Journal of Materials Science: Materials in Electronics - In this work, the very rapid one-step mechanochemical synthesis of nanocrystalline ternary chalcogenide chalcostibite CuSbS2 prepared from... 相似文献
Developing a Pt-based electrocatalytic material able to selectively catalyze hydrogen oxidation (HOR) while supressing oxygen reduction (ORR) is beneficial for durability of the fuel cells. Namely, degradation of carbon supported Pt particles is dramatically influenced by the unwanted ORR enrolling at the anode due to the air penetration during start-up/shut-down events. We present an organic matrix tris(aza)pentacene (TAP), which belongs to π-functional materials with ladder-like conjugated nitrogen-containing units, as the support for Pt to form a “smart” fuel cell anode able to selectively catalyze HOR and to suppress ORR. “Switching-on/off” of the composite material activity is provided by reversible reduction/oxidation of the TAP in the low potential region which provokes TAP - HxTAP transition. Conductivity of the reduced HxTAP enables supported Pt particles to effectively run HOR. In contrast, restricted conductivity of oxidized TAP analogue leads to the substantial drop in the ORR activity with respect to benchmark Pt/C catalyst. 相似文献
Journal of Superconductivity and Novel Magnetism - In this work, the RMO3 (R?=?Pr, Nd and M?=?Fe, Co) perovskites had been synthesized by hydrothermal method. The structural... 相似文献
Poly(methyl methacrylate-co-acrylic acid) [P(MMA-co-AA)] incorporated with 0–9 wt% of trimethoxyvinylsilane (TMVS) has been studied to investigate the effect of TMVS on the adhesion properties of P(MMA-co-AA) nanospheres coated on silicon substrate as well as on the power conversion efficiency (PCE) of silicon solar module coated with the polymer nanospheres. The incorporation of 7 and 9 wt% of TMVS into the copolymer has been found to render the copolymer stronger adhesion to glass substrate than the samples with lower amount of TMVS in them. The coating of the P(MMA-co-AA) nanospheres on the glass surface of solar module increases the light harvesting efficiency by serving as an anti-reflective layer. Solar module coated with an array of P(MMA-co-AA) nanospheres with 7 wt% of TMVS yielded the highest PCE enhancement of 98% under the illumination of an AM1.5 solar simulator. The natural weathering results indicate that the copolymer with 7% of TMVS was able to withstand prolonged natural weathering exposure and remained reasonably effective in PCE enhancement up to 130 days of outdoor exposure. This study demonstrates a cost-effective technique to bind [P(MMA-co-AA)] nanospheres onto the silicon surface of solar module via siloxane linkages and thus increases the PCE of the solar module effectively. The Tg of the copolymer increased linearly from 110.31 to 118.42 °C when 0–9 wt% of TMVS was added into it. Thermogravimetry results indicate that the incorporation of TMVS does not give any significant effect on the Td of the copolymer, which occurs at about 390 °C.
In this work a solver for two-dimensional, instationary two-phase flows on the basis of the extended discontinuous Galerkin (extended DG/XDG) method is presented. The XDG method adapts the approximation space conformal to the position of the interface. This allows a subcell accurate representation of the incompressible Navier-Stokes equations in their sharp interface formulation. The interface is described as the zero set of a signed-distance level-set function and discretized by a standard DG method. For the interface, resp. level-set, evolution an extension velocity field is used and a two-staged algorithm is presented for its construction on a narrow-band. On the cut-cells a monolithic elliptic extension velocity method is adapted and a fast-marching procedure on the neighboring cells. The spatial discretization is based on a symmetric interior penalty method and for the temporal discretization a moving interface approach is adapted. A cell agglomeration technique is utilized for handling small cut-cells and topology changes during the interface motion. The method is validated against a wide range of typical two-phase surface tension driven flow phenomena in a 2D setting including capillary waves, an oscillating droplet and the rising bubble benchmark. 相似文献
Cooperative perception represents an important technology to fulfil the higher automation levels of connected and automated mobility (CAM). In cooperative perception, the sensor data, either raw or processed, is shared among neighbour vehicles with the objective of enhancing or complementing the perception obtained by on-board sensors. The vehicle that requests this external perception data needs to have this data quickly. However, it first needs to discover the network address of the neighbour vehicle that wants to connect to. Specially in a dense urban area or in a congested radio channel, an inefficient method for neighbour vehicle discovery could prevent a timely start of the cooperative perception session. This paper describes a novel 5G multi-access edge computing (MEC) solution that that boosts the selection of interesting neighbour vehicles according to a geographical region of interest (ROI) after applying pertinent adjustments considering vehicles’ dynamics and network communication latencies. In contrast to broadcast-based methods, in the proposed method the vehicles are only sending their periodical position data to a MEC service, which centralises the vehicle discovery requests. The objective of this Vehicle Discovery Service (VDS) is to support the startup of Web Real-Time Communications (WebRTC)-based Extended Sensors CAM applications. The proposed VDS has been validated using a public vehicular traffic dataset evaluating geo-position accuracy. The WebRTC-based streaming pipeline has been validated testing its feasibility for a See-Through video streaming application.
ABSTRACTNumerous claims have been made about the benefits of activity-based working (ABW) on workers’ health and work performance. Yet, it is unclear if these claims are proven. This systematic review aims to establish whether there is an evidence base for the effects of ABW on health, work performance and perceptions of the work environment. Eight databases were searched in September 2016. Three reviewers independently screened titles and abstracts and assessed the studies and extracted the data. Seventeen studies involving 36,039 participants were included. The study designs varied in rigorousness from qualitative studies to pre–post-trials and in sample size ranging from 12 to 11,799. This review found that ABW has positive merits in the areas of interaction, communication, control of time and space, and satisfaction with the workspace; however, it is unfavourable for concentration and privacy. For physical and mental health, the evidence is equivocal. ABW seems to be a promising concept that can be implemented and promoted based on some benefits for work performance and perceptions of the work environment when it is coupled with appropriate management support and organization. More high-quality research is needed to strengthen the evidence base further and establish its health effects. 相似文献
This paper examines the potential of a biological activity control system (BACS) for biological activated carbon (BAC) in comparison to granular activated carbon (GAC) for the treatment of potable water. The overall objective of the project is to produce drinking water of a higher quality more economically by developing a BACS for exhausted GAC that can be transformed to BAC by the development of a natural biofilm during the bio-regeneration mode. The research therefore may be interesting for water companies and the activated carbon industry. Findings show that the lifetime of a GAC filter can be significantly extended by maintaining an active biofilm that has to be controlled in order to avoid filter clogging. The most important parameters are dissolved oxygen (DO), pH and a correct balance of nutrients, which enables a natural control of the biomass. pH control was required to maintain an optimal bacteria-protozoa level. Excessive growth of filamentous bacteria can be prevented by a decrease in DO, increase in pH and the reduction of one essential nutrient, e.g. total phosphorus (P). Total organic carbon (TOC) and chemical oxygen demand (COD) values were reduced by bioactivity. DO, turbidity and suspended solids (SS) values were kept in acceptable ranges with respect to drinking water objectives. Plants without a significant population of protozoa deliver turbid low quality effluent high on SS and biochemical oxygen demand (BOD). It was possible to control the biofilm on GAC containing a natural biofilm and BAC during the bio-regeneration mode. Natural and artificial bio-regeneration lead to similar performance characteristics. 相似文献