Influence of organophilic clay and preparation methods on EVA/montmorillonite nanocomposites

Ethylene‐vinyl acetate copolymer (EVA)/montmorillonite MMT nanocomposites have been prepared by using different methods: one is from the organophilic montmorillonite (OMT) and the other is from the pristine MMT and reactive compatibilizer hexadecyl trimethyl ammonium bromide (C16). In this study, different kneaders were used (twin‐screw extruder and twin‐roll mill) to prepare nanocomposites. The nanocomposite structures are evidenced by the X‐ray diffraction (XRD) and high‐resolution electronic microscope (HREM). The thermal properties of the nanocomposites were investigated by thermogravimetric analysis (TGA). Moreover, the tensile tests were carried out with a Universal testing machine DCS‐5000. It is shown that different methods and organophilic montmorillonite have influence on EVA/MMT nanocomposites.© 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2416–2421, 2004     

高速逆流色谱法分离β-谷甾醇和菜油甾醇的研究

利用高速逆流色谱法 ,并选用V(庚烷 )∶V(乙腈 )∶V(乙酸乙酯 ) =5∶5∶1溶剂体系 ,成功地分离了混合植物甾醇标准品中的 β 谷甾醇和菜油甾醇。经过HPLC检测 ,一次性分离可得到质量分数为 97%的 β 谷甾醇和质量分数为 91%的菜油甾醇产品 ,收率分别可达 5 6 %和 5 0 %。该方法简便、重现性好 ,可作为高纯度 β 谷甾醇和菜油甾醇标准品的制备分离方法     

墙地砖边缘检测中的小波去噪

在墙地砖的边缘检测过程中,噪声的引入是不可避免的,有效地消除噪声而不影响检测结果是检测过程中需要解决的关键问题。本文采用了小波去噪方法—对图像进行去噪后再进行边缘检测的方法,其检测结果较好地满足了检测要求。     

新型催化蒸馏塔在合成甲基叔丁基醚中的应用

分析了已有的合成MTBE催化蒸馏塔结构,同时构思了新型填料式催化蒸馏塔.在模拟催化蒸馏试验装置上,利用YLQ-1型"异形”树脂催化剂进行了合成MTBE研究,获得了反应温度、液空速、回流比等有关工艺条件数据.     

染料释放化合物及一当量成色剂浅谈

简述了染料释放化合物的发展过程 ,并由此引出一当量成色剂的概念 ,叙述了一当量成色剂应用和发展 ,对一当量成色剂应用前景做了预测。     

1-(5-乙基-1,3,4-噻二唑基)-3-苯基硫脲的合成及生物活性

研究了 1 - ( 5 -乙基 - 1 ,3,4-噻二唑基 ) - 3-苯基硫脲的合成及抗菌活性。以 5 -乙基 - 2 -氨基 - 1 ,3,4-噻二唑和异硫氰酸苯酯为原料 ,在十六烷基三甲基溴化铵催化下 ,合成 1 - ( 5 -乙基 - 1 ,3,4-噻二唑基 ) - 3-苯基硫脲 ,找到了较好的合成工艺条件 ,结果表明 :5 -乙基 - 2 -氨基 - 1 ,3,4-噻二唑和异硫氰酸苯酯的摩尔比为 1∶ 1 .8,乙腈为溶剂 ,水浴加热回流 4.0 h,十六烷基三甲基溴化铵为 2 g,1 - ( 5 -乙基 - 1 ,3,4-噻二唑基 ) - 3-苯基硫脲的产率为 5 9.76%。同时发现 1 - ( 5 -乙基 - 1 ,3,4-噻二唑基 ) - 3-苯基硫脲有较强的抗菌活性     

Learning to Rank with Extreme Learning Machine

Relevance ranking has been a popular and interesting topic over the years, which has a large variety of applications. A number of machine learning techniques were successfully applied as the learning algorithms for relevance ranking, including neural network, regularized least square, support vector machine and so on. From machine learning point of view, extreme learning machine actually provides a unified framework where the aforementioned algorithms can be considered as special cases. In this paper, pointwise ELM and pairwise ELM are proposed to learn relevance ranking problems for the first time. In particular, ELM type of linear random node is newly proposed together with kernel version of ELM to be linear as well. The famous publicly available dataset collection LETOR is tested to compare ELM-based ranking algorithms with state-of-art linear ranking algorithms.     

Identification of organochlorines and organobromines in coals

Four Chinese bituminous coals were extracted with CS₂, n-hexane, benzene, methanol, acetone, tetrahydrofuran (THF) and THF/methanol (1: 3 vol/vol) mixed solvent sequentially. The resulting 28 extracts were analyzed with GC/MS. Six organochlorines (OCs) and two organobromines (OBs) were identified in eight extracts from the coals. Our experiments provide, for the first time, the information on the molecular structure of OCs and OBs in coals.     

永乐宫壁画艺术对我国当代工笔人物画的影响

永乐宫壁画是中国古代壁画的奇葩,它代表了传统工笔重彩绘画在元代取得的最高成就。从宏伟的构图、绚丽的色彩和高超的线描技巧等方面分析了永乐宫壁画对当代工笔人物画的影响。当代工笔人物画要继承和发扬永乐宫壁画的优良传统．拓宽和创造出更多的表现手法．复兴和推动中国重彩人物画的发展。