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白石沟井田是近年来探明的大巾型井田,位于五指岭-白寨背斜东端之南翼,新密-新郑复向斜之北翼．岗亚腰断层和梁山断层之间的地垒构造上,其基本构造形态为-向东倾伏的宽缓背斜。二叠系下统山西组二1煤为主要开采煤层,探明二1煤资源量7206×10^7t。分析了井田含水岩组及其富水性,对断层带及其富水特征进行了研究,从矿床（二1煤层）充水的水源、通道、机理三个方面分析了矿床充水因素,指出二1煤层的主要充水水源为该煤层底板的石炭系岩溶裂隙-承压水,充水通道为断层带和灰岩的岩溶裂隙发育带,充水机理为矿压及高水头压力冲破煤层底板阻水层阻力,形成底鼓,迅速突水。认为该井田水文地质勘查类型为三类二型,提出了排除与隔离地表水体,预留防水安全煤柱,灌浆辅助采掘的井田突水防范措施。 相似文献
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李刚 《海洋学报(英文版)》2019,38(8):78-85
Mixing of freshwater and seawater creates the well-known salinity gradients along the estuaries. In order to investigate how phytoplankton respond to the acute salinity changes, we exposed natural phytoplankton assemblies from the Jiulong River Estuary to differential saline field water while continuously monitoring their photosynthetic performances under both indoor-and outdoor-growth conditions. When the natural cell assemblies from salinity 30 field water were exposed to series low saline field water(salinity 25, 17, 13 and 7.5), the effective Photosystem II quantum yield(ΔF/F_m′) decreased sharply, e.g., to one-fifth of its initials after 5 min exposure to salinity 7.5 field water, and then increased fast during the following 40 min and almost completely recovered after 320 min. During such an exposure process, non-photochemical quenching(NPQ) sharply increased from 0 to 0.85 within 5 min, and then decreased to nearly 0 within the following 70 min. When these cells re-acclimated to salinity 7.5 field water were exposed to series high saline field water(salinity 13, 17, 25 and 30), a similar response pattern was observed, with the decreased ΔF/F_m′ accompanied with increased NPQ, and followed by the recovery-induced increase in ΔF/F_m′ and decrease in NPQ. A similar response pattern as ΔF/F_m′to the acute osmotic stress was also observed in the photosynthetic carbon fixation capacity according to radiocarbon(~(14)C) incorporation. Our results indicate that estuarine phytoplankton assemblies could rapidly recover from the acute osmotic stress, implying a potential cause for their frequent blooms in coastal-estuarine waters where despite drastically varying salinity, available nutrients are abundant due to the land-derived runoffs or mixing-caused relaxations from sediments. 相似文献
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利用2006—2007年4次908计划ST06区块海洋光学调查的数据和MODIS水色遥感数据,对台湾海峡及周边海域的水色光谱特性进行了研究和分析。结果显示该海域的水色光谱主要有4个类型:类型1光谱峰值出现在580 nm附近,谱峰两侧遥感反射率随波长变化迅速减小,主要分布在紧靠中国大陆的海域;类型2光谱峰值出现在540～560 nm之间,具有谱峰宽的特点,主要分布在台湾海峡靠近大陆的一侧;类型3光谱与大洋水体光谱类似,主要分布在台湾西南的南海区域和吕宋海峡区域;类型4光谱在.450 nm附近出现极小值,在500～600 nm之间出现峰值,主要出现在台湾海峡中部和靠近台湾岛的一侧。其中类型2和4水体分布具有明显的季节特征。类型3、4、2、1对应的叶绿素a浓度和悬浮泥沙浓度呈上升趋势,对应的透明度依次降低,该海域以二类水体为主。 相似文献
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Tobelite (NH4) Al2 [AlSi3O10] (OH)2, the ammonium analogue of muscovite, and its deuterated form ND4-tobelite (ND4) Al2 [AlSi3O10] (OD)2 have been synthesised at 600?°C and 200 and 500 Mpa using a well homogenised, stoichiometric SiO2-Al2O3 oxide mix with Al2O3 in excess of 5 mol% and a 25% NH3 solution whose relative abundance was such that the amount of NH4 + stoichiometrically available was in excess of 50%. Characterisation of both tobelite and ND4-tobelite using IR-spectroscopy, Rietveld refinement of X-ray powder diffraction data, and electron microprobe analysis indicate that, similar to K+ in muscovite, the NH4 + or ND4 + molecule occupies the interlayer site. IR absorption bands caused by NH4 + and ND4 + can be explained, to a very good approximation, on the basis of Td symmetry. Nevertheless, substantial line broadening and the occurrence of shoulders indicate a deviation from ideal Td symmetry. However, even at 77?K, no discrete splitting of the degenerate states could be confirmed. The OH stretching frequencies observed for synthetic tobelite are quite similar to those for muscovite, indicating that the replacement of K+ by NH4 + has no effect. The low FWHH of the OH bands indicate that the hydroxyl groups are well ordered within the structure. Rietveld refinement of tobelite and ND4-tobelite indicates that all samples synthesised consist of the 3 different mica polytypes which are typical of muscovite – namely 1M (C2/m), 2M 1 (C2/c) and 2M 2 (C2/c). Tobelite and ND4-tobelite synthesised at 500 Mpa principally contain the 1M polytype, whereas the principle polytype for ND4-tobelite synthesised at 200 Mpa, is 2M 2. Rietveld refinement of X-ray diffraction spectra for tobelite synthesised at 200 Mpa was problematic due to the very broad FWHH of the X-ray peaks indicating poor crystallinity. In comparision to synthetic muscovite, the cell dimensions observed for tobelite and its deuterated analogue are quite similar except for the lattice constant c. Due to the larger radius of NH4 + or ND4 + compared to K+ cation, the c-direction is expanded form 10.275 Å in muscovite to approximately 10.540 Å in tobelite and ND4-tobelite. 相似文献
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在原有CHZ重力仪研制基础上,设计新一代海洋重力仪CHZ-Ⅱ并进行硬件搭建与测试。阐述了为CHZ-Ⅱ重力敏感结构设计的测试方案、实验过程及其结果分析,主要包括弹性系统的刚度、交叉耦合效应和漂移效应。实验表明,该结构在目前的测试内容下符合设计要求。 相似文献
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根据马莲河流域水资源总量极端贫乏、年际年内分配不均、常规水资源量低、水污染问题较严重等特点,利用系统分析理论和优化技术建立了流域的大系统、多目标水资源优化配置模型,并利用优化的NSGA-Ⅱ方法进行求解,得到流域2020年期望水资源配置下的最佳分配方案为:流域总供水量57 086×104m3,工业供水量21 690×104m3(总产值约为144.6亿元),能源基地供水量4 329×104m3(总产值约为346.32万元),农业供水量20 840×104m3,生活供水量9 452×104m3,生态供水量811×104m3。对比期望方案供水量增加了6 710×104m3,综合缺水率减少了11.41%。并根据预测的流域的分配方案和预测的流域需水量,进行了流域的水资源平衡分析,通过平衡分析的结果进行流域的综合管理研究。2020年在最优水资源分配方案下,工业缺水率3.21%、减少了4.51%;能源基地缺水率0.00%;农业缺水率4.64%、缺水率增加26.17%;生活缺水率0.00%;生态缺水率1.00%、缺水率增加了1.00%。配置方案实现了流域内水资源的最佳分配,使宝贵、有限的水资源产生最大的社会、经济及环境效益,为流域经济、能源产业的快速发展提供水资源保障。 相似文献
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以Web of Science数据库收录的有关研究Cyberspace的大量文献为数据源,采用文献计量学的分析方法,借助信息可视化软件CiteSpace Ⅱ对所采集的数据进行统计分析;获取1993 ～2013年检索数据,通过可视化图谱的方法挖掘出该领域的研究重点和学科分布;从地理学角度,揭示了该领域的研究热点和方向. 相似文献
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