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Modern observations have determined the presence of hyperpycnal flows; however, their presence in ancient rocks is scarcely reported in the literature, particularly with respect to continental strata. The present study is the first to use core and thin-section analyses and examination of physical reservoir properties to identify hyperpycnal flow sediment from the lower section of the Oligocene Huagang Formation in the central Xihu Sag, East China Sea Shelf Basin. The multiple fine sandy layers are characterized by lower reverse-graded and upper normal-graded bedding with horizontal bedding, climbing-ripple lamination, wavy bedding, and small foreset laminae. Microerosion surfaces are occasionally present between the reverse-graded and normal-graded bedding, and plant fragments are sometimes visible in the deposits. The same grain size sequence changes are observed in the thin sections. This lithologic combination is considered to be related to hyperpycnal flow sedimentation caused by flood events. The lower reverse-graded and upper normal-graded bedding sequences indicate that the flood energy first increased then decreased and the microerosion surfaces were formed through erosion of lower sediments by the flood. Hyperpycnal flows can directly transport deposits from an estuary to a deep-water basin, which distinguishes them from typical turbidity currents. This study also establishes a sedimentary model of the hyperpycnal flow in lacustrine basin, which can be used as a reference for future hyperpycnal deposit studies. Key words: hyperpycnal flow deposit model, lacustrine basin, paleoclimate, Huagang Formation, Xihu Sag. Si des observations ont permis d'établir l'existence actuelle de courants hyperpycnaux, la présence de tels courants dans des roches anciennes est rarement signalée dans la documentation, particulièrement dans des contextes de strates continentales. La présente étude est la première à utiliser l'analyse de carottes et de lames minces et l'examen des propriétés physiques de réservoirs pour cerner la présence de sédiments de courants hyperpycnaux dans la séquence inférieure de la Formation oligocène de Huagang, du centre de la dépression de Xihu, dans le bassin de la plateforme de la mer de Chine orientale. Les multiples couches de sable fin définissent des strates inférieures à classement inverse et supérieures à classement normal, avec une stratification horizontale, des laminations à rides ascendantes, une stratification ondulée et de petites laminations frontales. Des microsurfaces d'érosion sont occasionnellement présentes entre les strates à classement inverse et celles à classement normal, et des fragments de plantes sont parfois visibles dans les sédiments. Les mêmes variations du classement au fil de la séquence sont observées en lames minces. Cette combinaison lithologique est considérée être reliée à la sédimentation associée à des courants hyperpycnaux causés par des épisodes de crues. Les séquences à classement inverse inférieure et à classement normal supérieure indiquent que l'énergie des crues est d'abord allée en augmentant, puis en diminuant et les microsurfaces d'érosion se sont formées par l'érosion par les crues de sédiments plus bas dans la séquence. Les courants hyperpycnaux peuvent transporter des sédiments directement d'un estuaire à un bassin d'eau profonde, ce qui les distingue de courants de turbidité typiques. L'étude établit également un modèle sédimentaire du courant hyperpycnal dans un bassin lacustre qui peut servir de référence pour les études futures de dépôts hyperpycnaux. [Traduit par la Rédaction] Mots-clés : modèle de dépôt de courants hyperpycnaux, bassin lacustre, paléoclimat, Formation de Huagang, dépression de Xihu., Introduction A hyperpycnal flow is a stable turbidity flow that occurs during periods of flooding when water transports sediment from an estuary to shallow sea, slope, or deep-water regions without [...]

In this study, a novel fabrication method was used to synthesize phenolic resin/phosphate hybrid coatings using aluminum dihydrogen phosphate (Al(H2PO4)3, hereafter denoted as Al), SC101 silica sol (Si) as the primary film-forming agent, and phenolic resin (PF) as the organic matrix. This approach culminated in the formation of Al+Si+PF organo–inorganic hybrid coatings. Fourier-transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) results confirmed the successful integration of hybrid structures within these coatings. The crystalline structure of the coatings post-cured at various temperatures was elucidated using X-ray diffraction (XRD). Additionally, the surface and cross-sectional morphologies were meticulously analyzed using scanning electron microscopy (SEM), offering insights into the microstructural properties of the coatings. The coatings' porosities under diverse thermal and temporal regimes were quantitatively evaluated using advanced image processing techniques, revealing a significant reduction in porosity to a minimum of 5.88% following a thermal oxidation process at 600 °C for 10 h. The antioxidant efficacy of the phosphate coatings was rigorously assessed through cyclic oxidation tests, which revealed their outstanding performance. Specifically, at 300 °C across 300 h of cyclic oxidation, the weight losses recorded for phosphate varnish and the phenolic resin-infused phosphate coatings were 0.15 mg·cm−2 and 0.09 mg·cm−2, respectively. Furthermore, at 600 °C and over an identical period, the weight reduction was noted as 0.21 mg·cm−2 for phosphate varnish and 0.085 mg·cm−2 for the hybrid coatings, thereby substantiating the superior antioxidation capabilities of the phenolic resin hybrid coatings in comparison to the pure phosphate varnish. [ABSTRACT FROM AUTHOR]