Computational & Theoretical Chemistry eJournal最新文献

Arduino Weighing Machine Using Load Cell and HX711 Module 使用称重传感器和HX711模块的Arduino称重机

Computational & Theoretical Chemistry eJournal Pub Date : 2021-07-08 DOI: 10.2139/ssrn.3918720

Varshitha Itikala

引用次数: 7

Noble Gas Bubbles in Bcc Metals: Ab Initio-Based Theory and Kinetic Monte Carlo Modeling Bcc金属中的惰性气泡:基于从头算的理论和动力学蒙特卡罗模型

Computational & Theoretical Chemistry eJournal Pub Date : 2021-05-10 DOI: 10.2139/ssrn.3784442

Chao Jiang, Yongfeng Zhang, L. Aagesen, A. Jokisaari, Cheng Sun, J. Gan

{"title":"Noble Gas Bubbles in Bcc Metals: Ab Initio-Based Theory and Kinetic Monte Carlo Modeling","authors":"Chao Jiang, Yongfeng Zhang, L. Aagesen, A. Jokisaari, Cheng Sun, J. Gan","doi":"10.2139/ssrn.3784442","DOIUrl":"https://doi.org/10.2139/ssrn.3784442","url":null,"abstract":"Abstract Understanding the interactions of noble gases with metals is of fundamental importance for the design of radiation-resistant structural materials for fission and fusion nuclear reactors. Here we present a unified theory for describing the energetics of He, Ne, Ar, and Kr bubbles in bcc metals in group 5B (V, Nb, Ta), 6B (Cr, Mo, W) and 8B (Fe). Our predictive analytical model is based on the effective-medium and isotropic elasticity theories, and is parameterized using density functional theory (DFT) calculations of small gas-vacancy clusters. By performing kinetic Monte Carlo (KMC) simulations driven by our analytical model, we have predicted the lifetimes of noble gas bubbles and their coarsening by Ostwald ripening. Our most notable finding is the exceptionally higher thermal stability of Ne, Ar and Kr bubbles than He bubbles in bcc metals, conferring them outstanding resistance to Ostwald ripening. The physical origin of the unexpected stability of bubbles formed by large noble gas atoms has been further elucidated. Our theoretical finding is consistent with the experimental observation of He gas bubble superlattice (GBS) coarsening under thermal annealing, and provides new insights on the exceptional stability of fission GBS in bcc U-Mo up to a high homologous temperature of 0.78. The present calculated results also compare favorably with the existing thermal helium desorption spectrometry experiments in the literature.","PeriodicalId":10592,"journal":{"name":"Computational & Theoretical Chemistry eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74302923","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: 9

Single-Molecule Charge Transport in Discrete, π-Stacked Pyridinium Dimers 离散π-堆叠吡啶二聚体中的单分子电荷输运

Computational & Theoretical Chemistry eJournal Pub Date : 2021-03-22 DOI: 10.2139/ssrn.3809994

Hao Yu, Jialing Li, Songsong Li, Jeffrey S. Moore, Charles M. Schroeder

{"title":"Single-Molecule Charge Transport in Discrete, π-Stacked Pyridinium Dimers","authors":"Hao Yu, Jialing Li, Songsong Li, Jeffrey S. Moore, Charles M. Schroeder","doi":"10.2139/ssrn.3809994","DOIUrl":"https://doi.org/10.2139/ssrn.3809994","url":null,"abstract":"Charge transport through π-conjugated molecules plays an essential role in biochemical redox processes and energy storage applications. In this work, we show that molecular charge transport is greatly enhanced upon dimerization of certain pyridinium molecules in the cavity of a synthetic host (cucurbit[8]uril, CB[8]). Stable, homoternary complexes are formed between pyridinium molecules and CB[8] with high binding affinity, resulting in an offset stacked geometry of two pyridiniums inside the host cavity. The charge transport properties of free and dimerized pyridiniums are characterized using a scanning tunneling microscope-break junction (STM-BJ) technique. Remarkably, our results show that π-stacked methylated pyridinium dimers exhibit a 10-fold increase in molecular conductance compared to isolated, single pyridinium molecules. Control experiments using CB[8] homologues show that the synthetic host primarily serves to facilitate dimer formation and plays a minimal role on molecular conductance. Molecular modeling is used to determine transmission functions for molecular junctions using the non-equilibrium Green’s function formalism, with simulations showing good agreement with experimental results. Density functional theory (DFT) reveals that the closely stacked pyridinium dimer has a reduced energy gap and favorable orbital energy alignment with gold electrodes, thereby resulting in enhanced molecular conductance. Overall, this work demonstrates that supramolecular assembly provides a useful approach to understand intermolecular charge transport in π-stacked molecules.","PeriodicalId":10592,"journal":{"name":"Computational & Theoretical Chemistry eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87656706","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 Variability of Surface Free Energy and Zeta Potential of Volcanic Particles: Implications for Deposit Stability 火山颗粒表面自由能和Zeta电位的高变异性:对矿床稳定性的影响

Computational & Theoretical Chemistry eJournal Pub Date : 2021-01-01 DOI: 10.2139/ssrn.3927597

A. Ontiveros, Ivan Plaza, J. Calero, A. Moleon, J. Ibáñez

{"title":"High Variability of Surface Free Energy and Zeta Potential of Volcanic Particles: Implications for Deposit Stability","authors":"A. Ontiveros, Ivan Plaza, J. Calero, A. Moleon, J. Ibáñez","doi":"10.2139/ssrn.3927597","DOIUrl":"https://doi.org/10.2139/ssrn.3927597","url":null,"abstract":"Landslides on the flanks of stratovolcanoes can significantly modify the structure of the volcano. Macroscopic factors that determine the stability of volcanic deposits are well understood, but the microscopic interactions between particles and their impact on deposit cohesion remain poorly understood. Deposit cohesion is related to the energy of interaction between particles, and its calculation depends on the surficial properties of the eruptive materials. The purpose of this study was to perform a preliminary comparative analysis of the surficial properties of volcanic materials from various tectonic settings, including electrical (zeta potential) and thermodynamic (surface free energy) components and to calculate the total interaction energy between particles under different environmental conditions. We analyzed eruptive materials from six active volcanoes (El Hierro, Pico Do Fogo, Vulcano, Stromboli, Mt. Etna, and Deception Island). The results show that deposit cohesion varies among volcanoes, and changes drastically with the pH of the medium. Among the volcanic systems investigated, El Hierro (pH = 3) has the most cohesive materials, while Mt. Etna (pH = 8) has the least cohesive materials. Our results suggest that microscopic electrical and thermodynamic properties play a role in the stability of volcanic deposits, and confirm the need for a greater research focus in this area.","PeriodicalId":10592,"journal":{"name":"Computational & Theoretical Chemistry eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77092946","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

Identification of the Electronic and Structural Dynamics of Catalytic Centers in Single-Fe-Atom Material 单铁原子材料中催化中心的电子和结构动力学鉴定

Computational & Theoretical Chemistry eJournal Pub Date : 2020-10-28 DOI: 10.2139/ssrn.3713498

Xuning Li, Chang Chang, Sung-Fu Hung, Ying-Rui Lu, Weizheng Cai, A. Rykov, S. Miao, S. Xi, Hongbin Yang, Zehua Hu, Junhu Wang, Jiyong Zhao, E. Alp, W. Xu, T. Chan, Hao Ming Chen, Q. Xiong, Hai Xiao, Yanqiang Huang, Jun Li, Tao Zhang, Bin Liu

{"title":"Identification of the Electronic and Structural Dynamics of Catalytic Centers in Single-Fe-Atom Material","authors":"Xuning Li, Chang Chang, Sung-Fu Hung, Ying-Rui Lu, Weizheng Cai, A. Rykov, S. Miao, S. Xi, Hongbin Yang, Zehua Hu, Junhu Wang, Jiyong Zhao, E. Alp, W. Xu, T. Chan, Hao Ming Chen, Q. Xiong, Hai Xiao, Yanqiang Huang, Jun Li, Tao Zhang, Bin Liu","doi":"10.2139/ssrn.3713498","DOIUrl":"https://doi.org/10.2139/ssrn.3713498","url":null,"abstract":"Summary The lack of model single-atom catalysts (SACs) and atomic-resolution operando spectroscopic techniques greatly limits our comprehension of the nature of catalysis. Herein, based on the designed model single-Fe-atom catalysts with well-controlled microenvironments, we have explored the exact structure of catalytic centers and provided insights into a spin-crossover-involved mechanism for oxygen reduction reaction (ORR) using operando Raman, X-ray absorption spectroscopies, and the developed operando 57Fe Mossbauer spectroscopy. In combination with theoretical studies, the N-FeN4C10 moiety is evidenced as a more active site for ORR. Moreover, the potential-relevant dynamic cycles of both geometric structure and electronic configuration of reactive single-Fe-atom moieties are evidenced via capturing the peroxido (∗O2−) and hydroxyl (∗OH−) intermediates under in situ ORR conditions. We anticipate that the integration of operando techniques and SACs in this work shall shed some light on the electronic-level insight into the catalytic centers and underlying reaction mechanism.","PeriodicalId":10592,"journal":{"name":"Computational & Theoretical Chemistry eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79261725","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: 142

Short- and Medium-Range Orders in Al 90Tb 10 Glass and Their Relation to the Structures of Competing Crystalline Phases Al - 90Tb - 10玻璃中短程序及其与竞争晶相结构的关系

Computational & Theoretical Chemistry eJournal Pub Date : 2020-08-27 DOI: 10.2139/ssrn.3692997

L. Tang, Z. J. Yang, T. Wen, K. Ho, M. Kramer, Caizhuang Wang

{"title":"Short- and Medium-Range Orders in Al 90Tb 10 Glass and Their Relation to the Structures of Competing Crystalline Phases","authors":"L. Tang, Z. J. Yang, T. Wen, K. Ho, M. Kramer, Caizhuang Wang","doi":"10.2139/ssrn.3692997","DOIUrl":"https://doi.org/10.2139/ssrn.3692997","url":null,"abstract":"Molecular dynamics simulations using an interatomic potential developed by artificial neural network deep machine learning are performed to study the local structural order in Al90Tb10 metallic glass. We show that more than 80% of the Tb-centered clusters in Al90Tb10 glass have short-range order (SRO) with their 17 first coordination shell atoms stacked in a '3661' or '15551' sequence. Medium-range order (MRO) in Bergman-type packing extended out to the second and third coordination shells is also clearly observed. Analysis of the network formed by the '3661' and '15551' clusters show that ~82% of such SRO units share their faces or vertexes, while only ~6% of neighboring SRO pairs are interpenetrating. Such a network topology is consistent with the Bergman-type MRO around the Tb-centers. Moreover, crystal structure searches using genetic algorithm and the neural network interatomic potential reveal several low-energy metastable crystalline structures in the composition range close to Al90Tb10. Some of these crystalline structures have the '3661' SRO while others have the '15551' SRO. While the crystalline structures with the '3661' SRO also exhibit the MRO very similar to that observed in the glass, the ones with the '15551' SRO have very different atomic packing in the second and third shells around the Tb centers from that of the Bergman-type MRO observed in the glassy phase.","PeriodicalId":10592,"journal":{"name":"Computational & Theoretical Chemistry eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83568604","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

Multi Technique Investigation on Binding Interaction between 5-(2-Thiazolylazo)-2,4,6-Triaminopyrimidine and Hsa and Bsa 5-(2-噻唑偶氮)-2,4,6-三氨基嘧啶与Hsa和Bsa结合相互作用的多技术研究

Computational & Theoretical Chemistry eJournal Pub Date : 2020-01-01 DOI: 10.2139/ssrn.3707243

H. Dezhampanah, Amineh mousazadeh moghaddam pour

{"title":"Multi Technique Investigation on Binding Interaction between 5-(2-Thiazolylazo)-2,4,6-Triaminopyrimidine and Hsa and Bsa","authors":"H. Dezhampanah, Amineh mousazadeh moghaddam pour","doi":"10.2139/ssrn.3707243","DOIUrl":"https://doi.org/10.2139/ssrn.3707243","url":null,"abstract":"In research laboratories and various industries, azo compounds are among the most effective and commonly used organic dyes. Throughout this research the interaction between human and bovine serum albumins with 5-(2-Thiazolylazo)-2,4,6-Triaminopyrimidine (TTP) was explored using methods of spectroscopy and analysis of molecular modeling. The fluorescence quenching results revealed that static and dynamic processes are the quenching mechanisms for human and bovine serum albumins, respectively. The results of the quenching experiment were used to measure thermodynamic parameters [[EQUATION]] which showed that the binding process that takes place spontaneously and revealed that human and bovine serum albumins are very firmly binding through hydrogen bonds, van der Waals forces interactions and electrostatic forces. Calculations of Fӧrster energy transfer, synchronous fluorescence spectroscopy and docking analysis showed TTP bindings in short distances to the Trp residues of human and bovine serum albumin molecules. Docking study showed that TTP molecule has four hydrogen bonds with HSA, two hydrogen bonds with BSA and several hydrophobic contacts with human and bovine serum albumins. FT-IR results showed that serum albumins interact with TTP molecule primarily through hydrophobic and hydrophilic interactions, and that the secondary structure of serum albumins is modified.","PeriodicalId":10592,"journal":{"name":"Computational & Theoretical Chemistry eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75093218","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