Droplet impact on solid surfaces plays a critical role in a wide range of applications,including inkjet printing,spray cooling,surface coatings,and microdroplet chemistry.Precise control of droplet–surface interactio...Droplet impact on solid surfaces plays a critical role in a wide range of applications,including inkjet printing,spray cooling,surface coatings,and microdroplet chemistry.Precise control of droplet–surface interactions is essential,but the fundamental mechanisms governing this process are still not fully understood.In this study,we demonstrate that large contact angle hysteresis(CAH)on hydrophobic nanoporous surfaces significantly amplifies post-impact droplet oscillations.This reveals the critical influence of CAH on the redistribution of impact energy and the modulation of droplet–surface interactions.Using shape mode decomposition via Legendre polynomials and fast Fourier transform spectral analysis,we show that surfaces with larger CAH excite and sustain higher-order droplet shape mode oscillations,leading to persistent capillary waves even after contact line pinning.The observed amplitude modulation and multiple frequency components within individual shape modes reveal nonlinear energy transfer between different modes.These amplified and coupled oscillations are shown to promote daughter droplet coalescence.This study presents a framework for understanding the role of CAH in storing and redistributing impact energy through nonlinear mode excitation and establishes CAH as a critical design parameter for controlling fluid dynamics on solid surfaces.展开更多
Understanding the properties of warm dense hydrogen is of key importance for the modeling of compact astrophysical objects and to understand and further optimize inertial confinement fusion applications.The workhorse ...Understanding the properties of warm dense hydrogen is of key importance for the modeling of compact astrophysical objects and to understand and further optimize inertial confinement fusion applications.The workhorse of warm dense matter theory is thermal density functional theory(DFT),which,however,suffers from two limitations:(i)its accuracy can depend on the utilized exchange-correlation functional,which has to be approximated,and(ii)it is generally limited to single-electron properties such as the density distribution.Here,we present a new ansatz combining time-dependent DFT results for the dynamic structure factor S_(ee)(q,ω)with static DFT results for the density response.This allows us to estimate the electron-electron static structure factor S_(ee)(q)of warm dense hydrogen with high accuracy over a broad range of densities and temperatures.In addition to its value for the study of warm dense matter,our work opens up new avenues for the future study of electronic correlations exclusively within the framework of DFT for a host of applications.展开更多
Ab initio modeling of dynamic structure factors(DSF)and related density response properties in the warm dense matter(WDM)regime is a challenging computational task.The DSF,convolved with a probing X-ray beam and instr...Ab initio modeling of dynamic structure factors(DSF)and related density response properties in the warm dense matter(WDM)regime is a challenging computational task.The DSF,convolved with a probing X-ray beam and instrument function,is measured in X-ray Thom-son scattering(XRTS)experiments,which allow the study of electronic structure properties at the microscopic level.Among the various ab initio methods,linear-response time-dependent density-functional theory(LR-TDDFT)is a key framework for simulating the DSF.The standard approach in LR-TDDFT for computing the DSF relies on the orbital representation.A significant drawback of this method is the unfavorable scaling of the number of required empty bands as the wavenumber increases,making LR-TDDFT impractical for modeling XRTS measurements over large energy scales,such as in backward scattering geometry.In this work,we consider and test an alternative approach to LR-TDDFT that employs the Liouville–Lanczos(LL)method for simulating the DSF of WDM.This approach does not require empty states and allows the DSF at large momentum transfer values and over a broad frequency range to be accessed.We compare the results obtained from the LL method with those from the solution of Dyson’s equation using the standard LR-TDDFT within the projector augmented-wave formalism for isochorically heated aluminum and warm dense hydrogen.Additionally,we utilize exact path integral Monte Carlo results for the imaginary-time density-density correlation function(ITCF)of warm dense hydrogen to rigorously benchmark the LL approach.We discuss the application of the LL method for calculating DSFs and ITCFs at different wavenumbers,the effects of pseudopotentials,and the role of Lorentzian smearing.The successful validation of the LL method under WDM conditions makes it a valuable addition to the ab initio simulation landscape,supporting experimental efforts and advancing WDM theory.展开更多
Froth flotation of scheelite has regained new focus since the 2010s and research regarding floatability and reagents has made great progress over the years. The main objective was and remains the selective flotation o...Froth flotation of scheelite has regained new focus since the 2010s and research regarding floatability and reagents has made great progress over the years. The main objective was and remains the selective flotation of scheelite from other calcium-bearing minerals, in particular calcite, fluorite and apatite. Due to similar properties, most attempts have limited success or only specific application(linked to a type of ore or a location). This article aims at reviewing all general physical-chemical information on froth flotation of scheelite, including electrokinetic properties, influence of p H and already existing reagents as well as ones still under examination. It appears that chelating or mixed collectors and modified versions of sodium silicate and quebracho hold great promise for scheelite flotation, while the use of said depressants and/or promoters seems inevitable.展开更多
The microsegregation behavior of the Al-4.5 wt%Cu alloy solidified at different cooling rates under the alternating magnetic field(AMF) was investigated.The experimental results showed that the amount of non-equilibri...The microsegregation behavior of the Al-4.5 wt%Cu alloy solidified at different cooling rates under the alternating magnetic field(AMF) was investigated.The experimental results showed that the amount of non-equilibrium eutectics in the interdendritic region decreased upon applying the AMF at the same cooling rate.The change in microsegregation could be explained quantificationally by the modifications of dendritic coarsening,solid-state back diffusion and convection in the AMF.The enhanced diffusivity in the solid owing to the AMF was beneficial for the improvement in microsegregation compared to the cases without an AMF.In contrast,the enhanced dendritic coarsening and forced convection in the AMF were found to aggravate the microsegregation level.Considering the contributions of the changes in above factors,an increase in solid diffusivity was found to be primarily responsible for the reduced microsegregation in the AMF.In addition,the microsegregation in the AMF was modeled using the analytical model developed by Voller.The calculated and experimental results were in reasonable agreement.展开更多
An accurate theoretical description of the dynamic properties of correlated quantum many-body systems,such as the dynamic structure factor S(q,ω),is important in many fields.Unfortunately,highly accurate quantum Mont...An accurate theoretical description of the dynamic properties of correlated quantum many-body systems,such as the dynamic structure factor S(q,ω),is important in many fields.Unfortunately,highly accurate quantum Monte Carlo methods are usually restricted to the imaginary time domain,and the analytic continuation of the imaginary-time density–density correlation function F(q,τ)to real frequencies is a notoriously hard problem.Here,it is argued that often no such analytic continuation is required because by definition,F(q,τ)contains the same physical information as does S(q,ω),only represented unfamiliarly.Specifically,it is shown how one can directly extract key information such as the temperature or quasi-particle excitation energies from theτdomain,which is highly relevant for equation-of-state measurements of matter under extreme conditions[T.Dornheim et al.,Nat.Commun.13,7911(2022)].As a practical example,ab initio path-integral Monte Carlo results for the uniform electron gas(UEG)are considered,and it is shown that even nontrivial processes such as the roton feature of the UEG at low density[T.Dornheim et al.,Commun.Phys.5,304(2022)]are manifested straightforwardly in F(q,τ).A comprehensive overview is given of various useful properties of F(q,τ)and how it relates to the usual dynamic structure factor.In fact,working directly in theτdomain is advantageous for many reasons and opens up multiple avenues for future applications.展开更多
The current work combines numerical and experimental investigations based on a small-scale mockup using the eutectic alloy GaInSn.The jet flow discharging from the submerged entry nozzle was exposed perpendicularly to...The current work combines numerical and experimental investigations based on a small-scale mockup using the eutectic alloy GaInSn.The jet flow discharging from the submerged entry nozzle was exposed perpendicularly to a DC magnetic field across the entire wide face of the mold.Numerical calculations were performed by using the commercial package CFX with an implemented RANS-SST turbulence model.The anisotropic properties of the MHD turbulence were taken into account by specific modifications of the turbulence model.The comparison between our numerical calculations and the experimental results shows a very well agreement.In particular,the modified RANS-SST turbulence model is capable to reconstruct the peculiar phenomenon of the excitation of non-steady,non-isotropic large-scale flow perturbations caused by the application of the DC magnetic field.Another important finding of our study is the feature that the electrical boundary conditions,namely the wall conductivity ratio,have a great impact on the mold flow subjected to an external magnetic field.展开更多
An induction levitation melting （ILM） refining process is performed to remove most microsized inclusions in ultra-low carbon steel （UCS）. Nanosized, spheroid shaped sulfide precipitates remain dispersed in the UCS...An induction levitation melting （ILM） refining process is performed to remove most microsized inclusions in ultra-low carbon steel （UCS）. Nanosized, spheroid shaped sulfide precipitates remain dispersed in the UCS. During the ILM process, the UCS is molten and is rotated under an upward magnetic field. With the addition of Ti additives, the spinning molten steel under the upward magnetic field ejects particles because of resultant centrifugal, floating, and magnetic forces. Magnetic force plays a key role in removing sub-micrometer-sized particles, composed of porous aluminum titanate enwrapping alumina nuclei. Consequently, sulfide precipitates with sizes less than 50 nan remain dispersed in the steel matrix. These findings open a path to the fabrication of clean steel or steel bearing only a nanosized strengthen- ing phase.展开更多
Efficient extraction and recycling methods are an important issue for rare earth elements(REE). The significant differences in their magnetic moments make magnetic separation a promising step. Although the magnetic fi...Efficient extraction and recycling methods are an important issue for rare earth elements(REE). The significant differences in their magnetic moments make magnetic separation a promising step. Although the magnetic field gradient manipulation of ions seemed to be impossible, the robust enrichment of some paramagnetic RE ions was found in the vicinity of the magnet. The studies in recent years resolved the physical paradox of why, despite the Brownian motion of the ions, there is a reproducible enrichment of RE ions in magnetic field gradients. The existence of trigger process and energy barrier was proved.However, these studies usually used only high paramagnetic ions, e.g., Dy(Ⅲ) or Ho(Ⅲ). This work verifies the theory of the possible magnetic separation for 8 different rare earth ions, respectively. For this purpose, concentration distribution in rare earth chloride solutions were measured using a MachZehnder interferometer. The magnetic field was assured by a Halbach configuration to enhance the effect. The results show the classification of RE solutions into 2 classes: Class I contains the REs with low magnetic moment, whereas Class II includes the REs of high magnetic moment. Only the latter group shows the enrichment of ions in the vicinity of the magnet which encourages the implementation of magnetic separation into existing hydrometallurgical technology to enhance the selectivity of REE.展开更多
We present quasi-exact ab initio path integral Monte Carlo(PIMC)results for the partial static density responses and local field factors of hydrogen in the warm dense matter regime,from solid density conditions to the...We present quasi-exact ab initio path integral Monte Carlo(PIMC)results for the partial static density responses and local field factors of hydrogen in the warm dense matter regime,from solid density conditions to the strongly compressed case.The full dynamic treatment of electrons and protons on the same footing allows us to rigorously quantify both electronic and ionic exchange–correlation effects in the system,and to compare the results with those of earlier incomplete models such as the archetypal uniform electron gas or electrons in a fixed ion snapshot potential that do not take into account the interplay between the two constituents.The full electronic density response is highly sensitive to electronic localization around the ions,and our results constitute unambiguous predictions for upcoming X-ray Thomson scattering experiments with hydrogen jets and fusion plasmas.All PIMC results are made freely available and can be used directly for a gamut of applications,including inertial confinement fusion calculations and the modeling of dense astrophysical objects.Moreover,they constitute invaluable benchmark data for approximate but computationally less demanding approaches such as density functional theory or PIMC within the fixed-node approximation.展开更多
The demand for lithium-ion batteries(LIBs)is driven largely by their use in electric vehicles,which is projected to increase dramatically in the future.This great success,however,urgently calls for the efficient recyc...The demand for lithium-ion batteries(LIBs)is driven largely by their use in electric vehicles,which is projected to increase dramatically in the future.This great success,however,urgently calls for the efficient recycling of LIBs at the end of their life.Herein,we describe a froth flotation-based process to recycle graphite—the predominant active material for the negative electrode—from spent LIBs and investigate its reuse in newly assembled LIBs.It has been found that the structure and morphology of the recycled graphite are essentially unchanged compared to pristine commercial anode-grade graphite,and despite some minor impurities from the recycling process,the recycled graphite provides a remarkable reversible specific capacity of more than 350 mAh g^(−1).Even more importantly,newly assembled graphite‖NMC532 cells show excellent cycling stability with a capacity retention of 80%after 1000 cycles,that is,comparable to the performance of reference full cells comprising pristine commercial graphite.展开更多
In most cases,the redox activity of a U^(Ⅵ)O_(2)^(2+) complex is regarded as metal-centered phenomena,because uranium has small energy gaps amongst the 5f/6d/7s subshells,thereby exhibiting a wide range of oxidation ...In most cases,the redox activity of a U^(Ⅵ)O_(2)^(2+) complex is regarded as metal-centered phenomena,because uranium has small energy gaps amongst the 5f/6d/7s subshells,thereby exhibiting a wide range of oxidation states,commonly from+Ⅲ to+Ⅵ or in some cases even+I or+Ⅱ.While a wide variety of redox-active ligands are known for use as transition metal complexes including multi-electron reduction that could facilitate inert bond or small molecule activation,only a few such examples are known for U^(Ⅵ)O_(2)^(2+).In this study,three U^(Ⅵ)O_(2)^(2+)complexes bearing α-diimine-,o-quinonediimine-and 2,6-diiminopyridine-based ligands were synthesized,which exhibited two redox couples in the range of−0.79 V to−2.02 V vs.Fc+/0 to give singly-and doubly-reduced complexes by stepwise reduction.Unique electronic transitions of U^(Ⅵ)O_(2)^(2+) complexes with a variety of low-lying excited states helped us to combine spectroelectrochemistry and time-dependent density functional theory(TD-DFT)calculations which complemented each other to assign the redox-active site in these U^(Ⅵ)O_(2)^(2+) complexes,i.e.,whether or not a ligand of interest becomes redox-active.During all the redox processes observed here,the ligands employed are found to be exclusively redox-active,i.e.,non-innocent,whereas the centered U^(Ⅵ)O_(2)^(2+) is just“spectating”and remains unchanged,i.e.,innocent.Whereas the double reduction of the U^(Ⅵ)O_(2)^(2+) complexes usually involves breaking of strong UuO bonds,in the present examples this is not required and therefore a basis for the synthesis of new types of uranium molecular catalysts and magnetic materials may be found.展开更多
Highly crystalline UO_(2)nanoparticles(NPs)with sizes of 2–3 nm were produced by fast chemical deposition of uranium(IV)under reducing conditions at pH 8–11.The particles were then characterized by microscopy and sp...Highly crystalline UO_(2)nanoparticles(NPs)with sizes of 2–3 nm were produced by fast chemical deposition of uranium(IV)under reducing conditions at pH 8–11.The particles were then characterized by microscopy and spectroscopy techniques including high-resolution transmission electron microscopy(HRTEM),X-ray diffraction(XRD),high-energy resolution fluorescence detection(HERFD)X-ray absorption spectroscopy at the U M_(4)edge and extended X-ray absorption fine structure(EXAFS)spectroscopy at the U L_(3)edge.The results of this investigation show that despite U(IV)being the dominant oxidation state of the freshly prepared UO_(2)NPs,they oxidize to U_(4)O_(9)with time and under the X-ray beam,indicating the high reactivity of U(IV)under these conditions.Moreover,it was found that the oxidation process of NPs is accompanied by their growth in size to 6 nm.We highlight here the major differences and similarities of the UO_(2)NP properties to PuO_(2),ThO_(2)and CeO_(2)NPs.展开更多
Our concerns apply to the inadequate ways statistical distributions of crystallographic orientations are compared and occasionally confirmed to agree sufficiently well.The authors of“Machine learning enhanced analysi...Our concerns apply to the inadequate ways statistical distributions of crystallographic orientations are compared and occasionally confirmed to agree sufficiently well.The authors of“Machine learning enhanced analysis of EBSD data for texture representation”1 suggest a method to replace an EBSD dataset of crystallographic orientations with a much smaller synthetic dataset preserving the texture.They claim that their“texture adaptive clustering and sampling”algorithm generates datasets of a few hundred crystallographic orientations,realizing an equivalent crystallographic orientation distribution as the initial dataset.To prove the principle and substantiate their claim of equivalent orientation distributions,the authors content themselves with(i)a visual inspection of the crystallographic pole density function,in fact,of three crystallographic“pole figures”and(ii)Kolmogorov–Smirnov tests for each of the three Euler angles of the crystallographic orientations individually.However,these criteria are insufficient to confirm equivalence of orientation distributions,they do not provide scientific evidence to substantiate the authors’claim that“texture adaptive clustering and sampling”generates crystallographic orientations in terms of their Euler angles representing the same texture.展开更多
The temporal contrast requirements for high-power laser pulses have become increasingly stringent with rising irradiance levels.Over the past decade,in addition to discrete pre-pulses,spatiotemporal pulse pedestals ha...The temporal contrast requirements for high-power laser pulses have become increasingly stringent with rising irradiance levels.Over the past decade,in addition to discrete pre-pulses,spatiotemporal pulse pedestals have attracted significant attention as a major limiting factor for contrast quality in chirped-pulse amplification systems,primarily caused by imperfections in their stretching and compression optics.In this work,we present the first direct high-resolution singleshot measurement of these contributions in the spatiotemporal domain using an imaging spectrometer in combination with a two-dimensional self-referenced spectral interferometer.展开更多
1.Introduction When natural hazards such as floods,droughts,and wildfires continue to escalate globally,timely acquisition of disaster information remains crucial for rapid on ground situation assessment.Despite advan...1.Introduction When natural hazards such as floods,droughts,and wildfires continue to escalate globally,timely acquisition of disaster information remains crucial for rapid on ground situation assessment.Despite advances in satellite-based emergency mapping,delays persist highlighting the need to enhance early warning systems and overcome limitations of conventional,observation-based workflows.The integration of Big Data and Artificial Intelligence(BD&AI)through the fusion of available vast Remote Sensing(RS)datasets with Machine Learning(ML)algorithms allows us to achieve near real-time monitoring of hazards,improve their prediction.展开更多
Background Circulating cell-free tumor DNA(ctDNA)provides a non-invasive approach for assessing somatic alterations.The German PRAEGNANT registry study aims to explore molecular biomarkers and investigate their integr...Background Circulating cell-free tumor DNA(ctDNA)provides a non-invasive approach for assessing somatic alterations.The German PRAEGNANT registry study aims to explore molecular biomarkers and investigate their integration into clinical practice.In this context,ctDNA testing was included to understand the motivations of clinicians to initiate testing,to identify somatic alterations,and to assess the clinical impact of the results obtained.Methods Patients with advanced/metastatic breast cancer were prospectively enrolled in the Prospective Academic Translational Research Network for the Optimization of Oncological Health Care Quality in the Adjuvant and Advanced/Metastatic Setting(PRAEGNANT study;NCT02338167).The FDA-approved and CE-marked GUARDANT360 CDx test was used to assess somatic alterations.A ctDNA-analysis report was provided to the treating physician along with a questionnaire about the intent for testing and the clinical implications of test results.Results ctDNA from 49 patients was analyzed prospectively:37(76%)had at least one somatic alteration in the analyzed geneset;14 patients(29%)harbored alterations in TP53,12(24%)in PIK3CA,and 6(12%)in ESR1.Somatic mutations in BRCA1 or BRCA2 were detected in 3(6%)and 4(8%)patients,respectively,and 59%of patients had hormone receptor-positive,human epidermal growth factor receptor 2-negative breast cancer.Questionnaires regarding test intentions and clinical impact were completed for 48(98%)patients.These showed that ctDNA testing influenced treatment decisions for 35%of patients.Discussion The high prevalence of somatic alterations in TP53,PIK3CA,ESR1,and BRCA1/2 genes,identified by ctDNA genotyping,highlights their potential as biomarkers for targeted therapies.Detection of specific mutations affected treatment decisions,such as eligibility for alpelisib,and might further facilitate treatment with e.g.elacestrant or capiversatib in future treatment lines.展开更多
In order to understand the transport of fast electrons within solid density targets driven by an optical high power laser,we have numerically investigated the dynamics and structure of strong self-generated magnetic f...In order to understand the transport of fast electrons within solid density targets driven by an optical high power laser,we have numerically investigated the dynamics and structure of strong self-generated magnetic fields in such experiments.Here we present a systematic study of the bulk magnetic field generation due to the ponderomotive current,Weibel-like instability and resistivity gradient between two solid layers.Using particle-in-cell simulations,we observe the effect of varying the laser and target parameters,including laser intensity,focal size,incident angle,preplasma scale length,target thickness and material and experimental geometry.The simulation results suggest that the strongest magnetic field is generated with laser incident angles and preplasma scale lengths that maximize laser absorption efficiency.The recent commissioning of experimental platforms equipped with both optical high power laser and X-ray free electron laser(XFEL),such as European XFEL-HED,LCLS-MEC and SACLA beamlines,provides unprecedented opportunities to probe the self-generated bulk magnetic field by X-ray polarimetry via Faraday rotation with simultaneous high spatial and temporal resolution.We expect that this systematic numerical investigation will pave the way to design and optimize near future experimental setups to probe the magnetic fields in such experimental platforms.展开更多
The severe shortfall in testing supplies during the initial COVID-19 outbreak and ensuing struggle to manage the pandemic have affirmed the critical importance of optimal supplyconstrained resource allocation strategi...The severe shortfall in testing supplies during the initial COVID-19 outbreak and ensuing struggle to manage the pandemic have affirmed the critical importance of optimal supplyconstrained resource allocation strategies for controlling novel disease epidemics.To address the challenge of constrained resource optimization for managing diseases with complications like pre-and asymptomatic transmission,we develop an integro partial differential equation compartmental disease model which incorporates realistic latent,incubation,and infectious period distributions along with limited testing supplies for identifying and quarantining infected individuals.Our model overcomes the limitations of typical ordinary differential equation compartmental models by decoupling symptom status from model compartments to allow a more realistic representation of symptom onset and presymptomatic transmission.To analyze the influence of these realistic features on disease controllability,we find optimal strategies for reducing total infection sizes that allocate limited testing resources between‘clinical’testing,which targets symptomatic individuals,and‘non-clinical’testing,which targets non-symptomatic individuals.We apply our model not only to the original,delta,and omicron COVID-19 variants,but also to generically parameterized disease systems with varying mismatches between latent and incubation period distributions,which permit varying degrees of presymptomatic transmission or symptom onset before infectiousness.We find that factors that decrease controllability generally call for reduced levels of non-clinical testing in optimal strategies,while the relationship between incubation-latent mismatch,controllability,and optimal strategies is complicated.In particular,though greater degrees of presymptomatic transmission reduce disease controllability,they may increase or decrease the role of nonclinical testing in optimal strategies depending on other disease factors like transmissibility and latent period length.Importantly,our model allows a spectrum of diseases to be compared within a consistent framework such that lessons learned from COVID-19 can be transferred to resource constrained scenarios in future emerging epidemics and analyzed for optimality.展开更多
We have developed a new radiography setup with a short-pulse laser-driven x-ray source. Using a radiography axis perpendicular to both long- and short-pulse lasers allowed optimizing the incident angle of the short-pu...We have developed a new radiography setup with a short-pulse laser-driven x-ray source. Using a radiography axis perpendicular to both long- and short-pulse lasers allowed optimizing the incident angle of the short-pulse laser on the x-ray source target. The setup has been tested with various x-ray source target materials and different laser wavelengths.Signal to noise ratios are presented as well as achieved spatial resolutions. The high quality of our technique is illustrated on a plasma flow radiograph obtained during a laboratory astrophysics experiment on POLARs.展开更多
基金supported by the German Federal Ministry of Education and Research(BMBF)within the project H2Giga-SINEWAVE OxySep,grant no 03HY123Eand the Faculty of Mechanical Science and Engineering at TU Dresden.Pengfei Zhao would like to acknowledge the China Scholarship Council(CSC)+3 种基金supported by a Humboldt Research Fellowship from the Alexander von Humboldt Foundationthe financial support from Qinghai Province(No.2025ZY001,2024000060)Chinese Academy of Sciences(No.2023000024)funding from the Deutsche Forschungsgemeinschaft:Project ID 265191195-SFB1194 and 456180046.
文摘Droplet impact on solid surfaces plays a critical role in a wide range of applications,including inkjet printing,spray cooling,surface coatings,and microdroplet chemistry.Precise control of droplet–surface interactions is essential,but the fundamental mechanisms governing this process are still not fully understood.In this study,we demonstrate that large contact angle hysteresis(CAH)on hydrophobic nanoporous surfaces significantly amplifies post-impact droplet oscillations.This reveals the critical influence of CAH on the redistribution of impact energy and the modulation of droplet–surface interactions.Using shape mode decomposition via Legendre polynomials and fast Fourier transform spectral analysis,we show that surfaces with larger CAH excite and sustain higher-order droplet shape mode oscillations,leading to persistent capillary waves even after contact line pinning.The observed amplitude modulation and multiple frequency components within individual shape modes reveal nonlinear energy transfer between different modes.These amplified and coupled oscillations are shown to promote daughter droplet coalescence.This study presents a framework for understanding the role of CAH in storing and redistributing impact energy through nonlinear mode excitation and establishes CAH as a critical design parameter for controlling fluid dynamics on solid surfaces.
基金partially supported by the Center for Advanced Systems Understanding (CASUS), financed by Germany’s Federal Ministry of Education and Research and the Saxon State Government out of the State Budget approved by the Saxon State Parliamentthe European Union’s Just Transition Fund (JTF) within the project Röntgenlaser Optimierung der Laserfusion (ROLF), Contract No. 5086999001, co-financed by the Saxon State Government out of the State Budget approved by the Saxon State Parliament+3 种基金the European Research Council (ERC) under the European Union’s Horizon 2022 Research and Innovation Programme (Grant Agreement No. 101076233, “PREXTREME”)Computations were performed on a Bull Cluster at the Center for Information Services and High-Performance Computing (ZIH) at Technische Universität Dresden and at the Norddeutscher Verbund für Hoch- und Höchstleistungsrechnen (HLRN) under Grant No. mvp00024support by the National Natural Science Foundation of China under Grant No. 12274171support by the Advanced Materials–National Science and Technology Major Project (Grant No. 2024ZD0606900)
文摘Understanding the properties of warm dense hydrogen is of key importance for the modeling of compact astrophysical objects and to understand and further optimize inertial confinement fusion applications.The workhorse of warm dense matter theory is thermal density functional theory(DFT),which,however,suffers from two limitations:(i)its accuracy can depend on the utilized exchange-correlation functional,which has to be approximated,and(ii)it is generally limited to single-electron properties such as the density distribution.Here,we present a new ansatz combining time-dependent DFT results for the dynamic structure factor S_(ee)(q,ω)with static DFT results for the density response.This allows us to estimate the electron-electron static structure factor S_(ee)(q)of warm dense hydrogen with high accuracy over a broad range of densities and temperatures.In addition to its value for the study of warm dense matter,our work opens up new avenues for the future study of electronic correlations exclusively within the framework of DFT for a host of applications.
基金supported by the Center for Advanced Systems Understanding(CASUS),financed by Germany’s Federal Ministry of Education and Research(BMBF)and the Saxon State Government out of the State Budget approved by the Saxon State Parliamentfunding from the European Research Council(ERC)under the European Union’s Horizon 2022 research and innovation programme(Grant Agreement No.101076233,“PREXTREME”)funding from the European Union’s Just Transition Fund(JTF)within the project Röntgenlaser-Optimierung der Laserfusion(ROLF),Contract No.5086999001,co-financed by the Saxon State Government out of the State Budget approved by the Saxon State Parliament.
文摘Ab initio modeling of dynamic structure factors(DSF)and related density response properties in the warm dense matter(WDM)regime is a challenging computational task.The DSF,convolved with a probing X-ray beam and instrument function,is measured in X-ray Thom-son scattering(XRTS)experiments,which allow the study of electronic structure properties at the microscopic level.Among the various ab initio methods,linear-response time-dependent density-functional theory(LR-TDDFT)is a key framework for simulating the DSF.The standard approach in LR-TDDFT for computing the DSF relies on the orbital representation.A significant drawback of this method is the unfavorable scaling of the number of required empty bands as the wavenumber increases,making LR-TDDFT impractical for modeling XRTS measurements over large energy scales,such as in backward scattering geometry.In this work,we consider and test an alternative approach to LR-TDDFT that employs the Liouville–Lanczos(LL)method for simulating the DSF of WDM.This approach does not require empty states and allows the DSF at large momentum transfer values and over a broad frequency range to be accessed.We compare the results obtained from the LL method with those from the solution of Dyson’s equation using the standard LR-TDDFT within the projector augmented-wave formalism for isochorically heated aluminum and warm dense hydrogen.Additionally,we utilize exact path integral Monte Carlo results for the imaginary-time density-density correlation function(ITCF)of warm dense hydrogen to rigorously benchmark the LL approach.We discuss the application of the LL method for calculating DSFs and ITCFs at different wavenumbers,the effects of pseudopotentials,and the role of Lorentzian smearing.The successful validation of the LL method under WDM conditions makes it a valuable addition to the ab initio simulation landscape,supporting experimental efforts and advancing WDM theory.
基金the financial support of the Optim Ore projectthe European Union’s Horizon 2020 research and innovation programme under grant agreement No. 642201
文摘Froth flotation of scheelite has regained new focus since the 2010s and research regarding floatability and reagents has made great progress over the years. The main objective was and remains the selective flotation of scheelite from other calcium-bearing minerals, in particular calcite, fluorite and apatite. Due to similar properties, most attempts have limited success or only specific application(linked to a type of ore or a location). This article aims at reviewing all general physical-chemical information on froth flotation of scheelite, including electrokinetic properties, influence of p H and already existing reagents as well as ones still under examination. It appears that chelating or mixed collectors and modified versions of sodium silicate and quebracho hold great promise for scheelite flotation, while the use of said depressants and/or promoters seems inevitable.
基金supported financially by the National Natural Science Foundation of China(Nos.U1560202,51690162 and 51604171)Shanghai Municipal Science and Technology Commission Grant(No.17JC1400602)+2 种基金Shanghai Pujiang Program(No.18PJ1403700)the program of China Scholarships Council(No.201806890052)the National Science and Technology Major Project“Aeroengine and Gas Turbine”(No.2017-VII-0008-0102).
文摘The microsegregation behavior of the Al-4.5 wt%Cu alloy solidified at different cooling rates under the alternating magnetic field(AMF) was investigated.The experimental results showed that the amount of non-equilibrium eutectics in the interdendritic region decreased upon applying the AMF at the same cooling rate.The change in microsegregation could be explained quantificationally by the modifications of dendritic coarsening,solid-state back diffusion and convection in the AMF.The enhanced diffusivity in the solid owing to the AMF was beneficial for the improvement in microsegregation compared to the cases without an AMF.In contrast,the enhanced dendritic coarsening and forced convection in the AMF were found to aggravate the microsegregation level.Considering the contributions of the changes in above factors,an increase in solid diffusivity was found to be primarily responsible for the reduced microsegregation in the AMF.In addition,the microsegregation in the AMF was modeled using the analytical model developed by Voller.The calculated and experimental results were in reasonable agreement.
基金supported partially by the Center for Advanced Systems Understanding(CASUS),which is financed by Germany’s Federal Ministry of Education and Research(BMBF),and by the state government of Saxony from the State budget approved by the Saxon State Parliament.This work has received funding from the European Research Council(ERC)under the European Union’s Horizon 2022 research and innovation program(Grant No.101076233,“PREXTREME”)The PIMC calculations were carried out at the Norddeutscher Verbund für Hoch-und Höchstleistungsrechnen(HLRN)under Grant No.shp00026,and on a Bull Cluster at the Center for Information Services and High Performance Computing(ZIH)at Technische Universität Dresden.
文摘An accurate theoretical description of the dynamic properties of correlated quantum many-body systems,such as the dynamic structure factor S(q,ω),is important in many fields.Unfortunately,highly accurate quantum Monte Carlo methods are usually restricted to the imaginary time domain,and the analytic continuation of the imaginary-time density–density correlation function F(q,τ)to real frequencies is a notoriously hard problem.Here,it is argued that often no such analytic continuation is required because by definition,F(q,τ)contains the same physical information as does S(q,ω),only represented unfamiliarly.Specifically,it is shown how one can directly extract key information such as the temperature or quasi-particle excitation energies from theτdomain,which is highly relevant for equation-of-state measurements of matter under extreme conditions[T.Dornheim et al.,Nat.Commun.13,7911(2022)].As a practical example,ab initio path-integral Monte Carlo results for the uniform electron gas(UEG)are considered,and it is shown that even nontrivial processes such as the roton feature of the UEG at low density[T.Dornheim et al.,Commun.Phys.5,304(2022)]are manifested straightforwardly in F(q,τ).A comprehensive overview is given of various useful properties of F(q,τ)and how it relates to the usual dynamic structure factor.In fact,working directly in theτdomain is advantageous for many reasons and opens up multiple avenues for future applications.
基金Item Sponsored by Deutsche Forschungsgemeinschaft (DFG) in form of the SFB 609 "Electromagnetic Flow Control in Metallurgy,Crystal Growth and Electrochemistry"
文摘The current work combines numerical and experimental investigations based on a small-scale mockup using the eutectic alloy GaInSn.The jet flow discharging from the submerged entry nozzle was exposed perpendicularly to a DC magnetic field across the entire wide face of the mold.Numerical calculations were performed by using the commercial package CFX with an implemented RANS-SST turbulence model.The anisotropic properties of the MHD turbulence were taken into account by specific modifications of the turbulence model.The comparison between our numerical calculations and the experimental results shows a very well agreement.In particular,the modified RANS-SST turbulence model is capable to reconstruct the peculiar phenomenon of the excitation of non-steady,non-isotropic large-scale flow perturbations caused by the application of the DC magnetic field.Another important finding of our study is the feature that the electrical boundary conditions,namely the wall conductivity ratio,have a great impact on the mold flow subjected to an external magnetic field.
基金supported partly by the National Natural Science Foundation of China (No. 51472170)the Major State Basic Research Development Program of China (No. 2011CB932700)
文摘An induction levitation melting （ILM） refining process is performed to remove most microsized inclusions in ultra-low carbon steel （UCS）. Nanosized, spheroid shaped sulfide precipitates remain dispersed in the UCS. During the ILM process, the UCS is molten and is rotated under an upward magnetic field. With the addition of Ti additives, the spinning molten steel under the upward magnetic field ejects particles because of resultant centrifugal, floating, and magnetic forces. Magnetic force plays a key role in removing sub-micrometer-sized particles, composed of porous aluminum titanate enwrapping alumina nuclei. Consequently, sulfide precipitates with sizes less than 50 nan remain dispersed in the steel matrix. These findings open a path to the fabrication of clean steel or steel bearing only a nanosized strengthen- ing phase.
基金Project supported by the German Aerospace Center(DLR)with funds provided by The Federal Ministry for Economic Affairs and Climate Action(BMWi)due to an enactment of the German Bundestag under grant number 50WM1741(project SESIMAG II)。
文摘Efficient extraction and recycling methods are an important issue for rare earth elements(REE). The significant differences in their magnetic moments make magnetic separation a promising step. Although the magnetic field gradient manipulation of ions seemed to be impossible, the robust enrichment of some paramagnetic RE ions was found in the vicinity of the magnet. The studies in recent years resolved the physical paradox of why, despite the Brownian motion of the ions, there is a reproducible enrichment of RE ions in magnetic field gradients. The existence of trigger process and energy barrier was proved.However, these studies usually used only high paramagnetic ions, e.g., Dy(Ⅲ) or Ho(Ⅲ). This work verifies the theory of the possible magnetic separation for 8 different rare earth ions, respectively. For this purpose, concentration distribution in rare earth chloride solutions were measured using a MachZehnder interferometer. The magnetic field was assured by a Halbach configuration to enhance the effect. The results show the classification of RE solutions into 2 classes: Class I contains the REs with low magnetic moment, whereas Class II includes the REs of high magnetic moment. Only the latter group shows the enrichment of ions in the vicinity of the magnet which encourages the implementation of magnetic separation into existing hydrometallurgical technology to enhance the selectivity of REE.
基金supported by the Center for Advanced Systems Understanding(CASUS),financed by Germany’s Federal Ministry of Education and Research(BMBF)and the Saxon State Government out of the State Budget approved by the Saxon State Parliamentfunding from the European Research Council(ERC)under the European Union’s Horizon 2022 Research and Innovation Program(Grant Agreement No.101076233,“PREXTREME”).
文摘We present quasi-exact ab initio path integral Monte Carlo(PIMC)results for the partial static density responses and local field factors of hydrogen in the warm dense matter regime,from solid density conditions to the strongly compressed case.The full dynamic treatment of electrons and protons on the same footing allows us to rigorously quantify both electronic and ionic exchange–correlation effects in the system,and to compare the results with those of earlier incomplete models such as the archetypal uniform electron gas or electrons in a fixed ion snapshot potential that do not take into account the interplay between the two constituents.The full electronic density response is highly sensitive to electronic localization around the ions,and our results constitute unambiguous predictions for upcoming X-ray Thomson scattering experiments with hydrogen jets and fusion plasmas.All PIMC results are made freely available and can be used directly for a gamut of applications,including inertial confinement fusion calculations and the modeling of dense astrophysical objects.Moreover,they constitute invaluable benchmark data for approximate but computationally less demanding approaches such as density functional theory or PIMC within the fixed-node approximation.
基金Bundesministerium für Bildung und Forschung,Grant/Award Numbers:03XP0138C,03XP0306C。
文摘The demand for lithium-ion batteries(LIBs)is driven largely by their use in electric vehicles,which is projected to increase dramatically in the future.This great success,however,urgently calls for the efficient recycling of LIBs at the end of their life.Herein,we describe a froth flotation-based process to recycle graphite—the predominant active material for the negative electrode—from spent LIBs and investigate its reuse in newly assembled LIBs.It has been found that the structure and morphology of the recycled graphite are essentially unchanged compared to pristine commercial anode-grade graphite,and despite some minor impurities from the recycling process,the recycled graphite provides a remarkable reversible specific capacity of more than 350 mAh g^(−1).Even more importantly,newly assembled graphite‖NMC532 cells show excellent cycling stability with a capacity retention of 80%after 1000 cycles,that is,comparable to the performance of reference full cells comprising pristine commercial graphite.
基金supported in part by the Grants-in-Aid for Scientific Research(Grant No.20H02663 to KT,and 21J11942 to TT)of the Japan Society for the Promotion for Science(JSPS)the JAEA Nuclear Energy S&T and the Human Resource Development Project through concentrating wisdom(Grant No.JPJA19P19209861)the International Research Frontiers Initiative(IRFI)of Institute of Innovative Research,Tokyo Institute of Technology.
文摘In most cases,the redox activity of a U^(Ⅵ)O_(2)^(2+) complex is regarded as metal-centered phenomena,because uranium has small energy gaps amongst the 5f/6d/7s subshells,thereby exhibiting a wide range of oxidation states,commonly from+Ⅲ to+Ⅵ or in some cases even+I or+Ⅱ.While a wide variety of redox-active ligands are known for use as transition metal complexes including multi-electron reduction that could facilitate inert bond or small molecule activation,only a few such examples are known for U^(Ⅵ)O_(2)^(2+).In this study,three U^(Ⅵ)O_(2)^(2+)complexes bearing α-diimine-,o-quinonediimine-and 2,6-diiminopyridine-based ligands were synthesized,which exhibited two redox couples in the range of−0.79 V to−2.02 V vs.Fc+/0 to give singly-and doubly-reduced complexes by stepwise reduction.Unique electronic transitions of U^(Ⅵ)O_(2)^(2+) complexes with a variety of low-lying excited states helped us to combine spectroelectrochemistry and time-dependent density functional theory(TD-DFT)calculations which complemented each other to assign the redox-active site in these U^(Ⅵ)O_(2)^(2+) complexes,i.e.,whether or not a ligand of interest becomes redox-active.During all the redox processes observed here,the ligands employed are found to be exclusively redox-active,i.e.,non-innocent,whereas the centered U^(Ⅵ)O_(2)^(2+) is just“spectating”and remains unchanged,i.e.,innocent.Whereas the double reduction of the U^(Ⅵ)O_(2)^(2+) complexes usually involves breaking of strong UuO bonds,in the present examples this is not required and therefore a basis for the synthesis of new types of uranium molecular catalysts and magnetic materials may be found.
基金funded by the European Commission Council under ERC[grant no.759696]support from RFBR(projectnumber no.19-33-90127)+1 种基金support by the Russian Ministry of Science and Education under grant no.075-15-2019-1891support from the Swedish Research Council(grant 2017-06465).
文摘Highly crystalline UO_(2)nanoparticles(NPs)with sizes of 2–3 nm were produced by fast chemical deposition of uranium(IV)under reducing conditions at pH 8–11.The particles were then characterized by microscopy and spectroscopy techniques including high-resolution transmission electron microscopy(HRTEM),X-ray diffraction(XRD),high-energy resolution fluorescence detection(HERFD)X-ray absorption spectroscopy at the U M_(4)edge and extended X-ray absorption fine structure(EXAFS)spectroscopy at the U L_(3)edge.The results of this investigation show that despite U(IV)being the dominant oxidation state of the freshly prepared UO_(2)NPs,they oxidize to U_(4)O_(9)with time and under the X-ray beam,indicating the high reactivity of U(IV)under these conditions.Moreover,it was found that the oxidation process of NPs is accompanied by their growth in size to 6 nm.We highlight here the major differences and similarities of the UO_(2)NP properties to PuO_(2),ThO_(2)and CeO_(2)NPs.
文摘Our concerns apply to the inadequate ways statistical distributions of crystallographic orientations are compared and occasionally confirmed to agree sufficiently well.The authors of“Machine learning enhanced analysis of EBSD data for texture representation”1 suggest a method to replace an EBSD dataset of crystallographic orientations with a much smaller synthetic dataset preserving the texture.They claim that their“texture adaptive clustering and sampling”algorithm generates datasets of a few hundred crystallographic orientations,realizing an equivalent crystallographic orientation distribution as the initial dataset.To prove the principle and substantiate their claim of equivalent orientation distributions,the authors content themselves with(i)a visual inspection of the crystallographic pole density function,in fact,of three crystallographic“pole figures”and(ii)Kolmogorov–Smirnov tests for each of the three Euler angles of the crystallographic orientations individually.However,these criteria are insufficient to confirm equivalence of orientation distributions,they do not provide scientific evidence to substantiate the authors’claim that“texture adaptive clustering and sampling”generates crystallographic orientations in terms of their Euler angles representing the same texture.
文摘The temporal contrast requirements for high-power laser pulses have become increasingly stringent with rising irradiance levels.Over the past decade,in addition to discrete pre-pulses,spatiotemporal pulse pedestals have attracted significant attention as a major limiting factor for contrast quality in chirped-pulse amplification systems,primarily caused by imperfections in their stretching and compression optics.In this work,we present the first direct high-resolution singleshot measurement of these contributions in the spatiotemporal domain using an imaging spectrometer in combination with a two-dimensional self-referenced spectral interferometer.
文摘1.Introduction When natural hazards such as floods,droughts,and wildfires continue to escalate globally,timely acquisition of disaster information remains crucial for rapid on ground situation assessment.Despite advances in satellite-based emergency mapping,delays persist highlighting the need to enhance early warning systems and overcome limitations of conventional,observation-based workflows.The integration of Big Data and Artificial Intelligence(BD&AI)through the fusion of available vast Remote Sensing(RS)datasets with Machine Learning(ML)algorithms allows us to achieve near real-time monitoring of hazards,improve their prediction.
文摘Background Circulating cell-free tumor DNA(ctDNA)provides a non-invasive approach for assessing somatic alterations.The German PRAEGNANT registry study aims to explore molecular biomarkers and investigate their integration into clinical practice.In this context,ctDNA testing was included to understand the motivations of clinicians to initiate testing,to identify somatic alterations,and to assess the clinical impact of the results obtained.Methods Patients with advanced/metastatic breast cancer were prospectively enrolled in the Prospective Academic Translational Research Network for the Optimization of Oncological Health Care Quality in the Adjuvant and Advanced/Metastatic Setting(PRAEGNANT study;NCT02338167).The FDA-approved and CE-marked GUARDANT360 CDx test was used to assess somatic alterations.A ctDNA-analysis report was provided to the treating physician along with a questionnaire about the intent for testing and the clinical implications of test results.Results ctDNA from 49 patients was analyzed prospectively:37(76%)had at least one somatic alteration in the analyzed geneset;14 patients(29%)harbored alterations in TP53,12(24%)in PIK3CA,and 6(12%)in ESR1.Somatic mutations in BRCA1 or BRCA2 were detected in 3(6%)and 4(8%)patients,respectively,and 59%of patients had hormone receptor-positive,human epidermal growth factor receptor 2-negative breast cancer.Questionnaires regarding test intentions and clinical impact were completed for 48(98%)patients.These showed that ctDNA testing influenced treatment decisions for 35%of patients.Discussion The high prevalence of somatic alterations in TP53,PIK3CA,ESR1,and BRCA1/2 genes,identified by ctDNA genotyping,highlights their potential as biomarkers for targeted therapies.Detection of specific mutations affected treatment decisions,such as eligibility for alpelisib,and might further facilitate treatment with e.g.elacestrant or capiversatib in future treatment lines.
文摘In order to understand the transport of fast electrons within solid density targets driven by an optical high power laser,we have numerically investigated the dynamics and structure of strong self-generated magnetic fields in such experiments.Here we present a systematic study of the bulk magnetic field generation due to the ponderomotive current,Weibel-like instability and resistivity gradient between two solid layers.Using particle-in-cell simulations,we observe the effect of varying the laser and target parameters,including laser intensity,focal size,incident angle,preplasma scale length,target thickness and material and experimental geometry.The simulation results suggest that the strongest magnetic field is generated with laser incident angles and preplasma scale lengths that maximize laser absorption efficiency.The recent commissioning of experimental platforms equipped with both optical high power laser and X-ray free electron laser(XFEL),such as European XFEL-HED,LCLS-MEC and SACLA beamlines,provides unprecedented opportunities to probe the self-generated bulk magnetic field by X-ray polarimetry via Faraday rotation with simultaneous high spatial and temporal resolution.We expect that this systematic numerical investigation will pave the way to design and optimize near future experimental setups to probe the magnetic fields in such experimental platforms.
基金funded by the Center of Advanced Systems Understanding(CASUS)which is financed by Germany's Federal Ministry of Education and Research(BMBF)by the Saxon Ministry for Science,Culture and Tourism(SMWK)with tax funds on the basis of the budget approved by the Saxon State Parliament.
文摘The severe shortfall in testing supplies during the initial COVID-19 outbreak and ensuing struggle to manage the pandemic have affirmed the critical importance of optimal supplyconstrained resource allocation strategies for controlling novel disease epidemics.To address the challenge of constrained resource optimization for managing diseases with complications like pre-and asymptomatic transmission,we develop an integro partial differential equation compartmental disease model which incorporates realistic latent,incubation,and infectious period distributions along with limited testing supplies for identifying and quarantining infected individuals.Our model overcomes the limitations of typical ordinary differential equation compartmental models by decoupling symptom status from model compartments to allow a more realistic representation of symptom onset and presymptomatic transmission.To analyze the influence of these realistic features on disease controllability,we find optimal strategies for reducing total infection sizes that allocate limited testing resources between‘clinical’testing,which targets symptomatic individuals,and‘non-clinical’testing,which targets non-symptomatic individuals.We apply our model not only to the original,delta,and omicron COVID-19 variants,but also to generically parameterized disease systems with varying mismatches between latent and incubation period distributions,which permit varying degrees of presymptomatic transmission or symptom onset before infectiousness.We find that factors that decrease controllability generally call for reduced levels of non-clinical testing in optimal strategies,while the relationship between incubation-latent mismatch,controllability,and optimal strategies is complicated.In particular,though greater degrees of presymptomatic transmission reduce disease controllability,they may increase or decrease the role of nonclinical testing in optimal strategies depending on other disease factors like transmissibility and latent period length.Importantly,our model allows a spectrum of diseases to be compared within a consistent framework such that lessons learned from COVID-19 can be transferred to resource constrained scenarios in future emerging epidemics and analyzed for optimality.
基金the support of RFBR grant 14-29-06099Competitiveness Programme of NRNU MEPhI
文摘We have developed a new radiography setup with a short-pulse laser-driven x-ray source. Using a radiography axis perpendicular to both long- and short-pulse lasers allowed optimizing the incident angle of the short-pulse laser on the x-ray source target. The setup has been tested with various x-ray source target materials and different laser wavelengths.Signal to noise ratios are presented as well as achieved spatial resolutions. The high quality of our technique is illustrated on a plasma flow radiograph obtained during a laboratory astrophysics experiment on POLARs.
