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Abstract [Objective] The study aims to investigate the effects of different light exposure durations and intensities on the sugar, acid, and flavonoid contents of Cerasus humilis fruits, and to provide a reference for further exploration of the molecular mechanisms underlying the influence of light exposure on fruit quality. [Methods] The C. humilis varieties ‘Nongda 6’ and ‘Nongda 7’ were used as experimental materials. Fruit bags with three different light transmission rates (30%, 55%, and 100%) were applied during fruit enlargement period and color conversion period, respectively, and measured the fruit mass and titratable acid, soluble solid, and flavonoid content. [Results] (1) The single fruit mass and soluble solid content of both varieties were lower during fruit enlargement period than during color conversion period, and both were decreased gradually with increasing light-blocking rate of fruit bags. (2) The titratable acid content of ‘Nongda 6’ was significantly reduced under bagging treatment, and the higher the light-blocking rate of the fruit bag and the longer the bagging time, the more pronounced the reduction in acidity. In contrast, the titratable acid content of ‘Nongda 7’ was less affected. (3) The flavonoid content of bagged ‘Nongda 6’ was higher than the control, increasing first and then decreasing with the increase in lightblocking rate of the fruit bag, and the content during fruit enlargement period was higher than that during color conversion period. The flavonoid content of bagged ‘Nongda 7’ was significantly higher than the control only at a 30% light-blocking rate, and the content during fruit enlargement period was significantly lower than during color conversion period. [Conclusion] Bagging can effectively improve the sugar, acid, and flavonoid content of C. humilis fruits. Furthermore, bagging during fruit enlargement period is suitable for ‘Nongda 6’, while bagging during color conversion period is more effective for ‘Nongda 7’. Both varieties show the best overall improvement in sugar, acid, and flavonoid content with a 55% light-blocking rate of the fruit bag.

In order to clarify the effects of precooling treatments on the postharvest storability and neohesperidin metabolism of sweet cherries, forced-air precooling, ice-water precooling, cold storage precooling and ozone ice-water precooling were used to treat ‘Red Agate’ sweet cherries prior to being stored at (0.0 ± 0.5) ℃. The sensory quality, nutritional quality, respiratory metabolism, disease resistance-related enzyme activities, neohesperidin content and related gene expression in sweet cherries were analyzed during storage. In addition, the key indicators for the evaluation of storability and the key regulatory genes of neohesperidin metabolism in sweet cherries were selected by correlation analysis. The results showed that compared with commercial precooling (cold storage precooling), forced-air precooling significantly increased the activities of peroxisome (POD), superoxide dismutase (SOD), catalase (CAT), cinnamic acid-4-hydroxylase (C4H), cinnamyl-alcohol dehydrogenase (CAD) and 4-coumarate:coenzyme A ligase (4-CL), maintained higher fruit hardness, and reduced the disease index, dry fruit stem incidence, and browning index of sweet cherry during storage (P 0.05). VC content, and the activities of C4H, CAD and 4-CL (key enzymes in the phenylpropane metabolic pathway), SOD, PPO and lipoxygenase showed a significant correlation with the sensory quality of sweet cherries, which could be used as key physiological indicators to evaluate the storage stability of sweet cherry. The content of neohesperidin in sweet cherries fluctuated and decreased during storage. Forced-air precooling could promote neohesperidin synthesis by improving the gene expression of LOC110760277, LOC110751411, LOC110757814, QXJJ01001021, LOC110745765 and LOC110756675 and inhibiting the gene expression of LOC110758277 and LOC110771557. These results indicated that forced-air precooling was more effective in improving the storage storability of sweet cherries and promoting neohesperidin synthesis than ice-water precooling, cold storage precooling and ozone ice-water precooling.

BackgroundCAT-1 (China Astro-Torus 1) is a levitated dipole field magnetic confinement device, which mainly used for dipole plasma physics experiments, requiring a central floating superconducting coil to be stably levitated for at least 5 h without cooling or power supply.PurposeThis study aims to design a levitation control system of coupling superconducting levitation coil and floating coil for CAT-1 dipole device.MethodsAccording to the design parameters of the suspension magnet system of the CAT-1 device, Simulink model of the control system was established and applied to the simulation. Based on Routh-Hurwitz stability criterion, the influence of PID (Proportion-Integral-Derivative) control strategy on stability control was studied. The selection range of stability control parameters was determined to ensure the stable levitation of 1 200 kg, 5 MA floating magnet.ResultsSimulation results show that under ideal conditions, delay time of the PD (Proportion-Derivative) control system is 0.046 3 s, rise time is 0.154 5 s, peak time is 0.628 3 s, adjustment time is 0.084 8 s, and overshot δ=1.6. It means that PD can restore the levitated superconducting ring to the preset balance position in a short time, and the load of the circuit can be greatly reduced by adopting the appropriate starting mode.ConclusionThe results provide key technical support for the design and development of levitated superconducting dipole field devices.

BackgroundWhen the suspended dipole field coils experience significant disturbances during the operation of the suspended dipole field device, the Tilt-Slide-Rotate (TSR) coils are used to control the attitude of the dipole field coils, thereby preventing them from losing control.PurposeThis study aims at attitude control of dipole fields by coil forces of the TSR coils with relatively complex geometric structures.MethodsBased on the line segment approximation method, the modeling and analysis were conducted for scenarios where the dipole field coils return to their balanced position under conditions of dipole field tilt and offset by controlling the magnetic forces generated by the TSR coils on both opposite and same sides. The coupling magnetic field between the TSR coils and the dipole field coils was calculated, and the magnetic field line structure was analyzed. The excitation magnetic field of the TSR coils, in the form of sinusoidal currents, was simulated to induce azimuthal magnetic disturbances. Analysis was performed on the magnetic field line structure and phase of the perturbation magnetic field on the Poincaré section at the equatorial plane. [Results and Conclusions] If only one group of TSR coils on the same or opposite sides is used to control the dipole field coils to restore equilibrium, exhibited mechanical instability needs necessitating coordinated control by multiple sets of TSR coils. Applying pseudo-sinusoidal currents to all TSR coils induces compression and stretching effects on the background dipole magnetic field. By controlling the current of the TSR coils to control the phase of the compression position, the feasibility of controlling the attitude of the dipole field coils with multiple TSR coils has been validated. However, this process may also cause drift in the background magnetic field and the formation of open magnetic field lines, which could drive plasma instabilities and lead to particle loss.

The vast bulk of polystyrene (PS), a major type of plastic polymers, ends up in landfills, which takes up to thousands of years to decompose in nature. Chemical recycling promises to enable lower‐energy pathways and minimal environmental impacts compared with traditional incineration and mechanical recycling. Herein, we demonstrated that methanol as a hydrogen supplier assisted the depolymerization of PS (denoted as PS‐MAD) into alkylbenzenes over a heterogeneous catalyst composed of Ru nanoparticles on SiO2. PS‐MAD achieved a high yield of liquid products which accounted for 93.2 wt % of virgin PS at 280 °C for 6 h with the production rate of 118.1 mmolcarbon gcatal.−1 h−1. The major components were valuable alkylbenzenes (monocyclic aromatics and diphenyl alkanes), the sum of which occupied 84.3 wt % of liquid products. According to mechanistic studies, methanol decomposition dominates the hydrogen supply during PS‐MAD, thereby restraining PS aromatization which generates by‐products of fused polycyclic arenes and polyphenylenes. [ABSTRACT FROM AUTHOR]