检索结果-南通市图书馆

Analyzing voting power in decentralized governance:Who controls DAOs?

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Blockchain(Research and Applications) 2024年第3期5卷 123-129页

作者： Robin fritsch Marino Müller Roger Wattenhofer ETH Zurich 8092ZurichSwitzerland

We empirically study the state of three prominent DAO governance systems on the Ethereum blockchain:Compound,Uniswap and Ethereum name service(ENS).In particular,we examine how the voting power is distributed in these *** a comprehensive dataset of all governance token holders,delegates,propos-als,and votes,we analyze who holds the voting power and how this power is being used to influence governance *** we reveal that the majority of voting power is concentrated in the hands of a small number of addresses,we rarely observe these powerful entities overturning a vote by choosing a different outcome than that of the overall community and less influential voters.

关键词： Decentralized autonomous organization DAO governance Liquid democracy Blockchain

A simulation study on spatial and time resolution for a cost-effective positron emission particle tracking system

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2024年第5期88卷 312-322页

作者： Josephine Oppotsch Matthias Steinke Miriam fritsch Fritz-Herbert Heinsius Thomas Held Nikoline Hilse Viktor Scherer Ulrich Wiedner Ruhr-Universität Bochum Institut für Experimentalphysik I44801 BochumGermany Ruhr-Universität Bochum Lehrstuhl für Energieanlagen und Energieprozesstechnik44801 BochumGermany

This work is the second part of a simulation study investigating the processing of densely packed and moving granular assemblies by positron emission particle tracking (PEPT).Since medical positron emission tomography (PET) scanners commonly used for PEPT are very expensive,a PET-like detector system based on cost-effective organic plastic scintillator bars is being developed and tested for its *** this context,the spatial resolution of a resting positron source,a source moving on a freely designed model path,and a particle motion given by a discrete element method (DEM) simulation is studied using Monte Carlo simulations and the software toolkit *** not only extended the simulation and reconstruction to a moving source but also significantly improved the spatial resolution compared to previous work by adding oversampling and iteration to the reconstruction ***,in the case of a source following a trajectory developed from DEM simulations,a very good resolution of about 1 mm in all three directions and an average 3D deviation between simulated and reconstructed events of 2.3 mm could be ***,the resolution for realistic particle motion within the generic grate system (which is the test rig for further experimental studies) is well below the smallest particle *** simulation of the dependence of the reconstruction accuracy on tracer particle location revealed a nearly constant efficiency within the entire detector system,which demonstrates that boundary effects can be neglected.

关键词： Positron emission particle tracking Monte Carlo method Time-of-flight Plastic scintillators Silicon photomultipliers(SiPMs)

A simulation study for a cost-effective PET-like detector system intended to track particles in granular assemblies

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2024年第1期84卷 117-125页

作者： Josephine Oppotsch Antonios Athanassiadis Miriam fritsch Fritz-Herbert Heinsius Thomas Held Nikoline Hilse Viktor Scherer Matthias Steinke Ulrich Wiedner Ruhr-Universität Bochum Institut für Experimentalphysik I44801 BochumGermany Ruhr-Universität Bochum Lehrstuhl für Energieanlagen und Energieprozesstechnik44801 BochumGermany

Since many industrial applications rely on the processing of densely packed and moving granular ma-terial,obtaining bulk internal information on the particle movement inside the reactors is of great *** information can be delivered by Positron Emission Particle Tracking(PEPT).By marking pellets with a positron-emitting radioisotope,the position of these tracer particles can be determined via the time-of-flight differences of the emitted gamma-ray *** current paper proposes a PET-like detector system based on cost-effective organic plastic scintillators instead of the more common but expensive inorganic *** system is currently under construction and was tested for its resolution and efficiency in this simulation *** Monte Carlo simulations and the software toolkit Geant4,three different geometries(an empty glass box,a generic grate system,and a cubic box of 1 m3 completely filled with pellets)were investigated,leading to a spatial resolution in the millimeter range and an efficiency,defined as the ratio of reconstructed decay locations to simulated decays,of 2.7%,1.4%,and 0.3%.

关键词： Positron emission particle tracking Geant4 Monte Carlo method Time-of-flight Plastic scintillators Silicon photomultipliers(SiPMs)

Characterization and photoluminescence properties of ultrafine copper molybdate(α-CuMoO_4) powders prepared via a combustion-like process

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2016年第11期23卷 1340-1345页

作者： Mohamed Benchikhi Rachida El Ouatib Sophie Guillemet-fritsch Lahcen Er-Rakho Bernard Durand Laboratoire de Physico-Chimie des Matériaux Inorganiques Faculté des Sciences Ain Chock Université Hassan Ⅱ Casablanca Institut Carnot CIRIMAT CNRS Université de Toulouse

We report a simple method for preparing copper（II） molybdate（CuMoO_4） powders via a combustion-like process. A gel was first prepared by the polymerizable complex method, where citric acid was used as a complexing and polymerizing agent and nitric acid was used as an oxidizing agent. The thermal decomposition behavior of the（CuMo）-precursor gel was studied by thermogravimetry–differential thermal analysis（TG–DTA）, Fourier transform infrared spectroscopy（FTIR）, and X-ray diffraction（XRD）. We observed that the crystallization of CuMoO_4 powder was completed at 450°C. The obtained homogeneous powder was composed of grains with sizes in the range from 150 to 500 nm and exhibited a specific surface area of approximately 5 m^2/g. The average grain size increased with increasing annealing temperature. The as-prepared CuMoO_4 crystals showed a strong green photoluminescence emission at room temperature under excitation at 290 nm, which we mainly interpreted on the basis of the Jahn-Teller effect on [MoO_4^（2-）] complex anions. We also observed that the photoluminescence intensity increased with increasing crystallite size.

关键词： copper molybdate chemical synthesis photoluminescence Jahn-Teller effect

Sludge thickening in a wastewater treatment plant using a modified hydrocyclone

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

Carbon Resources Conversion 2021年第1期4卷 132-141页

作者： Thomas Senfter Lukas fritsch Manuel Berger Tobias Kofler Christian Mayerl Martin Pillei Michael Kraxner Dept.of Environmental Process&Energy EngineeringMCI-The Entrepreneurial SchoolAustria

The main application of hydrocyclones in most industry sectors is the separation of particles from *** thickening,however,the separation properties of the cyclone should be adjustable,which requires a different operating ***,we investigated an add-on thickening module,consisting of a conical plug and a secondary vortex finder in the underflow of the *** scale experiments are carried out to investigate the function of the concept of annular gap modification by the use of the thickening *** the second step,we transferred this concept to industrial scale for field tests at a municipal wastewater treatment *** the field tests,geometrical properties(annular gap modification)and operational parameters(volume flow rate,sludge type)were *** results show that thickening in terms of increasing the total solids content of sludge is possible with the modified *** the field tests,a thickening factor(total solids content of thickened sludge related to feed sludge)of 1.31(average)was reached for digested ***,a hydrocyclone could be a promising addition in wastewater treatment plants for dewatering of sludge.

关键词： Hydrocyclone Sludge thickening Dewatering Wastewater treatment Process optimization

Prediction of Extractable Cd,Pb and Zn in Contaminated Woody Habitat Soils Using a Change Point Detection Method

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Pedosphere 2016年第3期26卷 282-298页

作者： Christophe WATERLOT Christelle PRUVOT Géraldine BIDAR Clémentine fritsch Annette DE VAUFLEURY Renaud SCHEIFLER Francis DOUAY Groupe ISA Laboratoire Genie Civil et geo-Environnement(LGCgE)Lille 59046(France) Departement Chrono-Environment UMR UFC/CNRS 6249 USC INRAUniversite Bourgogne Franche-ComteBesancon 25030(France)

Accumulation of heavy metals in soils poses a potential risk to plant production, which is related to availability of the metals in soil. The phytoavailability of metals is usually evaluated using extracting solutions such as salts, acids or chelates. The purpose of this study was to identify the most significant soil parameters that can be used to predict the concentrations of acetic and citric acidextractable cadmium(Cd), lead(Pb) and zinc(Zn) in contaminated woody habitat topsoils. Multiple linear regression models were established using two analysis strategies and three sets of variables based on a dataset of 260 soil samples. The performance of these models was evaluated using statistical parameters. Cation exchange capacity, CaCO_3, organic matter, assimilated P, free Al oxide,sand and the total metal concentrations appeared to be the main soil parameters governing the solubility of Cd, Pb and Zn in acetic and citric acid solutions. The results strongly suggest that the metal solubility in extracting solutions is extractable concentrationdependent since models were overall improved by incorporating a change point. This change point detection method was a powerful tool for predicting extractable Cd, Pb and Zn. Suitable predictions of extractable Cd, Pb and Zn concentrations were obtained, with correlation coefficient(adjusted r) ranging from 0.80 to 0.99, given the high complexity of the woody habitat soils studied. Therefore,the predictive models can constitute a decision-making support tool for managing phytoremediation of contaminated soils, making recommendations to control the potential bioavailability of metals. The relationships between acetic and/or citric acid-extractable concentrations and the concentrations of metals into the aboveground parts of plants need to be predicted, in order to make their temporal monitoring easier.

关键词： acetic acid citric acid contaminated soil extractability metals multiple linear regression model soil parameters

Precision of Radiation Chemistry Networks: Playing Jenga with Kinetic Models for Liquid-Phase Electron Microscopy

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

Precision Chemistry 2023年第10期1卷 592-601页

作者： Birk fritsch Paolo Malgaretti Jens Harting Karl J.J.Mayrhofer Andreas Hutzler Helmholtz Institute Erlangen-Nürnberg for Renewable Energy(IEK-11) Forschungszentrum Jülich GmbH91058 ErlangenGermany Department of Chemical and Biological Engineering and Department of Physics Friedrich-Alexander-Universität Erlangen-Nürnberg91058 ErlangenGermany

Liquid-phase transmission electron microscopy(LP-TEM)is a powerful tool to gain unique insights into dynamics at the *** electron probe,however,can induce significant beam effects that often alter observed phenomena such as radiolysis of the aqueous *** magnitude of beam-induced radiolysis can be assessed by means of radiation chemistry simulations potentially enabling quantitative application of ***,the computational cost of these simulations scales with the amount of reactants *** minimize the computational cost,while maintaining accurate predictions,we optimize the parameter space for the solution chemistry of aqueous systems in general and for diluted HAuCl4 solutions in *** results indicate that sparsened kinetic models can accurately describe steady-state formation during LP-TEM and provide a handy prerequisite for efficient multidimensional *** emphasize that the demonstrated workflow can be easily generalized to any kinetic model involving multiple reaction pathways.

关键词： Electron beam effects gold radiolysis kinetic modeling simulation efficiency liquid cell transmission electron microscopy

Scalable high-repetition-rate sub-half-cycle terahertz pulses from spatially indirect interband transitions

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) 2022年第6期11卷 1304-1311页

作者： Christian Meineke Michael Prager Johannes Hayes Qiannan Wen Lukas Zheyi Kastner dieter Schuh Kilian fritsch Oleg Pronin Markus Stein Felix Schafer Sangam Chatterjee Mackillo Kira Rupert Huber Dominique Bougeard Department of Physics University of Regensburg93040 RegensburgGermany Department of Electrical Engineering and Computer Science University of MichiganAnn ArborMl 48109USA Faculty of Electrical Engineering Helmut Schmidt University22043 HamburgGermany Institute of Experimental Physics I Justus Liebig University Giessen35392 GiessenGermany

Intense phase-locked terahertz(THz)pulses are the bedrock of THz lightwave electronics,where the carrier field creates a transient bias to control electrons on sub-cycle time *** applications such as THz scanning tunnelling microscopy or electronic devices operating at optical clock rates call for ultimately short,almost unipolar waveforms,at megahertz(MHz)repetition ***,we present a flexible and scalable scheme for the generation of strong phase-locked THz pulses based on shift currents in type-ll-aligned epitaxial semiconductor *** measured THz waveforms exhibit only 0.45 optical cycles at their centre frequency within the full width at half maximum of the intensity envelope,peak fields above 1.1 kVcm^(-1) and spectral components up to the mid-infrared,at a repetition rate of 4 *** only positive half-cycle of this waveform exceeds all negative half-cycles by almost four times,which is unexpected from shift currents *** detailed analysis reveals that local charging dynamics induces the pronounced positive THz-emission peak as electrons and holes approach charge neutrality after separation by the optical pump pulse,also enabling ultrabroadband *** unipolar emitters mark a milestone for flexibly scalable,next-generation high-repetition-rate sources of intense and strongly asymmetric electric field transients.

关键词： pump repetition cycle

Pollen morphology of Gaultheriar *** related genera of subfamily Vaccinioideae:taxonomic and evolutionary significance

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Pollen morphology of Gaultheriar *** related genera of subfa...