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arXiv 2021年

作者： Chung, Ka Man Zeng, Jian Adapa, Sarath Reddy Feng, Tianshi Bagepalli, Malavika V. Loutzenhiser, Peter G. Albrecht, Kevin J. Ho, Clifford K. Chen, Renkun Material Science and Engineering Program University of California San Diego San DiegoCA92093 United States Department of Mechanical and Aerospace Engineering University of California San Diego San DiegoCA92093 United States George W. Woodruff School of Mechanical Engineering Georgia Institute of Technology AtlantaGA30332-0405 United States Concentrating Solar Technologies Department Sandia National Laboratories 1515 Eubank Blvd. SE AlbuquerqueNM87123 United States

A systematic study was performed to measure the effective thermal conductivity of ceramic particle beds, a promising heat transfer and thermal energy storage media for concentrating solar power (CSP). The thermal conductivity of the ceramic particle beds was measured using a transient hot-wire (THW) method within a temperature range of room temperature to 700 oC, the target operating temperature of the next-generation CSP systems. Two different types of ceramic particles were examined: (1) CARBOBEAD HSP 40/70 and (2) CARBOBEAD CP 40/100 with the average particle sizes of ~ 400 μm and ~280 μm, respectively, and thermal conductivities ranging from ~0.25 W m-1 K-1 to ~0.50 W m-1 K-1 from 20 oC to 700 oC in both air and N2 gas. The gaseous pressure dependence of the thermal conductivity of the ceramic particle beds was also studied in the N2 environment to differentiate the contributions from gas conduction, solid conduction, and radiation. Calculations using the Zehner, Bauer, and Schlünder (ZBS) model showed good agreements with the measurements. Based on the model, it is concluded that the effective thermal conductivity of the packed particle beds is dominated by the gas conduction while the solid conduction and radiation contributes to about 20% of the effective thermal conductivity at high temperature. Copyright © 2021, The Authors. All rights reserved.

关键词： Heat storage

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Magnetic Control of Soft Chiral Phonons in PbTe

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Physical Review Letters 2022年第7期128卷 075901-075901页

作者： Andrey Baydin Felix G. G. Hernandez Martin Rodriguez-Vega Anderson K. Okazaki Fuyang Tay G. Timothy Noe, II Ikufumi Katayama Jun Takeda Hiroyuki Nojiri Paulo H. O. Rappl Eduardo Abramof Gregory A. Fiete Junichiro Kono Department of Electrical and Computer Engineering Rice University Houston Texas 77005 USA Smalley-Curl Institute Rice University Houston Texas 77005 USA Instituto de Física Universidade de São Paulo São Paulo São Paulo 05508-090 Brazil Theoretical Division Los Alamos National Laboratory Los Alamos New Mexico 87545 USA Laboratório Associado de Sensores e Materiais Instituto Nacional de Pesquisas Espaciais São José dos Campos São Paulo 12201-970 Brazil Applied Physics Graduate Program Smalley-Curl Institute Rice University Houston Texas 77005 USA Department of Physics Graduate School of Engineering Science Yokohama National University Yokohama 240-8501 Japan Institute for Materials Research Tohoku University Sendai 980-8577 Japan Department of Physics Northeastern University Boston Massachusetts 02115 USA Department of Physics Massachusetts Institute of Technology Cambridge Massachusetts 02139 USA Department of Physics and Astronomy Rice University Houston Texas 77005 USA Department of Material Science and NanoEngineering Rice University Houston Texas 77005 USA

PbTe crystals have a soft transverse optical phonon mode in the terahertz frequency range, which is known to efficiently decay into heat-carrying acoustic phonons, resulting in anomalously low thermal conductivity. Here, we studied this phonon via polarization-dependent terahertz spectroscopy. We observed softening of this mode with decreasing temperature, indicative of incipient ferroelectricity, which we explain through a model including strong anharmonicity with a quartic displacement term. In magnetic fields up to 25 T, the phonon mode splits into two modes with opposite handedness, exhibiting circular dichroism. Their frequencies display Zeeman splitting together with an overall diamagnetic shift with increasing magnetic field. Using a group-theoretical approach, we demonstrate that these observations are the result of magnetic field-induced morphic changes in the crystal symmetries through the Lorentz force exerted on the lattice ions. Thus, our Letter reveals a novel process of controlling phonon properties in a soft ionic lattice by a strong magnetic field.

关键词： Chirality Diamagnetism Magneto-dielectric effect Optical phonons Thermal conductivity Zeeman effect Terahertz time-domain spectroscopy

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Phase Transformations, Microstructural Refinement and Defect Evolution Mechanisms in Al-Si Alloys under Non-Hydrostatic Diamond Anvil Cell Compression

SSRN

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SSRN 2020年

作者： Liu, Tingkun Olszta, Matthew Gwalani, Bharat Park, Changyong Mathaudhu, Suveen Devaraj, Arun Physical and Computational Science Directorate Pacific Northwest National Laboratory Energy and Environment Directorate Pacific Northwest National Laboratory High Pressure Collaborative Access Team X-ray Science Division Argonne National Laboratory Material Science and Engineering Program University of California Riverside Mechanical Engineering Department University of California Riverside

Non-hydrostatic compression of materials using a diamond anvil cell (DAC) can transform equilibrium microstructure of an alloy to novel, potentially metastable states. In this study, in situ synchrotron X-ray diffraction (XRD) during compression up to 24 GPa and subsequent ex situ, high resolution analytical electron microscopy (AEM) after decompression of an Al-Si alloy provided insight into the crystallographic changes during the compression as well as microstructural refinement, and defect structures caused by such a high pressure compression-decompression process. Pressure resolved in-situ synchrotron XRD was used to detail the phase transformation pathway of the eutectic Si phase in Al-Si alloy, from Si-I → Si-XI → Si-V during compression, and a final transformation predominantly to Si-III after decompression. Using scanning and transmission electron microscopy (S/TEM), site specific analysis of the alloy immediately underneath the anvil contact surface demonstrated a highly complex microstructure. A narrow region of thick amorphous Al oxide interspersed with nanocrystalline grains was found at the top surface. Underneath this Al oxide, while the majority the eutectic Si was transformed into highly-deformed, polycrystalline (PC) Si-III, a complex intermediate layer was discovered at the interface between Al and Si, comprised of a small fraction of Al nanocrystals and a majority of nanocrystalline Si-I. This combination of pressure resolved in-situ synchrotron XRD coupled with subsequent high resolution, electron microscopy resolved the phase transformation as well as non-equilibrium microstructures in a metallic alloy induced by a non-hydrostatic high pressure compression followed by decompression. © 2020, The Authors. All rights reserved.

关键词： Silicon alloys

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Intramolecular Cation-π Interactions Organize Bowl-Shaped, Luminescent Molecular Containers

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Angewandte Chemie 2024年第20期136卷

作者： Jia He Minggui Bai Xuedong Xiao Shuai Qiu Wenzhuo Chen Jiaqi Li Prof. Yang Yu Prof. Wei Tian Shaanxi Key Laboratory of Macromolecular Science and Technology Xi'an Key Laboratory of Hybrid Luminescent Materials and Photonic Device MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions School of Chemistry and Chemical Engineering Northwestern Polytechnical University. Xi'an 710072 Shaanxi P. R. China Center for Supramolecular Chemistry & Catalysis and Department of Chemistry College of Science Shanghai University 99 Shang-Da Road Shanghai 200444 China

Molecules with nonplanar architectures are highly desirable due to their unique topological structures and functions. We report here the synthesis of two molecular containers ( 1 ⋅ 3Br − and 1 ⋅ 3Cl − ), which utilize intramolecular cation-π interactions to enforce macrocylic arrangements and exhibit high binding affinity and luminescent properties. Remarkably, the geometry of the cation-π interaction can be flexibly tailored to achieve a precise ring arrangement, irrespective of the angle of the noncovalent bonds. Additionally, the C−H⋅⋅⋅Br − hydrogen bonds within the container are also conducive to stabilizing the bowl-shaped conformation. These bowl-shaped conformations were confirmed both in solution through NMR spectroscopy and in the solid state by X-ray studies. 1 ⋅ 3Br − shows high binding affinity and selectivity: F − >Cl − , through C−H ⋅⋅⋅ X − (X=F, Cl) hydrogen bonds. Additionally, these containers exhibited blue fluorescence in solution and yellow room-temperature phosphorescence (RTP) in the solid state. Our findings illustrate the utility of cation-π interactions in designing functional molecules.

关键词： Bowl-shaped molecular containers cation-π selective binding affinity room-temperature phosphorescence

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Terahertz cavity magnon polaritons

arXiv

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arXiv 2023年

作者： Kritzell, T. Elijah Baydin, Andrey Tay, Fuyang Rodriguez, Rodolfo Nojiri, Hiroyuki Everitt, Henry O. Barsukov, Igor Kono, Junichiro Department of Electrical and Computer Engineering Rice University HoustonTX77005 United States Applied Physics Graduate Program Smalley-Curl Institute Rice University HoustonTX77005 United States Smalley-Curl Institute Rice University HoustonTX77005 United States Physics and Astronomy University of California RiversideCA92521 United States Institute for Materials Research Tohoku University Sendai980-8577 Japan DEVCOM Army Research Laboratory-South HoustonTX77005 United States Department of Physics and Astronomy Rice University HoustonTX77005 United States Department of Material Science and NanoEngineering Rice University HoustonTX77005 United States

Hybrid light-matter coupled states, or polaritons, in magnetic materials have attracted significant attention due to their potential for enabling novel applications in spintronics and quantum information processing. However, most studies to date have been carried out for ferromagnetic materials with magnon excitations at gigahertz frequencies. Here, we have investigated strong resonant photon-magnon coupling at frequencies above 1 terahertz for the first time in a prototypical room-temperature antiferromagnetic insulator, NiO, inside a Fabry-Pérot cavity. The cavity was formed by the crystal itself when it was thinned down to an optimized thickness. By using terahertz time-domain spectroscopy in high magnetic fields up to 25 T, we swept the magnon frequency through Fabry-Pérot cavity modes and observed photon-magnon anticrossing behavior, demonstrating clear vacuum Rabi splittings exceeding the polariton linewidths. These results show that NiO is a promising platform for exploring antiferromagnetic spintronics and cavity magnonics in the terahertz frequency range. Copyright © 2023, The Authors. All rights reserved.

关键词： Polariton

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2D Nanosilicate for additive manufacturing: Rheological modifier, sacrificial ink and support bath

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Bioprinting 2022年 25卷

作者： Rajput, Satyam Deo, Kaivalya A. Mathur, Tanmay Lokhande, Giriraj Singh, Kanwar Abhay Sun, Yuxiang Alge, Daniel L. Jain, Abhishek Sarkar, Tapasree Roy Gaharwar, Akhilesh K. Department of Biomedical Engineering College of Engineering Texas A&M University College Station 77843 TX United States Nutrition College of Agriculture and Life Sciences Texas A&M University College Station 77843 TX United States Department of Material Science and Engineering College of Engineering Texas A&M University College Station 77843 TX United States Department of Biology Texas A&M University College Station 77843 TX United States Interdisiplinary Program in Genetics Texas A&M University College Station 77843 TX United States Center for Remote Health Technologies and Systems Texas A&M University College Station 77843 TX United States Department of Medical Physiology College of Medicine Texas A&M Health Science Center Bryan 77807 TX United States Department of Cardiovascular Sciences Houston Methodist Institute for Academic Medicine Houston Methodist Research Institute Houston 77030 TX United States

Extrusion-based 3D printing/bioprinting is a promising approach to generate patient-specific tissue engineered grafts. However, a major challenge in extrusion-based 3D printing/bioprinting is that most currently used materials lack the versatility to be used in a wide range of applications. In this study, we introduce colloidal solutions of two-dimensional (2D) nanosilicates as a platform technology to print complex structures via three different approaches. In the first approach, we designed a shear-thinning ink composed of nanosilicates, which can be further reinforced by adding different types of water-soluble polymers. In the second approach, we demonstrated the use of nanosilicates as a sacrificial ink to design microfluidic devices for in vitro disease modelling. In the third approach, we utilized a colloidal nanosilicate gel as a support bath for 3D printing by nullifying the surface tension and gravitational forces. Due to their exceptional versatility, nanosilicate-based biomaterials could be widely adopted in the fields of additive manufacturing, tissue engineering, drug delivery, and medical devices. © 2022 Elsevier B.V.

关键词： 3D printing / bioprinting Additive manufacturing Biomaterials ink Nanoparticles Regenerative medicine

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Overcoming the surface paradox: Buried perovskite quantum dots in wide-bandgap perovskite thin films

arXiv

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arXiv 2025年

作者： Zhang, Hao Pasha, Altaf Metcalf, Isaac Zhou, Jianlin Staunstrup, Mathias Zhu, Yunxuan Liao, Shusen Ssennyimba, Ken Chen, Jia-Shiang Reddy, Surya Prakash Thébaud, Simon Hou, Jin Shuai, Xinting Mandani, Faiz Sidhik, Siraj Jones, Matthew R. Ma, Xuedan Balakrishna, R. Geetha Susarla, Sandhya Ginger, David S. Katan, Claudine Kanatzidis, Mercouri G. Bawendi, Moungi G. Natelson, Douglas Tamarat, Philippe Lounis, Brahim Even, Jacky Mohite, Aditya D. Department of Chemical and Biomolecular Engineering Rice University HoustonTX77005 United States Applied Physics Program Smalley‐Curl Institute Rice University HoustonTX77005 United States Centre for Nano and Material Sciences Jain University Jain Global Campus Kanakapura Karnataka Bangalore562112 India Department of Materials Science and NanoEngineering Rice University HoustonTX77005 United States Université de Bordeaux LP2N Talence France Institut d’Optique CNRS LP2N Talence France Department of Physics and Astronomy Rice University HoustonTX77005 United States Center for Nanoscale Materials Argonne National Laboratory LemontIL60439 United States School for Engineering of Matter Transport and Energy Arizona State University TempeAZ85281 United States UMR 6082 CNRS INSA de Rennes Rennes35708 France Department of Chemistry Rice University HoustonTX77005 United States Department of Chemistry University of Washington Box 351700 SeattleWA98195-1700 United States UMR 6226 Rennes35000 France Department of Chemistry Northwestern University EvanstonIL United States Department of Chemistry Massachusetts Institute of Technology 77 Massachusetts Avenue CambridgeMA02139 United States Department of Electrical and Computer Engineering Rice University HoustonTX77005 United States

Colloidal perovskite quantum dots (PQDs) are an exciting platform for on-demand quantum, and classical optoelectronic and photonic devices. However, their potential success is limited by the extreme sensitivity and low stability arising from their weak intrinsic lattice bond energy and complex surface chemistry. Here we report a novel platform of buried perovskite quantum dots (b-PQDs) in a three-dimensional perovskite thin-film, fabricated using one-step, flash annealing, which overcomes surface related instabilities in colloidal perovskite dots. The b-PQDs demonstrate ultrabright and stable single-dot emission, with resolution-limited linewidths below 130 μeV, photon-antibunching (g2(0)=0.1), no blinking, suppressed spectral diffusion, and high photon count rates of 104/s, consistent with unity quantum yield. The ultrasharp linewidth resolves exciton fine-structures (dark and triplet excitons) and their dynamics under a magnetic field. Additionally, b-PQDs can be electrically driven to emit single photons with 1 meV linewidth and photon-antibunching (g2(0)=0.4). These results pave the way for on-chip, low-cost single-photon sources for next generation quantum optical communication and sensing. © 2025, CC BY.

关键词： Photons

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DNA-modulated Mo-Zn single-atom nanozymes: Insights from molecular dynamics simulations to smartphone-assisted biosensing

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Chinese Chemical Letters 2024年

作者： Zhimin Song Zhe Tang Yu Zhang Yanru Zhou Xiaozheng Duan Yan Du Chong-Bo Ma Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education National & Local United Engineering Laboratory for Power Batteries Key Laboratory of Nanobiosensing and Nanobioanalysis at Universities of Jilin Province Analysis and Testing Center Department of Chemistry Northeast Normal University Changchun 130024 China Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 China Department of Chemistry University of Science & Technology of China Hefei 230026 China School of Physics Science and Technology Yili Normal University Yining 835000 China School of Physics Northeast Normal University Changchun 130024 China State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular Science Fudan University Shanghai 200438 China

Recent advancements in nanotechnology have spotlighted the catalytic potential of nanozymes, particularly single-atom nanozymes (SANs), which are pivotal for innovations in biosensing and medical diagnostics. Among others, DNA stands out as an ideal biological regulator. Its inherent programmability and interaction capabilities allow it to significantly modulate nanozyme activity. This study delves into the dynamic interplay between DNA and molybdenum-zinc single-atom nanozymes (Mo-Zn SANs). Using molecular dynamics simulations, we uncover how DNA influences the peroxidase-like activities of Mo-Zn SANs, providing a foundational understanding that enhances the application scope of SANs in biosensing. With these insights as a foundation, we developed and demonstrated a model aptasensor for point-of-care testing (POCT), utilizing a label-free colorimetric approach that leverages DNA-nanozyme interactions to achieve high-sensitivity detection of lysozyme. Our work elucidates the nuanced control DNA exerts over nanozyme functionality and illustrates the application of this molecular mechanism through a smartphone-assisted biosensing platform. This study not only underscores the practical implications of DNA-regulated Mo-Zn SANs in enhancing biosensing platforms, but also highlights the potential of single-atom nanozyme technology to revolutionize diagnostic tools through its inherent versatility and sensitivity.

关键词： Single-atom nanozymes DNA-regulated biosensors Molecular dynamics simulations Colorimetric aptasensing Point-of-care diagnostics

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Real-time 3D analysis during electron tomography using tomviz

arXiv

引用

arXiv 2022年

作者： Schwartz, Jonathan Harris, Chris Pietryga, Jacob Zheng, Huihuo Kumar, Prashant Visheratina, Anastasiia Kotov, Nicholas A. Major, Brianna Avery, Patrick Ercius, Peter Ayachit, Utkarsh Geveci, Berk Muller, David A. Genova, Alessandro Jiang, Yi Hanwell, Marcus Hovden, Robert Department of Material Science and Engineering University of Michigan Ann ArborMI United States Kitware Inc Clifton ParkNY United States Argonne Leadership Computing Facility Argonne National Laboratory LemontIL United States Department of Chemical Engineering University of Michigan Ann ArborMI United States The Molecular Foundry Lawrence Berkeley National Laboratory BerkeleyCA United States School of Applied and Engineering Physics Cornell University IthacaNY United States Advanced Photon Source Argonne National Laboratory LemontIL United States National Synchrotron Light Source II Brookhaven National Laboratory UptonNY United States Applied Physics Program University of Michigan Ann ArborMI United States

The demand for high-throughput electron tomography is rapidly increasing in biological and material sciences. However, this 3D imaging technique is computationally bottlenecked by alignment and reconstruction which runs from hours to days. We demonstrate real-time tomography with dynamic 3D tomographic visualization to enable rapid interpretation of specimen structure immediately as data is collected on an electron microscope. Using geometrically complex chiral nanoparticles, we show volumetric interpretation can begin in less than 10minutes and a high-quality tomogram is available within 30 minutes. Real-time tomography is integrated into tomviz, an opensource and cross-platform 3D data analysis tool that contains intuitive graphical user interfaces (GUI), to enable any scientist to characterize biological and material structure in 3D. © 2022, CC BY.

关键词： Graphical user interfaces

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Insights into the Distinct Behaviors between Bifunctional and Binary Organoborane Catalysts through Terpolymerization of Epoxide, CO2, and Anhydride

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Angewandte Chemie 2024年第27期136卷

作者： Rui Xie Yuhui Wang Shuai Li Bo Li Jie Xu Jinqian Liu Yuchen He Guan-Wen Yang Guang-Peng Wu MOE Key Laboratory of Macromolecular Synthesis and Functionalization Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province Department of Polymer Science and Engineering Zhejiang University Hangzhou 310027 Zhejiang P. R. China College of Material Chemistry and Chemical Engineering Key Laboratory of Organosilicon Chemistry and Material Technology Ministry of Education Hangzhou Normal University Hangzhou 311121 Zhejiang P. R. China Shaanxi Coal Chemical Industry Technology Research Institute Co. Ltd. Xi'an 710100 Shaanxi P. R. China

Alkyl borane compounds-mediated polymerizations have expanded to Lewis pair polymerization, free radical polymerization, ionic ring-opening polymerization, and polyhomologation. The bifunctional organoborane catalysts that contain the Lewis acid and ammonium or phosphonium salt in one molecule have demonstrated superior catalytic performance for ring-opening polymerization of epoxides and ring-opening copolymerization of epoxides and CO 2 than their two-component analogues, i.e., the blend of organoborane and ammonium or phosphonium salt. To explore the origin of the differences of the one-component and two-component organoborane catalysts, here we conducted a systematic investigation on the catalytic performances of these two kinds of organoborane catalysts via terpolymerization of epoxide, carbon dioxide and anhydride. The resultant terpolymers produced independently by bifunctional and binary organoborane catalyst exhibited distinct microstructures, where a series of gradient polyester-polycarbonate terpolymers with varying polyester content were afforded using the bifunctional catalyst, while tapering diblock terpolymers were obtained using the binary system. The bifunctional catalyst enhances the competitiveness of CO 2 insertion than anhydride, which leads to the premature incorporation of CO 2 into the polymer chains and ultimately results in the formation of gradient terpolymers. DFT calculations revealed the role of electrostatic interaction and charge distribution caused by intramolecular synergistic effect for bifunctional organoborane catalyst.

关键词： organoborane bifunctional catalysts ring-opening polymerization copolymerization block copolymer

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