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arXiv 2022年

作者： Wong, Bryan M. Chevalier, Cameron Department of Chemical & Environment Engineering Materials Science & Engineering Program Department of Physics & Astronomy Department of Chemistry University of California-Riverside RiversideCA92521 United States

We present an open-source software package, HADOKEN (High-level Algorithms to Design, Optimize, and Keep Electrons in Nanowires), for predicting electron confinement/localization effects in nanowires with various geometries, arbitrary number of concentric shell layers, doping densities, and external boundary conditions. The HADOKEN code is written in the MATLAB programming environments to aid in its readability and general accessibility to both users and practitioners. We provide several examples and outputs on a variety of different nanowire geometries, boundary conditions, and doping densities to demonstrate the capabilities of the HADOKEN software package. As such, the use of this predictive and versatile tool by both experimentalists and theorists could lead to further advances in both understanding and tailoring electron confinement effects in these nanosystems. © 2022, CC BY.

关键词： Poisson equation

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AI for organic and polymer synthesis

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Science China Chemistry 2024年第8期67卷 2461-2496页

作者： Xin Hong Qi Yang Kuangbiao Liao Jianfeng Pei Mao Chen Fanyang Mo Hua Lu Wen-Bin Zhang Haisen Zhou Jiaxiao Chen Lebin Su Shuo-Qing Zhang Siyuan Liu Xu Huang Yi-Zhou Sun Yuxiang Wang Zexi Zhang Zhunzhun Yu Sanzhong Luo Xue-Feng Fu Shu-Li You Center of Chemistry for Frontier Technologies Department of ChemistryZhejiang UniversityHangzhou 310027China Center of Basic Molecular Science Department of ChemistryTsinghua UniversityBeijing 100084China Guangzhou National Laboratory Guangzhou 510005China Center for Quantitative Biology Academy for Advanced Interdisciplinary StudiesPeking UniversityBeijing 100871China State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai 200433China School of Materials Science and Engineering Peking UniversityBeijing 100871China Beijing National Laboratory for Molecular Sciences Center for Soft Matter Science and EngineeringKey Laboratory of Polymer Chemistry and Physics of Ministry of EducationCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China AI for Science(AI4S)-Preferred Program Shenzhen Graduate SchoolPeking UniversityShenzhen 518055China State Key Laboratory of Chemical Biology Shanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of SciencesShanghai 200032China Department of Chemical Sciences National Natural Science Foundation of ChinaBeijing 100085China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

Recent years have witnessed the transformative impact from the integration of artificial intelligence with organic and polymer synthesis. This synergy offers innovative and intelligent solutions to a range of classic problems in synthetic chemistry. These exciting advancements include the prediction of molecular property, multi-step retrosynthetic pathway planning, elucidation of the structure-performance relationship of single-step transformation, establishment of the quantitative linkage between polymer structures and their functions, design and optimization of polymerization process, prediction of the structure and sequence of biological macromolecules, as well as automated and intelligent synthesis platforms. Chemists can now explore synthetic chemistry with unprecedented precision and efficiency, creating novel reactions, catalysts, and polymer materials under the datadriven paradigm. Despite these thrilling developments, the field of artificial intelligence(AI) synthetic chemistry is still in its infancy, facing challenges and limitations in terms of data openness, model interpretability, as well as software and hardware support. This review aims to provide an overview of the current progress, key challenges, and future development suggestions in the interdisciplinary field between AI and synthetic chemistry. It is hoped that this overview will offer readers a comprehensive understanding of this emerging field, inspiring and promoting further scientific research and development.

关键词： organic synthesis polymer synthesis machine learning prediction chemical database automated synthesis

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A Comparative Study of Machine Learning Classifiers for Enhancing Knee Osteoarthritis Diagnosis

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Information (Switzerland) 2024年第4期15卷 183页

作者： Raza, Aquib Phan, Thien-Luan Li, Hung-Chung Hieu, Nguyen Van Nghia, Tran Trung Ching, Congo Tak Shing Graduate Institute of Biomedical Engineering National Chung Hsing University Taichung402 Taiwan Department of Physics and Electronic Engineering University of Science Vietnam National University of Ho Chi Minh City Ho Chi Minh City70000 Viet Nam Undergraduate Program of Intellectual Creativity Engineering National Chung Hsing University Taichung402 Taiwan VNU-HCM Ho Chi Minh City72409 Viet Nam Department of Electrical Engineering National Chi Nan University Puli Township545 Taiwan International Doctoral Program in Agriculture National Chung Hsing University Taichung402 Taiwan

Knee osteoarthritis (KOA) is a leading cause of disability, particularly affecting older adults due to the deterioration of articular cartilage within the knee joint. This condition is characterized by pain, stiffness, and impaired movement, posing a significant challenge in medical diagnostics and treatment planning, especially due to the current inability for early and accurate detection or monitoring of disease progression. This research introduces a multifaceted approach employing feature extraction and machine learning (ML) to improve the accuracy of diagnosing and classifying KOA stages from radiographic images. Utilizing a dataset of 3154 knee X-ray images, this study implemented feature extraction methods such as Histogram of Oriented Gradients (HOG) with Linear Discriminant Analysis (LDA) and Min–Max scaling to prepare the data for classification. The study evaluates six ML classifiers—K Nearest Neighbors classifier, Support Vector Machine (SVM), Gaussian Naive Bayes, Decision Tree, Random Forest, and XGBoost—optimized via GridSearchCV for hyperparameter tuning within a 10-fold Stratified K-Fold cross-validation framework. An ensemble model has also been made for the already high-accuracy models to explore the possibility of enhancing the accuracy and reducing the risk of overfitting. The XGBoost classifier and the ensemble model emerged as the most efficient for multiclass classification, with an accuracy of 98.90%, distinguishing between healthy and unhealthy knees. These results underscore the potential of integrating advanced ML methodologies for the nuanced and accurate diagnosis and classification of KOA, offering new avenues for clinical application and future research in medical imaging diagnostics. © 2024 by the authors.

关键词： Extraction

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Attenuation Correction for Phantom Images Acquired in the Second Generation PETcoil Insert for PET/MR Brain Imaging

Attenuation Correction for Phantom Images Acquired in the Se...

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IEEE Symposium on Nuclear Science (NSS/MIC)

作者： Y. Pan J. Fisher C. Wang C. Levin Applied Physics Stanford University Stanford California United States of America Electrical Engineering Stanford University Stanford California United States of America Rad/Molecular Imaging Program Stanford University Stanford California United States of America Radiology Physics Bioengineering Stanford University Stanford California United States of America

ISBN: (数字)9798350388152

ISBN: (纸本)9798350388169

This paper proposes a geometry-based attenuation correction method for phantom PET scans using emission data alone. The method reconstructs the phantom image without attenuation and scatter correction, registers the image with the known phantom, and calculates the intersection of every line of response (LOR) with the registered phantom geometry. Knowing the attenuation per LOR allows us to manipulate the list-mode emission data accordingly and generate a list-mode data file with an enhanced number of coincidences per LOR according to the estimated *** approach yielded promising results when applied to a Hoffman brain phantom study using the second-generation PETcoil insert scanner. The intensity line profile generated by summing the signal intensity along the transverse and coronal axes looked more like the expected line profile without scatter correction, as expected. This approach can be easily generalized to any other phantoms and scanners.

关键词： Neuroimaging Geometry Microwave integrated circuits Semiconductor detectors Phantoms Attenuation Imaging phantoms

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Study of Novel Photodetectors and Electronics to Enhance Coincidence Time Resolution of BGO-based PET Detectors

Study of Novel Photodetectors and Electronics to Enhance Coi...

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IEEE Symposium on Nuclear Science (NSS/MIC)

作者： Andrea Gonzalez-Montoro Shirin Pourashraf Joshua W Cates Craig S Levin Department of Radiology Stanford University Stanford CA USA Applied Nuclear Physics Program Lawrence Berkeley National Laboratory Berkeley CA USA Departments of Radiology Molecular Imaging Program Bioengineering Physics and Electrical Engineering Stanford University CA USA

Developing high sensitivity multiparametric medical imaging tools constitutes one of the main research topics in radionuclide *** time-of-flight positron emission tomography (TOF-PET) scanners have shown potential in this context. One of the most attractive solutions that have been proposed to improve the coincidence time resolution (CTR) of TOF-PET scanners includes exploiting the small population of promptly emitted light photons (i.e., Cherenkov photons). Bismuth germanate (BGO) is a legacy detection material for PET which exhibits a moderate Cherenkov yield. which new advancements in ultra-violet (UV) light sensitive photosensor technologies and associated detection techniques can exploit for fast timing. It has been demonstrated that exploiting the BGO–Cherenkov component may simultaneously facilitate high 511 keV photon detection sensitivity with excellent CTR, thus enabling high sensitivity, low cost TOF-PET systems. Accessing the timing information from these Cherenkov photons requires enhanced photodetector technology combined with low noise and fast readout electronics, as well as specific data post-processing *** this summary, we report the CTR evaluation of different length BGO crystals coupled to UV enhanced SiPMs and custom designed electronics. Average CTR values of 156 ± 6, 188 ± 5, 228 ± 8 and 297 ± 8 ps CTR FWHM have been achieved for 3 × 3 × 3, × 5, × 10, and × 15 mm 3 BGO crystal with chemically processed surface finishes.

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Electron Ptychography for Investigating Magnetic Textures in Micro- and Nano- Scale Magnets via Lorentz Transmission Electron Microscopy

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Microscopy and microanalysis : the official journal of Microscopy Society of America, Microbeam Analysis Society, Microscopical Society of Canada 2023年第1期29卷 1847-1848页

作者： Trujillo, Kayna L Mendoza Divan, Ralu N S Li, Yue Jiang, Yi McCray, Arthur R C Petford-Long, Amanda K. Phatak, Charudatta Department of Materials Science and Engineering Northwestern University Evanston IL United States Materials Science Division Argonne National Laboratory Lemont IL United States Center for Nanoscale Materials Argonne National Laboratory Lemont IL United States Advanced Photon Source Argonne National Laboratory Lemont IL United States Applied Physics Program Northwestern University Evanston IL United States

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Deformed Fredkin model for the ν=5/2 Moore-Read state on thin cylinders

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Physical Review Research 2024年第1期6卷 013105-013105页

作者： Cristian Voinea Songyang Pu Ammar Kirmani Pouyan Ghaemi Armin Rahmani Zlatko Papić School of Physics and Astronomy University of Leeds Leeds LS2 9JT United Kingdom Theoretical Division T-4 Los Alamos National Laboratory Los Alamos New Mexico 87545 USA Physics Department City College of the City University of New York New York 10031 USA Physics Program Graduate Center of City University of New York New York 10031 USA Department of Physics and Astronomy and Advanced Materials Science and Engineering Center Western Washington University Bellingham Washington 98225 USA

We propose a frustration-free model for the Moore-Read quantum Hall state on sufficiently thin cylinders with circumferences ≲7 magnetic lengths. While the Moore-Read Hamiltonian involves complicated long-range interactions between triplets of electrons in a Landau level, our effective model is a simpler one-dimensional chain of qubits with deformed Fredkin gates. We show that the ground state of the Fredkin model has high overlap with the Moore-Read wave function and accurately reproduces the latter's entanglement properties. Moreover, we demonstrate that the model captures the dynamical response of the Moore-Read state to a geometric quench, induced by suddenly changing the anisotropy of the system. We elucidate the underlying mechanism of the quench dynamics and show that it coincides with the linearized bimetric field theory. The minimal model introduced here can be directly implemented as a first step towards quantum simulation of the Moore-Read state, as we demonstrate by deriving an efficient circuit approximation to the ground state and implementing it on an IBM quantum processor.

关键词： Fractional quantum Hall effect Quantum computation Quantum many-body systems Strongly correlated systems Exact diagonalization Matrix product states

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Influence of Al doping on the crystal structure,optical properties,and photodetecting performance of ZnO film

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Progress in Natural Science:Materials International 2020年第1期30卷 28-34页

作者： Ni'matul Azizah Shibghatullah Muhammady Muhammad Abiyyu Kenichi Purbayanto Eka Nurfani Toto Winata Euis Sustini Rena Widita Yudi Darma Department of Physics Faculty of Mathematics and Natural SciencesInstitut Teknologi Bandung Materials Engineering Program Institut Teknologi SumateraTerusan RyacuduWay HuiJati Agung

The structural,optical,and electrical properties of undoped and Al-doped ZnO films deposited on p-Si(001)substrate were studied using DC-unbalanced magnetron *** study is motivated by the absence of detail reports concerning the orbital states inducing the optical bandgap(Eg) ***,the influences of Al on the possible modification of point defect and the photodetecting performance are highlighted to offer guidelines for better development in ZnO-based *** was found that the Al doping reduced the grain *** doping increased the lattice parameters and slightly decreased the local-symmetry distortion at *** the absorbance spectra,the doping increased Eg of ZnO film(3.28-3.36 eV),induced by the Burstein-Moss *** the density-functional calculation,the Burstein-Moss effect induced Egfrom the valence band maximum(VBM) to Fermi level located above the lowest Zn 4s conduction *** the photoluminescence spectra,the undoped film showed the transitions from O vacancy,Zn interstitial,and free-exciton states to the *** doped film showed the transitions from Zn interstitial to O interstitial and few Zn vacancy states at the cost of O ***,the energy level of free-exciton states slightly ***,O interstitials increased the lattice *** the electrical properties,the doping enhanced the ultraviolet-region photo-to-dark-current ratio up to 3.044 V,leading to the photodetecting sensitivity *** study emphasizes the significant effect of Al doping on the optical absorbance,point-defect evolution,and photodetecting performance of ZnO film for low-voltage ultraviolet photodetector applications.

关键词： ZnO Optical properties Point defect Photodetecting Local-symmetry distortion

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High-Temperature Decomposition of Diisopropyl Methylphosphonate (DIMP) on Alumina: Mechanistic Predictions from Ab Initio Molecular Dynamics

arXiv

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arXiv 2022年

作者： Biswas, Sohag Wong, Bryan M. Department of Chemical & Environmental Engineering Materials Science & Engineering Program Department of Physics & Astronomy Department of Chemistry University of California-Riverside RiversideCA92521 United States

The enhanced degradation of organophosphorous-based chemical warfare agents (CWAs) on metal-oxide surfaces holds immense promise for neutralization efforts;however, the underlying mechanisms in this process remain poorly understood. We utilize large-scale quantum calculations for the first time to probe the high-temperature degradation of diisopropyl methylphosphonate (DIMP), a nerve agent simulant. Our Born-Oppenheimer molecular dynamics (BOMD) calculations show that the γ-Al2O3 surface shows immense promise for quickly adsorbing and destroying CWAs. We find that the alumina surface quickly adsorbs DIMP at all temperatures, and subsequent decomposition of DIMP proceeds via a propene elimination. Our BOMD calculations are complemented with metadynamics simulations to produce free energy paths, which show that the activation barrier decreases with temperature and DIMP readily decomposes on γ-Al2O3. Our first-principle BOMD and metadynamics simulations provide crucial diagnostics for sarin decomposition models and mechanistic information for examining CWA decomposition reactions on other candidate metal oxide surfaces. © 2022, CC BY.

关键词： Free energy

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The assessment of climatic,environmental,and socioeconomic aspects of the Brazilian Cerrado

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Ecological Processes 2023年第1期12卷 274-285页

作者： Washington Luiz Félix Correia Filho JoséFrancisco de Oliveira-Júnior Dimas de Barros Santiago Hazem Ghassan Abdo Hussein Almohamad Ahmed Abdullah Al Dughairi Carlos Antonio da Silva Junior Postgraduate Program in Environmentrics(PPGAmb) Institute of MathematicsStatisticsand Physics(IMEF)Federal University of Rio Grande(FURG)Rio GrandeRio Grande do Sul 96203-900Brazil Institute of Atmospheric Sciences(ICAT) Federal University of Alagoas(UFAL)MaceióAlagoas 57072-260Brazil Postgraduate Program in Biosystems Engineering(PGEB) Federal Fluminense University(UFF)NiteróiRio de Janeiro 24220-900Brazil Postgraduate Program in Meteorology Unidade Acadêmica de Ciências Atmosféricas(UACA)Federal University of Campina Grande(UFCG)Campina GrandeParaíba 58429-140Brazil Geography Department Faculty of Arts and HumanitiesTartous UniversityTartousSyria Geography Department Faculty of Arts and HumanitiesDamascus UniversityDamascusSyria Geography Department Faculty of Arts and HumanitiesTishreen UniversityLat-takiaSyria Department of Geography College of Arabic Language and Social StudiesQassim UniversityBuraydah 51452Saudi Arabia Departamento de Geografia State University of Mato Grosso(UNEMAT)SinopMato Grosso 78555-000Brazil

Background The Cerrado is the most biodiverse savanna and maintains other *** of its significance,this paper evaluated the Brazilian Cerrado’s climatic,environmental,and socioeconomic aspects using remote sensing data and spatial statistics(correlation analysis and principal components analysis—PCA).Following the measures of sample adequacy(MSA)and Kaiser–Meyer–Olkin(KMO)tests,seventeen variables were *** The MSA revealed that the dataset had a good quality(0.76),and nine variables were selected:elevation,evapotranspiration,active fires,Human Development Index(HDI),land use and land cover(LULC;shrubland and cropland/rainfed),rainfall(spring and autumn),and *** correlation matrix indicated a positive(negative)association between HDI and autumn rainfall(HDI and active fires)with a value of 0.77(-0.55).The PCA results determined which three principal components(PC)were adequate for extracting spatial patterns,accounting for 68.02%of the total variance with respective values of 38.59%,16.89%,and 12.5%.Due to economic development and agribusiness,Cerrado’s northern(central,western,and southern)areas had negative(positive)score HDI values,as shown in ***(rainfall—spring and fall)and environmental(cropland/rainfed and shrubland)aspects dominated the PC2,with negative scores in northern and western portions due to the transition zone between Amazon and Cerrado biomes caused by rainfall *** the other hand,environmental aspects(LULC-shrubland and elevation)influenced the PC3;areas with high altitudes(>500 m)received a higher *** Agricultural expansion substantially affected LULC,leading to deforestation-caused suppression of native vegetation.

关键词： Environment Agribusiness Active fire Human Development Index Land use and land cover

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