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Electrochemical Realization of 3D Interconnected MoS_(3)/PPy Nanowire Frameworks as Sulfur-Equivalent Cathode Materials for Li-S Batteries

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Energy & Environmental Materials 2024年第2期7卷 9-17页

作者： Hongtao Yu Andreas Siebert Shilin Mei Raul Garcia-Diez Roberto Félix Ting Quan Yaolin Xu Johannes Frisch Regan G.Wilks Marcus Bär Chun Pei Yan Lu Department for Electrochemical Energy Storage Helmholtz-Zentrum Berlin für Materialien und Energie GmbH(HZB)Hahn-Meitner Platz 114109 BerlinGermany Guangdong Province Key Laboratory of Durability for Marine Civil Engineering School of Civil EngineeringShenzhen UniversityShenzhenGuangdong 518060China Department of Interface Design HZBAlbert-Einstein-Str.1512489 BerlinGermany Energy Materials In-Situ Laboratory berlin(EMIL) Albert-Einstein-Str.1512489 BerlinGermany Helmholtz-Institute Erlangen-Nürnberg for Renewable Energy(HI ERN) Albert-Einstein-Str.1512489 BerlinGermany Department of Chemistry and Pharmacy Friedrich-Alexander-Universität Erlangen-NürnbergEgerlandstr.391058Erlangen Germany Institute of Chemistry University of Potsdam14467Potsdam Germany

The development of freestanding and binder-free electrode is an effective approach to perform the inherent capacity of active materials and promote the mechanism study by minimizing the interference from ***,we construct a freestanding cathode composed of MoS_(3)/PPy nanowires(NWs)deposited on porous nickel foam(NF)(MoS_(3)/PPy/NF)through electrochemical methods,which can work efficiently as sulfur-equivalent cathode material for Li-S *** structural stability of the MoS_(3)/PPy/NF cathode is greatly enhanced due to its significant tolerance to the volume expansion of MoS_(3)during the lithiation process,which we ascribe to the flexible 3D framework of PPy NWs,leading to superior cycling performance compared to the bulk-MoS_(3)/NF *** the interference of binder and carbon additives,the evolution of the chemical and electronic structure of Mo and S species during the discharge/charge was studied by X-ray absorption near-edge spectroscopy(XANES).The formation of lithium polysulfides was excluded as the driving cathode reaction mechanism,suggesting the great potential of MoS_(3)as a promising sulfur-equivalent cathode material to evade the shuttle effect for Li-S *** present study successfully demonstrates the importance of structural design of freestanding electrode enhancing the cycling performances and revealing the corresponding mechanisms.

关键词： 3D-Network electrochemical lithium-sulfur battery MoS_(3) PPy

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Mechanism of cross-level settlements and void accumulation of wide and conventional sleepers in railway ballast

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Railway Engineering Science 2024年第3期32卷 361-383页

作者： Olga Nabochenko Mykola Sysyn Norman Krumnow Szabolcs Fischer Institute of Railway Systems and Public Transport Technical University of DresdenDresdenGermany Rhomberg Sersa Deutschland gmbh BerlinGermany Central Campus Győr Széchenyi István UniversityGyorHungary

The cross-level and twist irregularities are the most dangerous irregularity types that could cause wheel unloading with the risk of derailments and additional maintenance ***,the mechanism of the irregularities initiation and development is *** motivation of the present study was the previous experimental studies on the application of wide sleepers in the ballasted *** long-term track geometry measurements with wide sleepers show an enormous reduction of the vertical longitudinal irregularities compared to the conventional ***,wide sleepers had higher twist and cross-section level *** present paper aims to explain the phenomenon by discrete element method(DEM)modeling the development process of sleeper inhomogeneous support at cross-level depending on the sleeper *** DEM simulations show that the maximal settlement intensity is up to 3.5 times lower for a wide sleeper in comparison with the conventional ***,the cross-level differential settlements are almost the same for both *** particle loading distribution after all loading cycles is concentrated on the smaller area,up to the half sleeper length,with fully unloaded zones under sleeper *** flow limitation under the central part of the sleeper could improve the resilience of wide sleepers to the development of cross-level *** mechanism of initiation of the cross-level irregularity is proposed,which assumes the loss of sleeper support under sleeper *** further growth of inhomogeneous settlements along the sleeper is assumed as a result of the interaction of two processes:ballast flow due to dynamic impact during void closing and on the other side high pressure due to the concentration of the pressure under the middle part of the *** DEM simulation results support the assumption of the mechanism and agree with the experimental studies.

关键词： Wide sleeper Ballasted track Sleeper support inhomogeneity Sleeper foot form Discrete element modeling Void accumulation

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Numerical investigations of arc behaviour in gas metal arc welding using ANSYS cfx

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Frontiers of Materials Science 2011年第2期5卷 98-108页

作者： M. SCHNICK U. FUESSEL M. HERTEL A. SPILLE-KOHOFF A. B. MURPHY Institute of Surface and Manufacturing Technology Technische Universitat Dresden Dresden Germany cfx berlin software gmbh Berlin Germany CSIRO Materials Science and Engineering Lindfield NSW 2070 Australia

Current numerical models of gas metal arc welding（GMAW）are trying to combine magnetohydrodynamics （MRD） models of the arc and voiume of fluid （VoF） models of metal transfer They neglect vaporization and assume an argon atmosphere for the arc region, as it is common practice for models of gas tungsten arc welding, These models predict temperatures above 20 000K anda temperature distribution similar to tungsten inert gas （TIG） arcs： However. current spectroscopic temperature measuretemperatures. In contrast to TIG arcs temperature distrbution. The paper vapour and which is in a yery good res, Futhermore; the model is abile to predict the local central minimum in the radial temperature and the radial electric current density distributions for the first time. The axially symmetric model of the welding torch, the work piece, the wire and the arc （fluid domain） implements MHD as well as turbulent mixing and thermal demixing of metal vapour in argon. The mass fraction of iron vapour obtained from the simulation shows an accumulation in the arc core and another accumulation on the fringes of the arc at 2000 to 5000 K. The demixing effects lead to very low concentrations of iron between these two regions. Sensitive analyses demonstrate the influence of the transport and radiation properties of metal vapour, and the evaporation rate relative to the wire feed. Finally the model predictions are compared with the measuring results of Zielihska et al.

关键词： arc welding numericai simulation GMAW, ANSYS cfx

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Treatment of intermediate-risk prostate cancer with active surveillance in the routine care-Long-term outcomes of a prospective noninterventional study (HAROW)

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CURRENT UROLOGY 2024年第2期18卷 115-121页

作者： Weissbach, Lothar Schwarte, Andreas Boedefeld, Edith A. Herden, Jan Hlth Res Men gmbh Berlin Germany Urol Practice Borken Borken Germany Univ Cologne Fac Med & Univ Hosp Cologne Dept Urol Urooncol Robot Assisted & Reconstruct Ur Cologne Germany PAN Clin Urol Practice Cologne Germany Univ Hosp Cologne Dept Urol Kerpener Str 62 Cologne Germany

BackgroundWe report here the long-term outcomes of patients with intermediate-risk prostate cancer (PCa) treated with active surveillance (AS) in a daily routine *** and methodsHAROW (2008-2013) was a noninterventional, health service research study investigating the management of localized PCa in a community setting. A substantial proportion of the study centers were office-based urologists. A follow-up examination of all intermediate-risk patients with AS was conducted. Overall, cancer-specific, metastasis-free, and treatment-free survival rates, as well as reasons for discontinuation, were determined and *** the 2957 patients enrolled, 52 with intermediate-risk PCa were managed with AS and were available for evaluation. The median follow-up was 6.8 years (interquartile range, 3.4-8.6 years). Seven patients (13.5%) died of causes unrelated to PCa, of whom 4 were under AS or under watchful waiting. Two patients (3.8%) developed metastasis. The estimated 8-year overall, cancer-specific, metastasis-free, and treatment-free survival rates were 85% (95% confidence interval [CI], 72%-96%), 100%, 93% (95% CI, 82%-100%), and 31% (95% CI, 17%-45%), respectively. On multivariable analysis, prostate-specific antigen density of >= 0.2 ng/mL2 was significantly predictive of receiving invasive treatment (hazard ratio, 3.29; p = 0.006). Reasons for discontinuation were more often due to patient's or physician's concerns (36%) than due to observed clinical *** survival outcome data for intermediate-risk patients managed with AS in real-life health care conditions were promising, rates of discontinuation were high, and discontinuation was often a patient's decision, even when the signs of disease progression were absent. This might be an indication of higher levels of mental burden and anxiety in this specific subgroup of patients, which should be considered when making treatment decisions. From a psychological perspective,

关键词： Active surveillance Intermediate-risk prostate cancer HAROW study Conservative management Outcomes research TREATMENT OPTIONS GUIDELINES MANAGEMENT GRADE

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平衡三阳离子钙钛矿中带隙和电荷传输以实现高效的室内光伏

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Science China Materials 2024年第8期67卷 2611-2617页

作者：唐颖张祖宏刘海瑞马哈茂德・侯赛因・阿尔达马西穆罕默德・比拉尔杨枫杨纪恩秦朝朝杨勇刚李哲刘玉芳李萌 School of Physics Henan Normal UniversityXinxiang 453007China Key Lab for Special Functional Materials of Ministry of Education National&Local Joint Engineering Research Center for High-Efficiency Display and Lighting TechnologySchool of Nanoscience and Materials EngineeringCollaborative Innovation Center of Nano Functional Materials and ApplicationsHenan UniversityKaifeng 475004China School of Materials Science and Engineering Henan Normal UniversityXinxiang 453007China Helmholtz-Zentrum berlin fur Materialien und Energie gmbh Hahn-Meitner-Platz 1Berlin 14109Germany School of Engineering and Materials Science(SEMS) Queen Mary University of LondonLondon E14NSUK Institute of Physics Henan Academy of SciencesZhengzhou 450000China

带隙可调的钙钛矿材料在室内光伏(IPVs)领域具有广阔的应用前景.然而,与室内光相匹配的宽带隙钙钛矿通常导电性较差,缺陷密度较高,往往不利于电荷提取和传输,限制了其光伏特性.在这里,我们通过调节Br/I比,探究了不同带隙三阳离子钙钛矿... 详细信息

带隙可调的钙钛矿材料在室内光伏(IPVs)领域具有广阔的应用前景.然而,与室内光相匹配的宽带隙钙钛矿通常导电性较差,缺陷密度较高,往往不利于电荷提取和传输,限制了其光伏特性.在这里,我们通过调节Br/I比,探究了不同带隙三阳离子钙钛矿的IPVs特性.研究表明,宽带隙钙钛矿能充分利用室内光,在低照度下能获得较高的开路电压,但高Br/I比的钙钛矿具有较高的缺陷密度,不利于获得高短路电流密度和填充因子.通过进一步研究不同带隙钙钛矿的结晶动力学、缺陷密度和电荷传输特性,我们发现主流观念中高效IPVs着重考虑室内光伏材料的带隙是不全面的,我们证明了通过适当降低宽带隙晶体中的Br含量可以获得室内光伏特性更优异的器件.也就是说,室内光伏晶体材料的制备需要兼顾带隙和电荷传输特性.在此工作中,平衡带隙和电荷传输的器件(Br 0.23,1.62 eV)在1035 lux的LED灯照射下取得了40.71%的最佳效率.我们的研究为高效室内光伏的设计提供了新思路.

关键词：缺陷密度电荷传输光伏特性钙钛矿最佳效率光伏材料短路电流密度填充因子

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Model Experiments on Melting of Alloys with Low Melting Temperature in a Medium with High Melting Temperature

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Journal of Iron and Steel Research International 1999年第2期6卷 1-9页

作者： Becker Jens-Ulrik Oeters Franz Thyssen-Krupp Stahl gmbh Technical University berlin

Experiments of alloy melting were carried out in water/HCl H 2O eutectic model system. The eutectic has a solid liquid equilibrium temperature of -74 ℃. 5 cm diameter spheres of the eutectic in which three thermocouples in the core, on the edge and in the middle between them had been positioned were cooled to -196 ℃ in liquid nitrogen. After cooling the spheres were immersed into water of 10 ℃, and the changes of temperatures with time in the three thermocouples were measured. In some experiments the temperature on the outer side of the spheres where an ice shell grew up was also measured. In these experiments, the growing rate of the shell was additionally determined. The results for the first minute of the melting process, where the system can be considered as one dimensional, were described by an exact solution of Fouriers equation. The density of liquid ferromanganese at 1 500 ℃ was measured.

关键词： alloy melting model experiment

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Defect-density control of platinum-based nanoframes with high-index facets for enhanced electrochemical properties

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Nano Research 2019年第11期12卷 2881-2888页

作者： Shaohan Yang Shuna Li Lianghao Song Yipin Lv Zhongyao Duan Chunsheng Li Raphael Francesco Praeg Daowei Gao Guozhu Chen School of Chemistry and Chemical Engineering University of JinanJinan250022China Institute for Solar Fuels Helmholtz Zentrum Berlin für Materialien und Energie GmbHBerlin14109Germany Young Investigator Group Operando Characterization of Solar Fuel Materials Helmholtz-Zentrum Berlin für Materialien und Energie GmbHBerlin12489Germany

Structure-engineered platinum-based nanoframes(NFs)at the atomic level can effectively improve the catalytic performance for fuel cells and other heterogeneous catalytic *** report herein,a microwave-assisted wet-chemical method for the preparation of platinum-copper-cobalt NFs with tunable defect density and architecture,which exhibit enhanced activity and durability towards the electro-oxidation reactions of methanol(MOR)and formic acid(FAOR).By altering the reduction/capping agents and thus the nucleation/growth kinetics,trimetallic platinum-copper-cobalt hexapod NFs with different density high-index facets are ***,the rough hexapod nanoframes(rh-NFs)exhibit excellent specific activities towards MOR and FAOR,7.25 and 5.20 times higher than those of benchmark Pt/C,respectively,along with prolonged *** excellent activities of the rh-NFs are assigned to a synergistic effect,including high density of defects and high-index facets,suitable d-band center,and open-framework *** synergistic working mechanism opens up a new way for enhancing their electrocatalytic performances by increasing defect density and high-index facets in open-framework platinum-based NFs.

关键词： nanoframes defect-density high-index facets electrocatalyst

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Retinal microvascular signs and recurrent vascular events in patients with TIA or minor stroke

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Stroke & Vascular Neurology 2023年第5期8卷 379-386,I0001-I0007页

作者： Philipp Klyscz Thomas Ihl Inga Laumeier Maureen Steinicke Matthias Endres Georg Michelson Heinrich J Audebert Neurology Charité-Universitätsmedizin BerlinBerlinGermany Center for Stroke Research berlin Charité-Universitätsmedizin BerlinBerlinGermany berlin Institute of Health BerlinGermany Excellence Cluster NeuroCure Charité-Universitätsmedizin BerlinBerlinGermany German Center for Neurodegenerative Diseases partner site BerlinGermany German Center for Cardiovascular Research partner site BerlinGermany Ophthalmology Friedrich-Alexander-Universität Erlangen-Nürnberg Medizinische FakultätErlangenGermany Talkingeyes&More gmbh ErlangenGermany

Background and purpose Retinal pathologies are an independent risk factor for ischaemic stroke,but research on the predictive value of retinal abnormalities for recurrent vascular events in patients with prior stroke is *** investigated the association of retinal pathologies with subsequent vascular *** In a substudy of the Intensified secondary prevention intending a reduction of recurrent events in TIA and minor stroke patients(INSPiRE-TMS)trial,we enrolled patients with recent transient ischaemic attack(TIA)or minor stroke with at least one modifiable risk *** outcome was the composite of subsequent vascular *** photographs were taken at baseline and categorised into three different fundus groups by a telemedically linked *** 722 patients participated in the current study and 109 major vascular events *** multivariable adjustments,we did not find a significant association between fundus categories and risk for subsequent vascular events(HRs for moderate vascular retinopathy and vascular retinopathy with vessel rarefaction in comparison to no vascular retinopathy 1.03(95%CI 0.64 to 1.67),p=0.905 and 1.17(95%CI 0.62 to 2.20),p=0.626).In a selective post hoc analysis in patients with diabetes mellitus and hypertension,patients with vascular retinopathy with vessel rarefaction had a higher risk for recurrent stroke(HR 24.14(95%CI 2.74 to 212.50),p=0.004).Conclusions Retinal changes did not predict major subsequent vascular events in patients with recent TIA or minor *** studies are needed to examine the utility of fundus photography in assessing the risk of stroke recurrence in patients with diabetes mellitus and hypertension.

关键词： patients Retinal prevention

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Satellite Communications Integration with Terrestrial Networks

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China Communications 2018年第8期15卷 22-38页

作者： Adam Kapovits Marius-lulian Corici Ilie-Daniel Gheorghe-Pop Anastasius Gavras Frank Burkhardt Thomas Schlichter Stefan Covaci Eurescom gmbh Heidelberg 69123Germany Fraunhofer Institute for Open Communication Systems FOKUS Berlin 10589Germany Fraunhofer Institute for Integrated Circuits IIS Erlangen 91058Germany Technische Universitat berlin Berlin 10623Germany

In this paper we evaluate the feasibility of seamless and efficient integration of terrestrial communication systems with satellite networks. This aspect is considered by standardisation bodies such as ETSI [1], 5 G-PPP [2] and 3 GPP [3]. A comprehensive system is designed and implemented in an emulation prototype, including standard 3 GPP LTE core network functionality [4] with its different layers: networking, data forwarding, control, management and monitoring and is validated through performance measurements. This work is a technical feasibility study of extending terrestrial communication systems with satellite networks as backhaul, increasing the energy efficiency, network robustness during natural disasters as well as being an alternative for peak-time data forwarding of the terrestrial communication services. Due to its global coverage property, terrestrial-satellite integration provides an obvious extension of communication services towards isolated and remote areas and an alternative for rural or highly distributed/highly mobile enterprise networks.

关键词： network convergence application sector requirements experimental validation

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Radiofrequency induced heating of biodegradable orthopaedic screw implants during magnetic resonance imaging

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Bioactive Materials 2023年第7期25卷 86-94页

作者： Jonathan Espiritu Mostafa Berangi Hanna Cwieka Kamila Iskhakova Andre Kuehne D.C.Florian Wieland Berit Zeller-Plumhoff Thoralf Niendorf Regine Willumeit-Römer Jan-Marten Seitz Syntellix AG HannoverGermany MRI.TOOLS gmbh BerlinGermany Charité-Universitätsmedizin berlin Corporate Member of Freie Universität Berlin and Humboldt Universität zu BerlinBerlinGermany berlin Ultrahigh Field Facility(B.U.F.F.) Max-Delbrueck Center for Molecular Medicine in the Helmholtz AssociationBerlinGermany Institute of Metallic Biomaterials Helmholtz Zentrum HereonGeesthachtGermany

Magnesium(Mg)-based implants have re-emerged in orthopaedic surgery as an alternative to permanent *** reveals little information on how the degradation of biodegradable implants may introduce safety implications for patient follow-up using medical *** resonance imaging(MRI)benefits post-surgery monitoring of bone healing and implantation *** studies demonstrated radiofrequency(RF)heating of permanent implants caused by electromagnetic fields used in *** investigation is the first to report the effect of the degradation layer on RF-induced heating of biodegradable orthopaedic ***43 orthopaedic compression screws underwent in vitro *** techniques were applied to assess the corrosion process and the material composition of the degraded *** measurements were performed to quantify implant heating with respect to the degradation *** comparison,a commercial titanium implant screw was *** RF induced heating was observed for non-degraded WE43 screw *** heating had shown to decrease with the formation of the degradation *** statistical differences were observed for heating of the non-degraded WE43 material and the titanium *** highest risk of implant RF heating is most pronounced for Mg-based screws prior to *** to industry standards for MRI safety assessment is warranted to include biodegradable materials.

关键词： Biodegradable implants Magnesium Medical imaging Magnetic resonance imaging Patient safety

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