基于光谱技术的土壤多参数快速检测进展与展望

传统的土壤采样和实验室分析方法往往工作量大、前处理复杂、测定周期长、时效差、费用高,因此,迫切需要寻找快速、准确的土壤多参数检测方法,以实现多尺度土壤属性数据的快速获取与更新。系统梳理了便携式X射线荧光光谱(PXRF)、可见光-近红外反射光谱(Vis-NIR)、激光诱导击穿光谱(LIBS)和电弧发射光谱(AES)等光谱技术的原理、特点以及在土壤多参数快速检测中的应用及其研究进展。提出,未来在提高现有土壤多参数光谱检测精度和适用性的基础上,应结合ICP-MS等传统实验室方法,综合应用多种光谱技术以及化学计量学、现代信息技术和空间分析技术等,实现区域多种土壤属性的快速获取与实时监测,以满足我国当前土壤多参数、高精度快速检测及土壤质量精细化管理的需要。     

基于实测光谱的海河悬浮物浓度反演研究

悬浮物浓度是评价水质优劣的重要指标之一。以天津滨海新区海河为研究区域,进行光谱数据测量和水体样本采集,并在实验室进行水质参数提取,得到归一化光谱反射率和光谱一阶微分数据。然后对光谱测量数据和悬浮物浓度实测值进行相关性分析,发现896 nm归一化光谱反射率和光谱反射率比值(R_(896)/R_(546))与悬浮物浓度相关性较好。最后,分别建立单波段、波段比值和一阶微分函数拟合模型,进行对比分析。结果表明,基于R_(896)/R_(546)的二次多项式模型拟合效果最好,方差齐性检验(F)值也是最高的,可用于该地区水体的悬浮物浓度反演和预测。     

Determination of soil content in chlordecone (organochlorine pesticide) using near infrared reflectance spectroscopy (NIRS)

Chlordecone is a toxic organochlorine insecticide that was used in banana plantations until 1993 in the French West Indies. This study aimed at assessing the potential of near infrared reflectance spectroscopy (NIRS) for determining chlordecone content in Andosols, Nitisols and Ferralsols from Martinique. Using partial least square regression, chlordecone content conventionally determined through gas chromatography–mass spectrometry could be correctly predicted by NIRS (Q² = 0.75, R² = 0.82 for the total set), especially for samples with chlordecone content <12 mg kg⁻¹ or when the sample set was rather homogeneous (Q² = 0.91, R² = 0.82 for the Andosols). Conventional measures and NIRS predictions were poorly correlated for chlordecone content >12 mg kg⁻¹, nevertheless ca. 80% samples were correctly predicted when the set was divided into three or four classes of chlordecone content. Thus NIRS could be considered a time- and cost-effective method for characterising soil contamination by chlordecone.     

铊在黄铁矿中的相态分布及碳酸盐在其释放过程中的作用

采用分级提取-电感耦合等离子体质谱法,对黄铁矿中铊的相态分布进行了考察.结果表明,黄铁矿中的铊主要以存在于硅酸盐相中和以酸可交换的形式存在于矿物结构中的铊为主,这部分铊分别占到58.3%和25.1%;以可氧化态形式结合在黄铁矿(FeS2)中的铊次之,占11.2%;以易还原态形式存在于铁氧化物相中的铊最少,为5.4%.自然条件下铊的释放主要是酸可交换态铊和可氧化态铊的释放迁移过程.漫反射红外光谱表征发现,黄铁矿在表面氧化过程中其表面羟基增多,表明存在表面溶解及表面酸化现象.进一步的释放机理探讨认为,铊在黄铁矿表面存在一种"溶解-吸附沉淀"平衡,这一平衡由碳酸盐中和作用和黄铁矿表面氧化共同控制,并决定了铊的释放迁移.     

潜流人工湿地负荷变化对脱氮效果的影响研究

通过15个月的现场监测试验,研究了约40种入水负荷下人工湿地的脱氮效果,总结了芦苇、茭草、混合种植以及无植物潜流湿地在不同水力负荷和污染负荷下的单位面积出水氮负荷和去除率的变化规律.4种潜流系统入水负荷从400mg·(m²·d)^-1变化到8 000 mg·(m²·d)^-1,出水负荷小于7 000 mg·(m²·d)^-1,研究表明,潜流湿地出水负荷随着入水负荷的升高而升高,具有明显的线性相关关系.单位面积总氮的去除率在低负荷条件下随入水负荷的升高而升高,但在高负荷时单位面积去除率基本维持在一定的水平,不受入水负荷的影响,去除率变化波动较大.各系统的最佳运行范围在2 000～4 000mg·(m²·d)^-1之间,平均去除率在1 062～2 007 mg·(m²·d)^-1之间.床体间比较认为,植物床脱氮效果明显好于空白床,芦苇床、茭草床单位面积脱氮效率高出空白床63%和27%;同时考察的植物吸收量证明,植物吸收氮的量非常有限,不到去除量的5%,证明植物主要通过吸收以外的其它因素如改善水力条件和根系微环境来提高系统的氮去除效率.研究结果为潜流湿地脱氮机理的理解和设计提供参考.     

Surface solar ultraviolet radiation: A theoretical approach of the SUVR reaching the ground in Athens, Greece

Daily total ozone observations made during 1985–1993 by both the Total Ozone Mapping Spectrometer (TOMS) flown on the Satellite Nimbus-7 and the Dobson Spectrophotometer have been used in order to investigate the fluctuations of the daily broad-band and spectral solar ultraviolet radiation reaching the ground. This investigation has been performed by employing a recently developed parametric algorithm for the estimation of the spectral and broad-band solar ultraviolet radiation which takes the total ozone variations into consideration. Total ozone reductions during the summertime from 1985 to 1993 over Athens, Greece (37.6° N, 23.4° E), cause an increase in the ultraviolet irradiance which reaches the ground of 0.54 %, 0.98 %, 2.60 % and 0.79 % per decade for the months of July at 300 nm, 312 nm, 320 nm and UVB (280-320 nm), respectively.     

Quantitative assessment of tidal wetlands using remote sensing

Effective management of tidal wetlands requires periodic data on the boundaries, extent, and condition of the wetlands. In many states, wetlands are defined wholly, or in combination with other criteria, by the presence of particular emergent halophytic plants. Many important characteristics of the wetlands ecosystem are related directly to the production of emergent plant material or may be inferred from knowledge of the distribution of emergent plant species. Remote-sensing techniques have been applied to mapping of the distribution of wetland vegetation but not to quantitative evaluation of the condition of that vegetation.Recent research in the tidal wetlands of Delaware and elsewhere has shown that spectral canopy reflectance properties can be quantitatively related to the emergent green biomass ofSpartina alterniflora (salt marsh cord grass) throughout the peak growing season (April through September, in Delaware). Periodic measurements of this parameter could be applied to calculations of net aerial primary productivity for large areas ofS. alterniflora marsh in which conventional harvest techniques may be prohibitively time consuming. The method is species specific and, therefore, requires accurate discrimination ofS. alterniflora from other vegetation types. Observed seasonal changes in species spectral signatures are shown to have potential for improving multispectral categorization of tidal wetland vegetation types.     

烃源岩成熟度评价指标及选取

烃源岩成熟度评价是油气地质勘探中一项重要工作。作者以表格形式概括了烃源岩有机质成熟度评价指标。考虑到源岩有机质性质及岩性对成熟度评价的影响,除了选用镜质体反射率之外,在反射率受抑制和缺之镜质体的情况下,也应开展多方面研究。     

铜绿微囊藻、四尾栅藻和谷皮菱形藻在低光照度下的生长研究

实验研究了铜绿微囊藻、四尾栅藻和谷皮菱形藻在75～1 200lx光照度下的生长情况.实验结果表明光照度为600lx以下时,3种藻都受到了光的抑制作用,生长缓慢;光照度为600～1 200lx时,3种藻的生物量随光照度的增加均有不同程度的增加,其中增加最显著的是谷皮菱形藻,其次才是铜绿微囊藻和四尾栅藻.     

浅析泥石流堆积物的光谱特征——以蒋家沟泥石流堆积物为例

运用 10 0 BXMTS野外光谱仪探测了小江支流蒋家沟新、老泥石流堆积物的光谱反射率 ,总结了新、老堆积物的反射光谱特性 ,分析了影响泥石流堆积物反射光谱特性的因素 (岩性、水分含量、植被覆盖 ) ,最后讨论了应用高空间分辨率遥感图像解译泥石流堆积物的可能性。