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An oscillation-free Hermite WENO scheme for hyperbolic conservation laws

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Science China Mathematics 2024年第2期67卷 431-454页

作者： zhuang Zhao Jianxian Qiu School of Mathematical Sciences and Institute of Natural Sciences Shanghai Jiao Tong UniversityShanghai 200240China School of Mathematical Sciences and Fujian Provincial Key Laboratory of Mathematical Modeling and High-Performance Scientific Computing Xiamen UniversityXiamen 361005China

In this paper, the sixth-order oscillation-free Hermite weighted essentially non-oscillatory (OFHWENO) scheme is proposed for hyperbolic conservation laws on structured meshes, where the zeroth- andfirst-order moments are the variables for the governing equations. The main difference from other HWENOschemes existing in the literature is that we add high-order numerical damping terms in the first-order momentequations to control spurious oscillations for the OF-HWENO scheme. The OF-HWENO scheme not only canachieve the designed optimal numerical order, but also can be easily implemented as we use only one set ofstencils in the reconstruction procedure and the same reconstructed polynomials are applied for the zeroth- andfirst-order moment equations. In order to obtain the adaptive order resolution when facing discontinuities, atransition polynomial is added in the reconstruction, where the associated linear weights can also be any positivenumbers as long as their summation equals one. In addition, the OF-HWENO scheme still keeps compactnessas only immediate neighbor values are needed in the space discretization. Some benchmark numerical tests areperformed to illustrate the high-order accuracy, high resolution and robustness of the proposed scheme.

关键词： Hermite WENO scheme hyperbolic conservation laws oscillation-free adaptive order discontinuous Galerkin method

A hybrid deep neural network based on multi-time window convolutional bidirectional LSTM for civil aircraft APU hazard identification

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Chinese Journal of Aeronautics 2022年第4期35卷 344-361页

作者： Di ZHOU Xiao zhuang Hongfu ZUO Civil A viation Key Laboratory of Aircraft Health Monitoring and Intelligent Maintenance College of Civil AviationNanjing University of Aeronautics and AstronauticsNanjing 210016China Department of Mechanical and Industrial Engineering University of TorontoToronto M5S 3G8Canada College of Science Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Safety is one of the important topics in the field of civil aviation. Auxiliary Power Unit(APU) is one of important components in aircraft, which provides electrical power and compressed air for aircraft. The hazards in APU are prone to cause economic losses and even casualties. So,actively identifying the hazards in APU before an accident occurs is necessary. In this paper, a Hybrid Deep Neural Network(HDNN) based on multi-time window convolutional neural network-Bidirectional Long Short-Term Memory(CNN-Bi LSTM) neural network is proposed for active hazard identification of APU in civil aircraft. In order to identify the risks caused by different types of failures, the proposed HDNN simultaneously integrates three CNN-Bi LSTM basic models with different time window sizes in parallel by using a fully connected neural network. The CNN-Bi LSTM basic model can automatically extract features representing the system state from the input data and learn the time information of irregular trends in the time series data. Nine benchmark models are compared with the proposed HDNN. The comparison results show that the proposed HDNN has the highest identification accuracy. The HDNN has the most stable identification performance for data with imbalanced samples.

关键词： Civil aviation Convolutional neural networks Deep neural networks Hazard identification Long short-term memory

Dataset of temperature and precipitation over the major Belt and Road Initiative regions under different temperature rise scenarios

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Big Earth Data 2023年第2期7卷 375-397页

作者： Yuanhuang zhuang Jingyong Zhang Tianjin Meteorological Observatory TianjinChina Center for Monsoon System Research Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijingChina

Changes in temperature and precipitation have a profound effect on the ecological environment and socioeconomic *** this study,we focus on the major Belt and Road Initiative(BRI)regions and develop a dataset of temperature and precipitation at global temperature rise targets of 1.5°C,2°C,and 3°C above pre-industrial levels under the Representative Concentration Pathway(RCP)8.5 emission scenario using 4 downscaled global model datasets data at a fine spatial resolution of 0.0449147848°(~5 km)globally from *** temperature variables include the daily maximum(Tmax),minimum(Tmin)and average(Tmp)surface air temperatures,and the diurnal temperature range(DTR).We first evaluate the performance of the downscaled model data using CRU-observed gridded data for the historical period *** results indicate that the downscaled model data can generally reproduce the pattern characteristics of temperature and precipitation variations well over the major BRI regions for ***,we project temperature and precipitation variations over the major BRI regions at global temperature rise targets of 1.5°C,2°C,and 3°C under the RCP8.5 emission scenario based on the dataset by adopting the multiple-model ensemble *** dataset contributes to understanding detailed the characteristics of climate change over the major BRI regions,and provides data fundamental for adopting appropriate strategies and options to reduce or avoid disadvantaged consequences associated with climate change over the major BRI *** dataset is available at https://***/10.57760/sciencedb.01850.

关键词： Climate change multiple-model ensemble projection high-resolution downscaled model dataset global temperature rise scenarios BRI

Facile synthesis of hydrochar-supported catalysts from glucose and its catalytic activity towards the production of functional amines

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Green Energy & Environment 2023年第5期8卷 1358-1370页

作者： Xiuzheng zhuang Jianguo Liu Longlong Ma Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education School of Energy and EnvironmentSoutheast UniversityNanjing210096China Key Laboratory of Renewable Energy Guangzhou Institute of Energy ConversionChinese Academy of SciencesGuangzhou510640China

Since the utilization of abundant biomass to develop advanced materials has become an utmost priority in recent years,we developed two sustainable routes(i.e.,the impregnation method and the one-pot synthesis)to prepare the hydrochar-supported catalysts and tested its catalytic performance on the reductive *** techniques,such as TEM,XRD and XPS,were adopted to characterize the structural and catalytic features of *** indicated that the impregnation method favors the formation of outer-sphere surface complexes with porous structure as well as well-distributed metallic nanoparticles,while the one-pot synthesis tends to form the inner-sphere surface complexes with relatively smooth appearance and amorphous *** difference explains the better activity of catalysts prepared by the impregnation method which can selectively convert benzaldehyde to benzylamine with an excellent yield of 93.7%under the optimal reaction conditions;in contrast,the catalyst prepared by the one-pot synthesis only exhibits a low selectivity near to ***,the gram-scale test catalyzed by the same catalysts exhibits a similar yield of benzylamine in comparison to its smaller scale,which is comparable to the previously reported heterogeneous noble-based *** surprisingly,the prepared catalysts can be expediently recycled by a magnetic bar and remain the satisfying catalytic activity after reusing up to five *** conclusion,these developed catalysts enable the synthesis of functional amines with excellent selectivity and carbon balance,proving cost-effective and sustainable access to the wide application of reductive amination.

关键词： Impregnation method One-pot synthesis Hydrochar-supported catalyst Reductive amination

Paradoxical role of Id proteins in regulating tumorigenic potential of lymphoid cells

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Frontiers of Medicine 2018年第4期12卷 374-386页

作者： Sumedha Roy Yuan zhuang Department of Immunology Duke University Medical Center Durham NC 27710 USA

A family of transcription factors known as Id proteins, or inhibitor of DNA binding and differentiation, is capable of regulating cell proliferation, survival and differentiation, and is often upregulated in multiple types of tumors. Due to their ability to promote self-renewal, Id proteins have been considered as oncogenes, and potential therapeutic targets in cancer models. On the contrary, certain Id proteins are reported to act as tumor suppressors in the development of Burkitt＇s lymphoma in humans, and hepatosplenic and innate-like T cell lymphomas in mice. The contexts and mechanisms by which Id proteins can serve in such contradictory roles to determine tumor outcomes are still not well understood. In this review, we explore the roles of Id proteins in lymphocyte development and tumorigenesis, particularly with respect to inhibition of their canonical DNA binding partners known as E proteins. Transcriptional regulation by E proteins, and their antagonism by Id proteins, act as gatekeepers to ensure appropriate lymphocyte development at key checkpoints. We re-examine the derailment of these regulatory mechanisms in lymphocytes that facilitate tumor development. These mechanistic insights can allow better appreciation of the context-dependent roles of Id proteins in cancers and improve considerations for therapy.

关键词： Id proteins lymphoma leukemia T cells B cells tumor suppressor oncogene

Numerical study on indoor environment and thermal comfort in train station waiting hall with two different air-conditioning modes

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Building Simulation 2021年第2期14卷 337-349页

作者： Biyao zhuang Juan Shi Zhenqian Chen Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education of China School of Energy and EnvironmentSoutheast UniversityNanjing210096China

With the increasing size of the waiting hall,the large-area use of transparent envelope materials makes the interior surface temperature of the envelope too high,which puts forward higher requirements for the control of environment and thermal comfort *** this paper,the characteristics of indoor temperature distribution,relative humidity distribution and thermal comfort under the all air system(AAs)and the radiant floor cooling and wall cooling combined with air supply system(RC/ASs)were investigated in the large *** computational fluid dynamics(CFD)method was used,and the performance of the CFD model was validated by comparing the measured results with CFD simulation results in the *** numerical results clearly showed that the temperature and relative humidity indoors could satisfy the design requirement both in the AAs and RC/*** indoor air distribution in most areas under the RC/ASs was more uniform based on the indoor heat and humidity requirements under the cooling load of measured *** the AAs,the total cooling capacity of air conditioning unit was the highest when indoor thermal comfort was the best,that meant that to achieve the best working condition,the air-conditioning system need high energy ***,the RC/ASs addressed the problem that the temperature around the seated passengers in the waiting area was relatively high in the *** paper will provide reference for the air conditioning system design in the similar large spaces in the future.

关键词： radiant floor cooling radiant wall cooling large spaces thermal comfort

Characterization of Loading Rate Effects on the Interactions Between Crack Growth and Inclusions in Cementitious Material

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Computers, Materials & Continua 2018年第12期57卷 417-446页

作者： Shuai Zhou Xiaoying zhuang Division of Computational Mechanics Ton Duc Thang UniversityHo Chi Minh CityVietnam Faculty of Civil Engineering Ton Duc Thang UniversityHo Chi Minh CityVietnam College of Materials Science and Engineering Chongqing UniversityChongqingChina Leibniz Universität Hannover Appelstr.1130167HannoverGermany

The microcapsule-enabled cementitious material is an appealing building material and it has been attracting increasing research *** considering microcapsules as dissimilar inclusions in the material,this paper employs the discrete element method(DEM)to study the effects of loading rates on the fracturing behavior of cementitious specimens containing the inclusion and the *** numerical model was first developed and validated based on experimental *** is then used to systematically study the initiation,the propagation and the coalescence of cracks in inclusion-enabled cementitious *** study reveals that the crack propagation speed,the first crack initiation stress,the coalescence stress,the compressive strength and the ultimate strain increase with the loading *** initiation position,the propagation direction,the cracking length and the type of the initiated cracks are influenced by the loading *** new crack coalescence patterns are *** is easier to cause the coalescence between the circular void and a propagating crack at a slow loading rate than at a fast loading rate.

关键词： Microcapsule loading rate cracking processes DEM compressive loading

Aerial target threat assessment based on gated recurrent unit and self-attention mechanism

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Journal of Systems Engineering and Electronics 2024年第2期35卷 361-373页

作者： CHEN Chen QUAN Wei SHAO zhuang School of Automation Beijing Institute of TechnologyBeijing 100081China State Key Laboratory of Intelligent Control and Decision of Complex Systems Beijing 100081China

Aerial threat assessment is a crucial link in modern air combat, whose result counts a great deal for commanders to make decisions. With the consideration that the existing threat assessment methods have difficulties in dealing with high dimensional time series target data, a threat assessment method based on self-attention mechanism and gated recurrent unit(SAGRU) is proposed. Firstly, a threat feature system including air combat situations and capability features is established. Moreover, a data augmentation process based on fractional Fourier transform(FRFT) is applied to extract more valuable information from time series situation features. Furthermore, aiming to capture key characteristics of battlefield evolution, a bidirectional GRU and SA mechanisms are designed for enhanced ***, after the concatenation of the processed air combat situation and capability features, the target threat level will be predicted by fully connected neural layers and the softmax classifier. Finally, in order to validate this model, an air combat dataset generated by a combat simulation system is introduced for model training and testing. The comparison experiments show the proposed model has structural rationality and can perform threat assessment faster and more accurately than the other existing models based on deep learning.

关键词： target threat assessment gated recurrent unit(GRU) self-attention(SA) fractional Fourier transform(FRFT)

NUMERICAL INVESTIGATION ON OSCILLATING FLOWSPAST A HALF CIRCULAR CYLINDER ON A PLANE

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Journal of Hydrodynamics 1999年第2期11卷 38-48页

作者： Lu, Xiyun zhuang, Lixian Univ of Science and Technology of China Hefei China

Oscillating flow over a half circular on a plane was studied numerically by solving two-dimensional incompressible Navier-Stokes equations by using the non-staggered-grid, fraction step method for KC=0.5, 6.0, and Re=500, 2000, 10000. At small KC number, only the Stokes layer occurs and the thickness of the Stokes layer becomes thinner with Re increase. At higher KC value, the vortex shedding appears and the vortices shed from the cylinder interact further with the boundary layer formed on the plane. The influence of KC and Re on force behavior was also discussed.

关键词： Boundary layer flow Flow of water Fluid structure interaction Numerical analysis Numerical methods Vortex flow Vortex shedding