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Helical Magnetic Field-Induced Real-Time Plasmonic Chirality Modulation
摘要： Astrophysical phenomenon mimetic helical magnetic field (hB)-assisted self-assembly is herein introduced to build helical superstructures that display chiroptical properties. As a building block, magnetoplasmonic (MagPlas) Ag@Fe3O4 core-shell nanoparticles are used to guide plasmonic Ag nanoparticles onto a helical magnetic flux. The chirality of the assembled helical structures and tailored circular dichroism are successfully tuned in real-time, and the handedness of the assembled structures is dynamically switched by the hB at the millisecond level, which is at least 6,000-fold faster than other template-assisted methods. The peak position of circular dichroism can be reconfigured by altering the plasmonic resonance or coupling by controlling the size of the Ag core and magnetic flux density. The hB-induced chirality modulation represents a method to control the polarization state of light at the nexus of plasmonics, magnetic self-assembly, colloidal science, liquid crystals, and chirality. It presents active and dynamic chiral assemblies of magnetoplasmonic nanomaterials, enabling further practical applications in optical devices.
关键词： magnetoplasmonic nanoparticles,helical magnetic field (hB),self-assembly,dynamic chirality,real-time modulation
更新于2025-09-23 15:19:57
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Terahertz Spectroscopy of Gas Mixtures with Dual Quantum Cascade Laser Frequency Combs
摘要： Terahertz laser frequency combs based on quantum cascade lasers provide coherent, broadband, electrically pumped, THz radiation sources for use in future spectroscopic applications. Here, we explore the feasibility of such lasers in a dual-comb spectroscopy configuration for the detection of multiple molecular samples in the gas phase. The lasers span approximately 180 GHz of optical bandwidth, centered at 3.4 THz with sub-milliwatt total optical power. One of the main advantages of dual-comb spectroscopy is its high speed, which opens up the possibility for direct observations of chemical reaction dynamics in the terahertz spectral region. As a proof-of-concept, we recorded continuously evolving spectra from gas mixtures with 1 ms temporal resolution.
关键词： frequency comb,multi-species,Terahertz,real-time,dual-comb spectroscopy,quantum cascade laser
更新于2025-09-23 15:19:57
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A strategy for preparing non-fluorescent graphene oxide quantum dots as fluorescence quenchers in quantitative real-time PCR
摘要： In recent years, graphene oxide quantum dots (GOQDs) have emerged as novel nanomaterials for optical sensing, bioimaging, clinical testing, and environmental testing. However, GOQDs demonstrate unique photoluminescence properties, with GOQDs having quantum limitations and edge effects that often affect the accuracy of the test results in the sensory field. Herein, GOQDs with a large content of hydroxyl groups and low fluorescence intensity were first prepared via an improved Fenton reaction in this study, which introduces a large amount of epoxy groups to break the C–C bonds. The synthesized GOQDs show no significant variation in the fluorescence intensity upon ultraviolet and visible light excitations. We further utilized the GOQDs as fluorescence quenchers for different fluorescent dyes in real-time fluorescence quantitative polymerase chain reaction (qRT-PCR), and verified that the addition of GOQDs (5.3 mg ml?1) into a qRT-PCR system could reduce the background fluorescence intensity of the reaction by fluorescence resonance energy transfer (FRET) during its initial stage and its non-specific amplification, and improve its specificity. In addition, the qRT-PCR method could detect two different lengths of DNA sequences with a high specificity in the 104 to 1010 copies per ml range. It is of paramount importance to carry out further investigations to establish an efficient, sensitive, and specific RT-PCR method based on the use of GOQD nanomaterials as fluorescence quenchers.
关键词： Fenton reaction,fluorescence quenchers,DNA detection,quantitative real-time PCR,graphene oxide quantum dots
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Sozopol, Bulgaria (2019.9.6-2019.9.8)] 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Fiber Characterization Using Whispering Gallery Modes(Invited)
摘要： Dynamic magnetic resonance (MR)-imaging can provide functional and positional information in real-time, which can be conveniently used online to control a cancer therapy, e.g., using high intensity focused ultrasound or radio therapy. However, a precise real-time correction for motion is fundamental in abdominal organs to ensure an optimal treatment dose associated with a limited toxicity in nearby organs at risk. This paper proposes a real-time direct principal component analysis (PCA)-based technique which offers a robust approach for motion estimation of abdominal organs and allows correcting motion related artifacts. The PCA was used to detect spatio-temporal coherences of the periodic organ motion in a learning step. During the interventional procedure, physiological contributions were characterized quantitatively using a small set of parameters. A coarse-to-fine resolution scheme is proposed to improve the stability of the algorithm and afford a predictable constant latency of 80 ms. The technique was evaluated on 12 free-breathing volunteers and provided an improved real-time description of motion related to both breathing and cardiac cycles. A reduced learning step of 10 s was sufficient without any need for patient-specific control parameters, rendering the method suitable for clinical use.
关键词： Motion analysis,real-time system
更新于2025-09-23 15:19:57
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Real-time Concealed Object Detection from Passive Millimeter Wave Images Based on the YOLOv3 Algorithm
摘要： The detection of objects concealed under people’s clothing is a very challenging task, which has crucial applications for security. When testing the human body for metal contraband, the concealed targets are usually small in size and are required to be detected within a few seconds. Focusing on weapon detection, this paper proposes using a real-time detection method for detecting concealed metallic weapons on the human body applied to passive millimeter wave (PMMW) imagery based on the You Only Look Once (YOLO) algorithm, YOLOv3, and a small sample dataset. The experimental results from YOLOv3-13, YOLOv3-53, and Single Shot MultiBox Detector (SSD) algorithm, SSD-VGG16, are compared ultimately, using the same PMMW dataset. For the perspective of detection accuracy, detection speed, and computation resource, it shows that the YOLOv3-53 model had a detection speed of 36 frames per second (FPS) and a mean average precision (mAP) of 95% on a GPU-1080Ti computer, more e?ective and feasible for the real-time detection of weapon contraband on human body for PMMW images, even with small sample data.
关键词： YOLOv3,real-time,neural network,concealed object detection,deep learning,passive millimeter wave
更新于2025-09-23 15:19:57
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A Real-Time Method to Detect the Deformation Behavior during Laser Solid Forming of Thin-Wall Structure
摘要： Laser solid forming (LSF) is a promising additive manufacturing technology. In the LSF process, deformation behaviors dictate the accuracy of the produced parts. In this study, by using a laser displacement detector based on laser triangulation principle, an accurate and effective real-time detection method was established to monitor the real-time deformation behavior of the key position during the LSF of a thin-wall structure. The results confirmed that increasing thin-wall length results in increasing final deformation of the edge. The displacement fluctuation range and value in the middle of thin wall are both smaller than that of the positions near the end, while the entire displacement changing direction in the middle is opposite to that of the end positions. When the deposition process is paused, the deformation of the thin wall during the cooling stage will deviate the position of the deposited thin wall, resulting in the dislocation between the subsequent deposited part and that before the pause, which affect the dimensional accuracy of the thin wall structure. This non-contact real-time detection method also confirmed the ability to monitor the initiation of cracking during the LSF process, and a potential to be used for the on-line feedback control of deformation of detected key position of deposited structure.
关键词： laser solid forming,real-time detection,accuracy,crack,additive manufacturing,deformation behaviors
更新于2025-09-23 15:19:57
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100 GHz Multiple Colliding Pulse Generation From Cleaved Facet-Free Multi-Section Semiconductor Laser Diode
摘要： Terahertz (THz) cameras comprising an uncooled micro-bolometer array have been developed for simple THz imaging, and the improvement of their sensitivity is one of the important issues. We fabricated a new micro-bolometer array with a resonant cavity structure for a real-time THz camera, alongside a new method for evaluating the sensitivity across a wide range of the THz frequency region. The frequency dependence of the sensitivity of the THz camera is measured in the 0.5–2.0-THz frequency range taking the polarization dependence into account. It was found that the resonant cavity structure effectively increased the sensitivity of the THz camera, and, actually, the improvement by one order of magnitude was achieved in the frequency range below 1 THz. The THz camera with much enhanced sensitivity will expand the frontiers of real-time THz imaging such as molecular imaging and nondestructive inspection.
关键词： focal plane array,micro-bolometer,terahertz (THz),real-time imaging,Compact terahertz camera
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Predicting Open-Circuit Voltages in Atomically-Thin Monolayer Transition Metal Dichalcogenides-Based Solar Cells
摘要： District-wide real-time information sharing provides new opportunities to optimize infrastructures and, for example, the energy consumption of smart cities. However, information collection introduces new privacy threats that must be addressed. Existing anonymization solutions are not sufficient for the brokering of streaming real-time measurements. Advanced adversaries may utilize information available from different sources and correlation analyses to reveal a measurement’s actual source. We analyze security and privacy requirements and design a privacy-enhancing architecture for an information brokering platform. We propose an adaptive pseudonymization framework to make privacy attacks harder and to gain real-time awareness of the robustness of the privacy protection of platforms. Finally, we present an initial evaluation of the proposal using real-world energy consumption measurements.
关键词： authentication,privacy,real-time,smart city,Access control,anonymity,security,information sharing
更新于2025-09-23 15:19:57
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Optimization of rDNA degradation in recombinant Hepatitis B vaccine production plant wastewater using visible light excited Ag-doped TiO2 nanophotocatalyst
摘要： As widespread distribution of recombinant DNA of genetically modified microorganisms is a threat to the environment, the aim of this research is to investigate the efficiency of photocatalytic degradation of recombinant DNA under visible light. Using response surface methodology, a comprehensive evaluation of Ag doped-TiO2 photocatalytic degradation of recombinant DNA in Hepatitis B surface antigen production plant wastewater was performed. Photocatalytic synthesis parameters including dopant content, calcination temperature, and heating rate were investigated to model and optimize the recombinant DNA degradation efficiency. The Ag doped-TiO2 nanoparticles synthesis validation was accomplished by XRD, UV-Vis diffuse reflectance spectra, FESEM and energy-dispersive X-ray spectroscopy. A quadratic polynomial equation, developed by response surface methodology, with the correlation coefficient (R2) of 0.969 ensured the good fitness of the predicted data with the experimental results. The sensitivity analysis of model indicates that the square of silver content and calcination temperature have the greatest effect on the response, while the heating rate is the least important parameter. Furthermore, the optimum conditions of Ag content of 2.1%, calcination temperature of 485 ?C, and heating rate of 8 ?C/min resulted in 80.7% rDNA degradation experimentally.
关键词： photocatalytic degradation,genetically modified microorganisms,Ag-doped TiO2,Pichia Pastoris,recombinant DNA,Real-time PCR
更新于2025-09-23 15:19:57
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Effectiveness of a novel real-time dosimeter in interventional radiology: a comparison of new and old radiation sensors
摘要： Radiation dose management is important in interventional radiology (IR) procedures, such as percutaneous coronary intervention, to prevent radiation-induced injuries. Therefore, radiation dose should be monitored in real time during IR. This study evaluated the fundamental characteristics of a novel real-time skin dosimeter (RTSD) developed at our institution. In addition, we compared the performance of our new and old radiation sensors and that of a skin dose monitor (SDM), with ion chamber reference values. We evaluated the fundamental characteristics (e.g., energy dependence, dose dependence, and angular dependence) of the RTSD developed by us in the diagnostic X-ray energy range. The performance of our RTSD was similar to that of the SDM. In particular, the new radiation sensor of our RTSD demonstrated better dose rate dependence compared to the old sensor. In addition, the new sensor had the advantage of being small in size and thus minimally affecting the X-ray images compared to the old sensor. Therefore, the developed skin dosimeter and radiation sensor may be useful in real-time measurement of patients’ exposure to and multi-channel monitoring of radiation in IR procedures. The new dosimeter system can be recommended for visualization and management of the radiation dose to which the patients’ skin is exposed.
关键词： Radiation dose,Real-time skin dosimeter,Interventional radiology,Radiation skin injuries
更新于2025-09-23 15:19:57