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In this work, we report the thermal kinetics, thermodynamics, and decomposition mechanism of AP-based molecular perovskite energetic materials and estimate their thermal safety performance. Typical AP-based molecular perovskite energetic materials, ([H.sub.2]dabco)[N[H.sub.4][(Cl[O.sub.4]).sub.3]] (DAP-4), ([H.sub.2]pz)[N[H.sub.4][(Cl[O.sub.4]).sub.3]](PAP-4), ([H.sub.2]mpz)[N[H.sub.4][(Cl[O.sub.4]).sub.3]](PAP-M4), and ([H.sub.2]hpz)[N[H.sub.4][(Cl[O.sub.4]).sub.3]] (PAP-[H.sub.4]), were synthesized and characterized. These were studied using differential scanning calorimetry (DSC). The results show that all of the obtained AP-based molecular perovskite energetic materials have higher thermal decomposition temperatures, and the peak temperatures are more than 360 [degrees]C. All follow random nucleation and growth models. Other thermodynamic parameters, such as the reaction enthalpy ([DELTA]H), entropy change ([DELTA]S), and Gibbs free energy ([DELTA]G), show that they are generally thermodynamically stable. Moreover, their adiabatic induced temperatures were obtained; [T.sub.D24] of DAP-4, PAP-4, PAP-M4, and PAP-[H.sub.4] were 246.6, 201.2, 194.5, and 217.5 [degrees]C, respectively. This study offers an important and in-depth understanding of the thermal decomposition characteristics of AP-based molecular perovskite energetic materials and their potential applications. Key words: AP-based molecular perovskite energetic materials, DAP-4, thermal kinetics, thermal safety performance. Dans le cadre des présents travaux, nous avons étudié la cinétique thermique, la thermodynamique et le mécanisme de décomposition des matériaux énergétiques de type pérovskite moléculaire à base de perchlorate d'ammonium (PA), et nous avons évalué leurs performances en matière de sécurité thermique. Nous avons synthétisé et caractérisé des matériaux énergétiques représentatifs de type pérovskite moléculaire à base de PA ([H.sub.2]dabco)[N[H.sub.4][(Cl[O.sub.4]).sub.3]] (DAP-4), ([H.sub.2]pz) [N[H.sub.4][(Cl[O.sub.4]).sub.3]] (PAP-4), ([H.sub.2]mpz)[N[H.sub.4][(Cl[O.sub.4]).sub.3]] (PAP-M4) et ([H.sub.2]hpz)[N[H.sub.4][(Cl[O.sub.4]).sub.3]] (PAP-[H.sub.4]). Nous les avons également étudiés par calorimétrie différentielle à balayage (DSC, differential scanning calorimetry). Les résultats montrent que tous les matériaux énergétiques type pérovskite moléculaire à base de PA présentent des températures de décomposition thermique plus élevées, et que les températures de pointe sont supérieures à 360 [degrees]C. En outre, tous suivent le modèle de nucléation et de croissance aléatoires. D'autres paramètres thermodynamiques, tels que l'enthalpie de réaction ([DELTA]H), la variation d'entropie ([DELTA]S) et l'énergie libre de Gibbs ([DELTA]G), montrent qu'ils sont généralement stables sur le plan thermodynamique. De plus, nous avons obtenu les températures d'induction adiabatiques; le [T.sub.D24] du DAP-4, du PAP-4, du PAP-M4 et du PAP-[H.sub.4] étant respectivement de 246,6, de 201,2, de 194,5 et de 217,5 [degrees]C. Ces travaux permettent d'approfondir de manière importante la compréhension des caractéristiques de décomposition thermique des matériaux énergétiques de type pérovskite moléculaire à base de PA et de leurs applications potentielles. [Traduit par la Rédaction] Mots-clés : matériaux énergétiques de type pérovskite moléculaire à base de perchlorate d'ammonium, DAP-4, cinétique thermique, performances de sécurité thermique., 1. Introduction In recent years, with the increase in the functional requirements of energetic materials in civilian and military applications, energetic materials with unique and excellent characteristics have attracted widespread [...]

In recent years, the widespread introduction of bike-sharing systems in China has had a profound impact on the daily lives of Chinese citizens and the development of the urban transport system. This article attempts to analyse the impact of this phenomenon on sustainability. The gradual improvement of related monitoring measures has facilitated the maturation of the bike-sharing industry from the initial stage of uncontrolled growth to the current stage of standardised management. By tracing the global development of bike-sharing systems with a special focus on China, this study sheds light on the platformisation of bicycles and their multiple impacts on technical, environmental, cultural, economic and social sustainability. Furthermore, this study provides a comprehensive analysis of the transformation of bicycles in China and highlights the diverse impacts of platform-based bike sharing on various facets of Chinese society. The development of different bike-sharing systems in China is a unique and crucial case to interpret the current situation of bike sharing and imagine future scenarios. In contrast to the prevailing and uniform approach derived from the experiences of Northern European countries, the massive and widespread experimentation with different bike-sharing schemes in China reveals not only potentials and aspects of sustainability, innovation, and urban and social regeneration, but also some hidden shadows similar to those in small-scale contexts such as Northern Europe. Furthermore, this study emphasises the crucial role of sustainable development principles in addressing the urban challenges specific to China. [ABSTRACT FROM AUTHOR]

In China, due to the large-scale lockdowns and strict prevention policies of COVID-19, Chinese tennis coaches have started to open a new front of their career by offering online tennis training on social media platforms. This study introduces mediatisation theory as a theoretical framework to investigate the mediatisation process of tennis coaching on social media platforms in China. Both quantitative and qualitative data were collected to analyse three dimensions of Chinese tennis coaches' professional and living conditions: the career trajectory of tennis coaches, the mediatisation of the profession of tennis coaching, and the financial crisis faced by tennis clubs and the tennis industry. We monitored the BiliBili channels of the most popular tennis vloggers on BiliBili and analysed their media practices. We also collected data from job search websites and conducted in-depth interviews with 30 Chinese tennis coaches. The findings are as follows: The new approach has gradually gained the support of coaches thanks to its advantages such as flexibility, accessibility, self-promotion and marketing strategies. The mediatisation of tennis training has accelerated the popularisation of tennis in China, as have relevant government regulations regarding self-promotion platforms. [ABSTRACT FROM AUTHOR]

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We proposed with excitement a novel molecular co-assembly (MCSA) that can effectively overcome the agglomeration of energetic materials. Through the coordinated self-assembly of polymethyl methacrylate-polyvinyl acetate (PMMA-PVA) with honeycomb-like structure and nanoparticles, a controlled and orderly distribution of nitroamine explosive (cyclotetramethylenetetranitramine, HMX; cyclotrimethylenetrinitramine, RDX; and hexanitrohexaazaisowurtzitane, CL-20) structure was achieved, above all, resolving the agglomeration problem availably. The modification ability of PMMA to RDX, HMX, and CL-20 at different temperatures was simulated by Materials Studio, which provided guidance for the ambient temperature of collaborative self-assembly. In order to compare the priority of the morphology and performance, RDX/PMMA-PVA, HMX/PMMA-PVA, and CL-20/PMMA-PVA composite particles with the same PMMA content were also fabricated by water suspension coating method, respectively. Structural characterizations and thermal stability of the composites were systematically studied by scanning electron microscopy (SEM), X-ray diffraction (XRD), fourier-transform infrared (FT-IR) spectra, and differential scanning calorimeter (DSC). Moreover, the safety performance was analyzed by qualitative testing of impact sensitivity and friction sensitivity. The solid spherical PBX prepared via collaborative self-assembly all exhibited a perfect spherical structure, smooth, and flat coating, without any agglomeration. They had the same crystalline structure as the uncoated explosives, simultaneously demonstrating lower impact sensitivity and higher energy performance. The application of collaborative self-assembly technology has broken through the key technical bottleneck of the shell material being easy to form a separate phase in the desensitization coating of explosives, availably resolved the problems of particle exposure and low coverage during the coating, thus possessing vital significance for reference in the design and fabrication of PBXs with core-shell structure. [ABSTRACT FROM AUTHOR]