电子俘获材料CaS:Eu,Sm可见光激发优势机理的研究

实验测定了电子俘获材料CaS:Eu,Sm的荧光激发谱，辐射谱以及红外上转换光激发光谱，发现可见光对红外上转换辐射光的激发灵敏度高达50%，而紫外光只有18%，具有可见光激发的优势，根据电子俘获材料的能级模型，电子俘获发光机理以及稀土离子在立方晶场中的能级结构，并结合光谱测试所提供的信息，分析了电子俘获材料CaS:Eu,Sm在光激发过程中的能量传递途径，阐明了电子俘获材料CaS:Eu,Sm可见光激发优势的机理。     

在线周期反冲洗超滤膜污染过程研究

采用切割分子量105Da的中空纤维超滤膜,对污水厂二沉池出水进行了不同频度周期反冲洗超滤试验,试验结果与膜污染过程的理论分析相一致.过滤膜阻与反冲洗次数或过滤时间的关系曲线可分为两段:起初的增长段为不可逆滤饼层的累积阶段,直线的斜率为各次反冲洗不可逆膜阻增量;后期的水平段为滤饼层累积与剥离达到相对平衡的阶段.增加在线反冲洗频度降低了不可逆膜阻增量,有效提高了净产水速率.扫描电镜分析结果表明,水力反冲洗去除了部分膜表面污染物,将滤饼层变得松散,一定程度上减轻了膜污染,经化学清洗后,膜表面的滤饼层基本被去除.     

悬浮载体复合膜生物反应器过滤特性及滤饼层微结构特征

为研究悬浮载体复合式膜生物反应器(SCMBR)的膜过滤特性和膜表面滤饼层的微观结构特征,对SCMBR和传统膜生物反应器(CMBR)膜污染表面进行了对比分析.阻力构成分析表明,SCMBR滤饼层阻力所占总阻力比率在相同运行时间(15%,10 kPa,34 h)和跨膜压力(45%,30 kPa,89 h)下均小于CMBR(63.33%,34 h,30 kPa).污染膜表面扫描电镜分析表明,SCMBR反应器内膜表面滤饼层结构较疏松,孔隙较大.通过ISA3D软件对共聚焦显微镜图像进行分析,确定了滤饼层微观结构参数,结合Carman-Kozeny方程研究了SCMBR滤饼层阻力减小的机理.     

固体推进剂破坏过程的扫描电镜研究

利用扫描电子显微镜对几种固推进剂试件的拉伸行为及断口形貌进行了观察.并对拉伸过程中出现的几种断裂模式进行了分析.结果表明,解决高固体含量固体推进剂的脱湿问题,特别是较大固体颗粒的脱湿,是改善固体推进剂力学性能的一个重要方向。     

Investigation of electron transfer across the ice/liquid interface by scanning electrochemical microscopy

The study of interfacial electron transfer (ET) reaction between feericinium (Fc^ ) produced in situ in 1,2-dichloroethane (DCE) and ferrocyanide in ice matrix under low temperatures by the scanning electrochemical microscopy (SECM) is reported .Tetrabutylammonium (TBA^ ) is used as the common ion (potential -determining ion )in both phases to control the interfacial potential difference,The potential drop across the liquid/liquid interface can be quantitatively adjusted by changing the ratio of concentrations of TBA^ between beh two phases ,The apparent hetero-gencous rate constants for Fc^ reduction by Fe(CN)6^4- at the interface under different temperatures have been obtained by a best-fit analysis,where the experimental approach curves are fitted to the theoretical simulated curves.A sharp change has been observe for heterogeneous rate constants around the freezing point of the aqueous phase,which reflects the phase transition process.     

透射电镜在气溶胶单颗粒分析中的应用

透射电镜（TEM）具有很高的分辨率和放大率,可以同时提供形貌、成分、结构信息,非常适宜于对气溶胶细颗粒和超细颗粒等的研究。简述了国内外用TEM对大气气溶胶单颗粒分析的研究及其现状,主要围绕TEM对城市大气气溶胶、海洋气溶胶、燃烧烟尘和机动车废气的研究等方面进行了论述。介绍了作者利用TEM对北京市大气气溶胶的初步研究,提出了今后开展大气可吸入颗粒物的TEM研究的几点建议。     

分子自组装技术及表征方法

自组装单分子膜的研究是近年来倍受关注的研究领域。随着膜的应用领域的拓展,对膜的组装技术和表征方法不断提出新的要求。综述了现阶段分子自组装膜的主要制备方法和基底表面的处理方法;着重从电化学、谱学、显微学等方面综述了近几年来自组装单分子膜的表征方法研究进展,并对其发展前景作了展望。     

金斑喙凤蝶雄虫触角感觉器的扫描电镜观察

对金斑喙凤蝶雄虫触角进行扫描电镜观察发现：其触角有３种感觉器，即星形感器，毛形感器和鳞形感器。星形感器数量最多，几乎密布整个触角，鳞形感器数量以触角基部分布较多，同时也分布于鞭节各节；毛形感器（Ａ，Ｂ型）数量最少，稀疏分布于鞭节各节。     

In-situ study on γ phase transformation behaviour of γ-TiAl alloys at different cooling rates

γ-TiAl-based alloys are promising lightweight high-temperature structural materials, and the transformation from the α parent phase to γ lamellae during the cooling process has a great influence on the microstructures and mechanical properties of TiAl alloys. In this paper, an in-situ observation technique, high-temperature laser scanning confocal microscopy (HTLSCM), was utilized to investigate the continuous cooling transition (CCT) from the α phase in three compositions. The nucleation and growth behaviors of γ lamellae were studied at several moderate cooling rates. In addition, the processes of helium gas quenching for three alloys were investigated, and the massive transformation was observed in Ti–49Al. CCT diagraphs were concluded for three alloys. The Vickers hardness of TiAl alloys subjected to different cooling rates was tested, and it was found that the hardness of alloys was enhanced with increasing cooling rate due to the refinement of lamellar spacing.