- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Fluorescent Nanodiamonds || Producing Fluorescent Nanodiamonds
摘要： Natural diamonds in colors are commonly known as fancies, or fancy color diamonds, in gemstone industries. They are rare, beautiful, and some even carry impressive price tags in the jewelry market. By comparison, micro‐ and nanoscale diamond powders are low in price, with or without colors and fluorescent or not. These powders have been used as abrasives for grinding and polishing purposes since ancient time, mainly because of their extraordinary hardness. Little or no attention has been paid over the centuries to other properties of nanodiamonds such as their innate biocompatibility and light‐emitting capability. The invention of fluorescent nanodiamond (FND) in 2005 has revolutionized the field, opening a new area of research and development with diamonds. Experiments with FNDs in the last decade have demonstrated various promising applications of surface‐functionalized FNDs in diversified fields, ranging from physics and chemistry to biology and medicine. It is worthy of noting that as originated from the discovery of Radium by Marie Sk?odowska Curie (Section 3.2), FNDs may very well be called Madame Curie’s gemstones, valued appropriately as a scientist’s best friend.
关键词： fluorescent nanodiamonds,magnetically modulated fluorescence,fluorescence lifetime,size reduction,FND,ion irradiation,H3 centers,nitrogen-vacancy centers,electron irradiation,NV centers
更新于2025-09-23 15:21:01
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Atomic simulation of irradiation of Cu film using femtosecond laser with different pulse durations
摘要： It is necessary to understand the light-matter interaction for application of femtosecond laser micro/nanoprocessing. In this work, the authors investigated the melting and disintegration behavior of a Cu film irradiated by a femtosecond laser with different pulse durations in the range of 35–500 fs by using a combined two temperature model (TTM) and molecular dynamics (MD) method. On the basis of TTM-MD, the temperature and stress evolution of the Cu film were analyzed. The result indicated that the Cu film disintegrates when the pulse duration is shorter than 100 fs but melts at a pulse duration of 200 fs. The photomechanical and thermomechanical evolutions induced by the femtosecond laser were also analyzed. The stress wave and increasing temperature were the main reasons for film disintegration and vibration. The snapshots of the Cu film indicate the melting and disintegration processes on an atomic scale. It shows that the melting occurs homogeneously, whereas the disintegration occurs at the center of the film. These results are helpful to understand the mechanism of femtosecond laser materials ablation.
关键词： TTM-MD simulation,Cu film,pulse durations,femtosecond laser,irradiation
更新于2025-09-23 15:21:01
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The influence of the solar radiation database and the photovoltaic simulator on the sizing and economics of photovoltaic-diesel generators
摘要： This study evaluated the outcome differences when adopting five different solar irradiation databases on the sizing of hybrid solar photovoltaic-diesel generators designed to supply electricity to isolated minigrids. To do this, the two most widely adopted photovoltaic (PV) simulation packages in the market, namely PVsyst? and HOMER Energy? were used. The different origins, data timespan, space and time resolution, of the five most relevant solar irradiation databases available for the region were compared. A case study was presented to illustrate the influences of the solar irradiation database and the solar simulation tool on the resulting PV generator. Furthermore, the hourly behavior of the energy supply to an existing load in a minigrid in the Brazilian Amazon was evaluated, together with the savings in diesel obtained with the resulting PV generator. Evaluating the five options of solar radiation databases, for the same PV plant configuration, variations of up to 19.7% were found in the expectation of PV generation. When the simulation software package was varied, the combined effect (radiation database X PV system sizing tool) showed differences of up to 20.6%. This demonstrates that despite having different algorithms, computational tools have a small influence (less than 1%) on results. These combined differences, taking into account the load curve behavior and the total diesel generation capacity installed at the site, resulted in over 100% differences in the optimum PV generator size in the case study. The total savings in diesel fuel, over a 15-years period, ranged from $ 6.5 million to over $ 16 million (> 2.5 times) for the smallest PV system. This demonstrates the importance of the correct choice of database. These evaluations can be extended to minigrids of any size elsewhere. The novelty and originality of this study is to demonstrate and quantify for the first time the influence of the solar radiation database and the PV simulator package on the sizing of PV-diesel generators. The consequences of this study are not only of scientific and academic importance, but of economic and commercial interest as well.
关键词： Photovoltaic simulation tool,Hybrid photovoltaic-diesel power plant,Solar database,Minigrids,Solar irradiation
更新于2025-09-23 15:21:01
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The Strong Inhibitory Effect of Combining Anti-Cancer Drugs AT406 and Rocaglamide with Blue LED Irradiation on Colorectal Cancer Cells
摘要： There is still no satisfying method to treat colorectal cancer (CRC) currently. Inspired by cocktail therapy, the combination of 465 nm blue LED irradiation and two multi-target anticancer agents AT406 and Rocaglamide has been investigated for a revolutionary way to treat colorectal cancer cells in vitro. It showed a strong inhibitory effect on colorectal cancer cells, and its side effects on human normal cells are negligible. When applied to HCT116 cells, it can achieve an apoptotic rate up to 95%. It is also seen to significantly inhibit proliferation of HT29 cells. Furthermore, little to no cell inhibition or damage of normal MRC-5 cells were seen after treatment. The combination of blue LED irradiation and two anti-cancer drugs causes apoptosis of colorectal cancer cells by activating the apoptotic pathway, inhibiting autophagy and proliferation pathways as well as the production of reactive oxygen species (ROS).
关键词： Multi-targeted anticancer drugs,Colorectal cancer,Inhibitory effect,Blue LED irradiation
更新于2025-09-23 15:21:01
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Fluorinated graphene nanoparticles with 1-3 nm electrically active graphene quantum dots
摘要： A new perspective approach to how to create a new and locally nanostructured graphene-based material is reported on. We studied the electric and structural properties for the partially fluorinated graphene (FG) films obtained from a FG-suspension and nanostructured by high-energy Xe ions. Local shock heating in ion tracks is suggested to be the main driving force of the changes. It was found that ion irradiation leads to the formation of locally thermal expanded FG and its cracking into nanosized nanoparticles with embedded small (~1.5-3 nm) graphene quantum dots, which band gap was estimated as 1-1.5 eV, into them. A further developed approach was applied to correction of the functional properties of the printed FG-based crossbar memristors. Dielectric FG films with small quantum dots may offer prospects in graphene-based electronics due to their stability and promising properties.
关键词： memristor,molecular dynamics simulation,nanostructuring,swift ion irradiation,fluorinated graphene,graphene quantum dots
更新于2025-09-23 15:21:01
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Defect engineered mesoporous 2D graphitic carbon nitride nanosheet photocatalyst for Rhodamine B degradation under LED light illumination
摘要： In this work, a nitrogen vacancy induced 2D mesoporous graphitic carbon nitrogen (g-C3N4) nanosheet photocatalyst was successfully synthesized through a simple two step thermal treatment method. The morphology of the nanosheet photocatalyst and the presence of nitrogen vacancy was explored through a wide range of characterization techniques. The as prepared photocatalyst possess an improved visible light absorption efficiency as confirmed from the UV-Visible diffuse reflectance spectroscopy (DRS). Moreover, the improved charge carrier separation efficiency of the nitrogen vacant material was demonstrated from the photoluminescence spectrum. Most importantly, the photocatalyst exhibited an excellent photodegradation efficiency towards rhodamine B (RhB) dye under the illumination of an 18 W LED light. The vacancy induced nanosheets demonstrated a degradation co-efficient of 0.074 min-1 in RhB degradation, which is 9.25 fold higher than that of the bulk g-C3N4. The nanosheets further exhibited an enhanced degradation efficiency toward tetracycline antibiotic. Furthermore, the photocatalyst displayed an outstanding stability even after 5 cycles. A plausible photocatalytic mechanism has also been explained based on the results obtained from the radical scavenging experiments. This study would provide insight into the defect induction mechanism into the 2D g-C3N4 nanosheet and expected to help in rationally designing vacancy induced materials with cost effective application in various environmental fields.
关键词： nitrogen vacancy,LED light irradiation,rhodamine B,mesoporous,2D g-C3N4 nanosheet
更新于2025-09-23 15:21:01
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Laser-Induced Optoelectronic and Crystallographic Tuning of Methyl Ammonium Iodobismuthate Perovskite for Improved Performance of Sandwiched a?? Type Photodetectors
摘要： Towards development of high-performance perovskite based photodetectors, it is required that optical and crystallographic properties of perovskites materials be enhanced through perovskites materials modification. Many attempts on this quest result in alteration of chemical structure of perovskites materials through introduction of dopants. Here in, we present a clean and structural preservative technique of tuning optical and crystallographic properties of bismuth based lead free perovskite materials through irradiation with 2.5 mJ laser pulses ejected from Nd:YAG LASER operating in its second harmonics. XRD spectra show improved crystallinity and reduced crystallite size, SEM images show defect – minimized surface morphology, PL spectra show minimized rate of Auger recombination and absorbance spectra show improved absorbance at a constant band gap value. Consequently, simplified sandwiched architectural type photodetectors fabricated with the modified bismuth based perovskite materials display maximum photodetectivity of 4.5 × 109 Jones, maximum photoresponsivity of 25 μA/W, maximum photosensitivity of about 104 and minimum optical switching times of 10 ms under testing conditions of -2 V bias voltage, 15 mW/cm2 incident solar light and room temperature. Thus, laser pulses irradiation presents an alternative method of enhancing optical and crystallographic properties of perovskite materials from which highly efficient classes of photonics and photovoltaic devices can be developed.
关键词： Laser Irradiation,crystallographic properties,optical properties,perovskite photodetectors,lead free perovskites materials
更新于2025-09-23 15:21:01
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Kinetics of molecular decomposition under irradiation of gold nanoparticles with nanosecond laser pulsesa??A 5-Bromouracil case study
摘要： Laser illuminated gold nanoparticles (AuNPs) efficiently absorb light and heat up the surrounding medium, leading to versatile applications ranging from plasmonic catalysis to cancer photothermal therapy. Therefore, an in-depth understanding of the thermal, optical, and electron induced reaction pathways is required. Here, the electrophilic DNA nucleobase analog 5-Bromouracil (BrU) has been used as a model compound to study its decomposition in the vicinity of AuNPs illuminated with intense ns laser pulses under various conditions. The plasmonic response of the AuNPs and the concentration of BrU and resulting photoproducts have been tracked by ultraviolet and visible (UV–Vis) spectroscopy as a function of the irradiation time. A kinetic model has been developed to determine the reaction rates of two parallel fragmentation pathways of BrU, and their dependency on laser fluence and adsorption on the AuNP have been evaluated. In addition, the size and the electric field enhancement of the decomposed AuNPs have been determined by atomic force microscopy and finite domain time difference calculations, respectively. A minor influence of the direct photoreaction and a strong effect of the heating of the AuNPs have been revealed. However, due to the size reduction of the irradiated AuNPs, a trade-off between laser fluence and plasmonic response of the AuNPs has been observed. Hence, the decomposition of the AuNPs might be limiting the achievable temperatures under irradiation with several laser pulses. These findings need to be considered for an efficient design of catalytic plasmonic systems.
关键词： gold nanoparticles,plasmonic catalysis,5-Bromouracil,laser irradiation,photothermal therapy
更新于2025-09-23 15:21:01
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Optical phase change in bismuth through structural distortions induced by laser irradiation
摘要： Semimetal bismuth (Bi) is known to possess a wide range of peculiar properties, owing to its unique electronic band structure. Its electronic band can easily be distorted by structural changes, and thereby undergo transitions between semimetal to either semiconductor or metal states. Utilising a focused laser beam, one can easily introduce structural defects, along with phase changes, oxidation, and morphological modifications. Confocal Raman microscopy indicated that the as-fabricated Bi droplets inhibit the Raman signal from the underlying silicon (Si) substrate. After a laser flash heating step, the intensity of Si optical phonons was strongly enhanced at the positions of Bi droplets, and exceeding the intensity from the bare Si substrate. Thus, such laser irradiating step on the Bi droplets induces an optical phase change. The optical phase change was detected as going from inhibition to strong enhancement of the underlying Si substrate Raman signal. From the observed Bi optical phonon modes (Eg and A1g), alterations in the Raman peaks due to laser exposure indicated that the ordered crystallinity in pristine Bi droplets became deteriorated. The effects of atomic displacements and loss of structural order in Bi droplets impacts its dielectric response. The observed Si Raman signal enhancement is similar to the surface-enhanced Raman scattering effect typically known for noble metals.
关键词： phase change,Bismuth,structural defects,laser irradiation,Raman spectroscopy
更新于2025-09-23 15:21:01
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[IEEE 2018 International Conference on Radiation Effects of Electronic Devices (ICREED) - Beijing, China (2018.5.16-2018.5.18)] 2018 International Conference on Radiation Effects of Electronic Devices (ICREED) - Study on the Tracking & Pointing Accuracy Degeneration of Optical Communication System for CMOS Sensor Irradiation Damage
摘要： The CMOS sensor in space optical communication system may generate irradiation-induced noise, leading to deviation of image centroid. Based on test data, simulated defect spots have been used for calculating the value by grey-level centroid algorithm. It shows that both the amount and position of defect pixels contribute to deviation of image centroid and the accuracy decreasing.
关键词： tracking & pointing accuracy,CMOS sensor,optical communication,gray centroid algorithm,irradiation damage
更新于2025-09-23 15:21:01