蒸腾计

More meaningful comparisons can be made by comparing water loss from the potometer with that from an atmometer (an apparatus used to measure the rate of evaporation from a porous pot or other nonliving wet surface), which allows uncontrolled evaporation.

更有意义的是，可以比较蒸腾计的失水与蒸发计（通过有孔小罐或者潮湿表面来测量蒸发速率的仪器）的失水间的区别。

The fourth chapter analysesthe differences of the resistance between the boundariescalculated by different models.It can seen from the results thatthe differences between resistances calculated by variousfunctions can ignored under unstable conditions.There areobvious differences between different resistances calculated bydifferent functions under stable conditions.However,in bothcases,error from any function to predict transpiration rate isignoble.In order to make more applicable,the Monteith modelwas fished in this chapter.

第四章分析了各种边界层阻力计算模型计算结果的差异，比较结果表明，在空气层结不稳定时，各种φm函数经验模型计算阻力的差异可忽略，而当空气层结稳定时各种φm函数经验模型所算边界层阻力有明显差异，但不论是稳定和非稳定层结下，任选一中φm函数计算模型对蒸腾速率计算结果所造成的差异可忽略，为便于应用，本章还比较和检验了Monteith模型计算结果的差异，结果表明，该模型用于蒸腾计算，其误差可忽略不计。

Rna - Rns, see "Partitioning of net radiation", for multiple plants the fraction of radiation to each plant is calculated in the radiation section, see "Partitioning of radiation between plants", es is the vapour pressure at saturation, ea is the actual vapour pressure,ρa is air density, cp is the specific heat of air at constant pressure, Lν is the latent heat of vaporisation,Δ is the slope of saturated vapour pressure versus temperature curve,γ is the psychrometer "constant", rs is an "effective" surface resistance and ra is the aerodynamic resistance.

潜在蒸腾量 Etp 根据Monteith(1965)给出的彭曼联合方程形式计算：式中： Rn 为对于蒸腾的有效净辐射量(也就是 Rna - Rns ，见"净辐射划分"-Partitioning of net radiation，对于多重植被，每一株植物的辐射比率的计算见辐射一节的"植物间的辐射划分"Partitioning of radiation between plants)； es 为饱和水气压；ea 为实际水气压；ρa 为空气密度； cp 为常压下的空气比热；Lν为汽化潜热；Δ为与温度曲线饱和水气压关系曲线斜率；γ为干湿球湿度计"常数"；rs 为"有效"表面阻力；ra 为气动阻力。

The paper focuses on the tetraploidy black locust on Loess plaeatu of West Shanxi province, applys steady state promoter method and image processing technology to study the days transpiration water consumption in different weather ,different seasons and different site conditions,has primary analysis on the impact of environment on the transpiration and carries on the calculation to the tetraploidy locust tree by the single leaf water consumption to the single tree water consumption in CaiJiachuan watershed; Uses fast weighing method to measure and analyze the transpiration water consumption of five different herbs under the tetraploidy black locust forest (Capillary Wormwood,Vanilla,Agropyron Sristatum , Common Sowthistle and Medicago Sativa) in short time, in the same and different growcrop,and calculates the average transpiration water consumption per square metres ;the soil colome weighing method was used for determining diumal variation quantity of soil moisture evaporation, analyzing the dynamic variation and caculating the total quantity of soil evaporation water consumption from May to August ; then 5 kind of suppositions about the types of surface vegetation coverage are proposed in experimented site and the total evapotranspiration water consumption are calculated under 5 suppoitions ,aim at providing preliminary theoretic basis for ascertaining the transpiration water consumption of tetraploidy black locust forest,controling standing forest density and optimizing the forest grass deploy on loess plaeatu of west Shanxi province .

本文以两种不同立地条件下的四倍体刺槐林为研究对象，采用了气孔计法对蔡家川流域生长季内不同天气状况下(典型晴天、阴天和半阴天)四倍体刺槐日蒸腾耗水规律、不同季节(生长季初期、中期和末期)的蒸腾耗水规律、两种不同立地条件下四倍体刺槐蒸腾耗水比较以及影响四倍体刺槐蒸腾耗水的环境因子进行初步研究分析，并对四倍体刺槐由单叶耗水量向单株耗水量进行推算；采用经典快速连续称重法对四倍体刺槐林地生长的主要5种草本植物(白蒿、香青兰、冰草、苦苣和苜蓿)短时段内蒸腾耗水规律、不同生长季内蒸腾耗水规律、同一生长季不同种类草本植物蒸腾耗水量进行了比较分析，并且采用面积与重量比的方法推算出了单位面积四倍体刺槐林地几种主要草本植物平均蒸腾耗水量：采用土柱称重法测定了5月份～8月份土壤水分蒸发昼夜变化量、对试验期内土壤蒸发量动态变化作了分析、推算出了试验地5月份～8月份土壤蒸发耗水总量；对试验地地表植被覆盖类型提出了5种假设，推算出5种假设的情景下蒸散耗水总量，旨在为晋西黄土区四倍体刺槐林蒸腾耗水量的确定、林分密度调控以及林草优化配置等提供初步的理论依据。

An LI-1600 porometer was used to measure transpiration of Artemisia ordosica and Caragana korshinskii in four quadrats of a soil water balance experimental plot at the Shapotou Desert Research and Experiment Station.

本研究利用LI-1600气孔计测定了沙坡头试验站土壤水分平衡观测场4个样地的油蒿和柠条的蒸腾。

Many researchers have determined and estimated tree transpiration by using the methods of rapid weighting, steady-state porometer, photosynthesis system, whole-tree photometer, ventilated chamber, weighting potted-plant, sap flow measurements, lysimeter, water balance, energy balance, Bowen ratio, eddy covariance, Penman-monteith Method, and remote sensing.

针对不同的植被覆盖类型，国内外许多研究通过各种手段和方法，如快速称量、稳态气孔计、光合作用测定、整树容器、风调室、盆栽称量、液流测定法、蒸渗仪、水量平衡、能量平衡、波文比、涡动相关、彭曼联合法和遥感等来估算林木蒸腾作用。

Peanut or rice wereplanted in the large-scale weighing Lysimeter,pit plots,and standard runoff plots,wherehigh,moderate,and low soil moisture levels were designed as 3 treatments,assemblingwith some instruments such as time domain reflectometry,portable photosynthesis system,dew point microvoltmeter,and porometer.

季节性干旱缺水严重制约着我国红壤区农业的持续发展。1999～2000年在中国科学院红壤生态实验站，利用大型称重式蒸渗仪、测坑小区和径流小区，配合时域反射仪、光合蒸腾仪、水势仪及动态气孔阻力计等仪器，设计高、中、低3种土壤水分处理，进行了花生和早晚稻试验。

Rna - Rns, see "Partitioning of net radiation", for multiple plants the fraction of radiation to each plant is calculated in the radiation section, see "Partitioning of radiation between plants", es is the vapour pressure at saturation, ea is the actual vapour pressure,ρa is air density, cp is the specific heat of air at constant pressure, Lν is the latent heat of vaporisation,Δ is the slope of saturated vapour pressure versus temperature curve,γ is the psychrometer "constant", rs is an "effective" surface resistance and ra is the aerodynamic resistance.

潜在蒸腾量 Etp 根据Monteith(1965)给出的彭曼联合方程形式计算：式中： Rn 为对于蒸腾的有效净辐射量(也就是 Rna - Rns ，见&净辐射划分&-Partitioning of net radiation，对于多重植被，每一株植物的辐射比率的计算见辐射一节的&植物间的辐射划分&Partitioning of radiation between plants)； es 为饱和水气压；ea 为实际水气压；ρa 为空气密度； cp 为常压下的空气比热；Lν为汽化潜热；Δ为与温度曲线饱和水气压关系曲线斜率；γ为干湿球湿度计&常数&；rs 为&有效&表面阻力；ra 为气动阻力。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。