PREPARATION of ALUMINUM TITANATE FILM VIA NONHYDROLYTIC SOL–GEL METHOD AND ITS FUSED SALT CORROSION RESISTANCE

采用非水解溶胶–凝胶工艺,以无水三氯化铝和四氯化钛为前驱体,乙醇为氧供体,环保型高沸点二元酸酯混合物AgSE为溶剂,四丁基溴化铵为稳定剂,在碳化硅基片上制备出均匀、致密的钛酸铝薄膜。借助差热–热重、X射线衍射、场发射扫描电镜和扫描电镜等研究了钛酸铝干凝胶热处理过程中的相变化、钛酸铝薄膜的晶相组成、显微结构及其抗硝酸钠熔体腐蚀性能。结果表明:在750℃低温制备的钛酸铝薄膜晶粒约为10nM,薄膜具有良好的抗硝酸钠熔体腐蚀性能;热处理温度提高到1350℃后,钛酸铝薄膜的晶粒增大至120nM左右,晶界面积急剧减小,无定形相消失,钛酸铝薄膜的抗硝酸钠熔体侵蚀性能大大提高。The homogeneous dense aluminum titanate film was coated on the silicon carbide substrate via nonhydrolytic sol–gel method (NHSG), using anhydrous aluminum chloride and titanium tetrachloride as the precursors, ethanol as oxygen donor, binary mixed ester AGSE with the characteristic of environmental protection and high boiling point as solvent, and tetrabutyl ammonium bromide as stabilizer.The phase transformation of Al2TiO5 xerogel during heat treatment, the crystal composition and microstructure of Al2TiO5 film and its corrosion resistance to fused sodium nitrite were studied by means of differential thermal analysis–thermogravimetry, X-ray diffraction, field emission scanning electron microscopy and scanning electron microscopy.The results show that Al2TiO5 film annealed at 750 ℃ has the crystal size of about 10 nm and possesses good corrosion resistance to the fused sodium nitrite; the crystal size will grow to 120 nm or so when the heat treatment temperature increases to 1 350 ℃.The performance of Al2TiO5 film heat-treated at 1 350 ℃ will be greatly improved due to both sharp decrease of the grain boundary area and the dis-appearance of amorphous phase.国家自然科学基金(50762005;50962006);中国科学院特种无机涂层重点实验室开放基金资助项

Preparation of Aluminum Titanate Film by Sol-gel Method and Its Fused Salt Corrosion Resistance

以钛酸四丁酯和硝酸铝为原料,乙醇为溶剂,通过溶胶-凝胶法在碳化硅基片上制备钛酸铝薄膜。借助dSC-Tg、Xrd、fE-SEM和SEM研究了钛酸铝干凝胶在热处理过程中的热重效应与相变化、薄膜的晶相组成、显微结构及其抗硝酸钠熔体腐蚀性能。结果表明:制备的钛酸铝薄膜表面均匀、致密,晶粒尺寸在100nM左右,具有良好的抗硝酸钠熔体腐蚀性能。Aluminum titanate ( AT) film coated on the surface of SiC substrate was prepared via Sol-gel method,using tetrabutyl titanate and aluminum nitrate as raw materials,ethanol as solvent.The weight loss and phase transformation of AT xerogel during the heat treatment,the crystal composition and microstructure of the AT film and its corrosion resistance to fused sodium nitrite salt were studied by means of DSC-TG,XRD,FE-SEM and SEM.The results show that the prepared AT film is uniform and dense with the crystal size of about 100 nm,and has good corrosion resistance to fused sodium nitrite.国家自然科学基金(No.50762005;No.50962006);中国科学院特种无机涂层重点实验室开放基

Ecological characteristics of Phragmites australis vegetation at different water table levels and their relation to environmental factors in the Yellow River Delta

对黄河三角洲滨海湿地不同水位条件下芦苇植被生态特征进行动态调查,并分析其与土壤理化性质的相关关系。结果表明:芦苇湿地土壤电导率随水位梯度变化差异显著,长期水淹的芦苇区土壤电导率最低;在不同水位梯度下,芦苇生态特征表现出较强的差异性,相比之下,在水位较高的条件下,芦苇株高、茎粗、盖度和生物量均为最高值,产量达到了10 t·hm~(-2);研究区土壤营养元素含量总体均处于较低水平,且不同水位条件下营养元素在各土层中的分布具有一定的差异;相关性分析表明,土壤粘粒、粗粘粒、细粉粒、粗粉粒与土壤营养元素均呈现不同程度的相关性,土壤有效磷含量与高度、茎粗、盖度、生物量均呈极显著正相关,因此土壤有效磷可能是黄河三角洲滨海湿地芦苇植被生长的限制性营养因子

基于光纤布拉格光栅的智能服装人体测温模型研究11

根据热量传递机理建立了智能服装中光纤布拉格光栅人体测温的热传递物理模型,对人体、空气层和服装之间的热传递进行了有限元建模和稳态热分析,确定了智能服装中光纤布拉格光栅温度场的数学模型,利用该数学模型对光纤布拉格光栅测量温度值进行了修正。在多点加权皮肤平均温度的基础上,提出了由左右胸、左右腋和后背五处皮肤温度构成的智能服装人体温度加权模型。由克拉默法则得出了智能服装人体温度加权系数:左前胸为0.0826,左腋为0.3706,右腋为0.3706,后背为0.0936,右前胸为0.0826。人体穿着智能服装的实验结果表明,基于光纤布拉格光栅的智能服装温度检测动态范围为33~42℃,人体温度测量误差为±0.2℃,可应用于人体温度的高精度监测