黄河北岸兰州段丘陵区土壤生态化学计量与空间变异北大核心CSCD

为探究黄河北岸兰州段丘陵区土壤碳、氮、磷含量及化学计量比的空间变异特征,基于12个样地数据,采集1 m剖面内不同发生层土壤进行土壤含水率(SWC)、pH、有机碳(SOC)、全氮(STN)和全磷(STP)的测定。分析了研究区土壤碳、氮、磷含量及其生态化学计量特征在植被和土层上的差异及空间变异特征。结果表明:(1)研究区SOC、STN、STP均值分别为4.53、0.74、0.13 g·kg^(-1),C∶N、C∶P、N∶P均值分别为7.85、55.17、8.40;(2)研究区SOC、STN、C∶N和N∶P的块基比C_(0)/(C_(0)+C)<0.25,主要受气候、植被、地形等自然因素影响;STP、C∶P则C/(C+C)>0.75,主要受退耕还草等人为因素影响;(3)研究区土壤整体受到氮限制,与此同时有机碳更为匮乏,磷则在短期内不会成为限制因子。在黄河流域兰州段北岸丘陵区北岸的生态治理与恢复中,应重视有机肥和氮肥的配置与施加,同时需减少人为干扰,这对于植被的快速恢复与养分的固定具有重要意义。     

天津市服务业利用外商投资的实证分析

服务业的发展是促进全球经济增长的重要力量,发达国家普遍呈现出产业结构高级化特征。利用外商投资可以促进中国服务业的发展,是加快经济发展的有效手段。通过对天津市服务业发展以及服务业利用外商直接投资现状的分析,对服务业外商直接投资与经济增长的关系进行了实证研究。研究结果表明:服务业外商直接投资不仅促进了天津经济的增长,同时,还对资本积累、产业结构、技术水平、就业程度及人力资本产生了不同程度的促进作用;技术水平进步、就业水平的提高、人力资本的提升又将带动天津经济增长。天津市应发挥现代服务业发展的优势,发挥天津自贸区的区位优势和政策优势,积极承揽国际服务外包。     

Elasticity soltion of rupture model of shallow earthquake

Based on the theory of elastic mechanics, and using the typical rupture model of shallow earthquake, the authors considered the shallow earthquake as a plane mechanical problem, which was constructed the corresponding mechanical model. By the stress components' formulas of the semi-infinite model acted by the finite even shearing force, the main stress is deduced. It is clear that the sector on the right of the center section is squeezed zone, where the maximum principal stress points at the "source of stress", and that on the left is tensile zone, where the minimum principal stress points to the "source of stress".     

兰州大学(盘旋路校区)2003年生态足迹调查分析

人均消费产品的数量是计算区域人均生态足迹关键和基础的一步。通过实地问卷调查，运用自下而上法收集资料，计算小尺度生态足迹。兰州大学(盘旋路校区)2003年的生态足迹计算结果为：人均生态足迹0．892hm^2，男、女生的人均生态足迹分别为0．976hm^2和0．788hm^2。这些数据与全国或者西部的人均生态足迹相比明显偏低，但总生态足迹为4119．3hm^2，是校园面积的73．7倍。因此，应合理利用自然资源，减少学生的生态足迹，真正做到可持续发展。     

Nitrogen and phosphorus intake by phytoplankton in the Xiamen Bay

This paper describes a time series experiment examining the nitrogen and phosphorus intake of natural phytoplankton communities by a microcosms approach.Seawater samples containing natural phytoplankton communities were collected from waters around Baozhu Islet in inner Xiamen Bay and around Qingyu Islet in the outer bay.The goal was to elucidate the relationship between phytoplankton population enhancement,the biological removal of nitrogen and phosphorus from the seawater,and the phytoplankton nitrogen an...     

用前期海温预报四川夏季气温的EOF迭代方案

应用ＥＯＦ（经验正交函数）迭代方案，考虑多时次历史资料，在全球海区海温与四川盆地气温非同步联系的基础上，以海温为预报因子进行了夏季气温的长期预报。结果表明：西太平洋高温区等关键海区海温的异常对未来四川盆地夏季气温变化有重要影响，由此建立的引入多时次海温的ＥＯＦ迭代长期温度预报方法，具有较强的预报能力     

The key indicators of transboundary water apportionment based on international laws and cases

Transboundary water, more competitive utilization and uncertain availability under the globalization trend, the issue of its apportionment which directly impacts national benefits of each riparian state is becoming one of the important topics in the world. Water is scarce in China, the most important upstream state in Asia, and this task has to be thought over in the coming future. Based on ＂International Freshwater Treaties Database＂ （1820-2007） by Oregon State University, and publications and reports on transboundary water utilization and management since 1999, 28 indicators of water apportionment adopted in 49 international treaties and cases in 1864-2002 are divided into 6 types, the spatial and temporal characteristics of the adopted indicators are analyzed in order to find the key indicator（s） of transboundary water apportionment. The major results include： the major adopted indicators, have significant differences among 5 regions/continents, the indicators at rank first and second place in the developed region （North America and Europe） according to the adopted times are ＂keeping minimum water flow＂ and ＂mean annual runoff＂, but in the developing region （Asia, Africa and South America）, the ranking order of the above two indicators is reversed; the major adopted indicators in the watersheds with insufficient water are ＂mean annual runoff＂ and ＂keeping minimum water flow＂, the ones in the watersheds with sufficient water are ＂keeping minimum water flow＂ and ＂maximum water intake＂; the international treaties signed from the first phase to the fourth phase, the developing process shows a progress of ＂fewer-increasing a lot-decreasing rapidly-equation basically＂, the regional distribution of the treaties shifts mainly from the developed region to the developing one, especially to Asia and Africa; the major adopted indicators shifts from ＂keeping minimum water flow＂ and ＂mean annual runoff＂ in 1864-1945, to ＂keeping minimum water flow＂ and ＂maximum water intake＂ in 1946-1971, then to ＂hydraulic facility operation＂ and ＂mean annual runoff＂ in 1972-1991, and finally to ＂keeping minimum water flow＂ and ＂mean annual runoff＂ in 1992-2002, the process shows similar a loop. Finally, the key indicator on transboundary water apportionment can be determined as ＂keeping minimum water flow＂.     

广州市制造业与生产性服务业协同集聚与空间相似性

基于企业微观大数据,从空间相似性的视角,运用核密度法、双变量空间自相关法和地理探测器等分析方法,对广州市6个制造行业和5个生产性服务行业的空间协同关系展开分析,在街镇尺度下从行业层面探讨生产性服务业与制造业在城市内部的协同集聚.研究发现:行业集聚中心的空间布局形态显示,广州的制造业与生产性服务业布局具有空间相似性.制造...     

鄱阳湖流域史前人类遗址时空分布及其环境响应（英文）

The temporal-spatial geographic distribution of archaeological sites and its feature between 10.0–2.8 ka BP(ka BP= thousands of years before 0 BP, where "0 BP" is defined as the year AD 1950) were determined, based on GIS spatial analysis in the Poyang Lake Basin. The relationship between geographic distribution of sites of different periods under subsistence existence of ancient civilizations, climate and environmental change was investigated. The results revealed numerous archaeological sites of the Neolithic Age(10.0–3.6 ka BP). The sites were mainly located in the northern part of the Poyang Lake Basin, a hilly and mountainous area with many river terraces suitable for the development of human civilization. The number of archaeological sites rapidly increased during the Shang and Zhou dynasties(3.6–2.8 ka BP) and spread widely on the floodplains of the middle and lower reaches of Ganjiang River and onto the west, south, and southeast beach areas of the Poyang Lake. Holocene records of climate change suggested that it was possible that climate fluctuations had a great impact on human evolution in the study area. Before 3.6 ka BP, westward and northward expansion of Neolithic cultures in the Poyang Lake watershed occurred under the background of climate amelioration(becoming warmer and wetter). The ancient people lived in the hilly areas with high elevation. The simple mode of a fishing and gathering economy was mostly suited to this area in the early Neolithic Age. The scope of human activities was expanded and cultural diversity developed in the late Neolithic Age. However, with population growth and increasing survival pressure in a dry-cold climatic stage after 3.6 ka BP, this simple living mode had to be abandoned, and various forms of economy, the majority being agriculture, were developed on flood plains of the lower reaches of numerous rivers around Poyang Lake. This promoted flourishing of the Bronze culture of South China.     

基于K-Means聚类的辽宁省主体功能区试划研究

在国家提出的新的主体功能区概念体系和划分思路前提下,基于辽宁省主体功能区划定要求的8个基本指标项定量综合评价基础数据,选择“典型的”优化开发区、重点开发区、农产品主产区和重点生态功能区,采用K-Means聚类方法,分别在不指定初始聚类中心、指定初始聚类中心、以及PCA分析（即主成份分析）基础上指定初始聚类中心3种方法,对于全省100个县市区做4类主体功能区试划分.分别将划分结果与全省最终采用的划分方案进行比较,结果表明采用在PCA分析基础上指定初始聚类中心技术方法的划分结果更接近最终采用方案.