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{Nanoa??gold, Iron (III)a??1,3,5a??benzene tricarboxylate Metal Organic Framework (MOF)} nanoa??composite as precursor for Laser Ablation Generation of golda??iron AumFen+/a?? (m = 1a??35, n=1a??5) clusters. Mass spectrometric study
摘要： Gold-iron bimetallic materials have applications in many fields, especially in nanotechnology and biomedicine. The chemistry of iron doped gold clusters is still not fully understood but opens up the possibility of developing new materials, e.g. of gold cages doped with iron atoms. There have been several theoretical studies on these clusters but only a few experimental studies. Laser desorption ionisation (LDI) was used for the generation of Au-Fe bimetallic clusters via laser ablation (337 nm nitrogen laser) of the synthesised nano-composite {nano-gold; Fe(III) 1,3,5-benzene tricarboxylate}, i.e. {AuNPs, Fe-MOF}, while a quadrupole ion trap time of flight mass spectrometer, equipped with a reflectron, was used to acquire mass spectra. A {AuNPs, Fe-MOF} nano-composite was prepared and found suitable for the LDI generation of AumFen clusters. In addition to Aum+/- (m = 1-35) clusters, a series of positively and negatively charged gold-iron AumFen+/- ones were generated. The mass spectra exhibited evidence for the clusters containing up to five iron atoms. In total, 113 binary AumFen+/- clusters (m = 1-35, n =1-5) were identified in the gas phase. A synthesised {AuNPs, Iron (III)-1,3,5-benzene tricarboxylate MOF} nano-composite was found suitable for the generation of many new gold-iron clusters and mass spectrometry was shown to be an efficient technique for the determination of the cluster stoichiometry. A broad series of over 100 bimetallic AumFen clusters, some of them suggested to be gold cages doped with iron atoms (for m = 12 and higher), not only demonstrate a rich and complex chemistry, but also open wide possibilities of biomedical applications.
关键词： nanoparticles,Mass spectrometry,MOF,Gold-iron,Laser desorption ionisation,Clusters,Nano-composite
更新于2025-09-19 17:13:59
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Digital Magnetic Compass Integration with Stationary, Land-Based Electro-Optical Multi-Sensor Surveillance System
摘要： Multi-sensor imaging systems using the global navigation satellite system (GNSS) and digital magnetic compass (DMC) for geo-referencing have an important role and wide application in long-range surveillance systems. To achieve the required system heading accuracy, the specific magnetic compass calibration and compensation procedures, which highly depend on the application conditions, should be applied. The DMC compensation technique suitable for the operation environment is described and different technical solutions are studied. The application of the swinging procedure was shown as a good solution for DMC compensation in a given application. The selected DMC was built into a system to be experimentally evaluated, both under laboratory and field conditions. The implementation of the compensation procedure and magnetic sensor integration in systems is described. The heading accuracy measurement results show that DMC could be successfully integrated and used in long-range surveillance systems providing required geo-referencing data.
关键词： soft iron compensation,compass integration,swinging method,electro-optical surveillance system,hard iron compensation,measurement accuracy,magnetic heading angle,digital magnetic compass
更新于2025-09-16 10:30:52
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Influence of Work Media on Surface Property of Compacted Graphite Cast Iron Processed by Laser Local Processing
摘要： In order to enhance surface property of brake materials, compacted graphite cast iron (CGI) with non-smooth surface was processed by laser local processing. This study focuses on the influence of the work media on wear resistance and thermal fatigue resistance of specimens. The results showed that when the work media were air and water respectively, laser local processing could enhance surface property of CGI. Changing work media could not change phase compositions of the laser processing area, but refined their microstructures, which enhanced their micro-hardness. By this way, the specimens’ wear resistance and resistance to thermal crack initiation were further improved, while their resistance to thermal crack propagation was influenced by cracks on bionic units.
关键词： Work media,Laser,Compacted graphite cast iron,Wear resistance,Thermal fatigue resistance
更新于2025-09-16 10:30:52
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Nontoxic pyrite iron sulfide nanocrystals as second electron acceptor in PTB7:PC <sub/>71</sub> BM-based organic photovoltaic cells
摘要： Herein, we report the synthesis of nontoxic pyrite iron sulfide (FeS2) nanocrystals (NCs) using a two-pot method. Moreover, we study the influence of these NCs incorporated into the PTB7:PC71BM active layer of bulk-heterojunction ternary organic photovoltaic (OPV) cells. The OPV devices are fabricated with the direct configuration glass/ITO/PEDOT:PSS/PTB7:PC71BM:FeS2/PFN/FM. The Field’s metal (FM) is a eutectic alloy composed of 32.5% Bi, 51% In and 16.5% Sn by weight that melts at 62 °C. It is deposited on the active layer/PFN under atmospheric conditions. Ternary active layers are prepared by adding small amounts of the semiconducting FeS2 NCs at different weight ratios of 0.0, 0.25, 0.5, and 1.0 wt % with respect to the electron donor PTB7. With respect to the reference device (without FeS2), a 21% increase in the power conversion efficiency (PCE) is observed for OPVs with 0.5 wt % FeS2, such that the PCE of the OPVs is enhanced from 5.69 to 6.47%. According to the Kruskal–Wallis and Mann–Whitney statistical tests, all OPV devices follow the same trend.
关键词： iron disulfide,nanoparticles,pyrite,organic photovoltaic cells (OPVs),PTB7
更新于2025-09-16 10:30:52
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Feasibility Investigation for Online Elemental Monitoring of Iron and Steel Manufacturing Processes using Laser-Induced Breakdown Spectroscopy
摘要： The metallurgical industries are very important for social development. In order to improve the metallurgical techniques and quality of products, the real-time analysis and monitoring of iron and steel manufacturing processes are very significant. Laser-induced breakdown spectroscopy (LIBS) has been studied and applied for the contents measurement of iron and steel. In this paper, the remote open-path LIBS measurement was studied under different sample temperature, lens to target distance (LTD), sample angle conditions to clarify its online measurement features. The 3D profile measurement system of parallel laser beam fringes projection was also developed to measure the sample profile at different sample temperature. The measurement results demonstrated the robustness of remote open-path LIBS system and 3D profile measurement system. However, the correction is necessary to enhance the detection ability of LIBS online measurement. In order to improve the precision and accuracy of real-time elemental measurement, an innovative co-axial laser beam measurement system combining LIBS and 3D profile techniques is proposed to automatically adjust the focus unit and measure the sample components. The further study of this promising method will be developed for online application of iron and steel manufacturing processes.
关键词： remote measurement,laser-induced breakdown spectroscopy,3D profile,iron and steel manufacturing processes
更新于2025-09-16 10:30:52
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Enhanced thermal diffusivity of water in the presence of iron oxide nanoparticles: a laser induced thermal lens measurement
摘要： Iron oxide nanoparticles are prepared using co-precipitation method and its thermal diffusivity as a function of concentration in distilled water is measured using laser induced thermal lens technique. The morphology, distribution and particle size are determined using SEM measurements. The elemental composition and optical properties of the sample are obtained from EDAX and UV–visible absorption spectra. It is found that the thermal diffusivity of the nanoparticle solution is larger than that of pure water at low concentrations but it is decreasing with increase in concentration of the nanoparticles. Variation of electrical conductivity and magnetic susceptibility of the same sample are also studied.
关键词： thermal lens,iron oxide nanoparticles,thermal diffusivity
更新于2025-09-16 10:30:52
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Laser Cladding of Heat-Resistant Iron Based Alloy
摘要： The paper presents the results of the composition, structure and mechanical characteristics of heat-resistant iron based alloy samples produced by laser cladding. The samples were manufactured using secondary raw material (chips), which were converted into powder by plasma spheroidization. The crystalline transformations for the as-processed as well as after several heat treatment conditions were analyzed. Phase, chemical composition and mechanical characteristics were investigated.
关键词： mechanical properties,additive manufacturing,heat-resistant iron based alloy,microstructure,laser cladding
更新于2025-09-16 10:30:52
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Application of Scikit and Keras Libraries for the Classification of Iron Ore Data Acquired by Laser-Induced Breakdown Spectroscopy (LIBS)
摘要： Due to the complexity of, and low accuracy in, iron ore classification, a method of Laser‐Induced Breakdown Spectroscopy (LIBS) combined with machine learning is proposed. In the research, we collected LIBS spectra of 10 iron ore samples. At the beginning, principal component analysis algorithm was employed to reduce the dimensionality of spectral data, then we applied k‐nearest neighbor model, neural network model, and support vector machine model to the classification. The results showed that the accuracy of three models were 82.96%, 93.33%, and 94.07% respectively. The results also demonstrated that LIBS with machine learning model exhibits an excellent classification performance. Therefore, LIBS technique combined with machine learning can achieve a rapid, precise classification of iron ores, and can provide a completely new method for iron ores’ selection in the metallurgical industry.
关键词： machine learning,laser‐induced breakdown spectroscopy,iron ore,classification
更新于2025-09-16 10:30:52
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Visible light induced efficient activation of persulfate by a carbon quantum dots (CQDs) modified ?3-Fe2O3 catalyst
摘要： In this study, a carbon quantum dots modified maghemite catalyst (CQDs@γ-Fe2O3) has been synthesized by a one-step solvothermal method for efficient persulfate (PDS) activation under visible light irradiation. Transmission electron microscopy (TEM), scanning electron microscopy (SEM) and UV-vis diffuse reflectance spectroscopy (UV-vis DRS) characterization indicated that the formation of heterojunction structure between CQDs and γ-Fe2O3 effectively reduced the catalyst band gap (Eg), favoring the separation rate of electrons and holes, leading to remarkable efficient sulfamethoxazole (SMX) degradation as compared to the dark-CQDs@γ-Fe2O3/PDS and vis-γ-Fe2O3/PDS systems. The evolution of dissolved irons also demonstrated that CQDs could accelerate the in-situ reduction of surface-bounded Fe3+. Electron paramagnetic resonance (EPR) and radical scavenging experiments demonstrated that both ?OH and SO4?? were generated in the reaction system, while ?OH was relatively more dominant than SO4?? for SMX degradation. Finally, the reaction mechanism in the vis-CQDs@γ-Fe2O3/PDS system was proposed involving an effective and accelerated heterogeneous-homogeneous iron cycle. CQDs would enrich the photo-generated electrons from γ-Fe2O3, causing efficient interfacial generation of surface-bond Fe2+ and reduction of adsorbed Fe3+. This visible light induced iron cycle would eventually lead to effective activation of PDS as well as the efficient degradation of SMX.
关键词： Photocatalysis,Persulfate,Carbon quantum dots,Iron cycle
更新于2025-09-16 10:30:52
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The Influence of Iron in Minimizing the Microstructural Anisotropy of Ti-6Al-4V Produced by Laser Powder-Bed Fusion
摘要： There remains a significant challenge in adapting alloys for metal-based additive manufacturing (AM). Adjusting alloy composition to suit the process, particularly under regimes close to industrial practice, is therefore a potential solution. With the aim of designing new Ti-based alloys of superior mechanical properties for use in laser powder-bed fusion, this research investigates the influence of Fe on the microstructural development of Ti-6Al-4V. The operating mechanisms that govern the relationship between the alloy composition (and Fe in particular) and the grain size are explored using EBSD, TEM, and in situ high-energy synchrotron X-ray diffraction. It was found that Fe additions up to 3 wt pct lead to a progressive refinement of the microstructure. By exploiting the cooling rates of AM and suitable amount of Fe additions, it was possible to obtain microstructures that can be optimized by heat treatment without obvious precipitation of detrimental brittle phases. The resulting microstructure consists of a desirable and well-studied fully laminar a + b structure in refined prior-b grains.
关键词： iron,grain refinement,additive manufacturing,microstructure,Ti-6Al-4V
更新于2025-09-16 10:30:52