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407篇 您的检索式:作者名="CHAI Zhao"
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1Research and compilation of the Geomorphologic Atlas of the People's Republic of China (1:1,000,000)显示文摘Geomorphologic maps are one of the most fundamental materials of the natural environment. They have been widely used in scientific research,resource exploration and extraction,education and military affairs etc. An editorial committee was established in 2001 to collect materials for researching and compiling a set of new 1:1,000,000 geomorphologic atlas of China. A digital geomorphologic database was created with visual interpretation from Landsat TM/ETM imageries and SRTM-DEM etc. The atlas compiled from the database was finished. The main characteristics of the atlas are as follows:Firstly,Landsat TM/ETM imageries,published geomorphologic maps or sketches,geographical base maps,digital geological maps,and other thematic maps were collected,which were uniformly geometrically rectified,clipped into uniform sheets,and stored in the foundation database. Secondly,based on the legends of 15 sheets 1:1,000,000 maps published in the 1980s,a geomorphologic classification system was built by combining morphology and genesis types. The system comprised seven hierarchical layers:basic morphology,genesis,sub-genesis,morphology,micro-morphology,slope and aspect,material composition and lithology. These layers were stored in the database during visual image interpretation. About 2000 kinds of morpho-genesis and 300 kinds of morpho-structure were interpreted. Thirdly,the legend system was built,which included color,symbol bases and note bases etc.,compilation standards and procedures were developed,74 sheets of 1:1,000,000 covering all land and sea territories of China were compiled,the 1:1,000,000 geomorphologic atlas of the People's Republic of China was finished and published. The atlas will fill the blanks in national basic scale thematic maps,and the geomorphologic database could be applied widely in many fields in the future.CHENG Weiming ZHOU Chenghu CHAI Huixia ZHAO Shangmin LIU Haijiang ZHOU Zengpo 2011Journal of Geographical Sciences2011,21,1:17
2Synthesis and in vitro-Anti-hepatitis B Virus Activities of Several Ethyl 5-Hydroxy-1H-indole-3-carboxylates显示文摘A series of ethyl 5-hydroxyindole-3-carboxylates 6a—10r was designed and synthesized. The structures of all the compounds were confirmed by IR, 1H NMR, and MS and their anti-hepatitis B virus(HBV) activities were evaluated in 2.2.15 cells. Among them, compound 7g{ethyl 5-hydroxy-2-[(3-methoxyphenylsulfinyl) methyl]-1-methyl-4-[(4-methylpiperazin-1-yl)methyl]-1H-indole-3-carboxylate} displays a significant anti-HBV activity, which is more potent than the positive control lamivudine.ZHAO Chun-shen ZHAO Yan-fang CHAI Hui-fang GONG Ping 2006Chemical Research in Chinese Universities2006,22,5:16
3Pretreatment with Danhong injection protects the brain against ischemia-reperfusion injury显示文摘Danhong injection(DHI),a Chinese Materia Medica standardized product extracted from Radix Salviae miltiorrhizae and Flos Carthami tinctorii,is widely used in China for treating acute ischemic stroke.In the present study,we explored the neuroprotective efficacy of DHI in a rat model of temporary middle cerebral artery occlusion,and evaluated the potential mechanisms underlying its effects.Pretreatment with DHI(0.9 and 1.8 mL/kg)resulted in a significantly smaller infarct volume and better neurological scores than pretreatment with saline.Furthermore,DHI significantly reduced the permeability of the blood-brain barrier,increased occludin protein expression and decreased neutrophil infiltration,as well as profoundly suppressing the upregulation of matrix metallopeptidase-9 expression seen in rats that had received vehicle.Matrix metallopeptidase-2 expression was not affected by ischemia or DHI.Moreover,DHI(1.8 mL/kg)administered 3 hours after the onset of ischemia also improved neurological scores and reduced infarct size.Our results indicate that the neuroprotective efficacy of DHI in a rat model of cerebral ischemia-reperfusion injury is mediated by a protective effect on the blood-brain barrier and the reversal of neutrophil infiltration.Shaoxia Wang Hong Guo Xumei Wang Lijuan Chai Limin Hu Tao Zhao Buchang Zhao Xiaoxu Tan Feifei Jia 2014Neural Regeneration Research2014,9,15:12
4Geochemical environmental changes and dinosaur extinction during the Cretaceous-Paleogene (K/T) transition in the Nanxiong Basin, South China: Evidence from dinosaur eggshells显示文摘The complex patterns of trace elements including Ir and isotope distributions in the three K/T sections of the Nanxiong Basin prove the existence of two environmental events in the latest Cretaceous and earliest Paleocene. The first geochemical environmental event occurred at about 2 Ma prior to the K/T boundary interval, where the dinosaur diversity was hardly reduced, except that a number of patho-logical eggshells appeared. The second one was larger and occurred just at and near the Creta-ceous-Paleogene (K/T) boundary. The extinction of the dinosaurs spread out within 250 ka with major extinction beginning at the boundary interval. This is even later than their extinction in Montana, North America and in India. The cause of the dinosaur extinction may be the result of a complex multiple events brought about by the coincidence of global environment change marked by multiple Ir and δ 18O anomalies, and environmental poisoning characterized by other trace elements derived from the local source. Successive short- and long-term conditions of geochemically induced environmental stress negatively affected the reproductive process and thus contributed to the extinction of the dinosaurs.ZHAO ZiKui MAO XueYing CHAI ZhiFang YANG GaoChuang ZHANG FuCheng YAN Zheng 2009Chinese Science Bulletin2009,54,5:12
5Residents′Activity-travel Behavior Variation by Communities in Beijing,China显示文摘China's transition from a planned economy to a market economy has resulted in many changes in its urban structure and society and provided an opportunity for a quasi-longitudinal case study on the relationship between the built environment and activity-travel behavior.This paper draws upon data from an activity diary survey conducted in Beijing in 2007.The survey sample comprised 652 residents living in Danwei(work unit),commodity housing,and affordable housing neighborhoods.On the basis of the three-dimensional geo-visualization analysis of the space-time path and statistical multivariate regression models of daily travel and leisure time,it was found that both residential spatial factors and socio-demographics influence residents' daily behaviors.The findings show that Danwei residents have less daily travel time than those who live in commodity housing,but people living in affordable housing endure the longest travel time.Daily leisure time is associated more with individual attributes.We argue that although China's transition is currently gradual,the Danwei system may continue to play significant roles in daily life,and it might provide a valuable model for neighborhood spatial planning.ZHAO Ying CHAI Yanwei 2013Chinese Geographical Science2013,23,4:12
6The levels, sources and reactivity of volatile organic compounds in a typical urban area of Northeast China显示文摘Air concentrations of volatile organic compounds(VOCs) were continually measured at a monitoring site in Shenyang from 20 August to 16 September 2017. The average concentrations of alkanes, alkenes, aromatics and carbonyls were 28.54, 6.30, 5.59 and9.78 ppbv, respectively. Seven sources were identified by the Positive Matrix Factorization model based on the measurement data of VOCs and CO. Vehicle exhaust contributed the most(36.15%) to the total propene-equivalent concentration of the measured VOCs,followed by combustion emission(16.92%), vegetation emission and secondary formation(14.33%), solvent usage(10.59%), petrochemical industry emission(9.89%), petrol evaporation(6.28%), and liquefied petroleum gas(LPG) usage(5.84%). Vehicle exhaust, solvent usage and combustion emission were found to be the top three VOC sources for O_3 formation potential, accounting for 34.52%, 16.55% and 11.94%, respectively. The diurnal variation of the total VOCs from each source could be well explained by their emission characteristics,e.g., the two peaks of VOC concentrations from LPG usage were in line with the cooking times for breakfast and lunch. Wind rose plots of the VOCs from each source could reveal the possible distribution of the sources around the monitoring site. The O_3 pollution episodes during the measurement period were found to be coincident with the elevation of VOCs, which was mainly due to the air parcel from the southeast direction where petrochemical industry emission was found to be dominant, suggesting that the petrochemical industry emission from the southeast was probably a significant cause of O_3 pollution in Shenyang.Zhuobiao Ma Chengtang Liu Chenglong Zhang Pengfei Liu Can Ye Chaoyang Xue Di Zhao Jichen Sun Yiming Du Fahe Chai Yujing Mu 2019Journal of Environmental Sciences2019,31,5:12
7Elevated IL-37 levels in the plasma of patients with severe coronary arterycalcification显示文摘Background Coronary artery calcification (CAC) is a predictor of cardiovascular events and plaque burden and is closely associatedwith chronic inflammation. Intedeukin (IL)-37 is a newly discovered member of the IL-1 family and is considered an anti-inflammatorycytokine. Our recent study on mice indicated that IL-37 could attenuate atherosclerosis and vascular calcification, which suggests that IL-37could be associated with the development of atherosclerosis and related diseases. The aim of this study was to investigate if IL-37 plays arole in the progression of CAC in patients. Methods Two hundred participants with suspected cardiovascular disease were recruited. Thelevels of plasma IL-37, osteoprotegerin (OPG), hypersensitive C-reactive protein (hsCRP) together with other biochemical parameters weremeasured, and a coronary calcium assessment was carried out by multi-detector row CT. A score of 〈 10 AU (Agatston units) denotes anabsence of CAC, a score of 11-100 AU denotes mild CAC, 101-400 denotes moderate CAC, and 〉 400 AU denotes severe CAC. ResultsOur initial data showed that there were no apparent differences in plasma IL-37 levels among patients with or without mild or moderate CAC.However, IL-37 levels were significantly increased in patients with severe CAC (P 〈 0.001). Similar results were observed for plasma OPGand hsCRP levels. When IL-37 levels in patients with severe calcification were compared with that in all of the other non-severe CAC groups,it became apparent that there was a significant positive correlation between IL-37 level and severe CAC (r = 0.360, P 〈 0.001; OR = 1.033)using Spearrnan's correlation and binary logistic regression analysis. Conclusions This study demonstrates that the anti-inflammatory cy-tokine IL-37 is associated with high coronary calcium levels, suggesting that IL-37 expression may be caused by the activation ofinf/amma-tion and that IL-37 might become a predictor of severe CAC in the future, which requires further investigation.Meng CHAI Hai-Tao ZHANG Yu-Jie ZHOU Qing-Wei JI Qing YANG Yu-Yang LIU Ying-Xin ZHAO Dong-Mei SHI Wei LIU Li-Xia YANG Lin-Lin ZHANC Jing LIANG 2017Journal of Geriatric Cardiology2017,14,5:11
8Construction of an anchoring SSR marker genetic linkage map and detection of a sex-linked region in two dioecious populations of red bayberry显示文摘Red bayberry(Morella rubra)is an evergreen fruit tree found in southern China whose whole-genome sequence has recently been published.We updated the linkage map of the species by adding 118 SSR markers and the femalespecific marker MrFT2_BD-SEX.The integrated map included eight linkage groups and spanned 491 cM.Eleven sexassociated markers were identified,six of which were located in linkage group 8,in agreement with the previously reported location of the sex-determining region.The MrFT2_BD-SEX marker was genotyped in 203 cultivated accessions.Among the females of the accessions,we found two female-specific alleles,designated W-b(151 bp)and W-d(129 bp).We previously found that‘Dongkui’,a female cultivar,could produce viable pollen(we refer to such plants‘Dongkui-male’)and serve as the paternal parent in crosses.The genotypes of the MrFT2_BD-SEX marker were W-b/Z in‘Biqi’and W-d/Z in‘Dongkui-male’.The progeny of a cross between these parents produced a 3:1 female(W-)to male(ZZ)ratio and the expected 1:1:1:1 ratio of W-b/W-d:W-b/Z:W-d/Z:Z/Z.In addition,the flowering and fruiting phenotypes of all the F1 progeny fit their genotypes.Our results confirm the existence of ZW sex determination and show that the female phenotype is controlled by a single dominant locus(W)in a small genomic region(59 kb and less than 3.3 cM).Furthermore,we have produced a homozygous“super female”(WW)that should produce all-female offspring in the F2 generation,providing a foundation for commercial use and presenting great potential for use in modern breeding programs.Yan Wang Hui-Min Jia Yu-Tong Shen Hai-Bo Zhao Qin-Song Yang Chang-Qing Zhu De-Li Sun Guo-Yun Wang Chao-Chao Zhou Yun Jiao Chun-Yan Chai Li-Ju Yan Xiong-Wei Li Hui-Juan Jia Zhong-Shan Gao 2020Horticulture Research2020,7,1:10
9Characterization of refuse landfill leachates of three different stages in landfill stabilization process显示文摘Landfill leachates with different ages(mature leachate,11 years;semi-mature leachate,5 years;fresh leachate,under operation) were collected from Laogang Refuse Landfill,Shanghai to characterize the colloid size distribution and variations of leachate.These leachates were separated using micro-filtration and ultra-filtration into specific size fractions,i.e.,suspended particles(SP)(>1.2μm) ,coarse colloids(CC)(1.2-0.45μm) ,fine colloids(FC)(0.45μm,5 kDa/1 kDa molecular weight(MW) ) ,and dissolved organic matters(DM,<5 kDa/1 kDa MW) .The specific colloids in each size fraction were quantified and characterized through chemical oxygen demands(COD) ,total solid(TS) ,pH,NH4+-N,total organic carbon(TOC) and fixed solid(FS) .It was found that COD,NH4+-N and TS in leachate decreased significantly over ages,while pH increased.The dissolved fractions(<5 kDa/1 kDa) dominated(over 50%) in three leachates in terms of COD,and the organic matter content in dissolved fraction of leachates decreased and the inorganic matter increased as the disposal time extended,with the TOC/COD ratio 30%-7%.Dissolved fractions decreased from 82%to 40%in terms of TOC as the disposal time extended,suggested that the organic matter remained in leachate would form into middle molecular weight substances during the degradation process.LOU Ziyang DONG Bin CHAI Xiaoli SONG Yu ZHAO Youcai ZHU Nanwen 2009Journal of Environmental Sciences2009,21,9:9
10Effect of vitamin B12 on cleft palate induced by 2,3.7.8-tetrachlorodibenzo-p-dioxin and dexamethasone in mice显示文摘Shu-fan ZHAO Mao-zhou CHAI Min WU Yong-hong HE Tian MENG Bing SHI 2014Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)2014,15,3:9
11Co调变MoS2催化剂的作用本质及其FCC汽油选择性加氢脱硫机理显示文摘采用含硫前驱体四硫代钼酸铵直接构建MoS2催化剂,通过调变Co/Mo原子比深入认识Co调变MoS2催化剂的作用本质及其FCC汽油选择性加氢脱硫机理。借助XRD、HRTEM、XPS、H2-TPR和Py-FTIR表征发现,Co/Mo原子比能够影响催化剂的活性相微观结构组成,从而影响催化剂的加氢脱硫活性和选择性。当Co/Mo(atomicratio)<0.2时,助剂Co原子倾向于占据MoS2相的边角位而形成CoMoS活性相,明显提高了催化剂的加氢脱硫活性;当0.20.6时,过量的Co会形成大颗粒的Co9S8相,阻碍硫化物和烯烃与催化剂活性中心的接触,从而降低催化剂的活性和选择性。LIU Bin LIU Lei CHAI Yong-ming ZHAO Jin-chong LIU Chen-guang 刘宾 刘蕾 柴永明 赵晋翀 刘晨光 2018燃料化学学报2018,46,4:9
12Status of study on biological and toxicological effects of nanoscale materials显示文摘Because the physical and chemical properties of nanosized materials mostly differ from the existing microsized materials, their potential impacts on human health and the envi-ronment will be topics under the serious discussions in press and in a number of international scientific journals. We analyze and summarize the existing data of the experimental study on the biological activities and adverse effects of nanoscale materials/particles including single wall carbon nanotubes, multi wall carbon nanotubes, titanium oxide and iron powders. Though some biological behaviors of nanoscale materials observed cannot be understood on the basis of the current knowledge, as the existing data are mostly preliminary, it is too early to make some ex-clusive conclusions on biological activities (or the toxicity) of any of nanoscale materials. The experimental techniques, the current topics, and the future research directions for this new re-search field are also discussed.WANG Bing1, FENG Weiyue1, ZHAO Yuliang1, XING Gengmei1, CHAI Zhifang1, WANG Haifang2 & JIA Guang3 1. Laboratory for Bio-Environmental Health Sciences of Nanoscale Materials (Nanosafety Lab), Institute of High Energy Physics, Chi-nese Academy of Sciences, Beijing 100049, China 2. College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China 3. Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, Beijing 100083, China 2005Science China Chemistry2005,48,5:9
13Advanced Backcross QTL Analysis for the Whole Plant Growth Duration Salt Tolerance in Rice(Oryza sativa L.)显示文摘Salinity is a major factor limiting rice yield in coastal areas of Asia. To facilitate breeding salt tolerant rice varieties, the wholeplant growth duration salt tolerance(ST) was genetically dissected by phenotyping two sets of BC2F5 introgression lines(ILs) for four yield traits under severe natural salt stress and non-stress filed conditions using SSR markers and the methods of advanced backcross QTL(AB-QTL) analysis and selective introgression. Many QTLs affecting four yield traits under salt stress and nonstress conditions were identified, most(>90%) of which were clustered in 13 genomic regions of the rice genome and involved in complex epistasis. Most QTLs affecting yield traits were differentially expressed under salt stress and non-stress conditions. Our results suggested that genetics complementarily provides an adequate explanation for the hidden genetic diversity for ST observed in both IL populations. Some promising Huanghuazhan(HHZ) ILs with favorable donor alleles at multiple QTLs and significantly improved yield traits under salt stress and non-stress conditions were identified, providing excellent materials and relevant genetic information for improving rice ST by marker-assisted selection(MAS) or genome selection.CHAI Lu ZHANG Jian PAN Xiao-biao ZHANG Fan ZHENG Tian-qing ZHAO Xiu-qing WANG Wen-sheng Ali Jauhar XU Jian-long LI Zhi-kang 2014Journal of Integrative Agriculture2014,13,8:8
14Selective Ensemble Extreme Learning Machine Modeling of Effluent Quality in Wastewater Treatment Plants显示文摘Real-time and reliable measurements of the effluent quality are essential to improve operating efficiency and reduce energy consumption for the wastewater treatment process.Due to the low accuracy and unstable performance of the traditional effluent quality measurements,we propose a selective ensemble extreme learning machine modeling method to enhance the effluent quality predictions.Extreme learning machine algorithm is inserted into a selective ensemble frame as the component model since it runs much faster and provides better generalization performance than other popular learning algorithms.Ensemble extreme learning machine models overcome variations in different trials of simulations for single model.Selective ensemble based on genetic algorithm is used to further exclude some bad components from all the available ensembles in order to reduce the computation complexity and improve the generalization performance.The proposed method is verified with the data from an industrial wastewater treatment plant,located in Shenyang,China.Experimental results show that the proposed method has relatively stronger generalization and higher accuracy than partial least square,neural network partial least square,single extreme learning machine and ensemble extreme learning machine model.Li-Jie Zhao 1,2 Tian-You Chai 2 De-Cheng Yuan 1 1 College of Information Engineering,Shenyang University of Chemical Technology,Shenyang 110042,China 2 State Key Laboratory of Synthetical Automation for Process Industries,Northeastern University,Shenyang 110189,China 2012International Journal of Automation and computing2012,9,6:8
15Effects of glucocorticoids on traumatic brain injury related critical illness-related corticosteroid insufficiency显示文摘ZHAO Zi-long CHEN Xin ZHU Hui ZHANG Bao-liang CHAI Yan LI Xin-yuan DONG Jing-fei ZHANG Jian-ning 2013Chinese Medical Journal2013,,19:8
16H2 strain attenuated live hepatitis A vaccines:protective efficacy in a hepatitis A outbreak显示文摘AIM To investigate the protective efficacy ofH2 strain attenuated live hepatitis A vaccines(H2-strain vaccines)in hepatitis A(HA)outbreaks.METHODS With the permission of theirparents,5551 pre-school and grade 1-3 primaryschool children were inoculated with 1 dose(106.5TCID50)of H2-strain vaccines in anonrandomized,controlled trial conducted inFucheng County,Hebei Province in May 1997.Another 6485 children in the same grades andcompatible in gender and age were enrolled ascontrols.Epidemiological and serological surveywas conducted to evaluate the protectiveefficacy of the vaccines.ELISA was used todetect serum IgM anti-HAV.RESULTS HA outbreak started in early May1998,peaked in the middle of the same month,and lasted about 80 days.Overall 302 HA caseswere found,192(53.58%)were 5-9 years old.One vaccinee and 25 control cases were found tohave hepatitis A,which account for 0.28%(1/356)and 5.92%(25/422)of all vaccinees andcontrols in the 14 villages,respectively.The protective efficacy of vaccines was 95.27%(95% Cl:85.83%-104.72%).In subjects testedfor anti-HAV IgM from 13 villages,1(0.40%)overt and 11(4.06%)asymptomatic HAV caseswere found in 271 vaccinees,but 21(6.69%)ofovert and asymptomatic ones were found in 314controls.CONCLUSION H2 strain vaccines were excellent in preventing overt hepatitis A, but not so effective in preventing asymptomatic hepatitis A virus infection. A booster dose might be needed to get permanent reliable immunity.Yu Liang Zhao Zong Da Meng Zhi Yi Xu Jun Jie Guo Shao Ai Chai Cheng Gang Duo Xuan Yi Wang Jin Feng Yao Hong Bin Liu Shun Xiang Qi Hui Bin Zhu 2000World Journal of Gastroenterology2000,6,6:7
17Climate effects on an inland alpine lake in Xinjiang, China over the past 40 years显示文摘Inland lakes are important water resources in arid and semiarid regions. Understanding climate effects on these lakes is critical to accurately evaluate the dynamic changes of water resources. This study focused on the changes in Sayram Lake of Xinjiang, China, and addressed the effects of climate fluctuations on the inland lake based on long-term sequenced remote sensing images and meteorological data from the past 40 years. A geographic information system (GIS) method was used to obtain the hypsometry of the basin area of Sayram Lake, and estimation methods for evaporation from rising temperature and water levels from increasing precipitation were proposed. Results showed that: (1) Areal values of Sayram Lake have increased over the past 40 years. (2) Both temperature and precipitation have increased with average increases of more than 1.8℃ and 82 mm, respectively. Variation of the water levels in the lake was consistent with local climate changes, and the areal values show linear relationships with local temperature and precipitation data. (3) According to the hypsometry data of the basin area, the estimated lake water levels increased by 2.8 m, and the water volume increased by 12.9×10 8 m3 over the past 40 years. The increasing area of Sayram Lake correlated with local and regional climatic changes because it is hardly affected by human activities.HuiXia CHAI WeiMing CHENG ChengHu ZHOU ShangMin ZHAO HaiJiang LIU 2013Journal of Arid Land2013,5,2:7
18Intelligent optimal control system for ball mill grinding process显示文摘Operation aim of ball mill grinding process is to control grinding particle size and circulation load to ball mill into their objective limits respectively, while guaranteeing producing safely and stably. The grinding process is essentially a multi-input multi-output system (MIMO) with large inertia, strong coupling and uncertainty characteristics. Furthermore, being unable to monitor the particle size online in most of concentrator plants, it is difficult to realize the optimal control by adopting traditional control methods based on mathematical models. In this paper, an intelligent optimal control method with two-layer hierarchical construction is presented. Based on fuzzy and rule-based reasoning (RBR) algorithms, the intelligent optimal setting layer generates the loops setpoints of the basic control layer, and the latter can track their setpoints with decentralized PID algorithms. With the distributed control system (DCS) platform, the proposed control method has been built and implemented in a concentration plant in Gansu province, China. The industrial application indicates the validation and effectiveness of the proposed method.Dayong ZHAO Tianyou CHAI 2013控制理论与应用(英文版)2013,11,3:7
19Enhanced dewatering characteristics of waste activated sludge with Fenton pretreatment: effectiveness and statistical optimization显示文摘在这个工作,废物的提高的 dewaterabing 特征用 Fenton 激活污泥预告的处理以有效性和统计优化被调查。反应表面方法( RSM )和中央合成设计(电荷耦合器件)被使用评估并且优化重要运作的参数的有效性,即, H <潜水艇class=“ a-plus-plus ”> 2 O <潜水艇class=“ a-plus-plus ”> 2 集中, Fe <啜class=“ a-plus-plus ”>2+集中和起始的 pH 价值。一个重要二次的多项式模型被获得(R < 啜 class= “ a-plus-plus ” > 2 = 0.9189 ) 与毛状的吸时间(CST ) 减小效率作为反应。数字优化基于愿望功能被执行。为 H 的最佳价值 < 潜水艇 class= “ a-plus-plus ” > 2 O < 潜水艇 class= “ a-plus-plus ” > 2 , Fe < 啜 class= “ a-plus-plus ” >2+, 和起始的 pH 被发现是 178 mg??Guangyin ZHEN Xueqin LU Baoying WANG Youcai ZHAO Xiaon CHAI Dongjie NIU Tiantao ZAO 2014Frontiers of Environmental Science & Engineering2014,8,2:7
20Obstacle avoidance for a hexapod robot in unknown environment显示文摘Obstacle avoidance is quite an important issue in the field of legged robotic applications, such as rescuing and detecting in complicated environment. Most related researchers focused on the legged robot’s gait generation after ssuming that obstacles have been detected and the walking path has been given. In this paper we propose and validate a novel obstacle avoidance framework for a six-legged walking robot Hexapod-III in unknown environment. Throughout the paper we highlight three themes: (1) The terrain map modeling and the obstacle detection; (2) the obstacle avoidance path planning method; (3) motion planning for the legged robot. Concretely, a novel geometric feature grid map (GFGM) is proposed to describe the terrain. Based on the GFGM, the obstacle detection algorithm is presented. Then the concepts of virtual obstacles and safe conversion pose are introduced. Virtual obstacles restrict the robot to walk on the detection terrain. A safe path based on Bezier curves, passing through safe conversion poses, is obtained by minimizing a penalty function taking into account the path length subjected to obstacle avoidance. Thirdly, motion planning for the legged robot to walk along the generated path is discussed in detail. At last, we apply the proposed framework to the Hexapod-III robot. The experimental result shows that our methodology allows the robot to walk safely without encountering with any obstacles in unknown environment.CHAI Xun GAO Feng QI ChenKun PAN Yang XU YiLin ZHAO Yue 2017Science China(Technological Sciences)2017,60,6:7
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