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Research on numerical simulation of the groundwater funnels restoration in Shijiazhuang
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作者 GUO Chun-yan CUI Ya-li +2 位作者 LIU Wen-na CUI Xiang-xiang FEI Yu-hong 《Journal of Groundwater Science and Engineering》 2018年第2期126-135,共10页
In order to simulate the recovery of groundwater funnels under the condition of reducing groundwater abstraction, hydrogeological conditions of recoverability construction of Shijiazhuang groundwater funnel were analy... In order to simulate the recovery of groundwater funnels under the condition of reducing groundwater abstraction, hydrogeological conditions of recoverability construction of Shijiazhuang groundwater funnel were analyzed, and a numerical simulation method was used based on the change of various parameters. The results show that the groundwater flow model can accurately reflect groundwater hydrogeological characteristics, and can guarantee the reliability of groundwater restoration prediction. The research has set up four schemes for rural water-saving, planting structure adjustment, urban reducing abstraction and integrated method. The effect of four restoration schemes on the restoration of groundwater funnels was compared with water table variations of two observation well. Comparison results show that the level changes of plan Three and Four are different from the other two kinds of exploitation and the drop trend of water table in the funnel area is flat. So we can conclude that Plan Three and Four have significant effect on the groundwater funnel restoration of Shijiazhuang. 展开更多
关键词 Shijiazhuang Reducing groundwater abstraction Groundwater funnel Numeric simulation Restoration scheme
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Study of wind towers with different funnels attached to in crease natural ventilation in an underground building 被引量:1
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作者 C.A.Varela-Boydo S.L.Moya R.Watkins 《Frontiers of Architectural Research》 CSCD 2020年第4期925-939,共15页
Finding ways to cool buildings by natural,passive techniques is crucial in the context of global warming.For centuries,wind towers(traditi onal win dcatchers)have been used in the Middle East for cooling purposes.In t... Finding ways to cool buildings by natural,passive techniques is crucial in the context of global warming.For centuries,wind towers(traditi onal win dcatchers)have been used in the Middle East for cooling purposes.In this study,the use of funnels at the openings of wind towers for wind ingress and egress is proposed primarily to increase the mass flow captured by the wind tower.The use of funnels in the wind in gress openings in creases the inlet area,improving the capture of wind.In parallel,the use of funnels in the egress openings modifies the wake of the tower,which aims to ease the exit of the flow from inside the building.Several design configurations are presented,where the length and width of the funnels are changed and tested separately by computational fluid dynamics(CFD).Results of over 120 CFD simulations are presented and compared.The volumetric flow entering the wind towers in creases by 10.7% in several cases.These results in dicate that adding funnels to wind towers could positively in fluence their performance.Changing the dimensions of the funnels affects their efficacy and can increase or decrease the airflow entering the tower. 展开更多
关键词 Wind towers Passive cooling Natural ventilation funnels CFD Wind catchers
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Interpreting the Geomorphology of Carolina Bays as Secondary Impact Structures
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作者 Christopher Cottrell Antonio Zamora 《Journal of Environmental & Earth Sciences》 2025年第6期111-124,共14页
This study examines the Carolina Bays and Nebraska Rainwater Basins,using high-resolution LiDAR elevation models to analyze their unique shapes.The research reveals that well-preserved Bays exhibit precise elliptical ... This study examines the Carolina Bays and Nebraska Rainwater Basins,using high-resolution LiDAR elevation models to analyze their unique shapes.The research reveals that well-preserved Bays exhibit precise elliptical geometry,distinguishing them from various oriented lakes they are often compared to.While the timing of their formation is discussed,the primary goal of this paper is to establish a repeatable method for quantifying the elliptical nature of these dominant geomorphic landforms.By applying the least squares method to points selected along the perimeters of these extraordinary basins,the study confirms their elliptical geometry with an error margin of less than 3%.This rigorous mathematical approach sets a high standard for any hypothesis attempting to explain the origin of these depressions using natural environmental conditions.Notably,the long axes of these elliptical basins converge near the Great Lakes region,and since ellipses can be described as conic sections,this finding supports the plausibility of a cosmic impact origin.The study suggests that these basins may be secondary impact features formed during a past glacial cycle of the Laurentide Ice Sheet.This research establishes a strong mathematical foundation to support future studies on the possible impact origin of the Carolina Bays and Nebraska Rainwater Basins. 展开更多
关键词 Carolina Bays Nebraska Rainwater Basins Oblique Impacts Penetration funnels Elliptical Basins Conical Cavities THERMOKARST LiDAR
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Atmospheric‑pressure ion transfer in a gas flow device connected to the UniCell buffer gas cell for superheavy elements chemistry:simulation studies
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作者 Yeqiang Wei Alexander Yakushev +2 位作者 Jochen Ballof Jörg Krier Christoph E.Düllmann 《Nuclear Science and Techniques》 2025年第10期87-97,共11页
Man-made superheavy elements(SHE)are produced as energetic recoils in complete-fusion reactions and need to be thermalized in a gas-filled chamber for chemical studies.The ever-shorter half-lives and decreasing produc... Man-made superheavy elements(SHE)are produced as energetic recoils in complete-fusion reactions and need to be thermalized in a gas-filled chamber for chemical studies.The ever-shorter half-lives and decreasing production rates of the elements beyond Fl(atomic number Z=114)-the heaviest element chemically studied today-require the development of novel techniques for quantitative thermalization and fast extraction efficiency.The Universal high-density gas stopping Cell(UniCell),currently under construction,was proposed to achieve this.Within this work,we propose an Ion Transfer by Gas Flow(ITGF)device,which serves as a UniCell ejector to interface with a gas chromatography detector array for chemical studies.Detailed parameter optimizations,using gas dynamics and Monte Carlo ion-trajectory simulations,promise fast(within a few ms)and highly efficient(up to 100%)ion extraction across a wide mass range.These ions can then be transmitted quantitatively through the ITGF into the high-pressure environment needed for further chemical studies. 展开更多
关键词 Superheavy elements Buffer gas cell Ion funnel Fast extraction ATMOSPHERIC-PRESSURE Chemical studies
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Compensation for Heterogeneous Unknowns and Performance-Prescribed Consensus
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作者 Linzhen Yu Yungang Liu 《IEEE/CAA Journal of Automatica Sinica》 2025年第1期173-182,共10页
In this paper, the multi-agent systems(MASs) typically with heterogeneous unknown nonlinearities and nonidentical unknown control coefficients are studied. Although the model information of MASs is coarse, the leader-... In this paper, the multi-agent systems(MASs) typically with heterogeneous unknown nonlinearities and nonidentical unknown control coefficients are studied. Although the model information of MASs is coarse, the leader-following consensus is still pursued, with a prescribed performance and zero consensus errors. Leveraging a powerful funnel control strategy, a fully distributed and completely relative-state-dependent protocol is designed. Distinctively, the time-varying function characterizing the performance boundary is introduced, not only to construct the funnel gains but also as an indispensable part of the protocol,enhancing the control ability and enabling the consensus errors to converge to zero(rather than a residual set). Remark that when control directions are unknown, coexisting with inherent system nonlinearities, it is essential to incorporate an additional compensation mechanism while imposing a hierarchical structure of communication topology for the control design and analysis. Simulation examples are given to illustrate the effectiveness of the theoretical results. 展开更多
关键词 Fully distributed protocol funnel control nonidentical unknown control directions performance-prescribed consensus unknown heterogeneous nonlinearities
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基于AFF和SGA的科氏质量流量计信号处理方法 被引量:9
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作者 徐科军 徐文福 《计量学报》 EI CSCD 北大核心 2007年第1期48-51,共4页
采用一种新的方法来处理科里奥利质量流量传感器的信号。该方法将自适应Funnel滤波器(AFF)和滑动Goertzel算法(SGA)结合起来,能够精确地跟踪信号的频率,计算相位差。与以往的方法相比,该方法跟踪精度高且跟踪速度快,具有用定点实现其算... 采用一种新的方法来处理科里奥利质量流量传感器的信号。该方法将自适应Funnel滤波器(AFF)和滑动Goertzel算法(SGA)结合起来,能够精确地跟踪信号的频率,计算相位差。与以往的方法相比,该方法跟踪精度高且跟踪速度快,具有用定点实现其算法时不容易产生溢出和适合于时变信号的优点。 展开更多
关键词 计量学 科里奥利质量流量计 信号处理 自适应Funnel滤波器 滑动Goertzel算法
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基于改进Funnel控制的机械臂轨迹跟踪约束控制 被引量:4
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作者 张蕾 周嘉欣 +1 位作者 黄晨静 王晓华 《西安工程大学学报》 CAS 2022年第2期56-65,共10页
针对关节柔性机械臂系统在未知输入饱和的情况下的稳态和瞬态性能约束问题,提出一种改进Funnel控制结合RBF自适应神经网络的轨迹跟踪控制方法。设计了改进的Funnel控制变量以避免控制律中的微分不可导的情况;构造了时变的瞬态性能约束函... 针对关节柔性机械臂系统在未知输入饱和的情况下的稳态和瞬态性能约束问题,提出一种改进Funnel控制结合RBF自适应神经网络的轨迹跟踪控制方法。设计了改进的Funnel控制变量以避免控制律中的微分不可导的情况;构造了时变的瞬态性能约束函数,调节系统输出初始阶段的超调量和收敛速度;采用最小参数学习法的RBF自适应神经网络,逼近机械臂系统模型的未知函数和虚拟控制律的导数,简化了控制器的设计;通过李雅普诺夫稳定性定理,证明了闭环系统中所有变量是半全局一致最终有界的。仿真实验验证了所提方法有效性。 展开更多
关键词 轨迹跟踪控制 Funnel控制 自适应神经网络 输入饱和 输出约束
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带有饱和的电机伺服系统非奇异终端滑模funnel控制(英文) 被引量:8
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作者 陈强 汤筱晴 《控制理论与应用》 EI CAS CSCD 北大核心 2015年第8期1064-1071,共8页
本文提出一种非奇异终端滑模funnel控制(NTSMFC)方法,实现带有饱和输入电机伺服系统的指定性能跟踪控制.根据中值定理,非光滑饱和函数转化为放射形式,并且应用一个简单的神经网络进行逼近和补偿.为保证跟踪误差被限制在指定的界限内,同... 本文提出一种非奇异终端滑模funnel控制(NTSMFC)方法,实现带有饱和输入电机伺服系统的指定性能跟踪控制.根据中值定理,非光滑饱和函数转化为放射形式,并且应用一个简单的神经网络进行逼近和补偿.为保证跟踪误差被限制在指定的界限内,同时为避免构建复杂的barrier李雅普诺夫函数或逆函数,本文采用一个新的限制变量.然后,构建非奇异终端滑模funnel控制器保证电机伺服系统的指定跟踪性能.该方法无需事先已知输入饱和函数的界限等先验知识,且基于李雅普诺夫函数设计可以保证位置跟踪误差的收敛性,最后给出仿真对比实例证明了该方法的有效性. 展开更多
关键词 funnel控制 非奇异终端滑模 神经网络 输入饱和
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基于未知系统动态估计器的柔性关节机械臂funnel控制 被引量:2
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作者 陈强 顾贤拥 +2 位作者 南余荣 丁科新 战猛 《高技术通讯》 CAS 2022年第1期66-76,共11页
针对带有模型不确定和外部干扰的柔性关节机械臂,提出一种基于未知系统动态估计器的funnel控制方法。基于低通滤波器设计未知系统动态估计器,用于估计模型不确定和外部干扰,该估计器结构简单,仅有一个可调参数。构造带有时变约束边界的... 针对带有模型不确定和外部干扰的柔性关节机械臂,提出一种基于未知系统动态估计器的funnel控制方法。基于低通滤波器设计未知系统动态估计器,用于估计模型不确定和外部干扰,该估计器结构简单,仅有一个可调参数。构造带有时变约束边界的新型funnel变量,保证系统跟踪误差被限制在预先设定的边界内,进而改善系统瞬态性能。在此基础上,设计反演控制器,保证系统输出快速准确跟踪期望轨迹。为避免传统反演法中的“微分爆炸”问题,设计跟踪微分器逼近虚拟控制律导数。并给出数值仿真对比验证本文所提方法的有效性。 展开更多
关键词 柔性关节机械臂 未知系统动态估计器 funnel控制 跟踪微分器 输出约束
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Detection of Hazard Zones over Abandoned Mines of Albania through Geophysical Methods
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作者 Idriz Jata Hamza Reci Vladimir Kavaia 《Journal of Earth Science and Engineering》 2012年第12期704-711,共8页
This study consists to the detection of cavities that could be present over abandoned mines of Albania with the use of SP (self potential) and ERT (electrical resistance tomography). In general, natural and artifi... This study consists to the detection of cavities that could be present over abandoned mines of Albania with the use of SP (self potential) and ERT (electrical resistance tomography). In general, natural and artificial cavities represent an important investigation target in geotechnical, environmental and scientific studies. These studies could be engineering, archaeological or speleological. For the detection and localization of such cavities during the last 20 years, several geophysical studies have been used worldwide. In this field study, several geophysical methods could be used such as electrical, electromagnetic, gravimetric and seismic ones. Now days, the ground penetrating radar technique and ERT are widely used. Depending on geological formation conditions every used method is more or less effective. As a result of actual conditions of works on ore mines, the dynamic regime of the surroundings areas has undergone changes creating superficial cavities and funnels and as consequence the geological risk to the community is present. The detection of cavities is a challenge for geophysicists and in these cases the ambiguity on interpretation of geophysical data has to be solved properly. The simultaneous application of different geophysical methods and monitoring in time are necessary in order that the field data interpretation could be significant. Geophysical investigations were carried out as tests over galleries of ore mines of Albania. In this study, we present the SP and ERT results in two sites, in Dhrovjan and Perrenjas region. The effectiveness of the used geophysical methods was present. 展开更多
关键词 ERT geological risk self potential funnels CAVITIES geophysical investigation engineering geology
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多电机驱动系统的保性能鲁棒Funnel控制 被引量:13
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作者 王敏林 董雪明 +2 位作者 任雪梅 陈强 张策 《控制理论与应用》 EI CAS CSCD 北大核心 2020年第3期540-550,共11页
本文针对含参数不确定性的多电机驱动系统,提出一种基于最优保性能鲁棒的Funnel控制方法实现系统的规定跟踪性能.该控制方法通过构造Funnel函数对误差系统进行变换,并设计自适应反步控制器保证变换后系统的稳定性即可使跟踪误差的瞬态... 本文针对含参数不确定性的多电机驱动系统,提出一种基于最优保性能鲁棒的Funnel控制方法实现系统的规定跟踪性能.该控制方法通过构造Funnel函数对误差系统进行变换,并设计自适应反步控制器保证变换后系统的稳定性即可使跟踪误差的瞬态和稳态响应均被限制在给定的Funnel边界内.然而由于系统中存在的参数不确定性会影响系统的规定控制性能,本文在Funnel控制基础上又设计了最优保性能鲁棒控制器.它是通过将参数不确定性系统的保性能鲁棒控制问题转化为标称系统的最优控制问题,并求解新的黎卡提方程而得到的.因此所设计的控制器不但消除了参数不确定性对系统的影响并且能够使系统的性能指标达到一确定的上界.最后,对四电机驱动系统进行了仿真和实验验证,说明所提出控制方法的有效性. 展开更多
关键词 多电机伺服系统 参数不确定性 Funnel控制 最优保性能鲁棒控制
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基于DAF算法的地图寻径研究 被引量:4
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作者 陈娜 黄明和 刘清华 《科学技术与工程》 2010年第30期7536-7540,共5页
融合了Delaunay Triangulation算法,A*算法以及Funnel算法的优点,提出了DAF算法,并将其应用于网络游戏的地图寻径中,解决了地图信息获取不便捷和搜索路径比较曲折的问题,得出一条最优路径。计算机仿真结果表明DAF算法提高了搜索效率和... 融合了Delaunay Triangulation算法,A*算法以及Funnel算法的优点,提出了DAF算法,并将其应用于网络游戏的地图寻径中,解决了地图信息获取不便捷和搜索路径比较曲折的问题,得出一条最优路径。计算机仿真结果表明DAF算法提高了搜索效率和路径的平滑程度。 展开更多
关键词 地图寻径 DELAUNAY Triangulation算法 A~*算法 Funnel算法
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输入时滞非线性系统的新型动态面Funnel控制 被引量:2
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作者 王清华 刘烨 +2 位作者 张桂林 李洪芹 刘海珊 《控制理论与应用》 EI CAS CSCD 北大核心 2022年第8期1426-1432,共7页
本文针对一类带有输入时滞的不确定非线性系统,提出了新型动态面Funnel控制方案.首先设计补偿动态变量将输入时滞系统转换成无时滞的系统,仅需在递归控制的最后一步补偿,从而优化了控制器设计过程.其次,构造Funnel函数,使系统的瞬态和... 本文针对一类带有输入时滞的不确定非线性系统,提出了新型动态面Funnel控制方案.首先设计补偿动态变量将输入时滞系统转换成无时滞的系统,仅需在递归控制的最后一步补偿,从而优化了控制器设计过程.其次,构造Funnel函数,使系统的瞬态和稳态跟踪误差被限制在给定边界内.最后,提出新型非线性动态面控制方法,不仅避免了自适应反推控制中的“微分爆炸”问题,而且消除了边界层误差,使得系统的跟踪误差最终渐近收敛到零.理论分析表明该闭环系统的所有信号一致最终有界,仿真结果验证了该控制方案的有效性. 展开更多
关键词 自适应控制 动态面控制 输入时滞 神经网络 FUNNEL
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PI磁滞非线性系统的动态伪逆补偿控制算法 被引量:2
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作者 王清华 刘烨 +1 位作者 李洪芹 陈剑雪 《传感器与微系统》 CSCD 北大核心 2023年第8期119-122,共4页
通过设计磁滞动态伪逆补偿和新型动态面控制来消除非线性系统中未知饱和磁滞的影响。磁滞动态伪逆补偿通过构建辅助滤波器,提出了一种实时在线补偿磁滞的机制,且不需要构建显式磁滞逆和辨识相应的未知参数。此外,基于正时变积分函数设... 通过设计磁滞动态伪逆补偿和新型动态面控制来消除非线性系统中未知饱和磁滞的影响。磁滞动态伪逆补偿通过构建辅助滤波器,提出了一种实时在线补偿磁滞的机制,且不需要构建显式磁滞逆和辨识相应的未知参数。此外,基于正时变积分函数设计了新型非线性滤波器,该滤波器不仅避免“微分爆炸”问题,降低计算负担,而且补偿动态面边界层误差,使系统的跟踪误差收敛到零。理论分析表明:该方案能有效地消除未知磁滞的影响,保证闭环系统的稳定。最后,通过仿真实例验证了该方案的有效性。 展开更多
关键词 饱和磁滞 动态伪逆补偿 动态面控制 Funnel软件
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未知非线性多智能体系统的分布式有限时间自适应神经网络控制 被引量:3
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作者 楚东港 刘烨 《仪表技术与传感器》 CSCD 北大核心 2023年第5期112-117,126,共7页
针对一类具有未知磁滞输入的非线性多智能体系统,提出了一种基于改进命令滤波器的分布式预设性能自适应神经网络渐近一致控制方案。首先,为保证系统的跟踪性能,提出了基于新型性能函数的有限时间Funnel控制方案,使得跟随者与领导者在有... 针对一类具有未知磁滞输入的非线性多智能体系统,提出了一种基于改进命令滤波器的分布式预设性能自适应神经网络渐近一致控制方案。首先,为保证系统的跟踪性能,提出了基于新型性能函数的有限时间Funnel控制方案,使得跟随者与领导者在有限的时间内输出一致。其次,利用径向基神经网络和放缩方法消除了未知非线性的影响。然后,使用命令滤波器解决了传统递归方法的“微分爆炸”难题。理论分析表明:该控制方案消除了未知磁滞输入的影响并且实现了一致性误差渐近收敛至0。最后通过实例仿真验证了文中控制方案的有效性。 展开更多
关键词 自适应控制 径向基神经网络 有限时间Funnel控制 命令滤波器 磁滞输入
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Spatial-temporal Characteristics of Land Subsidence Corresponding to Dynamic Groundwater Funnel in Beijing Municipality,China 被引量:14
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作者 CHEN Beibei GONG Huili +5 位作者 LI Xiaojuan LEI Kunchao ZHANG Youquan LI Jiwei GU Zhaoqin DANG Yanan 《Chinese Geographical Science》 SCIE CSCD 2011年第6期753-764,共12页
Due to long-term over-exploitation of groundwater in Beijing Municipality, regional groundwater funnels have formed and land subsidence has been induced. By combining a groundwater monitoring network, GPS monitor- ing... Due to long-term over-exploitation of groundwater in Beijing Municipality, regional groundwater funnels have formed and land subsidence has been induced. By combining a groundwater monitoring network, GPS monitor- ing network data, radar satellite SAR data, GIS and other new technologies, a coupled process model based on the dy- namic variation of groundwater and the deformation response of land subsidence has been established. The dynamic variation of groundwater fimnels and the land subsidence response process were analyzed systematically in Beijing. Study results indicate that current groundwater funnel areas are distributed mainly in the southwest of Shunyi District, the northeast of Chaoyang District and the northwest of Tongzhou District, with an average decline rate of groundwa- ter level of 2.66 rn/yr and a maximum of 3.82 m/yr in the center of the funnels. Seasonal and interannual differences exist in the response model of land subsidence to groundwater funnels with uneven spatial and temporal distribution, where the maximum land subsidence rate was about --41.08 mm/yr and the area with a subsidence rate greater than 30 mm/yr was about 1637.29 km2. Although a consistency was revealed to exist between a groundwater funnel and the spatial distribution characteristics of the corresponding land subsidence funnel, this consistency was not perfect. The results showed that the response model of land subsidence to the dynamic variation of groundwater was more revealing when combining conventional technologies with InSAR, GIS, GPS, providing a new strategy for environmental and hydrogeological research and a scientific basis for regional land subsidence control. 展开更多
关键词 land subsidence groundwater funnel over-exploitation of groundwater INSAR deformation response
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Characteristics of Caragana korshinskii and Hippophae rhamnoides stemflow and their significance in soil moisture enhancement in Loess Plateau, China 被引量:8
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作者 ShengQi JIAN ChuanYan ZHAO +1 位作者 ShuMin FANG Kai YU 《Journal of Arid Land》 SCIE CSCD 2014年第1期105-116,共12页
Stemflow of xerophytic shrubs represents a significant component of water replenishment to the soil-root system and influences water utilization of plant roots at the stand scale,especially in water-scarce semi-arid e... Stemflow of xerophytic shrubs represents a significant component of water replenishment to the soil-root system and influences water utilization of plant roots at the stand scale,especially in water-scarce semi-arid ecosystems.The stemflow of two semi-arid shrubs(Caragana korshinskii and Hippophae rhamnoides)and its effect on soil moisture enhancement were evaluated during the growing season of 2011 in the semi-arid loess region of China.The results indicated that stemflow averaged 12.3%and 8.4%of the bulk precipitation for C.korshinskii and H.rhamnoides,respectively.Individual stemflow increased in a linear function with increasing rainfall depth.The relationship between funneling ratios and rainfall suggested that there existed a rainfall depth threshold of 11 mm for both C.korshinskii and H.rhamnoides.Averaged funneling ratios were 156.6±57.1 and49.5±30.8 for C.korshinskii and H.rhamnoides,respectively,indicating that the canopy architecture of the two shrubs was an effective funnel to channel stemflow to the root area,and C.korshinskii showed a greater potential to use stemflow water in the semi-arid conditions.For individual rainfall events,the wetting front depths were approximately 2 times deeper in the rooting zone around the stems than in the bare area outside canopy for both C.korshinskii and H.rhamnoides.Correspondingly,soil water content was also significantly higher in the root area around the shrub stem than in the area outside the shrub canopy.This confirms that shrub stemflow conserved in the deep soil layers may be an available moisture source for plant growth under semi-arid conditions. 展开更多
关键词 PRECIPITATION STEMFLOW funneling ratio rainfall intensity Anjiapo catchment
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Ectoparasites and other invertebrates in the nests of the Hair-crested Drongo (Dicrurus hottentottus)
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作者 Andrew CANTRELL 吕磊 +2 位作者 王勇 张正旺 李建强 《Chinese Birds》 CSCD 2013年第4期314-318,共5页
Ectoparasites and other invertebrates are known to play a role in bird behavior and in evolutionary adaptations such as preening and foraging strategies. We conducted an exploratory study by macro- and microscopically... Ectoparasites and other invertebrates are known to play a role in bird behavior and in evolutionary adaptations such as preening and foraging strategies. We conducted an exploratory study by macro- and microscopically evaluating the nests of Hair-crested Drongos(Dicrurus hottentottus) at Dongzhai National Nature Reserve, Henan Province, China in 2011 to determine if there was a presence of invertebrates. We developed a modified funneling technique to collect invertebrate samples and reduce contamination from outside sources in a field setting. We found several species of ectoparasites(lice and ticks) and other invertebrates(springtails and rove beetles) within the nests. Our findings warrant further investigation as to whether or not the presence of invertebrates in the nests of Hair-crested Drongos plays a role in the adaptation of the unique nest dismantling behavior exhibited by this species. 展开更多
关键词 China Dicrurus hottentottus Dongzhai National Nature Reserve ECTOPARASITE INVERTEBRATE modified funneling technique
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Feasibility of using recycled CRT funnel glass as partial replacement of high density magnetite sand in radiation shielding concrete 被引量:5
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作者 Hua-liang LIU Jian-jun SHI +1 位作者 Hui-qiong QU De-xin DING 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2019年第4期831-839,共9页
The recycled cathode ray tube(CRT)funnel glass was used as replacement of magnetite sand in the concrete,and its mass replacement rates were 0,20%,40%and 60%,respectively.The flowability,apparent density and mechanica... The recycled cathode ray tube(CRT)funnel glass was used as replacement of magnetite sand in the concrete,and its mass replacement rates were 0,20%,40%and 60%,respectively.The flowability,apparent density and mechanical properties of the radiation shielding concrete were investigated,while itsγ-ray radiation shielding parameters such as linear and mass attenuation coefficients(μandμm,respectively),thickness values of half-value layer(hHVL)and tenth-value layer(hTVL)were obtained by theoretical calculation,experiment and Monte.Carlo N-Particle(MCNP)simulation code.The experimental results show that the flowability of the concrete increases significantly,whilst its apparent density,compressive strength and static elastic modulus decrease slightly.The calculated,simulated and experimentalμm,μ,hHVL and hTVL values of all concrete samples are very consistent at the sameγ-ray photon energy,and it is feasible to use MCNP code to simulateγ-ray radiation shielding parameters of materials.The calculated results show that in a wide range ofγ-ray photon energy,theμm value of the concrete with CRT funnel glass replacing magnetite sand is improved effectively,and its radiation shielding performances are the same as those of the control concrete(M.1).By comprehensively comparing the flowability,mechanical properties andγ-ray radiation shielding properties,the concrete samples with 20%.40%funnel glass as fine aggregate have good performances. 展开更多
关键词 cathode ray tube funnel glass concrete Γ-RAY radiation shielding mechanical properties Monte-Carlo N-Particle simulation
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Corrosion mechanism of magnesia-chromite refractories by ZnO-containing fayalite slags: Effect of funnel glass addition 被引量:1
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作者 Zhe-nan Jin Jian-fang Lv +1 位作者 Hong-ying Yang Zhi-yuan Ma 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2019年第12期1604-1616,共13页
An efficient approach for lead extraction from waste funnel glass through the lead smelting process has been proposed. To clarify the effect of funnel glass addition on the degradation of magnesia-chromite refractorie... An efficient approach for lead extraction from waste funnel glass through the lead smelting process has been proposed. To clarify the effect of funnel glass addition on the degradation of magnesia-chromite refractories by ZnO-containing fayalite slag, the corrosion behavior of magnesia-chromite refractories in lead smelting slags with different funnel glass additions from 0wt% to 40wt% was tested. Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) was used to acquire the microstructural information of the worn refractory samples. Experimental results showed that the corrosion of magnesia-chromite refractory consisted predominantly of the dissolution of MgO into slag. ZnO and FeO reacted with periclase and chromite to form (Zn,Fe,Mg)O solid solution and (Zn,Fe,Mg)(Fe,Al,Cr)2O4 spinel, respectively. With the addition of funnel glass, the solubility of MgO increased whereas ZnO levels remained stable, thereby resulting in a reduced Mg content and an elevated Zn and Fe content in the (Zn,Fe,Mg)O solid solution and the (Zn,Fe,Mg)(Fe,Al,Cr)2O4 spinel. Considering the stability of the (Zn,Fe,Mg)O solid solution layer and the penetration depth of the slag, the optimal funnel glass addition for lead smelting was found to be 20wt%. 展开更多
关键词 FUNNEL GLASS zinc-containing FAYALITE slag magnesia-chromite refractory corrosion
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