Characteristics and Environmental Significance of pH and EC in Summer Rainfall and Shallow Firn Profile at Yulong Snow Mountain,Lijiang City,China

The seasonal and inter-annual variations of pH and EC(electrical conductivity) at Yu-long(玉龙) Snow Mountain,Lijiang(丽江) City,are sensitive to precipitation variations and are important indicators of the atmospheric environment.The pH of summer rainfall at Lijiang City ranges from 6.7 to 7.4,and alkaline mineral salts dominate the variations of rainfall acidity.pH values in theshallow firn profile at Baishui(白水) Glacier No.1 range from 5.6 to 6.3,and EC values from 2.4 to 7.3 μs/cm.The ranges are lower than ...     

燃料乙醇企业循环经济的实例研究

以北方某燃料乙醇生产系统为例,从物质、能量和水的流动等方面定量地分析其实践循环经济的情况,并结合清洁生产指标体系做了对比分析。着重分析了此生产系统的废物链的组成及其作用,并探讨了进一步发展循环经济的措施。结果表明:燃料乙醇生产系统的原料为可再生资源,主要产品燃料乙醇具有环境友好性;废物链的存在提高了物质利用率、能量利用率和能量保有率,减少了废物的排放,提高了经济效益;通过对废物链的补充还可进一步体现循环经济特性。     

琼东南华光凹陷深水重力搬运沉积体系及其油气勘探

重力搬运沉积作用形成的岩性地层圈闭对深水油气勘探具有非常重要的作用.为弄清琼东南盆地华光凹陷重力搬运沉积特征, 基于近年新采集的地震资料和经典层序地层模式, 开展了该区的深水沉积特征研究.南海西北部深水区重力搬运沉积特征发育, 主要包括中新统三亚组发育的复合水道、上新统变形滑坡体及第四系深水浊积水道.三亚组复合水道具有典型的强弱振幅相互叠置特征, 上新统变形滑坡体具有典型的下部变形、上部滑坡的双层结构, 第四系深水浊积水道具有典型的侧向迁移、分支水道等特征.这些沉积特征的形成与越南隆起的物源供给有关.复合水道充填可作为潜在的深水储层, 滑塌体的形成可能与天然气水合物的形成或解体有关.      

晚新生代以来青藏高原中部环境演化过程的地球化学证据

青藏高原中部发育一系列独立的内流断陷湖盆，其中位于南亚季风区边缘的错鄂湖盆发育了巨厚的湖泊沉积，是研究高原内部地质环境变迁与构造-气候旋回的理想场所。本文对青藏高原中部错鄂孔197m沉积岩心Sr、Rb、Zr含量及其比值以及沉积物有机质δ^13C、TOC含量进行了分析，同时结合岩性、粒度、粘土矿物组成，初步建立了青藏高原中部2．8Ma来岩石化学风化的相对强度和古环境演化过程。研究表明，2．8Ma来青藏高原中部经历了三次剧烈的环境演化过程：在约197～170m(2．8～2．5Ma)之间，低Sr含量，高Rb／Sr和Zr／Rb值记录了较弱的化学风化过程，δ^13C、TOC含量反映气候前期暖干，后期偏凉湿，揭示冷湿气候的云杉林突然增加，沉积岩性明显变粗，反映了一次强烈的构造隆升运动；在约170～38．5m(约2．5～0．8Ma)之间，高Sr含量，低Rb／Sr和Zr／Rb值记录流域经历较强的化学风化过程，δ^13C、TOC含量反映高原中部总体处于温湿或凉湿的环境下，沉积岩性较细，高原总体处于相对剥蚀夷平阶段；在38．5～0m(约0．8～0Ma)段，Sr含量处于相对低值，Rb／Sr值相对较高，化学风化相对较弱，δ^13C、TOC含量表明高原中部处于较寒冷的环境之中，沉积岩性的再次明显变粗表明高原中部又经历了一次强烈的构造运动，并使高原中部整体隆升到4000m以上，奠定了现代高原面的基本格局。     

The fluxes and controlling factors of N_2O and CH_4 emissions from freshwater marsh in Northeast China

Nitrous oxide (N2O) and methane (CH4) emissions were measured using a static chamber method in two adjacent plots of freshwater marsh predominated by Calamagrostis angustifolia, one is seasonal waterlogged (SW) and the other without surface water accumulation (NW), in Sanjiang Plain wetland (47°35′N, 133°31′E), northeast China, during 2002-2004. The diurnal and seasonal flux variations of both gases were significantly correlated with 5-cm-soil temperature. The NW marsh is a source of N2O and sink of CH4, wh...     

雷暴电活动对冰雹增长影响的数值模拟研究

利用三维强风暴动力-电耦合模式,数值模拟了风暴演变过程 中电活动对冰雹增长及地面降雹的影响. 结果指出,带电冰雹与云内强电场作用使地面降雹 量增加约50[HTK]髎[HTSS],雹块直径增大0.7mm,降雹时间滞后约3min. 文中还讨论了强电 场通过对水成物降落速度的调制来影响冰雹微观增长过程,即主要是影响碰并过程和冰雹融 化过程. 电活动使冰雹源、汇总量都减少,但汇总量减少更多,总体效果使冰雹总量增加, 数目减少,冰雹长得更大,更易降落到地面.     

Effect of Sediment Motion Patterns on Sorption of Cadmium Ions by Sediment Particles

I.INTRODUCTIONThefateofmanytraceheavymetalsinnaturalwatersis,toalargeextent,controlledbysorptionprocessesandthedynamicsoftheparticlesthemselves.Thepotentialinfluencesofenvironmentalvariablessuchastemperature,CaZ+,Na+andCI--,dissolvedorganiccarbonandPHvaluesontraceheavymetalpartitioninghavebeenwidelyinvestigated.Forexample,StumnandMorgan(1981)suggestthattheextentofsorptionvariespositivelywithtemperature.Itfollowsthatdecreasedsorptionmightbeexpectedatlowtemperatures,e.g.duringwintermont…     

Rapid Shrinking of Glaciers in the Middle Qilian Mountain Region of Northwest China during the Last ～50 Years

During the past five decades, fluctuations of glaciers were reconstructed from historical documents, aerial photographs, and remote sensing data. From 1956 to 2003, 910 glaciers investigated had reduced in area by 21.7% of the 1956 value, with a mean reduction for the individual glacier of 0.10 km2. The relative area reductions of small glaciers were usually higher than those of large ones, which exhibited larger absolute loss, indicating that the small glaciers were more sensitive to climate change than la...     

Selected Trace Elements in Snowpack on Urumqi Glacier No. 1, Eastern Tianshan, China: As Yielded by Leaching Treatment Representative of Real-World Environmental Conditions

To investigate the seasonal variability and potential environmental significance of trace elements in mountain glaciers, the surface snow and snow pit samples were collected at Urumqi Glacier No. 1 (43o06'N, 86o49'E, 4 130 m a.s.l.), eastern Tianshan (天山), from September 2002 to September 2003, and analyzed for Li, V, Cr, Mn, Co, Cu, and Ba. The samples were acidified (leached) in a manner intended to reasonably approximate the extent to which the natural hydrologic and weathering cycles would liberate elem...     

Two Necessary Conditions for the Glacial-Interglacial Cycles in the Quaternary

Milankovitch Theory shows that glacial-interglacial cycles in the Quaternary are related to the variation of solar insolation forcing linked to the earth's astronomical parameters.However,the summer insolation at northern high latitudes,usually considered as the main external forcing for the ice age as Milankovitch pointed out,is marked by the 19- and 23-ka precession periodicities,which is not consistent with the glacial-interglacial cycles.On the other hand,recent studies indicate that the annual mean ...