Adsorption Property of Ni-TiO_2-SiO_2 Synthesized by Using Rice Husks as Silicon Source and Template to Gentian Violet

[Objective] The aim was to study the adsorption property of adsorbent Ni-TiO2-SiO2 synthesized by using rice husks as silicon source and template to gentian violet.[Method] The renewable dye adsorbent Ni-TiO2-SiO2 was synthesized by using rice husks as raw material,and the adsorption property of Ni-TiO2-SiO2 to gentian violet was studied.[Result] The adsorption rate of Ni-TiO2-SiO2 to gentian violet reached about 90% after 1 h.In 100 ml gentian violet solution with concentration of 25 mg/L and pH=8,Ni-TiO2-SiO2 with dosage of 0.07 g had the best adsorption effect.More importantly,Ni-TiO2-SiO2 as adsorbent could be used repeatedly,and couldn’t lead to secondary pollution due to leaking.[Conclusion] The study could provide references for practical engineering application.

Mechanical research and development of a monocrystalline silicon neutron beam window for CSNS

The monocrystalline silicon neutron beam window is one of the key components of a neutron spectrom- eter. Monocrystalline silicon is brittle and its strength is generally described by a Weibull distribution due to the material inhomogeneity. The window is designed not simply according to the mean strength but also according to the survival rate. The total stress of the window is stress-linearized into a combination of membrane stress and bending stress by finite element analysis. The window is a thin circular plate, so bending deformation is the main cause of failure and tensile deformation is secondary and negligible. Based on the Weibull distribution of bending strength of monocrystalline silicon, the optimized neutron beam window is designed to be 1.5 mm thick. Its survival rate is 0.9994 and its transmittance is 0.98447, which meets both physical and mechanical requirements.

Effects of Soluble Silicate and Nanosilica Application on Rice Nutrition in an Oxisol

Silicon （Si） has been supplied to plants via application of calcium silicate to soil; however, high doses of calcium silicate are required because of its low solubility. Nanoparticles can reduce Si doses and be applied to seeding furrows. This study investigated the effects of liquid Si sources, i.e., highly soluble silicate （115.2 g L^-1 Si and 60.5 g L^-1 Na20） and nanosilica （〈 200 nm）, on Si uptake by rice plants, plant lignification, plant C：N：P stoichiometry, plant physiology, and grain yield using an Oxisol under greanhouse condistions. The treatments included the application of nanosilica and soluble silicate to seeding furrows at Si doses of 0, 605, 1210, and 2 420 g ha^-1. Plant uptake and treatment effects were evaluated by measuring C and lignin contents, Si, N, and P accumulation, physiological characteristics, and grain yield of rice. The deposition of silica bodies and amorphous silica in the flag leaves was analyzed using scanning electron microscopy. Application of liquid Si increased Si accumulation in rice by 47.3% in relation to the control （0 g ha^-1 Si）, regardless of the Si sources used. Nanosilica application increased leaf lignin content by 112.7% when compared to that in the control. Silicon moderately affected the net C assimilation （increased by 1.83%） and transpiration rates （increased by 48.3%）; however, Si influenced neither plant growth nor grain yield of rice. These results are explained by the lack of biotic or abiotic stress in rice plants during the experiment. To the best of our knowledge, in Brazilian agriculture, this is the first report on the use of nanosilica as a Si fertilizer and its effect on plant nutrition. This study provides evidence that rice plants absorb and accumulate nanoparticles; however, further studies are required to investigate the use of nanoparticles in other plant species.