基于GOCE梯度的地球引力场恢复(英文)

Given the second radial derivative Vr r ( P ) |S of the Earth’s gravitational potential V ( P ) on the surface S corresponding to the satellite altitude, by using the fictitious compress recovery method, a fictitious regular harmonic field rrVr r( P )* and a fictitious second radial gradient field Vr *r ( P) in the domain outside an inner sphere K i can be determined, which coincides with the real field Vr r( P ) in the domain outside the Earth. Vr *r ( P)could be further expressed as a uniformly convergent expansion series in the domain outside the inner sphere, because rrVr r( P )* could be expressed as a uniformly convergent spherical harmonic expansion series due to its regularity and harmony in that domain. In another aspect, the fictitious field V * ( P) defined in the domain outside the inner sphere, which coincides with the real field V ( P ) in the domain outside the Earth, could be also expressed as a spherical harmonic expansion series. Then, the harmonic coefficients contained in the series expressing V * ( P) can be determined, and consequently the real field V ( P ) is recovered. Preliminary simulation calculations show that the second radial gradient field Vr r( P ) could be recovered based only on the second radial derivative Vr r ( P )| S given on the satellite boundary. Concerning the final recovery of the potential field V ( P ) based only on the boundary value Vr r ( P )|S, the simulation tests are still in process.     

π型钢循环迈步支架在开采中厚煤层中的应用

在中厚煤层开采中,通过改进采煤工艺,采用“型钢循环迈步式支架代替高档炮采工作面常规的铰接顶梁支护工艺,在减少煤炭丢失的同时提高了资源回收率,也杜绝了老空区因丢失的煤炭自燃而引发的矿井火灾。     

矿山公园实例、特征及建设意义探讨

随着我国枯竭矿山的不断增多,针对废弃矿山和中晚期矿山的生态环境恢复治理,提出建设国家级矿山公园。解决矿山废墟带来的环境恶化,体现了矿山公园的核心价值,是矿山复垦、复绿浩大工程的一部分。它具有循环经济模式的特点,即矿山生产的周期完结后,投入旅游产业经济循环中,为社会提供的新的旅游资源;矿山公园也为保护矿业遗迹和地质遗迹提供可能。     

废弃矿山生态快速恢复技术

对喷混植生技术在废弃矿山生态恢复中的研究和应用进行了较全面的综合,主要涉及到喷混植生技术的概念、研究应用进展及研究现状,最后,对废弃矿山生态系统中喷混植生综合研究及示范推广进行了讨论。     

海泥细菌电池电催化降解效应——一种海底石油污染生态原位修复绿色新技术

海底石油污染可导致长期的生态灾难。一般海洋石油污染防治技术无法用于海底环境。文章描述了一种绿色的海底石油污染生态原位修复新技术,利用沉积层生物燃料电池电催化加速降解效应,即利用海底沉积层(海泥)中的多种细菌以石油污染物为营养物,代谢产生的电子被电池正极和负载消耗掉,反过来促进细菌加速降解污染物。该技术既可在海底加速石油污染物降解速率,又可原位产生电能驱动监测仪器工作,还可用于原位监测生态修复进展,故具有重要的应用前景。     

月球遥感制图回顾与展望

对月球探测任务、月球遥感制图技术与产品进行综述。从1958年开始,全世界已开展126次(其中70次成功)月球探测工程任务,其中月球遥感制图是其必需的基础性工作。由于月球环境的特殊性,其遥感制图技术与对地观测制图相比具有很大的挑战和更大的难度。目前,中国嫦娥二号轨道器获取的7 m分辨率立体影像是覆盖全月球分辨率最高的立体影像数据,美国月球侦察轨道器LRO任务的激光雷达高度计LOLA数据是精度和密度最高的激光测高数据,LRO NAC影像的分辨率最高(0.5—2 m)但未覆盖全球。在各个探测任务中,基于月球遥感数据和摄影测量技术,已经制作了大量的全球及区域的影像拼图、正射影像图和数字高程模型等制图产品。对月球遥感制图技术发展进行展望,探讨了利用国际多探测任务数据建立新一代控制网和进行精细制图的必要性及技术思路。     

Approaching four decades of forest watershed research at Upper Penticton Creek,British Columbia: A synthesis

Over the past 35 years, the Upper Penticton Creek (UPC) Watershed Experiment has supported forest hydrology research in south-central British Columbia (BC), Canada. This paper provides a synthesis of research results, highlights the challenges facing UPC and identifies new research directions. Clearcutting approximately 50% of two small, snow-dominated (Dfb Koppen classification) watersheds advanced the timing of snowmelt-generated high flows and decreased late-summer low flows, relative to predictions based on pre-treatment regressions. Changes in high flows did not have a significant effect on stream channels due to low stream power, coarse substrate, and limited riparian disturbance. Changes in summer low flows reduced modelled useable fish habitat by 20%–50%. Evaporation averaged 52% of the annual precipitation in the mature forest, was reduced to 30% in a clearcut, and recovered to 40% and 47% in a 10 and 25 year-old stand, respectively. Groundwater recharge to the bedrock was estimated at 19% of annual precipitation, indicating that, even with the large uncertainty associated with this estimate, deep groundwater should not be ignored in the water balance. Suspended sediment, turbidity, and colour increased post-logging; however, chemical surface water quality did not change. Aquatic community structure changed post-logging; and although this affected the processing of organic matter, the effects on habitat quality were considered minimal. The information gained at UPC has supported provincial policies, management guidelines, forest stewardship plans and watershed risk assessments. The undisturbed control watershed, re-growing treatment watersheds and ongoing long-term hydrometric monitoring continue to provide opportunities for future research addressing issues such as the effects of young forests on streamflow and hydrologic recovery, and the influence of climate change on the hydrologic regime.     

洞庭湖区湿地恢复的生态补偿效应评估

洞庭湖是我国最大的淡水湖泊湿地景观生态系统之一,湿地资源丰富。但由于人类不同历史时期的围垦和不合理的开发利用,导致湖泊湿地生态系统严重退化,湿地面积大为减少。随着洞庭湖区按照国家“退田还湖,移民建镇”的整体战略部署,以及“4350”工程的实施,湖泊面积、湿地资源将会得以恢复。然而,退田还湖中移民农户为保护与恢复湿地,牺牲了部分利益,成为受损方。洞庭湖区湖泊湿地的退田还湖工程是恢复长江生态功能系统工程中一个很重要的子系统,工程能否顺利实施的关键在于退田还湖农民在其中损失的利益能否得到补偿,及其为生态恢复所作的贡献能否得到承认。作者在实地调查和试验的基础上,依据环境经济学原理和方法,对洞庭湖湿地恢复引起的湖区农户收益减少和一系列的湿地生态服务功能的恢复表现,进行了价值评估,由此得出湿地恢复应对湖区移民农户的生态补偿值。以湿地恢复的生态补偿评估为基础,探讨了评估方法与建立补偿机制重要性,以期实现“以人为本”的战略目标,也为顺利进行退田还湖的后期工作,广泛调动广大群众生态建设的积极性,为合理建立生态补偿机制提供参考。     

多功能高分子固沙种草剂在民勤沙生植物复壮中的试验研究

试验选择在甘肃省武威市民勤县绿洲外缘与沙漠交接地带,以退化的人工梭梭林和天然白刺灌丛为受试植物,辅以滴灌措施,应用多功能高分子植物固沙种草剂进行沙生植物复壮试验研究。结果显示,白刺和梭梭施用试剂的抗旱、保水效果都很显著,尤其在白刺上的使用效果更好;滴灌施用试剂时,梭梭单梢干重平均值、最大新梢长平均值、最小新梢长平均值和最大新梢径平均值,滴灌施用试剂时均比滴灌对照、无滴灌对照和无滴灌试剂高得多;白刺灌丛高、径和冠幅增大,其中,滴灌试剂处理相对滴灌对照处理和免灌对照处理冠幅增长率分别为42.4%和174.4%。可见,该试剂不仅有利于保持林下土壤水分、有效提高其抗旱能力,而且还能够促使植物快速生长,对退化植被有很强的恢复能力。     

Regime theories in gravel‐bed rivers: models,controlling variables,and applications in disturbed Italian rivers

Downstream hydraulic geometry relationships describe the shape of alluvial channels in terms of bankfull width, flow depth, flow velocity, and channel slope. Recent investigations have stressed the difference in spatial scales associated with these variables and thus the time span required for their adjustment after a disturbance. The aim of this study is to explore the consequences in regime models considering the hypothesis that while channel width and depth adjust quickly to changes in water and sediment supply, reach slope requires a longer time span. Three theoretical models were applied. One model incorporates an extremal hypothesis (Millar RG. 2005. Theoretical regime equations for mobile gravel‐bed rivers with stable banks. Geomorphology 64 : 207–220), and the other two are fully physically based (Ikeda S, Parker G, Kimura Y. 1988. Stable width and depth of straight gravel rivers with heterogeneous bed materials. Water Resources Research 24 : 713–722; Parker G, Wilcock PR, Paola C, Dietrich W, Pitlick J. 2007. Physical basis for quasi universal relations describing bankfull hydraulic geometry of single‐thread gravel‐bed rivers. Journal of Geophysical Research 112 , DOI: 10.1029/2006JF000549). In order to evaluate the performance of models introducing the slope as an independent variable, we propose two modifications to previous models. The performance of regime models was tested against published data from 142 river reaches and new hydraulic geometry data from gravel‐bed rivers in Patagonia (Argentina) and north‐eastern Italy. Models that assume slope as a control (Ikeda et al., 1988; or Millar, 2005) predict channel depth and width reasonably well. Parker et al.'s (2007) model improved predictions because it filters the scatter in slope data with a relation slope–discharge. The extremal hypothesis model of Millar (2005) predicts comparably to the other physically based models. Millar's model was chosen to describe the recent changes in the Piave and Brenta rivers due to human intervention – mainly in‐channel gravel mining. The change in sediment supply and recovery was estimated for these rivers. This study supports the interpretation that sediment supply is the key factor guiding morphological changes in these rivers. Copyright © 2013 John Wiley & Sons, Ltd.