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The Boson peak interpretation and evolution in confined amorphous water

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Science China(Physics,Mechanics & Astronomy) 2019年第10期62卷 16-23页

作者： Francesco Mallamace Carmelo Corsaro Domenico Mallamace sow-hsin chen Emiliano Fratini Piero Baglioni Department of Nuclear Science and Engineering Massachusetts Institute of TechnologyCambridge MA 02139USA Center for Polymer Studies and Department of Physics Boston UniversityBoston MA 02215USA Dipartimento MIFT Universita di MessinaMessina 1-98166Italy Consorzio Interutiiversitario per lo Sviluppo dei Sistemi a Grande Interfase-CSGI Universita di FirenzeSesto FiorentinoFirenze 1-50019Italy Dipartimento di Chimica"Ugo Schiff" Universita di FirenzeSesto FiorentinoFirenze 1-50019Italy

We study the evolution of the Boson peak for water confined in cement paste obtained by means of Inelastic Neutron Scattering from room temperature to the deep supercooled *** analyze the data in terms of a universal-like model,developed for glass forming liquids in the frame of the energy *** such a way it is possible to discriminate between the fragile and strong glass forming character of supercooled liquids and the dynamical crossover,fragile to strong,between ***,we confirm the link between the Boson peak and the water *** particular,the main result is represented by a crossover from a local energetic minima configuration to that characteristic of saddle points on going towards the deep supercooled regime up to the dynamical arrest.

关键词： water water confined in cement Boson peak inelastic neutron scattering

The Boson peak in confined water： An experimental investigation of the liquid-liquid phase transition hypothesis

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Frontiers of physics 2015年第5期10卷 43-49页

作者： Francesco Mallamace Carmelo Corsaro Domenico Mallamace Zhe Wang sow-hsin chen Department of Nuclear Science and Engineering Massachusetts Institute of Technology Cambridge MA 02139 USA Dipartimento di Fisica e Scienze della Terra Universita di Messina I-98166 Messina Italy Consiglio Nazionale delle Ricerche-IPCF Messina I-98166 Messina Italy Dipartimento di Scienze dell'Ambiente della Sicurezza del Territorio degli Alimentie e della Salute Universit5 di Messina Viale F. Stagno d'Alcontres 31 98166 Messina Italy

The Boson peak （BP） of deeply cooled confined water is studied by using inelastic neutron scattering （INS） in a large interval of the （P, T） phase plane. By taking into account the different behavior of such a collective vibrational mode in both strong and fragile glasses as well as in glass-forming materials, we were able to determine the Widom line that characterizes supercooled bulk water within the frame of the liquid-liquid phase transition （LLPT） hypothesis. The peak frequency and width of the BP correlated with the water polymorphism of the LLPT scenario, allowing us to distinguish the ＂low-density liquid＂（LDL） and ＂high-density liquid＂（HDL） phases in deeply cooled bulk water. Moreover, the BP properties afford a further confirmation of the Widom line temperature Tw as the （P, T） locus in which the local structure of water transforms from a predominately LDL form to a predominately HDL form.

关键词： supercooled water liquid-liquid phase transition (LLPT) inelastic neutron scattering

Hydrophilic and hydrophobic competition in water-methanol solutions

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Science China(Physics,Mechanics & Astronomy) 2019年第10期62卷 8-15页

作者： Domenico Mallamace sow-hsin chen Carmelo Corsaro Enza Fazio Francesco Mallamace HEugene Stanley Dipartimento MIFT Universita di MessinaMessina 1-98166Italy Department of Nuclear Science and Engineering Massachusetts Institute of TechnologyCambridge MA 02139USA Istituto dei Sistemi Complessi(ISC)-CNR Rome 00185Italy Center for Polymer Studies and Department of Physics Boston UniversityBoston MA 02215USA

We study the thermal behavior of the longitudinal spin-lattice, T1, and the transverse spin-spin, T2, relaxation times of the macroscopic magnetization in water/methanol solutions. Our aim is to investigate the reciprocal influence of hydrophobic effects on water properties and of hydrophilicity（via hydrogen bond, HB, interactions） on the solute. Using classical Nuclear Magnetic Resonance spectroscopy, we find a single characteristic correlation time τcthat reflects all local structural configurations and characterizes the thermal motion effects of the magnetic nuclei on the spin-spin interaction. We find that in the supercooled regime the correlations are stronger, with respect to ambient temperature, because the HB interactions have a lifetime long enough to sustain a stable water network. However, increasing the temperature, progressively decreases the HB interaction lifetime and destroys the water clusters with a consequent decoupling in the dynamic modes of the system. In addition, at temperatures higher than about 265 K, the hydrophobicity becomes gradually stronger and governs the physical properties of the solutions.

关键词： hydrophobic-hydrophilic interactions water systems thermal properties

Contrasting microscopic interactions determine the properties of water/methanol solutions

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Frontiers of physics 2018年第1期13卷 51-56页

作者： Carmelo Corsaro Francesco Mallamace Sebastiano Vasi sow-hsin chen H. Eugene Stanley Domenico Mallamace CNR-IPCF Messina Istituto per i Processi Chimico-Fisici Viale F. Stagno D'Alcontres 37 98158 Messina Italy Dipartimento MIFT Sezione di Fisica Universita di Messina Viale F. Stagno D'Alcontres 31 98166 Messina Italy Department of Nuclear Science and Engineering Massachusetts Institute of Technology Cambridge MA 02139 USA Center for Polymer Studies and Department of Physics Boston University Boston MA 02215 USA Consorzio interuniversitario per lo sviluppo dei Sistemi a Grande Interfase - CSGI Via della Lastruccia 3 50019 Sesto Fiorentino Firenze Italy

Herein we study the different microscopic interactions occurring in water/methanol solutions at dif- ferent methanol molar fractions, using NMR spctroscopy. Temperature was found to determine which interaction dominates. It was found that the mixing between water and methanol is non-ideal because of the presence of interactions like hydrophobicity and hydrophilicity. These results indicate that the competition between hydrophilic and hydrophobic interactions is different in different thermal regions, and that the physical properties of the solution are determined by the character of the solution itself, which in turn depends on the mole fraction of methanol and on the temperature.

关键词： aqueous solutions hydrophobicity NMR hydrophilicity

Pressure Dependence of Fragile-to-Strong Dynamic Transition in Deeply Supercooled Confined Water Studied by Quasielastic and Inelastic Neutron Scattering

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Pressure Dependence of Fragile-to-Strong Dynamic Transition ...

Study of New Effective Protein-Protein Interaction Potential in Solution by Small-Angle Neutron Scattering

第二届散裂中子源多学科应用研讨会

作者： sow-hsin chen A. Faraone A. Kolesiukov Nuclear Science and Engineering Department MIT

＜正＞ IntroductionAnomalous properties of supercooled water: Ts Mesoporous Silica Materials: MCM-41（pore sizes ≤18 A） Model for dynamics of supercooled and interfacial waterResultsAnalyses of experimental results with RCM modelPressure dependence of fragile-to-strong cross-over transition at TLPossible location of the second L-L critical point

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Study of New Effective Protein-Protein Interaction Potential...

Halogen composition and heterogeneity in the continental lithospheric mantle

第二届散裂中子源多学科应用研讨会

作者： sow-hsin chen Emillano Fratini Pieto Baglioni Department of Nuclear Science and Engineering MIT

Introduction to small angle neutron scattering (SANS)Scattered neutronIntensity distribution Function, I(Q)Incident neutronSANS is an elastic neutron scattering technique, whereSANS probes periodic structure in the direction of Q ,whereQ = ki-kf, Q=2ksinθand Q is called the magnitude of scattering wave *** an isotrppic system, Outline1. Introduction to small angle neutron scattering and its applications to colloidal solutions.2. Study of the effective interaction potential between protein molecules in solution. Experimental & theoretical evidence for DLVO effective potential Experimental & theoretical evidence of non-DLVO effective potential Existence of a new effective long range attraction between protein molecules studied by SANS

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Science China Earth Sciences 2025年第1期68卷 310-314页

作者： Chunfei chen State Key Laboratory of Geological Processes and Mineral Resources School of Earth Sciences China University of Geosciences

1. Introduction Halogens, including fluorine(F), chlorine(Cl), bromine(Br), and iodine(I), are highly mobile and water-soluble elements that can become significantly enriched in melts and fluids. In fluids and melts, halogens react with nearly all metals and readily form complexes with metal cations, significantly influencing the distribution of metal elements between different phases. Therefore, halogens play a crucial role in the migration, enrichment, and mineralization of key metals in the lithosphere(Weis et al., 2012; Liu et al., 2024).

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Cyano migration-mediated radical-polar crossover cyclopropanation

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Science China Chemistry 2025年第1期68卷 241-248页

作者： Ziqiang Wang Yasu chen Jie Li chen Zhu Key Laboratory of Organic Synthesis of Jiangsu Province College of Chemistry Chemical Engineering and Materials ScienceSoochow University Frontiers Science Center for Transformative Molecules Zhangjiang Institute for Advanced Study and Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs Shanghai Jiao Tong University

We report a novel cyano migration-mediated radical-polar crossover process, whereby both the sulfonylcyanation of aliphatic alkenes and the formation of cyclopropanes are concurrently achieved. This transformation yields a diverse array of multisubstituted cyclopropanes under mild photocatalytic conditions. Mechanistic studies elucidate that the reaction proceeds via intramolecular nucleophilic substitution, leading to the formation of the cyclopropane derivatives.

关键词： cyclopropanation cyano migration radical-polar crossover radical reactions

Two paths, one goal: mechanism of calcium homeostasis to balance plant growth and immunity

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Science China Life Sciences 2025年第1期68卷 306-308页

作者： Aziz Ul Ikram Yanping Jing Huan chen Jian chen International Genome Center Jiangsu University Joint Center for Single Cell Biology School of Agriculture and BiologyShanghai Jiao Tong University

Calcium(Ca2+) is an essential nutrient and a cellular signal in plants. The level of free Ca2+in the apoplast is ～10,000-fold higher than that in the cytoplasm at the resting state. This large Ca2+level gradient across the membrane between the interior and exterior can cause Ca2+overload and toxicity. Plants have evolved mechanisms to export Ca2+out of the cytoplasm or store it in intracellular organelles, such as endoplasmic reticulum（ER）, mitochondria, and vacuole.

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