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DBN-GABP model for estimation of aircraft wake vortex parameters using Lidar data

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Chinese Journal of Aeronautics 2024年第9期37卷 347-368页

作者： zhiqiang wei Tong LU Runping GU Fei LIU College of Air Traffic Management Civil Aviation University of ChinaTianjin 300300China

Aircraft wake turbulence is an inherent outcome of aircraft flight,presenting a substan-tial challenge to air traffic control,aviation safety and operational *** upon data obtained from coherent Doppler Lidar detection,and combining Dynamic Bayesian Networks(DBN)with Genetic Algorithm-optimized Backpropagation Neural Networks(GA-BPNN),this paper proposes a model for the inversion of wake vortex *** the wake vortex flow field simulation analysis,the wind and turbulent environment were initially superimposed onto the simulated wake velocity ***,Lidar-detected echoes of the velocity field are simulated to obtain a data set similar to the actual situation for model *** the case study validation,real measured data underwent preprocessing and were then input into the established *** allowed us to construct the wake vortex characteristic parameter inversion *** final results demonstrated that our model achieved parameter inversion with only minor *** a practical example,our model in this paper significantly reduced the mean square error of the inverted velocity field when compared to the traditional *** study holds significant promise for real-time monitoring of wake vortices at airports,and is proved a crucial step in developing wake vortex interval standards.

关键词： Air traffic control Wake vortex flow field simulation Lidar echo simulation DBNmodel GA-BP model Wakevortex characteristic parameter inversion model

Potential Submarine Geologic Hazards at the Entrance of the Pearl River Estuary in the Northern South China Sea

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Journal of Ocean University of China 2016年第4期15卷 606-612页

作者： ZHANG zhiqiang wei zhiqiang HE Huizhong wei wei QIAN Libing LI Tuanjie Guangzhou Institute of Geochemistry Chinese Academy of Sciences CAS Key Laboratory of Marginal Sea GeologyGuangzhou 510640 P. R. China South China Sea Branch of State Oceanic Administration Guangzhou 510300 P. R. China

The potential submarine geologic hazards were distinguished and categorized at the entrance of the Pearl River Estuary in the northern South China Sea, based upon the analysis of side scan sonar and sub-bottom profiler surveying data of about 2500 km long, in an area about 2000 km^2 around the Wanshan Archipelago. The data obtained in the survey has the highest spatial resolution by far, which could reveal more detailed distributions and characteristics of the geologic hazards than before. In the study region, three paleo-channels that were buried about 10–30 m below the seabed were found; more than 10 shallow gas areas were discovered. The sand waves found in the region were generally small and located near the islands, and twenty pockmarks found on the seabed were mostly concentrated to north of Zhuzhou island. There are also many man-made obstacles in the region, such as wreckages, pipeline, etc. In this paper we provide a detailed distribution map of the submarine geologic hazards in this region for the first time, and discuss their formation and harmfulness, which will provide a scientific basis for marine engineering construction, marine geologic disaster prevention and mitigation.

关键词： geologic Pearl buried shallow submarine mostly mitigation north disaster sonar

Real-time moving object detection for video monitoring systems

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Journal of Systems Engineering and Electronics 2006年第4期17卷 731-736页

作者： wei zhiqiang Ji Xiaopeng Wang Peng Dept. of Computer Science Ocean Univ. of China Qingdao 266071 P.R. China Qingdao Branch Shandong Provincial Branch Corporation China Telecom Qingdao 266071P.R.China.

Moving object detection is one of the challenging problems in video monitoring systems, especially when the illumination changes and shadow exists. Amethod for real-time moving object detection is described. Anew background model is proposed to handle the illumination varition problem. With optical flow technology and background subtraction, a moving object is extracted quickly and accurately. An effective shadow elimination algorithm based on color features is used to refine the moving obj ects. Experimental results demonstrate that the proposed method can update the background exactly and quickly along with the varition of illumination, and the shadow can be eliminated effectively. The proposed algorithm is a real-time one which the foundation for further object recognition and understanding of video mum＇toting systems.

关键词： video monitoring system moving object detection background subtraction background model shadow elimination.

Safety assessment of approximate segregated parallel operation on closely spaced parallel runways

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Chinese Journal of Aeronautics 2019年第2期32卷 463-476页

作者： Fei LIU Xinze LIU Mingjiang MOU zhiqiang wei Air Traffic Management College Civil Aviation University of China

With the continuous growth of air traffic flow, some airports in China or other countries begin to construct Closely Spaced Parallel Runways(CSPR) to meet the capacity requirement of civil aviation. In this paper, the simulation and calculation method of flight trajectory is developed,as well as the collision risk calculation method and wake vortex encounter risk calculation *** methods for departure and go-around procedures are proposed to achieve approximate segregated parallel operation in an attempt to obtain approximately the same results on closely spaced parallel runways as on widely spaced parallel runways. By comparing with the independent parallel departure and segregated parallel operation in ICAO Doc. 9643, it is found that the lateral separation between aircraft in this proposal is not less than the separations in the other two cases. Based on the simulation calculation of flight trajectories under different conditions, the probabilities of collision conflict and encountering wake vortex are lower than those in current operation *** proposed plan has no special requirements in pilot operation, control command procedures,airport facilities, or meteorological observation and prediction, so it is convenient to promote and implement at the airports with closely spaced parallel runways.

关键词： Air traffic control Air transportation Closely spaced parallel runways Segregated parallel operation Wake vortex encounter Wake vortex separation standards

Release characteristics of different diameter ultrafine fibers as antibacterial materials

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Journal of Innovative Optical Health Sciences 2021年第2期4卷 1-10页

作者： zhiqiang wei Erniao Liu Hao Li Zhimei wei Zhi lv Department of Orthopaedics Shanxi Medical University Second Hospital Taiyuan 030001P.R.China Institute of Materials Science and Technology Sichuan University Chengdu 610065P.R.China

Although the electrospinning technique has been devoted to promoting therapeutic purposes as a drug carrier,however,there are still many fundamental problems in this *** work focuses on a comparison of various diameter polyethersulfone(PES)electrospun ultrafine fibers as an-timicrobial *** fibrous morphology,antimicrobial agent distribution,thermally property,and biocompatibility evaluation of PES-based ultrafine fibers were systematically *** results demonstrated that the PES-based ultrafine fibers were suitable as anti-microbial ***,the drug release behavior and mechanism were studied through total *** release mechanism was confirmed to Fickian *** was revealed that the drug max release amount(71.5%)and release rate(7.71)are the highest for the smallest diameter ultrafine ***,the antimicrobial activity of PES ultrafine fibers is also inversely correlated with the diameter of *** electrospun PES fibers would control their release behavior through the diameter and have a potential application in the wound dressings,such as chronic osteomyelitis and exposure injury.

关键词： Electrospinning polyethersulfone ultrafine fibers drug release antimicrobial activity

Switching from 2-pyridination to difluoromethylation:ligand-enabled nickel-catalyzed reductive difluoromethylation of aryl iodides with difluoromethyl 2-pyridyl sulfone

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Science China Chemistry 2023年第10期66卷 2785-2790页

作者： wei Du Qinyu Luo zhiqiang wei Xiu Wang Chuanfa Ni Jinbo Hu Key Laboratory of Organofluorine Chemistry Shanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of SciencesShanghai 200032China

The divergent reductive cross-coupling with an ambident electrophile is ***,we demonstrated a nickel-catalyzed reductive 2-pyridination of aryl iodides with difluoromethyl 2-pyridyl sulfone(2-Py SO_(2)CF_(2)H)via selective C(sp^(2))-S bond cleavage of the sulfone by using a phosphine *** this communication,we report a novel nickel-catalyzed reductive coupling of aryl iodides and 2-Py SO_(2)CF_(2)H reagent,which constitutes a new method for aromatic *** use of a tridentate terpyridine ligand is pivotal for the selective C(sp^(3))-S bond cleavage of the *** method employs readily available nickel catalyst and 2-Py SO_(2)CF_(2)H as the difluoromethylation reagent,providing a facile access to difluoromethylarenes under mild reaction conditions without pre-generation of arylmetal reagents.

关键词： nickel catalysis difluoromethylation 2-PySO_(2)CF_(2)H reductive cross-coupling

Strategies on designing multifunctional surfaces to prevent biofilm formation

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Frontiers of Chemical Science and Engineering 2015年第3期9卷 324-335页

作者： Yang Lu Zhanguo Yue wei Wang zhiqiang Cao Department of Chemical Engineering and Materials Science Wayne State University Detroit MI 48202 USA

Bacteria adhesion and biofilm formation have raised severe problems on public health, food industry and many other areas. A variety of reagents and surface coatings have been developed to kill bacteria and/or limit their interaction with surfaces. It has also attracted many efforts to integrate different bactericidal elements together and maximize antibacterial efficiency. Herein, we review mechanisms for both passive and active approaches to resist and kill bacteria respectively, and discuss integrated strategies based on these two approaches. We also offer perspective on future research direction.

关键词： antimicrobial surface multifunctional

Geochemistry of Sediments from a Subalpine Lake Sedimentary Succession in the Western Nanling Mountains,Southern China:Implications for Catchment Weathering During the Last 15400 Years

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Chinese Geographical Science 2022年第3期32卷 537-548页

作者： WANG Bingxiang ZHONG wei ZHU Chan OUYANG Jun wei zhiqiang SHANG Shengtan School of Geography Sciences South China Normal UniversityGuangzhou 510631China Guangdong Center for Marine Development Research Guangzhou 510220China Zhuhai Branch of State Key Laboratory of Earth Surface Processes and Resource Ecology Faculty of Geographical ScienceBeijing Normal UniversityZhuhaiGuangdong 519087China School of Earth Science and Engineering Sun Yat-sen UniversityZhuhai 519082China

In the present work,15400 yr old geochemical records of a core from the subalpine Daping swamp are presented with the aim to examine the relationship between the chemical weathering and the climatic changes in the region of the western Nanling Mountains,*** climate of the study region was deeply controlled by the East Asian summer *** results indicate that,in the past 15400 yrs,the values of chemical index of alteration(CIA)ranged from 73.9%to 88.2%(mean:85.3%),suggested a medium and high intensity of chemical *** local exogenous clastic materials,which were derived from the weathered residues,played a key role in contributing towards the *** the climate-induced chemical weathering exerted strong influences on the geochemical features of weathered residues,the geochemical characteristics of the sediments were deeply impacted by climatic *** and warmer conditions would favor increased chemical weathering,resulting in more leaching of soluble and mobile elements(e.g.,Ba and Sr)and leaving the resistant and immobile elements(e.g.,Al and Ti)enriched in the weathered *** materials were then eroded and transported into the lake,and led to the sediments characterized by the characteristic of having depleted soluble *** contrast,dry and cold conditions would result in an opposite *** this sense,the geochemical records can serve as proxies to indicate changes of chemical weathering intensity,which were closely related to the evolution of summer monsoon.

关键词： lacustrine sediments chemical weathering asian summer monsoon last deglacial western Nanling Mountains China

mTOR Signaling: The Interface Linking Cellular Metabolism and Hepatitis B Virus Replication

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Virologica Sinica 2021年第6期36卷 1303-1314页

作者： Xueyu Wang zhiqiang wei Yongfang Jiang Zhongji Meng Mengji Lu Department of Infectious Diseases The Second Xiangya HospitalCentral South UniversityChangsha 410011China Institute of Virology University Hospital EssenUniversity of Duisburg-Essen45122 EssenGermany Institute of Biomedical Research Hubei Clinical Research Center for Precise Diagnosis and Treatment of Liver CancerTaihe HospitalHubei University of MedicineShiyan 442000China Department of Infectious Diseases Taihe HospitalHubei University of MedicineShiyan 442000China

Mammalian target of rapamycin(m TOR) is a conserved Ser/Thr kinase that includes m TOR complex(m TORC) 1 and m TORC2. The m TOR pathway is activated in viral hepatitis, including hepatitis B virus(HBV) infection-induced ***, chronic HBV infection remains one of the most serious public health issues worldwide. The unavailability of effective therapeutic strategies for HBV suggests that clarification of the pathogenesis of HBV infection is urgently required. Increasing evidence has shown that HBV infection can activate the m TOR pathway, indicating that HBV utilizes or hijacks the m TOR pathway to benefit its own replication. Therefore, the m TOR signaling pathway might be a crucial target for controlling HBV infection. Here, we summarize and discuss the latest findings from model biology research regarding the interaction between the m TOR signaling pathway and HBV replication.

关键词： Mammalian target of rapamycin(mTOR) Hepatitis B virus(HBV) Metabolism Autophagy