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Fast neutron detectors with silicon photomultiplier readouts
摘要： This work summarizes a fast neutron detection performance of two different silicon photomultipliers from two manufacturers. The first SiPM (MAPD-3NK) from Zecotek Photonics consists of deeply buried cells with the active area 3.7x3.7 mm2. The second one (MPPC-S12572-010P) from Hamamatsu, however, consists of surface cell structure which the active area is 3x3 mm2. Both SiPMs have the same pixel density of 10000 mm-2. Both SiPMs coupled to Stilbene (5*5*5 mm3) and p-terphenyl (5*5*5 mm3) plastic scintillators were evaluated for detection ability of fast neutrons using a PuBe neutron source. Charge comparison and zero crossing neutron/gamma discrimination techniques were performed for these detectors and the results were compared. The obtained results prove a good fast neutron detection performance of the SiPMs which makes it possible to use these types of neutron detectors in fast neutron detection applications.
关键词： Pulse shape discrimination,Micropixel avalanche photodiode,Charge comparison,SiPM,MAPD,PSD,Zero crossing,Silicon photomultiplier
更新于2025-09-23 15:21:21
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Exploiting Evanescent Field Polarization for Giant Chiroptical Modulation from Achiral Gold Half-Rings
摘要： For applications seeking to realize on-chip polarization discriminating nanoantennas, efficient energy conversion from surface waves to far-field radiation is desirable. However, the response of individual nanoantennas to the particular polarization states achievable in surface waves, such as evanescent fields, has not yet been thoroughly investigated. Here, we report giant modulation of visible light scattering from achiral gold half-rings when switching between evanescent surface wave excitation produced from total internal reflection of left-handed and right-handed circularly polarized light. The effect is driven by a differing relative phase between the in-plane transverse and longitudinal field oscillations of the evanescent wave depending on the incident light handedness. As longitudinal field oscillations are not found in free-space excitation, this presents a fundamentally different mechanism for chiroptical responses as traditional mechanisms for circular dichroism only account for purely transversal field oscillations. Although the half-ring scattering modulation is dependent on the wave vector orientation, an orientation invariant response is also realized in planar chiral nanoantennas composed of eight half-rings in a rotationally symmetric arrangement, with up to 50% scattering modulation observed at 725 nm. Though both structures are found to produce scattering modulation when switching the handedness of free-space light, the distinct polarization properties of evanescent fields are shown to be strictly required to observe giant scattering modulation. These results ultimately deepen our understanding of the range of possible chiroptical effects in light-matter interactions.
关键词： nanoantenna,extrinsic chirality,evanescent fields,planar chirality,polarization discrimination,longitudinal field oscillations
更新于2025-09-23 15:21:21
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Discrimination of entangled photon pair from classical photons by de Broglie wavelength
摘要： Quantum optics largely relies on the fundamental concept that the diffraction and interference patterns of a multi-partite state are determined by its de Broglie wavelength. in this paper we show that this is still true for a mixed state with one sub-system being in a classical coherent state and one being in entangled state. We demonstrate the quantum-classical light discrimination using de Broglie wavelength for the states with all classical parameters being the same.
关键词： entangled photons,de Broglie wavelength,quantum optics,classical photons,quantum-classical discrimination
更新于2025-09-23 15:21:01
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Patterns of propagation of high-order nonlinear dispersion wave modelled by the generalised KP equation
摘要： A wide range of two-dimensional nonlinear wave is described by Kadomtsev–Petviashvili (KP) equation. We obtained the classi?cation of travelling wave patterns to the generalised KP equation with high-order nonlinear dispersive and dissipative terms. Among these patterns, some new phenomena can be acquired for the ?rst time. Representations of wave propagation patterns were achieved by taking speci?c values of parameters. This means that all these patterns can be realised under appropriate physical conditions.
关键词： patterns of propagation,solitons.,Complete discrimination system for the polynomial,generalised Kadomtsev–Petviashvili equation
更新于2025-09-23 15:21:01
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Stereoselective Sensing of <scp>l</scp> - and <scp>d</scp> -Amino Acids: Development of a Fluorescence-Array Based on Readily Available Chiral Phosphoric Acids
摘要： A chiral sensor-array for the identification of amino-acids was developed, using six readily available bis- and tris-phosphoric acids in combination with Ni2 + and Eu3 +, resulting in a fluorescence-based array with twelve sensors. This array was successfully applied for the chemoselective identification of 19 amino-acids, but also for the enantioselective discrimination between the l- and d-enantiomers.
关键词： amino-acids,chiral sensor-array,fluorescence-based array,enantioselective discrimination,chemoselective identification
更新于2025-09-23 15:21:01
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Discrimination of whiskies using an “add-a-fluorophore” fluorescent fingerprinting strategy
摘要： This study is concerned with the development of a fluorescent fingerprinting technique using external fluorophores. This approach is based on the quenching/dequenching of emissions by the components in the sample and therefore has wider possibilities than the common fingerprinting technique, which is based on the intrinsic fluorescence of a sample. The procedure involved mixing the sample with fluorophores in 96-well plates and recording emissions by digital photography using a Camag Visualizer 2 instrument. After RGB splitting of the images, the data were normalized and treated by principal component analysis (PCA). The quality of discrimination, characterized by the number of separate groups of points in the scores plot, was essentially improved when the images were contrasted using the bundled software. To enable interactions with a wide range of potential marker compounds, we studied six fluorophores of different chemical origins (rhodamine B on silica nanoparticles, fluorescein attached to polyethyleneimine, a Schiff base obtained using o?phthalaldehyde and polyethyleneimine, quantum dots of CdSe/CdS/ZnS, a ruthenium(II) complex with 2,2′?bipyridine (Ru(bpy)3 2+), and a zinc complex with 8?hydroxyquinoline?5?sulfonate). Interestingly, just one fluorophore, Ru(bpy)3 2+, sufficed to discriminate between 16 samples of whiskies (Scotch, Irish, Bourbon, and other varieties). The quality of discrimination by RGB images was at least equal to that obtained using the emission spectra measured with a spectrofluorimeter (400–700 nm). Using any of the studied fluorophores is more efficient for discrimination than depending on the intrinsic fluorescence of individual whiskies.
关键词： Fluorophore,Whisky,Tris(2,2′?bipyridyl)dichlororuthenium(II),Principal component analysis,Fluorescent fingerprints,Digital image,Contrasting,Discrimination
更新于2025-09-23 15:21:01
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Near optimal discrimination of binary coherent signals via atom–light interaction
摘要： We study the discrimination of weak coherent states of light with significant overlaps by nondestructive measurements on the light states through measuring atomic states that are entangled to the coherent states via dipole coupling. In this way, the problem of measuring and discriminating coherent light states is shifted to finding the appropriate atom–light interaction and atomic measurements. We show that this scheme allows us to attain a probability of error extremely close to the Helstrom bound, the ultimate quantum limit for discriminating binary quantum states, through the simple Jaynes–Cummings interaction between the field and ancilla with optimized light–atom coupling and projective measurements on the atomic states. Moreover, since the measurement is nondestructive on the light state, information that is not detected by one measurement can be extracted from the post-measurement light states through subsequent measurements.
关键词： Helstrom bound,state discrimination,atom–light interaction,nondestructive measurement,quantum communication,coherent state
更新于2025-09-23 15:21:01
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Setting Up Surface-Enhanced Raman Scattering Database for Artificial Intelligence-Based Label-Free Discrimination of Tumor Suppressor Genes
摘要： The quality of input data in deep learning is tightly associated with the ultimate performance of machine learner. Taking advantages of unique merits of surface-enhanced Raman scattering (SERS) methodology in the collection and construction of database (e.g., abundant intrinsic fingerprint information, noninvasive data acquisition process, strong anti-interfering ability, etc.), herein we set up SERS-based database of deoxyribonucleic acid (DNA), suitable for artificial intelligence (AI)-based sensing applications. The database is collected and analyzed by silver nanoparticles (Ag NPs)-decorated silicon wafer (Ag NPs@Si) SERS chip, followed by training with a deep neural network (DNN). As proof-of-concept applications, three kinds of representative tumor suppressor genes, i.e., p16, p21 and p53 fragments, are readily discriminated in label-free manners. Prominent and reproducible SERS spectra of these DNA molecules are collected and employed as input data for DNN learning and training, which enables selective discrimination of DNA target(s). The accuracy rate for the recognition of specific DNA target reaches 90.28%.
关键词： surface-enhanced Raman scattering,label-free discrimination,deep neural network,tumor suppressor genes,artificial intelligence
更新于2025-09-23 15:21:01
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Coal Discrimination Analysis Using Tandem Laser-Induced Breakdown Spectroscopy and Laser Ablation Inductively Coupled Plasma Time-of-Flight Mass Spectrometry
摘要： The contribution and impact of combined laser ablation inductively coupled plasma time of flight mass spectrometry (LA-ICP-TOF-MS) and laser induced breakdown spectroscopy (LIBS) were evaluated for the discrimination analysis of different coal samples. This Tandem approach allows simultaneous determination of major and minor elements (C, H, Si, Ca, Al, Mg, etc), and trace elements (V, Ba, Pb, U, etc.) in the coal. The research focused on coal classification strategies based on principle component analysis (PCA) combined with K-means clustering, partial least squares discrimination analysis (PLS-DA), and support vector machine (SVM) for analytical performance. Correlation analyses performed from TOF mass and LIBS emission spectra from the coal samples showed that most major, minor, and trace elements emissions had negative correlation with the volatile content. Suitable variables for the classification models were determined from these data. The individual TOF data, LIBS data, and the combined data of TOF and LIBS, respectively, as the input for different models were analyzed and compared. In all cases, the results obtained with the combined TOF and LIBS data were found to be superior to those obtained with the individual TOF or LIBS data. The nonlinear SVM model combined with TOF and LIBS data provided the best coal classification performance, with a classification accuracy of up to 98%.
关键词： Principal component analysis,Support vector machine,Partial least squares discrimination analysis,Laser-induced breakdown spectroscopy,K-means clustering,Coal discrimination,Laser ablation inductively coupled plasma time of flight mass spectrometry
更新于2025-09-23 15:19:57
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Multi-dimensional fluorescence spectroscopy coupled with chemometrics in rapid antibiotic detection and discrimination
摘要： Antibiotic residues in animal-derived foods pose risk to human health including chemical poisoning and antimicrobial resistance, and therefore, constant monitoring throughout the food supply chain is important. In the present study multi-dimensional fluorescence spectroscopy (3D and 2D) coupled with chemometric tools were tested for potential application to detect, discriminate and quantify penicillin G (PG), sulfadiazine (SF) and tetracycline (TC) in milk by direct measurement. Qualitative and quantitative calibration models were developed for prediction of antibiotic residues. Results demonstrated optimal discrimination of milk samples on the basis of antibiotic type and concentration with close to 100% of accuracy. Negative correlation between antibiotic concentration and fluorescence peak height was displayed (r ≥ 0.963 and p ≤ 0.002). A great potential for quantitative antibiotic determination was established with R2 > 0.9 and low standard errors of estimation indicating acceptable precision for the developed technique. Fluorescence spectroscopy demonstrated high specificity and sensitivity with detection limit below the maximum residue limit of PG, SF and TC in milk. Therefore, fluorescence spectroscopy can be used as an alternative method for rapid screening of antibiotic residues in milk at collection centers and processing plants to ensure product quality and safety.
关键词： Rapid detection,Antibiotics,Discrimination,Fluorescence spectroscopy,Milk
更新于2025-09-23 15:19:57