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Acta Oceanologica Sinica 2014年第5期33卷 1-7页

作者： liu junliang CAI Shuqun WANG Shengan State Key Laboratory of Tropical Oceanography South China Sea Institute of Oceanology Chinese Academy of Sciences University of Chinese Academy of Sciences

Diurnal wind （DW） and nonlinear interaction between inertial and tidal currents near the Xisha Islands of the South China Sea （SCS） during the passage of Typhoon Conson （2010） are investigated using observational data and a damped slab model. It is found that the DWs, which are dominated by clockwise wind components, are prominent at our observational site. The DWs increase after the passage of the typhoon from 1 to about 4 m/s, which may be due to the decrease of the sea surface temperature caused by the passage of the typhoon. Kinetic energy spectra and bicoherence methods reveal nonlinear interactions between the inertial currents and the 2MK3 tidal constituent at our observational site. The slab damped model reproduces the inertial currents successfully induced by the total observed winds, and it is shown that the inertial currents induced by DWs are positively proportional to the DWs speed. Even though the observed inertial currents are distinct, the proportion of inertial currents induced by DWs to those induced by the total observed winds is just 0.7%/4% before/after the passage of typhoon. This shows that the inertial currents induced by the DWs are unimportant near the Xisha Islands during the typhoon season.

关键词： diurnal winds typhoon inertial currents nonlinear interaction slab damped models

A Model Study on the Generation of Internal Tides by Tidal Flows Over a Submerged Seamount in the Channel

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Communications in Computational Physics 2010年第6期8卷 95-114页

作者： Shuqun Cai junliang liu Xiaomin Long LED South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou510301China Graduate School of the Chinese Academy of Sciences Beijing100049China

It is known that the submerged seamount/ridge is a source for the generation of internal *** this paper,a three-dimensional two-layer model is set up to study the generation of internal tides by tidal flows over a submerged seamount/ridge in the *** numerical experiments with different topographic features,upper layer depths,tidal flows and background currents are carried out to study the variations of the induced internal *** is shown that,for the specific stratification,the seamount feature,the slope,the initial upper layer depth and the imposing driven force determine the Froude number near the seamount *** when the Froude number is supercritical,the associated maximum amplitude of the induced internal tide is so large that the internal tide begins to disintegrate,which brings about severe variations of the current velocity and the water elevation fields,and the associated induced baroclinic tidal energy around the seamount peak is much larger than the barotropic *** Richardson number greater than 1/4 is a criterion for stability of shear *** the maximum tidal velocity changes within 0∼360◦with time in a period around the seamount peak,the induced internal tide does not stride the seamount peak before it disintegrates,which is different from the two-dimensional modeled *** asymmetrical slope of the submerged seamount is a mechanism for the asymmetrical internal tide generation.

关键词： Internal tides numerical modeling two-layer model sill channel

Effect of Boron Compounds on Properties of Chinese Fir Wood Treated with PMUF Resin

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Journal of Bioresources and Bioproducts 2019年第1期4卷 60-66页

作者： Fei WANG junliang liu Wenhua LYU College of Forestry Henan Agriculture UniversityZhengzhou 450002China Research Institute of Wood Industry Chinese Academy of ForestryBeijing 100091China

Plantation Chinese fir wood was modified by low molecular weight phenol melamine urea formaldehyde(PMUF)resin and boron compounds(BB)through a progressive gradual infiltration *** results showed that the limiting oxygen index(LOI)values,density,dimensional stability and static flexural properties of the PMUF resin treated wood gradually improved with the increase of resin solid *** boron compounds were additionally introduced into the PMUF resin,the density and the LOI values of the samples of compound modification increased,whereas the anti-swelling efficiency,the modulus of rupture and impact toughness decreased by more than 17.6%,10.1%and 42.9%,*** was demonstrated by X-ray diffraction and Fourier transform infrared spectroscopy that boron compounds could improve the crystallinity of resin modified samples and did not have a chemical reaction with resin or *** electron microscope analysis indicated boron compounds made the microstructure of the resin polymers loose,influencing the mechanical properties and dimensional stability of resin modified wood.

关键词： wood resin boron compounds dimensional stability mechanical properties

The spatiotemporal variation of the wind-induced near-inertial energy flux in the mixed layer of the South China Sea

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Acta Oceanologica Sinica 2015年第1期34卷 66-72页

作者： LI Juan liu junliang CAI Shuqun PAN Jiayi State Key Laboratory of Tropical Oceanography South China Sea Institute of OceanologyChinese Academy of Sciences University of Chinese Academy of Sciences Institute of Earth and Space Information Science Chinese University of Hong Kong

On the basis of the QSCAT/NCEP blended wind data and simple ocean data assimilation(SODA), the wind-induced near-inertial energy flux(NIEF) in the mixed layer of the South China Sea(SCS) is estimated by a slab model, and the model results are verified by observational data near the Xisha Islands in the SCS. Then, the spatial and temporal variations of the NIEF in the SCS are analyzed. It is found that, the monthly mean NIEF exhibits obvious spatial and temporal variabilities, i.e., it is large west of Luzon Island all the year, east of the Indo-China Peninsula all the year except in spring, and in the northern SCS from May to September. The large monthly mean NIEF in the first two zones may be affected by the large local wind stress curl whilst that in the last zone is probably due to the shallow mixed layer depth. Moreover, the monthly mean NIEF is relatively large in summer and autumn due to the passage of typhoons. The spatial mean NIEF in the mixed layer of the SCS is estimated to be about 1.25 m W/m2 and the total wind energy input from wind is approximately 4.4 GW. Furthermore, the interannual variability of the spatial monthly mean NIEF and the Ni?o3.4 index are negatively correlated.

关键词： near-inertial energy flux mixed layer spatiotemporal variation slab model South China Sea

Multi-port Network Modeling and Stability Analysis of VSC-MTDC Systems

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Journal of Modern Power Systems and Clean Energy 2024年第5期12卷 1666-1677页

作者： Shangning Tan junliang liu Xiong Du Jingyuan Su Lijuan Fan School of Electrical Engineering Chongqing UniversityChongqingChina the CSG Electric Power Research Institute China SouthernPower GridGuangzhouChina

The voltage source converter based multi-terminal high-voltage direct current(VSC-MTDC)system has attracted much attention because it can achieve the interconnection between AC ***,the initial phases and short-circuit ratios(SCRs)of the interconnected AC grids cause the steady-state phases(SSPs)of AC ports in the VSC-MTDC system to be *** can lead to the issues such as mismatches in multiple converter reference frame systems,potentially causing inaccuracies in stability analysis when this phenomenon is *** address the aforementioned issues,a multi-port network model of the VSC-MTDC system,which considers the SSPs of the AC grids and AC ports,is derived by multiplying the port models of different subsystems(SSs).The proposed multi-port network model can accurately describe the transmission characteristics between the input and output ports of the ***,this model facilitates accurate analysis of the system ***,it identifies the key factors affecting the system ***,the accuracy of the proposed multi-port network model and the analysis of key factors are verified by time-domain simulations.

关键词： Normalized sensitivity multi-port network model steady-state phase small-signal stability voltage source converter based multi-terminal high-voltage direct current(VSC-MTDC)

Micro-motion dynamics analysis of ballistic targets based on infrared detection

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Journal of Systems Engineering and Electronics 2017年第3期28卷 472-480页

作者： junliang liu Yanfang Li Shangfeng Chen Huanzhang Lu Bendong Zhao College of Electronic Science and Engineering National University of Defense TechnologyChangsha 410073China Beijing Institute of Remote Sensing Equipment Beijing 100854China

The dynamic characteristics related to micro-motions, such as mechanical vibration or rotation, play an essential role in classifying and recognizing ballistic targets in the midcourse, and recent researches explore ways of extracting the micro-motion features from radar signals of ballistic targets. In this paper, we focus on how to investigate the micro-motion dynamic characteristics of the ballistic targets from the signals based on infrared (IR) detection, which is mainly achieved by analyzing the periodic fluctuation characteristics of the target IR irradiance intensity signatures. Simulation experiments demonstrate that the periodic characteristics of IR signatures can be used to distinguish different micro motion types and estimate related parameters. Consequently, this is possible to determine the micro-motion dynamics of ballistic targets based on IR detection.

关键词： micro-motion dynamics infrared (IR) signatures target recognition parameters estimation

Convolutional neural networks for time series classification

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Journal of Systems Engineering and Electronics 2017年第1期28卷 162-169页

作者： Bendong Zhao Huanzhang Lu Shangfeng Chen junliang liu Dongya Wu College of Electronic Science and Engineering National University of Defense TechnologyChangsha 410073China

Time series classification is an important task in time series data mining, and has attracted great interests and tremendous efforts during last decades. However, it remains a challenging problem due to the nature of time series data: high dimensionality, large in data size and updating continuously. The deep learning techniques are explored to improve the performance of traditional feature-based approaches. Specifically, a novel convolutional neural network (CNN) framework is proposed for time series classification. Different from other feature-based classification approaches, CNN can discover and extract the suitable internal structure to generate deep features of the input time series automatically by using convolution and pooling operations. Two groups of experiments are conducted on simulated data sets and eight groups of experiments are conducted on real-world data sets from different application domains. The final experimental results show that the proposed method outperforms state-of-the-art methods for time series classification in terms of the classification accuracy and noise tolerance. © 1990-2011 Beijing Institute of Aerospace Information.

关键词： Convolution Data mining Neural networks Time series Virtual reality

Self-polymerization and co-polymerization kinetics of gadolinium methacrylate

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Journal of Rare Earths 2018年第3期36卷 298-303页

作者： Chunhong Wang Shuai Wang Yujuan Zhang Zhifeng Wang junliang liu Ming Zhang School of Chemistry and Chemical Engineering Yangzhou University Testing Center Yangzhou University

Gadolinium methacrylate（Gd（MAA）3） was synthesized by using gadolinium oxide and methacrylic acid as the starting materials and its self-polymerization kinetic was studied based on non-isothermal and isothermal analysis. Moreover, the monomer reactivity ratios of methyl methacrylate（MMA） and Gd（MAA）3 were evaluated by using Kelen-Tiidos method. The thermal neutron shielding properties of PMMA and poly（MMA-co-Gd（MAA）3） were calculated by MCNP program. The results show that the selfpolymerization of Gd（MAA）3 can be initiated by thermal and free radical and its activation energy is103.35 kJ/mol or 58.55 kJ/mol correspondingly in the solid state or aqueous solution. The polymerization rate,Rp,under low conversion at 65 ℃ is expressed as Rp = K[M]^（1.05）[I]^（0.60）. The reactivity ratios of r1（MMA） and r2（Gd（MAA）3） are 0.225 and 1.340, respectively. The ability of thermal neutron shielding of poly（MMA-co-Gd（MAA）3） is increased by gadolinium contents and is far better than PMMA.

关键词： Gadolinium methacrylate Thermal analysis Polymerization kinetic Thermal neutron shielding Rare earths

Design and Verification of High Attenuation Vibration Isolation Damper in Remote Sensing Satellite Transport

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Journal of Harbin Institute of Technology(New Series) 2021年第6期28卷 63-71页

作者： Hao Fu Wei Zhang junliang liu Shangjie Pan Beijing Institute of Spacecraft Environment Engineering Beijing 100094China Harbin Institute of Technology School of Mechatronics EngineeringHarbin 150001China

To solve the safe horizontal transportation by rail&road of remote sensing satellite problem in the process of unpredictable dynamic load,a high attenuation vibration isolation damper(hereinafter referred to as vibration isolation damper)was *** simulation analysis and transportation test using satellite structural model and engineering prototype,validity and reliability of the vibration isolation damper was verified,which can meet the requirements of vibration and shock from various transportation conditions.

关键词： satellite structural model high attenuation vibration isolation damper dynamic analysis

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Bi_(2)O_(2)Se nanoplates for broadband photodetector and full-color imaging applications

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Nano Research 2023年第5期16卷 7638-7645页

作者： Han Wang Songqing Zhang Xingxuan Wu Huijia Luo junliang liu Zesheng Mu Ruirui liu Guang Yuan Yujun Liang Jin Tan Yongling Ren Wen Lei Department of Electrical Electronic and Computer EngineeringThe University of Western AustraliaCrawley 6009Australia Department of Electronic Engineering School of IOT engineeringJiangnan UniversityWuxi 214122China College of Information Science and Engineering Ocean University of ChinaQingdao 266100China Faculty of Materials Science and Chemistry China University of GeosciencesWuhan 430074China

Broadband light detection and sensing are widely applied in modern *** a promising candidate for next-generation two-dimensional(2D)optoelectronic material,bismuth oxyselenide(Bi_(2)O_(2)Se)nanoplates exhibit many prospects in the application of visible light detection due to their peculiar *** this work,we report the photodetection performance of single-crystal 2D Bi_(2)O_(2)Se nanoplates grown on SiO_(2)based on a ternary-alloy growth model by utilizing chemical vapor deposition(CVD).The Bi_(2)O_(2)Se nanoplates were found to have an even and uniform square shape with side lengths up to 15μm and an approximate thickness of 15 nm.A visible-light photodetector was fabricated based on a CVD-grown Bi_(2)O_(2)Se nanoplate,and characterized by a set of illumination experiments using a 400 nm laser at temperatures ranging from 77 to 370 *** device exhibited superior performance at the temperature of 77 K,with a responsivity of 523 A/W,a specific detectivity of 1.37×10^(11)Jones,a response time of 0.2175 ms,an external quantum efficiency of 162,119.44%,resulting in high-quality and fullcolor imaging in the visible *** results indicate that the single-crystalline Bi_(2)O_(2)Se nanoplates have excellent potential in broadband photodetection and non-cryogenic imaging.

关键词： two-dimensional(2D)nanomaterial Bi_(2)O_(2)Se nanoplates chemical vapor deposition broadband light detection full-color imaging