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Abstract Background Paddy soil is a typical soil type affected by anthropogenic management and factors related to natural soil formation. The evolution from mudflats to typical paddy soils can significantly affect the soil microecology. Previous studies have reported the evolution of soil physicochemical properties, microbes, and related soil environmental factors in a millennium paddy soil chronosequence. However, the potential biological mechanisms of changes in metabolites and microbes–metabolites interaction are poorly understood. Therefore, a combination of high-throughput sequencing and environmental pseudotargeted metabolomics techniques was adopted to explore the effects of the millennium paddy soil chronosequence on microbial communities, metabolites, and their functions and interactions. Results The soil ecology changed greatly in the first 60 years of the transition from mudflat to paddy planting. Among the microbial communities, the response of the bacteria to the chronosequence was more sensitive than that of fungi. Among them, the bacterial communities of Proteobacteria, Bacteroidetes, Acidobacteria, and Nitrospirae exhibited regular succession over the chronosequence, but the fungal communities did not show regular changes. Bacterial function prediction revealed that the beginning of the critical stage of the evolution from mudflat to paddy soil involved the organic matter cycle and energy flow. In contrast, fungi were characterized mainly by pathogenic and saprophytic functions. The results of the principal component analysis of the metabolites revealed a similar pattern of change as that of the microbes. Seventy-five characteristic metabolites exhibited three trends of change during the development of the paddy soil chronosequence. Twenty-five differentially active metabolic pathways, including glyoxylate and dicarboxylate metabolism, starch and sucrose metabolism, and galactose metabolism, were enriched. In addition, correlation analysis revealed that long-chain fatty acids, short-chain fatty acids, phenolic acids, carbohydrates, and polyalcohols significantly regulate the microbial communities in paddy soil. Conclusions Combining metabolome and microbiome has expanded the overall understanding of the development of paddy soil under anthropogenic management. During the development of a paddy soil chronosequence, the synergistic regulation of soil physicochemical properties and metabolites in the microbial community results in increased productivity. This study provides a new perspective on microbes and metabolites interaction. Graphical Abstract

Functional characteristics of microbiomes are good predictors of nitrogen (N) biogeochemistry, but soil microbial N-functional profiles under different land use practices and their dominant drivers at continental scale remain unclear. For this study, we selected soils having a broad range of edaphic factors across different land use practices and soil types in China and used metagenomic sequencing to investigate N-functional profiles of microbiomes. The N-pathway frequencies were highest in paddy soils, and the composition of N-cycling genes in paddy soils significantly diverged from upland and forest soils. Differential abundance analysis showed that genes associated with nitrogen dissimilatory pathways exhibited enrichment in paddy soils, whereas those linked to assimilatory pathways were enriched in forest soils. Aggregated boosted tree analysis revealed that the frequencies of N-pathways and relative abundances of N-cycling genes were mainly explained by soil moisture and pH. Partial Mantel and redundancy analysis consistently showed that N-functional composition correlated strongest with moisture and pH. Overall, our results demonstrated that soil moisture and pH were vital drivers of microbial N-functional profiles, providing novel evidence for soil moisture and pH’s role in driving whole nitrogen cycling. Considering the large fluctuations in moisture over time, soil pH, with minor seasonality, could be used as indicators to reflect microbial N-functional profiles at the continental scale.

Undoubtedly, mobility remains a fundamental asset in wireless communications. Conversely, time-sensitive networking (TSN) represents a vital technology that enables determinism and low latency, fundamental for time-sensitive applications. In our study, we marry these two concepts by introducing a pioneering procedure that facilitates seamless roaming within a Wi-Fi-based Wireless Time-Sensitive Network (W-TSN). Through extensive real-world development and testing, we assess various techniques for optimizing handover moment selection and reducing handover delay. Our findings demonstrate that an integrated approach combining Received Signal Strength Indication (RSSI) and location-based online reduces the need for traditional channel scanning. This approach surpasses the offline and midpoint selection methods, excelling in identifying the optimal handover point and reducing handover delay to less than 20 milliseconds.

Whether nitrogen (N)-metabolic versatility is a common trait of N-transforming microbes or if it only occurs in a few species is still unknown. We collected 83 soil samples from six soil types across China, retrieved 19 publicly available metagenomic marine sample data, and analyzed the functional traits of N-transforming microorganisms using metagenomic sequencing. More than 38% and 35% of N-transforming species in soil and marine ecosystems, respectively, encoded two or more N-pathways, although N-transforming species differed greatly between them. Furthermore, in both soil and marine ecosystems, more than 80% of nitrifying and N-fixing microorganisms at the species level were N-metabolic versatile. This study reveals that N-metabolic versatility is a common trait of N-transforming microbes, which could expand our understanding of the functional traits of drivers of nitrogen biogeochemistry.

Energy structure transformation is the only way for China to achieve the “dual carbon” goal, and one of the difficulties faced by energy transformation is financing. In the context of China’s steadily promoting the high-level opening-up of financial industry, this paper uses the panel data of China’s provincial level from 2010 to 2019 to systematically examine the impact of financial opening-up on the transformation of energy structure. The results show that: 1) Financial openness has a significant positive impact on the energy structure transition; 2) In different stages of energy structure transformation, as the main driving force in the initial stage of energy structure transformation is the government’s policy support, with the continuous maturity of energy structure transformation, the impact of financial openness on energy structure transformation gradually increases; 3) With different levels of economic development, the driving effect of financial openness is also different. The lower the level of economic development is, the stronger the driving effect of financial openness on energy structure transformation is due to the lack of financing channels. This paper provides a theoretical basis for China’s energy structure transformation, and also provides rich policy implications for promoting China’s financial industry to open up at a high level.

There are many types of coal seams in China, and the mining of protective layers will cause different rates of stress reduction in protected coal seams at different intervals. Therefore, experiments were conducted at different unloading rates to explore the strength, deformation, and energy characteristics of coal. Research findings: the AE (acoustic emission) signal of the coal body before unloading has a small range of changes and similar characteristics. After unloading begins, because of the different development rates of internal crack in the coal body under different unloading states, the AE signal of the coal body varies at different unloading rates. The maximum stress increases exponentially with the increase of unloading rate. It was found that the higher the unloading rate, the easier and earlier the coal sample is to be damaged. And it was discovered that the dissipated energy of the coal sample in the elastic stage is extremely low, and a large amount of total energy is converted into elastic energy and stored inside the coal sample. The dissipation energy increases during the plastic stage, while the trend of increasing elastic energy slows down. After the peak stage, the dissipated energy rapidly increases and the elastic energy decreases.

In this work, an AA5183 alloy plate was successfully deposited by low-power cold metal transfer technology. The forming defects, microstructural characteristics, and mechanical properties were investigated. The results show that the number of defects increases gradually along the building direction of the deposited plate. X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, electron probe microanalysis, electron backscatter diffraction, and transmission electron microscopy were employed to study the distribution of alloying elements, deposited microstructural characteristics, and the crystal structure of intermetallic compounds in the Al alloy plate. The tensile samples perpendicular to the building direction presented greater tensile strength and superior plasticity compared to those parallel to the deposition direction. The average UTS was 327 ± 0.65 MPa and the average EL was 30.6 ± 2.0%. The UTS of conventionally forged 5083-H32 (Al-Mg4.5) alloy is 324 MPa; the UTS of extruded 5083-H116 (Al-Mg4.5) alloy is 305 MPa. Further, the strength of our prepared plate reaches the value needed for industrial applications of the 5083 Al alloy. The differences in the strength and plasticity of the samples assessed under multiple sampling methods were analyzed based on a synergistic strength–ductility mechanism.

The explosive emergence of wireless technologies and standards, covering licensed and unlicensed spectrum bands, has triggered the appearance of a huge amount of wireless technologies, with many of them competing for the same spectrum band instead of harmoniously sharing it. Unfortunately, the wireless spectrum is a scarce resource, and the available frequency bands will not scale with the foreseen demand for new capacity. Certain parts of the spectrum, in particular the license-free ISM bands, are overcrowded, while other parts, mostly licensed bands, may be significantly underutilized. As such, there is a need to introduce more advanced techniques to access and share the wireless medium, either to improve the coordination within a given band or to explore the possibilities of intelligently using unused spectrum in underutilized (e.g., licensed) bands. Therefore, in this paper, we present an open source software-defined radio-based framework that can be employed to devise disruptive techniques to optimize the sub-optimal use of radio spectrum that exists today. We describe three use cases where the framework can be employed along with intelligent algorithms to achieve improved spectrum utilization. In addition, we provide several experimental results showing the performance and effectiveness of the proposed framework.

Thanks to the digitization and softwarization of radio communication, the development cycle of new radio technologies can be significantly accelerated by prototyping on software-defined radio (SDR) platforms. However, a slow turnaround time (TT) of the front-end of an SDR for switching from receiving mode to transmitting mode or vice versa, are jeopardizing the prototyping of wireless protocols, standards, or systems with stringent latency requirements. In this paper, a novel solution called BaseBand processing unit operating in Half Duplex mode and analog Radio Frequency front-end operating in Full Duplex mode, BBHD-RFFD, is presented to reduce the TT on SDR. A prototype is realized on the widely adopted AD9361 radio frequency frontend to prove the validity of the proposed solution. Experiments unveil that for any type of application, the TT in time division duplex (TDD) operation mode can be reduced to zero by the BBHD-RFFD approach, with negligible impact on the communication system in terms of receiver sensitivity. The impact is measured for an in-house IEEE 802.15.4 compliant transceiver. When compared against the conventional TDD approach, only a 7.5-dB degradation is observed with the BBHD-RFFD approach. The measured sensitivity of -91 dBm is still well above the minimum level (i.e., -85 dBm at 2.4 GHz) defined by the IEEE 802.15.4 standard.

The next generation of wireless and mobile networks will have to handle a significant increase in traffic load compared to the current ones. This situation calls for novel ways to increase the spectral efficiency. Therefore, in this paper, we propose a wireless spectrum hypervisor architecture that abstracts a radio frequency (RF) front-end into a configurable number of virtual RF front ends. The proposed architecture has the ability to enable flexible spectrum access in existing wireless and mobile networks, which is a challenging task due to the limited spectrum programmability, i.e., the capability a system has to change the spectral properties of a given signal to fit an arbitrary frequency allocation. The proposed architecture is a non-intrusive and highly optimized wireless hypervisor that multiplexes the signals of several different and concurrent multi-carrier-based radio access technologies with numerologies that are multiple integers of one another, which are also referred in our work as radio access technologies with correlated numerology. For example, the proposed architecture can multiplex the signals of several Wi-Fi access points, several LTE base stations, several WiMAX base stations, etc. As it able to multiplex the signals of radio access technologies with correlated numerology, it can, for instance, multiplex the signals of LTE, 5G-NR and NB-IoT base stations. It abstracts a radio frequency front-end into a configurable number of virtual RF front ends, making it possible for such different technologies to share the same RF front-end and consequently reduce the costs and increasing the spectral efficiency by employing densification, once several networks share the same infrastructure or by dynamically accessing free chunks of spectrum. Therefore, the main goal of the proposed approach is to improve spectral efficiency by efficiently using vacant gaps in congested spectrum bandwidths or adopting network densification through infrastructure sharing. We demonstrate mathematically how our proposed approach works and present several simulation results proving its functionality and efficiency. Additionally, we designed and implemented an open-source and free proof of concept prototype of the proposed architecture, which can be used by researchers and developers to run experiments or extend the concept to other applications. We present several experimental results used to validate the proposed prototype. We demonstrate that the prototype can easily handle up to 12 concurrent physical layers.