Identification of the “source” and “sink” patterns influencing non-point source pollution in the Three Gorges Reservoir Area

Non-point source pollution is one of the primarily ecological issues affecting the Three Gorges Reservoir Area. In this paper, landscape resistance and motivation coefficient, which integrated various landscape elements, such as land use, soil, hydrology, topography, and vegetation, was established based on the effects of large-scale resistance and motivation on the formation of non-point source pollution. In addition, cost models of the landscape resistance and motivation coefficients were constructed based on the distances from the landscape units to the sub-basin outlets in order to identify the “source” and “sink” patterns affecting the formation of non-point source pollution. The results indicated that the changes in the landscape resistance and motivation coefficients of the 16 sub-basins exhibited inverse relationships to their spatial distributions. The landscape resistance and motivation cost curves were more volatile than the landscape resistance and motivation coefficient curves. The landscape resistance and motivation cost trends of the 16 sub-basins became increasingly apparent along the flow of the Yangtze River. The landscape resistance and motivation cost models proposed in this paper could be used to identify large-scale non-point source pollution “source” and “sink” patterns. Moreover, the proposed model could be used to describe the large-scale spatial characteristics of non-point source pollution formation based on “source” and “sink” landscape pattern indices, spatial localization, and landscape resistance and motivation coefficients.     

Temperature changes on the Tibetan Plateau during the past 600 years inferred from ice cores and tree rings

The climatological signal of δ¹⁸O variations preserved in ice cores recovered from Puruogangri ice field in the central Tibetan Plateau (TP) was calibrated with regional meteorological data for the past 50 years. For the period AD 1860–2000, 5-yearly averaged ice core δ¹⁸O and a summer temperature reconstruction derived from pollen data from the same ice core were compared. The statistical results provide compelling evidence that Puruogangri ice core δ¹⁸O variations represent summer temperature changes for the central TP, and hence regional temperature history during the past 600 years was revealed. A comparison of Puruogangri ice core δ¹⁸О with several other temperature reconstructions shows that broad-scale climate anomalies since the Little Ice Age occurred synchronously across the eastern and southern TP, and the Himalayas. Common cold periods were identified in the 15th century, 1625–1645 AD, 1660–1700 AD, 1725–1775 AD, 1795–1830 AD, 1850–1870 AD, 1890–1920 AD, 1940–1950 AD, and 1975–1985 AD. The period 1725–1775 AD was one of the most prolonged cool periods during the past 400 years and corresponded to maximum Little Ice Age glacier advance of monsoonal temperate glaciers of the TP.     

马氏珠母贝育珠效果影响因素分析

设立3个实验,分别比较了植核时间、植核贝龄、育珠模式对马氏珠母贝育珠效果影响。实验I,设立A1、A2和A3组,植核时间分别设置4月份、7月份和10月份;实验II,设立B1、B2、B3和B4组,植核贝龄分别设置1.0龄、1.5龄、2.0龄和2.5龄;实验III,设立C1、C2和C3组,育珠模式分别设置海区休养与育珠、池塘休养与育珠和池塘休养与海区育珠。按常规技术植核,经1个月的休养期和15个月的育珠结束后,比较各组间休养与育珠的成活率、留核率、成珠率、优良珠率及育珠绩效值的差异。结果表明:植核时间、植核贝龄、育珠模式对植核贝的成活率和育珠绩效值均存在显著的影响(p值<0.05);对育珠贝的留核率、收珠率和优良珠率无显著性影响(p值>0.05);实验I,A1组(4月份植核)育珠绩效值最高,A2组(7月份植核)育珠绩效值最低;实验II,B2(1.5龄)育珠绩效值最高,B4组(2.5龄)育珠绩效值最低;实验III,C3组(池塘休养与海区育珠)的育珠绩效值最高,C2组(池塘休养与育珠)育珠绩效值最低。马氏珠母贝适宜的植核时间为4月份,适宜的植核贝龄为1.5龄,利用池塘休养结合海区育珠能够有效提高育珠效果。     

关中地区重力场动态演化特征与地震活动分析

系统分析了陕西关中测区1983～2003年的流动重力观测资料,研究了重力场的时空动态演化特征,结 果表明:①地震孕育阶段,伴随异常点段增多,重力场在一定范围内出现区域性的重力负异常,地震往往发生在异 常区的边缘或重力异常梯度带上,震后逐渐回升;②重力场变化图像较好地反映了在区域应力场和震源应力场作 用下断层活动引起的重力效应;③关中重力场的转折变化受制于大区域应力场的影响和作用。     

珠母贝人工繁育优化技术的研究

在室内水泥池分别进行了移池培育、不同种类附着器、光照强度、水流和冲洗对珠母贝附着幼虫变态和稚贝存活的研究,结果表明:附着密度为2.18个/cm~2±0.50个/cm~2时,移池培育,其变态幼虫密度为0.95个/cm~2±0.13个/cm~2,20 d稚贝存活密度0.41个/~2±0.08个/cm~2,移池培育显著提高附着幼虫变态和稚贝存活;附着板、附着绳、网片、小石块变态幼虫密度分别为0.70个/cm~2±0.08个/cm~2、1.38个/cm~2±0.15个/cm~2、0.97个/cm~2±0.12个/cm~2、1.04个/cm~2±0.28个/cm~2,稚贝存活密度分别为0.36个/cm~2±0.06个/cm~2、0.62个/cm~2±0.07个/cm~2、0.45个/cm~2±0.07个/cm~2、0.60个/cm~2±0.08个/cm~2,附着绳显著提高附着幼虫变态和稚贝存活;光照强度为300～600 lx时变态幼虫密度为0.87个/cm~2±0.07个/cm~2,20 d稚贝存活密度0.45个/cm~2±0.08个/cm~2,强光不利于幼虫的变态和稚贝存活;水流速为2.3 cm/s时变态幼虫密度为1.08个/cm~2±0.07个/cm~2,20 d稚贝存活密度0.87个/cm~2±0.07个/cm~2,冲洗的变态幼虫密度为1.64个/cm~2±0.19个/cm~2,20 d稚贝存活密度1.00个/cm~2±0.12个/cm~2,水流或冲洗显著提高附着幼虫变态和稚贝存活.     

A standard format for reporting PILPS experiments

In model inter-comparisons one major obstacle is the format of the reported data. To facilitate the analysis of the results from the different models they should all be reported in the same format. This requires that the format is flexible enough to be easily implemented into the different land surface schemes. It should also be fault tolerant and allow a few consistence checks to avoid erroneous data to be submitted. The present note describes such a format developed for the PILPS project. After discussing the aim of this new format we present the routines which are used to write and read data. Finally two applications are described which allow the user to perform a number of consistency checks on the data.     

南极乔治王岛环境质量现状调查

本文以１９９２／１９９３年度中国第九次南极考察期间对南极乔治王岛的表土、地衣、苔藓等样品的分析资料为基础，研究探讨了８种无机重金属元素、５种有机污染物的浓度水平。其结果表明，重金属在三种环境样品中的含量分布存在着明显的差异；地衣、苔藓两种植物呈现对不同重金属元素的不同富集能力；∑６６６、∑ＤＤＴ和ＰＣＢｓ及油的沾污亦很明显。本文还对污染物质的来源、南极环境样品历次调查分析的结果以及世界部分地区的背景水平进行了讨论和比较     

陕西地洞河高分辨率石笋记录的DO18季风增强事件

千年尺度事件的结构特征和区域响应是理解和认识冰期气候变化及动力机制的关键。本文基于陕西汉中宁强县地洞河一支长417 mm石笋DDH1的11个U-Th年代和417个氧同位素（δ¹⁸O）数据,重建了末次冰期（64.8~33.2 ka B.P.）亚洲季风演化历史。石笋δ¹⁸O记录在64.7±0.2 ka B.P.和59.3±0.1 ka B.P.快速负偏,分别指示了DO18事件的开始和H6事件的结束。在DO18事件结束过程,石笋δ¹⁸O记录在64.0~60.4 ka B.P.持续正偏,振幅达2.9 ‰,反应季风逐渐减弱,但未出现明显转型阶段。其总体形态与大西洋Cariaco盆地岩芯反射率、南极冰芯的记录较为一致,但是不同于格陵兰冰芯的记录。因地洞河所处青藏高原、秦岭叠加影响的区域,纬度和地形的双重影响使得其石笋δ¹⁸O记录较其他地区偏负,振荡幅度更大。因地形阻挡了高纬信号,使得低纬甚至南半球的信号突现出来,ITCZ的移动、南半球温度和水汽潜热的释放作用在这一区域尤为显著。

     

末次冰盛期东亚夏季风变化的重庆石笋记录

基于重庆小山岩洞XSY1石笋的5个²³⁰Th年龄和582个氧同位素数据,重建了23134~19345 a B.P.期间分辨率约6.5 a的东亚夏季风变化历史。此石笋δ¹⁸O记录的长期趋势逐渐负偏,在其上叠加了一系列千年-百年尺度季风振荡,呈现为4谷3峰的结构形态。重庆XSY1和南京MSD石笋δ¹⁸O记录在数百年尺度的反相关系表明冰盛期时东亚大陆东部水汽并非来自印度洋。与北高纬记录对比显示东亚季风的增强与减弱基本对应格陵兰温度的升高与降低时期,暗示在冰量最大时期东亚季风与北高纬气候仍密切联系。此外,XSY1的δ¹⁸O与冰芯¹⁰Be通量亦存在明显的对应关系,表明太阳活动对东亚季风的调控作用受冰量边界条件影响较小。功率谱分析结果显示出1011 a、722 a、460 a、337 a和163 a的周期,与太阳活动周期相近,进一步确认太阳活动对东亚季风的驱动作用。石笋XSY1与澳大利亚石笋MC-S2 δ¹⁸O记录在千年尺度呈反相位变化,表明冰盛期时东亚季风与全球其他气候系统的动力联系。

     

流动注射-光度法测定地质样品中痕量碘

利用I~-对4,4′-四甲基二氨基二苯甲烷(4,4′-TMB-DPM)与氯胺T反应的催化作用,建立了流动注射-分光光度测定地质样品中痕量碘的方法。采用不等流速合并带法,分析速度快、节省试剂、灵敏度高。与高温水解法释放I~-相结合,使样品处理简单、干扰离子少。对于含I~-10μg/L的水样,其RSD(n=19)为1.1％,检出限为0.3ng/ml。用于水系沉积物、土壤分析时,含碘1.6×10~(-6)的样品RSD(n=10)为6.1％,检出限为0.08×10~(-6)。测量速度50N/h。