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111.
十二烷基硫酸钠对甲烷水合物生成过程影响研究 总被引:1,自引:0,他引:1
根据甲烷水合物含气率高、分解速度慢等特性,提出利用高压注水技术和表面活性剂促进作用促使矿井瓦斯水合化以预防煤与瓦斯突出的思路。进行了3·6~12℃、7·82~12·26MPa条件下两种浓度体系(10mmol/L和0·3mmol/L)中十二烷基硫酸钠(SDS)对甲烷水合物作用效果的实验研究,结合水合物诱导时间、生成速度及含气率等计算对实验数据进行了分析,并运用表面张力法测得8℃时SDS溶液的临界胶束浓度(CMC)为2·5mmol/L。结果表明,高浓度体系对水合物生成速度、含气率的影响较之低浓度体系的更强,但是低浓度体系中水合物生成的诱导时间却较短,表面活性剂溶液浓度超过其CMC后对水合物的生成影响显著。 相似文献
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Chen Xia DU Zhi Qiang WANG Qi XIN Yang Jie WU Wen Lian LI Department of Chemistry Zhengzhou University Zhengzhou Changchun institute of optics Fine Mechanics Physics Chinese Academy of Sciences Changchun 《中国化学快报》2005,(5)
In recent years, the interest in developing luminescent lanthanide complexes has been greatly stimulated by their potential use in electroluminescent displays1. Europium complexes appear most attractive in view of the high photoluminescent efficiency and the high monochromatic red light that are widely exploited in full-color displays2. It has been approved that the second ligand plays an important role in europium complexes, the synergistic complexation of the second ligand can not only lead … 相似文献
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Zhang Q Carpenter CJ Kemper PR Bowers MT 《Journal of the American Chemical Society》2003,125(11):3341-3352
The sequential association energies for one through six water molecules clustering to Na(2)I(+), as well as one and two water molecules clustering to Na(3)I(2)(+), are measured. The association energies show a pairwise behavior, indicating a symmetric association of water molecules to the linear Na(2)I(+) and Na(3)I(2)(+) ions. This pairwise behavior is well reproduced by Density Functional Theory (DFT) calculations. DFT calculations also suggest that a significant separation of charge for the Na-I ion pair occurs when four or more water molecules cluster to a single sodium center. Two different solvent-separated ion pairs have been identified with the DFT calculations. Experiments also show that the dissolution processes, loss of a neutral NaI unit, occurs when six or more water molecules have been added to Na(2)I(+) cluster. However, one or two water molecules are able to detach an NaI unit from the Na(3)I(2)(+) cluster. The difference in solubility of the Na(2)I(+) and Na(3)I(2)(+) ions is due to the difference in the energies required to lose an NaI unit from these two species. The experiment also confirms that the loss of a neutral NaI unit, instead of an Na(+) ion, occurs during the dissolution processes of Na(3)I(2)(+). The microsolvation schemes proposed to explain our experimental observations are supported by DFT and phase space theory (PST) calculations. 相似文献
117.
Cerium-doped terbium aluminum garnet phosphors, Tb3Al5O12:Ce3+ (TAG:Ce3+), were prepared with different methods: co-precipitation (CP), half dry-half wet (HDHW), sol-combustion (SC) and Pechini method plus conventional solid state reaction (SS) method. Comparative study on the phase-formation, particle size, morphologies and luminescent characteristics of the phosphors synthesized with different methods was carried out by means of XRD, FE-SEM and photoluminescence (PL) analysis and SC method was confirmed by the comparison of the results to be an easy and an effective process for preparing efficient and nano-sized Tb3Al5O12:Ce3+ phosphors. Various factors influencing particle size, morphology and PL of the phosphors, such as precursor preparation, reaction temperature and heating time, were also investigated. Light-emitting diodes (LEDs) were fabricated with each phosphor and a ∼460 nm emitting InGaN chip. The LEDs from SS, HDHW and CP exhibit strong white emission while those from SC and Pechini emit yellow, revealing that the emission characteristics of LEDs are influenced not only by the morphology and the particle size of the phosphors, but also by the preparing process of the phosphors. 相似文献
118.
铂锡双金属催化剂上丙烷脱氢反应研究 总被引:2,自引:0,他引:2
对比研究了Sn/Pt比为1;1,2,:1和5:1的原子簇担载于γ-Al2O3上制成的Pt=Sn原子簇催化剂,和用SnCl2和H2PtCl6浸渍制备的相应Sn/Pt比的催化剂对丙烷脱氢生成丙烯的催化性能。 相似文献
119.
By means of our proposed method for Hückel theory calculation, we have calculated the electronic structures of dihedral (D5h, D5d, D6h, D6d) fullerences, which are generated from icosahedral C20, C60, C80, C180, C240 and C540, respectively. From the calculated results of 1224 fullerence molecules, certain rules on the stability and chemical reactivity have been drawn for such types of dihedral fullerenes. 相似文献
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