反相微乳液聚合法制备有机-无机复合膜及对丙烯/丙烷的分离性能

采用反相微乳液聚合法,以甲基丙烯酸甲酯(MMA)和甲基丙烯酸羟乙酯(HEMA)为原料,聚氧乙烯-聚氧丙烯-聚氧乙烯F-127或Tween-80为乳化剂、偶氮二异丁腈(AIBN)为引发剂,银盐AgBF4为烯烃载体的条件下进行共聚合反应,制备了有机-无机复合膜,并用于丙烯/丙烷分离的研究。扫描电镜(SEM)显示AgBF4呈小球状均匀分布在复合膜内,粒径约为60nm;X射线衍射(XRD)测试显示,AgBF4的加入使膜的结晶性能明显下降;气体分离性能测试结果显示,复合膜对丙烯和丙烷的分离因子为5.103,具有明显的促进传递作用。     

基于偏振调制技术的晶体各向异性参数实时检测系统

介绍了基于偏振光电光调制技术对人工晶体各向异性参数的检测，设计了半嵌入式的微机实时检测系统，可完成对晶体光学双折射与二向色性特征参数计算分析，并可检测晶体缺陷。     

Metal–Organic Gel‐Derived FexOy/Nitrogen‐Doped Carbon Films for Enhanced Lithium Storage

The development of cost‐effective and flexible electrodes is demanding in the field of energy storage. Herein, flexible Fe_xO_y/nitrogen‐doped carbon films (Fe_xO_y/NC‐MOG) are prepared by facile electrospinning of Fe‐based metal–organic gels (MOGs) followed by high‐temperature carbonization. This approach allows the even mixing of fragile coordination polymers with polyacrylonitrile into flexible films while reserving the structural characteristics of coordination polymers. After thermal treatment, Fe_xO_y/NC‐MOG films possess uniformly distributed Fe_xO_y nanoparticles and larger accessible surface areas than traditional Fe_xO_y‐NC films without MOG. Taking advantage of the unique structure, Fe_xO_y/NC‐MOG exhibits a superior rate performance (449.8 mA h g^?1 at 5000 mA g^–1) and long cycle life (629.3 mA h g^–1 after 500 cycles at 1000 mA g^–1) when used as additive‐free anodes in lithium‐ion batteries.     

不同对虾种间共用微卫星DNA引物的研究

采用已发表的斑节对虾的30对微卫星引物,对部分微卫星引物在中国对虾、凡纳对虾、日本对虾中的通用性进行了研究。通过所建立的降温PCR(Touchdown PCR)方法对3种对虾的DNA进行PCR扩增,筛选出3对引物在3种对虾中均能产生清晰谱带。根据上述结果适当调整PCR反应体系中各试剂的量及反应条件,达到了理想的结果。利用这3对引物对3种对虾进行遗传标记分析,结果显示,PCR扩增产物条带清晰,特异性强,每对引物在3种对虾间扩增出的特异性片段大小几乎一致。研究表明,3种对虾基因组间存在一定程度的相似性,引物W15-16、W21-22和W45-46可直接应用于中国对虾、凡纳对虾、日本对虾、斑节对虾分子标记的基因组比较作图,也为图谱克隆法提供了新的思路。     

闭式冷却塔中空气与喷淋水同向和逆向流动的流阻试验研究

一些高效逆流闭式冷却塔盘管管外的空气流动和喷淋水的流动方向相同(顺流),其空气流动阻力的规律性尚待进一步探索,本文对此进行了试验研究。设计构建了相关的试验装置、试验件,进行了一系列的试验。为便于对比,分别针对盘管管外的空气流动和喷淋水的流动方向同向以及逆向(逆流)进行了试验。通过改变喷淋水的喷淋量和空气的流速,得到了相关的空气流动阻力的规律性。试验表明,顺流型式比逆流型式的空气流动阻力大为降低,逆流型式存在空气流动阻力的突增点,顺流型式不存在阻力的突增点。     

Influence of annealing temperature on the structural and optical properties of highly-oriented Al and Er co-doped ZnO films

High-quality c-axis oriented 7 mol% Al and 1.5 mol% Er co-doped ZnO films (ZEAO) were prepared on the quartz glass substrates by using sol–gel method. The influence of the annealing temperature on the crystal orientation, microstructure and optical properties of the ZEAO thin films were studied by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and UV–vis transmittance spectrophotometer, respectively. XRD results revealed that all the samples were polycrystalline with hexagonal structure and exhibited (002) preferential orientation. With increasing the annealing temperature, the grain size and orientation extent increased. The optical studies showed each ZEAO film had a relatively high transmittance above 85 %. The transmittance as high as 95 % was obtained at the annealing temperature of 800 °C, and the corresponding average grain size was about 50 nm. The cathodoluminescence (CL) spectra of these films were also used to characterize the luminescence properties. Strong UV emission centered at 380 nm was observed in the CL spectra taken for the pure ZnO. For the ZEAO sample, the blue-green emission is related to the 4f shell transition in the Er³⁺ ions of ZnO matrices, corresponding to a transition from the excited states (⁴F_5/2).     

基于镓基液态金属玻璃倾斜开关的制备及研究

本文通过气氛保护熔炼法制备GaInSnZn液态金属,利用该合金作为导电液滴成功制备倾斜开关.通过扫描电镜(SEM)和能谱分析仪(EDS)对其微观形貌和成分进行了测试和分析,利用差式扫描量热仪(DSC)对其进行了熔点和凝固点测试,通过接触角测定仪研究了该液态合金在不同环境、不同基底表面的润湿性.结果 表明:合金的质量比为...     

一种新的基于细化的汉字笔画抽取方法及其在汉字识别中的应用

文章提出了一种新的基于细化的汉字笔画抽取方法,并把笔画统计特征用于汉字的识别。实验结果表明,该方法可有效地抽取出汉字的笔画并可成功地用于汉字的识别。     

An optimal model for estimating suspended sediment concentration from Landsat TM images in the Caofeidian coastal waters

Suspended sediment concentration (SSC) is one of the most critical parameters in water quality and environmental evaluations. Remote sensing has the potential for monitoring the dynamics and spatial distribution of SSC efficiently. The primary objective of this study is to develop retrieval models that are reliable and sensitive to SSC levels in the Caofeidian area, a new seaport in northeast China, based on Landsat-5 Thematic Mapper (TM) images and a set of in situ data sets, including spectral reflectance data and water quality data. The study finds that the band reflectance ratio and binary combination factor (i.e. the ratio of the reflectance to the particle size) are more effective than single band reflectance, and a non-linear model is more potent than a linear model for predicting SSC in the Caofeidian waters. A quadratic polynomial regression model of the R_TM3/R_TM2 ratio is proposed as the optimal retrieval model after evaluating various models with respect to different sensitive factors. The accuracy of the model is acceptable with a relative error and a root mean square error of 25.35% and 7.22 mg l^–1, respectively; the correlation coefficient between the observed and estimated SSCs is 0.986. This study also indicates that the band reflectance ratio and binary combination factor are effective in weakening and even partially eliminating the effects of the changes in the sediment type (i.e. particle size and refractive index). And the band reflectance ratio is more efficient. Using the proposed model and TM data, SSC levels for the entire region were estimated. Such results can serve as a baseline for future environmental monitoring efforts.     

基于硬件查表的FROA业务设计与实现

帧中继技术是一种成熟的快速分组交换技术,而ATM技术则是宽带网络的重要技术。文章讨论了实现二者互通的技术和方法,并提出了一种基于硬件查表的FROA(FRoverATM)业务实现方案。