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Stand structure and height-diameter relationship of a degraded Populus euphratica forest in the lower reaches of the Tarim River, Northwest China

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Journal of Arid Land 2015年第4期7卷 544-554页

作者： AISHAN Tayierjiang HALIK ümüt florian BETZ TIYIP Tashpolat DING Jianli NUERMAIMAITI Yiliyasijiang Key Laboratory of Oasis Ecology College of Resource & Environmental Sciences Xinjiang University Faculty of Geography and Mathematics Catholic University of Eichstaett-Ingolstadt

Understanding stand structure and height-diameter relationship of trees provides very useful information to establish appropriate countermeasures for sustainable management of endangered forests. Populus euphratica, a dominant tree species along the Tarim River watershed, plays an irreplaceable role in the sustainable development of regional ecology, economy and society. However, as the result of climate changes and human activities, the natural riparian ecosystems within the whole river basin were degraded enormously, particularly in the lower reaches of the river where about 320 km of the riparian forests were either highly degraded or dead. In this study, we presented one of the main criteria for the assessment of vitality of P. euphrafica forests by estimating the defoliation level, and analyzed forest structure and determined the height-diameter （height means the height of a tree and diameter means the diameter at breast height （DBH） of a tree） relationship of trees in different vitality classes （i.e. healthy, good, medium, senesced, dying, dead and fallen）. Trees classified as healthy and good ac- counted for approximately 40% of all sample trees, while slightly and highly degraded trees took up nearly 60% of total sample trees. The values of TH （tree height） and DBH ranged from 0-19 m and 0-125 cm, respectively. Trees more than 15 m in TH and 60 cm in DBH appeared sporadically. Trees in different vitality classes had different distribution patterns. Healthy trees were mainly composed more of relatively younger trees than of degraded tress. The height-diameter relationships differed greatly among tress in different vitality classes, with the coefficients ranging from 0.1653 to 0.6942. Correlation coefficients of TH and DBH in healthy and good trees were higher than those in trees of other vitality classes. The correlation between TH and DBH decreased with the decline of tree vitality. Our results suggested that it might be able to differentiate degraded P. eup

关键词： stand structure height-diameter relationship Populus euphratica tree vitality Tarim River

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Helium droplet assisted synthesis of plasmonic Ag@ZnO core@shell nanoparticles

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Nano Research 2020年第11期13卷 2979-2986页

作者： Alexander Schiffmann Thomas Jauk Daniel Knez Harald Fitzek Ferdinand Hofer florian Lackner Wolfgang E.Ernst Institute of Experimental Physics Graz University of TechnologyA-8010GrazAustria Institute of Electron Microscopy and Nanoanalysis&Graz Centre for Electron Microscopy Graz University of TechnologyA-8010GrazAustria

Plasmonic Ag@ZnO core@shell nanoparticles are formed by synthesis inside helium droplets with subsequent deposition and controlled *** particle size and shape can be controlled from spherical sub-10 nm particles to larger elongated *** advantage of the method is the complete absence of solvents,precursors,and other chemical *** obtained particle morphology and elemental composition have been analyzed by scanning transmission electron microscopy(STEM)and energy dispersive X-ray spectroscopy(EDS).The results reveal that the produced particles form a closed and homogeneous ZnO layer around a 2–3 nm Ag core with a uniform thickness of(1.33±0.15)nm and(1.63±0.31)nm for spherical and wire-like particles,*** results are supported by ultraviolet photoelectron spectroscopy(UPS),which indicates a fully oxidized shell layer for the particles studied by *** plasmonic properties of the produced spherical Ag@ZnO core@shell particles are investigated by two-photon photoelectron(2PPE)*** excitation of the localized surface plasmon resonance in Ag at around 3 eV,plasmonic enhancement leads to the liberation of electrons with high kinetic *** is observed for both Ag and Ag@ZnO particles,showing that even if a Ag cluster is covered by the ZnO layer,a plasmonic enhancement can be observed by photoelectron spectroscopy.

关键词： nanoparticle helium droplet plasmonics photoelectrons

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Deformation and phase transformation behaviors of a high Nb-containing TiAl alloy compressed at intermediate temperatures

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Journal of Materials Science & Technology 2022年第7期102卷 89-96页

作者： Xu Liu Lin Song Andreas Stark Uwe Lorenz Zhanbing He Junpin Lin florian Pyczak Tiebang Zhang State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China Institute of Materials Research Helmholtz-Zentrum GeesthachtMax Planck-Str.1Geesthacht 21502Germany State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China

In modernβ-solidified TiAl alloys,the decomposition of α_(2) phase is frequently observed during heat treatment or high-temperature deformation of the *** this study,high-temperature deformation and decomposition mechanisms of α_(2) phase in a Ti-45Al-8.5Nb-0.2B-0.2W-0.02Y alloy are *** a sample deformed at 800℃,the precipitation ofβ_(o)(ω_(o))phase is observed within the equiaxed α_(2) *** nucleation ofω_(o) particles within theβ_(o) matrix indicates the α_(2)→β_(o)→ω_(o) *** addition,numerous y phase precipitates form within theβ_(o)(ω)*** α_(2) lamellae decompose into ultrafine( α_(2)+γ)lamellae and coarsened y lamellae via α_(2)→ α_(2)+γand α_(2)→γtransformation,***,theω_(o) phase nucleates within the ultrafine lamellae via α_(2)→ω_(o) ***,in a sample deformed at 1000℃,the nucleation ofβ_(o) particles is sluggish,which is caused by the efficient release of the internal stress via dynamic recrystallization(DRX).These results indicate that complex phase transformations can be introduced by the decomposition of α_(2) phase in TiAl alloys with a high amount ofβ-stabilizing elements.

关键词： TiAl alloys Phase transformation Microstructure Electron microscopy

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Influence of High-Speed Milling Process on Mechanical and Microstructural Properties of Ultrafine Grained Profiles Produced by Linear Flow Splitting

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Transactions of Nanjing University of Aeronautics and Astronautics 2017年第4期34卷 349-356页

作者： Abele Eberhard Müller Clemens Turan Emrah Niehuesbernd Joern Bruder Enrico Falk florian Institute of Production Management Technology and Machine Tools(PTW)Technische Universitt Darmstadt Physical Metallurgy(PhM) Technische Universitt Darmstadt

The effects of milling parameters on the surface quality,microstructures and mechanical properties of machined parts with ultrafine grained(UFG)gradient microstructures are *** effects of the cutting speed,feed per tooth,cutting tool geometry and cooling strategy are *** has been found that the surface quality of machined grooves can be improved by increasing the cutting ***,cryogenic cooling with CO_2 exhibits no significant improvement of surface *** and hardness investigations revealed similar microstructure and hardness variations near the machined groove walls for both utilized tool ***,cryogenic cooling can decrease more far-ranging hardness reductions due to high process temperatures,especially in the UFG regions of the machined parts,whilst it cannot prevent the drop in hardness directly at the groove walls.

关键词： high-speed milling ultrafine grained microstructure linear flow splitting hardness

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Smoking increases the risk of extraintestinal manifestations in Crohn's disease

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World Journal of Gastroenterology 2014年第34期20卷 12269-12276页

作者： Claudia Ott Angela Takses florian Obermeier Elisabeth Schnoy Martina Müller Department of Internal Medicine I University of Regensburg93042 RegensburgGermany

AIM:To demonstrate a high prevalence of extraintestinal manifestations(EIMs)in a prospective populationbased cohort of inflammatory bowel disease(IBD)patients at first diagnosis as well as during the early course of the ***:EIMs are common in patients with *** on the frequency of EIMs have mostly been assessed in patients from tertiary centers;however,data about the prevalence of EIMs at first diagnosis as well as factors influencing their incidence during the early course of disease from prospective population-based cohorts are *** present data of patients of our population-based"Oberpfalz cohort"(Bavaria,Germany)from first diagnosis(up to 3 mo after first diagnosis)as well as during the early course of the *** risk factors were assessed by calculating the relative risk(RR)as well as using logistic regression ***:In total,data of 257 newly diagnosed patients with IBD were evaluated[161 Crohn’s disease(CD),96 ulcerative colitis(UC)].Median duration of follow-up was 50 mo after first *** 63.4%of all patients(n=163),an EIM was diagnosed at any point during the observation *** first diagnosis,patients with CD had a significantly increased risk of an EIM[n=69(42.9%)]compared with UC patients[n=21(21.9%);P<0.001;RR=1.96;95%CI:1.30-2.98].Active smoking increased the risk of CD patients developing an EIM during the early course of the disease,but notably not of UC patients(P=0.046;RR=1.96;95%CI:1.01-3.79).In addition,using logistic regression analysis,the need for IBD-related surgery and a young age at first diagnosis were identified as risk factors for the development of an EIM in CD *** association with EIMs was found for the factors sex,localization of the disease and positive family history of *** contrast,no key factors which increased the risk of development of an EIM could be identified in UC ***:We found a high prevalence of EIM in this cohort at first diagnosis and during th

关键词： Extraintestinal manifestations Crohn's disease Ulcerative colitis Smoking Surgery Age at onset

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The effect of electrochemically inactive Ti substituted for Ru in Li_(2)Ru_(1-x)Ti_xO_(3) on structure and electrochemical performance

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Journal of Energy Chemistry 2021年第9期30卷 222-228页

作者： Ye Yao Lu Zhang florian Sigel Bjorn Schwarz Helmut Ehrenberg Gang Chen Fei Du Chunzhong Wang Changchun Normal University Changchun 130031China Key Laboratory of Physics and Technology for Advanced Batteries(Ministry of Education) State Key Laboratory of Superhard MaterialsCollege of PhysicsJilin UniversityChangchun 130012China Institute for Applied Materials(IAM) Karlsruhe Institute of Technology(KIT)76344 Eggenstein-LeopoldshafenGermany

The approach of substituting electrochemically active with inactive elements has widely been used to improve the electrochemical performance of Li-rich intercalation cathode materials. This especially is true for Li-rich compounds where almost all of the Li+ions are reversibly(de)intercalated during electrochemical cycling. The beneficial mechanism behind this substitution with electrochemically inactive elements is still not clear yet. Li_(2)RuO_(3) is chosen as basis for a model solid solution system to investigate the effect of electrochemically inactive elements owing to its high specific capacity of more than 300 m Ah g^(-1) and the significant contribution of anion redox mechanism. Herein, Li_(2)Ru_(1-x)Ti_xO_(3) solid solution series are synthesized and the effect of substituting with electrochemical inactive Ti for Ru on structure and electrochemical performance have been comprehensively investigated. The electrochemical performance is significantly improved, especially for Li_(2)Ru_(0.8)Ti_(0.2)O_(3), and the capacity retention after 50 cycles increases from 81% to 90%, as compared to the end member Li_(2)RuO_(3). Results of electrochemical impedance spectroscopy show that Ti substitution reduces the charge transfer impedance, which favors the Li+diffusion across the electrolyte–electrode interface and improves the electronic conductivity. For the first time,nuclear magnetic resonance was utilized to confirm that a small part of Ti ions exchange their position with Li ions in the Li layer. This research provides a better understanding of electrochemical inactive element substitution and strong insights for the functional design of the next generation of Li-rich cathode materials.

关键词： Li_(2)Ru_(1-x)Ti_xO_(3) Lithium ion batteries Inactive element substitution XRD NMR

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Precision Breeding Made Real with CRISPR: Illustration through Genetic Resistance to Pathogens

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Plant Communications 2020年第5期1卷 1-20页

作者： florian Veillet Mickael Durand Thomas Kroj Stella Cesari Jean-Luc Gallois IGEPP INRAEInstitut AgroUniv RennesPloudaniel 29260France Germicopa Breeding KerguivarchChateauneuf Du Faou 29520France Institut Jean-Pierre Bourgin INRAEAgroParisTechUniversitéParis-SaclayVersailles 78000France INRAE BGPIBiology and Genetics of Plant-Pathogen InteractionsCampus International de BaillarguetMontpellierFrance INRAE GAFLMontfavet F-84143France

Since its discovery as a bacterial adaptive immune system and its development for genome editing in eukaryotes,the CRISPR technology has revolutionized plant research and precision crop *** CRISPR toolbox holds great promise in the production of crops with genetic disease resistance to increase agriculture resilience and reduce chemical crop protection with a strong impact on the environment and public *** this review,we provide an extensive overviewon recent breakthroughs in CRISPR technology,including the newly developed prime editing system that allows precision gene editing in *** present how each CRISPR tool can be selected for optimal use in accordance with its specific strengths and limitations,and illustrate how the CRISPR toolbox can foster the development of genetically pathogen-resistant crops for sustainable agriculture.

关键词： CRISPR-Cas9 gene targeting base editing prime editing plant/pathogen interactions precision crop breeding

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A multifunctional rock testing system for rock failure analysis under different stress states: Development and application

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第5期14卷 1531-1544页

作者： Shucai Li Jie Hu florian Amann Liping Li Hongliang Liu Shaoshuai Shi Pooya Hamdi School of Qilu Transportation Shandong UniversityJinan250061China School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210094China Department of Engineering Geology and Hydrogeology RWTH Aachen UniversityAachen52064Germany

The stress state in a rock mass is complex. Stress redistribution around underground excavation may lead to various failure modes, including compressive-shear, tensile-shear, and tensile failures. The ability to perform laboratory tests with these complex stress states is significant for establishing new strength criteria. The present paper introduces a new rock testing system with “tensile-compressive-shear”loading functions. The device includes bi-directional and double-range hydraulic cylinders, auxiliary loading equipment, and roller rows that can perform direct compressive-shear tests, direct tensile tests,and direct tensile-shear tests. The testing system provides maximum vertical and lateral loading forces of2000 k N and allows testing cubical rock specimens with dimensions of 0.5 m × 0.5 m × 0.5 m. The performance of the testing machine was evaluated by testing a rock-like material based on cement mortar under compressive-shear, tensile, and tensile-shear stress states. The failure process and deformation characteristics were monitored during loading using acoustic emission(AE) transient recorder,piezoelectric AE sensors, a high-speed camera, and a thermal infrared camera. The failure mechanism was investigated by analyzing AE counts, AE amplitude, strain, and temperature changes on the rock specimen surface. The test results confirmed that the testing system could successfully simulate the abovementioned stress path. The AE counts and amplitude responses were influenced by different failure modes. The temperature response during the compressive-shear test indicated the development of a high-temperature band on the rock specimen surface. In contrast, a negligible temperature change was observed during the tensile and tensile-shear tests. The newly developed multifunctional rock testing system allows laboratory tests under various failure modes. The monitoring results of multiple variables during rock failure tests provide valuable information on failure char

关键词： Rock testing system Compressive-shear test Tensile test Tensile-shear test Failure behavior Multiple variable evolutions

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Geoecological parameters indicate discrepancies between potential and actual forest area in the forest-steppe of Central Mongolia

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Forest Ecosystems 2021年第4期8卷 735-754页

作者： Michael Klinge Choimaa Dulamsuren florian Schneider Stefan Erasmi Uudus Bayarsaikhan Daniela Sauer Markus Hauck Department of Physical Geography Institute of GeographyUniversity of GöttingenGoldschmidtstraBe 537077 GöttingenGermany Applied Vegetation Ecology Faculty of Environment and Natural ResourcesUniversity of FreiburgTennenbacher Str.479106 FreiburgGermany Institute of Farm Economics Thünen InstituteBundesallee 6338116 BraunschweigGermany Department of Biology School of Arts and SciencesNational University of MongoliaBaga toiruu 47Sukhbaatar duuregUlaanbaatarMongolia

Background:Forest distribution in the forest-steppe of Mongolia depends on relief,permafrost,and climate,and is highly sensitive to climate change and anthropogenic *** fires and logging decreased the forest area in the forest-steppe of *** intention of this study was to identify the geoecological parameters that control forest distribution and living-tree biomass in this semi-arid *** on these parameters,we aimed to delineate the area that forest might potentially occupy and to analyse the spatial patterns of actual and potential tree ***:We used a combination of various geographic methods in conjunction with statistical analyses to identify the key parameters controlling forest *** several field campaigns,we mapped tree biomass and ecological parameters in a study area within the Tarvagatai Nuruu National Park(central Mongolia).Forest areas,topographic parameters and vegetation indices were obtained from remote sensing *** correlations between forest distribution and living-tree biomass on one hand,and topographic parameters,climate data,and environmental conditions on the other hand,were used to delineate the area of potential forest distribution and to estimate total living-tree biomass for this ***:Presence of forest on slopes was controlled by the factors elevation,aspect,slope,mean annual precipitation,and mean growing-season *** these factors allowed for estimation of potential forest area but was less suitable for tree-biomass *** significant differences in mean living-tree biomass existed between sites exposed to different local conditions with respect to forest fire,exploitation,and soil *** biomass was reduced at forest edges(defined as 30m wide belt),in small fragmented and in large forest *** biomass in the study area was 20×10^(9) g(1,086 km^(2) forest area),whereas the potential tree biomass would reach up to 65×10^(9)

关键词： Biomass Fire Forest-steppe Geoecological factors Mongolia Permafrost

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Fundamental Investigations in the Design of Five-Axis Nanopositioning Machines for Measurement and Fabrication Purposes

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Nanomanufacturing and Metrology 2021年第3期4卷 156-164页

作者： Ralf Schienbein florian Fern Rene Theska Shraddha Supreeti Roland FuBl Eberhard Manske Department of Mechanical Engineering Institute of Design and Precision Engineering.Technical University of Ilmenau.IlmenauGermany Institute of Process Measurement and Sensor Technology Department of Mechanical EngineeringTechnical University of IlmenauIlmenauGermany Electronics Technology Group Department of Electrical Engineering and Information TechnologyTechnical University of IlmenauIlmenauGermany

The majority of nanopositioning and nanomeasuring machines(NPMMs)are based on three independent linear movements in a Cartesian coordinate *** in combination with the specific nature of sensors and tools limits the addressable part *** enhancement of an NPMM is introduced by the implementation of rotational movements while keeping the precision in the nanometer *** this purpose,a parameter-based dynamic evaluation system with quantifiable technological parameters has been set up and employed to identify and assess general solution concepts and adequate *** taken show high potential for three linear movements of the object in combination with two angular movements of the *** influence of the additional rotation systems on the existing structure of NPMMs has been investigated further *** series on the repeatability of an NPMM enhanced by a chosen combination of a rotary stage and a goniometer setup are *** a result of these test series,the necessity of in situ position determination of the tool became very *** tool position is measured in situ in relation to a hemispherical reference mirror by three Fabry-Perot *** optimization has been used to enhance the overall system structure with regard to reproducibility and long-term *** have been experimentally investigated by use of a retroreflector as a tool and the various laser interferometers of the *** knowledge gained has been formed into general rules for the verification and optimization of design solutions for multiaxial nanopositioning machines.

关键词： Multiaxial nanopositioning and nanomanufacturing Ultra-precision machine designs 5-Axis operation Ultraprecision rotations

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