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We predict two novel group 14 element alloys Si2Ge and SiGe2 in P6222 phase in this work through first-principles calculations. The structures, stability, elastic anisotropy, electronic and thermodynamic properties of these two proposed alloys are investigated systematically. The proposed P6222-Si2Ge and P6222-SiGe2 have a hexagonal symmetry structure, and the phonon dispersion spectra and elastic constants indicate that these two alloys are dynamically and mechanically stable at ambient pressure. The elastic anisotropy properties of P6222-Si2Ge and P6222-SiGe2 are examined elaborately by illustrating the surface constructions of Young's modulus, the contour surfaces of shear modulus, and the directional dependence of Poisson's ratio; the differences with their corresponding group 14 element allotropes P6222-Si3 and P6222-Ge3 are also discussed and compared. Moreover, the Debye temperature and sound velocities are analyzed to study the thermodynamic properties of the proposed P6222-Si2Ge and P6222-SiGe2. [ABSTRACT FROM AUTHOR]

In the present paper we study the influences of the bias voltage and the external components on the damage progress of a bipolar transistor induced by high-power microwaves. The mechanism is presented by analyzing the variation in the internal distribution of the temperature in the device. The findings show that the device becomes less vulnerable to damage with an increase in bias voltage. Both the series diode at the base and the relatively low series resistance at the emitter, Re, can obviously prolong the burnout time of the device. However, Re will aid damage to the device when the value is sufficiently high due to the fact that the highest hot spot shifts from the base-emitter junction to the base region. Moreover, the series resistance at the base Rb will weaken the capability of the device to withstand microwave damage. [ABSTRACT FROM AUTHOR]

This paper presents a theoretical study of the pulse-width effects on the damage process of a typical bipolar transistor caused by high power microwaves (HPMs) through the injection approach. The dependences of the microwave damage power, P, and the absorbed energy, E, required to cause the device failure on the pulse width т are obtained in the nanosecond region by utilizing the curve fitting method. A comparison of the microwave pulse damage data and the existing dc pulse damage data for the same transistor is carried out. By means of a two-dimensional simulator, ISE-TCAD, the internal damage processes of the device caused by microwave voltage signals and dc pulse voltage signals are analyzed comparatively. The simulation results suggest that the temperature-rising positions of the device induced by the microwaves in the negative and positive half periods are different, while only one hot spot exists under the injection of dc pulses. The results demonstrate that the microwave damage power threshold and the absorbed energy must exceed the dc pulse power threshold and the absorbed energy, respectively. The dc pulse damage data may be useful as a lower bound for microwave pulse damage data. [ABSTRACT FROM AUTHOR]

• Postharvest 24-epibrassinolide (EBR) treatment at 2 μM and 5 μM effectively inhibited broccoli yellowing. • The 2 μM EBR treatment inhibited enzymes related to chlorophyll degradation and ethylene synthesis Treatment with 20 μM EBR promoted ethylene production and chlorophyll degradation and chloroplast structure. • Chloroplast structure remained intact under the 2 μM EBR treatment but was destroyed under 20 μM EBR treatment. To explore the effect of 24-epibrassinolide (EBR) on the postharvest yellowing of broccoli (Brassica oleracea var. italica) florets, these were treated with 0–20 μM EBR and kept at 4 °C for 24 days (shelf life). Changes in color, chlorophyll fluorescence, chloroplast ultrastructure, and in the activities of enzymes and expression of genes related to ethylene synthesis and chlorophyll degradation were determined. Low EBR concentrations (2–5 μM) effectively inhibited the yellowing of broccoli, while high EBR concentrations (15–20 μM) accelerated it. On the 24th day, the grana thylakoids of the chloroplasts of 2 μM EBR-treated florets were neatly arranged and clearly visible, while the chloroplast membrane and grana thylakoids of the chloroplast of 20 μM EBR-treated florets were dissolved. Chlorophyll fluorescence was significantly higher in broccoli florets treated with low EBR concentrations than in control broccoli; the opposite was found for broccoli treated with high EBR concentrations. In 20 μM EBR- treated broccoli, the expressions of the genes coding for 1-aminocyclopropane-1-carboxylic acid (ACC) synthase 4 (BoACS4), ACC oxidase 3 (BoACO3), pheophytinase (PPH), and polyamine oxidase (PaO) were increased, accelerating the degradation of chlorophyll, while in 2 μM EBR-treated broccoli the expressions of BoACS4 and BoACO3 were lower than in control broccoli, thereby reducing the production of endogenous ethylene and delaying yellowing. Thus, treatment with 2 μM EBR extends the shelf life of broccoli. [ABSTRACT FROM AUTHOR]

We present an accurate through silicon via (TSV) thermal mechanical stress analytical model which is verified by using finite element method (FEM). The results show only a very small error. By using the proposed analytical model, we also study the impacts of the TSV radius size, the thickness, the material of Cu diffusion barrier, and liner on the stress. It is found that the liner can absorb the stress effectively induced by coefficient of thermal expansion mismatch. The stress decreases with the increase of liner thickness. Benzocyclobutene (BCB) as a liner material is better than SiO2. However, the Cu diffusion barrier has little effect on the stress. The stress with a smaller TSV has a smaller value. Based on the analytical model, we explore and validate the linear superposition principle of stress tensors and demonstrate the accuracy of this method against detailed FEM simulations. The analytic solutions of stress of two TSVs and three TSVs have high precision against the finite element result. [ABSTRACT FROM AUTHOR]

The contents of glucose, Nε-(carboxymethyl) lysine (CML), and two main intermediate products, glyoxal (GO) and fructoselysine (FL), were determined, and the corresponding mathematical models were established to investigate the formation and kinetics of CML in a glucose-lysine model heated at 80 °C for 50 h. The effects of oleic acid (OA), temperature, and energy on CML formation were considered in the kinetic models. The mathematical modeling results suggested that glucose consumption was incomplete at 50 h and 80 °C. Although OA contributed to the formation of GO, CML was primarily formed from FL via the Maillard reaction, not from GO. The Arrhenius model was used to deduce that FL is the main pathway in the glucose-lysine-OA system because 88.39 kJ/mol of activation energy via the GO pathway was significantly higher than the 73.97 kJ/mol of activation energy via the FL pathway, and because the rate constant k 4 was higher than k 3 at different temperatures. OA (50 mmol/L) acted as a catalyst as well as a reactant in CML formation. This is the first study in which CML formation has been determined by both multi-response modeling and kinetic models based on glycation and lipid oxidation. • The mathematical models of AGEs were established in a glucose-lysine model. • CML formation was determined by both multi-response modeling and kinetic models. • CML was quantified based on the influences of oleic acid, temperature and energy. • CML is formed mainly from FL via MR and OA acted as a catalyst and a reactant. [ABSTRACT FROM AUTHOR]

Bell peppers are valued for their plentiful vitamin C and nutritional content. Pepper fruits are susceptible to cold storage, which leads to chilling injury (CI); however, the crucial metabolic product and molecular basis response to cold stress have not been elucidated definitely yet. To comprehensively understand the gene regulation network and CI mechanisms in response to cold stress on a molecular level, we performed high-throughput RNA-Seq analysis to investigate genome-wide expression profiles in bell peppers at different storage temperatures (4 °C and 10 °C). A total of 61.55 Gb of clean data were produced; 3863 differentially expressed genes (DEGs) including 1669 up-regulated and 2194 down-regulated were annotated and classified between the CI group and control. Together, a total of 41 cold-induced transcription factor families comprising 250 transcription factors (TFs) were identified. Notably, numerous DEGs involved in biomembrane stability, dehydration and osmoregulation, and plant hormone signal transduction processes were discovered. The transcriptional level of 20 DEGs was verified by reverse transcription quantitative polymerase chain reaction (RT-qPCR). Our results present transcriptome profiles of bell peppers in response to cold stress; the data obtained may be useful for the identification of key candidate genes and elucidation of the mechanisms underlying membrane damage during chilling injury. Image 1 • Genome-wide expression profiles of bell peppers at 4 °C and 10 °C were obtained. • 3863 differentially expressed genes were identified in response to chilling injury. • 41 cold-induced transcription factor families were identified. • The findings reveal how cold stress affects bell pepper biochemistry. [ABSTRACT FROM AUTHOR]

• Melatonin may alleviate cold-induced membrane lipid peroxidation. • Melatonin treatment increased the ratio of unsaturated to saturated fatty acids. • Melatonin lightened phospholipids degradation and gene expression of CaPLD and CaLOX. • Melatonin treatment may activate an antioxidant defense system of bell peppers. • Melatonin treatment may be a reliable method to relieve chilling injury. Melatonin is a kind of indoleamine that plays an important role against abiotic stress. In the current study, we investigated the effect of exogenous melatonin (100 μM) on bell pepper during storage at 4 °C for 20 d and afterward shelf at 20 °C for 3 d. Melatonin treatment reduced cell structure damage and lightened the increase in chilling injury incidence, membrane permeability, and malonaldehyde (MDA) content under cold stress. The membrane lipid content and the ratio of unsaturated to saturated fatty acids increased by reducing the enzymatic activity and transcripts of phospholipase D (PLD) and lipoxygenase (LOX). Besides, melatonin application also inhibited the transcription of CaNAC1 , which is the direct targeted regulator of the CaPLD gene. In addition, peppers treated with melatonin had a higher proline content than untreated peppers. Moreover, melatonin triggered the antioxidation protection system in peppers to resist oxidative damage by up-regulating the transcription level of the CaSOD , CaPOD , CaCAT , and CaAPX genes. Our results show that melatonin treatment may be a reliable method to relieve chilling injury in bell pepper fruit via the alleviation of cold-induced membrane lipid peroxidation and activating an antioxidant defense system. [ABSTRACT FROM AUTHOR]

• Yellowing of broccoli involved plastid transformation and abnormal chloroplast development. • BoHO1 played a key role in maintaining broccoli as green, which has not been reported previously. • BoHO1 , BoNYC1 and BoVDE affected cell morphology and pigment content. • BoHO1 and BoZEP interacted with different metabolic pathways that are intrinsically related. Broccoli undergoes yellowing in unfavorable conditions, thereby diminishing the sensory quality and commodity value. This study aimed to investigate systematically cellular and/or biomolecular changes involved in broccoli yellowing by analyzing changes in microstructural integrity, pigment content, and gene expression. On day-5 of storage at 20 °C, the buds turned yellow without blooming and showed structural damage; ultrastructural analysis revealed plastid transformation and abnormal chloroplast development. Genes regulating pigment content and chloroplast structure directly were identified. More specifically, BoCAO and BoNYC1 regulated chlorophyll turnover, affecting chlorophyll a and b contents. Changes in the β-cryptoxanthin content were influenced by the combined action of up- (BoHYD) and downstream (BoZEP) genes. BoZEP and BoVDE were activated after cold-temperature induction. High BoHO1 expression delayed yellowing at low temperature, inducing BoZEP expression. Color intensity correlated significantly with the chlorophyll b , β-cryptoxanthin, and β-carotene contents, which were associated with increased yellowing of plant tissues. [ABSTRACT FROM AUTHOR]