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Abstract In order to assess the feasibility of utilizing renewable hydrogen as transport fuel for fuel cell vehicles, four possible low-carbon hydrogen supply routes for a hydrogen refueling station located in Shanghai are studied. Route Ⅰ and II are onsite hydrogen supply routes powered by a stand-alone or grid-connected photovoltaic (PV)-wind generation system separately. Route Ⅲ and IV are offsite hydrogen supply routes, in which hydrogen is produced by a stand-alone or grid-connected PV-wind generation system located in Qinghai Province respectively and delivered via liquid hydrogen truck to Shanghai. The microgrid system for hydrogen production is designed and optimized with the aid of HOMER Pro® software. The results show that in hydrogen production stage, Route Ⅳ shows the best economic performance, both in the total net present cost (NPC) cost and levelized cost of energy (LCOE) cost. As for the whole hydrogen supply chain, Route IV is also the most economic hydrogen supply way, the levelized cost of hydrogen (LCOH) of which is slightly lower than that of Route II. The sensitivity results show that the total LCOH cost of Route Ⅳ is feasible based on the current shorter electrolyzer's lifetime. Therefore, it indicates that nowadays, producing hydrogen from a grid connected PV-wind hybrid power system in renewable energy rich area (Qinghai Province) and delivering it via liquid hydrogen truck to a refueling station in east coast area (Shanghai) of China may be a feasible solution.

Abstract In order to assess the feasibility of utilizing renewable hydrogen as transport fuel for fuel cell vehicles, four possible low-carbon hydrogen supply routes for a hydrogen refueling station located in Shanghai are studied. Route Ⅰ and II are onsite hydrogen supply routes powered by a stand-alone or grid-connected photovoltaic (PV)-wind generation system separately. Route Ⅲ and IV are offsite hydrogen supply routes, in which hydrogen is produced by a stand-alone or grid-connected PV-wind generation system located in Qinghai Province respectively and delivered via liquid hydrogen truck to Shanghai. The microgrid system for hydrogen production is designed and optimized with the aid of HOMER Pro® software. The results show that in hydrogen production stage, Route Ⅳ shows the best economic performance, both in the total net present cost (NPC) cost and levelized cost of energy (LCOE) cost. As for the whole hydrogen supply chain, Route IV is also the most economic hydrogen supply way, the levelized cost of hydrogen (LCOH) of which is slightly lower than that of Route II. The sensitivity results show that the total LCOH cost of Route Ⅳ is feasible based on the current shorter electrolyzer's lifetime. Therefore, it indicates that nowadays, producing hydrogen from a grid connected PV-wind hybrid power system in renewable energy rich area (Qinghai Province) and delivering it via liquid hydrogen truck to a refueling station in east coast area (Shanghai) of China may be a feasible solution.

We reported the realization of assembling compact-designed supercapacitors using large-scaled free-standing and flexible single-walled carbon nanotube (SWCNT) films as both anode and cathode. A prototype of the processing procedures was developed to obtain the uniform spreading of the SWCNT films onto the separators serving as both electrodes and charge collectors without metallic current collectors, leading to a simplified and lightweight architecture. The area of SWCNT film on a separator can be scaled up and its thickness can be extended. High energy and power densities (43.7 Wh kg−1 and 197.3 kW kg−1, respectively) were achieved from the prepared SWCNT film-based compact-designed supercapacitors with small equivalent series resistance. The specific capacitance of this kind of compact-designed SWCNT film supercapacitor is about 35 F g−1. These results clearly show the potential application of free-standing SWCNT film in compact-designed supercapacitor with enhanced performance and significantly improved energy and power densities.

We reported the realization of assembling compact-designed supercapacitors using large-scaled free-standing and flexible single-walled carbon nanotube (SWCNT) films as both anode and cathode. A prototype of the processing procedures was developed to obtain the uniform spreading of the SWCNT films onto the separators serving as both electrodes and charge collectors without metallic current collectors, leading to a simplified and lightweight architecture. The area of SWCNT film on a separator can be scaled up and its thickness can be extended. High energy and power densities (43.7 Wh kg−1 and 197.3 kW kg−1, respectively) were achieved from the prepared SWCNT film-based compact-designed supercapacitors with small equivalent series resistance. The specific capacitance of this kind of compact-designed SWCNT film supercapacitor is about 35 F g−1. These results clearly show the potential application of free-standing SWCNT film in compact-designed supercapacitor with enhanced performance and significantly improved energy and power densities.

Assessing Biodiversity Declines Understanding human impact on biodiversity depends on sound quantitative projection. Pereira et al. (p. 1496 , published online 26 October) review quantitative scenarios that have been developed for four main areas of concern: species extinctions, species abundances and community structure, habitat loss and degradation, and shifts in the distribution of species and biomes. Declines in biodiversity are projected for the whole of the 21st century in all scenarios, but with a wide range of variation. Hoffmann et al. (p. 1503 , published online 26 October) draw on the results of five decades' worth of data collection, managed by the International Union for Conservation of Nature Species Survival Commission. A comprehensive synthesis of the conservation status of the world's vertebrates, based on an analysis of 25,780 species (approximately half of total vertebrate diversity), is presented: Approximately 20% of all vertebrate species are at risk of extinction in the wild, and 11% of threatened birds and 17% of threatened mammals have moved closer to extinction over time. Despite these trends, overall declines would have been significantly worse in the absence of conservation actions.

Assessing Biodiversity Declines Understanding human impact on biodiversity depends on sound quantitative projection. Pereira et al. (p. 1496 , published online 26 October) review quantitative scenarios that have been developed for four main areas of concern: species extinctions, species abundances and community structure, habitat loss and degradation, and shifts in the distribution of species and biomes. Declines in biodiversity are projected for the whole of the 21st century in all scenarios, but with a wide range of variation. Hoffmann et al. (p. 1503 , published online 26 October) draw on the results of five decades' worth of data collection, managed by the International Union for Conservation of Nature Species Survival Commission. A comprehensive synthesis of the conservation status of the world's vertebrates, based on an analysis of 25,780 species (approximately half of total vertebrate diversity), is presented: Approximately 20% of all vertebrate species are at risk of extinction in the wild, and 11% of threatened birds and 17% of threatened mammals have moved closer to extinction over time. Despite these trends, overall declines would have been significantly worse in the absence of conservation actions.