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Ultra‐wideband microwave absorbing (MA) materials covering the low‐frequency range (2–6 GHz) are highly desirable in civil and military fields. These materials can be fabricated based on the design of electromagnetic meta‐structure. Herein, a structural‐functional‐integrated ultra‐wideband SiO2 fiber reinforced cyanate ester (CE) MA composite based on an in situ‐grown graphene meta‐nanointerface layer (GrMI) (SiO2f/GrMI/CE) is reported. The relationship between the periodic structure of the graphene nano‐interface layer and the MA performance is discussed through experiments and simulations. The results show that SiO2f/GrMI/CE with a thickness of 8.78 mm exhibits an effective absorption bandwidth of 15.46 GHz (2.54–18 GHz). Remarkably, the reflection loss remains basically unchanged upon increasing the incident angle from 5° to 50°. Additionally, GrMI is an effective load‐bearing constituent, which increases the interfacial shear stress between SiO2f and the CE by ≈210% and contributes to achieving composites with an ultra‐high flexural strength (552.7 MPa). The excellent structural‐functional‐integrated performances ensure that the SiO2f/GrMI/CE composites are suitable for use as the skin materials of microwave stealth aircraft and other civil facilities. The work provides a novel pathway for the design of thinner, wider, lighter, and stronger MA components. [ABSTRACT FROM AUTHOR]

Glucocorticoid‐induced osteoporosis (GIOP) commonly accelerates bone loss, increasing the risk of fractures and osteonecrosis more significantly than traditional menopausal osteoporosis. The extracellular environment influenced by glucocorticoids heightens fracture and osteonecrosis risks. Fraxin (Fra), a key component of the traditional Chinese herbal remedy Cortex Fraxini, is known for its wide‐ranging pharmacological effects, but its impact on GIOP remains unexplored. This investigation aims to delineate the effects and underlying mechanisms of Fra in combating dexamethasone (Dex)‐induced ferroptosis and GIOP. We established a mouse model of GIOP via intraperitoneal injections of Dex and cultured osteoblasts with Dex treatment for in vitro analysis. We evaluated the impact of Fra on Dex‐treated osteoblasts through assays such as C11‐BODIPY and FerroOrange staining, mitochondrial functionality tests, and protein expression analyses via Western blot and immunofluorescence. The influence of Fra on bone microarchitecture of GIOP in mice was assessed using microcomputerized tomography, hematoxylin and eosin staining, double‐labeling with Calcein–Alizarin Red S, and immunohistochemistry at imaging and histological levels. Based on our data, Fra prevented Dex‐induced ferroptosis and bone loss. In vitro, glutathione levels increased and malondialdehyde, lipid peroxidation, and mitochondrial reactive oxygen species decreased. Fra treatment also increases nuclear factor erythroid 2‐related factor 2 (Nrf2), glutathione peroxidase 4 (GPX4), and COL1A1 expression and promotes bone formation. To delve deeper into the mechanism, the findings revealed that Fra triggered the activation of Nrf2/GPX4 signaling. Moreover, the use of siRNA‐Nrf2 blocked the beneficial effect of Fra in osteoblasts cultivated with Dex. Fra effectively combats GIOP by activating the Nrf2/GPX4 signaling pathway to inhibit ferroptosis. [ABSTRACT FROM AUTHOR]

Electromagnetic performance regulation in mid‐infrared (MIR) and microwave (MW) spectrums is crucially significant, which can be achieved by heterophase introduction and structural manufacturing. In this work, Si‐O amorphous phase is introduced into Pt film by magnetron co‐sputtering technique, the film thickness is optimized by adjusting deposition time. After annealing treatment, a double‐layered structure is constructed with the migration and growth of Pt crystals, in which the lower layer is composed of Pt coarse grains while the upper layer is Si‐O amorphous phase with embedded Pt fine grains. Furthermore, due to the thickness difference, diverse kinds of structural patterns (arrays or mesh) can be obtained with the solid‐state dewetting of the lower layer. According to the increasing thickness, the infrared emissivity can decrease from 0.67 to 0.25 (8–14 μm), demonstrating a great decline of apparent temperature of 162.9 °C when the background is 300 °C. And the microwave transmissivity also exhibits tremendous variation over 90% (from 96% to 5%), realizing the transformation from transmitting to shielding. [ABSTRACT FROM AUTHOR]

Fluorescent hydrogel as an advanced material has been used for anti‐counterfeiting, probe detection, and optical devices. A facile strategy to prepare fluorescent hydrogel is developed by carboxymethyl cellulose (CMC) with Europium(III) and polyvinyl alcohol (PVA). The hydrogel forms a physical cross‐linking network under mild reaction conditions without using volatile organic chemicals. The addition of CMC‐Eu(III) improves the mechanical properties of the hydrogel. At 15% CMC‐Eu(III), the hydrogel reaches its maximum tensile and compressive stress, which are 47.25 ± 10.35 and 10.14 ± 1.90 kPa, respectively. Meanwhile, the hydrogels exhibit a 5D0→7F2 characteristic emission peak assigned to Eu3+, which emits stable red fluorescence under 254 nm ultraviolet (UV) light. When this hydrogel is applied to paper, the paper showed hidden fluorescent dots under UV light. This additive also enhances the mechanical properties of the paper, which reveals the multifunctionality of this fluorescent hydrogel for anti‐counterfeiting and reinforcement. [ABSTRACT FROM AUTHOR]

Reducing off‐state and gate leakage current is crucial in the development of metal–insulator–semiconductor high‐electron‐mobility transistors (MIS‐HEMTs). This work reports interface engineering in the gate recess region through low‐damage digital etching during the fabrication of normally off GaN MIS‐HEMTs. Conventional plasma etching leads to a reduction of the N/(Al+Ga) ratio, but this value recovers to almost 1 with optimized oxidation condition during digital etching, suggesting a reduction of the Al/Ga dangling bonds based on the proposed technique. GaN MIS‐HEMTs with digital etching exhibits a threshold voltage of 1.0 V at 1 μA mm−1, a high ON/OFF current ratio of 1010, a gate breakdown voltage of 22 V, and a low gate leakage current of 10−8 mA mm−1. [ABSTRACT FROM AUTHOR]

A study published in the journal Clinical & Translational Medicine examined the relationship between immunoglobulin A nephropathy (IgAN) and immunoglobulin A vasculitis with nephritis (IgAVN) using single-cell RNA sequencing (scRNA-seq) of pediatric renal tissues. The study found similarities and distinctions between the two kidney diseases, providing insights into their pathogenesis, diagnosis, and treatments. The analysis revealed differences in cell type proportions, energy metabolism, and fibrosis levels between IgAN and IgAVN. These findings have the potential to impact future diagnostic approaches, treatment options, and predictive outcomes for patients with these conditions. The study was conducted by a team of researchers from the Children's Hospital, Zhejiang University School of Medicine. [Extracted from the article]

Recent advancements in single‐cell technologies have led to rapid developments in the construction of cell atlases. These atlases have the potential to provide detailed information about every cell type in different organisms, enabling the characterization of cellular diversity at the single‐cell level. Global efforts in developing comprehensive cell atlases have profound implications for both basic research and clinical applications. This review provides a broad overview of the cellular diversity and dynamics across various biological systems. In addition, the incorporation of machine learning techniques into cell atlas analyses opens up exciting prospects for the field of integrative biology. [ABSTRACT FROM AUTHOR]

Aims: Recent evidence indicated the biological basis of complement 1q (C1q)/tumor necrosis factor (TNF)‐related protein (CTRP) 3, 4, and 14 for affecting brain structure and cognitive function. Thus, we aimed to investigate the association between plasma CTRPs with Alzheimer's disease (AD). Methods: A multicenter, cross‐sectional study recruited patients with AD (n = 137) and cognitively normal (CN) controls (n = 140). After the data collection of demographic characteristics, lifestyle risk factors, and medical history, plasma levels of tau phosphorylated at threonine 217 (pT217), pT181, neurofilament light (NfL), CTRP3, 4, and 14 were examined and compared. Multivariate logistic regression analysis was applied to determine associations of plasma CTPRs with the presence of AD. The correlation analysis was used to explore correlations between plasma CTPRs with scores of Mini‐Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), Activities of Daily Living (ADL) scale, and Clinical Dementia Rating Sum of Boxes (CDR‐SB), and levels of plasma pT217, pT181, and NfL. Receiver‐operating characteristic (ROC) analysis and Delong's test were used to determine the diagnostic power of plasma CTPRs. Results: Plasma levels of CTRP3, 4, and 14 were higher in AD group than those in CN group. After adjusting for conventional risk factors, CTRP3, CTRP4, and CTRP14 were associated with the presence of AD. In AD patients, CTRP3 was negatively correlated with scores of MMSE and MoCA, while positively correlated with ADL score, CDR‐SB score, pT217, and pT181; CTRP4 was positively correlated with CDR‐SB score, pT181, and NfL; CTRP14 was negatively correlated with MMSE score, while positively correlated with CDR‐SB score, pT217, and NfL. An independent addition of CTRP3 and 4 to the basic model combining age, sex, years of education, APOE4 status, BMI, TG, and HDL‐C led to a significant improvement in diagnostic power for AD, respectively. Conclusions: All the findings preliminarily uncovered associations between plasma CTRPs and AD and suggested the potential of CTRPs as a blood‐derived biomarker for AD. [ABSTRACT FROM AUTHOR]

Aims: To compare cyclosporine (CSA) combining eltrombopag (EPAG) with or without antithymocyte globulin (ATG) in aplastic anemia (AA) patients in the real world. Methods: AA patients who received ATG combining CSA and EPAG (Group A) and CSA + EPAG (Group B) as front‐line treatment in 13 medical centers in China were enrolled. The efficacy and safety were compared. Results: A total of 89 patients were enrolled with 51 patients in Group A and 38 patients in Group B. The 6‐month overall response (OR)/complete response (CR) was 73.3%/24.4% and 60.6%/27.3% in Groups A and B (p >.1). For severe AA patients, the 6‐month OR was 74.1% versus 50% and 6‐month CR was 25.9% versus 20% in Groups A and B (p > 0.1). Multivariate analysis showed gender affects the 6‐month OR with females better OR (p =.017, OR 6.045, 95% CI: 1.377–26.546) and time from disease onset to treatment affected the 12‐month CR (p =.026, OR 0.263, 95% CI: 0.081–0.852). No difference was found in side effects except ATG infusion reaction and serum sickness. Mortality was 7.8% in Group A and no patient died in Group B. Conclusions: CSA + EPAG had a similar response and less side effects compared with standard immunosuppressive therapy + EPAG in newly diagnosed AA. [ABSTRACT FROM AUTHOR]

This paper investigates the influence of the New Development Bank (NDB) on the structure of the multilateral development financial system, using social network analysis. The findings show that some emerging economies have been significantly affected by establishment of the NDB, whereas developed countries still dominate. Although the influence of BRICS countries has increased, they still play a relatively weak role. Further analyses examine the influence of the NDB's expansion; developed countries and most BRICS countries are not affected, and the rankings of some entry countries has increased whereas that of non‐entry countries with nondominant power has decreased. [ABSTRACT FROM AUTHOR]

GPR21 belongs to class A orphan G protein‐coupled receptor (GPCR). The endogenous ligands for human GPR21 remain unidentified. GPR21 expression is associated with developing type 2 diabetes (T2DM), a multifactorial metabolic disease caused by pancreatic β‐cell dysfunction, decreasing insulin production, insulin resistance, and obesity. Animal studies suggested that GPR21 is a potential therapeutic target for T2DM treatment. The underlying mechanisms leading to GPR21 self‐activation remain unknown. In our co‐expression analysis, we noted that GPR21 could also form a stable complex with an unreported Gα protein subtype, Gαs. To gain further insights into the structural mechanisms of GPR21 activation, we employed cryo‐electron microscopy (cryo‐EM) and single‐particle analysis to resolve the high‐resolution structure of GPR21‐Gαs complexes. The clear electron density map of the GPR21‐Gαs provided direct evidence that GPR21 could couple to Gαs protein at physiological conditions. Thus, GPR21 might mediate previously unexplored pathways in normal or pathological conditions, which warrants further investigation. Structure‐guided mutagenesis and biochemical analysis revealed that extracellular loop 2 (ECL2) of GPR21 is essential for the receptor transducing intracellular signal via cAMP. Together, the new structure data reveal a novel signaling cascade of human GPR21 mediated by ECL2 and provide fundamental information for future structure‐based drug development. [ABSTRACT FROM AUTHOR]

Aim: Propofol and opioids are commonly used in anaesthesia, but are highly susceptible to haemodynamic instability, thereby threatening the patient's surgical safety and prognosis. The purpose of this study was to investigate the predictors of haemodynamic instability and establish its predictive model. Methods: A total of 150 Chinese patients undergoing thyroid or breast surgery participated in the study, with target‐controlled infusion concentrations of propofol, opioids dosage, heart rate (HR), mean arterial pressure (MAP) and Narcotrend Index recorded at key points throughout the procedure. The Agena MassARRAY system was used to genotype candidate single nucleotide polymorphisms related to pharmacodynamics and pharmacokinetics of propofol and opioids. Results: Among nongenetic factors, baseline HR (R = −.579, P <.001) and baseline MAP (R = −.725, P <.001) had a significant effect on the haemodynamic instability. Among genetic factors, the CT/CC genotype of GABRB1 rs4694846 (95% confidence interval [CI]: −11.309 to −3.155), AA/AG of OPRM1 rs1799971 (95%CI: 0.773 to 10.290), AA of CES2 rs8192925 (95%CI: 1.842 to 9.090) were associated with higher HR instability; the AA/GG genotype of NR1I2 rs6438550 (95%CI: 0.351 to 7.761), AA of BDNF rs2049046 (95%CI: −9.039 to −0.640) and GG of GABBR2 rs1167768 (95%CI: −10.146 to −1.740) were associated with higher MAP instability. The predictive models of HR and MAP fluctuations were developed, accounting for 45.0 and 59.2% of variations, respectively. Conclusion: We found that cardiovascular fundamentals and genetic variants of GABRB1, GABBR2, OPRM1, BDNF, CES2 and NR1I2 are associated with cardiovascular susceptibility, which can provide a reference for haemodynamic management in clinical anaesthesia. [ABSTRACT FROM AUTHOR]

GPR17 is a class A orphan G protein‐coupled receptor (GPCR) expressed in neurons and oligodendrocyte progenitors of the central nervous system (CNS). The signalling of GPR17 occurs through the heterotrimeric Gi, but its activation mechanism is unclear. Here, we employed cryo‐electron microscopy (cryo‐EM) technology to elucidate the structure of activated GPR17‐Gi complex. The 3.02 Å resolution structure, together with mutagenesis studies, revealed that the extracellular loop2 of GPR17 occupied the orthosteric binding pocket to promote its self‐activation. The active GPR17 carried several typical microswitches like other class A GPCRs. Moreover, the Gi interacted with the key residues of transmembrane helix 3 (TM3), the amphipathic helix 8 (Helix8), and intracellular loops 3 (ICL3) in GPR17 to engage in the receptor core. In summary, our results highlight the activation mechanism of GPR17 from the structural basis. Elucidating the structural and activation mechanism of GPR17 may facilitate the pharmacological intervention for acute/chronic CNS injury. [ABSTRACT FROM AUTHOR]

Summary: The two‐phase flow behaviors in a proton exchange membrane fuel cell with orientated‐type flow channels are monitored through the side‐view direction, and the changing behaviors of cell performance, as well as the temperature are recorded simultaneously in the present work. Moreover, the mutual effects among cell performance, liquid water movement, as well as the temperature changing are discussed accordingly. The results reveal that the extra heating device is always necessary during the fuel cell operating, while its launching or not depends on the immediate current situation and the operation temperature situation, where the time duration without needing heating is prolonged from 8 to 115 s. The orientational flow channel structure facilitates removing the liquid droplets appearing in channel regions, and it also enhances the convective heat transfer, which probably decreases the temperature at membrane electrode assembly regions and slightly reduces the electrochemical reaction rates. However, the performance enhancement caused by orientated‐type channels is higher than performance decrease caused by that. The observation through side view on liquid water movement in orientated‐type channels, the simultaneous measurements on temperature changing behaviors and the current generation processes conducted in the present study facilitate better understanding the two‐phase and heat transfer characteristics in fuel cells with orientated‐type flow channels. [ABSTRACT FROM AUTHOR]

Summary: In the field of measurement, high‐precision thermocouples need higher precision calibration equipment. However, the metal temperature equalizing block used in traditional thermocouple calibration equipment has poor temperature uniformity, and the structure of gas‐controlled heat pipe is complex and expensive, and the concentric annular heat pipes have high isothermal performance and simple structure, which can be used to improve the calibration equipment. In this study, a temperature comparison source based on potassium concentric annular heat pipe was fabricated to replace the metal temperature equalizing block, the temperature stability and temperature uniformity within 0 to 16 cm of the different metering wells at 400°C, 500°C, and 600°C were experimentally studied. The temperature stability was ±0.0026 K and the maximum axial temperature difference within 6 to 10 cm of the metering well was 0.027 K. On the vertical section of concentric annular heat pipe, due to the high specific heat of liquid working fluid, the temperature of the metering well near the bottom is higher. [ABSTRACT FROM AUTHOR]

Summary: The distribution of oxygen concentration along the flow channel direction is uneven in a proton exchange membrane fuel cell. To make the full use of the higher oxygen concentration in the inlet area, the platinum loading can be designed to be gradient decreasing distribution from inlet to outlet. A two‐dimensional, nonisothermal, two‐phase agglomerate model is established to study the segment number and segment length effects on heat and species distributions and the cell performance. Results indicate that the gradient decreasing distribution of platinum loading can enhance the cell performance compared with the uniform distribution. Furthermore, increasing the segment number is unfavorable to the enhancement of cell performance but can make the temperature and oxygen concentration distributions of cathode catalyst layer more uniform. Increasing the segment length near the inlet area can make the cell performance improved, whereas it is unfavorable to the temperature distribution uniformity. [ABSTRACT FROM AUTHOR]

Heterogeneous interface design to boost interfacial polarization has become a feasible way to realize high electromagnetic wave absorbing (EMA) performance of dielectric materials. However, interfacial polarization in simple structures such as particles, rods, and flakes is weak and usually plays a secondary role. In order to enhance the interfacial polarization and simultaneously reduce the electronic conductivity to avoid reflection of electromagnetic wave, a more rational geometric structure for dielectric materials is desired. Herein, a Ti3C2Tx/MoS2 self‐rolling rod‐based foam is proposed to realize excellent interfacial polarization and achieve high EMA performance at ultralow density. Different surface tensions of Ti3C2Tx and ammonium tetrathiomolybdate are utilized to induce the self‐rolling of Ti3C2Tx sheets. The rods with a high aspect ratio not only remarkably improve the polarization loss but also are beneficial to the construction of Ti3C2Tx/MoS2 foam, leading to enhanced EMA capability. As a result, the effective absorption bandwidth of Ti3C2Tx/MoS2 foam covers the whole X band (8.2–12.4 GHz) with a density of only 0.009 g cm−3, at a thickness of 3.3 mm. The advantages of rod structures are verified through simulations in the CST microwave studio. This work inspires the rational geometric design of micro/nanostructures for new‐generation EMA materials. [ABSTRACT FROM AUTHOR]

To tackle the increasing electromagnetic pollution, broadband electromagnetic wave (EMW) absorption materials are urgently needed. Toward this goal, traditional strategies resort to the construction of multicomponent dielectric/magnetic hybrid materials, including ternary, quaternary, or even more complicated systems. However, they always suffer from many intrinsic drawbacks in practical applications. Herein, a theory‐directed strategy is presented to design plainified EMW absorption materials (binary hybrids) via amplified interface effects, which are based on well‐designed multilayer alternating core‐shell nanostructures by chemical vapor deposition (CVD). A defect‐engineered CVD graphene (DG) core composed of graphitic open edges and in‐plane defects is used as a lossy phase. Correspondingly, a CVD Si3N4 layer with nanometer thickness is used as an impedance matching shell. By optimizing the alternating numbers of DG/Si3N4 units, enhanced interface polarization and strong frequency dispersion behavior of permittivity (especially the real part, ε′) are obtained, which helps the plainified binary hybrids to reach an effective absorption bandwidth (EAB) of 8.0 GHz at a thickness of 2.7 mm. Moreover, these plainified hybrids show excellent thermal and pH stability. Even after 1000 °C oxidation, for example, an EAB of 7.44 GHz coupling with a minimum reflection coefficient of −77.3 dB is still achieved. [ABSTRACT FROM AUTHOR]

Polymer‐derived TiC/SiC/SiOC ceramics were prepared using tetrabutyl titanate (TBT)‐modified polysiloxane (PSO) as precursor. The effects of heat treatment temperature and TBT content in precursor on the microstructure, phase composition, and microwave absorbing properties of TiC/SiC/SiOC ceramics were investigated. The crystallinity of the ceramics increases with the increase of heat treatment temperature. With the increase of TBT content, the TiC content of the ceramics increases and the SiC content decreases. When the TBT content ranges from 1 to 5 wt.%, the increase of TBT content has little effect on the real part of the dielectric constant of TiC/SiC/SiOC ceramics. When the TBT content is 7 wt.%, the imaginary part of the dielectric constant of the ceramics changes. For TiC/SiC/SiOC ceramic obtained from the pyrolysis of PSO‐TBT precursor with 7 wt.% TBT, the dielectric constant is within the target electromagnetic parameters. Therefore, it has an effective absorption bandwidth of 4.2 GHz, covering the entire X band, showing an excellent microwave absorbing performance. [ABSTRACT FROM AUTHOR]

You only look once (YOLO) is one of the most efficient target detection networks. However, the performance of the YOLO network decreases significantly when the variation between the training data and the real data is large. To automatically customize the YOLO network, we suggest a novel transfer learning algorithm with the sequential Monte Carlo probability hypothesis density (SMC-PHD) filter and Gaussian mixture probability hypothesis density (GM-PHD) filter. The proposed framework can automatically customize the YOLO framework with unlabelled target sequences. The frames of the unlabelled target sequences are automatically labelled. The detection probability and clutter density of the SMC-PHD filter and GM-PHD are applied to retrain the YOLO network for occluded targets and clutter. A novel likelihood density with the confidence probability of the YOLO detector and visual context indications is implemented to choose target samples. A simple resampling strategy is proposed for SMC-PHD YOLO to address the weight degeneracy problem. Experiments with different datasets indicate that the proposed framework achieves positive outcomes relative to state-of-the-art frameworks. [ABSTRACT FROM AUTHOR]

Acute kidney injury (AKI) is a devastating comorbidity in sepsis and correlates with a very poor prognosis and increased mortality. Currently, we use lipopolysaccharide (LPS) to establish sepsis‐related AKI and try to demonstrate the pathophysiological role of microRNA‐214‐5p (miR‐214‐5p) in this process. Mice were intravenously injected with the miR‐214‐5p agomir, antagomir or negative controls for three consecutive days and then received a single intraperitoneal injection of LPS (10 mg/kg) for 24 h to induce AKI. Besides, the Boston University mouse proximal tubular cell lines were stimulated with LPS (10 μg/ml) for 8 h to investigate the role of miR‐214‐5p in vitro. To inhibit adenosine monophosphate‐activated protein kinase (AMPK), compound C (CpC) was used in vivo. For glucagon‐like peptide‐1 receptor (GLP‐1R) silence, cells were transfected with the small interfering RNA against GLP‐1R. miR‐214‐5p level was upregulated in LPS‐treated kidneys and proximal tubular cell lines. The miR‐214‐5p antagomir reduced LPS‐induced renal inflammation and oxidative stress, thereby preventing renal damage and dysfunction. In contrast, the miR‐214‐5p agomir aggravated LPS‐induced inflammation, oxidative stress and AKI in vivo and in vitro. Mechanistically, we found that the miR‐214‐5p antagomir prevented septic AKI via activating AMPK and that CpC treatment completely abrogated its renoprotective effect in mice. Further detection showed that miR‐214‐5p directly bound to the 3′‐untranslational region of GLP‐1R to inhibit GLP‐1R/AMPK axis. Our data identify miR‐214‐5p as a promising therapeutic candidate to treat sepsis‐related AKI. [ABSTRACT FROM AUTHOR]

Summary: Nitrate salt with low melting point as heat transfer and storage fluid simplifies the heat transfer, storage, and exchange processes, and organic Rankine cycle as heat and power conversion system can realize the distributed energy supply. This study experimentally investigated the solar organic Rankine cycle with parabolic trough concentrator using nitrate salt as heat transfer and storage fluid, and the main problems and phenomena during the operation process have been described and analyzed in detail. Experimental results showed that the temperature difference of collector tube changes with direct normal irradiation and lags behind the changes of direct normal irradiation. Molten salt heat storage system can effectively restrain the temperature fluctuation at the collector tube outlet. The abrupt temperature drop at the evaporator inlet was caused by the heat imbalance between R123 and nitrate salt and inappropriate design of the evaporator. The effects of expander inlet pressure and expansion ratio on the ORC electrical power output were obtained at different superheating degrees of the expander inlet. The researches on each component are instructive to the technology of the parabolic trough concentrated solar power generation system with molten salt as heat transfer and storage fluid and provide some guides for the subsequent research. Furthermore, the energy and exergy analyses on overall system were developed, and results indicated the system average efficiency can reach 1.5%. Novelty statement: Experimental study on parabolic trough concentrated solar ORC system with nitrate salt as heat transfer and storage medium were firstly analyzed.Single screw expander was firstly applied in a real solar thermal power generation system and showed a stable performance.Dynamic changes on the temperatures of PTC, molten salt tanks, and ORC were shown, and energy and exergy analyses on overall system were carried on. [ABSTRACT FROM AUTHOR]

Gastric cancer is the fifth most common malignancy and the third most deadly tumor in the world. Zinc finger protein 479 (ZNF479) has been demonstrated to play crucial roles in hepatocellular carcinoma. However, the function of ZNF479 in gastric cancer remains to be clarified. The current study aimed to investigate the role of ZNF479 in gastric cancer progression and elucidate the potential molecular mechanism. In this study, Cell Count Kit‐8 and colony formation assays demonstrated that knockdown of ZNF479 inhibited cell proliferation in AGS and SGC‐7901 cells. Of note, knockdown of ZNF479 hinders tumor growth of xenograft tumor mice. What is more, knockdown of ZNF479 inhibited glucose uptake, lactate production, adenosine triphosphate level, and extracellular acidification ratio; increased oxygen consumption ratio in gastric cancer cells; and decreased the expression of glycolytic proteins both in vitro and in vivo. Furthermore, analysis mechanism suggests that ZNF479 participated in the regulation of gastric cancer progression through affecting the β‐catenin/c‐Myc signaling pathway. Collectively, ZNF479 plays a role as an oncogene through modulating β‐catenin/c‐Myc signaling pathway in the development of gastric cancer, which provides a new research target for future studies. [ABSTRACT FROM AUTHOR]

For the large-scale search and rescue (S&R) scenarios, the centralized and distributed multi-UAV multitask assignment algorithms for multi-UAV systems have the problems of heavy computational load and massive communication burden, which make it hard to guarantee the effectiveness and convergence speed of their task assignment results. To address this issue, this paper proposes a hierarchical task assignment strategy. Firstly, a model decoupling algorithm based on density clustering and negotiation mechanism is raised to decompose the large-scale task assignment problem into several nonintersection and complete small-scale task assignment problems, which effectively reduces the required computational amount and communication cost. Then, a cluster head selection method based on multiattribute decision is put forward to select the cluster head for each UAV team. These cluster heads will communicate with the central control station about the latest assignment information to guarantee the completion of S&R mission. At last, considering that a few targets cannot be effectively allocated due to UAVs' limited and unbalanced resources, an auction-based task sharing scheme among UAV teams is presented to guarantee the mission coverage of the multi-UAV system. Simulation results and analyses comprehensively verify the feasibility and effectiveness of the proposed hierarchical task assignment strategy in large-scale S&R scenarios with dispersed clustering targets. [ABSTRACT FROM AUTHOR]

Summary: Improving energy utilization efficiency and exploiting renewable energy source have become more crucial with the growing concern on energy crisis and environmental problem. Organic Rankine cycle, a clean, low‐cost, and efficient energy utilization technology, is eliciting increasing attention. In this study, the recent research studies on organic Rankine cycle configuration modifications integrated with pure organic fluid are summarized from the perspectives of nomenclature, configuration modifications, theoretical and numerical methods, and experimental development. Results reveal that the nomenclature on the common organic Rankine cycle configurations is confusing; the research studies on organic Rankine cycle configurations are mainly focused on numerical research studies, and theoretical and experimental research studies are relatively limited. The experimental and numerical studies are mostly related to organic Rankine cycle with a recuperator due to its higher thermal and exergy efficiencies. Most experimental research studies are contributed by Chinese scholars, which indicate that China has paid much attention to improving the global environment. More theoretical and experimental research studies on other organic Rankine cycle configurations are urgently needed. [ABSTRACT FROM AUTHOR]

Summary: The transfer processes of reactants and products affect each other in proton exchange membrane fuel cells (PEMFCs), because they have contrast transfer directions between flow channels and gas diffusion layers (GDLs). In this study, a two‐dimensional, two‐phase, non‐isothermal and steady state model is developed to analyze the species transportation behaviors through diffusion and convection in PEMFCs with orientated‐type flow channels. Five conventional shape baffles effects on mass transfers are compared, and the relationships between convection and diffusion of reactants and produced water vapor are discussed. Simulation results reveal that baffle shapes affect the mass transportation through the baffles leading angles and volumes, and larger leading angles enhance the reactants and the water vapor convective transferring into GDLs; meanwhile, larger baffle volumes enhance the reactant transferring into GDLs and water vapor transferring out from GDLs through diffusion processes. In addition, transportation processes of reactants and vapor affect each other, where more reactants convectively transferring into GDLs causes more water vapor entering GDLs; enhancing the reactants diffusively transferring into GDLs reduces water vapor diffusive transportation out from GDLs. [ABSTRACT FROM AUTHOR]

A new kind of structural and functional integration ceramic matrix composite material was prepared from high‐performance alumina (Al2O3) fibers and absorbing silicon carbonitride (SiCN) ceramics via a combination of polymer infiltration pyrolysis (PIP) and chemical vapor infiltration (CVI) methods. The Al2O3 fiber annealed at its cracked temperature had enhanced permittivity, because the sizing agent on the Al2O3 fiber surface was cracked into pyrolysis carbon. For PIP + CVI Al2O3f/SiCN composites, PIP SiCN matrix with low conductivity was used as the matching phase, while CVI SiCN matrix with medium permittivity and dielectric loss was regarded as the reinforcing phase distributed in porous PIP SiCN matrix and inter‐bundles of Al2O3 fiber to improve their mechanical and microwave absorption properties. The fracture toughness and flexural strength of Al2O3f/SiCN composite were determined to be 9.4 ± 0.5 MPa m1/2 and 279 ± 28 MPa, respectively. Based on the design principles for impedance matching, the Al2O3f/SiCN composites before and after oxidation were used as loss and impedance layers, respectively. It was found that the optimized composite had the lowest reflection coefficient (RC) of −70 dB and the effective absorption bandwidth covering the whole X‐band. In conclusion, Al2O3f/SiCN composite can serve as a high‐temperature structural material with excellent microwave absorption properties for aerospace applications. [ABSTRACT FROM AUTHOR]

Searching for advanced microwave absorption (MA) nanomaterials is one of the most feasible ways to address the increasing electromagnetic pollution in both military and civil fields. To this end, graphene and MXene have won the widespread attention as the main representatives due to their remarkable structures and properties. The common features such as the large aspect ratio, active chemical surface, and varieties of synthesis processes endow graphene and MXene with unique superiorities for developing high‐efficiency MA structures, in particular lightweight assemblies and various hybrids. Meanwhile, the structural and performance differences (such as different conductivities) between them result in distinctive techniques in the design, fabrication, and application of their MA materials. Herein, the research progress in graphene‐ and MXene‐based MA materials is reviewed, with a special focus on advances in general strategies. Moreover, through the comparison between graphene‐ and MXene‐based MA materials, their respective advantages in achieving high‐performance MA are presented. Furthermore, the future challenge, research orientation, and prospect for these MA materials are also highlighted and discussed. [ABSTRACT FROM AUTHOR]

The microstructure and electromagnetic (EM) properties of four kinds of SiC fibers have been studied. These fibers are composed of amorphous SiCxOy, SiC nanocrystallines, free carbon, and nanopores, whose volume fractions are analyzed quantitatively. The content of free carbon notably affects the fiber's conductivity: the logarithm of conductivity increases linearly with the increase in the free carbon content when the volume fraction sum of free carbon and SiC exceed the percolation threshold. The EM loss mechanism is mainly composed of the conduction loss caused by free carbon and the polarization loss caused by SiC nanocrystallines. The content of free carbon is the decisive factor for the type of EM loss mechanism: the proportion of conduction loss increases linearly with the increase in free carbon content. Conduction loss is necessary for good EM absorption property, and polarization loss favors broadband absorption. For SiC fibers dominated by polarization loss, excellent absorption properties can be obtained in composites with higher fiber volume fraction (>20 vol%), which is crucial for structural absorbing materials. [ABSTRACT FROM AUTHOR]

The tight sandstones of the Upper Triassic Xujiahe Formation are important gas reservoirs in the western part of the Sichuan Basin, China. However, their diagenesis and the factors controlling diagenetic processes are poorly constrained. The petrological and geochemical nature of diagenetic minerals of the Xujiahe sandstone reservoirs was analysed from 105 core samples of three wells in the Xinchang Gas Field. The lower member, Xu‐2, sandstones have an average framework composition of Q65F16R19, and 47% of the total lithic fragments are volcanic rock fragments (VRFs). In contrast, the upper member, Xu‐4, sandstones have an average framework composition of Q53F0R47 with a near absence of feldspar and VRFs. The main phase of carbonate cementation in the Xu‐2 sandstones is mesogenetic ferroan dolomite, whereas in the Xu‐4 sandstones, it is intergranular poikilotopic calcite. A fair amount (0.97% in bulk rock and 29% in clay fraction) of authigenic kaolinites appear in the Xu‐4 sandstones, but they are completely absent in the Xu‐2 sandstones. The observed textural occurrence of kaolinites, in combination with the positive relationship between δ13C and δ18O in the calcite cements, suggests that meteoric water flushed the Xu‐4 sandstones, resulting in the dissolution of feldspar to a negligible amount. Quartz cementation is more extensive (1.4 vol%) in the Xu‐2 sandstones than in the Xu‐4 sandstones (0.4 vol%). The fluid inclusions within the quartz cements in the Xu‐2 sandstones have a higher homogenization temperature interval (84–217°C) than those in the Xu‐4 sandstones (81–147°C), indicating that quartz cementation continued to affect the Xu‐2 sandstones during deep burial but ceased relatively early in the Xu‐4 sandstones. High‐intensity chlorite authigenesis, feldspar overgrowth, and albitization occur only in the Xu‐2 sandstones, suggesting that the source of these sandstones was primarily from the alteration of VRFs during late‐stage diagenesis. These clear variations in diagenetic features between the Xu‐2 and Xu‐4 members were most likely controlled by the significant variations in their depositional environments (marine vs. non‐marine) and in the original framework compositions. [ABSTRACT FROM AUTHOR]

Summary: Solar thermal electricity generating technology is an alternative solution to energy crises and environmental problems, which has caused wide concern in recent decades. In this paper, a molten salt parabolic trough‐based concentrated organic Rankine cycle system is proposed and investigated. A quadribasic nitrate salt with low melting temperature is employed as a heat transfer and storage medium. A stable heat transfer and economic model is established with Matlab. The radial and axial temperature distributions in the collector tube are obtained, and the impact of condensation and evaporation temperatures on the heat transfer area is analyzed. Results show that the temperature along the axial direction linearly increases, and the temperature at the collector tube exit decreases with the increase of molten salt mass flow rate. The maximum temperature difference along the radial direction of the collector tube happens in the annular gap. Heat transfer and thermodymanic analysis indicates that condensation temperature has a more evident effect on heat transfer area than that of evaporation temperature. An increase in condensation temperature leads to a decrease in the evaporator area, the condenser area increases, and the total area decreases. Economic analysis indicates the collector cost plays a predominant role in total capital costs, and decreasing molten salt mass flow rate can considerably reduce collector cost. Levelized energy cost sensitivity analysis indicated that operation time per year has a more evident effect than that of the four factors. Heat transfer and economic analysis on the system helps in the selection of operation parameters. [ABSTRACT FROM AUTHOR]

In order to solve the problem that radar emitter signal modulation recognition under low signal-to-noise ratio (SNR) has difficulty in selecting the parameters of the classifier and the problem of low recognition rate caused by the improper selection of features, a multi-feature fusion modulation recognition algorithm based on improved particle swarm optimisation (PSO) algorithm is proposed. Firstly, the algorithm uses Choi–Williams distribution time–frequency analysis to transform the radar signals into time–frequency images, and combines transfer learning and principal component analysis (PCA) to extract the transfer features. Then it extracts the Renyi entropy and AR model coefficients of the signals and combines with the image features to realise multi-feature fusion. Finally, the improved PSO algorithm optimises support vector machine parameters so that population converge quickly. The simulation results show that the recognition rate of this algorithm is 95.3% when the SNR is 0 dB. The number of iterations of this algorithm is small, the signal recognition rate of the system is improved, and the effectiveness of the system is improved by applying PCA. [ABSTRACT FROM AUTHOR]

Summary: In this study, the cell performance of nonuniform depth and conventional straight channel in a unitized regenerative fuel cell (URFC) is compared. Various shapes of oxygen‐side channel cases are also proposed. Several parameters, such as the distribution of reactants and products and current density and powers in fuel cell (FC) and electrolytic cell (EC) modes, are investigated. A steady‐state model of two‐dimensional, two‐phase, nonisothermal, and coupled electrochemical reaction is developed. Five oxygen‐side channel shapes are also designed, in which the depth along the flow direction is narrowed. Result shows that narrowing the average channel depth can promote and guide the reactant transfer to the catalyst layer and avoid the blocking of the production. Thus, in comparison with the conventional channel, the cell performances of nonuniform depth and shallow straight channel cases are improved in both modes. In addition, with the decrease of average channel depth, the temperature uniformity gets better, which is also conductive to the improvement of cell performance. Furthermore, in FC mode at low voltage and EC mode, the cell net power basically increases with the decrease of the average channel depth ratio. And when the average channel depth is the same, the net power of straight channel is always lower than nonuniform depth case. This study introduces the round‐trip energy efficiency as an evaluation indicator of URFC. This efficiency can be increased by improving the cell performance of both modes, especially at high current density. [ABSTRACT FROM AUTHOR]

Summary: In proton exchange membrane fuel cells, baffled flow channels enhance the reactant transfer from flow channels to gas diffusion layers. However, the reactant transfer depends on both the diffusive transfer and convective transfer, and how the baffles in flow channels affect them is still unknown. Therefore, in this work, a two‐dimensional, two‐phase, nonisothermal, and steady‐state model of proton exchange membrane fuel cells is developed, and these two transfer processes from flow channels to gas diffusion layers are comparatively studied. Simulation results show that first of all, the reactant transfer from flow channels to gas diffusion layers mainly depends on the diffusive transfer. Therefore, if the desire is to enhance the mass transfer from flow channels to gas diffusion layers, the diffusive mass transfer should be enhanced firstly. Being guided by this goal, a porous‐blocked baffled flow channel is developed. This flow channel design can further enhance the reactant transfer from flow channels to gas diffusion layers, and the cell performance can be improved. Moreover, when the porosities of porous blocks at the front place of flow channels are lower, the cell power is also increased but the pumping power can be reduced a lot. [ABSTRACT FROM AUTHOR]

Summary: In proton exchange membrane fuel cells, baffled flow channels can enhance the reactant transfer and improve the cell performance. Many different baffled flow channels have been numerically studied in previous published papers. However, what kind of baffled flow channels can improve the cell performance most is still unknown. In this simulation work, a two‐dimensional, two‐phase, nonisothermal, and steady‐state model of proton exchange membrane fuel cells is developed. The mass transfer and cell performance of PEMFCs with different baffled flow channels have been numerically compared. Simulation results show that the rectangular baffle can enhance the reactant transfer most and improve the cell performance most; however, the power loss in rectangular baffled flow channel is also the highest. To inherit the advantages and overcome the shortages of the rectangular baffled flow channel, an optimized baffled flow channel is developed. In this newly developed baffled flow channel, the windward side is designed as the streamline shape and the leeward side is designed as the sloped shape. Results of the simulation also show that the optimized baffled flow channel can reduce the power loss accounted by the pumping power in reactant delivering process and the cell performance can be further improved. [ABSTRACT FROM AUTHOR]

Summary: With the occurrence of reversible electrochemical reactions, mode switching considerably affects the electric performance of unitized regenerative fuel cells (URFCs) owing to the complicated mass and heat transfer. Although limited researches have been done, no such studies on mass and heat transfer through a three‐dimensional view are envisioned during mode switching. A three‐dimensional full‐cell model was developed and validated to study the dynamic characteristics of a proton exchange membrane‐based URFC during mode switching. Mode switching was performed by changing operation voltage from 0.60 to 1.65 V. Results showed that species and heat transfer affect the electric performance of the cell during mode switching, especially through the third dimensional. Local water starvation occurs on oxygen side catalyst layer and thus results in slight reduction on current density and hydrogen generation. Restricted to heat transfer capacity through ribs, heat transfer process adds total response time in URFCs. Heat flux and surface heat transfer coefficient are forecasted on the hydrogen and oxygen sides. A total time of 4 seconds is essential for URFC reaching a new relative balanced state. [ABSTRACT FROM AUTHOR]

Background: We aimed to investigate neuromelanin‐sensitive magnetic resonance imaging (NM‐MRI) features in the locus coeruleus of de novo Parkinson's disease patients with different cognitive states and to determine whether these features are associated with cognitive impairment. Methods: Three groups of subjects were recruited in this study, including patients with de novo PD with mild cognitive impairment (n = 23), patients with de novo PD without cognitive impairment (n = 48), and control subjects (n = 32). All subjects underwent clinical evaluations, as well as MRI scanning. The contrast‐to‐noise ratio of the locus coeruleus in the neuromelanin‐sensitive MRI images and cortical thickness were measured. Results: The contrast‐to‐noise ratio of the locus coeruleus in PD patients with mild cognitive impairment was significantly lower than that of controls (P = 0.016). The contrast‐to‐noise ratio of the locus coeruleus for PD patients without cognitive impairment was intermediate between that of controls and PD patients with mild cognitive impairment. Furthermore, multiple linear regression analysis showed that the contrast‐to‐noise ratio of the locus coeruleus was negatively associated with performance on the Trail Making Test B in all PD patients, controlling for age, sex, years of education, the Unified Parkinson's Disease Rating Scale motor scores from right upper limb, Geriatric Depression Rating Scales scores, Rapid Eye Movement Sleep Behavior Disorder Screening Questionnaire scores, and cortical thickness. Conclusions: Dysfunction of the locus coeruleus neurons may partly contribute to the decline in executive function in early de novo PD. In the future, the locus coeruleus‐norepinephrine system might be targeted for early‐intervention strategies in PD patients. © 2019 International Parkinson and Movement Disorder Society [ABSTRACT FROM AUTHOR]

Matriptase is an epithelia‐specific membrane‐anchored serine protease, and its dysregulation is highly related to the progression of a variety of cancers. Hepatocyte growth factor activator inhibitor‐1 (HAI‐1) inhibits matriptase activity through forming complex with activated matriptase. The balance of matriptase activation and matriptase/HAI‐1 complex formation determines the intensity and duration of matriptase activity. 3‐Cl‐AHPC, 4‐[3‐(1‐adamantyl)‐4‐hydroxyphenyl]‐3‐chlorocinnamic acid, is an adamantly substituted retinoid‐related molecule and a ligand of retinoic acid receptor γ (RARγ). 3‐Cl‐AHPC is of strong anti‐cancer effect but with elusive mechanisms. In our current study, we show that 3‐Cl‐AHPC time‐ and dose‐ dependently induces matriptase/HAI‐1 complex formation, leading to the suppression of activated matriptase in cancer cells and tissues. Furthermore, 3‐Cl‐AHPC promotes matriptase shedding but without increasing the activity of shed matriptase. Moreover, 3‐Cl‐AHPC inhibits matriptase‐mediated cleavage of pro‐HGF through matriptase/HAI‐1 complex induction, resulting in the suppression of pro‐HGF‐stimulated signalling and cell scattering. Although 3‐Cl‐AHPC binds to RARγ, its induction of matriptase/HAI‐1 complex is not RARγ dependent. Together, our data demonstrates that 3‐Cl‐AHPC down‐regulates matriptase activity through induction of matriptase/HAI‐1 complex formation in a RARγ‐independent manner, providing a mechanism of 3‐Cl‐AHPC anti‐cancer activity and a new strategy to inhibit abnormal matriptase activity via matriptase/HAI‐1 complex induction using small molecules. [ABSTRACT FROM AUTHOR]

For the future information confrontation, a single jamming mode is not effective due to the complex electromagnetic environment. Selecting the appropriate jamming decision to coordinately allocate the jamming resources is the development direction of the electronic countermeasures. Most of the existing studies about jamming decision only pay attention to the jamming benefits, while ignoring the jamming cost. In addition, the conventional artificial bee colony algorithm takes too many iterations, and the improved ant colony (IAC) algorithm is easy to fall into the local optimal solution. Against the issue, this paper introduces the concept of jamming cost in the cognitive collaborative jamming decision model and refines it as a multiobjective one. Furthermore, this paper proposes a tabu search-artificial bee colony (TSABC) algorithm to cognitive cooperative-jamming decision. It introduces the tabu list into the artificial bee colony (ABC) algorithm and stores the solution that has not been updated after a certain number of searches into the tabu list to avoid meeting them when generating a new solution, so that this algorithm reduces the unnecessary iterative process, and it is not easy to fall into a local optimum. Simulation results show that the search ability and probability of finding the optimal solution of the new algorithm are better than the other two. It has better robustness, which is better in the "one-to-many" jamming mode. [ABSTRACT FROM AUTHOR]

Abstract: With the aim to design a particular material for low and high frequency cooperative electromagnetic absorption at high temperature, a multiscale design is proposed by combining the microstructure and meta‐structure in one material. The SiCf/Si3N4 composite is prepared via the chemical vapor infiltration technique with SiCf as the EM wave absorbing phase and Si3N4 as the wave‐transparent ceramic matrix. The crossing grooved meta‐structure is designed and fabricated to further improve its absorbing properties and to guarantee its absorbing capacity stability at high temperature. A minimum reflection loss of −15.3 dB and −14.8 dB can be reached at 8 and 18 GHz with a total thickness of 5 mm. The temperature‐dependent reflection loss of the designed meta‐structure keeps relative reliable high temperature absorbing performances from room temperature to 500°C. This effective enhanced EM wave absorbing property is believed to be a consequence of multiscale effect induced by combining the traditional EM absorbing materials with metamaterial structure. [ABSTRACT FROM AUTHOR]

Abstract: The neurotoxicity of lead (Pb) is well established, and oxidative stress is strongly associated with Pb‐induced neurotoxicity. Heme oxygenase 1 (HO‐1) is an important antioxidative enzyme for protection against oxidative stress in many disease models. In this study, we applied hemin, the substrate and a well‐known inducer of HO‐1, to investigate the possible role of HO‐1 in protecting against Pb neurotoxicity. Hemin can significantly attenuate Pb acetate‐induced cell death and oxidative stress in the hippocampus and frontal cortex of developmental rats. Consistent with in vivo results, the protective effects of hemin were also observed in SH‐SY5Y cells after inducing cell survival and maintaining redox balance. However, knocking down HO‐1 could significantly abolish the cytoprotective action of hemin against Pb toxicity, confirming HO‐1 contributed to the protection. Finally, the HO‐1‐derived production of carbon monoxide, but not of bilirubin or Fe2+, mediated the protective effects of HO‐1 activation induced by hemin treatment against Pb‐induced cell death and oxidative stress in SHSY5Y cells. Overall, this study showed that hemin provided protection against Pb neurotoxicity by HO‐1/carbon monoxide activation. [ABSTRACT FROM AUTHOR]

Summary: In this work, a proton exchange membrane unitized regenerative fuel cell with a 25 cm2 active area and a transparent window was designed to study the influence of mode switching from the fuel cell mode to the electrolysis cell mode on the cell voltage and the gas‐liquid two‐phase flow behaviors in the oxygen flow channels. Results indicate that: the growth rate of electrolysis cell voltage before the water pumped to the oxygen flow channels decreases with the increase of the fuel cell current density; while the growth rate of electrolysis cell voltage before the water pumped to the oxygen flow channels increases with the cell temperature; the voltage of electrolysis cell mode before the water pumped to the oxygen flow channels decreases with the increase of water flow rate; the different voltage reduction speeds are attributed to the different water flow rates. The water temperature has an obscure influence on the cell voltage of electrolysis cell mode before the water pumped to the oxygen flow channels. [ABSTRACT FROM AUTHOR]

Summary: Mode switching between fuel cell and water electrolyzer of a unitized regenerative fuel cell alters two‐phase flow dynamics in the channels. To fully understand the mode switching, the observation of two‐phase flow is necessary. In this work, experiments are conducted to investigate the two‐phase flow in the flow field of a unitized regenerative fuel cell during mode switching. A transparent window is assembled at the oxygen side to allow a direct view of the serpentine flow field. The two‐phase flow are captured by a high‐speed camera. Water has a significant effect on the mode switching. The switching from water electrolyzer to fuel cell is difficult because of the flooding problem. High temperature causes insufficient water in water electrolyzer mode without water supply and membrane dehydration in fuel cell mode. The voltage in fuel cell mode decreases more rapidly with fuel cell current density during mode switching. [ABSTRACT FROM AUTHOR]

To eliminate potential evidence conflicts, an effective and accurate DS combination method is addressed in this paper. DS evidence theory is an outstanding information fusion approach with valid uncertainty treatment. Nevertheless, there are some limitations of the usage of the DS evidence theory. On the one hand, due to the complexity of a combat measurement environment and the inconsistency of sensor capabilities, sensor sources have enormous uncertainty, which would inevitably cause conflicts for evidence combination. On the other hand, DS combination rule realizes the unity property of fusing results with a compulsive normalization, which unavoidably leads to conflicting situations. To solve the possible evidence conflicts in a multisensor fusion system, we raise a robust DS combination method based on evidence correction and conflict redistribution. Firstly, two corrected indexes—the reliability index and consistency index—are separately addressed with the introduction of the Matusita distance function and closeness degree function. After the evidence modification based on two correction indexes, the conflicts caused by unreliable sensor sources are solved. Then, based on the corrected evidences, we put forward a weighted assignment of conflicting mass where the weight index lies on the evidence credibility. As the normalization step is abolished, the conflict redistribution strategy avoids the conflicts caused by straightforward normalization. Through comprehensive conflict management, the proposed DS combination method can not only guarantee the rationality and availability of fusing results, but also enhance the reliability and robustness of a multisensor system. Finally, three combination experiments with different conflicting degrees illustrate the advantage and superiority of the novel combination method for conflict management. Consequently, the innovation of the novel algorithm is verified. [ABSTRACT FROM AUTHOR]

ABSTRACT: High‐quality broadband data are required to promote the development of seismology research. Instrument response errors that affect data quality are often difficult to detect from visual waveform inspection alone. Here, we propose a method that uses ambient noise data in the period range of 5−25 s to monitor instrument performance and check data quality in situ. Amplitude information of coda waves and travel time of surface waves extracted from cross‐correlations of ambient noise are used to assess temporal variations in the sensitivity and poles–zeros of instrument responses. The method is based on an analysis of amplitude and phase index parameters calculated from pairwise cross‐correlations of three stations, which provides multiple references for reliable error estimates. Index parameters calculated daily during a two‐year observation period are evaluated to identify stations with instrument response errors in real time. During data processing, initial instrument responses are used in place of available instrument responses to simulate instrument response errors, which are then used to verify our results. The coda waves of noise cross‐correlations help mitigate the effects of a non‐isotropic field and make the amplitude measurements quite stable. Additionally, effects of instrument response errors that experience pole–zero variations on monitoring temporal variations in crustal properties appear statistically significant of velocity perturbation and larger than the standard deviation. Monitoring seismic instrument performance helps eliminate data pollution before analysis begins. [ABSTRACT FROM AUTHOR]

Abstract: High‐performance graphene microwave absorption materials are highly desirable in daily life and some extreme situations. A simple technique for the direct growth of graphene as absorption fillers in wave‐transmitting matrices is of paramount importance to bring it to real‐world application. Herein, a simple chemical vapor deposition (CVD) route for the direct growth of edge‐rich graphene (ERG) with tailored structures and tunable dielectric properties in porous Si3N4 ceramics using only methyl alcohol (CH3OH) as precursor is reported. The large O/C atomic ratio of CH3OH helps to build a mild oxidizing atmosphere and leads to a unique structure featuring open graphite nanosteps and freestanding nanoplanes, endowing the ERG/Si3N4 hybrid with an appropriate balance between good impedance matching and strong loss capacity. Accordingly, the prepared materials exhibit superior electromagnetic wave absorption, far surpassing that of traditional CVD graphene and reduced graphene oxide‐based materials, achieving an effective absorption bandwidth of 4.2 GHz covering the entire X band, with a thickness of 3.75 mm and a negligibly low loading content of absorbents. The results provide new insights for developing novel microwave absorption materials with strong reflection loss and wide absorption frequency range. [ABSTRACT FROM AUTHOR]

Summary: Mode switching is an important process in unitized regenerative fuel cells. The complex interactions of heat and mass transfer during the operation of mode switching have a significant effect on cell performance. Twelve different ways of mode switching were proposed by controlling inlet boundary conditions of supplies and operating voltage. Numerical simulations were applied to analyze the dynamic response of heat and mass transfer as well as electrochemical signals under the different ways of mode switching. Current density increased with mass fraction of reactants. Cell heat source had an instant response to current density, but the temperature was slow to respond to the heat source. Hydrogen‐side inlet velocity had minimal impact on mode switching. The time for cell reaching stability increased with the increase of voltage change time, and the time for current density, mass transfer, and temperature reaching stable values increased in order. Unitized regenerative fuel cell had similar dynamic response in the 2 period: cell temperature increased in the fuel cell mode and decreased in the water electrolysis mode after mode switching. [ABSTRACT FROM AUTHOR]

A kind of chemical vapor infiltration ( CVI) Si3N4- BN-Si CN composite ceramic with excellent electromagnetic wave ( EMW) absorbing properties is obtained by CVI BN interface and Si CN matrix on porous Si3N4 ceramics, and then annealed at high temperatures (1200°C-1500°C) in N2 atmosphere. The crystallization behavior, EMW absorbing mechanism and mechanical properties of the composite ceramics have been investigated. Results showed CVI Si CN ceramics with BN interface were crystallized in the form of nanograins, and the crystallization temperature was lower. Moreover, both EMW absorbing properties and mechanical properties of CVI Si3N4- BN-Si CN composite ceramics firstly increased and then decreased with the increase in annealing temperature due to the influence of BN interface on the microstructure and phase composition of the composite ceramics. The minimum reflection coefficient ( RC) and maximum effective absorption bandwidth ( EAB) of the composite ceramics annealed at 1300°C were −47.05 dB at the thickness of 4.05 mm and 3.70 GHz at the thickness of 3.65 mm, respectively. The flexural strength and fracture toughness of the composite ceramics annealed at 1300°C were 94 MPa and 1.78 MPa/m1/2, respectively. [ABSTRACT FROM AUTHOR]