Extensive research has been conducted on the effects of pollen activation temperature, cultivation temperature, and ambient temperature on germination rates and fruit sets. Yet, the influence of the temperature (pre-germination temperature) at which the pollen suspension is prepared within the storage container (tank) remains unexplored. In this study, we initially established the optimal time for pollen activation. Subsequently, pollen suspensions at varying temperatures were prepared, and their germination rates were analyzed using microscopy. Pollen suspensions of different temperatures were then sprayed onto Fojianxi pear flowers, and parameters such as flower fruit set rate, inflorescence fruit set rate, fruit longitudinal dimension, fruit transverse dimension, and fruit shape index were evaluated. The findings revealed that the optimal pollen activation duration was 6 h. A pollen suspension temperature of 30 °C resulted in the highest germination rate (72.06 ± 6.87%). However, a suspension temperature of 25 °C achieved the highest flower fruit set rate (57.29 ± 5.58%) and inflorescence fruit set rate (87.50 ± 4.84%). The fruit longitudinal dimension (68.12 ± 3.94 mm), transverse dimension (73.77 ± 4.04 mm), and fruit shape index (108.42 ± 6.02%) were most favorable at a suspension temperature of 15 °C. Our study concludes that the pollen in lower pollen suspension temperatures (15~25 °C) has higher germination energy and have higher stigmatic capacity. Thus, we advocate for a pollen suspension temperature range of 15~25 °C when employing liquid spray pollination techniques with Xuehuali (Pyrus bretschneiderilia) pollen.

The liquid floated gyro (LFG) is an inertial instrument widely used in aviation, aerospace, navigation, and other high-tech fields, with the advantages of high accuracy and good in-orbit reliability. The filling of internal floating oil is a key process in the manufacture of LFG, however, due to the limitation of technology level, environmental conditions, and other factors, the floating oil may be mixed with a certain amount of air, which affects the rheological characteristics of the oil, thus leading to the accuracy drift of the gyro instrument. Therefore, this paper analyzes the effect of air content on the fluid characteristics of the gyro oil by using the computational fluid dynamics method. The results show that the air content has a significant effect on the oil dynamics: when the air content increases from 0% to 3%, the average flow velocity of the oil decreases by 4.15%, and the viscous interference torque increases by 0.02%, which reduces the stability of the instrument accuracy to a certain extent, so the generation of air bubbles should be avoided or necessary measures should be taken to remove air bubbles during the oil filling process.