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Heat and drought impact on carbon exchange in an age-sequence of temperate pine forests

Ecological Processes 2022年第1期11卷 108-125页

作者： M.Altaf Arain Bing Xu Jason J.Brodeur Myroslava Khomik Matthias Peichl Eric Beamesderfer Natalia Restrepo‑couple robin Thorne School of Earth Environment and Society and McMaster Centre for Climate ChangeMcMaster University1280 Main Street WestHamiltonON L8S 4K1Canada Department of Biological Sciences University of CalgaryAlbertaCanada Department of Geography and Environmental Management University of WaterlooWaterlooONCanada Department of Forest Ecology and Management Swedish University of Agricultural SciencesUmeåSweden School of Informatics Computingand Cyber SystemsNorthern Arizona UniversityFlagstaffAZUSA Department of Ecology and Evolutionary Biology University of ArizonaTucsonAZUSA Department of Geography Wilfrid Laurier UniversityWaterlooONCanada

Background:Most North American temperate forests are plantation or regrowth forests,which are actively *** forests are in different stages of their growth cycles and their ability to sequester atmospheric carbon is affected by extreme weather *** this study,the impact of heat and drought events on carbon sequestration in an age‑sequence(80,45,and 17 years as of 2019)of eastern white pine(Pinus strobus L.)forests in southern Ontario,canada was examined using eddy covariance flux measurements from 2003 to ***:Over the 17‑year study period,the mean annual values of net ecosystem productivity(NEP)were 180±96,538±177 and 64±165 g c m^(–2)yr^(–1)in the 80‑,45‑and 17‑year‑old stands,respectively,with the highest annual carbon sequestration rate observed in the 45‑year‑old *** found that air temperature(Ta)was the dominant control on NEP in all three different‑aged stands and drought,which was a limiting factor for both gross ecosystem productivity(GEP)and ecosystems respiration(RE),had a smaller impact on ***,the simultaneous occurrence of heat and drought events during the early growing seasons or over the consecutive years had a significant negative impact on annual NEP in all three *** observed a similar trend of NEP decline in all three stands over three consecutive years that experienced extreme weather events,with 2016 being a hot and dry,2017 being a dry,and 2018 being a hot *** youngest stand became a net source of carbon for all three of these years and the oldest stand became a small source of carbon for the first time in 2018 since observations started in ***,in 2019,all three stands reverted to annual net carbon ***:Our study results indicate that the timing,frequency and concurrent or consecutive occurrence of extreme weather events may have significant implications for carbon sequestration in temperate conifer forests in Eastern North *** study is one of few globally available t

关键词： carbon fluxes Net ecosystem productivity Ecosystem respiration Extreme weather events Drought Temperate forest White pine Eddy covariance

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Interaction of Glufosinate and colletotrichum truncatumon Ammonia Levels and Glutamine Synthetase Activity in Hemp Sesbania

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American Journal of Plant Sciences 2018年第11期9卷 2320-2337页

作者： Robert E. Hoagland c. Douglas Boyette robin H. Jordan Kenneth c. Stetina crop Production Systems Research Unit USDA-ARS Stoneville MS USA Biological control of Pests Research Unit USDA-ARS Stoneville MS USA

The use of microbes and microbial products as bioherbicides has been studied for several decades, and combinations of bioherbicides and herbicides have been examined to discover possible synergistic interactions to improve weed control efficacy. Bioassays were conducted to assess possible interactions of the herbicide glufosinate [2-amino-4-(hydroxymethylphosphinyl) butanoic acid] and colletotrichum truncatum (cT), a fungal bioherbicide to control hemp sesbania (Sesbania exaltata)]. Glufosinate acts as a glutamine synthetase (GS) inhibitor that causes elevated ammonia levels, but the mode of action of cT is unknown. GS has also been implicated in plant defense in certain plant-pathogen interactions. The effects of spray applications of glufosinate (1.0 mM) orbioherbicide (8.0 × 104 conidia ml-1), applied alone or in combination were monitored (88 h time-course) on seedling growth, GS activity and ammonia levels in hypocotyl tissues under controlled environmental conditions. Growth (elongation and fresh weight) and extractable GS activity were inhibited in tissues by glufosinate and glufosinate plus cT treatments as early as 16 h, but cT treatment did not cause substantial growth reduction or GS inhibition until after ~40 h. Generally, ammonia levels in hemp sesbania tissues under these various treatments were inversely correlated with GS activity. Localization of hemp sesbania GS activity on electrophoretic gels indicated a lack of activity after 30 h in glufosinate and glufosinate plus cT-treated tissue. Untreated control tissues contained much lower ammonia levels at 24, 64, and 88 h after treatment than treatments with cT, glufosinate or their combination. cT alone caused elevated ammonia levels only after 64 - 88 h. Glufosinate incorporated in agar at 0.25 mM to 2.0 mM, caused a 10% - 45% reduction of cT colony radial growth, compared to fungal growth on agar without glufosinate, and the herbicide also inhibited sporulation of cT. Although no synergistic interac

关键词： Bioherbicide Hemp Sesbania Glutamine Synthetase Ammonia Glufosinate colletotrichum truncatum

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Interaction of the Bioherbicide Myrothecium verrucariawith Technical-Grade Glyphosate on Glyphosate-Susceptible and -Resistant Palmer Amaranth

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American Journal of Plant Sciences 2018年第11期9卷 2306-2319页

Previously we found that a strain of Myrothecium verrucaria (MV) exhibited bioherbicidal activity against several important weeds, and that some commercial formulations of glyphosate applied with MV resulted in synergistic interactions that improved weed control efficacy. We also found that MV had bioherbicidal activity against glyphosate-resistant Palmer amaranth. We have also reported that some commercial formulations are inhibitory to MV. Our objectives were to test the effect of unformulated glyphosate (high purity, technical-grade glyphosate) alone and in combination with MV for bioherbicidal activity on glyphosate-susceptible and -resistant Palmer amaranth biotypes under greenhouse conditions and to examine technical-grade glyphosate on the growth of this bioherbicide. High purity glyphosate (without adjuvants/surfactants) was not toxic to MV growth and sporulation at concentrations up to 2.0 mM when grown on agar supplemented with the herbicide. Both biotypes were injured by MV and MV plus glyphosate treatments as early as 19 h after application (3 h after a dew period of 16 h). These injury effects increased and were more evident through the 6-day time course, when after 120 h the MV plus glyphosate treatment had killed all glyphosate-susceptible and -resistant plants. The interaction of glyphosate plus MV was synergistic toward the control of Palmer amaranth. Data strongly suggest that the active ingredient is responsible for the synergy previously found when this bioherbicide was combined with some commercial formulations of glyphosate. Results demonstrated that MV can control both glyphosate-resistant and -susceptible Palmer amaranth seedlings and act synergistically with high-purity glyphosate to provide improved weed control.

关键词： Amaranthus palmeri Biocontrol Agent Bioherbicide Biological Weed control Glyphosate-Resistance Myrothecium verrucaria Palmer Amaranth Pigweed

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激光熔覆Sic/不锈钢粉末复合涂层的组织与性能

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中国激光 2000年第10期27卷 941-946页

作者：杨永强文效忠华南理工大学机电系广州510641 香港理工大学制造工程系

用 2 k W Nd:YAG激光在 4 0 cr钢基体上制取了 Si c强化的 Fe基复合材料涂层 ,并对熔覆层进行了显微组织结构和性能测试 .加入的 Si c包括颗粒状和纤维状两种形态 ,通过调整颗粒状Si cp和纤维状 Si cf的加入量 ,研究了 Si c在激光熔覆... 详细信息

用 2 k W Nd:YAG激光在 4 0 cr钢基体上制取了 Si c强化的 Fe基复合材料涂层 ,并对熔覆层进行了显微组织结构和性能测试 .加入的 Si c包括颗粒状和纤维状两种形态 ,通过调整颗粒状Si cp和纤维状 Si cf的加入量 ,研究了 Si c在激光熔覆过程中的演变、存在形式及对熔覆层硬度的影响 .结果表明 ,随着加入量的增加 ,熔覆层中未熔 Si c含量增加 ,熔覆层硬度也随之提高 ;对比加入颗粒状和纤维状 Si c的熔覆层的显微硬度表明 ,同含量情况下纤维状 Si c的强化效果更显著 ;造成熔覆层硬度显著提高的原因是未熔 Si c,析出相 Fe Si c的弥散强化和熔入的 Si,c元素引起的固溶强化作用 .

关键词：激光熔覆复合材料涂层组织性能碳化硅不锈钢

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Impact of colorectal cancer screening participation in remote northern canada:A retrospective cohort study

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World Journal of Gastroenterology 2020年第48期26卷 7652-7663页

作者： Heather A Smith Andrew D Scarffe Nicole Brunet cait champion Kami Kandola Alisha Tessier robin Boushey craig Kuziemsky Department of Surgery University of OttawaOttawa K1Y4E9OntarioCanada Telfer School of Management University of OttawaOttawa K1N6N5OntarioCanada Faculty of Medicine University of OttawaOttawa K1Y4E9OntarioCanada Department of Surgery Northern Ontario School of MedicineSudbury P3E2C6OntarioCanada Department of Health and Social Services Government of the Northwest TerritoriesYellowknife X1A1P5Northwest TerritoriesCanada Department of Surgery Stanton Territorial Health AuthorityYellowknife X1A0H1Northwest TerritoriesCanada Division of General Surgery University of OttawaOttawa K1H 8L6OntarioCanada Office of Research Services MacEwan UniversityEdmonton T5J4S2AlbertaCanada

BAcKGROUND Screening provides earlier colorectal cancer(cRc)detection and improves *** remains poorly understood if these benefits are realized with screening guidelines in remote northern populations of canada where cRc rates are nearly twice the national average and access to colonoscopy is *** To evaluate the participation and impact of cRc screening guidelines in a remote northern *** This retrospective cohort study included residents of the Northwest Territories,a northern region of canada,age 50-74 who underwent cRc screening by a fecal immunohistochemical test(FIT)between January 1,2014 to March 30,*** assess impact,individuals with a screen-detected cRc were compared to clinically-detected cRc cases for stage and location of cRc between *** assess participation,we conducted subgroup analyses of FIT positive individuals exploring the relationships between signs and symptoms of cRc at the time of screening,wait-times for colonoscopy,and screening *** sample Welch t-test was used for normally distributed continuous variables,Mann-Whitney-Wilcoxon Tests for data without normal distribution,and chi-square goodness of fit test for categorical variables.A P value ofconsidered to be statistically *** 6817 fecal tests were completed,meaning an annual average screening rate of 25.04%,843(12.37%)were positive,629 individuals underwent a follow-up colonoscopy,of which,24.48%had advanced neoplasia(AN),5.41%had *** were no significant differences in stage,pathology,or location between screen-detected cancers and clinically-detected *** assessing participation and screening outcomes,we observed 49.51%of individuals referred for colonoscopy after FIT were ineligible for cRc screening,most often due to signs and symptoms of *** were more likely to have AN if they had signs and symptoms of cancer at the time of screening,waited over 180 d for colonoscopy,or were indigenous[

关键词： Gastroenterology Rural health services Public health colorectal neoplasms Early detection of cancer Northwest Territories

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含全碳和多炔阴离子配体的银簇化合物的超分子组装及其结构研究（英文）

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高等学校化学学报 2015年第11期36卷 2115-2133页

作者：侯俊傑胡婷譚耀新麥松威香港中文大学化学系创新多功能材料中心中国香港852 香港浸会大学化学系中国香港852 中国科学院海西研究院厦门稀土材料研究所厦门361021

总结了我们在新型炔银簇化合物研究方面的最新进展.这些化合物分为以下几种类型:(a)1,3,5-己三炔基和1,3,5,7-辛四炔基;(b)1,5-己二炔基;(c)经膦酸配体组装的乙炔基和烷基乙炔基;(d)苯乙炔基、环烷基乙炔基和含氮杂环基乙炔基结构单元... 详细信息

总结了我们在新型炔银簇化合物研究方面的最新进展.这些化合物分为以下几种类型:(a)1,3,5-己三炔基和1,3,5,7-辛四炔基;(b)1,5-己二炔基;(c)经膦酸配体组装的乙炔基和烷基乙炔基;(d)苯乙炔基、环烷基乙炔基和含氮杂环基乙炔基结构单元的银簇化合物;(e)经不同类型的银-碳配位键连接,并进一步通过分子内/分子间作用力稳固其配位网络的炔银化合物.我们还进一步讨论了溶剂、配体的位阻大小和辅助配体类型对于多维配位网络结构的影响.

关键词：全碳配体亲银作用多炔配体炔基银簇网络结构超分子合成子

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Nanoelectromechanical Sensors Based on Suspended 2D Materials

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Research 2020年第1期2020卷 1612-1636页

作者： Max c.Lemme Stefan Wagner Kangho Lee Xuge Fan Gerard J.Verbiest Sebastian Wittmann Sebastian Lukas robin J.Dolleman Frank Niklaus Herre S.Jvan der Zant Georg S.Duesberg Peter G.Steeneken chair of Electronic Devices RWTH Aachen UniversityOtto-Blumenthal-Str.252074 AachenGermany AMO GmbH Advanced Microelectronic Center Aachen(AMICA)Otto-Blumenthal-Str.2552074 AachenGermany Institute of Physics Faculty of Electrical Engineering and Information TechnologyUniversität der Bundeswehr MünchenWerner-Heisenberg-Weg 3985577 NeubibergGermany Division of Micro and Nanosystems KTH Royal Institute of TechnologyMalvinas Vag 1010044 StockholmSweden Department of Precision and Microsystems Engineering Delft University of TechnologyMekelweg 22628 CD DelftNetherlands Infineon Technologies AG Wernerwerkstraße 293049 RegensburgGermany nd Institute of Physics RWTH Aachen UniversityOtto-Blumenthal-Str.52074 AachenGermany Kavli Institute of Nanoscience Delft University of TechnologyLorentzweg 12628 CJ DelftNetherlands

The unique properties and atomic thickness of two-dimensional(2D)materials enable smaller and better nanoelectromechanical sensors with novel *** the last decade,many studies have successfully shown the feasibility of using suspended membranes of 2D materials in pressure sensors,microphones,accelerometers,and mass and gas *** this review,we explain the different sensing concepts and give an overview of the relevant material properties,fabrication routes,and device operation ***,we discuss sensor readout and integration methods and provide comparisons against the state of the art to show both the challenges and promises of 2D material-based nanoelectromechanical sensing.

关键词： Sensors enable accelerometer

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Effects of Myrothecium verrucariaon Two Glyphosate-Resistant Amaranthus palmeriBiotypes Differing in Betacyanin content

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American Journal of Plant Sciences 2020年第2期11卷 214-225页

作者： Robert E. Hoagland clyde Douglas Boyette robin H. Jordan Kenneth c. Stetina crop Production Systems Research Unit USDA-ARS Stoneville MS USA Biological control of Pests Research Unit USDA-ARS Stoneville MS USA

Previously we found two biotypes of Amaranthus palmeri (Palmer amaranth) in a population of this economically important weed that were resistant to glyphosate but differed with respect to pigmentation. One biotype was typically red-pigmented (betacyanin) while the other was green, with no visual appearance of red hue on any plant part at any growth stage. We have also reported that a strain of Myrothecium verrucaria (MV) exhibited bioherbicidal activity against several important weeds including glyphosate-resistant Palmer amaranth. In greenhouse tests, MV was applied to these two biotypes (red and green) at two ages (3-week- and 6-week-old) and effects of this fungus monitored over a 5-day time course. Initial symptoms of MV (16 to 24 h after inoculation) were: epinastic curvature, wilting and development of lesions on leaves and stems. Generally, the younger plants tended to be more sensitive to MV than older plants. Bioherbicidal damage increased with time leading to necrosis and plant mortality and increasing disease progress. Severe loss of fresh weight occurred in both biotypes as compared to untreated plants. Results indicated that MV was effective on both biotypes, but effects on growth reduction and disease progression were more rapid and generally greater in the green biotype, suggesting that compounds responsible for red pigmentation may be more potent as defense against pathogen attack.

关键词： Betalain Bioherbicide Biological Weed control Palmer Amaranth Pigweed

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考虑区域碳排放均衡性的电力系统最优阶梯碳价

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电力系统自动化 2020年第6期44卷 98-105页

作者：胡静哲王旭蒋传文丛昊电力传输与功率变换控制教育部重点实验室(上海交通大学) 上海市200240

考虑到碳排放重灾区居民的环境诉求,提出基于区域碳排放均衡性的综合指标碳排放权分配方案,以基准法分配方案和发电厂所在区域的碳排放量为标准,根据熵值法进行碳配额分配。为了研究碳价对电力系统碳排放量的影响,建立了电力系统三阶段... 详细信息

考虑到碳排放重灾区居民的环境诉求,提出基于区域碳排放均衡性的综合指标碳排放权分配方案,以基准法分配方案和发电厂所在区域的碳排放量为标准,根据熵值法进行碳配额分配。为了研究碳价对电力系统碳排放量的影响,建立了电力系统三阶段最优阶梯碳价模型。第1阶段为正常情况下的机组组合问题,第2阶段为寻找最差的N-1故障场景,第3阶段为最优阶梯碳价的求解模型,通过列与约束生成(c&cG)算法和二分法求解。算例分析表明,在减排任务较小时,阶梯碳价能够以较少的碳交易成本控制系统碳排放量;基于综合指标的碳排放权分配方案在平衡区域碳排放差异性方面效果显著。

关键词：区域碳排放量碳排放权分配方案机组组合阶梯碳价

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Bioherbicidal Efficacy of a Myrothecium verrucaria-Sector on Several Plant Species

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American Journal of Plant Sciences 2016年第16期7卷 2376-2389页

作者： Robert E. Hoagland clyde D. Boyette Kenneth c. Stetina robin H. Jordan United States Department of Agriculture-Agricultural Research Service (USDA-ARS) Crop Production Systems Research Unit Stoneville MS USA United States Department of Agriculture-Agricultural Research Service (USDA-ARS) Biological Control of Pests Research Unit Stoneville MS USA

comparative studies were conducted on mycelial preparations of the bioherbicide, Myrothecium verrucaria (MV) strain IMI 361690 and a recently discovered sector (MV-Sector BSH) of this fungus. The whitish sector was discovered, isolated, grown in pure culture on PDA and found to be a stable, non-spore producing mutant when cultured over several months under conditions that cause circadian sporulation during growth of its MV parent. Application of MV and MV-Sector BSH mycelial preparations to intact plants (hemp sesbania and sicklepod) and leaf discs (kudzu and glyphosate-resistant Palmer amaranth) showed that the sector efficacy was generally equal to, or slightly lower than MV. Bioassays of MV and this sector on seed germination and early growth of sicklepod and hemp sesbania seeds demonstrated that hemp sesbania seeds were slightly more sensitive to the fungus than sicklepod seeds and that the sector bioherbicidal activity was slightly less than that of MV. SDS-PAGE protein profiles of cellular extracts of MV and the sector and their respective culture supernatants showed several differences with respect to quantity and number of certain protein bands. Overall results showed that the isolate was a non-spore producing mutant with phytotoxicity to several weeds (including weeds tolerant or resistant to glyphosate), and that the phytotoxic effects were generally equivalent to those caused by MV treatment. Results of this first report of a non-sporulating MV mutant that suggest additional studies on protein analysis, and an extended weed host range under greenhouse and field conditions are needed in order to further evaluate its possible bioherbicidal potential.

关键词： Bioherbicide Glyphosate-Resistance Palmer Amaranth Kudzu Hemp Sesbania Sicklepod Myrothecium verrucaria Fungal Sector

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