检索结果-南通市图书馆

Numerical investigation on characteristics of interfacial wave of liquid film in gas-liquid two-phase flow using OpenFOAM

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第2期37卷 233-248页

作者： Xiaoqi ma Yueshe WANG Jiaming TIAN state key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong UniversityXi’an 710049China

Liquid film cooling as an advanced cooling technology is widely used in space *** operation of liquid film along the rocket combustion inner wall is crucial for thermal protection of rocket *** stability of liquid film is mainly determined by the characteristics of interfacial wave,which is rarely investigated right *** to improve the stability of thin film has become a hot *** view of this,an advanced model based on the conventional Volume of Fluid(VOF)model is adopted to investigate the characteristics of interfacial wave in gas-liquid flow by using OpenFOAM,and the mechanism of formation and development of wave is revealed intuitively through numerical *** effects from gas velocity,surface tension and dynamic viscosity of liquid(three factors)on the wave are studied *** can be found that the gas velocity is critical to the formation and development of wave,and four modes of droplets generation are illustrated in this ***,a gas vortex near the gas-liquid interface can induce formation of wave easily,so changing the gas vortex state can regulate formation and development of ***’s more,the change rules of three factors influencing on the interfacial wave are obtained,and the surface tension has a negative effect on the formation and development of wave only when the surface tension coefficient is above the critical value,whereas the dynamic viscosity has a positive effect in this ***,the maximum height and maximum slope angle of wave will level off as the gas velocity ***,the maximum slope angle of wave is usually no more than 38°,no matter what happens to the three factors.

关键词： Interfacial wave Gas-liquid Two-phase flow VOF model OpenFOAM

Transient Response and Ionic Dynamics in Organic Electrochemical Transistors

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第11期16卷 191-223页

作者： Chao Zhao Jintao Yang Wei ma state key Laboratory for Mechanical Behavior of materials Xi’an Jiaotong UniversityXi′an 710049People’s Republic of China

The rapid development of organic electrochemical transistors(OECTs)has ushered in a new era in organic electronics,distinguishing itself through its application in a variety of domains,from high-speed logic circuits to sensitive biosensors,and neuromorphic devices like artificial synapses and organic electrochemical random-access *** recent strides in enhancing OECT performance,driven by the demand for superior transient response capabilities,a comprehensive understanding of the complex interplay between charge and ion transport,alongside electron–ion interactions,as well as the optimization strategies,remains *** review aims to bridge this gap by providing a systematic overview on the fundamental working principles of OECT transient responses,emphasizing advancements in device physics and optimization *** review the critical aspect of transient ion dynamics in both volatile and non-volatile applications,as well as the impact of materials,morphology,device structure strategies on optimizing transient *** paper not only offers a detailed overview of the current state of the art,but also identifies promising avenues for future research,aiming to drive future performance advancements in diversified applications.

关键词： Organic electrochemical transistors Transient response Ion dynamics Electronic dynamics Volatility and non-volatility

Extreme precipitation detection ability of four high-resolution precipitation product datasets in hilly area:a case study in Nepal

在线全文

学校读者我要写书评

暂无评论

Advances in Climate Change Research 2024年第3期15卷 390-405页

作者： sunil subba Yao-Ming ma Wei-Qiang ma Cun-Bo Han Land-Atmosphere Interaction and its Climatic Effects Group State Key Laboratory of Tibetan Plateau Earth SystemEnvironment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China College of Earth and Planetary sciences University of Chinese Academy of SciencesBeijing 100049China College of Atmospheric science Lanzhou UniversityLanzhou 730000China National Observation and Research station for Qomolongma special Atmospheric Processes and Environmental Changes Dingri 858200China kathmandu Center of Research and Education Chinese Academy of SciencesBeijing 100101China China-Pakistan Joint Research Center on Earth sciences Chinese Academy of SciencesIslamabad 45320Pakista

Given Nepal's vulnerability to extreme precipitation(EP),it is imperative to conduct a comprehensive analysis to comprehend the historical trends of such ***,acquiring precise precipitation data for EP remains challenging in mountainous countries like Nepal owing to the scarcity of densely gauged *** limitation impedes the dissemination of knowledge pertaining to EP variability events in *** current research on this topic is deficient for two main reasons:1)there is a lack of studies leveraging recently released high-resolution precipitation products to identify their EP detection capabilities,which further hinders the usability of those products in data-scarce regions like Nepal,and 2)most studies have focused on the characterisation of EP events in Nepal rather than their spatial and temporal *** address these issues,this study evaluated the EP detection capabilities of four high-resolution precipitation product datasets(PPDs)across Nepal from 1985 to *** datasets include the ERA5 Land reanalysis data,satellite-based precipitation data(PERsIANN_CCs_CDR and CHIRPs_V2.0)and a merged dataset(TPHiPr).We used various statistical and categorical indices to assess their ability to capture the spatial and temporal variability of EP *** annual EP events were characterised by 11 indices divided into frequency and intensity *** TPHiPr merged dataset offered a robust depiction of monthly precipitation estimates,achieving the highest critical success index,accuracy,probability of detection and a low false alarm ratio for daily precipitation detection of 0.1 mm in ***,the PERsIANN_CCs_CDR dataset exhibited poor *** PPDs showed increasing trends in EP ***,the TPHiPr dataset showcased those trends with fewer errors and stronger correlations for many frequency(R10mm,R20mm and R25mm)and intensity(RX1day,RX5day,PRCPTOT and R99p)*** results indicate that TPHiPr outperformed ot

关键词： Extreme precipitation Precipitation product Nepal TPHiPr ERA5 land PERsIANN_CCs_CDR CHIRPs_V2.0

Nuance of inward rectifying potassium(kir)channel dysfunctions in neurodegenerative diseases

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第6期19卷 1195-1196页

作者： Benjamin Garland Linlin ma Griffith Institute for Drug Discovery&school of Environment and science Griffith UniversityNathanBrisbaneQLDAustralia

Neurodegenerative disorders are highly prevalent and diverse in *** manifestation largely depends on the cell types involved,with aberrant inflammatory episodes progressively inducing a constellation of phenotypes that are classified into specific diseases based on their neuropathological *** two most prevalent neurodegenerative diseases worldwide,Alzheimer’s disease(AD)and Parkinson’s disease(PD),for example,share notable similarities,yet they differ in terms of the specific cell types lost within the central nervous system(CNs).The significant and progressive loss of cortical and certain subcortical neurons in various regions is a major defining trait of *** contrast,the specific loss of dopaminergic neurons(DA)within the substantial nigra pars compacta(sNpc)is sufficient to cause motor symptoms associated with *** devastating condition arising from neurodegeneration within the CNs,amyotrophic lateral sclerosis(ALs),results in the progressive death of upper and lower motor *** degeneration originates in oligodendrocytes,whose defective myelination abilities lead to the denervation of the anterior horn,aggravating motor neuron death.

关键词： diseases degenerative degeneration

Time-inconsistent stochastic linear-quadratic control problem with indefinite control weight costs

在线全文

学校读者我要写书评

暂无评论

science China mathematics 2024年第1期67卷 211-236页

作者： Qi Lü Bowen ma school of mathematics Sichuan UniversityChengdu 610064China

A time-inconsistent linear-quadratic optimal control problem for stochastic differential equations is *** introduce conditions where the control cost weighting matrix is possibly *** such conditions,we obtain a family of closed-loop equilibrium strategies via multi-person differential *** result extends Yong’s work(2017) in the case of stochastic differential equations,where a unique closed-loop equilibrium strategy can be derived under standard conditions(namely,the control cost weighting matrix is uniformly positive definite,and the other weighting coefficients are positive semidefinite).

关键词： linear-quadratic optimal control problem time-inconsistent cost functional generalized Riccati equation indefinite control weight cost closed-loop equilibrium strategy

Two-dimensional atomically thin Pt layers on MXenes: The role of electronic effects during catalytic dehydrogenation of ethane and propane

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第3期17卷 1251-1258页

作者： Zhe Li Tobias k.Misicko Fan Yang Xiaopeng Liu Zhenwei Wu Xiaoyang Gao Tao ma Jeffrey T.Miller Daniela s.mainardi Collin D.Wick Zhenhua Zeng Yang Xiao Yue Wu Department of Chemical and Biological Engineering Iowa State University618 Bissell RoadAmesIA 50011USA Institute for Micromanufacturing Louisiana Tech University505 Tech DriveRustonLA 71272USA Davidson school of Chemical Engineering Purdue University480 Stadium Mall DriveWest LafayetteIN 47907USA Michigan Center for materials Characterization University of Michigan2800 Plymouth RdAnn Arbor MI 48109USA College of Engineering and science Louisiana Tech UniversityRustonLA 71272USA

Atomically thin Pt nanolayers were synthesized on the surface of Mo2TiC2 MXenes and used for the catalytic dehydrogenation of ethane and propane into ethylene and propylene,two important chemicals for the petrochemical *** compared with Pt nanoparticles,the atomically thin Pt nanolayer catalyst showed superior coke-resistance(no deactivation for 24 h),high activity(turnover frequencies(TOFs)of 0.4–1.2 s^(-1)),and selectivity(>95%)toward ethylene and *** unique Pt nanolayer has a similar geometric surface to Pt nanoparticles,enabling the investigations of the electronic effect on the catalytic performance,where the geometric effect is *** is found that the electronic effect plays a critical role in dehydrogenative product selectivity and catalyst *** metal–support interaction is found dependent on the substrate and metal components,providing wide opportunities to explore high-performance MXene-supported metallic catalysts.

关键词： MXene catalysis alkane dehydrogenation nanolayers

serum amylase as a novel prognostic marker of organophosphorus poisoning: a retrospective study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Emergency and Critical Care Medicine 2024年第3期4卷 111-116页

作者： Guo X. Chen Z. Feng k. Zeng s. Zhang J. ma Z. Yuan C. school of Clinical Medicine Ningxia Medical University Ningxia Hui Yinchuan China Emergency Department General Hospital of Ningxia Medical University Ningxia Hui Autonomous Region Yinchuan China

Background: This study aims to explore the significance of serum amylase levels in patients with organophosphorus pesticide (OP) poisoning and to provide a new perspective for evaluating the severity and prognosis of OP poisoning. Methods: The clinical data of 67 patients with acute OP poisoning, who had been treated in the emergency department of the General Hospital of Ningxia Medical University between september 2020 and August 2022, were retrospectively analyzed. Using spearman rank correlation, serum amylase levels during admission and severity of poisoning correlated with discharge outcomes. Based on serum amylase levels, receiver operating characteristic curves were plotted to predict the severity and mortality of patients who experience organophosphate poisoning. The optimal threshold serum amylase level at admission was determined based on the maximum Youden index. Results: Using spearman rank correlation analysis, serum amylase levels at admission positively correlated with the severity of poisoning and discharge outcomes, but the degree of correlation was weak (rs: 0.344; 0.264; P s’ serum amylase levels at admission had receiver operating characteristic area under the curve values of 0.726 and 0.735 to predict the degree of severe poisoning and death, respectively. Based on the maximum Youden index, the optimal threshold of serum amylase were 97.8 and 194.1 U/L when the degree of poisoning was severe and the discharge outcome of patients was died. In comparison to patients with serum amylase levels ≤194.1 U/L at admission, the OR values of death in patients with serum amylase levels >194.1 U/L at admission was 15.944 (95% CI: 1.825–139.274). Conclusion: serum amylase levels in patients with organophosphate poisoning correlate with the degree of poisoning and discharge outcomes. Higher serum amylase level was a risk factor for organophosphorus poisoning death. © Wolters kluwer Health, Inc. All rights reserved.

关键词： Amylase Emergency department Organophosphorus pesticide poisoning Prognosis

A rigorous real-time acoustic positioning method for ocean bottom seismic exploration

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

satellite Navigation 2024年第1期5卷 168-190页

作者： Jinye ma shouchuan Fang Jianhu Zhao school of Geodesy and Geomatics Wuhan University129 Luoyu RoadWuhan430079China Institute of marine science and Technology Wuhan UniversityWuhan430079China surveying service Center BGP Inc.CNPCZhuozhou072751HebeiChina

The conventional technique for positioning seafloor geophones in ocean bottom seismic exploration encounters several challenges,including the significant impact of outliers on positioning results,underutilization of high-precision observations,and low efficiency in real-time data *** issues inevitably affect the quality of seismic exploration *** address these challenges and enhance the accuracy of geophone positioning,this paper proposes a rigorous real-time acoustic positioning method for geophones based on sequential adjustment and Baarda's outlier detection *** proposed method comprises three key steps:grouping the original acoustic observations,constructing the intra-group acoustic positioning model,and synthesizing the positioning results across the different *** validity and practicality of this approach are confirmed through a simulation experiment as well as the field experiment conducted in the Bohai sea,*** results demonstrate that the proposed method effectively eliminates outliers in the original observations and maximizes the utilization of high-quality *** to traditional acoustic positioning methods,it significantly reduces positioning errors from meters to decimeters,and in some cases can achieve centimeter-level *** the sound velocity profile in the operating sea area is measured,the method can attain the posterior standard deviation at the millimeter level and positioning errors within 10 *** the sound velocity profile is unknown,the method can achieve the posterior standard deviation at centimeter-level and positioning errors of approximately 20 cm.

关键词： Ocean bottom seismic exploration Geophone positioning Acoustic positioning method sequential adjustment Outlier detection

saliency-guided meta-hallucinator for few-shot learning

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

science China(Information sciences) 2024年第10期67卷 189-210页

作者： Hongguang ZHANG Chun LIU Jiandong WANG Linru ma Piotr kONIUsZ Philip H.s.TORR Lin YANG systems Engineering Institute Academy of Military Sciences Data61 Commonwealth Scientific and Industrial Research Organisation Australian National University Oxford University

Learning novel object concepts from limited samples remains a considerable challenge in deep learning. The main directions for improving the few-shot learning models include(i) designing a stronger backbone,(ii) designing a powerful(dynamic) meta-classifier, and(iii) using a larger pre-training set obtained by generating or hallucinating additional samples from the small scale dataset. In this paper, we focus on item(iii) and present a novel meta-hallucination strategy. Presently, most image generators are based on a generative network(i.e., GAN) that generates new samples from the captured distribution of images. However, such networks require numerous annotated samples for training. In contrast, we propose a novel saliency-based end-to-end meta-hallucinator, where a saliency detector produces foregrounds and backgrounds of support images. such images are fed into a two-stream network to hallucinate feature samples directly in the feature space by mixing foreground and background feature samples. Then, we propose several novel mixing strategies that improve the quality and diversity of hallucinated feature ***, as not all saliency maps are meaningful or high quality, we further introduce a meta-hallucination controller that decides which foreground feature samples should participate in mixing with backgrounds. To our knowledge, we are the first to leverage saliency detection for few-shot learning. Our proposed network achieves state-of-the-art results on publicly available few-shot image classification and anomaly detection benchmarks, and outperforms competing sample mixing strategies such as the so-called manifold Mixup.

关键词： few-shot learning saliency detection object recognition anomaly detection computer vision