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121.
掺铁纳米TiO_2的制备及其光催化性能 总被引:2,自引:0,他引:2
以TiC l4为原料,采用微波加热与常规加热2步合成法制备掺铁纳米TiO2。用X射线粉末衍射(XRD)、透射电镜(TEM)、紫外可见吸收光谱(UV-V is)、光电子能谱(XPS)等测试技术对其进行了表征。结果表明,所制得的掺铁纳米TiO2是以锐钛矿为主相的混晶,平均粒径约为10 nm,适量Fe3+的掺杂能促进金红石相变,抑制锐钛矿晶粒的生长,使Ti2p电子结合能升高0.3 eV,并使TiO2吸光能力增强,带边吸收向可见光区移动。在UVA段(320~400 nm)光照下,通过对维生素VB12的光催化降解,发现掺入摩尔分数为0.5%的Fe3+的纳米TiO2能明显提高其光催化活性,使维生素B12的降解速率提高2.3倍。 相似文献
122.
Multiblock poly(ester-block-amide)s (PEA) elastomers comprising hard blocks of oligoamide and oligoester soft segments were prepared and their structure-property relations were analysed. The polycondensation reaction of oligoesters (prepared from 1,4-butanediol and dimerized fatty acid) with oligolaurolactam (PA12) gave copolymer series with variable blocks content (the soft segments content was varied from 24 to 60 wt.%). PEAs are the phase system composed of crystallised sequences of oligoamide (hard segment phase) as well as oligoesters (soft segment phase). Mixing between the hard and soft phases was studied by thermal and mechanical measurements (DSC, DMTA). These results have indicated on a multiphase structure of investigated materials. The relationship between the observed thermal and tensile properties and the soft/hard segments content indicated on an increase of the phase separation with soft segments content. 相似文献
123.
Milaeva E. R. Shpakovsky D. B. Shaposhnikova E. N. Grigor"ev E. V. Berberova N. T. Egorov M. P. 《Russian Chemical Bulletin》2001,50(4):716-719
-Aryl trans-bistriphenylphosphine complexes based on 2,6-di-tert-butylphenol containing Pt—SnCl3, Pt—GeCl3 groups were synthesized. Oxidation of these compounds gives the corresponding phenoxyl radicals, which were studied by ESR spectroscopy. The transformation of the diamagnetic complexes to the paramagnetic state is accompanied by cleavage of the Pt—Sn, Pt—Ge bonds and by elimination of SnCl2, GeCl2. 相似文献
124.
钴与2-[2-(5-溴苯并噻唑)偶氮]-5-二甲氨基苯甲酸显色反应的分光光度法研究 总被引:1,自引:0,他引:1
本文合成丁新试剂2-[2-(5-溴苯并噻唑)偶氮-5-二甲氨基苯甲酸(5-Br-BTAMB)。研究了在表面活性剂存在下它与钴的显色反应。发现 TritonX-100存在下,钴与5-Br-BTAMB在 pH6.0~8.5范围内形成稳定的蓝色配合物。其最大吸收峰位于660nm。表观摩尔吸光系数为1.22×10~5L·mol·cm~(-1)。配合物中钴与5-Br-BTAMB 的组成比为1:2.钴浓度在0~12μg/25ml 范围内呈良好的线性关系。在硫脲存在下,该方法具有良好的选择性,用于测定含钴分子筛和 V_(B12)中微量钴。结果令人满意。 相似文献
125.
甲醇氨化反应中交联皂石的催化行为 总被引:1,自引:1,他引:1
层柱材料是具有规则孔结构且其表面酸性及孔结构可调变的固体酸催化剂.本文合成了皂石,并用十三聚铝羟基络离子(Al_(13))与其交联,在醇氨化反应中研究了此层柱材料孔结构及表面酸性与催化性能间的关系. 相似文献
126.
Eva Schneiderman Bruno Perly Elwood Brooks Apryll M. Stalcup 《Journal of inclusion phenomena and macrocyclic chemistry》2002,43(1-2):43-50
The characterization of binary and ternary complexes of benzoate, lauryl hexaoxyethylene (C12E6) and -CD is presented. The complexation equilibrium was characterized by UV-Vis spectrophotometry, titration microcalorimetry, capillary electrophoresis, and 2D ROESY 1H-NMR. Results suggested that -CD forms one complex with C12E6in the stoichiometric ratio of -CD : C12E61.5 : 1, with a stability constant 1.3 × 105 M-1.5. The 2-D ROESY 1H-NMR spectrum indicated that C12E6is included inside the -CD cavity. The primary binding site of C12E6 is on the lauryl subunit of this molecule. Analogous to a previously reported study of -CD, the combination of -CD and C12E6precipitated from the solution. Addition of benzoate seemed to dissolve the precipitate and nearly doubled the apparent stability constant of the complex. Results from the various techniques supported formation of ternary complexes between -CD, C12E6, and benzoate. 相似文献
127.
Zhenya Zhang Taisheng Quan Pomin Li Yansheng Zhang Norio Sugiura Takaaki Maekawa 《Applied biochemistry and biotechnology》2004,115(1-3):1033-1039
We studied biogas fermentation from alcohol waste fluid to evaluate the anaerobic digestion process and the production of
vitamin B12 as a byproduct. Anaerobic digestion using acclimated methanogens was performed using the continuously stirred tank reactor
(CSTR) and fixed-bed reactor packed with rock wool as carrier material at 55°C. We also studied the effects of metal ions
added to the culture broth on methane and vitamin B12 formation. Vitamin B12 production was 2.92 mg/L in the broth of the fixed-bed reactor, twice that of the CSTR. The optimum concentrations of trace
metal ions added to the culture liquid for methane and vitamin B12 production were 1.0 and 8 mL/L for the CSTR and fixed-bed reactor, respectively. Furthermore, an effective method for extracting
and purifying vitamin B12 from digested fluid was developed. 相似文献
128.
Graziella Tocco Michela Begala Giovanna Delogu Carmen Picciau Gianni Podda 《Tetrahedron letters》2004,45(37):6909-6913
In the presence of catalytic amount of indium(III) chloride (10 mol %), 2,2′-dihydroxybiphenyl and bis(2-hydroxyphenyl)methane react quickly, without using any solvent, with ketones or β-keto esters possessing at least one hydrogen atom in α to the ketone-carbonyl group, to afford some new dibenzo(d,f)(1,3)dioxepines and some 12H-dibenzo(d,g)(1,3)dioxocin derivatives, respectively. 相似文献
129.
Synthesis of 12-deoxyroyleanone, cryptoquinone, 11,14-dihydroxy-8,11,13-abietatrien-7-one, and related derivatives from dehydroabietic acid 总被引:1,自引:0,他引:1
Yoh-ichi Matsushita Yoshihisa Iwakiri Satoru Yoshida Kazuhiro Sugamoto Takanao Matsui 《Tetrahedron letters》2005,46(21):3629-3632
Naturally occurring abietane quinones and hydroquinone, namely, 12-deoxyroyleanone (1a), cryptoquinone (4a), and 11,14-dihydroxyabieta-8,11,13-trien-7-one (5a), together with the epimers of tryptoquinones D (2) and F (3), were first synthesized from dehydroabietic acid (6). 相似文献
130.
Elka Kraleva Alla Spojakina Rumiana Edreva-Kardjieva Kveta Jiratova Lacezar Petrov 《Reaction Kinetics and Catalysis Letters》2007,92(1):111-119
HDS catalysts were prepared by loading H3PMo12O40 or H4PMo11V1O40 polyoxometallates on TiO2 (0.5 and 1.0 mmol (Mo+V)). Activity of the catalysts was tested in the HDS of thiophene. The activity of catalysts of low
concentration was 2–3 times higher than the activity of those of high concentration. Temperature programmed reduction (TPR)
and IR spectroscopy were used to determine the properties of the catalyst. TPR measurements proved that vanadium promotes
and stabilizes HDS activity due to an increase in the Mo5+/Mo4+ ratio. 相似文献