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31.
大洋铁锰结壳的地球化学与古海洋环境示踪 总被引:5,自引:0,他引:5
主要回顾近年来铁锰结壳在深度定年、主量元素、微量元素及Sr,Nd,Pb同位素地球化学及其古海洋环境示踪方面的主要研究进展,并提出有关认识和展望。 相似文献
32.
在上流式好氧颗粒污泥床反应器中, 以厌氧颗粒污泥和好氧絮状活性污泥为接种泥, 采用人工配制的模拟废水, 成功培养出性能优异的好氧颗粒污泥.反应器内污泥浓度稳定在5g/L左右, 颗粒污泥粒径为0.5~2.0mm, 当进水COD为2000mg/L, 容积负荷为4.8kg/(m3·d)时, 系统对COD的去除率稳定在96%以上.通过扫描电镜观察, 好氧颗粒污泥是层状结构, 表面有大量丝状菌缠绕, 内部有短杆菌和空穴存在.逐步提高制药废水在进水中的比例, 经过47d的培养, 生物制药废水完全取代模拟废水, 系统对COD、NH3-N、TP的去除率分别稳定在90%、90%和70%以上. 相似文献
33.
Qing Qian Jun Gao Reiner Klemd Guoqi He Biao Song Dunyi Liu Ronghua Xu 《International Journal of Earth Sciences》2009,98(3):551-569
Traditionally the Chinese South Tianshan has been regarded as a late Paleozoic orogenic belt. However, little is known about
the early Paleozoic tectonic architecture of the region. This paper presents the first evidence of Cambrian–Ordovician MORB-type
basalts and adakitic diorites on the southern margin of the Yili plate in China. Basalts from Xiate in southwestern Tianshan
show a typical transitional (T-) MORB and ferrobasalt composition, which indicate a formation at a propagating spreading ridge.
The basalts give a weighted mean 206Pb/238U crystallization age of 516.3 ± 7.4 Ma by SHRIMP U–Pb zircon dating and have experienced contact metamorphism due to the
intrusion of a dioritic pluton. The dioritic pluton has a weighted mean 206Pb/238U crystallization age of 470 ± 12 Ma and geochemical characteristics resembling that of adakitic rocks. The pluton is considered
to have been formed by partial melting of garnet amphibolites from thickened lower crust in arc or continental collision settings.
The basalts and diorites are considered to outline the eastern extension of the early Paleozoic suture zone, the Nikolaev
Line, which stretches east–west for hundreds of kilometers between the Northern Tianshan and Central Tianshan terranes of
Kyrgyzstan. Our findings substantiate that the Yili and Central Tianshan plates were separated by the early Paleozoic Terskey
ocean. The Terskey ocean probably closed during the early stage of the late Ordovician (Lomize et al. in Geotectonics 31(6):463–482,
1997), resulting in the final amalgamation of the Yili and Central Tianshan plates. Consequently, an early Paleozoic suture zone
is documented in the Chinese Tianshan region, which is most likely represented by the North Nalati fault. 相似文献
34.
35.
Under the assumption that hydrograph generation was affected by n linear reservoirs with the same value of storage coefficient k, Nash proposed the formulation of the Instantaneous Unit Hydrograph (IUH), which has been widely used in rainfall–runoff simulation and flood forecasting. However, the assumption of the parameter k having the same value in all reservoirs is obviously unphysical as it results in the estimated value of n not being integral. In this study, for parameter n integral, the different k value for each reservoir was derived using the Laplace transform and developing a general rule for the equation of the IUH of any order. The relationship between parameter k and the slope of the river channel estimated using digital elevation model (DEM) data is established, the parameter estimation procedures are given. As in most unit hydrograph studies, only isolated storm events are considered here. Seventeen flood events in three catchments were selected for the case studies. Application results show that the proposed method is slightly better than Nash's IUH with higher model efficiency and smaller absolute relative errors. This work provides a new methodology for the formulation of the IUH. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
36.
基于DEM的新疆降水量空间分布 总被引:4,自引:2,他引:4
降水量是构成生态系统的重要气候参数之一。然而,由于降水量观测站布设的局限性,如站点稀少,空间分布不均匀等,绝大多数空间位置上的降水数据无法获得,估算降水量的空间分布难以得到理想的结果。地形特征对降水量空间分布的影响非常重要,通常利用降水量与地形因子之间的相关关系评估降水量的空间分布。近年来,GIS技术中数字高程模型的引入和精确的地形分析能力大大提高了降水量空间分布研究的准确性,已成为降水量空间分布研究的重要手段之一。利用GIS技术建立了新疆降水量的空间分布模型,其中,地理和地形因子的选取来自1 km×1 km的DEM数据,主要包括经度、纬度、海拔高度以及不同范围内不同方向上的最小和最大海拔高度等。此外,降水量资料来自1971-2005年新疆131个降水量测站(包括气象站和水文站),其中,112个站点的资料用于建立模型,剩余的19个站点的资料用于验证模型,研究结果表明模型是合适的,验证的模拟值与实际值之间的相关系数分别为在0.787 0~0.926 3之间,夏季较好,冬季较差。在新疆这个地形复杂的区域,利用GIS技术建立模型研究降水量的空间分布,对于研究新疆降水资源、农业气候资源区划以及生态环境变化等有一定的实际意义。 相似文献
37.
38.
Google地图应用之广东省地区JOPENS地震速报系统 总被引:1,自引:0,他引:1
利用Google公司提供的电子地图服务,以B/S结构(即浏览器和服务器结构)作为系统设计架构,监听JOPENS实时系统发送的地震触发消息,访问JOPENS数据库,根据广东省地区的监测要求,制定检索、筛选策略,获取地震详细信息,显示在浏览器网页上.采用Google地图的JOPENS地震速报系统可以使地震信息发布的显示内容... 相似文献
39.
对岩石剪切残余强度进行了浅析,主要以唐山马城铁矿的岩石试验为依据,探讨了岩石剪切峰值强度和残余强度的关系,分析了岩石剪切残余强度的影响因素,为大家了解、利用岩石的剪切残余强度提供了参考意义。 相似文献
40.
Earthquake early warning (EEW) systems are one of the most effective ways to reduce earthquake disaster. Earthquake magnitude estimation is one of the most important and also the most difficult parts of the entire EEW system. In this paper, based on 142 earthquake events and 253 seismic records that were recorded by the KiK-net in Japan, and aftershocks of the large Wenchuan earthquake in Sichuan, we obtained earthquake magnitude estimation relationships using the τe and Pa methods. The standard variances of magnitude calculation of these two formulas are ±0.65 and ±0.56, respectively. The Pd value can also be used to estimate the peak ground motion of velocity, then warning information can be released to the public rapidly, according to the estimation results. In order to insure the stability and reliability of magnitude estimation results, we propose a compatibility test according to the natures of these two parameters. The reliability of the early warning information is significantly improved though this test. 相似文献