Local Built-In Field at the Sub-nanometric Heterointerface Mediates Cascade Electrochemical Conversion of Lithium–sulfur Batteries

Heterogeneous catalytic mediators have been proposed to play a vital role in enhancing the multiorder reaction and nucleation kinetics in multielectron sulfur electrochemistry. However, the predictive design of heterogeneous catalysts is still challenging, owing to the lack of in-depth understanding of interfacial electronic states and electron transfer on cascade reaction in Li–S batteries. Here, a heterogeneous catalytic mediator based on monodispersed titanium carbide sub-nanoclusters embedded in titanium dioxide nanobelts is reported. The tunable catalytic and anchoring effects of the resulting catalyst are achieved by the redistribution of localized electrons caused by the abundant built-in fields in heterointerfaces. Subsequently, the resulting sulfur cathodes deliver an areal capacity of 5.6 mAh cm⁻² and excellent stability at 1 C under sulfur loading of 8.0 mg cm⁻². The catalytic mechanism especially on enhancing the multiorder reaction kinetic of polysulfides is further demonstrated via operando time-resolved Raman spectroscopy during the reduction process in conjunction with theoretical analysis.     

微软在数码港的新办公室

微软去年十月,将250名员工,从中环的办公室迁至数码港.他们现在占用三层由公共电梯连接的楼层,总面积共6000平方米.新办公室的室内空间由微软和执行建筑师Gens1er(香港)合作设计,体现了微软公司强调人力资源的信念.设计营造了一个鼓励合作与交流的、能够激发工作热情的环境,包括了开放空间、共享工作区、策略室(用于非正式会议)、娱乐休闲区等富有创意的设施.     

Post-interdisciplinary frames of reference: exploring permeability and perceptions of disciplinarity in the social sciences

The ProQuest Dissertations and Theses database contains records for approximately 2.3 million dissertations conferred at 1,490 research institutions across 66 countries. Despite the scope of the Dissertations and Theses database, no study has explicitly sought to validate the accuracy of the ProQuest SCs. This research examines the degree to which ProQuest SCs serve as proxies for disciplinarity, the relevance of doctoral work to doctoral graduates’ current work, and the permeability of disciplines from the perspective of the mismatch between SCs and disciplinarity. To examine these issues we conducted a survey of 2009–2010 doctoral graduates, cluster-sampled from Economics, Political Science, and Sociology ProQuest SCs. The results from the survey question the utility of traditional disciplinary labels and suggest that scholars may occupy a post-interdisciplinary space in which they move freely across disciplinary boundaries and identify with topics instead of disciplines.     

Cotton in the new millennium: advances,economics, perceptions and problems

Cotton is the most significant natural fibre and has been a preferred choice of the textile industry and consumers since the industrial revolution began. The share of man-made fibres, both regenerated and synthetic fibres, has grown considerably in recent times but cotton production has also been on the rise and accounts for about half of the fibres used for apparel and textile goods. To cotton’s advantage, the premium attached to the presence of cotton fibre and the general positive consumer perception is well established, however, compared to commodity man-made fibres and high performance fibres, cotton has limitations in terms of its mechanical properties but can help to overcome moisture management issues that arise with performance apparel during active wear.

This issue of Textile Progress aims to:

1. Report on advances in cotton cultivation and processing as well as improvements to conventional cotton cultivation and ginning. The processing of cotton in the textile industry from fibre to finished fabric, cotton and its blends, and their applications in technical textiles are also covered.

2. Explore the economic impact of cotton in different parts of the world including an overview of global cotton trade.

3. Examine the environmental perception of cotton fibre and efforts in organic and genetically-modified (GM) cotton production. The topic of naturally-coloured cotton, post-consumer waste is covered and the environmental impacts of cotton cultivation and processing are discussed. Hazardous effects of cultivation, such as the extensive use of pesticides, insecticides and irrigation with fresh water, and consequences of the use of GM cotton and cotton fibres in general on the climate are summarised and the effects of cotton processing on workers are addressed. The potential hazards during cotton cultivation, processing and use are also included.

4. Examine how the properties of cotton textiles can be enhanced, for example, by improving wrinkle recovery and reducing the flammability of cotton fibre.

     

Travel bans and scientific mobility: utility of asymmetry and affinity indexes to inform science policy

Scientometrics - This study explores the international profiles in collaboration and mobility of countries included in the so-called “travel bans” implemented by US President Trump as...     

A practical photoelectrochemical cell using non precious metal electrodes

In this study a Photoelectrochemical Cell (PEC) constructed with inexpensive materials photodegraded selected organic compounds present in model waste waters, with the concomitant production of electrical current. Organic substrates dissolved in salt water included formic acid, 2-propanol, 1,2-dihydroxybenzene and ascorbic acid. Significant degradation of ascorbic acid was achieved when the cell was illuminated with a household 60 W tungsten light bulb, although better results were achieved with UV sources. Degradation of all the compounds was found to occur by zero order kinetics, and the PEC was shown not to work appreciably in dark conditions. Using a conventional light bulb, a formic acid PEC produced a power density of 19.1 ± 2 mW m⁻². When exposed to natural daylight, a power density of 31.5 ± 2 mW m⁻² was achieved. There is considerable scope for scale up of this device for exterior use.     

Alterations in fatty acid composition and fluidity of cell membranes affect the accumulation of PCB congener 2,2′,5,5′‐tetrachlorobiphenyl by Ralstonia eutropha H850

The effect of alterations in fatty acid composition and fluidity of cell membranes on the accumulation of PCB congener 2,2′,5,5′‐tetrachlorobiphenyl (TeCB) by Ralstonia eutropha (formerly Alcaligenes eutrophus) H850 was studied. Cells of R eutropha H850 grown on either biphenyl or fructose were used. Significant increases in saturated fatty acid composition and decreases in membrane fluidity of bacteria grown on biphenyl at 28 °C were observed compared with those grown on fructose at 17 or 28 °C. The ratio of saturated fatty acids to unsaturated fatty acids and membrane fluidity of R eutropha H850 grown on biphenyl at 28 °C resembled those of cells grown on fructose at 37 °C. No inhibition effect of the uncoupler 2,4‐dinitrophenol (2,4‐DNP) on TeCB accumulation was observed, suggesting an energy‐independent mechanism for TeCB accumulation in cells of R eutropha H850. The amount of TeCB accumulated was considerably higher in R eutropha H850 grown on fructose at 17 and 28 °C than when grown on biphenyl at 28 °C. Similar amounts of TeCB accumulated in bacteria grown on biphenyl at 28 °C as compared with those grown on fructose at 37 °C. These results suggest the alterations in fatty acid composition and membrane fluidity of R eutropha H850 may affect the accumulation of TeCB. © 2002 Society of Chemical Industry