Effect of High Voltage Electrostatic Fields on Post-Harvest Quality of Strawberry Fruit

The paper studied the effect of high-voltage electrostatic fields on the postharvest quality of strawberries. The results showed that the respiration rate decreased significantly, the content of soluble solids kept at high level, and the activities of polygalacturonase and cx-cellulase decreased, while the fruit firmness declined slowly. On the seventh day of storage, the rotten rate of strawberries treated by HVEF was 5%, the control group was 15%.

热近非稳腔高重频双波长复合输出激光器研究

1064 nm/532 nm双波长固态激光器在多个领域应用广泛。针对目前该类激光器分光路可切换输出研究较多,而复合输出研究缺乏的现状,通过建立含热透镜的等价谐振腔模型,结合谐振腔稳定性和"热近非稳谐振腔"理论确定了最佳腔长,利用软件仿真分析了倍频晶体的长度、输出镜基频透过率、调Q频率的大小对复合输出的影响,根据双路激光干扰的实际需求,确定了最佳复合输出参数,从而完成了一台1064 nm/532 nm高重频双波长复合输出激光器的设计。实验表明,KTP晶体长度选为12 mm,输出镜基频透过率选为15%,调Q频率选为50 k Hz时,在最大泵浦功率下,基频光输出的平均功率为28.82 W,倍频光的输出的平均功率为2.23 W。测量得到的激光近场发散角与光斑半径的乘积近似等于同样位置处基模高斯光束发散角与光斑半径的乘积,这说明所设计的激光器在最大泵浦功率条件下是以近似基模的方式运转,具有较好的光束质量。