双面涂复法生产长效防水滴PVC农膜

详细介绍采用双面涂复法生产长效防水滴、防水雾、防尘污的ＰＶＣ农膜的配方及其实用结果．在ＳＧ－３型ＰＶＣ树脂１００ｗｔ％中，适量添加含氟系及山梨糖醇酐单棕榈酸酯等，所制薄膜的一表面（用于大棚外表面）涂布紫外线固化型环氧树脂涂料，另一表面（用于大棚内表面）涂布由胶态疏水性二氧化硅（疏水率６０％）和胶结料组成的涂料。将这种薄膜用于蔬菜大棚，经实用观察评价，防水滴、防水雾、防尘污效果极佳，２年后仍无降低．阳光透过性好，栽培作物无过湿、无病害发生，有效地提高了作物的产量．

用B_4C陶瓷先驱体涂复碳纤维研究

用溴苯和 BF3乙醚为起始原料 ,合成出聚对亚苯基硼 ( PPB) ,高温裂解后得到含 B4C 54.4 %、B2 O2 1 3 .6%、自由碳 3 2 %的陶瓷。用溶液浸涂碳纤维 ( CF)并高温裂解后得到 B4C涂层 CF,与未涂层 CF相比 ,B4C涂层 CF抗热氧化性提高 2 0 0°C。 1 80 0°C热压时 B4C涂层 CF较未涂层 CF制得的 CF/Si C复合材料的 σb 值提高 1 0 .5%,KIC值提高 1 9.4 %,1 850°C热压时相应的 σb 值提高 3 1 .6%,KIC提高 5.8%。

Increased photo-catalytic removal of sulfur using titania/MWCNT composite

Titania coating of multi wall carbon nano tube(MWCNT) was carried out by sol-gel method in order to improve its photo catalytic properties.The effect of MWCNT/TiO_2 mass to volume ratio on adsorption ability,reaction rate and photo-catalytic removal efficiency of dibenzothiophene(DBT) from n-hexane solution was investigated using a 9 W UV lamp.The results show that the addition of nanotubes improves the photo-catalytic properties of TiO_2 by two factors;however,the DBT removal rate versus MWCNT content is found to follow a bimodal pattern.Two factors are observed to affect the removal rate of DBT and produce two optimum values for MWCNT content.First,large quantities of MWCNTs prevent light absorption by the solution and decrease removal efficiency.By contrast,a low dosage of MWCNT causes recombination of the electron holes,which also decreases the DBT removal rate.The optimum MWCNT contents in the composite are found to be 0.25 g and 0.75 g MWCNT per 80 m L of sol.

国外桥面板修复的示范工程简介

在损坏部位注射或覆盖低粘滞度的粘结材料，防止结构的进一步破坏，为砼桥面板提供了一种有效的修补方法。