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Vertical distribution characteristics of soil saturated hydraulic conductivity under different land use patterns in the Mu Us sandy land
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作者 LIU Xingting QIAO Jiangbo +4 位作者 YANG Tao MA Yali TIAN Hanyang HAN Xiaoyang ZHU Yuanjun 《地球环境学报》 CSCD 2024年第4期665-674,共10页
Background,aim,and scope Soil saturated hydraulic conductivity(K_(s))is a key parameter in the hydrological cycle of soil;however,we have very limited understanding of K_(s) characteristics and the factors that inf lu... Background,aim,and scope Soil saturated hydraulic conductivity(K_(s))is a key parameter in the hydrological cycle of soil;however,we have very limited understanding of K_(s) characteristics and the factors that inf luence this key parameter in the Mu Us sandy land(MUSL).Quantifying the impact of changes in land use in the Mu Us sandy land on K_(s) will provide a key foundation for understanding the regional water cycle,but will also provide a scientific basis for the governance of the MUSL.Materials and methods In this study,we determined K_(s) and the basic physical and chemical properties of soil(i.e.,organic matter,bulk density,and soil particle composition)within the first 100 cm layer of four different land use patterns(farmland,tree,shrub,and grassland)in the MUSL.The vertical variation of K_(s) and the factors that influence this key parameter were analyzed and a transfer function for estimating K_(s) was established based on a multiple stepwise regression model.Results The K_(s) of farmland,tree,and shrub increased gradually with soil depth while that of grassland remained unchanged.The K_(s) of the four patterns of land use were moderately variable;mean K_(s)values were ranked as follows:grassland(1.38 mm·min^(-1))<tree(1.76 mm·min^(-1))<farmland(1.82 mm·min^(-1))<shrub(3.30 mm·min^(-1)).The correlation between K_(s) and organic matter,bulk density,and soil particle composition,varied across different land use patterns.A multiple stepwise regression model showed that silt,coarse sand,bulk density,and organic matter,were key predictive factors for the K_(s) of farmland,tree,shrub,and grassland,in the MUSL.Discussion The vertical distribution trend for K_(s) in farmland is known to be predominantly influenced by cultivation,fertilization,and other factors.The general aim is to improve the water-holding capacity of shallow soil on farmland(0-30 cm in depth)to conserve water and nutrients;research has shown that the K_(s) of farmland increases with soil depth.The root growth of tree and shrub in sandy land exerts mechanical force on the soil due to biophysical processes involving rhizospheres,thus leading to a significant change in K_(s).We found that shallow high-density fine roots increased the volume of soil pores and eliminated large pores,thus resulting in a reduction in shallow K_(s).Therefore,the K_(s) of tree and shrub increased with soil depth.Analysis also showed that the K_(s) of grassland did not change significantly and exhibited the lowest mean value when compared to other land use patterns.This finding was predominantly due to the shallow root system of grasslands and because this land use pattern is not subject to human activities such as cultivation and fertilization;consequently,there was no significant change in K_(s) with depth;grassland also had the lowest mean K_(s).We also established a transfer function for K_(s) for different land use patterns in the MUSL.However,the predictive factors for K_(s) in different land use patterns are known to be affected by soil cultivation methods,vegetation restoration modes,the distribution of soil moisture,and other factors,thus resulting in key differences.Therefore,when using the transfer function to predict K_(s) in other areas,it will be necessary to perform parameter calibration and further verification.Conclusions In the MUSL,the K_(s) of farmland,tree,and shrub gradually increased with soil depth;however,the K_(s) of grassland showed no significant variation in terms of vertical distribution.The mean K_(s) values of different land use patterns were ranked as follows:shrub>farmland>tree>grassland;all land use patterns showed moderate levels of variability.The K_(s) for different land use patterns exhibited differing degrees of correlation with soil physical and chemical properties;of these,clay,silt,sand,bulk density,and organic matter,were identified as important variables for predicting K_(s) in farmland,tree,shrub,and grassland,respectively.Recommendations and perspectives In this study,we used a stepwise multiple regression model to establish a transfer function prediction model for K_(s) for different land use patterns;this model possessed high estimation accuracy.The ability to predict K_(s) in the MUSL is very important in terms of the conservation of water and nutrients. 展开更多
关键词 Mu Us sandy land saturated hydraulic conductivity vertical distribution transfer function
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Heat Transfer Process of Bubble during the Occurrence of Cavitation in Hydraulic System
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作者 姜继海 张健 +2 位作者 李艳杰 罗念宁 于安才 《Journal of Donghua University(English Edition)》 EI CAS 2014年第3期229-234,共6页
Thermal characteristic of cavitation has great influence on the process of occurrence,development and collapse of bubble in hydraulic system. By choosing the stage of bubble growth as the research object,combining wit... Thermal characteristic of cavitation has great influence on the process of occurrence,development and collapse of bubble in hydraulic system. By choosing the stage of bubble growth as the research object,combining with the characteristic of the process of bubble occurrence and development in hydraulic system, and ignoring the impact of thermal radiation,the heat transfer situation of bubble growth was analyzed under appropriate assumptions of thermodynamic conditions in the bubble generation and development process. The mathematical expression of the temperature change of bubble was deduced using thermodynamic principle. Through combining the expression with classic Rayleigh-Plesset Equation,numerical calculation was carried out and the temperature variation over time( or bubble radius) was obtained. The influences of convective heat transfer coefficient of bubble and polytropic exponent on the thermodynamic process of bubble were analyzed. Finally,the thermal characteristic of bubble growth after cavitation occurrence was summarized. 展开更多
关键词 hydraulic system CAVITATION convective heat transfer coefficient of bubble polytropic exponent THERMODYNAMICS
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STUDY ON VIBRATION REDUCTION BEHAVIOR FOR THE HYDRAULIC ENGINE MOUNT
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作者 唐友刚 FROLOV K V SINIOV A V 《Transactions of Tianjin University》 EI CAS 2001年第4期238-241,共4页
In this paper,the metal hydraulic engine mount (HEM) with the orifice is presented,the construction of HEM is consist of hydraulic cylinder and the spring on the bottom,its mechanical model is given and dynamics equat... In this paper,the metal hydraulic engine mount (HEM) with the orifice is presented,the construction of HEM is consist of hydraulic cylinder and the spring on the bottom,its mechanical model is given and dynamics equations are set up with considering kinematics conditions and continuous of fluid,the dynamics behavior of HEM including dynamic stiffness of fluid and transferability of HEM are studied here.The example of hydraulic engine mount is calculated,it is shown that the vibration reduction performance of the hydraulic engine mount of this paper is better.The analysis method of vibration reduction behavior for HEM in this paper can be used in designing of the reduction vibration devices and the HEM in this paper can be used in the practical engineering for reduction vibration. 展开更多
关键词 hydraulic engine mount vibration reduction dynamic stiffness transfer function
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Vibration Performance Analysis of a Mining Vehicle with Bounce and Pitch Tuned Hydraulically Interconnected Suspension 被引量:7
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作者 Jie Zhang Yuanwang Deng +3 位作者 Nong Zhang Bangji Zhang Hengmin Qi Minyi Zheng 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2019年第1期195-211,共17页
The current investigations primarily focus on using advanced suspensions to overcome the tradeo design of ride comfort and handling performance for mining vehicles. It is generally realized by adjusting spring sti nes... The current investigations primarily focus on using advanced suspensions to overcome the tradeo design of ride comfort and handling performance for mining vehicles. It is generally realized by adjusting spring sti ness or damping parameters through active control methods. However, some drawbacks regarding control complexity and uncertain reliability are inevitable for these advanced suspensions. Herein, a novel passive hydraulically interconnected suspension(HIS) system is proposed to achieve an improved ride-handling compromise of mining vehicles. A lumped-mass vehicle model involved with a mechanical–hydraulic coupled system is developed by applying the free-body diagram method. The transfer matrix method is used to derive the impedance of the hydraulic system, and the impedance is integrated to form the equation of motions for a mechanical–hydraulic coupled system. The modal analysis method is employed to obtain the free vibration transmissibilities and force vibration responses under di erent road excitations. A series of frequency characteristic analyses are presented to evaluate the isolation vibration performance between the mining vehicles with the proposed HIS and the conventional suspension. The analysis results prove that the proposed HIS system can e ectively suppress the pitch motion of sprung mass to guarantee the handling performance, and favorably provide soft bounce sti ness to improve the ride comfort. The distribution of dynamic forces between the front and rear wheels is more reasonable, and the vibration decay rate of sprung mass is increased e ectively. This research proposes a new suspension design method that can achieve the enhanced cooperative control of bounce and pitch motion modes to improve the ride comfort and handling performance of mining vehicles as an e ective passive suspension system. 展开更多
关键词 hydraulically interconnected SUSPENSION transfer matrix method Modal VIBRATION analysis RIDE comfort Handling performance MINING VEHICLE
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Waveforms analysis and optimization of new electro-hydraulic excitation technology 被引量:3
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作者 韩冬 龚国芳 +2 位作者 杨华勇 刘毅 廖湘平 《Journal of Central South University》 SCIE EI CAS 2014年第8期3098-3106,共9页
A new electro-hydraulic exciter that consists of rotary valve and micro-displacement double-functioned hydraulic cylinder was proposed to realize different kinds of waveforms.Calculated fluid dynamics(CFD) simulation ... A new electro-hydraulic exciter that consists of rotary valve and micro-displacement double-functioned hydraulic cylinder was proposed to realize different kinds of waveforms.Calculated fluid dynamics(CFD) simulation of rotary valve orifice reveals that orifice exists the two-throttle phenomenon.According to the finding,the revised flow area model was established.Vibration waveforms analysis was carried out by means of mathematic model and the related experiments were validated.Furthermore,as a new analysis indicator,saturation percentage was introduced first.The experimental results indicate that the revised flow area model is more accurate compared to the original one,and vibration waveforms can be optimized through suitable spool parameters and the revised cylinder structure. 展开更多
关键词 rotary valve micro-displacement double-functioned hydraulic cylinder two-throttle phenomenon revised flow areamodel saturation drift motion
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Optimization of Heat-Sink Cooling Structure in EAST with Hydraulic Expansion Technique
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作者 许铁军 黄生洪 +4 位作者 谢韩 宋云涛 张平 戢翔 高大明 《Plasma Science and Technology》 SCIE EI CAS CSCD 2011年第6期765-768,共4页
Considering utilization of the original chromium-bronze material, two processing techniques including hydraulic expansion and high temperature vacuum welding were proposed for the optimization of heat-sink structure i... Considering utilization of the original chromium-bronze material, two processing techniques including hydraulic expansion and high temperature vacuum welding were proposed for the optimization of heat-sink structure in EAST. The heat transfer performance of heat-sink with or without cooling tube was calculated and different types of connection between tube and heat-sink were compared by conducting a special test. It is shown from numerical analysis that the diameter of heat-sink channel can be reduced from 12 mm to 10 mm. Compared with the original sample, the thermal contact resistance between tube and heat-sink for welding sample can reduce the heat transfer performance by 10%, while by 20% for the hydraulic expansion sample. However, the welding technique is more complicated and expensive than hydraulic expansion technique. Both the processing technique and the heat transfer performance of heat-sink prototype should be further considered for the optimization of heat-sink structure in EAST. 展开更多
关键词 EAST heat-sink heat transfer performance hydraulic expansion
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基于ADAMS/Hydraulics的井下巷道吊装转载装置液压系统动力学仿真研究 被引量:1
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作者 党静 王荣泉 《起重运输机械》 2015年第1期39-42,共4页
通过三维CAD软件Solid Works进行三维实体建模,并基于虚拟样机软件ADAMS中的Hydraulics模块,对井下巷道吊装转载装置进行了液压系统虚拟样机的建模与动态仿真,分析了该装置中提升液压缸进行提升与下降等动作时的动力学特性。
关键词 吊装转载装置 提升液压缸 ADAMS/hydraulics 仿真
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地热储层岩体粗糙裂隙的热流耦合效应研究
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作者 刘先珊 李宇 +1 位作者 李满 杨欣 《哈尔滨工程大学学报》 EI CAS CSCD 北大核心 2024年第5期852-862,共11页
为了解决地热开采涉及复杂的多物理场耦合问题,提高开采效率,本文针对开采过程中的渗流-传热问题以离散元软件3DEC构建岩体粗糙裂隙热-流耦合数值模型。考虑不同三维形貌特征的岩体裂隙,模拟水力开度为19.17μm在不同流速时的水-岩温度... 为了解决地热开采涉及复杂的多物理场耦合问题,提高开采效率,本文针对开采过程中的渗流-传热问题以离散元软件3DEC构建岩体粗糙裂隙热-流耦合数值模型。考虑不同三维形貌特征的岩体裂隙,模拟水力开度为19.17μm在不同流速时的水-岩温度变化规律。结果表明:由于裂隙形貌的阻滞作用,粗糙面出水口温度下降较慢,出水口温度有所上升,模型达到稳态所需的时间随流速和对流换热系数的增大而减小。裂隙形貌对流体和岩体温度分布均有影响,粗糙裂隙面的冷锋形态和裂隙面的形貌密切相关。光滑裂隙热突破快于粗糙裂隙,增加裂隙面的粗糙度有助于延长热突破时间。粗糙裂隙面相对于光滑裂隙面的总热量提取率略有提升,流速和对流换热系数的增加显著提高总热量提取率。通过本文研究可以为地热能系统的设计提供重要参数和指导,能够提高地热能开发利用效率。 展开更多
关键词 干热岩 渗流-传热 三维形貌 水力开度 流速 对流换热系数 粗糙裂隙面 热采率 热突破
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多目标拓扑优化算法在液压制动器传热优化中的应用
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作者 崔洪艳 《液压与气动》 北大核心 2024年第6期72-79,共8页
为有效提升液压制动器的传热性能,基于多目标优化算法对风冷盘的厚度、风槽高度、肋片倾角和肋片数量等设计变量进行拓扑优化,实现制动盘温度峰值和质量的同步降低。采用PDE方程建立风冷盘传热模型,以负热流为边界条件,求解出恒压匀速... 为有效提升液压制动器的传热性能,基于多目标优化算法对风冷盘的厚度、风槽高度、肋片倾角和肋片数量等设计变量进行拓扑优化,实现制动盘温度峰值和质量的同步降低。采用PDE方程建立风冷盘传热模型,以负热流为边界条件,求解出恒压匀速制动工况下的二维瞬态温度场。基于ANSYS Workbech建立风冷盘的三维参数化传热模型,利用台架试验法验证温度场仿真结果。采用中心组合设计法得出设计变量与优化目标的离散样本,通过多元二次回归模型构建代理模型并进行误差校核。构建优化数学模型,将质量优化目标转换为边界条件,通过序列二次规划算法得出不同质量区间的解集。结合min-max标准化和加权归一方法,得出无量纲的指标测评值,实现优化目标的性价比评价。优化结果表明,风冷盘质量降低8.3%,温度峰值降低3.7%,传热效率明显提升,经济效益和社会效益显著。 展开更多
关键词 液压制动器 传热 代理模型 拓扑优化 有限元
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基于转鼓转速传感的中低速新能源汽车联合制动系统控制方法
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作者 宗明建 马文胜 +1 位作者 袁望方 童晓帆 《传感技术学报》 CAS CSCD 北大核心 2024年第7期1244-1249,共6页
中低速新能源汽车是常见的交通工具,但是其制动控制存在响应时间长、控制效果差的问题,设计一种基于转鼓转速传感的中低速新能源汽车联合制动系统控制方法。首先,构建基于转鼓转速传感的中低速新能源汽车动力学方程,采集传感信息,然后,... 中低速新能源汽车是常见的交通工具,但是其制动控制存在响应时间长、控制效果差的问题,设计一种基于转鼓转速传感的中低速新能源汽车联合制动系统控制方法。首先,构建基于转鼓转速传感的中低速新能源汽车动力学方程,采集传感信息,然后,考虑开环控制容易导致控制系统的稳定性和鲁棒性差的问题,基于转鼓转速传感的联合制动系统传递函数推导出开环、闭环双传递函数,最后,根据系统传递函数,设计PID控制器的参数,通过PID控制器输出电-液联合制动控制信号,实现汽车联合制动系统控制。实验结果表明:所提方法的速度-位移曲线与现实速度-位移曲线基本一致,加速误差在-0.5 m/s2~0.5 m/s2范围内,平均制动控制响应时间为0.075 s,具有良好的制动控制能力。 展开更多
关键词 转鼓转速传感 联合制动控制 PID控制器 中低速新能源汽车 传递函数 电制动力 液压制动力
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南水北调中线京石段闸门间歇关闭水力响应特性
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作者 雷毓灵 崔巍 +3 位作者 王磊 丁志楠 穆祥鹏 陈文学 《南水北调与水利科技(中英文)》 CAS CSCD 北大核心 2024年第3期427-435,共9页
为减小闸门关闭引发的水位壅高,以南水北调中线工程京石段磁河闸至沙河北闸之间的渠池为研究对象,构建一维明渠非恒定渐变流仿真模型,比较分次间歇关闸与一次连续关闸,以及不同闸门间歇方案对闸前壅水峰值、水力振荡稳定时间的影响。研... 为减小闸门关闭引发的水位壅高,以南水北调中线工程京石段磁河闸至沙河北闸之间的渠池为研究对象,构建一维明渠非恒定渐变流仿真模型,比较分次间歇关闸与一次连续关闸,以及不同闸门间歇方案对闸前壅水峰值、水力振荡稳定时间的影响。研究表明:分次间歇关闸可带来更低的闸前壅水水位和更短的水力振荡稳定时间;设置1次间歇相较于多次间歇可减小闸前壅水峰值,将间歇开始时刻设置在上游降水波即将传播至闸前的时刻、设置间歇时长略小于关闸总时间的1/2均可有效降低闸前壅水峰值,缩短稳定时间。闸门分次间歇关闭水力响应特性与水波运动规律紧密关联,合理设置间歇有助于在应急调控阶段减少事故造成的影响。 展开更多
关键词 明渠水力学 南水北调中线工程 闸门分次间歇关闭 水力振荡 应急调度
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基于机液联合仿真模型的闸门启闭机故障注入及诊断研究
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作者 李浩宇 徐平 +1 位作者 铁瑛 黄建章 《振动与冲击》 EI CSCD 北大核心 2024年第13期198-209,共12页
为了对含故障特征的弧形闸门系统运行信号进行评估和故障诊断研究,基于某弧形闸门试验平台检测数据,建立弧形闸门启闭机构的机液联合仿真模型,进行模型相似度分析和修正。通过基于闸门实时开度反馈信号闸门状态控制策略对闸门进行工作... 为了对含故障特征的弧形闸门系统运行信号进行评估和故障诊断研究,基于某弧形闸门试验平台检测数据,建立弧形闸门启闭机构的机液联合仿真模型,进行模型相似度分析和修正。通过基于闸门实时开度反馈信号闸门状态控制策略对闸门进行工作状态的控制,提高了仿真效率和稳定性,获得更符合实际的状态特征。在模型中注入液压系统与机械系统故障,分析故障对闸门运行信号产生的影响。为了充分体现故障特征信息,选取多个信号进行融合并调整权重分配,基于加权多通道数据融合方法解决了故障识别精度波动大的问题,为了提高网络模型的泛化能力,在网络模型中加入残差结构进行优化,基于迁移学习的卷积神经网络解决了故障识别精度低的问题。结果表明,构建的模型可以表现出弧形闸门工作过程中重要信号比如压力、流量、振动等信号特征的动态变化;使用改进后的加权多通道数据融合的基于残差结构优化的神经网络准确率达到了97.17%。 展开更多
关键词 弧形闸门 机液联合仿真 故障诊断 迁移学习
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高内水压作用下围岩-叠合式衬砌承载机理力学分析
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作者 刘宜杰 黄本胜 +3 位作者 袁明道 史永胜 张旭辉 徐云乾 《长江科学院院报》 CSCD 北大核心 2024年第10期140-148,164,共10页
为探究圆形水工隧洞衬砌结构中围岩-叠合式衬砌联合承载的力学机理,针对珠江三角洲水资源配置工程“外衬管片-自密实混凝土填充层(SCC)-内衬钢管”三层叠合的衬砌结构形式,采用平面弹性复变函数理论的幂级数解法,从应力函数层面着手,基... 为探究圆形水工隧洞衬砌结构中围岩-叠合式衬砌联合承载的力学机理,针对珠江三角洲水资源配置工程“外衬管片-自密实混凝土填充层(SCC)-内衬钢管”三层叠合的衬砌结构形式,采用平面弹性复变函数理论的幂级数解法,从应力函数层面着手,基于围岩-衬砌相互作用关系以及应力边界条件建立了相应的力学模型,推导求解了在开挖荷载和内水压共同作用下围岩和各层衬砌域内任意点的应力分量,揭示了叠合式衬砌结构承载时的荷载传递机理和规律。然后通过边界应力结果以及与数值结果的比对,验证了提出方法的正确性;最后通过参数分析,着重讨论了高内水压对输水隧洞围岩和三层衬砌径向正应力和环向正应力的影响。结果表明:围岩-衬砌联合承载时,围岩和三层衬砌的径向正应力和环向正应力结果均符合余弦分布,而剪应力符合正弦分布;随着输水隧洞内水压增加,三层衬砌和围岩在径向上更趋于压缩,而环向正应力趋向于拉应力并增大。研究成果可为该类型衬砌防护工程的设计和施工提供理论依据。 展开更多
关键词 圆形输水隧洞 三层衬砌 高内水压 解析方法 荷载传递机理
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三峡库区典型农业小流域土壤饱和导水率特征
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作者 韩唯 陈晓燕 陶婷婷 《水土保持通报》 CSCD 北大核心 2024年第5期83-91,99,共10页
[目的]通过简单易测的土壤性质来建立传递函数从而间接获得土壤饱和导水率(K_(s)),为三峡库区典型农业小流域土壤水分运移及模拟提供数据支撑。[方法]试验以三峡库区石盘丘小流域为研究对象,通过测定典型土地利用类型(耕地、园地、草地... [目的]通过简单易测的土壤性质来建立传递函数从而间接获得土壤饱和导水率(K_(s)),为三峡库区典型农业小流域土壤水分运移及模拟提供数据支撑。[方法]试验以三峡库区石盘丘小流域为研究对象,通过测定典型土地利用类型(耕地、园地、草地)的饱和导水率及其他土壤基本理化性质,结合相关性和主成分分析,分别运用多元线性回归(MLR)、BP神经网络(BP-ANN)、支持向量机(SVM)法构建研究区表层土壤饱和导水率的传递函数模型。在此基础上,选取4种常见的饱和导水率传递函数模型,验证其在本研究区的适用性。[结果]土壤K_(s)均值大小表现为:草地>园地>耕地,且在不同土地利用类型间存在显著差异;土壤饱和导水率与容重、有机质含量、饱和含水量、土壤质地显著相关;与多元线性回归、BP神经网络、支持向量机构建的K_(s)传递函数模型相比,以往采用的土壤传递函数模型对本研究区土壤饱和导水率的预测效果较差,三种方法建立的传递函数预测精度表现为:SVM>BP-ANN>MLR,而采用主成分P 1和主成分P 2作为输入变量的预测精度更佳。[结论]不同土地利用类型下的K_(s)值具有较强的空间变异性,通过BP神经网络和支持向量机构建的饱和导水率传递函数模型能满足本研究区K_(s)预测要求,其中支持向量机法的预测精度优于BP神经网络。 展开更多
关键词 三峡库区 农业小流域 饱和导水率 土壤传递函数 支持向量机 BP神经网络
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Frequency-domain analysis of fluid-structure interaction in aircraft hydraulic pipeline systems: numerical and experimental studies
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作者 Yang DENG Zongxia JIAO Yuanzhi XU 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2024年第8期605-617,共13页
The fluid-structure interaction(FSI)in aircraft hydraulic pipeline systems is of great concern because of the damage it causes.To accurately predict the vibration characteristic of long hydraulic pipelines with curved... The fluid-structure interaction(FSI)in aircraft hydraulic pipeline systems is of great concern because of the damage it causes.To accurately predict the vibration characteristic of long hydraulic pipelines with curved segments,we studied the frequency-domain modeling and solution method for FSI in these pipeline systems.Fourteen partial differential equations(PDEs)are utilized to model the pipeline FSI,considering both frequency-dependent friction and bending-flexibility modification.To address the numerical instability encountered by the traditional transfer matrix method(TMM)in solving relatively complex pipelines,an improved TMM is proposed for solving the PDEs in the frequency domain,based on the matrix-stacking strategy and matrix representation of boundary conditions.The proposed FSI model and improved solution method are validated by numerical cases and experiments.An experimental rig of a practical hydraulic system,consisting of an aircraft engine-driven pump,a Z-shaped aero-hydraulic pipeline,and a throttle valve,was constructed for testing.The magnitude ratio of acceleration to pressure is introduced to evaluate the theoretical and experimental results,which indicate that the proposed model and solution method are effective in practical applications.The methodology presented in this paper can be used as an efficient approach for the vibrational design of aircraft hydraulic pipeline systems. 展开更多
关键词 Fluid-structure interaction(FSI) Frequency-domain analysis Aircraft hydraulic pipeline Pipeline vibration transfer matrix method(TMM)
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涡北煤矿842工作面顶板水力压裂转移侧向采动应力分布规律 被引量:1
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作者 周学斌 《科技和产业》 2024年第9期246-251,共6页
水力压裂技术是实现工作面采动应力转移的重要手段之一。以涡北煤矿842工作面为研究背景,通过数值模拟研究顶板水力压裂技术对842工作面侧向采动应力转移效果和规律的影响。结果表明,水力压裂技术可使距离采空区30 m范围内支承压力有较... 水力压裂技术是实现工作面采动应力转移的重要手段之一。以涡北煤矿842工作面为研究背景,通过数值模拟研究顶板水力压裂技术对842工作面侧向采动应力转移效果和规律的影响。结果表明,水力压裂技术可使距离采空区30 m范围内支承压力有较显著降低,但对距离采空区超过30 m外的区域卸压效果微弱。基于数值模拟结果,开展842工作面风巷水力压裂现场工程实践,结合现场智能钻孔窥视测试结果,发现水力压裂后老顶砂岩中产生了明显的压裂裂隙,为有效阻隔842工作面侧向采动应力向841工作面沿空掘巷传递提供了良好的条件。研究成果对于指导顶板侧向采动应力转移具有一定的理论与工程意义。 展开更多
关键词 水力压裂 应力转移 侧向支承压力 沿空掘巷
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Analysis of the Hydraulic and Heat Transfer Evolution Mechanism of a Single Rock Fracture 被引量:1
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作者 Biao Shu Fan Zeng +3 位作者 John Kemeny Runjun Zhu Keping Chen Jingqiang Tan 《Journal of Earth Science》 SCIE CAS CSCD 2023年第1期205-213,共9页
Mineral dissolution and mechanical deformation of granite are two main mechanisms that affect permeability evolution of rock fracture.In this study,two water flow-through experiments with large granite fractures were ... Mineral dissolution and mechanical deformation of granite are two main mechanisms that affect permeability evolution of rock fracture.In this study,two water flow-through experiments with large granite fractures were conducted at 200 0C with a constant flow rate for 24 h,under confining pressures of 5 and 10 MPa,respectively.Water pressure and temperature were measured,fracture aperture and permeability were calculated,and chemical element concentrations in effluent water were tested for mechanism analysis.The permeability fluctuates up and down between 2.62 × 10^(-12)and 3.16 ×10^(-12)m^(2)at confining pressure of 5 MPa;while it decreased monotonously by 24% from 1.92 × 10^(-12)to1.45 × 10^(-12)m^(2)at a confining pressure of 10 MPa.The heat transfer rates at both experiments stay stable at about 0.25 J/s.The mass concentration of Ca,Na,K,and Si in effluent water are between 5 to 23mg/L,indicating slight dissolution of Ca-plagioclase,Na-plagioclase,and K-feldspar,as well as possible precipitation of minor amount of kaolinite or quartz.The total amount of free-face dissolution and pressure dissolution are similar at 5 and 10 MPa.The geochemical reaction counts for only small part of the aperture change,while the mechanical deformation counts the major part of the aperture change. 展开更多
关键词 geothermal energy PERMEABILITY heat transfer confining pressure hydraulic aperture
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基于智慧水力学的长距离调水工程调度参数预测方法研究
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作者 刘宪亮 许新勇 +1 位作者 陈晓楠 罗全胜 《华北水利水电大学学报(自然科学版)》 北大核心 2024年第3期18-25,共8页
为提高长距离调水工程调度参数的计算精度,提出了智慧水力学的概念,基于南水北调中线工程的运行监测数据,采用人工智能方法开展了长距离调水工程调度参数预测方法研究。在对数据清洗的基础上,基于长短时记忆神经网络(LSTM)模型建立了白... 为提高长距离调水工程调度参数的计算精度,提出了智慧水力学的概念,基于南水北调中线工程的运行监测数据,采用人工智能方法开展了长距离调水工程调度参数预测方法研究。在对数据清洗的基础上,基于长短时记忆神经网络(LSTM)模型建立了白河、十二里河、东赵河节制闸调度参数的预测模型,采用鲸鱼优化算法(WOA)优化模型的超参数并进行调度参数预测。结果表明:3个节制闸的闸前水位和流量预测值与其实测值的最大平均绝对误差分别为0.655 cm和1.326 m^(3)/s,说明智慧水力学理念和人工智能方法在长距离调水工程调度参数预测中的适用性和精准性。研究内容可为实现工程调度参数预测与精准智能调度提供理论基础。 展开更多
关键词 智慧水力学 长距离调水工程 调度参数预测 人工智能 WOA-LSTM模型
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综采工作面支架快速回撤新工艺的设计与应用 被引量:1
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作者 宋凯 《能源与节能》 2024年第3期238-240,257,共4页
永红煤矿综采工作面以往采用的传统支架回撤工艺存在使用绞车多、劳动人数多、工作强度大、工效低、安全性差等问题,严重影响支架回撤效率和安全。针对性设计以液压支架调移装置、单轨吊机车为回撤设备的快速回撤新工艺,在3401综采工作... 永红煤矿综采工作面以往采用的传统支架回撤工艺存在使用绞车多、劳动人数多、工作强度大、工效低、安全性差等问题,严重影响支架回撤效率和安全。针对性设计以液压支架调移装置、单轨吊机车为回撤设备的快速回撤新工艺,在3401综采工作面进行实践应用。结果表明,采用支架快速回撤新工艺仅用20 d安全高效完成138架支架的拆、装、运及收口任务,对比以往支架回撤时间提前6 d,回撤费用节约4.4×10^(5)元,在保障生产安全的前提下提升了经济效益。 展开更多
关键词 永红煤矿 支架 回撤 液压支架调移装置 单轨吊机车
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基于相变复合材料的新型液压油箱设计及研究
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作者 张列 李良 +2 位作者 冯永保 何祯鑫 韩小霞 《兵器装备工程学报》 CAS CSCD 北大核心 2024年第3期238-246,共9页
针对液压系统存在“低温启动困难”和“高温散热效率低”的矛盾问题,影响了液压系统设备性能的整体提升。设计一种采用相变复合材料构建的新型液压油箱结构,利用ANSYS软件对先后添加复合相变材料新型油箱进行建模与仿真,得出径向传热、... 针对液压系统存在“低温启动困难”和“高温散热效率低”的矛盾问题,影响了液压系统设备性能的整体提升。设计一种采用相变复合材料构建的新型液压油箱结构,利用ANSYS软件对先后添加复合相变材料新型油箱进行建模与仿真,得出径向传热、瞬态传热等仿真云图并进行分析比较传热梯度的变化。仿真结果证实,相变复合材料能够快速吸收油液的热量,从而散热效果高于普通油箱。并且针对油箱传热的不同影响因素进行了仿真分析,得出油箱材料、环境温度、载荷温度仿真云图,仿真结果表明,利用相变复合材料的高储能及高导热特性,在低温条件下,液压油能够在油箱中快速均匀加热以及在高温条件下高效散热,提高油箱的换热效率,减小油箱体积,使其具备“容积小、导热快、换热面积大、油液加热均匀、对极端温度条件适应能力强”等优点,对延长液压油及液压元件的使用寿命,提高液压系统设备的工作可靠性和生存能力具有重要意义。 展开更多
关键词 相变复合材料 液压油箱 换热效率 瞬态传热 数值模拟
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