The intrinsic developmental age signal defines an age-dependent climbing behavior in cucumber

The tendril is a climbing organ in cucurbits and functions in physical support and to avoid shading by neighboring vegetation.However,how cucurbits produce tendrils to obtain climbing ability is largely unknown.In this study,tendril phenotypes were investigated during different developmental stages.Our results revealed that tendril growth exhibited an age-dependent pattern in cucurbits.Tendril growth was inhibited,and the tendril was formed as a short tendril[nonfunctional tendril(nonF-tendril),approximately 0.1 cm]during the seedling stage.In contrast,enhanced cell proliferation and cell expansion led to rapid elongation of the tendril during the climbing stage,and the tendril formed as a functional tendril(F-tendril,approximately 30 cm)to obtain climbing ability.RT-qPCR detection showed that age-dependent tendril growth correlated negatively with the abundance of the conserved age regulator CsmiR156.Defoliation induced CsmiR156 to inhibit CsSPLs,and F-tendril formation and climbing ability were delayed in defoliated cucumbers,which confirmed the role of CsmiR156 in regulating tendril growth in vivo.Additionally,exogenous gibberellin(GA)treatment showed that GA positively regulated tendril growth,and RT-qPCR detection showed that the GA bio-synthetic genes and metabolic genes were affected by age pathway,suggesting that the age pathway depended on GA bio-synthetic and metabolic pathway to regulate cell expansion to determine tendril growth.In summary,our work reveals that change in tendril type is an important marker of phase transition in cucumber,and tendril growth is regulated by an intrinsic developmental age signal,ensuring that the cucumber obtains climbing ability at a suitable age.

Spatial heterogeneity and driving mechanism of urban climbing and its impact on regional environment in varied landform types in the middle reaches of the Yellow River

Urbanization research is essential for the sustainable use of regional land resources and ecological environment protection.The expansion process and driving factors of urban construction land at different scales in the middle reaches of the Yellow River(MRYR)have not been comprehensively elucidated.In this study,we explored the distribution pattern of urban construction land on different slope gradients at different scales and analyzed its influencing factors.The main findings were as follows:(1)There has been significant expansion of urban construction land in the MRYR over the past 20 years.Spatial heterogeneity was observed in the regional urban construction land expansion process among different geomorphic regions.(2)The urban construction land in the MRYR was expanded vertically to areas with slopes of>5°,particularly in 2005–2010.Significant slope climbing of urban construction land was observed in the loess hilly-gully and rocky mountain areas.(3)In MRYR,68.45%of the counties were categorized as the slope-climbing types,including 37.38%high-slope-climbing types.(4)The regional population density and economic development level were closely associated with regional urban construction land area variability.(5)The climbing process of regional urban construction can effectively alleviate farmland encroachment and pressure on the regional ecological environment.The urban expansion of the metropolitan distribution areas in the Plain region(such as Xi'an,Taiyuan)had a relatively significant impact on the local carbon storage.

Stair climbing,genetic predisposition,and the risk of incident type 2 diabetes:A large population-based prospective cohort study

Background:Cross-sectional evidence and small-scale trials suggest positive effects of stair climbing on cardiometabolic disease and glucose regulation.However,few studies have examined the long-term association between stair climbing and the incidence of type 2 diabetes(T2D).We aimed to prospectively evaluate the association of stair climbing with T2D and assess modifications by genetic predisposition to T2D.Methods:We included 451,699 adults(mean age=56.3±8.1 years,mean±SD;55.2%females)without T2D at baseline in the UK Biobank and followed up to March 31,2021.Stair climbing information was collected through the touchscreen questionnaire.Genetic risk score for T2D consisted of 424 single nucleotide polymorphisms.Results:During a median follow up of 12.1 years,14,896 T2D cases were documented.Compared with participants who reported no stair climbing,those who climbed stairs regularly had a lower risk of incident T2D(10-50 steps/day:hazard ratio(HR)=0.95,95%confidence interval(95%CI):0.89-1.00;60-100 steps/day:HR=0.92,95%CI:0.87-0.98;110-150 steps/day:HR=0.86,95%CI:0.80-0.91;>150 steps/day:HR=0.93,95%CI:0.87-0.99,p for trend=0.0007).We observed a significant interaction between stair climbing and genetic risk score on the subsequent T2D risk(p for interaction=0.0004),where the risk of T2D showed a downward trend in subjects with low genetic risk and those who reported stair climbing activity of 110-150 steps/day appeared to have the lowest overall T2D risk among those with intermediate to high genetic risk.Conclusion:A higher number of stairs climbed at home was associated with lower T2D incidence risk,especially among individuals with a low genetic predisposition to T2D.These findings highlight that stair climbing,as incidental physical activity,offers a simple and low-cost complement to public health interventions for T2D prevention.

Investigation on the Effect of the Tension Degree of Tracks on the Adsorption Performance of Tracked Wall Climbing Robot

In this paper,a new tracked wall climbing robot with permanent magnetic units is designed,and the tension degree of robot’s tracks is found to have a significant impact on the robot’s adsorption performance.This tracked wall climbing robot is a remotely controlled robot.All the control devices can be installed on the robot body.All the permanent magnetic units are arranged on the light track.In order to illustrate the relationship between the tension degree and the adsorption performance,when absorbed on the vertical surface and 180⁃degree inverted surface,the static force analysis of the robot is presented.Finally,experiments were demonstrated to prove that higher tension degree of tracks can make adsorption performance better.

Efficient Clustering Using Memetic Adaptive Hill Climbing Algorithm in WSN

Wireless Sensor Networks are composed of autonomous sensing devices which are interconnected to form a closed network.This closed network is intended to share sensitive location-centric information from a source node to the base station through efficient routing mechanisms.The efficiency of the sensor node is energy bounded,acts as a concentrated area for most researchers to offer a solution for the early draining power of sensors.Network management plays a significant role in wireless sensor networks,which was obsessed with the factors like the reliability of the network,resource management,energy-efficient routing,and scalability of services.The topology of the wireless sensor networks acts dri-ven factor for network efficiency which can be effectively maintained by perform-ing the clustering process effectively.More solutions and clustering algorithms have been offered by various researchers,but the concern of reduced efficiency in the routing process and network management still exists.This research paper offers a hybrid algorithm composed of a memetic algorithm which is an enhanced version of a genetic algorithm integrated with the adaptive hill-climbing algorithm for performing energy-efficient clustering process in the wireless sensor networks.The memetic algorithm employs a local searching methodology to mitigate the premature convergence,while the adaptive hill-climbing algorithm is a local search algorithm that persistently migrates towards the increased elevation to determine the peak of the mountain(i.e.,)best cluster head in the wireless sensor networks.The proposed hybrid algorithm is compared with the state of art clus-tering algorithm to prove that the proposed algorithm outperforms in terms of a network life-time,energy consumption,throughput,etc.

新质生产力推动全球价值链攀升:理论逻辑与现实路径

新质生产力是生产力的新质态,是应用新技术、催生新产业、开辟新赛道、孕育新价值、重塑新动能的新型生产力。加快形成新质生产力不仅是中国突破价值链低端嵌入和低端锁定困境、实现全球价值链攀升的重要抓手,也能够促进国内价值链深化,实现全球价值链与国内价值链两条价值环流良性互动。本文丰富拓展新质生产力的核心要义与时代内涵,理清阐释新质生产力推动全球价值链攀升的逻辑机理,探讨挖掘新质生产力推动全球价值链攀升的现实路径。研究发现,相较于传统生产力,新质生产力由科技创新推动,布局战略性新兴产业和未来产业,致力于提升中国对整个全球价值链贸易网络的控制力,加快实现从全球价值链中低端向高端攀升。新质生产力以创新为新引擎,以战略性新兴产业为主阵地,以未来产业为策源地,发挥高素质人才的主力军作用,通过实现工序升级、产品升级和链条升级等途径推进全球价值链攀升。新质生产力以国内国际双循环相互促进为基础,以国内大循环为主阵地,以国内国际双循环为支撑,以构建国内价值链和全球价值链协同提升为重点,提升中国在全球价值链中的分工地位,培育国内价值链的竞争力;以绿色生产力与数字生产力双轮驱动为新动能,以有为政府与有效市场两部门结合为着力点,发挥有效市场的促进作用,发挥有为政府的引领作用,以人才引培制度与“链长制”为政策支撑,持续推动全球价值链攀升。面对当前国际背景和国内形势,必须牢牢把握生产力发展跃迁的大趋势,通过新质生产力的形成建立起一套符合中国国情的全球价值链攀升路径,加快塑造未来发展新优势,培育新动能,把握新机遇。新质生产力的形成能改变中国全球价值链“低端锁定”的被动局面并确保产业链安全韧性,为后发国家或地区在提升全球价值链地位、实现价值链升级方面提供中国方案与中国智慧,对中国抢抓全球价值链重塑契机下更深层次地提升竞争优势,实现中国式现代化具有重要理论价值和现实意义。

基于混合遗传算法的多无人机巡逻路径优化

假设无人机巡逻的起、终点均为派出所,提出了一种融合传统遗传算法和爬山算法的警用无人机巡逻路径优化模型——混合遗传算法。按照轮盘赌法则,进行种群个体的选择,以增大优秀种群个体被选中的概率,达到较好的优化效果。同时定义了与路径优化相适应的基因交叉和变异规则。仿真结果表明,提出的混合遗传算法在寻优效果上明显优于传统遗传算法。

地铁列车刨削式防爬吸能结构冲击力平稳行为参数优化

为提升地铁列车在碰撞过程的平稳性和耐撞性,提出一种刨削式吸能防爬器。该吸能结构因其抗偏载能力强,结构紧凑等优点被广泛应用于地铁列车的端部吸能结构中。以某型地铁列车的刨削式防爬器为研究对象,使用有限元仿真的方式建立该吸能结构的对称简化模型,并结合台车冲击的试验数据验证有限元模型的准确性;通过数值仿真的方式,将刨刀前角(α)、刨刀后角(β)、刨刀宽度(w)和刨削深度(d)作为输入变量,以总吸能量(E_(A))和吸能阶段的平均刨削力(M_(PF))为耐撞性指标,以样本方差(S^(2))作为考核参照,通过全因子法对输入变量进行参数化分析;在此基础上,利用径向基函数构建代理模型,并采用多目标遗传算法(MOGA)对该吸能结构的主要设计参数进行优化设计,以确定结构参数的最佳的配置方案。研究结果表明:在该型刨削式防爬吸能结构的主要设计尺寸参数中,β对E_(A)、M_(PF)以及S^(2)的影响均不明显;α对MPF、E_(A)呈负相关,同时与S^(2)呈正相关;w和d对E_(A)与M_(PF)呈正相关、与S^(2)呈负相关;通过优化设计得到的吸能结构的最优的参数设计方案中:d为3.94 mm;α为7.78°,w为34 mm;最优设计方案的E_(A)提高了5.91%,M_(PF)提高了5.89%,S^(2)降低了45.4%,耐撞性与平稳性得到了提高。研究结果可为地铁列车刨削式防爬吸能结构的设计提供工程参考。

矿用钢丝绳捻向攀爬轮式巡检机器人设计

针对矿用钢丝绳无人巡检需求,设计研制了一种沿钢丝绳捻向攀爬的巡检机器人。该机器人所需的驱动力约为传统沿轴向攀爬机器人的0.915倍,携带负载3 kg时,其越障高度比轴向攀爬机器人的越障高度大0.6 mm,障碍物高度为3 mm时,它携带的最大负载比轴向攀爬机器人大0.4 kg。模拟深井环境开展了钢丝绳振动工况下的巡检机器人攀爬实验。研究结果表明:在钢丝绳静止状态下,攀爬机器人展现出稳定的攀爬性能,最大攀爬速度达到8.25 m/min,可连续攀爬500 m;在低频大幅振动工况下,机器人攀爬速度高于静止时的速度;在高频小幅振动工况下,钢丝绳振动会导致攀爬速度小幅度波动。

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。

通信干扰信道和功率智能决策算法

智能干扰是一种利用环境反馈自主学习干扰策略,对敌方通信链路进行有效干扰的技术。然而,现有的智能干扰研究大多假设干扰机能够直接获取通信质量反馈(如误码率或丢包率),这在实际对抗环境中难以实现,限制了智能干扰的应用范围。为了解决这一问题,该文将通信干扰问题建模为马尔科夫决策过程(MDP),综合考虑干扰基本原则和通信目标行为变化制定干扰效能衡量指标,提出了一种改进的策略爬山算法(IPHC)。该算法按照“观察(Observe)-调整(Orient)-决策(Decide)-行动(Act)”的OODA闭环,实时观察通信目标变化,灵活调整干扰策略,运用混合策略决策,实施通信干扰。仿真结果表明,在通信目标采用确定性规避策略时,所提算法能够较快收敛到最优干扰策略,并且其收敛耗时较Q-learning算法至少缩短2/3;当通信目标变换策略时,能够自适应学习,重新调整到最优干扰策略。在通信目标采用混合性规避策略时,所提算法也能够快速收敛,取得较优的干扰效果。

爬壁机器人磁吸附模块设计分析与结构参数优化

作为磁吸附式爬壁机器人的关键部件,磁吸附模块的结构通常会影响机器人的整体质量及吸附稳定性。针对磁吸附模块磁路耦合关系复杂、优化设计困难等问题,结合虚拟仿真技术、代理模型和蜣螂优化算法提出了一种磁吸附模块结构优化方法,以提高其磁力计算和优化设计过程的效率。首先,介绍了爬壁机器人的结构设计方案,并通过对现有的Halbach阵列磁路模式进行仿真分析,确定了三磁路模式具有相对较高的吸附效率;同时,基于初设参数对磁吸附模块磁力仿真模型进行了实验验证,为后续代理模型的建立奠定了基础。然后,建立了以机器人吸附稳定性和结构参数为约束、以磁吸附模块轻量化为目标的优化模型。采用最优拉丁超立方设计、ANSYS参数化建模以及代理模型技术建立了磁吸附模块磁力与结构参数之间的四阶响应面模型,并对其可信度进行了验证。利用蜣螂优化算法对磁吸附模块的结构参数优化模型进行了求解。结果表明,所建立的代理模型的预测误差很小,能够较好地表征磁吸附模块磁力与结构参数之间的关系;优化后磁吸附模块的质量减小了12.7%。最后,通过机器人负载实验验证了优化过程的正确性。研究结果可为其他磁吸附式机器人的磁力分析与结构优化提供参考。

轮足复合式爬壁机器人研究综述

当前轮足复合式机器人机构主要包含轮足结合、分离复合以及变形轮足,分别能够实现不同障碍通道的移动作业、复杂未知环境的探索操作以及突发应急救援等应用。然而,针对船舶、压力储罐等金属立面环境,轮足复合式爬壁机器人必须兼具壁面适应、越障和壁面过渡的全位置自主作业能力,应用于壁面焊接、清洗、检测等作业任务。对比分析当前的国内外研究,轮足复合式爬壁机器人针对在垂直和倾斜壁面的工程应用有良好的适用性,它具备适应复杂曲面工作面的能力,并能够应对非结构化工作场景。轮足复合式爬壁结构在应对曲率变化、非结构化壁面等工作将会有良好的应用前景。

爬高型堰塞坝漫顶溃决机理研究

我国西南地区频发的地质构造活动和极端自然灾害诱发了大量的堰塞坝,属于堰塞坝的高发地,其形成的堰塞坝具有突然性强、危险性大的特点,严重威胁所在流域人民的生命财产安全,深入研究爬高型堰塞坝溃坝过程可为除险减灾提供科学理论支撑。为此,以土颗粒级配、背水面坡度、爬高型堰塞坝坝顶形状为影响堰塞坝漫顶溃决的主要因素,从漫顶溃决过程、溃口流量过程、溃口演变过程、溃后残留坝体及下游淤积情况等方面,分析了爬高型堰塞坝漫顶溃决演化过程。试验结果表明:随着土石料级配变宽,坝体整体稳定性增强溃决历时延长,洪峰流量减小,峰现时间较晚,残留溃口上宽小坝体体积大,距坝趾泥沙输移长度短且距坝趾1 m处泥沙厚度薄;背水坡面越陡,水流获得的动能越大,加速了整个坝体溃决过程,溃口扩展得到充足发育,洪峰流量增大,峰现时间提前,残留溃口上宽较大坝体体积小,距坝趾泥沙输移长度长且距坝趾1 m处泥沙厚度较厚;宽深比越大,则溃口相对位置越高,冲蚀阶段所具有的水头差大,加速了坝体冲刷进程,溃口扩展得到充分发育,残留溃口上宽尺度大坝体总量小,距坝趾泥沙输移距离远且距坝趾1 m处泥沙厚度较厚。

面向桁架攀爬的三分支机器人步态规划方法

为解决载荷大范围在轨平稳搬运问题,设计三分支机器人面向桁架攀爬的步态规划方法,使其能够平稳搬运载荷运动到部署位置完成大型航天器组装任务。以21自由度三分支机器人为研究对象,结合桁架结构划分多种攀爬步态单元;针对每种步态单元规划了单元周期内2条攀爬分支的交替夹持顺序以及末端的夹持位姿;针对大范围桁架搬运任务,基于可夹持区域构建表征桁架表面任意两杆间可过渡性的邻接矩阵,并利用Floyd算法生成距离矩阵与路径矩阵,规划出任意两杆间的最短攀爬路径,并将路径中的桁架杆件节点序列映射为机器人可执行的步态单元序列;基于三次B样条曲线对每种步态单元周期内2条攀爬分支的末端轨迹进行规划,实现攀爬分支末端在两夹持点间的攀爬过渡。仿真实验表明:所设计的步态规划方法能够使机器人实现在不同位置关系的桁架杆件之间的过渡,从而具备到达桁架表面任意位置的能力。

船用环保型爬壁喷漆机器人的设计及应用

为提升船舶外板的喷涂作业效率,解决喷涂过程中因漆雾和挥发性有机化合物(VOCs)的产生而造成环境污染的问题,设计一种自带VOCs和漆雾回收模块的爬壁式喷漆机器人。介绍该爬壁式喷漆机器人的结构和工作原理并对其进行受力分析,防止机器人作业过程中发生打滑和倾覆的失效形式,同时采用Maxwell软件针对永磁体与工作壁面之间的间隙大小对吸附力的影响进行仿真分析。通过Adams虚拟样机仿真软件分析并制作该型机器人样机,开展验证试验。结果表明,该爬壁式喷漆机器人能以稳定姿态在船舶外板上喷漆作业,具有VOCs和漆雾回收功能。

超高层异形爬架综合施工技术研究

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