湖泊水面温度遥感定量反演研究综述

湖泊水面温度与藻类生长密切相关,通过获取水体表层温度信息来监测湖泊水面温度时空动态变化,对于蓝藻水华预警监控具有重要意义。湖泊水面温度遥感定量反演的理论方法与反演地表、海洋表面温度基本相同。本文在介绍遥感反演地表温度原理的基础上,总结了国内外基于热红外波段反演水体表面温度的单窗算法、劈窗算法、多通道算法等几种常用方法,重点分析了各算法的优缺点和反演的主要难点,并对今后在内陆水体藻华预测顸警等方面的应用趋势进行了展望。     

多元回归-紫外分光光度法同时测定硝基苯类化合物

对多元线性回归、多元逐步回归和岭回归三种方法应用于硝基苯类五元体系进行定量分析的结果进行了比较研究,结果表明,对于所涉及的组分光谱重叠严重的病态的混合体系,多元逐步回归和岭回归间接校正都是合适的算法,总平均相对误差分别为3.84%和3.00%.     

便携式傅立叶红外快速检测环境中气态污染物

用Calmet软件,建立了便携式傅立叶红外快速检测气态污染物的方法。该方法适用于突发性环境污染事故的应急监测。     

Effects of climatic data low-pass filtering on the ICBM temperature- and moisture-based soil biological activity factors in a cool and humid climate

The air temperature (T_air), total precipitation (TP) and potential evapotranspiration (PET) are standard input data for soil carbon dynamic models, i.e., for calculating temperature and moisture effects on soil biological activity. The resolution needed depends on objectives, the complexity of models and inbuilt pedotransfer functions. The Introductory Carbon Balance Model (ICBM) soil climate front end model calculates a multiplicative soil-temperature (r_{e_temp}) and -moisture (r_{e_wat}) factor with a daily time-step to estimate soil biological activity, i.e., r_{e_crop} = r_{e_temp} × r_{e_wat}. Our objective was to determine how much r_{e_temp}, r_{e_wat} and r_{e_crop} are affected by low-pass filtering of the climatic input data for a cool, humid temperate region. To achieve this we conducted spectral analysis on T_air, TP, PET and r_{e_crop} in the frequency domain. Thereafter we applied Fourier low-pass filters of 5, 15, 30, 60 and 180 days on T_air, TP, PET and tracked their effects through the soil climate model's state variables and outputs. This was done using a sandy and a heavy clay soil and an 89-year daily time-series from a meteorological station in Quebec (Canada). The Fourier spectra showed that the variance for T_air, PET and r_{e_crop} was dominated by an annual cycle, as could be expected. There was no yearly cycle for TP. The variation in r_{e_temp} explained most of the variance in r_{e_crop}. The soil climate module outputs were not sensitive to low-pass filtering of PET. A daily time-step was needed to avoid overestimating r_{e_crop} for the sandy soil. Using a weekly time-step for TP and T_air allowed us to explain about 80% of the variance in r_{e_crop} for the heavy clay soil. This study also indicates that the standard leaf (and green) area index functions for calculating transpiration should receive more attention, since they have significant effects on the state and output variables.     

模拟酸雨淋溶条件下紫壤淋出液中溶解性有机质的三维荧光特性

运用三维荧光技术分析了模拟酸雨淋溶紫壤淋出液中溶解性有机质（dissolved organic matter,DOM）的组分与酸度及淋溶量的关系.研究结果表明,模拟酸雨淋溶紫壤淋出液中DOM荧光峰主要为类胡敏酸和类富里酸,荧光峰的中心位于Ex/Em=305—370 nm/420—450 nm和Ex/Em=260—270...     

生态文明建设与再生资源产业

党的十八大将生态文明建设提升到五位一体总体布局的战略高度,要求把生态文明建设放在突出地位,融入经济建设、政治建设、文化建设、社会建设各方面和全过程。从人类文明转型的高度,分析了推进生态文明建设的历史必然性,探寻了再生资源产业与生态文明建设间的内在联系,剖析了再生资源产业的典型特征,并对生态文明建设与再生资源产业的未来发展进行了展望.     

Rapid estimation of compost enzymatic activity by spectral analysis method combined with machine learning

The aim of this study was to investigate the feasibility of using visible near-infrared (VisNIR) diffuse reflectance spectroscopy (DRS) as an easy, inexpensive, and rapid method to predict compost enzymatic activity, which traditionally measured by fluorescein diacetate hydrolysis (FDA-HR) assay. Compost samples representative of five different compost facilities were scanned by DRS, and the raw reflectance spectra were preprocessed using seven spectral transformations for predicting compost FDA-HR with six multivariate algorithms. Although principal component analysis for all spectral pretreatments satisfactorily identified the clusters by compost types, it could not separate different FDA contents. Furthermore, the artificial neural network multilayer perceptron (residual prediction deviation = 3.2, validation r² = 0.91 and RMSE = 13.38 μg g^?1 h^?1) outperformed other multivariate models to capture the highly non-linear relationships between compost enzymatic activity and VisNIR reflectance spectra after Savitzky–Golay first derivative pretreatment. This work demonstrates the efficiency of VisNIR DRS for predicting compost enzymatic as well as microbial activity.     

Retrieval And Monitoring of Atmospheric Trace Gas Concentrations in Nadir and Limb Geometry Using the Space-Borne Sciamachy Instrument

The Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) onboard the European Envisat spacecraft performs continuous spectral observations of reflected, scattered and transmitted sunlight in various observation geometries. A unique feature of SCIAMACHY is the capability of probing the atmosphere in three different observation geometries:The nadir, limb, and occultation measurement modes. In nadir mode, column densities of trace gases are retrieved with a spatial resolution of typically 30× 60 km using the Differential Optical Absorption Spectroscopy (DOAS) technique (Platt and Perner, 1983). Alternating with the nadir measurement, vertical profiles of absorber concentration in the stratosphere are derived in limb and occultation. In this paper we present an overview over some applications of SCIAMACHY data in space-based monitoring of atmospheric pollution. The DOAS algorithms for the retrieval of total column amounts from nadir spectra are briefly described and case studies of pollution events are presented. We also illustrate the technique used to derive stratospheric concentration profiles from limb observations and show comparisons with other remote sensing systems. Special emphasis will be given to techniques, which take advantage of SCIAMACHY's different viewing geometries. In particular, we will discuss the potential and limits of strategies to infer tropospheric abundances of O₃and NO₂.     

基于多通道原位红外光谱技术的环氧涂层恒温固化反应研究

目的 拓展多通道原位红外光谱技术的应用,探究环氧树脂在固化行为中的分子结构变化以及不同固化深度下的动力学参数与恒温固化模型。方法 采用多通道原位红外光谱的表征方法,对N,N,O-三缩水甘油基对氨基苯酚(环氧树脂AFG-90)与甲基纳迪克酸酐(MNA)的环氧涂层的固化过程进行30、40、50、60、70 ℃等5个温度下的原位红外光谱监测,基于特征官能团吸光度的变化,研究恒温固化模型。结果 通过特征官能团吸光度与温度、时间的关系,计算得出AFG-90与MNA的环氧树脂固化体系在不同温度下的固化模型、达到不同固化度下的固化时间,求解得在不同固化深度下的活化能Ea主要在58~74 kJ/mol变化,且其均值为69.43 kJ/mol。结论 获得了AFG-90与MNA的环氧树脂固化体系在固化过程中动力学参数和模型,同时试验结果表明,多通道原位红外光谱技术是研究高分子材料固化反应动力学的有效表征方法。