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设计制备了一种新型微孔介孔复合核壳结构钛硅分子筛TS-1@Mesosilica(TS-l@Ms),核为MFI结构钛硅分子筛TS-1,壳层为以非离子表面活性剂P123为模板剂组装形成的介孔氧化硅.壳层氧化硅具有三维蠕虫状孔道结构,有利于微孔和介孔部分的连通及反应物和产物的扩散.通过沉积沉淀法将金纳米粒子负载在壳层介孔孔道,和TS-1中的钛活性中心协同,形成适合于C3H6和H2、O2直接气相环氧化制备环氧丙烷(PO)的双功能催化材料.实验结果表明,Au/TS-1@MS在空速8000mLg-h、温度473K条件下连续反应132h,活性和选择性没有明显下降,丙烯转化率保持在3.7%左右,PO选择性87%以上. 相似文献
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Meng Wang LiYan Ma YangTong Lou Chao Bian TingTing Zhou HaiBin Zhou HongZe Liao Zhao Ma DongSheng Yin AiZhong Chen ShaoZhong Wang ZhenYu Yang Bing Sun ZhuJun Yao 《中国科学:化学(英文版)》2012,55(12):2537-2547
Inhibitory effect on tumor necrosis factor-(TNF-) production by sinomenine derivatives with embedment of small drug-like nitrogen hetereocyclic moieties has been studied in this work.Several new sinomenine derivatives having chlorophenyl substituent have been found to exhibit much more potent TNF-α inhibitory activity than natural sinomenine and other derivatives. 相似文献
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Glycerol carbonate was synthesized by the oxidative carbonylation of glycerol catalyzed by the commercial Pd/C with the aid of NaI.High conversion of glycerol(82.2%),selectivity to glycerol carbonate(>99%),and TOF(900 h–1)were obtained under the conditions of 5 MPa(pCO:pO2=2:1),140 oC,2 h.The highly active palladium species were generated in situ by dissolution from the carbon support and stabilized by re-deposition onto the support surface after the reaction was finished.Palladium dissolution and re-deposition were crucial and inherent parts of the catalytic cycle,which involved heterogeneous reactions.This Pd/C catalyst could be recycled and efficiently reused for four times with a gradual decrease in activity.Moreover,the influences of various parameters,e.g.,types of catalysts,solvents,additives,reaction temperature,pressure,and time on the conversion of glycerol were investigated.A reaction mechanism was proposed for oxidative carbonylation of glycerol to glycerol carbonate. 相似文献
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为更好地提升《催化学报》的质量和国际影响力,经《催化学报》第四届编辑委员会主编林励吾院士推荐,并经过中国科学院大连化学物理研究所和《催化学报》所属学会中国化学会催化专业委员会批准,《催化学报》编辑委员会做出重大调整,由李灿院士和张涛院士担任主编,并邀请到80余位具有较大国际影响力的催化领域专家加入新一届编委会,其中约1/3编委来自美国、英国、澳大利亚和加拿大等科技发达国家.同时,办刊模式 相似文献
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Yuanfei LiYan Liu Changhao Lin 《Nonlinear Analysis: Theory, Methods & Applications》2011,74(13):4399-4417
In this paper, we establish the spatial decay bounds for homogeneous Boussinesq equations in a semi-infinite pipe flow. Assuming that the entrance velocity and magnetic field data are restricted appropriately, and it converges to laminar flow as the distance down the pipe tends to infinity, we derive a second order differential inequality that leads to an exponential decay estimate for the energy E(z,t) defined in (27). We also indicate how to establish the explicit bound for the total energy. 相似文献
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正为更好地提升《催化学报》的质量和国际影响力,经《催化学报》第四届编辑委员会主编林励吾院士推荐,并经过中国科学院大连化学物理研究所和《催化学报》所属学会中国化学会催化专业委员会批准,《催化学报》编辑委员会做出重大调整,由李灿院士和张涛院士担任主编,并邀请到80余位具有较大国际影响力的催化领域专家加入新一届编委会,其中约1/3编委来自美国、英国、澳大利亚和加拿大等科技发达国家.同时,办刊模式 相似文献
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The temperature dependence of internal friction ( T- tan φ curves) in pure aluminium (Al) is measured at sixteen different frequencies. Based on T- tan φ curves, the frequency dependence of internal friction (f -tan φ curves) is also obtained by the interpolation method. An internal friction peak is observed in both the T - tan φ curves and the f - tan φ curves. The activation energy of the peak in the f - tan φ curves is found to be 2.08 ± 0.02 eV and compared to the value of 1.60 ± 0.04 eV in the T - tan φ curves. It is suggested that the change of relaxation strength with temperature should be considered when one calculates the activation energy of the peak in T- tan φ curves. 相似文献
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采用熔盐法合成了红色荧光材料BaxWO4-Sr(0.985-x)MoO4:0.01Sm3+,为用于白光发光二极管(WLEDs),考察了其的发光性能。通过X射线粉末衍射、光致发光和扫描电镜等技术对粉体进行测试,研究Ba2+与Sr2+的不同比例和不同的烧结温度对该粉体的相结构、发光性能和微观形貌的影响。结果表明,当x=0.7时,即Ba2+与Sr2+的比例为7∶2.85时,在900℃下煅烧4 h合成的荧光粉为四方纯相结构,有优良的发光性能和微观形貌。在波长404 nm的光激发下,荧光粉的发射光谱呈3峰发射,分别位于565、602和648 nm附近,适合于用作被近紫外光激发的LED的红色荧光材料。 相似文献