湖南土壤生态系统对酸沉降的相对敏感性区划

以成土母质、土壤酸碱度、土壤类型、植被类型和湿度类型等5个生境因子为基础,建立湖南土壤生态系统对酸沉降的相对敏感性评价指标体系;利用地理信息系统(GIS)工具进行湖南土壤生态系统对酸沉降的相对敏感性区划,结果表明,湖南省可以划分为极敏感区、敏感区、中等敏感区、不敏感区和极不敏感区等5个酸相对敏感性分区,分别占湖南省总面积的2.15%、30.02%、55.01%、10.56%和2.26%.     

Supergene processes on ore deposits—a source of heavy metals

The study of supergene processes (i.e., secondary processes running in ore deposits and driven by thermodynamic nonequilibrium between ore-and rock-forming minerals and natural waters, gasses, etc.) is important in order to understand the migration of heavy metals from ore into their adjacent surroundings. The contamination of the local environment can be characterized by the composition of pore waters. The Pb-Zn-Cu ore deposits of Zlaté Hory (Czech Republic) have been chosen for a detailed study of pore solutions. A simple model has been created to describe the evolution of supergene processes in the ore deposits. This model is based on the determination of chemical composition of pore solutions. The dilution of pore solutions of such mineral deposits results in acid mine drainage. Pore solutions can have, during specific stages of their evolution, relatively high concentrations of Cu (0.09 mol/kg), Zn (0.1 mol/kg), SO₄ (0.8 mol/kg) and an extremely low pH (1.38). The supergene alteration of pyrite is the most important process determining the character of pore water. This reaction causes significant acidification and is a leading source of acid mine drainage. The leached zone originates from the interaction of pyrite and limonite. Increased concentrations of heavy metals and sulfates occur in pore waters. The dynamic composition of pore waters within ore deposits undergoing the supergene process can be used to distinguish: (1) three main zoneslimonite, transition, and primary zone and (2) two areas—an area with the highest intensity of weathering processes and an area of weathering initiation. In these areas the rate of sulfide oxidation is higher as a result of low pH. From the study of these zones and areas we can further our knowledge of ore body, pore solution, acid mine drainage, and contamination of the local environment.     

重庆市酸沉降污染造成的植被受害状况遥感监测研究

运用遥感技术,对重庆市酸沉降污染造成的植被受害状况进行了全面监测研究。建立了植物遥感监测、植物常规监测以及大气监测结果之间的相关关系。通过彩红外航空遥感调查,划分、圈定并计算了重庆市植被受害类型及其分布面积。     

CaCl2、NaHCO3和盐酸降pH的效果及其对水质的影响

本文于１９９８的８－１０月间选取山东省高青县赵店乡大芦湖养殖公司院内一口盐碱池塘的池水为实验用水,选用ＣａＣｌ２、ＮａＨＣＯ３和盐酸作试剂,进行了这三种试剂的降ｐＨ值实验。实验结果表明：ＮａＨＣＯ３有降ｐＨ效果须高浓度使用,但会使水体缓冲能力下降,不宜作为降ｐＨ的试剂。盐酸能迅速降低ｐＨ,但持续时间较短,适合急救时使用。２１９ｋｇ．ｈａ＾－１（１４．６ｋｇ／亩）的用量可降低ｐＨ１．５个单位。能长期     

新一代机载PMS粒子测量系统及应用

详细介绍新一代机载PMS粒子测量系统的组成结构、软件系统、各部分的工作原理及功能,并介绍该系统在人工影响天气中的应用情况.该系统具有自动化程度高、实时性和适用性强、运行稳定的特点,是进行人工增雨等外场试验和研究的重要手段.     

基于小时降水资料的贵州降水精细特征分析

摘要：利用2010—2019年贵州地区2683个自动气象站逐时降水观测资料,在结合地形特征分析了贵州降水总体时空特征的基础上,从平均雨强和降水概率方面进一步研究了贵州各季日内降水的精细化特征。结果表明：（1）贵州年降水时长和年降水量空间分布有所差异,其中位于大娄山脉北侧的遵义赤水和习水地区则仅为降水时长的大值区;（2）四季降水时长分布主要受当季主要降水系统位置的影响,而平均降水强度则兼受地理条件的影响,偏向山脉的南麓;（3）在日内降水分布上,贵州四季都存在明显的夜雨现象,其中下半夜到凌晨（00—06 时）降水发生概率更大且强度更强,其中心有明显自西向东传播的特征;（4）短时强降水主要出现在春夏两季且向东传播明显,并主要在夜间到早晨。     

Reactive trace element enrichment in a highly modified, tidally inundated acid sulfate soil wetland: East Trinity, Australia

This study examines the abundance of trace elements in surface sediments of a former acid sulfate soil (ASS) wetland subjected to marine tidal inundation. Sediment properties of this highly modified study site are compared with those of an adjacent unmodified, intertidal mangrove forest. Whilst some trace elements (Al, Cd, Mn, Ni and Zn) were clearly depleted due to mobilisation and leaching in the previous oxic-acidic phase, other trace elements (As and Cr) displayed significant enrichment in the tidally inundated ASS. Many trace elements were strongly associated with the reactive Fe and acid volatile sulfide (AVS) fractions, suggesting that trace elements may be adsorbed to abundant reactive Fe phases or sequestered as sulfide minerals. These findings provide an important understanding of the fate and mobility of reactive iron, AVS and trace elements during tidal remediation of a formerly acidified Great Barrier Reef (GBR) catchment.     

LIKELIHOOD TECHNIQUES FOR INTERLABORATORY CALIBRATION IN THE NATIONAL STREAM SURVEY

Techniques for testing for and estimating relative bias between two laboratories are developed andapplied to a survey of the chemistry of streams in the United States.The design of the quality assuranceprogram allows estimation of linear corrections for bias as well as testing of the hypothesis of linearity,Designs of this type are useful,but improvements are suggested.     

Biodegradability of Photographic Developers and Ingredients of Photographic Developers,especially of Hydroquinone and Isoascorbic Acid

The biodegradability of 5 different commercially available common photographic developers and their ingredients hydroquinone, isoascorbic acid, and its sodium salt was determined in parallel using the OECD-screening-test (OECD 301E). The results obtained from the degradation test on hydroquinone were compared with the results of other laboratories. Biodegradability of developers containing isoascorbic acid was in the same range as of comparable products containing hydroquinone.     

Assessing desertification

It is widely recognized that desertification is a serious threat to arid and semiarid environments—which cover 40% of the global land surface and are populated by approximately 1 billion humans. Given the potential relevance of this problem, it is surprising that there is no consensus on the proper way to assess the desertification status of a piece of land. During the last 70 years, conflicting definitions have produced both different assessment methodologies and divergent estimates. Contrary to conceptual issues on desertification, assessment methodologies have not been reviewed comprehensively. Here, we critically review the most common methodologies to assess desertification, and describe their principal consequences on scientific and social arenas.We show that desertification assessment has shifted from simple appraisals of the interannual movement of desert boundaries to complex multivariate field surveys, to practical methodologies based on indicators of ecosystem functioning, such as rain use efficiency. Although often regarded as an evidence of stagnation and failure, these methodologies reflect the progress that desertification ecology has experienced. Future challenges for properly assessing desertification are (1) the lack of reference situations against which actual desertification could be compared, and (2) the difficulties that appear when desertification operates through structural rather than functional ecosystem changes.The coexistence of conflicting definitions and divergent estimates negatively affects societal perception, leading to scepticism and, ultimately, to a delay of eventual solutions. Societies must recognize the progress desertification ecology has made, leave behind concepts that no longer represent current knowledge, grasp the opportunity to better assess the extent and intensity of the problem, and, for the time being, realize that assessing desertification is an unsolved issue.