摘要：以荞麦‘右玉26’为材料，在防雨棚下进行盆栽试验，研究外源硒对土壤铅污染下荞麦幼苗的农艺性状及生理特性、成熟期各器官铅累积和产量的影响，旨在探讨硒对土壤铅胁迫下荞麦的生长发育、产量及铅在荞麦体内富集量的影响，为发现硒缓解重金属铅对植物的毒害作用提供理论依据，以期为农业区铅污染治理及荞麦生产提供有价值的思路和方法。试验采用2因素完全随机设计，设置3个土壤铅浓度（0 mg·L-1、500 mg·L-1、1000 mg·L-1）、5个硒浓度（0 mg·kg-1、1 mg·kg-1、2.5 mg·kg-1、5 mg·kg-1和10 mg·kg-1）。研究结果表明：1）随铅浓度增加，荞麦的株高、总根长、干重、根系总面积、根系活力、叶绿素含量、叶绿素荧光参数、经济产量（千粒重、株粒数）均呈降低趋势。2）低浓度硒（1~2.5 mg·L-1）可缓解铅对荞麦的毒害，高浓度硒（5~10 mg·L-1）和铅为协同作用，加剧了对荞麦的毒害。3）硒浓度为2.5 mg·L-1时，缓解铅对荞麦毒害的效果最为明显，显著降低了铅胁迫下荞麦幼苗SOD和POD活性；降低成熟期荞麦各器官铅含量，各处理下荞麦各器官铅含量均表现为根〉茎〉叶〉种子；产量达到最大值。由此可见，外源硒可通过抑制荞麦对铅的吸收和转运，促进荞麦幼苗叶片的光合作用、提高叶片叶绿素含量和根系活力等途径来增强荞麦对铅胁迫的耐性。对本研究所用的5种浓度来说，缓解效果最佳的硒浓度为2.5 mg·L-1。

摘要：Design and preparation of frequency doubling antireflection coating with different thicknesses of interlayer were investigated for LIB3O5 （LBO） substrate. The design was based on the vector method. The thickness of the inserted SiO2 interlayer could be changed in a wide range for the four-layer design with two zeros at 1064 and 532 nm. The coatings without any interlayer and with 0.1 quarter-wave （λ/4）, 0.3 λ/4, 0.5 λ/4 SiO2 interlayer were deposited respectively on LBO by using electron beam evaporation technique. All the prepared coatings with SiO2 interlayer indicated satisfying optical behavior. This expanded our option for the thickness of an interlayer when coating on LBO substrate. The prepared films with SiO2 interlayer showed better adhesion than that without any interlayer. The thickness of the interlayer affected the adhesion, the adhesion for the coating with 0.5 λ/4 SiO2 interlayer was not as good as the other two.