Integrated Intensity Ratio Research Articles

Strong red upconversion luminescence of Yb3+/Er3+ co-doped Sc6WO12 phosphor for optical thermometry

Herein, a strong red upconversion phosphor of Yb3+/Er3+ co-doped Sc6WO12 was prepared by employing an equivalent substitution approach. When irradiated by 980 nm near-infrared laser, the phosphor emits strong 660 nm red light. The main excitation mechanism for its red upconversion luminescence emission is the energy transfer process, through which the Er3+ ions is promoted from the 4I13/2 energy level to the 4F9/2 energy level. In addition, it is noteworthy that the multimode upconversion luminescence phosphor exhibits three different trends upon temperature change, and its upconversion emission integral intensity ratio exhibits a linear relationship with temperature in the range of 298 K–623 K. This special property makes the phosphor promising for applications in optical temperature measurement.

Influence of argon plasma treatment on interfacial performance of CFRP at high temperature

ABSTRACT This study introduces a novel approach to significantly enhance the interfacial properties of carbon fiber reinforced composites at elevated temperatures. Utilizing argon plasma treatment significantly boosted the interlaminar shear strength (ILSS) of the CF/PI composite when subjected to high temperatures. An optimal treatment condition, utilizing a power setting of 200 W, facilitated a 33.37% enhancement in ILSS over the untreated CF/PI composite at 300 °C, demonstrated an 89.39% retention of ILSS at the same temperature, and preserved ILSS at 77.90 MPa at 350 °C. At an optimal plasma treatment power, the fiber surface exhibited protrusions; surface roughness augmented to 181.90 nm, and the AD/AG ratio (the ratio of integral intensity between the Raman’s D-peak and G-peak) increased to 2.692. These modifications are identified as crucial factors in the improvement of the ILSS of the CF/PI composite at elevated temperatures.

Construction of multifunctional core-shell structure nanoprobe integrating NIR dual-mode optical thermometer and nuclear magnetic imaging

Precise temperature regulation and imaging are critical for in vivo photothermal treatment. The goal of this work is to realize non-contact temperature measurement and imaging in biological tissues by building a multifunctional nano-platform using optical temperature probes and imaging for biological diagnosis and therapy. Here, NIR dual-mode temperature probes of NaYF4: Nd/Yb/Gd@NaNdF4 were designed according to the LIR-I of 4F3/2 → 4I9/2/2F5/2 → 2F7/2 levels in 850 – 1025 nm and LIR-II of 2F5/2 → 2F7/2/4F3/2 → 4I11/2 in 950 – 1100 nm from the emissions of Nd3+/Yb3+. Transmission electron microscope (TEM) and X-ray diffraction (XRD) data of the sample demonstrate its superior dispersibility and accurate structure. The integrated intensity ratio centered around various luminescence intensity peaks is used as a temperature sensor since luminescence intensity is temperature-dependent. Additionally, the temperature sensing capabilities of two ratio temperature sensors were examined under 808 nm laser excitation, utilizing LIR (luminescence intensity ratio) technology. Furthermore, the MRI test indicated that the sample exhibited good imaging capacity when Gd3+ was added. These results assure the auspicious application prospects of the samples in temperature sensing, photothermal therapy, and biomedical imaging.

Physical properties of the southwest outflow streamer in the starburst galaxy NGC 253 with ALCHEMI

Aims. The physical properties of galactic molecular outflows are important as they could constrain outflow formation mechanisms. In this work, we study the properties of the southwest (SW) outflow streamer including gas kinematics, optical depth, dense gas fraction, and shock strength through molecular emission in the central molecular zone of the starburst galaxy NGC 253. Methods. We imaged the molecular emission in NGC 253 at a spatial resolution of 1.6″(∼27 pc at D ∼ 3.5 Mpc) based on data from the ALMA Comprehensive High-resolution Extragalactic Molecular Inventory (ALCHEMI) large program. We traced the velocity and velocity dispersion of molecular gas with the CO(1–0) line and studied the molecular spectra in the region of the SW streamer, the brightest CO streamer in NGC 253. We constrained the optical depth of the CO emission with the CO/13CO(1–0) ratio, the dense gas fraction with the HCN/CO(1–0), H13CN/13CO(1–0) and N2H+/13CO(1–0) ratios, as well as the shock strength with the SiO(2–1)/13CO(1–0) and CH3OH(2k–1k)/13CO(1–0) ratios. Results. The CO/13CO(1–0) integrated intensity ratio is ∼21 in the SW streamer region, which approximates the C/13C isotopic abundance ratio. The higher integrated intensity ratio compared to the disk can be attributed to the optically thinner environment of CO(1–0) emission inside the SW streamer. The HCN/CO(1–0) and SiO(2–1)/13CO(1–0) integrated intensity ratios both approach ∼0.2 in three giant molecular clouds (GMCs) at the base of the outflow streamers, which implies a higher dense gas fraction and strength of fast shocks in those GMCs than in the disk, while the HCN/CO(1–0) integrated intensity ratio is moderate in the SW streamer region. The contours of those two integrated intensity ratios are extended in the directions of outflow streamers, which connect the enhanced dense gas fraction and shock strength with molecular outflow. Moreover, the molecular gas with an enhanced dense gas fraction and shock strength located at the base of the SW streamer shares the same velocity as the outflow. Conclusions. The enhanced dense gas fraction and shock strength at the base of the outflow streamers suggest that star formation inside the GMCs can trigger shocks and further drive the molecular outflow. The increased CO/13CO(1–0) integrated intensity ratio coupled with the moderate HCN/CO(1–0) integrated intensity ratio in the SW streamer region are consistent with the picture that the gas velocity gradient inside the streamer may decrease the optical depth of CO(1–0) emission, as well as the dense gas fraction in the extended streamer region.

Investigation of the sensitization effect of Yb3+ in Yb, Er co-doped Sr5(PO4)3F transparent ceramics: From single-band red upconversion to temperature sensing behavior

Lanthanide-ion-doped red upconversion (UC) fluorescent materials with excellent signal-to-noise ratio, stability, and red-green luminous intensity ratio have proven of tremendous research importance for biomedical, three-dimensional (3D) displays, sensors, and other sectors. In this study, xYb, 1Er: Sr5(PO4)3F (S-FAP) (x=0–5 at%) transparent ceramics with outstanding optical quality were fabricated by hot pressing the co-precipitation powder with high sintering activity. The energy dispersive X-ray (EDX) results showed that the trivalent lanthanide ions were evenly doped into the S-FAP ceramic lattice. Increased Yb3+ doping considerably restricted the growth of ceramic grain size, which should be attributable to a decrease in sintering activity under high Yb doping conditions. The co-doping of Yb3+ successfully resulted in a significant improvement in up/down conversion efficiency via effective energy transfer mechanisms and the optimization of the electron population at the energy level of red-green emission. Furthermore, single-band red upconversion luminescence with the greatest red-green upconversion luminescence integral intensity ratio of 125.74 was discovered under 980 nm laser pumping at room temperature. The energy transition process involved in the phenomenon of the up-conversion luminescence intensity shift of red-green emission has been thoroughly examined. Finally, the noncontact optical thermometric ability based on fluorescence intensity ratio (FIR) technology showed that the maximum absolute sensitivity (Sa) of the 5Yb1Er sample in the temperature range of 320–556 K is 1.1×10−3 K−1, implying the possible use of Yb/Er-doped S-FAP transparent ceramics in the field of optical thermometers.

Infrared spectroscopy for evaluating the effect of electron beam sterilization on polyethylene terephthalate medical tubes

The paper studies the effect of electron beam sterilization on the polyethylene terephthalate parts of blood sampling systems. The structural state and crystallinity degree of polyethylene terephthalate are estimated from the analysis of infrared spectra. Relative intensities are calculated by the reference band (overall intensity level) at 1410 cm−1. The Gaussian intensities of the absorption bands for trans and gauche conformations with respect to reference band at 1505 cm–1 are calculated. The spectral coefficients D973/D795, D848/D795, D1042/D795, D895/D795, D1098/D1370, and D1255/D1370 are determined. The dose of up to 25 kGy has no significant effect on either the ratio of integral intensities or the ratio of trans and gauche conformations.

CeF3-TbF3-YF3 nanoparticles for ratiometric temperature sensing

The Ce0.5Y0.5-XTbXF3 (X = 0.01, 0.02, 0.05, 0.1, and 0.5) nanoparticles demonstrated a single-phase hexagonal structure corresponding to CeF3 host. The average diameter was 15 ± 1 nm. Under Ce3+ excitation at 266 nm, the luminescence peaks of (5d – 4f) Ce3+ and 5D4 – 4FJ (J = 6, 5, 4, and 3) Tb3+ were observed. The emission peaks from 5D3 level of Tb3+ were not observed. We took the luminescence integrated intensity ratio (LIR) of Ce3+ and Tb3+ peaks as a temperature-dependent parameter (303–523 K range). The LIR functions decay with the temperature increase. Indeed, with the temperature rise, the depopulation rate of Ce3+ excited state by Tb3+ becomes higher (phonon-assisted process). Thus, the ICe/ITb decreases. However, the rate of the LIR decay decreases with the increase of Tb3+ concentration. It was suggested, that this phenomenon is related to the presence of two competing processes populating the 5D4 state of Tb3+. There are phonon-assisted non-radiate transition from 5D3 to 5D4 of Tb3+ and cross-relaxation between Tb3+ ions, which was considered less temperature-dependent. The contribution of less temperature-dependent cross-relaxation process to the population of 5D4 increases with the Tb3+ concentration increase compared to 5D3 – 5D4 non-radiative transition. More significant contribution of the cross-relaxation leads to the decrease in the LIR descent rate. The maximum Sa and Sr values were 0.19 K-1 and 1.74 %/K at 303 K, respectively.

Defective band enhance the single green upconversion luminescence of Ca9Y(VO4)7: Yb3+/Er3+ phosphors by doping with Ba2+ ions

The present work investigates the near-single green emission properties of Ba2+ doped Ca9Y(VO4)7: Yb3+/Er3+ upconversion luminescence. The Ba2+ doped Ca9Y(VO4)7: Yb3+/Er3+ phosphors were successfully synthesized via the high-temperature solid-phase method. XRD pattern analysis showed that Ca9Y(VO4)7: Yb3+/Er3+/Ba2+ was a single phase, and Ba2+ doping did not induce heterophase phase. Under 980 nm near-infrared laser irradiation, Ca9Y(VO4)7: Yb3+/Er3+/Ba2+ phosphors emit strong green luminescence (530 nm, 2H11/2→4I15/2, 557 nm, 4S3/2→4I15/2) and weak red luminescence (664 nm, 4F9/2→4I15/2). The upconversion green-red luminescence integral intensity ratio of Ca9Y(VO4)7: Yb3+/Er3+/Ba2+ phosphor is 32.1. This enhancement can be attributed to the presence of defect bands that facilitate excitation photon absorption and efficient energy transfer from abundant electrons into Yb3+ (2F5/2) and Er3+ (4I11/2) ions. More importantly, the maximum SA and SR of Ca9Y(VO4)7: Yb3+/Er3+/Ba2+ phosphor as a temperature sensor are 1.44 % K−1 (at 548 K) and 1.28 % K−1 (at 298 K), respectively.

Sulfur isotopes toward the extended envelope of Sagittarius B2 in the Galactic Center

Abstract Isotopic ratios are good tools for probing stellar nucleosynthesis and chemical evolution. We perform high-sensitivity mapping observations of the J = 7–6 rotational transitions of OCS, OC34S, O13CS, and OC33S toward the Galactic Center giant molecular cloud Sagittarius B2 with the IRAM 30 m telescope. Positions with optically thin and uncontaminated lines are chosen to determine the sulfur isotope ratios. A 32S/34S ratio of 17.1 ± 0.9 was derived with OCS and OC34S lines, while a 34S/33S ratio of 6.8 ± 1.9 was derived directly from the integrated intensity ratio of OC34S and OC33S. With independent and accurate measurements of the 32S/34S ratio, our results confirm the termination of the decreasing trend of 32S/34S ratios toward the Galactic Center, suggesting a drop in the production of massive stars at the Galactic Center.

An Experimental Study on the Effect of Magmatic Thermal Evolution on the Molecular Structure of Low-Rank Coal

Low-rank coal accounts for over half of China’s proven coal reserves. The possibility of coal and gas outbursts in low-rank coal is higher, especially in the m·agmatic thermal evolution area. The complexity of coal’s molecular structure is one of the reasons for problems during the process of mining operations. Different analysis techniques, including XRD, FTIR and Raman spectroscopy, were used to obtain the molecular characteristics of magmatic thermal evolution coal samples and normal coal samples, so that a comparative study could be carried out to investigate the influence of the magmatic thermal evolution effect on the molecular structure of low-rank coal. The ranges of the aromatic interlayer spacing (d002), average stacking heights (Lc) and stacking layer number (Nave) of the thermally evolved coal samples are 3.41–3.51 Å, 22.76–27.02 Å, and 6.68–7.70, respectively. The ranges of the full width at half maximum ratio (FD1/FG) and the peak integral intensity ratio (ID1/IG) are 2.16–2.19 and 1.55–1.84, respectively. Compared with the normal coal samples, those affected by magmatic thermal evolution have smaller d002, ID1/IG, and FD1/FG values, but larger Lc values. The results indicate that the thermally evolved coal samples have more ordered structures and more developed microcrystalline structure sizes than normal coal samples.

Mössbauer spectral analysis and Rietveld structural refinement for cationic distribution of Cr-Co ferrites

Sol-gel autocombustion was used to prepare Chromium-substituted Cobalt ferrite nanoparticles with the chemical formulas CoCrxFe2-xO4, with x (0.1 to 0.5 in steps of 0.1).The samples were systematically examined for providing information related to their structural aspects X-ray diffractometry and energy dispersive spectrometry and for determination of accurate ionic distribution using Mössbauer spectrometry and Rietveld structural refinement. The patterns obtained from the energy dispersive spectra ensure that the elemental concentrations of the samples match well with the ionic proportions set in the empirical formulae. Cationic distributions were first made by Mössbauer spectral analysis using hyperfine fields and then by Rietveld analysis based on integrated intensity ratios and profile matching. The results of the study are explained in terms of the compositional variations, cationic inversion degree associated with the fine particle nature of the materials and the relevant cationic distributions as a result of chromium substituted cobalt ferrite.

Variations of the HCO+, HCN, HNC, N2H+, and NH3 deuterium fractionation in high-mass star-forming regions

ABSTRACT We use spectra and maps of the J = 1 − 0 and J = 2 − 1 DCO+, DCN, DNC, $\rm N_2D^+$ lines, and 111−101 ortho- and para-NH2D lines, obtained with the Institut de Radioastronomie Millimétrique (IRAM)-30 m telescope, as well as observations of their hydrogenated isotopologues to study deuteration processes in five high-mass star-forming regions. The temperature was estimated from CH 3CCH lines, also observed with the IRAM-30 m telescope, and from NH 3 lines, observed with the 100 m radio telescope in Effelsberg, as well as using the integrated intensity ratios of the J = 1 − 0 H13CN and HN13C lines and their main isotopologues. Applying a non-local thermodynamic equilibrium radiative transfer model with radex, the gas density and the molecular column densities were estimated. D/H ratios are 0.001–0.05 for DCO+, 0.001–0.02 for DCN, 0.001–0.05 for DNC, and 0.02–0.4 for NH2D. The D/H ratios decrease with increasing temperature in the range of 20–40 K and slightly vary at densities $n(\rm H_2) \sim 10^4\!-\!10^6$ cm−3. The deuterium fraction of $\rm N_2H^{+}$ is 0.008–0.1 at temperatures in the range of 20–25 K and at a density of ∼105 cm−3. We also estimate relative abundances and find ∼10−11–10−9 for DCO+ and DNC, ∼10−11–10−10 for $\rm N_2D^+$, and ∼10−10–10−8 for NH2D. The relative abundances of these species decrease with increasing temperature. However, the DCN/H2 ratio is almost constant (∼10−10). The observational results agree with the predictions of chemical models (although in some cases there are significant differences).

Dense gas and star formation in the outer Milky Way

We present maps and spectra of the HCN(1−0) and HCO+(1−0) lines in the extreme outer Galaxy, at galactocentric radii between 14 and 22 kpc, with the 13.7 m Delingha telescope. The nine molecular clouds were selected from a CO/13CO survey of the outer quadrants. The goal is to better understand the structure of molecular clouds in these poorly studied subsolar metallicity regions and the relation with star formation. The lines are all narrow, less than 2 km s−1 at half power, enabling the detection of the HCN hyperfine structure in the stronger sources and allowing us to observationally test hyperfine collision rates. The hyperfine line ratios show that the HCN emission is optically thin with column densities estimated at N(HCN) ≈ 3 × 1012 cm−2. The HCO+ emission is approximately twice as strong as the HCN (taken as the sum of all components), in contrast with the inner Galaxy and nearby galaxies where they are similarly strong. For an abundance ratio χHCN/χHCO+ = 3, this requires a relatively low-density solution for the dense gas, with n(H2) ~ 103−104 cm−3. The 12CO/13CO line ratios are similar to solar neighborhood values, which are roughly 7.5, despite the low 13CO abundance expected at such large radii. The HCO+/CO and HCO+/13CO integrated intensity ratios are also standard at about 1/35 and one-fifth, respectively. The HCN is weak compared to the CO emission, with HCN/CO ~ 1 /70 even after summing all hyperfine components. In low-metallicity galaxies, the HCN deficit is attributed to a low [N/O] abundance ratio; however, in the outer disk clouds, it may also be due to a low-volume density. At the parsec scales observed here, the correlation between star formation, as traced by 24 μm emission as is standard in extragalactic work, and dense gas via the HCN or HCO+ emission is poor, perhaps due to the lack of dynamic range. We find that the lowest dense gas fractions are in the sources at high galactic latitude (b > 2°, h ≳ 300 pc above the plane), possibly due to lower pressure.

Enhanced upconversion luminescence and single-band red emission in β-Ba2ScAlO5: Yb3+/Er3+ phosphor through doping Cu2+

This study reports on a single-band red upconversion emission of Er3+ in a pure-phase β-Ba2ScAlO5: Yb3+/Er3+ fluorescent powder by doping Cu2+. The optimum concentration of Cu2+ ions in β-Ba2ScAlO5: Yb3+/Er3+ powder was 0.20. The red and green emission intensity of β-Ba2ScAlO5: Yb3+/Er3+ sample with optimum concentration of Cu2+ ions increased by 19.1 and 3.6 times, respectively, relative to the β-Ba2ScAlO5:Yb3+/Er3+ material lacking Cu2+ ions. The red-green integral intensity ratio of the β-Ba2ScAlO5:Yb3+/Er3+/Cu2+ phosphor reached 141.9. The potential upconversion luminescence (UCL) mechanism was explored by analyzing the down-shift luminescence (DS) spectra, upconversion luminescence spectra, and upconversion fluorescence lifetime decay curves of Yb3+/Er3+/Cu2+ triple-doped β-Ba2ScAlO5. Enhanced red emission and green upconversion emission are achieved by energy transfer between defect band by the oxygen vacancy and Er3+ energy levels. This study's findings establish the foundation for developing novel phosphors with single UC red light emission, which has potential applications in illumination displays, optical thermometry, and biomedicine.

Research on Physical Properties in NGC 1068 Nuclear Region Based on ALMA High-resolution Multi-spectral Lines

Using the multi-spectral lines from ALMA (Atacama Large Millimeter/submillimeter Array) with high-resolution (∼ 0.2″–0.7″) and the continuum data, this work studies the physical properties of the nuclear region of nearby galaxy NGC 1068. The spectral lines include CO (1-0), CO (2-1), CO (3-2), HCN (1-0), HCO+ (1-0), HCN (3-2), HCO+ (3-2), HCN (4-3) and HCO+ (4-3). The CND (CircumNuclear Disk) shows an asymmetric ring structure with a size of ∼ 300 pc in the velocity-integrated intensity images. All the molecular lines of the CND show stronger emission at the eastern knot (E-knot) than the western knot (W-knot) of the CND. Furthermore, the E-knot shows larger velocities than the W-knot, which indicates that there is significant rotational pattern in the CND. The dense gas fraction (traced by the different transitions of HCN or HCO+ to CO (1-0) integrated intensity ratios) and dense gas ratio (HCN/HCO+) are higher at the E-knot, implying that the E- and W-knots have different physical environments or chemical compositions. The HCN emission in the CND show enhancement compared with HCO+, which could be affected by the AGN (Active Galactic Nucleus) radiation and starburst activity. The CO (3-2)/CO (1-0) integrated intensity ratio is a significant indicator of gas excitation. CO (3-2)/CO (1-0) ratios show much higher values at the E-knot, suggesting that there is molecular excitation enhancement caused by the extreme physical environment. Compared with the fluxes of HCN (4-3) and HCO+ (4-3) from the single-dish telescope JCMT (James Clerk Maxwell Telescope), the ALMA missing fluxes of dense molecular gas on 1 kpc scale are about 10%–20%. The spectral lines show that the flux ratios between E-knot and W-knot are ∼ 1.8–3.9. These differences shown between E-knot and W-knot may be associated with the AGN feedback. In addition, the CO (2-1), CO (1-0) and HCO+ (1-0) spectra show absorption features in the position of AGN. This absorption could be caused by the strong background of continuum emissions, and the gas inflow around the AGN can produce self-absorption in spectra.

Zr4+ and Bi3+ codoped Cs2Ag0.3Na0.7InCl6 double perovskite for single-composition white-light emitting phosphors and multimodal optical anti-counterfeiting

Single-composition white-light emitter with excitation-dependent emissions is highly desired for phosphor-converted white-light emitting diodes (WLEDs) and optical anti-counterfeiting, in terms of the optical self-absorption and degeneration induced by the different components. However, the rational regulation of excitation-dependent multi-emissions in single perovskite materials is still a grand challenge. Herein, Bi3+ and Zr4+ codoped Cs2Ag0.3Na0.7InCl6 double perovskite microcrystals (DPMCs) were reported for single-composition white-light emitting phosphors and multimodal optical anti-counterfeiting. As a result, the photoluminescent quantum yield (PL QY) and color rendering index (CRI) were recorded up to 80.3% and 95.8, respectively. Specifically, under ultraviolet (UV) excitation at 365 nm, the Zr4+-doped DPMCs exhibited distinct emission profiles with single broad band centered at ∼570 nm for various Zr4+ doping concentrations, which could be attributed to the self-trapped exciton (STE) emission of the host. While the DPMCs show dual emission bands centered at ∼470 and ∼570 nm excited at 254 nm, which originates from the [ZrCl6]2- octahedral and STE, respectively, and their integral PL intensity ratio can be gradually adjusted by the content of Zr4+. The broad multicolor emissions with color kinetic features of the single-composition DPMCs offer exciting opportunities for constructing WLEDs and multimodal optical anti-counterfeiting.

Characterization of local non-equilibrium phonons in bulk MoS2 probed by temperature-dependent Raman scattering

This study presents an experimental implementation to determine the temperature dependence of Raman spectra of bulk 2H-MoS2 in the temperature range of 300–650 K. In addition, we have measured according to the anti-Stokes to Stokes integrated intensity ratio (). The results indicate that Raman shift of both the vibration modes and exhibits a linear temperature-dependent behavior in the heating and cooling processes. It is confirmed that the sample did not deteriorate by oxidization and decomposition at high temperatures. However, above 500 K, the measured phonon temperature deviated from the heat bath temperature. It is suggested that the does not correspond to the equilibrium population of optical phonons, thus indicating that the measurement was not in thermal equilibrium but in a thermal steady state under laser irradiation. We conclude that this is caused by the difference in relaxation times in the thermal steady state.

The impact of 3D Raman imaging and HR-TEM analysis on the observed changes in the orientation of the crystallites in 3D flower-like nanostructured layers

The presented study aims to explain the formation phenomena of titanium dioxide flower_like forms on Ti foil. TiO2 nanoforms were obtained by chemical oxidation using H2O2 and further crystallization at 600 °C under an argon atmosphere. The morphology of layers is determined by reaction time. Understanding the factors that indicate the transition sequence and control the phase stability may provide insight into how the properties of titanium dioxide nanomaterials can be manipulated. A cross-sectional view of the samples reveals the complex arrangement of grains and their different shapes. HR-TEM and 3D Raman spectroscopy allowed to gain new insights into the structure formation. Observations of vibrational modes of anatase (101) and (001) surfaces allow quantitatively defining the percentage of facets exposition. Moreover, the spectra collected from different z-heights for the sample and the analysis of the integrated intensity ratio of Eg (144 cm−1) and A1g (514 cm−1) anatase bands show the grains' variable nature. The results present that the inner layer of the nanostructure is composed of more oriented crystallites, in contrast to the oxide/substrate interface and the sample surface. The model of the growth mechanism of a multilayered TiO2 scale formed on Ti has been proposed. Data availability statementThe raw/processed data required to reproduce these findings cannot be shared at this time as the data also forms part of an ongoing study.

Efficient esterification over hierarchical Zr-Beta zeolite synthesized via liquid-state ion-exchange strategy

The eco-friendly zeolite-based solid acid catalysts constitute an important alternative to the liquid acid catalyst for the production of plasticizer tributyl citrate (TBC), due to their non-corrosive, high hydrothermal stability and easiness to recycle. Herein, a simple acid treatment to the H-Beta zeolite and subsequent incorporation of ZrIV ions into the vacated Al sites were conducted by liquid-state ion-exchange of ZrO(NO3)2 aqueous solution. The ZrIV ions were incorporated into the framework by the expand of the unit cell size, verified by XRD patterns, the emerging new band at ∼198 nm on UV–vis spectra, the enhanced binding energies of the Zr 3d5/2 and Zr 3d3/2 on XPS spectra, as well as the variations of isolated terminal silanol groups (Si-OH) by FTIR and the change of integrated intensity ratio of Q3/Q4 by 29Si MAS NMR. It was illustrated that the Lewis acid sites was the main active sites for esterification reaction and the produced abundant mesopores in the Zr-Beta-x catalysts would facilitate the transportation of TBC. The maximum conversion of citric acid as high as 80 % was obtained on Zr-Beta-128 (SiO2/ZrO2 molar ratio = 128) catalyst with the highest Lewis acid amount. Furthermore, the Zr-Beta-128 zeolite exhibited high stability without any detectable deactivation after 6 cycles with the 100 % selectivity to TBC. The efficient Zr-Beta catalyst could supply a novel possibility for the development of an environmentally-friendly solid acid catalyst with good performance for the TBC production.

Label-free testing strategy to evaluate packed red blood cell quality before transfusion to leukemia patients

Patients worldwide require therapeutic transfusions of packed red blood cells (pRBCs), which is applied to the high-risk patients who need periodic transfusions due to leukemia, lymphoma, myeloma and other blood diseases or disorders. Contrary to the general hospital population where the transfusions are carried out mainly for healthy trauma patients, in case of high-risk patients the proper quality of pRBCs is crucial. This leads to an increased demand for efficient technology providing information on the pRBCs alterations deteriorating their quality. Here we present the design of an innovative, label-free, noninvasive, rapid Raman spectroscopy-based method for pRBCs quality evaluation, starting with the description of sample measurement and data analysis, through correlation of spectroscopic results with reference techniques' outcomes, and finishing with methodology verification and its application in clinical conditions. We have shown that Raman spectra collected from the pRBCs supernatant mixture with a proper chemometric analysis conducted for a minimum one ratio of integral intensities of the chosen Raman marker bands within the spectrum allow evaluation of the pRBC quality in a rapid, noninvasive, and free-label manner, without unsealing the pRBCs bag. Subsequently, spectroscopic data were compared with predefined reference values, either from pRBCs expiration or those defining the pRBCs quality, allowing to assess their utility for transfusion to patients with acute myeloid leukemia (AML) and lymphoblastic leukemia (ALL).