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Superplasticiser (SP) is widely used in foam concrete industry to improve rheological properties since compaction and vibration adversely affect the stability of foam bubbles. This study aims to investigate the effect of polycarboxylate SP contents on the properties of foam concrete. Different water-cement ratios (w/c) were used, and the SP added to the mixture to adjust the spreadability. The density of 1500 kg/m3 was chosen for the production of foam concrete for semi-structural applications. Fresh, mechanical, transport and microstructure properties were analysed in this study. The results of this study showed that the content of w/c and SP had a significant impact on the performance of the foam concrete. Increasing the SP content enhanced the foam concrete’s mechanical and transport properties, but the best behaviour was through the use of 1.35% of SP. Smaller pore diameter, better pore distribution and higher portlandite peak intensity were achieved through the use of the SP. Overall, the superior behaviour of the foam concrete was achieved by the use of 1.35% polycarboxylate SP.

Converting the γ phase into the α phase completely is necessary in the presintering stage of industrial alumina (Al2O3), which requires high temperature and energy consumption. To reduce the presintering temperature, γ-Al2O3 was activated by oxalic acid. XRD, 27Al-MAS-NMR and TG-DSC were used to characterize the γ - alumina before and after activation, and the phase transformation was studied. The formation temperature of α-Al2O3 decreased to 1029 °C for oxalic acid activated γ-Al2O3, and the α-fraction was 100% for activated γ-Al2O3 at 1300 °C. After oxalic acid activation, the diffraction peak intensity of γ-Al2O3 decreased significantly; the results of 27Al-MAS-NMR suggested that octahedral [AlO6] in γ-Al2O3 was easier than tetrahedral [AlO4] to be attacked by oxalic acid, and the formation of pentavalent [AlO5] with higher reaction activity, which was in favour of the lowering formation temperature of α-Al2O3. The dissolution concentration of Al increased after oxalic acid activation, and the dissolution process was controlled by surface reactions. Oxalic acid mainly attacked the octahedral aluminium in γ-Al2O3 and extracted Al as three complexes of [Al(C2O4)]+, [Al(C2O4)2]- and [Al(C2O4)3]3-. Oxalic acid activated γ - Al2O3 with a lower phase transformation temperature has broad application prospects in the alumina industry.

Objective To explore the clinical role of contrast-enhanced ultrasound (CEUS) in a preoperative evaluation of early endometrial carcinoma. Methods This study included 14 patients who underwent preoperative CEUS and contrast-enhanced magnetic resonance imaging (CEMRI) and were ultimately diagnosed with stage I endometrial carcinoma from December 2019 to December 2020. The parameters of the time-intensity curve (TIC) were compared with the endometrial carcinoma group, the invaded myometrium group, and the normal myometrium group. Results TIC parameters between the endometrial carcinoma group and the invaded myometrium group were similar. Compared with the normal myometrium group, the time to peak (TTP) was significantly shorter and the ascending slope (AS) was significantly higher in the endometrial carcinoma group. The TTP of the invaded myometrium group was shorter than that of the normal myometrium group and the peak intensity (PI) was higher than that of the normal myometrium group. We then compared the TIC parameters between the endometrial carcinoma group and the invaded myometrium group after adjusting for the normal myometrium group, and the results still did not show any difference. Of the 14 cases of endometrial carcinoma, 9 cases were diagnosed by CEMRI and were consistent with the pathology results, 1 case was underestimated, and 4 cases were overestimated; while 11 cases diagnosed were diagnosed by CEUS and were consistent with the pathology results, 1 case was underestimated, and 2 cases were overestimated. Conclusions The contrast pulse sequencing technique used in the CEUS examinations performed well in evaluating the extent of the endometrial carcinoma. Future studies with larger sample sizes are needed to determine the applicability and value of this new procedure during preoperative assessments of early endometrial carcinoma.

The morphology, phase structure, saturation magnetization and coercive force of untreated, cryogenically treated and cryogenically treated and tempered cobalt samples has been investigated for studying the changes in microstructure, and magnetic properties. The result illustrates a noteworthy variation in the phase structure of cobalt after the cryogenic treatment. The saturation magnetization was unaffected, whereas an improvement in the coercive force has been detected. The XRD peak intensity of cryogenic cryogenically treated cobalt specimen reveals the cobalt phase transformation exhibiting a higher e-Co (hexagonal structure), which shoots up the coercive force. Additional tempering after cryogenic treatment has an insignificant effect on the analyzed properties.

The electrocatalytic oxidation of methanol on the Pt1Pd3 nanoparticles supported on rutile TiO2 in alkaline solution is investigated. The Pt1Pd3 nanoparticles are prepared by the chemical co-reduction of the precursors of Pt and Pd and then loaded on TiO2. The Pt1Pd3 nanoparticles with sizes of about 2–4 nm and a certain degree of aggregation are dispersed on TiO2. The position and shape of the methanol oxidation peak on Pt1Pd3/TiO2 are more similar to those on Pt/TiO2 than those on Pd/TiO2, while Pt1Pd3/TiO2 exhibits higher catalytic activity, e.g., a significantly higher peak intensity, than Pt1Pd3/C, Pt/TiO2 and Pd/TiO2. This indicates the advantage of TiO2 as a support material and the strong synergy between the Pt1Pd3 and TiO2 and between the Pt and Pd. Moreover, Pt1Pd3/TiO2 has a high tolerance for the poisoning caused by CO. Rutile TiO2 is shown to be suitable as a support material for the Pt1Pd3 to achieve enhanced catalytic activity and stability.

The porous Al2TiO5/Al2O3 composites were fabricated by reactive sintering at 1500–1700 °C in nitrogen atmosphere. The starting materials Al2O3 and TiO2 were mixed in an equimolar ratio and the addition of AlN was 5–40 mol%. The effects of AlN content and sintering temperature on phase composition, linear shrinkage, pore sized distribution, porosity and microstructure were investigated. The XRD results showed that the composites mainly consist of Al2TiO5 while the peak intensity of Al2O3 increased with AlN content. The median pore sizes decreased with increasing AlN content and were in the range of 2–6 μm, 1–2 μm, 0.4–0.7 μm, and 0.3–0.5 μm for composites using 10, 20, 30, 40 mol% AlN, respectively. The porosities of ATN10 and ATN20 were from 20% to 10% at 1600 °C to 1700 °C while the porosities of ATN30 and ATN40 were almost constant in between 11 and 13%. The addition of AlN effectively decrease the grain size of Al2TiO5 and led to reduce microcrack at the grain boundary.

In this research work, an attempt has been undertaken to improve the structural, morphological and electrical properties of RF sputtered CCTO thin films with the incorporation of HfO2 as a buffer layer and Zn as an intermediate layer. RF sputtering technique was used to deposit all the films with the optimized sputtering parameters. XRD pattern of HfO2 buffered CCTO thin films have shown an increase in (220) peak intensity with the enhancement in buffer layer thickness from 2.5 nm to 20 nm. Field emission scanning electron microscope images depicted the formation of smooth surface morphology. In addition, improved electrical and interface properties are observed with the increase in buffer layer thickness. CCTO films, deposited on 20 nm of HfO2 buffer layer, have shown lower leakage current of 3.15 × 10−7 Amp. In addition, reduced Dit value of 5.3 × 1010 eV−1cm−2 has been observed for film with 20 nm buffer layers. Improved morphological and electrical properties in CCTO films are attributed to suppression of defect states due to the presence of HfO2 buffer layer. Furthermore, the effect of different position of Zn intermediate layer, sandwiched between two CCTO layers, was also investigated. The appearance of splitted (220) peak has confirmed the incorporation of Zn in CCTO lattice. The surface morphology was found to be strongly dependent upon the multilayer geometry. Improved dielectric constant of 1078 at 100 kHz frequency is observed for the film configuration of 40-10-60, in which the Zn layer is situated towards the middle position.

Herein, we attempted to prepare MoS2/Fe@Fe3O4 nanocomposites capable of strongly absorbing broadband incident electromagnetic (EM) radiation and probed the effects of their composition on complex permittivity and permeability at 2–18 GHz. Calculations of normal-incidence reflection losses (RLs) based on EM parameters revealed that the Fe@Fe3O4 to MoS2 mass ratio strongly influenced the absorption peak intensity and bandwidth. Specifically, an RL peak of −31.8 dB@15.3 GHz and a bandwidth (RL

An ionospheric heating experiment was conducted using the dual-pump mode at the EISCAT/HEATING facility in Tromso, Norway. Some new features were found in the downshifted maximum (DM) component of the stimulated electromagnetic emission (SEE) spectra. During the experiment, the DM1 generated by pump 1 was enhanced under the action of pump 2 with the peak intensity being increased by ∼4.8–9.8 dB to achieve maximum value, when the frequency of pump 2 was 4.100 MHz. The gyro resonance at the upper hybrid altitude played an important role in this phenomenon. It was also observed that the development time of DM2 generated by pump 2 was greatly shorter than that of DM1 due to the precondition provided by the artificial field-aligned irregularities (AFAIs) stimulated by pump 1. Additionally, the frequency offset and peak intensity of the DM1 spectrum showed a significant negative correlation, where the correlation coefficient reached a value of −0.91.

Active capture and ultrasensitive SERS-based detection of hexachlorocyclohexane (HCH) has been a challenging task. A novel strategy based on 4-mercaptophenylboronic acid (4-MPBA) surface modification on Au nanosheets-built hollow sub-microcubes (ANHCs) was proposed to capture HCH pesticides effectively via Suzuki cross coupling reaction. The ANHCs structure composed of numerous intertwined nanosheets was firstly prepared by Au nanocrystals heteroepitaxial growth on AgCl cubes. Then, the 4-MPBA molecules were selected to modify on the surface of ANHCs for SERS-based detection of HCH. The SERS results proved that active capture and ultrasensitive detection of HCH could be implemented, and the limit of detection is 0.3 ppb. Besides, 4-MPBA modified substrate show high reproducibility and sensitivity than unmodified one. Moreover, the characteristic peak intensity ratio IHCH/I4-MPBA presents a good linear relationship with the logarithm of a certain concentrations, and achieve SERS-based quantitative detection of HCH. In addition, this strategy has been successfully used for the detection and differentiation of mixed HCH isomers in water samples. The surface modification strategy on high performance SERS substrate provides a good route for the highly ultrasensitive detection and active capture of HCH, and paves a way for the detection of organochlorine pesticide residues in water samples.

Based on the nonlinear Schrodinger equation, we discuss the variation dynamics of the peak intensity of high-order rogue wave with shift parameters theoretically, and reveal a non-derivable transformation point in it. The critical behavior of rogue waves shows that the ultimate cause of the transformation point is the ephemeral four-peak state of them. As a practical example, we discuss the experimental feasibility for observing the transformation point in nonlinear fiber optics.

We have established a data set of 58 major hybrid SEP events associated with meter-to-decahectometer wavelength (m-to-DH) type II bursts, solar flares, and radio-load CMEs during the period of 1997–2014. The main focus of our study is to address the following two questions: Does the interaction of CMEs play a role in the enhancement of SEP intensity? Is there any difference in the seed population, and parent eruptions in the SEP events with and without CME interactions? Hence, the sample of 58 events is classified into two sets: (i) 35 non-interacting-CME-associated SEP events; (ii) 23 interacting-CME-associated SEP events. All the characteristics of SEPs, their associated CMEs/flares and the relationships between them are statistically analyzed and compared. Some of the basic attributes and relative elemental abundances (Fe/O ratios) of the both the sets are also compared. The results indicate that the seed particles in non-interacting-CME-associated SEP events are mostly from solar wind/coronal materials. But in the case of interacting-CME-associated SEP events, it may be associated with both flare material from preceding flares and coronal materials from solar wind/preceding CMEs. The correlation studies reveal that there are clear correlations between logarithmic peak intensity of SEP events and properties of CMEs (space speed: cc = 0.56) and solar flares (peak intensity: cc = 0.40; integrated flux: cc = 0.52) for non-interacting-CME-associated SEP events. But these correlations are absent for the interacting-CME-associated events. In addition, the results suggest that interaction of primary CMEs with their preceding CMEs plays an important role in the enhancement of peak intensity of SEPs at least for a set of m-to-DH type II bursts associated SEP events.

In this paper, we study the collision properties of rogue waves in optical fiber theoretically. Based on the triplet solution of the nonlinear Schrodinger equation with two parameters, the factors that affect the initial conditions of colliding rogue waves are discussed. Meanwhile, the variation dynamics of peak intensity in collision is studied with each parameter, and the approximate formula of this variation law is derived by drawing an analogy between the collision of rogue waves and that of classical particles, which is consistent with the numerical results. The variation with both two parameters is also discussed, which is found the abnormal behavior of peak intensity in this case. This effect can be potentially used to generate rogue waves with higher peak intensity in optical fiber, which is confirmed by our simulation results.

Respiratory syncytial virus (RSV) infections peak during the winter months in the United States, yet the timing, intensity, and onset of these outbreaks vary each year. An RSV vaccine is on the cusp of being released; precise models and accurate forecasts of RSV epidemics may prove vital for planning where and when the vaccine should be deployed. Accurate forecasts with sufficient spatial and temporal resolution could also be used to support the prevention or treatment of RSV infections. Previously, we developed and validated an RSV forecast system at the regional scale in the United States. This model-inference system had considerable forecast skill, relative to the historical expectance, for outbreak peak intensity, total outbreak size, and onset, but only marginal skill for predicting the timing of the outbreak peak. Here, we use a superensemble approach to combine three forecasting methods for RSV prediction in the US at three different spatial resolutions: national, regional, and state. At the regional and state levels, we find a substantial improvement of forecast skill, relative to historical expectance, for peak intensity, timing, and onset outbreak up to two months in advance of the predicted outbreak peak. Moreover, due to the greater variability of RSV outbreaks at finer spatial scales, we find that improvement of forecast skill at the state level exceeds that at the regional and national levels. Such finer scale superensemble forecasts may be more relevant for effecting local-scale interventions, particularly in communities with a high burden of RSV infection. Keywords: RSV, Superensemble, Forecast, Infectious disease, Bayesian modeling, Outbreaks, Epidemics, Computational biology

Structural deterioration of a soil subjected to freezing-thawing cycles can significantly influence its engineering performances. The nuclear magnetic resonance (NMR) technique provides a powerful tool for studying the structural evolution of water-saturated porous media such as soils. In the present work, three soils were tested under repeated freezing-thawing cycles. The process was monitored by measuring T2 distribution curves, T1-T2 correlation spectra and distributions of log (T1/T2) with NMR technique, and then adsorptive water contents were calculated. The variation of the adsorptive water contents increased as the fraction of sand in the soil increased, implying that the higher the sand content, the more significantly the soil microstructure varied. The T2 distribution curves for soil with sand fraction of 30% did not significantly change, whereas those for soils with higher sand fractions (50% and 70%) were quite different. In addition, Peak 2 changed from a flattened peak to a sharp peak, implying a more uniform microstructure after cyclic freezing-thawing. The peak intensity in T1-T2 correlation spectra changed quite significantly during the freezing-thawing process, implying that the two porosity systems in the soil exchanged water during the process. Significant change of soils usually occurred only in the first 5 freezing-thawing cycles. The microstructure variation for soil with sand fraction of 70% was larger, and then soils with sand fractions of 30% and 50% were less in order, suggesting a ranking of variation degree in agreement with sand fraction.

In this paper, based on the simple model of fiber laser, the transmission characteristics of Akhmediev breathers in fiber laser is studied numerically by the split-step Fourier method. The Akhmediev breathers are influenced by the average dispersion and the small signal gain coefficient in fiber laser. The results show that Akhmediev breathers can be stable transmitted when the average dispersion and nonlinear effects are balanced. The larger the small signal gain coefficient, the peak intensity of Akhmediev breathers is greater with the width narrower. And the spatial separations of the sub-pulses are gradually reduced. In addition, the collision of two breathers can form the localized high-amplitude pulse trains in fiber laser. The results obtained in this paper can provide a theoretical basis for the study of the transmission of Akhmediev breathers in fiber laser.

The optically stimulated luminescence (OSL) and thermoluminescence (TL) signals of an Al2O3:C,Mg single crystal were investigated as a function of the heating temperature and illumination time before readout, respectively. The TL and OSL results were analyzed in complementary ways, including the area under the curve, whole range and partial integration, and peak intensity. A correlation between the continuous decay of the main TL peak intensity (at 185 °C at a heating rate of 1 °C/s) against blue light (470 nm) illumination times and the decay of the OSL signal for higher temperatures was found. Both these results showed that the emptying of the OSL active trap was closely related to the emptying of the trap related to the main TL peak, indicating a correlation of both phenomena.

In this work, we have investigated the compensation effect of defects in lightly Si-doped GaN layer. It is found that the compensation of defects can be enhanced by increasing Si doping concentration and dislocation density in GaN layer. Subsequently, through theoretical analysis it is found that a more effective compensation is activated by increasing Si doping, which is mainly due to the enhanced effect of deep defects in the compensation role rather than by the increase of density of deep defects. Meanwhile, it is found that the yellow luminescence (YL) intensity of lightly Si-doped GaN samples increases with the increasing Si doping concentration, which can also be caused by the enhancement of compensation of deep level defects, while the increase of peak intensity of band edge luminescence with increasing Si doping is mainly caused by the increase of free carriers.

Given the growing interest in the application of Raman spectroscopy for quantitative purposes in solid pharmaceutical preparations, a revision of the effect of particle size on Raman spectra of compacted samples is presented. For this purpose, a set of tablets of potassium hydrogen phthalate (KHP) of different particle size were prepared. KHP was used because of its purity and stability, which allow to consider that samples will not be altered during measurements; but also because of its chemical structure (aromatic ring and carboxylic groups), that are present in many active pharmaceutical ingredients (API). The latter makes possible to consider KHP as a model pseudo-API. As KHP tablets only contain a pure compound, the mapping strategy that was considered for measuring our samples will not be affected by subsampling issues. The spectra variance can be attributed to the intrinsically reproducibility in recording the spectra (which mainly depends on the instrument set-up) and the site-to-site differences in elastic scattering properties. Two different instrumental optics have been studied: a macro-Raman system and a Raman microscope (500 μm and 50 μm laser spot size, respectively). The effect of the spectra preprocessing is also evaluated. The overall results demonstrate raw Raman intensity increases with particle size up to a value that depends on tablet width and that the applied spectral preprocessing (baseline correction and a unit vector normalization), reduces the differences in Raman intensities due to the particle size, but does not completely eliminate it for the lower particle sizes (< 20 μm). For tablets containing particles with predefined sizes, it corrects the mapping site-to-site differences in elastic scattering.

Thermoluminescence of a high temperature secondary glow-peak in natural quartz annealed at 900 °C is reported. The glow-curve of a sample irradiated to 10 Gy and measured at 1 °C/s shows three peaks; the main peak at 71 °C and two other weaker-intensity peaks at 125 °C and 177 °C. For reference, the peaks are labelled as I, II and III. This study is concerned with the secondary peak at 177 °C (peak III). The electron trap responsible for peak III is stable at ambient temperature as determined by monitoring the peak intensity after various delays between irradiation and measurement. The activation energy and frequency factor of the peak were estimated as ~1.24 eV and ~1012 s−1 respectively. The dose response of the peak in the range 1–300 Gy is sublinear. The influence of either partial heating or irradiation dose on the peak position suggest that the peak follows non-first-order kinetics.

Nanodiamonds (NDs) have been synthesized by using microplasma facility. Ethanol is chosen as a Carbon precursor. A mixture of Ethanol and Argon has been dissociated in microplasma to fabricate NDs. In order to quench, etch and stabilize the NDs, Hydrogen has been used as a stabilizing agent. The motivation behind this project is to find an effective root for the introduction of Hydrogen into microplasma. The experiments are performed by introducing the Hydrogen either directly or indirectly into the microplasma. The results obtained from Raman, TEM and XRD confirmed that the highest quality (in terms of smallest size and near stress free) diamonds have been obtained in the case of indirect dilution. The decreased PL peak intensity with indirect dilution indicates the decreased defect density in the diamond. It is possible to produce and control the defect center only by controlling the Hydrogen introduction way in to the microplasma. The indirect dilution decreases the amount of Hydrogen bonded to trans-polyacetylene and enhances the Hydrogen termination to the surface of diamond grains.

In the current study the association rate between solar energetic particles (protons) and filaments and/or filament eruptions (FEs) is investigated using the largest reported event sample. Proton events observed in the period 2010–2016 are accompanied by filaments in 92% (143/156) of the cases. Due to the lack of comprehensive catalog of all filaments, a catalog of FEs is used for the reversed association. Only 5% of FEs have in situ proton signatures with larger peak intensity, compared to the median of the entire proton sample. Other solar activity phenomena (flares and coronal mass ejections) related to the proton events show differences in their distributions compared to the respective FE-samples. The indication for a shock wave formation using the type II radio signatures is also considered and discussed.

As natural weather disasters, tropical cyclones (TCs) are destructive in proportion to their peak intensity. This study investigates the association of North Atlantic, western North Pacific, and eastern North Pacific TC peak intensities with tropospheric air temperature, respectively, by applying NCEP–NCAR and MERRA reanalysis data. Both the correlation between TC peak intensity and air temperature and the difference in air temperature between strong and weak TC peak intensity conditions reveal that significant cooling of the tropopause and upper-tropospheric warming are accompanied by strengthening TC peak intensity for North Atlantic TCs, suggesting an important effect of upper-tropospheric static stability on TC peak intensity. However, warming in the lower troposphere is associated with strong TC peak intensity for eastern North Pacific TCs, indicating a major effect of lower-tropospheric static stability on TC peak intensity. The peak intensity of western North Pacific TCs is mainly affected by vertical wind shear, not the atmospheric temperature. 摘要台风作为一种灾害性天气, 其破坏性大小与自身强度有很大的关系. 因此, 本项研究利用NCEP–NCAR和MERRA再分析数据, 考查了北大西洋, 西北太平洋, 东北太平洋台风强度峰值与对流层温度的关系. 台风强度峰值与大气温度的相关系数, 以及极大和极小台风强度峰值下大气温度的差值, 共同显示: 北大西洋台风强度峰值受到对流层顶低温和对流高层增温的正向作用, 表明了对流高层稳定性对北大西洋台风强度峰值的重要作用. 但是, 东北太平洋台风强度峰值却受到对流低层增温的正向作用, 表明了对流低层稳定性对东北太平洋台风强度峰值的重要作用. 西北太平洋台风强度峰值较少受大气温度影响, 主要受到垂直风切变的作用.

Gallium doped ZnO nanorods exhibiting good PL performance were grown via a solution method. The as-grown, Ga-doped, and undoped ZnO nanorods displayed a broad yellow–orange emission and a UV emission peak, respectively. By applying an annealing process, the broad yellow–orange emission almost disappeared and the UV emission increased significantly (for ZnO:Ga (1.2%) peak intensity ratio ≅ 56). With Ga doping, the UV emission peak shifted from 3.27 eV to 3.28 eV. Also, experimental results revealed that a sample doped with Ga at 1.2% by mass exhibited a stronger PL intensity than either the undoped ZnO (higher by 57% acc. to peak intensities) sample or a ZnO sample doped with Ga at 2% (higher by 88% acc. to peak intensities). Both doped and undoped samples were also tested as alpha particle scintillators , and similarly the ZnO:Ga (1.2%) nanorods were found to have higher scintillation response than ZnO:Ga (2%) or undoped ZnO.

Bacterial pathogens such as Yersinia pestis, Francisella tularensis, and Bacillus anthracis are classified into the highest rank of potential bioterrorism agents. Colorimetric lateral flow assay (LFA) strips are commercially available but these conventional strips have drawbacks in terms of low sensitivity and limit of quantitative analysis. Therefore, there is an urgent need for a new sensing platform to detect these pathogens in the early contamination stage. In this study, a novel surface-enhanced Raman scattering (SERS)-based LFA strip was developed for sensitive detection of bacterial pathogens. Target-specific SERS nanotags (Raman reporter-labeled gold nanoparticles) were used as an alternative to the gold nanoparticles in conventional LFA strips. Using these SERS nanotags the presence of bacteria could be identified through a simple color change in the test line. Additionally, highly sensitive and accurate quantitative analysis could be performed by monitoring the characteristic Raman peak intensity of SERS nanotags that were captured in the test line. This highly sensitive method required a short assay time (15 min) and a tiny volume of pathogen sample (40 μL). We believe that the proposed SERS-based LFA technique has great potential as a valuable tool in the early detection of specific bacterial pathogens in the field due to its excellent analytical sensitivity.

In this paper, we investigate the propagation dynamics of circular Airy beams (CAB) in a medium with radial parabolic potential both analytically and numerically. Our results show that CAB will exhibit periodic abruptly autofocusing behavior under the action of radial parabolic potentials. Within every period, we interestingly observe a novel autodefocusing behavior, which manifests that optical peak intensity abruptly decreases by several orders of magnitude. In particular, such unique “autofocusing-to-autodefocusing” effect can lead to the formation of a series of elegant periodic optical bottles having paraboloidal shapes during the whole propagation process. Our findings indicate that CAB is expected to provide a unique tool in optical micromanipulation and optical trapping.

The chemical quantitative analysis at trace level has been widely explored by means of various techniques. While it still remains challenging to achieve ultrasensitive but facile, rapid, and inexpensive detection methods. In this paper, the possibility of employing surface-enhanced Raman scattering technique on a portable Raman system for rapid and accurate quantitative analysis of target chemicals in unknown systems was investigated. This detection approach contains 3 steps: (1) adding target chemicals with different amount to the initial unknown solution, leading to new solutions with target molecules of various concentrations; (2) Obtaining different samples' SERS spectra and capturing featured SERS peaks whose intensity grew up with the addition of target chemicals; (3) examining the relationship between featured peak intensity increment after adding target chemicals and its corresponding addition amount, and thus we could perform quantitative analysis of the chemical in an unknown solution and obtain its initial concentration. The validity of this method was systematically demonstrated by estimating the concentrations of 2-Naphthalenethiol (2-NaT) and 4-Mercaptopyridine (4-MPY) both in their single-component solutions and binary solutions, respectively. Predictions are close to their real values. Furthermore, we successfully predicted the concentrations of malachite green (MG) in fish water and benzidine in ground water. This study clearly demonstrates an accurate and facile approach to calculate the concentration of target chemicals in unknown systems, which fully exploit the potential of SERS quantitative analysis.

The paper demonstrates the possibility of measuring the carbon dioxide (CO2) concentration in atmospheric air using Raman spectroscopy. Three methods have been studied for deriving the CO2 concentration from the Raman spectra (the peak intensity ratio, the integrated intensity ratio, the contour fit method). The best results were obtained when the contour fit method is applied for Raman spectra processing. In this case the deviations from reference mixtures of known concentration were below 3 ppm. Methods for improving the sensitivity of the Raman gas analysis method are proposed and the possibility for using this technique for the simultaneous determination of the concentrations of significant amount of greenhouse gases in air with single device is discussed.

Nanostructures in the PAN-based carbon fibres were investigated by means of the Raman spectroscopy which was performed using a series of different excitation wavelengths. UV-Raman measurements showed the predominance of sp2 carbon for the carbon fibres with Young’s moduli ranging from 55 to 440 GPa. The excitation wavelength dependence of the spectral line shape implied the presence of the graphitic (sp2 carbon layers) as well as the amorphous carbon-like component (sp2 carbon clusters) in these fibres. An analytical modelbased upon the Tuinstra-Koenig relation and the rule-of-mixtures concept was proposed to account for the observed behaviour of the peak intensity ratio ID/IG. It was suggested that the carbonisation heat treatment led to the sp2 carbon layers extending rapidly throughout the nanostructure, resulting in the complete loss of the sp2 carbon clusters for the higher-modulus carbon fibres. These new findings together with the proposed analytical model are believed to be essential keys towards the development of new generation carbon fibres.

The X-ray fluorescence technique using peak intensity ratios of trace elements is one of the faster, less expensive and less invasive methods for obsidian sourcing. Moreover, XRF peak intensity ratios are particularly useful when the artifact is slightly altered, particularly affecting the alkali cations, or when its surfaces are covered with a fine film of carbonate deposits formed while the sample was buried. The limitation of this technique results from the dimensions of the obsidian samples: very small obsidian samples, nowadays about 1 cm in size, are difficult to measure given the very few X-rays emitted by their surface. An aluminium holder closed with a very thin Mylar© polyester film was prepared and the specimen, positioned at the centre of the surface of the Mylar film, was placed in the XRF spectrometer. The use of recent technology XRF apparatus equipped with a 4 kW Rh anode X-ray tube coupled with an accurate measurement of refined X-ray characteristic lines, that exclude the X-ray background contribution, of five trace elements (Rb, Sr, Y, Zr, Nb), made it possible to determine the source geological outcrop of archaeological obsidian samples as little as 7 mm and as light as 40 mg. A database of peak intensity ratios, background and interference free, of five trace elements was produced for obsidian samples from Monte Arci, Palmarola, Lipari, Pantelleria, Gyali and Melos. This database may be used by other laboratories provided the X-ray intensity of the trace elements Rb, Sr, Y, Zr, Nb are measured as net intensities, that is purified from the contribution of the background and from interelemental interferences. A comparison between data obtained with two spectrometers, of different generation and differently calibrated, confirmed the possibility of obtaining a database that can be shared with other laboratories. The proposed XRF method was tested on Neolithic obsidians from four Apulian sites (Ripa Tetta at Lucera, Palestra ex G.I.L. at Foggia, Pulo di Molfetta and Grotta di Santa Barbara at Polignano a Mare), whose source outcrops had been also determined by SEM-EDS.

Summary Objective A V ˙ O 2 slow component V ˙ O 2 SC typically occurs during continuous, constant work rate exercises conducted at both intense and maximal intensities. The extent to which V ˙ O 2 SC also develops during intermittent exercises in field condition warrants investigations. This study aimed to test the occurrence of a V ˙ O 2 SC during a field-based intermittent exercise performed at an intensity that elicits V ˙ O 2 peak . Material and methods For this purpose, ten male tennis players performed two intermittent field exercises that mimic several aspects of tennis activity: an incremental test to determine their peak rate of oxygen consumption, and a discontinuous, constant work rate exercise (DCWR) conducted at V ˙ O 2 peak intensity until exhaustion. Cardio-respiratory variables were measured breath-by-breath using a portable device. Results The coefficients of determination of the V ˙ O 2 kinetics models were 0.74 ± 0.18 ( P P V ˙ O 2 was detected above a threshold intensity corresponding to 86 ± 6% of V ˙ O 2 peak . During DCWR, the occurrence of the V ˙ O 2 SC was significant for 6 subjects, with a magnitude of 4.0 ± 3.3 mL.min −1 .kg −1 representing 6.0 ± 3.2% of the total V ˙ O 2 response. Conclusion This study showed that a mathematical model used to describe V ˙ O 2 response to an intermittent exercise is appropriate and a V ˙ O 2 SC was detected for the majority of the participants during intermittent exercises that elicit V ˙ O 2 peak .

Waxy maize starch was subjected to crosslinking, HMT, crosslinking-HMT and HMT-crosslinking, and physicochemical properties and digestibility were examined. Crosslinked-HMT and HMT-crosslinked starch exhibited lower and higher phosphorus contents than crosslinked starch at the same concentrations of STMP/STPP (99:1, w/w), respectively. A low swelling power, a low paste clarity, a high melting temperature and a low ΔH were observed in crosslinked-HMT starch and HMT-crosslinked starch like crosslinked and/or HMT starch. Crosslinking-HMT and HMT-crosslinking mitigated the reduced XRD peak intensity observed for HMT. Crosslinked-HMT starch effectively produced RS, showing 28.7–41.5% RS in raw starch and 23.3–25.0% in gelatinized starch. The RS proportion of crosslinking-HMT was similar to that of crosslinking in raw starch, but HMT and crosslinking-HMT showed similar RS proportions in gelatinized starch. Crosslinking-HMT advantageously produced RS from both crosslinking and HMT; however, this was not observed in HMT-crosslinking.

Paper-based microfluidic chips have shown great potential for use in rapid clinical diagnostics. In this work, we present a paper-based device that integrates an electromagnetically actuated valve and an adjustable time controller for the simultaneous detection of multiple tumor biomarkers. The time controller consists of a timing channel and two movable conductive iron bands that function as an electric switch. Once the conductive iron bands are connected by the fluid flow, the circuit would be closed to actuate the magnetic valve, initiating chemiluminiscent immunoassay (CLIA) reactions. Using a HRP- O -phenylenediamine-H 2 O 2 detection system, simultaneous detection of different concentrations of carcinoembryonic antigens (CEA) was demonstrated. The resulting CLIA peak intensity exhibited a good linear relationship with the logarithm of the CEA concentration from 0.1–80 ng mL −1 . Further experiments showed that the developed device was capable of detecting multiple tumor biomarkers simultaneously. We can program different incubation times for the detection of different biomarkers by moving the conductive bands on this paper-based device. In this study, only 16 min was required to complete CEA detection. This strategy greatly shortens detection time compared to the conventional chemiluminiscence technique for CEA detection (nearly 2 h). This paper-based device provides a simple and inexpensive platform for immunoassay-based detection of disease-related biomarkers.

The retrogradation properties of rice starch (RS) treated with transglucosidase (TG) were investigated. The degree of branching (DB) increased from 12.26 to 15.16% with increasing TG treatment time except for 20 h. The relative crystalline of the retrograded TG-treated starches decreased from 26.44 to 21.57% with increasing DB. While the crystalline peak intensity became narrower and sharpener due to the formation of a much more uniform crystal structure, hence resulting in a lower mobility of water. Also, the spin-spin relaxation time (T2) decreased with increasing DB. The T22 and T23 significantly decreased by 80.47 and 64.46%, respectively. The Avrami kinetics demonstrated that the retrogradation rate of rice starch was retarded due to the decrease of rate constant k after TG treatment. The study may provide a promising theoretical basis on retarding retrogradation of rice starch to improve the qualities and extend shelf life of the rice staple foods.

This paper presents composite substrates consisting of (i) Au film/polymethyl methacrylate (PMMA) grating and (ii) Au-nanocube coatings for use in surface-enhanced Raman scattering (SERS). The SERS properties of the substrate are analyzed theoretically and studied experimentally. Raman spectra were collected from three random positions on the substrates, and the results show that the Raman peaks remain basically unchanged, with the relative standard deviation in peak intensity of each peak remaining below 14.9%. Meanwhile, the Raman enhancement factor for the 1520 cm−1 band is 1.45 × 104, which is close to the theoretically calculated enhancement factor of 3.6 × 104. The results of experimentation and numerical simulation show that the substrates are highly uniform, reproducible, and physically stable, which can greatly improve the practicality of Raman measurements and should thus promote the use of Raman spectroscopy.

We demonstrate experimentally propagation and evolution of high-order three-Airy beams in this letter. Our results show clearly that, a high-order three-Airy beam tends to evolve into a Laguerre-Gaussian-like beam, in consistence with previous prediction. Moreover, by analyzing the internal transverse power flow of three-Airy beams during propagation, we found that, as the order of three-Airy beams goes higher, the initial beam intensity distributes more in the “side lobes”, and it takes longer propagation for the beams to reach a maximum peak intensity and then transform into patterns of corresponding Laguerre-Gaussian-like modes.

Sodium saccharin (SS) is a commonly used synthetic sweetener in carbonated soft drinks and beverages. Long-term consumption of SS could result in health problems. Here, a sensitive surface-enhanced Raman spectroscopy (SERS) method with silver nanorod (AgNR) array substrates was explored for quantification of SS in soft drinks. The AgNR array substrates fabricated by an oblique angle deposition technique exhibited an excellent SERS activity with an enhancement factor of ∼108. A good linear relationship was demonstrated between SERS peak intensity and SS concentration in the concentration range of 0.5–100 mg/L, and a limit of detection was determined to be 0.3 mg/L. The detection of SS in different soft drinks was further explored by combining SERS spectra with the partial least squares discriminant analysis. The results showed that the LODs of SS from Sprite, Cola, Fanta and Schweppes detected by SERS were 20, 5, 20 and 10 mg/L, respectively, which was far below the national standard. This SERS-based method enables the rapid and highly sensitive detection of SS with minimal sample pretreatment, and holds great promise in this food safety application.

This paper analyzes and compares the two methods for suppressing the subsidiary fringes in white-light correlograms with two-wavelength light source. One of the methods adds the intensities of the two wavelength components and the other multiplies them. Peak intensity difference between the central fringe and the subsidiary fringes is investigated. A mathematical expression for a rapid estimation of the optimum wavelength difference between the two wavelengths is given for suppressing the subsidiary fringes. The effects of the intensities of the two wavelength components have also been investigated.

We report on the great improvement of optical properties of a InGaAs quantum well structure by inserting ultra-thin GaAs layers between the InGaAs well and the InGaP barrier grown by molecular beam epitaxy. The room temperature photoluminescence from the quantum well structure with insertion of 3 monolayers GaAs shows 1.5 times enhancement in peak intensity, as well as a drastic reduction of peak linewidth from 46 nm to 30 nm. The dependence of the quantum well optical properties has been investigated with inserted GaAs thickness in the range of 0–12 MLs, and optimized GaAs thickness has been obtained. This methodology might be beneficial for growth of high quality quantum well optical devices.

This work aimed to develop an intelligent packaging film based on bacterial cellulose (BC) and pelargonidin (Pg) for tilapia fillets freshness. The color of Pg solution and Pg-BC films changed from red to blue within pH3−pH10. The introduction of Pg reduced the light transmittance and improved the mechanical properties of the film. FTIR results showed that BC and Pg formed intermolecular interactions. The diffraction peak intensity of Pg-BC film decreased during storage. The cross section and surface of Pg-BC film were damaged during storage by SEM. The Pg-BC film had a great color difference from red to colorless when employed to monitor the freshness of fillets stored at 4 °C and 25 °C, which was consistent with the change of TVB-N and sensory scores of fish. Therefore, the Pg-BC film can be used as intelligent packaging film to monitor and visualize the freshness of fish during storage.

Hyperthyroidism and hypothyroidism may cause a series of clinical complications have a high incidence, and early diagnosis is beneficial to treatment. Based on Raman spectroscopy and deep learning algorithms, we propose a rapid screening method to distinguish serum samples of hyperthyroidism patients, hypothyroidism patients and control subjects. We collected 99 serum samples, including 38 cases from hyperthyroidism patients, 32 cases from hypothyroidism patients and 29 cases from control subjects. By comparing and analyzing the Raman spectra of the three, we found differences in the peak intensity of the spectra, indicating that Raman spectra can be used for the subsequent identification of diseases. After collecting the spectral data, Vancouver Raman algorithm (VRA) was used to remove the fluorescence background of the data, and kernel principal component analysis (KPCA) was used to extract the spectral data features with a cumulative explained variance ratio of 0.9999. Then, five neural network models, the adjusted AlexNet, LSTM-CNN, IndRNN CNN, the adjusted GoogLeNet and the adjusted ResNet, were constructed for classifications. The total accuracy was 91%, 84%, 82%, 75% and 71% respectively. The results of our study show that it is feasible to use Raman spectroscopy combined with deep learning to distinguish hyperthyroidism, hypothyroidism and control subjects. After comparing the models, we found that as the neural network deepens and the complexity of the model increases, the classification effect of Raman spectroscopy gradually deteriorates, and we put forward three conjectures for this.

The eigenmodes based on paraxial accelerating beams in nonlinear atomic vapors with Kerr and cubic-quintic nonlinearities are demonstrated from mathematical models and numerical simulations. Upon adjusting the generation and propagation conditions, these nonlinear accelerating beams exhibit different evolution properties. We show numerically that the adopted beams can propagate robustly in the medium regardless of its absorption properties. The shape and peak intensity of the main lobes of these beams, based on the fact that they are the eigenmodes of the nonlinear Schrodinger equation in atomic media, are preserved for a significantly long propagation distance. If such beams are not the modes of the system, they are subject to the under-healing or over-healing effect, which damages the shape of the self-accelerating beams. In a numerical investigation, we also discuss the interactions between truncated accelerating beams, which readily generate non-accelerating solitons and soliton pairs.

Homogeneous concentration Si1-XGeX crystals (0.3 ≤ X ≤ 0.9) with 20 mm in diameter were grown using the Travelling Liquidus Zone (TLZ) method. Infrared (IR) absorption spectra of the SiGe crystals were measured at room temperature, which revealed the interstitial oxygen Oi related Si Oi Si absorption peak shifted −25.7x cm−1 from 9.09 µm (1100 cm−1) for Si0.7Ge0.3 to 9.18 µm (1089 cm−1) for Si0.3Ge0.7. That shift gives the Mode-Gruneisen parameter of Si Oi Si vibration of 0.67 + 0.03x. The oxygen concentration in the four Si1−XGeX (x ~ 0.3) crystals was measured using secondary ion mass spectroscopy (SIMS). The correlation coefficient used to convert the oxygen concentration into the Si Oi Si absorption peak intensity of Si1−XGeX (x ~ 0.3) was 2.56 × 1017 atoms/cm2.

Several countries around the world are confronted solid waste management most especially from aluminum beverage containers. The recycling process is seen as an effective approach since it is energy saving, cost effective and reduced emission. In this study, the Sol-gel method was used to process the aluminum wastes and to consequently synthesize them into aluminum oxide (α-Al2O3) and presented in several crystalline structures. The result from this study indicated that the synthesized α-alumina at lower calcination time exhibited a lower FTIR peak intensity which indicated a more crystallinity. However, the synthesized α-alumina exhibited higher and sharper FTIR bands at higher calcination time. Moreover, the morphological characteristic shows that exhibited almost similar features with a non-spherical heterogeneous particle sizes. The results of the elemental analysis suggest a direct proportionality between the calcination time, and atomic percentage of aluminum among the samples. Conclusively, this study shows that the waste aluminum can be converted into economical value-added products.

The estimation of the postmortem interval (PMI) is an essential part of forensic practice investigations. In this experiment, attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) and chemometrics were combined to explore the estimation of PMI in adipose tissue and the effect of temperature. Through principal component analysis (PCA) and two-factor ANOVA, we found that the change in adipose tissue degradation was mainly reflected in the peak intensity in the 1743 cm−1 (the bond between fatty acids and glycerol) decrease with the prolongation of PMI and the peak intensity in the 1711 cm−1 (free fatty acids) increase with the prolongation of PMI. Furthermore, temperature has a significant effect on the postmortem changes in adipose tissue; it will not change the mechanism of adipose tissue degradation but will affect the rate of adipose tissue degradation. Our next step was to establish partial least squares (PLS) regression models at different temperatures to estimate PMI. We found that the temperature affects the robustness and reliability of the model by affecting the rate of adipose tissue decomposition. In the high-temperature group, the adipose tissue changes more with time, which is beneficial to the detection of FTIR and the establishment of the model (25 °C: Rp2 = 0.82, RMSEP = 1.78 d; 35 °C: Rp2 = 0.82, RMSEP = 0.59 d), while low temperature is the opposite (5 °C: Rp2 = 0.12, RMSEP = 3.73 d; 15 °C: Rp2 = 0.60, RMSEP = 2.57 d). This study shows that the combination of ATR-FTIR and chemometrics is feasible to explore the estimation of PMI in adipose tissue and the effect of temperature.

Cross-sectional Raman spectroscopy is used to characterize the defect formation and the defect recovery in MeV H+ implanted bulk GaN and 4H-SiC in the high energy MeV ion-cut process. The Raman intensity decreases but the forbidden modes are activated at the damage region, and the intensity decrease is proportional to the damage level. The Raman spectrum is quite sensitive to detect the damage recovery after annealing. The main peak intensity increases and the forbidden mode disappears in both annealed GaN and 4H-SiC samples. The Raman spectra of GaN samples annealed at different temperatures suggest that higher annealing temperature is more efficient for damage recovery. While, the Raman spectra of SiC indicate that higher implantation temperature results in heavier lattice damage and other polytype clusters might be generated by high annealing temperature in the annealed SiC samples. The cross-sectional Raman spectroscopy is a straightforward method to characterize lattice damage and damage recovery in high energy ion-cut process. It can serve as a fast supplementary measurement technique to Rutherford backscattering spectrometry (RBS), nuclear reaction analysis (NRA) and transmission electron microscope (TEM) for the defect characterizations.

Evolution of the peak intensity for different grain orientations was in-situ measured by neutron diffraction for a twinning induced plasticity steel during tension-compression fatigue tests. Amplitude of the intensity variation is larger in high cycles than that at early cycles. The hysteresis loop features an asymmetric shape at early cycles and becomes symmetric with increase of cycles. Different twinning/detwinning activities correspond to different shape of the hysteresis loop. In cycle one, limited fresh twin volume is expected to correspond to short period of detwinning/retwinning. At later cycles, the twinning and detwinning are expected to happen together throughout the whole cycle.

Phototransferred thermoluminescence (PTTL) in α-Al 2 O 3 :C,Mg under 470 nm blue light has been investigated. Conventional thermoluminescence (TL) measured at 1 °C/s following irradiation to 10 Gy shows the main peak (labelled as III) at 163 °C and six secondary peaks I, II, IV, V, VI and VII at 45, 74, 200, 279, 328, 370 °C respectively. When a sample irradiated to 10 Gy is preheated to 220 °C at 1 °C/s to remove peaks I, II, III and IV and then exposed to 470 nm blue light for 100 s, it is found that three peaks I, II and III are reproduced under phototransfer. Kinetic analysis of the PTTL peaks shows that their kinetic parameters are similar to those of peaks I, II and III from conventional TL. Pulse annealing experiments, intended to study the dependence of PTTL peak intensity on preheating temperature, show that the electron traps corresponding to peaks V, VI and VII act as donor traps whereas the traps corresponding to peaks I, II and III act as acceptor traps. Further, it was found that no PTTL can be generated when all the traps corresponding to peaks I, II…VII are erased by preheating after irradiation. The primary conclusion here is that α-Al 2 O 3 :C,Mg does not have any deep traps beyond 400 °C sensitive to 470 nm stimulation or if there are any, their concentration is negligible. The PTTL for any of the PTTL peaks mentioned earlier increases with illumination time to a maximum within 400 s for measurements corresponding to doses between 6 and 15 Gy. The dose response of PTTL peaks II and III is linear within 1–15 Gy. Regarding fading, PTTL peak II fades to background level within 18000 s whereas in the same time, PTTL peak III fades down to 40% of its initial intensity.

The concentration and temperature dependence of photoluminescence (PL) performance was investigated, which indicated that the main emission in CsPbBr3 perovskite quantum dots was related to the band-edge mechanism. As the concentration increased from 0.1 to 10.0 mol/L at 293 K, the center of emission band exhibited a regular redshift, as well as the peak intensity increased initially and then declined, which could be attributed to the self-absorption processes. Along with the variation of temperature (273–353 K), peak wavelength, full width of half maximum (FWHM), and peak intensity of PL spectra presented a corresponding linear changes. In addition, the temperature reversibility revealed that CsPbBr3 QDs were reliable candidates for temperature sensor and optoelectronic devices.

The oxidation behavior of a Zr–Nb–Cu alloy under high-temperature water conditions, with different dissolved hydrogen concentrations, was investigated using in situ Raman spectroscopy. The results were subsequently compared to those of ex situ TEM analyses. Upon decreasing the dissolved hydrogen concentration from 4.15 to 2.49 mg/kg at STP, the peak intensity of tetragonal phase oxide weakened, while that of monoclinic oxide strengthened due to the phase transformation. Ex situ analyses revealed that the Zr–Nb–Cu alloy was oxidized slowly as compared to the Zr–Nb–Sn alloy due to the number of β-Nb precipitates in the oxide.