Search

Abstract A bi‐level planning strategy of a hydrogen‐supercapacitor hybrid energy storage system (H‐S HESS) has been proposed in this study for wind power fluctuation suppression. The proposed system consists of a supercapacitor array and a hydrogen energy storage unit, and the bi‐level planning strategy consists of an Energy Management Level and a Capacity Configuration Level. In the upper level, with Hilbert–Huang transform frequency analysis, a novel energy management strategy based on adaptive power allocation (APA) is designed. The lower level applies multi‐objective Harris hawks optimizer to solve the optimal parameters of each device in the system. Based on the data measured from a 2‐MW wind system in a hydrogen‐electric coupled DC microgrid demonstration project, the optimal system capacity configuration scheme is obtained. The annualized cost of the system is $150,212, which is 41.1% lower than the scheme without optimization. The fluctuation unsuppressed rate of H‐S HESS is 0.64% under the APA strategy, which is only 0.14% higher than the conventional HESS (supercapacitor + lithium‐ion batteries) with the same annualized cost of system. The proposed strategy reduces the frequency of HESS operational power fluctuations, improves capacity configuration accuracy, and significantly decreases the cost gap between the proposed H‐S HESS and conventional structures.

Abstract In July and August 2022, the Yangtze River basin (YRB) experienced its hottest summer since 1961. The SINTEX‐F2 seasonal prediction system initialized in early May predicted the hotter‐than‐normal summer due to its successful prediction of central Pacific La Niña, negative Indian Ocean Dipole and the resultant warming in the tropical West Pacific‐East Indian Ocean (TWP_EIO). The common SST forcing explains only about 26% to the heatwave strength, while the internal variations in the anomalous warming in the TWP_EIO and Europe, surplus precipitation in Pakistan, and local land‐air interaction account for approximately 65%, based on the analysis of 108 ensemble members. These factors have collectively increased the maximum temperature over the YRB through the enhancement and westward expansion of western North Pacific subtropical high. Our findings quantify the relative contributions of external forcing and internal variations to the unprecedented hot event, offering insights into its forming mechanism and potential predictability.

Abstract Mapping flood risk zone is an essential task in the arid region for sustainable water resources management. Due to the lack of hydrological and meteorological information and disaster event inventory in Xinjiang, China, storm flood disaster (SFD) risk zoning is an effective technique in investigating the potential impact of SFD. In this study, the statistics about natural, social, and risk related to SFD are collated. With the help of the compiled inventory data, a disaster risk assessment model for storm flood is proposed for the Xinjiang region based on the random forest (RF) algorithm. Randomly selected negative and positive samples from the historical SFD locations are composed of five different total samples. The overall prediction accuracy of the five sample groups attained 83.48%, indicating that the proposed RF model can well capture the spatial distribution of SFD in Xinjiang. It should also be noted that the spatial heterogeneity and complexity of SFD had a significant effect on its spatial distribution in Xinjiang. There are spatial distribution characteristics of lowland plains and high plateaus; the main mountainous regions, plains in the middle‐lower reaches of major rivers, and areas surrounding major lakes are prone to flooding. The variable importance RF indicates that the disaster risk is mainly affected by the following factors, including hazard factors, catastrophic intensity, population density, as well as economic development in the affected area. Besides, latitude, longitude, agricultural acreage, road density, distance from rivers, and the maximum monthly precipitation account for most of the increase in storm flooding disasters, and they are the main triggering point for SFD in Xinjiang. The proposed model provides some insight into the disaster in the mountainous region, and gives useful guidance for the national macro‐control of flood prevention and disaster reduction.

Abstract Background Circular RNAs (circRNAs) have been reported to be involved in the initiation and development of cancers. The aim of this study was to determine the role of a circRNA, circ_0020123, in the development of non‐small cell lung cancer (NSCLC). Methods The expression of circ_0020123, microRNA‐146a‐5p (miR‐146a‐5p), and eukaryotic translation initiation factor 4 gamma 2 (EIF4G2) mRNA was detected by quantitative real‐time PCR (qPCR). Western blot was used to determine the protein levels of cyclin D1, Bax, MMP‐9, and EIF4G2. Cell proliferation was assessed by cell counting kit‐8 (CCK‐8) assay and colony formation assay. Flow cytometry assay was applied to determine cell cycle apoptosis. Cell migration and invasion were assessed using transwell assay. The potential relationship between miR‐146a‐5p and circ_0020123 or EIF4G2 was ascertained by dual‐luciferase reporter assay and RIP assay. The role of circ_0020123 in vivo was explored by xenograft assay. Results Circ_0020123 was upregulated in NSCLC, and circ_0020123 knockdown repressed proliferation, migration, and invasion of NSCLC cells. Circ_0020123 targeted miR‐146a‐5p, and miR‐146a‐5p inhibitor reversed the effects of circ_0020123 knockdown on NSCLC cells. In addition, miR‐146a‐5p suppressed cell proliferation, migration, and invasion by targeting EIF4G2. Moreover, the antitumor role of circ_0020123 knockdown was verified in vivo. Conclusion Knockdown of circ_0020123 inhibited NSCLC cell progression and tumor growth by targeting the miR‐146a‐5p/EIF4G2 axis.

Abstract Background Cancer‐associated fibroblasts (CAFs) are potential targets for cancer therapy. Due to the heterogeneity of CAFs, the influence of CAF subpopulations on the progression of lung cancer is still unclear, which impedes the translational advances in targeting CAFs. Methods We performed single‐cell RNA sequencing (scRNA‐seq) on tumour, paired tumour‐adjacent, and normal samples from 16 non‐small cell lung cancer (NSCLC) patients. CAF subpopulations were analyzed after integration with published NSCLC scRNA‐seq data. SpaTial enhanced resolution omics‐sequencing (Stereo‐seq) was applied in tumour and tumour‐adjacent samples from seven NSCLC patients to map the architecture of major cell populations in tumour microenvironment (TME). Immunohistochemistry (IHC) and multiplexed IHC (mIHC) were used to validate marker gene expression and the association of CAFs with immune infiltration in TME. Results A subcluster of myofibroblastic CAFs, POSTN+ CAFs, were significantly enriched in advanced tumours and presented gene expression signatures related to extracellular matrix remodeling, tumour invasion pathways and immune suppression. Stereo‐seq and mIHC demonstrated that POSTN+ CAFs were in close localization with SPP1+ macrophages and were associated with the exhausted phenotype and lower infiltration of T cells. POSTN expression or the abundance of POSTN+ CAFs were associated with poor prognosis of NSCLC. Conclusions Our study identified a myofibroblastic CAF subpopulation, POSTN+ CAFs, which might associate with SPP1+ macrophages to promote the formation of desmoplastic architecture and participate in immune suppression. Furthermore, we showed that POSTN+ CAFs associated with cancer progression and poor clinical outcomes and may provide new insights on the treatment of NSCLC.

In insulating liquid, a conductive particle becomes charged through the interaction with a conductor exposed to an applied field. Then, it migrates in the action of both electric field and fluid and causes the enhancement of local field when it is in proximity of the conductor with opposite polarity. The enhancement will lead to partial discharge (PD) and may even ignite full gap breakdown in special cases. This study reviews comprehensive researches relevant to these topics. In the first place, several theoretical methods about how to obtain the charges held by a conductive particle with known potential are introduced, so are experimental methods. Then, forces acting on the charged particle in liquid are classified, and its migration characteristics, as well as influential factors, are described. Subsequently, PD and breakdown mechanisms of liquid initiated by conductive particles are presented. The latter involves two cases: electric-field enhancement when the particle concentration is low and bridging phenomenon when it is high. At last, two important, but frequently ignored factors, i.e. dielectric barrier and oil flow, are highlighted, and the authors’ suggestions for future work are put forward.