检索结果-南通市图书馆

the stability of carbon from a maize-derived hydrochar as a function of fractionation and hydrothermal carbonization temperature in a Podzol

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Biochar 2022年第1期4卷 315-326页

作者： Megan de Jager Frank Schröter Michael Wark Luise Giani Institut Für Biologie Und Umweltwissenschaften Carl Von Ossietzky Univer-sitätOldenburgGermany Institut Für Chemie Carl Von Ossietzky UniversitätOldenburgGermany

Hydrochar(HC)produced by the hydrothermal carbonization(HtC)of typically wet biomass is generally considered to be less effective for carbon(C)sequestration in soils compared to biochar(BC)by pyrolysis,due to a higher content of more easily decomposable *** the recalcitrance of HC is suggested to improve with increasing HtC production temperature,the way it interacts and becomes associated with soil organic matter(SOM)fractions of different stabilities against decomposition,may also influence its effectiveness for C sequestration in *** that respect,this study aimed to verify the potential of HCs from maize silage produced at different HtC temperatures(190,210 and 230℃)for C sequestration in a HC-amended sandy loam *** do this,we conducted a pot trial experiment and traced the fate of HC-derived C(HC-C)within different SOM fractions,namely the free-and occluded particulate organic matter(POMF and POMO,respectively)fractions and that comprising organic matter(OM)bound to clays(OMCl).Approx.1 year after applying 5%of the different HtC temperature HCs to the soil,the SOM fractions were isolated by density fractionation for each HC treatment(HC190,HC210 and HC230)and the control(absent of HC).All fractions and the HCs were analyzed for organic C(OC)content and isotopic signatures(δ^(13)C).From the δ^(13)C signatures,the amount of HC-C and native soil organic carbon(SOC)within each fraction was *** C contents and decreased H/C and O/C ratios were observed with increasing HtC production temperatures,which sug-gests a lower stability for the low temperature *** ca.1 year,a loss of~20-23%of the bulk soil tOC was found in the HC-amended *** POMF fraction of the HC-amended soils showed losses of 68-81%HC-C and 52-72%native SOC,which may be due to a positive priming effect caused by HC *** POM_(O) and OM_(Cl) fractions of the HC-amended soils contained more OC than the control,indicating the integration of HC-C together wi

关键词： Hydrochar Carbon sequestration Carbon stabilization Soil organic matter fractions Soil density fractionation δ^(13)C analysis

two-photon emission from a superlattice-based superconducting light-emitting structure

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第7期13卷 1331-1340页

作者： Shlomi Bouscher Dmitry Panna Ronen Jacovi Fauzia Jabeen Christian Schneider Sven Höfling Alex Hayat Department of Electrical Engineering TechnionHaifa 32000Israel. technische Physik Universität WürzburgAm HublandD-97074 WürzburgGermany. Institute of Physics Carl von Ossietzky Universität OldenburgD-26111 OldenburgGermany

Superconductor-semiconductor hybrid devices can bridge the gap between solid-state-based and photonics-based quantum systems,enabling new hybrid computing schemes,offering increased scalability and *** example for a hybrid device is the superconducting light-emitting diode(SLED).SLEDs have been theoretically shown to emit polarization-entangled photon pairs by utilizing radiative recombination of Cooper ***,the twophoton nature of the emission has not been shown experimentally *** demonstrate two-photon emission in a GaAs/AlGaAs *** electroluminescence spectra reveal unique two-photon superconducting features below the critical temperature(tc),while temperature-dependent photon-pair correlation experiments(g(2)(τ,t))demonstrate temperature-dependent time coincidences below tc between photons emitted from the *** results pave the way for compact and efficient superconducting quantum light sources and open new directions in light-matter interaction studies.

关键词： photon quantum utilizing

Learning the optimal power flow:Environment design matters

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy and AI 2024年第3期17卷 432-443页

作者： thomas Wolgast Astrid Nieße Carl von Ossietzky Universität oldenburg Department of Computing ScienceDigitalized Energy SystemsAmmerländer Heerstraße 114-118Oldenburg26129Germany

to solve the optimal power flow(OPF)problem,reinforcement learning(RL)emerges as a promising new ***,the RL-OPF literature is strongly divided regarding the exact formulation of the OPF problem as an RL *** this work,we collect and implement diverse environment design decisions from the literature regarding training data,observation space,episode definition,and reward function *** an experimental analysis,we show the significant impact of these environment design options on RL-OPF training ***,we derive some first recommendations regarding the choice of these design *** created environment framework is fully open-source and can serve as a benchmark for future research in the RL-OPF field.

关键词： Reinforcement learning Optimal power flow Environment design Economic Dispatch Voltage control Reactive power market

the Performance of EOS Models in the Prediction of Vapor-Liquid Equilibria in Asymmetric Natural Gas Mixtures

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 1998年第3期6卷 29-37页

作者：王利生 H.Gardeler J.Gmehling Department of technical Chemisity University of OldenburgP.O.Box 2503D-26111 OldenburgGermany

the aim of this work is to apply cubic equations of state(EOS)to vapor-liquid equilibriacalculations of gas-heavy hydrocarbon systems,which are asymmetric in molecular size and areusually found in natural *** has been done to test the validity of the original PSRKand the cubic simplified perturbed hard-chain(CSPhC)models for global phase *** results show that both equations overpredict vapor pressure in the near critical *** the prediction of the solubilities of high molecular weight(MW)hydrocarbons in the naturalgas,the PSRK model gives good agreement for the dew point pressure-vapor composition *** of the pure component parameters of the CSPHC EOS for heavy components to fit thevapor-liquid equilibrium(VLE)data has been proved to give significant promoting in ***,further improvement of a van der Waals EOS,such as SRK,Pt and DG modelsfor the asymmetric systems by adjusting the three pure component properties,t_c, p_c and ?

关键词： equation of state natural gas vapor-liquid equilibria asymmetric systems

An investigation of the effects of hydrochar application rate on soil amelioration and plant growth in three diverse soils

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Biochar 2021年第3期3卷 349-365页

作者： Megan de Jager Luise Giani Carl Von Ossietzky Universität Institut Für Biologie Und UmweltwissenschaftenOldenburgGermany

the hydrothermal carbonization(HtC)of biogas digestate alters the raw materials inherent characteristics to produce a carbon(C)-rich hydrochar(HC),with an improved suitability for soil *** studies report conflicting impacts of various HC application rates on soil properties and plant *** this study,the influence of HC application rate on soil improvement and plant growth aspects was investigated in three diverse soils(Chernozem,Podzol,and Gleysol).Pot trials were conducted in which all soils were amended with 5,10,20 and 30%(w/w)HC in quintuplicate,with two controls of pure soil(with and without plants,respectively)also *** to potting,soil samples were collected from all HC-amended soils and controls and analyzed for soil pH,plant available nutrients(PO4-P and K),and microbial activity using standard laboratory and statistical *** after potting,a 6-week seed germination experiment using Chinese cabbage was conducted to determine germination success,followed by a plant growth experiment of equal duration and plant species to determine biomass *** the end of the study(after a total plant growth period of 12 weeks),each pot was sampled and comparatively analyzed for the same soil properties as at the beginning of the *** pH shifted toward the pH of the HC(6.6)in all soils over the course of the study,but was most expressed in the 20%and 30%application rates,confirming the well-documented liming effect of *** addition of HC increased the PO4-P and K contents,particularly with 20%and 30%HC *** results are proposedly due to the large labile C fraction of the HC,which is easily degradable by *** rapid decomposition of this C fraction prompted the quick release of the HCs inherently high PO4-P and K content into the soil,and in turn,further stimulated microbial activity,until this fraction was essentially *** addition did not inhibit seed germination at any rate,presumabl

关键词： Biogas digestate Hydrochar application rate Soil improvement Nutrient availability Microbial activity

Revealing true coupling strengths in two-dimensional spectroscopy with sparsity-based signal recovery

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2017年第1期6卷 322-327页

作者： Hadas Frostig tim Bayer Yonina C Eldar Yaron Silberberg Department of Physics of Complex Systems Weizmann Institute of ScienceRehovot 76100Israel Institut für Physik Carl von Ossietzky Universität OldenburgOldenburg 26129Germany Department of Electrical Engineering TechnionHaifa 32000Israel

two-dimensional(2D)spectroscopy is used to study the interactions between energy levels in both the field of optics and nuclear magnetic resonance(NMR).Conventionally,the strength of interaction between two levels is inferred from the value of their common off-diagonal peak in the 2D spectrum,which is termed the cross ***,stronger diagonal peaks often have long tails that extend into the locations of the cross peaks and alter their ***,we introduce a method for retrieving the true interaction strengths by using sparse signal recovery techniques and apply our method in 2D Raman spectroscopy experiments.

关键词： multidimensional spectroscopy nonlinear optics sparsity-based algorithms

Long-lived electron emission reveals localized plasmon modes in disordered nanosponge antennas

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2017年第1期6卷 458-465页

作者： Germann Hergert Jan Vogelsang Felix Schwarz Dong Wang Heiko Kollmann Petra Groß Christoph Lienau Erich Runge Peter Schaaf Carl von Ossietzky Universität Institut für PhysikCenter of Interface ScienceD-26129 OldenburgNiedersachsenGermany technische Universität Ilmenau Institut für Physik and Institut für Mikro-und Nanotechnologien MacroNano®D-98693 IlmenauThüringenGermany technische Universität Ilmenau Institut für Mikro-und Nanotechnologien MacroNano®and Institut für WerkstofftechnikFachgebiet Werkstoffe der ElektrotechnikD-98693 IlmenauThüringenGermany Forschungszentrum Neurosensorik Carl von Ossietzky UniversitätD-26111 OldenburgNiedersachsenGermany

We report long-lived,highly spatially localized plasmon states on the surface of nanoporous gold nanoparticles—nanosponges—with high excitation *** is well known that disorder on the nanometer scale,particularly in two-dimensional systems,can lead to plasmon localization and large field enhancements,which can,in turn,be used to enhance nonlinear optical effects and to study and exploit quantum optical ***,we introduce promising,three-dimensional model systems for light capture and plasmon localization as gold nanosponges that are formed by the dewetting of gold/silver bilayers and *** study light-induced electron emission from single nanosponges,a nonlinear process with exponents of n≈5...7,using ultrashort laser pulse excitation to achieve femtosecond time *** long-lived electron emission process proves,in combination with optical extinction measurements and finite-difference time-domain calculations,the existence of localized modes with lifetimes of more than 20 *** electrons couple efficiently to the dipole antenna mode of each individual nanosponge,which in turn couples to the ***,individual gold nanosponges are cheap and robust disordered nanoantennas with strong local resonances,and an ensemble of nanosponges constitutes a meta material with a strong polarization independent,nonlinear response over a wide frequency range.

关键词： disorder-induced plasmon localization nanoantennas nanoporous gold nanoparticles ultrafast photoemission spectroscopy

Observing charge separation in nanoantennas via ultrafast point-projection electron microscopy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2018年第1期7卷 532-539页

作者： Jan Vogelsang Germann Hergert Dong Wang Petra Groß Christoph Lienau Carl von Ossietzky Universität Institut für Physik and Center of Interface Science26129 OldenburgNiedersachsenGermany tU Ilmenau Institut für Werkstofftechnik und Institut für Mikro-und Nanotechnologien98693 IlmenauThüringenGermany Carl von Ossietzky Universität Forschungszentrum Neurosensorik26129 OldenburgNiedersachsenGermany Department of Physics Lund UniversityBox 11822100 LundSweden

Observing the motion of electrons on their natural nanometer length and femtosecond time scales is a fundamental goal of and an open challenge for contemporary ultrafast science1–*** present,optical techniques and electron microscopy mostly provide either ultrahigh temporal or spatial resolution,and microscopy techniques with combined space-time resolution require further development6–*** this study,we create an ultrafast electron source via plasmon nanofocusing on a sharp gold taper and implement this source in an ultrafast point-projection electron *** source is used in an optical pump—electron probe experiment to study ultrafast photoemissions from a nanometer-sized plasmonic antenna12–*** probe the real space motion of the photoemitted electrons with a 20-nm spatial resolution and a 25-fs time resolution and reveal the deflection of probe electrons by residual holes in the *** is a step toward time-resolved microscopy of electronic motion in nanostructures.

关键词： projection separation sized

Electronic fingerprint mechanism of NO_(x) sensor based on single-material SnP_(3) logical junction

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

npj Computational Materials 2022年第1期8卷 2107-2116页

作者： Muhammad S.Ramzan Agnieszka B.Kuc Han Seul Kim Department of Physics and Earth Sciences Jacobs University BremenCampus Ring 128759BremenGermany Institut für Physik Carl von Ossietzky Universität Oldenburg26129OldenburgGermany Helmholtz-Zentrum Dresden-Rossendorf Abteilung RessourcenökologieForschungsstelle LeipzigPermoserstr.1504318LeipzigGermany Division of National Supercomputing R&D Korea Institute of Science and Technology Information(KISTI)245 Daehak-roYuseong-guDaejeon34141Republic of Korea

An extraordinary sensing ability of the SnP3-based single-material logical junction for harmful NO_(x)gases was explored in the present work through a set of first-principles electronic structure *** a sensing platform,a metal-semiconductor-metal lateral junction composed of a single material was designed based on the metallic/semiconducting characteristics of trilayer/monolayer SnP_(3).Lacking a Schottky barrier at the electrode-channel interface,the gas-specific charge transfer between the SnP_(3) layer and gas molecules was precisely detected based on the current-voltage ***_(x)gases with strong adsorption strength and charge transfer amount on the SnP_(3)substrate were shown to be particularly well detected in this manner,in terms of either the absolute magnitude of the current or negative differential resistance(NDR)at a reasonably small bias voltage as a sensing *** work will provide a new pathway to design a Schottky barrier-free metal-semiconductor junction for highly sensitive sensor applications.

关键词： gases barrier charge