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Characterization of different plasma-treated cobalt oxide catalysts for oxygen reduction reaction in alkaline media

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Science Bulletin 2016年第8期61卷 612-618页

作者： lisa M.Uhlig Gustav Sievers Volker Brüser Alexander Dyck Gunther Wittstock NEXT ENERGY EWE-Research Centre for Energy Technology26129 OldenburgGermany Faculty of Mathematics and Science CIS-Center of Interface ScienceInstitute of ChemistryCarl von Ossietzky University of Oldenburg26111 OldenburgGermany Leibniz Institute for Plasma Science and Technology 17489 GreifswaldGermany

Plasma-synthesized cobalt oxide supported on carbon has been analyzed for its use for electrocatalytic oxygen reduction reaction （ORR） in alkaline anion exchange membrane fuel cells （AEMFC）. This work presents the ORR activity in 0.1 mol L-1 KOH and 0.1 tool L-1 K2CO3 at 25 ℃. Cyclic voltammetry （CV） was used to determine the potentials at which the ORR occurs and to evaluate the stability of catalyst. Moreover, a rotating ring-disk electrode （RRDE） was used to investigate the activity of the catalysts and the formation of the by-product hydroperoxide anion （HO2-） as well as to identify the preferred pathway of the ORR. Calculated kinetic parameters for the ORR for the cobalt catalysts are shown in this work together with a comparison to a commercial platinum catalyst. However, the cobalt oxide produced more by-products which could lead to damage of the membrane in a fuel cell through a radical attack of the polymer backbone.

关键词： Oxygen reduction reaction Alkalinemedia - Electrocatalytic activity RRDE Cobaltcatalyst Alkaline fuel cell

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用于电视制作的内容管理系统

电视技术 2000年第1期24卷 71-74页

作者： J.heimann 曹怡 SMPTSstudygroup 信息产业部电子第三研究所北京100015

1 引言1998年的国际广播会议(IBC＇98)再一次证明在电视制作与分配领域信息技术势不可挡,这是因为其不断增加的性能和不断降低的价格.越来越多的用途已被挖掘出来,不仅在管理数据处理方面,而且也在经典的视频技术领域--声像录制、编辑... 详细信息

1 引言1998年的国际广播会议(IBC＇98)再一次证明在电视制作与分配领域信息技术势不可挡,这是因为其不断增加的性能和不断降低的价格.越来越多的用途已被挖掘出来,不仅在管理数据处理方面,而且也在经典的视频技术领域--声像录制、编辑、分配和归档保存.非线性编辑系统已经得到广泛使用,电视广告往往从以盘片为基础的播出服务器播出,自动化盒式磁带系统的供应商已看到自动存储装置是未来电视归档系统的核心.视音频技术、信息技术和电信技术三者相融合,注定了将来诱人的前景与机遇,但同时也会产生一些问题:

关键词：内容管理系统电视节目制作

Delineation of homogeneous forest patches using combination of field measurements and LiDAR point clouds as a reliable reference for evaluation of low resolution global satellite data

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Forest Ecosystems 2018年第1期5卷 1-12页

作者： krzysztof stereńczak marek lisańczuk yousef erfanifard department of forest resources management forest research instituteSekocin Stary 3 Braci Lesnej，05-090 Raszyn，Poland department ofnatural resources and environment college of agriculture shiraz universityp.o.box ***shiraziran

Backgrounds： There are many satellite systems acquiring environmental data on the world. Acquired global remote sensing datasets require ground reference data in order to calibrate them and assess their quality. Regarding calibration and validation of these datasets with broad geographical extents, it is essential to register zones which might be considered as Homogeneous Patches （HPs）. Such patches enable an optimal calibration of satellite data/sensors, and what is more important is an analysis of components which significantly influence electro-magnetic signals registered by satellite sensors. Methods： We proposed two structurally different methods to identify HPs： predefined thresholding-based one （static one）, and statistical thresholding-based technique （dynamic one）. In the first method, 3 different thresholds were used： 5%, 10%, and 20%. Next, it was aimed to assess how delineated HPs were spatially matched to satellite data with coarse spatial resolution. Selected cell sizes were 25, 50, 100, 250, and 500 m. The number of particular grid cells which almost entirely fell into registered HPs was counted （leaving 2% cell area tolerance level）. This procedure was executed separately for each variant and selected structural variables, as well as for their intersection parts. Results： The results of this investigation revealed that ALS data might have the potential in the identification of HPs of forest stands. We showed that different ALS based variables and thresholds of HPs definition influenced areas which can be treated as similar and homogeneous. We proved that integration of more than one structural variable limits size of the HPs, in contrast, visual interpretation revealed that inside such patches vegetation structure is more constant. Conclusions： We concluded that ALS data can be used as a potential source of data to ＂enlarge＂ small ground sample plots and to be used for evaluation and calibration of remotely sensed datasets provided by global systems

关键词： Forest structure Stratification Global satellite missions

Friction transitions and connections to third bodies for a Cd coating on steel substrate

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Friction 2020年第4期8卷 784-801页

作者： Priyadarshi BEHERA lisa LEE Sriraman K.RAJAGOPALAN Richard R.CHROMIK Stephen YUE Department of Mining&Materials Engineering McGill UniversityMontrealQC H3A 0C5Canada

Cd coating is used in aerospace industries from last five decades due to its sacrificial protection and lubrication properties. Although Cd coating is primarily used due to its sacrificial corrosion protection when applied on steel substrate, the added benefit of modifying the tribological behavior by acting as a lubricious layer gives it a leading-edge than other coatings. Often the measurement of friction coefficient (CoF) is reported as a value generated after full sliding cycle. This measurement of average CoF generally limits the study of local variation in CoF occurring within one sliding cycle, which can be significantly different with change in spatial position due to change in third body morphology. In this study, a linearly reciprocating sliding test is used to measure the CoF at a sampling rate of 800 Hz along the track length to generate triboscopic image with steel countersphere. The instantaneous CoF obtained with triboscopy is correlated with the wear track morphology using scanning electron microscope (SEM) and optical profilometer for variation in contact conditions. Tribological test performed in dry atmosphere shows an average CoF of 0.4 till the end of the test whereas with increase in relative humidity to 60%, the average CoF changes from 0.4 to 0.8 at the end of the test due to change in contact conditions. Soft Cd coating on low carbon steel substrate is used to study these variations in third body morphology.

关键词： tribology Cd coating triboscopy third body aerospace coating humidity

Natural variation in social conditions affects male mate choosiness in the amphipod Gammarus roeselii

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Current Zoology 2022年第4期68卷 459-467页

作者： Konrad Lipkowski Sophie Steigerwald lisa M Schulte Carolin Sommer-Trembo Jonas Jourdan Department of Wildlife/Zoo-Animal-Biology and Systematics Institute for EcologyEvolution and Diversity Goethe University FrankfurtMaxvon-Laue-Straße 13Frankfurt am MainD-60438Germany Department of Environmental Science Stockholm UniversitySvante Arrheniusväg 8StockholmSE-11418Sweden Zoological Institute University of BaselVesalgasse 1BaselCH-4051Switzerland Department of Aquatic Ecotoxicology Institute for EcologyEvolution and DiversityGoethe University Frankfurt am MainFrankfurt am MainGermany

The extent of male mate choosiness is driven by a trade-off between various environmental factors associated with the costs of mate acquisition,quality assessment and opportunity *** knowledge about natural variation in male mate choosiness across different populations of the same species,however,remains *** this study,we compared male mate choosiness across 10 natural populations of the freshwater amphipod Gammarus roeselii(Gervais 1835),a species with overall high male mating investments,and evaluated the relative influence of population density and sex ratio(both affecting mate availability)on male mate *** investigated amplexus establishment after separating mating pairs and presenting focal males with a novel,size-matched female from the same *** analysis revealed considerable effects of sex ratio and(to a lesser extent)population density on time until amplexus establishment(choosiness).Male amphipods are able to perceive variable social conditions(e.g.,sex ratio)and modify their mating strategy accordingly:We found choosiness to be reduced in increasingly male-biased populations,whereas selectivity increases when sex ratio becomes female *** this,our study expands our limited knowledge on natural variations in male mate choosiness and illustrates the importance of sex ratio(i.e.,level of competition)for male mating decisions in natural *** for variation in sex ratios,therefore,allows envisioning a distinctive variation of choosiness in natural populations and highlights the importance of considering social background information in future behavioral studies.

关键词： amplexus Crustacea local adaptation mate choice population density sex ratio

Microfluidics for interrogating live intact tissues

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Microsystems & Nanoengineering 2020年第1期6卷 538-564页

作者： lisa F.Horowitz Adan D.Rodriguez Tyler Ray Albert Folch Department of Bioengineering University of WashingtonSeattleWA 98195USA Department of Mechanical Engineering University of Hawaiʻi at MānoaHonoluluHI 96822USA

The intricate microarchitecture of tissues–the“tissue microenvironment”–is a strong determinant of tissue *** offers an invaluable tool to precisely stimulate,manipulate,and analyze the tissue microenvironment in live tissues and engineer mass transport around and into small tissue *** control is critical in clinical studies,especially where tissue samples are scarce,in analytical sensors,where testing smaller amounts of analytes results in faster,more portable sensors,and in biological experiments,where accurate control of the cellular microenvironment is *** also provides inexpensive multiplexing strategies to address the pressing need to test large quantities of drugs and reagents on a single biopsy specimen,increasing testing accuracy,relevance,and speed while reducing overall diagnostic ***,we review the use of microfluidics to study the physiology and pathophysiology of intact live tissues at sub-millimeter *** categorize uses as either in vitro studies–where a piece of an organism must be excised and introduced into the microfluidic device–or in vivo studies–where whole organisms are small enough to be introduced into microchannels or where a microfluidic device is interfaced with a live tissue surface(*** skin or inside an internal organ or tumor)that forms part of an animal larger than the *** microfluidic systems promise to deliver functional measurements obtained directly on intact tissue–such as the response of tissue to drugs or the analysis of tissue secretions–that cannot be obtained otherwise.

关键词： fluid drugs testing

Review of the achievement of ssop and its inspiration for future regional cooperation

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Tropical Cyclone Research and Review 2021年第4期10卷 229-236页

作者： Jixin Yu Jinping Liu lisa Kou UNESCAP/WMO Typhoon Committee Secretariat MacaoChina

Countries in Asia and the Pacific are more prone to natural disasters than those in other parts of the *** of this,there is an urgent need to continue developing effective,end-to-end early warning systems that lead to an effective response by emergency managers and people at ***/WMO Typhoon Committee(TC),in cooperation with WMO/ESCAP Panel on Tropical Cyclones(PTC),conducted a regional cooperation project on Synergized Standard Operating Procedures for Coastal Multi-Hazards Early Warning System(SSOP)with fund support from ESCAP Multi-Donor Trust Fund for Tsunami,Disaster and Climate Preparedness in Indian Ocean and South East *** project was conducted successfully and achieved its proposed *** results and achievements greatly benefit the Members not only in the region but also in all other regions of *** paper reviewed its implementation process,strategy and activities;briefed its main achievements including SSOP Manual,capacity building and cooperation mechanism between TC and PTC;summarized the experiences and lessons from project implementation;and highlighted its *** paper also suggested the approaches to enhance the sustainability of SSOP results and the cooperation between two regional bodies TC and PTC.

关键词： Ynergized Standard operating procedure Coastal hazards Early warning system Regional cooperation

Development of barium@alginate adsorbents for sulfate removal in lithium refining

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Frontiers of Chemical Science and Engineering 2021年第1期15卷 198-207页

作者： lisa Xu Kaifei Chen George Q.Chen Sandra E.Kentish Gang(Kevin)Li Department of Chemical Engineering The University of MelbourneParkvilleVIC 3010Australia

The demand for lithium has been steadily growing in recent years due to the boom of electric *** purity lithium is commonly used in the manufacture of battery grade lithium *** residuals originating from acid leaching of lithium ores must be limited to below 20 mg·L^(−1) during *** are methods to remove sulfate such as membrane processing and chemical precipitation using barium ***,membrane separation is unable to achieve the required purity while chemical precipitation often causes secondary contamination with barium and requires extra filtration processes that lead to increased processing *** this study,we developed a polymeric matrix entrapped with barium ions as a novel adsorbent to selectively adsorb sulfate in aqueous *** adsorbent was prepared by dropwise injection method where alginate droplets were crosslinked with barium to form hydrogel *** a typical scenario,the microcapsules had a diameter of 3 mm and contained 5 wt-%*** microcapsules could successfully reduce sulfate concentration in a solution from 100 to 16 mg·L^(−1),exceeding the removal ***,the microcapsules were mechanically unstable in the presence of an excess amount of ***,calcium ions were added as a secondary crosslinking agent to improve the integrity of the *** two-step Ca/Ba@alginate microcapsules showed an exceptional adsorption performance,reducing the sulfate concentration to as low as 0.02 mg·L^(−1).Since the sulfate selective microcapsules can be easily removed from the aqueous system and do not result in secondary barium contamination,these Ca/Ba@alginate adsorbents will find applications in ultra-refining of lithium in industry.

关键词： barium@alginate microcapsules dropwise injection sulfate removal lithium

Genetic epidemiology of diabetic retinopathy

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Annals of Eye Science 2017年第1期2卷 289-297页

作者： lisa Tom Samaneh Davoudi Lucia Sobrin Massachusetts Eye and Ear Infirmary Department of OphthalmologyHarvard Medical SchoolBostonMAUSA

The disease burden of diabetic retinopathy(DR)is tremendous around the *** DR is correlated with hemoglobin A1c(HbA1c)and duration of diabetes,genetic differences likely account for variation in susceptibility to *** is a polygenic disorder with demonstrated ***,linkage and admixture analyses,candidate gene association studies,and genome-wide association studies(GWAS)have not identified many loci for DR that can be consistently ***,collaborative,multi-ethnic GWAS are needed to identify common variants with small *** defining of controls groups as patients with a long duration of diabetes without DR,and case groups as patients with severe DR will also aid in finding genes associated with *** in independent cohorts will be key to establishing associated loci for *** of mitochondrial DNA and epigenetics in DR are *** exome sequencing presents new opportunities to identify rare variants that might be implicated in DR *** research in the genetic epidemiology of DR is needed,with the potential to elucidate pathogenesis and treatment of an important disease.

关键词： Diabetic retinopathy(DR) genetics genome-wide association studies genetic association studies diabetes complications