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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

Plant Phosphatidylcholine-Hydrolyzing Phospholipases C NPC3 and NPC4 with Roles in Root Development and Brassinolide Signaling in Arabidopsis thaliana

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Molecular Plant 2010年第3期3卷 610-625页

作者： Rinukshi Wimalasekera Premysl Pejchar Andre Holka Jan Martinec gunther RE. Scherer Leibniz University of Hannover Institute of Floriculture and Wood Science Section of Applied Molecular Physiology Herrenhauser Strasse 2 D-30419Hannover Germany Institute of Experimental Botany Academy of Sciences of the Czech Republic v.v.i. Rozvojova 263 165 02 Prague 6 Czech Republic

Phosphatidylcholine-hydrolyzing phospholipase C （PC-PLC） catalyzes the hydrolysis of phosphatidylcholine （PC） to generate phosphocholine and diacylglycerol （DAG）. PC-PLC has a long tradition in animal signal transduction to generate DAG as a second messenger besides the classical phosphatidylinositol splitting phospholipase C （PI-PLC）. Based on amino acid sequence similarity to bacterial PC-PLC, six putative PC-PLC genes （NPC1 to NPC6） were identified in the Arabidopsis genome. RT-PCR analysis revealed overlapping expression pattern of NPC genes in root, stem, leaf, flower, and silique. In auxin-treated PNPc3：GUS and PNPc4：GUS seedlings, strong increase of GUS activity was visible in roots, leaves, and shoots and, to a weaker extent, in brassinolide-treated （BL） seedlings. PNPc4：GUS seedlings also responded to cytokinin with increased GUS activity in young leaves. Compared to wild-type, T-DNA insertional knockouts npc3 and npc4 showed shorter primary roots and lower lateral root density at low BL concentrations but increased lateral root densities in response to exogenous 0.05-1.0 I^M BL BL-induced expression of TCH4 and LRX2, which are involved in cell expansion, was impaired but not impaired in repression of CPD, a BL biosynthesis gene, in BL-treated npc3 and npc4. These observations suggest NPC3 and NPC4 are important in BL-mediated signaling in root growth. When treated with 0.1 I^M BL, DAG accumulation was observed in tobacco BY-2 cell cultures labeled with fluorescent PC as early as 15 min after application. We hypothesize that at least one PC-PLC is a plant signaling enzyme in BL signal transduction and, as shown earlier, in elicitor signal transduction.

关键词： Auxin brassinolide signaling phosphate deficiency phosphatidylcholine-splitting phospholipase C (PC-PLC) NPC genes.

The Case for Stabilizing China's Exchange Rate:Setting the Stage for Fiscal Expansion

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China & World Economy 2009年第1期17卷 1-32页

作者： Ronald McKinnon gunther Schnabl Stanford University Leipzig University

China＇s financial conundrum arises from two sources. First, its large saving （trade） surplus results in a currency mismatch because it is an immature creditor that cannot lend in its own currency. Instead, foreign currency claims （largely US dollars） build up within domestic financial institutions. Second, economists, both American and Chinese, mistakenly attribute the surpluses to an undervalued RMB. To placate the USA, the result was a gradual and predictable appreciation of the RMB against the dollar of 6 percent or more per year from July 2005 to July 2008. Together with the fall in US interest rates since mid-2007, this one- way bet in the foreign exchanges markets not only attracted hot money inflows but inhibited private capital outflows from financing China＇ s huge trade surplus. Therefore, the People＇s Bank of China had to intervene heavily to prevent the RMB from ratcheting upwards, and so became the country＇s sole international financial intermediary as official exchange reserves exploded Because of the currency mismatch, floating the RMB is neither feasible nor desirable, and a higher RMB would not reduce China＇ s trade surplus. Instead, monetary control and normal private-sector finance for the trade surplus require a return to a credibly fixed nominal RMB/USD rate similar to that which existed between 1995 and 2004. However, for any newly reset RMB/USD rate to be credible as a monetary anchor, foreign ＂China bashing＂ to get the RMB up must end. Then the stage would be set for fiscal expansion to both stimulate the economy and reduce its trade surplus.

关键词： China bashing China's exchange rate currency mismatch fiscal expansion

Estimating potential yield of wheat production in China based on cross-scale data-model fusion

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Frontiers of Earth Science 2012年第4期6卷 364-372页

作者： Zhan TIAN Honglin ZHONG Runhe SHI Laixiang SUN gunther FISCHER Zhuoran LIANG Key Laboratory of Geographic Information Science Ministry of Education East China Normal University Shanghai 200062 China Shanghai Climate Center Shanghai Meteorological Bureau Shanghai 200030 China International Institute for Applied System Analysis Laxenburg 2361 Austria

The response of the agro-ecological system to the environment includes the response of individual crop＇s physiologic process and the adaption of the crop commu- nity to the environment. Observation and simulation at the single scale level cannot fully explain the above process. It is necessary to develop cross-scale agro-ecological models and study the interaction of agro-ecological processes across different scales. In this research, two typical agro- ecological models, the Decision Support System for Agro- technology Transfer （DSSAT） model and the Agro- ecological Zone （AEZ） model, are employed, and a framework for effective cross-scale data-model fusion is proposed and illustrated. The national observed data from 36 different agricultural observation stations and historical weather stations （1962-1999） are employed to estimate average crop productivity. Comparison of the two models＇ estimations are consistent, which would indicate the possibility ofcross-scale crop model fusion.

关键词： DSSAT model AEZ model data-model fusion agro-ecological system

Assessing the inter-annual variability of separation distances around odour sources to protect the residents from odour annoyance

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Journal of Environmental Sciences 2019年第5期31卷 11-24页

作者： Marlon Brancher Martin Piringer Davide Franco Paulo Belli Filho Henrique De Melo Lisboa gunther Schauberger Postgraduate Program in Environmental Engineering (PPGEA) Federal University of Santa Catarina (UFSC) 88040900 Florianopolis Brazil.CAPES Foundation scholarship holder (main author) Brazilian Ministry of Education Brasilia Brazil WG Environmental Health Department of Biomedical Sciences University of Veterinary Medicine ViennaVeterinarplatz1 A-1210Vienna Austria Central Institute for Meteorology and Geodynamics Hohe Warte 38 A-1190 Vienna Austria

In recent years, there has been a growing concern about potential impacts on public health and wellbeing due to exposure to environmental odour. Separation distances between odour-emitting sources and residential areas can be calculated using dispersion models, as a means of protecting the neighbourhood from odour annoyance. This study investigates the suitability of using one single year of meteorological input data to calculate reliable direction-dependent separation distances. Accordingly, we assessed and quantified the inter-annual variability of separation distances at two sites with different meteorological conditions, one in Brazil and the other in Austria. A 5-year dataset of hourly meteorological observations was used for each site. Two odour impact criteria set in current regulations were selected to explore their effect on the separation distances. The coefficient of variation was used as a statistical measure to characterise the amount of annual variation. Overall,for all scenarios, the separation distances had a low degree of inter-annual variability(mean coefficient of variation values from 8% to 21%). Reasonable agreements from year to year were therefore observed at the two sites under investigation, showing that one year of meteorological data is a good compromise to achieve reliable accuracy. This finding can provide a more cost-effective solution to calculate separation distances in the vicinity of odour sources.

关键词： Environmental odour Odour annoyance Impact assessment Dispersion modelling Regulatory criteria Separation distance

A holistic approach for the investigation of lining response to mechanized tunneling induced construction loadings

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Underground Space 2018年第1期3卷 45-60页

作者： Vojtech Ernst Gall Ahmed Marwan Mario Smarslik Markus Obel Peter Mark gunther Meschke Inustitute for Structural Mechanics Ruhr University BochumBochunGermany Institute of Concrete Structures Ruhr University BochumBochumGermany

Design methods for segmental tunnel linings used in mechanized tunnel constructions typically employ numerical bedded beam mod-els and/or classical analytical solutions for the determination of structural forces(*** and shear and axial forces)and simple load spreading assumptions for the design of the reinforcement in joint *** effcient such methods may be,many physical details are often overlooked and/or oversimpliﬁed in the process of reducing the actual structure to a structural beam model,***-lytically derived loadings are employed,the grouting and ground reactions are reduced to a spring bedding,and the conﬁnement due to grouting at the longitudinal joint is largely not considered in reinforcement *** a design process is not able to account for,or predict,the susceptibility of tunnel linings to often observed damages that,although they may not be structurally relevant,lead to ser-viceability or durability issues,such as crack development or chipping at the segment *** methods,such as the Finite Element Method,provide an opportunity to model the segmental tunnel lining and its response to the entire TBM construction process and to explicitly model the crack development within individual segments using modern methods to model the discontinuities in *** this contribution,a holistic modeling procedure for the representation of the tunnel lining within the tunneling process is pro-posed and compared to traditional lining models.A 3D process oriented Finite Element model is used to calculate the predicted forces on the tunnel lining and the obtained results are compared with those generated by traditional ***,the predicted defor-mations are then transferred to a detailed segment model in which the nonlinear response of the segment at the longitudinal joint is mod-eled using an interface element based approach to simulate concrete cracking.

关键词： Mechanized tunneling Segmental tunnel linings Finite element method

Patterns and Timing in Expression of Early Auxin-Induced Genes Imply Involvement of Phospholipases A （pPLAs） in the Regulation of Auxin Responses

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Molecular Plant 2013年第5期6卷 1473-1486页

作者： Corinna Labusch Maria Shishova Yunus Effendi Maoyin Li Xuemin Wang gunther RE. Scherera Leibniz Universit&t Hannover Institut for Zierpflanzenbau und Geh61zwissenschaften Abt. Molekulare Ertragsphysiologie Herrenhauser Str. 2 D-30419 Hannover Germany Department of Plant Physiology and Biochemistry State University of St. Petersburg Universitetskaya em. 7/9 St. Petersburg 199034 Russia Department of Biology University of Missouri St Louis MO 63121 USA Donald Danforth Plant Science Center St Louis MO 63132 USA

While it is known that patatin-related phospholipase A （pPLA） activity is rapidly activated within 3min by auxin, hardly anything is known about how this signal influences downstream responses like transcription of early auxin-induced genes or other physiological responses. We screened mutants with T-DNA insertions in members of the pPLA gene family for molecular and physiological phenotypes related to auxin. Only one in nine Arabidopsis thaliana ppla knockdown mutants displayed an obvious constitutive auxin-related phenotype. Compared to wild-type, ppla-IIlδ mutant seedlings had decreased main root lengths and increased lateral root numbers. We tested auxin-induced gene expression as a molecular readout for primary molecular auxin responses in nine ppla mutants and found delayed up- regulation of auxin-responsive gene exRression in all of themL Thirty minutes after auxin treatment, up-regulation of up to 40% of auxin-induced genes was delayed in mutant seedlings. We observed only a few cases with hypersensitive auxin-induced gene expression in ppla mutants. While, in three ppla mutants, which were investigated in detail, rapid up- regulation （as early as 10 min after auxin stimulus） of auxin-regulated genes was impaired, late transcriptional responses were wild-type-like. This regulatory or dynamic phenotype was consistently observed in different ppla mutants with delayed up-regulation that frequently affected the same genes. This defect was not affected by pPLA transcript levels which remained constant. This indicates aposttranslational mechanism as a functional link of pPLAs to auxin signaling. The need for a receptor triggering an auxin response without employing transcription regulation is discussed.

关键词： hormonal regulation hormone biology signal transduction.

Can Quick Release Experiments Reveal the Muscle Structure？ A Bionic Approach

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Journal of Bionic Engineering 2012年第2期9卷 211-223页

作者： D. F. B. Haeufle M. gunther R. Blickhan S. Schmitt Institute of Sports and Exercise-Science University of Stuttgart Allmandring 28 D-70569 Stuttgart Germany Stuttgart Research Centre for Simulation Technology （SRC SimTech） University of Stuttgart Pfaffenwaldring 7a D-70569 Stuttgart Germany Institute of Motion Science Friedrich-Schiller-University Seidelstraβe 20 D-07749 Jena Germany

The goal of this study was to understand the macroscopic mechanical structure and function of biological muscle with respect to its dynamic role in the contraction. A recently published muscle model, deriving the hyperbolic force-velocity relation from first-order mechanical principles, predicts different force-velocity operating points for different load situations. With a new approach, this model could be simplified and thus, transferred into a numerical simulation and a hardware experiment. Two types of quick release experiments were performed in simulation and with the hardware setup, which represent two extreme cases of the contraction dynamics： against a constant force （isotonic） and against an inertial mass. Both experiments revealed hyperbolic or hyperbolic-like force-velocity relations. Interestingly, the analytical model not only predicts these extreme cases, but also additionally all contraction states in between. It was possible to validate these predictions with the numerical model and the hardware experiment. These results prove that the origin of the hyperbolic force-velocity relation can be mechanically explained on a macroscopic level by the dynamical interaction of three mechanical elements. The implications for the interpretation of biological muscle experiments and the realization of muscle-like bionic actuators are discussed.

关键词： force-velocity relation isotonic quick release proof of concept artificial muscle

Review of current methods of acousto-optical tomography for biomedical applications

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Frontiers of Optoelectronics 2017年第3期10卷 211-238页

作者： Jacqueline gunther Stefan ANDERSSON-ENGELS Tyndall National Institute Lee Maltings Dyke Parade Cork T12 R5CP Ireland Department of Physics University College Cork Cork T12 YN60 Ireland

The field of acousto-optical tomography （AOT） for medical applications began in the 1990s and has since developed multiple techniques for the detection of ultrasound-modulated light. Light becomes frequency shifted as it travels through an ultrasound beam. This ＂tagged＂ light can be detected and used for focused optical imaging. Here, we present a comprehensive overview of the techniques that have developed since around 2011 in the field of biomedical AOT. This includes how AOT has advanced by taken advantage of the research conducted in the ultrasound, as well as, the optical fields. Also, simulations and reconstruction algorithms have been formulated specifically for AOT imaging over this time period. Future progression of AOT relies on its ability to provide significant contributions to in vivo imaging for biomedical applications. We outline the challenges that AOT still faces to make in vivo imaging possible and what has been accomplished thus far, as well as possible future directions.

关键词： acousto-optic ultrasound modulation optical imaging biomedical imaging