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Search results for: near-infrared
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Short Term Monitor of Photodegradation Processes in Ranitidine Hydrochloride Observed by FTIR and ATR FTIR
PublicationThe effects of degradation of ranitidine hydrochloride exposed to UVB radiation (l = 310 nm) and oxygen in a weathering chamber were studied by Fourier Transform Infrared spectroscopy (FTIR) and Attenuated Total Reflectance Fourier Transform Infrared spectroscopy (ATR-FTIR). ATR-FTIR profile indicated that the degradation was spatially heterogeneous. Significant amounts of photoproducts were detected only in a directly...
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Sport-related concussion alters cerebral hemodynamic activity during controlled respiration
PublicationThis study investigated cerebral hemodynamic activity following sport-related concussion. Prefrontal cortex oxygenation was assessed by near-infrared spectroscopy (NIRS) during a controlled breathing protocol. Wavelet transformation of the NIRS signals showed significant decreases in HbO2 and HbD amplitude at the respiratory frequency interval (0.10–0.6 HZ) from preseason baseline to acute concussion. These results suggest a decreased...
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The luminescence study of Ca14Zn6Ga10−xMnxO35 coumpounds.
Open Research DataManganese in the pentavalent state (Mn 5+) is both rare and central in materials exhibiting narrow-band near-infrared (NIR) emission and is highly sought after for phosphor-converted light-emitting diodes as promising candidates for future miniature solid-state NIR light source. We develop the Ca 14 Zn 6 Ga 10−x Mn x O 35 (x = 0.3, 0.5, 1.0, 1.25, 1.5,...
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Application of vibrational spectroscopy, thermal analyses and X-Ray diffraction in the rapid evaluation of the stability in solid-state of ranitidine, famotidine and cimetidine
PublicationThis paper reports the study on applicability of Fourier transform infrared (FTIR), near-infrared (NIR) and Raman spectroscopy, differential scanning calorimetry (DSC) and X-ray diffraction (XRD) for the estimation of the chemical stability and photostability of histamine H2-receptor antagonist substances. Ranitidine hydrochloride (RAN), famotidine (FAM) and cimetidine (CIM) were tested and differences in sensitivity were measured...
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Transiluminacyjne monitorowanie stanu przestrzeni podpajęczynówkowej
PublicationTransiluminacja tkanek ludzkiego ciała w celach diagnostycznych jest stosowana od ponad stu lat. Metoda transiluminacji w bliskiej podczerwieni z rozpraszaniem zwrotnym (NIRT-BSS) umożliwia ciągłe, bezinwazyjne monitorowanie zmian szerokości przestrzeni podpajęczynówkowej, które może być cennym narzędziem w ocenie zagrożenia obrzękiem mózgu. W rozprawie przedstawiono optyczny model rozchodzenia się promieniowania podczerwonego...
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MONTE CARLO MODELING OF OPTICAL SENSOR FOR POST-OPERATIVE FREE FLAP MONITORING
PublicationAfter a preliminary study of the currently employed methods in vitality monitoring of the tissue flaps (TRAM, DIEP, SIEA), a usefulness of optical techniques is discussed. It seems that one of the most promising in monitoring tissue flaps blood flow is a near infrared spectrometry (NIRS). However, a special design of a measurement sensor has to be developed. First, basing on the literature study an optical “window” is characterized....
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Effects of consecutive apneas on pial artery pulsation and subarachnoid width in healthy subjects
PublicationHypercapnia is known to dilate the pial artery, disrupt cerebral autoregulation and increase pial artery pulsation. The cerebral blood flow velocity (CBFV) response to hypercapnia is biphasic. Below the threshold for the increase of blood pressure (BP) with carbon dioxide partial pressure (pCO2), the CBFV measurement reflects vascular reactivity to pCO2 alone at a constant BP. Above this threshold, the CBFV measurement provides...
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The luminescence study of Ga2–x(Al0.68In0.32)xO3:Cr3+ coumpounds.
Open Research DataNear-infrared (NIR) phosphor-converted light-emitting diodes (pc-LEDs) are a highly efficient perspective NIR light source, with application hindered by a narrow emission band. In this work, we broaden the emission of a new series of NIR phosphors by controlling crystal structure disorder through cation cosubstitution. By substituting Ga3+ with (Al0.68In0.32)3+,...
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Effect of Maximal Breath Hold Apnea on Pial Artery Pulsation and Subarachnoid Width in Human
PublicationLittle is known about intracranial pressure (ICP)-cerebral hemodynamic interplay during maximal breath-hold apnea. A recently developed method based on near-infrared transillumination/backscattering sounding (NIR-T/BSS) noninvasively measures changes in pial artery pulsation (cc-TQ) as well as subarachnoid width (sas-TQ) in humans. Changes in sas-TQ correlate with ICP to a considerable extent, whereas cc-TQ reflects the functional...
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Solid state versus fiber picosecond infrared lasers applied to two-photon vision tests
PublicationDevelopment of new microperimetric tools dedicated for imaging of early functional changes in the retina may help in the monitoring of various ocular diseases progression e.g. Age-Related Macular Degeneration. Recently described two-photon vision may be applied to microperimetric devices. Many subjects with well-known disease history could be investigated with newly developed instrumentation that tests ability of human eye to perceive...
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Analyzing the Impact of Simulated Multispectral Images on Water Classification Accuracy by Means of Spectral Characteristics
PublicationRemote sensing is widely applied in examining the parameters of the state and quality of water. Spectral characteristics of water are strictly connected with the dispersion of electromagnetic radiation by suspended matter and the absorp-tion of radiation by water and chlorophyll a and b.Multispectral sensor ALI has bands within the ranges of electromagnetic radia-tion: blue and infrared, absent in sensors such as Landsat, SPOT,...
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Two-photon perimetry utilizing picosecond laser
PublicationAge-related impairments are becoming more and more severe for aging societies. The sensory organ diseases are particularly troublesome as they exclude seniors from their everyday activity. Therefore, maintaining good quality eyesight is essential for normal functioning. New medical therapies help restrain age-related changes, but still, monitoring is essential to the treatment process. Humans do not have the natural ability to...
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Spectroscopic evaluation on pseudopolymorphs of sodium naproxen
PublicationThis paper demonstrates the assessment of vibrational spectroscopy methods such as middle infrared, near infrared and Raman spectroscopy (FTIR, FT-NIR, Raman) for the identification of pseudopolymorphic forms of a model active pharmaceutical ingredient (API) - sodium naproxen (NpxNa). NpxNa, in the form of three different pseudopolymorphs, was investigated by methods dedicated for solid state characterization: DSC (differential...
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The luminescence study of SrAl11.88−xGaxO19:0.12Cr3+ coumpounds.
Open Research DataPortable near-infrared (NIR) light sources are in high demand for applications in spectroscopy, night vision, bioimaging, and many others. Typical phosphor designs feature isolated Cr3+ ion centers, and it is challenging to design broadband NIR phosphors based on Cr3+–Cr3+ pairs. Here, we explore the solid-solution series SrAl11.88–xGaxO19:0.12Cr3+...
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The luminescence study of Ga1.98–xAlxO3:0.02Cr3+ coumpounds.
Open Research DataA chemical and mechanical pressure-induced photoluminescence tuning method was developed through structural evolution and hydrostatic pressure involving phase transition. A series of Ga1.98−xAlxO3:0.02Cr3+ phosphors were synthesized by collaborators from National Taiwan University. Structural evolution reveals a crystal phase change with the incorporation...
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Operational algae bloom detection in the Baltic Sea using GIS and AVHRR data
PublicationDuring the blooming season, algal colonies can, in extreme cases, cover up to 200 000 square kilometres of the Baltic Sea water surface. Because the position and shape of the blooms may significantly change in very short time due to the influence of wind and waves, regular monitoring of the blooms' development is necessary. Currently, the desired monitoring frequency may only be achieved by means of remote sensing. The article...
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Implementation of SiN thin film in fiber-optic sensor working in telecommunication range of wavelengths
PublicationMirrors are used in optical sensors and measurement setups. This creates a demand for mirrors made of new materials and having various properties tailored to specific applications. In this work, we propose silicon covered with a thin silicon nitride layer as a mirror for near-infrared measurements. SiN layer was deposited on a standard silicon wafer with a Low-Pressure Chemical Vapor Deposition furnace. Then, the created layer...
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Polydopamine Biomaterials for Skin Regeneration
PublicationDesigning biomaterials capable of biomimicking wound healing and skin regeneration has been receiving increasing attention recently. Some biopolymers behave similarly to the extracellular matrix (ECM), supporting biointerfacial adhesion and intrinsic cellular interactions. Polydopamine (PDA) is a natural bioadhesive and bioactive polymer that endows high chemical versatility, making it an exciting candidate for a wide range of...
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Optical properties of the chemotherapy drugs used in the central nervous system lymphoma therapy: monitoring drug delivery
PublicationOur aim is to optically monitor the delivery of the chemotherapy drugs for brain tumours, particularly used in the central nervous system (CNS) lymphoma therapy. In vivo monitoring would help to optimize the treatment and avoiding unnecessary medications. Moreover, it would be beneficial to be able to measure which of the multi-regimen drugs actually do penetrate and how well into the brain tissue. There exist several potential...
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The Analysis of Vodka: A Review Paper
PublicationVodka is the most popular alcoholic beverage in Poland, Russia and other Eastern European countries, made from ethyl alcohol of agricultural origin that has been produced via fermentation of potatoes, grains or other agricultural products. Despite distillation and multiple filtering, it is not possible to produce 100 % ethanol. The solution with a minimum ethanol content of 96 %, which is used to produce vodkas, also contains trace amounts...
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Human subarachnoid space width oscillations in the resting state
PublicationAbnormal cerebrospinal fluid (CSF) pulsatility has been implicated in patients suffering from various diseases, including multiple sclerosis and hypertension. CSF pulsatility results in subarachnoid space (SAS) width changes, which can be measured with near-infrared transillumination backscattering sounding (NIR-T/BSS). The aim of this study was to combine NIR-T/BSS and wavelet analysis methods to characterise the dynamics of the...
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Featuring Semitransparent p–i–n Perovskite Solar Cells for High-Efficiency Four-Terminal/Silicon Tandem Solar Cells
PublicationTwo issues need to be resolved when fabricating p–i–n semitransparent perovskite solar cells (ST-PVSCs) for four-terminal (4 T) perovskite/silicon tandem solar cells: 1) damage to the underlying absorber (MAPbI3), electron transporting layer ([6,6]-phenyl-C61-butyric acid methyl ester, PCBM), and work function (WF) modifier (polyethylenimine, PEI), resulting from the harsh sputtering conditions for the transparent electrodes (TEs)...
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Comprehensive Review of Fluorescence Applications in Gynecology
PublicationSince the introduction of indocyanine green (ICG) as a fluorophore in near-infrared imaging, fluorescence visualization has become an essential tool in many fields of surgery. In the field of gynecology, recent new applications have been proposed and found their place in clinical practice. Different applications in gynecology were investigated, subcategorized, and overviewed concerning surgical applications and available dyes....
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Physics augmented classification of fNIRS signals
PublicationBackground. Predictive classification favours performance over semantics. In traditional predictive classification pipelines, feature engineering is often oblivious to the underlying phenomena. Hypothesis. In applied domains such as functional Near Infrared Spectroscopy (fNIRS), the exploitation of physical knowledge may improve the discriminative quality of our observation set. Aims. Give exemplary evidence that intervening the...
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Analysis
PublicationNew food products and diverse formulations containing the regulated steviol glycoside(s) as well as Stevia extracts or Stevia leaves have been brought on the global market. The upcoming multitude of such food products, but also their falsification and adulteration, does have impact on food analysis. Robust high-throughput methods that cope with different food matrices are required for food control to ensure food safety. The analysis...
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Two-photon microperimetry with picosecond pulses
PublicationTwo-photon vision is a phenomenon associated with the perception of short pulsesof near-infrared radiation (900-1200 nm) as a visible light. It is caused by the nonlinear processof two-photon absorption by visual pigments. Here we present results showing the influence ofpulse duration and repetition rate of short pulsed lasers on the visual threshold. We comparedtwo-photon sensitivity maps of the retina obtained for subjects with...
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Treated wasetewater as a source of humic substances in surface waters
PublicationHumic substances impose substantial effect on the aquatic environment as well as the water organisms and human health. Among other features, the humic acids determine organoleptic properties of surface waters. Therefore explanation of the origin and properties of humic acids in surface waters is one of the priorities of water technology.Recently it was pointed out that in the wastewater treatment process organic compounds characterized...
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The chemical and mechanical pressure influence on chromium luminescence
Open Research DataIn this study, we aim to compare the changes in the luminescence properties of Ga2O3:Cr3+ modified by Al or Sc ion substitution (chemical pressure) and hydrostatic pressure. We find the same behavior for Ga2–xAlxO3:Cr3+ and different behavior for Ga2–xScxO3:Cr3+ in terms of the optical properties under chemical and mechanical pressure. We consider Al...
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Effect of Maximal Apnoea Easy-Going and Struggle Phases on Subarachnoid Width and Pial Artery Pulsation in Elite Breath-Hold Divers
PublicationPurpose: The aim of the study was to assess changes in subarachnoid space width (sas-TQ), the marker of intracranial pressure (ICP), pial artery pulsation (cc-TQ) and cardiac contribution to blood pressure (BP), cerebral blood flow velocity (CBFV) and cc-TQ oscillations throughout the maximal breath hold in elite apnoea divers. Non-invasive assessment of sas-TQ and cc-TQ became possible due to recently developed method based on...
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Feasibility study of a Raman spectroscopic route to drug detection
PublicationWe present an surface-enhanced Raman spectroscopy (SERS) approach for detection of drugs of abuse in whole human blood. We utilize a near infrared laser with 830 nm excitation wavelength in order to reduce the influence of fluorescence on the spectra of blood. However, regular plasmon resonance peak of plasmonic nanoparticles, such as silver or gold fall in a much lower wavelength regime about 400 nm. Therefore, we have shifted...
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Multi-layered tissue head phantoms for noninvasive optical diagnostics
PublicationExtensive research in the area of optical sensing for medical diagnostics requires development of tissue phantoms with optical properties similar to those of living human tissues. Development and improvement of in vivo optical measurement systems requires the use of stable tissue phantoms with known characteristics, which are mainly used for calibration of such systems and testing their performance over time. Optical and mechanical...
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Investigations of Energy Conversion and Surface Effect for Laser-Illuminated Gold Nanorod Platforms
PublicationAchieving a quick temperature increase is a burning issue for biophysical applications, like germ inactivation and tumor ablation, and for energy performances, like solar collectors and steam generators. Based on the plasmon resonance phenomenon, noble metallic nanoparticles have emerged as promising weapons due to their very high biocompatibility, optical properties, and high surface-to-volume ratio, increasing energy conversion...
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Pupil detection supported by Haar feature based cascade classifier for two-photon vision examinations
PublicationThe aim of this paper is to present a novel method, called Adaptive Edge Detection (AED), of extraction of precise pupil edge coordinates from eye image characterized by reflections of external illuminators and laser beams. The method is used for monitoring of pupil size and position during psychophysical tests of two-photon vision performed by dedicated optical set-up. Two-photon vision is a new phenomenon of perception of short-pulsed...
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Subarachnoid Space: New Tricks by an Old Dog
PublicationPurpose: The purpose of the study was to: (1) evaluate the subarachnoid space (SAS) width and pial artery pulsation in both hemispheres, and (2) directly compare magnetic resonance imaging (MRI) to near-infrared transillumination/backscattering sounding (NIR-T/BSS) measurements of SAS width changes in healthy volunteers.Methods: The study was performed on three separate groups of volunteers, consisting in total of 62 subjects (33...
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In vivo imaging of the human eye using a two-photon excited fluorescence scanning laser ophthalmoscope
PublicationBACKGROUND. Noninvasive assessment of metabolic processes that sustain regeneration of human retinal visual pigments (visual cycle) is essential to improve ophthalmic diagnostics and to accelerate development of new treatments to counter retinal diseases. Fluorescent vitamin A derivatives, which are the chemical intermediates of these processes, are highly sensitive to UV light; thus, safe analyses of these processes in humans...
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Pial artery and subarachnoid width response to apnoea in normal humans
PublicationBackground: Little is known about intracranial pressure (ICP)-cerebral haemodynamic interplay during repetitive apnoea. A recently developed method based on near-infrared transillumination/backscattering sounding (NIR-T/BSS) noninvasively measures changes in pial artery pulsation (cc-TQ) as well as subarachnoid width (sas-TQ) in humans. Method: We tested the complex response of the pial artery and subarachnoid width to apnoea...
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Multispectral Imaging Using Fluorescent Properties of Indocyanine Green and Methylene Blue in Colorectal Surgery—Initial Experience
PublicationIntroduction: Image-guided surgery is becoming a new tool in colorectal surgery. Intraoperative visualisation of different structures using fluorophores helps during various steps of operations. In our report, we used two fluorophores—indocyanine green (ICG), and methylene blue (MB)— during different steps of colorectal surgery, using one camera system for two separate near-infrared wavelengths. Material and methods: Twelve patients...
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Wavelet transform analysis to assess oscillations in pial artery pulsation at the human cardiac frequency
PublicationPial artery adjustments to changes in blood pressure (BP)may last only seconds in humans. Using a novelmethod called near-infrared transillumination backscattering sounding (NIR-T/BSS) that allows for the non-invasive measurement of pial artery pulsation (cc-TQ) in humans, we aimed to assess the relationship between spontaneous oscillations in BP and cc-TQ at frequencies between 0.5 Hz and 5 Hz. We hypothesized that analysis of...
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Increased inspiratory resistance affects the dynamic relationship between blood pressure changes and subarachnoid space width oscillations
PublicationBackground and objective Respiration is known to affect cerebrospinal fluid (CSF) movement. We hypothesised that increased inspiratory resistance would affect the dynamic relationship between blood pressure (BP) changes and subarachnoid space width (SAS) oscillations. Methods Experiments were performed in a group of 20 healthy volunteers undergoing controlled intermittent Mueller Manoeuvres (the key characteristic of the procedure...
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Development of biocompatible iron oxide-silicon oxide core-shell nanoparticles as subcellular delivery platform for glucosamine-6-phosphate synthase inhibitors
PublicationIn order to develop the preparation of iron oxide-silica coreshell nanoparticles (CSNPs), thesis deeply explores the cetyltrimethylammonium (CTA+) directed silica coating methods of the oleic-acid capped iron oxide nanoparticles (OA-IONPs) initialized under near-neutral pH conditions. It is demonstrated that the initial alkaline hydrolysis of ethyl acetate in the presence of CTA+ and OA-IONPs induces an unusual ligand exchange...
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The influence of chitosan hydrogel cross-linking by agarose on coating physico-chemical properties
Open Research DataThis dataset contains various physicochemical analyses showing the effect of different concentration of chitosan and the cross-linking agent agarose. Each sample is labeled by C and A representing chitosan and agarose concentrations, respectively, while the exact amounts are depicted in the attached table. Fourier-transform infrared (FT-IR) spectroscopy...
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Sympathetic Activation Does Not Affect the Cardiac and Respiratory Contribution to the Relationship between Blood Pressure and Pial Artery Pulsation Oscillations in Healthy Subjects
PublicationUsing a novel method called near-infrared transillumination backscattering sounding (NIR-T/BSS) that allows for the non-invasive measurement of pial artery pulsation (cc-TQ) and subarachnoid width (sas-TQ) in humans, we assessed the influence of sympathetic activation on the cardiac and respiratory contribution to blood pressure (BP) cc-TQ oscillations in healthy subjects. The pial artery and subarachnoid width response to handgrip...
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Towards spectral sensitivity curve for two-photon vision mechanism
PublicationAbstract Purpose: The perceived brightness of different visible light sources can be compared with photometric units based on the standardized luminosity curves (300-780nm range). As reported previously (PNAS 111(50), pp. E5445-E5454 (2014)), near-infrared (NIR) radiation can cause isomerization of visual pigments by one- or two-photon absorption. The perceived color of the stimulus is red in the case of one-photon vision (1PV)...
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Development of Biocompatible Fe3O4@SiO2 Nanoparticles as Subcellular Delivery Platform for Glucosamine-6-phosphate Synthase Inhibitors
PublicationNumerous inhibitors of glucoseamine-6-phophate synthase (GlcN-6-P), the enzyme responsible from catalysis of the first step of metabolic pathway leading to metabolism 5’-diphospho-N-acetyl-D- glucosamine, were reported as effective agents for inhibiting the growth of various fungal pathogens. Among the reported inhibitors,...
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The luminescence study of Sr3−xBaxP5N10Cl: Eu2+ nitridophosphate.
Open Research DataA series of zeolitic nitridophosphate phosphors Sr2.91−xBaxP5N10Cl:0.09Eu2+ was synthesized by our collaborators from National Taiwan University using a hot isostatic press. Detailed thermal properties were determined using the temperature-dependent photoluminescence intensity and decay time. This research provides a different perspective to analyze...
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The luminescence study of LiGa5(1−x)O8:5xCr3+ coumpounds
Open Research DataInfrared luminescent materials have evoked much attention from chemists and material scientists. Although substantial progress is made in materials design, the luminescent mechanism remains ambiguous in the complex structures, presenting major barriers to developing novel infrared luminescent materials. Herein, this study aims to deliberate a complete...