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Impact of natural disturbance, forest management and vegetation cover on topsoil biochemical characteristics of Tatra Mts.(Slovakia)

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Journal of Mountain Science 2020年第6期17卷 1294-1309页

作者： Jana GáFRIkOVá Milan ZVARík peter hanajík Marek SúLOVSkY Ivana VYkOUkOVá Faculty of Natural Sciences Comenius UniversityBratislava84104Slovak Republic Faculty of Mathematics Physics and InformaticsComenius UniversityBratislava84104Slovak Republic Water Research Institute Bratislava81249Slovak Republic

Perturbations caused by windstorms usually lead to the harvesting and clearcutting of fallen trees and wood debris,especially in the areas of managed forest *** shifts in soils due to management practices play a crucial role in the restoration and maintaining of key ecosystem *** paper focuses on topsoil chemical properties in relation to vegetation type(trees,shrubs and herbs)evolving at windstorm damaged(in 2004)areas with former Norway spruce(Picea abies)forests in the Tatra ***(Slovakia).We assessed the content of topsoil organic matter fractions(extractives,holocellulose(HC)and lignin(Lig)),carbon in microbial biomass(Cmic),soil organic matter(SOM)and the content of elements N,C,H and *** study plots represent different types of post-windthrow disturbance history/regime:wooden debris extraction(EXT),wooden debris not extracted(NEX),wooden debris extraction followed by wildfire(FIR),affected by the windstorm in 2014 with the subsequent wooden debris extraction(REX)and unaffected(REF).Our results revealed significant differences among sites in the content of dichloromethane extractives(EXT *** and FIR),acetone extractives(NEX ***,FIR and REF),ethanol extractives(FIR ***,NEX and REF),water extractives(FIR ***,NEX)and Cmic(EXT ***,FIR and REF).The topsoil of Vaccinium myrtillus and Picea abies showed a higher ratio of C/N,N/Lig,and Lig/HC compared to Rubus idaeus,Avenella flexuosa,Calamagrostis villosa,and Larix *** content of N,C,H and S varied between topsoil with shrubs(Vaccinium myrtillus,Rubus idaeus)and grasses(Avenella flexuosa,Calamagrostis villosa).A positive correlation between soil organic matter(SOM)and polar extractives(r=0.81)and a negative correlation between SOM and HC(r=-0.83)was *** carbon content in microbial biomass(Cmic)is positively correlated with acid soluble lignin(ASL)(r=0.85).We also identified a strong correlation between klason lignin(kL)and the Lig/HC ratio(r=0.97).

关键词： Windthrow Wildfire Organic matter fractions Vegetation type Norway spruce Topsoil chemical properties

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Hydrogenic Donor in a Spherical Quantum Dot with Different Confinements

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Chinese Physics Letters 2009年第8期26卷 309-312页

作者： A. John peter k. Navaneethakrishnan Govt. Arts College Melur-625 106 Madurad India Madurai kamaraj-University Madurai-625 021 India

Binding energies of a hydrogenic donor in a spherical GaAs quantum dot surrounded by Ga1-xA4xAs matrix are calculated. The results are presented for realistie barrier heights corresponding to different values of x （x 〈 0.4）. The calculations are performed under two different conditions：（i） a spherical dot with square well confinement and （ii） a dot with parabolic potential well confinement. The results show that （i） the donor ionization energies are always higher under parabolic confinement as compared to a dot of the same radius under square well confinement and （ii） the oscillator strengths coupling ground state with excited states are two orders larger under parabolic confinement. Our results are in agreement with the results of other researchers.

关键词： ELECTRON donor-acceptor complexes QUANTUM dots BINDING energy OSCILLATOR strengths PLASMA confinement QUANTUM wells GALLIUM arsenide semiconductors

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Influence of degree of interlock on confined strength of jointed hard rock masses

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Journal of Rock Mechanics and Geotechnical Engineering 2020年第6期12卷 1152-1170页

作者： Navid Bahrani peter k.kaiser a Department of Civil and Resource Engineering Dalhousie UniversityHalifaxNova ScotiaCanada b Bharti School of Engineering Laurentian UniversitySudburyOntarioCanada

The strength of jointed rock mass is strongly controlled by the degree of interlock between its constituent rock *** degree of interlock constrains the kinematic freedom of individual rock blocks to rotate and slide along the block forming *** HoekeBrown(HB)failure criterion and the geological strength index(GSI)were developed based on experiences from mine slopes and tunneling projects in moderately to poorly interlocked jointed rock *** has since then been demonstrated that the approach to estimate the HB strength parameters based on the GSI strength scaling equations(called the‘GSI strength equations’)tends to underestimate the confined peak strength of highly interlocked jointed rock masses(***>65),where the rock mass is often non-persistently jointed,and the intact rock blocks are strong and *** estimation of the confined strength of such rock masses is relevant when designing mine pillars and abutments at great depths,where the confining pressure is high enough to prevent block rotation and free sliding on block *** this article,a grain-based distinct element modeling approach is used to simulate jointed rock masses of various degrees of interlock and to investigate the influences of block shape,joint persistence and joint surface condition on the confined peak *** focus is on non-persistently jointed and blocky(persistently jointed)rock masses,consisting of hard and homogeneous rock blocks devoid of any strength degrading defects such as *** results from this investigation confirm that the GSI strength equations underestimate the confined strength of highly interlocked and non-persistently jointed rock ***,the GSI strength equations are found to be valid to estimate the confined strength of persistently jointed rock masses with smooth and non-dilatant joint surfaces.

关键词： Rock mass strength Degree of interlock Non-persistently jointed rock mass Blocky rock mass Geological strength index(GSI) GSI strength equations

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Contribution of precursor compounds to the release of per-and polyfluoroalkyl substances(PFASs) from waste water treatment plants(WWTPs)

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Journal of Environmental Sciences 2017年第11期29卷 80-90页

作者： Ulrika Eriksson peter Haglund Anna k?rrman Man-Technology-Environment (MTM) Research Centre School of Science and Technology ?rebro University Department of Chemistry Umea University

Per-and polyfluoroalkyl substances（PFASs） are ubiquitous in sludge and water from waste water treatment plants, as a result of their incorporation in everyday products and industrial processes. In this study, we measured several classes of persistent PFASs,precursors, transformation intermediates, and newly identified PFASs in influent and effluent sewage water and sludge from three municipal waste water treatment plants in Sweden, sampled in 2015. For sludge, samples from 2012 and 2014 were analyzed as *** of precursors in sludge exceeded those of perfluoroalkyl acids and sulfonic acids（PFCAs and PFSAs）, in 2015 the sum of polyfluoroalkyl phosphoric acid esters（PAPs） were 15–20 ng/g dry weight, the sum of fluorotelomer sulfonic acids（FTSAs） was 0.8–1.3 ng/g,and the sum of perfluorooctane sulfonamides and ethanols ranged from non-detected to 3.2 ng/g. Persistent PFSAs and PFCAs were detected at 1.9–3.9 ng/g and 2.4–7.3 ng/g dry weight, respectively. The influence of precursor compounds was further demonstrated by an observed substantial increase for a majority of the persistent PFCAs and PFSAs in water after waste water treatment. Perfluorohexanoic acid（PFHxA）, perfluorooctanoic acid（PFOA）, perfluorohexane sulfonic acid（PFHxS）, and perfluorooctane sulfonic acid（PFOS）had a net mass increase in all WWTPs, with mean values of 83%, 28%, 37% and 58%,respectively. The load of precursors and intermediates in influent water and sludge combined with net mass increase support the hypothesis that degradation of precursor compounds is a significant contributor to PFAS contamination in the environment.

关键词： diPAPs FTSAs Waste water Daily discharge PFCA precursor

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Blind spots in climate finance for innovation peter WARREN

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Advances in Climate Change Research 2020年第1期11卷 60-64页

作者： peter WARREN School of Public Policy University College London(UCL)LondonWCIH 9QUUK

International climate finance is a sub-set of green finance and refers to investments specifically in climate change mitigation and adaptation activities,which primarily involve public finance and the leveraging of private finance in developing *** addition to continued international support for scaling low carbon solutions and facilitating replicability in developing countries,there remains an important need to increase the amount of climate finance provided to innovation,particularly demonstration(for technology innovation)and pilot implementation(for policy innovation),and to channel a greater proportion of Official Development Assistance(ODA)to‘hard-to-abate'areas,such as industrial decarbonisation,international transport and cross-sectoral issues like cooling and behavioural insights,to accelerate the commercialisation and implementation of technological,linancial and policy solutions to contribute to meeting the Paris Agreement's goal of limiting global warming to‘well-below'2℃ in these *** research,development and demonstration(RD&D)support with technical assistance is important in providing the route to obtain wider donor finance(concessional finance)and private finance to enable deployment through scalability and replicability.

关键词： Climate finance Climate policy Paris Agreement Official development assistance Industrial decarbonisation Sustainable cooling Behavioural insights International transport

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Ultrastrong and ductile BCC high-entropy alloys with low-density via dislocation regulation and nanoprecipitates

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Journal of Materials Science & Technology 2022年第15期110卷 109-116页

作者： Xuehui Yan peter k.Liaw Yong Zhang Beijing Advanced Innovation Center of Materials Genome Engineering State Key Laboratory for Advanced Metals and MaterialsUniversity of Science and Technology BeijingBeijing 100083China Department of Materials Science and Engineering The University of TennesseeKnoxvilleTN 37996United States of America

The high strength is a typical advantage of body-centered-cubic high-entropy alloys(BCC–HEAs).However,brittleness and weak strain-hardening ability are still their Achilles'***,extraordinary strength together with good tensile ductility are achieved in(Zr_(0.5)Ti_(0.35)Nb_(0.15))_(100-x)Al_(x) alloys(at.%,x=10 and 20)at room *** low densities of less than 6 g/cm^(3)are exhibited in these *** nanoprecipitates and diversifying dislocation motions are the keys to achieving such salient *** is worth noting that the tensile strength of 1.8 GPa in(Zr_(0.5)Ti_(0.35)Nb_(0.15))_(80)Al_(20)alloy is a record-high value known in reported BCC–HEAs,as well as a tensile strain over 8%.Furthermore,the maximum strain of~25%in(Zr_(0.5)Ti_(0.35)Nb_(0.15))_(90)Al_(10)alloy can challenge existing limit value,and is accompanied with a tensile strength of 1.2 *** current work does not only provide novel ultra-strong and tough structural materials with low density,but also sheds new light on designing BCC–HEAs with attractive performances and strain-hardening ability.

关键词： High-entropy alloys Mechanical properties Dislocation Nanoprecipitates Strain hardening

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Structure design and property of multiple-basis-element(MBE)alloys flexible films

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Nano Research 2022年第6期15卷 4837-4844页

作者： Hao Huang peter k.Liaw Yong Zhang Qinghai Provincial Engineering Research Center of High Performance Light Metal Alloys and Forming Qinghai UniversityXining 810016China State key Laboratory of Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China Department of Materials Science and Engineering The University of TennesseeKnoxvilleTN 37996-2100USA Shunde Graduate School University of Science and Technology BeijingFoshan 528399China

A controlled wrinkled structure is a simple and effective approach to achieve unique properties and has been widely used in flexible *** this study,we reported a substrate prestrain method for fabricating wrinkle-structured Zr52Ti34Nb14 multiplebasis-element(MBE)alloy films as biocompatible *** in the film thickness and substrate prestraining enabled a precise control of the amplitude and wavelength of the wrinkled structures,ranging from micrometers to ***,owing to the flexibility of the wrinkled structures,the wrinkle-structure pattern could be adjusted by simply relaxing or further stretching of the substrate,leading to dynamically tunable transmittance and wetting *** result not only reveals Zr52Ti34Nb14 MBE alloy films as a potential flexible material,but also provides a new structural design approach for other MBE alloy systems.

关键词： multiple-basis-element alloy thin films microstructures optical transmission wetting behavior

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Nanoscale fluctuation of stacking fault energy strengthens multi-principal element alloys

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Journal of Materials Science & Technology 2023年第27期158卷 218-225页

作者： Zongrui Pei Markus Eisenbach peter k.Liaw Mingwei Chen New York University New York 10012USA Oak Ridge National Laboratory Oak RidgeTennessee 37831USA Department of Materials Science and Engineering The University of TennesseeKnoxvilleTN 37996USA Department of Materials Science and Engineering Johns Hopkins UniversityBaltimoreMaryland 21218USA Engineering and Hopkins Extreme Materials Institute Johns Hopkins UniversityBaltimoreMaryland 21218USA

Chemical randomness and the associated energy fluctuation are essential features of multi-principal ele-ment alloys(MPEAs).Due to these features,nanoscale stacking fault energy(SFE)fluctuation is a natural and independent contribution to strengthening ***,existing models for conventional alloys(i.e.,alloys with one principal element)cannot be applied to *** extreme values of SFEs required by such models are unknown for MPEAs,which need to calculate the nanoscale volume relevant to the SFE *** the present work,we developed an analytic model to evaluate the strengthening ef-fect through the SFE fluctuation,profuse in *** model has no adjustable parameters,and all parameters can be determined from experiments and ab initio *** model explains available experimental observations and provides insightful guidance for designing new MPEAs based on the SFE *** generally applies to MPEAs in random states and with chemical short-range order.

关键词： Nanoscale energy fluctuation Staking fault energy Chemical short-range order Multi-principal element alloy Mechanism

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Gender-specific associations between coronary heart disease and other chronic diseases: cross-sectional evaluation of national survey data from adult residents of Germany

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Journal of Geriatric Cardiology 2019年第9期16卷 663-670,I0002-I0005页

作者： Marie-Isabel k Murray kerstin Bode peter Whittaker Department of Cardiology University Hospital Frankfurt am Main Frankfurt Germany Department of Electrophysiology Heart Center Leipzig Leipzig Germany Cardiovascular Research Institute and Department of Emergency Medicine Wayne State University Detroit MI USA

Background Combinations of coronary heart disease(CHD) and other chronic conditions complicate clinical management and increase healthcare costs. The aim of this study was to evaluate gender-specific relationships between CHD and other comorbidities. Methods We analyzed data from the German Health Interview and Examination Survey(DEGS1), a national survey of 8152 adults aged 18-79 years. Female and male participants with self-reported CHD were compared for 23 chronic medical conditions. Regression models were applied to determine potential associations between CHD and these 23 conditions. Results The prevalence of CHD was 9%(547 participants): 34%(185) were female CHD participants and 66%(362) male. In women, CHD was associated with hypertension(OR = 3.28(1.81-5.9)), lipid disorders(OR = 2.40(1.50-3.83)), diabetes mellitus(OR = 2.08(1.24-3.50)), kidney disease(OR = 2.66(1.101-6.99)), thyroid disease(OR = 1.81(1.18-2.79)), gout/high uric acid levels(OR = 2.08(1.22-3.56)) and osteoporosis(OR = 1.69(1.01-2.84)). In men, CHD patients were more likely to have hypertension(OR = 2.80(1.94-4.04)), diabetes mellitus(OR = 1.87(1.29-2.71)), lipid disorder(OR = 1.82(1.34-2.47)), and chronic kidney disease(OR = 3.28(1.81-5.9)). Conclusion Our analysis revealed two sets of chronic conditions associated with CHD. The first set occurred in both women and men, and comprised known risk factors: hypertension, lipid disorders, kidney disease, and diabetes mellitus. The second set appeared unique to women: thyroid disease, osteoporosis, and gout/high uric acid. Identification of shared and unique gender-related associations between CHD and other conditions provides potential to tailor screening, preventive, and therapeutic options.

关键词： Chronic diseases Comorbidities Gender Heart disease Risk factors Survey data

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Calcium at the Cell Wall-Cytoplast Interface

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Journal of Integrative Plant Biology 2010年第2期52卷 147-160页

作者： peter k.Hepler Lawrence J.Winship Department of Biology University of MassachusettsAmherstMA 01003USA School of Natural Science Hampshire CollegeAmherstMA 01002USA

Attention is given to the role of Ca^2＋ at the interface between the cell wall and the cytoplast, especially as seen in pollen tubes. While the cytoplasm directs the synthesis and deposition of the wall, it is less well appreciated that the wall exerts considerable self control and influences activities of the cytoplasm. Ca^2＋ participates as a crucial factor in this two way communication. In the cytoplasm, a [Ca^2＋] above 0.1 μM, regulates myriad processes, including secretion of cell wall components. In the cell wall Ca^2＋ , at 10μM to 10 mM, binds negative charges on pectins and imparts structural rigidity to the wall. The plasma membrane occupies a pivotal position between these two compartments, where selective channels regulate influx of Ca^2＋ , and specific carriers pump the ion back into the wall. In addition we draw attention to different factors, which either respond to the wall or are present in the wall, and usually generate elevated[Ca^2＋ ] in the cytoplasm. These factors include：（i） stretch activated channels; （ii） calmodulin; （iii） annexins; （iv） wall associated kinases; （v） oligogalacturonides; and （vi） extracellular adenosine 5＇-triphosphate. Together they provide evidence for a rich and multifaceted system of communication between the cytoplast and cell wall, with Ca^2＋ as a carrier of information.

关键词： Calcium at the Cell Wall-Cytoplast Interface CNGC

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