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151.
Cu-Fe composite oxides were prepared by co-precipitation method and tested for higher alcohol synthesis from syngas. The selectivity to C2+OH and C6+OH in alcohol distribution was very high while the methane product fraction in hydrocarbon distribution was rather low, demonstrating a promising potential in higher alcohols synthesis from syngas. The distribution of alcohols and hydrocarbons approximately obeyed Anderson-Schulz-Flory distribution with similar chain growth probability, indicating alcohols and hydrocarbons derived from the same intermediates. The effects of Cu/Fe molar ratio, reaction temperature and gas hourly space velocity (GHSV) on catalytic performance were studied in detail. The sample with a Cu/Fe molar ratio of 10/1 exhibited the best catalytic performance. Higher reaction temperature accelerated water-gas-shift reaction and led to lower total alcohols selectivity. GHSV showed great effect on catalytic performance and higher GHSV increased the total alcohol selectivity, indicating there existed visible dehydration reaction of alcohol into hydrocarbon.  相似文献   
152.
三角翼动态大迎角气动力特性数值分析研究   总被引:1,自引:0,他引:1  
采用数值计算方法,对三角翼从 0°上仰至 90°的动态流场和气动力特性进行了计算,并对俯仰角速度对三角翼流场和气动力特性的影响进行了计算分析。给出了三角翼纵向动态情况下的气动力系数变化,特别是大迎角横侧力矩系数的变化特征。结果表明,随着机翼俯仰角速度的提高,前缘分离涡破裂位置相对滞后,机翼升力和阻力系数明显增加,机翼抵抗旋涡非对称破裂的能力明显增强。  相似文献   
153.
采用半径微扰的光滑壁圆波导产生HE11模,避免了常规微波领域中采用的波纹渐变转换器在高功率微波领域应用时易发生齿间打火的不足。采用基于模式耦合理论的迭代综合方法优化了不规则的半径渐变轮廓,使输出产生组成HE11模的混合模式。并通过全电磁波仿真软件进行了对比, 输出波束标量高斯含量在9.1~9.7 GHz范围内均高于99.5%,功率容量4.9 GW。  相似文献   
154.
修正的期权定价模型及定价公式   总被引:2,自引:0,他引:2  
通过一系列函数变换,求出了修正的Black—Scholes欧式定价模型方程的解,并对股票与国债的投资组合进行了分析。  相似文献   
155.
Poly(dimethylsiloxane)‐block‐poly(methyl methacrylate)‐block‐poly(2,2,3,3,4,4,4‐heptafluorobutyl methacrylate) was successfully synthesized via ATRP. The chemical composition and structure of the copolymer was characterized by NMR and FT‐IR spectroscopy and molecular weight measurement. Gel permeation chromatography was used to study the molecular weight distribution of the triblock copolymer. The surface properties of the resulting copolymer were investigated. The effects of fluorine content and bulk structure on surface energy were investigated by static water contact angle measurements. Surface composition was studied by XPS.

  相似文献   

156.
Yan X  Cai Z  Yi C  Liu W  Tan M  Tang Y 《Inorganic chemistry》2011,50(6):2346-2353
To confirm how different anions influence sup-ramolecular self-assembly of lanthanide-organic frameworks (LnOFs) as well as their luminescent properties, a new flexible achiral tripodal ligand, 1,1,1-tris-{[(2'-benzylaminoformyl)phenoxyl]methyl}ethane (L) and the LnOFs {[EuL(NO(3))(3)]·1.5CHCl(3)}(n) and [EuL(pic)(3)](n) have been designed and assembled. In the two LnOFs, {[EuL(NO(3))(3)]·1.5CHCl(3)}(n) demonstrates an unprecedented chiral noninterpenetrated two-dimensional (2D) honeycomblike (6,3) (hcb, Schla?fli symbol 6(3), vertex symbol 6·6·6) topological network, and [EuL(pic)(3)](n) confirms an unusual chiral LnOF with three-dimensional (3D) (10,3)-a (srs, SrSi(2), Schla?fli symbol 10(3), vertex symbol 10(2)·10(4)·10(4)) topological framework. Also the anion-induced structures and energy transfer processes in the luminescence behavior of the two LnOFs were discussed in detail.  相似文献   
157.
An efficient procedure for the stereocontrolled construction of 2H‐thiopyrano[2,3‐b]quinoline scaffolds has been developed, starting from simple compounds. The domino Michael/aldol reactions between 2‐mercaptobenzaldehydes and enals, promoted by chiral diphenylprolinol TMS ether, proceed with excellent chemo‐ and enantioselectivity to give the corresponding synthetically useful and pharmaceutically valuable 2H‐thiopyrano[2,3‐b]quinolines in high yields with 90–99 % ee.  相似文献   
158.
合成了新的以水杨酰苄胺为功能端基的开环冠醚1,7-二(2'-苯甲酰苄胺)-1,4,7-三氧杂庚烷(L)有机配体及其硝酸铕和硝酸铽的配合物.利用元素分析、电导、红外光谱对配合物进行了表征,结果表明两个配合物均符合23(RE(NO3)3L)的化学计量比.此外还初步研究了铕、铽配合物在室温下的固体荧光性质,结果表明虽然配体保持了苯羰基共轭结构对铕、铽离子的敏化发光性质,两个配合物均能表现出一定强度的特征荧光,但是配体向Tb(Ⅲ)的能量传输效率明显要强于Eu(Ⅲ).  相似文献   
159.
周正洪  赵军 《应用化学》1998,15(2):72-75
对α-(1H-1,2,4-三唑-1-基)-α-芳氧烷基芳乙酮肟的合成和生物活性进行了研究,合成了12个新型化合物,所有化合物的结构经1HNMR、MS和元素分析确证;初步生物活性测试结果表明,该类化合物具有一定的杀菌和植物生长调节活性.  相似文献   
160.
This paper reported the degradation behaviors and thermal properties of polystyrene (PS)/polyolefin elastomer (POE) blends with AlCl3 as the catalyst of Friedel-Crafts alkylation reaction. Gel permeation chromatography (GPC) and thermogravimetric analysis (TGA) were adopted to reveal the effects of in situ grafting reaction and degradation of blending compounds on the thermal properties of PS/POE blends. It was found that the changes in both catalyst content and blend composition influenced the competition between in situ grafting reaction and degradation, resulting in the complexity of the thermal properties of PS/POE/AlCl3 blends.  相似文献   
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