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Cover Crops as Affecting Soil Chemical and Physical Properties and Development of Upland Rice and Soybean Cultivated in Rotation

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Rice science 2018年第6期25卷 340-349页

作者： Adriano stephan NASCENTE Luis Fernando STONE Embrapa Arroz e Feij(CNPAF) Rodovia GO-462km 12 Zona RuralCP.17975375-000Santo Antoio de GoiasGOBrasil

Cover crops can provide changes in soil chemical and physical properties, which could allow a sustainable development of soybean and upland rice rotation in Brazilian Cerrado. The objective of this study was to determine the effects of cover crops(cultivated in the offseason) in the soybean-upland rice rotation(cultivated in the summer season) on the soil chemical and physical properties, yield components and grain yield of the cash crops. The experimental design was a randomized block design in factorial scheme 4 × 2 with six replications. Treatments were composed by four cover crops: fallow, millet(Pennisetum glaucum) + Crotalaria ochroleuca, millet + pigeon pea(Cajanus cajans), and millet + pigeon pea + Urochola ruziziensis in the offseason with one or two cycles of cover crops, with rice(Oryza sativa)or soybean(Glycine max) in the summer season. Cover crops alone provided no changes in soil chemical properties. However, the rotation cover crops/cash crops/cover crops/cash crops reduced p H, Al and H + Al and increased Ca, Mg, K and Fe contents in the soil. The cover crops millet + pigeon pea and millet + pigeon pea + U. ruziziensis improved soil physical properties in relation to fallow,especially in the 0–0.10 m soil layer. In spite of the improvement of the soil physical properties after two years of rotation with cover crops and cash crops, the soil physical quality was still below the recommended level, showing values of macroporosity, S index and soil aeration capacity lower than 0.10 m3/m3, 0.035 and 0.34, respectively. Upland rice production was higher under mixtures of cover crops than under fallow, mainly because of soil physical changes done by these mixtures of cover *** grain yield was similar under all cover crops tested, but was higher after the rotation cover crops/upland rice/cover crops than after only one cycle of cover crops.

关键词： crop rotation no-tillage system sustainable agriculture tropical agriculture rice soybean

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Plasma and nanoparticle shielding during pulsed laser ablation in liquids cause ablation efficiency decrease

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Opto-Electronic Advances 2021年第1期4卷 1-13页

作者： Sarah Dittrich stephan Barcikowski Bilal Gökce Technical Chemistry I and Center of Nanointegration Duisburg Essen(CENIDE) University of Duisburg-EssenUniversitaetsstr.745141 EssenGermany

Understanding shielding cross-effects is a prerequisite for maximal power-specific nanosecond laser ablation in liquids(LAL).However,discrimination between cavitation bubble(CB),nanoparticle(NP),and shielding,e.g.,by the plasma or a transient vapor layer,is ***,CB imaging by shadowgraphy is performed to better understand the plasma and laser beam-NP interaction during *** comparing the fluence-dependent CB volume for ablations performed with 1 ns pulses with reports from the literature,we find larger energy-specific CB volumes for 7 *** increased CB for laser ablation with higher ns pulse durations could be a first explanation of the efficiency decrease reported for these laser systems having higher pulse ***,1 ns-LAL shows superior ablation ***,a CB cascade occurs when the focal plane is shifted into the *** effect is enhanced when NPs are present in the *** minute amounts of NPs trapped in a stationary layer decrease the laser energy significantly,even under liquid ***,this local concentration in the sticking film has so far not been *** presents an essential obstacle in high-yield LAL,shielding already the second laser pulse that arrives and presenting a source of satellite ***,measures to lower the NP concentration on the target must be investigated in the future.

关键词： shadowgraphy power-specific productivity flow dynamics ablation mechanism

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Immunopathogenesis of inflammatory bowel disease

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World Journal of Gastroenterology 2008年第3期14卷 390-400页

作者： David Q Shih stephan R Targan Cedars-Sinai Inflammatory Bowel Disease Center Los Angeles CA United States Department of Medicine Division of Digestive Diseases University of California Los Angeles CA United States Cedars-Sinai Inflammatory Bowel Disease Center Los Angeles CA United States

Crohn’s disease and ulcerative colitis are chronic relapsing immune mediated disorders that results from an aberrant response to gut luminal antigen in genetically susceptible host. The adaptive immune response that is then triggered was widely considered to be a T-helper-1 mediated condition in Crohn’s disease and T-helper-2 mediated condition in ulcerative colitis. Recent studies in animal models, genome wide association, and basic science has provided important insights in in the immunopathogenesis of inflammatory bowel disease, one of which was the characterization of the interleukin-23/Th-17 axis.

关键词：克罗恩氏病溃疡性结肠炎免疫系统症状

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Surface modification of polypropylene non-woven fibers with TiO_2 nanoparticles via layer-by-layer self assembly method:Preparation and photocatalytic activity

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Journal of Environmental Sciences 2015年第11期27卷 59-66页

作者： Suttipan Pavasupree stephan T.Dubas Ratthapol Rangkupan Metallurgy and Materials Science Research Institute Chulalongkorn University Petroleum and Petrochemical College Chulalongkorn University Chulalongkorn University Nanotec-CU Center of Excellence on Food and Agriculture Chulalongkorn University

Polypropylene（PP） meltblown fibers were coated with titanium dioxide（Ti O2） nanoparticles using layer-by-layer（Lb L） deposition technique. The fibers were first modified with 3layers of poly（4-styrenesulfonic acid）（PSS） and poly（diallyl-dimethylammonium chloride）（PDADMAC） to improve the anchoring of the Ti O2 nanoparticle clusters. PDADMAC, which is positively charged, was then used as counter polyelectrolyte in tandem with anionic Ti O2 nanoparticles to construct Ti O2/PDADMAC bilayer in the Lb L fashion. The number of deposited Ti O2/PDADMAC layers was varied from 1 to 7 bilayer, and could be used to adjust Ti O2 loading. The Lb L technique showed higher Ti O2 loading efficiency than the impregnation approach. The modified fibers were tested for their photocatalytic activity against a model dye, Methylene Blue（MB）. Results showed that the Ti O2 modified fibers exhibited excellent photocatalytic activity efficiency similar to that of Ti O2 powder dispersed in solution. The deposition of Ti O23 bilayer on the PP substrate was sufficient to produce nanocomposite fibers that could bleach the MB solution in less than 4 *** O2-Lb L constructions also preserved Ti O2 adhesion on substrate surface after 1 cycle of photocatalytic test. Successive photocatalytic test showed decline in MB reduction rate with loss of Ti O2 particles from the substrate outer surface. However, even in the third cycle, the Ti O2 modified fibers are still moderately effective as it could remove more than 95% of MB after 8 hr of treatment.

关键词： Layer-by-layer Self assembly TiO2 Nanocomposite Photocatalytic activity

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Tribological performance and microstructural evolution ofα-brass alloys as a function of zinc concentration

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Friction 2020年第6期8卷 1117-1136页

作者： Zhilong LIU Philipp MESSER-HANNEMANN stephan LAUBE Christian GREINER Institute for Applied Materials(IAM) Karlsruhe Institute of Technology(KIT)Karlsruhe 76131Germany KIT IAM-CMS MikroTribologie CentrumμTC Karlsruhe 76131Germany

Tailoring a material's properties for low friction and little wear in a strategic fashion is a long-standing goal of materials *** deformation plays a major role when metals are employed in a sliding contact;therefore,the effects of stacking fault energy and mode of dislocation glide need to be ***,we investigated how a decrease in the stacking fault energy affects friction,wear,and the ensuing sub-surface microstructure *** samples with increasing zinc concentrations of 5,15,and 36 wt%were tested in non-lubricated sphere-on-plate contacts with a reciprocating linear tribometer against Si3N4 *** the sliding distance from 0.5(single trace)to 5,000 reciprocating cycles covered different stages in the lifetime of a sliding *** the results among the three alloys revealed a profound effect of the zinc concentration on the tribological ***15 and CuZn36 showed similar friction and wear results,whereas CuZn5 had a roughly 60%higher friction coefficient(COF)than the other two ***15 and CuZn36 had a much smaller wear rate than *** dislocation motion in CuZn5 and CuZn15 allowed for dislocation self-organization into a horizontal line about 150 nm beneath the contact after a single trace of the *** feature was absent in CuZn36 where owing to planar dislocation slip band-like features under a 45°angle to the surface were *** results hold the promise to help guide the future development of alloys tailored for specific tribological applications.

关键词： brass tribology sliding contact microstructure stacking fault energy electron microscopy

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Theoretical study on decay of the 4d core-excited states of Cs Ⅲ

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Chinese Physics B 2008年第6期17卷 2033-2039页

作者：丁晓彬董晨钟 stephan Fritzschec College of Physics and Electronic Engineering Northwest Normal University Center of Theoretical Nuclear Physics National Laboratory of Heavy-Ion Accelerator of Lanzhou Department of Physics University of Kassel Heinrich-Plett-Strαβe 40 D-34132 Kassel Germany

In a recent XUV photoabsorption spectrum of Cs Ⅲ ions by Cummings and O＇Sullivan [2001 J. Phys. B 34 199], rather large linewidths were found for the 4d^95s^25p^6 - 4d^105s^25p^5 transition which are quite in disagreement with corresponding quasi-relativistic multiconfiguration Hartree Fock （MCHF） calculation. In the present work, a detailed multiconfiguration Dirac-Fock study has been carried out to explore this discrepancy. Owing to the detailed consideration of electron correlation effects, some ‘forbidden＇ Auger decay channels, such as 4d^105s^25p^35d and 4d^105s^05p^6, would become ‘open＇. As a result, remarkable improvement of the linewidths has been obtained in our calculation. Furthermore, the theoretical Auger spectrum of the 4d^ 95s^25p^6 core-excited states of Cs Ⅲ ions is Riven in the present work.

关键词： correlation effects linewidth Auger decay

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Life cycle assessment of alkali‑activated materials:a systematic literature review

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Low-carbon Materials and Green Construction 2023年第1期1卷 157-180页

作者： Morteza Nikravan Rafia Firdous Dietmar stephan Department of Civil Engineering Building Materials and Construction ChemistryTechnische Universitat BerlinGustav‑Meyer‑Allee 2513355 BerlinGermany

碱激发材料(AAMs)的物化特性、力学性能与耐久性能已被广泛研究。然而,关于AAMs的生命周期分析(LCA)的最新报道,尚未进行全面回顾。因此,本研究旨在通过对全球范围内发表的有关该主题的文章进行系统的文献综述来填补这一空白。通过对不... 详细信息

碱激发材料(AAMs)的物化特性、力学性能与耐久性能已被广泛研究。然而,关于AAMs的生命周期分析(LCA)的最新报道,尚未进行全面回顾。因此,本研究旨在通过对全球范围内发表的有关该主题的文章进行系统的文献综述来填补这一空白。通过对不同数据库进行检索,本文筛选出使用AAMs作为净浆、砂浆、混凝土、砖和夯土/土块的LCA研究。筛选出的研究根据前驱体、碱活化剂、功能单元、系统边界、生命周期清单数据库、分配、影响方法和使用的软件等方面进行分类和回顾。此外,本文还对AAMs的LCA面临的关键挑战进行批判性分析,其中首要的难题是功能单元的选择、边界系统的主观性和数据的解释说明。研究表明,与普通硅酸盐水泥相比,AAMs在减缓全球变暖潜能方面有利,而在其他方面(如海洋生态毒性和臭氧层破坏)的潜能值高一些。

关键词：碱激发材料地质聚合物生命周期评估 (LCA) 功能单元生命周期清单(LCI)

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TiNiHf/SiO_(2)/Si shape memory film composites for bidirectional micro actuation

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International Journal of Smart and Nano Materials 2022年第2期13卷 293-314页

作者： Sabrina M.Curtis Marian Sielenkamper Gowtham Arivanandhan Duygu Dengiz Zixiong Li Justin Jetter Lisa Hanke Lars Bumke Eckhard Quandt stephan Wulfinghoff Manfred Kohl Institute for Materials Science Kiel University(CAU)KielGermany Materials Science and Engineering University of MarylandCollege ParkMDUnited States Institute of Microstructure Technology Karlsruhe Institute of Technology(KIT)KarlsruheGermany

The martensitic phase transformation in Ti_(40.4)Ni_(48)Hf_(11.6) shape memory alloys is leveraged for bi-directional actuation with TiNiHf/SiO_(2)/Si *** shape memory properties of magnetron sputtered Ti_(40.4)Ni_(48)Hf_(11.6) films annealed at 635℃-5 min are influenced by film thickness and the underlying *** TiNiHf film thick-ness from 21μm to 110 nm results in the reduction of all characteristic transformation temperatures until a critical thickness is ***,Ti_(40.4)Ni_(48)Hf_(11.6) thin films as low as 220 nm show transfor-mations above room temperature when deposited on SiO_(2) buffer layer,which is of great interest in *** comparison,220 nm films on Si substrates are austenitic at room temperature,and thus not suitable for *** fatigue tests on TiNiHf/SiO_(2)/Si bimorphs demonstrate better functional fatigue characteristics than freestanding films,with an average reduction of 15℃ after 125 cycles,with tempera-ture stabilization *** bi-directional actuation results are promising in the development of bistable actuators within a PMMA/TiNiHf/Si trimorph composite,whereby the additional PMMA layer undergoes a glass transition at 105℃.With the aid of constitutive modeling,a route is elaborated on how bistable actuation can be achieved at micro-to nanoscales by showing favorable thickness combinations of PMMA/TiNiHf/Si composite.

关键词： Bimorph microactuator NiTiHf bistable actuator shape memory alloy thin films

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Quantum Transport Properties of Chemically Functionalized Long Semiconducting Carbon Nanotubes

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Nano Research 2010年第4期3卷 288-295页

作者： Alejandro Lopez-Bezanilla Xavier Blase stephan Roche Commissariat a l’Energie Atomique 38054 Grenoble CedexFrance Institut Néel CNRS and UniversitéJoseph FourierB.P.16638042 Grenoble Cedex 09France CIN2(CSIC-ICN)Barcelona Campus UABE-08193 BellaterraSpain

We present a first-principles study of the electronic transport properties of micrometer long semiconducting carbon nanotubes randomly covered with carbene functional groups. Whereas prior studies suggested that metallic tubes are hardly affected by such addends, we show here that the conductance of semiconducting tubes with standard diameter is, on the contrary, severely damaged. The configurational-averaged conductance as a function of tube diameter, with a coverage of up to one hundred molecules, is extracted. Our results indicate that the search for a conductance-preserving covalent functionalization route remains a challenging issue.

关键词： Nanotubes functionalization carbene electronic transport

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Spatial distributions of tropical tree species in northern Vietnam under environmentally variable site conditions

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Journal of Forestry Research 2014年第2期25卷 257-268页

作者： Nguyen Hong Hai Kerstin Wiegand stephan Getzin Department of Ecosystem Modelling Faculty of Forest Sciences and Forest EcologyUniversity of Goettingen Faculty of Agricultural Techniques Hatay Community College UFZ Helmholtz Centre for Environmental Research–UFZ Department of Ecological Modeling

Ecological interactions of species and thus their spatial pat- terns may differ between homogeneous and heterogeneous forests. To account for this, techniques of point pattern analysis were implemented on mapped locations of tree individuals from two 1-ha tropicalforest plots in Vietnam. We analyzed the effect of environmental heterogeneity on tree distributions; spatial distribution patterns of dominant species; inter-specific associations; and conspecific associations between life stages. Our analyses showed that： environmental conditions were homo- geneous at plot 1 but heterogeneous at plot 2; in both plots, all six domi- nant species were aggregated at various scales up to 30 m, and tree spe- cies were aggregated at larger scales in the homogeneous site than in the heterogeneous site; attraction between pairs of species was remarkably higher at the homogeneous site while negative associations were more frequent in the heterogeneous site; some species, H. kurzii, T. ilicifolia （homogeneous plot） and D. sylvatica, S. wightianum （heterogeneous plot） showed a lack of early life-stage individuals near conspecific adults. Moreover, additional clustering of young individuals was independent from conspecific adults, except D. sylvatica in both sites. These findings are consistent with the Janzen-ConneU hypothesis. Overall, habitat het- erogeneity influences spatial patterns and inter-specific associations of the tree species and evidences of self-thinning are shown in most species.

关键词： environmental heterogeneity spatial point pattern analysis tropical evergreen forest northern Vietnam.

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