Nickel supported over MCM-41 coated ceramic membrane for steam reforming of real tar

A novel catalyst, Nickel supported over MCM-41 coated ceramic membrane (NMC), was developed using coating method and deposition-precipitation method and applied for steam reforming of real tar in fixed bed. The effects of reaction conditions such as Ni loading amount, reaction temperature and mass ratio of steam to tar were also studied. The good dispersion of Ni nanoparticles and the strong interaction between Ni particles and the support were identified by BET, XRD, H₂-TPR and SEM/EDS, resulting in the excellent performance of NMC catalysts. Maximum tar conversion of 96.4% and H₂ yield of 98.7 mmol g^?1 were obtained using 20NMC with a mass ratio of steam to coal tar of 2 at 800 °C. Moreover, 20 NMC exhibited a good stability in 10 h of lifetime test and the resistance of graphitic carbon formation prone to easier regeneration of catalysts illustrated by Raman spectroscopy. It indicates that the utilization of NMC catalysts for tar steam reforming is a promising way.     

Learn from the past – sequentially one-to-one video deblurring network

With the growing availability of hand-held cameras in recent years, more and more images and videos are taken at any time and any place. However, they usually suffer from undesirable blur due to camera shake or object motion in the scene. In recent years, a few modern video deblurring methods are proposed and achieve impressive performance. However, they are still not suitable for practical applications as high computational cost or using future information as input. To address the issues, we propose a sequentially one-to-one video deblurring network (SOON) which can deblur effectively without any future information. It transfers both spatial and temporal information to the next frame by utilizing the recurrent architecture. In addition, we design a novel Spatio-Temporal Attention module to nudge the network to focus on the meaningful and essential features in the past. Extensive experiments demonstrate that the proposed method outperforms the state-of-the-art deblurring methods, both quantitatively and qualitatively, on various challenging real-world deblurring datasets. Moreover, as our method deblurs in an online manner and is potentially real-time, it is more suitable for practical applications.     

Adsorption performance of mesoporous silicas towards a cationic dye. Influence of mesostructure on adsorption capacity

The dye adsorption performance of four mesoporous silicas with different structure and textural properties, MCM-41, MCM-48, SBA-15 and mesocellular silica foam (MCF), was studied and compared by using toluidine blue O (TBO) as dye model in aqueous solution. These materials were characterized by X-ray diffraction (XRD), small-angle X-ray scattering, nitrogen adsorption-desorption analyses, and transmission electron microscopy (TEM). The effect of some parameters such as adsorbent dosage, contact time, temperature, and pH on the TBO removal in aqueous solution was studied. Results showed that adsorption capacity raised when adsorbent dosage, contact time and pH solution were increased while an increase in temperature decreased the adsorption of TBO. Langmuir, Freundlich and Temkin isotherm models were employed to elucidate the adsorption mechanism while the adsorption rate data were analyzed according to the pseudo-first and second-order kinetic models. Results showed that adsorption of TBO onto MCM-48, SBA-15, and MCF fitted well the Freundlich isotherm model while the kinetic studies showed that adsorption process could be better described by the pseudo-second-order model for all mesoporous silicas. Finally, some solvents were evaluated to carried out dye desorption from the TBO-loaded mesoporous silicas founding that acetic acid was the most efficient.     

Synthesis and characterization of MCM-41-supported nano zirconia catalysts

Series of MCM-41 supported sulfated Zirconia (SZ) catalysts with different loadings (2.5–7.5% wt.) were prepared using direct impregnation method. The acquired solid catalysts were characterized structurally and chemically using X-RD, HRTEM, BET, FT-IR, Raman spectroscopy and TPD analysis. The acidity of the solid catalysts was investigated through cumene cracking and isopropanol dehydration at different temperatures. As the SZ loading increases, the surface acidity of the mesoporous catalysts was enhanced, this was reflected by the higher catalytic activity toward cumene cracking and isopropanol dehydration.     

Mineralization of Para-Chlorobenzoic Acid in Water by Cobalt-Incorporated MCM-41 Catalyzed Ozonation

Cobalt-incorporated MCM-41(Co-MCM-41) was used as a heterogeneous catalyst for the ozonation of para-chlorobenzoic acid (p-CBA) in aqueous solution. Cobalt oxide supported on MCM-41(Co/MCM-41) was synthesized for comparison. Their textural properties were elucidated by various characterization techniques to understand the relationship between surface texture and catalytic activity. TOC removal at 60 min reached 91% with Co-MCM-41, 83% with Co/MCM-41 and only 52% with ozone alone, respectively. Observations from diffuse reflection spectroscopy demonstrated that different metal phases were formed in these cobalt-modified molecular sieves samples. Radical scavenger experiments indicated the formation of hydroxyl radicals that were responsible for the effective degradation of p-CBA. An integrated approach to the catalytic mechanism was proposed by considering the variation of pH in the course of ozonation as well as its subsequent influence on the dissociation of targeted compounds and surface charge of the catalyst. In the reusability experiments, the reused Co-MCM-41 was able to regain the same catalytic capability as the fresh one within 5 cycles. X-ray photoelectron spectroscopy results indicated that a part of Co²⁺ was oxidized to Co³⁺ after oxidation reaction.     

新型高水热稳定性MOR/MCM-41复合分子筛的合成

以丝光沸石分子筛为硅铝源,通过碱液处理和表面活性剂的自组装作用,水热条件下合成了MOR/MCM-41复合分子筛。通过XRD、SEM、TEM、N2吸附/脱附和水热稳定性处理等手段对合成的复合材料进行了表征。结果表明,复合材料不仅保留了原丝光沸石晶体的规则形貌,同时兼具微孔分子筛MOR和介孔分子筛MCM-41的特征,且介孔(20~30 nm)在微孔分子筛中较均匀地分布。水热处理测试结果表明,MOR/MCM-41复合分子筛具有较高的水热稳定性,水热处理100 h后介孔结构依然存在。     

无硼体系MCM-22分子筛的合成

以哌啶(PI)为模板剂,在不添加晶化助剂下,采用动态水热晶化法合成MCM-22分子筛,考察了晶化时间、PI和Si O2、OH-和Si O2、Si O2和Al2O3的物质的量之比等对晶化产物的影响,结果表明,PI和Si O2,OH-和Si O2,Si O2和Al2O3的物质的量之比为0.50~0.70,0.09~0.10和30~40,晶化时间48~72 h的条件下,能较好地合成MCM-22分子筛。在苯与乙烯液相烷基化制乙苯反应中,以哌啶为模板剂与采用六亚甲基亚胺为模板剂合成的MCM-22分子筛的催化性能相当。     

Geographically and technologically mediated knowledge spillovers between European regions

This paper aims at investigating inter-regional knowledge spillovers across European sub-national regions. The basic questions that we wish to answer may be formulated in the following way: do regional geographical and technological proximities matter for the creation of new knowledge within the European regional landscape? After a review of the related literature, we consider a regional knowledge production function that allows for extra regional innovation-generating inputs. Accounting for regional specific social capability, this knowledge production function is applied to an extended sample of 153 European sub-national regions over the period 1989–1996. Interregional knowledge spillovers are shown to exist between geographically close regions and between regions displaying similar technological profiles. However, technological proximity and geographical proximity coincides to a certain extent. Knowledge spillovers are mainly driven by the private business sector. If knowledge spillovers occur within a given country, the national border turns out to seriously hamper interregional spillovers on the European scale. The author wishes to thank Eckhardt Bode, Henri Capron, Raymond J.G.M. Florax, Charlie Karlsson, Roger Stough and Roger Vickerman for their useful comments and suggestions. An earlier version of this paper was presented at the 41st Annual Meeting of the Western Regional Science Association in February 2002, Monterey, California.     

Restricting access in a job chains model of local employment creation

The job chains model of local labor market change is a demand-driven analytic device for estimating the effects of new job creation. This paper explores the effects of restricting supply, i.e., limiting job access, on the model’s primary outcomes: vacancy chain multipliers, welfare effects, and distributional impacts. Major sources of labor supply are the local unemployed, out of the labor force and in-migrants. Three simulations are reported relating to (1) restricting new jobs to current local residents (i.e., no in-migrants), (2) restricting new jobs to current residents in the first round of hiring only, and (3) restricting hiring to local unemployed/out of labor force on the first round alone. The results are compared to the basic model that assumes no supply-side restrictions. In terms of chain length, welfare effects, distributional impacts, and policy palatability, first-round restrictions on in-migrants would seem to be the most plausible option. However, as an economic development strategy, well-targeted demand-side initiatives would still seem to be preferable.