Habitat selection and food choice of White-naped Cranes(Grus vipio)at stopover sites based on satellite tracking and stable isotope analysis

By combining satellite tracking,land-cover extracted from Landsite 8 images,and the traditional stable isotope analysis,we studied the habitat selection and food preference of a vulnerable migratory waterbird,the Whitenaped Crane(Grus vipio),in one of its key stagging sites,the Shandian River Basin in the semi-arid northern China,to provide knowledge that is critical for its conservation in the Anthropocene.Our results showed that the White-naped Cranes used both uplands and natural wetlands in the stopover site.While the cranes used farmland and natural land cover equally as night-time roosting grounds,they spent most daytime foraging at farmlands.Despite the extensive usage of croplands as their foraging ground,the Bayesian mixing models based on stable isotopic analysis revealed that crop residues after harvesting,such as Maize(Zea mays)and Naked Oat(Avena chinensis),were only a small fraction of the White-naped Cranes’diet(~19%),and their diet composited mainly natural plants,such as Allium ledebourianum,Potentilla anserina,and P.tanacetifoli.Moreover,more than 20%of the total wetlands in the region were modelled as home range of the cranes.On contrast,less than 10%of croplands and about 1%of the unused uplands were identified as home range.In addition,the entire core habitats were located in natural wetlands.Our findings demonstrated the importance of natural wetlands for the survival of the threatened crane.However,the satellite-derived land cover data showed that croplands increased rapidly in the last decade in this area,at the expense of natural wetlands.With the sharp decrease of White-naped Crane population in China,the conservation of stopover sites becomes imperative.Based on our analysis,we recommend the following management actions:conserving adequate natural wetland area,regulating anthropogenic pressures such as the use of herbicides,expanding the duration and extent of current conservation regulations,establishing a comprehensive monitoring program,and initiating basin-scale ecological restoration,for effective conservation of this threatened species.These integrated conservation strategies for migratory waterbirds are necessary,considering the rapid land-cover changes and agricultural expansion that have been occurring in East Asian-Australasian Flyway,especially in the semi-arid temperate zone.

Impact of marsh changes on breeding cranes in Sanjiang Plain,northeastern China

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.

Tower crane path planning based on improved ant colony algorithm

In order to solve the problem of path planning of tower cranes,an improved ant colony algorithm was proposed.Firstly,the tower crane was simplified into a three-degree-of-freedom mechanical arm,and the D-H motion model was established to solve the forward and inverse kinematic equations.Secondly,the traditional ant colony algorithm was improved.The heuristic function was improved by introducing the distance between the optional nodes and the target point into the function.Then the transition probability was improved by introducing the security factor of surrounding points into the transition probability.In addition,the local path chunking strategy was used to optimize the local multi-inflection path and reduce the local redundant inflection points.Finally,according to the position of the hook,the kinematic inversion of the tower crane was carried out,and the variables of each joint were obtained.More specifically,compared with the traditional ant colony algorithm,the simulation results showed that improved ant colony algorithm converged faster,shortened the optimal path length,and optimized the path quality in the simple and complex environment.

Evaluation of Driver-Induced Human Errors in Smart Construction Tower Crane Operations Based on DEMATEL-ISM-MICMAC

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. .

一种随机应力谱在线分析方法及其在冶金起重机疲劳损伤分析中的应用

冶金起重机工况复杂且长期连续进行吊装作业,其结构应力监测数据量大,连续周期长,使用常规的应力谱分析方法处理时会产生残波累积现象,导致结果准确性下降。针对此问题提出一种面向冶金起重机疲劳损伤评估的随机应力谱在线分析方法,首先采用阶跃式雨流计数法对实时生成的随机应力数据进行分段计数并且实时输出随机应力谱,当循环分段计数产生的残波累积到一定程度时,对残波进行二次融合计数,并将此计数结果加入随机应力谱中修正实时计数结果,提升计数精度并用于后续的疲劳损伤评估。采用S-N曲线结合Miner损伤理论分析阶跃式雨流计数实时产生的应力谱并计算疲劳寿命,形成面向疲劳损伤评估的随机应力谱在线分析方法。分别采用四点雨流计数与阶跃式雨流计数对随机应力谱数据进行仿真实验,结果表明阶跃式雨流计数精度达到常规雨流计数的99%。使用该随机应力谱在线分析方法分析某冶金起重机副主梁连接处测点应力数据集并计算该测点处的有效疲劳寿命,结果证明该随机应力谱在线分析方法能够有效提升冶金起重机疲劳评估的实时性,评估结果合理,对起重机长期安全维护可提供及时有效的可靠依据。

基于刚度折减法的岸边集装箱起重机结构损伤模拟

岸边集装箱桥式起重机是码头集装箱进行装卸的专业设备,其前大梁、梯形架和拉杆往往受到交变载荷、冲击载荷,且在露天码头环境下受到锈蚀、涂膜剥离、裂纹等故障的侵袭,这会对其结构的刚度产生较大影响。鉴于此,文中以岸边集装箱起重机为研究对象,提出了一种基于刚度折减法的岸边集装箱起重机损伤模拟方法 ,建立有限元模型对岸边集装箱起重机的前大梁、梯形架和拉杆分别进行损伤模拟,得到不同刚度折减程度下损伤状态的位移、应变等响应;同时,考虑到这3种损伤并不独立发生,采用正交试验方法基于该损伤模型对这3种损伤进行分组模拟,得到多损伤条件下的响应数据,从而进一步反映岸边集装箱起重机实际工况下的损伤规律。

Habitat utilization and resource partitioning of wintering Hooded Cranes and three goose species at Shengjin Lake

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.

Effects of human disturbance on the Hooded Crane (Grus monacha) at stopover sites in northeastern China

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.

Fatigue behavior of crane beam strengthened with CFRP

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.

Suitable distance to observe Red-crowned Cranes:a note on the observer effect

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.

ROBOTIC DYNAMIC MODEL ON LOAD SWING OF SLEWING CRANE

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.

Status and behavior of the Black-necked Crane (Grus nigricollis) in the Altun Mountain Reserve,Xinjiang

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％).

基于人机耦合模型和肌电实验的单轨吊车司机生物力学分析

针对单轨吊车井下运输的工作环境易导致司机驾驶疲劳的问题,提出了基于生物力学仿真和表面肌电实验的驾驶员操作舒适性分析方法。通过Anybody构建了驾驶员操作系统生物力学耦合模型,并对驾驶员操作过程中的疲劳特性进行了量化分析,结果表明:肱二头肌的肌肉激活度均值为0.171,肌肉力最大为106.9 N;腓肠肌的肌肉激活度为0.288,肌肉力最大为235.6 N;司机下肢整体疲劳程度大于上肢。肌电实验验证了仿真数据的准确性,相对误差小于15%,相关系数均超过0.966(P<0.05)。

船体异形分段吊码设置的要点分析

中大型船舶的建造正常都是以分段为单位按区域进行建造。考虑到船体线型、内部结构的布置和施工的方便性,分段划分的形状各异,建造方式也不同。分段建造完毕需要移送冲砂房进行抛丸除锈、根据船舶保护涂层标准(Performance Standard of Protective Coatings,PSPC)保护、喷涂防锈漆等,再运送至船台进行合拢。此过程中的安全起吊、侧翻和翻身等需要考虑的因素很多,特别是特殊形状的异形分段,这就要求分段吊码的设计必须非常谨慎。根据历来多种船型分段吊码的理论设计和现场经验进行分析,并归纳总结异形分段吊码设计的要点。研究结果可为后续不同建造方式和不同结构外形的分段吊码设计提供一定的参考依据。

On Naturalism in Stephen Crane's The Open Boat

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.

海洋平台吊机iCrane自动控制模型

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。

综合交通枢纽工程盖挖逆作法研究与应用

基于北京城市副中心站综合交通枢纽工程的特殊地理位置和地质条件,本项目采用盖挖逆作法进行地下建筑的施工。首先对地下结构工程的施工方法进行了概述,基于项目实际工程情况对盖挖逆作的施工重难点进行分析,确定了合理高效的盖挖逆作施工顺序;其次对盖挖逆作工程中的土方开挖技术、基坑降水施工技术、基坑监测技术等进行创新改进,提高了工程效率的同时保证了安全度。此外,针对盖挖逆作塔式起重机基础施工技术进行改进,采用钢管桩式混凝土承台塔式起重机基础。最后,在盖挖逆作技术基础上结合BIM和AR技术进行了创新应用,推动了盖挖逆作工程的现代化发展。

吊车梁设计CAD系统YJ-CRANEBEAM软件的研究开发

吊车梁普遍应用于工业厂房中。为方便设计人员计算吊车梁系统,研究开发出吊车梁设计CAD系统软件YJ-CRANEBEAM。它可以对简支吊车梁进行内力计算、截面自动选择或截面验算,对吊车梁节点、吊车梁制动系统进行设计;根据计算结果自动绘制施工图。

起重机检验中危险因素的识别与控制研究

随着工业的快速发展,起重机在各个领域的应用越来越广泛,如建筑工地、港口、工厂等。起重机的安全运行至关重要,一旦发生事故,可能会造成严重的人员伤亡和财产损失。起重机检验作为确保起重机安全运行的重要程序,其过程存在着多种危险因素。因此,对起重机检验中的危险因素进行识别与控制研究具有重要的现实意义。

茅台成义烧房旧址钢筋混凝土行车梁结构性能分析

为了深入研究茅台成义烧房旧址行车梁的结构性能,通过现场调研和有限元模型分析,揭示了行车梁在正常使用和极端荷载作用下的性能表现,发现其存在锈蚀、裂缝和变形等问题。针对这些问题,提出了采用同形制钢材更换和碳纤维布加固等创新措施,以提高行车梁的结构稳定性和承载能力。加固措施不仅适用于茅台成义烧房旧址,也为类似工业遗产的保护与利用提供了有益参考。研究成果为工业遗产改造工程提供了科学依据,有助于推动工业遗产保护工作的深入发展。