低浓乙酸的乙酸／水混合物分离

实验和模拟计算考察了低浓乙酸的乙酸／水混合物精馏特性,如体系物性和操作参数对精馏的影响。在较低乙酸浓度范围内,进一步精制乙酸,采用精馏方法所需理论级数大大增加。模拟计算表明,通过精馏－膜集成过程制备无水乙酸可望成为一种有应用前景的分离技术。     

保存人羊膜用于角膜缘缺陷兔眼表面重建

探讨羊膜移植术在角膜缘缺陷兔眼表面的作用,建立兔全角膜缘缺陷的动物模型,移植眼早期应用保存的人羊膜移植于受损区域,对照眼常规保守治疗,观察其角膜新生管及上皮层愈合情况。愈合后1个月,取角膜,做普通病理及扫描电镜检查。结果显示对照眼角膜上皮层愈合较慢,新生血管粗大丰富,愈合后上皮层不稳定,含有杯状细胞。羊膜移植的眼表面上皮层愈合快,新生血管细小,愈合后的上皮层光滑,稳定, 杯状细胞主要分布于周边角膜。表明羊膜移植能促进上皮细胞移行、增殖、获管稳定的眼表层。羊膜移植后,上皮仍为结膜型上皮。     

有机无机杂聚膜的制备与分析

为了实现较高温度下有机物的分离 ,选择了氯代对苯二甲酸酯和 3-氨丙基三乙氧基硅烷为原料 ,用溶胶凝胶法制备了有机无机杂聚分离膜 ,讨论了酸度、浓度、水解时间、温度、底膜等各种因素对成膜的影响 ,并对膜的机械性能、耐热性以及膜的断面和表面结构进行了表征和分析。结果表明 :该种杂聚膜具有较好的耐热性 ,分解温度在 333℃左右 ;聚四氟乙烯 (PTFE)微孔膜是一种理想的支撑体 ,可以与杂聚材料很好复合 ;但膜的脆性较大。     

中空纤维膜萃取器内流动特性

对中空纤维膜器内流动特性的研究是膜器设计和放大的基础。该文通过测量装填因子不同的 3个聚丙烯中空纤维膜萃取器壳程和管程的停留时间分布曲线 ,研究了不同流速下膜器的流动状况 ,并用轴向扩散模型描述了流动的非理想性。结果表明 ,中空纤维膜萃取器的管程和壳程流动与理想平推流和理想全混流相差较大 ,装填因子与流速对二者均有较大影响。采用轴向扩散模型得到的响应曲线的计算值与实验值符合较好 ,且中空纤维膜萃取器中轴向返混的影响不可忽略。     

Pyrolysis of Iron(III) porphyrin coated Pt/C toward oxygen reduction reaction in acidic medium

Design and synthesis of highly active and durable electrocatalysts toward oxygen reduction reaction (ORR) is of particular importance for proton exchange membrane fuel cells (PEMFCs), yet remains a grand challenge. Herein, we report the deposition of iron (III) porphyrin (FeP) on house-made Pt/C by rotary evaporation of the mixture of FeP and house-made Pt/C dispersed in chloroform, followed by pyrolysis at 650 °C in argon atmosphere. This approach led to the synthesis of new non-precious metal electrocatalyst (NPME)-Pt/C composites (Pt/C–FeP) with an average nanoparticle diameter of 3.1 ± 1.5 nm without aggregation. According to X-ray photoelectron spectroscopy (XPS), the binding energy of Pt 4f_7/2 became larger due to the presence of pyrolyzed FeP. In addition, the electrochemically active surface area (ECSA) of Pt/C–FeP-650 is 65 m²/g less than that of house-made Pt/C (80.2 m²/g). This implies that the pyrolyzed FeP may have partially covered the surface of Pt nanoparticles and thus lowering the ECSA. Interestingly, the mass activity (MA) of Pt/C–FeP turns out to be 349.0 mA/mg_Pt @0.9 V vs. RHE, which is 2.6 times and 1.5 times of house-made Pt/C and commercial Pt/C, respectively. It is speculated that the electronic interaction and possible synergy between Pt and pyrolyzed FeP as NPME might have contributed to the ORR activity improvement despite of partial loss of ECSA. During accelerated durability tests (ADTs), the MA of Pt/C–FeP-650 degrades 64.3% inferior to commercial Pt/C (52.2%). The main reason likely arises from the degradation of pyrolyzed FeP, which is a bottleneck problem confronting NPMEs.     

C度规(m=0,e≠0)的时空结构

采用ｘ－ｙ方块图及虚Ｗｅｙｌ坐标的方法研究了Ｃ度规（ｍ＝０，ｅ≠０）的时空结构，特别研究了Ｃ度规（ｍ＝０，ｅ≠ｍ）的视界内部区域，进一步证明了用这２种方法所描述的时空区域是完全相同的．     

大型挑檐式膜结构制造与施工的质量控制

大型挑檐膜结构施工的质量关键技术：膜结构作为一种新型的结构体系,在大跨度,大悬挑空间结构中应用越来越广泛,例如奥运场馆＂鸟巢＂和＂水立方＂都是膜结构的代表作。本文依据本人多年的工程实践,论述膜结构在施工质量控制的施工技术,总结膜结构施工质量的具体技术经验。为该类型结构在制造与施工的质量控制应用提供了依据。     

尼龙PA6/CuCl_2复合膜表面金属化研究

以聚己内酰胺(尼龙6,PA6)为基体制备PA6/CuCl_2复合膜,在NaBH_4溶液中用化学还原法制得导电薄膜。研究了复合膜组成、还原剂浓度、还原时间、还原温度对导电薄膜表面电阻的影响,得到较优的反应条件:温度为35℃-40℃,PA6与CuCl_2的质量比为5:1,还原剂浓度0.1%,还原时间90 s-100s,测得薄膜的最小电阻为2Ω/cm~2-5Ω/cm~2。