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％).

Population dynamics and habitat use of the Black-necked Crane (Grus nigricollis) in the Yarlung Tsangpo River basin, Tibet, China

Background:The Black-necked Crane (Grus nigricollis)is an internationally threatened crane living on the plateau, mainly in winter, in the Yarlung Tsangpo River basin in Tibet,western China. In the past five years,some economic development projects have been conducted in this area,posing potential threats to the wintering populations of the cranes and their habitats. Therefore, the current population dynamics of wintering Black-necked Cranes and habitat suitability in the Yarlung Tsangpo River basin were investigated. Methods: Twenty counties were surveyed using the line transect method in December 2017 and January 2018, and we recorded the location,flock size,number of individuals,habitat types and presence of human disturbance in which they occurred.We compared the results from the middle wintering period in this survey with those from 2014. Results: The highest number of cranes recorded was 8291,and the results showed that the cranes were mainly distributed in Lhaze, Namling, Samzhubze, and Lhunzub.A total of 577 and 495 flocks were recorded in the early and middle wintering periods, respectively. In the early wintering period,there were signi ficant differences in the number of individuals across the di fferent habitats,with crop stubble land and plowed land representing more than 30% of the total habitat utilization.In the middle wintering period, there were also signi ficant differences in the number of individuals, and the utilization of crop stubble land represented over 60% of the total. Conclusions: Wintering Black-necked Cranes mainly fed on spilled grains in stubble habitat after harvest. In the middle wintering period, some of the farmlands were plowed and irrigated,which resulted in food shortages in these areas,and the cranes tended to gather in mixed flocks of large size instead of as a single family.There were still considerable regional wintering populations decreases in Quxu,Nedong,and Sakya in 2018 compared with 2014,and these decreases were mainly due to some recently emerging threats,including farmlands being converted into areas of greenhouse cultivation,highway and railway construction, river dredging,the rapid development of the manufacturing and mining industries,and the lack of protection of important wintering sites.

Foraging habitat selection of overwintering Black-necked Cranes in the farming area surrounding the Caohai Wetland, Guizhou Province, China

Background: Understanding how overwintering birds choose foraging habitats is very important for conservation management. The overwintering Black-necked Crane(Grus nigricollis) feeds on crop remains in farmlands;thus, reasonable conservation management of this type of farmland that surrounds wetlands is critical for the overwintering populations of the Black-necked Crane;however, it is not clear how the Black-necked Crane chooses the foraging land in the farmland.Methods: A thorough field positioning survey of all foraging sites in farmland areas around the Caohai Wetland and a-sampling analysis of habitat selection by the Black-necked Crane were conducted during the winters from 20162017 and 2017-2018.Results: Multiple factors contributed to the selection of foraging habitat in farmlands, i.e., food factors(crop remains and tillage methods) > human disturbance factors(distance to road and settlement) > topography factors(slope aspect), listed according to the strength of influence. Additionally, Black-necked Cranes tend to choose farmland sites where there was no machine tillage, the crop remains were > 500 g/m^2, the distance to residences ranged from 100 to 500 m, the distance to roads ranged from 50 to 100 m, and the slopes exhibited western or eastern aspects. As the winters progressed, the volume of the edible crop remains declined, and the influences of the other main factors also changed, i.e., the factors of human disturbance(distance to road and settlement) became less important, while the effect of the food factor(crop remains) was strengthened. Thus, the foraging sites near the road became more important.Conclusion: The farming area surrounding the Caohai Wetland is very important for the overwintering Black-necked Crane. Food factors and human disturbance factors are the main factors that influence the choice of feeding ground.

Sequential vigilance is unpredictable in reproductive Black-necked Cranes

Background:Vigilance refers to the behavior of animals scanning their surroundings with a main purpose of antipredation.Whether vigilance can serve the function of anti-predation depends on its unpredictability,meaning instantaneous randomness,sequential randomness,and independence,the three assumptions from Pulliam model(J Theor Biol 38:419,1973).Here we tested two of these three assumptions in reproductive Black-necked Cranes(Grus nigricollis) in Tibetan Plateau:instantaneous randomness and sequential randomness.Methods:Observations were carried out in July and September of 2014,July and August in 2017 in Selincuo National Nature Reserve,Tibet,with the help of focal sampling method.For instantaneous randomness,we used Kolmogorov–Smirnov test for its negative exponential distribution;for sequential randomness,we used Run test,correlation analysis,and generalized linear model to see if an inter-scan and its previous scan were correlated.Results:Not similar to some recent studies,we did not find a significant predictable vigilance in this crane.Most inter-scan intervals(86/100,86.0%) passed negative exponential distribution test,meaning vigilance sequences with instantaneous randomness;most inter-scan intervals(91/100,91.0%) passed sequential random test,showing vigilance sequences were random organized.Conclusion:Our results suggest that keeping a vigilance pattern with unpredictability is beneficial to the survival of the Black-necked Cranes,which are facing with both cruel natural environments and high predation risks.

The Relationship of Black-necked Crane Migration to the Uplift of the Qinghai-tibetan Plateau

Bird migration is a seasonal movement between breeding and wintering grounds.Opinions are widely divided on the reasons for this movement.According to biological data including:geographic distribution,reproductive physiology,comparison of breeding and wintering habitats,geological data including Qinghai Tibetan Plateau uplift and Quatemary Period glaciation,it is inferred that bird migration is a survival mechanism,and that migration originated on the breeding grounds.

Speciation of Black-necked Crane

Based on the concepts of species and speciation,the speciation of Black necked Grane(Grus nigricollis) was discussed using bio geographic principles and some evidences suggest that Black necked Grane had a close relationship with Red crowned Crane(Grus japonensis).The Qinghai Tibetan Plateau uplift may be the most important factor in allopatric speciation for Black necked Crane.

Number and nest-site selection of breeding black-necked cranes over the past 40 years in the Longbao Wetland Nature Reserve,Qinghai,China

Black-necked crane(Grus nigricollis,BNC),facing serious threats from human activities and habitat variations,is an endangered species classified as vulnerable under the revised IUCN Red List.In this article,we investigated and analyzed the population and nesting microhabitat of BNCs in the Longbao National Nature Reserve(NNR)from 1978 to 2016,and found the number of BNCs increased from 24 in 1978 to 216 in 2016.This establishment of the Longbao NNR represented the activities of protecting endangered animal species are effective.However,the land cover classification results of Landsat images showed that the marsh wetland,which was the BNC’s primary habitat,decreased during 1978–2016,while artificial buildings increased,which affected the habitat of BNCs.The increase in average temperature over the past 40 years has also had an impact on the number of BNCs.BNCs preferred to nest in marsh wetlands or on islands with open water or star-like distributions through observation.The results of the principal component analysis showed that the nearest distance between nests and habitat type were the primary factors influencing nesting site selection.To protect BNC,we suggest decreasing wetland fragmentation,reducing habitat degradation and providing an undisturbed habitat.

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. .

Effects of diet shift on the gut microbiota of the critically endangered Siberian Crane

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.

Fecal DNA metabarcoding reveals the dietary composition of wintering Red-crowned Cranes(Grus japonensis)

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.

Rehabilitation of Overhead Crane in HPP

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.

融合Unity3D的缆索起重机安全运行数字孪生模型构建方法

为降低缆索起重机(下文简称为缆机)运行的安全风险,分析缆机运行流程,提取缆机安全运行知识语义,通过物联网技术获取实时数据,利用3DS Max软件构建大坝缆机运行初始场景,实现孪生模型三维可视化,将模型导入Unity3D引擎,使用高清渲染管线对模型进行渲染,改善视觉效果,编写C#脚本对缆机运行全过程进行安全模拟仿真。研究结果表明:应用本文所构建的缆机安全运行数字孪生模型监测隐患与故障,综合准确率达到96.7%,可有效实现缆机运行过程的安全监控、参数化控制以及可视化展示。研究结果可为缆机施工过程的安全控制提供技术支持。

轻量化系列桥式起重机结构分析

以轻量化桥式起重机为研究对象,分析了轻量化桥机各结构的特点及模块化、参数化设计方法的应用,并将研究成果与国内外知名企业轻量化桥机性能参数进行了对比。分析得出,司轻量化桥机系列采用了多配置互换技术,实现了标准产品快速模块化设计、定制化产品快速变形设计,国内国际市场上具备明显的竞争优势。

超高层建筑工程内爬塔式起重机附着提升拆除关键技术

内爬塔式起重机是适用于超高层建筑的一种大型设备,本研究介绍了内爬塔结构系统构造及爬升流程,通过设置支撑梁承受结构重力和塔式起重机设计荷载、设置液压油缸和内爬框架进行顶升操作,完成内爬塔结构提升。以小塔拆大塔为塔式起重机拆除原则,设计了两次屋面吊拆除过程,保障拆除工期和屋面结构安全。建立了支撑梁和内爬框架的三维实体有限元计算模型,优化支撑梁系统设计,得到了支撑梁和内爬框架在满载支撑状态下的应力和位移计算结果。结果表明,支撑系统安全可靠。

矿用单轨吊气动道岔的结构设计与研究

我国煤炭现代化高速发展,生产规模也日益增大,所需设备的自动化、机械化程度也越来越高,但使用的辅助运输系统却十分落后。为了克服上述困扰,提出了一种带有气动道岔的单轨吊辅助运输设备,能够克服卡轨车运输条件的限制,使得多条巷道能够连通使用。这种设备在多弯道、多起伏的巷道中具有较高的灵活性和适应性,对于优化运输环境、提升运输效率、确保运输安全具有重大的实际价值。其结构设计包含道岔部分,其中道岔部分主要由道岔直轨、弯轨和气缸构成。首先通过SOLIDWORKS进行三维建模,再通过ANSYS WORKBENCH对轨道部分进行有限元静力学分析,可以直观的呈现出轨道受力变形情况。

偶然性载荷作用下的桥式起重机摆角模型研究

对起重机建立准确的数学模型是研究其防摇摆控制策略的基础。构建在偶然载荷作用下桥式起重机摇摆数学模型,分析桥式起重机一个作业循环以及大小车运行时的受力情况,在充分考虑偶然载荷作用下构建桥式起重机工作过程中的三维动力学数学模型。通过在驱动力及风载作用下对模型的仿真分析,研究桥式起重机的摆角变化规律。桥式起重机在偶然载荷作用下的摆角模型及其变化规律可为后续桥式起重机的防摇摆控制提供理论基础,保证桥式起重机在偶然性载荷作用下工作安全可靠。

铸造起重机主梁应力测试与疲劳寿命研究

以某钢厂一台在用进口铸造起重机为研究对象,对起重机性能指标质量检测、主梁主要受力板材的无损探伤检测、主梁跨中关键部位的应力测试以及根据应力测试所得应力谱对主梁疲劳寿命进行分析估算,对设备目前的安全状况作出评估。

武汉青山长江公路大桥宽幅钢箱梁悬臂拼装横向线形匹配技术

武汉青山长江公路大桥主桥为主跨938 m的双塔双索面全飘浮体系斜拉桥,主跨整体式钢箱梁高4.5 m、全宽48 m,采用500 t架梁吊机分节段悬臂拼装架设。钢箱梁悬臂拼装时,架梁吊机站位节段、待架节段由于荷载及约束不同,横截面变形呈现出不同的趋势,线形匹配难度大。为解决该问题,主跨钢箱梁悬臂拼装时选择上、下游分体式架梁吊机,减少架梁吊机自重;经比选选择横桥向27.7 m间距的架梁吊机站位,减小了架梁吊机荷载对横向线形匹配的影响;通过设置顶压装置(由顶压牛腿、支承底座组成),在架梁吊机站位节段、待架节段钢箱梁边腹板处施加1500 kN顶压力,配合少量马板,一次加载完成对接口竖向变形匹配调整。施工后,钢箱梁横向线形匹配精度均满足要求。

面向起重机结构承载能力评估的数字孪生系统构建方法

针对当前起重机本质安全所面临的监测力度差、能力指标单一、数据利用率不高导致承载能力评估效率低、评估结果不够全面的问题,本着“虚实互控-互调-互补”的思想,提出面向起重机结构承载能力评估的数字孪生系统构建方法。从设备服役场景出发,结合数字孪生五维模型,设计起重机结构承载能力数字孪生框架;以多指标下的结构承载能力动态综合评估方法为支撑,围绕虚实映射、数据交互与服务交互,分层分级阐述结构承载能力数字孪生系统构建方法;从模块内聚,功能集成的角度,搭建数字孪生系统平台。以YDC20/30轻小型移动式起重机为例,验证了所提方法及系统的有效性,为及时精准判断起重机服役过程中的安全性提供了一种新途径、新策略。