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Chinese Journal of Chemical Engineering 2022年第10期50卷 347-351页

作者： zhaoyang Yu Jing Li Xianren Zhang State Key Laboratory of OrganicInorganic Composites Beijing University of Chemical TechnologyBeijing 100029China College of Biomedical Engineering&the Key Laboratory for Medical Functional Nanomaterials Jining Medical UniversityJining 272067China

Cavitation in water generally takes place at much lower negative pressure than predicted from *** this work,we try to stress the discrepancy from the influence of the dissolved gas on cavitation *** combining molecular dynamics simulation and thermodynamic analysis,we evaluated the lowering of surface tension as a function of density of gas molecules in gas clusters formed in aqueous *** found that the obtained surface tension of small gas clusters is much more substantially reduced than *** surface tension lowering and the non-ideality of gas molecules in the clusters are then taken into account in determining the nucleation of cavitation,and as a consequence,the required negative pressure for cavitation becomes comparable to experimental ***,we give an alternative explanation for the discrepancy of cavitation pressure between experiment and theory,i.e.,it is the substantially reduced surface tension for small gas nuclei,which have not been taken into account in theory,along with the ideal gas approxiamtion that induce its deviation from the experimental values.

关键词： Cavitation Dissolved gas Thermodynamics Molecular simulation Surface tension

Determination of H^+ diffusion coefficient in the course of H^+ response of a W/WO_3 pH electrode

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Rare Metals 2005年第4期24卷 351-357页

作者： CHEN Dongchu FU zhaoyang ZHENG Jiashen College of Mechanical Engineering South China University of Technology Guangzhou 510640 China School of Science Foshan University Foshan 528000 China Chemistry Department Huazhong University of Science and Technology Wuhan 430074 China

A WAVO3 pH electrode was prepared by a method of sol-gel. In order to study the H^＋ response dynamic mechanism, the electrochemical impedance spectroscopy （EIS） experiment was conducted. It was found that the H^＋ response course is controlled by the H^＋ diffusion from the solution to the WO3 film, based on the analysis of EIS spectra. The EIS and potential step method were used to determinate the H＋ diffusion coefficient （D） in the course of H^＋ response of this WAVO3 electrode, and the values of D calculated by these two method correspond very well, which all are about 10^-19cm^2/s The imposed different potential steps make little effect on the calculation of H^＋ diffusion coefficient, and it was found that the limiting Cottrell equation of short elapsed time fits well to the current transient caused by a potential step, based on the analysis of the time constant.

关键词： pH electrode diffusion coefficient dynamic mechanism tungsten oxide sol-gel

Physical layer security for massive access in cellular Internet of Things

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Science China(Information Sciences) 2020年第2期63卷 104-115页

作者： Qiao QI Xiaoming CHEN Caijun ZHONG zhaoyang ZHANG College of Information Science and Electronic Engineering Zhejiang University

The upcoming fifth generation(5G) cellular network is required to provide seamless access for a massive number of Internet of Things(IoT) devices over the limited radio spectrum. In the context of massive spectrum sharing among heterogeneous Io T devices, wireless security becomes a critical issue owing to the broadcast nature of wireless channels. According to the characteristics of the cellular IoT network,physical layer security(PHY-security) is a feasible and effective way of realizing secure massive access. This article reviews the security issues in the cellular IoT network with an emphasis on revealing the corresponding challenges and opportunities for the design of secure massive access. Furthermore, we provide a survey on PHY-security techniques to improve the secrecy performance. Especially, we propose a secure massive access framework for the cellular Io T network by exploiting the inherent co-channel interferences. Finally, we discuss several potential research directions to further enhance the security of massive IoT.

关键词： 5G and beyond PHY-security massive access cellular IoT

A new tunable elastic metamaterial structure for manipulating band gaps/wave propagation

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Applied Mathematics and Mechanics(English Edition) 2021年第11期42卷 1543-1554页

作者： Zhenyu WANG zhaoyang MA Xingming GUO Dongsheng ZHANG Institute of Applied Mathematics and Mechanics Shanghai Key Laboratory of Mechanics in Energy EngineeringShanghai UniversityShanghai 200444China

A one-dimensional mechanical lattice system with local resonators is proposed as an elastic metamaterial model,which shows negative mass and negative modulus under specific frequency *** proposed representative units,consisting of accurately arranged rigid components,can generate controllable translational resonance and achieve negative mass and negative modulus by adjusting the local structural parameters.A shape memory polymer is adopted as a spring component,whose young’s modulus is obviously affected by temperature,and the proposed metamaterials’tunable ability is achieved by adjusting *** effect of the shape memory polymer’s stiffness variation on the band gaps is investigated detailedly,and the special phenomenon of intersecting dispersion curves is discussed,which can be designed and controlled by adjusting *** dispersion relationship of the continuum metamaterial model affected by temperature is obtained,which shows great tunable ability to manipulate wave propagation.

关键词： tunable elastic metamaterial negative mass negative modulus

Simulation Performance Evaluation and Uncertainty Analysis on a Coupled Inundation Model Combining SWMM and WCA2D

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International Journal of Disaster Risk Science 2022年第3期13卷 448-464页

作者： zhaoyang Zeng Zhaoli Wang Chengguang Lai School of Civil Engineering and Transportation State Key Laboratory of Subtropical Building ScienceSouth China University of TechnologyGuangzhou510641China Pazhou Lab Guangzhou510335China Guangdong Engineering Technology Research Center of Safety and Greenization for Water Conservancy Project Guangzhou510641China

Urban floods are becoming increasingly more frequent,which has led to tremendous economic *** application of inundation modeling to predict and simulate urban flooding is an effective approach for disaster prevention and risk reduction,while also addressing the uncertainty problem in the model is always a challenging *** this study,a cellular automaton(CA)-based model combining a storm water management model(SWMM)and a weighted cellular automata 2D inundation model was applied and a physical-based model(LISFLOOD-FP)was also coupled with SWMM for *** simulation performance and the uncertainty factors of the coupled model were systematically *** results show that the CA-based model can achieve sufficient accuracy and higher computational efficiency than can a physical-based *** resolution of terrain and rainstorm data had a strong influence on the performance of the CA-based model,and the simulations would be less creditable when using the input data with a terrain resolution lower than 15 m and a recorded interval of rainfall greater than 30 *** roughness value and model type showed limited impacts on the change of inundation depth and occurrence of the peak inundation ***,the CA-based coupled model demonstrated laudable applicability and can be recommended for fast simulation of urban flood *** study also can provide references and implications for reducing uncertainty when constructing a CA-based coupled model.

关键词： Guangzhou LISFLOOD-FP Uncertainty analysis Urban flood WCA2D

Zika virus and Zika fever

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Virologica Sinica 2016年第2期31卷 103-109页

作者： zhaoyang Wang Peigang Wang Jing An Department of Microbiology School of Basic Medical Sciences Chinese Capital Medical University

An emerging mosquito-borne arbovirus named Zika virus(ZIKV), of the family Flaviviridae and genus Flavivirus, is becoming a global health threat. ZIKV infection was long neglected due to its sporadic nature and mild symptoms. However, recently, with its rapid spread from Asia to the Americas, affecting more than 30 countries, accumulating evidences have demonstrated a close association between infant microcephaly and Zika infection in pregnant women. Here, we reviewed the virological, epidemiological, and clinical essentials of ZIKV infection.

关键词： Flaviviridae accumulating neglected pregnant sporadic threat affecting borne becoming emerging

Application of system identification in a practical active noise control system

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Control Theory and Technology 2024年第2期22卷 282-291页

作者： Yu Yuan zhaoyang Sun Hongwei Zhang School of Mechanical Engineering Xihua UniversityChengdu610039SichuanChina School of Electrical Engineering Southwest Jiaotong UniversityChengdu611756SichuanChina School of Mechanical Engineering and Automation Harbin Institute of TechnologyShenzhen518055GuangdongChina

Noise pollution has become increasingly severe around the world due to fast urbanization. How to soundproof windows from outside noise is of significant interest for both academia and industry. This paper reports an experimental implementation of normalized minmax active noise control (ANC) algorithm on an open window system, where identifying the model of acoustic sound paths plays a central role. By doing this, traffic noise is attenuated by the ANC system, leading to a relatively quiet indoor environment, while the natural lighting and ventilation functions of a window are remained. Our experiments show that an average of 19 dB(A) noise reduction is achieved.

关键词： Active noise control Multi-input-multi-output system Normalized minimax algorithm System identification

Development and test of an automatic height-adjusting cotton topper

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International Journal of Agricultural and Biological Engineering 2017年第2期10卷 44-55页

作者： Chen zhaoyang Shi Lei Graduate School of Chinese Academy of Agricultural Sciences Beijing 100081China Nanjing Research Institute for Agricultural Mechanization Ministry of AgricultureNanjing 210014China

A fine-tuned height-adjustable cotton topper was developed and evaluated in this *** is topped at the late flowering stage because spindling reduces cotton production and complicates *** main disadvantage of traditional cotton toppers is that their topping height cannot be adjusted according to the heights of individual cotton plants,resulting in a high percentage of missed tops and overcutting that damages fruit *** solve this problem,a mechanical-electronic topping prototype was developed that could be adjusted according to the height of *** prototype includes a shearing machine system that can be tuned vertically and an automatic height control system that can detect cotton heights and actuate the mechanical *** cotton topper was attached to a tractor by a three-point hitch and tested in the *** the trial,the prototype was tested at ground speeds of 1.1 km/h,1.5 km/h and 2.2 km/h and excision lengths(from the peak to the cutting point)of 9 cm and 11 *** all tested conditions,the pass rate(the percentage of buds accurately cut without hurting the fruit branch),which reached 74%,was significantly higher than the ideal pass rates of traditional toppers,which were much lower than 50%or even 40%.The dominate factors affecting topping quality were *** pass rate was significantly influenced by the forward speed;the missing rate(rate of missed topping)was significantly influenced by the forward speed and excision length;and the overcut rate was significantly influenced by the excision *** optimized topping speed and excision length were 1.1 km/h and 11 cm respectively,and the other parameters varied according to different user preferences.A replicate trial was conducted and showed that topping at 1.1 km/h and 9 cm prevented further spindling of 90%of the plants,and topping at 1.5 km/h and 11 cm prevented further spindling of 83%of the plants.

关键词： cotton topper height-adjusting topping quality field test automatic control

Current advances of biocontainment strategy in synthetic biology

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Chinese Journal of Chemical Engineering 2023年第4期56卷 141-151页

作者： Xueying Zhu zhaoyang Zhang Bin Jia Yingjin Yuan Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering(Ministry of Education) School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China

Synthetic biotechnology has led to the widespread application of genetically modified organisms(GMOs)in biochemistry, bioenergy, and therapy. However, the uncontrolled spread of GMOs may lead to genetic contamination by horizontal gene transfer, resulting in unpredictable biosafety risks. To deal with these challenges, many effective methods have been developed for biocontainment. In this article, we summarize and discuss recent advances in biocontainment strategies from three aspects: DNA replication, transcriptional regulation, and protein translation. We also briefly introduce the efforts in the biocontainment convention, such as the recent publication of the Tianjin Biosecurity Guidelines for the Code of Conduct for Scientists.

关键词： Genetically modified organisms(GMOs) Biocontainment Biosecurity Synthetic biology Molecular biology Biotechnology

Investigation on the Velocity-Dependent Adhesion Hysteresis via Molecular Dynamics Simulation

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Acta Mechanica Solida Sinica 2024年第3期37卷 423-429页

作者： Jinshan He Yiran Li zhaoyang Ma Ganyun Huang Department of Mechanics School of Mechanical EngineeringTianjin UniversityTianjin300350China

Adhesion plays an important role in miniaturized devices and technologies,which depends not only on indentation depth but also on the history of contact making and breaking,giving rise to adhesion *** the present work,adhesion hysteresis has been investigated via molecular dynamics simulations on approaching and retracting a rigid tip to and from a *** results show that hysteresis in the force-displacement curve that depends on approaching and retraction velocities arises under both elastic and plastic *** underlying mechanisms have been *** implications of the results in friction have been discussed briefly.

关键词： Adhesion hysteresis Molecular dynamics simulation Contact instability Plastic deformation