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Introducing high-density growth twins in aluminum alloys by laser surface remelting via templated nucleation of grains 被引量:1
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作者 Chunfeng Ma Qinglong Zhao +2 位作者 Xiao Liu Yanjun Li Qichuan Jiang 《Journal of Materials Science & Technology》 2025年第10期315-324,共10页
It is difficult to generate coherent twin boundaries in bulk Al alloys due to their high intrinsic stacking fault energy. Here, we report a strategy to induce high-density growth twins in aluminum alloys through the h... It is difficult to generate coherent twin boundaries in bulk Al alloys due to their high intrinsic stacking fault energy. Here, we report a strategy to induce high-density growth twins in aluminum alloys through the heterogeneous nucleation of twinned Al grains on twin-structured TiC nucleants and the preferred growth of twinned dendrites by laser surface remelting of bulk metals. The solidification structure at the surface shows a mixture of lamellar twinned dendrites with ultra-fine twin boundary spacing (∼2 µm), isolated twinned dendrites, and regular dendrites. EBSD analysis and finite element method (FEM) simulations have been used to understand the competitive growth between twinned and regular dendrites, and the solidification conditions for the preferred growth of twinned dendrites during laser remelting and subsequent rapid solidification are established. It is shown that the reduction in the ratio of temperature gradient G to solidification rate V promotes the formation of lamellar twinned dendrites. The primary trunk spacing of lamellar twinned dendrites is refined by the high thermal gradient and solidification rate. The present work paves a new way to generate high-density growth twins in additive-manufactured Al alloys. 展开更多
关键词 Heterogeneous nucleation Twinned dendrites Solidification Aluminum alloys
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Exceptional grain refinement induced by dispersed MgO particles in TIG-welded AZ31 alloy 被引量:1
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作者 Le Zai Xin Tong +2 位作者 Yun Wang Hao Zhang Xiaohuai Xue 《Journal of Materials Science & Technology》 2025年第2期1-13,共13页
Due to the low content of alloying elements and the lack of effective nucleation sites,the fusion zone(FZ)of tungsten inert gas(TIG)welded AZ31 alloy typically exhibits undesirable coarse columnar grains,which can res... Due to the low content of alloying elements and the lack of effective nucleation sites,the fusion zone(FZ)of tungsten inert gas(TIG)welded AZ31 alloy typically exhibits undesirable coarse columnar grains,which can result in solidification defects and reduced mechanical properties.In this work,a novel welding wire containing MgO particles has been developed to promote columnar-to-equiaxed transition(CET)in the FZ of TIG-welded AZ31 alloy.The results show the achievement of a fully equiaxed grain structure in the FZ,with a significant 71.9%reduction in grain size to 41 μm from the original coarse columnar dendrites.Furthermore,the combination of using MgO-containing welding wire and pulse current can further refine the grain size to 25.6 μm.Microstructural analyses reveal the homogeneous distribution of MgO particles in the FZ.The application of pulse current results in an increase in the number density of MgO(1-2 μm)from 5.16 × 10^(4) m^(-3) to 6.18 × 10^(4) m^(-3).The good crystallographic matching relationship between MgO and α-Mg matrix,characterized by the orientation relationship of[11(2)0]α-Mg//[0(1)1]MgO and(0002)_(α-Mg)//(111)_(MgO),indicates that the MgO particles can act as effective nucleation sites for α-Mg to reduce nucleation undercooling.According to the Hunt criteria,the critical temperature gradient for CET is greatly enhanced due to the significantly increased number density of MgO nucleation sites.In addition,the correlation with the thermal simulation results reveals a transition in the solidification conditions within the welding pool from the columnar grain zone to the equiaxed grain zone in the CET map,leading to the realization of CET.The exceptional grain refinement has contributed to a simultaneous improvement in the strength and plasticity of welded joints.This study presents a novel strategy for controlling equiaxed microstructure and optimizing mechanical properties in fusion welding or wire and arc additive manufacturing of Mg alloy components. 展开更多
关键词 AZ31 alloy TIG welding Columnar-to-equiaxed transition Grain refinement Heterogeneous nucleation
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Wafer‑Scale Ag_(2)S‑Based Memristive Crossbar Arrays with Ultra‑Low Switching‑Energies Reaching Biological Synapses
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作者 Yuan Zhu Tomas Nyberg +3 位作者 Leif Nyholm Daniel Primetzhofer Xun Shi Zhen Zhang 《Nano-Micro Letters》 SCIE EI CAS 2025年第3期328-339,共12页
Memristive crossbar arrays(MCAs)offer parallel data storage and processing for energy-efficient neuromorphic computing.However,most wafer-scale MCAs that are compatible with complementary metal-oxide-semiconductor(CMO... Memristive crossbar arrays(MCAs)offer parallel data storage and processing for energy-efficient neuromorphic computing.However,most wafer-scale MCAs that are compatible with complementary metal-oxide-semiconductor(CMOS)technology still suffer from substantially larger energy consumption than biological synapses,due to the slow kinetics of forming conductive paths inside the memristive units.Here we report wafer-scale Ag_(2)S-based MCAs realized using CMOS-compatible processes at temperatures below 160℃.Ag_(2)S electrolytes supply highly mobile Ag+ions,and provide the Ag/Ag_(2)S interface with low silver nucleation barrier to form silver filaments at low energy costs.By further enhancing Ag+migration in Ag_(2)S electrolytes via microstructure modulation,the integrated memristors exhibit a record low threshold of approximately−0.1 V,and demonstrate ultra-low switching-energies reaching femtojoule values as observed in biological synapses.The low-temperature process also enables MCA integration on polyimide substrates for applications in flexible electronics.Moreover,the intrinsic nonidealities of the memristive units for deep learning can be compensated by employing an advanced training algorithm.An impressive accuracy of 92.6%in image recognition simulations is demonstrated with the MCAs after the compensation.The demonstrated MCAs provide a promising device option for neuromorphic computing with ultra-high energy-efficiency. 展开更多
关键词 Wafer-scale Ag_(2)S films Reactive sputter Silver nucleation Ag^(+)migration Energy-efficient neuromorphic computing
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Nucleation control for the growth of two-dimensional single crystals
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作者 Jinxia Bai Chi Zhang +3 位作者 Fankai Zeng Jinzong Kou Jinhuan Wang Xiaozhi Xu 《Journal of Semiconductors》 2025年第9期10-18,共9页
The unique structure and exceptional properties of two-dimensional(2D)materials offer significant potential for transformative advancements in semiconductor industry.Similar to the reliance on wafer-scale single-cryst... The unique structure and exceptional properties of two-dimensional(2D)materials offer significant potential for transformative advancements in semiconductor industry.Similar to the reliance on wafer-scale single-crystal ingots for silicon-based chips,practical applications of 2D materials at the chip level need large-scale,high-quality production of 2D single crystals.Over the past two decades,the size of 2D single-crystals has been improved to wafer or meter scale,where the nucleation control during the growth process is particularly important.Therefore,it is essential to conduct a comprehensive review of nucleation control to gain fundamental insights into the growth of 2D single-crystal materials.This review mainly focuses on two aspects:controlling nucleation density to enable the growth from a single nucleus,and controlling nucleation position to achieve the unidirectionally aligned islands and subsequent seamless stitching.Finally,we provide an overview and forecast of the strategic pathways for emerging 2D materials. 展开更多
关键词 2D materials single crystals nucleation density nucleation position
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Effect of pH-dependent bath speciation on cobalt electrodeposition from sulfate-gluconate solutions
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作者 Ewa RUDNIK 《Transactions of Nonferrous Metals Society of China》 2025年第7期2399-2420,共22页
pH-dependent multiple equilibria in cobalt sulfate-gluconate baths were calculated using stability constants adopted from literature.Changes of the bath speciation were then discussed in terms of spectrophotometric ex... pH-dependent multiple equilibria in cobalt sulfate-gluconate baths were calculated using stability constants adopted from literature.Changes of the bath speciation were then discussed in terms of spectrophotometric experiments and buffering properties of the solutions(pH 3-10).Cyclic voltammetry indicated changes in electrochemical behavior of cobalt species caused by different ionic compositions of the electrolytes.Tafel slopes were calculated and discussed in relation to electroreduction of cobalt species.Chronoamperometric studies showed 3D instantaneous nucleation of cobalt followed by diffusion-controlled growth,but it was disturbed at higher pH due to the release of cation from gluconate complexes as a limiting step.Diffusion coefficients of cobalt species were found.Changes in the pH were also reflected by modifications of morphology(SEM),development of preferred orientation planes(XRD,texture coefficients)and current efficiency,but not the thickness of the coatings deposited at constant potential of-1.0 V(vs Ag/AgCl).Anodic stripping analysis showed changes in anodic responses originated from the existence of preferentially oriented planes in cobalt layers. 展开更多
关键词 COBALT ELECTRODEPOSITION nucleation SPECIATION structure
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Effect of Different Admixtures on the Formation of Ettringite
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作者 LUO Mingyao MI Hongtu +4 位作者 WANG Dengbing ZHANG Yahui WU Kai XU Linglin LI Haoxin 《Journal of Wuhan University of Technology(Materials Science)》 2025年第4期1028-1036,共9页
Four typical admixtures,polycarboxylate superplasticiser(PCE),tartaric acid(TA),sorbitol and polyacrylamide(PAM),were selected to systematically investigate their regulatory mechanisms on the formation of ettringite t... Four typical admixtures,polycarboxylate superplasticiser(PCE),tartaric acid(TA),sorbitol and polyacrylamide(PAM),were selected to systematically investigate their regulatory mechanisms on the formation of ettringite through Fourier transform infrared spectroscopy,X-ray diffraction,particle size analysis and nucleation kinetic model.The experimental results indicate that the admixtures alter the formation of ettringite through physical adsorption,complexation and solution viscosity modulation without changing its chemical structure.Low concentrations of PCE inhibit size growth by forming an adsorption layer on the surface of ettringite,whereas high concentrations of PCE alter the size change of ettringite by modulating the distribution of ionic concentrations.TA significantly reduces the size of ettringite by complexing Ca^(2+).Sorbitol and PAM promote the local growth of ettringite at low concentrations,leading to larger sizes.But at high concentrations,the size growth of ettringite is inhibited due to the increase in viscosity or the enhancement of complexation.Matlab nucleation kinetic modelling further shows that the addition of admixtures enhances the initial nucleation during ettringite synthesis,with values ranging from 14.45%to 114.25%.However,the subsequent nucleation rate of ettringite is significantly affected,decreasing by 12.79%to 71.74%.The results provide a theoretical basis for the design of ettringite materials and the optimisation of the application of admixtures. 展开更多
关键词 ETTRINGITE NUCLEATION GROWTH ADMIXTURE
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An investigation of single-phased metallic solidification process using high-temperature confocal laser scanning microscope combined with differential scanning colorimetry
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作者 Xing-zhi Zhou De-yong Wang +6 位作者 Tian-peng Qu Dong Hou Shao-yan Hu Jun Tian Xiang-long Li Lei Fan Zhi-xiao Zhang 《Journal of Iron and Steel Research International》 2025年第2期437-451,共15页
To investigate the nucleation behavior during the single-phased metallic solidification process,the commercial ultrapure ferritic stainless steels with no(Initial steel)and various melt treatments(R1,MR1,Y2,MY1,and M1... To investigate the nucleation behavior during the single-phased metallic solidification process,the commercial ultrapure ferritic stainless steels with no(Initial steel)and various melt treatments(R1,MR1,Y2,MY1,and M1 steels)were used to carry out the differential scanning colorimetry(DSC)and high-temperature confocal laser scanning microscope(HT-CLSM)experiments.Based on the results of DSC experiments,the equilibrium solidification process as well as the relationship among the critical undercooling degree(△T_(c)^(DSC)),latent heat of fusion/crystallization(△H_(f)/△H_(c)),equiaxed grain ratio(ER),and average grain size(△_(ave)^(ingot))was revealed.ER is increased with the decreasing△T_(c)^(DSC)and increasing△H_(f)/△H_(c);however,△_(ave)^(ingot)is decreased with them.Referring to the results of HT-CLSM experiments,the average sizes of micro-/macrostructures(d_(ave)/D_(ave)/)are decreased with the increasing cooling rate,as well as the difference between and apparent critical undercooling degree(△T_(c)^(CLSM))was revealed.The heterogeneous nucleation of the crystal nuclei occurs only if△T_(c)^(CLSM)>△T_(c)^(DSC).Combining with the interfacial wetting-lattice mismatch heterogeneous nucleation model,the dynamic mechanism of the metallic solidification was revealed.The as-cast grains of the melt-treated samples were obviously refined,owing to the much higher actual heterogeneous nucleation rates(I_(heter.,i))obtained through melt treatments,and the heterogeneous nucleation rates(I_(heter.,ij))for all samples are increased with the cooling rates,firmly confirming that the as-cast grains of each sample could be refined by the increasing cooling rates. 展开更多
关键词 NUCLEATION Metallic solidification process Differential scanning colorimetry High-temperature confocal laser scanning microscope Interfacial wetting-lattice mismatch heterogeneous nucleation model
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Abnormally enhanced displacement burst at elevated temperatures of AZ31 magnesium alloy during nanoindentation
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作者 Song-Yu Yan Zhang-Jie Wang Zhi-Wei Shan 《Journal of Materials Science & Technology》 2025年第8期171-178,共8页
The unveiling of temperature effects on the deformation behaviors of wrought magnesium(Mg)alloys is beneficial for optimizing the hot forming parameters of these alloys with limited room temperature(RT)formability.In ... The unveiling of temperature effects on the deformation behaviors of wrought magnesium(Mg)alloys is beneficial for optimizing the hot forming parameters of these alloys with limited room temperature(RT)formability.In the present work,we performed nanoindentations on individual grains of textured wrought AZ31 alloy along the normal direction(ND)from RT to 300℃to investigate the intrinsic non-basal dislocation behaviors at various temperatures.Interestingly,we observed abnormally enhanced nanoindentation displacement bursts(pop-ins)at elevated temperatures ranging from 150 to 250℃,which is beyond the general scenario that higher temperatures typically result in smoother plastic flow.The bursts exhibited Gaussian-like statistics,which differ from the well-reported bursts with power-law size distributions resulting from the destruction of jammed dislocation configurations.Through transmission electron microscopy(TEM)examination of the microstructure beneath the indentation just after the burst,we found that the abnormal displacement bursts originated from the heterogeneous nucleation of prismatic screw(a)dislocations due to the exhaustion of dislocation sources within the specified temperature range. 展开更多
关键词 NANOINDENTATION POP-IN Gaussian-like distribution Dislocation nucleation Prismatic slip
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Herbal Nanomedicines Potential Development of Pharmaceuticals and Health Care Products
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作者 Van Nguyen Anh Nghia Nguyen Duc Hung Kieu Dinh 《材料科学与工程(中英文A版)》 2025年第1期1-11,共11页
The amalgamation of herbal medicine and nanoformulation technology presents a compelling avenue for the advancement of pharmaceutical and health food products.This synergy capitalizes on the inherent therapeutic prope... The amalgamation of herbal medicine and nanoformulation technology presents a compelling avenue for the advancement of pharmaceutical and health food products.This synergy capitalizes on the inherent therapeutic properties of herbal extracts while harnessing the innovative capabilities of nano-scale formulation.Nano-technology has revolutionized drug delivery systems,offering enhanced bioavailability and targeted delivery of active compounds.The global research landscape reflects a burgeoning interest in nano-based pharmaceuticals,driven by their potential to overcome traditional limitations and optimize therapeutic outcomes.Vietnam,with its rich biodiversity and burgeoning nano-industry,stands at the forefront of this convergence.Vietlife,a prominent player in health product research and manufacturing,is poised to capitalize on this convergence.By leveraging indigenous herbal knowledge and cutting-edge nanoformulation techniques,Vietlife can pioneer the development of novel pharmaceutical and health food solutions.In conclusion,the integration of herbal medicine and nanoformulation technology opens up promising opportunities for the development of pharmaceuticals and healthcare products.Vietnam and Vietlife can capitalize on this trend to drive sustainable development and establish their presence in the international market. 展开更多
关键词 NANOCRYSTALS herbal medicine drug delivery preparation nucleation and polymorphism applications.
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Direct Observation of Early-Stage Polymer Crystallization Driven by Surface Wrinkling and Compressive Stress in Thin Films
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作者 Peng Zhang Stephan V.Roth +1 位作者 Peter Muller-Buschbaum Tian-Bai He 《Chinese Journal of Polymer Science》 2025年第2期360-367,共8页
The early stages of crystallization and occurrence of surface wrinkling were investigated using poly(butadiene)-block-poly(ε-caprolactone)with an ordered lamellar structure.Direct evidence has demonstrated that surfa... The early stages of crystallization and occurrence of surface wrinkling were investigated using poly(butadiene)-block-poly(ε-caprolactone)with an ordered lamellar structure.Direct evidence has demonstrated that surface wrinkling precedes nucleation and crystal growth.This study examined the relationship between surface wrinkling,nucleation,and the formation of crystalline supramolecular structures using atomic force microscopy(AFM)and X-ray scattering measurements.Surface wrinkling is attributed to curving induced by accumulated stresses,including residual stress from the sample preparation and thermal stress during cooling.These stresses cause large-scale material flow and corresponding changes in the molecular conformations,potentially reducing the nucleation barrier.This hypothesis is supported by the rapid crystal growth observed following the spread of surface wrinkles.Additionally,the surface curving of the polymer thin film creates local minima of the free energy,facilitating nucleation.The nuclei subsequently grow into crystalline supramolecular structures by incorporating polymer molecules from the melt.This mechanism highlights the role of localized structural inhomogeneity in the early stages of crystallization and provides new insights into structure formation processes. 展开更多
关键词 Polymer crystallization NUCLEATION Surface wrinkling Stress Thin film
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Orientation-dependence of incipient plasticity in a coarse-grained Mg revealed by nanoindentation pop-ins
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作者 Moein Imani Foumani Syed Taha Khursheed +1 位作者 Yushun Liu Guo-zhen Zhu 《Journal of Magnesium and Alloys》 2025年第6期2554-2564,共11页
The nanoindentation pop-in behaviors of 13 grains with diverse crystallographic orientations were analysed using a coarse-grained Mg-2 wt.% Gd alloy.Within nanoscale stressed volumes within all grains,the converted sh... The nanoindentation pop-in behaviors of 13 grains with diverse crystallographic orientations were analysed using a coarse-grained Mg-2 wt.% Gd alloy.Within nanoscale stressed volumes within all grains,the converted shear stresses for the first pop-in,calculated using the indentation Schmid factor,ranged from 1 to 1.3 GPa,consistent with theoretical predictions for dislocation nucleation in Mg.The estimated activation volume of the first pop-in was approximately 27–40 A3(involving about ~2 atoms),aligning with reported atomistic simulations of the surface dislocation semi-loop nucleation.While indented near the -axis,grains exhibit higher first pop-in loads and successive pop-ins,implying the possibility of a cross-slip nucleation mechanism to accommodate -axis deformation. 展开更多
关键词 Incipient plasticity Dislocation nucleation MAGNESIUM NANOINDENTATION
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Physical mechanisms of earthquake nucleation and foreshocks:Cascade triggering,aseismic slip,or fluid flows?
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作者 Zhigang Peng Xinglin Lei 《Earthquake Research Advances》 2025年第2期32-47,共16页
Earthquakes are caused by the rapid slip along seismogenic faults.Whether large or small,there is inevitably a certain nucleation process involved before the dynamic rupture.At the same time,significant foreshock acti... Earthquakes are caused by the rapid slip along seismogenic faults.Whether large or small,there is inevitably a certain nucleation process involved before the dynamic rupture.At the same time,significant foreshock activity has been observed before some but not all large earthquakes.Understanding the nucleation process and foreshocks of earthquakes,especially large damaging ones,is crucial for accurate earthquake prediction and seismic hazard mitigation.The physical mechanism of earthquake nucleation and foreshock generation is still in debate.While the earthquake nucleation process is present in laboratory experiments and numerical simulations,it is difficult to observe such a process directly in the field.In addition,it is currently impossible to effectively distinguish foreshocks from ordinary earthquake sequences.In this article,we first summarize foreshock observations in the last decades and attempt to classify them into different types based on their temporal behaviors.Next,we present different mechanisms for earthquake nucleation and foreshocks that have been proposed so far.These physical models can be largely grouped into the following three categories:elastic stress triggering,aseismic slip,and fluid flows.We also review several recent studies of foreshock sequences before moderate to large earthquakes around the world,focusing on how different results/conclusions can be made by different datasets/methods.Finally,we offer some suggestions on how to move forward on the research topic of earthquake nucleation and foreshock mechanisms and their governing factors. 展开更多
关键词 FORESHOCKS Earthquake swarms 2024 Noto earthquake Earthquake nucleation FLUIDS Aseismic slip Haicheng earthquake
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Observation and mechanism of non-uniform distribution of tin nuclei in preparing vapor diffusion coated Nb_(3)Sn thin film for SRF applications
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作者 Shuai Wu Yang Ye +17 位作者 Zi-Qin Yang Yuan He Jian-Peng Li Guang-Ze Jiang Lu Li Shi-Chun Huang An-Dong Wu Hang-Xu Li Shao-Hua Lu Tao Liu Feng Qiu Cang-Long Wang Ji-Zheng Duan Teng Tan Zhi-Jun Wang Sheng-Hu Zhang Hong-Wei Zhao Wen-Long Zhan 《Nuclear Science and Techniques》 2025年第1期22-34,共13页
Growth of high-quality Nb_(3)Sn thin films for superconducting radiofrequency(SRF)applications using the vapor diffusion method requires a uniform distribution of tin nuclei on the niobium(Nb)surface.This study examin... Growth of high-quality Nb_(3)Sn thin films for superconducting radiofrequency(SRF)applications using the vapor diffusion method requires a uniform distribution of tin nuclei on the niobium(Nb)surface.This study examines the mechanism underlying the observed non-uniform distribution of tin nuclei with tin chloride SnCl_(2).Electron backscatter diffraction(EBSD)analysis was used to examine the correlation between the nucleation behavior and orientation of niobium grains in the substrate.The findings of the density functional theory(DFT)simulation are in good agreement with the experimental results,showing that the non-uniform distribution of tin nuclei is the result of the adsorption energy of SnCl_(2)molecules by varied niobium grain orientations.Further analysis indicated that the surface roughness and grain size of niobium also played significant roles in the nucleation behavior.This study provides valuable insights into enhancing the surface pretreatment of niobium substrates during the growth of Nb_(3)Sn thin films using the vapor diffusion method. 展开更多
关键词 NUCLEATION Tin chloride Non-uniform distribution Vapor diffusion Crystal orientation Adsorption energy
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Achieving 20%Toluene‑Processed Binary Organic Solar Cells via Secondary Regulation of Donor Aggregation in Sequential Processing
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作者 Yufei Wang Chuanlin Gao +15 位作者 Wen Lei Tao Yang Zezhou Liang Kangbo Sun Chaoyue Zhao Lu Chen Liangxiang Zhu Haoxuan Zeng Xiaokang Sun Bin He Hanlin Hu Zeguo Tang Mingxia Qiu Shunpu Li Peigang Han Guangye Zhang 《Nano-Micro Letters》 2025年第9期75-93,共19页
Sequential processing(SqP)of the active layer offers independent optimization of the donor and acceptor with more targeted solvent design,which is considered the most promising strategy for achieving efficient organic... Sequential processing(SqP)of the active layer offers independent optimization of the donor and acceptor with more targeted solvent design,which is considered the most promising strategy for achieving efficient organic solar cells(OSCs).In the SqP method,the favorable interpenetrating network seriously depends on the fine control of the bottom layer swelling.However,the choice of solvent(s)for both the donor and acceptor have been mostly based on a trial-and-error manner.A single solvent often cannot achieve sufficient yet not excessive swelling,which has long been a difficulty in the high efficient SqP OSCs.Herein,two new isomeric molecules are introduced to fine-tune the nucleation and crystallization dynamics that allows judicious control over the swelling of the bottom layer.The strong non-covalent interaction between the isomeric molecule and active materials provides an excellent driving force for optimize the swelling-process.Among them,the molecule with high dipole moment promotes earlier nucleation of the PM6 and provides extended time for crystallization during SqP,improving bulk morphology and vertical phase segregation.As a result,champion efficiencies of 17.38%and 20.00%(certified 19.70%)are achieved based on PM6/PYF-T-o(all-polymer)and PM6/BTP-eC9 devices casted by toluene solvent. 展开更多
关键词 Organic solar cells Non-halogen solvent Sequential processing Secondary nucleation Stability
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Corrigendum to‘Tuning the nucleation kinetics of phosphate chemical conversion coating on Mg-Gd-Y-Zr magnesium alloy:The effect of pretreatment and organic additive’[Journal of Magnesium and Alloys 13(2025)207–218]
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作者 Siyu Sun Peng Zhou +5 位作者 Yan Chen JinTao Xiao Jingli Sun Yong Yuan Tao Zhang Fuhui Wang 《Journal of Magnesium and Alloys》 2025年第5期2433-2434,共2页
The authors regret that due to negligence,the picture was misplaced in the original manuscript,resulting in Fig.6d being incorrectly included.The correct version of Fig.6d is provided below for reference.This error do... The authors regret that due to negligence,the picture was misplaced in the original manuscript,resulting in Fig.6d being incorrectly included.The correct version of Fig.6d is provided below for reference.This error does not affect the conclusions of the study,and we apologize for any confusion it may have caused. 展开更多
关键词 nucleation kinetics fig d PRETREATMENT phosphate chemical conversion coating organic additive magnesium alloy
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Nanoparticle Distribution in Compression Ignition Engines Using Rapeseed Methyl Ester
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作者 Hayder A.Dhahad Miqdam T.Chaichan +2 位作者 Mohammed A.Fayad Hasanain A.Abdul Wahhab T.Magrites 《Energy Engineering》 2025年第4期1249-1264,共16页
One of the most important of these emissions is fine particulate matter,which is a harmful emission of diesel engines,leading to the imposition of strict regulations.Biodiesel,with its high oxygen content,is an effect... One of the most important of these emissions is fine particulate matter,which is a harmful emission of diesel engines,leading to the imposition of strict regulations.Biodiesel,with its high oxygen content,is an effective alternative to significantly reduce these emissions.In this study,rapeseed methyl ester(RME)was used as a diesel engine fuel and the emitted particulate matter was comparedwith ultra-lowsulfur diesel(ULSD).Inmost experimental studies,the emission of soot wasmeasured.In this work,the effects of injection timing,injection pressure(IP),and engine load on fine particulate matter in both nucleation and accumulation modes were studied.The results show that IP increases the number of particles in the accumulation mode while the number of particles in the crystallization mode is higher for rapeseed methyl ester(RME)than for ultra-low sulfur diesel(ULSD).Conversely,the formation rates of particles in the accumulationmode are higher for ULSD.Cumulative concentration numbers(CCN)are generally higher for RME in crystallization mode but higher for ULSD in accumulation mode.Increasing the IP reduces the CCN values.The particle size in crystallizationmode reaches a maximum of 22 nm at IPs of 800 and 1000 bar but decreases to 15 nm at 1200 bar.Most fine particles fall in the 5–100 nm diameter range.High engine loads reduce the particle size distribution in nucleationmode for both fuels,with a slight increase in particle size in nucleationmode.Thestudy concluded that the use of rapeseed methyl ester as an engine fuel benefits the environment and improves air quality due to the significant reduction in the size,number,and concentration of nano-soot particles and total particles emitted from the engine. 展开更多
关键词 Injection pressure injection timing nucleation and accumulation particulate matter premixed burn smoke number
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Enhanced Boiling Heat Transfer in Water Pools with Perforated Copper Beads and Sodium Dodecyl Sulfate Surfactant
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作者 Pengcheng Cai Teng Li +4 位作者 Jianxin Xu Xiaobo Li Zhiqiang Li Zhiwen Xu Hua Wang 《Fluid Dynamics & Materials Processing》 2025年第2期325-349,共25页
In modern engineering,enhancing boiling heat transfer efficiency is crucial for optimizing energy use and several industrial processes involving different types of materials.This study explores the enhancement of pool... In modern engineering,enhancing boiling heat transfer efficiency is crucial for optimizing energy use and several industrial processes involving different types of materials.This study explores the enhancement of pool boiling heat transfer potentially induced by combining perforated copper particles on a heated surface with a sodium dodecyl sulfate(SDS)surfactant in saturated deionized water.Experiments were conducted at standard atmospheric pressure,with heat flux ranging from 20 to 100 kW/m2.The heating surface,positioned below the layer of freely moving copper beads,allowed the particle layer to shift due to liquid convection and steam nucleation.The study reports on the influence of copper bead diameter(2,3,4,and 5 mm),particle quantity,arrangement,and SDS concentration(20,200,and 500 ppm).It is shown that the combination of 5 mm particles and a 500 ppm SDS concentration can yield a remarkable 139%improvement in heat transfer efficiency.As demonstrated by direct flow visualization,bubble formation occurs primarily in the gaps between the particles and the heated surface,with the presence of SDS reducing bubble size and accelerating bubble detachment. 展开更多
关键词 Pool boiling heat transfer enhancement perforated copper beads SURFACTANT bubble nucleation mechanism flow visualization
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Mechanism and application of seed-induced goethite crystal growth for iron removal from rich-zinc solution
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作者 ZHU Qiang YANG Jian-guang +5 位作者 NAN Tian-xiang ZENG Wei-zhi TANG Shi-yang LIU Jiang ZHANG Yan TANG Chao-bo 《Journal of Central South University》 2025年第3期837-852,共16页
The goethite residue generated from zinc hydrometallurgy is classified as hazardous solid waste,produced in large quantities,and results in significant zinc loss.The study was conducted on removing iron from FeSO_(4)-... The goethite residue generated from zinc hydrometallurgy is classified as hazardous solid waste,produced in large quantities,and results in significant zinc loss.The study was conducted on removing iron from FeSO_(4)-ZnSO_(4) solution,employing seed-induced nucleation methods.Analysis of the iron removal rate,residue structure,morphology,and elemental composition involved ICP,XRD,FT-IR,and SEM.The existing state of zinc was investigated by combining step-by-step dissolution using hydrochloric acid.Concurrently,iron removal tests were extended to industrial solutions to assess the influence of seeds and solution pH on zinc loss and residue yield.The results revealed that seed addition increased the iron removal rate by 3%,elevated the residual iron content by 6.39%,and mitigated zinc loss by 29.55%in the simulated solution.Seed-induced nucleation prevented excessive nuclei formation,fostering crystal stable growth and high crystallinity.In addition,the zinc content of surface adsorption and crystal internal embedding in the residue was determined,and the zinc distribution on the surface was dense.In contrast,the total amount of zinc within the crystal was higher.The test results in the industrial solution demonstrated that the introduction of seeds expanded the pH range for goethite formation and growth,and the zinc loss per ton of iron removed was reduced by 50.91 kg(34.12%)and the iron residue reduced by 0.17 t(8.72%). 展开更多
关键词 iron removal crystal growth homogeneous and heterogeneous nucleation goethite process zinc hydrometallurgy
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Synergistic inhibition of colorectal cancer progression by silencing Aurora A and the targeting protein for Xklp2
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作者 Gui-Xian Sheng Yu-Jia Zhang Tao Shang 《World Journal of Gastrointestinal Surgery》 2025年第1期217-233,共17页
BACKGROUND Unraveling the pathogenesis of colorectal cancer(CRC)can aid in developing prevention and treatment strategies.Aurora kinase A(AURKA)is a key participant in mitotic control and interacts with its co-activat... BACKGROUND Unraveling the pathogenesis of colorectal cancer(CRC)can aid in developing prevention and treatment strategies.Aurora kinase A(AURKA)is a key participant in mitotic control and interacts with its co-activator,the targeting protein for Xklp2(TPX2)microtubule nucleation factor.AURKA is associated with poor clinical outcomes and high risks of CRC recurrence.AURKA/TPX2 co-overexpression in cancer may contribute to tumorigenesis.Despite its pivotal role in CRC development and progression,the action mechanism of AURKA remains unclear.Further research is needed to explore the complex interplay between AURKA and TPX2 and to develop effective targeted treatments for patients with CRC.AIM To compare effects of AURKA and TPX2 and their combined knockdown on CRC cells.METHODS We evaluated three CRC gene datasets about CRC(GSE32323,GSE25071,and GSE21510).Potential hub genes associated with CRC onset were identified using the Venn,search tool for the retrieval of interacting genes,and KOBAS platforms,with AURKA and TPX2 emerging as significant factors.Subsequently,cell models with knockdown of AURKA,TPX2,or both were constructed using SW480 and LOVO cells.Quantitative real-time polymerase chain reaction,western blotting,cell counting kit-8,cell cloning assays,flow cytometry,and Transwell assays were used.RESULTS Forty-three highly expressed genes and 39 poorly expressed genes overlapped in cancer tissues compared to controls from three datasets.In the protein-protein interaction network of highly expressed genes,AURKA was one of key genes.Its combined score with TPX2 was 0.999,and their co-expression score was 0.846.In CRC cells,knockdown of AURKA,TPX2,or both reduced cell viability and colony number,while blocking G0/G1 phase and enhancing cell apoptosis.Additionally,they were weakened cell proliferation and migration abilities.Furthermore,the expression levels of B-cell lymphoma-2-Associated X,caspase 3,and tumor protein P53,and E-cadherin increased with a decrease in B-cell lymphoma-2,N-cadherin,and vimentin proteins.These effects were amplified when both AURKA and TPX2 were concurrently downregulated.CONCLUSION Combined knockdown of AURKA and TPX2 was effective in suppressing the malignant phenotype in CRC.Coinhibition of gene expression is a potential developmental direction for CRC treatment. 展开更多
关键词 Aurora kinase A Targeting protein for Xklp2 Microtubule nucleation factor Colorectal cancer Proliferation Migration INVASION
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Molecular dynamics simulation of heat transfer during liquid hydrogen boiling on surfaces at the nanoscale
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作者 Xiao-Jia Li He-Ying Chen +1 位作者 Yi-Zheng Sun Zhi-Chun Fan 《Nuclear Science and Techniques》 2025年第7期179-190,共12页
Liquid hydrogen, known for its high energy density and eco-friendly properties, has garnered significant attention in the context of sustainable development and clean energy. A comprehensive understanding of its nucle... Liquid hydrogen, known for its high energy density and eco-friendly properties, has garnered significant attention in the context of sustainable development and clean energy. A comprehensive understanding of its nucleation mechanisms and boiling heat transfer characteristics is crucial. However, current experimental and macroscopic simulation methods offer limited insights. This study employs molecular dynamics simulations to investigate the vaporization nucleation and boiling heat transfer properties of liquid hydrogen at the microscopic scale, with a focus on the effects of hydrogen film thickness, surface temperature, and wettability. The results indicate that hydrogen film thickness plays a critical role in nucleation. Thinner layers disrupt the shape of liquid films, leading to increased errors, whereas a thickness of 7 nm ensures film stability. Different heating methods and temperatures influence nucleation in various ways. Rapid heating results in a higher heat flux, while an increase in temperature under the same heating method accelerates nucleation, resulting in earlier nucleation and enhanced surface heat flow. Surfaces with varying wettability levels exhibit distinct nucleation behaviors. Specifically, an increase in α delays nucleation, causing a shift from the surface to within the liquid film due to stronger solid–liquid interaction forces. This study offers a microscale perspective on the nucleation and boiling processes of liquid hydrogen and provides valuable insights for phase transition studies. 展开更多
关键词 Molecular dynamics Liquid hydrogen Vaporization nucleation
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