Characteristics and main controlling factors of helium resources in the main petroliferous basins of the North China Craton

At present, the main controlling factors of helium accumulation is one of the key scientific problems restricting the exploration and development of helium reservoir. In this paper, based on the calculation results of He generation rate and the geochemical characteristics of the produced gas, both the similarities and differences between natural gas and He resources in the Bohai Bay, Ordos and the surrounding Songliao Basin are compared and analyzed, discussing the main controlling factors of helium resources in the three main petroliferous basins of the North China Craton. It is found that the three basins of Bohai Bay, Ordos and Songliao have similar characteristics of source rocks, reservoirs and cap rocks, that's why their methane resource characteristics are essentially the same. The calculated ~4He generation per cubic metamorphic crystalline basement in the three basins is roughly equivalent, which is consistent with the measured He resources, and it is believed that the ~4He of radiogenic from the crust is the main factor controlling the overall He accumulation in the three basins;there is almost no contribution of the mantle-derived CH_4, which suggests that the transport and uplift of mantle-derived ~3He carried by the present-day magmatic activities along the deep-large faults is not the main reason for the mantle-derived ~3He mixing in the basins. Combined with the results of regional volcanic and geophysical studies,it is concluded that under the background of the destruction of North China Craton, magma intrusion carried a large amount of mantle-derived material and formed basic volcanic rocks in the Bohai Bay Basin and Songliao Basin, which replenished mantle-derived ~3He for the interior of the basins, and that strong seismic activities in and around the basins also promoted the upward migration of mantle source ~3He. This study suggests that the tectonic zone with dense volcanic rocks in the Cenozoic era and a high incidence of historical strong earthquakes history may be a potential area for helium resource exploration.

Perovskite single-pixel detector for dual-color metasurface imaging recognition in complex environment

Highly efficient multi-dimensional data storage and extraction are two primary ends for the design and fabrication of emerging optical materials.Although metasurfaces show great potential in information storage due to their modulation for different degrees of freedom of light,a compact and efficient detector for relevant multi-dimensional data retrieval is still a challenge,especially in complex environments.Here,we demonstrate a multi-dimensional image storage and retrieval process by using a dual-color metasurface and a double-layer integrated perovskite single-pixel detector(DIP-SPD).Benefitting from the photoelectric response characteristics of the FAPbBr2.4l0.6 and FAPbl3 films and their stacked structure,our filter-free DIP-SPD can accurately reconstruct different colorful images stored in a metasurface within a single-round measurement,even in complex environments with scattering media or strong background noise.Our work not only provides a compact,filter-free,and noise-robust detector for colorful image extraction in a metasurface,but also paves the way for color imaging application of perovskite-like bandgap tunable materials.

流态化气相沉积过程中稀释气体流量对颗粒表面SiO_(2)沉积的影响

利用Fe(Si)合金球形粉末为沉积基底,正硅酸乙酯为SiO_(2)气相介质前驱体,采用引入流化环节的化学气相沉积工艺合成了Fe(Si)/SiO_(2)复合粉末。考察了沉积过程中Ar稀释气体流量对Fe(Si)基底粉末表面SiO_(2)绝缘介质沉积过程的影响规律及形成完整核壳异质结构的稀释气体流量范围。实验结果表明,随着流态化气相沉积过程中Ar稀释气体流量的逐渐增大,SiO_(2)绝缘介质在Fe(Si)粉末基底表面的微观形貌从亚微米级团簇转变为完整薄膜再向多孔薄膜转变,沉积速率先减小后增大再降低,在250 sccm时SiO_(2)绝缘介质均匀性最好,沉积速率为0.069 nm/s。此外,形成完整Fe(Si)/SiO_(2)核壳异质结构的Ar稀释气体流量范围为200~300 sccm。

A highly active VOx-MnOx/CeO_(2) for selective catalytic reduction of NO:The balance between redox property and surface acidity

Excellent catalysts with low-temperature activity and relatively wide temperature window for selective catalytic reduction of NO with ammonia(NH_(3)-SCR) are highly demanded in view of the practical treatment of NO.Herein,we have designed a highly active VOx-MnOx/CeO_(2) material based on the intrinsic requirement of SCR reaction for catalyst,namely redox sites and surface acid sites.The vanadium oxide and manganese oxide are highly dispersed over the ceria mesosphere via simple incipient wetness impregnation.The loading of manganese could introduce acid sites and enhance the redox property remarkably,while the loading of vanadium increases acid sites and weakens redox property.Through tentatively controlling the appropriate loading ratio of the two components,the optimal catalyst achieves a balance between redox property and surface acidity.The work shed light on the development of new SCR catalyst with superior low temperature activity,wide work temperature window and good hydrothermal stability.