检索结果-内蒙古大学图书馆

Local and global measures of the shear moduli of jammed disk packings

Physical Review E 2023年第5期107卷 054903-054903页

作者： Shiyun Zhang Weiwei Jin Dong Wang Ding Xu Jerry Zhang Mark D. Shattuck Corey S. O'Hern Department of Physics University of Science and Technology of China Hefei Anhui 230026 China Department of Mechanical Engineering and Materials Science Yale University New Haven Connecticut 06520 USA Benjamin Levich Institute and Physics Department The City College of New York New York New York 10031 USA Department of Physics Yale University New Haven Connecticut 06520 USA Department of Applied Physics Yale University New Haven Connecticut 06520 USA Graduate Program in Computational Biology and Bioinformatics Yale University New Haven Connecticut 06520 USA

Strain-controlled isotropic compression gives rise to jammed packings of repulsive, frictionless disks with either positive or negative global shear moduli. We carry out computational studies to understand the contributions of the negative shear moduli to the mechanical response of jammed disk packings. We first decompose the ensemble-averaged, global shear modulus as 〈G〉=(1−F−)〈G+〉+F−〈G−〉, where F− is the fraction of jammed packings with negative shear moduli and 〈G+〉 and 〈G−〉 are the average values from packings with positive and negative moduli, respectively. We show that 〈G+〉 and 〈|G−|〉 obey different power-law scaling relations above and below pN2∼1. For pN2>1, both 〈G+〉N and 〈|G−|〉N∼(pN2)β, where β∼0.5 for repulsive linear spring interactions. Despite this, 〈G〉N∼(pN2)β′ with β′≳0.5 due to the contributions from packings with negative shear moduli. We show further that the probability distribution of global shear moduli P(G) collapses at fixed pN2 and different values of p and N. We calculate analytically that P(G) is a Γ distribution in the pN2≪1 limit. As pN2 increases, the skewness of P(G) decreases and P(G) becomes a skew-normal distribution with negative skewness in the pN2≫1 limit. We also partition jammed disk packings into subsystems using Delaunay triangulation of the disk centers to calculate local shear moduli. We show that the local shear moduli defined from groups of adjacent triangles can be negative even when G>0. The spatial correlation function of local shear moduli C(r⃗) displays weak correlations for pnsub2<10−2, where nsub is the number of particles within each subsystem. However, C(r⃗) begins to develop long-ranged spatial correlations with fourfold angular symmetry for pnsub2≳10−2.

关键词： Jamming Packing & jamming problems Granular materials

来源：评论

学校读者我要写书评

暂无评论

Cell- And Serum-Derived Proteins Act as DAMPs to Activate RAW 264.7 Macrophages in the Foreign Body Response to Silicone Implants

SSRN

引用

SSRN 2023年

作者： Blackman, Samuel A. Miles, Dalton Suresh, Joshita Calve, Sarah Bryant, Stephanie J. Department of Chemical and Biological Engineering University of Colorado Boulder 3415 Colorado Ave BoulderCO80309-0596 United States Paul M. Rady Department of Mechanical Engineering University of Colorado Boulder 1111 Engineering Dr BoulderCO80309-0427 United States BioFrontiers Institute University of Colorado Boulder 3415 Colorado Ave BoulderCO80309-0596 United States Materials Science and Engineering Program University of Colorado Boulder 4001 Discovery Dr BoulderCO80300-0613 United States

Protein adsorption after biomaterial implantation is the first stage of the foreign body response (FBR). However, the source(s) of the adsorbed proteins that lead to damaged associated molecular patterns (DAMPs) and induce inflammation has not been fully elucidated. This study examined the effects of different protein sources: cell-derived (from a NIH/3T3 fibroblast cell lysate) and serum-derived (from fetal bovine serum), which were compared to implant-derived proteins (after a 30-min subcutaneous implantation in mice) on activation of RAW 264.7 macrophages cultured in minimal (serum-free) medium. Both cell-derived and serum-derived protein sources when pre-adsorbed to either tissue culture polystyrene or medical grade silicone induced macrophage activation. The combination led to an even higher expression of pro-inflammatory cytokines genes and proteins. Implant-derived proteins on silicone explants induced a rapid inflammatory response that then subsided more quickly and to a greater extent than the studies with in vitro cell-derived or serum-derived protein sources. Proteomic analysis of the implant-derived proteins identified proteins that included cell-derived and serum-derived, but also other protein sources (e.g., extracellular matrix), suggesting the latter may help to temper the inflammatory response in vivo. These findings indicate that both serum-derived and cell-derived proteins can act as DAMPs to drive inflammation in the FBR, but that other protein sources may play an important role in controlling inflammation. © 2023, The Authors. All rights reserved.

关键词： Proteins

来源：评论

学校读者我要写书评

暂无评论

Magnetic structure and field-induced transitions in the triangular spin-1 antiferromagnet NiNb2O6: Observation of a triple point

引用

Physical Review B 2023年第22期108卷 224430-224430页

作者： Maruthi R Sobhit Singh Sayandeep Ghosh Mohindar S. Seehra Bruno Weise Wilfrid Prellier Subhash Thota Department of Physics Indian Institute of Technology Guwahati Assam 781039 India Department of Physics B.M.S. College of Engineering Bangalore 560019 Karnataka India Department of Mechanical Engineering University of Rochester Rochester New York 14627 USA Materials Science Program University of Rochester Rochester New York 14627 USA Department of Physics Chungnam National University Daejeon 34134 Republic of Korea Department of Physics Kunsan National University Gunsan 54150 Republic of Korea Department of Physics & Astronomy West Virginia University Morgantown West Virginia 26506 USA Leibniz-IFW Dresden Institute for Complex Materials D-01069 Dresden Germany CRISMAT laboratory Normandy University ENSICAEN UNICAEN National Center for Scientific Research 14000 Caen France

A comprehensive experiment-theory study on the magnetic field-induced spin-flip transitions (HC1 and HC2) and the field-temperature (H−T) phase diagram of nickel niobate (NiNb2O6) polycrystals is reported. Magnetic susceptibility (χ) measurements reveal the presence of quasi-one-dimensional magnetism with spin-1 Ni2+ Heisenberg spin chains, instead of Ising chains, along the easy axis (c axis). The ferromagnetic intrachain exchange-interaction strength, J0/kB (=4.20 K), between Ni2+ ions in the c axis is estimated from the molecular-field theory approximation. The interchain exchange interactions J1/kB=−1.335 K and J2/kB=−1.298 K have been determined from the experimentally obtained magnitudes of HC1=10.8 kOe and spin-saturated field HS=38 kOe. These magnitudes are consistent with the total magnetic exchange-interaction strength, J/kB=7.00 K obtained from χ−T data fitted with the Heisenberg linear chain model and our density-functional theory (DFT+U) calculations. The overall antiferromagnetic behavior of the NiNb2O6 system, correctly captured within our DFT+U calculations, occurs below TN=5.59±0.02 K as determined from the analysis of the specific heat (CP−T) data. The CP vs T data near TN is fitted to power-law expression CP=A|T−TN|−α yielding the critical exponent α=0.349(2) [0.349(1)] for T>TN (T

关键词： Magnetic interactions Magnetic phase transitions Magnetism Structural properties

来源：评论

学校读者我要写书评

暂无评论

Machine Learning Moment Tensor Potential for Modelling Dislocation and Fracture in L10-TiAl and D019-Ti3Al Alloys

arXiv

引用

arXiv 2023年

作者： Qi, Ji Aitken, Z.H. Pei, Qingxiang Tan, Anne Marie Z. Zuo, Yunxing Jhon, M.H. Quek, S.S. Wen, T. Wu, Zhaoxuan Ong, Shyue Ping Materials Science and Engineering Program University of California San Diego 9500 Gilman Dr Mail Code 0448 La Jolla CA92093-0448 United States 1 Fusionopolis Way Connexis #16-16 Singapore138632 Singapore Department of NanoEngineering University of California San Diego 9500 Gilman Dr Mail Code 0448 La Jolla CA92093-0448 United States Department of Mechanical Engineering The University of Hong Kong Hong Kong Department of Materials Science and Engineering City University of Hong Kong Hong Kong Hong Kong Institute for Advanced Study City University of Hong Kong Hong Kong

Dual-phase γ-TiAl and α2-Ti3Al alloys exhibit high strength and creep resistance at high temperatures. However, they suffer from low tensile ductility and fracture toughness at room temperature. Experimental studies show unusual plastic behaviour associated with ordinary and superdislocations, making it necessary to gain a detailed understanding on their core properties in individual phases and at the two-phase interfaces. Unfortunately, extended superdislocation cores are widely dissociated beyond the length scales practical for routine first-principles density-functional theory (DFT) calculations, while extant interatomic potentials are not quantitatively accurate to reveal mechanistic origins of the unusual core-related behaviour in either phases. Here, we develop a highly-accurate moment tensor potential (MTP) for the binary Ti-Al alloy system using a DFT dataset covering a broad range of intermetallic and solid solution structures. The optimized MTP is rigorously benchmarked against both previous and new DFT calculations, and unlike existing potentials, is shown to possess outstanding accuracy in nearly all tested mechanical properties, including lattice parameters, elastic constants, surface energies, and generalized stacking fault energies (GSFE) in both phases. The utility of the MTP is further demonstrated by producing dislocation core structures largely consistent with expectations from DFT-GSFE and experimental observations. The new MTP opens the path to realistic modelling and simulations of bulk lattice and defect properties relevant to the plastic deformation and fracture processes in γ-TiAl and α2-Ti3Al dual-phase alloys. © 2023, CC BY.

关键词： Aluminum alloys

来源：评论

学校读者我要写书评

暂无评论

Linking the polyatomic arrangements of interstitial H2O and cations to bonding within Prussian blue analogues ab initio using gradient-boosted machine learning

引用

Physical Review materials 2021年第3期5卷 035003-035003页

作者： Sizhe Liu Kyle C. Smith Department of Mechanical Science and Engineering University of Illinois at Urbana-Champaign Urbana Illinois 61801 USA Department of Materials Science and Engineering University of Illinois at Urbana-Champaign Urbana Illinois 61801 USA Computational Science and Engineering Program University of Illinois at Urbana-Champaign Urbana Illinois 61801 USA Beckman Institute for Advanced Science and Technology University of Illinois at Urbana-Champaign Urbana Illinois 61801 USA

Prussian blue analogues (PBAs) are model host compounds for the intercalation of monovalent cations for electrochemical energy storage and separations. However, the interactions among interstitial species and their effects on atomic arrangements therein are understood mainly at a phenomenological level. Analyzing correlations between electronic interactions and polyatomic arrangements in hydrated Prussian blue analogues is complicated by the nonlocal hydrogen-bonding interactions between zeolitic water and framework lattices. Here, we train machine-learning (ML) models to learn DFT-calculated energy landscapes of nickel hexacyanoferrate PBA lattices with various lattice hydration degrees, oxidation states, and types of intercalated alkali cations based on various three-particle feature parameters. This ML approach is enabled by using gradient-boosted regression trees with features that are rotationally invariant geometric parameters. ML model accuracy is shown to be a cation-specific indicator of correlations between energy and polyatomic arrangements. Overlap population analysis among correlated atoms further confirms that such correlations are caused by the competition for dative bonding between Lewis-acid intercalated cations and Lewis bases (cyanide and oxygen in H2O). Examination of lowest-energy structures reveals that cation hydrophilicity and bare ionic radius determine dative-bonding strength, resulting in cation-H2O ordering in interstitial space. The projected energy landscapes of hydrated PBA lattices is also explored in subspaces spanned by certain many-particle feature parameters inspired by ML analysis. The downhill traces in such landscapes indicate that lattice distortion is accompanied by two kinds of collective movements: (1) rearrangements in the hydration shells around small and hydrophilic cations and (2) collective attack of H2O molecules on nickel-cyanide bonds promoted by large, hydrophobic cations.

关键词： Chemical binding Density functional theory Electrochemistry Electron correlation calculations for atoms & ions Electronic structure of atoms & molecules Energy storage Interatomic & molecular potentials Organic & organometallic chemistry Water Data mining Electronic structure Machine learning

来源：评论

学校读者我要写书评

暂无评论

Synthesis of Metal-Modified Nanocellulose as a Biofilm Analogue for Biofilm Mimicry in Biomedical and Environmental Applications

引用

Biopolymers 2025年第4期116卷 e70029页

作者： Darryl W Taylor A-Andrew D Jones University Program in Materials Science & Engineering Duke University Durham North Carolina USA. Department of Civil & Environmental Engineering Pratt School of Engineering Duke University Durham North Carolina USA. Thomas Lord Department of Mechanical Engineering & Materials Science Pratt School of Engineering Duke University Durham North Carolina USA.

Bacterial biofilms are complex, multi-component structures consisting primarily of four key elements: polysaccharides, metal ions, proteins, and extracellular DNA. In our research, we specifically focus on the polysaccharide and metal ion components, which play a crucial role in determining the biofilm's mechanical properties. Polysaccharides provide the structural matrix, although metal ions, particularly divalent cations like calcium and cobalt, cross-link with the polysaccharides, thereby modulating the biofilm's rigidity and viscoelastic behavior. By introducing divalent cations into nanocellulose, we can replicate this natural cross-linking process, allowing us to finely tune the material's mechanical properties to more closely resemble those of bacterial biofilms. This approach not only enhances the accuracy of synthetic biofilm models over alginate hydrogels but also provides valuable insights into how biofilms maintain their structural integrity in various environments. Our findings indicate that nanocellulose exhibits mechanical properties closer to biofilms than alginate analogs, making it a suitable non-living control for biofilm studies. Furthermore, divalent nickel, followed by calcium and magnesium, demonstrate a closer mechanical mimicry to biofilms. In conclusion, this research shows the potential of nanocellulose as a versatile material for bacterial biofilm mimicry.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Author Correction:Automated classification of big X-ray diffraction data using deep learning models

引用

npj Computational materials 2024年第1期10卷 1928-1928页

作者： Jerardo E.Salgado Samuel Lerman Zhaotong Du Chenliang Xu Niaz Abdolrahim Materials Science program University of Rochester Rochester New York 14627 USA Department of Mechanical Engineering University of Rochester Rochester New York 14627 USA Laboratory for Laser Energetics University of Rochester Rochester New York 14627 USA Department of Computer Science University of Rochester Rochester New York 14627 USA

In the Acknowledgements section of this article the grant number relating to National science Foundation given for Chenliang Xu and Niaz Abdolrahim was incorrectly given as NSF 2202124 and should have been *** origina... 详细信息

关键词： knowledge learning corrected

来源：评论

学校读者我要写书评

暂无评论

Inter-Site Distance Effect in Electrocatalysis

引用

Angewandte Chemie 2025年

作者： Jiongcan Xiang Pengfei Wang Panpan Li Min Zhou Guihua Yu Zhaoyu Jin Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of China Chengdu 611731 China College of Materials Science and Engineering Sichuan University Chengdu 610065 China State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 China Materials Science and Engineering Program and Walker Department of Mechanical Engineering the University of Texas at Austin Austin TX 78712 USA

The inter-site distance effect (ISDE) has gained significant attention in heterogeneous catalysis, challenging classical models that treat adjacent nonbonded sites as isolated. Recent studies demonstrate that these sites can exhibit long-range cooperative interactions, enhancing reaction efficiencies. Fully leveraging the ISDE to overcome limitations in site reactivity requires a multidisciplinary approach and advanced techniques. This review provides a comprehensive overview of ISDE in electrocatalysis, starting with strategies for synthesizing materials with tunable inter-site distances. It examines ISDE across various catalyst models, including monometallic and heteronuclear atomic sites, active sites within clusters, and the lattice of nanocatalysts, focusing on their electronic structures, spatial geometries, and synergistic interactions. Advanced characterization and computational methods are highlighted as essential for identifying inter-site structures and distances, providing a systematic framework for understanding ISDE's role in electrocatalysis. The review also proposes best practices for studying ISDE, addressing current challenges and offering future perspectives. These insights aim to inform the design of highly efficient catalysts, enhance the understanding of catalytic mechanisms, and contribute to the development of more efficient energy conversion technologies, providing a foundation for further research into optimizing electrocatalysts.

关键词： Electrocatalysis Inter-site distance Single-atom catalysts Site density

来源：评论

学校读者我要写书评

暂无评论

Protein folding as a jamming transition

arXiv

引用

arXiv 2024年

作者： Grigas, Alex T. Liu, Zhuoyi Logan, Jack A. Shattuck, Mark D. O’Hern, Corey S. Graduate Program in Computational Biology and Bioinformatics Yale University New HavenCT06520 United States Integrated Graduate Program in Physical and Engineering Biology Yale University New HavenCT06520 United States Department of Mechanical Engineering and Materials Science Yale University New HavenCT06520 United States Benjamin Levich Institute and Physics Department The City College of New York New YorkNY10031 United States Department of Physics Yale University New HavenCT06520 United States Department of Applied Physics Yale University New HavenCT06520 United States

Proteins fold to a specific functional conformation with a densely packed hydrophobic core that controls their stability. We develop a geometric, yet all-atom model for proteins that explains the universal core packing fraction of φc = 0.55 found in experimental measurements. We show that as the hydrophobic interactions increase relative to the temperature, a novel jamming transition occurs when the core packing fraction exceeds φc. The model also recapitulates the global structure of proteins since it can accurately refold to native-like structures from partially unfolded states. © 2024, CC BY.

关键词： Proteins

来源：评论

学校读者我要写书评

暂无评论

High-flux and stable thin-film evaporation from fiber membranes with interconnected pores

引用

Joule 2025年

作者： Tianshi Feng Yu Pei Haowen Zhang Brooklyn Asai Gaoweiang Dong Atharva Joshi Abhishek Saha Shengqiang Cai Renkun Chen Department of Mechanical and Aerospace Engineering University of California San Diego La Jolla CA USA Program in Materials Science and Engineering University of California San Diego La Jolla CA USA

Capillary-driven thin-film evaporation in nanoporous membranes has emerged as a promising thermal management strategy for high-power electronic devices, owing to its high theoretical critical heat flux (CHF) enabled by the extensive evaporating areas within the nanopores. In this study, we investigate fiber membranes with three-dimensional interconnected open pores as efficient evaporators. Unlike traditional membranes with isolated pores, these open structures facilitate rapid and uniform liquid transport through multiple pathways, effectively reducing clogging and ensuring consistent wetting across the surface. Capillary-driven evaporation achieved a maximum CHF of over 800 W cm −2 on a relatively large heating area of approximately 0.5 cm 2 , attributed to the larger effective thin-film evaporation areas provided by the open-pore structures. Moreover, the fiber membranes demonstrated long-term stability. These findings suggest that 3D fiber membrane evaporators are highly promising for advanced thermal management, offering efficient, stable cooling solutions to meet the demands of modern electronic systems.

关键词：

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：