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Evaluation of Driver-Induced Human Errors in Smart Construction Tower Crane Operations Based on DEMATEL-ISM-MICMAC
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作者 Jiahao Wang Wen Si 《Journal of Applied Mathematics and Physics》 2024年第4期1541-1556,共16页
With the advent of Industry 4.0, smart construction sites have seen significant development in China. However, accidents involving digitized tower cranes continue to be a persistent issue. Among the contributing facto... With the advent of Industry 4.0, smart construction sites have seen significant development in China. However, accidents involving digitized tower cranes continue to be a persistent issue. Among the contributing factors, human unsafe behavior stands out as a primary cause for these incidents. This study aims to assess the human reliability of tower crane operations on smart construction sites. To proactively enhance safety measures, the research employs text mining techniques (TF-IDF-Truncated SVD-Complement NB) to identify patterns of human errors among tower crane operators. Building upon the SHEL model, the study categorizes behavioral factors affecting human reliability in the man-machine interface, leading to the establishment of the Performance Shaping Factors (PSFs) system. Furthermore, the research constructs an error impact indicator system for the intelligent construction site tower crane operator interface. Using the DEMATEL method, it analyzes the significance of various factors influencing human errors in tower crane operations. Additionally, the ISM-MICMAC method is applied to unveil the hierarchical relationships and driving-dependent connections among these influencing factors. The findings indicate that personal state, operating procedures, and physical environment directly impact human errors, while personal capability, technological environment, and one fundamental organizational management factor contribute indirectly. . 展开更多
关键词 Text Mining DEMATEL-ISM-MICMAC Performance Shaping Factors Smart Construction Tower crane Operator
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Number and distribution of cranes wintering at Poyang Lake,China during 2011-2012 被引量:16
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作者 李凤山 吴建东 +1 位作者 James HARRIS James BURNHAM 《Chinese Birds》 2012年第3期180-190,共11页
Poyang Lake is a very important wintering place for cranes in China and East Asia.Two crane surveys were conducted at Poyang Lake during the 2011/2012 winter,the first on 18-19 December 2011 and the second on 18-19 Fe... Poyang Lake is a very important wintering place for cranes in China and East Asia.Two crane surveys were conducted at Poyang Lake during the 2011/2012 winter,the first on 18-19 December 2011 and the second on 18-19 February 2012.The survey covered the entire Poyang Lake basin,as well as two main lakes in Jiujiang (Saicheng Hu and Chi Hu),i.e.,a total of 85 sub-lakes were surveyed.Both surveys recorded four species of cranes.The first survey on 18-19 December 2011 recorded 4577 Siberian Cranes (Grus leucogeranus),mostly in Bang Hu,Sha Hu and Dahu Chi,302 Hooded Cranes (G.monacha),885 White-naped Cranes (G.vipio) and 8408 Eurasian Cranes (G.grus),for the most part in the center of the lake basin.The second survey on 18-19 February 2012 recorded 3335 Siberian Cranes (mostly in Poyang Lake National Nature Reserve (PLNR) and its surrounding areas),110 Hooded Cranes (largely in PLNR and its surrounding areas),283 White-naped Cranes (86% in Bang Hu) and 2205 Eurasian Cranes (particularly in Duchang and Nanjishan NNR).The number of Siberian Cranes enumerated in December was 1000 more than the second count in February 2012.It is not possible to rule out double counting due to the close proximity of the main sites of the Siberian Cranes.During winters from 1998 to 2009,the average of the highest counts each winter was 3091,ranging from 2345 in 1996 to 4004 in 2002.By comparison with counts taken at other times,we therefore estimate a wintering population of Siberian Cranes of ~3800-4000 at Poyang Lake.Additional evidence will be needed to raise the world population estimate.Our more recent surveys indicate a continuing decline in the number of White-naped Cranes and an increase in Eurasian Cranes. 展开更多
关键词 crane survey Siberian crane Hooded crane White-napaed crane Eurasian crane wintering population
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Effects of diet shift on the gut microbiota of the critically endangered Siberian Crane 被引量:1
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作者 Wenjuan Wang Yafang Wang +1 位作者 Qing Chen Huifang Ding 《Avian Research》 SCIE CSCD 2023年第3期443-452,共10页
Wetlands worldwide have suffered from serious degradation and transformation,leading to waterbirds increasingly dependent on agricultural fields for feeding.Although gut microbiota is an essential component of host he... Wetlands worldwide have suffered from serious degradation and transformation,leading to waterbirds increasingly dependent on agricultural fields for feeding.Although gut microbiota is an essential component of host health,the impacts of agricultural feeding on gut microbial community and pathogen transmission remain poorly understood.To fill this knowledge gap,we used 16S rRNA sequencing to characterize the fecal bacterial community of the Siberian Crane(Grus leucogeranus),a Critically Endangered species,that recently has shifted its foraging from largely Vallisneria tubers in Poyang Lake natural wetlands to crops(i.e.,rice seeds and lotus rhizomes) in agricultural fields.We compared the bacterial communities between tuber foraging cranes and crop foraging cranes.Our results indicate that diet shift greatly modified the gut microbiota diversity,composition and function.Crop foraging cranes had higher microbiota diversity than tuber foraging cranes.The alteration in microbiota composition and function were correlated with change in food nutrition.Tuber(i.e.,high in fiber)foraging cranes were enriched in Clostridiaceae with fiber digestion ability,and crop(i.e.,high in carbohydrate)foraging cranes were enriched in bacterial taxa and functions related to carbohydrate metabolism.The flexibility of gut microbiota might enhance Siberian Cranes’ ability to adapt to novel diet and environment.However,many enriched families in crop foraging cranes were pathogenic bacteria,which might increase the susceptibility of cranes to pathogenic infection.Special caution should be taken to agricultural feeding waterbirds in Asia,where the widespread poultry-keeping in over-harvested rice fields might increase the transmission probability of pathogenetic bacteria among wild birds,domestic poultry and humans. 展开更多
关键词 Diet shift Pathogenic bacteria Poyang Lake Siberian crane Vallisneria tuber Wetland degradation
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Fecal DNA metabarcoding reveals the dietary composition of wintering Red-crowned Cranes(Grus japonensis)
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作者 Hongyi Liu Wei Xu +6 位作者 Nan Xu Wenwen Zhang Haoming Jiang Yongqiang Zhao Changhu Lu Ying Zhu Peng Xu 《Avian Research》 SCIE CSCD 2023年第4期647-655,共9页
Understanding the diet of threatened wildlife is vital for species-specific conservation and habitat management measures.The Red-crowned Crane(Grus japonensis)is a vulnerable bird distributed in Northeast Asia.Previou... Understanding the diet of threatened wildlife is vital for species-specific conservation and habitat management measures.The Red-crowned Crane(Grus japonensis)is a vulnerable bird distributed in Northeast Asia.Previous dietary studies of this bird focused mainly on its plant food composition based on field observations and microhistological identification.Herein,a total of 45 fecal samples were collected in November,December and January(15 fecal samples each month)from wintering cranes,and then subjected to a high throughput sequencing meta-barcoding approach to determine the primary plant(rbcL)and animal(COI)food items in their diet.A total of 230 operational taxonomic units(OTUs)of plant foods and 371 OTUs of animal foods were obtained.The main plant foods in the wintering period were Miscanthus,Zea,and Hordeum genera,which were similar to those in the breeding and the migration periods.Both agricultural and natural plants were detected,indicating a relatively broad dietary niche for this crane species.However,the main animal foods were representatives of Theridiidae,Megascolecidae,and Agelenidae,in sharp contrast to previous studies.The higher number of small terrestrial arthropods in animal foods might be due to the indirect intake of plants.The composition of both plant and animal foods in the diet showed the highest diversity in December,while it was homogeneous in January.The plant of Zea genus became the main source of nutrition in late winter,as supplementary feeding was performed in the reserve,which could help Red-crowned Cranes to get through the cold season.The results obtained in this work would contribute to the development of effective conservation strategies for the Red-crowned Crane. 展开更多
关键词 Dietary composition Dietary niche Metabarcoding Molecular diet analysis Red-crowned crane
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Rehabilitation of Overhead Crane in HPP
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作者 Nannan Qu Yonggang Si +2 位作者 Fupeng Zheng Zhi Chen Jiuqiang Huang 《Modern Electronic Technology》 2023年第2期7-12,共6页
This paper presents a case study on the repair of a mechanical component of an overhead crane.The problem was initially identified through on-site inspection and analysis of the crane’s performance.The mechanical par... This paper presents a case study on the repair of a mechanical component of an overhead crane.The problem was initially identified through on-site inspection and analysis of the crane’s performance.The mechanical part was found damaged,leading to safety concerns and operational inefficiencies.The paper details the process of diagnosing the issue,developing a repair plan,and executing the repair work.The repair plan involved replacing the damaged component with a new one and conducting additional maintenance work to ensure optimal performance.The paper also discusses the outcomes of the repair work,which led to improved safety and increased efficiency of the overhead crane.The case study provides insights into the importance of regular maintenance and on-site inspections in ensuring the safe and efficient operation of mechanical systems. 展开更多
关键词 Mechanical component Overhead crane Operational inefficiencies
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Impact of marsh changes on breeding cranes in Sanjiang Plain,northeastern China 被引量:1
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作者 江红星 钱法文 +5 位作者 刘春悦 李晓民 侯韵秋 张国钢 戴铭 刘冬平 《Chinese Birds》 2012年第3期165-179,共15页
In order to measure the impact of changes in the marsh on breeding Red-crowned Cranes (Grus japonensis) and White-naped Cranes (G.vipio) in the Sanjiang Plain,we conducted a complete crane súrvey in each of the s... In order to measure the impact of changes in the marsh on breeding Red-crowned Cranes (Grus japonensis) and White-naped Cranes (G.vipio) in the Sanjiang Plain,we conducted a complete crane súrvey in each of the summers of 2007 and 2008,and obtained information on the changes in its marsh through interpretation of satellite images in 1986,1995,2000 and 2005.A comparison between the 1984 and 2008 census shows that:1) the number of Red-crowned Cranes remained stable at about 300 birds,while the number of White-naped Cranes increased markedly; 2) the estimates of nests of Red-crowned cranes are close to the numbers of 1984,while approximately 90% of the nests of these two crane species were distributed over five national nature reserves (NNRs); 3) the two crane species became more concentrated in three regions,i.e.,the Fuyuan Delta,the middle reaches of the Naoli and Qixing rivers,and the Xingkai Lake wetlands,rather as formerly in six regions.The area of the marsh decreased by 45% within the 20-year period from 1986 to 2005.The major loss of the marsh area was in the form of a conversion to paddy fields and dry land,which can be primarily attributed to direct human activity under various economic and policy drivers.The disappearance of cranes in the Dulu and Abuqin rivers was induced by large-scale agricultural development.The fragmentation into and isolation of small areas of the marsh became increasingly more serious,which resulted in unsuitable condtions for crane breeding in small patches of the marsh.The number of cranes declined from 1984-1995 but had recovered remarkably by 2008,which may be due to theestablishment of a system of nature reserves,in place since 2000.The land ownership of the reserve plays a key role in maintaining the integrity of the wetland ecosystem,especially in Sanjiang,Honghe,Naolihe and Qixinghe NNRs,which together accommodated approximately 80% of the population of cranes.However,we did not discover any nests at all in the provincial and municipal reserves,which may be attributed to high human disturbances in these areas.In the end,we propose some recommendations on reserve management. 展开更多
关键词 Red-crowned crane White-naped crane BREEDING population size marsh change habitat loss Sanjiang Plain
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Biological Status of Captive Crane in Southern Districts of Northern Pakistan
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作者 Farzana Perveen 《Journal of Life Sciences》 2012年第3期304-311,共8页
A study was aimed to overlook biological status including egg hatching, diet and diseases of common, Grus grus L. and demoiselle, Anthropoidedes virgo L. cranes in captive form in the southern districts of the Norther... A study was aimed to overlook biological status including egg hatching, diet and diseases of common, Grus grus L. and demoiselle, Anthropoidedes virgo L. cranes in captive form in the southern districts of the Northern Pakistan. Field survey, questionnaire and interview with communities were the major tools for the data collection. Total 165 and 85 camps were visited, respectively, in fall, 2008 and spring, 2009. These camps were established in Baran dam, Kurram, Kashu, Kethu and Dowa in Bannu; and Gambilla, Lunder and Chall rivers in Lakki. The numbers of 1,650 hunters have 6,600 demoiselle and 3,300 common captive cranes in Bannu and Lakki, respectively. From 920 breeding pairs, 900 eggs were obtained, from which only 640 were hatched. Among natural foods of the cranes, snails, grasshoppers and earthworms, the pebbles were the most favorite foods. The young ones of cranes were fed on maize bread, eggs of insects and other small animals like wasp's larvae and grasshoppers by hunters. They faced the problems of development of feathers, trapping in mud and parasitic attack during their development. The cranes suffered from many diseases; head tumor, influenza and stomach blockage were the most common in the adults and young ones. The hunters used traditional things, garlic, coriander and brown sugar with antibiotics for treatments of diseases. Migratory cranes were found to be declining viewed by hunters in southern districts of Northern Pakistan. Knowledge about egg hatching, foods and diseases of common and demoiselle captive cranes, might be assisted in their conservation. 展开更多
关键词 Biological status captive cranes common cranes demoiselle crane endangered species Northern Pakistan.
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Fatigue behavior of crane beam strengthened with CFRP 被引量:2
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作者 石启印 李爱群 惠卓 《Journal of Southeast University(English Edition)》 EI CAS 2007年第4期561-565,共5页
In order to study the fatigue behavior of the damaged reinforced concrete (RC) beams strengthened by carbon fiber reinforced polymer (CFRP) laminate, three T-shaped beams strengthened by CFRP and one contrasting b... In order to study the fatigue behavior of the damaged reinforced concrete (RC) beams strengthened by carbon fiber reinforced polymer (CFRP) laminate, three T-shaped beams strengthened by CFRP and one contrasting beam are tested under fatigue loading, with the parameters of different modes of strengthening and different fatigue load levels considered. The main results obtained from the tests are: the width of the crack decreases 50. 2% to 66%, and the development of the crack is limited; the stress of steel decreases 24. 1% to 28. 2%, and the stiffness increases 14.9% to 16. 1% after being strengthened. Based on the technical specification for strengthening concrete structures with CFRP and the conclusions from the tests, a calculating scheme of the flexure stiffness is given, which can be used for reference in engineering design. Finally, some suggestions are given for design in fatigue strengthening. 展开更多
关键词 RC crane beam structure strengthening fatigue test carbon fiber reinforced polymer (CFRP)
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Effects of human disturbance on the Hooded Crane (Grus monacha) at stopover sites in northeastern China 被引量:7
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作者 罗金明 王永洁 +1 位作者 杨帆 刘志军 《Chinese Birds》 2012年第3期206-216,共11页
There is a lack of information of whether the behavior pattern and physical condition of the Hooded Crane (Grus monacha) have been limited by conditions encountered at stopover sites in Changgou village,which is adjac... There is a lack of information of whether the behavior pattern and physical condition of the Hooded Crane (Grus monacha) have been limited by conditions encountered at stopover sites in Changgou village,which is adjacent to Zhalong Nature Reserve in northeastern China,one of the most important stopover sites of this crane.The objective of our research was to investigatethe impact of human-caused disturbances on the Hooded Cranes.We investigated three behavior activities of the Hooded Cranes,i.e.,flying time,flushing distance and the duration of vigilance.The results indicate that the auditory stimuli caused by local people provoked the most pronounced disturbances to the Hooded Crane.Human-caused disturbances not only frequently interrupt the feeding process of the cranes,but also lead to an increase of 200% in the duration of their vigilance and a significant increase in flying time from 0.4 to 0.7 h (p < 0.05).In addition,high-intensity noise can cause larger flushing distances; foraging cranes will flush away by about 600 m when disturbed by the honking of vehicles.Whistles or shouts by local farmers in the field generated the largest sound intensity,about 120 dB,which caused a flushing distance of over 700 m.In order to reduce the negative effect of human-caused disturbances on these cranes,it is imperative to define a buffer zone around sensitive areas during the fall stopover period.To solve the conflict between the interest of farmers and the demand for crops on the part of the cranes requires financial compensation to the farmers for the crops consumed by the Hooded Crane in order to enhance the conservation of this vulnerable bird species. 展开更多
关键词 migratory cranes foraging performance bahavior pattern flushing distance
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起重机专用445/80R25 ETCRANE工程机械轮胎有限元优化设计及产品性能改善
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作者 印海建 孟庆伟 +2 位作者 潘国徽 孙熙林 刘本鑫 《轮胎工业》 CAS 2023年第11期659-663,共5页
针对高速场景下起重机轮胎胎肩脱层、生热问题,运用有限元分析方法建立纵向花纹445/80R25工程机械轮胎有限元分析模型,进行数值分析和优化及产品性能改善。通过对比分析原始方案轮胎刚性和接地数据的仿真结果与实测结果,验证有限元模型... 针对高速场景下起重机轮胎胎肩脱层、生热问题,运用有限元分析方法建立纵向花纹445/80R25工程机械轮胎有限元分析模型,进行数值分析和优化及产品性能改善。通过对比分析原始方案轮胎刚性和接地数据的仿真结果与实测结果,验证有限元模型的准确性;优化胎肩部位材料分布,在此基础上采用不同带束层结构方案对胎肩部位受力进行有限元分析,优化带束层端点受力状态。结果表明:胎肩和胎里曲线优化后的B3带束层方案(1^(#)—4^(#)带束层宽度分别为165,103,138和123mm)轮胎胎肩部位受力状态最优,达到改善设计目标;B3方案轮胎的耐久性能比原始方案轮胎提升17%,接地印痕矩形率增大,耐磨性能提升;海外目标客户测试显示,B3方案轮胎早期行驶10000km无胎肩脱层问题,达到改善目标。 展开更多
关键词 起重机轮胎 工程机械轮胎 胎肩脱层 生热 有限元分析
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Population sizes and group characteristics of Siberian Crane(Leucogeranus leucogeranus) and Hooded Crane(Grus monacha) in Poyang Lake Wetland 被引量:3
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作者 Ming-Qin SHAO Hong GUO +1 位作者 Jian-Hong JIANG 《Zoological Research》 CAS CSCD 北大核心 2014年第5期373-379,共7页
Both the Siberian Crane(Leucogeranus leucogeranus) and Hooded Crane(Grus monacha) have limited population sizes and are considered endangered by domestic Chinese and international agencies.To document the current size... Both the Siberian Crane(Leucogeranus leucogeranus) and Hooded Crane(Grus monacha) have limited population sizes and are considered endangered by domestic Chinese and international agencies.To document the current size of their respective populations and characterize their groups,between October 2012 and April 2013 we undertook fieldwork at four nature reserve areas within the Poyang Lake wetlands.We divided Poyanghu National Nature Reserve(PYH) into the Wucheng(PWC) and Hengfeng areas(PHF),because each are each located in different counties.Our fieldwork showed that the Siberian Crane occurred mainly in PYH(364 in the PHF,158 in the PWC) and the Nanjishan Wetland National Nature Reserve(NJS,with 200 individuals).The Hooded Crane was mainly distributed in PYH(302 in the PHF and 154 in the PWC).Family groups accounted for more than 50% of the total number of groups among both species,with Hooded Cranes forming more family groups than Siberian Cranes.Typically,these groups were formed of two adults with one offspring(Siberian Crane),and two adults with two offspring(Hooded Crane),with the mean family group size of the Siberian Crane and Hooded Crane being respectively 2.65±0.53(n=43) and 3.09±0.86(n=47) individuals per group.The mean collective group size of the Siberian Crane and Hooded Crane included 28.09±24.94(n=23) and 28.94±27.97(n=16) individuals per group,respectively,with the proportion of juveniles among Hooded Cranes being more than double that seen among the Siberian Cranes. 展开更多
关键词 Siberian crane Hooded crane Group characteristics Poyang Lake wetland
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ROBOTIC DYNAMIC MODEL ON LOAD SWING OF SLEWING CRANE 被引量:1
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作者 王帮峰 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2000年第1期10-14,共5页
This paper sets up a robotic manipulator model on slewing crane. The model can synthetically describe the dynamic behavior of the load of slewing crane in rotating, elevating and hoisting motions. The dynamic equation... This paper sets up a robotic manipulator model on slewing crane. The model can synthetically describe the dynamic behavior of the load of slewing crane in rotating, elevating and hoisting motions. The dynamic equations of the system are recursively derived by a Newton Euler method. The dynamic behavior of the load of slewing crane in rotating motion is simulated on a computer. The method of robotic dynamics to derive the dynamic equations of the swing of load is accurate and convenient and it has good regularity. The result of the study provides a base in theory on design of crane and an accurate mathematical model for controlling the swing of load. 展开更多
关键词 ROBOT crane dynamics modeling swing of load computer simulation
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Suitable distance to observe Red-crowned Cranes:a note on the observer effect 被引量:4
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作者 李忠秋 《Chinese Birds》 2011年第3期147-151,共5页
In order to assess the effect of the observer distance on the behavior of Red-crowned Cranes (Grus japonensis),we studied their time budgets with a gradient of observer distances in Yancheng,China from December 2008 t... In order to assess the effect of the observer distance on the behavior of Red-crowned Cranes (Grus japonensis),we studied their time budgets with a gradient of observer distances in Yancheng,China from December 2008 to March 2009.Observer distance was classified into four levels,i.e.,< 200 m,200-300 m,300-400 m and > 400 m.The results indicated that cranes increased their vigilance when the observer was less than 300 m away.A safe distance for the observer was often as far as or more than 300 m.Cranes increased scan frequency when observers were within 200 m,whereas they prolonged the duration of their scan when observers were between 200 m and 300 m away,indicating two distinct vigilant strategies,given the observer distance.We suggest an observer distance of at least 300 m,in order to minimize the observer effect. 展开更多
关键词 crane observer distance observer effect VIGILANCE
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Status and behavior of the Black-necked Crane (Grus nigricollis) in the Altun Mountain Reserve,Xinjiang
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作者 张同 马鸣 +2 位作者 丁鹏 徐峰 Paul J.BUZZARD 《Chinese Birds》 2012年第3期199-205,共7页
The Black-necked Crane (Grus nigricollis) is an endemic species of the Qinghai-Tibetan Plateau,with its population in Xinjiang largely found in the Kunlun and Altun mountain regions.A survey of the distribution,popula... The Black-necked Crane (Grus nigricollis) is an endemic species of the Qinghai-Tibetan Plateau,with its population in Xinjiang largely found in the Kunlun and Altun mountain regions.A survey of the distribution,population dynamics,flock size and behavior was conducted in Altun Mountain National Natural Reserve from September to November 2011.We investigated the size and distribution of its population in this area with a sample spot survey and by direct counting.We found Black-necked Cranes on the wetlands of Wuzunxiaoer,Yusup Aleksei,Yaziquan,Qimantag,Tula Ranch and elsewhere,where we recorded 126 individual birds of the species in Yixiekepati (37° 15′-37°23′N,90°11′-90°20′E,elevation 3903 m),the largest population we have observed in this area.In the reserve,the population consists of about 180-200 birds.Combined with previous records,we conclude that more than 260 Black-necked Cranes live in Xinjiang.Cranes gathered conspicuously in the middle of October where the highest number of birds appeared on 29 October.All of the cranes had migrated out of this area by 6 November.Time budgets and diurnal behavior rhythms of Blacknecked Cranes were observed in the Yixiekepati wetland at daylight (from 06:00 to 18:00).Foraging was the most prevalent type of behavior during the autumn period,accounting for 58.9% of the diurnal time budget,followed by preening (13.2%),vigilance (9.5%),walking (8.2%),flying (3.5%),resting (3.4%),chirping (2.7%) and other types of behavior (0.6%). 展开更多
关键词 Black-necked crane Grus nigricollis distribution population size behavior rhythm XINJIANG
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On Naturalism in Stephen Crane's The Open Boat
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作者 王秀红 陈贝贝 《海外英语》 2014年第17期212-217,共6页
Stephen Crane is one of the greatest figures in the history of American literature and his novella The Open Boat is widely known by people all over the world as a representative work of Naturalism. This paper aims at ... Stephen Crane is one of the greatest figures in the history of American literature and his novella The Open Boat is widely known by people all over the world as a representative work of Naturalism. This paper aims at exploring Naturalism in Stephen Crane's The Open Boat,which will guide the readers to understand American Naturalism accurately and thoroughly. It firstly introduces the author and his novel The Open Boat. Secondly,it progressively dissects Naturalism. It not only analyses the general characteristics of Naturalism with details in The Open Boat,but also interprets the distinguishing features of American Naturalism so that readers can better understand the features of American Naturalism. Through textual perusal,it further studies the unique characteristics of Stephen Crane's Naturalism and lays particular emphasis on Crane's special concern on the awakening of humanity. It is hoped that this thesis can help readers get an in-depth comprehension of Naturalism and gain some inspiration from TheOpenBoat. 展开更多
关键词 NATURALISM Stephen crane the OPEN BOAT
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Detection of mechanical stress in the steel structure of a bridge crane
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作者 Leopold Hrabovsky Daniel Cepica Karel Frydrysek 《Theoretical & Applied Mechanics Letters》 CSCD 2021年第6期320-329,共10页
A significant negative aspect in the operation of bridge-type cranes are the technical problems associated with wear of the wheels and the crane track,which causes crane skewing.The main causes of crane skewing includ... A significant negative aspect in the operation of bridge-type cranes are the technical problems associated with wear of the wheels and the crane track,which causes crane skewing.The main causes of crane skewing include unevenness of the crane track,unequal loading of the traction drives depending on the position of the crane trolley,slips and different sizes of travel wheels and combinations of these causes.Firstly,this paper presents a design solution that can be used to detect the magnitude of mechanical stress and deformation of the steel structure of the crane,caused by the effects of skewing.The mechanical stress generated by the transverse forces of the deformed geometric shape of the crane bridge structure is recorded by mechanical stress detectors installed in the inner corners of the crane bridge.The resulting electrical signal from element mechanical voltage detectors,loaded by axial forces,can be used for feedback control of separate crane travel drives controlled by frequency converters.Secondly,this paper presents the calculation of the lateral transverse forces according to CSN 270103 and the determination of the values of mechanical stresses of the deformed steel structure of the crane bridge of a two-girder bridge crane using the finite element method in the program MSC.MARC 2019.Finally,this paper presents the structural and strength design of mechanical stress detectors and the conclusions of laboratory tests of axial force loading of mechanical stress detectors on the test equipment.At the same time,it presents records of the measured axial forces acting in the mechanical stress detectors,arising from the deformation and warping of the crane bridge by the known magnitude of the axial force acting on the crossbeam and from the deformation of the crane bridge caused by the crane operating modes. 展开更多
关键词 crane skewing Mechanical stress detector Mechanical stress FEM Overhead crane
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Habitat utilization and resource partitioning of wintering Hooded Cranes and three goose species at Shengjin Lake 被引量:11
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作者 赵凤婷 周立志 徐文彬 《Chinese Birds》 CSCD 2013年第4期281-290,共10页
The loss and degradation of wetlands have adversely affected waterbirds, which depend on wetland habitats. Interspecific competition has an important effect on habitat utilization of wintering waterbirds. Resource uti... The loss and degradation of wetlands have adversely affected waterbirds, which depend on wetland habitats. Interspecific competition has an important effect on habitat utilization of wintering waterbirds. Resource utilization, including partitioning, in degraded wetlands has become a hot issue in ecological studies of wintering waterbirds. In order to have an insight into the habitat utilization and resource partitioning between a Hooded Crane(Grus monacha) population and the guild of three goose species, i.e., Anser fabalis, A. albifrons and A. erythropus wintering in lake wetlands, we carried out a study at Shengjin Lake National Nature Reserve from November 2011 to April 2012. We surveyed the Hooded Cranes and goose guild foraging in various habitats during the wintering periods with a combined method of fixed route searching and fixed site observations. Resource partitioning was studied by means of calculating habitat utilization rates and the width and overlap of spatial niches. The results showed that the habitat utilization rate and the width of spatial niches of the Hooded Crane population and goose guild shifted with the season. The habitat utilization rates of the cranes in grasslands were high at all three wintering stages. The habitat utilization rates were 0.454, 0.435 and 0.959 respectively for the Hooded Cranes and 0.627, 0.491 and 0.616 for the goose guild. This suggests that the overlap in grasslands was higher between cranes and goose guild. Most habitats were accessible at the middle stage, so the width of the spatial niche of the cranes(1.099) and goose guild(1.133) both reached their peak at this stage. The greatest niche overlap was 0.914 for these two groups at the late stage, followed by 0.906 at the middle stage and the smallest was 0.854 at the early stage. Ecological response to the changes in habitats of wintering waterbirds was clearly shown in the dynamic variations of the niche of both the Hooded Cranes and the three goose species. Coexistence among waterbirds was achieved by regulation of niche width to reduce niche overlap and relieve interspecific resource partitioning. 展开更多
关键词 habitat utilization NICHE wintering ecology Hooded crane(Grus monacha) goose guild
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Pressure from hunting on crane species in southern districts of northern Pakistan
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作者 Farzana PERVEEN Hafeez Ullah KHAN 《Chinese Birds》 2010年第4期244-250,共7页
This study was carried out to assess the biological status of two crane species, the Common Crane (Grus grus L.) and the Demoiselle Crane (Anthropoides virgo L.), with respect to the hunting pressure in two southern d... This study was carried out to assess the biological status of two crane species, the Common Crane (Grus grus L.) and the Demoiselle Crane (Anthropoides virgo L.), with respect to the hunting pressure in two southern districts of northern Pakistan, Bannu and Lakki. Field surveys, interviews and questionnaires were the major tools for data collection. We visited 165 hunting camps in the fall of 2008 and 85 in the spring of 2009 in the two districts. Of the hunters, most possessed wildlife permits for hunting and most people hunted for recreation. According to our survey, the population of two crane species is declining due to overhunting, destruction of natural habitats, anthropogenic activities and geographical factors. Suggestions for protection of the cranes are proposed. 展开更多
关键词 Common crane Demoiselle crane HUNTING CONSERVATION northern Pakistan
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海洋平台吊机iCrane自动控制模型 被引量:1
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作者 刘启蒙 孙传轩 +3 位作者 徐小鹏 冯文龙 蔡娟 张鹏飞 《石油机械》 2017年第3期71-74,共4页
为了促进海洋平台吊机产品系列化、自动化及信息化发展进程,针对多样化的海洋平台吊机产品,提出一种iCrane控制系统模型。描述了模型组成、功能和应用方法。介绍了载荷力矩指示、运动及调速、安全保护及报警等关键技术,并以一种常用的... 为了促进海洋平台吊机产品系列化、自动化及信息化发展进程,针对多样化的海洋平台吊机产品,提出一种iCrane控制系统模型。描述了模型组成、功能和应用方法。介绍了载荷力矩指示、运动及调速、安全保护及报警等关键技术,并以一种常用的海洋钻井平台配套吊机为控制对象设计开发了一套应用样机。样机在模拟试验和应用实例中取得了良好的效果。最后指出,在此模型下的各个层面和单元都集中体现海洋平台吊机系列化产品的自动化和信息化水平,并可积累大量宝贵的信息和数据资源,为将来实现油气装备大数据库管理打下坚实基础。 展开更多
关键词 海洋平台吊机 技术现状 icrane控制模型 关键技术 建议
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Pendulation reduction on ship-mounted container crane via T-S fuzzy model 被引量:9
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作者 JANG Jae Hoon KWON Sung-Ha JEUNG Eun Tae 《Journal of Central South University》 SCIE EI CAS 2012年第1期163-167,共5页
Ship-mounted container cranes are challenging industrial applications of nonlinear pendulum-like systems with oscillating disturbance which can cause them unstable.Since wave-induced ship motion causes the hoisted con... Ship-mounted container cranes are challenging industrial applications of nonlinear pendulum-like systems with oscillating disturbance which can cause them unstable.Since wave-induced ship motion causes the hoisted container to swing during the transfer operation,the swing motion may be dangerously large and the operation must be stopped.In order to reduce payload pendulation of ship-mounted crane,nonlinear dynamics of ship-mounted crane is derived and a control method using T-S fuzzy model is proposed.Simulation results are given to illustrate the validity of the proposed design method and pendulation of ship-mounted crane is reduced significantly. 展开更多
关键词 ship-mounted crane DISTURBANCE pendulation control T-S fuzzy model
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