- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Metal-Ion Displacement Approach for Optical Recognition of Thorium: Application of a Molybdenum(VI) Complex for Nanomolar Determination and Enrichment of Th(IV)
摘要： An azine-based molybdenum (Mo(VI)) complex (M1) is exploited for selective detection of thorium (Th(IV)) ions through a metal-ion displacement protocol. Th(IV) displaces Mo(VI) from M1 instantly leading to the formation of the Th(IV) complex, having orange-red emission. Consequently, a red shift of the emission wavelength along with 41-fold ?uorescence enhancement is observed. This unique method allows detection of Th(IV) as low as 1.5 × 10?9 M. The displacement of Mo(VI) from M1 by Th(IV) is established by spectroscopic studies and kinetically followed by the stopped-?ow technique. The displacement binding constant for Th(IV) is notably strong, 4.59 × 106 M?1. Extraction of Th(IV) from aqueous solution to the ethyl acetate medium using M1 has been achieved. The silica-immobilized M1 e?ciently enriches Th(IV) from its reservoir through solid-phase extraction. Computational studies (density functional theory) support experimental ?ndings.
关键词： Solid-phase extraction,Molybdenum(VI) complex,Fluorescence enhancement,Thorium detection,Metal-ion displacement
更新于2025-09-23 15:21:01
-
[IEEE 2018 IEEE 17th International Conference on Mathematical Methods in Electromagnetic Theory (MMET) - Kiev (2018.7.2-2018.7.5)] 2018 IEEE 17th International Conference on Mathematical Methods in Electromagnetic Theory (MMET) - Facet Model Processing for Complex Shape Object Scattering Calculation
摘要： The problem of construction a facet model of complex shape object for simulation of scattering electromagnetic is considered. It is proposed to use the approach of ray-tracing and kd-trees in order to take into account the re-reflections between some parts of the object. An algorithm for simplifying the geometric model of the object is proposed in order to reduce the time necessary for modeling. Comparison of calculated fields for identical objects, but with a different number of facets, showed that combining facets accelerates the simulation without violating its accuracy.
关键词： Complex shape object,RCS,facet,ray-tracing,kd-tree
更新于2025-09-23 15:21:01
-
Method for Mapping Rice Fields in Complex Landscape Areas Based on Pre-Trained Convolutional Neural Network from HJ-1 A/B Data
摘要： Accurate and timely information about rice planting areas is essential for crop yield estimation, global climate change and agricultural resource management. In this study, we present a novel pixel-level classi?cation approach that uses convolutional neural network (CNN) model to extract the features of enhanced vegetation index (EVI) time series curve for classi?cation. The goal is to explore the practicability of deep learning techniques for rice recognition in complex landscape regions, where rice is easily confused with the surroundings, by using mid-resolution remote sensing images. A transfer learning strategy is utilized to ?ne tune a pre-trained CNN model and obtain the temporal features of the EVI curve. Support vector machine (SVM), a traditional machine learning approach, is also implemented in the experiment. Finally, we evaluate the accuracy of the two models. Results show that our model performs better than SVM, with the overall accuracies being 93.60% and 91.05%, respectively. Therefore, this technique is appropriate for estimating rice planting areas in southern China on the basis of a pre-trained CNN model by using time series data. And more opportunity and potential can be found for crop classi?cation by remote sensing and deep learning technique in the future study.
关键词： mapping rice ?elds,convolutional neural network,time series of vegetation index,complex landscape,transfer learning
更新于2025-09-23 15:21:01
-
Luminescence and reactivity of a charge-transfer excited iron complex with nanosecond lifetime
摘要： Iron’s abundance and rich coordination chemistry are potentially appealing features for photochemical applications. However, the photoexcitable charge-transfer (CT) states of most Fe complexes are limited by picosecond or sub-picosecond deactivation through low-lying metal centered (MC) states, resulting in inefficient electron transfer reactivity and complete lack of photoluminescence. Here we show that octahedral coordination of Fe(III) by two mono-anionic facial tris-carbene ligands can suppress such deactivation dramatically. The resulting complex [Fe(phtmeimb)2]+, where phtmeimb is [phenyl(tris(3-methylimidazol-1-ylidene))borate]-, exhibits strong, visible, room temperature photoluminescence with a 2.0 ns lifetime and 2% quantum yield via spin-allowed transition from a ligand-to-metal charge-transfer (2LMCT) state to the ground state (2GS). Reductive and oxidative electron transfer reactions were observed for the 2LMCT state of [Fe(phtmeimb)2]+ in bimolecular quenching studies with methylviologen and diphenylamine.
关键词： charge-transfer,iron complex,electron transfer,photoluminescence,N-heterocyclic carbene
更新于2025-09-23 15:21:01
-
Novel and Easy Accessible Method for the Estimation of Copper Spectrophotometrically in Water and Soil Samples
摘要： A simple and sensitive spectrophotometric method has been established for the determination of copper in water and soil sample. The method simply involves the chelation of Dimethylglyoxime ligand with Copper under optimal conditions. The method is based on the formation of 1:2 complexes between Copper and Dimethylglyoximine. The optimal condition for the determination of copper was established. The Beer’s law was applicable in the range 0.05 to 0.995 μg/ml. The molar extinction coefficient of the said complex was found to be 1.2 × 105 mol-1 cm-1. The method was successfully applied for the determination of Copper in the water and soil samples.
关键词： Copper,Dimethylglyoximine,Mole ratio method,Chelate complex,Spectrophotometry
更新于2025-09-23 15:21:01
-
Magnetic and Luminescence Properties of Two Dinuclear Lanthanide Complexes with Butterfly-like Arrangement
摘要： Two dinuclear lanthanide complexes with pentadentate ligand 3-[bis(pyridine-2-ylmethyl)amino]propane-1,2-diol (H2L), formulated as [Ln2(HL)2(NO3)2(H2O)2]·1.5NO3·0.5I [Ln = Tb (ZTU-1) and Eu (ZTU-2); ZTU = Zhaotong University] were synthesized and structurally characterized. ZTU-1 and ZTU-2 are isomorphous and feature a butterfly-like arrangement. The fluorescence properties of ZTU-1 and ZTU-2 are investigated and slow magnetic relaxation behavior is observed in ZTU-1.
关键词： Lanthanides,Slow magnetic relaxation,Luminescence,Dinuclear lanthanide complex
更新于2025-09-23 15:21:01
-
High-capacity super-channel-enabled multi-core fiber optical switching system for converged inter/intra data center and edge optical networks
摘要： Timely diagnosis and treatment of these diseases are crucial to prevent death and dangerous complications. One of the important tools in early diagnosis of arrhythmias is analysis of electrocardiograms (ECGs) obtained from ambulatory long-term recordings. The design of novel patch-type ECG recorders has increased the accessibility of these long-term recordings. In many applications, it is furthermore an advantage for these devices that the recorded ECGs can be analyzed automatically in real time. The purpose of this study was therefore to design a novel algorithm for automatic heart beat detection, and embed the algorithm in the CE marked ePatch heart monitor. The algorithm is based on a novel cascade of computationally ef?cient ?lters, optimized adaptive thresholding, and a re?ned search back mechanism. The design and optimization of the algorithm was performed on two different databases: The MIT-BIH arrhythmia database (Se = 99.90%, P+ = 99.87) and a private ePatch training database (Se = 99.88%, P+ = 99.37%). The of?ine validation was conducted on the European ST-T database (Se = 99.84%, P+ = 99.71%). Finally, a double-blinded validation of the embedded algorithm was conducted on a private ePatch validation database (Se = 99.91%, P+ = 99.79%). The algorithm was thus validated with high clinical performance on more than 300 ECG records from 189 different subjects with a high number of different abnormal beat morphologies. This demonstrates the strengths of the algorithm, and the potential for this embedded algorithm to improve the possibilities of early diagnosis and treatment of cardiovascular diseases.
关键词： Automatic QRS complex detection,ePatch ECG recorder,real-time ECG analysis,embedded ECG analysis,patch type ECG recorder
更新于2025-09-23 15:19:57
-
[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Advanced Characterisation of Black Silicon Surface Topography with 3D PFIB-SEM
摘要： Modeling complex natural and human systems to support policy or management decision making is becoming increasingly common. The resulting models are often designed and implemented by researchers or domain experts with limited software engineering expertise. To help this important audience, we present our experience and share lessons learned from the design and implementation of an agent-based model of agricultural production systems in the Argentine Pampas, emphasizing the software engineering perspective. We discuss the model’s design including the model classes; the activity diagram, and data flow; the package and folder layout; the use of design patterns; performance optimization; initialization approaches; the analysis of results; and model measurement, validation, and verification.
关键词： agent-based modeling,coupled human and natural systems,Complex adaptive systems,software engineering,model design and implementation
更新于2025-09-23 15:19:57
-
[Laser Institute of America ILSC?? 2019: Proceedings of the International Laser Safety Conference - South Kissimmee, Florida, USA (March 18a??21, 2019)] International Laser Safety Conference - Safety issues concerning technical realization and usage of a mobile laser rescue device
摘要： Safety aspects are essential for modular, mobile laser cutting, specially designated for complex rescue operations. The development described here was inspired by the enhanced performance requirements of equipment for complex technical rescue operations, resulting from the increased strengths of materials actually used e.g. in vehicles to improve the overall safety. The new laser rescue tool shall be an alternative to conventional rescue systems such as hydraulic shears. Based on a fiber laser with a maximum output power of 2.5 kW and a specially developed hand-held laser processing head, adaptable to different drive units, a first integrated demonstrator has been set up to investigate performance and practicality in the course of selected rescue situations. The main challenge is to realize cutting of multilayer structures containing various materials, taking into account harsh outdoor conditions. To ensure laser safety concerning all people at the scene of an accident, i.e. injured persons, rescue teams, police officers, onlookers, etc., several technical safety functions are implemented. Furthermore, laser-protective goggles, beam dumps and laser-protective curtains are relevant protection components for the local and peripheral laser safety. The rescue operations are to be supported by a safety officer who has to ensure that all protective measures are taken.
关键词： safety aspects,mobile laser cutting,laser rescue device,complex rescue operations,laser safety
更新于2025-09-23 15:19:57
-
Tracing harmonic distortion and voltage unbalance in secondary radial distribution networks with photovoltaic uncertainties by an iterative multiphase harmonic load flow
摘要： Secondary radial distribution networks (SRDNs) have been increasingly affected by the uncertainties of harmonic sources associated with photovoltaic (PV) systems. The quantitative assessment of uncertainty propagation causing harmonic distortion and voltage unbalance can be successively handled by probabilistic or affine formulations of harmonic load flows (HLFs). This study developed a general analytical technique (GAT) for solving iterative multiphase HLFs in SRDNs with PV uncertainties. This technique merges the point-estimate method (PEM) and complex affine arithmetic (AA), combined with Legendre series approximation (LGSA). It also models the input correlation. One advantage of this GAT is that the iterative harmonic penetration (IHP) method, modeled for HLF, accounts for the interaction of background harmonic voltage with the PV harmonic current. The first prerequisite was evidently an uncertainty model for PV harmonic current. This paper presents the results for a real unbalanced three-phase SRDN and compares them with those obtained with the Monte-Carlo simulation (MCS). These confirmed the accuracy of GAT as well as its lower computational cost. The numerical results obtained showed that the GAT outperformed the incomplete GAT (IGAT), which is solely based on PEM and Cornish-Fisher expansion, thanks to the ability of AA to bound the outputs used in the LGSA.
关键词： PV system,Unbalance,Complex affine arithmetic,Harmonic load flow,Harmonic distortion,Point estimate methods
更新于2025-09-23 15:19:57