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Geographic variation in growth and phenology of two dominant central US grasses:consequences for climate change

Journal of Plant Ecology 2014年第3期7卷 211-221页

作者： Amanda L.Giuliani eugene f.kelly Alan K.Knapp Department of Biology Colorado State UniversityFort CollinsCO 80523USA Department of Soils and Crops Science Colorado State UniversityFort CollinsCO 80523USA Graduate Degree Program in Ecology and Department of Biology Colorado State UniversityFort CollinsCO 80523USA

Aims The rate of climate change may exceed many plant species’migration rates,particularly for long-lived perennial species that dominate most *** bioclimatic envelopes shift more rapidly than dominant species can migrate,individuals located peripheral to biomes or in adjacent biomes may become a significant source of traits for future dominant populations(DPs).Thus,traits of individuals from peripheral populations(PPs)may affect future ecosystem functioning more than those of today’s *** We assessed key traits of individuals collected from populations that currently dominate two central US grasslands,the shortgrass steppe(Bouteloua gracilis)and the tallgrass prairie(Andropogon gerardii).We compared these to individuals from PPs in a reciprocal-transplant common garden experiment with gardens at the Shortgrass Steppe Long Term Ecological Research site in Colorado and the Konza Prairie Biological Station Long Term Ecological Research site in *** and PPs were subjected to high and reduced water availability in common gardens located in each *** measured included the following:individual plant biomass,reproductive allocation,specific leaf area(SLA)and plant–water *** focused on the climate-change relevant comparisons of traits from PPs versus DPs expressed under the climate of *** findings PPs of *** differed from DPs primarily in phenological *** a semiarid shortgrass steppe climate,PPs initiated flowering later in the season,produced fewer reproductive tillers and were more sensitive to water *** differences between populations were *** ***,biomass in PPs was 50%lower than in DPs under the mesic tallgrass prairie climate and reproductive tillers were considerably smaller,despite higher SLA in *** of PPs was less sensitive to water stress,*** these results,we conclude that key traits of PPs differed from DPs in both grassland types,but potential effects on r

关键词： grassland phenology productivity traits water stress

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一种鉴别植被和气候变化的定量方法——植物岩中的稳定碳同位素比率

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地质地球化学 1993年第5期21卷 55-62页

作者： eugene f.kelly 刘俊峰苏英陕西咸阳师专

大平原北部的蛋白石植物岩(Opal Phytoliths)中封存碳的^(13)C/^(12)C比值可作为重建古气候的依据。宿主植物的碳同位素组成与植物岩中有机质的碳同位素组成之间存在着明显的相关关系。沿气候梯度土壤表层分布的植物岩的^(13)C/^(12)C... 详细信息

大平原北部的蛋白石植物岩(Opal Phytoliths)中封存碳的^(13)C/^(12)C比值可作为重建古气候的依据。宿主植物的碳同位素组成与植物岩中有机质的碳同位素组成之间存在着明显的相关关系。沿气候梯度土壤表层分布的植物岩的^(13)C/^(12)C此值反映了当前植被中C_3和C_4植物的比例。土壤中植物岩的δ^(13)C值随土壤深度的变化而变化,而这种变化是由多种作用引起的:尘土对土壤表面的埋藏作用、生物扰动和可能由于雨水的渗透而引起的淋滤作用。此外,尘土和植物根系对植物岩的贡献是否有同位素效应还不清楚。土壤中植物岩的δ^(13)C值随^(14)C年龄的减小而增加,表明全新世期间,本区C_4植物的比例增大。视年龄为全新世中期的植物岩主要以C_4植物独占优势,这一事实与干旱的中全新世古气候解释相吻合。

关键词：植被气候变化植物岩

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flow Management Mechanism in Software-Defined Network

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Computers, Materials & Continua 2022年第1期70卷 1437-1459页

作者： eugene Tan Yung-Wey Chong Mohammed f.R.Anbar National Advanced IPv6 Centre Universiti Sains MalaysiaUSMPenangMalaysia

Software-defined networking(SDN)is a paradigm shift in modern ***,centralised controller architecture in SDNimposed flow setup overhead issue as the control plane handles all flows regardless of size and *** frameworks strictly reduce control plane overhead and it does not focus on rule placement of the flows ***,existing frameworks do not focus on managing elephant flows like ***,the proposed mechanism will use the flow statistics gathering method such as random packet sampling to determine elephant flow and microflow via a predefined *** mechanism will ensure that the control plane works at an optimum workload because the controller only manages elephant flows via reactive routing and rule placement *** routing has reduced link bandwidth usage below the pre-defined ***,rule placement has increased average throughput and total transfer to 238%.Meanwhile,the data plane switches will be able to forward microflows via multipath wildcard routing without invoking controller in greater responding time by 85 ms faster in two Transmission Control Protocol(TCP)traffic and achieved 11%and 12%higher total transfer size and throughput ***,the controller’s workload reduced significantly to 48%in two TCP traffic.

关键词： Software-defined network controller flow management

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High quality large single crystals of metal halide perovskites for optoelectronic applications

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Science China Chemistry 2017年第10期60卷 1326-1327页

作者： eugene A.Katz Alexandre Yersin Department of Solar Energy and Environmental Physics J. Blaustein Institutes for Desert Research Ben-Gurion University of the Negev Sede Boqer Campus 8499000 Israel Ilse-Katz Institute for Nanoscale Science and Technology Ben-Gurion University of the Negev Beer Sheva 8410501 lsrael

As the technological development of large single-crystalline wafers have revolutionized many industries including electronics and photovoltaics,one can predict that the availability of large single-crystalline perovskite crystals and wafers can revolutionize its broad applications in photodetectors,solar cells,LEDs,lasers,*** 2015,Liu et al.

关键词： crystalline halide perovskite technological electronics inverse optoelectronic wafer availability render

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NONHOMOGENEOUS BOUNDARY VALUE PROBLEMS fOR THE KORTEWEG-DE VRIES EQUATION ON A BOUNDED DOMAIN

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Journal of Systems Science & Complexity 2010年第3期23卷 499-526页

作者： eugene f. KRAMER Bingyu ZHANG Department of Mathematics Physics and Computer Science University of Cincinnati Raymond Walters College Cincinnati Ohio 45236 USA Department of Mathematical Sciences University of Cincinnati Cincinnati Ohio 45221 USA

This paper studies an initial-boundary-value problem (IBVP) of the Korteweg-de Vriesequation posed on a finite interval with general nonhomogeneous boundary *** thestrong Kato smoothing property of the associated linear problem,the IBVP is shown to be locallywell-posed in the space H^s(0,1) for any s≥0 via the contraction mapping principle.

关键词： KdV equation Korteweg-de Vries equation well-posed.

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Alternative kind of hydrogen atoms as a possible explanation for the latest puzzling observation of the 21 cm radio line from the early Universe

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Research in Astronomy and Astrophysics 2020年第7期20卷 172-176页

作者： eugene Oks Physics Department 380 Duncan DriveAuburn UniversityAuburnAL 36849USA

There is a puzzling astrophysical result concerning the latest observation of the absorption profile of the redshifted radio line 21 cm from the early Universe(as described in Bowman et al.). The amplitude of the profile was more than a factor of two greater than the largest predictions. This could mean that the primordial hydrogen gas was much cooler than expected. Some explanations in the literature suggested a possible cooling of baryons either by unspecified dark matter particles or by some exotic dark matter particles with a charge a million times smaller than the electron charge. Other explanations required an additional radio background. In the present paper, we entertain a possible different explanation for the above puzzling observational result: the explanation is based on the alternative kind of hydrogen atoms(AKHA),whose existence was previously demonstrated theoretically, as well as by the analysis of atomic experiments. Namely, the AKHA are expected to decouple from the cosmic microwave background(CMB) much earlier(in the course of the Universe expansion) than usual hydrogen atoms, so that the AKHA temperature is significantly lower than that of usual hydrogen atoms. This seems to lower the excitation(spin) temperature of the hyperfine doublet(responsible for the 21 cm line) sufficiently enough for explaining the above puzzling observational result. This possible explanation appears to be more specific and natural than the previous possible explanations. further observational studies of the redshifted 21 cm radio line from the early Universe could help to verify which explanation is the most relevant.

关键词： Cosmology:Early Universe explanation of the puzzle of 21cm radio line Galaxies:intergalactic medium Cosmology:observations Cosmology:theory

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Galactic Dark Matter Halos Containing H Ⅰ Regions:A Possible Overestimation of the Column Densities

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Research in Astronomy and Astrophysics 2023年第3期23卷 100-103页

作者： eugene Oks Physics Department Auburn UniversityAuburnAL 36849USA

We analyze how the column density of hydrogen atoms in the HⅠregions,observed in dark matter halos of a number of galaxies,can be *** we study how the determination of the column density of hydrogen atoms from the observed astrophysical data would be affected by the possible presence of the Second flavor of Hydrogen Atoms(SfHA),whose existence had been previously demonstrated in four different types of atomic experiments and had helped in explaining two puzzling astrophysical observations:the anomalous absorption in the 21 cm line from the early Universe and the smoother,less clumpy distribution of dark matter in the Universe than predicted by Einstein’s *** a model example we demonstrate that the neglect of the SfHA leads to the overestimation of the column density of hydrogen atoms in dark matter halos by about 30%.We perform these relatively simple estimates just to get the message across and to motivate further corresponding theoretical and experimental studies.

关键词： galaxies anomalous estimation

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DES map shows a smoother distribution of matter than expected:a possible explanation

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Research in Astronomy and Astrophysics 2021年第10期21卷 1-4页

作者： eugene Oks Physics Department 380 Duncan DriveAuburn UniversityAuburnAL 36849USA

The largest and most detailed map of the distribution of dark matter in the Universe has been recently created by the Dark Energy Survey(DES)*** distribution was found to be slightly(by a few percent)smoother and less clumpy than predicted by general *** result was considered as a hint of some new physical *** the present paper we offer a relatively simple model that could explain the above result without resorting to any new physical *** model deals with the dynamics of a system consisting of a large number of gravitating neutral particles,whose mass is equal to the mass of hydrogen *** central point of the model is a partial inhibition of the gravitation for a relatively small subsystem of the entire *** would be sufficient for this subsystem to constitute just about a few percent of the total ensemble of particles for explaining the few percent more smooth distribution of dark matter(observed by the DES team)compared to the prediction of general *** most viable candidate for the dark matter particles in this model is the second flavor of hydrogen atoms(SfHA)that has only S-states and therefore does not couple to the electric dipole radiation or even to higher multipole radiation,so that the SfHA is practically *** SfHA has experimental confirmation from atomic experiments,it does not go beyond the Standard Model,it is based on standard quantum mechanics and it explains puzzling astrophysical observations of the redshifted line 21 cm from the early ***,our model explaining the DES result of a little too smooth distribution of dark matter without resorting to any new physical laws seems to be self-consistent.

关键词： (cosmology:)dark matter gravitation atomic processes astroparticle physics

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Reminiscing my sixty year pursuit of the physics of the Sun and the Galaxy

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Research in Astronomy and Astrophysics 2014年第1期14卷 1-14页

作者： eugene N.Parker Department of Physics Department of Astronomy and AstrophysicsUniversity of Chicago

Reminiscing begins with childhood and passes on to student days through graduate school and the first real contact with research. Then early academic posi- tions and stumbling efforts to pursue my ideas. The first significant progress came as a research associate with Prof. W. M. Elsasser at the University of Utah, beginning with an introduction to magnetohydrodynarnics and the generation of the geomagnetic field through induction in the liquid metal core of Earth. A move to the University of Chicago to work with Prof. J. A. Simpson, on the implications of cosmic ray varia- tions and interplanetary magnetic fields, led to the theory of coronal expansion and the solar wind and then to exploring the dynamical effects of cosmic rays on the galactic magnetic field. Spontaneous current sheets and intrinsic rapid reconnection in interlaced magnetic field line topologies were the next big project, leading up to retirement. finally, it is a pleasure to recall my many associates, whose fresh thinking helped stimulate the daily research activities.

关键词： dynamo -- magnetohydrodynamics -- plasma

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A practical geometrical comparison between free-repelled hydraulic jumps within inclined channels

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Science China(Technological Sciences) 2009年第11期52卷 3363-3367页

作者： John Demetriou eugene Retsinis National Technical University of Athens School of Civil Engineering. JD Research Hydrolab-A non Profit Foundation 12 Polykarpou St. N. Smymi Athens 17123 Greece National Technical University of Athens School of Civil Engineering. 23 Loid Tzortz St. Athens 11744 Greece

In this experimental study a practical geometrical comparison between inclined (angle φ) free and repelled hydraulic jumps (the latter in non prismatic but abruptly expanding channels) is presented, analysed and discussed. for repelled hydraulic jumps a considerable parameter is the expansion ratio r (=channels' width ratio), which here is changing from r =0.5 to r =0.7. The comparison is made with the free jump (in prismatic channel, r =1), in the same ranges of angles φ (0°≤φ≤8°) and froude numbers (2≤fr1≤8). A practical arithmetic example is presented to show the behavioral change of conjugate depths, lengths L and depths at 0.5L, in order to receive a comparison among all pertinent geometrical quantities. The present results may be useful for the hydraulic engineering when designing open channels.

关键词： free jumps repelled jumps inclined channels

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