Vulnerability of water discharge of large Chinese rivers to environmental changes: an overview

In an era of rapid environmental change, China is facing increasing problems in the management of its large rivers and water resources. The disastrous 1998 Yangtze floods and the emerging water shortages in north China raised further concerns about the potential impact of environmental change on extreme hydrological events such as floods and droughts. Over the past few decades, increasing water consumption by the domestic, industrial and agricultural sectors, as well as a number of human activities such as deforestation, agricultural land expansion, wetland reclamation, construction of reservoirs and roads, water diversion, and sand/stone excavation significantly affect hydro-geomorphic processes such as water discharge and sediment flux throughout China. This paper aims to provide an overview of recent research on the water discharge changes occurring in major Chinese rivers and their vulnerability to environmental change. Most of the rivers, notably in north China, have experienced significant changes in water discharge over the last few decades, indicating that they are vulnerable to climatic variations and human activities. In contrast to north China, the rivers in south China have experienced less change, but some of the detected changes displayed similar trends to those in north China, though at a slower pace. These profound changes, in addition to the on-going projects such as the Three Gorges Dam Project and the South-North Water Transfer Project, will completely alter Chinas waterscape.     

GIS在固体废弃物管理规划中的研究应用

文章在综合阅读国内外文献资料的基础上,结合计算机技术和GIS的发展,详细阐述了GIS在固体废弃物管理规划中的研究应用现状、存在的问题及其发展趋势。文章首先介绍了GIS的功能及其在环境保护特别是在固体废弃物管理规划中的应用,然后针对固体废弃物管理规划中存在的具体问题,指出了应用GIS技术对固体废弃物进行管理规划的方便性、灵活性和可视化优势之所在,强调了通过加强GIS在固体废弃物管理规划应用中的完整性和普适性,并逐步实现网络化,必将大大提高固体废弃物的管理和决策的科学性、规范性和可靠性。     

金属大气暴露与模拟加速腐蚀结果相关性探讨

阐述了金属大气暴露腐蚀试验与模拟加速腐蚀试验2种腐蚀试验结果的相关性,具体介绍了相关性的评价原则和常见的评价方法,并提出了现阶段相关性评价中尚存在的问题,探讨了相关性研究的发展趋势和重要意义。     

广州地区秋冬季细颗粒物PM_(2.5)化学组分分析

本文对广州地区2009~2010年秋冬季节大气中PM2.5进行采样,并分析PM2.5样品的水溶性离子、重金属元素、有机碳/元素碳(OC/EC)、有机酸、多环芳烃浓度和粒径分布。通过分析初步掌握了广州地区秋冬季节大气中PM2.5的化学组分和特点:广州地区秋冬季PM2.5呈现城区高于城郊,PM2.5中有机质(OM)是最主要的成分,其次是硫酸根离子、硝酸根离子和铵根;PM2.5中有机碳和元素碳的空间分布特征相似,并受一次源排放影响;PM2.5中铝、锌、铅是含量最高的重金属,且城区重金属浓度高于城郊;PM2.5中17种多环芳烃、苯并a芘(BaP)均为城郊浓度最高。     

Composition and crystal structure of N doped TiO2 film deposited at different O2 flow rate by direct current sputtering

N doped Ti0₂ films were deposited by direct current pulse magnetron sputtering system at room temperature. The influence of 0₂ flow rate on the crystal structure of deposited films was studied by Stylus profilometer, X-ray photoelectron spectroscopy, and X-ray diffractometer. The results indicate that the 0₂ flow rate strongly controls the growth behavior and crystal structure of N doped Ti0₂ film. It is found that N element mainly exists as substitutional doped state and the chemical stiochiometry is near to TiO_1.68±0.06N_0.11±0.01 for all film samples. N doped Ti0₂ film deposited with 2 sccm (standard-state cubic centimeter per minute) 0₂ flow rate is amorphous structure with high growth rate, which contains both anatase phase and rutile phase crystal nucleuses. In this case, the film displays the mix-phase of anatase and rutile after annealing treatment. While N doped Ti0₂ film deposited with 12 cm³/min 0₂ flow rate displays anatase phase before and after annealing treatment. And it should be noticed that no TiN phase appears for all samples before and after annealing treatment.     

Influence of coating method on catalyst activity of AgCl/Al2O3/SUS304 composite plate

The γ-Al₂0₃ and AgCl/Al₂0₃ catalyst powder were coated on a stainless steel substrate by dip coating and electrophoretic deposition method. And AgCl/Al₂0₃ catalyst was produced by three kinds of methods, and the difference between the NOx reduction catalysis of the coated sample was compared. XRD and SEM were used to study the crystalline structure and cross-section of the coatings. The coating of γ-Al₂0₃ with the thickness of 3-5 μm and AgCl/Al₂0₃ catalyst with the thickness of 5-9 μrn were made on the surface of SUS304 plate without exfoliation. The NOx conversion of the coated sample with catalyst was about 70% at the maximum.     

Geographic variations in seed dispersal by ants: are plant and seed traits decisive?

The effect of local ant species on the dispersal success of a myrmecochorous plant, Helleborus foetidus, was analyzed in two populations of the Iberian Peninsula (Caurel and Cazorla, respectively). The contribution of the various local ant species to dispersal was very unequal. While 5 and 19 ant taxa visited the plants of Caurel and Cazorla, respectively, most removal activity (67 and 80%) was performed by two species only (Formica lugubris and Camponotus cruentatus, respectively). Visits by dispersers were also unequally distributed between neighboring plants. While some plants were always visited during the period of seed release, others were never visited. A regression model indicated that this pattern might be explained by two plant traits: ants preferred to visit plants that released more seeds and whose elaiosomes were richer in oleic acid. Although it has long been known that this compound triggers removal by ants, it is the first demonstration that quantitative variations in elaiosome traits contribute to variation in dispersal success. Finally, other variables being equal, morphological traits (seed size, elaiosome size, and elaiosome/seed size ratio) did not affect ant behavior. Although myrmecochory has long been considered a diffuse interaction, our results support the idea that, at local scale, a limited number of ant species may be decisive to its evolution.     

泰安丘陵地区土地整理项目区的土壤质量时空变异研究

在农用地整理过程中,由于移动了耕层土壤,所以土壤剖面变异和表层土壤养分不均匀的现象普遍存在,重构土壤的质量状况及其变化成为决定土地整理成败的关键.以泰安市丘陵区的土地整理项目为例,分析了土地整理后1 a、2 a和4 a土壤质量的时空变异特性.采样点利用GPS定位,在每个土地整理项目区以及相应对照样点地块采样,并对所采120份土样进行土壤养分分析;根据所测数据,对各土壤养分进行时空变异分析,其中空间变异主要通过变异系数说明,时间变异分析则引入了养分指数的概念.结果表明:表层土壤养分时空变异具有比较明显的规律性,其中有机质、速效K和有效P的变异系数随着整理年限的延长而增大,有机质、速效K和碱解N在土壤中的质量比则随整理时间的增长与相应对照值趋于一致.     

锦州市农村饮用水水源地环境评估

为了研究锦州市农村饮用水水源地基础环境状况综合评估工作,从环境禀赋、污染状况、环境监管和环境风险四个领域入手,分析农村饮用水水源地存在的主要环境问题和原因。有以下几点:水文地质参数匮乏,上游来水水质较差;由于地质因素及当地人民生活、牲畜饲养所排废物以及长期施用化肥导致总硬度及高锰酸盐指数超标;基本没有开展保护区的划分,也没有进行勘界、树立水源保护区标志、污染源搬迁等工作。