The use of inverse modelling and dipwell data in the calibration and evaluation of a soil water simulation model

The soil water regime is a key component of the current UK land evaluation systems. However, direct quantification requires many years of measurements which are not available for large parts of the country. One method for extending existing data is through the use of soil water simulation models. A physically based, one-dimensional soil water simulation model (SOIL) was calibrated against relatively easily obtained dipwell, soil water retention and saturated hydraulic conductivity data for eight relatively level sites in Scotland with limited potential for lateral flow. However, the calibration was only possible through the use of an inverse modelling procedure to select a matric potential which gave a ‘best-fit' to the appearance of saturated conditions in the dipwells. The calibrated model was subsequently able to accurately predict the fluctuations in the perched watertable to within one depth class in five soil profiles and only slightly greater than one depth class in the remainder. The technique offers the potential to extrapolate from a limited period of measured soil watertable data. However, care is needed as there were additional errors associated with the restrictions imposed by the model, by the input data and due to the nature of the calibration data.     

基于SWAT模型的降雨数据适用性评价

为评价降雨产品在流域尺度水文模拟中的适用性,该文首先依据实际降雨数据评价GLDAS、TMPA和ERA-Interim 3种降雨产品在研究流域的可替代性。多指标模糊优选评价表明,基于双线性插值法的TMPA和ERA-Interim降雨产品数据在日、月尺度上的模拟效果均较好,相对误差(Bias)分别为5.48%和7.46%,均小于10%,相关系数(CC)在0.82~0.98之间,具有站点降雨的可替代性,可作为水文模型的输入。然后用此2种降雨产品分别驱动SWAT模型,进行研究流域的水文模拟精度分析。TMPA产品的日、月尺度水文模拟结果的Bias分别为10.88%和11.03%,纳什系数(NSE)分别为0.46和0.78,而ERA-Interim的日、月尺度水文模拟结果的Bias分别为9.11%和9.27%,NSE分别为0.44和0.70。以Bias、CC和NSE为特征指标的多指标模糊优选模型的评价结果为:TMPA产品日、月尺度水文模拟结果的相对隶属度值分别为0.51和0.53,大于ERA-Interim的相对隶属度值0.49和0.47,表明TMPA产品更适用于流域尺度的水文模拟。该文评价方法及结论可为类似流域尺度的水文模拟提供参考。     

The solubility of aluminium in two Swedish acidified forest soils: An evaluation of lysimeter measurements using batch titration data

This paper presents aluminium (Al)-solubility data for two acid forest soils (Inceptisol and Spodosol), obtained in connection with lysimeter measurements (tension-cup and zero-tension lysimeters) and batch equilibrium experiments. The solubility of Al obtained in the batch experiments was used as a reference to test whether Al³⁺in soil solutions collected by the lysimeters was in equilibrium with secondary forms of solid-phase Al (Al(OH)₃or organically bound Al). The relation between pH and Al³⁺activity found for the zero-tension lysimeter solutions collected from the Inceptisol agreed well with that obtained in the batch experiment. This suggests that Al³⁺in the lysimeter solutions were in, or close to, equilibrium with the solid phase, whether this was organically bound Al (A horizon) or an Al(OH)₃phase (B horizon). For the tension-cup lysimeters, solutions obtained from the Inceptisol B and Spodosol Bs1 horizons were generally close to equilibrium with respect to secondary solid-phase Al (apparently Al(OH)₃; average ion activity product was 10^9.3and 10^8.8, respectively), whereas the Inceptisol A and Spodosol Bh solutions were not. The Al solubility in Inceptisol A and Spodosol Bh horizons was consistently higher than that obtained in the batch equilibrium experiment, indicating that the sampled solution partly originated from the underlying horizons. Thus, tension-cup lysimeters should be used with care in soils (or in parts of soil profiles) having steep solute concentration gradients because the soil volume from which the sample is drawn with this lysimeter type seems to be poorly defined.     

Analyzing highly variable potency data using a linear mixed-effects measurement error model

A house standard lot is tested along with experimental samples in a variable TCID₅₀ assay in order to monitor and control assay performance. Instead of being simply a control, it is proposed to use this lot as a calibration standard to reduce the systematic variability in the assay caused by acknowledged sources of variability such as the age of the cells used in the assay and interlaboratory differences. Because of this new proposal, the consistency of the relationship between the test sample and the house standard is assessed within the acceptance range of the house standard. A linear mixed-effects measurement error model is proposed for the data. The slope curve is then used to assess the dynamic relationship between the sample and the house standard within the house standard range. It is shown with these analyses that the sample and the house standard have uniformly good agreement within the house standard range.     

Iron bioavailability of hemoglobin from soy root nodules using a Caco-2 cell culture model

Heme iron has been identified in many plant sources-most commonly in the root nodules of leguminous plants, such as soy. Our objective was to test the effectiveness of soy root nodule (SRN) and purified soy hemoglobin (LHb) in improving iron bioavailability using an in vitro Caco-2 cell model, with ferritin response as the bioavailability index. We assessed bioavailability of iron from LHb (either partially purified (LHbA) or purified (LHbD)) with and without food matrix and compared it with that from bovine hemoglobin (BHb), ferrous sulfate (FeSO4), or SRN. Bioavailability of each treatment was normalized to 100% of the FeSO4 treatment. When iron sources were tested alone (100 ug iron/mL), ferritin synthesis by LHbD and BHb were 19% (P > 0.05) and 113% (P < 0.001) higher than FeSO4, respectively. However, when iron sources were used for fortification of maize tortillas (50 ppm), LHbA and BHb showed similar bioavailability, being 27% (P < 0.05) and 33% (P < 0.05) higher than FeSO4. Heat treatment had no effect on heme iron but had a significant reduction on FeSO4 bioavailability. Adding heme (LHbA) iron with nonheme (FeSO4) had no enhancement on nonheme iron absorption. Our data suggest that heme iron from plant sources may be a novel value-added product that can provide highly bioavailable iron as a food fortificant.     

Fitting crop growth data using marquardt's algorithm

A least-squares method using Marquardt's algorithm is used to fit crop growth data to a non-linear growth model. This non-linear model is expressed as a differential equation which cannot be integrated analytically. For comparison purposes, two other non-linear models based on the logistic and Gompertz equation are fitted to the same data.     

Proper methods and its calibration for estimating reference evapotranspiration using limited climatic data in Southwestern China

Proper methods for estimating reference evapotranspiration (ET₀) using limited climatic data are critical, if complete weather data are unavailable. Based on the weather data of 19 stations in Guizhou Province, China, several simple methods for ET₀ estimation, including the Hargreaves, Priestley–Taylor, Irmak–Allen, McCloud, Turk, and Valiantzas methods, were involved in comparison with the standard FAO-56 Penman–Monteith (PM) method. The Turk equation performs well for estimating ET₀ in humid locations. Both the Turk method and the Valiantzas method initially performed acceptably with mean root-mean-square difference (RMSD) of 0.1472 and 0.1282 mm d^?1, respectively, with only requiring parameters of temperature (T), relative humidity (RH), and sunshine duration (n). The corresponding calibration formulas to Turk and Valiantzas method were suggested as the most appropriate method for ET₀ estimation with the RMSD of 0.0098 and 0.0250 mm d^?1, respectively. The local calibrated Hargreaves–Samani method performed well and can be applied as the substitute of FAO-56 PM method under the condition that only the daily mean, maximum, and minimum temperatures were available, and local calibrated McCloud method was acceptable if only the mean temperature was available.     

A mixed model for investigating a population of asymptotic growth curves using restricted B-splines

We introduce a new method for modeling a population of growth curves with B-splines, adapting the usual regression spline basis to ensure a horizontal upper asymptote in all fitted curves. The new method is easily implemented in standard statistical software. We motivate and illustrate our method using data on the growth of Brown Kiwi (Apteryx mantelli) in the North Island of New Zealand, including a time-dependent covariate to investigate the effects of different rearing environments on patterns of weight increase.     

基于双层数据分解混合模型预测鄱阳湖COD

化学需氧量（Chemical Oxygen Demand, COD）是衡量水质状况的最重要参数之一,反映水体受还原性物质污染的程度。该研究采用改进的完全集合经验模式分解（Improved Complete Ensemble Empirical Mode Decomposition With Adaptive Noise, ICEEMDAN）、变分模式分解（Variational Mode Decomposition, VMD）相结合的双层数据分解算法,并利用双向长短期记忆（Bidirectional Long Short-term Memory, BLSTM）神经网络,提出了一种混合模型IVB（Improved Complete Ensemble Empirical Mode Decomposition With Adaptive Noise-Variational Mode Decomposition - Bidirectional Long Short-term Memory）,并以鄱阳湖高锰酸盐指数（Permanganate index, CODMn）监测数据为研究对象,进行案例研究。结果表明,IVB模型具有良好的预测性能：1 d以后的CODMn预测中,IVB模型的平均绝对百分比误差为2.21%,与单一BLSTM神经网络模型相比降低了10.57个百分点,而与IB (Improved Complete Ensemble Empirical Mode Decomposition With Adaptive Noise - Bidirectional Long Short-term Memory)模型相比降低了4.62个百分点;7 d以后的CODMn预测中,IVB模型的平均绝对百分比误差为8.18%,与单一BLSTM神经网络模型相比降低了16.34个百分点,而与IB模型相比降低了4.68个百分点。这项研究表明,所开发的IVB模型可以用作水资源管理的有效分析与决策工具。     

基于JAVA的批量数据导入导出探讨

本文介绍在WEB应用系统中实现基于Java的数据导入导出的技术与方法,并给出该方法在中国农业大学学生体质测试系统中的具体应用,本方法主要采用了Java语言以及JXL,Spring等开源技术。     

基于Swin Transformer模型的玉米生长期分类

快速准确识别玉米生长的不同阶段,对于玉米种植周期的高效精准管理具有重要意义。针对大田环境下玉米生长阶段分类辨识易受复杂背景、户外光照等因素影响的问题,该研究采用无人机获取玉米不同生长阶段的图像信息,以苗期、拔节期、小喇叭口期、大喇叭口期4个生长阶段为对象,利用Swin Transformer（Swin-T）模型引入迁移学习实现玉米不同生长阶段的快速识别。首先结合玉米垄面走向特性,将训练集旋转8次用以扩充数据集;为探究各模型在非清晰数据集上的表现,采用高斯模糊方法将测试集转换6次;最后以AlexNet,VGG16,GoogLeNet做为对比,评估Swin-T模型性能。试验结果表明,Swin-T模型在原始测试集的总体准确率为98.7%,相比于AlexNet,VGG16,GoogLeNet模型分别高出6.9、2.7和2.0个百分点;在错误分类中,大喇叭口期和小喇叭口期由于冠层特征相似,造成识别错误的概率最大;在非清晰数据集下,AlexNet,VGG16,GoogLeNet模型精度总体退化指数分别为12.4%、10.4%和15.0%,Swin-T模型总体退化指数为8.31%,并且退化均衡度、平均退化指数、最大退化准确率均表现最佳。研究结果表明：在分类精度、模糊图像输入等方面,Swin-T模型能够较好地满足实际生产中玉米不同生长阶段分类识别的需求,可为玉米生长阶段的智能化监测提供技术支撑。     

基于SLEUTH模型的城市扩张场景预测与分析

Scenario prediction was introduced to better understand urban dynamics and to support urban planning. Taking the Dongguan central urban area of the Pearl River Delta, China as an example, three urban development scenarios, historical trend (HT) scenario, forest protection (FP) scenario, and growth restriction (GR) scenario, were designed and transplanted into the SLEUTH model through the parameter self-modification method. The quantitative analysis results showed that the urban area would expand continuously from 2003 to 2030 under the HT scenario. More land resources would be saved under the GR scenario than FP scenario. Furthermore, the urban growth under the HT and FP scenarios would come to a steady state by 2020, while this deadline of the GR scenario would be postponed to 2025. The spatial pattern analysis using five spatial metrics, class area, number of patches, largest patch index, edge density, and contagion index, showed that under all the scenarios, the urban patches would become bigger and the form would become more compact, and the urban form under the GR scenario would be the smallest and most heterogeneous. These demonstrated that the GR scenario was more effective in meeting the goal of land protection and sustainable development for the study area.     

荒漠土壤有机质含量高光谱估算模型

为解决荒漠土壤有机质含量高光谱估算存在的困难,提高土壤有机质含量估算的精准性,该文对准噶尔盆地东部荒漠土壤进行采样、化验分析和光谱测量、处理,分析土壤光谱与有机质含量的相关性,确定敏感光谱波段,建立荒漠土壤有机质含量多种高光谱估算模型,旨在通过模型精度的比较,确定最优模型。结果表明：反射率、倒数对数光谱与荒漠土壤有机质含量相关性低,而经过一阶微分、二阶微分变换后,相关系数有所提高,部分波段的相关系数通过0.01显著水平的检验,可以用来荒漠土壤有机质含量的估算;一元线性回归建立的估算模型的精度低,不适用荒漠土壤有机质含量高光谱的估算。荒漠土壤有机质多元逐步回归模型的二阶微分、倒数对数二阶微分修正决定系数得到了较大提高,分别提高了0.22和0.31,均方根误差下降了0.66和0.80,建模精度高于一元线性回归模型。荒漠土壤有机质一阶微分、二阶微分光谱的最小偏二乘回归模型的决定系数比其多元逐步回归模型提高了0.07、0.04,一阶微分、二阶微分均方根误差都下降了0.11,二阶微分偏最小二乘法回归模型是该研究所建12个模型的最优估算模型。在多元逐步、偏最小二乘回归模型中,最优估算模型是二阶微分模型,因而用偏最小二乘法回归估算荒漠土壤有机质含量是个可行的方法。该研究的成果为荒漠土壤有机质高光谱遥感分析提供了支撑,实现荒漠土壤有机质监测的时效性、准确性,为区域生态环境的修复提供依据。     

基于生长模型的温室小型西瓜栽培管理专家系统(ESWCM)的研究和建立

运用知识工程和信息技术原理,将温室小型西瓜生长模型与AIP1.0专家系统平台相结合,建立了基于生长模型的温室小型西瓜栽培管理专家系统(ESWCM),包括知识库(KB)、模型库(MB)、数据库(DB)、推理机(IE)和人机界面。系统综合运用推理、预测、解释等机制帮助用户设计栽培管理方案,解答栽培技术问题,以及动态模拟和预测温室小型西瓜的生育进程。基于生长模型的温室小型西瓜栽培管理专家系统将模型的预测功能与专家系统的逻辑推理相结合,提高了温室小型西瓜的栽培管理水平。     

Influence of soil strength on root growth: experiments and analysis using a critical-state model

Roots grow thicker in compacted soil, even though it requires greater force for a large object to penetrate soil than it does for a small one. We examined the advantage of thickening in terms of the stresses around a root penetrating with constant shape, rather than the stresses around an expanding cylinder or sphere, as has been studied previously. We combined experiments and simulations of the stresses around roots growing in compacted soils. We measured the diameter of pea roots growing in sandy loam and clay loam at four different densities, and the critical‐state properties of the soils. At a penetration resistance of about 1 MPa the diameter of the roots in the sandy loam was about 40% greater than that at 0.7 MPa, and at 2 MPa it was about 60% greater. In the clay loam, there was less thickening – about 10% greater at 1 MPa and about 20% greater at 1.5 MPa. The maximum axial stresses were predicted using a critical‐state finite‐element model to be at the very tip of the root cap. When there was friction between the root and the soil, shear stresses were predicted with smaller values at the tip than just behind the tip. When the interface between the soil and the root was assumed to be frictionless, there were by definition no shear stresses. In the frictionless case the advantage of root thickening on relieving peak stress at the root tip was diminished. The axial and shear stresses were predicted to be smaller in the clay loam than in the sandy loam and may explain why the roots did not thicken in this soil although its resistance to penetration was similar. Our results suggest that the local values of axial and shear stresses experienced by the root near its tip may be as important in constraining root growth as the total penetration resistance.     

遥感信息与作物生长模型的区域作物单产模拟

利用外部数据同化作物生长模型提高区域作物单产模拟精度是近年来的研究热点.该文以遥感反演的叶面积指数(LAI)作为结合点,以黄淮海粮食主产区典型县市夏玉米为研究对象,在区域尺度利用全局优化的复合形混合演化( SCE-UA)算法进行了遥感反演LAI信息同化EPIC (environmental policy integra...     

基于遥感数据与作物生长模型同化的作物长势监测

遥感观测和作物生长模型模拟是进行农作物长势监测的2种有效手段,并具有较好的互补性,构建二者的同化系统是目前农业遥感研究领域的热点。同化涉及多学科的交叉集成,十分有必要将同化方法中的模型、算法、数据进行集成,构建基础作物模型同化系统平台,降低科学研究和应用的难度。采用模块化结构设计,将同化系统构建所需的主要模型、算法、数据等进行有机结合和无缝集成,实现基于极快速模拟退火算法的遥感数据与CERES-Wheat作物生长模型的同化原型系统构建。此外,通过所开发的系统利用地面高光谱作为遥感数据,通过同化小麦叶面积指数对同化系统进行了检验和初步应用。同化LAI与实测结果较好的拟合度,表明所开发的同化系统基本可行,能为遥感技术与作物模型的基础研究和应用提供一个平台。     

Nitrous oxide production in a sequence batch reactor wastewater treatment system using synthetic wastewater

The rate of nitrous oxide emission from a laboratory sequence batch reactor （SBR） wastewater treatment system using synthetic wastewater was measured under controlled conditions. The SBR was operated in the mode of 4 h for aeration, 3.5 h for stirring without aeration, 0.5 h for settling and drainage, and 4 h of idle. The sludge was acclimated by running the system to achieve a stable running state as chemical oxygen demand, NO2^-, NO3^-, NH4^＋, pH, and N2O. indicated by rhythmic changes of total N, dissolved oxygen, Under the present experimental conditions measured nitrous oxide emitted from the off-gas in the aerobic and anaerobic phases, respectively, accounted for 8.6%-16.1% and 0-0.05% of N removed, indicating that the aerobic phase was the main source of N2O emission from the system. N2O dissolved in discharged water was considerable in term of concentration. Thus, measures to be developed for the purpose of reducing N2O emission from the system should be effective in the aeration phase.     

Assessment of carotenoid bioavailability of whole foods using a Caco-2 cell culture model coupled with an in vitro digestion

Epidemiological studies have shown that consumption of carotenoid-rich fruits and vegetables is associated with a reduced risk of developing chronic diseases. beta-Carotene, alpha-carotene, and beta-cryptoxanthin are precursors of vitamin A, a nutrient essential for human health. However, little is known about the bioavailability of carotenoids from whole foods. This study characterized the intestinal uptake performance of carotenoids using monolayers of differentiated Caco-2 human intestinal cells and mimicked human digestion to assess carotenoid absorption from carrots and corn. Results showed that Caco-2 cellular uptake of beta-carotene and zeaxanthin was higher than that of lutein. Uptake performances of pure carotenoids and carotenoids from whole foods by Caco-2 cells were both curvilinear, reaching saturated levels after 4 h of incubation. The time kinetics and dose response of carotenoid uptake presented a similar pattern in Caco-2 cells after plating for 2 and 14 days. Furthermore, the applicability of this new model was verified with whole grain corn, showing that cooked corn grain significantly enhanced carotenoid bioavailability. These results support the feasibility of the in vitro digestion cell model for assessing carotenoid absorption from whole foods as a suitable and cost-effective physiological alternative to current methodologies.