黄河中游岩土侵蚀问题及防治对策探讨

黄河中游出露地层岩性主要有古生界奥陶系碳酸盐岩、石炭系和二叠系碎屑岩;中生界三叠系砂泥岩、侏罗系砂泥岩和白垩系砂泥岩;新生界古近系砂泥岩、新近系(原为第三系)红土及第四系风积黄土和现代风积沙。第四系黄土厚度大,结构松散,遇水易解体,具湿陷性,是黄河中游粗泥砂的主要物源;第四系风积沙分布于黄河中游北部,亦是黄河中游粗泥砂的主要物源。岩土侵蚀类型有五:一是风力侵蚀—风沙侵蚀;二是降雨对谷坡面的面状冲刷—坡面侵蚀;三是地表径流对谷底的侧蚀—沟谷侵蚀;四是滑塌对谷坡坡体的破坏—重力侵蚀;五是潜蚀。并对不同侵蚀类型提出了不同的防治对策。     

世界政治新形势下的中国经济安全观

当前，世界政治形势处于动荡催生调整，调整蕴含机遇，在单极与多极矛盾的碰撞与互动中，正在形成某种更有效的机制，培育更为成熟、理性竞争的意识，促使各主要大国为世界的持久和平与繁荣共同担负起应有的责任。因此，国家经济安全是世界各国都普遍关注的战略问题。本文首先总结了就当今世界政治发展的四个特点，并在分析国际形势新变化对中国经济安全影响的基础上，提出了维护我国经济安全的六点思考。     

Dynamic Prediction Model of Overburden Settlement in Deep Mining Areas based on Space–Time Relationship

Natural Resources Research - Depletion of shallow mineral resources caused by deep mining has become an inevitable trend, and deep mining can increase safety accidents and geological hazards....     

A novel set pair analysis method based on variable weights for liquefaction evaluation

To ensure the safety of structures, high-speed railway and highway founded on liquefiable soils, liquefaction evaluation is a primary task. Herein, a dynamic set pair analysis method based on variable weights is introduced to assess liquefaction. A concept of connection degree of set pair consisting of the evaluation sample and the classification standard was described to interpret the uncertainty of liquefaction and relationship. Moreover, based on reward and penalty mechanism, state variable vectors were presented to assign composite weights of evaluation indicators in order to take into account impacts of indicator variation. And the integrated connection degree to each grade was calculated to evaluate liquefaction of the evaluated cases. Results from practical example and comparison with field investigation and extension method indicated that this proposed model used to evaluate liquefaction is feasible and effective. In addition, it can quantitatively describe liquefaction hierarchy of evaluated samples.     

Distribution of the indigenous microorganisms and mechanisms of their orientational activation in Daqing Oilfield

The distribution of indigenous microorganisms was surveyed in Block 1 of Daqing Oilfield. Based on this survey, the indigenous microorganisms in the formation water were activated with different activator systems at the simulated stratum ecological environment. The changes of the number of bacteria of various physiological groups were determined during the process of activation. Also changes of pH value and composition of gas productions were analyzed at the end of culturing. The results showed that the selected block formation water contained a great number of saprophytic bacteria, hydrocarbon-oxidizing bacteria, fermentative bacteria, methane-producing bacteria and sulfate-reducing bacteria. Under the conditions that the growth of sulfate-reducing bacteria was controlled the block had the potential to enhance oil recovery by activating beneficial bacteria. The growth of sulfate-reducing bacteria can be inhibited through the activation of nitrate-reducing bacteria. The number of nitrate-reducing bacteria reached 10⁶–10⁷ cells/mL, but sulfate-reducing bacteria reached only 0–45 cells/mL in A system. Methane-producing bacteria can be activated by C, D activators. The relative content of biological methane in the light hydrocarbon gas reached 80% in C, D systems. B activator was conducive to the propagation of acid-producing bacteria, so that the pH value of the culture medium decreased from 7.5 to around 5.0. Hydrocarbon-oxidizing bacteria can be activated by various activator systems. There was low molecular light hydrocarbon in gas production according to the analysis of gas chromatograph. According to the content of methane and the number of methane-producing bacteria, methane only can be generated through activating methane-producing bacteria. By choosing different activator systems, various populations of indigenous microorganisms can be activated accordingly.     

2014 IGU Regional Conference held in Krakow,Poland

The 2014 Regional Conference of the International Geographical Union（IGU）was held on August 18-22 in Krakow,Poland.The total number of participants was 1374 from 64 countries and regions,including 357 from Poland.Germany,Japan,Czech,UK,China,Russia,USA,France and Hungary are the top countries of attendees in this conference.     

河西走廊最近一次强沙尘暴的调查分析

1996年5月29~31日在甘肃河西走廊又出现了一次强沙尘暴天气。从这次强沙尘暴和1993年"5·5"强沙尘暴的比较分析可知,春季在河西走廊周围易形成以沙漠为中心的高温低压区,与西西伯利亚向东南方向移动的高压冷气流形成明显的气压梯度,这就是大风的动力源。大风前期,在气温、压温比等方面有明显的预兆,由此可进行强沙尘暴的预测预报。     

基于POI数据的长沙市生活性服务业空间格局研究

生活性服务业是服务经济的重要组成部分,其合理布局对发展城市经济、满足居民消费需求具有重要作用。基于长沙市六区POI数据,运用核密度分析、熵指数、频数密度分析及空间聚类等方法研究长沙市生活性服务业的空间格局特征,发现长沙市生活性服务业的分布具有以下特点：1）主要受交通及城市规划指向性影响,沿交通主干道集聚分布,整体布局呈“一核四轴多极”且空间分布与人口集中度联系紧密,东西差异明显,东部多而密集、西部少而分散;2）不同类型的生活性服务业分布特征各异,在空间形态上主要表现为“单核心”、“双核心”和“多核心”等;3）其功能多样性布局呈现以五一广场为核心的“中心-外围”结构特征,功能多样且混合程度高的区域位于城市中心,城市边缘区生活性服务业集聚性较弱且多为单一功能或者双功能混合区。     

吉林省西部沙化土地持续农业体系建立的实践

吉林省沙化土地的８７．９％分布在吉林省西部白城、松原半干旱地区，统属科尔沁和松嫩沙地，面积９２１６．５ｋｍ２，占吉林省西部总面积的１９．６％。８年（１９８６年～１９９３年）实践证明：针对沙地环境特点建立的“乔、灌、草”、“果、药、杂”、“田、林、草”为主体的三种持续农业体系效果明显。     

祁连山中部亚高山草地作物系数估算

利用Lysimeter蒸散仪于2011-2014年对祁连山中部黑河上游天涝池流域亚高山草地实际蒸散量进行观测。用FAO Penman-Monteith模型对草地参考蒸散量进行估算,根据草地植被高度结合气象数据,以估算日尺度作物系数,以估算的作物系数与模拟的参考蒸散量计算草地实际蒸散量,并用观测值进行验证。结果表明：FAO改进后的作物系数计算方法适合该区域草地作物系数的计算;以FAO Penman-Monteith模型估算的日蒸散量为0.50~7.26 mm,生长季日均蒸散量有年际变化,2011年 > 2014年 > 2012年 > 2013年。总体来看,土壤蒸发总量年际变化不大,影响蒸散量年际变化的主要部分是植被的蒸腾。