Effect of Transition Metals (Cu, Co and Fe) on the Autothermal Reforming of Methane over Ni/Ce_(0.2)Zr_(0.1)Al_(0.7)O_δ Catalyst

The transition metals （Cu, Co, and Fe） were applied to modify Ni/Ce0.2Zr0.1Al0.7Oδ catalyst. The effects of transition metals on the catalytic properties of Ni/Ce0.2Zr0.1Al0.7Oδ autothermal reforming of methane were investigated. The Ni-supported catalysts were characterized by XRD, TPR and XPS. Tests in autothermal reforming of methane to hydrogen showed that the addition of transition metals （Cu and Co） significantly increased the activity of catalyst under the conditions of lower reaction temperature, and Ni/Cu0.05Ce0.2Zr0.1Al0.65Oδ was found to have the highest conversion of CH4 among all catalysts in the operation temperatures ranging from 923 K to 1023 K. TPR, XRD and XPS measurements indicated that the cubic phases of CexZr1-xO2 solid solution were formed in the preparation process of catalysts. Strong interaction was found to exist between NiO and CexZr1-xO2 solid solution. The addition of Cu improved the dispersion of NiO, inhibited the formation of NiAl2O4, and thus significantly promoted the activity of the catalyst Ni/Cu0.05Ce0.2Zr0.1Al0.65Oδ

Autothermal reforming of methane over Ni catalysts supported over ZrO2-CeO2-Al2O3

Ni catalysts supported on Al2O3, ZrO2-Al2O3, CeO2-Al2O3 and ZrO2-CeO2-Al2O3 were prepared by coprecipitation method, and their catalytic performances for autothermal reforming of methane to hydrogen were investigated. The Ni-supported catalysts were characterized by XRD, TPR and XPS. The relationship between the structures and catalytic activities of the catalysts was discussed. The results showed that the catalytic activity and stability of the Ni/ZrO2-CeO2-Al2O3 catalyst was better than those of other catalysts with the highest CH4 conversion, H2/CO and H2/COx ratio at 750 ℃. The catalyst showed a little deactivation along the reaction time during its 72 h on stream with the mean deactivation rate of 0.08%/h. The catalytic performance of the Ni/ZrO2-CeO2-Al2O3 catalyst was also affected by reaction temperature, no2 ： nCH4 molar ratio and nH2O ： nCH4 molar ratio. TPR, XRD and XPS measurements indicated that the formation of ZrO2-CeO2 solid solution could improve the dispersion of NiO, and inhibit the formation of NiAl2O3, and thus significantly promoted the catalytic activity of the Ni/ZrO2-CeO2-Al2O3 catalyst.

Effect of CeO2 on the catalytic performance of Ni/Al2O3 for autothermal reforming of methane

The effect of promoter Ce on the catalytic performance of Ni/Al2O3 catalyst for autothermal reforming of methane to hydrogen was investigated. The catalysts were characterized by X-ray diffraction （XRD）, temperature-programmed reduction （TPR）, and X-ray photoelectron spectroscopy （XPS）. The results indicated that the catalytic performance of the catalysts was improved with the addition of Ce. Ni/Ce30Al70Oδ showed the highest CH4 conversion in operation temperatures ranging from 650 ℃ to 850 ℃. At the same time, the decrease in H2/CO ratio with increasing reaction temperature was consistent with the fact that water-gas shift reaction was thermodynamically unfavorable at higher temperatures. The XRD result indicated that adding Ce to Ni/Al2O3 catalyst prevented the formation of NiAl2O4 and facilitated the formation of NiO. The formation of NiO increased the number of active sites, resulting in higher activity. Comparing the TPR profiles of Ni/Ce30Al70Oδ with Ni/Al2O3, it could be clearly observed that with the addition of Ce, the total reduction peak areas in the middle and low temperatures increased. It was most probably that the addition of Ce inhibited the stronger interaction between Ni and Al2O3 to form the phase of NiAl2O4, and favored the formation of the strong interaction between NiO species and CeO2. Therefore, the addition of Ce to the Ni/Al2O3 catalyst increased the active surface that promoted the activity of the catalyst.

Selective Oxidation of CO in Excess H_2 over Ru/Al_2O_3 Catalysts Modified with Metal Oxide

The Ru/Al2O3 catalysts modified with metal oxide （K20 and La2O3） were prepared v/a incipient wetness impregnation method from RuCl3.nH2O mixed with nitrate loading on Al2O3 support. The activity of catalysts was evaluated under simulative conditions for the preferential oxidation of CO （CO-PROX） from the hydrogen-rich gas streams produced by reforming gas, and the performances of catalysts were investigated by XRD and TPR. The results showed that the activity temperature of the modified catalysts Ru-K20/Al2O3 and Ru-La2O3/Al2O3 were lowered approximately 30℃ compared with pure Ru/Al2O3, and the activity temperature range was widened. The conversion of CO on Ru-K20/Al2O3 and Ru-La2O3/Al2O3 was above 99% at 140-160℃, suitable to remove CO in a hydrogen-rich gas and the selectivity of Ru-La2O3/Al2O3 was higher than that of Ru-K2O/Al2O3in the active temperature range. Slight methanation reaction was detected at 220℃ and above.

Kinetics of methanol steam reforming over COPZr-2 catalyst

The COPZr-2 catalyst, which was prepared in our prophase research, showed good catalytic performance in methanol steam reforming reaction. In this article, the best one was chosen as an example to study the reaction kinetics of methanol steam reforming over this type of catalyst. First, the effects of methanol conversion to outlet CO2 and methanol conversion to outlet CO on methanol pseudo contact time W/FMeOH were investigated. Then by applying the reaction route that methanol direct reforming （DR） and methanol decomposition （DE） were carried out in parallel, the reaction kinetic model with power function type was established. And the parameters for the model were estimated using a non-linear regression program which computed weighted least squares of the defined objects function. Finally, the kinetic model passed the correlation test and the F-test.

Removal of CO from reformed fuels by selective methanation over Ni-B-Zr-O_δ catalysts

The Ni-B-Oδ and Ni-B-Zr-Oδ catalysts were prepared by the method of chemical reduction, and the deep removal of CO by selective methanation from the reformed fuels was performed over the as-prepared catalysts. The results showed that zirconium strongly influenced the activity and selectivity of the Ni-B-Zr-Oδ catalysts. Over the Ni-B-Oδ catalyst, the highest CO conversion obtained was only 24.32% under the experi-mental conditions studied. However, over the Ni-B-Zr-Oδ catalysts, the CO methanation conversion was higher than 90% when the temperature was increased to 220℃. Additionally, it was found that the Ni/B mole ratio also affected the performance of the Ni-B-Zr-Oδ catalysts. With the increase of the Ni/B mole ratio from 1.8 to 2.2, the CO methanation activity of the catalyst was improved. But when the Ni/B mole ratio was higher than 2.2, the performance of the catalyst for CO selective methanation decreased instead. Among all the catalysts, the Ni29B13Zr58Oδ catalyst investigated here exhibited the highest catalytic performance for the CO selective methanation, which was capable of reducing the CO outlet concentration to less than 40 ppm from the feed gases stream in the temperature range of 230-250℃, while the CO2 conversion was kept below 8% all along. Characterization of the Ni-B-Oδ and Ni-B-Zr-Oδ catalysts was provided by XRD, SEM, DSC, and XPS.

Preparation and oxygen permeation properties of SrFe(Cu)O_(3-δ) dense ceramic membranes

Mixed oxygen-ionic and electronic conducting membranes of SrFe（Cu）O3-δ were prepared by solid-state reaction method. The crystal structure, oxygen nonstoichiometry, and phase stability of the materials were studied by TGA and XRD. Oxygen permeation fluxes through these membranes were studied at operating temperature ranging from 750 to 950 ℃. Results showed that doping Cu in SrFeO3-δ compound had a significant effect on the formation of single-phased perovskite structure. For SrFe1-xCu2O3-δ series materials, the oxygen nonstoichiometry and the oxygen permeation flux increased considerably with the increase of Cu-doping content （x = 0.1-0.3）. The sintering property of the membrane decreased significantly when the Cu substitution amount reached 40%. SrFe0.7Cu0.3O3-δ showed high oxygen permeation flux, but SrCuO2 and Sr2Fe2O5 phases formed in the compound after oxygen permeation test induced cracks in the membrane.

Carbon nanotubes-Nafion composites as Pt-Ru catalyst support for methanol electro-oxidation in acid media

Carbon nanotubes-Nafion （CNTs-Nation） composites were prepared by impregnated CNTs with Nation in ethanol solution and characterized by FT-IR. Pt-Ru catalysts supported on CNTs-Nafion composites were synthesized by microwave-assisted polyol process. The physical and electrochemical properties of the catalysts were characterized by X-ray diffraction （XRD）, transmission electron microscope （TEM）, CO stripping voltammetry, cyclic voltammetry （CV） and chronoamperometry （CA）. The results showed that the Nation incorporation in CNTs-Nation composites did not significantly alter the oxygen-containing groups on the CNTs surface. The Pt-Ru catalyst supported on CNTs-Nafion composites with 2 wt% Naton showed good dispersion and the best CO oxidation and methanol electro-oxidation activities.

Carbon Nanotubes Supported Pt-Ru-Ni as Methanol Electro-Oxidation Catalyst for Direct Methanol Fuel Cells

Carbon nanotubes （CNTs） supported Pt-Ru and Pt-Ru-Ni catalysts were prepared by chemical reduction of metal precursors with sodium borohydride at room temperature. The crystallographic properties and composition of the catalysts were characterized by X-ray diffraction （XRD） and energy dispersive X-ray （EDX） analysis, and the catalytic activity and stability for methanol electro-oxidation were measured by electrochemical impedance spectroscopy （EIS）, linear sweep voltammetries （LSV）, and chronoamperometry （CA）. The results show that the catalysts exhibit face-centered cubic （fcc） structure. The particle size of Pt-Ru-Ni/CNTs catalyst is about 4.8 nm. The catalytic activity and stability of the Pt-Ru-Ni/CNTs catalyst are higher than those of Pt-Ru/CNTs catalyst.

One-step fabrication of cell sheet-laden hydrogel for accelerated wound healing

Full-thickness skin wounds are have continued to be reconstructive challenges in dermal and skin appendage regeneration, and skin substitutes are promising tools for addressing these reconstructive procedures. Herein, the one-step fabrication of a cell sheet integrated with a biomimetic hydrogel as a tissue engineered skin for skin wound healing generated in one step is introduced. Briefly, cell sheets with rich extracellular matrix, high cell density, and good cell connections were integrated with biomimetic hydrogel to fabricate gel + human skin fibroblasts (HSFs) sheets and gel + human umbilical vein endothelial cells (HUVECs) sheets in one step for assembly as a cell sheet-laden hydrogel (CSH). The designed biomimetic hydrogel formed with UV crosslinking and ionic crosslinking exhibited unique properties due to the photo-generated aldehyde groups, which were suitable for integrating into the cell sheet, and ionic crosslinking reduced the adhesive force toward the substrate. These properties allowed the gel + cell sheet film to be easily released from the substrate. The cells in the harvested cell sheet maintained excellent viability, proliferation, and definite migration abilities inside the hydrogel. Moreover, the CSH was implanted into a full-thickness skin defects to construct a required dermal matrix and cell microenvironment. The wound closure rate reached 60.00 ± 6.26% on the 2nd day, accelerating mature granulation and dermis formation with skin appendages after 14 days. This project can provide distinct guidance and strategies for the complete repair and regeneration of full-thickness skin defects, and provides a material with great potential for tissue regeneration in clinical applications.

Dynamic photoelectrical regulation of ECM protein and cellular behaviors

Dynamic regulation of cell-extracellular matrix(ECM)-material interactions is crucial for various biomedical applications.In this study,a light-activated molecular switch for the modulation of cell attachment/detachment behaviors was established on monolayer graphene(Gr)/n-type Silicon substrates(Gr/Si).Initiated by light illumination at the Gr/Si interface,pre-adsorbed proteins(bovine serum albumin,ECM proteins collagen-1,and fibronectin)underwent protonation to achieve negative charge transfer to Gr films(n-doping)throughπ-πinteractions.This n-doping process stimulated the conformational switches of ECM proteins.The structural alterations in these ECM interactors significantly reduced the specificity of the cell surface receptor-ligand interaction(e.g.,integrin recognition),leading to dynamic regulation of cell adhesion and eventual cell detachment.RNA-sequencing results revealed that the detached bone marrow mesenchymal stromal cell sheets from the Gr/Si system manifested regulated immunoregulatory properties and enhanced osteogenic differentiation,implying their potential application in bone tissue regeneration.This work not only provides a fast and feasible method for controllable cells/cell sheets harvesting but also gives new insights into the understanding of cell-ECM-material communications.

富血小板血浆促进髋关节发育不良截骨术后恢复1例

富血小板血浆(platelet-rich plasma,PRP)在骨科中的应用越来越受到重视,因其具有促进细胞增殖和损伤修复的作用,可为细胞的增殖、修复提供一个富含细胞因子和生长因子的微环境[1],此外,PRP中还富含巨噬细胞,有助于吞噬炎性介质,促进炎症消散。发育性髋关节发育不良(developmental dysplasia of the hip,DDH)是临床常见的骨关节疾病,也是发生髋关节炎常见原因之一[2],如果治疗不及时或不当,随着年龄增大,病情加重,可出现严重髋关节脱位,影响患者的身心健康和生活质量[3]。CroweⅣ型DDH是最严重的一种DDH类型,可引起患者髋关节严重脱位,股骨头上移,导致形成假臼的骨关节炎,同时使周围软组织出现肌群挛缩、坐骨神经结构异常等情况出现,增加了手术治疗难度[4]。成人CroweⅣ型DDH患者髋关节旋转中心上移明显,肢体严重短缩,周围软组织明显挛缩,手术治疗原则首先要恢复髋关节正常的生物力学结构及髋关节正常的旋转中心,消除疼痛和跛行状态;若要达到这一点,必然需要股骨下移,也就导致了下肢的延长。常规THA常因过度牵拉下肢而导致下肢延长,可能造成周围神经及血管的损伤。研究发现,下肢延长4 cm以上坐骨神经损伤的风险将成倍增加,且周围软组织张力明显增高,会影响髋关节功能。因此,对于成人CroweⅣ型DDH患者,大部分学者提倡THA联合粗隆下截骨治疗[5]。而PRP疗法为促进CroweⅣ型DDH患者粗隆下横行截骨术后恢复的治疗带来了新思路,虽然目前大量的临床研究已经证实了PRP疗法对于骨关节、肌腱韧带软组织损伤的疗效,但少有研究探讨PRP对于CroweⅣ型DDH患者粗隆下横行截骨术后恢复的治疗效果。本篇报道了1例CroweⅣ型DDH患者使用PRP促进截骨术后恢复的案例。

Formal semantic description standard family for Chinese KOS(Ⅱ): Research and implementation of Classification Scheme Sharing Service System

In the context of globalization of network information, it is an urgent need to consider networked development and sharing for classification schemes. Since 2000, the international mainstream classification schemes have published their Web versions one after another, while there is still a lack of an integrated, reusable and Semantic-Web-oriented solution for classification schemes and classification-like knowledge organization systems. By using computer programs to automatically analyze the source files of the classification schemes in the MARC or HTML format, this paper adopts CNKOS to produce the semantic description of the classification schemes. On account of this, this paper employs international advanced open-source technologies, takeing the representative domestic CLC as an example, to construct the CLSS prototype system. It is proved that this solution can be put into practical use and can facilitate the quick deployment of other classification-like Chinese knowledge organization systems. The successful implementation of the system verifies the scientificity and practicality of CNKOS, and it plays a demonstrating and promoting role and provides a reusable solution for other domestic classification schemes and classification-like knowledge organization systems. The solution can serve as a reference for similar international knowledge organization systems in realizing their Semantic Web style sharing services.