硅素营养研究进展

 综述了硅在土壤和植物体内的含量及对植物生长的影响及其作用机理,同时还讨论了硅在减少铁、锰、铝等毒害和减轻病虫为害等方面的作用。     

水工泄水建筑物高性能抗冲磨混凝土试验研究

针对水工泄水建筑物高性能混凝土高抗裂性和高抗冲磨性的要求,通过掺用具有梳型结构的聚羧酸减水剂实现水工泄水建筑物高性能混凝土,同时研究了聚丙烯纤维、粉煤灰和硅粉等因素对混凝土抗冲磨性能的影响。研究表明：聚羧酸减水剂掺量为1.0%,粉煤灰掺量为15%,硅粉掺量为10%,聚丙烯纤维掺量0.9 kg/m3时,混凝土的抗裂性和抗冲磨性能满足水工泄水建筑物高性能混凝土工程的使用要求。     

Effect of Application of Acidified Porous Hydrate Calcium Silicate and Porous Hydrated Calcium Silicate on the Growth of Rice Plants (Oryza sativa L.)

The effect of the application of acidified porous hydrate calcium silicate (APS) in nursery bed soil and porous hydrate calcium silicate (PS) in paddy fields on the growth of rice plants ( Oryza sativa L. cv. Hitomebore) was examined in 2002 and 2003. The results revealed the following: 1) Shoot dry weight of rice seedlings increased by APS treatment in nursery bed soil. The tiller number of rice plants after transplanting in both years also increased by APS treatment in nursery bed soil, and in 2003, the tiller number in the treatment with a combination of APS in nursery bed soil and PS in paddy fields was significantly higher than that in the other treatments until the maximum tiller number stage. Furthermore, the root length of rice plants 14 d after transplanting increased by APS treatment in nursery bed soil. 2) Silicon concentration in the soil solution significantly increased by PS treatment in paddy fields, and the concentration of dissolved carbon oxide increased by APS treatment in nursery bed soil. 3) Only in the APS treatment the rice yield was 341 g m⁻², while 400 and 450 g m⁻² in the PS and both APS and PS treatments, respectively, in 2003. Percentages of ripened grains in the plots without PS treatment ranged from 57 to 63%, respectively, while, those in the PS treated plots were 82%. The numbers of panicles and ripened grains in both APS and PS treatments were the highest among the treatments. Based on the above results, we concluded that both APS in nursery bed soil and PS in paddy field treatments were effective in improving the silicon nutrition and growth of rice plants, and that this effect was enhanced by a combination of treatments with the two.     

The status of atmospheric concentrations of ammonia in an intensive dairy farming area in central Japan

(pp. 41–46)
Silicon availability in 36 commercial nursery bed soils was evaluated by four methods the phosphate buffer (pH 6.2, 40 mmol L⁻¹), incubation, supernatant and acetate buffer (pH 4.0, 1 mol L⁻¹) Methods. The influence of silicon availability in the nursery bed soils on the silicon uptake of rice Oryza sativa L. cv. Hitomebore seedlings and the effect of silicon fertilizer application were examined in a glass house in 2002.
The results revealed that the best correlation between silicon content in rice seedlings and available silicon in soils was obtained with the phosphate buffer-solution method ( r  = 0.86). More precise evaluation of available silicon was achieved by grouping soils based on these phosphate absorption coefficients (PAC). The correlation coefficients between silicon content in rice seedlings and available silicon in soils were 0.92 and 0.72 for volcanic soils (PAC > 1500) and non volcanic soils (PAC < 1500), respectively.
We concluded that the phosphate buffer method is the most easily adjusted method for estimation of silicon availability in nursery bed soils, and silicon fertilizers should be applied when silicon availability in non-volcanic nursery bed soils goes below 200 mg kg⁻¹, whereas the level is less than 350 mg kg⁻¹ in volcanic soils.     

Silicon Ameliorates the Adverse Effects of Salinity on Turfgrass Growth and Development

An experiment was conducted to assess the effect of foliar application of potassium silicate on Cynodon dactylon [L.] Pers., Festuca arundinacea Schreb. and Lolium perenne L. With increased salinity level, chlorophyll content and relative water content (RWC) in these three turfgrasses were reduced significantly when compared with the untreated control. Supplementary silicon (Si) ameliorated the adverse effects of salinity on chlorophyll content. Silicon treatments decreased proline at all salinity levels. Moreover, addition of Si increased shoot length and shoot number in all turfgrasses. Sodium (Na) concentration was increased in both leaves and roots of turfgrasses at high salinity level; however, Si treatment significantly reduced Na concentration in all of them. Silicon increased Potassium concentration in shoots and roots (though not significantly) in most cases. It can be concluded that Si alleviated the adverse effects of salt stress in all turfgrasses.     

爪极式无刷硅整流发电机的负载特性分析

本文简单介绍爪极式无刷硅整流发电机的构造和负载特性曲线,着重分析外特性曲线并论证发电机限流作用的条件和范围。本文导出了发电机整流线路在空载和负载状态下输出直流工作电压的计算公式。     

有机硅废水处理方法研究

总结了近几年有机硅废水的处理方法,有物理法、化学氧化法、气提处理工艺、微电解处理工艺和生化处理工艺等,并结合近几年国内外的研究成果,介绍了国内外有机硅废水的深度处理技术,同时对有机硅废水处理技术的发展趋势进行了展望。     

不同砧木对嫁接黄瓜蜡粉形成及硅吸收分配的影响

 为探讨嫁接影响黄瓜果实表面蜡粉形成的机制,选择对嫁接黄瓜果实表面蜡粉形成具有明显不同影响的砧木品种,研究了嫁接黄瓜的植株生长和硅吸收分配特性,结果表明：少蜡粉砧木嫁接黄瓜,结果期株高、叶片数和前期产量低于多蜡粉砧木和中蜡粉砧木嫁接的黄瓜,但显著高于自根黄瓜;黄瓜叶片中硅含量显著高于茎和根系;少蜡粉砧木嫁接黄瓜叶片和茎中硅含量低于中蜡粉、多蜡粉砧木嫁接黄瓜和自根黄瓜;根系中硅含量以‘云南黑籽南瓜’嫁接的黄瓜最高;黄瓜果实发育过程中果实中硅含量呈先升高后降低的变化趋势,位于果实同节位的叶片中硅含量逐渐减少;少蜡粉砧木嫁接黄瓜果实中硅含量明显低于多蜡粉砧木、中蜡粉砧木嫁接黄瓜和自根黄瓜。不同砧木影响嫁接黄瓜果实表面蜡粉形成可能与硅的吸收分配特性有关。     

不同土壤水分条件下硅对坪用高羊茅种子出苗及生物学特性的影响

水肥耦合不仅可以维持草坪草的正常生长,而且可以减少一定的灌溉量。采用盆栽试验研究了不同土壤条件下硅对坪用高羊茅种子出苗及生长的影响。结果表明,不添加硅时,高羊茅种子适宜出苗时的土壤含水量应为饱和含水量的４５％～６０％,植株生长适宜的土壤含水量应为饱和含水量的７５％以上;当土壤含水量大于或等于饱和含水量的６０％时,添加硅不仅能够提前坪用高羊茅种子的初始出苗时间,缩短集中出苗时期,提高出苗率,而且能够显著促进高羊茅的株高和叶长生长,增加地上和地下生物量（P＜０．０５）,而当土壤含水量小于或者等于饱和含水量的４５％时,添加硅对高羊茅种子出苗和生长发育没有明显影响,说明添加硅对坪用高羊茅生长的有益作用受土壤含水量的约束;土壤含水量为饱和含水量的６０％时,添加硅处理中植株的分蘖数、株高、叶长和生物量与对照处理中土壤含水量为饱和含水量的７５％时植株的分蘖数、株高、叶长和生物量差异不显著,说明添加硅能降低高羊茅植株正常生长所需的土壤含水量,有利于节约灌溉量。     

有机硅溶胶-凝胶法改性木材Si元素的分布状态

采用正硅酸乙酯(TEOS)为改性剂先驱体,通过溶胶-凝胶法处理木材,以改善木材性能.为了探究有机硅溶胶-凝胶法改性处理木材的作用机理,应用电镜-能谱方法,分析改性木材中的碳、氧、硅三种元素的相对含量及分布状态.结果表明:随着增重率的增加,硅元素的相对质量分数不断升高,而碳元素相对质量分数降低,氧元素先降低后升高;验证了在木材内部SiO2的生成,而且硅元素主要分布在木材细胞壁表面.