磷矿中P2O5的快速测定

本文用自行设计的一种简易,安全的聚四氟乙烯溶样罐,与新型,高效的微波溶样技术相结合,进行磷矿的分解,溶样时间仅需２ｍｉｎ,并首次将该技术与流动注射一分光光度法联用,测定其中Ｐ２Ｏ２质量分数,结果准确,可靠,实现了从溶样到测定的一套快速分析方法。     

Changes in Relative Plate Motion during the Isan Orogeny (1670-1500 Ma) and Implications for Pre-Rodinia Reconstructions

Foliation inflexion/intersection axes(FIAs)preserved within porphyroblasts that grew throughout Isan orogenesis reveal significant anticlockwise changes in the direction of bulk horizontal shortening between 1670 and 1500 Ma from NE-SW,N-S,E-W to NW-SE.This implies an anticlockwise shift in relative plate motion with time during the Isan orogeny.Dating monazite grains amongst the axial planar foliations defining three of the four FIAs enabled an age for the periods of relative plate motion that produced these structures to be determined.Averaging the ages from monazite grains defining each FIA set revealed 1649±12 Ma for NE-SW shortening,1645±7 Ma for N-S shortening,and 1591±10 Ma for that directed E-W.Inclusion trail asymmetries indicate shear senses of top to the SW for NW-SE FIAs and dominantly top to the N for E-W FIAs,reflecting thrusting towards the SW and N.No evidence for tectonism related to early NE-SW bulk horizontal shortening has previously been detected in the Mount Isa Inlier.Amalgamation of the Broken Hill and possibly the Gawler provinces with the Mount Isa province may have taken place during these periods of NE-SW and N-S-directed thrusting as the ages of tectonism are similar.Overlapping dates,tectonic,metamorphic,and metallogenic similarities between eastern Australia(Mount Isa and Broken Hill terranes)and the southwest part of Laurentia imply a most probable connection between both continental masses.Putting Australia in such position with respect to North America during the Late-Paleo-to-Mesoproterozoic time is consistent with the AUSWUS model of the Rodinia supercontinent.     

金在树脂相表面化学发光行为的研究

研究了金在树脂相表面吸附、发光行为、实验方法、仪器装置和仪器工作参数，建立了金的在线分离、富集发光检测新方法。pH值小于1的含金试样，通过装有717阴离子交换树脂脂柱后，金被定量吸队，通以碱性鲁米诺溶液，产生定量化学发光信号，方法的线性范围为0－0.200mg/L，检出限为0.003mg/L。结合金矿石国家二级标准物质分析验证，结果与标准值无显著性差异，RSD（n=10)为2.0%。     

A comparison of techniques for generating forest ownership spatial products

To fully understand forest resources, it is imperative to understand the social context in which the forests exist. A pivotal part of that context is the forest ownership. It is the owners, operating within biophysical and social constraints, who ultimately decide if the land will remain forested, how the resources will be used, and by whom. Forest ownership patterns vary substantially across the United States. These distributions are traditionally represented with tabular statistics that fail to capture the spatial patterns of ownership. Existing spatial products are not sufficient for many strategic-level planning needs because they are not electronically available for large areas (e.g., parcels maps) or do not provide detailed ownership categories (e.g., only depict private versus public ownership). Thiessen polygon, multinomial logit, and classification tree methods were tested for producing a forest ownership spatial dataset across four states with divergent ownership patterns: Alabama, Arizona, Michigan, and Oregon. Over 17,000 sample points with classified forest ownership, collected as part of the USDA Forest Service, Forest Inventory and Analysis (FIA) program, were divided into two datasets, one used as the dependent variable across all of the models and 10 percent of the points were retained for validation across the models. Additional model inputs included a polygon coverage of public lands from the Conservation Biology Institute’s Protected Areas Database (PAD) and data representing human population pressures, road densities, forest characteristics, land cover, and other attributes. The Thiessen polygon approach predicted ownership patterns based on proximity to the sample points in the model dataset and subsequent combining with the PAD ownership data layer. The multinomial logit and classification tree approaches predicted the ownership at the validation points based on the PAD ownership information and data representing human population, road, forest, land cover, and other attributes. The percentage of validation points across the four states correctly predicted ranged from 76.3 to 78.9 among the methods with corresponding weighted kappa values ranging from 0.73 to 0.76. Different methods performed slightly, but statistically significantly, better in different states Overall, the Thiessen polygon method was deemed preferable because: it has a lower bias towards dominant ownership categories; requires fewer inputs; and is simpler to implement.     

流动注射技术在土壤压出液系统分析中的应用研究

本文将流动注射分析用于土壤压出液中电导率、pH值、K~+、Na~+、Ca~(2+)、Mg~(2+)、HCO_3~-、Cl~-和SO_4~(2-)含量的连续测定。样品用量仅2—5ml,分析速度快,精密、准确,自动化程度较高。对合成样品分析的结果符合计算值,是少量样品多组份分析的有效方法。     

反向流动注射分析法连续测定氰化物和硫氰化物的研究

运用反向流动注射分析法以吡啶－巴比舀酸和Ｆｅ（Ⅲ）作为显色剂建立了连续测定ＣＮ＾－和ＳＣ＾－的方法，借助于聚四氟乙烯微孔膜分离ＣＮ＾－和ＳＣＮ＾－，经切换阀实现测定转换。通过优化实验找到了两者连续测定的适宜条件，ＣＮ＾－和ＳＣＮ＾－的测定范围分别为：５－２０ｍｇ／Ｌ和０－８０ｍｇ／Ｌ．     

Estimating regional forest cover in East Texas using Advanced Very High Resolution Radiometer (AVHRR) data

This study tested the degree to which single date, near-nadir AVHRR image could provide forest cover estimates comparable to the phase I estimates obtained from the traditional photo-based techniques of the Forest Inventory and Analysis (FIA) program. FIA program is part of the United States Department of Agriculture-Forest Service (USFS). A six-county region in east Texas was selected for this study. Manual identification of ground control points (GCPs) was necessary for geo-referencing this image with higher precision. Through digital image classification techniques forest classes were separated from other non-forest classes in the study area. Classified AVHRR imagery was compared to two verification datasets: photo-center points and the USFS FIA plots. The overall accuracy values obtained were 67 and 71%, respectively. Analyses of the error matrices indicated that the AVHRR image correctly classified more forested areas than non-forested areas; however, most of the errors could be attributed to certain land cover and land use classes. Several pastures with tree cover, which were field-identified as non-forest, were misclassified as forest in the AVHRR image using the image classification system developed in this study. Recently harvested and young pine forests were misclassified as non-forest in the imagery. County-level forest cover estimates obtained from the AVHRR imagery were within the 95% confidence interval of the corresponding estimates from traditional photo-based methods. These results indicate that AVHRR imagery could be used to estimate county-level forest cover; however, the precision associated with these estimates was lower than that obtained through traditional photo-based techniques.     

SHORT COMMUNICATION USE OF A LINEAR FUNCTION OF SEVERAL VARIABLES IN SIMPLEX OPTIMIZATION AS A PROCEDURE FOR ASSESSING ANALYTICAL VERSATILITY IN FIA

A linear response function RF=C_H R_H+C_T(1-R_T)(R_H=peak height,used as a measure of‘sensitivity’,and R_T=analysis time,1-R_T,used as a measure of sampling rate)was used to optimize aFIA system for the determination of nitrite in water with respect to four experimental parameters(twotube lengths and two flow rates)by a Simplex procedure.The weights C_H and C_T placed on R_H and R_Twere systematically varied to cover their allowed range and the system obtained in each optimizationexperiment was implemented and evaluated by determining the following analytical parameters:reproducibility,limit of detection and sampling rate,It was found that these depend very markedly onthe weights used in the response function.Hence the use of a linear function for optimization provides auseful procedure for assessing the versatility of the experimental technique and for choosing the systemsfor its implementation in different practical situations.     

FIA—双光束分光光度法测定河泥中痕量铝

本文采用一套流动注射(FIA)-双光束分光光度计装置,选用适宜工作条件测定了河泥中的痕量Al。该法设备简单,灵敏度比普通FIA-单光束光度法高1倍,分析速度快(90样/小时),相对标准偏差为0.8％(n=13),检出限小于0.04μg/ml。     

关于流动注射分析今后发展的若干见解

针对目前流动注射分析（ＦＩＡ）的应用广泛程度落后于ＦＩＡ技术的研究和发展问题，提出了未来发展中的关键环节是商品仪器的稳定性、耐用性、简易性和专用化。未来发展的重要方向是开发其它分析技术不可替代的功能，即不稳定反应的定量分析、高分辨过程分析、ＦＩ在线分离与浓集、智能化校正体系等。