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•Dynamic evolutions of working forces are revealed by Micro-PIV results.•Critical values of the initial gap width are confirmed as a function of Cac.•Flow pattern maps are built using ...dimensionless parameters.•Universal transitional lines are obtained by considering both driving forces.•Scaling laws of the droplet volume are proposed.
The formation of liquid metal droplets in a microfluidic cross junction with different viscosities of the continuous phase is experimentally and theoretically investigated. The flow pattern is distinguished into squeezing and dripping by the presence of gaps. The differences in driving forces between the two patterns are analyzed theoretically and confirmed experimentally by Micro-PIV results. Roles of the squeezing force and the shear force in droplet formation are varying due to the dynamic evolutions of the gap width which reduces with time. Therefore, critical values of the initial gap width are obtained which are the outcome of the competition between neck thinning and tip growing. Compared to water–oil systems, gaps are more difficult to be formed due to the extremely high interfacial tension. Moreover, universal flow pattern maps are constructed using dimensionless parameters of Wed, Cac, and Rec, proving the important roles of both the squeezing force and the shear force. A scaling law of the droplet volume considering the influence of the viscosity ratio is proposed and a very good agreement between experimental data and theoretical predictions is obtained for different liquid systems.
Early fault signature detection and background noise removal are essential for bearing fault diagnosis. A novel multiscale enhanced morphological top-hat filter fault diagnosis method, adaptive ...variational mode decomposition-sample entropy-multiscale enhanced top-hat filter (AVMD-SE-MEMTF), is proposed based on AVMD-SE noise reduction. First, gray wolf optimization algorithm is proposed to optimize the VMD to achieve the optimal decomposition parameters adaptively and combine with SE to eliminate the high noise components and improve the noise reduction effect. Then, based on the pulse extraction property of morphological operations, the concept of MEMTF is proposed. To enhance the multiscale index selection strategy, a synthesis method of eigenfrequency envelope coefficients is constructed to increase the accuracy of the operator during the vibration signal process. Finally, experimental and engineering results show that the proposed method has good diagnostic performance for weak faults in the presence of noise interference.
The inflammatory response has a complex pathogenesis; thus, it is a critical contributor to the development and complication of many diseases. Zhishi and Zhiqiao are famous Citrus herbal medicines ...that are rich in bioactive phenolic constituents with multiple anti-inflammatory activities.
Establishment of a multi-component-target-pathway network strategy to investigate the usage of Zhishi and Zhiqiao on inflammatory diseases can provide a reference for mechanisms of traditional Chinese medicine (TCM).
A multi-component-target-pathway network strategy was constructed to elucidate the various antiinflammatory effects of Zhishi and Zhiqiao by integrating multi-constituent determination, network pharmacology, molecular mechanisms in cells and integrated metabolomics in animals.
Based on the quantitatively determined global and characteristic chemical profiles of Zhishi and Zhiqiao, the component-target-pathway network was predicted by network pharmacology coupled with text mining and docking. The potential antiinflammatory mechanism of the various components in Zhishi and Zhiqiao were verified using LPS-induced inflammatory responses in RAW 264.7 cells. The different metabolic regulating effects of Zhishi and Zhiqiao against an LPS-induced inflammation model were investigated using a plasma metabolomics strategy.
The molecular mechanism of Zhishi mainly suppressed the MAPK signaling pathway, whereas Zhiqiao emphasized the PPAR-AKT signaling pathways simultaneously to block the inflammatory process. Meanwhile, Zhishi and Zhiqiao both exhibited an anti-inflammatory effect by inhibiting the NF-κB signaling pathway to reduce the production of inflammatory mediators. In the metabolomics study, Zhishi and Zhiqiao exhibited variant corrections of the disordered metabolic pathways through amino acid metabolism, glycometabolism and lipid metabolism.
All of these results indicate that Zhishi and Zhiqiao, in a diversified mixture, exert their anti-inflammatory effect through variant pathways. These findings can assist in developing the use of Zhishi and Zhiqiao for inflammatory diseases.
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The properties of alfalfa-derived biochars etched with phosphoric (PBC) or hydrochloric acid (ClBC) compared with raw materials (BC) were examine in this paper. SEM, FT-IR, XRD, BET and elemental ...analysis were performed to characterize the micromorphology and chemical structure comprehensibly. The results showed that the porous structure was enhanced, and surface area was increased via etching with inorganic acids. Batch adsorption experiments were performed for sulfamethoxazole (SMX) to biochars. The experimental data showed that modified biochars exhibited higher adsorption capacity for SMX, i.e., the adsorption quantity of ClBC and PBC had risen by 38% and 46%. The impact on pH values suggested that the physisorption, including pore-filling and electrostatic interaction, might be applied to original biochar. In addition, chemisorption also played a role, including hydrogen bonding, π-π electron donor acceptor interaction (π-π EDA), and so on. Furthermore, both pH and coexisting ions also had a certain effect on sorption. Enhancement of the electrostatic attraction between biochar and SMX might also account for the enhanced capacity of SMX at pH < 7, and coexisting ions could decrease the amount of SMX adsorbed onto biochars, mainly because of competition for adsorption sites.
Blockchain is making headlines due to it promises to provide a decentralized, transparent, tamper-resistant, traceable and verifiable historical transaction records that can resist faults of any ...single node. According to the latest data from State of the Dapps, developers have currently released 3,717 Decentralized Applications (DApps), only three have an average of more than 10,000 daily active users. Most of the real-world DApps exercise little of their potential power. The key reason is that the current permissioned blockchain systems suffer from poor performance and lack of confidentiality. To address this issue, we present Hybridchain, a system that combines blockchain with Trusted Execution Environment (TEE). Hybridchain decouples computation from consensus and adopts hierarchical network to minimize the computational burden and latency of on-chain execution by performing most of the heavy-weight computation off-chain. Hybridchain leverages secure communication protocols to enable each participant to share transaction data in a secure way. To mitigate the small enclave memory restriction of TEE, Hybridchain extends the enclave memory that allows blockchain applications running in TEE to securely store transaction records to the whole key-value storage codes placed outside of TEE. Analysis and experiments of sealed-bid auction show that Hybridchain can support confidentiality-preserving along with high performance.
The increase in intense tropical cyclone (TC) activity across the western North Pacific (WNP) has often been attributed to a warming ocean. However, it is essential to recognize that the tropical WNP ...region already boasts high temperatures, and a marginal increase in oceanic warmth due to global warming does not exert a significant impact on the potential for TCs to intensify. Here we report that the weakened vertical wind shear is the primary driver behind the escalating trend in TC intensity within the summer monsoon trough of the tropical WNP, while local ocean surface and subsurface thermodynamic factors play a minor role. Through observational diagnoses and numerical simulations, we establish that this weakening of the vertical wind shear is very likely due to the increase in temperature of the Tibetan Plateau. With further warming of the Tibetan Plateau under the Representative Concentration Pathway 4.5 scenario, the projected TCs will likely become stronger.
The rising demand to electrify power‐intensive energy devices and systems, as well as fast charging, has imposed a great challenge in current chemistries for lithium‐ion batteries (LIBs), whose rate ...capabilities are predominantly restricted by the conventional graphite anode. Niobium pentoxide (Nb2O5) is a promising high‐rate anode material for LIBs with extraordinary rate performance beyond 5 C and good theoretical capacity (~202 mAh ⋅ g−1). With many possible crystal structures, Nb2O5 has a complicated family of different polymorphs, each of which can possess distinct electrochemical properties, specific capacity, cycling stability, and rate capability. This special feature of Nb2O5 makes it a challenging material to understand and requires a comprehensive investigation of every one of its polymorphs. In this paper, we summarize the state‐of‐the‐art research on Nb2O5 polymorphs for LIBs, with an emphasis on the advanced characterisation techniques that have been used to probe the electrochemical processes of Nb2O5. Key findings related to Nb2O5 that have emerged from the previous studies are highlighted, and new scientific questions that are important for its scale‐up and commercialization are proposed for future research.
Niobium pentoxide (Nb2O5) is a promising high‐rate anode material for lithium‐ion batteries (LIBs) with extraordinary rate performance beyond 5 C and good theoretical capacity (~202 mAh g−1). This paper summarizes the state‐of‐the‐art research on Nb2O5 polymorphs for LIBs, with an emphasis on the advanced characterisation techniques that have been used to probe the electrochemical processes of Nb2O5. Key findings related to Nb2O5 that have emerged from the previous studies are highlighted, and new scientific questions that are important for its scale‐up and commercialization are proposed for future research.
This study examines the differences in service level and coverage of public transit (PT) and private vehicles (PV) with multi-source data in Shanghai. To construct computable networks and address ...visual results, the constrained shortest path algorithm and a spatial grid accessibility model are employed to seek the optimal path for travelers to city key points. Travel time ratio of PV and PT is applied to reflect the competitiveness of the two modes over different areas of Shanghai. Results show that for PV, although the average travel time meets the needs of car travel, 51 % of the population cannot get to graded city centers within 45 min. In addition, the PV accessibility gradually weakens from the central city to the outside, highways and expressways may be feasible solutions. For PT, half of the population can't reach any city key points within two transfers, and almost all of these people live in the suburbs. Less than 30 % of the population can reach the city key points within 1 h, of which rail transit contributes more than conventional buses. Furthermore, the travel accessibility of PV is much better than that of PT. The average travel time ratio in all comparable grids is 2.04 for hubs, and 2.10 for graded city centers. For travels to graded city centers, the travel time ratio of suburbs is 35 % higher than that of central city, indicating that the inequity distribution of public transportation resources is worse in the suburbs than in the central city. This study also measures equity performance of groups based on spatial location and income level, and we find out that more core locations and higher income lead to higher accessibility. The gap among groups is significant, with a Gini coefficient over 0.5.
Wide Area Protection System (WAPS) undertakes the important task of maintaining system reliability and stability when the power system is subject to abnormal or predetermined unstable conditions. The ...existing WAPS adopts a centralized mechanism to record and audit communication messages, which faces the risk of excessive authority and tampering with communication records and audit logs, thus making it impossible to achieve true transparency and fairness. Due to the involvement of multiple parties and equipment maintained by different manufacturers in the communication of WAPS, there are difficulties in tracing the cause of the accident and determining the at-fault party following misoperations and miss trips. To address this issue, we propose a semi-centralized blockchain system with multi-chain for auditing communications of WAPS. We first propose a semi-centralized system architecture according to the system architecture and management requirements of WAPS. Then, we utilize the blockchain network as a self-recording channel to achieve tamper-proof and non-repudiation verification interaction. We also design a multi-chain structure and classification node mechanism to meet the communication auditing requirements of multiple WAPS. We have designed a new block structure that conforms to the communication protocol of WAPS. To reduce the storage burden caused by the ever-expanding blockchain ledger, we propose a deletable blockchain scheme while maintaining the integrity and security of blockchain. Analysis and experiments show that the proposed blockchain system can support the secure, transparent, tamper-proof and traceable communication recording and auditing of WAPS along with high performance.
The hydrogen evolution reaction (HER) is a critical process in the electrolysis of water. Recently, much effort has been dedicated to developing low‐cost, highly efficient, and stable ...electrocatalysts. Transition metal phosphides are investigated intensively due to their high electronic conductivity and optimized absorption energy of intermediates in acid electrolytes. However, the low stability of metal phosphide materials in air and during electrocatalytic processes causes a decay of performance and hinders the discovery of specific active sites. The HER in alkaline media is more intricate, which requires further delicate design due to the Volmer steps. In this work, phosphorus‐modified monoclinic β‐CoMoO4 is developed as a low‐cost, efficient, and stable HER electrocatalyst for the electrolysis of water in alkaline media. The optimized catalyst shows a small overpotential of 94 mV to reach a current density of 10 mA cm−2 for the HER with high stability in KOH electrolyte, and an overpotential of 197 mV to reach a current density of 100 mA cm−2. Combined computational and in situ spectroscopic techniques show P is present as a surface phosphate ion; that electron holes localize on the surface ions and both (PO1−) and Co3+OH− are prospective surface active sites for the HER.
A P‐doped Ni foam/CoMoO4 electrocatalyst is successfully prepared by a facile hydrothermal‐annealing method. Optimized P‐doped Ni foam/CoMoO4 shows excellent hydrogen evolution reaction (HER) activity (94 mV@10 mA cm−2) and remarkable stability in 1 M KOH. A combined in situ spectroscopic and computational study shows the mechanism of P doping and active sites for the catalyst.
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