陕北沙漠区浅埋厚煤层开采潜水位及生态响应

煤炭开采造成上覆岩层破裂、移动，破坏了矿区含（隔）水层结构，改变了地表水及地下水循环演化状态，对浅表层生态环境造成严重影响，引发一系列环境地质问题。为深入研究沙漠地区厚煤层开采给潜水位及生态环境造成的影响，以毛乌素沙漠金鸡滩矿为例，对水文地质条件进行了研究，采用数值模拟的方法，模拟了沙漠区厚煤层开采潜水位的变化，并通过采动潜水位监测数据验证了预测结果。调查分析了研究区及周边地表生态环境现状，预测采后潜水位基本满足植物生长需求，对生态环境影响不大。     

基于遥感解译与模糊数学的矿山地质环境综合评价——以戈壁荒漠区某有色金属矿山为例

戈壁荒漠区属生态环境脆弱区,原生地质环境敏感性强,矿业开发一定程度上加剧了土地沙化、盐渍化和荒漠区砾幕层的破坏,但戈壁荒漠区以往矿山地质环境调查工作程度较低,亦亟需开展矿山地质环境调查与评价工作。通过基于遥感解译的地质环境调查,查明了矿山地质环境现状。建立了适用于戈壁荒漠区矿山地质环境评价指标体系,通过模糊数学综合评价与综合指数模型评价,得到模糊综合评判指数与综合评价指数分别为4.806、4.833,确定矿山地质环境影响程度为中度影响。基于遥感解译与模糊数学的评价方法在戈壁荒漠区有色金属矿山地质环境综合评价中有效可行,为有色金属矿山地质环境调查与评价提供了方法借鉴,为矿山地质环境保护与恢复治理及土地复垦提供了依据。     

Atmospheric deposition of carbon and nutrients across an arid metropolitan area

Urbanization is increasing rapidly in semi-arid environments and is predicted to alter atmospheric deposition of nutrients and pollutants to cities as well as to ecosystems downwind. We examined patterns of wet and coarse dry deposition chemistry over a five-year period at 7 sites across the Central Arizona-Phoenix (CAP) study area, one of two urban sites within the National Science Foundation's Long-Term Ecological Research (LTER) program. Wet and dry deposition of organic carbon (oC) were significantly elevated in the urban core; in contrast, mean annual wet and dry fluxes of nitrogen (N) were low (<6 kg ha(-1) yr(-1)) compared to previous estimates and did not differ significantly among sites. Wet deposition of sulfate (SO(4)2-) was high across CAP (mean 1.39 kg ha(-1) yr(-1) as S) and represented the dominant anion in rainfall. Dry deposition rates did not show strong seasonal trends with the exception of oC, which was 3-fold higher in winter than in summer; ammonium (NH4+) deposition was high but more variable. Dry deposition of NO3- and oC was strongly correlated with particulate base cations and dust-derived soluble reactive phosphorus (SRP), suggesting that urban-derived dust is scrubbing the atmosphere of acidic gases and entrained particles and increasing local deposition. Differences between measured and predicted rates of dry N deposition to the urban core may be explained by incomplete collection of gas phase N on surrogate deposition surfaces in this hot and arid environment. The extent of urban enhancement of cations and oC inputs to desert ecosystems appears to be restricted to the urbanized metropolitan area rather than extending far downwind, although a low number of sites make it difficult to resolve this spatial pattern. Nevertheless, wet and dry inputs may be important for biogeochemical cycles in nutrient and carbon-poor desert ecosystems within and near arid cities.     

The complex aerodynamic footprint of desert locusts revealed by large-volume tomographic particle image velocimetry

Particle image velocimetry has been the preferred experimental technique with which to study the aerodynamics of animal flight for over a decade. In that time, hardware has become more accessible and the software has progressed from the acquisition of planes through the flow field to the reconstruction of small volumetric measurements. Until now, it has not been possible to capture large volumes that incorporate the full wavelength of the aerodynamic track left behind during a complete wingbeat cycle. Here, we use a unique apparatus to acquire the first instantaneous wake volume of a flying animal''s entire wingbeat. We confirm the presence of wake deformation behind desert locusts and quantify the effect of that deformation on estimates of aerodynamic force and the efficiency of lift generation. We present previously undescribed vortex wake phenomena, including entrainment around the wing-tip vortices of a set of secondary vortices borne of Kelvin–Helmholtz instability in the shear layer behind the flapping wings.     

水坠砂地基处理在沙漠地区工程中的试验及应用

本文对靖边化工园区砂土地区砂土的工程性质和砂土的水理性质进行了试验性研究，对水坠砂地基处理技术在工程中应该如何应用的问题进行了试验和分析，以便为水坠沙技术的广泛应用提供一些科学的试验性基础数据。     

在沙地治理中诞生的CO2产业链 ——以毛乌素生物热电厂“三碳经济”模式为例

文章介绍了在毛乌素沙地种植沙生灌木治理沙地吸收二氧化碳、用灌木枝条发电减排二氧化碳、以电厂余热和烟气养殖螺旋藻捕集二氧化碳的"三碳经济"产业链。该产业链极大地增强了生物质发电厂的活力,提高了农牧民营林治沙的积极性,显著带动了农牧民增收,并创造了巨大的生态效益。更为重要的是,该产业链实现了被动治沙到主动治沙的转变,在我国沙漠沙地治理的机制建设中也有重要价值。     

江陵凹陷白垩系红花套组沙漠沉积特征

通过大量钻井、岩心和野外露头资料,提出江陵凹陷上白垩统的红花套组是冲积扇-沙漠沉积组合。结合岩心、测井及野外露头资料,详细划分出江陵凹陷红花套组沙漠沉积亚相,包括戈壁、风成沙丘、丘间、旱谷和沙漠湖等,并建立了各个沉积亚相的相标志。沙漠沉积具有良好的储层,江陵凹陷红花套组勘探实践证实了沙漠沉积储层的油气地质意义。     

高精度三维地震采集技术在塔中沙漠区碳酸盐岩勘探中的应用

塔中沙漠区碳酸盐岩储层是塔里木盆地最主要的油气勘探目标之一。如何提高沙漠地表条件下小缝洞型储层在地震资料上的成像质量是目前该区地震勘探中亟待解决的主要问题。为此,在地震采集技术方面提出了相应的措施。首先,调查了疏松沙丘对地震波的吸收衰减情况,并进行了高速层中检波器接收试验,结果表明,疏松沙丘对地震波(主频35 Hz及以下)的吸收衰减作用不严重,检波器组合接收是提高地震资料信噪比的一种重要手段;其次,研究了针对碳酸盐岩缝洞型储层的三维观测系统设计方法,提出了道密度设计方法及保证面元属性均匀的观测系统设计原则;最后,对沙漠地表条件下的组合高差设计方法进行了论证分析,提出了基于沙丘性质的灵活的检波器组合高差设计方法。将这些方法应用于塔中沙漠区的三维地震勘探,取得了非常明显的勘探效果。     

The Hinterland Urbanised?

What defines the urban? And can the non-urban necessarily always be classified as rural? Neil Brenner , Director of the Urban Theory Lab at Harvard University Graduate School of Design, reflects on the lack of an overarching theory to describe these realms, and argues that what we call the countryside or the hinterland has become key to the process of capitalist urbanisation.     

仿生表面的离心风机叶轮抗冲蚀性能研究

目的 针对传统方法对提高离心风机叶轮抗冲蚀性能效果不显著的问题,从仿生学角度出发,对基于沙漠红柳优异抗冲蚀机理的仿生离心风机叶轮抗冲蚀性能进行了研究.方法 对沙漠红柳、垂柳树皮进行顺纹拉伸和冲蚀试验,定性定量分析沙漠红柳抗冲蚀磨损性能.基于对沙漠红柳树干、树枝体表形态表征测试,建立仿生表面模型,并利用Fluent对其进行数值模拟,比较分析不同仿生表面模型的冲蚀磨损性能及机理.参照ASTM-G76-83标准,设计制造离心风机冲蚀磨损试验装置.并基于有限元仿真结果和风机叶轮冲蚀性能的可视化研究,优化并制造离心风机仿生叶轮,对其进行冲蚀试验,评价分析各试验因素对叶轮冲蚀性能的影响.结果 沙漠红柳树皮弹性模量(509.17 MPa)大于垂柳树皮弹性模量(313.19 MPa),沙漠红柳冲蚀磨损量最大值(21.6 mg)小于垂柳冲蚀磨损量的最小值(24.1 mg),表明沙漠红柳具有较优的抗冲蚀性能.进一步观测沙漠红柳树皮形貌,发现其体表分布有大量的凹槽和凸包等特殊形态,通过模拟发现,这些特殊形态相较于光滑表面,可有效降低粒子对表面的冲蚀磨损量.基于对样件的冲蚀试验发现,影响叶轮冲蚀性能的主次因素依次为:单元形态、间距、特征尺寸.最优样件组合为:V形槽、间距2 mm、特征尺寸4 mm.结论 沙漠红柳树皮具有优异的抗冲蚀性能,这与其体表特殊形态紧密相关.基于沙漠红柳体表特殊形态设计的仿生离心风机叶轮较光滑叶轮,具有优异的抗冲蚀性能,经测试发现,最优组合样件的抗冲蚀性能较传统的光滑件提高了28.97％.