Micro & Nano Letters最新文献_第9页

Nanometals and Metal Ion Pollution from Dental Materials in Dental Environment 口腔环境中口腔材料中的纳米金属和金属离子污染

IF 1.3 4区材料科学 Q4 MATERIALS SCIENCE, MULTIDISCIPLINARY

Micro & Nano Letters

Pub Date : 2023-04-17 DOI: 10.3390/micro3020031

A. C. B. Fernandes, R. França

The dental environment is being polluted with metals from dental materials in many ways, mainly due to aerosol-generating procedures; this could affect the long-term well-being of dentists, dental students, and dental personnel. The current dental pollution incorporates metallic nanoparticles, which are highly reactive and quickly become airborne, especially those particles that become unbound in the bulk composition. In addition, liquid mercury or mercury vapors may be released from dental amalgam, causing concerns in the dental community. In our study, we reviewed the behavior of metallic elements present in dental materials, their routes of exposure, and their potentially toxic effects on the dental team. This review found that skin and lung disorders are the most harmful effects of metallic exposure for dentists, dental students, and dental personnel. Therefore, chronic exposure to low concentrations of metals in the dental environment, especially in nanosized forms, should be further investigated to improve the environmental matrix, material choice, and safety protocols.

牙科环境正以多种方式受到来自牙科材料的金属污染，主要是由于产生气溶胶的程序;这可能会影响牙医、牙科学生和牙科人员的长期健康。目前的牙齿污染包括金属纳米颗粒，它们具有高度的反应性，并且很快就会在空气中传播，特别是那些在大块成分中未结合的颗粒。此外，牙科汞合金可能会释放液态汞或汞蒸气，引起牙科界的关注。在我们的研究中，我们回顾了存在于牙科材料中的金属元素的行为，它们的暴露途径，以及它们对牙科团队的潜在毒性作用。这篇综述发现，对于牙医、牙科学生和牙科人员来说，皮肤和肺部疾病是金属接触最有害的影响。因此，长期暴露于牙齿环境中的低浓度金属，特别是纳米形式的金属，应该进一步研究，以改善环境基质、材料选择和安全方案。

引用次数: 0

Properties of Mechanochemically Synthesized Famatinite Cu3SbS4 Nanocrystals 机械化学合成法马褐铁矿Cu3SbS4纳米晶的性质

IF 1.3 4区材料科学 Q4 MATERIALS SCIENCE, MULTIDISCIPLINARY

Micro & Nano Letters

Pub Date : 2023-04-13 DOI: 10.3390/micro3020030

E. Dutková, J. Kováč, J. Kováč, J. Hejtmánek, P. Levinský, A. Kashimbetova, M. Sayagués, M. Fabián, Z. Lukáčová Bujňáková, M. Baláž, Katarína Gáborová, V. Puchý, L. Čelko

In this study, we report the optoelectric and thermoelectric properties of famatinite Cu3SbS4 that was mechanochemically synthesized in a planetary mill from powder elements for 120 min in an inert atmosphere. The tetragonal famatinite Cu3SbS4 was nanocrystalline with a crystallite size of 14 nm, as endorsed by Rietveld refinement. High-resolution transmission electron microscopy showed several crystallites in the range of 20–50 nm. Raman spectroscopy proved the purity of the synthesized famatinite Cu3SbS4 and chemical-state characterization performed by X-ray photoelectron spectroscopy confirmed that the prepared sample was pure. The Cu1+, Sb5+, and S2− oxidation states in Cu3SbS4 sample were approved. The morphology characterization showed homogeneity of the prepared sample. The photoresponse of Cu3SbS4 was confirmed from I–V measurements in the dark and under illumination. The photocurrent increase reached 20% compared to the current in the dark at a voltage of 5 V. The achieved results confirm that synthesized famatinite Cu3SbS4 can be applied as a suitable absorbent material in solar cells. The performed thermoelectric measurements revealed a figure of merit ZT of 0.05 at 600 K.

在本研究中，我们报道了由粉末元素在惰性气氛中机械化学合成120 min的褐铁矿Cu3SbS4的光电和热电性质。方形黄铁矿Cu3SbS4为纳米晶，晶粒尺寸为14 nm，经Rietveld细化。高分辨率透射电子显微镜显示在20-50 nm范围内有几个晶体。拉曼光谱证实了所合成的黄铁矿Cu3SbS4的纯度，x射线光电子能谱的化学态表征证实了所制备样品的纯度。Cu3SbS4样品的Cu1+、Sb5+和S2−氧化态得到了证实。形貌表征表明制备的样品具有均匀性。Cu3SbS4在黑暗和光照条件下的光响应通过I-V测量得到了证实。在5v电压下，光电流比黑暗中的电流增加了20%。结果表明，合成的黄褐铁矿Cu3SbS4可以作为一种合适的吸收材料应用于太阳能电池中。所进行的热电测量显示，在600 K时，性能值ZT为0.05。

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引用次数: 0

Designing Viscoelastic Gelatin-PEG Macroporous Hybrid Hydrogel with Anisotropic Morphology and Mechanical Properties for Tissue Engineering Application 设计具有各向异性形态和力学性能的粘弹性明胶-聚乙二醇大孔杂化水凝胶用于组织工程

IF 1.3 4区材料科学 Q4 MATERIALS SCIENCE, MULTIDISCIPLINARY

Micro & Nano Letters

Pub Date : 2023-04-11 DOI: 10.3390/micro3020029

K. Dey, S. Agnelli, L. Sartore

The mechanical properties of scaffolds play a vital role in regulating key cellular processes in tissue development and regeneration in the field of tissue engineering. Recently, scaffolding material design strategies leverage viscoelasticity to guide stem cells toward specific tissue regeneration. Herein, we designed and developed a viscoelastic Gel-PEG hybrid hydrogel with anisotropic morphology and mechanical properties using a gelatin and functionalized PEG (as a crosslinker) under a benign condition for tissue engineering application. The chemical crosslinking/grafting reaction was mainly involved between epoxide groups of PEG and available functional groups of gelatin. FTIR spectra revealed the hybrid nature of Gel-PEG hydrogel. The hybrid hydrogel showed good swelling behavior (water content > 600%), high porosity and pore interconnectivity suitable for tissue engineering application. Simple unidirectional freezing followed by a freeze-drying technique allowed the creation of structurally stable 3D anisotropic macroporous architecture that showed tissue-like elasticity and was capable of withstanding high deformation (50% strain) without being damaged. The tensile and compressive modulus of Gel-PEG hybrid hydrogel were found to be 0.863 MPa and 0.330 MPa, respectively, which are within the range of normal human articular cartilage. In-depth mechanical characterizations showed that the Gel-PEG hybrid hydrogel possessed natural-tissue-like mechanics such as non-linear and J-shaped stress-strain curves, stress softening effect, high fatigue resistance and stress relaxation response. A month-long hydrolytic degradation test revealed that the hydrogel gradually degraded in a homogeneous manner over time but maintained its structural stability and anisotropic mechanics. Overall, all these interesting features provide a potential opportunity for Gel-PEG hybrid hydrogel as a scaffold in a wide range of tissue engineering applications.

在组织工程领域，支架的力学性能对组织发育和再生的关键细胞过程的调控起着至关重要的作用。最近，支架材料设计策略利用粘弹性来引导干细胞向特定组织再生。在此，我们设计并开发了一种具有各向异性形态和力学性能的粘弹性凝胶-PEG杂化水凝胶，该水凝胶以明胶和功能化PEG(作为交联剂)为原料，在良好的条件下用于组织工程应用。化学交联/接枝反应主要发生在聚乙二醇的环氧基团与明胶的有效官能团之间。FTIR光谱揭示了Gel-PEG水凝胶的杂化性质。混合水凝胶具有良好的溶胀性(含水量> 600%)、较高的孔隙度和孔隙连通性，适合于组织工程应用。简单的单向冷冻，然后是冷冻干燥技术，可以创造出结构稳定的3D各向异性大孔结构，显示出类似组织的弹性，能够承受高变形(50%的应变)而不被破坏。凝胶- peg混合水凝胶的拉伸模量和压缩模量分别为0.863 MPa和0.330 MPa，在正常人体关节软骨的范围内。深入的力学表征表明，凝胶- peg杂化水凝胶具有自然组织样的力学特性，具有非线性的j型应力-应变曲线，具有应力软化效果，具有较高的抗疲劳性能和应力松弛响应。为期一个月的水解降解试验表明，随着时间的推移，水凝胶逐渐以均匀的方式降解，但保持其结构稳定性和各向异性力学。总的来说，所有这些有趣的特性为Gel-PEG混合水凝胶作为支架在广泛的组织工程应用中提供了潜在的机会。

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引用次数: 2

Digitally Based Precision Time-Domain Spectrometer for NMR Relaxation and NMR Cryoporometry 用于核磁共振弛豫和核磁共振冻孔测定的数字精密时域光谱仪

IF 1.3 4区材料科学 Q4 MATERIALS SCIENCE, MULTIDISCIPLINARY

Micro & Nano Letters

Pub Date : 2023-04-03 DOI: 10.3390/micro3020028

J. Webber, Pavel Demin

NMR Relaxation (NMRR) is an extremely useful quantitative technique for material science, particularly for studying polymers and porous materials. NMR Cryoporometry (NMRC) is a powerful technique for the measurement of pore-size distributions and total porosities. This paper discusses the use, capabilities and application of a newly developed compact NMR time-domain relaxation spectrometer suitable for studying both solid and liquid samples (Mk3 NMR Relaxation spectrometer & Cryoporometer, Lab-Tools (nano-science), Ramsgate, Kent, UK. (2019)). This highly compact precision NMR Spectrometer is based on a Field Programmable Gate array (FPGA) module and custom surface mount low-noise NMR receiver and NMR linear transmitter. A high proportion of the RF circuitry is in a digital form, implemented as firmware in the FPGA, which gives the instrument an excellent long-term stability. It also includes an on-chip Linux computer. The FPGA module is credit-card sized, and both the NMR receiver and NMR transmitter are even smaller. The software, including the top-level NMR pulse sequence definitions, are written in an array processing language, Apl. The spectrometer comes complete with a Graphical User Interface (GUI) for control and on- and offline curve fitting and data analysis. The recent development of the Lab-Tools Peltier thermo-electrically cooled NMR variable-temperature (V-T) probe that cools the sample below −60 °C is also discussed. This Peltier cooling gives the precision temperature control and smoothness needed by NMR Cryoporometry (10 mK near the probe liquid bulk melting point). This enables the NMRC measurement of pore-size distributions in porous materials, for the unusually wide pore-size range of sub-nano to over 1 micron-sized pores. The NMR Spectrometer’s unusually small size, ability to measure solids, low noise and high performance make it particularly suitable for material science studies both in the field and in university, research institute, company and even school laboratories. A human portable version now exists. Use of the controlling GUI is described, and results from example NMR Relaxation and NMR Cryoporometric measurements are given.

核磁共振弛豫(NMRR)是材料科学中非常有用的定量技术，特别是用于研究聚合物和多孔材料。核磁共振冻孔法(NMRC)是一种测量孔隙大小分布和总孔隙率的强大技术。本文讨论了一种新开发的适用于研究固体和液体样品的紧凑型核磁共振时域弛豫光谱仪(Mk3核磁共振弛豫光谱仪&冷冻孔计，Lab-Tools(纳米科学)，拉姆斯盖特，肯特，英国)的用途，功能和应用。(2019))。这款高度紧凑的精密核磁共振光谱仪基于现场可编程门阵列(FPGA)模块和定制的表面安装低噪声核磁共振接收器和核磁共振线性发射器。高比例的射频电路是数字形式的，在FPGA中作为固件实现，这使仪器具有出色的长期稳定性。它还包括一个片上Linux计算机。FPGA模块只有信用卡大小，核磁共振接收器和核磁共振发射器甚至更小。该软件，包括顶级核磁共振脉冲序列定义，是用数组处理语言编写的。该光谱仪配有完整的图形用户界面(GUI)，用于控制和在线和离线曲线拟合和数据分析。还讨论了Lab-Tools Peltier热电冷却核磁共振变温(V-T)探针的最新发展，该探针可将样品冷却至- 60°C以下。这种珀尔帖冷却提供了核磁共振冻孔法所需的精确温度控制和平滑度(探针液体体熔点附近10 mK)。这使得NMRC能够测量多孔材料中的孔径分布，用于亚纳米到超过1微米孔径的异常宽的孔径范围。核磁共振光谱仪异常小的尺寸，测量固体的能力，低噪音和高性能使其特别适用于现场和大学，研究所，公司甚至学校实验室的材料科学研究。现在有了人体便携版。描述了控制图形用户界面的使用，并给出了核磁共振弛豫和核磁共振低温测量的实例结果。

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引用次数: 0

Effect of Functionalized CdSSe Quantum Dots in the CYP450 Activity of HEPG2 Cells 功能化CdSSe量子点对HEPG2细胞CYP450活性的影响

IF 1.3 4区材料科学 Q4 MATERIALS SCIENCE, MULTIDISCIPLINARY

Micro & Nano Letters

Pub Date : 2023-04-03 DOI: 10.3390/micro3020027

L. Alamo-Nole, Jury Cruz-Hernandez

Quantum dots (QDs) have different properties: high electron density, magnetic moment, phosphorescence, photoluminescence (fluorescence), and strong optical absorption. The layer or ligands on the QDs surface has a vital role because they allow the stabilization and practical uses on different matrixes. Ligand exchange is a commonly carried out methodology to incorporate functional groups that alter the solubility, introduce electron transfer partners, integrate biological receptors, or improve the properties of the QDs surface. CdSSe QDs were synthesized using a microwave system using thioglycolic acid (TGA) as a sulfur source and cover agent. The TGA ligand was interchanged with cysteine (Cys), glutamic acid (GA), glutathione (GTO), glutaraldehyde (GLT), and lysine (Lys). The viability and response of the CYP1A1, CYP1A2, and CYP3A4 isoenzymes were directly measured in HEP-G2 cells after exposure to CdSSe-TGA, CdSSe-Cys, CdSSe-GA, CdSSe-GTO, CdSSe-GLT, and CdSSe-Lys. CdSSe and CdSSe-GTO (10 mg/L) decrease viability by around 65%. The response of the cytochrome isoenzymes is based on the organic ligand on the surface of the CdSSe QDs. Changes in CYP 1A1 could be related to carcinogenic xenobiotics. Fluorescence microscopy shows CdSSe QDs on and inside HEPG2 cells. The results confirm that apoptosis and necrosis are the principal mechanisms of decreased viability.

量子点(QDs)具有不同的性质:高电子密度、磁矩、磷光、光致发光(荧光)和强光吸收。量子点表面的层或配体具有至关重要的作用，因为它们允许在不同的基质上稳定和实际应用。配体交换是一种常用的方法，用于结合改变溶解度的官能团，引入电子转移伙伴，整合生物受体或改善量子点表面的性质。以巯基乙酸(TGA)为硫源和覆盖剂，采用微波系统合成了CdSSe量子点。TGA配体与半胱氨酸(Cys)、谷氨酸(GA)、谷胱甘肽(GTO)、戊二醛(GLT)和赖氨酸(Lys)交换。在暴露于cdse - tga、cdse - cys、cdse - ga、cdse - gto、cdse - glt和cdse - lys后，直接测定HEP-G2细胞中CYP1A1、CYP1A2和CYP3A4同工酶的活性和应答。CdSSe和CdSSe- gto (10 mg/L)使活性降低约65%。细胞色素同工酶的反应是基于CdSSe量子点表面的有机配体。CYP 1A1的变化可能与致癌性外源药物有关。荧光显微镜显示HEPG2细胞上和细胞内的CdSSe量子点。结果证实细胞凋亡和坏死是细胞活力下降的主要机制。

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引用次数: 0

Evaluation of the biological activity of nanoemulsions fabricated by walnut oil (Juglans regia L.) 核桃油制备纳米乳液的生物活性评价

IF 1.3 4区材料科学 Q4 MATERIALS SCIENCE, MULTIDISCIPLINARY

Micro & Nano Letters

Pub Date : 2023-03-31 DOI: 10.1049/mna2.12161

Somayeh Khezri, Sara Karimian, Ehsan Yousefi, Ali Es-haghi

Herbal medicines are currently attracting much attention as a potential cancer treatment. Juglans regia’s wide variety of anticancer actions have been demonstrated. The aim of this study is evaluating the cytotoxic and antioxidant effects of walnut oil (J. regia) nanoemulsion (WO-NE) on CT26 colon cancer cell line. The dimensions and structure of the nanoemulsion were studied by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The 1,1-Diphenyl-2-picrylhydrazyl (DPPH) technique was used to determine whether or not the nanoemulsions had any antioxidant properties. The cytotoxic effects of 3-[4,5-dimethylthiazol-2-yl-2-5-[diphenyltetrazolium bromide] (MTT) on CT26 colon cancer cells and umbilical vein endothelial cells (HUVEC) as normal cells were measured. The DPPH experiment demonstrated that the manufactured nanoemulsion had the ability to scavenge free radicals in a dose-dependent manner, with an IC₅₀ of approximately 500 µg/mL. The WO-NE were found to be toxic to both HUVEC and CT26 cancer cells, with an IC₅₀ of 10 ± 2.6 µg/mL for the CT26 and 160 ± 7.1 µg/mL for the HUVEC after 24 h of incubation. For comparison the effects of walnut oil also have been investigated. Due to their antioxidant and anticancer capabilities, the WO-NE synthesized here have been proposed for future study as potential anti-tumour agents.

草药作为一种潜在的癌症治疗方法，目前正备受关注。核桃具有多种抗癌作用。本研究的目的是评估胡桃油（J.regia）纳米乳液（WO-NE）对CT26结肠癌癌症细胞系的细胞毒性和抗氧化作用。通过动态光散射（DLS）和透射电子显微镜（TEM）研究了纳米乳液的尺寸和结构。使用1,1-二苯基-2-苦基肼（DPPH）技术来确定纳米乳液是否具有任何抗氧化性能。测定3-[4,5-二甲基噻唑-2-基-2-5-[溴化二苯基四氮唑]（MTT）对作为正常细胞的CT26结肠癌细胞和脐静脉内皮细胞（HUVEC）的细胞毒性作用。DPPH实验表明，所制备的纳米乳液具有以剂量依赖的方式清除自由基的能力，IC50约为500µg/mL。WO-NE被发现对HUVEC和CT26癌症细胞都有毒性，孵育24小时后，CT26和HUVEC的IC50分别为10±2.6µg/mL和160±7.1µg/mL。为了进行比较，还对核桃油的作用进行了研究。由于其抗氧化和抗癌能力，这里合成的WO-NE已被提议作为潜在的抗肿瘤剂进行未来的研究。

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引用次数: 0

Methodic Approach of Atomic-Force Microscopy (AFM) to Study Morphological Changes of Cells and Model Systems 原子力显微镜(AFM)研究细胞和模型系统形态变化的方法

IF 1.3 4区材料科学 Q4 MATERIALS SCIENCE, MULTIDISCIPLINARY

Micro & Nano Letters

Pub Date : 2023-03-28 DOI: 10.3390/micro3020026

V. Binyukov, E. Mil, L. Matienko, A. Albantova, A. Goloshchapov

For the first time AFM (atomic-force microscopy) was used to record significant changes in the geometric parameters of the image of erythrocytes in vitro under conditions of glycolytic starvation (ATP (Adenosine triphosphate) deficiency). The difference in the action of antioxidants, phenosan K, and Ihfan-10 on erythrocytes that we detected with AFM seems to be mainly due to their difference in hydrophobicity. We used the AFM method to research the self-organization of the components of the active center of P450 (Porphyrin-450) metalloenzymes that are part of a class of hemoproteins with functions of affinity to molecular oxygen O2. Stable supramolecular nanostructures in the form of triangular prisms based on the iron porphyrin complex with amino acids due to self-assembly involving intermolecular hydrogen bonds were received. A possible scheme for the formation of such structures is proposed.

首次使用原子力显微镜(AFM)记录了糖酵解饥饿(ATP (Adenosine triphosphate)缺乏)条件下红细胞体外图像几何参数的显著变化。我们用AFM检测到的抗氧化剂，phenosan K和Ihfan-10对红细胞作用的差异似乎主要是由于它们的疏水性不同。我们使用AFM方法研究了P450(卟啉-450)金属酶活性中心组分的自组织，P450金属酶是一类具有分子氧亲和功能的血红蛋白的一部分。通过分子间氢键的自组装，获得了基于铁卟啉与氨基酸配合物的稳定的三角棱柱状超分子纳米结构。提出了形成这种结构的一种可能方案。

引用次数: 1

Effects of Mode of Preparation of Titanium Dioxide Nanotube Arrays on Their Photocatalytic Properties: Application to p-Nitroaniline Degradation 二氧化钛纳米管阵列制备方式对其光催化性能的影响:在对硝基苯胺降解中的应用

IF 1.3 4区材料科学 Q4 MATERIALS SCIENCE, MULTIDISCIPLINARY

Micro & Nano Letters

Pub Date : 2023-03-22 DOI: 10.3390/micro3010025

Nisreen Alshibeh Alwattar, F. Vacandio, L. Vassalo, T. Djenizian, B. Coulomb, J. Boudenne

The aim of this study was to investigate the photoactivity of dioxide titanium (TiO2) nanotube films depending on different structure factors including pore size, tube length, tube wall thickness and crystallinity. Aqueous p-nitroaniline was used as a probe to assess the photocatalytic activity of titanium dioxide nanotube layers under UV irradiations. Self-organized titanium dioxide nanotube thin films were prepared by electrochemical anodization of titanium (Ti) foils and Ti thin films sputtered onto silicon (Si). The amorphous as-formed titanium nanotube layers were then annealed at different temperatures ranging from 450 to 900 °C in order to form crystalline phases. The structure and the morphology of the films were characterized by surface analysis techniques and scanning electron microscopy, respectively. The photocatalytic activity of the resulting TiO2 thin films was evaluated by monitoring the UV degradation of p-nitroaniline by UV spectrophotometry and by determining nitrification yields of by ion chromatography. The highest photocatalytic activity was exhibited for titanium nanotubes annealed at 450 °C. The presence of rutile -obtained for an annealing temperature of 900 °C—appeared to reduce the photodegradation yield of p-nitroaniline. Finally, the TiO2 nanotubes obtained from Ti foils revealed the most efficient photocatalytic properties.

本研究的目的是研究二氧化钛(TiO2)纳米管薄膜的光活性对不同结构因素(孔径、管长、管壁厚度和结晶度)的影响。以对硝基苯胺为探针，考察了二氧化钛纳米管层在紫外光照射下的光催化活性。采用电化学阳极氧化法制备自组织二氧化钛纳米管薄膜，并将其溅射到硅(Si)上。然后在450 ~ 900℃的不同温度下对非晶钛纳米管层进行退火，以形成结晶相。利用表面分析技术和扫描电镜对膜的结构和形貌进行了表征。通过紫外分光光度法监测对硝基苯胺的紫外降解和离子色谱法测定对硝基苯胺的硝化产率来评价制备的TiO2薄膜的光催化活性。450℃退火钛纳米管的光催化活性最高。金红石的存在-在900°c的退火温度下获得-似乎降低了对硝基苯胺的光降解收率。最后，由钛箔制备的TiO2纳米管显示出最有效的光催化性能。

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引用次数: 1

Influence of multilayer graphene doping concentrations on detection properties of MLG/Mg2Si/Si heterojunction photodetector 多层石墨烯掺杂浓度对MLG/Mg2Si/Si异质结光电探测器探测性能的影响

IF 1.3 4区材料科学 Q4 MATERIALS SCIENCE, MULTIDISCIPLINARY

Micro & Nano Letters

Pub Date : 2023-03-21 DOI: 10.1049/mna2.12160

Hong Yu, Xichen Xiong, Zhangjie Mo, Rui Deng, Li Li, Deliang Chen

This paper presents a structural model for a photodetector (PD) with a multilayer graphene (MLG)/Mg₂Si/Si heterojunction and an examination of the impacts of MLG doping concentrations on the detection abilities of these PDs. The results show that under the conditions of different thicknesses of the monolayer, five-layer, and 10-layer grapheme (Gr), the detection properties of heterojunction PDs degrade as the doping concentrations of the MLG layer increase from 10¹³ to 10¹⁷ cm⁻³, respectively. The electric field intensity at the heterojunction MLG/Mg₂Si interface diminishes as MLG doping concentrations increase. The effectiveness of photo-generated carrier separation and transfer in the space charge area at the MLG/Mg₂Si interface therefore declines. The detection properties are outstanding when the MLG doping concentration is 10¹³ cm⁻³. The maximum values of peak responsivity, external quantum efficiency (EQE), detectivity (D*), and on/off ratio are found to be 0.81 A/W, 103.28%, 6.1×10¹⁰ Jones, and 610.5, respectively. A minimum peak noise equivalent power (NEP) of 1.64×10⁻¹¹ WHz^−1/2 is obtained. The results also show that PD has a great potential as a replacement for other visible and near-infrared (NIR) poisonous devices. The facts presented above provide a theoretical framework for the fabrication and application of optoelectronic devices.

本文提出了具有多层石墨烯（MLG）/Mg2Si/Si异质结的光电探测器（PD）的结构模型，并考察了MLG掺杂浓度对这些PD探测能力的影响。结果表明，在单层、五层和十层石墨烯（Gr）厚度不同的条件下，异质结PD的检测性能分别随着MLG层的掺杂浓度从1013 cm−3增加到1017 cm−3而降低。异质结MLG/Mg2Si界面处的电场强度随着MLG掺杂浓度的增加而减小。因此，在MLG/Mg2Si界面的空间电荷区域中，光生载流子分离和转移的有效性下降。当MLG掺杂浓度为1013cm−3时，检测性能突出。峰值响应度、外量子效率（EQE）、探测率（D*）和开/关比的最大值分别为0.81A/W、103.28%、6.1×1010Jones和610.5。最小峰值噪声等效功率（NEP）为1.64×10−11 WHz−1/2。结果还表明，PD作为其他可见光和近红外（NIR）有毒设备的替代品具有很大的潜力。上述事实为光电子器件的制造和应用提供了理论框架。

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引用次数: 0

The Influence of Fibre Cross Section Shape and Fibre Surface Roughness on Composite Micromechanics 纤维截面形状和表面粗糙度对复合材料细观力学的影响

IF 1.3 4区材料科学 Q4 MATERIALS SCIENCE, MULTIDISCIPLINARY

Micro & Nano Letters

Pub Date : 2023-03-20 DOI: 10.3390/micro3010024

J. Thomason

Many of the carbon and natural fibres used in composite reinforcement have a non-circular cross section. Recently non-circular, or flat, cross section glass fibre products have become commercially available. This paper explores the potential effects that such non-circular fibre cross section shapes may have on the micromechanics of stress transfer at the composite fibre–matrix interface and the resulting changes in composite strength performance. Analytical modelling is used to show how the critical fibre length in composites with non-circular fibres is always less when compared to circular fibres with an equal cross-sectional area. This can result in significant changes to the strength performance of discontinuous fibre reinforced composites. Additionally, it is shown that the surface roughness found on natural and carbon fibres, many of which are also non-circular in cross section, can decrease the critical fibre length still further. These effects have important consequences for the use of single fibre micromechanical tests used for the characterisation of interfacial strength.

许多用于复合材料增强的碳和天然纤维具有非圆形截面。最近，非圆形或扁平截面玻璃纤维产品已商品化。本文探讨了这种非圆形纤维截面形状可能对复合材料纤维-基体界面应力传递的微观力学以及由此导致的复合材料强度性能变化的潜在影响。分析模型表明，与具有相同横截面积的圆形纤维相比，非圆形纤维复合材料的临界纤维长度总是更短。这将导致不连续纤维增强复合材料强度性能的显著变化。此外，研究表明，在天然纤维和碳纤维上发现的表面粗糙度，其中许多在横截面上也是非圆形的，可以进一步降低临界纤维长度。这些影响对用于界面强度表征的单纤维微力学测试的使用具有重要影响。

引用次数: 0