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Nested Metal Catalysts:Metal Atoms and Clusters Stabilized by Confinement with Accessibility on Supports

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Precision Chemistry 2023年第1期1卷 3-13页

作者： Bruce C.Gates alexander Katz Jingyue Liu Department of Chemical Engineering University of CaliforniaDavisDavisCalifornia 95616United States Department of Chemical and Biomolecular Engineering University of CaliforniaBerkeleyBerkeleyCalifornia 94720United States Department of Physics Arizona State UniversityTempeArizona 85287United States

Supported catalysts that are important in technology prominently include atomically dispersed metals and metal *** the metals are noble,they are typically unstablesusceptible to sinteringespecially under reducing *** the metals in supports such as organic polymers,metal oxides,and zeolites confers stability on the metals but at the cost of catalytic activity associated with the lack of accessibility of metal bonding sites to *** approach to stabilizing noble metal catalysts while maintaining their accessibility involves anchoring them in molecular-scale nests that are in or on *** nests include zeolite pore mouths,zeolite surface cups(half-cages),raft-like islands of oxophilic metals bonded to metal oxide supports,clusters of non-noble metals(e.g.,hosting noble metals as single-atom alloys),and nanoscale metal oxide islands that selectively bond to the catalytic metals,isolating them from the *** examples illustrate a trend toward precision in the synthesis of solid catalysts,and the latter two classes of nested catalysts offer realistic prospects for economical large-scale application.

关键词： catalyst synthesis supported metal catalysts encapsulated catalysts nested catalysts atomically dispersed metal catalysts

Genome and clonal hematopoiesis stability contrasts with immune,cfDNA,mitochondrial,and telomere length changes during short duration spaceflight

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Precision Clinical Medicine 2024年第1期7卷 1-13页

作者： J.Sebastian Garcia-Medina Karolina Sienkiewicz S.Anand Narayanan Eliah G.Overbey Kirill Grigorev Krista A.Ryon Marissa Burke Jacqueline Proszynski Braden Tierney Caleb M.Schmidt Nuria Mencia-Trinchant Remi Klotz Veronica Ortiz Jonathan Foox Christopher Chin Deena Najjar Irina Matei Irenaeus Chan Carlos Cruchaga Ashley Kleinman JangKeun Kim alexander Lucaci Conor Loy Omary Mzava Iwijn De Vlaminck Anvita Singaraju Lynn E.Taylor Julian C.Schmidt Michael A.Schmidt Kelly Blease Juan Moreno Andrew Boddicker Junhua Zhao Bryan Lajoie Andrew Altomare Semyon Kruglyak Shawn Levy Min Yu Duane C.Hassane Susan M.Bailey Kelly Bolton Jaime Mateus Christopher E.Mason Department of Physiology and Biophysics Weill Cornell MedicineCornell UniversityNew YorkNY 10021USA The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine Weill Cornell MedicineNew YorkNY 10021USA Department of Immunology Weill Cornell MedicineCornell UniversityNew YorkNY 10021USA Department of Stem Cell Biology and Regenerative Medicine Keck School of MedicineUniversity of Southern CaliforniaLos AngelesCA 90033USA Space Exploration Technologies Corporation HawthomeCA 90250USA Sovaris Aerospace BoulderCO 80302USA Advanced Pattern Analysis&Human Performance Group BoulderCO 80302USA Children's Cancer and Blood Foundation Laboratories Departments of Pediatrics and Cell and Developmental BiologyDrukier Institute for Children's HealthMeyer Cancer CenterWeill Cornell MedicineNew YorkNY 10021USA Meyer Cancer Center Weill Cornell MedicineNew YorkNY 10065USA Department of Nutrition and Integrative Physiology Florida State UniversityTallahasseeFL 32306USA Department of Systems Engineering Colorado State UniversityFort CollinsCO 80523USA Element Biosciences San DiegoCA 10055USA Department of Environmental and Radiological Health Sciences Colorado State UniversityFort CollinsCO 80523USA Cell and Molecular Biology Program Colorado State UniversityFort CollinsCO 80523USA BioAstra Inc New YorkNYUSA Washington University St Louis Oncology Division St.LouisMO 63100USA Meinig School of Biomedical Engineering Cornell UniversityIthacaNY 14853USA The Feil Family Brain and Mind Research Institute Weill Cornell MedicineNY 10021USA WorldQuant Initiative for Quantitative Prediction Weill Cornell MedicineNew YorkNY 10021USA

Background The Inspiration4(I4)mission,the first all-civilian orbital flight mission,investigated the physiological effects of short-duration spaceflight through a multi-omic *** advances,there remains much to learn about human adaptation to spaceflight's unique challenges,including microgravity,immune system perturbations,and radiation *** To provide a detailed genetics analysis of the mission,we collected dried blood spots pre-,during,and post-flight for DNA *** length was measured by quantitative PCR,while whole genome and cfDNA sequencing provided insight into genomic stability and immune adaptations.A robust bioinformatic pipeline was used for data analysis,including variant calling to assess mutational *** Telomere elongation occurred during spaceflight and shortened after return to ***-free DNA analysis revealed increased immune cell signatures *** significant clonal hematopoiesis of indeterminate potential(CHIP)or whole-genome instability was *** long-term gene expression changes across immune cells suggested cellular adaptations to the space environment persisting months *** Our findings provide valuable insights into the physiological consequences of short-duration spaceflight,with telomere dynamics and immune cell gene expression adapting to spaceflight and persisting after return to *** sequencing data will serve as a reference point for studying the early development of CHIP in astronauts,an understudied phenomenon as previous studies have focused on career *** study will serve as a reference point for future commercial and non-commercial spaceflight,low Earth orbit(LEO)missions,and deep-space exploration.

关键词： genomes clonal hematopoiesis stability immune mitochondria ribosomes spaceflight

Predicting the propensity for thermally activated β events in metallic glasses via interpretable machine learning

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npj Computational Materials 2020年第1期6卷 46-57页

作者： Qi Wang Jun Ding Longfei Zhang Evgeny Podryabinkin alexander Shapeev Evan Ma Department of Materials Science and Engineering Johns Hopkins UniversityBaltimoreMD 21218USA Center for Advancing Materials Performance from the Nanoscale(CAMP-Nano) State Key Laboratory for Mechanical Behavior of MaterialsXi’an Jiaotong UniversityXi’an 710049China Department of Computer Science Johns Hopkins UniversityBaltimoreMD 21218USA Center for Energy Science and Technology Skolkovo Institute of Science and Technology3 Nobel StreetMoscow 143026Russia

The elementary excitations in metallic glasses(MGs),i.e.,β processes that involve hopping between nearby sub-basins,underlie many unusual properties of the amorphous alloys.A high-efficacy prediction of the propensity for those activated processes from solely the atomic positions,however,has remained a daunting ***,employing well-designed site environment descriptors and machine learning(ML),notable progress has been made in predicting the propensity for stress-activated β processes(i.e.,shear transformations)from the static structure.

关键词： structure glasses metallic

Construction of ground-state preserving sparse lattice models for predictive materials simulations

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npj Computational Materials 2017年第1期3卷 203-211页

作者： Wenxuan Huang alexander Urban Ziqin Rong Zhiwei Ding Chuan Luo Gerbrand Ceder Department of Material Science and Engineering Massachusetts Institute of TechnologyCambridgeMAUSA Department of Materials Science and Engineering UC BerkeleyBerkeleyCAUSA Institute of Computing Technology Chinese Academy of SciencesBeijing 100190China Materials Science Division Lawrence Berkeley National LaboratoryBerkeleyCAUSA

First-principles based cluster expansion models are the dominant approach in ab initio thermodynamics of crystalline mixtures enabling the prediction of phase diagrams and novel ground ***,despite recent advances,the construction of accurate models still requires a careful and time-consuming manual parameter tuning process for ground-state preservation,since this property is not guaranteed by *** this paper,we present a systematic and mathematically sound method to obtain cluster expansion models that are guaranteed to preserve the ground states of their reference *** method builds on the recently introduced compressive sensing paradigm for cluster expansion and employs quadratic programming to impose constraints on the model *** robustness of our methodology is illustrated for two lithium transition metal oxides with relevance for Li-ion battery cathodes,i.e.,Li_(2x)Fe_(2(1−x))O_(2) and Li_(2x)Ti_(2(1−x))O_(2),for which the construction of cluster expansion models with compressive sensing alone has proven to be *** demonstrate that our method not only guarantees ground-state preservation on the set of reference structures used for the model construction,but also show that out-of-sample ground-state preservation up to relatively large supercell size is achievable through a rapidly converging iterative *** method provides a general tool for building robust,compressed and constrained physical models with predictive power.

关键词： cluster preserving thermodynamics

Superconductivity in La and Y hydrides: Remaining questions to experiment and theory

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Matter and Radiation at Extremes 2020年第2期5卷 62-72页

作者： Viktor Struzhkin Bing Li Cheng Ji Xiao-Jia Chen Vitali Prakapenka Eran Greenberg Ivan Troyan alexander Gavriliuk Ho-kwang Mao Center for High Pressure Science and Technology Advanced Research ShanghaiChina Geophysical Laboratory Carnegie Institution of WashingtonWashingtonDC 20015USA Center for Advanced Radiation Sources The University of Chicago5640 South Ellis AvenueChicagoIllinois 60637USA Federal Scientific Research Center Crystallography and Photonics Russian Academy of Sciences59 Leninskii Pr-tMoscow 119333Russia Institute for Nuclear Research Russian Academy of SciencesMoscowTroitsk 108840Russia

Recent reports of the superconductivity in hydrides of two different families(covalent lattice,as in SH3 and clathrate-type H-cages containing La and Y atoms,as in LaH10 and YH6)have revealed new families of high-Tc materials with Tc’s near room temperature *** findings confirm earlier expectations that hydrides may have very high Tc’s due to the fact that light H atoms have very high vibrational frequencies,leading to high Tc values within the conventional Bardeen–Cooper–Schrieffer phonon mechanism of ***,as is pointed out by Ashcroft,it is important to have the metallic hydrogen“alloyed”with the elements added to *** concept of a metallic alloy containing a high concentration of metal-like hydrogen atoms has been instrumental in finding new high-Tc *** new superhydride“roomtemperature”superconductors are stabilized only at very high pressures above 100 GPa,making the experimental search for their superconducting properties very *** will review the current experimental and theoretical results for LaH10−x and YH6−x superhydrides.

关键词： hydrides alloy metallic

Impact Estimation and Filtering of Disturbances in fg5 Absolute Gravimeter Observations

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International Journal of Geosciences 2013年第2期4卷 302-308页

作者： Martin Orlob alexander Braun Department of Geosciences School of Natural Sciences and Mathematics The University of Texas at Dallas Richardson USA

Instrumental and environmental disturbances do affect fg5 absolute gravimeter observations and the estimated gravity values, sometimes to the degree that entire measurement campaigns are discarded. We propose a method which moves towards the re-assessment of previously discarded observations. Once an estimate of the frequency and amplitude of a disturbance in a fg5 data set exists, the proposed method can estimate its impact on the estimated gravity value. This is performed through a Gaussian Bell Summation approach of the functional relationship between disturbance frequency and standard deviation of gravity. The filtering of the identified disturbance is realized through a modification of the functional model of the equation of motion in the least squares adjustment of fg5 observations. The results reveal that the Gaussian Bell Summation approximates the frequency—gravity impact relationship sufficiently well with negligible uncertainties, while the accuracy of the detected disturbance frequency defines a limiting factor for the gravity impact estimation. A realistic disturbance of 15 Hz with an amplitude of 1.5 nm had an impact of ≈48 [μGal] on the gravity estimate. The proposed filter approach reduced the impact to ≈12 [μGal], with the remaining effect being almost entirely associated to the uncertainty in disturbance frequency detection.

关键词： fg5 Absolute Gravimetry Gravity Disturbance Filtering Gaussian Bell Summation Least Squares Adjustment

Unravelling Critical Thermodynamic Polymer Properties with Fast Molecular Dynamics Simulations

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Unravelling Critical Thermodynamic Polymer Properties with F...

Computational understanding of Li-ion batteries

中国化学会2017全国高分子学术论文报告会

作者：王坚 alexander goldberg Caroline M.Krauter H.Shaun Kwak Jeffrey M.Sanders Thomas J.L.Mustard Andrea R.Browning Mathew D.Halls 极诚信息科技有限公司 Schr?dinger Inc. Schr?dinger GmbH

Recent advances make it possible to use GPU hardware for molecular dynamics（MD）simulations,enable simulation time scales that were not previously *** studies based on long MD trajectories for molecular systems that contain 104-105 atoms make it possible to obtain thermodynamic observables with high accuracy that can help inform the development of new materials.

关键词： molecular dynamics density glass transition solubility coefficient of thermal expansion.

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npj Computational Materials 2016年第1期2卷 149-149页

作者： alexander Urban Dong-Hwa Seo Gerbrand Ceder Department of Materials Science and Engineering University of California Berkeley CA USA Department of Materials Science and Engineering Massachusetts Institute of Technology Cambridge MA USA Materials Science Division Lawrence Berkeley National Laboratory Berkeley CA USA

Correction to:npj Computational Materials(2016)2,16002;doi:10.1038/npjcompumats.2016.2;published online 18 March 2016 Since the online publication of the above article,it has been noted that an acknowledgement section should have been included and the text should read:‘This work was supported primarily by the *** of Energy(DOE)under Contract ***-fg02-96ER45571.’.

关键词： primarily knowledge DOE

Crystallography of low Z material at ultrahigh pressure:Case study on solid hydrogen

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Matter and Radiation at Extremes 2020年第3期5卷 40-54页

作者： Cheng Ji Bing Li Wenjun Liu Jesse S.Smith alexander Bjoorling Arnab Majumdar Wei Luo Rajeev Ahuja Jinfu Shu Junyue Wang Stanislav Sinogeikin Yue Meng Vitali B.Prakapenka Eran Greenberg Ruqing Xu Xianrong Huang Yang Ding alexander Soldatov Wenge Yang Guoyin Shen Wendy L.Mao Ho-Kwang Mao Center for High Pressure Science and Technology Advanced Research Beijing 100094China High Pressure Collaborative AccessTeam Geophysical LaboratoryCarnegie Institution of WashingtonArgonneIllinois 60439USA Center for the Study of Matter at Extreme Conditions and Department of Mechanical and Materials Engineering Florida International UniversityMiamiFlorida 33199USA Advanced Photon Source Argonne National LaboratoryLemontIllinois 60439USA HPCAT X-Ray Science DivisionArgonne National LaboratoryLemontIllinois 60439USA MAX IV Laboratory Lund University22100 LundSweden Condensed Matter Theory Group Materials Theory DivisionDepartment of Physics and AstronomyUppsala UniversityUppsala S-75120Sweden Center for Advanced Radiation Sources University of ChicagoChicagoIllinois 60637USA Department of Engineering Sciences and Mathematics Lule°a University of Technology97187 Lule°aSweden Department of Geological Sciences Stanford UniversityStanfordCalifornia 94305USA Stanford Institute for Materials and Energy Sciences SLAC National Accelerator LaboratoryMenlo ParkCalifornia 94025USA

Diamond anvil cell techniques have been improved to allow access to the multimegabar ultrahigh-pressure region for exploring novel phenomena in ***,the onlyway to determine crystal structures of materials above 100 GPa,namely,X-ray diffraction(XRD),especially for lowZ materials,remains nontrivial in the ultrahigh-pressure region,even with the availability of brilliant synchrotron X-ray *** thiswork,we performa systematic study,choosing hydrogen(the lowest X-ray scatterer)as the subject,to understand how to better perform XRD measurements of low Z materials at multimegabar *** techniques that we have developed have been proved to be effective in measuring the crystal structure of solid hydrogen up to 254GPa at room temperature[*** et al.,Nature 573,558–562(2019)].Wepresent our discoveries and experienceswith regard to several aspects of thiswork,namely,diamond anvil selection,sample configuration for ultrahigh-pressure XRDstudies,XRDdiagnostics for low Z materials,and related issues in data interpretation and pressure *** that these methods can be readily extended to other low Z materials and can pave the way for studying the crystal structure of hydrogen at higher pressures,eventually testing structural models of metallic hydrogen.

关键词： ultrahigh solid eventually