Beijing international symposium on climatic change

Reports

Beijing international symposium on climatic change     

不同电离层映射函数对导航精度的影响分析

介绍广播星历映射函数、投影映射函数、几何映射函数和椭球映射函数4种不同的电离层映射函数,基于Klobuchar电离层模型分析不同电离层映射函数对导航精度的影响。结果表明,不同电离层映射函数对导航精度的影响在厘米级到分米级;在不同太阳活动期,椭球映射函数和几何映射函数对导航精度影响基本相同;在太阳活动活跃期,导航精度由高到低依次为几何映射函数、投影映射函数、广播星历映射函数;在太阳活动平稳期,导航精度由高到低依次为广播星历映射函数、投影映射函数、几何映射函数。建议在导航定位中,电离层映射函数在太阳活动活跃期时采用几何映射函数,在太阳活动低谷期时采用广播星历映射函数。     

响应曲面法优化生物质炭去除水溶液中的阿特拉津

将农业废弃物大豆秆在450℃缺氧条件下热裂解制备生物质炭。采用元素分析仪、扫描电镜(SEM)、傅里叶变换红外光谱(FTIR)、光电子能谱分析(XPS)等手段对生物质炭进行理化性质分析;应用响应曲面法(RSM)下的中心合成设计(CCD)功能研究4个因素(初始pH、吸附剂质量浓度、阿特拉津质量浓度、温度)对阿特拉津去除率的影响;建立二阶模型,并通过方差分析验证二阶方程的有效性。结果表明:生物质炭表面充满孔状结构,且富含C=C、C-C、CHx、-C-OR、-COOR等官能团;吸附阿特拉津后生物质炭在羟基(-OH)的位置产生了新的吸收峰,推测羟基官能团在吸附过程中发挥了重要作用。RSM法优化最佳吸附去除阿特拉津条件为:初始阿特拉津质量浓度为5mg/L、pH=6.67,吸附剂质量浓度为7.75g/L、温度为32℃;在该条件下阿特拉津的吸附去除率达到92.18%。该研究可为评价施加生物质炭土壤中阿特拉津的迁移规律及阿特拉津污染水体修复提供参考。     

后碰撞伸展环境下的盆地特征与成盆机制

与造山带结合,动态、系统地探讨伸展盆地的成盆机制是大陆动力学研究的新思路。本文以后碰撞环境下的伸展盆地为对象,与其它类型伸展盆地相区别,尝试探讨其大陆构造属性和成盆机制。后碰撞伸展盆地一般平行于造山带展布,受相邻活动造山带控制,形成于造山带后碰撞构造环境。盆地的转换、叠合过程与相邻造山带的演化密切相关,表现为动态的耦合关系,即由前陆盆地与主碰撞造山带相耦合,发展为伸展盆地与后碰撞造山带相耦合。其成盆机制实质是地壳缩短增厚后的去"山根"作用,拆沉作用造成加厚地壳减薄,并诱发基性岩浆活动,在地表形成裂谷或断陷,接受河湖相沉积。     

Radionuclide dating(~(210)Pb,~(137)Cs) of recent inter-dune saline lake sediment cores in the Badain Jaran Desert,Inner Mongolia,Northwest China

正Inter-dune lake sediment cores are ideal and unavailable materials for study climate and environmental changes of arid region.The precious dating of lake sediment cores is required for carrying out high resolution climate and environmental changes with these cores.The Badain Jaran inter-dune lake group embedding in the sand sea is the     

柴达木西部地区新生代主控断裂演化过程及其意义

基于主干地震剖面的解释结果,本文探讨了柴达木西部地区新生代主控性断裂的活动模式、活动时间及空间演化过程。结果表明,断裂演化明显存在两个大的旋回:路乐河组—下干柴沟组上段沉积期间(约54～31 Ma)和下油砂山组沉积至今(约22 Ma至今);其中第2个构造期断裂活动强烈,尤其是狮子沟组沉积以来(约8 Ma至今),中部及北部区域北西西向断裂开始大规模逆冲活动,反映了盆地晚期强烈变形过程。断层生长指数定量分析结果与其空间演化过程相吻合,共同记录了印度—欧亚板块碰撞远程效应控制下的柴达木盆地在新生代具有阶段性变形特征,从而为青藏高原东北部分阶段隆升模式提供了新的证据。     

基于优化-模拟技术的生态库容

为发挥水库在水资源开发利用与河流生态环境问题之间的协调作用,以丹江口水库为例,探讨了综合利用水库生态库容划分方法。以丹江口水库下游襄阳和仙桃为控制断面,采用Tennant法计算下游河道生态流量的参考值。在考虑丹江口水库的防洪、生态、供水、调水、发电、航运等综合任务和汉江中下游水量联系的基础上,建立了综合利用水库的生态库容优化模型,拟定了4组调度规则,应用自适应遗传算法和模拟调度方法进行求解。计算结果表明:设置生态库容后的调度图能较好地满足控制断面对生态流量的需求,获得较佳综合利用效益。     

中国洋板块地层分布及构造演化

以大地构造相研究为主导,以《中国沉积大地构造图(1∶2 500 000)》编图为研究平台,对洋板块地层类型进行了初步划分,简述了中国新元古代以来洋板块地层分布及其构造演化规律。本文阐述了北方的古亚洲洋的洋陆转换从西往东具穿时现象,西部主要在早、晚石炭世之间,东部主要在中、晚二叠世之间;宽坪-佛子岭混杂岩带是华北与扬子之间大洋消亡的产物;中央造山带从北部的祁连-阿尔金到南部的昆仑-秦岭,洋陆转换从北向南依次完成：西昆仑北-阿尔金-祁连-祁曼塔格为晚奥陶世末,西昆仑南-东昆仑-秦岭为早三叠世末;青藏高原中部的龙木错-双湖、班公湖-怒江、昌宁-孟连蛇绿混杂岩带一起构成了原-古特提斯大洋连续演化、分阶段增生至最终消亡的对接带,洋壳持续时代自寒武纪-早白垩世;江绍-郴州-钦防混杂岩带是扬子陆块与华夏增生造山系之间华南洋最终消亡的对接带,主碰撞期是晚奥陶世-早志留世。     

Spatial and temporal variability and size fractionation of chlorophyll a in the tropical and subtropical Pacific Ocean

The spatial and temporal variability and size fractionation of chlorophyll a(Chl a) were investigated in the tropical and subtropical Pacific Ocean during four survey cruises from 2005 to 2009.The surface Chl a(S-Chl a) concentration ranged from 0.002 to 0.497 mg/m 3 and was obviously higher in the eastern Pacific than in the western and central Pacific.The vertical distribution of Chl a displayed a single peak pattern,and the maximum Chl a layer(MCL) was observed at a shallower depth in the eastern Pacific than in the western Pacific.All three size fractions of Chl a measurements in the surface water showed a similar distribution to total Chl a and were found in higher concentrations in the eastern Pacific than in the western and central Pacific.Picoplankton dominated the phytoplankton in the surveyed tropical and subtropical Pacific Ocean.Furthermore,pico-Chl a(0.2-2 μm) accounted for a larger percentage of the total Chl a in the central Pacific than it did in the western Pacific and eastern Pacific.In the western Pacific,there seemed to be a latitudinal variability in the phytoplankton community composition where small-sized phytoplankton(<2 μm) were more dominant in the tropical than in the subtropical western Pacific.The spatial and temporal variability and size fractionation of Chl a were controlled by hydrological and chemical characteristics and climate events,such as El Nin o and La Nin a.     

Cenozoic Stratigraphy Deformation History in the Central and Eastern of Qaidam Basin by the Balance Section Restoration and its Implication

The Qaidam Basin,located in the northern margin of the Qinghai-Tibet Plateau,is a large Mesozoic-Cenozoic basin,and bears huge thick Cenozoic strata.The geologic events of the Indian-Eurasian plate-plate collision since～55 Ma have been well recorded.Based on the latest progress in high-resolution stratigraphy,a technique of balanced section was applied to six pieces of northeast-southwest geologic seismic profiles in the central and eastern of the Qaidam Basin to reconstruct the crustal shortening deform...