Pub Date : 2025-05-21Epub Date: 2025-05-16DOI: 10.1063/5.0267697
Wenyi Zhu, Guanchun Rui, Yongsheng Chen, Bo Li, Shihai Zhang, Patrick T Mather, Q M Zhang
Electrospun piezoelectric nanofibers from polyvinylidene fluoride (PVDF) have been widely used in many applications. In PVDF-based polymers, the molecular weight (Mw) plays an important role in determining both crystallization and polarization responses. In the past, polyvinylidene fluoride trifluoroethylene [P(VDF-TrFE)] electrospun nanofibers were produced strictly from high molecular weight polymers (Mw > 200 kDa). Here, we study the electrospun P(VDF-TrFE) nanofibers from comparatively lower Mw polymers (Mw ∼ 100 kDa). We demonstrated a highly electroactive phase in electrospun P(VDF-TrFE) nanofibers without post treatments. During electrospinning, shorter P(VDF-TrFE) polymer chains exhibited higher mobility, which facilitate the formation of all-trans ferroelectric crystals with high crystallinity. By optimizing the mean size of electrospun nanofiber through tailoring the solution concentration and other controlling parameters, P(VDF-TrFE) nanofibers achieved the crystallinity as high as 67% and all-trans conformation reached 79%. The results pave a way for improving the electroactive performance in ferroelectric polymer electrospun nanofibers.
{"title":"High crystallinity and polar-phase content in electrospun P(VDF-TrFE) nanofibers with low molecular weight.","authors":"Wenyi Zhu, Guanchun Rui, Yongsheng Chen, Bo Li, Shihai Zhang, Patrick T Mather, Q M Zhang","doi":"10.1063/5.0267697","DOIUrl":"10.1063/5.0267697","url":null,"abstract":"<p><p>Electrospun piezoelectric nanofibers from polyvinylidene fluoride (PVDF) have been widely used in many applications. In PVDF-based polymers, the molecular weight (M<sub>w</sub>) plays an important role in determining both crystallization and polarization responses. In the past, polyvinylidene fluoride trifluoroethylene [P(VDF-TrFE)] electrospun nanofibers were produced strictly from high molecular weight polymers (M<sub>w</sub> > 200 kDa). Here, we study the electrospun P(VDF-TrFE) nanofibers from comparatively lower M<sub>w</sub> polymers (M<sub>w</sub> ∼ 100 kDa). We demonstrated a highly electroactive phase in electrospun P(VDF-TrFE) nanofibers without post treatments. During electrospinning, shorter P(VDF-TrFE) polymer chains exhibited higher mobility, which facilitate the formation of all-trans ferroelectric crystals with high crystallinity. By optimizing the mean size of electrospun nanofiber through tailoring the solution concentration and other controlling parameters, P(VDF-TrFE) nanofibers achieved the crystallinity as high as 67% and all-trans conformation reached 79%. The results pave a way for improving the electroactive performance in ferroelectric polymer electrospun nanofibers.</p>","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"137 19","pages":"194102"},"PeriodicalIF":2.7,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12085232/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144093855","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}
Pub Date : 2025-04-07Epub Date: 2025-04-01DOI: 10.1063/5.0235806
Liqin Ren, Na Thi Vy Nguyen, Tingfeng Yao, Kytai T Nguyen, Baohong Yuan
The ultrasound-assisted transport of drugs or fluorophore-loaded nanoagents plays an important role in the desirable drug delivery and imaging contrasts. Unlike conventional ultrasound techniques that rely on thermal or cavitation effects, this study aims to conduct an experimental investigation into the dynamics of interstitial fluid streaming and tissue recovery in ex vivo chicken breast and porcine loin muscle tissues during and after ultrasound exposures, which has not been experimentally investigated in the literature. Biological tissues consist of both a fluid and a solid matrix, and an ultrasound beam compresses the tissues within a small focal volume from all directions, which generates macroscopic streaming of interstitial fluid and compression of the tissue's solid matrix. After the ultrasonic exposure, the solid matrix undergoes recovery, leading to a backflow of the fluid matrix. Temperature-insensitive sulforhodamine-101 encapsulated poly(lactic-co-glycolic acid) nanoparticles with an average diameter size of 175 nm were locally injected into ex vivo chicken breast and porcine loin muscle tissues to study the ultrasound-induced dynamics in the tissues during and after ultrasound exposure by analyzing the distribution of fluorescence. The changes in fluorescence over time caused by the streaming and backflow of interstitial fluid were studied with two ex vivo tissue models, and a faster recovery was observed in porcine tissues compared with chicken tissues. The ultrasound-induced transportability of the nanoagent in porcine muscle tissues was much higher (∼8.75 times) than in chicken breast tissue likely due to structural differences. The study reveals a promising, non-invasive strategy for enhancing drug delivery in dense tissues by leveraging mechanical ultrasound effects, potentially advancing therapeutic and diagnostic applications.
{"title":"Experimental studies on squeezing interstitial fluid via transfer of ultrasound momentum (SIF-TUM) in <i>ex vivo</i> chicken and porcine tissues.","authors":"Liqin Ren, Na Thi Vy Nguyen, Tingfeng Yao, Kytai T Nguyen, Baohong Yuan","doi":"10.1063/5.0235806","DOIUrl":"10.1063/5.0235806","url":null,"abstract":"<p><p>The ultrasound-assisted transport of drugs or fluorophore-loaded nanoagents plays an important role in the desirable drug delivery and imaging contrasts. Unlike conventional ultrasound techniques that rely on thermal or cavitation effects, this study aims to conduct an experimental investigation into the dynamics of interstitial fluid streaming and tissue recovery in <i>ex vivo</i> chicken breast and porcine loin muscle tissues during and after ultrasound exposures, which has not been experimentally investigated in the literature. Biological tissues consist of both a fluid and a solid matrix, and an ultrasound beam compresses the tissues within a small focal volume from all directions, which generates macroscopic streaming of interstitial fluid and compression of the tissue's solid matrix. After the ultrasonic exposure, the solid matrix undergoes recovery, leading to a backflow of the fluid matrix. Temperature-insensitive sulforhodamine-101 encapsulated poly(lactic-co-glycolic acid) nanoparticles with an average diameter size of 175 nm were locally injected into <i>ex vivo</i> chicken breast and porcine loin muscle tissues to study the ultrasound-induced dynamics in the tissues during and after ultrasound exposure by analyzing the distribution of fluorescence. The changes in fluorescence over time caused by the streaming and backflow of interstitial fluid were studied with two <i>ex vivo</i> tissue models, and a faster recovery was observed in porcine tissues compared with chicken tissues. The ultrasound-induced transportability of the nanoagent in porcine muscle tissues was much higher (∼8.75 times) than in chicken breast tissue likely due to structural differences. The study reveals a promising, non-invasive strategy for enhancing drug delivery in dense tissues by leveraging mechanical ultrasound effects, potentially advancing therapeutic and diagnostic applications.</p>","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"137 13","pages":"135103"},"PeriodicalIF":2.7,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11964473/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143779927","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}
A large class of experiments consists of measuring the parameters of physical models. In these experiments, the goal is to learn about these parameters as accurately and, often, quickly as possible. Adaptive experiment design works by yielding instrument control to Bayesian-based algorithms that alter instrument settings based on potential information gain about the parameters. By actively learning from data in real-time where to measure instead of determining instrument settings a priori, striking improvements in experiment efficiency are possible. Here, two new algorithms that improve upon previous implementations of adaptive experiment design are introduced. The first algorithm focuses on learning the model parameters that matter the most. The second algorithm considers the expense of a measurement and prioritizes information that can be gained at a lower cost. We demonstrate the remarkable improvement in efficiency and sensitivity that these algorithms provide for quantum sensing, specifically magnetometry, with nitrogen-vacancy centers in diamond. Most notably, we find an almost five-fold improvement in magnetic field sensitivity.
{"title":"Weighing unequal parameter importance and measurement expense in adaptive quantum sensing.","authors":"M Kelley, R D McMichael","doi":"10.1063/5.0251881","DOIUrl":"10.1063/5.0251881","url":null,"abstract":"<p><p>A large class of experiments consists of measuring the parameters of physical models. In these experiments, the goal is to learn about these parameters as accurately and, often, quickly as possible. Adaptive experiment design works by yielding instrument control to Bayesian-based algorithms that alter instrument settings based on potential information gain about the parameters. By actively learning from data in real-time where to measure instead of determining instrument settings <i>a priori</i>, striking improvements in experiment efficiency are possible. Here, two new algorithms that improve upon previous implementations of adaptive experiment design are introduced. The first algorithm focuses on learning the model parameters that matter the most. The second algorithm considers the expense of a measurement and prioritizes information that can be gained at a lower cost. We demonstrate the remarkable improvement in efficiency and sensitivity that these algorithms provide for quantum sensing, specifically magnetometry, with nitrogen-vacancy centers in diamond. Most notably, we find an almost five-fold improvement in magnetic field sensitivity.</p>","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"137 7","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11984354/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144017991","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}
Pub Date : 2024-11-01Epub Date: 2022-04-12DOI: 10.1080/08869634.2022.2062137
James Dunning, Raymond Butts, Paul Bliton, Konstantinos Vathrakokoilis, Grant Smith, Chelsea Lineberger, Noah Eshleman, César Fernández-de-Las-Peñas, Ian A Young
Objective: To compare the effects of dry needling and upper cervical spinal manipulation with interocclusal splint therapy, diclofenac, and temporomandibular joint (TMJ) mobilization in patients with temporomandibular disorder (TMD).
Methods: One hundred-twenty patients with TMD were randomized to receive six treatment sessions of dry needling plus upper cervical spinal manipulation (n = 62) or interocclusal splint therapy, diclofenac, and joint mobilization to the TMJ (n = 58).
Results: Patients receiving dry needling and upper cervical spinal manipulation experienced significantly greater reductions in jaw pain intensity over the last 7 days (VAS: F = 23.696; p < 0.001) and active pain-free mouth opening (F = 29.902; p < 0.001) than those receiving interocclusal splint therapy, diclofenac, and TMJ mobilization at the 3-month follow-up.
Conclusion: Dry needling and upper cervical spinal manipulation was more effective than interocclusal splint therapy, diclofenac, and TMJ mobilization in patients with TMD.
目的比较干针疗法和上颈椎手法治疗与夹板疗法、双氯芬酸和颞下颌关节（TMJ）活动疗法对颞下颌关节紊乱症（TMD）患者的治疗效果：120名颞下颌关节紊乱症（TMD）患者被随机分配到接受干针疗法加上颈椎手法治疗（62人）或夹板疗法、双氯芬酸和颞下颌关节活动术（58人）的六个治疗疗程：结果：接受干针疗法和上颈椎手法治疗的患者在过去 7 天内的下颌疼痛强度明显减轻（VAS：F = 23.696；p p 结论：干针疗法和上颈椎手法治疗可显著减轻患者的下颌疼痛强度：对 TMD 患者而言，干针疗法和上颈椎手法比夹板疗法、双氯芬酸和颞下颌关节活动疗法更有效。
{"title":"Dry needling and upper cervical spinal manipulation in patients with temporomandibular disorder: A multi-center randomized clinical trial.","authors":"James Dunning, Raymond Butts, Paul Bliton, Konstantinos Vathrakokoilis, Grant Smith, Chelsea Lineberger, Noah Eshleman, César Fernández-de-Las-Peñas, Ian A Young","doi":"10.1080/08869634.2022.2062137","DOIUrl":"10.1080/08869634.2022.2062137","url":null,"abstract":"<p><strong>Objective: </strong>To compare the effects of dry needling and upper cervical spinal manipulation with interocclusal splint therapy, diclofenac, and temporomandibular joint (TMJ) mobilization in patients with temporomandibular disorder (TMD).</p><p><strong>Methods: </strong>One hundred-twenty patients with TMD were randomized to receive six treatment sessions of dry needling plus upper cervical spinal manipulation (n = 62) or interocclusal splint therapy, diclofenac, and joint mobilization to the TMJ (n = 58).</p><p><strong>Results: </strong>Patients receiving dry needling and upper cervical spinal manipulation experienced significantly greater reductions in jaw pain intensity over the last 7 days (VAS: F = 23.696; <i>p</i> < 0.001) and active pain-free mouth opening (F = 29.902; <i>p</i> < 0.001) than those receiving interocclusal splint therapy, diclofenac, and TMJ mobilization at the 3-month follow-up.</p><p><strong>Conclusion: </strong>Dry needling and upper cervical spinal manipulation was more effective than interocclusal splint therapy, diclofenac, and TMJ mobilization in patients with TMD.</p>","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"42 1","pages":"809-822"},"PeriodicalIF":2.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80593953","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}
This work proposed a fast inverse design method for microwave and infrared (IR) bi-stealth metamaterials based on the equivalent circuit model (ECM). Using this method, we designed a microwave and IR bi-stealth metamaterial by deploying a multilayered structure of the indium tin oxide (ITO) film based metasurface. First, the IR emissivity of the ITO film was calculated in the framework of the ECM. Then, an ITO metasurface was proposed to implement low IR emission and high microwave transmission simultaneously. Based on the ECM of the square patch, the ECM of the whole metamaterial was established at the microwave band. An inverse design program was built by incorporating the ECM with genetic algorithm (GA). Structure parameters of the metamaterial were optimized by GA to achieve the broadest microwave stealth bandwidth for the given thickness. Finally, the sample of the optimized bi-stealth metamaterial was prepared and tested. The calculated, simulated, and measured results are in good agreement, showing that such a metamaterial has an IR emissivity of 0.18 in the band from 3 to 14 μm and an efficient microwave stealth band from 4.8 to 17 GHz with a thickness of 4.9 mm. The proposed method will benefit the design and application of microwave and IR bi-stealth metamaterials.
{"title":"Fast inverse design of microwave and infrared Bi-stealth metamaterials based on equivalent circuit model","authors":"Shiju Liu, Fengjie Zhu, Jianguang Huang, Hua Zhao, Mengqi Han, Kebin Fan, Ping Chen","doi":"10.1063/5.0222949","DOIUrl":"https://doi.org/10.1063/5.0222949","url":null,"abstract":"This work proposed a fast inverse design method for microwave and infrared (IR) bi-stealth metamaterials based on the equivalent circuit model (ECM). Using this method, we designed a microwave and IR bi-stealth metamaterial by deploying a multilayered structure of the indium tin oxide (ITO) film based metasurface. First, the IR emissivity of the ITO film was calculated in the framework of the ECM. Then, an ITO metasurface was proposed to implement low IR emission and high microwave transmission simultaneously. Based on the ECM of the square patch, the ECM of the whole metamaterial was established at the microwave band. An inverse design program was built by incorporating the ECM with genetic algorithm (GA). Structure parameters of the metamaterial were optimized by GA to achieve the broadest microwave stealth bandwidth for the given thickness. Finally, the sample of the optimized bi-stealth metamaterial was prepared and tested. The calculated, simulated, and measured results are in good agreement, showing that such a metamaterial has an IR emissivity of 0.18 in the band from 3 to 14 μm and an efficient microwave stealth band from 4.8 to 17 GHz with a thickness of 4.9 mm. The proposed method will benefit the design and application of microwave and IR bi-stealth metamaterials.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"99 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260238","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}
K. K. Pandey, Valery I. Levitas, Changyong Park, Guoyin Shen
The detailed study of the effect of the initial microstructure on its evolution under hydrostatic compression before, during, and after the irreversible α→ω phase transformation and during pressure release in Zr using in situ x-ray diffraction is presented. Two samples were studied: one is plastically pre-deformed Zr with saturated hardness and the other is annealed. Phase transformation α→ω initiates at lower pressure for a pre-deformed sample but for a volume fraction of ω Zr, c>0.7, a larger volume fraction is observed for the annealed sample. This implies that the proportionality between the athermal resistance to the transformation and the yield strength in the continuum phase transformation theory is invalid; an advanced version of the theory is outlined. Phenomenological plasticity theory under hydrostatic loading is outlined in terms of microstructural parameters, and plastic strain is estimated. During transformation, the first rule is suggested, i.e., the average domain size, microstrain, and dislocation density in ω Zr for c<0.8 are functions of the volume fraction, c of ω Zr only, which are independent of the plastic strain tensor prior to transformation and pressure. The microstructure is not inherited during phase transformation. Surprisingly, for the annealed sample, the final dislocation density and the average microstrain after pressure release in the ω phase are larger than for the severely pre-deformed sample. The results suggest that an extended experimental basis is required for the predictive models for the combined pressure-induced phase transformations and microstructure evolutions.
{"title":"In situ study of microstructure evolution and α → ω phase transition in annealed and pre-deformed Zr under hydrostatic loading","authors":"K. K. Pandey, Valery I. Levitas, Changyong Park, Guoyin Shen","doi":"10.1063/5.0208544","DOIUrl":"https://doi.org/10.1063/5.0208544","url":null,"abstract":"The detailed study of the effect of the initial microstructure on its evolution under hydrostatic compression before, during, and after the irreversible α→ω phase transformation and during pressure release in Zr using in situ x-ray diffraction is presented. Two samples were studied: one is plastically pre-deformed Zr with saturated hardness and the other is annealed. Phase transformation α→ω initiates at lower pressure for a pre-deformed sample but for a volume fraction of ω Zr, c&gt;0.7, a larger volume fraction is observed for the annealed sample. This implies that the proportionality between the athermal resistance to the transformation and the yield strength in the continuum phase transformation theory is invalid; an advanced version of the theory is outlined. Phenomenological plasticity theory under hydrostatic loading is outlined in terms of microstructural parameters, and plastic strain is estimated. During transformation, the first rule is suggested, i.e., the average domain size, microstrain, and dislocation density in ω Zr for c&lt;0.8 are functions of the volume fraction, c of ω Zr only, which are independent of the plastic strain tensor prior to transformation and pressure. The microstructure is not inherited during phase transformation. Surprisingly, for the annealed sample, the final dislocation density and the average microstrain after pressure release in the ω phase are larger than for the severely pre-deformed sample. The results suggest that an extended experimental basis is required for the predictive models for the combined pressure-induced phase transformations and microstructure evolutions.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"22 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260244","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}
Solar-driven semiconductor photocatalysts are highly appealing in applications of environmental remediation and energy conversion. However, photocatalytic reactions, particularly oxygen evolution reaction (OER), are often constrained by the swift recombination of electron–hole pairs, thereby resulting in low reaction efficiency. Although it is effective to separate charge carriers by constructing heterojunctions to form built-in electric field, the lattice mismatch and inefficient interlayer charge transfer of heterojunctions in the photocatalysts limit their further development. Here, we propose a new strategy by constructing an internal electric field for OER through an individual piezoelectric two-dimensional material. The results indicate that the piezoelectric effect regulates the electronic structure, reduces bandgap, improves light absorption efficiency, and that the displacement of positive and negative charge centers is the key factor in the enhanced OER. This research indicates the feasibility of combining piezoelectric properties of two-dimensional materials with OER (1.19 eV), providing new insights and guidance for applying the piezoelectric effect in the OER and opening up a way to promote efficient separation of charge carriers.
太阳能驱动的半导体光催化剂在环境修复和能源转换应用中极具吸引力。然而，光催化反应，尤其是氧进化反应（OER），往往受到电子-空穴对迅速重组的限制，从而导致反应效率低下。虽然通过构建异质结形成内置电场来分离电荷载流子是有效的，但光催化剂中异质结的晶格失配和低效的层间电荷转移限制了其进一步发展。在此，我们提出了一种新策略，即通过单独的压电二维材料构建内部电场来实现 OER。研究结果表明，压电效应可以调节电子结构、减小带隙、提高光吸收率，而正负电荷中心的位移是增强 OER 的关键因素。该研究表明，将二维材料的压电特性与 OER（1.19 eV）相结合是可行的，为在 OER 中应用压电效应提供了新的见解和指导，并开辟了一条促进电荷载流子高效分离的途径。
{"title":"Piezo-photocatalysis synergy in γ-GeSe for highly efficient oxygen evolution reaction","authors":"Tianqi Zhang, Long Zhou, Guobo Chen, Songrui Wei, Rong Sun, Yunping Li, Lijian Meng, Guanglong Zhang, Shuwei Xia, Zhongchang Wang, Meng Qiu","doi":"10.1063/5.0217893","DOIUrl":"https://doi.org/10.1063/5.0217893","url":null,"abstract":"Solar-driven semiconductor photocatalysts are highly appealing in applications of environmental remediation and energy conversion. However, photocatalytic reactions, particularly oxygen evolution reaction (OER), are often constrained by the swift recombination of electron–hole pairs, thereby resulting in low reaction efficiency. Although it is effective to separate charge carriers by constructing heterojunctions to form built-in electric field, the lattice mismatch and inefficient interlayer charge transfer of heterojunctions in the photocatalysts limit their further development. Here, we propose a new strategy by constructing an internal electric field for OER through an individual piezoelectric two-dimensional material. The results indicate that the piezoelectric effect regulates the electronic structure, reduces bandgap, improves light absorption efficiency, and that the displacement of positive and negative charge centers is the key factor in the enhanced OER. This research indicates the feasibility of combining piezoelectric properties of two-dimensional materials with OER (1.19 eV), providing new insights and guidance for applying the piezoelectric effect in the OER and opening up a way to promote efficient separation of charge carriers.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"25 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260246","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}
Magnetic force microscopy (MFM) is long established as a powerful tool for probing the local stray fields of magnetic nanostructures across a range of temperatures and applied stimuli. A major drawback of the technique, however, is that the detection of stray fields emanating from a sample’s surface rely on a uniaxial vertical cantilever oscillation, and thus are only sensitive to vertically oriented stray field components. The last two decades have shown an ever-increasing literature fascination for exotic topological windings where particular attention to in-plane magnetic moment rotation is highly valuable when identifying and understanding such systems. Here, we present a method of detecting in-plane magnetic stray field components, by utilizing a split-electrode excitation piezo that allows the simultaneous excitation of a cantilever at its fundamental flexural and torsional modes. This allows for the joint acquisition of traditional vertical mode images and a lateral MFM where the tip–cantilever system is only sensitive to stray fields acting perpendicular to the torsional axis of the cantilever.
{"title":"Toward 3D magnetic force microscopy: Simultaneous torsional cantilever excitation to access a second, orthogonal stray field component","authors":"Jori F. Schmidt, Lukas M. Eng, Samuel D. Seddon","doi":"10.1063/5.0226570","DOIUrl":"https://doi.org/10.1063/5.0226570","url":null,"abstract":"Magnetic force microscopy (MFM) is long established as a powerful tool for probing the local stray fields of magnetic nanostructures across a range of temperatures and applied stimuli. A major drawback of the technique, however, is that the detection of stray fields emanating from a sample’s surface rely on a uniaxial vertical cantilever oscillation, and thus are only sensitive to vertically oriented stray field components. The last two decades have shown an ever-increasing literature fascination for exotic topological windings where particular attention to in-plane magnetic moment rotation is highly valuable when identifying and understanding such systems. Here, we present a method of detecting in-plane magnetic stray field components, by utilizing a split-electrode excitation piezo that allows the simultaneous excitation of a cantilever at its fundamental flexural and torsional modes. This allows for the joint acquisition of traditional vertical mode images and a lateral MFM where the tip–cantilever system is only sensitive to stray fields acting perpendicular to the torsional axis of the cantilever.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"17 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260248","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}
Although the global market for wind energy is growing rapidly, leading-edge erosion is a critical issue hindering the development of wind power. The impact force of a droplet colliding with flat surfaces has been investigated in previous studies. However, the impact force exerted on curved surfaces, such as that experienced by eroded wind turbine blades, is not well understood. This study discusses the relationship between the impact force generated on a solid surface by a water droplet and the radius of curvature of the impacting surface. The impact force by a droplet was measured using a force sensor mounted on semi-cylindrical caps with different radii of curvature. The measurement results showed that the impact force decreased as the radius of curvature decreased. A computational fluid dynamics model solving incompressible flows showed that, unlike the case of a curved surface, the initial momentum of the droplet was mostly transferred to the flat surface. This resulted in a high impulse for an impact with a flat surface. The falling droplet was blocked by the surface, and the lateral jet was accelerated sideward. This acceleration was moderate for curved surfaces. When colliding with a flat surface, a higher impact force was generated owing to the wider area of the excited surface pressure compared with that of the curved surface. Finally, the relationship between the peak of the impact force and the surface curvature was derived, suggesting that the force peak is inversely proportional to the curvature.
{"title":"Influence of surface curvature on the impact force of water droplet","authors":"A. Aihara, M. Tanaka, N. Fujisawa","doi":"10.1063/5.0219757","DOIUrl":"https://doi.org/10.1063/5.0219757","url":null,"abstract":"Although the global market for wind energy is growing rapidly, leading-edge erosion is a critical issue hindering the development of wind power. The impact force of a droplet colliding with flat surfaces has been investigated in previous studies. However, the impact force exerted on curved surfaces, such as that experienced by eroded wind turbine blades, is not well understood. This study discusses the relationship between the impact force generated on a solid surface by a water droplet and the radius of curvature of the impacting surface. The impact force by a droplet was measured using a force sensor mounted on semi-cylindrical caps with different radii of curvature. The measurement results showed that the impact force decreased as the radius of curvature decreased. A computational fluid dynamics model solving incompressible flows showed that, unlike the case of a curved surface, the initial momentum of the droplet was mostly transferred to the flat surface. This resulted in a high impulse for an impact with a flat surface. The falling droplet was blocked by the surface, and the lateral jet was accelerated sideward. This acceleration was moderate for curved surfaces. When colliding with a flat surface, a higher impact force was generated owing to the wider area of the excited surface pressure compared with that of the curved surface. Finally, the relationship between the peak of the impact force and the surface curvature was derived, suggesting that the force peak is inversely proportional to the curvature.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"3 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260278","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}
C. Le Bras, E. Lescoute, J-M. Chevalier, G. Boutoux, D. Hébert
Laser pulses were applied to a target mounted on a ballistic pendulum to study the momentum imparted by a laser shock impact. Photonic Doppler Velocimetry was used to assess the momentum imparted by each laser pulse. To increase the momentum produced, a layer of polymer transparent to the laser wavelength was applied to the surface of the targets to confine the plasma generated as a result of the laser–matter interaction. This yielded momentum coupling coefficients one hundred times higher than those obtained for equivalent laser parameters in the classical direct regime configuration. The study was completed by simulating the experiments with the one-dimensional Lagrangian hydrodynamics code ESTHER, which showed good agreement with the experimental results.
{"title":"Impulse coupling enhancement of aluminum targets under laser irradiation in a soft polymer confined geometry","authors":"C. Le Bras, E. Lescoute, J-M. Chevalier, G. Boutoux, D. Hébert","doi":"10.1063/5.0225973","DOIUrl":"https://doi.org/10.1063/5.0225973","url":null,"abstract":"Laser pulses were applied to a target mounted on a ballistic pendulum to study the momentum imparted by a laser shock impact. Photonic Doppler Velocimetry was used to assess the momentum imparted by each laser pulse. To increase the momentum produced, a layer of polymer transparent to the laser wavelength was applied to the surface of the targets to confine the plasma generated as a result of the laser–matter interaction. This yielded momentum coupling coefficients one hundred times higher than those obtained for equivalent laser parameters in the classical direct regime configuration. The study was completed by simulating the experiments with the one-dimensional Lagrangian hydrodynamics code ESTHER, which showed good agreement with the experimental results.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"261 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260240","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}
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