检索结果-内蒙古大学图书馆

Modifying BiVO4 as a photocatalyst for water oxidation using constant-duration alkaline-etched post treatments

New Journal of Chemistry 2023年第2期48卷 569-577页

作者： Hsu, Chuan-Chih Chuang, Kai-Jie Huang, Hsiao-Wen Pan, Bo-Jin Chen, Hung-Ming Husain, Sadang Yougbaré, Sibidou Hsiao, Yu-Cheng Wu, Yung-Fu Lin, Lu-Yin Division of Cardiovascular Surgery Department of Surgery School of Medicine College of Medicine Taipei Medical University Taiwan Division of Cardiovascular Surgery Department of Surgery Taipei Medical University Hospital Taiwan Department of Chemical Engineering and Biotechnology National Taipei University of Technology Taipei Taiwan Department of Chemical Engineering Ming Chi University of Technology New Taipei City24301 Taiwan Gingen Technology Co. Ltd. Rm. 7 10F. No. 189 Sec. 2 Keelung Rd. Xinyi Dist. Taipei11054 Taiwan Department of Physics Faculty of Mathematics and Natural Science Lambung Mangkurat University Banjarmasin70124 Indonesia /Nanoro Ouagadougou03 Burkina Faso International PhD Program in Biomedical Engineering College of Biomedical Engineering Taipei Medical University Taipei11031 Taiwan Stanford Byers Center for Biodesign Stanford University CA94305-5428 United States Graduate Institute of Biomedical Optomechatronics College of Biomedical Engineering Taipei Medical University Taipei11031 Taiwan Cell Physiology and Molecular Image Research Center Wan Fang Hospital Taipei Medical University Taipei11696 Taiwan

BiVO4 with suitable band edges and a small band gap is considered an efficient photocatalyst for the oxygen evolution reaction (OER), but short charge-transfer lengths limit its photocatalytic ability. Increasing active sites can essentially enhance oxidation reactions and photocatalytic ability. The alkaline etching technique can refine the surface properties of BiVO4 by introducing oxygen vacancies and possibly establishing a heterojunction, but suitable alkaline etching methods are rarely discussed. In this study, three alkaline etching methods, including hydrothermal, soaking, and electrodeposition processes, are first applied for a constant duration to tailor the surface properties of BiVO4 as a photocatalyst for the OER. Alkaline-etched BiVO4 prepared using hydrothermal and soaking processes shows better photocatalytic abilities due to the generation of additional oxygen vacancies, while poor photocatalytic ability is found for that fabricated using electrodeposition due to the formation of less photocatalytic VO2. The highest photocurrent density of 2.38 mA cm−2 is obtained at 1.23 V versus a reversible hydrogen electrode in an electrolyte without a hole scavenger for the BiVO4 etched in the hydrothermal process, while the untreated BiVO4 presents a photocurrent density of 0.58 mA cm−2. A photocurrent retention of 92.3% is achieved after 5000 seconds of continuous illumination. The study supplies blueprints for establishing effective alkaline etching methods for enhancing the photocatalytic ability of BiVO4, with the exception of time costs. © 2024 The Royal Society of Chemistry.

关键词： Charge transfer

来源：评论

学校读者我要写书评

暂无评论

The Radial Dynamics and Acoustic Emissions of Phase-Shift Droplets are Impacted by Mechanical Properties of Tissue-Mimicking Hydrogels

SSRN

引用

SSRN 2024年

作者： Kaushik, Anuj Abeid, Bachir A. Estrada, Jonathan B. Fowlkes, Jeffry Brian Fabiilli, Mario L. Aliabouzar, Mitra Department of Radiology University of Michigan Ann ArborMI United States Department of Mechanical Engineering University of Michigan Ann ArborMI United States Department of Biomedical Engineering University of Michigan Ann ArborMI United States Applied Physics Program University of Michigan Ann ArborMI United States

Acoustic droplet vaporization (ADV) offers a dynamic approach for generating bubbles on demand, presenting new possibilities in biomedical applications. Although ADV has been investigated in various biomedical applications, its potential in tissue characterization remains unexplored. Here, we investigated the effects of surrounding media on the radial dynamics and acoustic emissions of ADV bubbles using theoretical and experimental methodologies. For theoretical studies, bubble dynamics were combined with the Kelvin-Voight material constitutive model, accounting for viscoelasticity of the media. The radial dynamics and acoustic emissions of the ADV-bubbles were recorded via ultra-high-speed microscopy and passive cavitation detection, respectively. Perfluoropentane phase-shift droplets were embedded in tissue-mimicking hydrogels of varying fibrin concentrations, representing different elastic moduli. Radial dynamics and the acoustic emissions, both temporal and spectral, of the ADV-bubbles depended significantly on fibrin elasticity. For example, an increase in fibrin elastic modulus from ≈0.2 kPa to ≈6 kPa reduced the maximum expansion radius of the ADV-bubbles by 50%. A similar increase in medium elasticity significantly impacted both linear (e.g., fundamental) and nonlinear (e.g., subharmonic) acoustic responses of the ADV-bubbles, by up to 10 dB. The sensitivity of ADV to the surrounding media was dependent on acoustic parameters such as driving pressure and the droplets concentration. Further analysis of the acoustic emissions revealed distinct ADV signal characteristics, which were significantly influenced by the surrounding media. © 2024, The Authors. All rights reserved.

关键词： Drops

来源：评论

学校读者我要写书评

暂无评论

Experimental & Numerical Investigations of Ultra-High-Speed Dynamics of Optically Induced Droplet Vaporization in Soft Materials

SSRN

引用

SSRN 2024年

作者： Abeid, Bachir A. Fabiilli, Mario L. Aliabouzar, Mitra Estrada, Jon B. Department of Mechanical Engineering University of Michigan Ann ArborMI United States Department of Radiology University of Michigan Ann ArborMI United States Department of Biomedical Engineering University of Michigan Ann ArborMI United States Applied Physics Program University of Michigan Ann ArborMI United States

Perfluorocarbon (PFC) droplets represent a novel class of phase-shift contrast agent with a promise in applications in biomedical and bioengineering fields. PFC droplets undergo a fast liquid-gas transition upon exposure to acoustic or optical triggering, offering a potential adaptable and versatile tool as contrast agent in diagnostics imaging and localized drug delivery vehicles in therapeutics systems. In this paper, we utilize advanced imaging techniques to investigate ultra-high-speed inertial dynamics and rectified quasi-static (low-speed) diffusion evolution of optically induced PFC droplet vaporization within three different hydrogels, each of different concentrations, examining effects such as droplet size and PFC core on bubble dynamics and material viscoelastic properties. Gelatin hydrogels reveal concentration-dependent impacts on bubble expansion and material elasticity. Embedding PFC droplets in gelatin increases internal pressure, resulting in higher equilibrium radius and continuous bubble growth during quasi-static evolution. Similar trends are observed in fibrin and polyacrylamide matrices, with differences in bubble behavior attributed to matrix properties and droplet presence. Interestingly, droplet size exhibits minimal impact on bubble expansion during inertial dynamics but influences quasi-static evolution, with larger droplets leading to continuous growth beyond 60 seconds. Furthermore, the core composition of PFC droplets significantly affects bubble behavior, with higher boiling point droplets exhibiting higher maximum expansion and slower quasi-static dissolution rates. Overall, the study sheds light on the intricate interplay between droplet characteristics, matrix properties, and multi-timescale bubble dynamics, offering valuable insights into their behavior within biomimetic hydrogels. © 2024, The Authors. All rights reserved.

关键词： Viscoelasticity

来源：评论

学校读者我要写书评

暂无评论

The abundance and localization of environmental microplastics in gastrointestinal tract and muscle of Atlantic killifish (Fundulus heteroclitus): a pilot study

引用

Microplastics and Nanoplastics 2024年第1期4卷 23页

作者： Pitt, Jordan A. Gallager, Scott M. Youngs, Sarah Michel, Anna P. M. Hahn, Mark E. Aluru, Neelakanteswar Biology Department Woods Hole Oceanographic Institution Woods Hole 02543 MA United States Massachusetts Institute of Technology (MIT) – Woods Hole Oceanographic Institution (WHOI) Joint Graduate Program in Oceanography and Oceanographic Engineering Woods Hole 02543 MA United States CoastalOceanVision Inc 10 Edgerton Drive North Falmouth 02556 MA United States Department of Applied Ocean Physics and Engineering Woods Hole Oceanographic Institution Woods Hole 02543 MA United States

Microplastics (MPs) have been found in a diverse range of organisms across trophic levels. While a majority of the information on organismal exposure to plastics in the environment comes from gastrointestinal (GI) data, the prevalence of MP particles in other tissues is not well understood. Additionally, many studies have not been able to detect the smallest, most prevalent, MPs (1 µm – 5 mm) that are the most likely to distribute to tissues in the body. To address these knowledge gaps, MPs in the GI tract and muscle of Atlantic killifish (Fundulus heteroclitus) collected from two sites (Falmouth and Bourne) on Buzzards Bay, Cape Cod, MA were quantified down to 2 µm in size. Eight fish from Falmouth and 10 fish Bourne site were analyzed. Fourier-transform infrared spectroscopy and Raman spectroscopy were used to identify all particles. The mean concentrations of MPs in the GI tract and muscle from fish collected from Falmouth was 85.5 ± 70.2 and 11 ± 12.5 particles per gram wet weight, respectively. Fish collected from Bourne site had mean particle concentrations of 12.2 ± 18.1 and 1.69 ± 5.36 particles per gram wet weight. Of the 2,008 particles analyzed in various fish tissue samples, only 3.4% (69 particles) were identified as plastic;polymers included nylon, polyethylene, polypropylene, and polyurethane. MPs detected in the GI tract samples also tended to be more diverse in both size and polymer type than those found in the muscle. We found that MPs < 50 µm, which are often not analyzed in the literature, were the most common in both the GI tract and muscle samples. There was not a significant correlation between the MP content in the muscle compared to the GI tract, indicating that GI tract MP abundance cannot be used to predict non-GI tract tissue MP content;however, MP abundance in muscle correlated with fish total length, suggesting potential bioaccumulation of these small MPs. © The Author(s) 2024.

关键词： Bioaccumulation Fish Fourier-transform infrared spectroscopy Microplastics Raman spectroscopy Translocation

来源：评论

学校读者我要写书评

暂无评论

Quantum Wrapper Networking: Investigating the Noise Impact of Classical Headers on the Quantum Payload

Quantum Wrapper Networking: Investigating the Noise Impact o...

引用

2024 Frontiers in Optics, FiO 2024

作者： Gül, Gamze On, Mehmet Berkay Tan, Shannon G. Proietti, Roberto Kanter, Gregory S. Yoo, S.J. Ben Kumar, Prem Graduate Program in Applied Physics Northwestern University 2145 Sheridan Road EvanstonIL60208 United States Department of Electrical and Computer Engineering University of California Davis DavisCA95616 United States Center for Photonic Communication and Computing Dept. of Electrical and Computer Eng. Northwestern University EvanstonIL60208 United States Department of Electronics and Telecommunications Engineering Politecnico di Torino Italy

We study the impact in time and frequency domains of classical headers on quantum payloads in quantum wrapper networking. We identify and characterize in-fiber scattering processes that produce noise photons degrading...

关键词：

来源：评论

学校读者我要写书评

暂无评论

Positive Emotional State Recognition Using Nonlinear Dynamics Analysis and Machine Learning Algorithms with Electroencephalogram Signals

Positive Emotional State Recognition Using Nonlinear Dynamic...

引用

International Symposium on applied Science 2024, ISAS 2024

作者： Gia, Quynh Nguyen Le, Quoc Khai Department of Biomedical Engineering Physics Faculty of Applied Science Ho Chi Minh city University of Technology 268 Ly Thuong Kiet Street District 10 Ho Chi Minh City Viet Nam Vietnam National University Ho Chi Minh City Linh Trung Ward Thu Duc City Ho Chi Minh City Viet Nam

Electroencephalogram (EEG) signals processing has gathered increased interest from the scientific community for a long time, especially in the field of emotion recognition. The objective of this research is to propose a method that analyzes EEG signals from a publicly available dataset called SJTU Emotion EEG Dataset (SEED) to classify different emotional states, especially positive emotions. The dataset consists of EEG signals recorded from fifteen subjects while watching different film clips, each of which corresponds to a type of emotions. Initial analysis involves the extraction of features from the preprocessed data including time-domain analysis, frequency-domain analysis using Fast Fourier Transform (FFT) and nonlinear dynamics method. Machine learning algorithms are then applied as classifiers in order to determine the emotional states of each subject – categorized as positive, negative, or neutral – with the input is the extracted features. In this work, Support Vector Machine (SVM), Linear Discriminant Analysis (LDA) and Subspace Discriminant (SD) are used for training and testing the labeled data. The classification step achieved the highest accuracy level of 82.2% while the highest micro-F1 score value is 0.92 for positive emotions. The established methodology not only proposes an automated model for determining positive emotional states but also plays an important role at the beginning of the investigation further into emotion recognition by providing better visualization of how different emotional states are determined. © 2025 Institute of physics Publishing. All rights reserved.

关键词： Frequency domain analysis

来源：评论

学校读者我要写书评

暂无评论

Control of skyrmion lattice order in the van der Waals ferromagnet Fe3GeTe2 16

Control of skyrmion lattice order in the van der Waals ferro...

引用

Spintronics XVI 2023

作者： Li, Yue McCray, Arthur R.C. Wang, Wei Basnet, Rabindra Pandey, Krishna Ma, Xuedan Hu, Jin Petford-Long, Amanda K. Phatak, Charudatta Materials Science Division Argonne National Laboratory LemontIL60439 United States Applied Physics Program Northwestern University EvanstonIL60208 United States Center for Nanoscale Materials Argonne National Laboratory LemontIL60439 United States Department of Physics University of Arkansas FayettevilleAR72701 United States Materials Science and Engineering Program University of Arkansas FayettevilleAR72701 United States Department of Materials Science and Engineering Northwestern University EvanstonIL60208 United States

ISBN: (纸本)9781510665262

Van der Waals ferromagnets are an intersting class of materials for exploring fundamental physics of magnetic order in the 2D limit as well as for technological applicaitons due to possibility of creating novel heterostructures. These materials have shown to host magnetic skyrmion lattices with their organization controlled by the magnetic properties such as anisotropy, exchange, and Dzyaloshinkii-Moriya interaction. For technological applications, it is also necessary to understand to the behavior of skyrmions in response to electric currents. In this work, we show the effect of electric current pulses on the magnetic skyrmions formed in Fe3GeTe2which has a Curie temperature of 220 K. We demonstrate via real-space in situ imaging using Lorentz transmission electron microscopy (LTEM) the effect of temperture and pulse width. © 2023 SPIE.

关键词： High resolution transmission electron microscopy

来源：评论

学校读者我要写书评

暂无评论

Impact of wavefront shape on nonlinear ultrasound imaging of monodisperse microbubbles

arXiv

引用

arXiv 2024年

作者： Matalliotakis, Agisilaos Waasdorp, Rick Verweij, Martin D. Maresca, David Department of Imaging Physics Faculty of Applied Sciences Delft University of Technology Delft2628 CJ Netherlands Department of Biomedical Engineering Erasmus University Medical Center Rotterdam3000 CA Netherlands

The field of contrast-enhanced ultrasound (CEUS) combines nonlinear, resonant microbubbles (MBs) with dedicated pulse sequences to reveal the vascular function of organs. Clinical ultrasound contrast agents consist of polydisperse MB suspensions with diameters ranging from 0.5 to 10 µm and resonance frequencies ranging from 1 to 15 MHz. As a result, just a small fraction of MBs resonates at a given ultrasound frequency. MB suspensions with narrow size distributions can be tuned for a specific imaging frequency, boost CEUS sensitivity and enable deeper vascular imaging. However, their enhanced nonlinear behavior makes imaging susceptible to nonlinear wave propagation artifacts. Here, we numerically investigate the impact of the acoustic wavefront shape on the imaging of nonlinear, monodisperse MBs. Specifically, our approach relies on an extension of the Iterative Nonlinear Contrast Source (INCS) method that accounts for all nonlinear effects in CEUS. We demonstrate that supersonic x-shaped wavefronts referred to as x-waves can be used to generate ultrasound images of monodisperse MBs without nonlinear wave propagation artifacts. On the contrary, imaging based on focused, planar and diverging wavefronts leads to significant nonlinear artifacts. Taken together, our results show that x-waves can harness the full potential of monodisperse MBs by enabling their sensitive and specific detection in a tissue context. © 2024, CC BY-NC-ND.

关键词： Wavefronts

来源：评论

学校读者我要写书评

暂无评论

RN-SDEs: Limited-Angle CT Reconstruction with Residual Null-Space Diffusion Stochastic Differential Equations

arXiv

引用

arXiv 2024年

作者： Guo, Jiaqi Lopez-Tapia, Santiago Li, Wing Shun Wu, Yunnan Carignano, Marcelo Backman, Vadim Dravid, Vinayak P. Katsaggelos, Aggelos K. The Department of Electrical and Computer Engineering Northwestern University IL60201 United States The Applied Physics Program Northwestern University EvanstonIL60201 United States

Computed tomography is a widely used imaging modality with applications ranging from medical imaging to material analysis. One major challenge arises from the lack of scanning information at certain angles, leading to distorted CT images with artifacts. This results in an ill-posed problem known as the Limited Angle Computed Tomography (LACT) reconstruction problem. To address this problem, we propose Residual Null-Space Diffusion Stochastic Differential Equations (RN-SDEs), which are a variant of diffusion models that characterize the diffusion process with mean-reverting (MR) stochastic differential equations. To demonstrate the generalizability of RN-SDEs, our experiments are conducted on two different LACT datasets, i.e., ChromSTEM and C4KC-KiTS. Through extensive experiments, we show that by leveraging learned Mean-Reverting SDEs as a prior and emphasizing data consistency using Range-Null Space Decomposition (RNSD) based rectification, RN-SDEs can restore high-quality images from severe degradation and achieve state-of-the-art performance in most LACT tasks. Additionally, we present a quantitative comparison of computational complexity and runtime efficiency, highlighting the superior effectiveness of our proposed approach. Copyright © 2024, The Authors. All rights reserved.

关键词： Stochastic systems

来源：评论

学校读者我要写书评

暂无评论

Polydisperse versus monodisperse microbubbles: A simulation study for contrast-enhanced ultrasound imaging

arXiv

引用

arXiv 2024年

作者： Matalliotakis, Agisilaos Verweij, Martin D. Department of Imaging Physics Faculty of Applied Sciences Delft University of Technology Delft2628 CJ Netherlands Department of Biomedical Engineering Erasmus University Medical Center Rotterdam3000 CA Netherlands

Objective: Contrast-enhanced ultrasound (CEUS) presents distinct advantages in diagnostic echography. Utilizing microbubbles (MBs) as conventional contrast agents enhances vascular visualization and organ perfusion, facilitating real-time, non-invasive procedures. There is a current tendency to replace the traditional polydisperse MBs by novel monodisperse formulations in an attempt to optimize contrast enhancement and guarantee consistent behavior and reliable imaging outcomes. This study investigates the contrast enhancement achieved by monodisperse MBs of different sizes, and their influence on nonlinear imaging artifacts observed in traditional CEUS. Methods: To explore the differences between monodisperse and polydisperse populations without excessive experimentation, numerical simulations are employed for delivering precise, objective and expeditious results. The Iterative Nonlinear Contrast Source (INCS) method has previously demonstrated its efficacy in simulating ultrasound propagation in large populations in which each bubble has individual properties and several orders of multiple scattering are significant. Therefore, this method is employed to realistically simulate both monodisperse and polydisperse MBs. Results: Our findings in CEUS imaging indicate that scattering from resonant monodisperse microbubbles is 11.8 dB stronger than scattering from the polydisperse population. Furthermore, the amplitude of nonlinear imaging artifacts downstream of the monodisperse population is 19.4 dB stronger compared to polydisperse suspension. Conclusion: Investigating the impact of multiple scattering on polydisperse populations compared to various monodisperse suspensions reveals that monodisperse MBs are more effective contrast agents, especially when on resonance. Despite the strong signal to noise ratio of monodisperse populations, the imaging artifacts due to nonlinear wave propagation are also enhanced, resulting in more missclassification of MBs as tissue. © 2

关键词： Numerical methods

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：