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1.
刘丽慧  孙皓  李传华 《地理研究》2021,40(5):1253-1264
Biome-BGC模型被广泛用于估算植被净初级生产力(Net Primary Productivity, NPP),但是该模型未考虑冻土区土壤冻融水循环过程对植被生长的影响。本文基于Biome-BGC模型,改进冻土区活动层土壤冻融水循环,估算了2000—2018年青藏高原高寒草地NPP。通过比较原模型和改进后的模型,并对NPP模拟结果的时空特征进行了分析,结果表明:① 增加冻融循环提高了NPP估算精度,青藏高原草地NPP均值由114.68 gC/(m2·a)提高到128.02 gC/(m2·a)。② 原模型和改进后NPP的空间分布差异较大,时间变化趋势差异不明显。③ 青藏高原草地NPP总量为253.83 TgC/a,呈东南向西北递减的空间格局,年均增速为0.21gC/(m2·a)(P=0.023),显著增加的占17.85%,主要分布在羌塘高寒草原地带的大部分地区和藏南山地灌木草原地带的西部。④ 该冻融水循环改进方法简单可靠,具有在其他多年冻土区推广的价值。  相似文献   

2.
黄河源区冻土分布制图及其热稳定性特征模拟   总被引:5,自引:0,他引:5  
以黄河源区多年冻土分布现状和热力特征为研究目标,通过野外调查及实测数据,分析了黄河源区不同地形地貌、不同地表覆盖条件下的冻土形成、分布特征和以地温为基础的热学特征,探讨了不同尺度因素对多年冻土分布的影响。结果表明,在高程低于4 300 m的平原区,多年冻土多不发育;在高于4 350 m的山区,局地地形对多年冻土的形成与分布作用显著。除阳坡地形外,多年冻土均比较发育;介于4 300~4 350 m的低山丘陵和平原区,局地地形、地表植被、土壤湿度等因素共同决定着多年冻土的形成和分布格局。以年均地温指标为基础,构建了以纬度、经度和高程为自变量的回归模型,并对阳坡地形进行微调和校正。结果表明,以0oC作为划分季节冻土和多年冻土的标准和界限,多年冻土面积2.5×104km2,约占整个源区面积的85.1%;季节冻土面积0.3×104km2,约占整个源区面积的9.7%。进一步以0.5oC或1.0oC为分类间隔绘制了黄河源区多年冻土热稳定性空间分布图。  相似文献   

3.
Soil freeze-thaw process is closely related to surface energy budget,hydrological activity,and terrestrial ecosystems.In this study,two numerical experiments(including and excluding soil freeze-thaw process)were designed to examine the effect of soil freeze-thaw process on surface hydrologic and thermal fluxes in frozen ground region in the Northern Hemisphere based on the state-of-the-art Community Earth System Model version 1.0.5.Results show that in response to soil freeze-thaw process,the area averaged soil temperature in the shallow layer(0.0175?0.0451 m)decreases by 0.35℃in the TP(Tibetan Plateau),0.69℃in CES(Central and Eastern Siberia),and 0.6℃in NA(North America)during summer,and increases by 1.93℃in the TP,2.28℃in CES and 1.61℃in NA during winter,respectively.Meanwhile,in response to soil freeze-thaw process,the area averaged soil liquid water content increases in summer and decrease in winter.For surface heat flux components,the ground heat flux is most significantly affected by the freeze-thaw process in both summer and winter,followed by sensible heat flux and latent heat flux in summer.In the TP area,the ground heat flux increases by 2.82 W/m2(28.5%)in summer and decreases by 3.63 W/m2(40%)in winter.Meanwhile,in CES,the ground heat flux increases by 1.89 W/m2(11.3%)in summer and decreases by 1.41 W/m2(18.6%)in winter.The heat fluxes in the Tibetan Plateau are more susceptible to the freeze-thaw process compared with the high-latitude frozen soil regions.Soil freeze-thaw process can induce significant warming in the Tibetan Plateau in winter.Also,this process induces significant cooling in high-latitude regions in summer.The frozen ground can prevent soil liquid water from infiltrating to deep soil layers at the beginning of thawing;however,as the frozen ground thaws continuously,the infiltration of the liquid water increases and the deep soil can store water like a sponge,accompanied by decreasing surface runoff.The influence of the soil freeze-thaw process on surface hydrologic and thermal fluxes varies seasonally and spatially.  相似文献   

4.
龚婷婷  高冰  吉子晨  曹慧宇  张蕴灵 《地理科学》2022,42(10):1848-1856
基于MODIS温度数据,采用TTOP模型和Stefan公式模拟了青藏高原地区的冻土分布并计算了活动层厚度,并与地面观测结果进行了对比。结果表明:2003—2019年青藏高原多年冻土面积为1.01×106 km2;多年冻土活动层厚度区域平均值为1.79 m, 活动层厚度区域平均的变化率为3.67 cm/10a,且草甸地区的变化率明显大于草原地区,5100~5300 m高程带的活动层厚度变化速率最大。  相似文献   

5.
河西走廊不同强度冷锋型沙尘暴环流和动力特征   总被引:1,自引:1,他引:0  
利用常规气象观测资料、ECMWF ERA-Interim 逐6 h的0.75°×0.75°再分析资料,对河西走廊3次不同强度区域性典型冷锋型沙尘暴的大气环流形势和高低层水平螺旋度、uv分量场和垂直速度进行对比分析。结果表明:(1)影响沙尘暴强度和范围的主要因素有高空冷空气强度、高低空风速、地面热低压中心、冷锋前后变压梯度以及冷锋入侵河西走廊的时间;(2)700 hPa风速和冷锋入侵河西走廊的时间影响最明显,低空风速越大,沙尘暴往往越强,强沙尘暴一般出现在中午到傍晚。一般、强和特强沙尘暴700 hPa风速阈值分别为18、22 m·s-1和24 m·s-1;(3)高(低)层正(负)水平螺旋大值中心越大,配合越好,下游沙尘暴强度越强,一般、强和特强沙尘暴的高(低)层水平螺旋度正(负)值中心阈值分别为400(-200)m2·s-2、800(-1 000)m2·s-2和1 000(-1 000)m2·s-2;(4)高空强风动量下传到近地面的风速越大,沙尘暴强度越强,一般、强和特强沙尘暴下传到近地面的uv分量风速阈值分别为8、10 m·s-1和12 m·s-1;(5)700 hPa以下上升运动越强,沙尘暴强度越强,一般、强和特强沙尘暴700 hPa以下垂直速度中心阈值分别为-0.4、-0.7 Pa·s-1和-1.40 Pa·s-1;(6)垂直风场表现为≥15 m·s-1大风下传高度越低,沙尘暴强度越强,一般、强和特强沙尘暴下传高度分别为600、500 m和50 m以下。  相似文献   

6.
提出以无人机季节航拍影像为数据源,采用ENVI5.3软件中的CART方法对广西北部湾的典型岛群红树林景观类型进行解译,借助于Python语言实现CASA模型并将其引入到对岛群红树林生态系统的研究中,得出了不同海岛和红树林生态系统净初级生产力(NPP)的空间分布特征。结果表明:1)可见光波段差异性植被指数(VDVI)可以很好地区分海岛及红树林植被等典型地物,可应用在岛群红树林生态系统NPP的估算上;2)研究区NPP的总量为127.09 t·C/a,NPP的年均碳密度值介于0~1 437.12 g·C/m2,年均碳密度为399.85 g·C/m2。红树林生态系统的NPP值较高,而海岛生态系统的NPP值较低;3)季节尺度上NPP碳密度的大小与年内太阳辐射有直接的关系,夏季的NPP碳密度最大,冬季最小;4)白骨壤的单位面积NPP最大,为1 123.09 g·C/m2,而桐花树最小,为649.65 g·C/m2。红树林生态系统NPP平均碳密度低于实测样地和深圳福田红树林计算结果,这与不同红树林群落的植被光谱特征有关。  相似文献   

7.
In the last several decades, the underlying surface conditions on the Qinghai-Tibet Plateau have changed dramatically, causing permafrost degradation due to climate change and human activities. This change severely influenced the cold regions environment and engineering infrastructure built above permafrost. Permafrost is a product of the interaction between the atmosphere and the ground. The formation and change of permafrost are determined by the energy exchange between earth and atmosphere system. Fieldwork was performed in order to learn how land surface change influenced the thermal regime in permafrost regions. In this article, the field data observed in the Fenghuo Mountain regions was used to analyze the thermal conditions under different underlying surfaces on the Qinghai-Tibet Plateau. Results show that underlying surface change may alter the primary energy balance and the thermal conditions of permafrost. The thermal flux in the permafrost regions is also changed, resulting in rising upper soil temperature and thickening active layer. Vegetation could prevent solar radiation from entering the ground, cooling the ground in the warm season. Also, vegetation has heat insulation and heat preservation functions related to the ground surface and may keep the permafrost stable. Plots covered with black plastic film have higher temperatures compared with plots covered by natural vegetation. The reason is that black plastic film has a low albedo, which could increase the absorbed solar radiation, and also decrease evapotranspiration. The "greenhouse effect" of transparent plastic film might effectively reduce the emission of long-wave radiation from the surface, decreasing heat loss from the earth's surface, and prominently increasing ground surface temperature.  相似文献   

8.
青土湖区域属于绿洲—荒漠过渡带,生态系统脆弱,极易发展为荒漠。梭梭、白刺和芦苇为青土湖区域的植被优势种,对其生态系统稳定与健康发展起着关键作用。以青土湖区域梭梭、白刺和芦苇为研究对象,利用空间分辨率为0.5 m的高分辨率遥感影像Worldview-2,采用辅以纹理特征的面向对象分类方法,提取梭梭和白刺的冠幅面积以及芦苇的分布面积;根据野外试验数据,建立梭梭和白刺地上生物量与冠幅面积、芦苇地上生物量与分布面积关系模型。利用关系模型、冠幅面积以及分布面积对青土湖区域植被优势种地上生物量进行了估算,实现了植被优势种地上生物量估算由“点”到“面”的转换。结果表明:(1) 采取辅以纹理特征的面向对象分类方法取得了较高的分类精度,总体Kappa系数为87.9%,总体精度达到91.3%。(2) 研究区植被优势种地上生物量总量为3.17×103 t,其中梭梭地上生物量为0.54×103 t,白刺地上生物量为0.90×103 t,芦苇地上生物量为1.73×103 t,地上生物量芦苇>白刺>梭梭。该研究可以为深入研究青土湖区域生态恢复与碳储量提供参考。  相似文献   

9.
i
Terrestrial heat flow has been measured in three Alpine railroad tunnels. The geothermal gradients were calculated from temperatures measured during the construction of the tunnels, and corrections for topographic irregularities were made. The thermal conductivity of 113 rock specimens from the vicinity of the tunnels was measured. The heat flow in the Gotthard tunnel was found to be 1.6 10-6 cal/cm2 sec, in the Simplon 2.2 10-6 cal/cm2 sec, and in the Loetschberg 1.9 10-6 cal/cm2 sec. Most of the flux at the surface can be attributed to radioactive decay in a thickened crust, but a non-uniform distribution of radioactive elements may be required to explain the relatively high heat flow in the Simplon and Loetschberg tunnels.  相似文献   

10.
利用2009-2011年塔克拉玛干沙漠大气环境观测试验站测得的土壤热通量数据,分析了塔克拉玛干沙漠腹地土壤热通量在不同天气条件下的变化特征。结果表明:(1)塔克拉玛干沙漠腹地1 cm处土壤热通量年平均值为1.9 W·m-2,5、20、40 cm处分别为1.0、0.4、0.4 W·m-2;1 cm处土壤热通量年最大值为334.1 W·m2,年最小值为-184.2 W·m-2;土壤热通量基本表现为夏季 > 春季 > 秋季 > 冬季。(2)各土层土壤热通量具有明显的日变化特征。随着土壤深度的加大,土壤热通量的日变化幅度明显减小,最大值出现的时间有一定的滞后性。土壤热通量5 cm出现最大值的时间比1 cm处延迟3 h,延迟速率为0.75 h·cm-1,20 cm比5 cm出现最大值的时间晚2 h,延迟速率约为0.13 h·cm-1。(3)不同天气情况下的土壤热通量日变化特征有一定的差异,晴天较为规则,阴天、雨天、沙尘天则较不规则,且1 cm处土壤热通量受天气影响最显著。晴天1 cm处土壤热通量平均值为9.0 W·m-2;阴天、雨天、沙尘天1 cm处土壤热通量值平均值分别为5.1、-6.1、-1.9 W·m-2。  相似文献   

11.
研究和确定流域生态基流及天然植被需水量是为了遏制因河道断流或流量减少而造成的生态环境退化,以确保流域生态系统健康发展。根据孔雀河流域植被类型分布及多年径流状况,将河道分为A、B两部分,A段为孔雀河上游塔什店至第三分水枢纽常年未断流河道;B段为第三分水枢纽以下天然植被主要分布区。基于塔什店水文站近50 a水文数据,结合Tennant法等4种方法对A段河道生态基流进行估算;选择潜水蒸发法、定额法对B段距河道1 km辐射范围内的天然植被需水量进行计算。结果表明:Tennant法估算的年均生态基流为9.13 m3·s-1,对应基本生态水量为2.88×108 m3·a-1,满足A段河道2000—2018年多年平均河损,且近10 a(2009—2018年)塔什店实测年均流量均可满足此生态基流标准;B段河道辐射范围内天然植被总面积为4.66×104 hm2,生态需水量为0.95×108 m3·a-1,以孔雀河生态输水工程为例科学调控水资源,在满足A段基本生态基流的同时兼顾B段天然植被需水量。研究结果对实现孔雀河河道修复和不同水平年下生态供水具有一定的意义。  相似文献   

12.
浅层地温能的开发利用有助于优化区域能源结构、节约常规化石能源、减少CO2排放。为掌握兰州新区浅层地温能的适宜性特点,对该类资源的开发规划和政府决策提供科学依据,以兰州新区建成区和规划区为研究对象,在分析区内浅层地温能赋存条件的基础上,依据掌握的多年实际勘查资料和测试数据,通过综合运用改进的层次分析法、综合指数法,对兰州新区440 km2的区域进行了土壤源热泵系统适宜性评价分析。结果表明:(1) 兰州新区拥有较为优异的浅层地温能赋存条件,区内地层结构简单且分布稳定,岩土体综合热导率、比热容、地温梯度均较高,十分有利于土壤源热泵系统的应用;而受到含水层富水性弱、水质差等因素的影响,地下水源热泵系统适宜性差。(2) 基于层次分析法建立的适宜性评价模型共划分3个属性准则和7个要素指标,采用指数标度分别构建了各层次的判断矩阵,并全部高精度通过一致性检验,同时优化了各要素参数的无量纲化方法,构建的评价模型更符合实际。(3) 研究区内对于土壤源热泵适宜性影响较大的要素主要是平均热导率和地温梯度。评价显示兰州新区土壤源热泵系统适宜、较适宜区总面积359.46 km2,占评价区总面积的81.70%,主要分布于秦王川盆地平原区,其余丘陵山区地带不适宜土壤源热泵系统的建设。评价结果对兰州新区乃至其他地质条件类似地区土壤源热泵系统的开发利用规划具有指导意义。  相似文献   

13.
毛乌素沙地植被水分利用效率的时空格局   总被引:1,自引:1,他引:0  
水分利用效率(WUE)是衡量生态系统碳水循环耦合程度的重要指标,明晰其动态变化规律有助于判断区域植被生态建设是否与当地的自然条件相适应。利用基于CASA(Carnegie-Ames-Stanford Approach)模型得到的植被净初级生产力(NPP)数据和MODIS系列产品中的蒸散发(ET)数据,估算了2001—2016年毛乌素沙地植被的WUE,并探讨了其时空演变特征及与气象因子的关系。结果显示:(1)WUE的多年平均值为0.62 gC·mm-1·m-2,空间上自东向西递减,在不同植被类型间表现为栽培植物>灌丛>草甸>草原>荒漠;(2)WUE以0.009 gC·mm-1·m-2·a-1的速率上升,东部地区变化尤为显著,NPP的快速增长是WUE呈增加趋势的主要原因;(3)WUE与各气象因子的相关程度由大至小依次为太阳辐射、降水量、风速和气温,分布在西部地区的荒漠植被WUE受气象因子影响最小。经过一系列生态建设工程的治理,毛乌素沙地大部分地区自2001年以来NPPWUE均呈增加趋势,即生态系统在变“绿”的同时还实现了水分的高效利用,有利于当地生态环境的健康发展;但在水热条件较差的中西部地区,新建设的植被生长缓慢且导致蒸散发产生强烈变化,使WUE呈减少趋势,暴露出植被建设规模与水资源承载能力不匹配的问题,需引起格外重视。  相似文献   

14.
Permafrost thickness under identical climates in cold regions can vary significantly because it is severely affected by climate change, topography, soil physical and thermal properties, and geothermal conditions. This study numerically in- vestigates the response of ground thermal regime and talik development processes to permafrost with different thicknesses under a thermokarst lake on the Qinghai-Tibet Plateau. On the basis of observed data and information from a representative monitored lake in the Beiluhe Basin, we used a heat transfer model with phase change under a cylindrical coordinate system to conduct three simulation cases with permafrost thicknesses of 45 m, 60 m, and 75 m, respectively. The simulated results indicate that increases in permafrost thickness not only strongly retarded the open talik formation time, but also delayed the permafrost lateral thaw process after the formation of open talik. Increasing the permafrost thickness by 33.3% and 66.7% led to open talik formation time increases of 83.66% and 207.43%, respectively, and resulted in increases in the lateral thaw duration of permafrost under the modeled thermokarst lake by 28.86% and 46.54%, respectively, after the formation of the open taliks.  相似文献   

15.
黄河源区多年冻土空间分布变化特征数值模拟   总被引:3,自引:1,他引:2  
马帅  盛煜  曹伟  吴吉春  胡晓莹  王生廷 《地理学报》2017,72(9):1621-1633
基于IPCC第五次评估报告预估的气温变化情景,采用数值模拟的方法对黄河源区典型冻土类型开展模拟,推算过去及预测未来黄河源区冻土分布空间变化过程和发展趋势。结果表明:1972-2012年源区多年冻土只有少部分发生退化,退化的冻土面积为833 km2,季节冻土主要集中在源区东南部的热曲谷地、小野马岭以及两湖流域南部的汤岔玛地带;RCP 2.6、RCP 6.0、RCP 8.5情景下,2050年多年冻土退化为季节冻土的面积差别不大,分别为2224 km2、2347 km2、2559 km2,占源区面积的7.5%、7.9%、8.6%;勒那曲、多曲、白马曲零星出现季节冻土,野牛沟、野马滩以及鄂陵湖东部的玛多四湖所在黄河低谷大片为季节冻土;2100年多年冻土退化为季节冻土的面积分别为5636 km2、9769 km2、15548 km2,占源区面积的19%、32.9%、52.3%;星宿海、尕玛勒滩、多格茸的多年冻土发生退化,低温冻土变为高温冻土,各类年平均地温出现了不同程度的升高。到2100年,RCP 2.6情景下源区多年冻土全部退化为季节冻土主要发生在目前年平均地温高于-0.15 oC的区域,而-0.15~-0.44 oC的区域部分发生退化;RCP 6.0、RCP 8.5情景下目前年平均地温分别为高于-0.21 oC以及-0.38o C的区域多年冻土全部发生退化,而-0.21~-0.69 oC以及-0.38~-0.88 oC的区域部分发生退化。  相似文献   

16.
青海省属于全国四大牧区之一,及时监测草地植被长势、准确估算牧草产量对青海牧区可持续发展与生态保护具有重要意义。草地产草量遥感估算主要基于植被指数与地面实测数据的统计关系,但是估算涉及植被指数、统计模型和建模指标等因素,不同组合建立的估算模型的精度不同。本文基于青海省MODIS数据与地面实测产草量数据,选择了6种植被指数(NDVIEVIRVIDVIRDVIMSAVI)、5种统计模型(简单线性模型、二次多项式模型、幂函数模型、指数函数模型、对数函数模型)以及3种建模指标(植被指数年度最大值VImax、植被指数生长季累积值VIseason-cum、植被指数年度累积值VIannual-cum),研究不同组合下估算模型的精度差异,并从中选出最优产草量估算模型,用于估算青海省2015年和2016年的产草量。结果表明:(1)6种植被指数中,基于NDVI的产草量估算精度最高;非线性模型的估算精度高于线性模型,尤其是指数模型,适用于大多数草地类型产草量的估算;基于NDVI年度最大值的估算模型对大多数草地类型都具有最高的决定系数(R2)。(2)从干重来看,高产草量区(>1 200 kg·hm-2)主要位于青海东部的高寒草原,中等产草量区(600~1 200 kg·hm-2)位于青海南部和东部的高寒草原和禾草草原,低产草量区(<600 kg·hm-2)位于青海西部和北部的高寒草甸、高寒草原、高寒荒漠和盐生草甸。(3)与2015年相比,2016年青海省干草总产量减少31.60×104 t,减幅为1.36%。其中,禾草草原和高寒草甸的减产幅度最大,而荒漠草原和盐生草甸的产量则有所增加。本文可为草地产草量遥感估算的研究和实践提供参考。  相似文献   

17.
Six rock glaciers in the Southern Carpathians have been investigated by means of geoelectrical soundings in order to detect their internal stratigraphy and the existence of frozen sediments. In the case of three relict rock glaciers, the electrical resistivity measurements indicated a typical internal structure. Low resistivity values (<10 kΩm) which are typical of unfrozen fine‐grained materials were obtained, but high resistivity values (25–240 kΩm) measured in the Pietroasa, Ie?u and Pietrele rock glaciers denote the presence of sediments cemented by interstitial ice and ice lenses. Based on the moderate resistivity values, the ice content is probably low to medium in the upper portion of these rock glaciers, that is, above 2040 m. At two sites (Pietroasa and V?iuga rock glaciers), ground surface temperature (GST) evolution was monitored using digital dataloggers. Mean annual ground surface temperature and GST regime throughout the winter were extracted from the recordings and confirmed the probability of permafrost occurrence in Pietroasa rock glacier. In the Ie?u and Pietrele rock glaciers, measurements of bottom temperatures of the winter snow cover were performed in March 2012. Considering the thick active layer, the reduced ice content and the presence of scarce vegetation on their surface it could be assumed that the permafrost exists in marginal conditions in the Southern Carpathians. The ground ice in permafrost is produced by the groundwater freezing or by snow banks buried by coarse angular boulders following large rockfalls.  相似文献   

18.
沙漠腹地人工绿地地表能量交换特征   总被引:1,自引:0,他引:1       下载免费PDF全文
运用涡度相关法开路系统对塔克拉玛干沙漠腹地人工灌溉绿地生长季地表能量交换特征以及与环境因子的关系进行测定分析。结果表明:在典型晴天条件下,无论是沙漠区还是沙漠腹地灌溉绿地,白天感热通量在净辐射通量的分配中所占的份额最大,潜热交换仅占很小的比例,人工绿地感热通量和潜热通量的峰值为230.54 W/m2和88.5 W/m2,沙漠区为220 W/m2和17.55 W/m2,沙漠腹地人工灌溉造林后潜热交换明显增加。沙漠腹地造林后,绿地波文比日变幅和日均波文比均减小,绿地日均波文比为沙漠区的15%,人工绿地的营建促使了局地气候的改变。绿地地表能量交换受气象因子和下垫面条件的影响和制约,按相关系数的高低,环境因子对感热、潜热通量的影响依次为:Rn>△Ta>△TS>v>TS,沙漠区人工造林后地表能量交换与多个环境因子有着密切的关系。这些研究结果将加深我们对沙漠地区人工灌溉造林地近地层能量交换的认识。  相似文献   

19.
黑河下游绿洲植被优势种生物量空间分布及蒸腾耗水估算   总被引:2,自引:1,他引:1  
基于典型样点试验,建立了研究区植被优势种柽柳、胡杨与苦豆子地上生物量与其生态参数关系模型;利用高分辨率遥感影像Geoeye-1对植被优势种进行分类得到生态参数,实现了其地上部分生物量空间分布估算;最后利用生物量与蒸腾系数关系,估算植被优势种蒸腾耗水。结果显示:植被优势种总生物量为2.53×106t,河流距离对生物量影响显著。根据试验测得的植被优势种蒸腾系数估算出总蒸腾耗水量为10.89×108t,柽柳、胡杨与苦豆子所占比例分别为12.94%,82.93%与4.13%。  相似文献   

20.
Taking advantage of heat absorbing and releasing capability of phase change material (PCM),Paraffin wax-based concrete was prepared to assess its automatic temperature control performance.The mechanical properties of PCM concrete with eight different Paraffin wax contents were tested by the cube compression test and four-point bending test.The more Paraffin wax incorporated,the greater loss of the compressive strength and bending strength.Based on the mechanical results,four contents of Paraffin wax were chosen for studying PCM concrete's thermal properties,including thermal conductivity,thermal diffusivity,specific heat capacity,thermal expansion coefficient and adiabatic temperature rise.When the Paraffin wax content increases from 10% to 20%,the thermal conductivity and the thermal diffusivity decrease from 7.31 kJ/(m·h·℃) to 7.10 kJ/(m·h·℃) and from 3.03×10~(-3)m~2/h to 2.44×10~(-3)m~2/h,respectively.Meanwhile the spe‐cific heat capacity and thermal expansion coefficient rise from 5.38×10~(-1)kJ/(kg·℃) to 5.76×10~(-1)kJ/(kg·℃) and from9.63×10~(-6)/℃ to 14.02×10~(-6)/℃,respectively.The adiabatic temperature rise is found to decrease with an increasing Paraffin wax content.Considering both the mechanical and thermal properties,15%of Paraffin wax was elected for the mass con‐crete model test,and the model test results confirm the effect of Paraffin wax in automatic mass concrete temperature control.  相似文献   

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