检索结果-南通市图书馆

f?(H2O)+CH3I Ligand Exchange reaction Dynamics

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Physics 2020年第2期33卷 210-216,I0003,I0039-I0040页

作者： Bjorn Bastian Tim Michaelsen Milan Oncák Jennifer Meyer roland Wester institut für Ionenphysik und angewandte physik Universitat InnsbruckTechnikerstraβe 256020 InnsbruckAustria

Single hydration of the gas phase f^-+CH3I→CH3f reaction allows to probe solvent effects on a fundamental nucleophilic substitution *** the same time,the addition of a solvent molecule opens alternative product ***,we present crossed beam imaging results on the dynamics of the f^-(H2O)+CH3I→[fCH3I]^-+H2O ligand exchange pathway at collision energies between 0.3 and 2.6 *** kinetic energies are constrained by the stability requirement of the weakly bound product *** implies substantial internal excitation of the water molecule and disfavors effcient energy redistribution in an intermediate complex,which is reflected by the suppression of low kinetic energies as collision energy *** 0.3 eV,internal nucleophilic displacement is important and is discussed in light of the competing nucleophilic substitution pathways that form I^- and I^-(H2O).

关键词： reaction dynamics Ligand exchange Microsolvation Crossed beams Velocity map imaging

Quantum Impurity Models with Coupled Cluster 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

Communications in Theoretical Physics 2010年第9期54卷 509-517页

作者： Clive Emary Tobias Brandes institut für Theoretische physik

We investigate the ground-state properties of the Anderson single impurity model （finite Coulomb impurity repulsion） with the Coupled Cluster Method. We consider different CCM reference states and approximation schemes and make comparison with exact Green＇s function results for the non-interacting model and with Brillouin-Wigner perturbation theory for the full interacting model. Our results show that coupled cluster techniques are well suited to quantum impurity problems.

关键词： strongly correlated electrons Anderson model coupled-cluster method quantum impurity

Applying ionic liquids as oil additives for gearboxes:Going beyond the state of the art by bridging the nano-scale and component level

在线全文

学校读者我要写书评

暂无评论

friction 2023年第6期11卷 1057-1078页

作者： Azhaarudeen ANIfA MOHAMED fArUCK Philipp G.GrÜTZMACHEr Chia-Jui HSU Dominik DWOrSCHAK Hsiu-Wei CHENG Markus VALTINEr Kristof STAGEL Philipp MIKSOVSKY Apurba ranjan SAHOO Aitor SAINZ MArTINEZ Katharina BICA-SCHrODEr Michael WEIGAND Carsten GACHOT institut für Konstruktionswissenschaften und Produktentwicklung(IKP) Tribology Research DivisionTU WienVienna1060Austria institut für angewandte physik(IAP) Applied Interface Physics research groupTU WienVienna1040Austria institut für angewandte Synthesechemie(IAS) Sustainable Organic Synthesis and Catalysis research groupTU WienVienna1060Austria

Ionic liquids(ILs)have been used effectively in many applications for reducing problems related to friction and *** this work,the potential of ILs as an anti-wear and extreme pressure lubricant additive for high load-carrying gearbox applications such as helicopter transmissions has been *** halide-free ILs:P_(8881)(BuO)_(2)PO_(2)^(-)(1)and P_(8881)(MeO)_(2)PO_(2)^(-)(2),which are blended at 5 wt%each into a standard non-additivated fVA2 base oil(BO)are *** solid-liquid interface,friction and load-carrying capacity,and wear(scuffing)behavior are studied on the nano-,lab-,and component-scale,respectively,at a different range of temperature and loading conditions by using the atomic force microscopy(AfM),Schwing-reib-Verschleiβ(SrV)friction tests,and Brugger tests,as well as forschungsstelle für zahnrader und getriebebau(fZG)back-to-back gear test *** AfM analysis shows nearly no change of adhesion over the full range of studied temperature for the IL blends compared to the ***,IL blends demonstrate a very stable coefficient of friction(COf)of around 0.16,which even decreases with increasing test temperatures ranging from 40 to 120℃.A clear reduction in COf up to 25%is achieved by adding only 5 wt%of the investigated Ils in the BO,and the Brugger tests also show a pronounced enhancement of load-carrying ***,on the component-scale,a significant improvement in gear scuffing performance has been observed for both used IL blends.A detailed characterization of the wear tracks from the SrV friction tests via the transmission electron microscopy(TEM)revealed the formation of a phosphate(P-O)-based amorphous tribo-chemical layer of about 20 nm ***,this work may present an approach for Ils to be used as an additive in conventional lubricants due to their ability to enhance the lubrication properties,making them an alternative lubricant solution for high load-carrying gearbox applications.

关键词： ionic liquids(ILs) additives gears scuffing friction load-carrying capacity

A hybrid algorithm for reengineering the refractive index profile of inhomogeneous coatings from optical in-situ broadband monitoring data

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

光学精密工程 2005年第4期13卷 487-491页

作者： S. Wilbrandt O. Stenzel D. Gbler N. Kaiser friedrich-Schiller-Universitt Jena Institut für Angewandte Physik Max-Wien-Platz 1 07743 Jena GermanyFraunhofer-Institut für Angewandte Optik und Feinmechanik Albert-Einstein-Str. 7 D-07745 Jena GermanyFraunhofer-Institut für Angewandte Optik und Feinmechanik Albert-Einstein-Str. 7 D-07745 Jena GermanyFraunhofer-Institut für Angewandte Optik und Feinmechanik Albert-Einstein-Str. 7 D-07745 Jena Germany

reengineering the refractive index profile of inhomogeneous coatings is a troublesome task. Multiplicity of solutions may significantly reduced by providing additional information. for this reason an in-situ broadband monitoring system was developed to measure the transmittance of the growing film directly at the rotating substrate. for characterization of these coatings, a new model was developed, which significantly reduces the number of parameters. The refractive index profile may be described by a proper number of equally spaced volume fraction values using the Bruggeman effective media approach. A good initial approximation of the refractive index profile can be generated based on deposition rates for both materials recorded with quartz crystal monitor during manufacturing. During the optimization process, a second order minimization algorithm was used to vary the refractive index profile of the whole coating and film thickness of the intermediate stages. finally, a significantly improved accuracy of the modelled transmittance was achieved.

关键词：光学涂覆技术折射率宽带混合模型管理方式

Emerging smart design of electrodes for micro-supercapacitors:A review

在线全文

学校读者我要写书评

暂无评论

SmartMat 2022年第3期3卷 447-473页

作者： Jiajia Qiu Huaping Zhao Yong Lei fachgebiet angewandte Nanophysik Institut für Physik&IMN MacroNanoTechnische Universität IlmenauIlmenauGermany

Owing to high power density and long cycle life,micro-supercapacitors(MSCs)are regarded as a prevalent energy storage unit for miniaturized electronics in modern life.A major bottleneck is achieving enhanced energy density without sacrificing both power density and cycle *** this end,designing electrodes in a“smart”way has emerged as an effective strategy to achieve a trade-off between the energy and power densities of *** the past few years,considerable research efforts have been devoted to exploring new electrode materials for high capacitance,but designing clever configurations for electrodes has rarely been investigated from a structural point of view,which is also important for MSCs within a limited footprint area,in *** review article categorizes and arranges these“smart”design strategies of electrodes into three design concepts:layer-by-layer,scaffoldassisted and rolling *** corresponding strengths and challenges are comprehensively summarized,and the potential solutions to resolve these challenges are pointed ***,the smart design principle of the electrodes of MSCs and key perspectives for future research in this field are outlined.

关键词： energy density layer-by-layer micro-supercapacitors rolling origami scaffold smart design of electrodes

recent results from NA48/2

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 Physics C 2010年第6期34卷 749-752页

作者： Cristina Morales Morales institut für physik Universitt Mainz

recent results on radiative K^± decays from the NA48/2 experiment are reported. from the full NA48/2 data set, about a million K^±→π^±π^γ decays were reconstructed. Based on this sample, the first measurement of the interference between direct photon emission and inner bremsstrahlung in K^±→π^±π^γ decays was performed. Stringent limits on CP violation in this decay were also set. In addition, a precise measurement of the branching fraction of K^±→π^±γγ is presented. This measurement was based on a data sample of more than 1000 event candidates. Also the related decay K^±→π^±e^＋e^-γ has first been observed. results of the measurement of the decay rate and the decay parameter 5 are summarized.

关键词： radiative K^± decays NA48/2 CP violation

Anode materials for potassium-ion batteries: Current status and prospects

在线全文

学校读者我要写书评

暂无评论

Carbon Energy 2020年第3期2卷 350-369页

作者： Mo Sha Long Liu Huaping Zhao Yong Lei fachgebiet angewandte Nanophysik Institut für Physik&IMN MacroNano®(ZIK)Technische Universität IlmenauIlmenauGermany

Potassium-ion batteries(KIBs)as one of the most promising alternatives to lithium-ion batteries have been highly valued in recent ***,progress in KIBs is largely restricted by the sluggish development in anode ***,it is imperative to systematically outline and evaluate the recent research advances in the field of anode materials for KIBs toward promoting the development of high-performance anode materials for *** this review,the recent achievements in anode materials for KIBs are *** electrochemical properties(*** storage mechanism,capacity,rate performance,and cycling stability)of these reported anode materials,as well as their advantages/disadvantages,are discerned and analyzed,enabling high-performance KIBs to meet the requirements for practical ***,technological developments,scientific challenges,and future research opportunities of anode materials for KIBs are briefly reviewed.

关键词： anode materials capacity and stability electrochemical properties energy density potassium-ion batteries

Advances on three-dimensional electrodes for micro-supercapacitors:A mini-review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

InfoMat 2019年第1期1卷 74-84页

作者： Long Liu Huaping Zhao Yong Lei fachgebiet angewandte Nanophysik Institut für Physik&IMN MacroNano®(ZIK)Technische Universität IlmenauIlmenauGermany

Owing to the high power density,long cycle life and maintain-free,micro-supercapacitors(MSCs)stand out as preferred miniaturized energy source for themiscellaneous autonomous electronic ***,the shortage of energy density is the main stumbling block for their practical *** solve this energy issue,constructing a three-dimensional(3D)electrode within the limited footprint area is proposed as a new solution for improving the energy storage capacity *** the last few years,extensive efforts have been devoted to developing 3D electrodes for MSCs,and significant progress and breakthrough have been ***,there is still lack of systematic summary on the 3D electrode design *** this end,it is imperative to outline the basic design conception,summarize the current states,and discuss the future research about 3D electrodes in MSCs based on the latest development.

关键词： in-plane configuration Internet of Things micro-supercapacitors sandwich configuration threedimensional electrodes

Dust growth in protoplanetary disks-a comprehensive experimental / theoretical approach

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

research in Astronomy and Astrophysics 2010年第12期10卷 1199-1214页

作者： Jürgen Blum institut für Geophysik und extraterrestrische physik University of Braunschweig

More than a decade of dedicated experimental work on the collisional physics of protoplanetary dust has brought us to a point at which the growth of dust aggregates can - for the first time - be self-consistently and reliably modeled. In this article, the emergent collision model for protoplanetery dust aggregates, as well as the numerical model for the evolution of dust aggregates in protoplanetary disks, is reviewed. It turns out that, after a brief period of rapid collisional growth of fluffy dust aggregates to sizes of a few centimeters, the protoplanetary dust particles are subject to bouncing collisions, in which their porosity is considerably decreased. The model results also show that low-velocity fragmentation can reduce the final mass of the dust aggregates but that it does not trigger a new growth mode as discussed previously. According to the current stage of our model, the direct formation of kilometer-sized planetesimals by collisional sticking seems unlikely, implying that collective effects, such as the streaming instability and the gravitational instability in dust-enhanced regions of the protoplanetary disk, are the best candidates for the processes leading to planetesimals.

关键词： planetary systems: protoplanetary disks -- planetary systems: formation-- methods: laboratory -- methods: numerical