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Revisiting the cytotoxicity of quantum dots: an in-depth overview
摘要： Recently, medical research has been shifting its focus to nanomedicine and nanotherapeutics in the pursuit of drug development research. Quantum dots (QDs) are a critical class of nanomaterials due to their unique properties, which include optical, electronic, and engineered biocompatibility in physiological environments. These properties have made QDs an attractive biomedical resource such that they have found application as both in vitro labeling and in vivo theranostic (therapy-diagnostic) agents. Considerable research has been conducted exploring the suitability of QDs in theranostic applications, but the cytotoxicity of QDs remains an obstacle. Several types of QDs have been investigated over the past decades, which may be suitable for use in biomedical applications if the barrier of cytotoxicity can be resolved. This review attempts to report and analyze the cytotoxicity of the major QDs along with relevant related aspects.
关键词： Theranostic agents,Quantum dots,Biocompatibility,Cytotoxicity,Biomedical applications
更新于2025-09-16 10:30:52
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Distributed optical fiber sensing: Review and perspective
摘要： Over the past few decades, optical fibers have been widely deployed to implement various applications in high-speed long-distance telecommunication, optical imaging, ultrafast lasers, and optical sensors. Distributed optical fiber sensors characterized by spatially resolved measurements along a single continuous strand of optical fiber have undergone significant improvements in underlying technologies and application scenarios, representing the highest state of the art in optical sensing. This work is focused on a review of three types of distributed optical fiber sensors which are based on Rayleigh, Brillouin, and Raman scattering, and use various demodulation schemes, including optical time-domain reflectometry, optical frequency-domain reflectometry, and related schemes. Recent developments of various distributed optical fiber sensors to provide simultaneous measurements of multiple parameters are analyzed based on their sensing performance, revealing an inherent trade-off between performance parameters such as sensing range, spatial resolution, and sensing resolution. This review highlights the latest progress in distributed optical fiber sensors with an emphasis on energy applications such as energy infrastructure monitoring, power generation system monitoring, oil and gas pipeline monitoring, and geothermal process monitoring. This review aims to clarify challenges and limitations of distributed optical fiber sensors with the goal of providing a pathway to push the limits in distributed optical fiber sensing for practical applications.
关键词： energy applications,Brillouin scattering,Rayleigh scattering,Raman scattering,optical time-domain reflectometry,distributed optical fiber sensing,optical frequency-domain reflectometry
更新于2025-09-16 10:30:52
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Evidence for Ferroelectricity of All-Inorganic Perovskite CsPbBr3 Quantum Dots
摘要： The ferroelectric-optical combination of properties in halide perovskites has attracted tremendous interests because of its potential for optoelectronic and energy applications. However, very few reports focus on the ferroelectricity of all-inorganic halide perovskites quantum dots. Herein, we report a excellent ferroelectricity in CsPbBr3 quantum dots (QDs) with a saturation polarization of 0.25 μC/cm2. Differential scanning calorimeter (DSC), X-ray diffraction (XRD), transmission electronic microscopy (TEM) revealed that the mechanism of ferroelectric-paraelectric switching of CsPbBr3 QDs can be attributed to the phase transition from cubic phase (????3??) to orthorhombic phase (Pna21). In the orthorhombic CsPbBr3, the distortion of octahedral [PbBr6]4- structural units and the off-center Cs+ generated the slightly separated centres of positive charge and negative charge, resulting in the ferroelectric properties. The variable temperature emission spectrum from 328 K to 78 K exhibits green luminescence and the gradually red shift due to the phase transition. This finding opens up a avenue to explore the ferroelectric-optical properties of inorganolead halide perovskites for high-performance multifunctional materials.
关键词： CsPbBr3 quantum dots,all-inorganic perovskite,phase transition,optoelectronic applications,ferroelectricity
更新于2025-09-16 10:30:52
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Solar Engineering of Thermal Processes, Photovoltaics and Wind || Solar Water Heating
摘要： This is the first of a set of chapters on thermal energy applications. In this chapter, we treat the use of solar heating for domestic or institutional hot-water supplies. Descriptions of systems, components, and important design considerations are outlined. Considerations important in designing water heating systems are also basic to solar heating and cooling systems, applications that are covered in succeeding chapters. Many of the principles noted here for service hot water for buildings also apply to industrial process heat, discussed in Chapter 16.
关键词： active systems,solar water heating,passive systems,thermal energy applications
更新于2025-09-16 10:30:52
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Effect of incorporating different polyanilinea??surface modified nanosilica content into polyurethanea??based quasia??solida??state electrolyte for dyea??sensitized solar cells
摘要： Polyaniline-surface modified nanosilica (S-PANi) was incorporated into polyurethane (PU) to form a polymer matrix able to entrap liquid electrolyte and to function as a quasi-solid state electrolyte (QSE) in dye-sensitized solar cells (DSSCs). Nanosilica was first synthesized via sol–gel technique and was post modified with aniline to form S-PANi. The effects of introducing different S-PANi content (5, 10, 15, and 20 wt%) on the nanoparticle distribution, surface morphology, surface porosity, thermal stability, and the structure of the PU matrix were analyzed using transmitted and reflected light microscopes, TGA and X-ray powder diffraction. Additionally, polymer matrix absorptivity, conductivity, and ion diffusion of the formulated QSEs were investigated by using a digital analytical balance, the AC impedance method, and cyclic voltammetry. Lastly, all of the formulated quasi-solid-state electrolytes were applied for use in DSSCs wherein their charge recombination, photovoltaic performance, and lifespan were measured. The quasi-solid-state electrolyte based on 15 wt% S-PANi (PU-15%S-PANi) exhibited the highest light-to-energy conversion efficiency, namely 3.17%, with an open circuit voltage of 708 mV, a short circuit current of 4.13 mA cm?2, and a fill factor of 0.65.
关键词： films,swelling,nanoparticles,nanowires and nanocrystals,optical and photovoltaic applications,polyurethane
更新于2025-09-16 10:30:52
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Developer Design of Hybrid Plasmonic Nano Patch Antenna with Metal Insulator Metal Multilayer Construction
摘要： Hybrid plasmonic nanopatch antenna with metal-insulator-metal (HMIM) multilayer has been investigated for operation at the frequency of 125–250 THz using the finite element method (FEM) implemented in Ansoft High Frequency Structure Simulator (HFSS). The proposed antenna exhibits a wide bandwidth of 49.5 THz (151.5 THz–201 THz) for the slots thicknesses Wg = 50 nm and Ws = 100 nm and dual bandwidth for Ws = 20 nm. The obtained results show the input impedance of 50.3 Ω input resistance (real part) and 2.3 Ω reactance (imaginary part) occurring at (near) the operation frequency. The maximum gain of 23.98 dB has been observed for resonant frequencies of 176 THz, and the maximum directivity remains above 6.73 dB and 7.46 dB at resonant frequencies of 170 THz and 190 THz, respectively. Our proposed antenna performance is compared to previously reported designs. The copolar and cross-polar radiation patterns are simulated at different resonant frequencies of 160 THz and 197 THz for planes Φ = 90° and Φ = 0° . The arrays of a proposed antenna are designed in one and two dimensions in order to appropriate high-gain applications.
关键词： Ansoft High Frequency Structure Simulator,wide bandwidth,hybrid plasmonic nanopatch antenna,high-gain applications,metal-insulator-metal,finite element method
更新于2025-09-12 10:27:22
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[IEEE 2019 49th European Microwave Conference (EuMC) - Paris, France (2019.10.1-2019.10.3)] 2019 49th European Microwave Conference (EuMC) - Design of Aperture Coupled Feeding Ku-Band Phased Array Antenna on Multi-Layer PCB for Satellite Communications
摘要： In a phased array antenna system, beamforming integrated circuit (IC) is located directly behind the antenna and uses a multi-layer printed circuit board (PCB). As the frequency band becomes higher, the direct via feed method is not suitable for multi-layer PCB structure due to the decrease of transmission characteristics and the increase of manufacturing difficulty by use of blind via. This paper introduces the antenna using an aperture coupled feeding technique on multi-layer PCB for a Ku-band phased array antenna system. To verify the design, an antenna prototype is developed and measured at Ku-band for satellite applications. The antenna operates with left-handed circular polarization (LHCP) at center frequency of 11.9GHz and a peak gain of 15.2dBic.
关键词： automotive applications,Ku-band,slot antennas,satellite communication,phased arrays
更新于2025-09-12 10:27:22
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All-Optical Switching Based on the Plasma Channel Induced by Laser Pulses
摘要： We display a theoretical and experimental study of all-optical switching for signal lasers based on the plasma channel induced by the control laser. Using the plasma channel generated in the carbon disulfide (CS2) solution, the signal light can be modulated as some spatial distributions including unchanging, ring-shaped beam, and other intensity profiles. The modulation on the signal light can be conveniently adjusted by changing the control light’s incident intensity distribution. We can infer the dark spot shape in the modulated signal laser through the intensity profile of control laser beam. These results provide the great potential of plasma channel induced by lasers as an all-optical switching for various optoelectronic applications.
关键词： all-optical switching,plasma channel,spatial modulation,optoelectronic applications,laser pulses
更新于2025-09-12 10:27:22
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Introducing an Application of a Charged Coupled Device (CCD) in an Optical Tomography System
摘要： A tomographic system is a method used for capturing an image of an internal object section. Optical tomography is one method which widely used in medical and industrial fields. This paper reviews several applications of Charged Coupled Devices (CCD) and introduces an application of a CCD in an optical tomography system. Most of the previous research used this component for displacement measurement and as a video camera. This paper discusses its basic principle of operation, basic construction, its criteria, application, and its advantages compared to other optoelectronic sensors available in today’s market. The applications of this sensor in fields such as astronomy and medical has proved the ability and the good performance of CCD in capturing images. This sensor should widen its usage in optical tomography fields because it can give high performance in image reconstruction.
关键词： Tomography,applications,Charged Coupled Device (CCD),optical tomography
更新于2025-09-12 10:27:22
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SUBSTRATE INTEGRATED WAVEGUIDE CIRCULAR ANTENNA FOR TERAHERTZ APPLICATION
摘要： This paper presents a multi-band annular ring antenna that is obtained from a single-layer probe-fed substrate integrated waveguide based on a graphene material, with three top plan slits. In order to create a multi-bands antenna, we conduct simulation of the antenna structure based on CST/HFSS, so we use parametric tuning to adjust TM modes. Simulations show a good results between the two methods (finite element method and integral method) CST and HFSS Simulators. The bandwidths for three modes are 340 GHz in first mode, 346 GHz in the second mode, and 104 GHz in the third mode. The simulation gains at T M11, T M02, and T M12 are 8.2 dB, 8 dB, and 11 dB, respectively. The proposed antenna can be used in therahertz applications.
关键词： graphene material,terahertz applications,multi-band annular ring antenna,substrate integrated waveguide
更新于2025-09-12 10:27:22