Aircraft tyres play a critical role in ensuring the safety of aircraft landings. This paper introduces a novel multi-scale analytical method for evaluating tyre impact performance, explicitly studying the effect of damage defects in the manufacturing and service process on tyre landing dynamic performance. Building on this approach, a numerical simulation of aircraft tyre static and impact load scenarios was conducted, followed by experimental validation. The study systematically compares and analyses the effects of void volume fraction, cord volume fraction and material scale factor on the maximum impact force experienced by aircraft tyre. The variations in maximum impact force arising from changes in tyre structural strength, and deformation can be explained by specific parameters. The findings of this research have significant implications for tyre design and engineering, as well as for enhancing the understanding of the factors that influence tyre performance and safety.

The description and delineation of trematode species is a major ongoing task. Across the field there has been, and currently still is, great variation in the standard of this work and in the sophistication of the proposal of taxonomic hypotheses. Although most species are relatively unambiguously distinct from their congeners, many are either morphologically very similar, including the major and rapidly growing component of cryptic species, or are highly variable morphologically despite little to no molecular variation for standard DNA markers. Here we review challenges in species delineation in the context provided to us by the historical literature, and the use of morphological, geographical, host, and molecular data. We observe that there are potential challenges associated with all these information sources. As a result, we encourage careful proposal of taxonomic hypotheses with consideration for underlying species concepts and frank acknowledgement of weaknesses or conflict in the data. It seems clear that there is no single source of data that provides a wholly reliable answer to our taxonomic challenges but that nuanced consideration of information from multiple sources (the ‘integrated approach’) provides the best possibility of developing hypotheses that will stand the test of time.

Station-keeping control is a critical technology for stratospheric aerostats. For those aerostats that utilise wind field environments to achieve trajectory control, the station-keeping capability of a single aerostat is inherently limited. This limitation can lead to instances of the aerostat flying outside the designated task area, thereby diminishing the effectiveness of station-keeping control. To ensure continuous monitoring of the restricted area for long endurance, dynamic adjustments and cooperative coverage among multiple aerostats are necessary. This paper introduces an optimal coverage algorithm based on Voronoi diagrams and presents a formation control method for stratospheric aerostats that employs the virtual force method and the ${A^{\rm{*}}}$ algorithm, respectively. In a real wind field environment, ten aerostats are deployed to optimally cover the restricted area. Simulation results indicate that the coverage rate of the stratospheric aerostats within the restricted area can exceed 70%, while the network connectivity rate among the aerostats can reach 80% following guidance control during return flights. Furthermore, the stratospheric aerostats that flying out of the restricted area can return through path planning and optimal coverage algorithm, and the networking connectivity rate between aerostats is higher than that using the virtual force method.

The dynamic model of the distributed propulsion vehicle faces significant challenges due to several factors. The primary difficulties arise from the strong coupling between multiple power units and aerodynamic rudder surfaces, the interaction between thrust and vehicle dynamics, and the complexity of the aerodynamic model, which includes high-dimensional and high-order variables. To address these challenges, wind tunnel tests are conducted to analyse the aerodynamic characteristics and identify variables affecting the aerodynamic coefficients. Subsequently, a deep neural network is employed to investigate the influence of the power system and aerodynamic rudder on the aerodynamic coefficients. Based on these findings, a multi-dynamic coupled aerodynamic model is developed. Furthermore, a control-oriented nonlinear dynamics model for the distributed propulsion vehicle is established, and a flight controller is designed. Finally, closed-loop simulations for the climb, descent and turn phases are performed, validating the effectiveness of the established model.

Turbulent flow widely exists in the aerospace field, and it is still challenging to realise the accurate prediction in the numerical simulation. To realise the high-fidelity numerical simulation of compressible turbulent flow, a high-order accurate self-adaptive turbulence eddy simulation (SATES) method is developed on the PHengLEI-HyOrder open-source solver, combining with the high-order accurate weighted compact nonlinear schemes (WCNS). The compressible flow in the subsonic and transonic is numerically simulated, including some typical cases, such as subsonic flow past a circular cylinder and flow past a square cylinder, high-lift configuration DLR-F11, transonic flow around a circular cylinder. The results predicted by the current high-order accurate SATES are in good agreement with the available experimental and numerical data. The present numerical method can also accurately capture the interactions between shock waves and turbulence while accurately simulating flow separation, shear layer instability and large-scale vortex shedding. The results obtained show that the current high-order accurate SATES simulations based on PHengLEI-HyOrder solver can accurately simulate complex turbulent flows with high reliability.

Rogue waves (RWs) can form on the ocean surface due to the well-known quasi-four-wave resonant interaction or superposition principle. The first is known as the nonlinear focusing mechanism and leads to an increased probability of RWs when unidirectionality and narrowband energy of the wave field are satisfied. This work delves into the dynamics of extreme wave focusing in crossing seas, revealing a distinct type of nonlinear RWs, characterised by a decisive longevity compared with those generated by the dispersive focusing (superposition) mechanism. In fact, through fully nonlinear hydrodynamic numerical simulations, we show that the interactions between two crossing unidirectional wave beams can trigger fully localised and robust development of RWs. These coherent structures, characterised by a typical spectral broadening then spreading in the form of dual bimodality and recurrent wave group focusing, not only defy the weakening expectation of quasi-four-wave resonant interaction in directionally spreading wave fields, but also differ from classical focusing mechanisms already mentioned. This has been determined following a rigorous lifespan-based statistical analysis of extreme wave events in our fully nonlinear simulations. Utilising the coupled nonlinear Schrödinger framework, we also show that such intrinsic focusing dynamics can be captured by weakly nonlinear wave evolution equations. This opens new research avenues for further explorations of these complex and intriguing wave phenomena in hydrodynamics as well as other nonlinear and dispersive multi-wave systems.

Artist Tetsu Takeda left Japan for America in 1986 and returned to Japan in 2011. Shortly after the Fukushima nuclear disaster, Takeda started identifying himself as a “professional artist” and only doing “high art” by rethinking life and our role as human beings interfering with nature. Takeda is an eccentric collector of ocean rubbish flushed ashore by waves. In his tiny home studio, he creates various big-eyed rubbish creatures in diverse forms, shapes, dimensions, and colors in his unorthodox way reminiscent of Victor Frankenstein in this lab. For him, doing new artistic endeavors is a ritual of giving life—to “vitalize” rubbish—and inhabiting a reformulated society of nature, whether privately (in his home) or publicly (in galleries).

There is widespread concern over the scale of China's consumption of fossil fuels, and particularly over recent increases in coal burning in the electric power sector. Nevertheless it is a fact that China is greening its power sector more than blackening it. We present updated evidence that China's electric power system has been greening – in terms of capacity added from renewable (WWS) sources, growth in electricity generated from WWS sources, and investment in new generation infrastructure. We present the results for the green renewable sector (WWS), the black fossil fuel sector (thermal) and the nuclear sector (growing, but not nearly as fast as WWS). This evidence reveals that China's extreme dependence on coal and other fossil fuels is moderating, as it ramps up alternatives – particularly the generation of domestic power from renewable sources based on water, wind and sun (WWS). In short, China's energy system is diversifying: it is greening within a large and growing carbon-intensive existing system. At the same time, China has steadily increased levels of coal burning in the past two to three years – even while the green trend in domestic power generation has continued. China's level of fossil fuel investments abroad (particularly through the Belt and Road Initiative) remain a source of concern. China continues to send disconcertingly mixed messages on the energy front.

Are China's energy investments around the world promoting green and clean power generation in countries other than China, or are they exporting China's dirty coal-fired power generation capacity to third countries? This is an important question, and much hangs on how it is answered. China's Belt and Road is a conduit for polluting investments by Chinese policy banks around the world, argues Professor Kelly Sims Gallagher (The Fletcher School, Tufts University) in a Beyondbrics comment in the Financial Times on August 10, 2018. But when examined, this argument is not persuasive. If we use the same China Global Energy Finance (CGEF) database that Gallagher uses, it is easy to demonstrate the opposite finding, namely that China's investments globally in power generation over the past five years have been more green than black.

The world's electric power system continues to be a principal source of carbon emissions, comparable to transport and such industries as steel and cement. Intense debate surrounds the issue of the pace at which it is greening. In this paper we offer a precise definition of greening as a rising proportion of electric power sourced from water, wind and sun (WWS), since these are all fundamentally renewable. Using the latest data from the BP Energy Review as well as national and regional sources, we demonstrate that by 2019 the EU-28 had reached a proportion of electricity generated from WWS of 34%, followed by China at 27%, Japan at 19% and the US at 17%. Moreover, the EU-28 achieved the fastest pace of transition, increasing its WWS-share of electricity generated from 20% in 2010 to 34% in 2019, or a 14% green shift in a decade. Over the same period, China's green shift in power generation was 10%, while that of Japan was 9% (all achieved in the decade following the Fukushima disaster) and the US at an 7% shift. The IEA has just issued a report revealing that globally renewable sources of energy account for 29% of electricity generated in 2020, up 2% on 2019 levels.

In this paper we examine the performance of China in greatest detail, since it is now the world's largest burner of coal, operates the world's largest electric power system, and is responsible for the highest levels of carbon emissions. We make the case that China has overall goals of decarbonization and dematerialization (i.e. using less material per unit of GDP), where the former goal is met by the shift to renewable sources of energy and the latter by the shift towards urban mining and the circular economy. Based on newly published data from the China Energy Council, we update our previous analyses of China's energy choices, looking for the green shoots in an otherwise black energy system. China's electric power system, now the largest in the world, continues to burn a lot of coal – nearly 4 billion tonnes in 2020, a 1% decrease on the 2019 total. But within this black power economy the green shoots are increasingly significant. We show that the proportion of China's electric power generation sourced from water, wind and sun (WWS) by 2020 reached 27%, up from 17% a decade earlier – a 10% green shift in a decade. In terms of generating capacity the figures for China are even more striking. In 2020 China's generating capacity sourced from WWS reached 41%, up from 25% in 2011, or a 16% green shift in capacity in 10 years. At this rate of a 1.6% green shift in generating capacity per year, China's electric power system would be more green than black by 2026, with widespread repercussions, for China and the world. We put these data in their international comparative perspective, and in the perspective that China is electrifying its economy faster than any other major region. But the levels of carbon emissions continue to rise (reaching 13.5 billion tonnes carbon dioxide in 2020), with China's leadership not predicting their peaking before 2030. So there is much to be done in terms of decarbonizing energy and electric power in particular. The wider significance of China's green choices, in the context of its increasing assertiveness internationally, is discussed.

China operates the world's largest electric power system, which over the course of the 21st century has been consistently greening at the margin, even as the whole energy system and the manufacturing system it powers remain largely black. In this article we update our argument to reveal how in terms of capacity, of electricity generated and of investment, China's electrical system is continuously greening and within less than five years, would be expected to be more green than black in terms of generating capacity. We demonstrate how the sourcing of generating power from hydro, wind and sun is becoming ever more significant, outranking the contribution from nuclear.

The techniques employed to collect and store trematodes vary between research groups, and although these differences are sometimes necessitated by distinctions in the hosts examined, they are more commonly an artefact of instruction. As a general rule, we tend to follow what we were taught rather than explore new techniques. A major reason for this is that there are few technique papers in the published literature. Inspired by a collaborative workshop at the Trematodes 2024 symposium, we outline our techniques and processes for collecting adult trematodes from fishes and discuss the improvements we have made over 40 years of dissections of 20,000+ individual marine fishes. We present these techniques for two reasons: first, to encourage unified methods across the globe, with an aim to produce optimally comparable specimens across temporal periods, across geographic localities, and between research groups; and second, as a resource for inexperienced researchers. We stress the importance of understanding differences in host biology and the expected trematode fauna, which ultimately enables organised and productive dissections. We outline our dissection method for each key organ separately, discuss handling, fixation, and storage methods to generate the most uniform and comparable samples, and explore ethical considerations, issues of accurate host identification, and the importance and potential of clear record keeping.