共查询到20条相似文献,搜索用时 109 毫秒
1.
2.
3.
4.
5.
6.
钼酸盐作为一种新型的功能材料应用于社会的各个领域,探究钼酸盐材料的制备合成方法、研究钼酸盐材料的性质成为材料领域的一个热点。本文介绍了常见的几种合成钼酸盐的方法,例如,高温固相法、化学沉淀法、液相合成法、微乳液法、水热/溶剂热法、模板法等以及钼酸盐在催化方面的应用。 相似文献
7.
8.
稀土氯氧化物作为一种重要的发光基质,具有较高的光吸收效率和传能效率,在彩色显示、催化、生物医药、光电转换、气敏等领域均有广泛的应用,已成为光功能材料领域的研究热点之一。目前研究者已用固相法、沉淀法、液相-高温焙烧法、水热与溶剂热法、前驱体热解法、溶胶-凝胶法、静电纺丝法等方法成功地制备了稀土氯氧化物微米颗粒,纳米颗粒、纳米条、纳米片、纳米棒、纳米针、纳米纤维、纳米带、纳米管等稀土氯氧化物微纳米材料。总结了各种制备方法的研究进展及优缺点,并结合本课题组在稀土氯氧化物纳米材料方面的研究工作,对稀土氯氧化物微纳米材料的制备方法的发展方向进行了展望。 相似文献
9.
Fe_xO_y/C复合材料作为催化剂,在有机化合物的催化氧化方面表现出非常高的活性,如对苯甲醇催化氧化苯甲醛,苯乙烯催化氧化苯甲醛,苯甲醛催化氧化苯甲酸,苯催化氧化苯酚,是最高效的催化剂之一。近年来的研究报道中,Fe_xO_y/C复合材料的制备方法主要有水热合成法,浸渍法和超声喷雾热解法。比较了三种方法各有利弊,以期寻找一种更加高效,方便,省时的制备Fe_xO_y/C复合材料的方法。其中溶液燃烧法尤为重要,溶液燃烧法给Fe_xO_y/C复合材料的制备带来了新的机遇。 相似文献
10.
异丙醇铝水解制备超微细高纯氧化铝 总被引:7,自引:0,他引:7
高纯超细氧化铝是重要的功能材料,其制备方法有拜耳法、硫酸铝铵热解法、碱式碳酸铝铵热解法和近期开发的有机铝水解热解法。本文报道用醇铝水解法获得水合氧化铝,通过高温焙烧制备超微细高纯氧化铝。本法工艺简单,水解反应后在同一容器中通过蒸馏回收醇,水解产物可以不经过滤、烘干和粉碎处理直接进高温炉焙烧,原料消耗小,无污染,制得氧化铝的粒度比其他方法细而均匀、纯度高。 相似文献
11.
Jin Motoyanagi Kiriko Higashi Masahiko Minoda 《Journal of polymer science. Part A, Polymer chemistry》2014,52(19):2800-2805
We have newly designed an original bifunctional monomer (PAVE) containing both a phenylacetylene (PA) group and a vinyl ether (VE) group, which is expected to be a key material for the synthesis of brush‐shaped polymers consisting of a poly(phenylacetylene) (polyPA) main chain and polyVE side chains. Actually, we have demonstrated the selective chemical transformation of the VE moiety of PAVE to an initiator site for the living cationic polymerization of isobutyl vinyl ether (IBVE), and then succeeded in the controlled synthesis of a novel PA‐end‐capped polyIBVE macromonomer. Moreover, using this macromonomer, the first synthesis of a brush‐shaped polyPA bearing polyVE side chains was achieved via Rh complex‐mediated homopolymerization. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2800–2805 相似文献
12.
13.
High-performance thin-layer chromatography (HPTLC) is a widely used, fast and relatively inexpensive method of separating complex mixtures. It is particularly useful for smaller, apolar compounds and offers some advantages over HPLC. This review gives an overview about the special features as well as the problems that have to be considered upon the HPTLC analysis of lipids. The term "lipids" is used here in a broad sense and comprises fatty acids and their derivatives as well as substances related biosynthetically or functionally to these compounds. After a short introduction regarding the stationary phases and the methods how lipids can be visualized on an HPTLC plate, the individual lipid classes will be discussed and the most suitable solvent systems for their separation indicated. The focus will be on lipids that are most abundant in biological systems, i.e. cholesterol and its derivates, glycerides, sphingo- and glycolipids as well as phospholipids. Finally, a nowadays very important topic, the combination between HPTLC and mass spectrometric (MS) detection methods will be discussed. It will be shown that this is a very powerful method to investigate the identities of the HPTLC spots in more detail than by the use of common staining methods. Future aspects of HPTLC in the lipid field will be also discussed. 相似文献
14.
理想模型化法、标准状态法、可逆过程极值法和微元法是物理化学中具有典型学科特征的基本理论研究方法,在物理化学理论体系的形成和发展过程中相应形成并贯穿整个学科。本文从科学方法论的角度,归纳总结了四种理论研究方法的研究目的、处理方法及相应规定和结论,并对它们在物理化学理论体系中的具体应用通过实例予以分析和说明。同时阐述了如果掌握并深刻领会了这些科学研究方法,将有助于学习者构建物理化学宏观知识体系,培养逻辑思维能力,增强分析问题和解决问题能力。 相似文献
15.
Jian-Hua Huang Hua-Lin Xie Jun Yan Hong-Mei Lu Qing-Song Xu Yi-Zeng Liang 《Analytica chimica acta》2013
T-lymphocyte (T-cell) is a very important component in human immune system. T-cell epitopes can be used for the accurately monitoring the immune responses which activation by major histocompatibility complex (MHC), and rationally designing vaccines. Therefore, accurate prediction of T-cell epitopes is crucial for vaccine development and clinical immunology. In current study, two types peptide features, i.e., amino acid properties and chemical molecular features were used for the T-cell epitopes peptide representation. Based on these features, random forest (RF) algorithm, a powerful machine learning algorithm, was used to classify T-cell epitopes and non-T-cell epitopes. The classification accuracy, sensitivity, specificity, Matthews correlation coefficient (MCC), and area under the curve (AUC) values for proposed method are 97.54%, 97.22%, 97.60%, 0.9193, and 0.9868, respectively. These results indicate that current method based on the combined features and RF is effective for T-cell epitopes prediction. 相似文献
16.
Summary A simple, sensitive, accurate and rapid gas chromatographic method for the quantitative determination of phosphorus in copper-phosphorus
alloys is described. The method is based on the chlorination of the sample with carbon tetrachloride in a sealed glass capsule
at 550°C. The volatile products are introduced into the gas chromatograph after crushing the capsule in a special device.
The method is very quick (ca. 20 min), involves simple manipulations and the error is about ±0.5%. 相似文献
17.
A convenient and efficient method was developed for the synthesis of naphtho[2,1-b]furans via 4-dimethylaminopyridine(DMAP)-catalyzed cascade reaction of 2-hydroxy-1-naphthaldehydes and α-halogenated ketones in moderate to good yields in the presence of Na2CO3 at 80℃ for 6 h. The mechanism for this process was briefly discussed with a tentative catalytic cycle proposed. Moreover, this method features organocatalysts and high step-economy, which makes it practical and attractive. 相似文献
18.
19.
Rudolf J. Bruessau 《Macromolecular Symposia》1992,61(1):190-218
Size exclusion chromatography (=SEC) is a widly used method for determining the molecular weight distribution of polymer samples. But using aqueous elution solvents, this method is even today combined with numerous problems, mostly caused by the polyelectrolyte structure of water soluble polymers. Therefore we will firstly give a survey of this special features and discuss preventive measures. From this view then some working rules will be derived with special regard to the devices, columns and calibration standards available today. Finally we will give some remarks about the specific experimental conditions for ultrahigh molecular weight samples. 相似文献
20.
MO calculations by CNDO/2 method on some conjugated ketenes were carried out. Several special features obtained and the evaluation of a role of the in plane π*-orbital for the intramolecular ene-ketene cycloaddition are described. 相似文献