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641.
高地应力条件下Q系统在某勘探洞围岩分类中的应用 总被引:1,自引:0,他引:1
西南地区某水电站勘探洞高地应力是一个突出问题,高地应力洞段岩体属于坚硬岩或较坚硬岩,主要破坏方式是岩爆。高地应力区非岩爆岩体中未见结构性流变和软岩塑性流动等变形破坏现象,岩体质量较好。通过对岩体质量分类Q系统在该勘探洞高地应力洞段的应用,发现Q系统对于高地应力区非岩爆段岩体没有给出相应的SRF值;岩爆的发育条件是多方面的,但Q系统对岩爆的发育条件考虑较单一,所以它在高地应力区岩爆段的分类结果不能准确地体现出岩爆的等级和围岩类别。基于这2个问题,本文对Q系统做了相应的修改,以适应该勘探洞围岩分类,从修改后Q系统的分类结果看,效果良好。 相似文献
642.
An investigation of the impacts from elevated intertidal Pacific oyster culture in a New Zealand estuary showed enhanced sedimentation
beneath culture racks compared with other sites. Seabed elevation beneath racks was generally lower than between them, suggesting
that topographic patterns more likely result from a local effect of rack structures on hydrodynamic processes than from enhanced
deposition. Compared with control sites, seabed sediments within the farm had a greater silt/clay and organic content, and
a lower redox potential and shear strength. While a marked trend in macrofaunal species richness was not evident, species
composition and dominance patterns were consistent with a disturbance gradient, with farm effects not evident 35 m from the
perimeter of the racks. Of the environmental variables measured, sediment shear strength was most closely associated with
the distribution and density of macrofauna, suggesting that human-induced disturbance from farming operations may have contributed
to the biological patterns. To evaluate the taxonomic sufficiency needed to document impacts, aggregation to the family level
based on Linnean classification was compared with an aggregation scheme based on `general groups' identifiable with limited
taxonomic expertise. Compared with species-level analyses, spatial patterns of impact were equally discernible at both aggregation
levels used, provided density rather than presence/absence data were used. Once baseline conditions are established and the
efficacy of taxonomic aggregation demonstrated, a `general group' scheme provides an appropriate and increasingly relevant
tool for routine monitoring. 相似文献
643.
赵秋雯 《中国环境管理干部学院学报》2009,19(1):30-33
良好的生态环境是人类生存和发展的基础,是经济社会发展的物质条件。保护和管理好自然生态环境,是实施可持续发展的关键,也是实现跨世纪绿色工程的重要战略。本文通过对秦皇岛生态环境保护与旅游开发的调查与思考得出结论:将秦皇岛建设成以旅游为龙头的生态城市是秦皇岛市建设和发展的方向。 相似文献
644.
Heather E. Golden Elizabeth W. Boyer Michael G. Brown S. Thomas Purucker René H. Germain 《Journal of the American Water Resources Association》2009,45(4):945-962
Abstract: Nitrate‐nitrogen (NO3‐N) concentrations in stream water often respond uniquely to changes in inter‐annual conditions (e.g., biological N uptake and precipitation) in individual catchments. In this paper, we assess (1) how the spatial distribution of NO3‐N concentrations varies across a dense network of nonnested catchments and (2) how relationships between multiple landscape factors [within whole catchments and hydrologically sensitive areas (HSAs) of the catchments] and stream NO3‐N are expressed under a variety of annual conditions. Stream NO3‐N data were collected during two synoptic sampling events across >55 tributaries and two synoptic sampling periods with >11 tributaries during summer low flow periods. Sample tributaries drain mixed land cover watersheds ranging in size from 0.150 to 312 km2 and outlet directly to Cayuga Lake, New York. Changes in NO3‐N concentration ratios between each sampling event suggest a high degree of spatial heterogeneity in catchment response across the Cayuga Lake Watershed, ranging from 0.230 to 61.4. Variations in NO3‐N concentrations within each of the large synoptic sampling events were also high, ranging from 0.040 to 8.7 mg NO3‐N/l (March) and 0.090 to 15.5 mg NO3‐N/l (October). Although Pearson correlation coefficients suggest that this variability is related to multiple landscape factors during all four sampling events, partial correlations suggest percentage of row crops in the catchments as the only similar factor in March and October and catchment area as the only factor during summer low flows. Further, the strength of the relationships is typically lower in the HSAs of catchment. Advancing current understanding of such variations and relationships to landscape factors across multiple catchments – and under a variety of biogeochemical and hydrological conditions – is important, as (1) nitrate continues to be employed as an indicator of regional aquatic ecosystem health and services and (2) a unified framework approach for understanding individual catchment processes is a rapidly evolving focus for catchment‐based science and management. 相似文献
645.
Yu-Chi Weng Takeshi Fujiwara Yuzuru Matsuoka 《Journal of Material Cycles and Waste Management》2009,11(2):110-122
Industrialization and urbanization result in significant changes in lifestyle. These lifestyle changes seem to lead to unsustainable
consumption patterns and increase the generation of various kinds of environmental loads, especially the amount of municipal
solid waste (MSW). Taiwan is a small island with scarce natural resources. The economic development in Taiwan has resulted
in the generation of large amounts of MSW. As a result, the Taiwan Environmental Pollution Administration (TEPA) has produced
regulations for waste minimization and has imposed several important policy measures that have successfully reduced the MSW
discard rate in recent years and have established a public recycling network as a part of the MSW collection. Nowadays, the
objective of the MSW policies in Taiwan is to develop a “zero-waste society.” This article aims to review the MSW management
progress in Taiwan and to project future MSW discards up to 2011 based on the national plan and assumed scenarios for socioeconomic
variables. According to the analysis results, a more sustainable consumption pattern can be proposed and the corresponding
MSW management system can be planned so as to develop a low-waste-discard society. 相似文献
646.
647.
648.
重庆近48年来高温天气气候特征及其环流形势 总被引:5,自引:0,他引:5
利用重庆23个气象观测站1960~2007年逐日最高气温观测资料,NCEP/NCAR再分析数据集中的高度场格点资料,运用EOF、REOF等方法,探讨重庆高温日数的空间分布特征,并对多高温天气的2006年和少高温天气年7~8月的环流特征进行了分析。结果表明:重庆高温天气主要出现在7~8月份,高温日数具有显著的年代际和区域性差异,20世纪70年代最多,80年代最少,沿长江、乌江为高温多发带。一致性异常分布是重庆高温日数的最主要空间模态;高温日数的异常空间分布可分为以下3个关键区:重庆中西部、重庆东南部、重庆东北部。乌拉尔山至鄂霍次克海地区阻塞高压偏弱,东亚大槽偏浅;100 hPa 高空南亚高压偏东,500 hPa 高空副高偏北偏西,形成一种上高下高的叠加形势是重庆7~8月出现多高温天气的主要原因。 相似文献
649.
650.
以污泥蛋白为实验材料,通过加入不同量的稳定剂GP-1,配制成高稳定性污泥蛋白发泡剂,并对高稳定性污泥蛋白发泡剂的发泡特性和影响因素进行研究。结果表明,以污泥蛋白10 mL、水90 mL、GP-1 0.4 g配方组合为研究对象,所制备的泡沫初始体积为770 mL,泡沫泌水时间大于15 h,泡沫半衰期大于64 h,泡沫综合发泡能力为2.2×106 mL·min,泡沫的最佳搅拌时间为5 min,泡沫的泌水时间和泡沫的半衰期都是随着温度的上升而下降,在pH为3~13时泡沫稳定。经过对高稳定性污泥蛋白发泡剂发泡特性研究以及对水泥的胶凝时间、特性进行比较,研制出污泥蛋白泡沫混凝土发泡剂,并制备污泥蛋白泡沫混凝土块;结果表明,当污泥蛋白泡沫混凝土发泡剂的用量分别为0、6、6.8、7.6、8.4和9.2 mL,水泥为200 g时,制备泡沫混凝土块,其密度由2.07 g/cm3下降到0.34 g/cm3,体积由130 cm3 上升到755 cm3;在泡沫混凝土块脱模后的第1 d、第7 d、第28 d分别称量他们的重量变化情况,结果表明,泡沫混凝土块第1 d和第7 d无重量变化,第28 d的重量明显减轻。该研究为污泥蛋白研制成为泡沫混凝土发泡剂,并应用于屋面隔热、保温建立前期基础。 相似文献