Determinants of social gratifications obtained by older adults moderated by public supports for Internet access in Spain

As the standard of living constantly improves, and as life expectancy increases in developed countries, the number of adults who want to have a gratifying life increases as well. Furthermore, although the Internet offers a world of potentially rewarding experiences, there is much heterogeneity among older people with respect to those who are able to benefit from its use. To reduce this gap, public access and digital literacy programs have been implemented. The aim of the study was to find out the extent to which these programs moderate the effects of age and socioeconomic status on social access to and use of the Internet in a sample of older users in Spain. Through quota sampling of retired users over 54 years of age in Spain (N = 560), who were regular users of public supports for Internet access, a structural equation modeling and multi-group analysis was conducted. The data showed a staggered association of access indicators (physical access, digital skills and social e-activities) on the social gratifications obtained, as well as the moderating role of institutional supports. This study provides empirical evidence of the ability of public supports to moderate the effect of socioeconomics inequalities on access and social exploitation of the Internet by older people. The findings point to the need to strengthen digital literacy actions, especially in supports that are more sensitive to the effect of age and socio-economic status.     

Synergetic photocatalytic and thermocatalytic aqueous phase reforming of methanol for hydrogen production based on noble metal/photosensitive supports catalysts

To overcome high Gibbs free energy and low reaction rate of thermal catalytic and photocatalytic hydrogen production from methanol-H₂O mixture, photo-thermal synergistic catalysis (PC-TC) reforming has proved to be an effective strategy owing to the photo-assited thermal synergistic effect to accelerate the step controlling kinetic behavior. In order to efficiently produce H₂, proper photosensitive catalysts which absorb light energy and also show efficient thermal catalytic (TC) performance need to be developed. To study the designing principle for catalysts, herein we incorporate Pt/Pd and three different supports which show similar band gaps (ZnO, CeO₂, and P25) through the in-situ photo-deposition, which act as catalysts for PC-TC methanol aqueous reforming. The resultant 0.1%Pt/P25 catalyst exhibits H₂ evolution activity ～3.1 times than that of the TC condition and ～5.5 times than that of the photocatalytic reforming (PC) condition in the proposed PC-TC process; meanwhile 0.1%Pt/ZnO and 01%Pt/CeO₂ under PC-TC condition show ～1.3 times and ～2.0 times than that of the catalytic performance under TC condition. The physical characterizations prove that the metal-support interaction and the supports may be key factors for the catalytic performance. The active intermediate trapping experiments demonstrate possible intermediates in the PC-TC process and established reaction mechanisms to explain the synergetic effect for improved efficiency of hydrogen production. These findings may open up a new avenue of designing catalysts based on semiconductors for the PC-TC reforming of methanol-water to produce hydrogen in a high-efficiency and low-cost way, serving the needs of the future hydrogen economy.     

A facile one‐step method for spherical support preparation of Ziegler‐Natta catalyst

This study reports a novel one‐step method to synthesize a new spherical support for Ziegler‐Natta catalyst under moderate condition. The support is obtained from a dispersion system where the particle stabilizer polyvinylpyrrolidone plays a main role to stabilize the spherical particles. The new chemical of the support is CH₃CH₂OMgOCH(CH₂Cl)₂, which is first reported here, has been approved by newly filed patents and also confirmed by solution NMR, solid state NMR, pyrolysis‐gas chromatography‐mass spectrometry (Py‐GC‐MS), and ICP‐MS. The support and catalyst particles have uniform distributions. The catalyst prepared from this support has been evaluated with high activity. The polypropylene obtained has high isotacticity. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41014.     

某机关住宅楼基坑支护工程实践

结合实例介绍预应力管桩-钢结构内支撑的支护方案、及施工中的部分技术要点控制     

八渡南盘江特大桥使用性能综合评价

介绍了南昆铁路八渡南盘江特大桥主桥V形支撑连续梁结构的自振特性及横向刚度、舒适度斯佩林指数及狄克曼指数、抗脱轨安全度脱轨系数及卸载系数的计算结果,说明了这一新型铁路桥式结构具有良好的使用性能.     

壳牌煤气化工艺技术中水汽管道的设计特点分析

水汽系统是壳牌粉煤气化技术的核心之一。介绍了壳牌煤气化技术中水汽系统的工艺流程,并结合实际工程经验,探讨了以气化炉、合成气冷却器、中压蒸汽汽包、中压循环水泵为核心的水汽系统的设备布置;提出了水汽系统进水主管、进水支管、回水主管、回水支管、汽包进出口管道、循环水泵进出口管道等主要管道的设计要点,并对水汽系统管道的支吊架设置特点进行了分析与研究。     

Platinum on nitrogen doped graphene and tungsten carbide supports for ammonia electro-oxidation reaction

Ammonia electrooxidation reaction involving multistep electron-proton transfer is a significant reaction for fuel cells, hydrogen production and understanding nitrogen cycle. Platinum has been established as the best electrocatalyst for ammonia oxidation in aqueous alkaline media. In this study, Pt/nitrogen-doped graphene (NDG) and Pt/tungsten monocarbide (WC)/NDG are synthesized by a wet chemistry method and their ammonia oxidation activities are compared to commercial Pt/C. Pt/NDG exhibits a specific activity of 0.472 mA∙cm^–2, which is 44% higher than commercial Pt/C, thus establishing NDG as a more effective support than carbon black. Moreover, it is demonstrated that WC as a support also impacts the activity with further 30% increase in comparison to NDG. Surface modification with Ir resulted in the best electrocatalytic activity with Pt-Ir/WC/NDG having almost thrice the current density of commercial Pt/C. This work adds insights regarding the role of NDG and WC as efficient supports along with significant impact of Ir surface modification.     

全断面锚索施工钻机辅助支架的研制

普通锚索钻机难以在巷道帮部和底板施工,极大地制约了锚索支护的使用范围.为此,鹤煤公司六矿研制了一种可以实现全断面锚索施工的辅助支架,井在现场得到了应用.实践表明,使用该支架节省工时且安装方便,移动及维护简单,实现了全断面锚索施工.     

Effect of anode structure on performance of cone-shaped solid oxide fuel cells fabricated by phase inversion

Anode-supported cone-shaped tubular solid oxide fuel cells (SOFCs) are successfully fabricated by a phase inversion method. During processing, the two opposite sides of each cone-shaped anode tube are in different conditions--one side is in contact with coagulant (the corresponding surface is named as “W-surface”), while the other is isolated from coagulate (I-surface). Single SOFCs are made with YSZ electrolyte membrane coated on either W-surface or I-surface. Compared to the cell with YSZ membrane on W-surface, the cell on I-surface exhibits better performance, giving a maximum power density of 350 mW cm⁻² at 800 °C, using wet hydrogen as fuel and ambient air as oxidant. AC impedance test results are consistent with the performance. The sectional and surface structures of the SOFCs were examined by SEM and the relationship between SOFC performance and anode structure is analyzed. Structure of anodes fabricated at different phase inversion temperature is also investigated.     

Buckling of shear deformable thin-walled members—I. Variational principle and analyticalsolutions

A variational formulation for the buckling analysis of thin-walled members is developed based on the principle of stationary potential energy. The formulation is based on non-orthogonal coordinates and captures shear deformation effects due to bending and warping. It is applicable to members of doubly symmetric cross-sections subject to general axial and transverse forces and naturally incorporates the effect of load position relative to the shear centre. Applying the conditions of neutral stability to the variational expression, the governing differential equations of neutral stability and associated boundary conditions are formulated. The resulting field equations are exactly solved for benchmark cases involving column flexural buckling, column torsional buckling, and lateral-torsional buckling for beams, and the results are compared to closed form solutions based on classical and other modern theories.