This paper is devoted to the study of nonlinear stability of steady incompressible Euler flows in two dimensions. We prove that a steady Euler flow is nonlinearly stable in L^p norm of the vorticity ...if its stream function is a semistable solution of some semilinear elliptic problem with nondecreasing nonlinearity. The idea of the proof is to show that such a flow has strict local maximum energy among flows whose vorticities are rearrangements of a given function, with the help of an improved version of Wolansky and Ghil’s stability theorem. The result can be regarded as an extension of Arnol’d’s second stability theorem.
Recently, a variety of solutions have been proposed to tackle the controller placement problem in SDN. The objectives include minimizing the latency between controllers and their associated switches, ...enhancing reliability and resilience of the network, and minimizing deployment cost and energy consumption. In this article, we first survey the state-of-the-art solutions and draw a taxonomy based on their objectives, and then propose a new approach to minimize the packet propagation latency between controllers and switches. In order to encourage future research, we also identify the ongoing research challenges and open issues relevant to this problem.
Radio frequency (RF) based wireless power transfer provides an attractive solution to extend the lifetime of power-constrained wireless sensor networks. Through harvesting RF energy from surrounding ...environments or dedicated energy sources, low-power wireless devices can be self-sustaining and environment-friendly. These features make the RF energy harvesting wireless communication (RF-EHWC) technique attractive to a wide range of applications. The objective of this article is to investigate the latest research activities on the practical RF-EHWC design. The distribution of RF energy in the real environment, the hardware design of RF-EHWC devices and the practical issues in the implementation of RF-EHWC networks are discussed. At the end of this article, we introduce several interesting applications that exploit the RF-EHWC technology to provide smart healthcare services for animals, wirelessly charge the wearable devices, and implement 5G-assisted RF-EHWC.
As a useful generalization of fuzzy sets, the hesitant fuzzy set is designed for situations in which it is difficult to determine the membership of an element to a set because of ambiguity between a ...few different values. In this paper, we define the ith-order polymerization degree function and propose a new ranking method to further compare different hesitant fuzzy sets. In order to obtain much more information in the process of group decision making, we combine the power average operator with the Bonferroni mean in hesitant fuzzy environments and develop the hesitant fuzzy power Bonferroni mean and the hesitant fuzzy power geometric Bonferroni mean. We investigate the desirable properties of these new hesitant fuzzy aggregation operators and discuss some special cases. The new aggregation operators are utilized to present techniques for hesitant fuzzy multiple attribute group decision making. Finally, a numerical example is provided to illustrate the effectiveness of the developed techniques.
One grand challenge in software defined networking is to select appropriate locations for controllers to shorten the latency between controllers and switches in wide area networks. In the literature, ...the majority of approaches are focused on the reduction of packet propagation latency, but propagation latency is only one of the contributors of the overall latency between controllers and their associated switches. In this paper, we explore and investigate more possible contributors of the latency, including the end-to-end latency and the queuing latency of controllers. In order to decrease the end-to-end latency, the concept of network partition is introduced and a clustering-based network partition algorithm (CNPA) is then proposed to partition the network. The CNPA can guarantee that each partition is able to shorten the maximum end-to-end latency between controllers and switches. To further decrease the queuing latency of controllers, appropriate multiple controllers are then placed in the subnetworks. Extensive simulations are conducted under two real network topologies from the Internet Topology Zoo. The results verify that the proposed algorithm can remarkably reduce the maximum latency between controllers and their associated switches.
Delirium is a common psychiatric complication of chronic obstructive pulmonary disease (COPD). The relief of delirium is considered one of the beneficial ways to treat COPD. However, there are ...currently no specific drugs that alleviate delirium in COPD patients. Our research aimed to elucidate the specific mechanisms underlying delirium in COPD mice, while also seeking more effective therapeutic targets. In our study, bioinformatics analysis and qRT PCR were used to identify key factors in the development of delirium in COPD animal models. Open field and elevated plus maze tests were used to detect delirium in mice. Tunel staining and HE staining were used to analyze the apoptosis of mouse hippocampus cells. EdU and CCK-8 experiments were used to analyze PC-12 cells vitality and proliferation. JASPAR online database, dual luciferase reporting experiments, ChIP experiments, and IF staining were used to analyze the interaction between RXRA and PLA2G2A. RXRA is highly expressed in the brain tissue of COPD mice with delirium symptoms. The downregulation of RXRA inhibits the delirium state in COPD mice. This is mainly due to the reduction of endoplasmic reticulum stress and cell apoptosis by inhibiting the expression of RXRA. In addition, we also confirmed that RXRA is a transcription factor of PLA2G2A. RXRA has an inhibitory effect on the expression of PLA2G2A. In vitro experiments have confirmed that inhibition of the RXRA/PLA2G2A axis reduces cell apoptosis, thereby alleviating the occurrence and development of delirium in COPD mice. Inhibition of the RXRA/PLA2G2A axis reduces endoplasmic reticulum stress and cell apoptosis. This process alleviates the development of delirium in COPD mice.
The cascade reactions between NH 2-functionalized enaminones and sulfonyl hydrazines have been developed for the synthesis of fully substituted pyrazoles. By making use of the hydrophilic primary ...amino group in the enaminones, the reactions proceed well in the medium of pure water in the presence of molecular iodine, TBHP, and NaHCO3 via cascade C-H sulfonylation and pyrazole annulation. The cleavage of the C–N bond in enaminones is confirmed by the experiment using 15 N-labeled enaminone.
Isoflavonoids constitute a well-investigated category of phenylpropanoid-derived specialized metabolites primarily found in leguminous plants. They play a crucial role in legume development and ...interactions with the environment. Isoflavonoids usually function as phytoalexins, acting against pathogenic microbes in nature. Additionally, they serve as signaling molecules in rhizobial symbiosis. Notably, owing to their molecular structure resembling human estrogen, they are recognized as phytoestrogens, imparting positive effects on human health. This review comprehensively outlines recent advancements in research pertaining to isoflavonoid biosynthesis, transcriptional regulation, transport, and physiological functions, with a particular emphasis on soybean plants. Additionally, we pose several questions to encourage exploration into novel contributors to isoflavonoid metabolism and their potential roles in plant-microbe interactions.
Slot‐die coating is generally regarded as the most effective large‐scale methodology for the fabrication of organic solar cells (OSCs). However, the corresponding device performance significantly ...lags behind spin‐coated devices. Herein, the active layer morphology, flexible substrate properties, and the processing temperature are optimized synergistically to obtain high power conversion efficiency (PCE) for both the flexible single cells and the modules. As a result, the 1 cm2 flexible devices produce an excellent PCE of 12.16% as compared to 12.37% for the spin‐coated small‐area (0.04 cm2) rigid devices. Likewise, for modules with an area of 25 cm2, an extraordinary PCE of 10.09% is observed. Hence, efficiency losses associated with the upscaling are significantly reduced by the synergistic optimization. Moreover, after 1000 bending cycles at a bending radius of 10 mm, the flexible devices still produce over 99% of their initial PCE, whereas after being stored for over 6000 h in a glove box, the PCE reaches 103% of its initial value, indicating excellent device flexibility as well as superior shelf stability. These results, thus, are a promising confirmation the great potential for upscaling of large‐area OSCs in the near future.
With synergistic optimization of the active layer morphology, flexible substrate properties, and processing temperature, large‐area flexible organic solar cells with high performance are achieved by the slot‐die coating process. The 1 cm2 flexible devices produce an excellent power conversion efficiency (PCE) of 12.16%, and, for modules with an area of 25 cm2, an extraordinary PCE of 10.09% is observed.
A regioselective green approach for the nickel(II)-catalyzed C–N cross-coupling between arylamines and pyrazoles through a photoredox process is reported. Moderate to good yield was observed for ...this reaction, performed in water under air at room temperature. This strategy provides a powerful tool for the green synthesis of pyrazole-containing bioactive molecules. In addition, a single-electron-transfer mechanism is proposed in this report.
PDF
