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Nonlinear Adaptive Robust Control design for Static Synchronous Compensator Based on Improved Dynamic Surface Method

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International Journal of Automation and computing 2014年第3期11卷 334-339页

作者： wen-lei Li Ming-Ming Li School of Information Science and Engineering Ningbo University

In view of single machine to infinite bus system with static synchronous compensator, which is affected by internal and external disturbances, a nonlinear adaptive robust controller is constructed based on the improved dynamic surface control method(IDSC). Compared with the conventional DSC, the sliding mode control is introduced to the dynamic surface design procedure, and the parameter update laws are designed using the uncertainty equivalence criterions. The IDSC method not only reduces the complexity of the controller but also greatly improves the system robustness, speed and accuracy. The derived controller cannot only attenuate the influences of external disturbances against system output, but also has strong robustness to system parameters variance because the damping coefficient is considered in the internal parameter uncertainty. Simulation result reveals that the designed controller can effectively improve the dynamic performances of the power system.

关键词： Power systems robust control parameter uncertainty disturbance attenuation dynamic surface control(DSC)

Biomimetic smart nanochannels for power harvesting

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Nano Research 2016年第1期9卷 59-71页

作者： Ganhua Xie Liping wen lei Jiang Beijing National Laboratory for Molecular Sciences (BNLMS) Key Laboratory of Green Printing Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China Laboratory of Bioinspired Smart Interfacial Science Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing100190 China

With the increasing requirements of reliable and environmentally friendly energy resources, porous materials for sustainable energy conversion technologies have attracted intensive interest in the past decades. As an important block of porous materials, biomimetic smart nanochannels （BSN） have been developed rapidly into an attractive field for their well-tunable geometry and chemistry. With inspiration from nature, many works have been reported to utilize BSN to harvest clean energy. In this review, we summarize recent progress in the BSN for power harvesting from four parts of brief introduction of BSN, biological prototypes for power harvesting, BSN-based energy conversion, and conclusion and outlook. Overall, by learning from nature, exploiting new avenues and improving the performance of BSN, a number of exciting developments in the near future may be anticipated.

关键词： energy conversion biomimetic nanochannel photoelectric salinity gradient

Damage Initiation and Propagation in Composites Subjected to Low-Velocity Impact:Experimental Results,3D Dynamic Damage Model,and FEM Simulations

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Transactions of Nanjing University of Aeronautics and Astronautics 2019年第3期36卷 488-499页

作者： JIA wenbin wen Weidong FANG lei Jiangsu Province Key Laboratory of Aerospace Power System College of Energy and Power EngineeringNanjing University of Aeronautics and Astronautics

A three-dimensional dynamic damage model that fits both small and large damage sizes is developed to predict impact damage initiation and propagation for each lamina of T300-carbon/epoxy ***,13 specimens of the same lamination sequence are subjected to three different impact energies(10 J,15 J,and 20 J).After the impact,the laminates are inspected by the naked eye to observe the damage in the outer layers,and subsequently X-rayed to detect the inner ***,the stress analysis of laminates subjected to impact loading is presented,based on the Hertz contact law and virtual displacement *** on the analysis results,a three-dimensional dynamic damage model is proposed,including the Hou failure criteria and Camanho stiffness degradation model,to predict the impact damage shape and *** numerical predictions of the damage shape and area show a relatively reasonable agreement with the ***,the impact damage initiation and propagation for each lamina are investigated using this damage model,and the results improve the understanding of the impact process.

关键词： composites impact three-dimensional dynamic damage model impact damage initiation and propagation

Genomic insights into ruminant evolution: from past to future prospects

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Zoological Research 2019年第6期40卷 476-487页

作者： Bao Wang lei Chen wen Wang State Key Laboratory of Genetic Resources and Evolution Kunming Institute of ZoologyChinese Academy of SciencesKunming Yunnan 650223China Kunming College of Life Science University of Chinese Academy of SciencesKunming Yunnan 650204China Center for Ecological and Environmental Sciences Northwestern Polytechnical UniversityXi'an Shaanxi 710072China Center for Excellence in Animal Evolution and Genetics Chinese Academy of SciencesKunming Yunnan 650223China

Ruminants(Ruminantia) are among the most successful herbivorous mammals, exhibiting wideranging morphological and ecological characteristics(such as headgear and multichambered stomach)and including various key livestock species(e. g.,cattle, buffalo, yak, sheep, and goat). Understanding their evolution is of great significance not only in scientific research but also in applications potential for human society. The rapid growth of genomic resources provides unprecedented opportunities to dissect the evolutionary histories and molecular mechanisms underlying the distinct characteristics of ruminants. Here we summarize our current understanding of the genetic, morphological, and ecological diversity of ruminants and provide prospects for future studies.

关键词： Rumin antia Genome evolution Phylogenomics Traits Adaptive evolution

Complex patterns of precipitation and extreme events during 1951-2011 in Sichuan Basin, Southwestern China

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Journal of Mountain Science 2018年第2期15卷 340-356页

作者： ZHOU Xiang-yang lei wen-juan Guizhou Provincial Key Laboratory of Public Big Data Guizhou University State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University College of Architecture & Environment Sichuan University

Sichuan Basin is located in southwestern China and affected by a complex water vapor （WV） sources. Here, the spatial and temporal patterns of precipitation and extreme events are investigated by six indices of World Meteorology Organization Commission, including annual precipitation total （AP）, maximum daily precipitation （Maxld）, intensity of rainfall over 1 mm/d （IR1）, maximum and mean consecutive dry days （Max CDD, Mean CDD） and coefficient of variance. Based on 24 daily precipitation time series from 1951 to 2o11, Mann-Kendall test is employed to quantify the significant level of these indices, from which the classification of precipitation change and its spatial patterns are obtained. Meanwhile, the probability distributions of these indices are identified by L-moment analysis and the Goodness-of-fit test, and the corresponding values are calculated by theoretical model at different return periods. The results reveal that the western basin displays normal drought： less AP and precipitation intensity while longer drought. The southern basin shows normal increase： larger AP and precipitation intensity but shorter CDD. However, in hilly region of the central basin and the transition zone between basin and mountains, precipitation changes abnormally： increasing both drought （one or both of Mean CDD and MaxCDD） and precipitation intensity （one or both of Maxld and trend of AP is. Probability IR1） no matter what the distribution models also demonstrate the complex patterns： a negative correlation between Maxld and Max CDD in the west （R2≥0.61） while a positive correlation in the east （R2≥0.41） at all return periods. These patterns are induced by the changes in WV sources and the layout of local terrain. The increase of WV in summer and decrease in spring leads to the heavier rainfall and longer drought respectively. The large heat island effect of the basin contributes to a lower temperature in transition zones and more precipitation in the downwind area. These resul

关键词： Extreme precipitation events Climatechange Sichuan Basin Trend analysis Probability distribution

Effects of sediment and its re-suspension on the growth of Vallisneria asiatica Miki

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Journal of China University of Mining and Technology 2008年第1期18卷 144-148页

作者： lei Ze-xiang XIE Yi-fa XU de-lan LIU Zheng-wen department of Environmental Science and Engineering Zhongkai University of Agriculture and Technology Guangzhou 510225 China Institute of Hydrobiology Jinan University Guangzhou 510632 China department of Environment Engineering Xuzhou Engineering College Xuzhou Jiangsu 221008 China Nanfing Institute of Geography and Limnology Chinese Academy of Sciences Nanjing Jiangsu 210008 China

Aquatic macrophytic growth and its distribution in eutrophic lakes are described in relation to its sediment type and irradiance. Hence, it is necessary to characterize the response of macrophytic growth to lake sediment and its re-suspension. We conducted two independent experiments to measure the effects of sediment and its re-suspension on the growth of Vallisneria asiatica Miki. Based on our study, we conclude that the amount of total biomass of V. asiatica is related, in important ways, to the type of sediment and its re-suspension. According to our comparison, plants and biomass cultured on lake sediments are 2.1 times and 1.5 times greater than that on brown clay from nearby places beside Lake Taihu. The number of plants and the amount of biomass in a turbid water column are smaller than those in a clear water column. The results indicate that the nutrient-rich lake sediments have promoted the growth of V. asiatica, while the re-suspension of the sediment leads to a high turbid level and low light penetration which has a negative impact on the growth of V. asiatica.

关键词： submersed macrophytes sediment re-suspension

脱氢表雄酮对饲喂高脂饲料肉鸡脂肪沉积、血脂、抗氧化能力和血管内皮功能的影响

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安徽科技学院学报 2025年第1期39卷 1-8页

作者：姜锦鹏李磊闻爱友安徽科技学院动物科学学院安徽凤阳233100 安徽省动物营养调控与健康重点实验室安徽凤阳233100

为探讨脱氢表雄酮(dehydroepiandrosterone,DHEA)对饲喂高脂饲料肉鸡脂质代谢、抗氧化和血管内皮功能的影响,将200只15日龄青脚麻鸡随机分为5组,其中对照组(CON)饲喂基础饲料,高脂饲料组(High Fat Diet,HFD)、DHEA低剂量干预组(HFD+D5)... 详细信息

为探讨脱氢表雄酮(dehydroepiandrosterone,DHEA)对饲喂高脂饲料肉鸡脂质代谢、抗氧化和血管内皮功能的影响,将200只15日龄青脚麻鸡随机分为5组,其中对照组(CON)饲喂基础饲料,高脂饲料组(High Fat Diet,HFD)、DHEA低剂量干预组(HFD+D5)、DHEA中剂量干预组(HFD+D15)、DHEA高剂量干预组(HFD+D45)分别饲喂添加0、5、15、45 mg/kg DHEA的高脂饲料。于试验第2、4周,测定肌间脂肪宽、皮下脂肪厚、皮脂质量、腹脂质量,计算腹脂率、皮脂率;采集血样检测激素和生化指标;采集肝脏组织检测抗氧化功能和肝脂酶(Hepatic Lipase,HL)活性。与对照组相比,高脂饲料显著增加肉鸡的腹脂质量、腹脂率、皮脂率及血液甘油三酯(Triglyceride,TG)、脂蛋白a(Lipoprotein a,LP(a))、血管紧张素Ⅱ(AngiotensimⅡ,AngⅡ)水平,但降低血清高密度脂蛋白(High density Lipoprotein,HDL)、T_(3)、T_(4)、FT_(3)、FT_(4)和一氧化氮(NO)水平;同时,高脂饲料显著提高肝脏丙二醛(Malondiadehyde,MDA)含量,但降低肝脏(HL)、总超氧化物歧化酶(Superoxide Dismutase,SOD)和谷胱甘肽过氧化物酶(Glutathione Peroxidase,GSH-Px)活性。与HFD组相比,DHEA处理对饲喂高脂饲料肉鸡的体脂沉积及血清中TG、TC、LP(a)含量均有降低趋势;同时,DHEA能够升高血清T_(3)、T_(4)、FT_(3)、FT_(4)、NO水平及肝脏HL、SOD、GSH-Px活性,并降低肝脏MDA含量和血浆AngⅡ水平。补充DHEA对高脂饲料引发的肉鸡脂代谢紊乱、氧化应激和内皮功能障碍有一定缓解作用,其作用机理可能是通过调节血清甲状腺激素水平,增强肝脏HL活性,从而加速脂肪的分解,抑制脂肪沉积,继而减弱氧化应激,并改善血管内皮功能。

关键词：肉鸡高脂饲料脂肪代谢氧化应激内皮功能脱氢表雄酮

Dynamic Positioning Capability Analysis for Marine Vessels Based on A DPCap Polar Plot Program

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China Ocean Engineering 2018年第1期32卷 90-98页

作者： WANG lei YANG Jian-min XU Sheng-wen State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center for Advanced Shipand deep-Sea Exploration(CISSE) Shanghai 200240China

Dynamic positioning capability(DPCap) analysis is essential in the selection of thrusters, in their configuration, and during preliminary investigation of the positioning ability of a newly designed vessel dynamic positioning *** analysis can help determine the maximum environmental forces, in which the DP system can counteract in given headings. The accuracy of the DPCap analysis is determined by the precise estimation of the environmental forces as well as the effectiveness of the thrust allocation logic. This paper is dedicated to developing an effective and efficient software program for the DPCap analysis for marine vessels. Estimation of the environmental forces can be obtained by model tests, hydrodynamic computation and empirical formulas. A quadratic programming method is adopted to allocate the total thrust on every thruster of the vessel. A detailed description of the thrust allocation logic of the software program is given. The effectiveness of the new program DPCap Polar Plot(DPCPP)was validated by a DPCap analysis for a supply vessel. The present study indicates that the developed program can be used in the DPCap analysis for marine vessels. Moreover, DPCap analysis considering the thruster failure mode might give guidance to the designers of vessels whose thrusters need to be safer.

关键词： DPCap analysis thrust allocation logic quadratic programming method

Numerical Analysis of Rolling-sliding Contact with the Frictional Heat in Rail

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Chinese Journal of Mechanical Engineering 2014年第1期27卷 41-49页

作者： LI Wei wen Zefeng JIN Xuesong WU lei State Key Laboratory of Traction Power Southwest Jiaotong University

Thermal damage caused by frictional heat of rolling-sliding contact is one of the most important failure forms of wheel and rail. Many studies of wheel-rail frictional heating have been devoted to the temperature field, but few literatures focus on wheel-rail thermal stress caused by frictional heating. However, the wheel-rail creepage is one of important influencing factors of the thermal stress In this paper, a thermo-mechanical coupling model of wheel-rail rolling-sliding contact is developed using thermo-elasto-plastic finite element method. The effect of the wheel-rail elastic creepage on the distribution of heat flux is investigated using the numerical model in which the temperature-dependent material properties are taken into consideration. The moving wheel-rail contact force and the frictional heating are used to simulate the wheel rolling on the rail. The effect of the creepage on the temperature rise, thermal strain, residual stress and residual strain under wheel-rail sliding-rolling contact are investigated. The investigation results show that the thermally affected zone exists mainly in a very thin layer of material near the rail contact surface during the rolling-sliding contact. Both the temperature and thermal strain of rail increase with increasing creepage. The residual stresses induced by the frictional heat in the surface layer of rail appear to be tensile. When the creepage is large, the frictional heat has a significant influence on the residual stresses and residual strains of rail. This paper develops a thermo-meehanical coupling model of wheel-rail rolling-sliding contact, and the obtained results can help to understand the mechanism of wheel/rail frictional thermal fatigue.

关键词： wheel-rail rolling-sliding contact frictional heating creepage residual stress/strain,thermo-elasto-plastic finite element method