丙烯酸系有机亲水涂料制备研究

亲水涂料主要用于空调热交换器翅片表面,以提高其亲水性、耐蚀性等。本文采用丙烯酸(AA)/丙烯酰胺(AM)水溶液共聚法制备高亲水树脂,同时对交联剂及涂料的pH值对涂膜的影响进行了研究。     

La_(1-x)Ce_xMnO_3微波吸收特性

用溶胶-凝胶法制备了La1-xCexMnO3(x=0.1,0.2,0.3,0.4,0.5)样品,用微波矢量网络分析仪测试了该样品在2～18 GHz微波频率范围的复介电常数、复磁导率,根据测量数据计算了电磁损耗角正切及微波反射率与频率的关系.结果表明,在x=0.4时,样品微波吸收效果最好.当样品厚度为2.20 mm、x=0.4时,吸收峰值为27 dB,10 dB以上频带宽度达3.2 GHz.初步探讨了该材料的电磁损耗机理,发现损耗吸收来自磁损耗和介电损耗的共同作用,吸收峰所在频率介于介电损耗角正切最大值与磁损耗角正切最大值对应的频率之间,即在13.2 GHz附近.对样品的电阻率测试表明,其室温范围内电导在半导体范围内,有利于降低微波在样品表面的反射率.     

Electrochemical behavior of diverse vanadium ions at modified graphite felt electrode in sulphuric solution

PAN-based graphite felt (PGF) treated in 98% sulphuric acid for 5 h and then kept at 450 ℃ for 2 h was evaluated for their electrochemical performance as electrodes of vanadium redox battery (VRB). Structure and characteristic of treated PAN-based graphite felt (TPGF) were determined by means of Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, Brunauer-Emmett-Teller surface area analysis and VRB test system. The results show that the acid and heat synergistic effect increase the number of —COOH functional groups on the PGF surface, and the PGF is eroded by sulphuric acid oxidation, resulting in the surface area increases from 0.31 m2/g to 0.45 m2/g. The V(Ⅱ)/V(Ⅲ) redox reaction is electrochemically reversible on the TPGF electrode, while the V(Ⅳ)/V(Ⅴ) couple is a quasi reversible process. The diffusion coefficients of the oxidation for V(Ⅳ)/V(Ⅴ) obtained from the scope of peak current Ip vs scan rate v1/2 is 4.4×10-5 cm2/s. The improvement of electrochemical activity for the electrode is mainly ascribed to the increase of the number of —COOH groups on the TPGF, which behaves as active sites catalyzing the vanadium species reactions and accelerating electron transfer reaction and oxygen transfer.     

Syntheses and cofluorescence of complexes of Eu（Ⅲ）/Y（Ⅲ） with terephthalic acid, 2-thenoyltrifluoroacetone and trioctylphosphine oxide

A series of Eu（ Ⅲ）/Y（Ⅲ） complexes of terephthalic acid（TPA） with 2-thenoyltrifluoroacetone（HTTA） and trioctylphosphine oxide（TPPO） were synthesized. Compositions of these complexes are revealed to be Eu2（1-x）Y2x（TPA）（TTA）4- （TPPO）4 or EU1-xYx（TPA）（TTA）（TPPO）2. Their 1R spectra, fluorescent spectra and the thermal and optical stability were studied. The fluorescent excitation spectra of these complexes show more broad excitation bands than those of Eu2（TPA）3（TPPO）4 and Eu（TTA）3（TPPO）2 corresponding to their formations. In addition, both the binuclear complex EuY（TPA）（TTA）4（TPPO）4 and the chain complex EU0.4Y0.6（TPA）（TTA）（TPPO）2 present higher thermal stability and better optical stability than the mononuclear complex Eu（TTA）3（TPPO）2 does. And their thermal and optical stabilities are preferably interpreted from the binuclear structure together with the chain polynuclear structure of the complexes. The fluorescence enhancement of cofluorescence Y^3＋ ions to the Eu（Ⅲ） complexes is clear. The optimum content of Y^3＋ is 0.6 （molar fraction） for the chain complexes Eu1-xYx（TPA）（TTA）- （TPPO）2 and 0.5 for the binuclear complexes Eu^2（1-x）Y2x（TPA）（TTA）4（TPPO）4. The formation of polynuclear structure of the complex Eu1-xYx（TPA）（TTA）（TPPO）2 appears to be responsible for the good cofluorescence effect of Y^3＋ ions.     

椎弓根钉固定结合骨屑填充伤椎治疗胸腰椎骨折

目的探讨椎弓根钉复位固定结合骨屑填充伤椎成形治疗胸腰椎骨折的方法和疗效。方法 2008年1月至2009年12月对34例胸腰椎骨折采用椎弓根钉复位固定后自体骨屑填充伤椎的方法治疗,术后随访并评估此方法的临床疗效。结果随访6～20个月,34例患者均未出现明显椎体高度再度丢失,无一例发生内固定断裂、松动。结论椎弓根钉复位固定后采用自体骨屑填充植骨,可减少椎体高度再丢失及内固定断裂、松动等并发症。     

MSnO3(M=Ca,Sr,Ba)的溶胶-凝胶法合成及性能

采用溶胶-凝胶法制备了钙钛矿结构的MSnO3(M=Ca,Sr,Ba)晶体.将其作为锂离子电池负极材料的活性物质,利用恒电流电池测试仪研究其电化学性能.结果表明CaSnO3、SrSnO3和BaSnO3的首次放电容量分别为894.3 mAh/g、703.8 mAh/g和673.6 mAh/g,首次充电容量分别为418.3 mAh/g、257.8 mAh/g和224.8 mAh/g,不可逆容量损失分别达53.2%、63.3%和66.6%.     

手性配体交换乳状液膜选择性萃取扁桃酸对映体

基于手性配体交换反应,研究了在含有N-n-十二烷基-L-羟基脯氨酸和铜离子的配合物为手性配体的乳状液膜体系中选择性萃取扁桃酸对映体.考察了扁桃酸外消旋体浓度,手性萃取方向,有机溶剂和表面活性剂配比,从外水相到内水相pH值的梯度变化以及外水相的pH值变化对选择性萃取性能的影响,从而确定了合适的选择性萃取条件.     

空调机铝散热片表面无机亲水膜的研究

针对空调机铝散热片应用性能的要求，探讨了铝箔表面无机薄膜的设计和最佳工艺配方，测定了涂膜的亲水性，耐蚀性，抗溶性，耐热性，耐碱性认及抗弯曲性等性能，进行了扫描电镜表征，并据此对涂膜固化机理作了初步探讨，经该涂膜处理过的铝片其亲水性接触角由８０°改善至５°以下，其余所有性能指标都有大幅度提高，表明该项研究具有实用价值。     

中空纤维膜孔径及其分布的测定

研究了中空纤维膜孔径及其分布的测定方法．液液置换法。通过研究建立了能够准确描述跨膜压差与流体通量的数学模型，采用不同的液液体系（正丁醇．纯净水、正戊醇．纯净水和正己醇一纯净水）测定了膜孔径为0.2μm的中空内压疏水膜的孔径及其分布，并对测试结果进行比较分析。实验研究结果与电镜扫描结果符合较好，研究表明液液置换法装置简单、易操作、是一种理想的膜孔径分布表征方法。     

环氧改性有机硅密封胶的研制

用Ｅ－４４环氧树脂与端羟基硅氧烷共混反应制备改性有机硅树脂，研究了共混比，共混反应时间等对改性树脂胶的影响。以改性树脂为基料制备了单组分室温固化有机硅密封胶，提出了制备配方和条件。