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The off-flavor disorder is one of the most quality deteriorating and undesirable postharvest physiological disorders in fresh fruits. Over-biosynthesis and accumulation of ethanol metabolism-related metabolites such as acetaldehyde and ethanol have been associated with an alcoholic off-flavor disorder in various fresh fruits at both pre- and postharvest stages. Correspondingly, many studies have reported the association of such off-flavor disorders with several inducing factors, including anaerobic respiration, low O2 stress, high CO2 stress, and storage temperature stress, that upregulate ethanol metabolism in fruits. Furthermore, numerous metabolic and physiological mechanisms that govern ethanol metabolism under such factors are subsequently addressed. These mechanisms include the γ-aminobutyric acid (GABA) shunt pathway, mitochondrial energy metabolism, glycolysis, Krebs or TCA cycle, cytosolic malate metabolism, and starch and sugar metabolism. To summarize the relevant findings, the current paper reviews the literature on alcoholic off-flavor disorder, focusing on the role of significant underlying causes and key metabolic and physiological mechanisms in boosting ethanol metabolism in fresh fruits. In addition, recent measures that have been already taken or are in progress to control the higher activity of ethanol metabolism that may eventually result in limiting the alcoholic off-flavor disorder in harvested fresh fruits have also been discussed. Moreover, functions of metabolic mechanisms, including respiratory mechanisms, and other factors such as fruit genetic makeup, degree of maturity, and postharvest handling and storage conditions, are needed to be investigated in future work at both physiological and transcriptomics levels to reveal the additional relation to alcoholic off-flavor disorders in fresh fruits during ripening and storage.

The changes of mechanical properties and carbides coarsening behavior of marine atmospheric corrosion resistant steel at different tempering processes were studied. The results of tensile and impact tests showed that the best mechanical properties obtained when the steel was quenched at 940 °C and tempered at 520 °C. The impact toughness at −20 °C increased firstly and then decreased with the tempering temperature increasing. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations showed that with the increase in tempering temperature, cementite particles gradually grow up and the size of cementite particles at grain boundaries was larger than that of cementite particles in grains. The coarsening of cementite may be related to the lack of Cr element during high temperature tempering, resulting in the decrease in impact toughness.

Cold deformation is an effective approach for enhancing the strength of many metallic materials. Efforts continue to be expended to improve existing processes for manufacturing non-quenched and tem...

In this paper, we consider the global adaptive output feedback control design problem for a class of stochastic nonlinear systems with general unknown output gain. Different from the existing literature, the uncertainty on the output gain of the considered system is more general, that is to say, only the sign of the gain is known, which directly leads to the ineffectiveness of the existing methods. In order to achieve the control objective, besides designing a full-order observer, inspired by the existing adaptive design technique, a new unknown parameter is introduced to depict the system uncertainties and facilitate the adaptive control design. Then, by adopting the adding a power integrator technique and the homogeneous control method, we successfully design an adaptive output feedback controller to render the uncertain stochastic nonlinear systems globally asymptotically stable in probability, which means that all the closed-loop system states are bounded almost surely, and especially the original system states converge to the origin with probability one.

The shaft parts surface was treated by ultrasonic surface machining (USM) technology after surface induction hardening and tempering. In order to study the surface strengthening mechanism of ultrasonic punching on the surface of induction quenching and tempering, nano-intendation, X-ray diffraction, and scanning electron microscopy equipped with energy dispersive spectroscopy were utilized to evaluate the mechanical and corrosion properties of untreated and USM-treated surface. The results indicated that the surface treated by USM had an obviously gradient plastic deformation layer and the grain of lath martensite was refined by this deformation. The surface mircohardness of USM-treated sample had a gradient trend, and the surface highest hardness was increased. Surface residual stress of USM-treated specimen was higher than untreated surface. The surface of USM-treated specimen also exhibited a lower friction coefficient, and a smaller wear scar. In addition, the surface of USM-treated sample had better corrosion resistance than untreated surface.