Head-on collision of magnetoacoustic solitary waves in magnetized quantum electron-positron-ion plasma

This article presents the first study of the head-on collision between two magnetoacoustic solitary waves (MASWs) in magnetized quantum plasma consisting of electrons, positrons, and ions, using the extended Poincaré-Lighthill-Kou (PLK) method. The effects of the magnetic field intensity, the positron to ion number density ratio, the quantum parameter, the Fermi temperature ratio, and plasma number density on the solitary wave collisions are investigated. It is shown that these factors significantly modify the phase shift.     

中太平洋海山区尖顶和平顶海山结壳成矿与分布的比对研究

尖顶海山和平顶海山是洋底海山的两种类型,同时也是富钴结壳资源赖以成长的主要载体,两者在地形上具有显著差别,资源状况和分布也不尽一致。以地形分类为基础,就中太平洋海山区两类海山结壳的成矿特征、宏微观构造、矿物和化学组成以及空间分布等进行了比对研究。研究认为,尖顶海山体积虽小,但地形演化连续,底层流及环境氧化性较强,有利于结壳的长期稳定生长,结壳厚度总体较大,富成矿元素和生物组分,远景成矿区域连续绵长。平顶海山山体巨大,顶部和斜坡陡崖区不利于结壳成长,底流活动只在山顶边缘和山脊地带表现突出,环境氧化性整体较弱,后期构造活动相对频繁,结壳总体厚度较小,铁,碎屑和热液组分含量较高,远景矿区相对狭窄。     

The influence of climate change and human activities on runoff in the middle reaches of the Huaihe River Basin,China

This study presents a soil and water integrated model (SWIM) and associated statistical analyses for the Huaihe River Basin (HRB) based on daily meteorological, river runoff, and water resource data encompassing the period between 1959 and 2015. The aim of this research is to quantitatively analyze the rate of contribution of upstream runoff to that of the midstream as well as the influence of climate change and human activities in this section of the river. Our goal is to explain why extreme precipitation is concentrated in the upper reaches of the HRB while floods tend to occur frequently in the middle reaches of this river basin. Results show that the rate of contribution of precipitation to runoff in the upper reaches of the HRB is significantly higher than temperature. Data show that the maximum contribution rate of upstream runoff to that of the midstream can be as high as 2.23%, while the contribution of temperature is just 0.38%. In contrast, the rate of contribution of human activities to runoff is 87.20% in the middle reaches of the HRB, while that due to climate change is 12.80%. Frequent flood disasters therefore occur in the middle reaches of the HRB because of the combined effects of extreme precipitation in the upper reaches and human activities in the middle sections.     

Microbiotic crusts and their interrelations with environmental factors in the Gurbantonggut desert,western China

Located in the Junggar Basin in Xinjiang, the Gurbantonggut Desert is the second largest desert in China. Microbiotic crusts consisting of animalcule, lichen, moss, and algae species develop extensively in the region. Their formation, species composition and distribution pattern are closely related to the environmental conditions along the different parts of sand dune. Analysis of microbiotic crust distribution and relationship to environmental factors shows that average microbiotic crust thickness is 0.05–0.1 cm at the tops dunes, 0.2–1.5 cm in the upper part, 1.5–2.5 cm in middle and lower parts of dunes, and 1.5–5.0 cm in interdune areas, while areal coverage is 30.5, 48.5, 55.5, and 75.5%, respectively. Microbiotic crust differentiation along dune slopes is a result of the development stage and converse-succession resistance of the different microbiotic crusts. The numbers of species, thickness and degree of development of microbiotic crusts increase from the upper part to the middle and lower parts of dune slopes. The development and differentiation of microbiotic crusts at various dune slope positions are a reflection of the ecological expression of the comprehensive adaptability and natural selection of different microbiotic crust species to the local environmental conditions, and are closely related to such ecological conditions as the physiochemical properties of soils and topsoil textural stability.     

桑坪红柱石物相分析方法研究

本文以桑坪红柱石矿的矿物组合为依据,建立了以铝量法为基础,铝铁比值法校正十字石的干扰,测定红柱石含量的物相分析方法。研究了红柱石在确定条件下的溶解规律,粒度效应及其它影响分析的因素。提出了接近矿区实际的、较准确的分析结果校正办法,制定了较合理的试样加工流程,效果良好。     

西藏冈底斯带始新世曲水岩基的岩浆混合作用:来自斜长石阴极发光特征和成分变化的证据

斜长石作为主要造岩矿物,是研究岩石成因、示踪岩浆演化和岩浆混合过程的有效工具.对冈底斯带曲水岩基始新世花岗闪长岩、二长花岗岩、闪长岩脉和暗色包体中的斜长石进行了阴极发光图像结构特征、电子探针主量元素和LA-ICP-MS微量元素成分的分析,揭示了斜长石复杂环带的成因和相关的岩浆过程.该区斜长石的阴极发光图像呈现出多种颜色且与其An值相对应,随着An值降低依次为绿色、蓝色和暗灰色或暗红色等,并发育补丁状环带、筛状环带、韵律环带等.花岗闪长岩、二长花岗岩中斜长石的An值具有相似的变化范围(20~55),而闪长岩脉和暗色包体中An值的变化范围较大(25~85),表明曲水岩基经历了复杂的开放过程.微量元素结果表明:花岗闪长岩与闪长岩脉和暗色微粒包体具有相同的Sr含量范围(600×10^-6~1 100×10^-6);而二长花岗岩的Sr含量(1 000×10^-6~2 400×10^-6)整体高于前者.以上研究表明,花岗闪长岩中阴极发光呈现绿色的核部或幔部是偏中性岩浆注入寄主岩岩浆混合的结果;具有高Sr含量的二长花岗岩认为是高Sr含量的岩浆结晶形成的;闪长岩脉和暗色微粒包体中的筛状结构斜长石为寄主岩捕掳晶.     

降雨对青藏高原多年冻土区地表辐射的影响 ——以北麓河地区为例

青藏高原地表辐射变化影响多年冻土地表能量收支平衡、热工计算温度场边界条件以及冻土热稳定性.降雨变化是影响地表辐射的重要因素,以青藏高原北麓河地区的地表辐射资料和浅层地表水热监测数据为基础,分析了降雨对多年冻土区地表辐射特征的影响.研究表明:受降雨影响,辐射分量具有明显的日变化和年际变化特征,短波辐射被严重削弱,地面长波...     

河北省冷暖变化气候特征分析

利用河北省70个站自建站至2000年近50a的系统气温观测资料,分析了河北省冷暖变化的年际和年代际特征,及其区域差异和季节差别,并估计了河北省未来50a冷暖变化趋势。结果表明：河北省年平均气温、年平均最高气温、年平均最低气温的年际和年代际变化都呈现增温趋势,增温幅度由大到小依次为：年平均最低气温、年平均气温、年平均最高气温;全省年平均、最高、最低气温变化趋势与其五个分区的变化趋势具有整体一致性,都皇现升温趋势,但各区域的增温幅度不一,增幅最大的区域是冀东平原区,最小的区域是河北省北部;各季气温变化呈现春、秋季平均气温变化程度相对比较平缓,冬季增温幅度最大的特点,自80年代末始,暖冬现象明显;在全球和中国气候将继续变暖的背景下,河北省气温估计未来50a升高在1～2℃之间。     

激光雨滴谱仪测速误差对雨滴谱分布的影响

该文研究PARSIVEL激光雨滴谱仪的测量误差并提出订正方法。对2014年在广东阳江的PARSIVEL激光雨滴谱仪采集的两次降水过程数据进行分析发现,雨滴下落速度V随粒径D变化与静止大气中雨滴下落末速度随粒径变化的Atlas-Ulbrich曲线分布趋势一致,但D < 1 mm及D > 3 mm的速度偏差较大。其主要原因是大粒径雨滴形变造成速度偏离较大,仪器测量误差造成小粒径测速偏大,激光雨滴谱仪所在高度的大气垂直运动影响雨滴下落速度。根据PARSIVEL激光雨滴谱仪测量原理,基于雨滴形变与粒径关系,给出形变订正后的Atlas-Ulbrich修正曲线,并用于对小粒径测速订正。比较订正前后的雨滴谱分布,订正后的小雨滴浓度明显增加,大雨滴浓度略有减小,订正后浓度参数和斜率参数均增加,形状参数变化不明显。     

气候变化对闽东粮食产量影响分析

气候变化对粮食产量具有重要的影响作用,加强气候变化对粮食产量影响分析和风险评估,对应对气候变化、进行粮食生产结构合理调整和保障粮食安全具有重要的意义。为此,应用部分经验公式,推导出了一种计算粮食气候产量评价模式,用以估测气候因子(气温、降水)变化对粮食产量的影响。利用该模式,根据1981—2010年闽东地区逐年气温降水推算粮食产量,运用聚类分析、概率函数拟合等统计学方法对粮食产量时间序列进行分析。结果表明,闽东粮食产量与气温相关不显著,而与降水量显著相关。降水的增加有利于产量的增加。气温升高,在一定条件下,有利于产量增加,但达到一定程度后,气温升高,却可能造成产量的降低。聚类分析闽东粮食产量年型可分为歉收年、正常略少年、正常略多年和丰产年,闽东粮食产量主要年份为正常略少或略多,大多数年份粮食产量较为稳定,粮食产量评价结果与历史实况较为一致。本文推算的粮食产量评价模式能够反映出不同气候年景对产量的变化影响,是一种较为便捷和实用的气候变化对粮食产量的评估方式。