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Occupancy of avian foraging guilds in soybean fields and borders in Entre Ríos, Argentina: responses to vegetation structure and prey resources

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Avian Research 2020年第4期11卷 398-411页

作者： Andrea P.Goijman Michael J.Conroy Vanina D.Varni Jeffrey J.Thompson María Elena Zaccagnini Instituto de Recursos Biológicos CIRNInstituto Nacional de Tecnología Agropecuaria(CNIA-INTA)HurlinghamBuenos AiresArgentina D.B.Warnell School of Forestry and Natural Resources University of GeorgiaAthensGA 30602USA present address:Athens GAUSA present address:Laboratorio de Genómica Ecológica y Evolutiva IrapuatoGtoMéxico present address:Guyra Paraguay-CONACYT Av.Cnel.Carlos BóvedaParque Ecológico Capital-Viñas CuéAsunciónParaguay present address:Instituto Saite AsunciónParaguay present address:The Ronin Institute MontclairNJUSA present address:Instituto Nacional de Tecnología Agropecuaria(INTA) CABAArgentina

Background:Reconciling agriculture and biodiversity conservation is a challenge given the growing demand for agricultural *** recent decades,Argentina has witnessed agricultural expansion and intensification affecting biodiversity and associated ecosystem *** agroecosystems,the level of habitat quality is critical for birds,and may depend on vegetation structure,availability of invertebrate prey,and the use of *** the relationship between vegetation structure and avian occurrence has been widely studied,to our knowledge,there are no studies that also incorporate prey availability throughout the cycle of soybean crops in *** estimated and predicted the effects of land cover and temporal variation on the occurrence of avian foraging guilds in Entre Ríos,Argentina,in order to guide management related to potential ecosystem services provided by *** also estimated temporal effects of vegetation structure and insecticides on the main arthropod orders consumed by birds to evaluate prey ***:We conducted bird and arthropod surveys for 2 years along transects located in 20 randomly selected soybean fields(N=60)and their adjacent borders(N=78)throughout the crop growing season,in four *** estimated avian occupancy,accounting for imperfect detection,and arthropod counts fitting generalized linear mixed ***:The number of native trees in field borders positively influenced the occurrence of most bird species,mainly *** foliage gleaners,also were positively affected by grass *** and aerial foragers were weakly affected by distance to forest and native *** general,the availability of invertebrates to birds was highest during the third *** counts in borders were greater during the last three crop stages than during the pre-sowing ***:We found that with 10 to 15 native tree species in borders,coupled with a complex vegetation structure w

关键词： Agriculture Birds Ecosystem services Insecticide Insectivores Invertebrates Management Native trees Occurrence

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Electronic properties of wurtzite GaAs： A correlated structural, optical, and theoretical analysis of the same polytypic GaAs nanowire

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Nano Research 2018年第9期11卷 4708-4721页

作者： Alexander Senichev Pierre Corfdir Oliver Brandt Manfred Ramsteiner Steffen Breuer Jorg Schilling Lutz Geelhaar Peter Werner Max-Planck-lnstitut fur Mikrostrukturl)hysik Halle 06120 Germany PauI-Drude-lnstitut for Festkorperelektronik Berlin 10117 Germany Centre for Innovation Competence SiLi-nano Martin-Luther-Universitat Halle 06120 Germany present address: Birck Nanotechnology Center Purdue University West Lafayette Indiana 47907 USA present address: Fraunhofer HHI Berlin 10587 Germany present address: ABB Corporate Research Baden-Dattwi15405 Switzerland

III-V compound semiconductor nanowires are generally characterized by the coexistence of zincblende and wurtzite structures. So far, this polytypism has impeded the determination of the electronic properties of the metastable wurtzite phase of GaAs, which thus remain highly controversial. In an effort to obtain new insights into this topic, we cross-correlate nanoscale spectral imaging by near-field scanning optical microscopy with a transmission electron microscopy analysis of the very same polytypic GaAs nanowire dispersed onto a Si wafer. Thus, spatially resolved photoluminescence spectra could be unambiguously assigned to nanowire segments whose structure is known with lattice-resolved accuracy. An emission energy of 1.528 eV was observed from extended zincblende segments, revealing that the dispersed nanowire was under uniaxial strain presumably due to interaction with its supporting substrate. These crucial information and the emission energy obtained for extended pure wurtzite segments were used to perform envelope function calculations of zincblende quantum disks in a wurtzite matrix as well as the inverse structure. In these calculations, we varied the fundamental bandgap, the electron mass, and the band offset between zincblende and wurtzite GaAs. From this multi-parameter comparison with the experimental data, we deduced that the bandgap between the F8 conduction and A valence band ranges from 1.532 to 1.539 eV in strain-free wurtzite GaAs, and estimated values of 1.507 to 1.514 eV for the F7-A bandgap.

关键词： nanowires crystal-phase quantumstructures wurtzite GaAs strain near-field scanning optical microscopy photoluminescence

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In Situ TEM Observation of the Gasification and Growth of Carbon Nanotubes Using Iron Catalysts

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Nano Research 2011年第8期4卷 767-779页

作者： Xiaofeng Feng See Wee Chee Renu Sharma Kai Liu Xu Xie Qunqing Li Shoushan Fan Kaili Jiang Department of Physics and Tsinghua-Foxconn Nanotechnology Research Center Tsinghua University Beijing 100084 China Leroy Eyring Center for Solid State Science Arizona State University Tempe AZ 85287 USA present address： Department of Materials Science and Engineering University of California Berkeley CA 94720 USA present address： Department of Materials Science and Engineerig Rensselaer Polytechnic Institute Troy NY 12180 USA present address： National Institute of Science and Technology Gaithersburg MD 20899 USA present address： Department of Materials Science and Engineering University of Illinois at Urbana-Champaign Urbana IL 61801 USA

We report the in situ transmission electron microscope (TEM) observation of the catalytic gasification and growth of carbon nanotubes (CNTs). It was found that iron catalysts can consume the CNTs when pumping out the precursor gas, acetylene, at the growth temperature, and reinitiate the growth when acetylene is re-introduced. The switching between gasification and growth of CNTs can be repeated many times with the same catalyst. To understand the phenomenon, thermogravimetric analysis (TGA) coupled with mass spectroscopy was used to study the mechanism involved. It was shown that the residual water molecules in the growth chamber of the TEM react with and remove carbon atoms of CNTs as carbon monoxide vapor under the action of the catalyst, when the precursor gas is pumped out. This result contributes to a better understanding of the water-assisted and oxygen-assisted synthesis of CNT arrays, and provides useful clues on how to extend the lifetime and improve the activity of the catalysts.

关键词： Carbon nanotubes gasification growth iron catalyst environmental transmission electron microscopy (ETEM),thermogravimetric analysis (TGA)

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Single photon emission and recombination dynamics in self-assembled GaN/AlN quantum dots

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Light(Science & Applications) 2022年第5期11卷 751-765页

作者： Johann Stachurski Sebastian Tamariz Gordon Callsen Raphaël Butté Nicolas Grandjean Institute of Physics École Polytechnique Fédérale de LausanneEPFLCH-1015 LausanneSwitzerland present address:UniversitéCôte d’Azur CNRSCRHEAF-06560 ValbonneFrance present address:Institut für Festkörperphysik Universität Bremen28359 BremenGermany

Ⅲ-nitride quantum dots(QDs)are a promising system actively studied for their ability to maintain single photon emission up to room ***,we report on the evolution of the emission properties of self-assembled GaN/AlN QDs for temperatures ranging from 5 to 300 *** carefully track the photoluminescence of a single QD and measure an optimum single photon purity of g^((2))(0)=0.05±0.02 at 5 K and 0.17±0.08 at 300 *** complement this study with temperature dependent time-resolved photoluminescence measurements(TRPL)performed on a QD ensemble to further investigate the exciton recombination dynamics of such polar zero-dimensional *** comparing our results to past reports,we emphasize the complexity of recombination processes in this *** of the more conventional mono-exponential decay typical of exciton recombination,TRPL transients display a bi-exponential feature with short-and long-lived components that persist in the low excitation *** the temperature insensitivity of the long-lived excitonic component,we first discard the interplay of dark-to-bright state refilling in the exciton recombination ***,this temperature-invariance also highlights the absence of nonradiative exciton recombinations,a likely direct consequence of the strong carrier confinement observed in GaN/AlN QDs up to 300 ***,our results support the viability of these dots as a potential single-photon source for quantum applications at room temperature.

关键词： temperature. process. quantum

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FAST W TRANSFORM——ALGORITHMS AND PROGRAMS

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Science China Mathematics 1989年第3期32卷 338-350页

作者：王中德 Beijing University of Posts & Telecommunications present address:Beijing University of Posts & Telecommunications.

The W transform is an approach to spectrum analysis in real domain. There are fourcommonly used types of the discrete W transform (DWT), all of which may be appliedto digital signal processing. In this paper, new fast algorithms for computing the fourtypes of the DWT are introduced. These algorithms are simple in structure and moreefficient than any other algorithms for the DWT. FORTRAN subroutines to realize thesealgorithms have been provided.

关键词： fast algorithm W transform spectral analysis.

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SINGLE CRYSTAL HARDENING——MECHANISMS AND DESCRIPTION

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Acta Mechanica Sinica 1995年第2期11卷 162-167页

作者：孙守光黄克智 present address: Department of Mechanical Engineering Northern Jiaotong UniversityBeijing China 100044 Department of Engineering Mechanics Tsinghua University Beijing China 100084

Various work hardening mechanisms, on the basis of their characteristics, are classified into two categories: the pile-up hardening and the tangle hardening. Together with a discussion about the experimental investigations of work hardening, the descriptions for those two basic hardening mechanisms are suggested, respectively. Combining these descriptions, a new single crystal hardening law is proposed, which can be used to describe work hardening, particularly the cyclic hardening of a crystal grain in a polycrystalline material. Furthermore, some relevant discussion on the new single crystal hardening law is also made in this paper.

关键词： CRYSTAL PLASTICITY SINGLE CRYSTAL HARDENING CYCLIC HARDENING

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THE DELAY OF TRANSITION OF A LAMINAR BOUNDARY LAYER OVER COMPLIANT WALL

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Acta Mechanica Sinica 1990年第1期6卷 15-21页

作者： Li Wanping Zhou Heng Tianjin University present address:Department of Mechanics Huazhong University of Science and TechnologyWuhan 430074

In a previous paper, a method has been developed to study the stability characteristics of laminar boundary layers over compliant walls. In this paper, the effect of double layered compliant wall and Kramer type compliant wall on delaying the transition is investigated, and it is shown that there does exist the possibility to de- lay the transition by applying such compliant walls.

关键词： transition compliant wall stability

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Blocking the Metabolism of Starch Breakdown Products in Arabidopsis Leaves Triggers Chloroplast Degradation

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Molecular Plant 2009年第6期2卷 1233-1246页

作者： Michaela Stettler Simona Eicke Tabea Mettler Gaelle Messerli Stefan Hortensteiner Samuel C. Zeeman Department of Biology ETH Zurich CH-8092 Zurich Switzerland Institute of Plant Biology University of Zurich CH-8008 Zurich Switzerland present address: Max Planck Institute for Molecular Plant Physiology Potsdam-Golm 14476 Germany present address: Johnson & Johnson Medical CH-8957 Spreitenbach Switzerland

In most plants, a large fraction of photo-assimilated carbon is stored in the chloroplasts during the day as starch and remobilized during the subsequent night to support metabolism. Mutations blocking either starch synthesis or starch breakdown in Arabidopsis thaliana reduce plant growth. Maltose is the major product of starch breakdown exported from the chloroplast at night. The maltose excess 1 mutant （mex1）, which lacks the chloroplast envelope maltose transporter, accumulates high levels of maltose and starch in chloroplasts and develops a distinctive but previously unexplained chlorotic phenotype as leaves mature. The introduction of additional mutations that prevent starch synthesis, or that block maltose production from starch, also prevent chlorosis of mex1. In contrast, introduction of mutations in disproportionating enzyme （DPE1） results in the accumulation of maltotriose in addition to maltose, and greatly increases chlorosis. These data suggest a link between maltose accumulation and chloroplast homeostasis. Microscopic analyses show that the mesophyll cells in chlorotic mex1 leaves have fewer than half the number of chloroplasts than wild-type cells. Transmission electron microscopy reveals autophagy-like chloroplast degradation in both mex1 and the dpe1/mex1 double mutant. Microarray analyses reveal substantial reprogramming of metabolic and cellular processes, suggesting that organellar protein turnover is increased in mex1, though leaf senescence and senescence-related chlorophyll catabolism are not induced. We propose that the accumulation of maltose and malto-oligosaccharides causes chloroplast dysfunction, which may by signaled via a form of retrograde signaling and trigger chloroplast degradation.

关键词： Carbohydrate metabolism photosynthesis senescence chloroplast biology Arabidopsis autophagy.

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Sequence-Independent Identification of Active LTR Retrotransposons in Arabidopsis

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Molecular Plant 2018年第3期11卷 508-511页

作者： Jayne,Griffiths Marco,Catoni Mayumi,Iwasaki Jerzy,Paszkowski The Sainsbury Laboratory University of Cambridge Cambridge UK [∗]Corresponding author present address: University of Geneva Geneva Switzerland

Dear Editor,LTR retrotransposons （LTR-TEs） are mobile genetic elements that often comprise a large portion of the host genome and are particularly abundant in genomes of plants （Lisch, 2013）. They transpose through an RNA transcript that is reverse transcribed to an extrachromosomal DNA （ecDNA） of the original element that can insert at a new genomic location （Wicker et al., 2007）.

关键词： Arabidopsis LTR 鉴定人染色体 DNA RNA 元素植物

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Autoionizing Process of the Double Rydberg State

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Chinese Physics Letters 1995年第12期12卷 713-716页

作者： XU Chengbin XU Xiangyuan HUANG Wen XUE Ping ZHAO Runchuan ZHU Cheng CHEN Dieyan Department of Modern Applied Physics Tsinghua UniversityBeijing 100084 present address:Institute of Physics Academia SinicaBeijing 100080

Using five-laser resonance excitation and double time-of-flight spectroscopy,the double Rydberg states NLnl(N≤66;n≤85;L,1<4)of Ca have been *** distribution of Ca^(+)Rydberg states,which is from the autoionization o... 详细信息

关键词： Rydberg double excitation

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