The Journal of Chemical Physics最新文献_第10页

The propagation behavior of reaction wave for Ni/Al clad particle composites under shock loading. 镍/铝包覆颗粒复合材料在冲击载荷下的反应波传播行为。

The Journal of Chemical Physics Pub Date : 2024-04-23 DOI: 10.1063/5.0202099

Yifan Xie, Jian-Li Shao, Pengwan Chen

{"title":"The propagation behavior of reaction wave for Ni/Al clad particle composites under shock loading.","authors":"Yifan Xie, Jian-Li Shao, Pengwan Chen","doi":"10.1063/5.0202099","DOIUrl":"https://doi.org/10.1063/5.0202099","url":null,"abstract":"Prior studies indicate that the reaction wave can propagate from the impact surface, but the possibility and the influencing factors of the reaction wave formation are still unclear. This work investigates the propagation behavior of the shock-induced reaction wave for Ni/Al clad particle composites with varying stoichiometry (from 0.5 to 0.75 of the Ni mole fraction) through molecular dynamics simulations. It is found that the solid-state reaction processes with or without wave propagation strongly depend on the conjunction of stoichiometry and shock intensity. Within the cases of wave propagation, the calculated propagation velocity (in the range of 135-170 m/s) increases linearly or exponentially with the Ni mole fraction. Furthermore, the thermodynamic criteria for the reaction wave formation, including Al melting at the collision surface and higher temperature gradient, are established by analysis of the shock-induced high-entropy layer. In addition, microstructural characterization reveals the intrinsic mechanisms of the propagation of the reaction wave and the formation of additional reaction wave, namely, the dissolution of Ni into Al and the coalescence of reaction zones. Apart from the propagation behavior, the initial stoichiometry influences the crystallization-dissolution of B2-NiAl during reaction processes, notably through an exponential growth relationship between maximum crystallinity and the Ni mole fraction. These findings may provide a physical basis for improving traditional reaction rate models to break through phenomenological understanding.","PeriodicalId":501648,"journal":{"name":"The Journal of Chemical Physics","volume":"55 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140666311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

High spatial resolution surface plasmon resonance imaging using a plasmonic chip. 利用等离子体芯片实现高空间分辨率表面等离子体共振成像。

The Journal of Chemical Physics Pub Date : 2024-04-23 DOI: 10.1063/5.0201230

Yasunori Nawa, Keiko Tawa

引用次数: 0

Light-induced photoluminescence enhancement in chiral CdSe quantum dot films. 手性硒化镉量子点薄膜的光诱导光致发光增强。

The Journal of Chemical Physics Pub Date : 2024-04-23 DOI: 10.1063/5.0201365

Yang Wang, Pan Liang, Yumeng Men, Meizhen Jiang, Lin Cheng, Jinlei Li, T. Jia, Zhenrong Sun, D. Feng

引用次数: 0

A novel non-adiabatic spin relaxation mechanism in molecular qubits 分子量子比特中的新型非绝热自旋弛豫机制

The Journal of Chemical Physics Pub Date : 2024-04-23 DOI: 10.1063/5.0198519

Philip Shushkov

{"title":"A novel non-adiabatic spin relaxation mechanism in molecular qubits","authors":"Philip Shushkov","doi":"10.1063/5.0198519","DOIUrl":"https://doi.org/10.1063/5.0198519","url":null,"abstract":"The interaction of electronic spin and molecular vibrations mediated by spin–orbit coupling governs spin relaxation in molecular qubits. We derive an extended molecular spin Hamiltonian that includes both adiabatic and non-adiabatic spin-dependent interactions, and we implement the computation of its matrix elements using state-of-the-art density functional theory. The new molecular spin Hamiltonian contains a novel spin–vibrational orbit interaction with a non-adiabatic origin, together with the traditional molecular Zeeman and zero-field splitting interactions with an adiabatic origin. The spin–vibrational orbit interaction represents a non-Abelian Berry curvature on the ground-state electronic manifold and corresponds to an effective magnetic field in the electronic spin dynamics. We further develop a spin relaxation rate model that estimates the spin relaxation time via the two-phonon Raman process. An application of the extended molecular spin Hamiltonian together with the spin relaxation rate model to Cu(II) porphyrin, a prototypical S = 1/2 molecular qubit, demonstrates that the spin relaxation time at elevated temperatures is dominated by the non-adiabatic spin–vibrational orbit interaction. The computed spin relaxation rate and its magnetic field orientation dependence are in excellent agreement with experimental measurements.","PeriodicalId":501648,"journal":{"name":"The Journal of Chemical Physics","volume":"244 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140801283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

What is the best simulation approach for measuring local density fluctuations near solvo-/hydrophobes? 什么是测量溶解/吸水器附近局部密度波动的最佳模拟方法？

The Journal of Chemical Physics Pub Date : 2024-04-23 DOI: 10.1063/5.0203088

Nigel B. Wilding, Robert Evans, Francesco Turci

{"title":"What is the best simulation approach for measuring local density fluctuations near solvo-/hydrophobes?","authors":"Nigel B. Wilding, Robert Evans, Francesco Turci","doi":"10.1063/5.0203088","DOIUrl":"https://doi.org/10.1063/5.0203088","url":null,"abstract":"Measurements of local density fluctuations are crucial to characterizing the interfacial properties of equilibrium fluids. A specific case that has been well-explored involves the heightened compressibility of water near hydrophobic entities. Commonly, a spatial profile of local fluctuation strength is constructed from the measurements of the mean and variance of solvent particle number fluctuations in a set of contiguous subvolumes of the system adjacent to the solvo-/hydrophobe. An alternative measure proposed by Evans and Stewart [J. Phys.: Condens. Matter 27, 194111 (2015)] defines a local compressibility profile in terms of the chemical potential derivative of the spatial number density profile. Using Grand canonical Monte Carlo simulation, we compare and contrast the efficacy of these two approaches for a Lennard-Jones solvent at spherical and planar solvophobic interfaces and SPC/E water at a hydrophobic spherical solute. Our principal findings are as follows: (i) the local compressibility profile χ(r) of Evans and Stewart is considerably more sensitive to variations in the strength of local density fluctuations than the spatial fluctuation profile F(r) and can resolve much more detailed structure; and (ii) while the local compressibility profile is essentially independent of the choice of spatial discretization used to construct the profile, the spatial fluctuation profile exhibits a strong systematic dependence on the size of the subvolumes on which the profile is defined. We clarify the origin and nature of this finite-size effect.","PeriodicalId":501648,"journal":{"name":"The Journal of Chemical Physics","volume":"86 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140801284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Molecular chirality quantification: Tools and benchmarks 分子手性量化：工具和基准

The Journal of Chemical Physics Pub Date : 2024-04-23 DOI: 10.1063/5.0200716

Ethan Abraham, Abraham Nitzan

引用次数: 0

Generalized Helmholtz model describes capacitance profiles of ionic liquids and concentrated aqueous electrolytes. 广义亥姆霍兹模型描述了离子液体和浓水性电解质的电容曲线。

The Journal of Chemical Physics Pub Date : 2024-04-23 DOI: 10.1063/5.0194360

Suehyun Park, Jesse G McDaniel

{"title":"Generalized Helmholtz model describes capacitance profiles of ionic liquids and concentrated aqueous electrolytes.","authors":"Suehyun Park, Jesse G McDaniel","doi":"10.1063/5.0194360","DOIUrl":"https://doi.org/10.1063/5.0194360","url":null,"abstract":"In this work, we propose and validate a generalization of the Helmholtz model that can account for both \"bell-shaped\" and \"camel-shaped\" differential capacitance profiles of concentrated electrolytes, the latter being characteristic of ionic liquids. The generalization is based on introducing voltage dependence of both the dielectric constant \"ϵr(V)\" and thickness \"L(V)\" of the inner Helmholtz layer, as validated by molecular dynamics (MD) simulations. We utilize MD simulations to study the capacitance profiles of three different electrochemical interfaces: (1) graphite/[BMIm+][BF4-] ionic liquid interface; (2) Au(100)/[BMIm+][BF4-] ionic liquid interface; (3) Au(100)/1M [Na+][Cl-] aqueous interface. We compute the voltage dependence of ϵr(V) and L(V) and demonstrate that the generalized Helmholtz model qualitatively describes both camel-shaped and bell-shaped differential capacitance profiles of ionic liquids and concentrated aqueous electrolytes (in lieu of specific ion adsorption). In particular, the camel-shaped capacitance profile that is characteristic of ionic liquid electrolytes arises simply from combination of the voltage-dependent trends of ϵr(V) and L(V). Furthermore, explicit analysis of the inner layer charge density for both concentrated aqueous and ionic liquid double layers reveal similarities, with these charge distributions typically exhibiting a dipolar region closest to the electrode followed by a monopolar peak at larger distances. It is appealing that a generalized Helmholtz model can provide a unified description of the inner layer structure and capacitance profile for seemingly disparate aqueous and ionic liquid electrolytes.","PeriodicalId":501648,"journal":{"name":"The Journal of Chemical Physics","volume":"57 24","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140666662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Time-resolved solvation of alkali ions in superfluid helium nanodroplets. 超流体氦纳米液滴中碱离子的时间分辨溶解。

The Journal of Chemical Physics Pub Date : 2024-04-23 DOI: 10.1063/5.0205951

E. García-Alfonso, M. Barranco, Nadine Halberstadt, M. Pi

引用次数: 0

Floquet non-equilibrium Green’s function and Floquet quantum master equation for electronic transport: The role of electron–electron interactions and spin current with circular light 用于电子传输的 Floquet 非平衡格林函数和 Floquet 量子主方程：电子-电子相互作用和圆光自旋电流的作用

The Journal of Chemical Physics Pub Date : 2024-04-23 DOI: 10.1063/5.0184978

Vahid Mosallanejad, Yu Wang, Wenjie Dou

引用次数: 0

Surface tension of aqueous electrolyte solutions. A thermomechanical approach 电解质水溶液的表面张力。热力学方法

The Journal of Chemical Physics Pub Date : 2024-04-22 DOI: 10.1063/5.0191937

Yury A. Budkov, Nikolai N. Kalikin, Petr E. Brandyshev

引用次数: 0