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Negative enthalpy alloys and local chemical ordering:a concept and route leading to synergy of strength and ductility

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National Science Review 2024年第4期11卷 172-184页

作者： Zibing An Tao Yang Caijuan Shi Shengcheng Mao Lihua Wang Ang Li Wei Li Xianmeng Xue Ming Sun Yifan Bai Yapeng He Fuzeng Ren Zhouguang Lu Ming Yan Yang Ren Chain-Tsuan Liu Ze Zhang Xiaodong Han Beijing Key Lab of Microstructure and Property of Advanced materials College of Materials Science &Engineering Beijing University of Technology department of materials Science and Engineering City University of Hong Kong Key Laboratory of Partial Acceleration physics& Technology Institute of High Energy PhysicsChinese Academy of Sciences department of materials Science &Engineering Southern University of Science and Technology department of physics City University of Hong Kong State Key Laboratory of Silicon materials Department of Materials Science and Engineering Zhejiang University

Solid solutions are ubiquitous in metals and alloys. Local chemical ordering(LCO) is a fundamental sub-nano/nanoscale process that occurs in many solid solutions and can be used as a microstructure to optimize strength and ductility. However, the formation of LCO has not been fully elucidated, let alone how to provide efficient routes for designing LCO to achieve synergistic effects on both superb strength and ductility. Herein, we propose the formation and control of LCO in negative enthalpy alloys. With engineering negative enthalpy in solid solutions, genetic LCO components are formed in negative enthalpy refractory high-entropy alloys(RHEAs). In contrast to conventional ‘trial-and-error' approaches, the control of LCO by using engineering negative enthalpy in RHEAs is instructive and results in superior strength(1160 MPa) and uniform ductility(24.5%) under tension at ambient temperature, which are among the best reported so far. LCO can promote dislocation cross-slip, enhancing the interaction between dislocations and their accumulation at large tensile strains; sustainable strain hardening can thereby be attained to ensure high ductility of the alloy. This work paves the way for new research fields on negative enthalpy solid solutions and alloys for the synergy of strength and ductility as well as new functions.

关键词： negative enthalpy alloys local chemical ordering strength ductility dislocation

Mutation in a non-force-bearing region of protein L influences force-dependent unfolding behavior

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Chinese physics B 2024年第7期33卷 624-629页

作者：蒋环杰王艳伟陈家媛胡丹潘海郭子龙陈虎 department of physics Wenzhou UniversityWenzhou 325035China Center of Biomedical physics Wenzhou InstituteUniversity of Chinese Academy of SciencesWenzhou 325000China research Institute for Biomimetics and Soft Matter Fujian Provincial Key Laboratory for Soft Functional Materials ResearchDepartment of PhysicsXiamen UniversityXiamen 361005China

Single-molecule magnetic tweezers(MTs) have revealed multiple transition barriers along the unfolding pathway of several two-state proteins, such as GB1 and Csp. In this study, we utilized MTs to measure the force-dependent folding and unfolding rates of both protein L(PLWT) and its Y47W mutant(PLY47W) where the mutation point is not at the force-bearing β-strands. The measurements were conducted within a force range of 3–120 pN. Notably, the unfolding rates of both PLWT and PWY47W exhibit distinct force sensitivities below 50 pN and above 60 pN, implying a two-barrier free energy landscape. Both PLWT and PLY47W share the same force-dependent folding rate and the same transition barriers,but the unfolding rate of PLY47W is faster than that of PLWT. Our finding demonstrates that the residue outside of the force-bearing region will also affect the force-induced unfolding dynamics.

关键词： protein folding magnetic tweezers protein L

Anisotropic Mechanical Response of Nacre to Heat Treatment Under Indentation:Effect of Structural Orientation

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Journal of Bionic Engineering 2024年第3期21卷 1453-1464页

作者： Simin Liang Yingying Li Hongmei Ji Xiaowu Li department of materials physics and Chemistry School of Materials Science and EngineeringKey Laboratory for Anisotropy and Texture of MaterialsMinistry of EducationNortheastern UniversityShenyang110819China

It is generally considered that heat treatments have a negative impact on the mechanical properties of nacre due to thermal decomposition of the organic ***,the present work investigated the microindentation behavior on fresh and heat-treated nacres from two orthogonal directions,and the results demonstrate that both hardness value and damage tolerance can remain almost unchanged on the cross-section with the organic matrix degeneration,despite a significant deterioration on the platelet *** analyses suggest that the anisotropic response of indentation behavior to heat treatment in nacre is primarily caused by its structural ***,compared with a single layer of irregular interplatelet interfaces in cross-sectional specimens,the multiple layers of parallel interlamellar interfaces in in-plane specimens exhibit a much greater ability to impede indenter-triggered destruction,and heat treatments would reduce the in-plane hardness but nearly have no effect on the cross-sectional ***,the deeper embedding of platelets in cross-sectional specimens enhances their resistance to interface cracking caused by organic matrix degradation at high temperatures,leading to a reduced sensitivity to ***,the indentation behavior of nacre shows different tendencies in response to variations in the organic matrix state along normal and parallel directions.

关键词： Nacre Structural orientation Heat treatment Indentation behavior Organic matrix

Micelle-directed self-assembly of single-crystal-like mesoporous stoichiometric oxides for high-performance lithium storage

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National Science Review 2024年第4期11卷 195-205页

作者： Yanhua Wan Changyao Wang Xingmiao Zhang Yang Yin Mengmeng Liu Bing Ma Linlin Duan Yuzhu Ma Wei Zhang Changlin Zheng Dongliang Chao Fei Wang Yongyao Xia Wei Li department of Chemistry Laboratory of Advanced Materials Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials State Key Laboratory of Molecular Engineering of Polymers College of Chemistry and Materials ScienceFudan University State Key Laboratory of Surface physics and department of physics Fudan University

Due to their uncontrollable assembly and crystallization process,the synthesis of mesoporous metal oxide single crystals remains a formidable ***,we report the synthesis of single-crystal-like mesoporous Li2TiSiO5by using soft micelles as *** key lies in the atomic-scale self-assembly and step-crystallization processes,which ensure the formation of single-crystal-like mesoporous Li2TiSiO5microparticles via an oriented attachment growth mechanism under the confinement of an in-situ formed carbon *** mesoporous Li2TiSiO5anode achieves a superior rate capability(148 mAh g-1at5.0 A g-1) and outstanding long-term cycling stability(138 mAh g-1after 3000 cycles at 2.0 A g-1) for lithium storage as a result of the ultrafast Li+diffusion caused by penetrating mesochannels and nanosized crystal frameworks（5-10 nm）.In comparison,bulk Li2TiSiO5exhibits poor rate capability and cycle performance due to micron-scale diffusion *** method is very simple and reproducible,heralding a new way of designing and synthesizing mesoporous single crystals with controllable frameworks and chemical functionalities.

关键词： mesoporous materials micelles single-crystal-like Li2TiSiO5 lithium-ion batteries

Computational and dark-field ghost imaging with ultraviolet light

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Photonics research 2024年第2期12卷 226-234页

作者： JIAQI SONG BAOLEI LIU YAO WANG CHAOHAO CHEN XUCHEN SHAN XIAOLAN ZHONG LING-AN WU FAN WANG School of physics Beihang UniversityBeijing 102206China Australian research Council Centre of Excellence for Transformative Meta-Optical Systems Department of Electronic Materials EngineeringResearch School of PhysicsThe Australian National UniversityCanberraACT 2600Australia Institute of physics Chinese Academy of SciencesBeijing 100190China

Ultraviolet(UV)imaging enables a diverse array of applications,such as material composition analysis,biological fluorescence imaging,and detecting defects in semiconductor ***,scientific-grade UV cameras with high quantum efficiency are expensive and include complex thermoelectric cooling ***,we demonstrate a UV computational ghost imaging(UV-CGI)method to provide a cost-effective UV imaging and detection *** applying spatial–temporal illumination patterns and using a 325 nm laser source,a singlepixel detector is enough to reconstruct the images of *** use UV-CGI to distinguish four UV-sensitive sunscreen areas with different densities on a ***,we demonstrate dark-field UV-CGI in both transmission and reflection *** only collecting the scattered light from objects,we can detect the edges of pure phase objects and small scratches on a compact *** results showcase a feasible low-cost solution for nondestructive UV imaging and *** combining it with other imaging techniques,such as hyperspectral imaging or time-resolved imaging,a compact and versatile UV computational imaging platform may be realized for future applications.

关键词： ghost illumination versatile

Assembly of functional carboxymethyl cellulose/polyethylene oxide/anatase TiO_(2) nanocomposites and tuning the dielectric relaxation, optical, and photoluminescence performances

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Journal of Semiconductors 2024年第7期45卷 26-38页

作者： Asmaa M.Ismail Abeer A.Reffaee Fawzy G.El Desouky Spectroscopy department Physics Research InstituteNational Research CentreGizaCairo 12622Egypt Microwave physics and Dielectrics department National Research CentreDokkiCairoEgypt Solid State physics department Physics Research InstituteNational Research CentreGizaCairo 12622Egypt

Nanocomposite films consisting of carboxymethyl cellulose,polyethylene oxide(CMC/PEO),and anatase titanium diox-ide(TO)were produced by the use of sol-gel and solution casting ***2 nanocrystals were effectively incorporated into CMC/PEO polymers,as shown by X-ray diffraction(XRD)and attenuated total reflectance fourier transform infrared(ATR-FTIR)*** roughness growth is at high levels of TO nanocrystals(TO NCs),which means increasing active sites and defects in CMC/*** differential scanning calorimetry(DSC)thermograms,the change in glass transition temperature(Tg)val-ues verifies that the polymer blend interacts with TO *** increment proportions of TO NCs have a notable impact on the dielectric performances of the nanocomposites,as *** electrical properties of the CMC/PEO/TO nanocomposite undergo significant *** nanocomposite films exhibit a red alteration in the absorption edge as the concentration of TO NCs increases in the polymer *** decline in the energy gap is readily apparent as the weight percentage of TO NCs *** photoluminescence(PL)emission spectra indicate that the sites of the luminescence peak maximums show slight variation;peaks get wider,while their intensities decrease dramatically as the concentration of TO *** nanocomposite materials show potential for multifunctional applications including optoelectronics,antireflection coatings,pho-tocatalysis,light emitting diodes,and solid polymer electrolytes.

关键词： anatase TiO_(2) CMC/PEO nanocomposites optical photoluminescent electrical optoelectronics

Surface-induced interaction of colloidal particles in isotropic liquid crystals

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Communications in Theoretical physics 2024年第7期76卷 116-124页

作者： Hualing Zhang Kaifeng Weng Rui Ma department of physics College of Physical Science and Technology Xiamen University Fujian Provincial Key Laboratory for Soft Functional materials research Research Institute for Biomimetics and Soft Matter Xiamen University

In this work, we study the interaction between two colloidal particles in a liquid crystal that is in the isotropic phase. The interaction is caused by surface-induced polarization of the liquid crystal molecules in the vicinity of the particles. We find that the interaction is short-ranged in both 2D and 3D geometry. Under symmetric homeotropic anchoring conditions, the interaction is repulsive. While under anti-symmetric homeotropic anchoring conditions, the interaction is repulsive at short distances but attractive at intermediate distances. The particle size has a strong impact on the effective interaction force.

关键词： colloidal particles liquid crystals surface-induced interaction

Simulation Study on Constraining Gravitational Wave Propagation Speed by Gravitational Wave and Gamma-ray Burst Joint Observation on Binary Neutron Star Mergers

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research in Astronomy and Astrophysics 2024年第8期24卷 44-53页

作者： Jin-Hui Rao Shu-Xu Yi Lian Tao Qing-Wen Tang department of physics School of Physics and Materials ScienceNanchang University Institute of High Energy physics Chinese Academy of Sciences

Theories of modified gravity suggest that the propagation speed of gravitational waves （GW） vgmay deviate from the speed of light c.A constraint can be placed on the difference between c and vgwith a simple method that uses the arrival time delay between GW and electromagnetic wave simultaneously emitted from a burst *** simulated the joint observation of GW and short gamma-ray burst signals from binary neutron star merger events in different observation campaigns,involving advanced LIGO （aLIGO） in design sensitivity and Einstein Telescope（ET） joint-detected with Fermi/*** a result,the relative precision of constraint on vgcan reach～10-17（aLIGO） and～10-18（ET）,which are one and two orders of magnitude better than that from GW170817,*** continue to obtain the bound of graviton mass mg≤7.1（3.2）×10-20eV with aLIGO （ET）.Applying the Standard-Model Extension test framework,the constraint on vgallows us to study the Lorentz violation in the nondispersive,nonbirefringent limit of the gravitational *** obtain the constraints of the dimensionless isotropic coefficients ■at mass dimension d=4,which are■for aLIGO and■for ET.

关键词： (stars:) gamma-ray burst: general gravitational waves stars: neutron

Microstructure and magnetocaloric properties of melt-extracted SmGdDyCoAl high-entropy amorphous microwires

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Rare Metals 2024年第3期43卷 1234-1242页

作者： Shi-Jie Wei Hong-Xian Shen Lun-Yong Zhang Lin Luo Xin-Xing Tang Jian-Fei Sun Xiao-Qing Li School of materials Science and Engineering Harbin Institute of TechnologyHarbin150001China Applied materials physics Department of Materials Science and EngineeringKTH-Royal Institute of Technology10044StockholmSweden

This paper presents a systematic investigation of the microstructure and magnetocaloric properties of melt-extracted Sm_(20)Gd_(20)Dy_(20)Co_(20)Al_(20)high-entropy *** fabricated wires exhibited an amorphous structure,and the temperature interval of the undercooled liquid AT was 45 *** microwires underwent a second-order magnetic transition from a ferromagnetic to a paramagnetic state near the Curie temperature(T_(C)=52 K),The maximum magnetic entropy change(-ΔS_M^(max)),the relative cooling power and the refrigeration capacity reached 6.34 J·kg^(-1)·K^(-1).422.09 J·kg^(-1)and 332.94 J·kg^(-1),respectively,under a magnetic field change of 5 *** addition,the temperature-averaged entropy changes with two temperature lifts(3 and 10 K)were 6.32 and 6.27 J·kg^(-1)·K^(-1),*** good magnetocalorie performance highlights the significant potential for the Sm_(20)Gd_(20)Dy_(20)Co_(20)Al_(20)microwires to be used as magnetic refrigerant materials in low-temperature region *** work will serve as a valuable reference for future investigations on low-temperature high-entropy magnetocaloric materials.

关键词： Melt-extraction High-entropy amorphous microwires Magnetocaloric effect Magnetic refrigeration