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Promise and pitfalls of modeling grassland soil moisture in a free-air CO_(2) enrichment experiment(BioCOn)using the ShAW model

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Pedosphere 2021年第5期31卷 783-795页

作者： Raquel h.FLInKER M.Bayani CARDEnAS todd G.CALDWELL Gerald n.FLERChInGER Roy RICh Peter B.REICh Department of Geological Sciences The University of Texas at AustinAustin 78712(USA) Bureau of Economic Geology The University of Texas at AustinAustin 78713(USA) Agricultural Research Service United States Department of AgricultureBoise 83712(USA) Smithsonian Environmental Research Center Edgewater 20137(USA) Department of Forest Resources University of MinnesotaSt.Paul 55108(USA) hawkesbury Institute for the Environment Western Sydney UniversitySydney 2753(Australia)

Free-air carbon dioxide(CO_(2))enrichment(FACE)experiments provide an opportunity to test models of heat and water flow under novel,controlled situations and eventually allow use of these models for hypothesis *** study assesses whether the United States Department of Agriculture ShAW(Simultaneous heat and Water)numerical model of vertical one-dimensional soil water flow across the soil-plant-atmosphere continuum is able to adequately represent and explain the effects of increasing atmospheric CO_(2) on soil moisture dynamics in temperate *** in a FACE experiment,the Bio COn(Biodiversity,CO_(2),and nitrogen)experiment,in Minnesota,USA,were compared with results of vertical soil moisture *** scenarios represented by different plots were assessed:bare,vegetated with ambient CO_(2),and similarly vegetated with high CO_(2).From the simulations,the bare plot soil was generally the wettest,followed by a drier high-CO_(2) vegetated plot,and the ambient CO_(2) plot was the *** ShAW simulations adequately reproduced the expected behavior and showed that vegetation and atmospheric CO_(2) concentration significantly affected soil moisture *** differences in modeled soil moisture amongst the plots were largely due to transpiration,which was low with high CO_(2).however,the modeled soil moisture only modestly reproduced the ***,while ShAW is able to replicate and help broadly explain soil moisture dynamics in a FACE experiment,its application for point-and time-specific simulations of soil moisture needs further *** typical design of a FACE experiment makes the experimental observations challenging to model with a one-dimensional distributed *** addition,FACE instrumentation and monitoring will need improvement in order to be a useful platform for robust model *** after this can we recommend that models such as ShAW are adequate for process interpretation of datasets from FACE exp

关键词： carbon dioxide FACE experiment soil water flow vadose zone vegetation

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Seasonal influence and local factors affecting macroinvertebrate structure in a high-altitude Andean stream

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Journal of Mountain Science 2020年第6期17卷 1374-1386页

作者： SChEIBLER Erica E FERnánDEZ CAMPón Florencia LAGOS SILnIK Susana WELLnITZ todd Laboratorio de Entomologia IADIZACCT CONICET MendozaAvenida Ruiz Leal s/nParque Gral.San MartinCC 5075500MendozaArgentina Consejo nacional de Investigaciones Cientificas y Tecnicas(COnICET) Avenida Rivadavia 1917C1033AAJCABAArgentina Facultad de Ciencias Exactas y naturales Universidad Nacional de CuyoPadre Jorge Contreras 1300M5502JMA MendozaArgentina Biology Department University o f Wisconsin-Eau Claire105 Garfield Avenue54701Eau ClaireWisconsinUSA

Small water bodies are critical for maintaining freshwater biodiversity,but are among the least investigated aquatic *** examined physical and chemical variables at two reaches in Arroyo Tambillos,a small,high-elevation Andean stream,in nW Mendoza province,Argentina,across four seasons to examine how local factors and seasonality affected the structure of the macroinvertebrate *** Arroyo Tambillos community was numerically dominated by ephemeropterans(mainly Massartellopsis irarrazavali)while the dipteran Chironomidae were the most species *** macroinvertebrate abundance was highest in summer,driven mainly by taxa that were secondary in dominance(Austrelmis *** Andesiops peruvianus),while richness did not differ between ***,benthic composition was different in Fall 2013(March)compared to other seasons,largely because of the increased abundance of *** correspondence analysis discriminated Chironomidae species distributions in Fall 2013 by substrate type(i.e.,big and small boulder substrate).By contrast,discharge,velocity,and depth were the variables which most affected the macroinvertebrate abundance and *** to our expectations,most community changes observed occurred in fall instead of ***-kryal stream communities like the one described here have become increasingly important for conserving mountain stream biodiversity as anthropogentic impacts and climate change increasingly impact lower stream ***,monitoring high-altitude streams like the Arroyo Tambillos may be critical for preventing the future loss of unique and sensitive stream biota.

关键词： Ephemeroptera dominance Chironomidae richness Mountain small stream Physical variables Biodiversity Ecosystem

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Upper bounds on a two-term exponential sum

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Science China Mathematics 2001年第8期44卷 1003-1015页

作者： todd COChRAnE 郑志勇 Department of Mathematics Kansas State University Manhattan KS 66506 USA Department of Mathematics Tsinghua University Beijing 100084 China

We obtain upper bounds for mixed exponential sums of the type $S(\chi ,f,p^m ) = \sum\nolimits_{x = 1}^{p^n } {\chi (x)e} _{p^m } (ax^n + bx)$ where pm is a prime power with m? 2 and X is a multiplicative character (mod pm). If X is primitive or p?(a, b) then we obtain |S(χ,f,p m)| ?2np 2/3 m . If X is of conductor p and p?( a, b) then we get the stronger bound |S(χ,f,p m)|?np m/2.

关键词： exponential sums primitive character weil’sbound

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Environmental Stresses Modulate Abundance and Timing of Alternatively Spliced Circadian Transcripts in Arabidopsis

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Molecular Plant 2015年第2期8卷 207-227页

作者： Sergei A. Filichkin Jason S. Cumbie Palitha Dharmawardhana Pankaj Jaiswal Jeff h. Chang Saiprasad G. Palusa A.S.n. Reddy Molly Megraw todd C. Mockler Department of Botany and Plant Pathology Oregon State University Corvallis OR 97331 USA Center for Genome Research and Biocomputing Oregon State University Corvallis OR 97331 USA Department of Biology and Program in Molecular Plant Biology Colorado State University Fort Collins CO 80523 USA Donald Danforth Plant Science Center Saint Louis MO 63132 USA Co-corresponding author

Environmental stresses profoundly altered accumulation of nonsense mRnAs including intron-retaining （IR） transcripts in Arabidopsis. Temporal patterns of stress-induced IR mRnAs were dissected using both oscillating and non-oscillating transcripts. Broad-range thermal cycles triggered a sharp increase in the long IR CCA1 isoforms and altered their phasing to different times of day. Both abiotic and biotic stresses such as drought or Pseudomonas syringae infection induced a similar increase. Thermal stress induced a time delay in accumulation of CCA1 14Rb transcripts, whereas functional mRnA showed steady oscillations. Our data favor a hypothesis that stress-induced instabilities of the central oscillator can be in part compensated through fluctuations in abundance and out-of-phase oscillations of CCA1 IR transcripts. Taken together, our results support a concept that mRnA abundance can be modulated through altering ratios between functional and nonsense/IR transcripts. SR45 protein specifically bound to the retained CCA1 intron in vitro, suggesting that this sp!icing factor could be involved in regulation of intron retention. Transcriptomes of nonsense-mediated mRnA decay （nMD）-impaired and heat-stressed plants shared a set of retained introns associated with stress- and defense-inducible transcripts. Constitutive activation of certain stress response networks in an nMD mutant could be linked to disequilibrium between functional and nonsense mRnAs.

关键词： Arabidopsis alternative splicing circadian clock intron retention nonsense-mediated mRnA decay(nMD) environmental stress

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Unraveling biochar surface area on structure and heavy metal removal performances of carbothermal reduced nanoscale zero-valent iron

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Journal of Bioresources and Bioproducts 2023年第4期8卷 388-398页

作者： Tharindu n.Karunaratne Prashan M.Rodrigo Daniel O.Oguntuyi todd E.Mlsna Jilei Zhang Xuefeng Zhang Department of Sustainable Bioproducts Mississippi State UniversityMississippi StateMS 39762USA Department of Chemistry Mississippi State UniversityMississippi StateMS 39762USA

Carbothermal reduction using biochar(BC)is a green and effective method of synthesizing BCsupported nanoscale zero-valent iron(nanoFe^(0))***,the effect of BC surface area on the structure,distribution,and performance such as the heavy metal uptake capacity of nanoFe^(0)particles remains *** stover-based BCs with different surface areas(1.7−1472 m^(2)/g)were prepared in this *** have been used for in-situ synthesis BCs-supported nanoFe^(0)particlesthrough carbothermal reduction of ferrous *** BCs-supported nanoFe^(0)particles were found to be covered with graphene shells and dispersed onto BC surfaces,forming the BC-supported graphene-encapsulated nanoFe^(0)(BC-G@Fe^(0))*** graphene shells covering the nanoFe^(0)particles were formed because of gaseous carbon evolved from biomass carbonization reacting with iron oxides/iron *** BC surface area decreased the average diameters of nanoFe^(0)particles,indicating a higher BC surface area alleviated the aggregation of nanoFe^(0)particles,which resulted in higher heavy metal uptake *** the optimized condition,BC-G@Fe^(0)composite exhibited uptake capacities of 124.4,121.8,254.5,and 48.0 mg/g for Cu^(2+),Pb^(2+),Ag^(+),and As^(3+),respectively(ph 5,25℃).Moreover,the BC-G@Fe^(0)composite also demonstrated high stability for Cu^(2+)removal from the fixed-bed continuous flow,in which 1 g of BC-G@Fe^(0)can work for 120 h in a 4 mg/L Cu^(2+)flow continually and clean 28.6 L Cu^(2+)contaminated ***,the BC-G@Fe^(0)composite can effectively immobilize the bioavailable As^(3+)from the contaminated soil,i.e.,5%(w)of BC-G@Fe^(0)composite addition can immobilize up to 92.2%bioavailable As^(3+)from the contaminated soil.

关键词： Carbothermal reduction nanoscale zero-valent iron heavy metal Fix-bed sorption Soil remediation

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Radiogenic Source Identification for the helium Production-Diffusion Equation

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Communications in Computational Physics 2013年第6期14卷 1-20页

作者： Gang Bao todd A.Ehlers Peijun Li Department of Mathematics Zhejiang UniversityHangzhou 310027China Department of Mathematics Michigan State UniversityEast LansingMI 48824USA Department of Geosciences Wilhelmstrasse 56Universitat TubingenD-72074TubingenGermany Department of Mathematics Purdue UniversityWest LafayetteIN 47907USA

Knowledge of helium diffusion kinetics is critical for materials in which helium measurements are made,particulary for *** most cases the helium ages were younger than expected,an observation attributes to diffusive loss of helium and the ejection of high energy alpha *** it is important to accurately calculate the distribution of the source term within a *** this paper,the prediction of the helium concentrations as function of a spatially variable source term are *** the forward and inverse solutions are *** the assumption of radially symmetric geometry,an analytical solution is deduced based on the eigenfunction *** regularization methods,the Tikhonov regularization and the spectral cutoff regularization,are considered to obtain the regularized *** estimates with optimal convergence order are shown between the exact solution and the regularized *** examples are presented to illustrate the validity and effectiveness of the proposed methods.

关键词： Inverse source problem production-diffusion equation Tikhonov regularization

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A meta-analytic review of Elliot's (1999) hierarchical Model of Approach and Avoidance Motivation in the sport, physical activity, and physical education literature

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Journal of Sport and health Science 2017年第1期6卷 68-80页

作者： Marc Lochbaum Javan Jean-noel Colleen Pinar todd Gilson Department of health Exercise and Sport Sciences Texas Tech University Department of Kinesiology Northern Illinois University

Purpose: The purpose of this quantitative review was to summarize the state of Elliot's hierarchical Model of Approach and Avoidance Motivation, specifically the antecedents of the 2 × 2 achievement goals in the sport, physical activity, and physical education literature. In addition,the intercorrelations amongst the 2 × 2 goals were also ***: A systematic review of the literature was conducted. Meta-analytic procedures were used with the mean weighted sample correlation(rw) as the effect size metric. The antecedents were coded by Elliot's(1999) antecedent categories. A number of moderators were coded a ***: Based on a fixed effects model from 47 published studies(total unique n = 15,413) that met inclusion criteria, the 2 × 2 achievement goals were significantly correlated amongst each other ranging from small to medium to large in meaningfulness. Concerning the antecedents, overall they were theoretically correct in associations, but only a few of the relationships were medium in meaningfulness. Most relationships were small in meaningfulness. heterogeneity was present for the interrcorrelation and antecedent ***: Future research is encouraged to grow and enrich the understanding of achievement goals within Elliot's complete hierarchical Model of Approach and Avoidance Motivation to include both antecedents and outcomes simultaneously to improve upon the understanding of achievement motivation in sport, exercise, and physical activity settings.

关键词： Achievement motivation Antecedents Competence Mastery goals Meta-analysis Performance goals

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Synthesis and Characterization of Bionanoparticle-Silica Composites and Mesoporous Silica with Large Pores

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nano Research 2009年第6期2卷 474-483页

作者： Zhongwei niu Saswat Kabisatpathy Jinbo he LAndrew Lee Jianhua Rong Lin Yang Godfrey Sikha Branko n.Popov todd S.Emrick Thomas P.Russell Qian Wang Department of Chemistry and Biochemistry and nanocenter University of South CarolinaColumbiaSC 29208USA Department of Polymer Science and Engineering University of MassachusettsAmherstMA 01003USA Brookhaven national Laboratory UptonNY 11973USA Department of Chemical Engineering University of South CarolinaColumbiaSC 29208USA

A sol-gel process has been developed to incorporate bionanoparticles,such as turnip yellow mosaic virus,cowpea mosaic virus,tobacco mosaic virus,and ferritin into silica,while maintaining the integrity and morphology of the *** structures of the resulting materials were characterized by transmission electron microscopy,small angle X-ray scattering,and n2 adsorption desorption *** results show that the shape and surface morphology of the bionanoparticles are largely preserved after being embedded into *** removal of the bionanoparticles by calcination,mesoporous silica with monodisperse pores,having the shape and surface morphology of the bionanoparticles replicated inside the silica,was produced,.This study is expected to lead to both functional composite materials and mesoporous silica with structurally well-defi ned large pores.

关键词： Mesoporous silica bionanoparticles virus ferritin sol gel

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Analysis of trace dicyandiamide in stream water using solid phase extraction and liquid chromatography UV spectrometry

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Journal of Environmental Sciences 2015年第9期27卷 38-42页

作者： huidong Qiu Dongdi Sun Sameera R.Gunatilake Jinyan She todd E.Mlsna Department of Chemistry and Chemical Engineering Chongqing University of Science and Technology Department of Chemistry Mississippi State University

An improved method for trace level quantification of dicyandiamide in stream water has been developed. This method includes sample pretreatment using solid phase *** extraction procedure（including loading, washing, and eluting） used a flow rate of1.0 m L/min, and dicyandiamide was eluted with 20 m L of a methanol/acetonitrile mixture（V/V = 2：3）, followed by pre-concentration using nitrogen evaporation and analysis with high performance liquid chromatography–ultraviolet spectroscopy（hPLC–UV）. Sample extraction was carried out using a Waters Sep-Pak AC-2 Cartridge（with activated carbon）.Separation was achieved on a ZIC-hydrophilic Interaction Liquid Chromatography（ZIC-hILIC）（50 mm × 2.1 mm, 3.5 μm） chromatography column and quantification was accomplished based on UV absorbance. A reliable linear relationship was obtained for the calibration curve using standard solutions（R^2〉 0.999）. Recoveries for dicyandiamide ranged from 84.6% to 96.8%, and the relative standard deviations（RSDs, n = 3） were below 6.1% with a detection limit of 5.0 ng/m L for stream water samples.

关键词： Dicyandiamide Solid phase extraction Stream water samples high performance liquid chromatography–ultraviolet spectrometry

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The acceleration of a high-charge electron bunch to 10 GeV in a 10-cm nanoparticle-assisted wakefield accelerator

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Matter and Radiation at Extremes 2024年第1期9卷 15-24页

作者： Constantin Aniculaesei Thanh ha Samuel Yoffe Lance Labun Stephen Milton Edward McCary Michael M.Spinks hernan J.Quevedo Ou Z.Labun Ritwik Sain Andrea hannasch Rafal Zgadzaj Isabella Pagano Jose A.Franco-Altamirano Martin L.Ringuette Erhart Gaul Scott V.Luedtke Ganesh Tiwari Bernhard Ersfeld Enrico Brunetti hartmut Ruhl todd Ditmire Sandra Bruce Michael E.Donovan Michael C.Downer Dino A.Jaroszynski Bjorn Manuel hegelich University of Texas at Austin AustinTexas 78712USA SUPA Department of Physics University of StrathclydeGlasgowScotland G4 ONGUnited Kingdom Tau Systems Inc.AustinTexas 78701USA Lawrence Livermore national Laboratory LivermoreCalifornia 94550USA Los Alamos national Laboratory Los AlamosNew Mexico 87545USA Brookhaven national Laboratory UptonNew York 11973USA Ludwig-Maximilians-Universität MunichGermany

An intense laser pulse focused onto a plasma can excite nonlinear plasma *** appropriate conditions,electrons from the background plasma are trapped in the plasma wave and accelerated to ultra-relativistic *** scheme is called a laser wakefield *** this work,we present results from a laser wakefield acceleration experiment using a petawatt-class laser to excite the wakefields as well as nanoparticles to assist the injection of electrons into the accelerating phase of the *** find that a 10-cm-long,nanoparticle-assisted laser wakefield accelerator can generate 340 pC,10±1.86 GeV electron bunches with a 3.4 GeV rms convolved energy spread and a 0.9 mrad rms *** can also produce bunches with lower energies in the 4–6 GeV range.

关键词： acceleration nanoparticle charge

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