Half-peak Width Research Articles

Effects of soy protein isolate hydrolysate on the structural and functional properties of yam starch during extrusion.

This study investigated the interaction between yam starch (YS) and soy protein isolate hydrolysate (SPH), and their effects on in vitro digestibility of starch through extrusion treatment. Results indicated that SPH with 6% hydrolysis degree had the lowest relative molecular mass. X-ray diffraction and Raman spectroscopy revealed an increase in the relative crystallinity of extruded yam starch (EYS) from 17.45% to 22.45% and a decrease in the half-peak width at 480cm-1. Its short-range ordering improved with increased SPH addition. Differential scanning calorimetry results demonstrated that SPH enhanced the thermal properties of EYS. Additionally, the solubility, peak viscosity, and setback viscosity of EYS decreased with an increase in the SPH content. Particle size analysis revealed that SPH addition decreased the particle size of EYS. Scanning electron microscopy and confocal laser scanning microscopy showed that the surface of EYS roughened and SPH molecules attached to the surface. In vitro digestion results indicated that SPH hindered the contact between EYS molecules and digestive enzymes and increased the resistant starch content of EYS from 8.31% to 23.39%. This study presents a new method for modification of starch using protein hydrolysates during extrusion.

Differences in M‐components between triggered lightning striking the ground and overhead line

AbstractIn the summer of 2018–2019, rocket‐triggered lightning experiments were conducted in Guangzhou, China. There were two types of lightning targets: ground and overhead line. By comparing the current and the electric field data in the two cases, it was found that when the continuous current level (ICC) and current amplitude (IM) of M‐components (current pulses generated during the continuous current stage) are large, the time difference between the electric field peak and the current peak (TD) will always be small. The rise time (RT) and half peak width (THPW) of M‐components with high ICC and IM are low in both the cases. The threshold upper limit of TD in the case of lightning striking the ground is higher, approximately 2.6 times than that in the case of lightning striking the overhead line. We use an optimised guided wave model to simulate the electric field waveforms of M‐components. It was found that the shorter RT and THPW of the M‐component, the smaller TD. The changes in wave speed and IM cannot affect the size of TD, and the impact of distance changes is very weak. The difference in the threshold upper limit of TD may be related to the significant difference in ground impedance in two cases.

High Efficiency and Narrow-Band Green Emission in Eu2+ and Mn2+ Co-Doped Na2MgAl10O17 Phosphor for Backlight Display Application.

Wide color gamut display has become a new generation of display technology because of its good color saturation. However, the low quantum efficiency and wide half peak width of narrow-band green phosphors are still the main barriers in their development and application. This work addresses these challenges by using Mn2+ as the luminescent center and constructing efficient Eu2+ → Mn2+ energy transfer in Na2MgAl10O17 (NMAO) matrix. The NMAO:0.15Eu2+, 0.30Mn2+ phosphor presents a single-band emission peaking at 513 nm with a full width at half maximum (FWHM) of only 33 nm under the excitation of 365 nm LED chip. In addition, under the excitation wavelength of 365 nm, the energy transfer efficiency reaches 74%. Compared with the NMAO:0.30Mn2+, the intensity of the NMAO:0.15Eu2+, 0.30Mn2+ increases by 5.5 times and the internal quantum efficiency is up to 61.82%. A white LED device with the CIE coordinates of (0.2871, 0.3472) and a color gamut area of 94% NTSC has been assembled successfully by combining 365 nm LED chips with NMAO:0.15Eu2+, 0.30Mn2+, BaMgAl10O17:Eu2+, and K2SiF6:Mn4+ as green, blue, and red component. This work enriches the relevant content of Mn2+-doped phosphors and provides a constructive insight into improving luminescent performance through energy transfer.

In-depth investigation on macro-properties and micro-mechanism of sustainable alkali-activated slag/fly ash paste incorporating seawater

The impacts of seawater on the workability, hydration product features, and mechanical properties of alkali-activated fly ash (FA)/ground blast furnace slag (GBFS) binary system (AAFS) are investigated. The potential suitability of the AAFS for application in marine construction projects is discussed. The findings illustrate that seawater considerably enhances the dissolution of AAFS. The high pH of the seawater AAFS (SAAFS) pore solution accelerates the early hydration process. The presence of seawater leads to a relatively wide half-peak width and an increased average crystallite spacing in calcium (alumina) silicate hydration (C-(A)-S-H) gels. Moreover, seawater facilitates the transformation of silicate ions ([SiO4]4-) into highly polymerized state. The final setting time and fluidity of AAFS are reduced by the addition of seawater. Furthermore, the introduction of seawater contributes to higher contents of C-(A)-S-H gels, which densifies the SAAFS matrix and improves the compressive strength of SAAFS.

SOGCN: Prediction of key properties of MR-TADF materials using graph convolutional neural networks

The exploration of the structure and properties of the luminescent materials in OLED devices using Multiple Resonance Thermally Activated Delayed Fluorescence (MR-TADF) is constrained by challenges related to long cycles and high experimental costs, making it a key obstacle in the development of new materials. In response to this challenge, we propose an innovative approach by constructing a graph convolutional neural network model named SOGCN to quickly determine whether an unsynthesized material has the potential to become an MR material, and accurately predict its energy gap and half-peak width, thereby expediting the development process of MR-TADF materials. We constructed the MR220 dataset for training the model based on 220 MR-TADF molecules reported in experiments. To ensure the reliability of the SOGCN model in predicting new samples, we have established a rigorous set of theoretical calculation evaluation standards, providing crucial references for the model. In the prediction of the properties of 37 new samples of MR-TADF molecules, SOGCN successfully predicted the singlet–triplet energy gap (ΔEST) of some samples, demonstrating a good trend in FWHM prediction as well. Finally, we have synthesized our designed molecule, Design3 (DtCzB-Boz), the organic light-emitting diodes based on DtCzB-Boz exhibit an emission peak at 508 nm, with the FWHM is 27 nm. The result of photophysical characterization is highly consistent with the predicted value of SOGCN. Notably, the mean absolute errors (MAE) between our model predictions and experimental/computational values were as low as 0.037 eV and 10 nm, respectively. This indicates that SOGCN exhibits higher efficiency and accuracy in predicting the properties of MR-TADF materials.

Thermal atomic layer deposition of Ga2O3 films using trimethylgallium and H2O

The Atomic Layer Deposition (ALD) technique is regarded as an effective method for fabricating high-quality Ga2O3 thin films. Trimethyl gallium (TMG), with its high vapor pressure at room temperature (227 Torr), is widely utilized as a gallium precursor in this technique. For oxygen precursors, common choices include O3 and O2 plasma. However, the impact of H2O as an oxygen precursor on Ga2O3 thin films during Thermal Atomic Layer Deposition (TALD) remains insufficiently explored. This study investigates the temperature window and growth characteristics of Ga2O3 thin films, deposited using TMG and H2O as precursors, on sapphire substrates within the temperature range of 250–500 °C. At 250 °C, deposited Ga2O3 films exhibit an amorphous structure, whereas within the 300–500 °C substrate temperature range, they transition to the α-phase. The half-peak width (FWHM) narrows as the temperature increases, with characteristic peaks of the (0006) facets shifting to higher angles at 500 °C. STEM analysis reveals complete coherence between α-Ga2O3 films and the sapphire substrate, indicating a pseudo-crystalline structure formation. The growth rate of the films at 450 °C is 0.083 Å/cycle. Ga2O3 films prepared with H2O as the oxygen precursor exhibit Ga-rich properties, with (Ga + Al)/O atomic ratios between 0.88 and 0.91 across the 250–500 °C temperature range. The films’ roughness (Ra) ranges from 0.453 to 0.646 nm. Island-like particles form on the film surface within the 400–500 °C range, smoothing out as the temperature rises. The film’s band gap peaks at 5.50 eV at 450 °C. The reaction of TMG with H2O on sapphire substrates yields Ga2O3 films and CH4 by-products, akin to the trimethylaluminum process.

The Characterization of Electric Field Pulses Observed in the Preliminary Breakdown Processes of Normal and Inverted Intracloud Flashes

We have studied the parameters of preliminary breakdown (PB) pulses in 395 normal and 319 inverted intracloud (IC) flashes observed in Gifu, Japan, and Ningxia, China, respectively, by using a low-frequency mapping system called fast antenna lightning mapping array (FALMA). These parameters are extracted from the first half of the PB pulses. It is found that compared to normal IC flashes, inverted IC flashes exhibited PB pulses with slower rise times (6.8 vs. 3.1 μs), wider half-peak widths (3.8 vs. 2.5 μs), longer zero-crossing times (26.2 vs. 14 μs), and extended fall times (4 vs. 3.2 μs). We further demonstrated that such discrepancies between normal and inverted IC flashes should not be caused by subjective factors, like noise threshold setting, or objective factors, like signal propagation distance. Based on this analysis, finally, we inferred that the discrepancies should be a reflection of the PB channel properties of normal and inverted IC flashes.

Synergistic effect induces self crystallization of CsPbBr3 quantum dots in borosilicate glass matrix by LiF

Cesium lead halide perovskite (CsPbX3) quantum dots (QDs) are recognized as viable substitutes for conventional fluorescent powder color converters, which can improve the color gamut and reproducibility of liquid crystal displays (LCDs). Encapsulating QDs in glass can effectively solve the water oxygen stability of QDs, but the glass matrix impedes the nucleation of QDs and the precipitation of QDs requires secondary heating. In our research, we successfully accomplished the self-crystallization of CsPbBr3 QDs facilitated by LiF within a B2O3-SiO2-ZnO borosilicate glass matrix. The results indicate that the self crystallization of CsPbBr3 QDs induced by LiF in borosilicate glass matrix has a synergistic effect. The Li + ions can break the glass network structure and facilitate ionic migration and transport, while F− ions have good electronegativity due to ion aggregation, and can strongly attract Cs+ and Pb2+ ions with larger atomic radii, thereby promoting the rapid nucleation and growth of CsPbBr3 QDs, ultimately synthesizing QDs with uniform particle size, narrow half peak width, good optical properties, and thermal stability.

A forwarding spoofing detection algorithm for Beidou navigation satellite system vulnerability

With the Beidou navigation system's fast expansion in China, it is popular in military and civilian aspects. However, since the satellite orbit operates at an extremely high position and there is energy loss during the propagation process, the receiver only picks up a very faint signal, which makes the Beidou receiver very vulnerable to interference. The interference of the receiver is divided into natural interference and human interference, of which the human interference is particularly serious. Deception is commonly used in human interference. The deception interference detection technology in Beidou navigation system is studied in this research. Firstly, the signal in the signal capture stage is detected by multi-peak detection algorithm to determine the signal type. If it cannot be determined, the signal is detected by the half-peak full-width algorithm, so as to determine the signal type. In the stage of signal tracking, the Doppler shift of the spoofing signal is applied to determine whether the signal is spoofed or not. When the spoofing signal forwarding delay is set to 0.5 and 1 chip respectively, the full width of half peak is 8.56 and 11.35 after fitting the main peak. If the half-peak full width exceeds the normal navigation signal, it indicates spoofing interference. The constructed model can effectively track downspoofing signals and improve the Beidou navigation system’s detection performance.

Uniform and large-size perovskite CsPb(BrxI1-x)3 quantum dot glass for laser display application

As a new display mode, laser display is becoming popular in the industry, and it has served our lives. In addition, a new material, perovskite quantum dots(QDs) is more capable of energizing laser displays with a narrow half-peak width, tunable emission and high color purity. Here, by incorporating perovskite CsPb(BrxI1-x)3 quantum dots into the glass, we explored the performance of large-size glass in laser display. It is demonstrated that the sheet of CsPbBr3 and CsPb(Br0.25I0.75)3 glasses has good wavelength uniformity, and the phosphor wheel with the sheets yields a wide color gamut (its color gamut reaches 124.3 % of NTSC and 91.3 % of Rec.2020), which will play a significant advantage in the field of laser projection.

Stage development characteristics of oxygen-lean combustion of coal in fire zone: Leap-migration mechanism, kinetic transition mechanism, and critical oxygen concentration

Effectively preventing the re-ignition of fire zones and safely unsealing enclosed fire zones are challenging. To address these issues, a thermogravimetric analysis technique was used to explore the leap-migration mechanism of the characteristic parameters (burnout index (H), comprehensive combustion performance parameters (Cb, S, and HF), and maximum combustion mass loss rate (dWmax))/temperatures (maximum pyrolysis mass loss rate point temperature (TVmax), pyrolysis endpoint temperature (Td), thermal polycondensation endpoint temperature (Tp), maximum combustion mass loss rate point temperature (TWmax), burnout temperature (Th), and combustion half-peak width (ΔT1/2)) of low-rank coal oxygen-lean combustion under different time-scale effects (TSEs). The sensitivity of characteristic parameters/temperatures to changes in oxygen concentration under coal rank transition was analyzed. Simultaneously, the kinetic real-time transformation mechanism during the oxygen-lean combustion stage progression was investigated. The results revealed that because of the competition between oxidation and pyrolysis, the leap-migration interval of characteristic parameters/temperatures for oxygen-lean combustion of low-rank coals is in the range of 5 %–3% oxygen concentration. This feature was less affected by the coal rank but is not affected by the TSE. In the low oxygen-lean range (5 %-1%), a change of oxygen concentration was more sensitive to the coal rank, and the high sensitivity of the oxygen concentration change reduced the influence of the coal rank on coal combustion performance. In addition, the apparent activation energy (Eα) curves during the early stage of combustion were relatively concentrated with the change of oxygen concentration, but relatively dispersed during the late stage of combustion. At 3 % oxygen concentration, the Eα values of different coals began to continuously decrease with increasing conversion rate, approaching the spontaneous reaction activation energy value of 40 kJ/mol. At oxygen concentration of 1 % reflected the complete limitation of the oxidation consumption reaction. Therefore, the critical oxygen concentration of typical low-rank coal oxygen-lean combustion was determined below 3 % oxygen concentration. The results of this study can provide scientific guidance for the unsealing of fire zones, and the effective prevention and control of the formation of new fire zone disasters.

Tailored detection efficiency for linear variable filter-based sensors: applying simulation models of spectral characteristics in optical design

To accurately model the specific detection characteristics of spectral sensors based on linear variable filters (LVFs) within an optical design tool, it is essential to consider crucial position-variable spectral properties, such as peak transmittance, central wavelength, half width, or slope steepness. In this context, we propose a straightforward approach, integrating a dynamic link library (DLL) containing all position-dependent spectral properties of the LVF into a commercial optical design software. Exemplary investigations are conducted for an LVF with a detection range of 450–850 nm. For ease of use, the measured position-, wavelength-, and angle-dependent transmission properties of the LVF have been described through a simple yet highly accurate model system. Moreover, to highlight the essential value of this simulation for specific applications, an efficiency-enhancing spectral module is simulated, which is an LVF-mirror arrangement characterized by a multiple-reflected beam path. The introduced optical design tool demonstrates its particular strength by enabling the optimization of the highest detection efficiency for either the short- or long-wavelength range.

Synthesis of high‑nitrogen-content doped-g-C3N4 (A new nitrogen source) diamond under high-pressure and high-temperature conditions

This study reports the successful synthesis of high‑nitrogen-content diamond (2723 ppm) within the Fe-Ni-C-N system, utilizing g-C3N4 as a new nitrogen source via the temperature gradient method under high-pressure and high-temperature (HTHP) conditions. The study investigated the role of nitrogen atoms in facilitating the growth of large diamonds with {111} plane orientation. Analysis of crystal morphology, nitrogen defect content, and nitrogen incorporation forms were conducted. As the amount of g-C3N4 increased, the crystal size decreased, the color changed from yellow to green with increasing depth, and the growth rate notably decreased. The Fourier transform microscopy infrared spectroscopy (FT-IR) characterization revealed increased nitrogen content within the crystal due to nitrogen atom introduction. Raman characterization indicated increased residual stress with higher nitrogen content, leading to shifts in Raman peak positions and broadening of half-peak widths of the diamond. Photoluminescence (PL) characterization indicated that g-C3N4 addition increased, resulting in a fading state of NV− and W8 defects. The results indicated that g-C3N4, as a new nitrogen source, exhibited superior doping efficiency within the diamond lattice compared with traditional nitrogen sources. The study offered valuable insights into the preparation and potential applications of high‑nitrogen diamond single crystals.

Long-wavelength emission room-temperature phosphorescent carbon dots activated by an ortho-carboxyl substitution strategy and employed for achieving tunable LED

While room temperature phosphorescence (RTP) associated with carbon dots (CDs) has been widely achieved, obtaining long-wavelength emission RTP, especially while mitigating the quenching effect of water or dissolved oxygen, remains a challenging yet desirable goal. We synthesized three types of phosphorescent CDs with varying luminescent properties by using three precursors with carboxyls positioned differently. The formation process of these CDs resulted in a well-ordered and compact structure, effectively inhibiting molecular vibrations and reducing non-radiative transitions. Consequently, it successfully prevented the quenching effect of dissolved oxygen on the RTP of CDs in an aqueous environment. Significantly, PA-AIBN synthesized with phthalic acid, rather than iso-phthalic acid and terephthalic acid, exhibited long-wavelength emission RTP, with the phosphorescent emission center reaching as far as 640 nm. To be specific, the ortho-substituted carboxyls played a critical role in boosting the formation of intramolecular hydrogen bonds. Simultaneously, an increase in the doping levels of both nitrogen (N) and phosphorus (P) in PA-AIBN facilitated the long-wavelength emission RTP. The increased sp2 conjugated carbon core of PA-AIBN narrowed the optical band gap, contributing to the long-wavelength emission. Taken together, these factors cooperatively promoted the long-wavelength emission of RTP. Importantly, the PA-AIBN synthesized in this study exhibited a broad half-peak width and long-wavelength emission. It was successfully used in the preparation of white-light-emitting diodes without the need for commercial phosphor powder, demonstrating its enormous potential for practical lighting devices.

Exploration of the Existence Forms and Patterns of Dissolved Oxygen Molecules in Water

HighlightsA clear negative correlation between the size of water clusters and theconcentration of dissolved oxygen was observed. This implied that smaller clusters water exhibits higher concentrations of dissolved oxygen.Oxygen molecules are primarily existed at the surfaces or interfaces of waterclusters and can rapidly traverse the gas liquid interface.A semi empirical formula relating the average number of water molecules in acluster to 17O NMR half peak width was derived, demonstrating an approximatelin ear relationship.

Luminescent Perovskite-Cross-Linked Polymer with Low Shrinkage and Excellent Stability.

When organic cross-linked polymers are combined with metal halide perovskite nanocrystals (PNCs) for realizing luminescent perovskite-polymer display materials, the stability of PNCs is enhanced and their shrinkage is suppressed. This work presents a feasible strategy for preparing CsPbBr3 nanocrystals (NCs) within a polydicyclopentadiene (PDCPD) thermosetting cross-linked resin matrix simultaneously via a one-step reaction. The obtained PDCPD@PNCs composite exhibits narrow peak half-widths (15-20 nm), high light transmittance (80%), low curing volume shrinkage (1.4%), tunable tensile properties, excellent stability, and a photoluminescence quantum yield (PLQY) of 44.3%. The composite material exhibits long-term stability in water, acid, and base solutions for over 90 days, with the PL intensity being maintained at over 90%. Furthermore, the composite is highly resistant to polar organic solvents owing to the insolubility imparted by cross-linking. White LEDs (WLED) fabricated using the as-prepared composite demonstrate excellent potential as light sources in optical devices.

Ultrabroad distribution of multiple anelasticities in O-doped refractory multiprincipal element alloys

The Snoek anelastic internal friction (IF) peak due to stress-induced dipole ordering associated with interstitial atoms was well observed in IF curves of single-principal element alloys (SPEAs) as early as in the 1950s, however, its behavior remains elusive in multi-principal element alloys (MPEAs) to date. Here the temperature-dependent IF spectra of NbTiV0.5Zr refractory MPEAs with varying O contents were presented, and the analysis of these data indicates that for O-doped NbTiV0.5Zr MPEAs, the O addition triggers two anelastic IF peaks (the PO1 and PO2), corresponding to the O-Snoek-type relaxation in random solid solution (RSS) and local chemical ordering (LCO) structures, respectively. The half-peak width of the PO1 is 2–3 times broader than that for SPEAs, associated with the wide O migration energy barrier distribution in MPEAs. These phenomena show a striking contrast to the single and narrow Snoek-type peak observed for SPEAs. Our analysis further reveals an approximate linear correlation between the half-peak width of the Snoek-type peak and the mixing entropy. The introduction of O also shifts grain boundary relaxation peaks (PG) towards higher temperatures. Interestingly, high-temperature anomalous modulus changes were observed for the first time in TiV-based lightweight refractory MPEAs, which is suggested to be originated from the order reduction of the body-centered cubic (bcc) structure at elevated temperatures. Moreover, the 1 at.%O doped NbTiV0.5Zr MPEA with a favorable balance between the peak heights of the PO2 and PG, exhibits outstanding specific yield stress (SYS) among refractory MPEAs while maintaining an elongation as high as 20 %. This work provides not only a bridge between the anelastic behavior of SPEAs and MPEAs for upcoming studies and theories concerning bcc MPEAs with interstitial atoms, but contributes to the holistic design of bcc MPEAs with high strength and excellent ductility.

Temperature-Driven Structural Evolution during Preparation of MCM-41 Mesoporous Silica.

This study explores the influence of micelles on the evolution of MCM-41's pore structure via 24 h hydrothermal treatments in a range of temperatures from 100 °C to 200 °C. MCM-41 was characterized using BET, SAXD, FTIR, TEM, and TG-DSC. The findings demonstrate that with temperature elevation from 100 °C to 160 °C, the micelles undergo expansion, leading to an enhanced lattice constant from 4.50 nm to 4.96 nm and an increase in pore diameter from 3.17 nm to 3.45 nm, while maintaining the structural orderliness of the pore channels. Upon cooling, the reversible contraction of micelles and the strategic addition of water glass contribute to a reduction in pore size. However, at a threshold of 180 °C, the SAXD (100) peak's half-peak width surges by approximately 40% relative to that at 160 °C, illustrating a progressive disruption of the hexagonal configuration of MCM-41. Coupled with elevated silica dissolution at higher temperatures in an alkaline solution, a total disintegration of the ordered pore structure at 200 °C results in a drastic reduction in the specific surface area to 307 m2/g. These results are beneficial to developing structural transformation mechanisms of MCM-41 materials and designing mesoporous materials via temperature modulation innovatively.

Investigating a defect width identification based on half-peak width for LDC-based eddy current testing

ABSTRACT The eddy current testing (ECT) technology based on the Inductance-to-Digital Converter (LDC) has the advantages of low power consumption and simple signal conditioning circuitry, which contributes to the miniaturisation of the instrument and low power consumption design. Existing defect identification methods primarily focus on the conventional Analog-to-Digital Converter (ADC)-based ECT. These methods rely on complex analytical models to analyze the phase and amplitude information of voltage signal. However, these approaches do not apply to the LDC-based ECT. The paper proposes a method to identify defects employing the R p -Inductance 2D plane, and use the half-peak width of the inductance signal to evaluate the defect width for symmetric slots. Using finite element simulation and experimental verification, the half-peak widths of the inductive signal wave crests at the defects are the same for the four slots with 1 mm width and different depths on the aluminum specimen; for four wire-cut slots with 4 mm depth and different widths, the half-peak widths are positively correlated with the defect widths. These experimental results demonstrate that the relationship between crack width, wave crest, and half-peak width can serve as the foundation for width identification and classification. This also offers a fresh perspective for further quantifying crack widths.

Growth, optical and thermal properties of YbxHo1-xCa4O(BO3)3 crystals

YbxHo1-xCa4O(BO3)3 (Yb:HoCOB, x = 0, 0.1, 0.2, 0.3) crystals were grown by the Bridgman method for the first time. The crystal structure, rocking curve, transmission spectra, absorption spectra, band structure and thermal properties of Yb:HoCOB were characterized in detail. The maximum half peak width (FMHW) of Yb0.1Ho0.9COB and Yb0.2Ho0.8COB is 26.7″ and 23.8″, respectively, and the effective segregation coefficient is greater than 0.9. In addition, the transmittance of Yb:HoCOB is 88 %. New absorption peaks are introduced by doping Yb3+ at 850–1000 nm. The UV absorption cut-off edge of Yb:HoCOB is red-shifted with increasing Yb3+ doping. The thermal diffusivity and thermal conductivity of Yb:HoCOB decrease with increasing temperature. The specific heat increases with the increasing temperature and finally approaches a constant value. The specific heat of Yb:HoCOB crystal are above 0.670 J/gK at room temperature. Yb:HoCOB with good crystallization quality, high transmittance and high specific heat has the application potential in laser frequency and QPCPA. This work provides a useful exploration for the study of nonlinear optical materials in solid state lasers.