting peptides are perhaps the most widely studied subclass of AMPs due to their common fundamental characteristics that allow for detailed structure-function analysis and therefore offer a promising solution to the threat of multidrug resistant strains of bacteria. The majority of the studies of AMP activity focused on the biological and biophysical aspects of membrane disruption; the understanding of the molecular mechanism of action from the physicochemical point of view forms a relatively small subfield. This review will provide an overview of these works, focusing on the empirical and thermodynamic models of AMP action.

关键词： Antimicrobial peptides (AMPs) Membrane disrupting peptides Empirical models Thermodynamic models

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Spatial analysis and evaluation of a coal deposit by coupling AHP & GIS techniques

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International Journal of Mining Science and Technology 2019年第6期29卷 943-953页

作者： Nikolaos Paraskevis Christos Roumpos Nikolaos Stathopoulos Aikaterini adam Department of Mining Engineering Public Power Corporation of GreeceAthens 10432Greece School of Mining and Metallurgical Engineering National Technical University of AthensAthens 15780Greece

Nowadays,the evaluation of coal deposits becomes crucial,due to many uncontrollable factors,which affect the energy sector.A comparative evaluation of coal deposits is essential for their hierarchical classification regarding their sustainable exploitation,when compared to other coal deposits or competitive fuels,which may be used as alternative solutions for electricity *** this paper,a method for spatial analysis and evaluation of a lignite deposit is proposed,by creating four spatial key indicators via GIS analysis,which are then aggregated by applying a weighted linear *** analytical hierarchy process is applied to estimate the relative weights of the indicators,in order to perform a weighted cartographic *** the synthesis of the indicators,an overall,total spatial quality indicator is *** weighted analysis was shown to be more effective compared to the unweighted one,because it can provide more reliable results regarding the exploitation of the examined lignite *** implementation of GIS-based analytical hierarchy process in spatial analysis and evaluation of lignite deposits,in terms of sustainable exploitation,demonstrates that this method can be extensively applied for evaluating the economic potential of mineral deposits.

关键词： Lignite/coal deposit Spatial analysis Evaluation Cartographic overlay Analytical hierarchy process Geographic information systems Weighted linear combination(WLC) Weighted spatial quality indicator(WSQI)

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User scheduling and power allocation for downlink multi-cell multi-carrier NOMA systems

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Digital Communications and Networks 2023年第1期9卷 252-263页

作者： Abuzar B.M.adam.Xiaoyu Wan Zhengqiang Wang School of Communications and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing400065China

In Non-Orthogonal Multiple Access(NOMA),the best way to fully exploit the benefits of the system is the efficient resource *** the NOMA power domain,the allocation of power and spectrum require solving the mixed-integer nonlinear programming NP-hard *** this paper,we investigate user scheduling and power allocation in Multi-Cell Multi-Carrier NOMA(MCMC-NOMA)*** achieve that,we consider Weighted Sum Rate Maximization(WSRM)and Weighted Sum Energy Efficiency Maximization(WSEEM)***,we tackle the problem of user scheduling for fixed power using Fractional Programming(FP),the Lagrange dual method,and the decomposition ***,we consider Successive Pseudo-Convex Approximation(SPCA)to deal with the WSRM ***,for the WSEEM problem,SPCA is utilized to convert the problem into separable scalar problems,which can be parallelly ***,the Dinkelbach algorithm and constraints relaxation are used to characterize the closed-form solution for power *** simulations have been implemented to show the efficiency of the proposed framework and its superiority over other existing schemes.

关键词： Weighted sum rate Weighted energy efficiency Non-orthogonal multiple access Successive pseudo-convex approximation Fractional programming

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