On concentration footprints for a tall tower in the presence of a nocturnal low-level jet

This paper reports on the location of sources contributing to a point concentration measurement in the stable boundary layer. Concentration footprints for sensors located at different heights during the night are examined using a backward-in-time Lagrangian stochastic dispersion model. Simulations of air parcel transport in a non-steady-state atmospheric boundary layer above a bare surface and a forest under different insolation suggest that sources located as far as several hundred kms away contribute to a concentration measurement made at levels as high as 500 m. The origin of the maximal contribution area shifts during the night depending on the wind direction at the sensor location, a feature most prominent in the presence of decoupling between sensor levels and surface sources. Simulations suggest that atmospheric static stability alone is not a sufficient criterion to trigger flow decoupling. The presence of the low-level jet provides vertical mixing of air parcels even for stable boundary layers with Richardson numbers higher than the critical. This finding is in agreement with earlier observations suggesting that the level of the low-level jet nose acts as a strong lid prohibiting vertical gas propagation. These findings have important implications in the interpretation of eddy-flux measurements in nocturnal conditions.     

环青海湖地区草地近地层气象要素变化特征

利用青海湖北岸海北牧业气象试验站2006年5月-12月观测的天然草地近地面层气象要素梯度资料，分析了该地区近地层温度、湿度和风速的日变化规律及其廓线特征。结果表明：青海湖北岸草地近地层0．3—10．0m高度范围内温度、相对湿度和风速都呈现出明显的以24h为周期的日变化规律；各层温度最高和最低时的位相随高度增加而滞后，相对湿度和风速最大与最小时的位相随高度增加而提前；14时温度随高度的增加而降低，20时的温度随高度增加先增后降，温度廓线在4．0m高度存在一拐点，随后逐渐进入逆温状态，至8时逆温程度达到最大；不论白天还是夜间，相对湿度随高度的增加而减小；风速随高度的增加而增大。     

Spatial and vertical distribution of <Superscript>137</Superscript>Cs in soils in the erosive area of southeastern Serbia (Pčinja and South Morava River Basins)

Purpose

The area of southeastern Serbia, the P?inja and South Morava River Basins, is under the influence of very strong erosion, and the aim of this study was to investigate the vertical and spatial distribution of the ¹³⁷Cs in the eroded soils of this area.

Materials and methods

Vertical soil profiles were collected with 5-cm increments from the uppermost layer down to 20, 25, 30, 40, and 50 cm of depth, depending on the thickness of the soil layers, i.e., down to the underlying parent rocks. Measurements of ¹³⁷Cs activity concentration were performed by using the HPGe gamma-ray spectrometer ORTEC-AMETEK (34 % relative efficiency and high resolution 1.65 keV at 1.33 MeV for ⁶⁰Co), from its gamma-ray line at 661.2 keV.

Results and discussion

The mean ¹³⁷Cs activity concentration across all 18 soil profiles (for all soil layers) was found to be 20 Bq kg^?1. In the greatest number of soil profiles, the ¹³⁷Cs activity concentration was generally highest in the first soil layer (0–5 cm) and decreased with soil depth, while in a few soil profiles, the peak of either the ¹³⁷Cs activity concentration occurred in the second soil layer (5–10 cm) or the ¹³⁷Cs activity concentration was almost equal throughout the entire soil profile. The mean ¹³⁷Cs activity concentration in the first soil layer (0–5 cm) was found to be 61 Bq kg^?1, and the high coefficient of variation of 92 % pointed out high spatial variability and large range of the ¹³⁷Cs activity concentrations in the study area.

Conclusions

The obtained results indicate that in the greatest number of soil profiles, ¹³⁷Cs is present in the upper layers, with concentration decreasing with depth, as is typical in uncultivated soil. Its spatial distribution was very uneven among the surface soil layers of the investigated sites. One of the main reasons for such pattern of ¹³⁷Cs in the study area may be soil erosion. Additional investigations which would support this hypothesis are required.

     

基于多源数据的土壤水分反演及空间分异格局研究

温度植被干旱指数(TVDI)是一种通过反演土壤水分来反映土壤干旱状况的重要方法。在TVDI的基础上引入数字高程模型(DEM)数据对地表温度进行校正,能够减少地形起伏对能量二次分配的影响。用阈值将研究区分割成不同土地利用类型,结合野外同步实测数据,用分段反演模型反演渭-库绿洲土壤水分分布图,并对渭-库绿洲土壤水分的空间格局和分异规律进行分析。结果表明:(1)地形校正后的TVDI能够更好地反映土壤水分状况;(2)土壤水分总体上从西至东,由北向南降低,在绿洲内部较为稳定,在交错带变化较为剧烈,土壤水分垂直变异系数呈现幂函数递减的整体变化趋势;(3)针对研究区不同土地利用类型用分段反演模型进行反演,有效地实现优势互补,总体上提高了土壤水分的反演精度,在区域土壤水分研究中值得关注和应用。     

一维马尔可夫链模拟黑河中游流域土壤质地垂向变异

黑河中游地区土壤剖面砂、黏层次相间排列的特点及部分区域剖面中出现的不透水层对土壤中的水分运动和溶质迁移具有重要影响。该研究调查了黑河中游100 km2区域内土壤剖面的质地分层情况,运用一维嵌入马尔可夫链模型模拟该地区的土壤质地剖面。研究表明,研究区土壤剖面共出现砂土、壤质砂土、砂质壤土、壤土、黏质壤土、粉黏壤土和粉黏土7种质地类型,层次厚度呈对数正态分布。粉黏土未在表层土壤出现,而砂土在表层出现的概率明显高于其余质地类型,剖面某一质地层之下多出现细粒含量比其高的下一质地类型。剖面上相邻两质地层之间的转移具有明显的马尔可夫链特征（简称马氏性）,且马氏链是平稳的。一维嵌入马尔可夫链模型能够较好地描述研究区土壤质地层次的垂向变化,剖面主要的质地层次组合为：砂—壤、壤—砂、壤—黏、黏—壤。对土壤质地剖面的定量模拟,可以为开展该区域土壤水循环、转化和溶质迁移等相关研究提供参考。     

Mercury distribution in tephra soil layers in Hokkaido, Japan, with reference to 34,000-year stratification

Tephra from volcanic eruptions contains only small amounts of mercury (Hg) right after the eruption because the high temperature at eruption evaporates Hg in volcanic ash. Thus, accumulation of Hg in tephra soil layers during the dormant periods of the volcano may reflect Hg deposition while the layer was exposed to the atmosphere. To estimate sequential changes in Hg deposition, we measured the Hg content and accumulation in tephra layers from 6 sites in Hokkaido known to have many tephra layers derived from volcanic eruptions over a 34,000-year period. Mercury content and accumulation rate in the soil profiles varied widely depending on the tephra. In each tephra layer, the Hg content and accumulation rates increased principally at the upper soil horizons and decreased at the lower depths. The Hg deposition rates calculated from the amount of Hg accumulated in the tephra layers were similar within the same tephra. These characteristics of Hg distribution indicate that Hg deposition accumulated on the surface of each tephra layer during the period the tephra layer was exposed to the atmosphere. Although physicochemical processes such as leaching out, wind erosion, and volatilization might lead to over- and/or underestimation of the deposition rates, our estimated amounts of Hg were markedly higher in the tephra soils after 1,600 year BP than before that time. The results of this study suggest that tephra layers in Hokkaido offer important implications for understanding of the historical changes in atmospheric Hg deposition.     

基于温度差监测西北地区的土壤相对湿度

在2012年黑河生态水文遥感试验（HiWATER）观测资料的基础上,结合卫星的地表温度产品计算观测点的垂直温度差及温度的日较差,并分析了不同时间尺度上温度差与浅层土壤相对湿度（包括土层深度2 cm,4 cm和10 cm的土壤相对湿度）的相关性。为检验温度差在区域含水量监测中的效果,利用经度、纬度和海拔高度对气温进行插值。同时为消除温度的区域性差异,将各温度差进行归一化处理,最后将归一化后的垂直温度差区域分布与土壤相对湿度进行了对比。结果表明:在各温度差中,地表温度和气温计算的垂直温度差与浅层土壤相对湿度的相关性最好;在时间尺度上,温度差与浅层土壤相对湿度的相关系数随时间尺度的增加而增大;在各土层深度中,温度差与4 cm的浅层土壤相对湿度相关性更好;在气温插值中,在纬度和海拔高度基础上插值出的气温与实测值之间更为接近;区域尺度上,归一化后的垂直温度差有效地解决了地理位置和下垫面对垂直温度差的影响,可以很好地监测月尺度上土壤湿度的变化的情况。     

Temperature regime of some soil types in Georgia

The thermal regime of the different soil types of Georgia has been studied on the basis of soil temperature records obtained at 60 weather stations in 1947–1995. It is shown that the thermal conductivity and temperature gradients in the soil profiles depend on the soil type. In the upper 0–20 cm of the soils in the intermontane depressions, the lowest temperature gradients in the summer are typical of the red ferrallitic soils (0.5–1.1°C/dm), and the highest gradients are observed in the chernozems of eastern Georgia (1.0–1.3°c/dm). The soil temperature gradients are especially high in the late spring (1.4–1.8°c/dm), when the atmospheric convection is formed. In the mountains, the lowest gradients in the summer are observed in the cinnamonic soils (0.4–0.9°c/dm), and the highest gradients are established in the brown forest soils (0.5–1.3°c/dm). The redistribution of the temperatures in the deeper layers depends on the soil texture. The lowest temperature gradient is in the soils of Telavi (3.1°c/m), where a stony layer is found at the depth of 60 cm, which causes the good heating of the deep layers. The highest gradients are seen in the clayey and loamy soils of western (Chakva, 3.8°c/m) and eastern (Tbilisi, 3.9°c/m) Georgia. This is probably related to the high water content in the heavy-textured soils.     

基于聚类分析的土壤盐渍剖面特征及其空间分布研究

通过对黄河三角洲地区典型地块土壤盐渍剖面的聚类分析,研究并总结该地区不同盐分剖面类型土壤含盐量在水平方向以及垂直方向的分布特征和规律,运用该规律对各盐渍剖面类型的空间分布进行了探讨。结果表明:研究区土壤盐分剖面可以明显分为表聚型、底聚型和平均型3类,按照垂直分布特征可将0～180cm土体划分为0～20cm、20～80cm、80～120cm和120～180cm四个层次;研究区土壤含盐量在垂直方向和水平方向上变异较强,总体上盐分分布具有一定的表聚性,且各土层含盐量的规律性可以作为判断土壤盐分剖面类型的依据;受结构性因素和随机性因素的共同影响,各土层含盐量均表现为中等的空间自相关性和相同的空间自相关变化尺度。Kriging插值与空间分析结果表明,微地形和气候条件是影响表层土壤盐分空间分布的主要因素,地下水性质主导深层土壤盐分的空间分布;表聚型盐分剖面是研究区最主要的剖面类型,其次分别为底聚型和均匀型;不同盐分剖面类型的空间分布反映了植被类型和土地利用方式的差异,人为农业措施是形成底聚型与平均型盐分剖面的最直接因素。该研究结果为黄河三角洲地区盐渍土地的分区、改良、管理以及合理利用提供了理论基础和实践依据。     

基于AMSR-E与MODIS数据的新疆土壤水分协同反演与验证

针对当前遥感在大范围土壤水分估算中面临的问题,提出将被动微波遥感数据与光学/热红外遥感数据在模型中协同反演陆表土壤水分的新方法:利用MODIS的光学与热红外波段反演土壤水分的基准值;利用AMSR-E传感器的X波段反演土壤水分的日变化量,然后集成二者建立土壤水分协同反演模型。以新疆为实验区,采用在典型地区获取的365个土壤水分实测值,对该模型进行了验证与精度分析。结果表明,协同反演模型的估算结果与地面实测值之间有着更好的相关性和较小的均方根误差,明显优于单一数据源或单一模型的反演结果。     

Detection of methane biogenesis in a shallow urban lake in summer

Purpose

Sediments are significant methane (CH₄) sources of the atmosphere. However, the mechanisms of CH₄ generation remain unclear in sediments of shallow urban lakes. The aims of this investigation were to study the characterization of environmental parameters, CH₄ generation, and methanogen populations in Wulongtan Lake, China, which is affected solely by nonpoint pollution.

Materials and methods

The concentrations of CH₄ in the atmosphere and of vertical sediment profiles and the methane flux at the air–water interface were monitored in the summer of 2012. Environmental parameters in the water column and in the vertical sediment profiles were assayed. The activities of cellulose, saccharase, polyphenol oxidase, and urease enzyme and 16S rRNA gene copy numbers of Archaea (ARC), Methanobacteriales (MBT), Methanococcales (MCC), Methanomicrobiales (MMB), Methanosarcinales (MSL), Methanosarcinaceae (MSC), and Methanosaetaceae (MST) were determined in the vertical sediment profiles. The abundance of methyl–coenzyme A reductase (ME) gene was also determined to evaluate the total activities of methanogens.

Results and discussion

High CH₄ concentrations were detected in the atmosphere above the lake, and the mean CH₄ flux at the air–water interface was 6.21 mM m^?2 h^?1. Dissolved oxygen decreased with an increase of water depth. Eh values and CH₄ contents increased, but total nitrogen, water content, and total organic carbon (TOC) decreased with an increase of sediment depth. Cellulose, saccharase, polyphenol oxidase, and urease activities were detected in all sedimentary layers. The copy number of 16S rRNA gene (wet weight) for Archaea reached the highest value in the surface sediment. Copy numbers of ME were higher at 12–33 cm than at 0–6 cm. In general, abundances of MMB, MBT, and MSL were higher than that of MCC in the same sedimentary layer. 16S rRNA gene copy numbers of MST decreased with increasing depth, while MSC was higher at 18–27 cm than that at other sections. These indicate that hydrogenotrophic, aceticlastic, and methylotrophic pathways coexisted in these sediments. Principal component analysis revealed that in the sediments, the level of CH₄ was closely related with several parameters including saccharase, urease, ME, and MBT, while TOC content was related to CEL, MST, ARC, water content, and Eh.

Conclusions

High CH₄ release potential was detected in this shallow urban lake and can be ascribed to the anaerobic aquatic environment, bacterial enzyme activities, and methanogens. The orders MMB, MBT, and MSL were dominant in sediments for CH₄ production. The presence of orders or families of methanogens might be determined by the types of available substrates in lake sediments.     

Soil aggregate stability and organic matter as affected by land-use change in central Iran

This study aimed to evaluate the soil aggregate stability and selected soil quality indicators in various land uses in a semiarid region in central Iran. Random soil sampling was used to collect soil samples from surface (0–5 cm) and subsurface (5–25 cm) soil layers in rangelands of different condition classes, dry farmland and abandoned land. The aggregate size distribution indices including mean weight diameter (MWD), geometric mean diameter (GMD) and median diameter (D₅₀) of water-stable aggregates in the collected soil samples were measured. Our findings showed that percent of macroaggregates (>0.25 mm) of the surface and subsurface layers in rangelands of different condition classes were significantly higher than dry farmlands and abandoned lands (P < 0.05). Results showed that the trend of changes in soil organic matter was similar to soil aggregate stability in different land uses in both soil layers as follows: rangeland with good condition > rangeland with poor condition > abandoned land > dry farmlands. The structural stability indices (i.e. MWD, GMD and D₅₀) of rangelands with good condition were significantly greater than other land uses (P < 0.05). This highlights the importance of maintaining native rangeland to prevent organic matter loss, structure deterioration and soil erosion.     

GIS‐based regionalization of soil profiles with Classification and Regression Trees (CART)

A map of soil texture profiles was derived from readily available spatial data in combination with information from soil profiles using CART (classification and regression trees). The primary purpose was to provide a regionalized predictor for the vertical hydraulic conductivity profiles to be used as an input variable to an evapo‐transpiration model. In contrast to former studies, the texture of 110 soil profiles taken in the 10 km² area was not averaged vertically but the profiles were grouped according to their hydraulic properties. Therefore, it was possible to include site specific profiles, e.g. with histic or argillic horizons. Despite of small sampling quantities (110 soil profiles grouped into 8 classes) a prediction probability of 60 to 70 % was achieved in most classes. The resulting map provides valuable information for the granulometric and hydrologic characterization of the study area.<?show $6#>     

Spatial distribution of soil nutrient at depth in black soil of Northeast China: a case study of soil available phosphorus and total phosphorus

Purpose

The spatial variability of soil available phosphorus (AP) and total phosphorus (TP) influences crop yield and the environment. The paper aims to identify the spatial heterogeneity of P (AP and TP) and clarify the main driving mechanisms in a Mollisol watershed of Northeast China.

Materials and methods

Both geostatistical and traditional analysis were used to describe the spatial distribution of P at different depths. P in cultivated fields on the upper slopes was compared with secondary forest areas on the lower slopes within the same watershed.

Results and discussion

The horizontal distribution of P was found to be primarily influenced by structural factors (58–95 %). TP was high at both the summit and the bottom of slopes at all depths, being especially high at the watershed outlet due to erosion on the back slope and deposition at the base. AP was higher on south-facing slopes than on north-facing slopes and typically decreased from the summit to the base of south-facing slopes at the 0–40-cm depths, mainly due to solar radiation, soil loss, and water loss. The vertical distribution of TP typically decreased with increasing depths in farmland but did not show systematic variation in the forest profiles. AP was lower in the middle of the 0–60-cm soil profiles in the farmland, reflecting the influence of fertilization, infiltration, and crop absorption. AP in the 30–60-cm and TP in the 20–60-cm layers were lower in farmland than in the secondary forest, and only 2 % of the area showed a risk of P loss through ground flow and infiltration in the 0–20-cm layer.

Conclusions

The horizontal distribution of P in the 0–60-cm layers was mainly influenced by soil and water loss, deposition, and hydrothermal dynamics, while the vertical distribution of P, especially AP, was more affected by fertilization, infiltration, organic matter, and crop absorption. Secondary forestland that had been converted from farmland was found to effectively hold P, especially in deep soil layers, as the loss of P dissolved in water is not a primary process.     

Contribution and stability of forest-derived soil organic carbon during woody encroachment in a tropical savanna. A case study in Gabon

In this study, we quantified the contribution of forest-derived carbon (FDC) to the soil organic C (SOC) pool along a natural succession from savanna (S) to mixed Marantaceae forest (MMF) in the Lopè National Park, Gabon. Four 1-ha plots, corresponding to different stages along the natural succession, were used to determine the SOC stock and soil C isotope composition (δ¹³C) to derive the FDC contribution in different soil layers down to 1 m depth. Besides, to investigate changes in SOC stability, we determined the ¹⁴C concentration of SOC to 30 cm depth and derived turnover time (TT). Results indicated that SOC increased only at the end of the succession in the MMF stage, which stored 46% more SOC (41 Mg C ha^?1) in the 0–30 cm depth than the S stage (28.8 Mg C ha^?1). The FDC contribution increased along forest succession affecting mainly the top layers of the initial successional stages to 15 cm depth and reaching 70 cm depth in the MMF stage. The TT suggests a small increase in stability in the 0–5 cm layer from S (146 years) to MMF (157 years) stages. Below 5 cm, the increase in stability was high, suggesting that FDC can remain in soils for a much longer time than savanna-derived C. In conclusion, the natural succession toward Marantaceae forests can positively impact climate change resulting in large SOC stocks, which can be removed from the atmosphere and stored for a much longer time in forest soils compared to savanna soils.     

Monitoring Nitrogen Dioxide Levels in Urban Areas in Rawalpindi, Pakistan

Nitrogen dioxide is an important gaseous air pollutant. It plays a major role in atmospheric chemistry, particularly in the formation of secondary air pollutants, and contributes to environmental acidification. A comprehensive assessment of NO₂ levels in the atmosphere is required for developing effective strategies for control of air pollution and air quality improvement. Air pollution is a serious problem in all major cities of Pakistan and needs to be addressed to minimize detrimental effects on human health and urban vegetation. In this research, we focused on the monitoring of NO₂ levels in the urban environment of Rawalpindi city. Because of the lack of expensive continuous sampling devices and to get a good spatial coverage of the NO₂ concentrations in the study area, NO₂ passive samplers were exposed at 42 different sites within the city limits of Rawalpindi from January to December, 2008. Samplers were exchanged every 10 days and the associated meteorological conditions like temperature, wind speed, rainfall and relative humidity were also monitored. The average NO₂ concentration was found to be 27.46?±?0.32 ppb. The highest values of NO₂ were measured near to main roads and educational institutions due to intense flow of road vehicles. Moreover, the study showed that the values obtained for NO₂ for all sampling points exceeded the annual limit value set by World Health Organization. So, this is very important to take different steps to control this before it becomes a serious hazard for people living in those areas.     

Atmospheric mercury concentrations above mercury contaminated mill tailings in the Carson River Drainage Basin,NV

During processing of the historic Comstock Ore, Virginia City, NV, an estimated 5.5 × 10⁹ g of metallic mercury (Hg) were released into the Carson River Drainage Basin. The Bessels Mill site is one of at least 75 locations where Hg was used to amalgamate the gold and silver from the ore. Although the mill is no longer standing, Hg contaminated tailings attest to its past location. Mercury concentrations in samples of tailings from the Bessels Mill site are as high as 1570 μg/g. Mercury concentrations vary spatially over the site. Total Hg concentrations in air measured directly over the site are well above regional background levels (1 to 7.1 ng/m³). The highest average atmospheric Hg concentration measured at the site was 240 ng/m³ for October 1993. The estimated range of Hg flux to the atmosphere from the site was 37 to 500 ng/m² hr. Atmospheric Hg concentrations varied seasonally, diurnally and spatially. Atmospheric Hg concentrations varied as a function of Hg concentration, soil and air temperature, wind speed and surface morphology.     

Carbon mineralization in response to nitrogen and litter addition in surface and subsoils in an agroecosystem

More than 50% of global soil organic carbon stocks are stored below 20 cm of soil depth capable of massively altering global C cycle and climate. However, subsoil C dynamics are largely overlooked implicitly assuming that surface and subsoil C dynamics are similar. Here, we compared the soil C dynamics in surface and subsurface soil layers in response to nitrogen and maize leaf litter additions. Soils, sampled from 0 to 5, 15 to 35, 35 to 55 and 55 to 75 cm depths, were incubated at 25°C after adding litter, nitrogen (NH₄NO₃) or litter plus nitrogen. Soil respiration (C mineralization) was measured throughout the incubation period. Litter addition significantly increased C mineralization in all the soil layers. However, the soil CO₂ release relative to control was more than twofold higher in 15–35 and 35–55 cm soil layers than the surface layer. Nitrogen additions significantly decreased C mineralization in 0–15 cm soil, increased in 35–55 cm and had minimal effects in the 15–35 and 55–75 cm layers. Different soil C dynamics in surface and subsurface soil layers found in our study contradict the general assumption that soil C dynamics may be treated similarly along different soil depths.     

Impact of Field Application of Treated Wastewater on Hydraulic Properties of Vertisols

Fifteen soil profiles were taken from Ar-Ramtha wastewater treatment plant, 65 km north of Amman. Twelve of them represent soil planted with barley and irrigated with wastewater for the past 2, 5, and 15 years. The remaining three profiles represented a control area that has been only rainfed. Soil samples were collected in four replicates from each depth in each soil profile. Field and laboratory experiments were conducted to study the effect of irrigation with treated wastewater on hydraulic properties of surface and subsurface vertisols. Soil infiltration rate (IR), hydraulic conductivity (HC), and water retention (at 33 kPa and 1.5 MPa) were measured. The application of wastewater for 2, 5, and 15 years reduced soil hydraulic conductivity, whereas the infiltration rate decreased for 2 and 5 years, compared with non-irrigated area. Sites irrigated for 15 years with treated wastewater are characterized by higher percentages of large cracks, therefore revealed the highest infiltration rate. Soil available water changed due to wastewater application in decreasing order of: control (rainfed), 15, 5, 2 years of wastewater application.     

5H-1.5A型花生换向通风干燥机研制

为了解自行研发的5H-1.5A型花生换向通风干燥机作业性能,该文介绍了研发设备总体结构、工作原理及烘干箱体、导风组件、换向通风机构、余热回收装置等关键部件,并开展了整机作业性能试验研究,对比了空载工况下有无导风组件时,介质空气穿过承料板后的风场分布特性,测得有导风组件时承料板上方10 cm处风速均在0.68～0.73 m/s范围内,水平方向介质空气通风均匀性显著提高。测试了双入风口并行通风干燥10 h和单入风口换向通风干燥38 h过程中床层物料温度变化及干燥终止含水率分布情况:0～10 h,底层物料温度快速升高,上层物料温度上升缓慢,物料层温差先快速增大后逐渐缩小;10 h后,上、中、下物料层温度呈类波浪式升落,波动幅度逐渐减小,物料层温度逐渐逼近设定干燥温度;干燥终止时,左、右2个干燥半区最大含水率差值分别为1.42%、1.74%,为左、右干燥区含水率总降幅的4.1%、5.1%,干燥均匀性良好。测试并评估了余热回收装置对整机加热贡献率、热效率、能耗成本等的影响:余热回收装置在换向通风阶段对干燥系统的加热贡献率约为61%,系统热效率提高至80%以上,批次干燥能耗成本降低48.7%。与传统固定床干燥设备相比,可节省能耗成本约64.7%,干燥不均匀度降低约82.6%。研究结果可为设备的改进熟化及推广应用提供技术支撑。