Journal of Physics D: Applied Physics最新文献

Emerging strategies in radiation therapy: promises and challenges of spatial fractionation, ultra-high dose rates, and nanoparticles. 放射治疗的新策略：空间分割、超高剂量率和纳米粒子的前景和挑战。

IF 3.2 3区物理与天体物理

Journal of Physics D: Applied Physics Pub Date : 2025-10-13 DOI: 10.1088/1361-6463/ae0e2d

Hamid Ghaznavi, Mohammad Rezaee, Francisco Reynoso, Arash Darafsheh

{"title":"Emerging strategies in radiation therapy: promises and challenges of spatial fractionation, ultra-high dose rates, and nanoparticles.","authors":"Hamid Ghaznavi, Mohammad Rezaee, Francisco Reynoso, Arash Darafsheh","doi":"10.1088/1361-6463/ae0e2d","DOIUrl":"10.1088/1361-6463/ae0e2d","url":null,"abstract":"Radiation therapy (RT) employs ionizing radiation to kill cancerous cells. However, delivering radiation to tumors, typically embedded within normal tissues, inevitably exposes healthy organs to radiation, leading to collateral damage. This creates a tradeoff between the tumor control probability and normal tissue complication probability, ultimately limiting the dose that can be safely administered. While highly conformal RT techniques have improved tumor targeting and treatment efficacy, they remain inadequate for treating large and radioresistant tumors, pointing out the need for alternative strategies. Spatially fractionated RT, ultra-high dose rate RT, and nanoparticle-enhanced RT are emerging techniques with promise in enhancing tumor control while minimizing normal tissue toxicity. Successful clinical translation of these advanced techniques requires cross-disciplinary efforts aimed at technological innovation, a deeper understanding of the underlying radiobiological mechanisms, and the development of early-phase clinical trials. This paper provides an overview of these techniques and their associated challenges and opportunities.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"58 41","pages":"413002"},"PeriodicalIF":3.2,"publicationDate":"2025-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12516303/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145292554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

On the applicability of x-ray strain imaging using the edge illumination technique in biomedical applications. 基于边缘照明技术的x射线应变成像在生物医学应用中的适用性。

IF 3.2 3区物理与天体物理

Journal of Physics D: Applied Physics Pub Date : 2025-08-04 DOI: 10.1088/1361-6463/adf452

Carlo Peiffer, A Astolfo, M Endrizzi, C K Hagen, A Olivo, P R T Munro

{"title":"On the applicability of x-ray strain imaging using the edge illumination technique in biomedical applications.","authors":"Carlo Peiffer, A Astolfo, M Endrizzi, C K Hagen, A Olivo, P R T Munro","doi":"10.1088/1361-6463/adf452","DOIUrl":"10.1088/1361-6463/adf452","url":null,"abstract":"Strain imaging using conventional x-ray tomography is a widely established technique for investigating the mechanical deformation of materials, including cement and batteries. However, its biomedical applications are primarily restricted to bone tissue due to the low contrast of soft tissues. X-ray phase contrast imaging, offering superior contrast-to-noise ratios in soft tissues, can in principle overcome this limitation. This study explores the feasibility of x-ray strain imaging for soft tissues using edge illumination (EI), a laboratory-based x-ray phase contrast technique. A phantom mimicking the mechanical properties of healthy and tumorous soft tissues, with a stiff inclusion invisible to conventional x-ray imaging, was tested alongside chicken soft tissue fixed in ethanol. While our study confirmed that EI phase contrast imaging provides improved contrast for such samples compared to absorption imaging, it also revealed a reduction in strain retrieval precision. Artefacts caused by absorbing bridges in the mask design and errors arising from differential phase signal integration, which vary spatially between scans, were identified as key limiting factors. Consequently, EI phase contrast strain imaging was unable to locate phantom inclusions based on mechanical contrast. However, EI's capability to increase spatial sampling frequency without compromising the field of view improved strain retrieval precision using its absorption contrast beyond that achieved with conventional x-ray strain imaging. These findings highlight the potential and challenges of applying EI to strain analysis in soft tissues, providing insights into its limitations and opportunities for further improvement.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"58 31","pages":"315402"},"PeriodicalIF":3.2,"publicationDate":"2025-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12319699/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144789353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of excitation field amplitude on magnetic particle imaging performance: a modeling study. 激发场振幅对磁颗粒成像性能的影响：一个模型研究。

IF 3.1 3区物理与天体物理

Journal of Physics D: Applied Physics Pub Date : 2025-07-28 Epub Date: 2025-07-22 DOI: 10.1088/1361-6463/adeea2

Ebrahim Azizi, Changzhi Li, Jenifer Gómez-Pastora, Rui He, Kai Wu

{"title":"Effects of excitation field amplitude on magnetic particle imaging performance: a modeling study.","authors":"Ebrahim Azizi, Changzhi Li, Jenifer Gómez-Pastora, Rui He, Kai Wu","doi":"10.1088/1361-6463/adeea2","DOIUrl":"10.1088/1361-6463/adeea2","url":null,"abstract":"Magnetic particle imaging (MPI) is a new tomographic imaging technique that can quantitatively correlate MPI signal intensity to the spatial distribution of magnetic nanoparticle (MNP) tracers. Due to its non-ionizing nature, low background signal from biological matrices, high contrast, and relatively good spatial and temporal resolution, MPI has been actively studied and applied to biomedical imaging and is expected to reach the clinical stage soon. To further improve the spatial resolution limit in MPI, researchers have been working towards optimizing the image reconstruction algorithms, magnetic field profiles, tracer designs, circuitry, etc. Recent studies reported that lower excitation field amplitudes can improve spatial resolution, though this comes at the expense of lower MPI signal and tracer sensitivity. Different excitation field profiles directly affect the collective dynamic magnetizations of tracers recorded by the receiver coil in MPI. However, there is a gap between understanding the relaxation dynamics of MNP tracers, the signal-to-noise ratio (SNR) of MPI signals, and the MPI spatial resolution. In this work, we used a stochastic Langevin equation with coupled Brownian and Néel relaxations to model the magnetic dynamics of different MNP tracers subjected to varying excitation fields. We analyzed the collective time-domain dynamic magnetizations (M-t curves), magnetic-field hysteresis loops (M-H curves), point spread functions (PSFs), higher harmonics, and SNR of the third harmonic to understand how the excitation field affects MPI performance. We employed Full Width at Half Maximum and SNR as evaluation metrics for imaging resolution and signal quality, respectively. Our study supports previous findings on the impact of excitation field amplitude on MPI performance while offering more profound insights into the interplay of nonequilibrium Néel and Brownian relaxation, tracer core size, and SNR.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"58 30","pages":"305002"},"PeriodicalIF":3.1,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12281415/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144698900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Phase-restoring subpixel image registration: enhancing motion detection performance in Fourier-domain optical coherence tomography. 相位恢复亚像素图像配准：增强傅里叶域光学相干层析成像的运动检测性能。

IF 3.1 3区物理与天体物理

Journal of Physics D: Applied Physics Pub Date : 2025-04-07 Epub Date: 2025-02-21 DOI: 10.1088/1361-6463/adb3b4

Huakun Li, Bingyao Tan, Vimal Prabhu Pandiyan, Veluchamy Amutha Barathi, Ramkumar Sabesan, Leopold Schmetterer, Tong Ling

{"title":"Phase-restoring subpixel image registration: enhancing motion detection performance in Fourier-domain optical coherence tomography.","authors":"Huakun Li, Bingyao Tan, Vimal Prabhu Pandiyan, Veluchamy Amutha Barathi, Ramkumar Sabesan, Leopold Schmetterer, Tong Ling","doi":"10.1088/1361-6463/adb3b4","DOIUrl":"10.1088/1361-6463/adb3b4","url":null,"abstract":"Phase-sensitive Fourier-domain optical coherence tomography (FD-OCT) enables in-vivo, label-free imaging of cellular movements with detection sensitivity down to the nanometer scale, and it is widely employed in emerging functional imaging modalities, such as optoretinography (ORG), Doppler OCT, and optical coherence elastography. However, when imaging tissue dynamics in vivo, inter-frame displacement introduces decorrelation noise that compromises motion detection performance, particularly in terms of sensitivity and accuracy. Here, we demonstrate that the displacement-related decorrelation noise in FD-OCT can be accurately corrected by restoring the initial sampling points using our proposed Phase-Restoring Subpixel Image Registration (PRESIR) method. Derived from a general FD-OCT model, the PRESIR method enables translational shifting of complex-valued OCT images over arbitrary displacements with subpixel precision, while accurately restoring phase components. Unlike conventional approaches that shift OCT images either in the spatial domain at the pixel level or in the spatial frequency domain for subpixel correction, our method reconstructs OCT images by correcting axial displacement in the spectral domain (k domain) and lateral displacement in the spatial frequency domain. We validated the PRESIR method through simulations, phantom experiments, and in-vivo ORG in both rodents and human subjects. Our approach significantly reduced decorrelation noise during the imaging of moving samples, achieving phase sensitivity close to the fundamental limit determined by the signal-to-noise ratio.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"58 14","pages":"145102"},"PeriodicalIF":3.1,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11843479/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143482086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Recent progresses and applications on chiroptical metamaterials: a review 奇光超材料的最新进展与应用：综述

IF 3.4 3区物理与天体物理

Journal of Physics D: Applied Physics Pub Date : 2024-09-18 DOI: 10.1088/1361-6463/ad6f20

Yan Wang, Zeyu Wu, Wenming Yu and Zhengqi Liu

引用次数: 0

Electrical surface breakdown characteristics of micro- and nano-Al2O3 particle co-doped epoxy composites 微纳米 Al2O3 粒子共掺环氧树脂复合材料的电表面击穿特性

IF 3.4 3区物理与天体物理

Journal of Physics D: Applied Physics Pub Date : 2024-09-17 DOI: 10.1088/1361-6463/ad773e

Guobao Zhang, Wei Yang, Lei Zhang, Zhengyang Wu, Mengyi Cai, Taiyun Zhu, Lei Sun, He Gao and Zhen Li

{"title":"Electrical surface breakdown characteristics of micro- and nano-Al2O3 particle co-doped epoxy composites","authors":"Guobao Zhang, Wei Yang, Lei Zhang, Zhengyang Wu, Mengyi Cai, Taiyun Zhu, Lei Sun, He Gao and Zhen Li","doi":"10.1088/1361-6463/ad773e","DOIUrl":"https://doi.org/10.1088/1361-6463/ad773e","url":null,"abstract":"Epoxy microcomposites are basic materials for gas-insulated switchgear (GIS) spacers that are subjected to huge electrical stress. Previous works have indicated that nanoparticles are beneficial to dielectric performance. However, surface electrical breakdown, a typical fault in GIS of co-doped micro- and nanoparticles in epoxy composites, is seldom studied. In this work, numerous concentrations of micro- and nano-Al2O3 are co-doped into an epoxy matrix; the surface traps, surface charging, and surface breakdown voltages (Vsb) of the co-doped composites are studied, and the influence of micro- and nano-Al2O3 on the electrical surface breakdown is clarified. The results show that Vsb first decreases and then increases with the microparticles, and Vsb decreases from 25.34 kV to 19.52 kV. As the number of nanoparticles increases, Vsb increases and then decreases when the microparticle loading is low, but decreases and then increases when the microparticle loading exceeds 40 wt%. Micro-Al2O3 particles introduce surface shallow traps into epoxy composites, while small amounts of nano-Al2O3 introduce deep traps. Two different mechanisms dominate the surface charging and Vsb of epoxy micro-nanocomposites. When the surface conductivity is lower than 7 × 10−14 S, the surface charges are reduced by the suppression of electrode injection as the trap depth increases, and Vsb increases. When the surface conductivity exceeds 7 × 10−14 S, the surface charge dissipation rate increases with the surface conductivity and Vsb increases as the surface conductivity increases. Our work indicates that co-doped micro- and nano-particles should keep the surface conductivity away from the specic value (7 × 10−14 S) to safeguard insulation properties for GIS spacers.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"19 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical simulations of a low-pressure electrodeless ion source intended for air-breathing electric propulsion 用于喷气式电力推进的低压无电极离子源的数值模拟

IF 3.4 3区物理与天体物理

Journal of Physics D: Applied Physics Pub Date : 2024-09-17 DOI: 10.1088/1361-6463/ad7471

Marek Šťastný, Kryštof Mrózek, Karel Juřík, Lukáš Havlíček, Michal Novotný and Adam Obrusník

{"title":"Numerical simulations of a low-pressure electrodeless ion source intended for air-breathing electric propulsion","authors":"Marek Šťastný, Kryštof Mrózek, Karel Juřík, Lukáš Havlíček, Michal Novotný and Adam Obrusník","doi":"10.1088/1361-6463/ad7471","DOIUrl":"https://doi.org/10.1088/1361-6463/ad7471","url":null,"abstract":"Air breathing electric propulsion (ABEP) systems offer a promising solution to extend the lifetime of very low earth orbit (VLEO) missions by using residual atmospheric particles as propellants. Such systems would operate in very low-pressure environments where plasma ignition and confinement prove challenging. In this contribution, we present results of a global plasma model (GPM) of a plasma ignited in a very low-pressure air mixture. The results are validated against experimental measurements acquired using a laboratory electrodeless ion source utilizing a resonator for plasma ignition. The device is specifically designed to operate within low-pressure environments as it holds potential applications in ABEP systems for VLEO missions. Parametric studies are carried out via GPM to investigate the resonant behavior and its implications. The potential of the model serving as a predictive tool is assessed through experimental validation against measured data, mainly investigating the extracted ion current dependency on operational pressure and external magnetic field strength. The verified model is further utilized to extrapolate additional information about the resonant plasma such as ion composition or a degree of ionization.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"66 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Oxygen vacancies kinetics in TaO 2 − ... TaO 2 中的氧空位动力学 - ...

IF 3.4 3区物理与天体物理

Journal of Physics D: Applied Physics Pub Date : 2024-09-17 DOI: 10.1088/1361-6463/ad7155

C Ferreyra, R Leal Martir, D Rubi and M J Sánchez

引用次数: 0

Dispersion compensation design of high-density stacking RFSS absorbers for wideband applications 用于宽带应用的高密度堆叠 RFSS 吸收器的色散补偿设计

IF 3.4 3区物理与天体物理

Journal of Physics D: Applied Physics Pub Date : 2024-09-16 DOI: 10.1088/1361-6463/ad7511

Zhinan Luo, Xiaoxiao Ding, Jie Yang, Yuhan Wu, Bichao Wang, Ling Miao, Shaowei Bie and Jianjun Jiang

{"title":"Dispersion compensation design of high-density stacking RFSS absorbers for wideband applications","authors":"Zhinan Luo, Xiaoxiao Ding, Jie Yang, Yuhan Wu, Bichao Wang, Ling Miao, Shaowei Bie and Jianjun Jiang","doi":"10.1088/1361-6463/ad7511","DOIUrl":"https://doi.org/10.1088/1361-6463/ad7511","url":null,"abstract":"A dispersion compensation design absorber realized by high-density stacking resistive frequency selective surface (RFSS) is proposed for wideband applications. Firstly, the quantitative relationship between the equivalent impedance of RFSS and the permittivity of the effective media is constructed with the help of the transmission matrix method. The dispersion regulation of permittivity is achieved by changing the pattern and the square resistance of RFSS. In terms of absorber design, a uniform absorber with dispersion manipulation is developed as a precursor absorber. The uniform absorber has an absorption performance better than −8.5 dB above 2 GHz at normal incidence. The loss mechanism is analyzed in detail by electric field distribution and surface power loss density distribution, indicating that the uniform design cannot achieve thickness saving when extending to low frequency. Therefore, a dispersion compensation design absorber is proposed to extend −10 dB bandwidth to 1.64–28.8 GHz. Experiment results agree well with the simulation results, validating the analytic methods and design principles.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"18 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Impact of c- and m- sapphire plane orientations on the structural and electrical properties of β-Ga2O3 thin films grown by metal-organic chemical vapor deposition c- 和 m- 蓝宝石平面取向对金属有机化学气相沉积法生长的 β-Ga2O3 薄膜的结构和电学特性的影响

IF 3.4 3区物理与天体物理

Journal of Physics D: Applied Physics Pub Date : 2024-09-16 DOI: 10.1088/1361-6463/ad76bb

E Serquen, F Bravo, Z Chi, L A Enrique, K Lizárraga, C Sartel, E Chikoidze and J A Guerra

{"title":"Impact of c- and m- sapphire plane orientations on the structural and electrical properties of β-Ga2O3 thin films grown by metal-organic chemical vapor deposition","authors":"E Serquen, F Bravo, Z Chi, L A Enrique, K Lizárraga, C Sartel, E Chikoidze and J A Guerra","doi":"10.1088/1361-6463/ad76bb","DOIUrl":"https://doi.org/10.1088/1361-6463/ad76bb","url":null,"abstract":"This work presents a comprehensive investigation into the structural and electrical properties of Ga2O3 thin films grown via metal-organic chemical vapor deposition on both c- and m-plane sapphire substrates. Structural characterization revealed the β-Ga2O3 phase formation in both substrate orientations, with strong epitaxial preferential growth on c-plane substrates and polycrystalline films on m-plane substrates. Results show that Ga2O3/m-sapphire exhibits the lower electrical resistivity than its counterpart grown on c-sapphire. Activation energies of acceptor levels were estimated at ~1.4 and ~0.7 , for Ga2O3 films grown on c- and m-plane, respectively. This result shows that growing Ga2O3 on m-plane sapphire is beneficial to reach a weakly compensated sample. Cathodoluminescence analysis suggests that the additional low activation energy of ~0.18 observed in Ga2O3 grown with the highest oxygen flow on m-plane sapphire can be associated to thermally-induced migration of self-trapped hole states.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"214 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0