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Assessing the impacts of climate change and anthropogenic activities on vegetation in southwest China

Journal of Mountain Science 2022年第9期19卷 2678-2692页

作者： ZHANG Yu-xin liu Qin WANG Yu-kuan HUANG Jing-han Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China China-Pakistan Joint Research Center on Earth Sciences CAS-HECIslamabad 45320Pakistan Yunnan Provincial Building Materials Science Research and Design Institute Co. LtdKunming 650033China

The topography and geomorphology of southwest China are complex,and the intensity of human activities not *** impact of climate change and anthropogenic activities on vegetation shows temporal and spatial ***,we used normalized difference vegetation index(NDVI)to analyze the impact of climate change and anthropogenic activities on vegetation in four provinces and municipality in the southwest China from 2000 to *** results showed that(1)NDVI increased 0.004–0.005/yr during this *** 57.74%–69.09%of the area with significant changes was found to be primarily affected by anthropogenic activities during all four seasons and the growing season,while 6.05%–10.74%and 5.09%–9.77%of the area was affected by temperature and precipitation,respectively.(2)The impact of temperature and precipitation changes were spatially *** had a positive impact during spring and summer in the northwestern ***,NDVI was positively affected in the southwestern and eastern regions,while the western region was negatively affected by *** temperatures and precipitation had the greatest impact throughout the year.(3)Returning farmland to forests and improving agricultural management demonstrated positive impacts of anthropogenic activities on the vegetation,while areas with significant negative impacts due to anthropogenic activities were located near the provincial capitals of the four provinces and *** study can provide a scientific basis for accurately identifying key ecological protection areas in Southwest China.

关键词： Climate change NDVI Southwest China Vegetation Anthropogenic activities

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New Knowledge Network Evaluation Method for Design Rationale Management

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Chinese Journal of Mechanical Engineering 2015年第1期28卷 173-186页

作者： JING Shikai ZHAN Hongfei liu Jihong WANG kuan JIANG Hao ZHOU Jingtao School of Mechanical Engineering Beijing Institute of Technology Shanghai Aircraft Design and Research Institute School of Mechanical Engineering and Automation Beihang University School of Mechanical Engineering Northwestern Polytechnical University

Current design rationale （DR） systems have not demonstrated the value of the approach in practice since little attention is put to the evaluation method of DR knowledge. To systematize knowledge management process for future computer-aided DR applications, a prerequisite is to provide the measure for the DR knowledge. In this paper, a new knowledge network evaluation method for DR management is presented. The method characterizes the DR knowledge value from four perspectives, namely, the design rationale structure scale, association knowledge and reasoning ability, degree of design justification support and degree of knowledge representation conciseness. The DR knowledge comprehensive value is also measured by the proposed method. To validate the proposed method, different style of DR knowledge network and the performance of the proposed measure are discussed. The evaluation method has been applied in two realistic design cases and compared with the structural measures. The research proposes the DR knowledge evaluation method which can provide object metric and selection basis for the DR knowledge reuse during the product design process. In addition, the method is proved to be more effective guidance and support for the application and management of DR knowledge.

关键词： design rationale knowledge reasoning justification support decision support knowledge network evaluation

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Adsorption of cationic copolymer nanoparticles onto bamboo fiber surfaces measured by conductometric titration

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Chinese Chemical Letters 2015年第9期26卷 1174-1178页

作者： Xiu-Ming liu Dong-Qin He kuan-Jun Fang School of Textiles Tianjin Polytechnic University

Monosized nanoparticles of 57.3 nm were prepared by cationic emulsion polymerization using a polymerizable emulsifier *** adsorption of nanoparticles onto bamboo fibers was measured by conductometric *** results indicated that the adsorption capacity increased with increasing contact time until 120 *** equilibrium data for nanoparticles adsorption onto bamboo fibers were well fitted to the Langmuir ***,the monolayer adsorption capacity of nanoparticles in the concentration range（from 0.03 g/L to 0.6 g/L） studied,as calculated from Langmuir isotherm model at 25 C,was found to be 38.61 mg/g of *** SEM images showed that the nanoparticles form a uniform monolayer on bamboo fiber surfaces.

关键词： Adsorption Copolymer Cationic nanoparticles Bamboo fibers

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Real-Time Dwell Scheduling Based on a Unified Pulse Interleaving Framework for Phased Array Radar

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Tsinghua Science and Technology 2024年第5期29卷 1540-1553页

作者： ting Cheng Luqing liu Zhongzhu Li Siyu Heng School of Information and Communication Engineering University of Electronic Science and Technology of ChinaChengdu 614000China

Dwell scheduling is a key for phased array radar to realize multi-function and it becomes especially challenging in complex tactical *** this manuscript,a real-time radar dwell scheduling algorithm based on a unified pulse interleaving framework is proposed.A unified pulse interleaving framework that can realize pulse interleaving analysis for phased array radars with different receiving modes is put forward,which greatly improves the time utilization of the *** on above framework,a real-time two-stage approach is proposed to solve the optimization problem of dwell *** importance and urgency criteria are guaranteed by the first pre-schedule stage,and the desired execution time criterion is improved at the second stage with the modified particle swarm optimization(PSO).Simulation results demonstrate that the proposed algorithm has better comprehensive scheduling performance than up-to-date algorithms that consider the pulse interleaving technique for both single beam and multiple beams receiving ***,the proposed algorithm can realize dwell scheduling in realtime.

关键词： phased array radar dwell scheduling receiving mode pulse interleaving particle swarm optimization

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Fast Cycle Structure Detection for Power Grids Based on Graph Computing

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CSEE Journal of Power and Energy Systems 2023年第6期9卷 2204-2213页

作者： Xinqiao Wang Kewen liu Weijiang Lu ting Zhao Baohua Zhao Xiaoming liu the Computing&Application Technology Research Division Global Energy Interconnection Research InstituteBeijing 102209China

The cycle structure in a power grid may lower the stability of the network;thus,it is of great significance to accu-rately and timely detect cycles in power grid ***,detecting possible cycles in a large-scale network can be highly time consuming and computationally *** addition,since the power grid's topology changes over time,cycles can appear and disappear,and it can be difficult to monitor them in real *** traditional computing systems,cycle detection requires considerable computational resources,making real-time cycle detection in large-scale power grids an impossible *** computing has shown excellent performance in many areas and has solved many practical graph-related problems,such as power flow calculation and state *** this article,a cycle detection method,the Paton method,is implemented and optimized on a graph computing *** cases are used to test its performance in an actual power grid topology *** results show that the graph computing-based Paton method reduces the time consumption by at least 60%compared to that of other methods.

关键词： Cycle detection graph computing power grid distribution grid

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Vertical distributions of tropospheric SO_(2) based on MAX-DOAS observations: Investigating the impacts of regional transport at different heights in the boundary layer

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Journal of Environmental Sciences 2021年第5期33卷 119-134页

作者： Qianqian Hong Cheng liu Qihou Hu Chengzhi Xing Wei Tan ting liu Jianguo liu School of Environment and Civil Engineering Jiangnan UniversityWuxi214122China Center for Excellence in Regional Atmospheric Environment Institute of Urban EnvironmentChinese Academy of SciencesXiamen361021China Key Lab of Environmental Optics&Technology Anhui Institute of Optics and Fine MechanicsHefei Institutes of Physical ScienceChinese Academy of SciencesHefei230031China Department of Precision Machinery and Precision Instrumentation University of Science and Technology of ChinaHefei230026China School of Earth and Space Sciences University of Science and Technology of ChinaHefei230026China Anhui Province Key Laboratory of Polar Environment and Global Change University of Science and Technology of ChinaHefei230026China

Information on the vertical distribution of air pollutants is essential for understanding their spatiotemporal evolution underlying urban atmospheric environment. This paper presents the SO_(2) profiles based on ground-based Multi-Axis Differential Optical Absorption Spectroscopy(MAX-DOAS) measurements from March 2018 to February 2019 in Hefei, East China. SO_(2) decrease rapidly with increasing heights in the warm season, while lifted layers were observed in the cold season, indicating accumulation or long-range transport of SO_(2) in different seasons might occur at different heights. The diurnal variations of SO_(2) were roughly consistent for all four seasons, exhibiting the minimum at noon and higher values in the morning and late afternoon. Lifted layers of SO_(2) were observed in the morning for fall and winter, implying the accumulation or transport of SO_(2) in the morning mainly occurred at the top of the boundary layer. The bivariate polar plots showed that weighted SO_(2) concentrations in the lower altitude were weakly dependent on wind, but in the middle and upper altitudes, higher weighted SO_(2) concentrations were observed under conditions of middlehigh wind speed. Concentration weighted trajectory(CWT) analysis suggested that potential sources of SO_(2) in spring and summer were local and transported mainly occurred in the lower altitude from southern and eastern areas;while in fall and winter, SO_(2) concentrations were deeply affected by long-range transport from northwestern and northern polluted regions in the middle and upper altitudes. Our findings provide new insight into the impacts of regional transport at different heights in the boundary layer on SO_(2) pollution.

关键词： Sulfur dioxide MAX-DOAS Vertical distribution Regional transport

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Rapid prediction of damaged ship roll motion responses in beam waves based on stacking algorithm

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Journal of Hydrodynamics 2024年第2期36卷 394-405页

作者： Xin-ran liu ting-qiu Li Zi-ping Wang School of Naval Architecture Ocean and Energy Power EngineeringWuhan University of TechnologyWuhan430063China

Accurate modeling for highly non-linear coupling of a damaged ship with liquid sloshing in waves is still of considerable interest within the computational fluid dynamics(CFD)and AI *** paper describes a data-driven Stacking algorithm for fast prediction of roll motion response amplitudes in beam waves by constructing a hydrodynamics model of a damaged ship based on the dynamic overlapping grid CFD *** general idea is to optimize various parameters varying with four types of classical base models like multi-layer perception,support vector regression,random forest,and hist gradient boosting *** offers several attractive properties in terms of accuracy and efficiency by choosing the standard DTMB 5415 model with double damaged compartments for *** is clearly demonstrated that the predicted response amplitude operator(RAO)in the regular beam waves agrees well with the experimental data available,which verifies the accuracy of the established damaged ship hydrodynamics *** high-quality CFD samples,therefore,implementation of the designed Stacking algorithm with its optimal combination can predict the damaged ship roll motion amplitudes effectively and accurately(e.g.,the coefficient of determination 0.9926,the average absolute error 0.0955 and CPU 3s),by comparison of four types of typical base models and their various ***,the established Stacking algorithm provides one potential that can break through problems involving the time-consuming and low efficiency for large-scale lengthy CFD simulations.

关键词： Ship motion damaged ship computational fluid dynamics(CFD) machine learning stacking algorithm

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Non-contact and full-field online monitoring of curing temperature during the in-situ heating process based on deep learning

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Advances in Manufacturing 2024年第1期12卷 167-176页

作者： Qiang-Qiang liu Shu-ting liu Ying-Guang Li Xu liu Xiao-Zhong Hao College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing210016People’s Republic of China School of Mechanical and Power Engineering Nanjing Tech UniversityNanjing211816People’s Republic of China

Online monitoring of the curing temperature field is essential to improving the quality and efficiency of the manufacturing process of composite *** embedded sensor-based technologies have difficulty monitoring the full temperature field or have to introduce heterogeneous items that could have an undesired impact on the *** this paper,a non-contact,full-field monitoring method based on deep learning that predicts the internal temperature field of composite parts in real time using surface temperature measurements of auxiliary materials is *** the proposed method,an average temperature monitoring accuracy of 97%is achieved in various heating *** addition,this method also demonstrates satisfying feasibility when a stronger thermal barrier covers the *** method was experimentally validated during the self-resistance electric heating process,in which the monitoring accuracy reached 93.1%.This method can potentially be applied to automated manufacturing and process control in the composites industry.

关键词： Online monitoring Curing temperature field Deep learning(DL) In-situ heating

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Mutual comparative analysis:a new topography-guided custom ablation protocol referencing subjective refraction to modify corneal topographic data

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Eye and Vision 2020年第4期7卷 347-355页

作者： Kaiwei Cao Lina liu Tao Zhang ting liu Ji Bai 77120 unit of People’s Liberation Army(PLA) No.1441 FengJu Ring RoadJinniu DistrictChengdu 610081China Chongqing vision institute No.77 Changjiang 2 RoadYuzhong DistrictChongqing 400042China Department of Ophthalmology Daping Hospital and the Research Institute of Surgery of the Army Medical University of PLANo.10 Changjiangzhi RoadYuzhong DistrictChongqing 400042China

Background:Several planning algorithms have been developed for topography-guided custom ablation treatment(T-CAT),but each has its own *** purpose of this study is to demonstrate the potential of a novel mutual comparative analysis(MCA)informed by manifest refraction and corneal topographic data and the patient’s subjective perception in correcting ***:This retrospective review included patients with significant preoperative differences in the power or axis of astigmatism according to the manifest refraction and corneal topographic data(power>0.75 D and/or axis>10°).T-CAT planning was designed using ***-ups were conducted for at least 6 ***:Seventy-nine patients(121 eyes)were *** mean preoperative deviation in the astigmatic power and axis were 0.72±0.43 D and 20.18±23.68°,*** average oculus residual astigmatism(ORA)was 0.81±0.32 D(range:0.08–1.66 D).Six months postoperatively,the mean spherical equivalent refraction was 0.04±0.42 D,and the mean cylinder was−0.27±0.24 *** mean efficacy and safety indices were 1.10 and 1.15,*** uncorrected distance visual acuity in 92%of the eyes was the same or better than the corrected distance visual *** angle of error was±5°in 61%of eyes and±15°in 84%of *** astigmatism was≤0.5 D in 91%of *** quality and photopic contrast sensitivity did not change significantly(p>0.05),and the scotopic contrast sensitivity decreased at 3,6,and 12 cpd(p<0.05).The vertical coma and horizontal coma of the anterior corneal surface significantly decreased postoperatively but increased during ***:The MCA demonstrated safety,efficacy,accuracy,predictability,and stability and can be used as a complementary and feasible method for T-CAT.

关键词： Mutual comparative analysis Topography-guided custom ablation treatment Astigmatism Manifest refraction Topography

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A Fast Vision-inertial Odometer Based on Line Midpoint Descriptor

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International Journal of Automation and computing 2021年第4期18卷 667-679页

作者： Wen-kuan Li Hao-Yuan Cai Sheng-Lin Zhao Ya-Qian liu Chun-Xiu liu State Key Laboratory of Transducer Technology Aerospace Information Research InstituteChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100190China

Visual simultaneous localization and mapping(VSLAM) are essential technologies to realize the autonomous movement of vehicles. Visual-inertial odometry(VIO) is often used as the front-end of VSLAM because of its rich information, lightweight, and robustness. This article proposes the FPL-VIO, an optimization-based fast vision-inertial odometer with points and lines. Traditional VIO mostly uses points as landmarks;meanwhile, most of the geometrical structure information is ignored. Therefore, the accuracy will be jeopardized under motion blur and texture-less area. Some researchers improve accuracy by adding lines as landmarks in the ***, almost all of them use line segment detector(LSD) and line band descriptor(LBD) in line processing, which is very time-consuming. This article first proposes a fast line feature description and matching method based on the midpoint and compares the three line detection algorithms of LSD, fast line detector(FLD), and edge drawing lines(EDLines). Then, the measurement model of the line is introduced in detail. Finally, FPL-VIO is proposed by adding the above method to monocular visual-inertial state estimator(VINSMono), an optimization-based fast vision-inertial odometer with lines described by midpoint and points. Compared with VIO using points and lines(PL-VIO), the line processing efficiency of FPL-VIO is increased by 3-4 times while ensuring the same accuracy.

关键词： High efficiency visual-inertial odometry(VIO) non-linear optimization points and lines sliding window

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