A restoration-promoting integrated floating bed and its experimental performance in eutrophication remediation

Numerous studies on eutrophication remediation have mainly focused on purifying water first, then restoring submerged macrophytes. A restoration-promoting integrated floating bed （RPIFB） was designed to combine the processes of water purification and macrophyte restoration simultaneously. Two outdoor experiments were conducted to evaluate the ecological functions of the RP1FB. Trial 1 was conducted to compare the eutrophication purification among floating bed, gradual-submerging bed （GSB） and RPIFB technologies. The results illustrated that RPIFB has the best purification capacity. Removal efficiencies of RPIFB for TN, TP,NH4＋-N, NO3-N, CODcr, Chlorophyll-a and turbidity were 74.45%, 98.31%, 74.71%, 88.81%, 71.42%, 90.17% and 85%, respectively. In trial 2, influences of depth of GSB and photic area in RPIFB on biota were investigated. When the depth of GSB decreased and the photic area of RPIFB grew, the height of Potamogeton crispus Linn. increased, but the biomass of Canna indica Linn. was reduced. The mortalities of Misgurnus anguillicaudatus and Bellamya aeruginosa in each group were all less than 7%. All results indicated that when the RPIFB was embedded into the eutrophic water, the regime shift from phytoplankton-dominated to macrophyte-dominated state could be promoted. Thus, the RPIFB is a promising remediation technology for eutrophication and submerged macrophyte restoration.     

岷江上游大沟流域驱动植被退化的人为干扰体研究

研究了岷江上游大沟流域内的人为干扰体,分析了干扰的类型、强度、频率及其时空变化特征,揭示了不同干扰类型及其特性对植被退化的作用、干扰体与人口增长、植被退化等的关系．结果表明：大沟流域人为干扰类型多达８种,但优势的干扰类型是砍伐薪材和牲畜放牧．从近３０ａ的干扰强度变化看,以８０年代初的干扰强度最大,并在近２０ａ内保持很高的干扰强度水平;干扰强度的年内变化表现为春末、夏、秋大而冬、早春小．近４０ａ来的干扰频率愈趋增高,年内表现为春秋季干扰频率最高,夏季中等,而冬季最小．人为干扰的空间差异十分明显,反映出人为干扰的现状及其对植被的破坏强度差异,即由村寨向沟尾和高海拔区、由近及远、由低到高,形成“钟形”干扰格局．认为大沟流域植被的严重退化是所有人为干扰长期共同驱动的结果,与该区人口及其需求迅速增长密切相关．结果还表明,不同性质的干扰对植被的影响作用具协同性,同一干扰体长期连续对植被的影响具累加和放大的作用     

长期不同施肥方式对江南稻田系统生产力与抗逆性的影响

依据29 a的田间施肥小区试验和4 a的养分耗竭盆栽试验,比较分析了不同施肥方式对江南丘陵稻田生产力及抗逆性的综合影响。结果表明,有机无机肥配施(NPK+OM处理)方式下,双季稻各季和周年生产力最高,其周年平均生物量和籽粒产量比化肥氮磷钾配施(NPK处理)高24.5%和20.2%。与单施氮肥相比,化肥氮磷钾配施显著提高了双季稻的氮素利用效率,而适量增施有机氮能够进一步提高氮素利用效率。化肥单施方式(N和NPK处理)下水稻周年籽粒产量呈递减趋势,下降幅度分别为43.7和1.8 kg.hm-2.a-1,而有机无机肥配施方式下水稻周年籽粒产量呈递增趋势,上升幅度为6.9 kg.hm-2.a-1。平衡施肥方式(NPK和NPK+OM处理)下,水稻各季及周年籽粒产量的年际变异较小,可持续性产量指数和系统生产力稳定性较高。养分耗竭试验4 a后,各处理水稻各季及周年生物量和籽粒产量高低基本表现为NPK+OM>NPK>N,试验期内周年籽粒平均产量以有机无机肥配施处理最高,说明有机无机肥配施的稻田土壤耐瘠能力高于其他施肥处理。可见,有机无机肥配施不仅能使稻田系统持续保持较高的生产力,而且能够提升系统的抗逆性,有利于江南丘陵稻田系...     

Sulfamethoxazole sorption by sediment fractions in comparison to pyrene and bisphenol A

The environmental behavior of antibiotics has attracted great research attention. However, their sorption mechanisms in soils/sediments are still unknown. Comparison of the sorption properties between the widely-studied hydrophobic organic contaminants (HOCs) and antibiotics may provide valuable insight to antibiotic sorption mechanisms. Thus, in this study batch experiments for pyrene (PYR), bisphenol A (BPA), and sulfamethoxazole (SMX) sorption were conducted on a sediment sample and its separated fractions. Our results showed the high sorption of PYR on black carbon and organic matter. Although high sorption of SMX was observed for both separated organic fractions (humic acids) and inorganic mineral particles, the original sediment particles showed relatively low sorption. Competitive sorption between SMX and dissolved humic acid on mineral particles was observed in this study. This competitive interaction is a unique process for antibiotic sorption in soils/sediments compared with apolar HOCs and may be one of the important factors controlling the antibiotic sorption.     

Mineral exploration in the USSR and the USA

This article compares non-fuel mineral exploration in the USSR and the USA. It examines the organization of exploration; recent trends in the level and distribution of expenditures; exploration productivity; and planning and decision making. It shows that although the sequence of exploration stages and activities is very similar in both countries, substantial differences overshadow these similarities, largely because of different economic and political systems and mineral endowments. However, the article concludes that we still have much to learn before making a full comparison of Soviet and US exploration.     

镁渣配料煅烧硅酸盐水泥熟料的研究

研究了镁渣矿物组成和镁渣配料煅烧硅酸盐水泥熟料的反应动力在数和物理性能。结果表明：镁渣的主要矿物组成为γ－Ｃ２Ｓ、β－Ｃ２Ｓ、ＭｇＯ、ＣＦ、Ｃ２Ｆ、ＦｅＯ、ＣａＦ２等，并且镁渣可降低熟料形成反应表观活化能，加速熟料矿物的形成，提高熟料的强度。     

Application of Holdridge life-zone model based on the terrain factor in Xinjiang Automous Region

This study improved the application of the Holdridge life-zone model to simulate the distribution of desert vegetation in China which gives statistics to support eco-recovery and ecosystem reconstruction in desert area. This study classified the desert vegetation into four types： （1） LAD： little arbor desert; （2） SD： shrub desert： （3） HLHSD： half-shrub, little half-shrub desert; （4） LHSCD： little halfshrub cushion desert. Based on the classification of Xinjiang desert vegetation, the classical Holdridge life-zone model was used to simulate Xinjiang desert vegetation＇s distribution and compare the Kappa coefficient result of the model with table of accuracy represented by Kappa values. The Kappa value of the model was only 0.19, it means the simulation result was poor. To improve the life-zone model application to Xinjiang desert vegetation type, a set of plot standards for terrain factors was developed by using the plot standard as the reclassification criterion to climate sub-regime. Then the desert vegetation in Xinjiang was simulated. The average Kappa value of the second simulation to the respective climate regime was 0.45. The Kappa value of final modeling result was 0.64, which is the better value. The modification of the model made it in more application region. In the end, the model＇ s ecological relevance to the Xinjiang desert vegetation types was studied.     

To breed or not to breed—food competition and other factors involved in female breeding decisions in the pair-living nocturnal fork-marked lemur (<Emphasis Type="Italic">Phaner furcifer</Emphasis>)

Differential access to food resources is thought to be the main determinant of differences in female reproductive success but is poorly studied in both pair-living and nocturnal primates. The modes of food competition within and between families were investigated following the principles proposed by the ecological model using 3 years of field data from seven fork-marked lemur (Phaner furcifer) families. The major food resources were identified from year-round feeding observations and the strength and mode of competition were inferred from differences in physical condition. The most important food resource of fork-marked lemurs were tree exudates which occurred in small, defendable food patches, characterized by fast depletion and rapid renewal. These characteristics led to strong within-group contest and scramble competition, which were found to yield a positive dominance effect and a negative group-size effect on female net energy gain. Differential physical condition, however, did not translate directly into differential reproductive success. Low female fertility was best predicted by large family size associated with delayed dispersal by previous offspring. Although there is no obvious benefit from full-grown offspring in their territory, adults tolerate delayed natal dispersal, probably because dispersal poses extraordinary costs for the offspring. These costs are likely to accrue from decreased foraging efficiency in unfamiliar habitats because exudate feeding requires very rigid feeding itineraries. In conclusion, the presented evidence for group-size effects on reproductive success in pair-living females opens a new area for research on the costs and benefits of delayed dispersal and female reproductive decisions.This revised version was published in September 2003 with corrections to the Authors Present address.An erratum to this article can be found at Communicated by E.H.M. Sterck     

环太平洋陆缘成矿带区段对比及中国东南找矿思路

环太平洋陆缘弧系按其演化历史不同可分为挤压型、盆岭型和裂解型三种。不同类型弧系的不同区段金属成矿分带互有差别,甚至相反,其主要原因在于:1.构造演化历史不同,板块俯冲的势态不同;2.火山岩系列和火山岩组合,花岗岩成因类型及其发育程度和分布特征不同;3.地壳厚度和结构、基底杂岩的性质、基底构造特点和基底所赋存时代较老的金属矿化不同。在对比环太平洋成矿带各区段金属成矿特征的基础上,提出中国东南Au、Cu找矿的战略目标应在浙中闽西,江南古陆南缘和长江中下游;矽卡岩型Pb-Zn-Ag矿在浙闽沿海火山岩区有一定远景;裂谷式火山构造洼地可成为浅成热液贵金属和有色金属矿化的远景地段。     

Beyond the material grave: Life Cycle Impact Assessment of leaching from secondary materials in road and earth constructions

In industrialized countries, large amounts of mineral wastes are produced. They are re-used in various ways, particularly in road and earth constructions, substituting primary resources such as gravel. However, they may also contain pollutants, such as heavy metals, which may be leached to the groundwater. The toxic impacts of these emissions are so far often neglected within Life Cycle Assessments (LCA) of products or waste treatment services and thus, potentially large environmental impacts are currently missed. This study aims at closing this gap by assessing the ecotoxic impacts of heavy metal leaching from industrial mineral wastes in road and earth constructions. The flows of metals such as Sb, As, Pb, Cd, Cr, Cu, Mo, Ni, V and Zn originating from three typical constructions to the environment are quantified, their fate in the environment is assessed and potential ecotoxic effects evaluated. For our reference country, Germany, the industrial wastes that are applied as Granular Secondary Construction Material (GSCM) carry more than 45,000 t of diverse heavy metals per year. Depending on the material quality and construction type applied, up to 150 t of heavy metals may leach to the environment within the first 100 years after construction. Heavy metal retardation in subsoil can potentially reduce the fate to groundwater by up to 100%. One major challenge of integrating leaching from constructions into macro-scale LCA frameworks is the high variability in micro-scale technical and geographical factors, such as material qualities, construction types and soil types. In our work, we consider a broad range of parameter values in the modeling of leaching and fate. This allows distinguishing between the impacts of various road constructions, as well as sites with different soil properties. The findings of this study promote the quantitative consideration of environmental impacts of long-term leaching in Life Cycle Assessment, complementing site-specific risk assessment, for the design of waste management strategies, particularly in the construction sector.