ERRATUM Estimation of peak relative velocity and peak absolute acceleration of linear SDOF systems

We have found some mistakes in the article by Jianwei Song et al. (2007). The revisions are given below:     

A MATHEMATICAL QUASI-2D OVERLAND FLOW MODEL

1 INTRODUCTIONThe prediction of future impacts on terrestrial ecosystems by atmospheric, climatic and land-usechanges is the aim of watershed management. Meeting these requirements scientists, managers and policymakers try to achieve the sustainable management of the vitally important resources of watersheds due toan integrated ecosystem approach at the catchment scale. As composite landscapes often have a highdegree of contingency between its elements, the transport over these landscape s…     

Eco-economic evolution, emergy evaluation and policy options for the sustainable development of Tibet

l introductionTibet-the name alone conjures up visions of mystery and fantasy, visions of spirituality, exotic andmysticism. On the face of it this cloud of mystery was not surprising. Because of its geographicalisolation and lack of roads and modem communication netWorks for so many years, just line manymountain areas of China, Tibet escaped, for most part, the development opportUnities in the world duringthe 18th and 19th centUries, and almost half of the 20th centUry. In 1950 Tibet was a…     

Study on ecological fragility of wetlands in Sanjiang Plain

Along with tile approaching to the Zlst cenny the eec-environmental pressure on human beingsaggravates rapidly. Both the spatial extent and the fragile degree of the ECOTONE are increasingconsiderably [1]. NatUral resources are threatened more and more seriously. Consequently. much moreattenhon 11as been paid to the StUdy on ecological ffugility by hUInan beings. Weakeds, as one of the keyregions with the highest biodiversity, are a kind of precious resources and special ecosystem. Wetla…     

小比例尺地图面状水系名称注记自动配置研究

在丰富面状水系的注记配置规则基础上,深入研究了其名称注记自动配置中两个关键算法,即要素主骨架线求取和注记配置方案的设计,并提出了基于单调链化简思想确定面状水系主骨架线的改进算法,在此基础上设计了面状水系名称注记自动配置方案。     

HHT方法在研究地震旋回体中的应用

HHT(Hilbert-Huang变换)是一种近年才发展起来的非线性信号处理方法,具有明确的物理意义、高度的精确性和自适应性,但在地震信号处理中尚未得到广泛的应用。简要介绍了HHT的方法原理,然后分析了模型信号和地震旋回体的HHT时频谱。结果表明:HHT对模型信号的识别能力强,且不同类型地震旋回体与其HHT时频谱之间存在对应关系,这为地震层序的划分以及进一步的沉积相分析提供理论依据。     

塔克拉玛干沙漠公路人工防护林植被的C, N化学计量特征及其固存能力研究

本研究以塔克拉玛干沙漠公路沿线生物防护林为研究对象,研究防护林三种主要建林植物不同器官的C,N含量及其生物量,进而估算其C, N固存能力及固碳释氧价值。结果显示：沙拐枣每个器官的生物量均显著高于梭梭和柽柳(P<0.05),个体的总生物量是梭梭和柽柳的2-3倍。整个防护林在建林8年后的总生物量达到116786.4 t。C,N含量在不同器官中的含量不尽相同,三种植物均表现为凋落物C含量最低。而植物叶中的N含量均显著高于枝,凋落物和根系(P<0.05)。建林8年后梭梭单株的固碳量为1404.6g,固氮量为201.5g,柽柳单株的固碳量为1449.7g,固氮量为195.4g,沙拐枣单株的固碳量和固氮量显著高于其他两种,分别为3979.8g,为520.9g,(P<0.05)。建林8年后整个防护林的总固碳植为35886.3 t,总固氮值为4917.7 t。整个防护林的固碳总价值为22555.3万元,释氧价值为50320万元,总的固碳释氧价值达72875.3万元。     

橄榄石湿润性质研究揭示俯冲带地幔楔内部流体循环北大核心CSCD

流体是控制地球内部能量传递和物质迁移的重要媒介之一。俯冲带流体循环对弧火山的形成、全球物质循环和地震的发生能起着至关重要的作用。因此,准确限定流体在俯冲带的分布范围和迁移机制对理解全球动力学具有重要意义。早期的研究普遍认为:俯冲洋壳脱水产生的流体只在较深的深度(通常在弧火山以下~105 km处)才开始进入上覆地幔,降低地幔物质部分熔融的温度,进而控制弧火山的位置。     

到2020年把我国建成海洋经济强国（之四）——建设海洋经济强国的保障措施

提高全民族的现代海洋意识, 增强海洋国土观念, 海洋是资源宝库、世界通道、人类的新生存和发展空间的观念, 海洋健康观念,在当今国际海洋法律制度发生重大变化, 海洋权益斗争日益激烈的情况下尤为重要, 也是建设海洋经济强国的思想基础。