28 research outputs found

    Airport Surface Modelling and Simulation Based on Timed Coloured Petri Net

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    In order to satisfy the requirements of International Civil Aviation Organization (ICAO) for aircraft taxi route planning in Advanced Surface Movement Guidance and Control System (A-SMGCS), an airport surface operation modelling and simulation approach based on timed and coloured Petri net is presented. According to the layout of the airport surface and the features of surface operation units, a static Petri net model of the airport surface is established. On this basis, in line with the requirements on the aircraft taxiing velocity in ICAO DOC 9830, the dynamic Petri net model of the airport surface operation is established by adding the time attribute to the static model. Additionally, the method of defining the capacity of airport operation unit place is proposed and the constraints of the airport surface operation are incorporated using Petri net elements. Unlike other papers in the field, the airport surface Petri net model established in this paper can simulate conflict-free taxiing using a Petri net simulator without relying on other model-independent algorithms. Based on the CPN Tools software, taking Toulouse Airport as an example, the validity of the model has been verified by comparing the model running data with real flight data.</p

    Quantum metric nonlinear Hall effect in a topological antiferromagnetic heterostructure

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    Quantum geometry - the geometry of electron Bloch wavefunctions - is central to modern condensed matter physics. Due to the quantum nature, quantum geometry has two parts, the real part quantum metric and the imaginary part Berry curvature. The studies of Berry curvature have led to countless breakthroughs, ranging from the quantum Hall effect in 2DEGs to the anomalous Hall effect (AHE) in ferromagnets. However, in contrast to Berry curvature, the quantum metric has rarely been explored. Here, we report a new nonlinear Hall effect induced by quantum metric by interfacing even-layered MnBi2Te4 (a PT-symmetric antiferromagnet (AFM)) with black phosphorus. This novel nonlinear Hall effect switches direction upon reversing the AFM spins and exhibits distinct scaling that suggests a non-dissipative nature. Like the AHE brought Berry curvature under the spotlight, our results open the door to discovering quantum metric responses. Moreover, we demonstrate that the AFM can harvest wireless electromagnetic energy via the new nonlinear Hall effect, therefore enabling intriguing applications that bridges nonlinear electronics with AFM spintronics.Comment: 19 pages, 4 figures and a Supplementary Materials with 66 pages, 4 figures and 3 tables. Originally submitted to Science on Oct. 5, 202

    Locoregional therapy combined with systemic therapy (LRT + ST) for unresectable and metastatic intrahepatic cholangiocarcinoma: a systematic review and meta-analysis

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    The outcome of systemic therapy (ST) for unresectable and metastatic intrahepatic cholangiocarcinoma (iCCA) is poor. This study aims to further evaluate the efficacy and safety of locoregional therapy combined with systemic therapy (LRT + ST) compared with only ST in unresectable and metastatic iCCA by performing a systematic literature review and meta-analysis

    Lamina characteristics of gas-bearing shale fine-grained sediment of the Silurian Longmaxi Formation of Well Wuxi 2 in Sichuan Basin, SW China

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    Based on various test data, the composition, texture, structure and lamina types of gas-bearing shale were determined based on Well Wuxi 2 of the Silurian Longmaxi Formation in the Sichuan Basin. Four types of lamina, namely organic-rich lamina, organic-bearing lamina, clay lamina and silty lamina, are developed in the Longmaxi Formation of Well Wuxi 2, and they form 2 kinds of lamina set and 5 kinds of beds. Because of increasing supply of terrigenous clasts and enhancing hydrodynamics and associated oxygen levels, the contents of TOC and brittle mineral reduce and content of clay mineral increases gradually as the depth becomes shallow. Organic-rich lamina, organic-rich + organic-bearing lamina set and organic-rich bed dominate the small layers 1-3 of Member 1 of the Longmaxi Formation, suggesting anoxic and weak hydraulic depositional setting. Organic-rich lamina, along with organic-bearing lamina and silty lamina, appear in small layer 4, suggesting increased oxygenated and hydraulic level. Small layers 1-3 are the best interval and drilling target of shale gas exploration and development. Key words: Sichuan Basin, Longmaxi Formation, fine-grained sediment, shale gas, lamina, Well Wuxi

    Prognostic implications of left ventricular hypertrophy defined by the thresholds from the international and Chinese guidelines

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    Abstract To compare the predictive value of mortality between left ventricular hypertrophy (LVH) defined by Chinese thresholds and defined by international guidelines in hypertension individuals and investigate better indexation methods for LVH in Chinese population. We included 2454 community hypertensive patients with Left ventricular mass (LVM) and relative wall thickness. LVM was indexed to body surface area (BSA), height2 7 and height 1 7. The outcomes were all‐cause and cardiovascular mortality. Cox proportional hazards models were used to explore the association between LVH and the outcomes. C‐statistics and time‐dependent receiver operating characteristic curve (ROC) was used to evaluate the value of those indicators. During a median follow‐up of 49 months (interquartile range 2–54 months), 174 participants (7.1%) died from any cause (n = 174), with 71 died of cardiovascular disease. LVM/BSA defined by the Chinese thresholds was significantly associated with cardiovascular mortality (HR: 1.63; 95%CI: 1.00‐2.64). LVM/BSA was significantly associated with all‐cause mortality using Chinese thresholds (HR: 1.56; 95%CI: 1.14‐2.14) and using Guideline thresholds (HR: 1.52; 95%CI: 1.08‐2.15). LVM/Height1.7 was significantly associated with all‐cause mortality using Chinese thresholds (HR: 1.60; 95%CI: 1.17‐2.20) and using Guideline thresholds (HR: 1.54; 95%CI: 1.04‐2.27). LVM/Height2.7 was not significantly associated with all‐cause mortality. C‐statistics indicated that LVM/BSA and LVM/Height1.7 by Chinese thresholds had better predictive ability for mortality. Time‐ROC indicated that only LVM/Height1.7 defined by Chinese threshold had incremental value for predicting mortality. We found that in community hypertensive populations, race‐specific thresholds should be used to classify LV hypertrophy related to mortality risk stratification. LVM/BSA and LVM/Height1.7 are acceptable normalization method in Chinese hypertension

    Different Types of Vaccines against Pestiviral Infections: “Barriers” for “<i>Pestis</i>”

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    The genus Pestivirus of the family Flaviviridae mainly comprises classical swine fever virus (CSFV), bovine viral diarrhea virus 1 (BVDV-1), BVDV-2, border disease virus (BDV), and multiple new pestivirus species such as atypical porcine pestivirus (APPV), giraffe pestivirus, and antelope pestivirus. Pestiviruses cause infectious diseases, resulting in tremendous economic losses to animal husbandry. Different types of pestivirus vaccines have been developed to control and prevent these important animal diseases. In recent years, pestiviruses have shown great potential as viral vectors for developing multivalent vaccines. This review analyzes the advantages and disadvantages of various pestivirus vaccines, including live attenuated pestivirus strains, genetically engineered marker pestiviruses, and pestivirus-based multivalent vaccines. This review provides new insights into the development of novel vaccines against emerging pestiviruses, such as APPV and ovine pestivirus

    Nonreciprocal thermal radiation in ultrathin magnetized epsilon-near-zero semiconductors

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    Spectral/angular emissivity ee and absorptivity α{\alpha} of an object are widely believed to be identical by Kirchhoff's law of thermal radiation in reciprocal systems, but this introduces an intrinsic and inevitable energy loss for energy conversion and harvesting devices. So far, experimental evidences of breaking this well-known balance are still absent, and previous theoretical proposals are restricted to narrow single-band nonreciprocal radiation. Here we observe for the first time, to our knowledge, the violation of Kirchhoff's law using ultrathin (<λ/40<{\lambda}/40, λ{\lambda} is the working wavelength) magnetized InAs semiconductor films at epsilon-near-zero (ENZ) frequencies. Large difference of αe>0.6|{\alpha}-e|>0.6 has been experimentally demonstrated under a moderate external magnetic field. Moreover, based on magnetized ENZ building blocks supporting asymmetrically radiative Berreman and surface ENZ modes, we show versatile shaping of nonreciprocal thermal radiation: single-band, dual-band, and broadband nonreciprocal emission spectra at different wavebands. Our findings of breaking Kirchhoff's law will advance the conventional understanding of emission and absorption processes of natural objects, and lay a solid foundation for more comprehensive studies in designing various nonreciprocal thermal emitters. The reported recipe of diversely shaping nonreciprocal emission will also breed new possibilities in renovating next-generation nonreciprocal energy devices in the areas of solar cells, thermophotovoltaic, radiative cooling, etc.Comment: 21 pages, 4 figure

    Enhanced Electricity Generation from Graphene Microfluidic Channels for Self-Powered Flexible Sensors

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    As a novel energy harvesting method, generating electricity from the interaction of liquid-solid interface has attracted growing interest. Although several functional materials have been carried out to improve the performance of the flow-induced hydrovoltaic generators, there are few reports on influencing the droplet flow behavior to excavate its electricity generation by governing the device structure. Here, the output performance of the graphene microfluidic channel (GMC) structure is similar to 13 times higher than that of the flat-open space graphene morphology. The strong slip flow and high surface charge density near the graphene-droplet interface originate from the GMC structure, which produces an effective liquid-solid interaction and rapid relative movement of the droplet. Additionally, based on the GMC structure a self-powered pressure sensor is designed. The droplet motion is regulated by external forces to generate specific voltages, which provide a new approach for the development of wearable self-powered electronics

    Enhanced Electricity Generation from Graphene Microfluidic Channels for Self-Powered Flexible Sensors

    No full text
    As a novel energy harvesting method, generating electricity from the interaction of liquid-solid interface has attracted growing interest. Although several functional materials have been carried out to improve the performance of the flow-induced hydrovoltaic generators, there are few reports on influencing the droplet flow behavior to excavate its electricity generation by governing the device structure. Here, the output performance of the graphene microfluidic channel (GMC) structure is similar to 13 times higher than that of the flat-open space graphene morphology. The strong slip flow and high surface charge density near the graphene-droplet interface originate from the GMC structure, which produces an effective liquid-solid interaction and rapid relative movement of the droplet. Additionally, based on the GMC structure a self-powered pressure sensor is designed. The droplet motion is regulated by external forces to generate specific voltages, which provide a new approach for the development of wearable self-powered electronics

    Antibody-Dependent Enhancement: ″Evil″ Antibodies Favorable for Viral Infections

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    The pandemics caused by emerging viruses such as severe acute respiratory syndrome coronavirus 2 result in severe disruptions to public health. Vaccines and antibody drugs play essential roles in the control and prevention of emerging infectious diseases. However, in contrast with the neutralizing antibodies (NAbs), sub- or non-NAbs may facilitate the virus to enter the cells and enhance viral infection, which is termed antibody-dependent enhancement (ADE). The ADE of most virus infections is mediated by the Fc receptors (FcRs) expressed on the myeloid cells, while others are developed by other mechanisms, such as complement receptor-mediated ADE. In this review, we comprehensively analyzed the characteristics of the viruses inducing FcRs-mediated ADE and the new molecular mechanisms of ADE involved in the virus entry, immune response, and transcription modulation, which will provide insights into viral pathogenicity and the development of safer vaccines and effective antibody drugs against the emerging viruses inducing ADE
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