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To solve the problems in restoring sedimentary facies and predicting reservoirs in loose gas-bearing sediment, based on seismic sedimentologic analysis of the first 9-component S-wave 3D seismic dataset of China, a fourth-order isochronous stratigraphic framework was set up and then sedimentary facies and reservoirs in the Pleistocene Qigequan Formation in Taidong area of Qaidam Basin were studied by seismic geomorphology and seismic lithology. The study method and thought are as following. Firstly, techniques of phase rotation, frequency decomposition and fusion, and stratal slicing were applied to the 9-component S-wave seismic data to restore sedimentary facies of major marker beds based on sedimentary models reflected by satellite images. Then, techniques of seismic attribute extraction, principal component analysis, and random fitting were applied to calculate the reservoir thickness and physical parameters of a key sandbody, and the results are satisfactory and confirmed by blind testing wells. Study results reveal that the dominant sedimentary facies in the Qigequan Formation within the study area are delta front and shallow lake. The RGB fused slices indicate that there are two cycles with three sets of underwater distributary channel systems in one period. Among them, sandstones in the distributary channels of middle-low Qigequan Formation are thick and broad with superior physical properties, which are favorable reservoirs. The reservoir permeability is also affected by diagenesis. Distributary channel sandstone reservoirs extend further to the west of Sebei-1 gas field, which provides a basis to expand exploration to the western peripheral area.

For insight into the productive and storage mechanisms of biogas in the Qaidam Basin, efforts were made to investigate the groundwater recharge and the processes of hydrocarbon generation by CDOM-EEM (fluorescence excitation-emission matrix of Chromophoric dissolved organic matter) spectrum, hydrogen and oxygen isotopes, and geochemical characters in the central depression of the Qaidam Basin, China. The samples contain formation water from three gas fields (TN, SB, and YH) and surrounding surface water (fresh river and brine lake). The results indicate that modern precipitation significantly controls the salinity distribution and organic matter leaching in the groundwater system of the central depression of the Qaidam Basin. Higher salinity levels inhibit microbial activity, which leads to organic matter degradation and to gas generation efficiency being limited in the groundwater. The inhabitation effect is demonstrated by the notable negative correlation between the extent of organic matter degradation and its concentration with hydrogen and oxygen isotopes. The conclusion of this study indicated that modern precipitation emerges as a crucial factor affecting the biogas production and storage in the Qaidam Basin by influencing the ultimate salinity and organic matter concentration in the formation, which provides theoretical insight for the maintenance of modern gas production wells and the assessment of gas production potential.

Abstract Human skin comprises multiple hierarchical layers that perform various functions such as protection, sensing, and structural support. Developing electronic skin (E‐skin) with similar properties has broad implications in health monitoring, prosthetics, and soft robotics. While previous efforts have predominantly concentrated on sensory capabilities, this study introduces a hierarchical polymer system that not only structurally resembles the epidermis‐dermis bilayer structure of skin but also encompasses sensing functions. The system comprises a polymeric hydrogel, representing the “dermis”, and a superimposed nanoporous polymer film, forming the “epidermis”. Within the film, interconnected nanoparticles mimic the arrangement of interlocked corneocytes within the epidermis. The fabrication process employs a robust in situ interfacial precipitation polymerization of specific water‐soluble monomers that become insoluble during polymerization. This process yields a hybrid layer establishing a durable interface between the film and hydrogel. Beyond the structural mimicry, this hierarchical structure offers functionalities resembling human skin, which includes (1) water loss protection of hydrogel by tailoring the hydrophobicity of the upper polymer film; (2) tactile sensing capability via self‐powered triboelectric nanogenerators; (3) built‐in gold nanowire‐based resistive sensor toward temperature and pressure sensing. This hierarchical polymeric approach represents a potent strategy to replicate both the structure and functions of human skin in synthetic designs.

The biogas of Quaternary weak diagenetic shale has a wide exploration prospect, and the understanding of pore structure and physical properties of these shales is conducive to promote the geological theory of shale biogas reservoir. The Quaternary weak diagenetic shale from the Sanhu area of Qaidam Basin was employed as an example in this study, to study the pore structure and physical properties by the means of scanning electron microscopy, thin section observation, X-ray diffraction of whole-rock samples, overpressure pore permeability determination, relative permeability of gas-water etc. Results show that there are three types of lithofacies for the Quaternary weak diagenetic shales including clay shales, mixed shales and felsic shales, and pores appeared to include intergranular pores, inner pores of brittle mineral grains, inner pores of clay mineral grains and organic pores. The pore size of felsic shale is large, mainly micron pores. The pore size of clay shale and mixed shale are dominated by nano-scale pores. The peak porosity and permeability of Quaternary weak diagenetic shale distribute in the range of 15%-30% and (0.1-10) ×10-3 μm2, respectively, and significantly reduce under overburden conditions. The residual water saturation after displacement is high (with an average value of 58.7%). Due to clay expansion, the effective pore space is reduced and the fluidity of gas and water is restrained, resulting in very low relative permeability of gas and water in the two-phase co-flow zone.

The Sanhu Depression in Qaidam Basin is the largest Quaternary biogenic gas exploration area with the shallowest burial depth in the world. The shallow high abundance of gas reservoirs and high-quality pure methane have become the main production areas. The development characteristics of loose mudstone reservoirs are restricted by extreme heterogeneity. Therefore, the Quaternary Qigequan Formation mudstone in Qaidam Basin is selected as the research object. Based on the study of the sedimentary background, petrological characteristics, and pore structure characteristics, by comparing the characteristics of different mudstone reservoirs, the controlling factors of the development of different mudstone reservoirs and the control of gas migration are clarified. Research shows the following: (1) The mudstone reservoirs of the Qigequan Formation mainly develop intergranular pores, clay mineral pores, and intragranular pores. The pore size distribution varies from nanometers to micrometers, and mesopores mainly contribute to the specific surface area. (2) Rigid minerals and clay minerals are the main controlling factors for the pore structure of mudstone reservoirs. The increase in the content of rigid minerals is conducive to the development of macropores or larger micropores, while the increase in the content of clay minerals is conducive to the development of mesopores and provides an important specific surface area for gas adsorption. (3) The gas migration form of pure mudstone is mainly dominated by Fick diffusion and slippage flow, which has the characteristics of self-sealing accumulation. The gas migration form of silty mudstone is the coexistence of Fick diffusion, slippage flow, and Darcy flow, which has the features of self-sealing and Darcy flow accumulation. The gas migration form of sandy mudstone is mainly Darcy flow, only with Darcy flow accumulation characteristics. The flow form of gas creates different accumulation modes of mudstone biogas. The Quaternary mudstone reservoir shows different particularity under different material components, and the exploration targets should be treated differently according to specific mudstone types.

The rise of Industry 4.0 is pushing more machine devices into the connection of the communication network. Internet of Things (IoT) emerges as an enabling technique to support automatic information transmission and the universal interconnection among massive machine devices. Unlike the human type communication (HTC) in the conventional Internet, IoT features machine type communication (HTC) with small data granularity and massive connections, which impose new challenges on the network resource allocation earlier designed for HTC communication. One of the challenging issues is how we can manage the network resource for the IoT service provisioning. As a promising network architecture for the “last-mile” access in 5G communication, Fiber-Wireless (FiWi) access network compromises the high bandwidth capacity of the optical access network and the flexibility of wireless access network. Especially, network virtualization as an emerging technique provides FiWi with the feasibility for the coordinated bandwidth allocation of wireless access network and optical access network. The evolution of FiWi access network should be not only oriented to the technological breakthrough in regular traffic, but also be supportive of the emerging IoT traffic. In this paper, we focus on the resource allocation problem in FiWi access network supporting IoT service. We first analyze the dynamics of regular traffic and propose the traffic prediction method based on Q-Learning. Then, we propose a virtual network embedding algorithm to map exactly the virtual networks of IoT traffic to the idle resource of the virtual networks of regular traffic without degrading the performance of regular traffic. Thus, the proposed algorithm can improve the resource utilization more effectively. The simulation results demonstrate that the proposed algorithm can achieve a higher acceptance ratio and lower migration ratio of IoT traffic.

Biogas resources in the Sanhu area of the Qaidam Basin have great potential, but there are few studies on biogas from shale, especially on the accumulation conditions of shale biogas. The study of biogas accumulation conditions of quaternary shale in the Sanhu area is of great significance to the theory of biogas accumulation and the guidance of exploration and development. This paper takes Quaternary shale in the Sanhu area as the research object. It is analyzed from multiple perspectives of shale hydrocarbon generation conditions, reservoir conditions, as well as hydrodynamic and structural conditions. Through the experiments of soluble organic carbon analysis and porosity and permeability analysis, the accumulation conditions of shale biogas reservoirs are clarified. The results show that the quaternary shale has a high soluble organic carbon content and high salinity formation water, which is conducive to late methane biochemical generation. Quaternary shale has the characteristics of high porosity and low permeability, mainly developing intergranular pores and intragranular pores. The large pore volume and specific surface area provide a lot of storage space for free gas and adsorbed gas, and the reservoir conditions are good. Under the structural characteristics of high in the south and low in the north and the action of formation hydrodynamics, biogas migrated from the south and deep to the north of the basin. The north slope is the main biogas-rich zone. On the whole, the quaternary shale in the Sanhu area has the characteristics of continuous hydrocarbon generation and dynamic accumulation, which has huge resource potential and exploration and development value.