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Unveiling the local elemental arrangements across the interfaces inside CdSe/Cd1-xZnxS core-shell and CdSe/CdS/ Cd1-xZnxS core-crown-shell quantum wells

arXiv

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arXiv 2024年

作者： Lastovina, Tatiana Usoltsev, Oleg Işik, Furkan Budnyk, Andriy Harfouche, Messaoud Canımkurbey, Betul Demir, Hilmi Volkan Department of Electrical and Electronics Engineering Department of Physics UNAM Institute of Materials Science and Nanotechnology The National Nanotechnology Research Center Bilkent University Ankara06800 Turkey ALBA Synchrotron Carrer de la Llum 2 26 Cerdanyola del Vallès Barcelona08290 Spain P.O. Box 7 Allan19252 Jordan Luminous! Center of Excellence for Semiconductor Lighting and Displays School of Electrical and Electronic Engineering Division of Physics and Applied Physics School of Physical and Mathematical Sciences School of Materials Science and Engineering Nanyang Technological University Singapore639798 Singapore

Colloidal CdSe-based nanoplatelets (NPLs) have found various applications in optoelectronics thanks to their bright and narrow photoluminescent (PL) emission. The peak emission wavelength of their PL is conveniently tunable and controllable through structural parameters such as the number of monolayers (ML) in the core, framing the CdSe core with a wider bandgap CdS crown, and covering either core or core-crown with a gradient Cd1-xZnxS shell. The resulting heterostructures contain the core-shell interfaces, which significantly affect the PL emission efficiency. The internal structure and related atomic distribution within the interface region of NPLs are hardly accessible with conventional lab-scale instruments. Such critical studies rely on X-ray absorption spectroscopy (XAS), possibly available at synchrotron radiation facilities. We report on a systematic study of the Cd, Zn, Se, and S elemental distributions across the interfaces in CdSe/Cd1-xZnxS core-shell and CdSe/CdS/Cd1-xZnxS core-crown-shell quantum wells (QWs) with the CdSe core thickness ranging from 3.5 to 5.5 ML. By processing the XAS data (X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS)), we observe that the Cd‒Se bonds dominate at the CdSe/Cd1-xZnxS core-shell interface of structures with the 3.5 ML cores, while the Cd‒Se bonds were more abundant in the cases of the 4.5 and 5.5 ML cores. The complementary information about prevailing bonds were extracted for other constituting elements, thus, describing the distribution of the elements at the core-shell interface of CdSe-based NPLs. The naked CdSe cores are covered with an organic shell (mostly oleic acid) via bridging oxygen atoms. Also, we address the issue of stability of such core-shell systems over the time. We demonstrate that after a half year of aging of the commercial-ready 4.5 ML CdSe/CdxZn1–xS NPLs, the Cd–Se bonds become more evident due to the partial degradation of the Cd–S bonds. This

关键词： Nanocrystals

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Realization of a three-dimensional photonic higher-order topological insulator

arXiv

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arXiv 2024年

作者： Wang, Ziyao Meng, Yan Yan, Bei Zhao, Dong Yang, Linyun Chen, Jing-Ming Cheng, Min-Qi Xiao, Tao Shum, Perry Ping Liu, Gui-Geng Yang, Yihao Chen, Hongsheng Xi, Xiang Zhu, Zhen-Xiao Xie, Biye Gao, Zhen State Key Laboratory of Optical Fiber and Cable Manufacture Technology Department of Electronic and Electrical Engineering Southern University of Science and Technology Shenzhen518055 China School of Electrical Engineering and Intelligentization Dongguan University of Technology Dongguan523808 China Hubei Province Key Laboratory of Systems Science in Metallurgical Process College of Science Wuhan University of Science and Technology Wuhan430081 China Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University 21 Nanyang Link Singapore637371 Singapore Interdisciplinary Center for Quantum Information State Key Laboratory of Modern Optical Instrumentation ZJU-Hangzhou Global Science and Technology Innovation Center College of Information Science and Electronic Engineering ZJU-UIUC Institute Zhejiang University Hangzhou310027 China School of Science and Engineering The Chinese University of Hong Kong Shenzhen518172 China

The discovery of photonic higher-order topological insulators (HOTIs) has significantly expanded our understanding of band topology and provided unprecedented lower-dimensional topological boundary states for robust photonic devices. However, due to the vectorial and leaky nature of electromagnetic waves, it is challenging to discover three-dimensional (3D) topological photonic systems and photonic HOTIs have so far still been limited to two dimensions (2D). Here, we report on the first experimental realization of a 3D Wannier-type photonic HOTI in a tight-binding-like metal-cage photonic crystal, whose band structure matches well with that of a 3D tight-binding model due to the confined Mie resonances. By microwave near-field measurements, we directly observe coexisting topological surface, hinge, and corner states in a single 3D photonic HOTI, as predicted by the tight-binding model and simulation results. Moreover, we demonstrate that all-order topological boundary states are self-guided even in the light cone continuum and can be exposed to air without ancillary cladding, making them well-suited for practical applications. Our work thus opens routes to the multi-dimensional robust manipulation of electromagnetic waves at the outer surfaces of 3D cladding-free photonic bandgap materials and may find novel applications in 3D topological integrated photonics devices. © 2024, CC BY.

关键词： Topological insulators

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Design for telecom-wavelength quantum emitters in silicon based on alkali-metal-saturated vacancy complexes

arXiv

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arXiv 2024年

作者： Udvarhelyi, Péter Narang, Prineha Department of Chemistry and Biochemistry University of California Los AngelesCA90095 United States Division of Physical Sciences College of Letters and Science University of California Los AngelesCA90095 United States Department of Electrical and Computer Engineering University of California Los AngelesCA90095 United States

Defect emitters in silicon are promising contenders as building blocks of solid-state quantum repeaters and sensor networks. Here we investigate a family of possible isoelectronic emitter defect complexes from a design standpoint. We show that the identification of key physical effects on quantum defect state localization can guide the search for telecom wavelength emitters. We demonstrate this by performing first-principles calculations on the Q center, predicting its charged sodium variants possessing ideal emission wavelength near the lowest-loss telecom bands and ground state spin for possible spin-photon interface and nanoscale spin sensor applications yet to be explored in experiments. © 2024, CC BY.

关键词： Nanocrystals

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Gait Analysis in Powered Exoskeleton-Assisted Walking in Patients with Stroke: A Case Series Cohort

Gait Analysis in Powered Exoskeleton-Assisted Walking in Pat...

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Asia-Pacific Signal and Information Processing Association Annual Summit and Conference (APSIPA)

作者： Jian-Jia Huang Shih-Chieh Chang Cheng-Hsu Cheng Timothy Wan Yu-Cheng Pei Department of Physical Medicine and Rehabilitation Chang Gung Memorial Hospital Taiwan Master of Science Degree Program in Innovation for Smart Medicine Chang Gung University Taoyuan City Taiwan Department of Electrical Engineering Chang Gung University Taoyuan City Taiwan Walker Department of Mechanical Engineering The University of Texas at Austin Austin TX USA

This case series cohort study investigated gait characteristics based on sensor data obtained from personalized active powered lower limb exoskeletal robot-assisted gait training and assessed its putative therapeutic effects in patients with stroke. Preliminary findings suggest that the application of the exoskeletal robot did not improve gait symmetry under robot assistance and could facilitate inter-joint coordination within the hip-knee joint movement on the affected side. These findings suggest that robot-assisted gait training could improve gait by guiding motor learning.

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Copper halide-based portable personal dosimeter for real-time X-ray monitoring

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Cell Reports physical science 2025年第5期6卷

作者： Khaliq, Samiya de Oliveira Filho, Jose I. Faleiros, Murilo C. He, Tengyue Zhou, Yang Abulikemu, Mutalifu Bakr, Osman M. Salama, Khaled N. Mohammed, Omar F. Computer Electrical Mathematical Sciences and Engineering (CEMSE) Division King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia Advanced Membranes and Porous Materials Center (AMPMC) King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia Physical Science and Engineering (PSE) Division King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia Catalysis Center (KCC) King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia

With an increasing demand for radiation detection devices in diverse sectors such as healthcare, industrial safety, and environmental monitoring, there is an urgent need for portable and affordable personal dosimeters. We demonstrate a Mn-doped Cs₃Cu₂I₅ metal halide portable personal dosimeter for X-ray detection. The device is specifically tailored for individuals working in medical and security environments, providing a crucial safety measure when exposed to scattered X-ray beams. The portable dosimeter has a compact size of 20 × 20 mm and is highly sensitive to X-ray radiation. Equipped with photocurrent readout circuitry and advanced signal processing, our device ensures precise real-time monitoring of X-ray radiation, achieving a low-dose detection capability of 0.1 nGy/s. The device surpasses state-of-the-art personal dosimeters with its fast low-dose detection and easy readout using a mobile phone app, ensuring accurate measurements at minimum radiation levels. The device's compact size and low power consumption make it ideal for dosimetry applications. © 2025 The Author(s)

关键词： copper-halide-based portable personal dosimeter dosimetry electronic personal dosimeter EPD high-sensitivity dosimetry portable dosimeter radiation detection radiation safety real-time X-ray monitoring wearable dosimeter X-ray detectors X-ray dosimeter

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Unlocking Complex Chemical and Morphological Transformations During Thermal Treatment of O-Hydroxyl-Substituted Polyimide of Intrinsic Microporosity: Impact on Ethanol/Cyclohexane Separation

SSRN

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SSRN 2023年

作者： Ogieglo, Wojciech Knozowska, Katarzyna Puspasari, Tiara Ali, Zain Kujawa, Joanna Korczeniewski, Emil Terzyk, Artur P. Kujawski, Wojciech Pinnau, Ingo Functional Polymer Membranes Group Chemical Engineering Program Division of Physical Science and Engineering King Abdullah University of Science and Technology Thuwal23955-6900 Saudi Arabia Advanced Membranes and Porous Materials Center Division of Physical Science and Engineering King Abdullah University of Science and Technology Thuwal23955-6900 Saudi Arabia Nicolaus Copernicus University in Toruń Membranes and Membrane Techniques Research Group Faculty of Chemistry 7 Gagarina Street Toruń87-100 Poland Nicolaus Copernicus University Faculty of Chemistry Physicochemistry of Carbon Materials Research Group Faculty of Chemistry Gagarin Street 7 Toruń87-100 Poland

In this work, we investigated the pervaporation separation performance of an ethanol – cyclohexane mixture using a thin-film composite membrane based on a heat-treated, o-hydroxyl-substituted polyimide of intrinsic microporosity (PIM-6FDA-OH). We report in detail the complex chemical and structural transformations that are associated with the development of thermally-rearranged (TR, 400 – 450 °C), and carbon molecular sieve (CMS) membranes (> 500 °C). These transformations strongly affect the affinity-related (e.g. swelling behavior) and morphology-related (e.g. microporosity) properties of the TR and CMS membrane materials which translate into a complex molecular-level separation behavior toward an organic solvent mixture during pervaporation. We show that excellent separation performance (total flux ~ 4 kg / m2h and ethanol/cyclohexane separation factor of ~1250) can be achieved after precise thermal treatment at the onset of the CMS formation. In addition, we highlight the unique property of pervaporation where, in contrast to e.g. liquid solvent permeation, the downstream side of the membrane remains essentially dry due to exposure to high vacuum. As a result, a sharp molecular cut-off can be achieved within this dry downstream region of the membrane despite considerable overall swelling/penetrant concentration in the upstream region of the membrane. © 2023, The Authors. All rights reserved.

关键词： Pervaporation

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Enhancing Diagnostic Accuracy for Knee Osteoarthritis Using a Deep Learning Approach

Enhancing Diagnostic Accuracy for Knee Osteoarthritis Using ...

引用

International Symposium on Applied science 2024, ISAS 2024

作者： Raza, Aquib Ching, Congo Tak Shing Liu, Peng-Ta Phan, Thien-Luan Tran, Ngoc-Luan Nguyen, Ha Anh T. Rameez, Mohammad Li, Hung-Chung Linh, Dao Nguyen Phuong Van Hieu, Nguyen Tran, Trung Nghia National Taiwan University Taipei City10673 Taiwan Research Center for Information Technology Academia Sinica Taipei City11529 Taiwan Graduate Institute of Biomedical Engineering National Chung Hsing University Taichung402 Taiwan Department of Electrical Engineering National Chi Nan University Nantou County Taiwan Advanced Plant and Food Crop Biotechnology Center National Chung Hsing University Taichung402 Taiwan International Doctoral Program in Agriculture National Chung Hsing University Taichung402 Taiwan Fall Prevention Center Department of Physical Medicine & Rehabilitation Changhua Christian Hospital Changhua500 Taiwan Department of Physics and Electronic Engineering University of Science Vietnam National University - Ho Chi Minh City Ho Chi Minh City70000 Viet Nam Department of Computer Science University of York York HeslingtonYO10 5DD United Kingdom Undergraduate Program of Intellectual Creativity Engineering National Chung Hsing University Taichung402 Taiwan Ho Chi Minh City72409 Viet Nam HCMUT Vietnam National University Ho Chi Minh City Thu Duc Ho Chi Minh City71308 Viet Nam

This research introduces a deep learning framework that combines convolutional neural networks with autoencoders to improve the diagnostic accuracy of knee osteoarthritis. The study utilized a publicly available dataset from the Mendeley Data repository, where knee joint images were preprocessed using Contrast Limited Adaptive Histogram Equalization to enhance contrast and ensure consistent image sizing. Initially, an autoencoder was employed in an unsupervised manner to learn compressed representations of the data. These representations were then used to train a CNN to classify knee images into 'healthy' and 'osteoarthritic' categories. The model was trained using an 80:20 split for training and testing data, incorporating early stopping and data augmentation techniques to prevent overfitting and enhance generalization. Performance metrics such as accuracy, precision, recall, and the area under the Receiver Operating Characteristic curve (ROCAUC) were used to evaluate the model, resulting in a high test accuracy of 98.95%. The high precision and recall rates further confirmed the model's robustness in diagnosing KOA. To enhance interpretability, Gradient-weighted Class Activation Mapping (Grad-CAM) was applied to identify critical regions in the images that influenced the model's decisions. Additionally, t-Distributed Stochastic Neighbor Embedding (t-SNE) was used to visualize the high-dimensional encoded features in a two-dimensional space, providing deeper insights into how the model differentiates between classes. The promising results of this deep learning approach suggest its potential for broader applications in medical imaging diagnostics. By providing healthcare professionals with a tool that enhances diagnostic accuracy and operational efficiency, this framework lays the foundation for developing scalable, AI-driven diagnostic systems for various complex medical conditions. © 2025 Institute of Physics Publishing. All rights reserved.

关键词： Joints (anatomy)

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Nonequilibrium transport and the fluctuation theorem in the thermodynamic behaviors of nonlinear photonic systems

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physical Review Research 2025年第1期7卷 013084-013084页

作者： Yang Liu Jincheng Lu Zhongfei Xiong Fan O. Wu Demetrios Christodoulides Yuntian Chen Jian-Hua Jiang School of Physical Science and Technology & Collaborative Innovation Center of Suzhou Nano Science and Technology Soochow University 1 Shizi Street Suzhou 215006 China Key Laboratory of Efficient Low-carbon Energy Conversion and Utilization of Jiangsu Provincial Higher Education Institutions School of Physical Science and Technology Suzhou University of Science and Technology Suzhou 215009 China School of Optical and Electronic Information Huazhong University of Science and Technology Wuhan 430074 China CREOL College of Optics and Photonics University of Central Florida Orlando Florida 32816-2700 USA Ming Hsieh Department of Electrical and Computer Engineering University of Southern California Los Angeles California 90089 USA School of Biomedical Engineering Division of Life Sciences and Medicine University of Science and Technology of China Hefei 230026 China Suzhou Institute for Advanced Research University of Science and Technology of China Suzhou 215123 China School of Physical Sciences University of Science and Technology of China Hefei 230026 China

Nonlinear multimode optical systems have attracted substantial attention due to their rich physical properties. Complex interplay between the nonlinear effects and mode couplings makes it difficult to understand the collective dynamics of photons. Authors of recent studies have shown that such collective phenomena can be effectively described by Rayleigh-Jeans thermodynamics theory, which is a powerful tool for the study of nonlinear multimode photonic systems. These systems, in turn, offer a compelling platform for investigating fundamental issues in statistical physics, attributed to their tunability and the ability to access negative temperature regimes. However, to date, a theory for nonequilibrium transport and fluctuations is yet to be established. Here, we employ full counting statistics theory to study the nonequilibrium transport of particles and energy in nonlinear multimode photonic systems in both positive and negative temperature regimes. Furthermore, we discover that, in situations involving two reservoirs of opposite temperatures and chemical potentials, an intriguing phenomenon known as the loop current effect can arise, wherein the current in the positive energy sector runs counter to that in the negative energy sector. In addition, we numerically confirm that the fluctuation theorem remains applicable in optical thermodynamics systems across all regimes, from positive temperatures to negative ones. Our findings closely align with numerical simulations based on first-principles nonlinear wave equations. In this paper, we seek to deepen the understanding of irreversible nonequilibrium processes and statistical fluctuations in nonlinear many-body photonic systems which will enhance our grasp of collective phenomena of photons and foster a fruitful intersection between optics and statistical physics.

关键词： Chemical potential

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Antithetic Multilevel Methods for Elliptic and Hypo-Elliptic Diffusions with Applications

arXiv

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arXiv 2024年

作者： Iguchi, Yuga Jasra, Ajay Maama, Mohamed Beskos, Alexandros Department of Statistical Science University College London LondonWC1E 6BT United Kingdom School of Data Science The Chinese University of Hong Kong Shenzhen China Applied Mathematics and Computational Science Program Computer Electrical and Mathematical Sciences and Engineering Division King Abdullah University of Science and Technology Thuwal23955-6900 Saudi Arabia

In this paper we present a new antithetic multilevel Monte Carlo (MLMC) method for the estimation of expectations with respect to laws of diffusion processes that can be elliptic or hypo-elliptic. In particular, we consider the case where one has to resort to time discretization of the diffusion and numerical simulation of such schemes. Motivated by recent developments, we introduce a new MLMC estimator of expectations, which does not require simulation of intractable Lévy areas but has a weak error of order 2 and achieves the optimal computational complexity. We then show how this approach can be used in the context of the filtering problem associated to partially observed diffusions with discrete time observations. We illustrate with numerical simulations that our new approaches provide efficiency gains for several problems relative to some existing methods. © 2024, CC BY.

关键词： Diffusion

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Cyclodextrin-Modified Layered Double Hydroxide Thin-Film Nanocomposite Desalination Membrane for Boron Removal

SSRN

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SSRN 2023年

作者： Ee, Liang Ying Zhao, Qipeng Gao, Jie Lim, Chit Kai Xue, Kai Chin, Sze Yuet Li, Sam Fong Yau Chung, Tai-Shung Chen, Shing Bor Department of Chemical and Biomolecular Engineering College of Design and Engineering National University of Singapore 4 Engineering Drive 4 Singapore117585 Singapore Department of Chemistry College of Humanities and Sciences National University of Singapore 3 Science Drive 3 Singapore117543 Singapore Chemical Engineering Program Physical Science and Engineering Division King Abdullah University of Science and Technology Thuwal23955-6900 Saudi Arabia Centre of High Field NMR Spectroscopy and Imaging School of Physical and Mathematical Sciences College of Science Nanyang Technological University 21 Nanyang Link Singapore637371 Singapore NUS Environmental Research Institute National University of Singapore T-Lab Building 5A Engineering Drive 1 Singapore117411 Singapore Graduate Institute of Applied Science and Technology National Taiwan University of Science and Technology Taipei106335 Taiwan

The elimination of small and potentially toxic boron species in water is always a significant challenge for conventional membrane technologies. In this study, facile intercalation and functionalization of β-cyclodextrin (CD) onto layered double hydroxides (LDHs) have resulted in the formation of accessible hydroxyl functional groups and anions that exhibit strong sorption with boron. Through meticulous molecular design and optimization, the modified LDH possessing the maximum boron adsorption capacity of 96.1 mg g-1 was employed to fabricate a polyamide-based thin-film nanocomposite (TFN) membrane with a loading of 0.10 wt.%. This resultant membrane displayed a high salt rejection and water permeance of 99.4 % and 2.68 LMH bar-1 for brackish water, respectively, which can be attributed to the increased interlayer spacing of 1.67 nm and the thinner selective layer. The innovative TFN membrane also achieved a high boron rejection of 82.3 % against brackish water containing 2,000 mg L-1 NaCl and 15 mg L-1 B at pH 8. This pioneering study provides valuable insights into the design of brackish water reverse osmosis (BWRO) membranes, through the synergistic use of macrocyclic molecules and inorganic layered nanomaterials, that could potentially revolutionize water reuse and boron removal applications. © 2023, The Authors. All rights reserved.

关键词： Sodium chloride

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