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The fully correlated frequency-independent Dirac–Coulomb–Breit Hamiltonian provides the most accurate description of electron–electron interaction before going to a genuine relativistic quantum electrodynamics theory of many-electron systems. In this work, we introduce a correlated Dirac–Coulomb–Breit multiconfigurational self-consistent-field method within the frameworks of complete active space and density matrix renormalization group. In this approach, the Dirac–Coulomb–Breit Hamiltonian is included variationally in both the mean-field and correlated electron treatment. We also analyze the importance of the Breit operator in electron correlation and the rotation between the positive- and negative-orbital space in the no-virtual-pair approximation. Atomic fine-structure splittings and lanthanide contraction in diatomic fluorides are used as benchmark studies to understand the contribution from the Breit correlation. [ABSTRACT FROM AUTHOR]

Fault diagnosis of rotating machinery plays an important role in modern industrial machines. In this paper, a modified sparse Bayesian classification model (i.e., Standard_SBC) is utilized to construct the fault diagnosis system of rotating machinery. The features are extracted and adopted as the input of the SBC-based fault diagnosis system, and the kernel neighborhood preserving embedding (KNPE) is proposed to fuse the features. The effectiveness of the fault diagnosis system of rotating machinery based on KNPE and Standard_SBC is validated by utilizing two case studies: rolling bearing fault diagnosis and rotating shaft fault diagnosis. Experimental results show that base on the proposed KNPE, the feature fusion method shows superior performance. The accuracy of case1 and case2 is improved from 93.96% to 99.92% and 98.67% to 99.64%, respectively. To further prove the superiority of the KNPE feature fusion method, the kernel principal component analysis (KPCA) and relevance vector machine (RVM) are utilized, respectively. This study lays the foundation for the feature fusion and fault diagnosis of rotating machinery. [ABSTRACT FROM AUTHOR]

Auricularia heimuer is a widely cultivated jelly mushroom. The fruiting bodies are categorized into cluster and chrysanthemum types. With changing consumer demands and the need to reduce bio-waste, the demand for clustered fruiting bodies is increasing. Therefore, gene mining for fruiting body types is a matter of urgency. We determined that the A. heimuer locus for fruiting body type was located at one end of the genetic linkage map. The locus was localized between the markers D23860 and D389 by increasing the density of the genetic linkage map. BlastN alignment showed that the marker SCL-18 was also located between D23860 and D389, and a total of 25 coding genes were annotated within this interval. Through parental transcriptome analysis and qRT-PCR verification, the locus g7219 was identified as the gene controlling the fruiting body type. A single-nucleotide substitution in the TATA box of g7219 was detected between the parents. By PCR amplification of the promoter region of g7219, the TATA-box sequences of the cluster- and chrysanthemum-type strains were found to be CATAAAA and TATAAAA, respectively. This study provides a foundation for the breeding of fruiting body types and strain improvement of A. heimuer. [ABSTRACT FROM AUTHOR]

Color is a crucial feature to consider when breeding and improving strains of Auricularia cornea. To uncover the mechanism of white strain formation in A. cornea, this study selected parental strains that were homozygous for the color trait and analyzed the genetic laws of A. cornea color through genetic population construction, such as test-cross, back-cross, and self-cross populations, and the statistical analysis of color trait segregation. Moreover, the study developed SSR molecular markers to construct a genetic linkage map, perform the fine mapping the color-controlling genetic locus, and verify candidate genes using yeast two-hybrid, transcriptome analysis, and different light treatments. The results of the study indicated that the color trait of A. cornea is controlled by two pairs of alleles. When both pairs of loci are dominant, the fruiting body is purple, while when both pairs of loci are recessive or one pair of loci is recessive, the fruiting body is white. Based on the linkage map, the study finely mapped the color locus within Contig9_29,619bp-53,463bp in the A. cornea genome and successfully predicted the color-controlling locus gene A18078 (AcveA), which belongs to the Velvet factor family protein and has a conserved structure domain of the VeA protein. It can form a dimer with the VelB protein to inhibit pigment synthesis in filamentous fungi. Lastly, the study validated the interaction between AcVeA and VelB (AcVelB) in A. cornea at the gene, protein, and phenotype levels, revealing the mechanism of inhibition of pigment synthesis in A. cornea. Under dark conditions, dimerization occurs, allowing it to enter the nucleus and inhibit pigment synthesis, leading to a lighter fruiting body color. However, under light conditions, the dimer content is low and cannot enter the nucleus to inhibit pigment synthesis. In summary, this study clarified the mechanism of white strain formation in A. cornea, which could aid in improving white strains of A. cornea and studying the genetic basis of color in other fungi. [ABSTRACT FROM AUTHOR]

For permanent magnet DC motors (PMDCMs), the amplitude of the current signals gradually decreases after the motor starts. In this work, the time domain features and time-frequency-domain features extracted from several successive segments of current signals make up a feature vector, which is adopted for fault diagnosis of PMDCMs. Many redundant features will lead to a decrease in diagnosis efficiency and increase the computation cost, so it is necessary to eliminate redundant features and features that have negative effects. This paper presents a novel supervised filter feature selection method for reducing data dimension by employing the Gaussian probability density function (GPDF) and named Gaussian vote feature selection (GVFS). To evaluate the effectiveness of the proposed GVFS, we compared it with the other five filter feature selection methods by utilizing the PMDCM's data. Additionally, Gaussian naive Bayes (GNB), k -nearest neighbor algorithm (k -NN), and support vector machine (SVM) are utilized for the construction of fault diagnosis models. Experimental results show that the proposed GVFS has a better diagnostic effect than the other five feature selection methods, and the average accuracy of fault diagnosis improves from 97.89% to 99.44%. This paper lays the foundation of fault diagnosis for PMDCMs and provides a novel filter feature selection method. [ABSTRACT FROM AUTHOR]

Titanium matrix composites (TMCs) with excellent mechanical properties, reinforced by graphene, is deemed the lightweight and high strength structural materials. In this study, TC11 titanium alloy powder and graphene nanosheets (GNPs) were used as raw materials, and the composite powder with good uniformity and fluidity was obtained through non-interventional homogeneous mixing by a planetary mixer. The microstructure and mechanical properties of the GNPs-TC11 composites and TC11 alloy were compared. The results showed that the microstructure of TC11 and the composites was acicular martensite α' phase under the process parameters of 280 W laser power, 1200 mm/s scanning speed, and 0.1 mm hatch spacing. The GNPs in addition, in the composites, reduced the acicular martensite particle size and expanded the proportion of low-angle grain boundaries. The tensile strength and percentage elongation after the fracture of the TC11 titanium alloy were 1265 MPa and 4.3%, respectively. Because of addition of the GNPs, the strength and percentage elongation after the fracture of the composite increased to 1384 MPa and 8.1%, respectively, at a GNPs mass content of 0.2%. The enhancement of mechanical properties can be attributed to grain refinement, dislocation strengthening, Orowan strengthening, and load transfer strengthening. [ABSTRACT FROM AUTHOR]

Global temperatures have risen as a result of climate change, and the resulting warmer seawater will exert physiological stresses on many aquatic animals, including Apostichopus japonicus. It has been suggested that the sensitivity of aquatic poikilothermal animals to climate change is closely related to mitochondrial function. Therefore, understanding the interaction between elevated temperature and mitochondrial functioning is key to characterizing organisms' responses to heat stress. However, little is known about the mitochondrial response to heat stress in A. japonicus. In this work, we investigated the morphological and functional changes of A. japonicus mitochondria under three representative temperatures, control temperature (18 °C), aestivation temperature (25 °C) and heat stress temperature (32 °C) temperatures using transmission electron microscopy (TEM) observation of mitochondrial morphology combined with proteomics and metabolomics techniques. The results showed that the mitochondrial morphology of A. japonicus was altered, with decreases in the number of mitochondrial cristae at 25 °C and mitochondrial lysis, fracture, and vacuolization at 32 °C. Proteomic and metabolomic analyses revealed 103 differentially expressed proteins and 161 differential metabolites at 25 °C. At 32 °C, the levels of 214 proteins and 172 metabolites were significantly altered. These proteins and metabolites were involved in the tricarboxylic acid (TCA) cycle, substance transport, membrane potential homeostasis, anti-stress processes, mitochondrial autophagy, and apoptosis. Furthermore, a hypothetical network of proteins and metabolites in A. japonicus mitochondria in response to temperature changes was constructed based on proteomic and metabolomic data. These results suggest that the dynamic regulation of mitochondrial energy metabolism, resistance to oxidative stress, autophagy, apoptosis, and mitochondrial morphology in A. japonicus may play important roles in the response to elevated temperatures. In summary, this study describes the response of A. japonicus mitochondria to temperature changes from the perspectives of morphology, proteins, and metabolites, which provided a better understanding the mechanisms of mitochondrial regulation under environment stress in marine echinoderms. [Display omitted] • Mitochondria were the focus of exploring the response of A. japonicus to heat stress. • Morphology, proteomics and metabolomics indicated changes in mitochondria. • Regulation existed in oxidative stress, energy metabolism, and material transport. • A hypothesized network of proteins and metabolites in mitochondria was summarized. [ABSTRACT FROM AUTHOR]

Microencapsulated paraffin with polyurea/acrylic resin hybrid shells as phase change energy storage materials was obtained in situ by combining interfacial polymerization and suspension-like polymerization. Glycerin (GC) acts as a cross-linking agent to modify the shells. The morphologies, particle size distributions, thermal storage properties, thermal stabilities and thermal reliabilities of microencapsulated phase change materials (MicroPCMs) were determined by scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TG). The temperature regulation performance of the foam with MicroPCMs was investigated by an infrared thermal imager. DSC results showed that MicroPCMs with polyurea/butyl methacrylate (PU/BMA) possess an improved heat ability and thermal reliability compared to MicroPCMs with polyurea/methyl methacrylate (PU/MMA). The incorporation of GC to shell-forming composition led to an enhancement in thermal storage capacity of the MicroPCMs. The MicroPCMs with GC-modified PU/BMA hybrid shell has the highest PCMs content by as much as 82.6 mass%. The change in latent heat of MicroPCMs with GC-modified PU/BMA hybrid shell was very small of less than 4 mass% after 500 thermal cycles. The infrared thermography indicated that the PU foam incorporating the MicroPCMs with GC-modified PU/BMA hybrid shell has better temperature-regulated property. In conclusion, the MicroPCMs with PU/BMA hybrid shells, especially with GC-modified PU/BMA hybrid shell, possess a promising prospect applying in energy-conserving building materials and thermal control system of shipping packages. [ABSTRACT FROM AUTHOR]

Microencapsulated phase change materials (MicroPCMs) can be incorporated into a traditional thermal insulation material, such as a foam, to form a new temperature-adaptable material. Polyurea/polyurethane (PU) as the encapsulating shell makes the MicroPCMs more compatible with the polyurethane foam matrix. This study focuses on increasing the thermal storage abilities and reliabilities of the PU-based MicroPCMs as well as improving the temperature-regulating properties of PU foams treated with these materials by incorporating lauryl methacrylate (LMA) and polyols into the MicroPCM particles. Paraffin was successfully microencapsulated by a PU/PLMA hybrid shell via staged polymerization of jointly using interfacial and suspension-like polymerization. PU foams integrating the as-prepared MicroPCMs were produced. The thermal storage abilities as well as working reliabilities of the MicroPCMs were improved when PLMA was introduced in the shells and were further enhanced when they were modified by polyols. The PU foams containing MicroPCMs with polyol-modified hybrid shells have better mechanical properties and temperature-regulating properties than do the foams containing MicroPCMs with unmodified shells. In conclusion, MicroPCMs with polyol-modified PU/PLMA hybrid shells possess promising application prospects for energy efficient buildings and advanced cold-chain logistics systems. [ABSTRACT FROM AUTHOR]

This research attempts to fabricate a novel type of pressure‐sensitive adhesive (PSA) tape utilizing epoxidized linseed oil (ELO) as the primary component in an effort to reduce reliance on petrochemical polymers. This raw material comes from the natural renewable resources, making this tape a more environmentally friendly choice in reducing impact on the environment and alleviating resource pressure. The ester groups on ELO are subjected to hydrolysis in order to yield a combination of epoxy linseed oil fatty acids (ELFAs) containing both epoxy and carboxyl groups. By controlling the temperature and catalyst conditions, the epoxy and carboxyl groups undergo a ring‐opening reaction, resulting in the self‐polymerization of the ELFA mixture and the formation of hydroxy‐functionalized polymers. These polymers are then applied as a coating on kraft paper and subsequently cut to produce PSA tapes. The tapes produced using this method exhibit a peak peel strength of 20.538 N per 25 mm. Moreover, the incorporation of glycerol ester of rosin serves to enhance the peel strength, resulting in a higher value of 21.883 N per 25 mm. The utilization of sealing the cardboard box by the tapes also serves as validation for the immense capabilities of the tapes in practical applications. [ABSTRACT FROM AUTHOR]

Simulations of photochemical reaction dynamics have been a challenge to the theoretical chemistry community for some time. In an effort to determine the predictive character of current approaches, we predict the results of an upcoming ultrafast diffraction experiment on the photodynamics of cyclobutanone after excitation to the lowest lying Rydberg state (S2). A picosecond of nonadiabatic dynamics is described with ab initio multiple spawning. We use both time dependent density functional theory (TDDFT) and equation-of-motion coupled cluster singles and doubles (EOM-CCSD) theory for the underlying electronic structure theory. We find that the lifetime of the S2 state is more than a picosecond (with both TDDFT and EOM-CCSD). The predicted ultrafast electron diffraction spectrum exhibits numerous structural features, but weak time dependence over the course of the simulations. [ABSTRACT FROM AUTHOR]

Infections with strains of Staphylococcus sciuri are a potential threat to animal and public health, and a cause for considerable concern. We isolated and identified S. sciuri as a pathogen from an acute outbreak of exudative epidermitis in piglets for further genetic identification using experimental infections. The results of this study showed that S. sciuri strain NJ1306 reproduced exudative epidermitis in experimentally infected 5-day-old piglets. The isolated bacteria also caused sudden death in BALB/c mice following intraperitoneal injection with 5 × 10 8 CFU of the isolate. The data indicated that strain NJ1306 of S. sciuri was pathogenic to piglets and mice, and the study provided the first known report of clinical lung lesions and endocarditis in piglets due to S. sciuri . [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare the effects of different concentrations of the amine-functionalized isoreticular metal-organic framework-3 loaded with carvacrol (IRMOF-3/CA) on the properties of sodium alginate (SA) composite films, thus determining the optimal addition amount and further preparing bioactive packaging film with antibacterial and antioxidant activities. The morphology, structure, physical properties, antioxidant and antibacterial activities of the films were characterized and analyzed. The results showed that the thermal stability and light barrier property of the films were improved by the addition of IRMOF-3/CA. When the additional concentration was 0.4 wt%, the tensile, water vapor barrier and hydrophobic properties of the films were increased by 30.13%, 9.06% and 46.43% respectively compared with those of pure SA film. Moreover, the film added with IRMOF-3/CA had sustained antioxidant and antibacterial activities, and had an apparent fresh-keeping effect on pork, suggesting its application potential in food packaging. [Display omitted] • SA-based composite active films added with IRMOF-3/CA have been successfully developed. • The tensile, water vapor barrier and hydrophobic properties of the composite film with 0.4 wt% IRMOF-3/CA have been improved. • The composite film added with IRMOF-3/CA showed excellent UV barrier performance. • The composite active film SMC 2 had significant antioxidant and antibacterial activity and showed good preservation effect. [ABSTRACT FROM AUTHOR]

This study deals with fabrication, thermal properties and thermal reliabilities of microencapsulated paraffin by suspension-like copolymerization of ethyl methacrylate (EMA) with acrylic acid (AA) and styrene (St). Trimethylolpropanetriacrylate (TMPTA) was employed as crosslinking agents. The microencapsulated phase change materials (MicroPCMs) were characterized by using scanning electron microscopy (SEM), differential scanning calorimetry and thermal gravimetric analysis (TG). The microcapsule with P(EMA-co-AA-co-St-co-TMPTA) copolymer as shell exhibits higher phase change enthalpies of melting (117.8 J g) and crystallization (115.3 J g) compared with the microcapsule with P(EMA-co-AA-co-TMPTA) copolymer. TG analysis demonstrated that the thermal resistant temperatures of these two MicroPCMs were increased by more than 10 °C compared with the raw paraffin. The PCMs content of these two MicroPCMs dropped by <6 % after 1000 thermal cycling. Thermal images showed that the foam with microcapsule exhibits an upgraded thermal regulation capacity. As a consequence, microcapsules with EMA-based copolymer possess good potentials for thermal energy storage and thermal regulation. [ABSTRACT FROM AUTHOR]

A finite element method ( FEM) approach using COMSOL Multiphysics software was presented to solve unsteady-state moisture diffusion differential equations and predict the shelf life of crackers based on critical moisture content obtained by sensory evaluation. The crackers' moisture contents were given as a function of storage time, environment conditions (temperature and relative humidity) and the package materials. Classical Oswin model was used to fit the moisture sorption data at four different temperatures. Effective moisture diffusivity of crackers as a function of moisture content and temperature were investigated. In addition, the relationship of moisture permeability coefficient and temperature of two selected packaging films, low-density polyethylene ( LDPE) and cast polypropylene ( CPP) film, was determined based on Arrhenius equation. The crackers were packaged in LDPE and CPP packaging pouches, and stored at four different conditions to simulate actual storage conditions and determine the shelf life experimentally. There was a good agreement between experimental results and finite element predictions for moisture-sensitive crackers subjected to different storage and packaging conditions. Practical Applications This paper describes the shelf life prediction of crackers using a simulation model based on unsteady-state Fickian diffusion of moisture through the food. The temperature effect on the moisture sorption, moisture diffusivity of foods and the moisture permeability coefficient of packaging films are considered. The food product's moisture content was simulated using COMSOL Multiphysics as a function of storage time under different storage conditions and packaging film. The finite element simulation provides a powerful support tool for shelf life estimation and packaging development. [ABSTRACT FROM AUTHOR]

Microencapsulation of n -octadecane or paraffin with poly(lauryl methacrylate) (PLMA) shell was performed by a suspension-like polymerization. The polymer shell was crosslinked by pentaerythritol tetraacrylate (PETRA). The surface morphologies of microcapsules were investigated by scanning electron microscopy (SEM). Phase change properties, thermal reliabilities and thermal stabilities of microcapsules were determined by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The n -octadecane microcapsule exhibits higher melting enthalpy (118.0 J g −1 ) and crystallization enthalpy (108.3 J g −1 ) compared with the paraffin microcapsule. The thermal resistant temperatures were enhanced by more than 25 °C when n -alkanes were microencapsulated by PLMA. The PCM contents of microcapsules decreased by less than 4 wt% and 6 wt% after 500 and 1000 thermal cycles, respectively. Heat-up experiments indicated that microcapsule-treated foams exhibited upgraded thermal regulation capacities. Consequently, microencapsulated n -octadecane or paraffin with PLMA as shell possesses good potentials for heat storage and thermal regulation. [ABSTRACT FROM AUTHOR]

The aim of this research is to study the effect of gas phase on the effective thermal conductivity of heterogeneous materials with high solid phase mass fraction. A general model based on Maxwell–Eucken model and Effective Medium Theory model was proposed first and compared with the previous models, showing some potential significance of the present model. The present model shows that the gas phase in heterogeneous materials is significantly affected by maximum volume fraction of solid phase. Then, the effect of the shape parameters of solid particle on the maximum volume fraction of solid phase was discussed. The results indicate the maximum volume fraction of solid phase tends to grow up by increasing the particle diameter or decreasing the particle diameter ratio. Finally, the effective thermal conductivity of heterogeneous materials predicted by the proposed model was compared with that by direct experiment, showing great agreement. [ABSTRACT FROM AUTHOR]

This paper was aimed to prepare, characterize and determine the comprehensive evaluation of promising composite macrocapsules containing microencapsulated PCMs (phase change materials) with calcium alginate gels as the matrix material. Macrocapsules containing microcapsules were fabricated by piercing-solidifying incuber method. Two kinds of microcapsules with n-tetradecane as core material, UF (urea-formaldehyde) and PMMA (poly(methyl methacrylate)) respectively as shell materials were prepared initially. For application concerns, thermal durability and mechanical property of macrocapsules were investigated by TGA (thermal gravimetric analysis) and Texture Analyser for the first time, respectively. The results showed excellent thermal stability and the compressive resistance of macrocapsules was sufficient for common application. The morphology and chemical structure of the prepared microcapsules and macrocapsules were characterized by SEM (scanning electron microscopy) and FT-IR (fourier transform infrared) spectroscopy method. Phase change behaviors and thermal durability of microcapsules and macrocapsules were investigated by DSC (differential scanning calorimetry). In order to improve latent heat of composite microcapsules, the core-shell weight ratio of tetradecane/UF shell microcapsules was chosen as 5.5:1 which obtained the phase change enthalpy of 194.1 J g −1 determined by DSC. In conclusion, these properties make it a feasible composite in applications of textile, building and cold-chain transportation. [ABSTRACT FROM AUTHOR]

Explicit solutions of the cohesive energy for the interfaces between film/coat, sphere/coat, sphere/matrix and sphere/substrate are obtained by continuum modeling of the van der Waals interaction between them. The analytical results show that the cohesive energy strongly depends on their size and spacing. For a given film thickness and sphere radius, the cohesive strength increases with increasing coat thickness and then tends to a constant when the coat thickness is up to a critical value. The cohesive strength for the interface between sphere/matrix keeps a constant when the sphere radius is up to a critical value. Checking against full atom molecular mechanics calculations show that the continuum solution has high accuracy. The established analytical solutions should be of great help for understanding the interactions between the nanostructures and substrates, biomaterials, designing nanocomposites and nanoelectromechanical systems. [ABSTRACT FROM AUTHOR]

The tensile and shear failure behavior dependence on chain length and temperature in amorphous polymers are scrutinized using molecular dynamics simulations. A wide range chain length of alkane is tested under tension and shear with various temperatures. We find that the broken rate (the broken bond number to all polymer chain number ratios) under tension and shear increases with increasing chain length and temperature. For a given chain length and temperature, the broken rates under shear are always higher than those under tension at a same large strain. For a given chain length, the tensile and shear stresses decrease with increasing temperature. We propose three typical fracture mechanisms to effectively elucidate the ductile fracture response based on the predominance of chain scission process. [ABSTRACT FROM AUTHOR]

This study focused on preparation and thermal properties of poly(stearyl methacrylate) shell (PSMA) microcapsules containing n-octadecane as a phase change material (PCM). Pentaerythritol triacrylate (PETA) and divinylbenzene (DVB) were employed as crosslinking agents. The surface morphologies, particle sizes, and distributions of the microencapsulated phase change material (microPCM) were studied by scanning electron microscopy. The thermal properties, thermal reliabilities, and thermal stabilities of the microPCMs were investigated by differential scanning calorimetry and thermal gravimetric analysis. The microPCM with DVB exhibits higher phase change enthalpies of melting (87.9 J g) and crystallization (94.8 J g) and a greater thermal stability in comparison with the microPCM with PETA. The phase change temperatures and enthalpies of the microPCMs varied little after thermal cycles. Thermal images showed that the gypsum board with PSMA/ n-octadecane microPCM possessed temperature-regulated property. Therefore, microencapsulated n-octadecane with PSMA as shell has good thermal energy storage and thermal regulation potential. [ABSTRACT FROM AUTHOR]

Microcapsules containing n -octadecane with different n -butyl methacrylate (BMA)-based copolymer shells were fabricated by a suspension-like polymerization method. n -butyl acrylate (BA), methacrylic acid (MAA) and acrylic acid (AA) were employed as monomers to copolymerize with BMA. The surface morphologies of the microencapsulated phase change materials (MicroPCMs) were studied by scanning electron microscopy (SEM). The thermal properties, thermal reliabilities and thermal stabilities of the MicroPCMs were investigated by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The temperature-regulated properties of the MicroPCMs were determined by an infrared thermography. The incorporation of MAA or AA to the acrylic composition of the polymer shells led to an increase in both the heat storage capacities and thermal stabilities of the MicroPCMs. The MicroPCMs with P(BMA-co-MAA) exhibit a greater heat capacity and thermal stability compared with the MicroPCMs with P(BMA-co-AA). The MicroPCMs with P(BMA-co-MAA) have the highest latent heats of melting (144.3 J/g) and crystallization (152.9 J/g) as well as the highest thermal resistant temperature (249 °C). The phase change temperatures and enthalpies of the MicroPCMs varied little after 1000 thermal cycles. Thermal images showed that the gypsum board containing the MicroPCMs with BMA-based copolymers as shells, especially with P(BMA-co-MAA) and P(BMA-co-AA) as shells, possessed temperature-regulated properties. As a result, the MicroPCMs with BMA-based copolymers as shells have good thermal energy storage and thermal regulation potentials, such as solar energy-saving building materials. [ABSTRACT FROM AUTHOR]

The Dimethyl ether (DME) kinetic model is significant to understand the DME combustion in the atmosphere containing high CO 2 concentration, such as pressurized oxy-fuel combustion process and exhaust gas recirculation, and design the combustor. In this paper, the ignition delay times (IDTs) of DME were measured in a shock tube under the conditions of equivalence ratios of 0.5, 1 and 1.5, temperature ranges from 1007 K to 1340 K, and pressures of 2 and 11 atm. A detailed kinetic model of DME named as OXYDME was put forward based on the OXY-Aramco model, and was validated by the low and high temperature IDTs, laminar flame speeds, and species profiles measured in this work and those from literatures in atmospheres of O 2 /Ar/CO 2 , O 2 /N 2 , O 2 /N 2 /He/CO 2 and O 2 /CO 2. The OXYDME model was compared with OXY-Aramco, Liu-DME model in detail. The effects of CO 2 on the DME ignition are very weak and not sensitive to the temperature and pressure. The reason for the weak effects of CO 2 is that the chemical effects of CO 2 promote ignition, which counteracts the inhibition effects caused by the physical properties of CO 2. The chaperon effects of CO 2 dominate the chemical effects. Meanwhile, the effects of the reactions with CO 2 are very small. [ABSTRACT FROM AUTHOR]

Forced-air precooling is more conductive to achieve a rapid cooling, and it is widely applied in the commercial processing treatment of fresh produce after harvest and recognized to be an efficient cooling method. Emphatically, the temperature plays a critical role during the whole cooling process that influencing the comfort of packed fruits and then the shelf life. In order to predict and monitor the temperature changes of produce inside the ventilated packages, a transient mathematical model was developed that considering the latent heat source due to respiration and evaporation of spherical fruits inside tray-layered packaging box during forced-air precooling process. Based on computational fluid dynamics, Fluent TM 2.3.26 along with the standard k-e model and SIMPLE algorithm for the pressure velocity coupling solution was employed to simulate the three-dimensional transient temperature field of layered fruits in forced-air precooling. Particularly, the inner heat source was added to the energy equation and loaded to the numerical solution dynamically by UDF (user defined function) for interpreting corresponding heat source files. Temperature fields of fruits stacked in three different patterns (spaced stacking pattern, paralleled stacking pattern and crossed stacking pattern) in different ventilated packages with circle and oblong side vents in the same opening area of 11.2% were analyzed. The experimental validations were performed, and the simulated data agreed well with the experimental results. Thus the mathematical model was reliable and can be used to the research of produce precooling. It is demonstrated that temperature distribution was more homogeneous for fruits in paralleled stacking pattern, while the slowest cooling rate and the highest temperature of fruit for spaced stacking pattern condition. What's more, the temperature gradient in fruit can not be ignored for the center temperature and surface temperature difference up to about 7?. Additionally, oblong vents design can balance the lateral and longitudinal diffusion of inlet airflow and ease the turbulent fluid inside packages for promoting the overall cooling rate and uniformity. Specifically for fruits in crossed stacking pattern, the cooling uniformity of oblong vents condition increased by about 10% and the slowest cooling temperature of fruit was 2? lower compared with the circle vents condition. As a result, ventilated packaging design for cooling fruits should be in tune with the internal stacking pattern as well as the trays to adjust the airflow and provide a adequate but uniform cooling environment, and for tray-layered fruits in crossed stacking pattern, oblong vents configuration with large ratio of the major axis to the minor axis can be suggested as better ventilated packaging design. [ABSTRACT FROM AUTHOR]

For permanent magnet DC motors (PMDCMs), the amplitude of the current signals gradually decreases after the motor starts. Only using the signal features of current in a single segment is not conducive to fault diagnosis for PMDCMs. In this work, multi-segment feature extraction is presented for improving the effect of fault diagnosis of PMDCMs. Additionally, a support vector machine (SVM), a classification and regression tree (CART), and the k-nearest neighbor algorithm (k-NN) are utilized for the construction of fault diagnosis models. The time domain features extracted from several successive segments of current signals make up a feature vector, which is adopted for fault diagnosis of PMDCMs. Experimental results show that multi-segment features have a better diagnostic effect than single-segment features; the average accuracy of fault diagnosis improves by 19.88%. This paper lays the foundation of fault diagnosis for PMDCMs through multi-segment feature extraction and provides a novel method for feature extraction. [ABSTRACT FROM AUTHOR]

In this study, a climate version of the Regional Atmospheric Modeling System (ClimRAMS) was used to investigate the sensitivity of regional climate simulations to changes in vegetation distribution in the Great Plains and Rocky Mountain regions of the United States. The evolution of vegetation phenology was assimilated into the ClimRAMS in the form of estimates of the leaf area index (LAI) derived from the normalized difference vegetation index (NDVI). Initially, two model integrations were made. In the first, the NDVI-derived vegetation distribution was used, while the second integration used the model's “default” description of vegetation. The simulated near-surface climate was drastically altered by the introduction of NDVI-derived LAI, especially in the growing season, with the run in which observed LAI was assimilated producing, in general, a wetter and colder near-surface climate than the default run. A third model experiment was then carried out in which the (comparatively more homogeneous) spatial distribution of the LAI remained the same as in the “default” run, but the overall, domain-averaged magnitude of the LAI was reduced to be consistent with that of NDVI-derived LAI. This third run simulated a drier and warmer near-surface climate compared to the default run. Taken together, these results indicate that regional climates are indeed sensitive to seasonal changes in vegetation phenology, and that they are especially sensitive to the land surface heterogeneity associated with vegetation cover. The need to realistically represent both the spatial and temporal distribution of vegetation in regional climate models is thus highlighted, and the value of assimilating remotely sensed measures of vegetation vigor in Four-Dimensional Data Assimilation (4DDA) systems is demonstrated. [ABSTRACT FROM AUTHOR]

• A central self-similar strategy is proposed to develop bio-inspired honeycombs. • Central self-similar degradable polymer honeycombs are additively manufactured. • The interaction effect of different connections between the two walls can promote EA. • Theoretical models of the proposed central self-similar honeycombs are built. At present, improving the energy absorption capacity of lightweight degradable polymer honeycombs is crucial for one of the future engineering applications and bio-inspired strategy based on hierarchy is considered an efficient method for designing honeycomb structures. To improve the energy absorption performance and stability of polymer honeycombs, this study develops three central self-similar bio-inspired honeycombs combining the microstructure of horsetails and designs different connections between the two walls and connecting structures for the central self-similar honeycombs. Bio-inspired honeycombs are fabricated using toughened polylactic acid (PolyMax™ PLA) through fused deposition modelling and subjected to axial compression tests. The finite element (FE) models of the bio-inspired honeycombs are developed to simulate the axial compression process and verified with experimental results. Results show that the connecting structures distributed on the outer wall of the central self-similar honeycombs considerably improve the energy absorption performance of the bio-inspired honeycombs. In the double-cell honeycombs, connecting structures interact with the cell walls, leading to the formation of more folding lobes on the cell walls and increased cell wall utilisation. Furthermore, the effects of geometrical parameters on the energy absorption performance of the bio-inspired honeycombs are investigated. Suitable connecting structure size and cell wall thickness can improve the energy absorption performance and stability of the honeycombs. In addition, the theoretical calculation models of the three bio-inspired honeycombs are established, and the errors with the FE calculation results are within 6 %, which verifies the accuracy of the theoretical models. [Display omitted] [ABSTRACT FROM AUTHOR]

Nanoparticles are used as fillers to improve the properties of biopolymers, and their particle size is an important parameter. This work aims to investigate the effect of particle size of isoreticular metal-organic framework-3 (IRMOF-3) on the mechanical, physical, and release properties of sodium alginate (SA)-based composite active film. In our study, IRMOF-3 with six different particle sizes was synthesized by introducing additives. IRMOF-3 loading with carvacrol (IRMOF-3/CA nanoparticles) was incorporated into the SA matrix to prepare the composite film. The characterization and testing results of films showed that the particle size of nanoparticles affected the physical morphology and chemical structure of the film. Especially smaller nanoparticles uniformly dispersed into the SA matrix more easily, forming a denser and more stable spatial network structure with SA, which could more significantly improve the tensile strength, water vapor barrier, and hydrophobic properties of the film (P < 0.05). In addition, the CA release rate from the active film could be significantly reduced by about 33.90 % even when the smallest particle size of the IRMOF-3/CA nanoparticles was added. Therefore, when IRMOF-3/CA is used as the nano-filler to develop SA-based active film, its particle size has a potential influence on the properties of the film. [ABSTRACT FROM AUTHOR]

• Ignition delay times of dimethyl ether/ethane/O 2 /CO 2 mixtures were first provided. • OXYMECH predicts well on the IDTs of the mixtures in O 2 /CO 2 and O 2 /N 2 atmosphere. • IDTs of the mixtures first decrease and then increase as adding DME at 10 atm. • The effect of DME addition and CO 2 on the IDTs of the mixtures were analyzed. The ignition delay times (IDTs) of dimethyl ether (DME)/ethane/O 2 /CO 2 mixtures were measured in a shock tube at pressures of 0.8, 2, and 10 atm; temperatures within the range of 1126–1449 K; equivalence ratio of 0.5; and DME proportions within the range of 0–100%. Four chemical kinetic models named OXYMECH, AramcoMech 3.0, San-Diego 2016 and Wang-DME were validated using the IDTs measured in this work. The results indicate that the OXYMECH predicts well the experimental data under O 2 /CO 2 and O 2 /N 2 atmospheres. At P = 0.8 and 2 atm, T = 1300 K, the increase of the DME proportion inhibits the ignition of the mixtures under O 2 /N 2 and O 2 /CO 2 atmospheres. At P = 10 atm, T = 1300 K, the IDTs of the mixtures firstly decrease when DME proportion increases from 0 to 20%, and then increase when DME proportion increases from 20 to 100% under O 2 /CO 2 atmosphere, while the IDTs of the mixtures increase as the DME proportion increases under O 2 /N 2 atmosphere. The valley-values of the IDTs of the mixtures appear at the certain DME proportion at P = 10 atm, T = 1100 K and 1200 K under O 2 /N 2 and O 2 /CO 2 atmospheres. The analyses of sensitivity and the rate of production were conducted to interpret the effect of DME addition and the properties of CO 2 on the ignition of the DME/C 2 H 6 /O 2 /CO 2 mixtures. [ABSTRACT FROM AUTHOR]

• Ignition delay times of n-heptane/DME were measured in the various blending ratio. • A blended model shows favorable performance on the prediction of the ignition delay times. • The effect of DME addition on the IDTs of fuel mixtures were analyzed in detail. The addition of oxygenated fuels to fossil fuels has been considered as a promising approach for reducing the issues associated with hazardous substances. The ignition delay time data of dimethyl ether/n-heptane mixtures were obtained using a shock tube under the following conditions: pressures of 0.8, 4.5, and 10 atm; equivalence ratio of 1; temperature within the range of 1171–1571 K; and dimethyl ether proportion within the range of 0–100%. The Arrhenius dependence of the ignition delay times on temperature and pressure was fitted. The experimental results show that the ignition delay times of dimethyl ether/n-heptane mixtures are less than those of pure dimethyl ether and pure n-heptane within a certain blending ratio range. A combined model named "blended model" was proposed based on the LLNL n-heptane version 3.1 and Zhao dimethyl ether models. The effect of DME addition on the IDT of the fuel mixtures was investigated using the blended model in detail. [ABSTRACT FROM AUTHOR]

The diffusion of five flavor organic molecules, including D-limonene, myrcene, ethyl hexanoate, 2-nonanone, and linalool in low density polyethylene (LDPE) film were investigated by combined experimental and molecular dynamics (MD) simulation studies. The diffusion coefficients derived from the prediction model, experimental determination, and MD simulation were compared, and the related microscopic diffusion mechanism was investigated. The effects of the presence of the flavor organic molecules on the diffusion of O2 and H2O in polyethylene (PE) were also studied by MD simulation. Results show that: The diffusion of five flavor molecules in LDPE is well followed to Fick's second law by the immersion experiment; MD simulation indicates the dual mode diffusion mechanism of the flavor molecules is in LDPE; the diffusion coefficients from MD simulation are close to those from the experimental determination, but are slightly larger than those values; the presence of the flavor organic molecules hinders the diffusion of O2 and H2O, which can be well explained from the fraction of free volume (FFV) and interaction energy calculation results derived from MD simulation. [ABSTRACT FROM AUTHOR]

In this work, a novel grafted film with both antimicrobial and antioxidant properties was developed. ε-polylysine (EPL) and caffeic acid (CA) were used as raw materials, and EPL-CA was synthesized by grafting CA onto EPL by the carbodiimide coupling method. Using dicumyl peroxide (DCP) as a radical initiator, EPL-CA was crosslinked with low-density polyethylene (LDPE) by reactive co-extrusion to produce grafted films with both antimicrobial and antioxidant properties. Compared with pure LDPE film, all graft films show antimicrobial and antioxidant properties. Specifically, when the EPL-CA concentration is >3%, the inhibition rates against Escherichia coli (>91%) and Staphylococcus aureus (>97%) significantly increase, and the DPPH free radical scavenging rate (>60%) also significantly increases. Compared with the control film, the grafted film exhibits increased tensile strength and decreased elongation at break. In addition, the migration levels of all graft films in food simulants are below the migration standards set by the European Union. Overall, immobilizing EPL-CA on the LDPE matrix improves antimicrobial, antioxidant, and mechanical properties. Among them, the film exhibits the best comprehensive performance when the EPL-CA content is 3%. Therefore, the development of antimicrobial and antioxidant active LDPE film is proposed. These results indicate that active packaging films can be prepared through reactive extrusion, a promising and industrializable technology, and have broad prospects in improving food safety and other aspects. [Display omitted] • ε-polylysine is functionalized with caffeic acid by carbodiimide coupling. • Low density polyethylene is grafted with caffeic acid functionalized ε-polylysine. • The composite film was prepared by reaction co-extrusion technology. • The prepared films exhibits antibacterial and antioxidant functions. [ABSTRACT FROM AUTHOR]

It is of great significance to understand the diffusion rate of the volatile corrosion inhibitor (VCI) in the VCI films for corrosion inhibition. The diffusion behavior of 1,2,3-Benzotriazole (BTA) in pure low density polyethylene (LDPE) and VCIs/LDPE blends was investigated using molecular dynamics (MD) simulation at 310, 328 and 353 K temperatures. The temperature dependence and diffusion property of BTA in LDPE were revealed. Subsequently, the accuracy of the MD simulations was confirmed by comparing the diffusion coefficients obtained from the MD simulations with those obtained from the experiments. The fractional free volume, interaction energy between BTA and VCIs/LDPE, activation energy of BTA and the self-diffusion behavior of LDPE on the diffusion of BTA were explored, which illustrated the microscopic diffusion mechanism of BTA in LDPE. Results showed that the diffusion coefficients of BTA increased with increasing temperature, increasing free volume and the more flexible chain of LDPE, while the increase in the interaction energy between BTA and VCIs/LDPE slowed down the diffusion of BTA. It can be concluded that the increase in the interaction energy between BTA and the system, the activation energy of BTA and the formation of H-bonds due to the addition of other VCIs led to the decrease in the diffusion coefficients of BTA. The strong molecular interactions between BTA and VCIs were the main reason for the decrease in the BTA diffusion coefficients. Adjusting the formulation of the VCI films can provide new ideas for regulating the BTA diffusion rate, which is beneficial for extending the corrosion inhibition time of BTA. [ABSTRACT FROM AUTHOR]

A new methodology using microwave extraction, gas-diffusion microextraction (GDME) and high-performance liquid chromatography-mass spectrometer (HPLC-MS) was developed for the analysis of the quantitative detection of gaseous and solid benzotriazole (BTA) and the mass transfer behavior of BTA in volatile corrosion inhibitor (VCI) packaging. The best extraction conditions of BTA in the VCI films were obtained, and the vapor pressure of BTA in the VCI packaging was detected and characterized by a mathematical model using the new methodology. The migration content of BTA in the VCI films and the BTA content on the surface of the films were detected, and the diffusion coefficients at three temperatures were calculated. The vapor pressure and diffusion coefficients of BTA increased with increasing temperature, and the volatilization of BTA promoted the migration of BTA from the VCI films. Moreover, a molecular dynamics (MD) simulation was performed to determine the migration of the BTA molecules within the VCI films at three temperatures; the overall trend of the experimental values was the same and the simulated values were generally within two orders of magnitude of the corresponding experimental values, with the difference likely due to the ignoring of the crystallinity of LDPE. [ABSTRACT FROM AUTHOR]

Neonatal hypoxic ischemic encephalopathy (HIE) is an important cause of neonatal death and disability. At present, there is no unified standard and specialized treatment method for neonatal HIE. In clinical practice, we have found that a gap remains between preclinical medical research and clinical application in the treatment of neonatal HIE. To promote an organic combination of preclinical research and clinical application, we propose the different phases as intervention targets, based on the pathophysiologic changes in phases I, II, and III of neonatal HIE; moreover, we suggest transformative medicine as a principle that may improve the therapeutic effect by blocking the progression of the disease to an irreversible stage. For instance, in phase I, mild hypothermia, free radical scavenger (erythropoietin, hydrogen-rich saline), excitatory amino acid receptor blocker, and neuroprotective agents should be administered to neonates with moderate/severe HIE; in phase II, following phase I treatment, anti-inflammatory agents, neuroprotective or nerve regeneration agents, and stem cell transplantation should be administered to patients; in phase III, anti-inflammatory agents, neuroprotective or nerve regeneration agents, and stem cell transplantation should be administered to patients. As soon as the patient's condition has stabilized, acupuncture, massage, and rehabilitation training should be performed. Following further study of stem cells, stem cell transplantation is expected to become the most promising therapeutic candidate for treatment of severe neonatal HIE with its sequelae. [ABSTRACT FROM AUTHOR]

In this paper a honeycomb paperboard filled with foam particles is presented. The effect of parameters such as the cell size, the honeycomb paperboard thickness and the foam particles size on the interaction, energy absorption capacity, and the half wavelength are investigated theoretically and experimentally. The experiment results show that foam particles of honeycomb paperboard increase their initial crushing strength and energy absorption and the stress in the honeycomb paperboard filled with foam particles rises exponentially during the crushing stage. Furthermore, decrease in the densification strain; increase in number of folds; and decrease in half wavelength are other results of this research. And the smaller the foam particles, the greater the effect of foam particles filling. In the theoretical section, the interaction between the foam particles and the honeycomb paperboard cell wall are studied by regarding as point contact. Expressions are derived to predict the stress and half wavelength of honeycomb paperboard filled with foam '''''''''''''''''''particles in the crushing stage. A comparison between theoretical predictions and experimental results shows that the theoretical models can effectively predict this stress. It is expected that these studies can help to improve the application of honeycomb paperboard and provide a reference for further research on foam particle filling. [ABSTRACT FROM AUTHOR]

Lean combustion has wide range of applications due to very low emissions and very high efficiency. The study of the ignition of the fuel under dilution conditions is crucial for the satisfactory operation and performance of dilution fuel combustion processes. In present study, the ignition temperatures of CH 4 diluted with CO 2 were measured in a counterflow ignition facility for the mixtures of 9–25% of CH 4 in CO 2 and 30%, 35%, and 40% oxygen concentration in the O 2 /CO 2 atmospheres, respectively. The experimental results show that for a fixed fuel concentration, the higher the oxygen concentration, the lower the ignition temperature. The differences between ignition temperatures of CH 4 for various oxygen concentration cases decrease notably with the decrease of the CH 4 concentration, and are not obvious when the fuel is intensively diluted at 9%. A mechanism has been updated based on our previous research work and named as IDIM (Intensive dilution ignition mechanism). The performance of the USC Mech 2.0, Aramco Mech 2.0, FFCM-1 and IDIM has been evaluated. IDIM can predict well the ignition temperatures of three different oxygen concentrations, while FFCM-1 markedly over-predicts the experimental results for all the cases. The effects of the oxidation pathways of CH 3 , CH 3 →CH 3 O, CH 3 →CO, CH 3 →CH 2 O and CH 3 →CH 2 (S), on the ignition temperature have been analyzed in detailed. The pathway of CH 3 →CH 3 O→CH 2 O plays an important role on the ignition when the oxygen concentration is high in the oxidant and the fuel is intensely diluted. Weakening the path of CH 3 →CH 3 O→CH 2 O is the main reason for the over-prediction of FFCM-1. Moreover, the effect of the fuel dilution on the ignition temperature is stronger than that of the oxygen concentration at the fuel concentration of 9%, resulting in that the conversion ratios of CH 3 to CH 3 O, CH 2 O, CH 2 (S), and CO are almost same for 30% and 40% oxygen concentrations. Therefore, the ignition temperature is almost insensitive of the oxygen concentration within the range of our experiment. • A mechanism for the ignition of CH 4 intensely diluted under high O 2 concentration. • Evaluate the performance of the USC 2.0, Aramco 2.0, FFCM-1, and our mechanism. • The pathway of CH 3.→CH 3 O→CH 2 O plays an important role on the ignition. • The effect of O 2 on the ignition weakens as the CH 4 is gradually diluted. [ABSTRACT FROM AUTHOR]

Abstract The ignition temperatures of CH 4 intensely diluted with N 2 and CO 2 have been measured in a counterflow ignition facility with mixtures of 6–25% CH 4 in N 2 and 9–25% CH 4 in CO 2. The simulation by GRI Mech 1.2, GRI Mech 3.0, USC Mech 2.0, and Aramco Mech 2.0 cannot predict well the present experimental results. A modified mechanism has been proposed by substitution of the news channels of CH 3 + O and CH 2 + O 2 for the corresponding channels in USC Mech 2.0 and updating some reaction accordingly. The modified mechanism has been verified by present experiments and other experiments under the intensely diluted CH 4 condition. The analysis by the modified mechanism shows that when CH 4 is intensely diluted with N 2 or CO 2 , the path of CO → CO 2 becomes important to produce ignition, because the reaction CO + OH = CO 2 + H can provide sufficient radical H for the rapid growth of the radical pool, thus, the main oxidation chain of CH 3 is extended furtherly to CO 2 , that is, CH 3 → CH 2 O → HCO → CO → CO 2. The channels of CH 3 + O becomes increasing important for the ignition with the decease of the CH 4 concentration, because the reaction CH 3 + O = CO + H + H 2 significantly promotes the ignition of the intensively diluted CH 4 due to facilitating the rapid growth of the radical pool. Consequently, the secondary CH 3 oxidation path, CH 3 → CO → CO 2 , makes additional but critical contribution to produce ignition. The channels of CH 2 + O 2 are CH 2 + O 2 = CO + H 2 O, CH 2 + O 2 = CO 2 + H + H, CH 2 + O 2 = CH 2 O + O, CH 2 + O 2 = CO 2 + H 2 , and CH 2 + O 2 = CO + OH + H. Among the channels of CH 2 + O 2 , the variation of the effects of the reaction CH 2 + O 2 = CO + OH + H on the ignition is the most significant when the concentration of CH 4 changes from 20% to 6%. Therefore, the third CH 3 oxidation path, CH 3 → CH 2 (s) → CH 2 → CO → CO 2 , makes evident contribution to produce ignition under intensely diluted fuel condition due to CH 2 + O 2 = CO + OH + H. When diluent gas N 2 is replaced by CO 2 in intensely diluted CH 4 , the ignition temperature in the CH 4 /CO 2 is higher than that in the CH 4 /N 2 , which is mainly attributed to the higher heat capacity of CO 2 compared to N 2. Highlights • Propose a mechanism for the ignition of CH 4 intensely diluted. • The main oxidation path of CH 3 extends to CO 2 because CO → CO 2 provides radical H. • CH 3 → CO → CO 2 makes additional but critical contribution to produce ignition. • CH 3 → CH 2 (s) → CH 2 → CO → CO 2 makes evident contribution to produce ignition. [ABSTRACT FROM AUTHOR]

A practical prediction method for the Total volatile basic nitrogen (TVB-N) content evaluation of beef covered by the packaging films was proposed by using visible-near infrared hyperspectral imaging (HSI). Hyperspectral image under three conditions: beef without films, beef covered by appressed films, and beef covered by non-touch films was obtained. The results indicated that the influence on prediction accuracy of TVB-N content with the presence of films could be properly eliminated by spectral preprocessing methods and modeling methods. Moreover, the successive projections algorithm (SPA) combined with least squares support vector machines (SPA-LSSVM) was the best predictive model for beef without film, beef covered by non-touch polypropylene and polyethylene, and determination coefficient in prediction (R P 2) were 0.9167, 0.9157, and 0.9423 respectively, and root mean square errors in prediction (RMSEP) was 1.7808, 1.8758, and 1.4304 respectively. The competitive adaptive reweighted sampling (CARS) combined with LSSVM (CARS-LSSVM) was more effective for beef covered by appressed films of polypropylene and polyethylene, and R P 2 were 0.9046 and 0.9533 respectively, and RMSEP was 2.0444 and 1.2858 respectively. This study demonstrated that it is feasible to predict the TVB-N content of packaged beef using visible-near infrared hyperspectral technology. • Hyperspectral technology was used to predict the TVB-N content of packaged beef. • Three conditions were designed to investigate the influence of packaging films on the predicted results. • The reflectance spectrum of beef with film was affected by the dual effects of films scattering and transmission. • CARS-LSSVM was suitable for the condition of beef covered by appressed films, while SPA-LSSVM was better for non-touch films. [ABSTRACT FROM AUTHOR]

Magnetic molecularly imprinted polymers (MIPs) capable of selectively recognizing and absorbing 4,4 ′ -methylenedianiline (MDA) were successfully synthesized, using Fe3O4 coated with mesoporous silicon (Fe3O4@mSiO2) as the magnetic carrier, 4-vinyl pyridine (4-VP) as the functional monomer, ethylene glycol dimethacrylate (EGDMA) as the cross-linking agent, and MDA as the template molecule. The morphology, structure, and properties of MIPs were characterized, suggesting that the MIPs had obvious core-shell structure and strong magnetic responsiveness. The results of adsorption property tests showed that the MIPs could specifically recognize and adsorb MDA with excellent selectivity and reusability. The adsorption kinetic process could be described by the pseudo-second-order kinetic model, and the adsorption isotherm could be fitted by the Langmuir model, with a maximum adsorption capacity of 59.5 μmol/g. Furthermore, the magnetic MIPs have been applied to the electrochemical detection of MDA from the composite film sample, with recoveries in the range from 87.8% to 92.5% and the RSD values less than 4.4%. The prepared magnetic MIPs showed potential for the selective separation and detection of MDA in food-contact materials. [ABSTRACT FROM AUTHOR]

MicroPCMs (microencapsulated phase-change materials) were successfully synthesized using PMMA (poly(methyl methacrylate)) and UF (urea-formaldehyde) as raw materials for hybrid shells, and n -tetradecane as core materials. NMA ( n -methylol acrylamide) with two functional groups of double-bond and hydroxymethyl was used as a crosslinking agent. The morphologies and chemical structures of microPCMs were characterized using scanning electron microscopy (SEM) and Fourier transformed infrared (FTIR) spectroscopy. The agglomerations of the UF/PMMA hybrid samples might be influenced by two factors: cross linking action of NMA and PMMA/UF ratio in shell materials. The phase change properties and thermal durability were investigated by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA), respectively. The UF/NMA/PMMA hybrid shell microcapsules has an enthalpy of 175.5 J/g which is higher than the single-layer shell samples of PMMA and UF, and a better leakproofness than the UF/PMMA hybrid samples without NMA owing to the semi-IPN microstructure. Likewise, the UF/NMA/PMMA hybrid samples have higher thermal durability than the single layer shell samples of PMMA and UF and the UF/PMMA hybrid samples without NMA. Moreover, the thermal cycling test of the UF/PMMA hybrid samples with NMA was carried out for 100 heating/cooling cycles and indicated that the developed hybrid shell microPCMs have good chemical stability and thermal reliability. The heating-up experiment revealed that the foam treated by microcapsules had a better thermoregulatory property than the raw foam. Based on the results obtained, it can be concluded that n -tetradecane/UF/PMMA microPCMs have potential thermal energy storage applications. [ABSTRACT FROM AUTHOR]

An analytical model was presented for calculating the effective thermal conductivity for disperse systems based on fractal theory and percolation theory. The shortcomings of previous models for the high mass fraction of solid particles can be overcome by the recent model. Experiments were conducted on liquid phase mixed aluminum powder, copper powder and graphite powder, and the experimental results were compared with the model results. The results indicate that the proposed model is in good agreement with the experimental results, whereas the Maxwell–Eucken model deviates from the test results at a high mass fraction. The new model also provides more structural models using the modeling procedure previously proposed by authors. [ABSTRACT FROM AUTHOR]

Pulsed electric fields (PEF) processing is a promising nonthermal food preservation technology, which is ongoing from laboratory and pilot plant scale level to the industrial level. Application of PEF processing may be a good alternative treatment to thermal methods in protein-based foods. A large number of literatures have fully demonstrated that small molecule compounds in plant-based foods, mainly aroma compounds and health-related phytochemicals, were not significantly affected by PEF. However, there was a lack of knowledge on the effects of PEF on proteins and qualities of protein-based foods. This review focuses on effects of PEF processing on endogenous enzymes, safety, and quality of protein-based foods. Finally, the ways to achieve food quality assurance and food safety in PEF processing of protein-based foods are proposed. [ABSTRACT FROM AUTHOR]

Time-temperature indicators (TTIs) with the capability to visually reflect the accumulated time and temperature effect for real time are of substantial significance for securing the safety and quality of perishable products, such as foods and medical products. Herein, we design a novel TTI with high accuracy and low cost based on a ratiometric fluorescent nanosensor capable of self-calibration. The nanosensor was fabricated via the co-assembly of amphiphilic block copolymer and a responsive triplet-triplet annihilation upconversion (TTA-UC) system. The pH responsiveness of the triplet-sensitized nanomicelle was well investigated experimentally and theoretically. A linear relationship between the intensity ratio (of the integrated upconversion emission to the integrated phosphorescence emission) and pH was revealed for the ratiometric fluorescent nanomicelle. The TTA-UC functionalized nanomicelle turned out to be an extraordinary nanosensor with excellent sensitivity, reliability, and anti-reference. Subsequently, the nanomicelle was firstly applied for enzymatic time-temperature indicators (TTIs). Comprehensive kinetic study of the TTI prototype and the released total volatile basic nitrogen during meat storage was conducted under isothermal and non-isothermal conditions, which demonstrated remarkable correlation between the TTI response and the food spoilage. The activation energy of the TTI prototype could be readily modified to satisfy diverse food products including meat, diary, and aquatic products. The TTI based on triplet-sensitized ratiometric fluorescent nanosensor could be employed for visual monitoring food quality with low cost, high accuracy, and good reliability. [Display omitted] • A novel TTI prototype is designed for monitoring food quality for real time. • The TTI is fabricated with a ratiometric fluorescent nanosensor based on triplet-triplet annihilation upconversion. • It shows self-calibration and superior accuracy more than excellent sensitivity, reliability, and anti-reference ability. • Comprehensive kinetic study validates the high accuracy of the TTI prototype. [ABSTRACT FROM AUTHOR]

Due to the low direct thermal effect of solar irradiation, conventional phase-change microcapsules have poor solar energy utilization capability. To increase the solar-to-thermal energy storage efficiency, in this work, we reported a light-driven microencapsulated n-eicosane based on a crystalline TiO 2 shell coated by graphene oxide (GO)-based copper monosulfide (CuS) (CuS-GO) nanoconverter. Due to the combination of local surface plasma resonance (LSPR), semiconductor and synergetic effects, the CuS-GO nanoconverter conferred full-spectrum solar light-to-thermal conversion capability on the microcapsule system. The resultant n-eicosane@TiO 2 @CuS-GO microcapsules achieved high full-spectrum solar-to-thermal storage efficiency (97.1%) under stimulated solar light with no compromise of the latent heat density (212.0 ± 1.2 J/g). Furthermore, the thermal conductivity of n-eicosane@TiO 2 @CuS-GO (0.985 ± 0.004 W/(m·K)) significantly increased by 39.9% compared with that of n-eicosane@TiO 2. These results indicate that this light-driven microcapsule with superior properties is advantageous for direct solar-to-thermal energy utilization applications. Image 1 • CuS-GO nanoconverter encapsulated the microcapsules uniformly like a second shell. • The light-driven microcapsules exhibited full-spectrum absorption and conversion capability. • The solar energy storage efficiency was improved up to 97.1%. • The thermal energy storage capability of the microcapsules was 212.0 ± 1.2 J/g with high encapsulation ration (86.5%). [ABSTRACT FROM AUTHOR]

Congenital microtia-atresia affects patients in two specific ways: severe conductive hearing loss and difficulty in integrating into social environments due to auricle malformation. To investigate the safety and efficacy of single-stage auricular reconstruction and hearing rehabilitation in children with microtia and external auditory canal atresia. From January 2016 to December 2019, we included 32 patients with microtia and external canal atresia who received auricle reconstruction with high-density polyethylene (Medpor) framework and three different hearing rehabilitation approaches at the Ninth People's Hospital affiliated to Shanghai Jiao Tong University School of Medicine. Twenty patients underwent the traditional external auditory canal and middle ear repair (EACR), eight patients were implanted with Bonebridge (BB) devices, and four patients were implanted with bone-anchored hearing aid (BAHA) in one stage. Postoperative changes in auricle morphology and hearing and speech recognition and occurrence of complications were evaluated. After 6–24 months of follow-up, the auricle shape recovered well in all three groups, and the average score of 14 fine structures in the auricle was 9.43 (EACR), 10.67 (BB), and 9.75 (BAHA) points. The average score of auricle symmetry was 6.83 (EACR), 6.00 (BB), and 6.44 (BAHA) points. No significant differences in auricle shape were observed among the three groups (p >.05). After surgery, the average hearing improvement in the BB group was 43.33 dB, and the average speech recognition threshold declined to 42.28 dB. In the BAHA group, the average hearing improvement was 35 dB, and the average speech recognition threshold declined to 33.5 dB, similar to that of the BB group. However, in the EACR group, the average hearing improvement was only 4.13 dB, and the average speech recognition threshold declined to 11.36 dB. No vertigo, tinnitus, cerebrospinal fluid leakage, facial nerve paralysis, osseointegration failure, and other complications occurred in all the patients. In the EACR group, auricle stent fracture, ear canal restenosis, and canal atresia occurred in one patient each. In the BAHA group, two patients developed local ear infections. The procedure of single-stage auricular reconstruction and hearing rehabilitation for microtia is feasible and effective. The appropriate method of hearing reconstruction should be determined by evaluating the development of the inner and middle ear of the patients. For those patients with poor development of the mastoid and ossicular chain, hearing aid devices are recommended to achieve a stable and significant hearing effect. [ABSTRACT FROM AUTHOR]

The quality of aircraft components is directly affected by the positional accuracy of aviation drilling robot, which may further affect the assembly accuracy, flight performance and service life of aircraft. In this work, positional error compensation based on Bayesian linear regression (BLR) is proposed to improve the positional accuracy of aviation drilling robot. Firstly, the stochastic model of robot positional error is constructed by utilizing kinematic error model involving with random uncertainties. It proves that the positional error of robot joint space follows the Gaussian process (GP) and can be modeled through a linear regression model. Secondly, BLR is utilized to construct the positional error model of aviation drilling robot, which can provide the predicted positional error and the corresponding confidence interval (CI) of target position. These predicted values and CIs are used to realize error compensation. Experimental results show that, after error compensation, the average/maximum absolute positional error of the self-developed aviation drilling robot is decreased from 1.393mm/1.795 mm–0.081mm/0.167 mm. This indicates that the BLR-based positional error compensation is conductive to ameliorating the positional accuracy of aviation drilling robot. This study lays the foundation for the positional error compensation of industrial robots in aircraft assembly. [ABSTRACT FROM AUTHOR]

The chitosan (CS)-based bioactive packaging film with good antibacterial and antioxidant activities was developed using AHNT (modified halloysite nanotube) loaded with carvacrol (AHNT-Car) as the nanofiller. The zeta potential, Fourier transform infrared, and rheology analysis indicated that hydrogen bonding and electrostatic interactions were formed between AHNT-Car and CS film substrate, and scanning electron microscope images exhibited that the cross-sections of the bioactive film were denser. The mechanical and barrier properties (water vapor, oxygen, and light barrier properties) of the bioactive film were enhanced by adding AHNT-Car due to the hydrogen bonding, electrostatic interactions, and compact structure. Specifically, when the additional amount of AHNT-Car was 10 wt%, the film's tensile, oxygen barrier, and water vapor barrier properties were improved by 49.7%, 36.78%, and 11.92%, respectively. Moreover, compared to CS-Car film (adding Car into the CS film directly), the CS-10% film (AHNT-Car added at 10 wt%) had a slow-release effect on Car and could effectively protect the Car from external high temperature and UV light. In addition, the prepared bioactive film had sustained antioxidant and antibacterial properties and could significantly slow down the spoilage of pork during storage, proving the promising application of the bioactive film as food packaging. [Display omitted] • The CS-based bioactive film incorporated with AHNT-Car was successfully developed. • CS film connected AHNT-Car via electrostatic interaction and hydrogen bonding. • Physical property and functional activity were improved of the bioactive film. • The prepared bioactive film had a significant preservation effect on pork. [ABSTRACT FROM AUTHOR]

Alpine regions are changing rapidly due to loss of snow and ice in response to ongoing climate change. While studies have documented ecological responses in alpine lakes and streams to these changes, our ability to predict such outcomes is limited. We propose that the application of fundamental rules of life can help develop necessary predictive frameworks. We focus on four key rules of life and their interactions: the temperature dependence of biotic processes from enzymes to evolution; the wavelength dependence of the effects of solar radiation on biological and ecological processes; the ramifications of the non‐arbitrary elemental stoichiometry of life; and maximization of limiting resource use efficiency across scales. As the cryosphere melts and thaws, alpine lakes and streams will experience major changes in temperature regimes, absolute and relative inputs of solar radiation in ultraviolet and photosynthetically active radiation, and relative supplies of resources (e.g., carbon, nitrogen, and phosphorus), leading to nonlinear and interactive effects on particular biota, as well as on community and ecosystem properties. We propose that applying these key rules of life to cryosphere‐influenced ecosystems will reduce uncertainties about the impacts of global change and help develop an integrated global view of rapidly changing alpine environments. However, doing so will require intensive interdisciplinary collaboration and international cooperation. More broadly, the alpine cryosphere is an example of a system where improving our understanding of mechanistic underpinnings of living systems might transform our ability to predict and mitigate the impacts of ongoing global change across the daunting scope of diversity in Earth's biota and environments. [ABSTRACT FROM AUTHOR]