内蒙古迪彦庙蛇绿岩带早石炭世闪长岩成因与古亚洲洋洋内俯冲作用

由于缺少对SSZ型蛇绿岩和洋内弧火成岩的系统研究,制约了古亚洲洋东段古生代洋内俯冲过程的进一步认识。本文报道了内蒙古迪彦庙SSZ型蛇绿岩带北部新发现的巴嘎哈尔早石炭世闪长岩。LA-ICP-MS锆石U-Pb定年显示,巴嘎哈尔闪长岩的侵位年龄为324.2±1.8 Ma,其形成时代为早石炭世末期。巴嘎哈尔闪长岩SiO₂含量为57.71%～61.24%;高铝(Al₂O₃含量为15.58%～16.68%);具有相对富钠(Na₂O含量为3.29%～4.15%)、低钾(K₂O含量为1.05%～1.69%)的特征,Na₂O/K₂O比值为2.18～3.95;MgO含量较高(3.30%～4.23%),Mg^#为47.20～51.82;贫TiO₂(0.65%～0.76%)和P₂O₅(0.14%～0.15%);稀土元素总量(ΣREE为85.19×10^-6     

漠河盆地多年冻土区天然气水合物地球化学调查及远景评价

漠河盆地是我国冻土发育的主要地区之一,发育良好的天然气水合物成藏系统,具有天然气水合物形成的良好条件。为了圈定天然气水合物远景区,识别油气聚集体,判别天然气水合物成因,在漠河盆地冻土较发育地区开展了1∶5万天然气水合物地球化学资源调查。结果表明：(1)在森林沼泽景观区,顶空气和荧光光谱指标是天然气水合物勘查的主要指标,借鉴青海木里冻土区天然气水合物地球化学勘查成功的经验,结合AMT、地质等资料分析,元宝山凹陷是天然气水合物较为有利的远景区;(2)岩心样品甲烷碳同位素分析显示,烃类气体分异明显,浅层烃类气体基本为生物气,深部烃类气源主要为混合成因气,个别解吸气为微生物气和热解气;(3)试验性应用了分形-GIS技术,可以细致可靠地进行异常区范围划定,消除干扰因素,有效地圈定水合物远景区。     

沙漠化:从圈层耦合到全球变化

从沙漠化概念提出伊始 ,沙漠化成因机理的研究就一直成为学术界关注的焦点。沙漠化过程究竟有多少是由自然因素所致 ,多少是由人类活动所为 ,诸因素与沙漠化之间有何内在关系 ,沙尘天气发生发展过程及其诱因等 ,当属地球系统科学应解决的难题。文章从全球变化的角度 ,将沙漠系统视作一种类生命的非线性动力系统 ,指出沙漠化源于地球表层系统各圈层之间复杂的相关与耦合作用 :气候变化是控制沙漠进退的首要因素 ;陆表水持续亏损则是导致干旱、半干旱地区沙漠化发展的直接原因 ;岩石圈构造运动塑造了不同的地形地貌单元 ,奠定了沙漠分布的地理格局 ;人类的不当活动和气候变化引起的生物生产力的衰退及土地覆盖的破坏 ,造成了现代沙漠化的快速扩张。     

多源信息方法在殷庄矿开采水文地质预测分区中的应用

根据对殷庄矿地质、水文地质、开采条件与矿井涌水之间关系的研究，提出了煤矿开采水文地质条件预测分区的方法——多源信息方法。该方法借助于地理信息系统技术实现了矿井涌水因素间的有机处理。经过将模型与实际情况反复拟合，最终得出了分区预测模型。     

氨基酸螯合微量元素的研究及其在水产动物中的应用

微量元素在水产动物的生命过程中是必不可少的,但是仅靠从水体中吸收是不能满足机体的正常需要的,还必须从饲料中摄取。至今,微量元素添加剂的发展经历了三代:第一代为无机盐类,常用的为硫酸盐等。无机盐类的微量元素添加剂易潮易结块,易与维生素发生拮抗,在植酸等抗营养因子存     

高效铝合金牺牲阳极的研究

在铝中添加合金元素Zn,Mg,In,Ga,Ca,利用正交设计方法,研制出一种高效的铝合金牺牲阳极,它在海水中的电流效率达95.6％,电位为-1.09V(SCE)。并研究了合金元素In,Ga,Ca对铝合金电化学性能的影响及阳极活化机理。     

全国自动地震速报系统综合评估

通过对2011年1月1日至12月31日的3套独立自动地震定位系统结果进行综合处理,得出中国自动地震综合目录,并与正式速报结果进行对比,得出全国自动地震速报系统综合评估结果,发现该目录对于国内绝大部分5级以上、国外7级以上地震实现整体覆盖,且没有误报发生,可以作为国家台网中心正式地震速报的重要参考,对于建立“自动报～正式报”的两级地震速报制度可提供技术支撑。     

全国自动地震速报系统评估

对全国自动地震速报系统进行了初步的评估. 通过2010年1月1日—2011年12月31日的自动定位结果与全国正式目录的对比, 分别得出了3套自动定位系统总体误差以及全国和全球的误差插值图, 并对结果进行了总结. 同时, 还针对3套自动定位系统的漏报和误报情况进行了分析和讨论. 总体来说, 现阶段自动地震速报系统整体上对于首都圈地区M≥3.0, 国内其它地区M≥4.0(部分台站稀疏的西部地区M≥5.0), 国外M≥7.0的地震基本可以达到全面覆盖的程度, 可以作为正式地震速报的参考, 对于建立“自动报—正式报”的两级地震速报制度能提供有力的技术支撑.     

Soil moisture dynamics across landscape types in an arid inland river basin of Northwest China

A combination of field measurements, continuous monitoring and numerical modelling was used to evaluate soil moisture regimes at four sites across a landscape gradient of the Heihe River Basin. Recorded data of precipitation, irrigation and floods were used to build the model, and an optimization technique was employed to calibrate the parameters. Based on the optimized parameters and estimates of future scenarios, the modelling structure was employed to predict the changes in the growing season soil moisture regimes due to climate change and intensive management. The results suggest that the upper‐reach Yeniugou and Xishui sites will become wetter because of alterations in the precipitation regime, and this trend could be strengthened by the expected amplified interannual variability. Precipitation features at middle‐reach Linze and lower‐reach Ejina, however, are not expected to change in the future. We assumed that a more water‐saving irrigation system will replace the current traditional one, and hence, the soil moisture probability density function at the Linze site would tend to be narrowed to ranges around either the wilting point or the point of incipient water stress, depending on how the intervention point and target level are settled. Ejina is expected to experience the most extreme ecological conversion effects in the future, and soil moisture would be more frequently recharged by water delivery. However, the soil moisture regime would not change much because of the poor water‐holding capacity and intensive evaporation. The revealed patterns and predicted shifts in soil moisture dynamics could provide a useful reference for identifying robust long‐term water resource management strategies for the Heihe River Basin. Copyright © 2015 John Wiley & Sons, Ltd.     

Optimizing layout of pumping well in irrigation district for groundwater sustainable use in northwest China

Optimizing layout of pumping well plays a vital role in curbing the groundwater level decline. A novel optimization model is presented in this study. First, the optimal well number is obtained by taking into account factors of local economy and environment based on nonlinear programming model. Then, the well spatial layout assessment model is attained based on information entropy weight and technique for order preference by similarity to ideal solution (TOPSIS). After that, the relative closeness to positive ideal solution of alternative (c_i) on the rationality of well spatial layout in cultivated land is calculated, and a set of alternatives are ranked according to the descending order of c_i. Finally, the well optimization layout is obtained by combining the optimal well number with well spatial layout assessment result based on the GIS data of pumping wells. As a case study, this method was applied in Yongchang Irrigation District of Shiyang River Basin, the arid region of northwest China. Results show that under the conditions of sustainable use of water resources, the irrigation district needed 724 wells for irrigation, with a decrease of 31.0% when compared with the existing number of wells. The wells with low flow rate and operating efficiency distributed in high density where groundwater is over‐exploitation were recommended to be closed. This well optimization layout method is expected to play a significant role in helping make plans for exploiting groundwater at more sustainable level, curbing the groundwater level decline trend, and improving the local ecological environment. Copyright © 2015 John Wiley & Sons, Ltd.