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A Turbulence-Oriented Approach to Retrieve Various Atmospheric Parameters Using Advanced Lidar Data Processing Techniques
摘要： The article is aimed at presenting a semi-empirical model coded and computed in the programming language Python, which utilizes data gathered with a standard biaxial elastic lidar platform in order to calculate the altitude profiles of the structure coefficients of the atmospheric refraction index C2N(z) and other associated turbulence parameters. Additionally, the model can be used to calculate the PBL (Planetary Boundary Layer) height, and other parameters typically employed in the field of astronomy. Solving the Fernard–Klett inversion by correlating sun-photometer data obtained through our AERONET site with lidar data, it can yield the atmospheric extinction and backscatter profiles α(z) and β(z), and thus obtain the atmospheric optical depth. Finally, several theoretical notions of interest that utilize the solved parameters are presented, such as approximated relations between C2N(z) and the atmospheric temperature profile T(z), and between the scintillation of backscattered lidar signal and the average wind speed profile U(z). These obtained profiles and parameters also have several environmental applications that are connected directly and indirectly to human health and well-being, ranging from understanding the transport of aerosols in the atmosphere and minimizing the errors in measuring it, to predicting extreme, and potentially-damaging, meteorological events.
关键词： RCS,temperature profile,structure coefficients,environment,human health,atmospheric extinction,atmospheric backscatter,wind speed profile,lidar,turbulence
更新于2025-09-19 17:15:36
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Selective formation of ternary Cu–Ge–S nanostructures in solution
摘要： Selective formation of ternary Cu–Ge–S nanostructures in solution. In this paper, special attention is given to ternary copper germanium sulfides (Cu–Ge–S), which belong to an important class of mixed-metal chalcogenide materials called the copper-based multinary sulfides (CMSs). Like most members of the CMS family, the Cu–Ge–S compounds display enormous potential in energy-related applications especially in their nanostructured forms, but there exists very little research on the preparation of Cu–Ge–S materials in the nanometer size range. Herein, we report a simple noninjection protocol for the selective synthesis of Cu–Ge–S nanomaterials. We show that variations in the solvent environment can lead to different types of Cu–Ge–S nanostructures (i.e., from large, faceted Cu8GeS6 to smaller, irregularly-shaped Cu2GeS3). Our investigation of the growth process revealed interesting formation pathways, which could help advance our understanding of the selective formation of compositionally and structurally diverse multinary materials in solution.
关键词： selective synthesis,solvent environment,formation mechanism,Cu–Ge–S nanostructures,noninjection protocol
更新于2025-09-19 17:15:36
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Soil Salinity Mapping and Hydrological Drought Indices Assessment in Arid Environments Based on Remote Sensing Techniques
摘要： Vegetation indices are mostly described as crop water derivatives. Normalized Difference Vegetation Index (NDVI) is one of the oldest remote sensing applications that widely used to evaluate crop vigor directly and crop water relationships indirectly. Recently, several NDVI derivatives are exclusively used to assess crop water relationships. Four hydrological drought indices are examined in the current research study. Water Supply Vegetation Index (WSVI), Soil Adjusted Vegetation Index (SAVI), Moisture Stress Index (MSI) and Normalized Difference Infrared Index (NDII) are implemented in the current study as an indirect tool to map the effect of different soil salinity level on crop water stress in arid environments. In arid environments; such as Saudi Arabia, water resources are under pressure especially groundwater levels. Groundwater wells are rapidly depleted due to the heavy abstraction of the reserved water. Heavy abstractions of groundwater; which exceed crop water requirements in most of the cases are powered by high evaporation rates in the designated study area because of the long days of extremely hot summer. Landsat OLI-8 data were extensively used in the current research to obtain several vegetation indices in response to soil salinity in Wadi Ad-Waser. Principal Component Analysis and Artificial Neural Network Analysis are complementary tools to understand the regression pattern of the hydrological drought indices in the designated study area.
关键词： Soil Salinity Mapping,Arid Environment,Vegetation Indices,Remote Sensing techniques
更新于2025-09-19 17:15:36
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Acid Environment-improved fluorescence sensing performance: a quinoline Schiff base-containing sensor for Cd2+ with high sensitivity and selectivity
摘要： The development of acid environment-applicable fluorescence sensor is challenging but attractive topic, which can achieve the rapid and comprehensive evaluation of total soluble heavy metal content in natural water. In this work, a quinoline-containing Schiff base, AMQD, was utilized as fluorescence probe for Cd2+. Interestingly, the obtained chemosensor exhibited much better fluorescence detection sensitivity and selectivity toward Cd2+ in acidic 10% methanol aqueous solution (pH 4) comparing to those in neutral environment. Initially, the fluorescence emission of AMQD was almost invisible with the absence of metal ions, while a significant turn-on fluorescence response (~425 nm) can be observed with the addition of Cd2+. The fluorescence detection possesses excellent selectivity without the interference of any other metal cation. The recognition ratio between the fluorescence sensor AMQD and Cd2+ was confirmed to be 1:1, and the detection limit was calculated to be 2.4 nM.
关键词： Fluorescence,Quinoline,Sensing in acidic environment,Cd2+ ion
更新于2025-09-19 17:15:36
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Rapid evaluation of micro-scale photovoltaic solar energy systems using empirical methods combined with deep learning neural networks to support systems’ manufacturers
摘要： Solar energy is becoming one of the most attractive renewable sources. In many cases, due to a wide range of financial or installation limitations, off-grid small scale micro power panels are favoured as modular systems to power lighting in gardens or to be integrated together to power small devices such as mobile phone chargers and distributed smart city facilities and services. Manufacturers and systems’ integrators have a wide range of options of micro-scale photo voltaic panels to choose from. This makes the selection of the right panel a challenging task and risky investment. To address this and to help manufacturers, this paper suggests and evaluates a novel approach based on integrating empirical lab-testing with short-term real data and neural networks to assess the performance of micro-scale photovoltaic panels and their suitability for a specific application in specific environment. The paper outlines the combination of lab testing power output under seasonal and hourly conditions during the year combined with environmental and operating conditions such as temperature, dust accumulation and tilt angle performance. Based on the lab results, a short in-situ experimental work is implemented and the performance over the year in the selected location in Kuwait is evaluated using deep learning neural networks. The findings of this approach are compared with simulation and long-term real data. The results show a maximum error of 23% of the neural network output when compared with the actual data, and a correlation values with previous work within 87.3% and 91.9% which indicate that the proposed approach could provide an experimental rapid and accurate assessment of the expected power output. Hence, supporting the rapid decision-making process for manufacturers and reducing investment risks.
关键词： Solar energy,neural networks,smart cities,system manufacturing,photovoltaic,micro-scale,urban environment
更新于2025-09-19 17:13:59
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Repetition Rate Locking of Mutually Injected Monolithic Passively Mode-Locked Semiconductor Quantum Dot Lasers
摘要： Rendering large-scale 3-D scenes on a thin client is attracting increasing attention with the development of the mobile Internet. Efficient scene prefetching to provide timely data with a limited cache is one of the most critical issues for remote 3-D data scheduling in networked virtual environment applications. Existing prefetching schemes predict the future positions of each individual user based on user traces. In this paper, we investigate scene content sequences accessed by various users instead of user viewpoint traces and propose a user access pattern-based 3-D scene prefetching scheme. We make a relationship graph-based clustering to partition history user access sequences into several clusters and choose representative sequences from among these clusters as user access patterns. Then, these user access patterns are prioritized by their popularity and users’ personal preference. Based on these access patterns, the proposed prefetching scheme predicts the scene contents that will most likely be visited in the future and delivers them to the client in advance. The experiment results demonstrate that our user access pattern-based prefetching approach achieves a high hit ratio and outperforms the prevailing prefetching schemes in terms of access latency and cache capacity.
关键词： 3-D scenes,user access patterns,networked virtual environment,prefetching
更新于2025-09-19 17:13:59
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A 2.77 μW Ambient RF Energy Harvesting Using DTMOS Cross-Coupled Rectifier on 65 nm SOTB and Wide Bandwidth System Design
摘要： This paper proposes a structure of the μW RF energy harvesting (RFEH) system that is used for scavenging RF power from an ambient environment. A cross-coupled recti?er (CCR) with ?oating sub-circuit structures was utilized in the application of dynamic threshold MOSFET (DTMOS) on Silicon on Thin Buried Oxide (SOTB) to obtain high drain conductance of the MOSFET. A wide bandwidth matching between antenna and recti?er was designed to receive energy from the orthogonal frequency division multiplexing (OFDM) RF signal with a bandwidth of 15 MHz at 950 MHz band. Realistic measurements with a 950 MHz LTE mobile phone signal from the ambient environment indicate that an average DC output power of 2.77 μW is harvested with the proposed RFEH system at a level of ?19.4 dBm input power. The proposed RFEH system exhibits the best performance when compared to that of other realistic RFEH systems and is a potential candidate for battery-less Internet of Things (IoT) applications.
关键词： wide band matching circuit,DTMOS cross-coupled recti?er,ambient environment,LTE mobile phone signal,RF energy harvesting
更新于2025-09-19 17:13:59
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Facile Preparation of MnO <sub/>2</sub> Quantum Dots with Enhanced Fluorescence via the Micro-environment Engineering with the Assistance of Some Reductive Biomolecules
摘要： MnO2 nanomaterials have been aroused wide attention because of their nano-enzyme activity, redox property, good biocompatibility and therapy-related activities. However, not any report about self-luminescent MnO2 materials are concerned to date, which greatly hampered their further development in various fields. In this paper, luminescent MnO2 quantum dots (MnO2 QDs) has been firstly prepared via a facile one-step ultrasonic method. With the assistant of bovine serum albumin (BSA) or cysteine (Cys), the synthesized MnO2 QDs (BSA-MnO2 QDs or Cys-MnO2 QDs) display strongly enhanced fluorescence (FL). The prepared BSA-MnO2 QDs with the particles size of about 1-2 nm show the maximum excitation and emission peaks at 320 and 410 nm with excellent salt stability, anti-photo bleaching ability and time stability. It is confirmed that BSA play the dual function as the exfoliating agent to promote the exfoliation of bulk MnO2 nanosheets and as the capping agent to provide a friendly micro-environment for MnO2 QDs. Ag ions can destroy the micro-environment of BSA-MnO2 QDs owing to the in-situ formation of Ag nanoparticles (Ag NPs) mediated by the BSA on the surface of the QDs. Then these Ag NPs can quench the FL intensity of the QDs by fluorescence resonance energy transfer. However, the FL strength of BSA-MnO2 QDs is recovered after adding H2O2 and NaHS since they may react with Ag NPs to produce Ag+ and Ag2S, which further confirmed the role of BSA. This work not only opens a facile and universal avenue to synthesize luminescent MnO2 QDs with enhanced FL, but provide a possible sensing platform through tuning the micro-environment of MnO2 QDs. The MnO2 QDs with outstanding performance may show great potential as promising fluorescent probes in the fields of biological imaging, optical sensing, drug delivery and therapy.
关键词： micro-environment engineering,reductive biomolecules,MnO2 QDs,enhanced fluorescence,Ag ions
更新于2025-09-19 17:13:59
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Detecting Frost Stress in Wheat: A Controlled Environment Hyperspectral Study on Wheat Plant Components and Implications for Multispectral Field Sensing
摘要： Radiant frost during the reproductive stage of plant growth can result in considerable wheat (Triticum aestivum L.) yield loss. Much effort has been spent to prevent and manage these losses, including post-frost remote sensing of damage. This study was done under controlled conditions to examine the effect of imposed frost stress on the spectral response of wheat plant components (heads and flag leaves). The approach used hyperspectral profiling to determine whether changes in wheat components were evident immediately after a frost (up to 5 days after frosting (DAF)). Significant differences were found between frost treatments, irrespective of DAF, in the Blue/Green (419–512 nanometers (nm)), Red (610–675 nm) and Near Infrared (NIR; 749–889 nm) regions of the electromagnetic spectrum (EMS) in head spectra, and in the Blue (415–494 nm), Red (670–687 nm) and NIR (727–889 nm) regions in the leaf spectra. Significant differences were found for an interaction between time and frost treatment in the Green (544–575 nm) and NIR (756–889 nm) in head spectra, and in the UV (394–396 nm) and Green/Red (564–641 nm) in leaf spectra. These findings were compared with spectral and temporal resolutions of commonly used field agricultural multispectral sensors to examine their potential suitability for frost damage studies at the canopy scale, based on the correspondence of their multispectral bands to the results from this laboratory-based hyperspectral study.
关键词： REML,wheat,hyperspectral,multispectral,Agri-sensors,controlled environment room,remote sensing,frost
更新于2025-09-19 17:13:59
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A Greenhouse Test to Explore and Evaluate Light-Emitting Diode (LED) Insect Traps in the Monitoring and Control of Trialeurodes vaporariorum
摘要： Population control of small sucking insects has been challenging, and alternative control methods are constantly being sought. Visual traps have long been used to monitor and control pests. Colored sticky cards are widely used for diurnal pests, but their effects are influenced by environmental light conditions. Artificial light traps are mostly used for nocturnal pests. Here, we explored and evaluated light-emitting diode (LED) traps for the monitoring and control of small diurnal sucking insects using greenhouse tests targeting the greenhouse whitefly Trialeurodes vaporariorum. We tested the trapping efficacy of the LED water pan trap, assessed the most attractive LED light and analyzed its efficacy under different weather conditions. The results showed that the LED water pan trap was too inefficient to be useful. Green LEDs were more attractive than yellow LEDs, UV LEDs and green-UV combinations. Regardless of sunny or cloudy conditions, the green LED trap caught more than twice the number of whiteflies than the yellow sticky card alone under summer shading conditions. Our study suggests that LED traps have a significant field application value in whitefly mass trapping and may also be efficient for other diurnal insects. The design of LED traps specific for diurnal insects is discussed.
关键词： phototaxis,attractive light,field evaluation,light trap,environment light intensity
更新于2025-09-19 17:13:59