Sedimentary systems of the Oligocene Huagang Formation in the central anticline zone of the Xihu Depression,East China Sea Shelf Basin

The Xihu Depression is the largest hydrocarbon-bearing depression of the East China Sea Shelf Basin(also referred to as the ECSSB).However,the depositional systems and reservoir distribution of the Oligocene Huagang Formation in the Xihu Depression are still controversial.Under the guidance of sedimentology and stratigraphy,this study documented a marine-terrestrial transitional environment in the restricted bay setting of the Oligocene Huagang Formation through core description,well logging,and seismic data analysis.This study also revealed that the Oligocene Huagang Formation is dominated by tidal delta,estuary,and gravity flow deposits in the central anticline zone of the Xihu Depression.The new understanding of the sedimentary systems and the discovery of the transgressive gap in the eastern Diaoyu Islands uplift explain the origin of fine-grained sediments and the EW-trending sand bodies in the central depression and the sand bodies parallel to shoreline in the west slope belt,which cannot be explained by previous study results,such as southern transgression or fluvial deltas and even lacustrine deposition.Moreover,the tidal channels,tidal sand flats,and gravity flow sand bodies formed by the transgressive tides are high-quality reservoirs.The study will provide a basis for well placement and serve as guidance for the selection of favorable hydrocarbon exploration areas in the Xihu Depression.

Hybrid silicon-barium-titanate tunable racetrack resonators based on chemical solution deposition

Integrated electro-optic tuning devices are essential parts of optical communication,sensors,and optical machine learning.Among the available materials,silicon is the most promising for on-chip signal processing and networks.However,silicon is limited owing to the absence of efficient Pockels electro-optic tuning.Herein,we propose a new hybrid silicon-barium-titanate(Si-BTO)integrated photonic platform,in which the BTO thin film is deposited by the chemical solution deposition(CSD)method.A tunable racetrack resonator is demonstrated to confirm the Pockels electro-optic tuning potential of the BTO thin film.The hybrid racetrack resonator has a tuning efficiency of 6.5 pm∕V and a high-power efficiency of 2.16 pm∕nW.Moreover,the intrinsic quality factor of the fabricated racetrack resonator is 48,000,which is the highest in hybrid Si-BTO platforms,to the best of our knowledge.The high-speed test verifies the stability of the racetrack resonator.The hybrid Si-BTO technology based on the CSD method has the advantages of low equipment cost and simple fabrication process,which holds promise for low-power electro-optic tuning devices.

Thermal shock resistance enhancement by improved interfacial bonding for carbon/aluminium composites

Carbon/aluminium(C/Al)composites have the advantages of low density and high electrical conductivity,which have potential applications in aerospace,rail transportation and other fields.However,the unstable bonding of the C/Al interface and significant thermal expansion differences have resulted in risks of the composites'failure once suffering from severe thermal shock.In this work,the C/Al composites were prepared by the pressure impregnation method,and silicon(Si)was added to overcome the problems of C/Al non-wettability and thermal expansion differences.The effects of mass fractions of doped silicon on the mechanical properties,electrical conductivity and thermal shock resistance of C/Al composites were also examined.Results show that the formed SiC interlayer has effectively enhanced the interfacial bonding and reduced the differences in the thermal expansion coefficient of each component.As a result,the thermal shock resistance of the composites has been remarkably improved,and the flexural strength could remain 90%of the original level after the thermal shock test,compared with 50%of that without Si doping.