液流目视指示器

HPV 茎流量传感器/Sap Flow SensorHPV茎流量传感器是一款校准型、低成本的热脉冲液流传感器，输出校准液流量、热速、茎水含量、茎温等数据，功耗低，内置加热控制，同时改善了传统的加热方式，其原理采用双方法（DMA）热脉冲法，测量范围：-200~+1000cm/hr(热流速度)或-100~+2000cm3/cm2/hr (茎流通量密度)，可广泛用于于茎流量监测、植物茎流蒸发计算、植物茎流蒸腾量、植物灌溉等植物茎流是树木内部的“水”运动，而蒸腾是从叶片通过光合作用蒸发流出的水分。树液流量和蒸腾量之间有很强的关联性，通常理解是同一回事。但是，严格地说，它们是不同的，这体现在它们是如何被测量的。SAP流量以L/hr（或每天、每周等）为单位进行测量。蒸腾量以每小时、每天、每星期等毫米（mm）为单位测量。 蒸散量=蒸腾量+蒸发量 蒸腾量以毫米为测量单位，可与降雨量以毫米计作比较。随着时间的推移，降雨量（水输入）应与蒸腾量（输出）相匹配。如果蒸腾作用更高，通常是树木作物的蒸腾作用，那么这种差异必须通过灌溉来弥补。 蒸发量（evaporation），蒸发量是指在一定时段内，由土壤或水中的水分经蒸发而散布到空中的量。1mm(降雨量)=1㎡地面1kg水1mm(蒸腾量)=1㎡叶面积的1升树液流量（水） 例如：在果园和葡萄园等有管理的树木作物系统中，蒸发量与蒸腾量相比非常小。因此，为了简化测量，通常忽略蒸发量，将蒸腾量取为平均蒸散量（ETo）。 技术指标测量范围：-200~+1000cm/hr(热流速度)分辨率：0.001cm/hr准确度：±0.1cm/hr探针尺寸：φ1.3mm*L30mm温度位置：外10mm，内20mm针距：6mm探针材质：316不锈钢温度范围：-30~+70℃响应时间：200ms加热电阻：39Ω，400J/m电源：12V DC电流：空闲5mA, 测量270mA信号输出：SDI-12线缆：5m，最大60m茎流量传感器参考文献：1. Kim, H.K. Park, J. Hwang, I. Investigating water transport through the xylem network in vascular plants.J. Exp. Bot. 2014, 65, 1895–1904. [CrossRef] [PubMed]2. 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A comparison of sap flux density using thermaldissipation, heat pulse velocity and heat field deformation methods. Agric. For. Meteorol. 2010 , 150, 1046–1056. [CrossRef]30. López-Bernal, A. Testi, L. Villalobos, F.J. A single-probe heat pulse method for estimating sap velocity in trees. New Phytol. 2017, 216, 321–329. [CrossRef] [PubMed]31. Forster, M.A. How significant is nocturnal sap flow? Tree Physiol. 2014, 34, 757–765. [CrossRef] [PubMed]32. Cohen, Y. Fuchs, M. Falkenflug, V. Moreshet, S. Calibrated heat pulse method for determining water uptake in cotton. Agron. J. 1988, 80, 398–402. [CrossRef]33. Cohen, Y. Takeuchi, S. Nozaka, J. Yano, T. Accuracy of sap flow measurement using heat balance and heat pulse methods. Agron. J. 1993, 85, 1080–1086. [CrossRef]34. Lassoie, J.P. Scott, D.R.M. Fritschen, L.J. Transpiration studies in Douglas-fir using the heat pulse technique. For. Sci. 1977, 23, 377–390.35. Wang, S. Fan, J. Wang, Q. Determining evapotranspiration of a Chinese Willow stand with three-needleheat-pulse probes. Soil Sci. Soc. Am. J. 2015, 79, 1545–1555. [CrossRef]36. Bleby, T.M. Burgess, S.S.O. Adams, M.A. A validation, comparison and error analysis of two heat-pulse methods for measuring sap flow in Eucalyptus marginata saplings. Funct. Plant Biol. 2004 , 31, 645–658.[CrossRef]37. Madurapperuma, W.S. Bleby, T.M. Burgess, S.S.O. Evaluation of sap flow methods to determine water use by cultivated palms. Environ. Exp. Bot. 2009, 66, 372–380. [CrossRef]38. Green, S.R. Measurement and modelling the transpiration of fruit trees and grapevines for irrigationscheduling. Acta Hortic. 2008, 792, 321–332. [CrossRef]39. Intrigliolo, D.S. Lakso, A.N. Piccioni, R.M. Grapevine cv. ‘Riesling’ water use in the northeastern UnitedStates. Irrig. Sci. 2009, 27, 253–262. [CrossRef]40. Eliades, M. Bruggeman, A. Djuma, H. Lubczynski, M. Tree water dynamics in a semi-arid, Pinus brutiaforest. Water 2018, 10, 1039. 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[CrossRef]创新点：HPV茎流量传感器是一款校准型、低成本的热脉冲液流传感器，输出校准液流量、热速、茎水含量、茎温等数据，功耗低，内置加热控制，同时改善了传统的加热方式，其原理采用双方法（DMA）热脉冲法，测量范围：-200~+1000cm/hr(热流速度)或-100~+2000cm3/cm2/hr (茎流通量密度)，可广泛用于于茎流量监测、植物茎流蒸发计算、植物茎流蒸腾量、植物灌溉等植物茎流是树木内部的“水”运动，而蒸腾是从叶片通过光合作用蒸发流出的水分。树液流量和蒸腾量之间有很强的关联性，通常理解是同一回事。但是，严格地说，它们是不同的，这体现在它们是如何被测量的。HPV 植物茎流传感器/植物液流计

全钒液流电池储能技术通过不同价态的金属钒离子相互转化实现电能的存储与释放，具有本质安全、设计灵活、成熟度高的特点。该技术是双碳战略下国家电力系统长时储能领域首选的电化学储能技术路线。 “新一代100MW级全钒液流电池储能技术及应用示范”作为国家“十四五”重点研发计划支持项目，对高性能全钒液流电池储能系统运行提出了更高的性能要求。而电极系统作为钒离子电化学氧化还原反应发生的媒介，其传质特性与活化特性直接决定全钒液流电池的转换效率。 因此，开发适用于工程化应用的电极结构优化策略与材料调控方法，是实现高性能全钒液流电池运行的基础与核心。近期，中国科学院金属研究所材料腐蚀与防护中心腐蚀电化学课题组在高性能全钒液流电池储能技术研究领域取得一系列新进展。科研人员在深入理解电池极化特性的基础上，以电极系统传质特性和电化学活性为切入点，以工程化应用为导向，先后通过引入流场优化设计和电极改性调控，显著降低了电池浓差极化与活化极化，实现了全钒液流电池高性能长循环运行。 全钒液流电池正负极以不同价态钒离子为活性物质，以水系溶液为支持电解质，具有环境友好和容量可恢复等优势，但受电极内部活性物质传质特性和流阻的局限，目前高功率全钒液流电池电堆运行仍面临挑战。 针对这一问题，研究人员运用有限元仿真与实验相结合的方式，通过在电极系统中引入结构化流场设计，开展传质、传动量与电化学反应多物理场耦合作用下的电池内部模拟分析（图1），优化了高电流密度下电极内部的传质特性，协同降低了电池浓差极化与流动阻力，有效提升了高电流密度下单电池的转换效率。 同时，对32kW电堆的动态模拟预测显示，电堆在200 mA cm-2高电流密度下恒流运行系统转换效率可提升约15%（图2），为实现高功率电堆设计与开发提供了新方法与新途径。相关成果以Regulating flow field design on carbon felt electrode towards high power density operation of vanadium flow batteries为题，发表在《化学工程杂志》（Chemical Engineering Journal 2022, 450, 138170）上。 传质特性的优化在提升全钒液流电池高功率运行方面展示了显著效果，但全钒液流电池负极侧V2+/V3+迟缓的电化学动力学特性仍在一定程度制约了全钒液流电池高功率运行下的转换效率。针对这一问题，在课题组前期杂原子掺杂调控电极的研究基础上，科研人员提出了工程化易操作的基于固-固转化的电脱氧工艺方法。 该方法在碱性条件下通过还原涂覆在电极纤维界面Bi2O3粉末，制备了具有高氧化还原可逆性的Bi负载电极（图3），显著提升了负极V2+/V3+电化学动力学特性。理论计算进一步揭示了V-3d和Bi-6p轨道杂化作用对电荷转移过程的促进作用。以此为基础组装的全电池实现了350 mA cm-2电密下450个循环73.6%的稳定能量转换效率输出（图4），400 mA cm-2高电密下运行转换效率有效提升近10%，为高功率电堆开发提供了技术支撑。相关成果以Boosting anode kinetics in vanadium flow batteries with catalytic bismuth nanoparticle decorated carbon felt via electro-deoxidization processing为题，发表在《材料化学杂志A》（Journal of Materials Chemistry A，DOI：10.1039/D2TA09909H）上。 图3.(a)电脱氧制备工艺；(b)热力学计算和脱氧反应机理；(c)电解池示意图及循环伏安曲线图；(d)还原电位及表面形貌图；(e)电极成分表征。图4.(a)电极物理及电化学表征；(b)界面电化学理论计算；(c)全钒液流电池实验。

TA仪器网络讲堂-关于胶体悬浮液流变的介绍如欲参加此次网络讲堂或收看录播版本，请直接点击如下链接：https://event.on24.com/eventRegistration/EventLobbyServlet?target=registration.jsp&eventid=824443&sessionid=1&key=F601B31A4694634578D156D4F8C28659&sourcepage=register 胶体悬浮体系在自然现象和工业产品及过程中非常常见，从涂料、油墨到食品、药品、胶体粒子形成的溶胶、凝胶以及玻璃等均表现出复杂、多变的流变行为。本网络讲座主要展示这类体系丰富多彩的流变特征并从布朗运动、表面张力以及流体动力学等微观尺度上揭示其成因。将重点阐述流场、微观结构及其力学响应之间的关联关系以及和究胶体悬浮体系的策略和方法。