高山草甸下垫面夏季近地层能量输送及微气象特征

利用青藏高原东坡理塘站2007年6～8月的观测资料, 分析了高原东坡草甸下垫面夏季近地层气象要素和湍流通量日变化特征, 并用涡动相关法估算地面的曳力系数。结果表明: 水平风速、 动量通量、 摩擦速度等均在下午最大, 早晨最小。二氧化碳浓度表现为早晚高、 中午低的日变化特征, 比湿的最大值出现在早晨。地表辐射、 热量平衡各分量最高值出现在中午, 最低值出现在早晨。地表反照率表现出早晚高中午低的 “U” 型分布, 日平均值为0.164。夏季地面热源强度在白天午后表现为强的热源, 在夜里表现为弱的冷、 热源交替出现。夏季近地层地气热量交换中, 感热输送作用小, 潜热输送占主要地位。     

Vulnerability of water resources and its spatial heterogeneity in Haihe River Basin,China

To manage water resources effectively, a multiscale assessment of the vulnerability of water resources on the basis of political boundaries and watersheds is necessary. This study addressed issues on the vulnerability of water resources and provided a multiscale comparison of spatial heterogeneity under a climate change background. Using improved quantitative evaluation methods of vulnerabil- ity, the Theil index and the Shannon-Weaver index, we evaluated the vulnerability of water resources and its spatial heterogeneity in the Haihe River Basin in four scales, namely, second-class water resource regions （Class II WRRs）, third-class water resource regions （Class III WRRs）, Province-Class II WRRs, and Province-Class III WRRs. Results show that vulnerability enhances from the north to south in the different scales, and shows obvious spatial heterogeneity instead of moving toward convergence in multiscale assessment results. Among the Class II WRRs, the Tuhai-Majia River is the most vulnerable area, and the vulnerability of the Luanhe River is lower than that of the north of the Haihe River Basin, which in turn is lower than that of the south of the Haihe River Basin. In the scales of Class III WRRs and Province-Class III WRRs, the vulnerability shows obvious spatial heterogeneity and diversity measured by the Theil index and the Shannon-Weaver index. Multiscale vulnerability assessment results based on political boundaries and the watersheds of the Haihe River Basin innovatively provided in this paper are important and useful to characterize the real spatial pattern of the vulnerability of water resources and improve water resource management.     

优化BP神经网络的多特征融合遥感影像分类方法

针对BP神经网络在遥感影像分类中存在易陷入局部极值和单一影像特征缺乏有效地物判别信息的问题,该文提出了一种遗传算法(GA)结合指数粒子群算法(ExpPSO)优化BP神经网络的多特征融合遥感影像分类方法(GA-ExpPSO-BP).该方法将设计的基于指数函数的ExpPSO与GA结合构建GA-ExpPSO算法,利用GA-ExpPSO算法对BP神经网络的权阈值进行初始寻优从而构建GA-ExpPSO-BP模型.以高分二号、资源三号遥感影像为实验数据,通过制作多特征融合数据集训练及实验验证.结果 表明:该方法的类别精度、总体精度和Kappa系数均最高,且训练耗时和误差最小,能有效改善影像的分类效果,提高分类效率和精度.     

Arsenic Geochemistry of the Great Dismal Swamp,Virginia, USA: Possible Organic Matter Controls

Surface water samples for arsenic (As) concentration and speciation analysis were collected from organic matter-rich blackwaters of the Lake Drummond portion of the Great Dismal Swamp in southeastern Virginia, USA. Arsenic concentrations and speciation were determined by selective hydride generation, gas chromatography with photoionization detection. Surface waters from the Great Dismal Swamp are high in dissolved organic carbon (DOC) concentrations (445–9,600 μmol/kg) and of low pH (4.2–6.4). Total dissolved As concentrations [i.e., As(III) + As(V)], hereafter As_T, range from 2.2 nmol/kg to 21.4 nmol/kg. Arsenite, As(III), concentrations range from ∼1 nmol/kg to 17.7 nmol/kg, and As(V) ranges from ∼1 nmol/kg to 14.1 nmol/kg. Arsenate, As(V), is the predominant form of dissolved As in the inflow waters to the Great Dismal Swamp, whereas within the swamp proper arsenite, As(III), dominates. Arsenite accounts for 8–37% of As_T in inflow waters west of the Suffolk Scarp, and between 54% and 81% of As_T in Lake Drummond and Great Dismal Swamp waters east of the scarp. Arsenite is strongly correlated to DOC (r = 0.94) and inversely related to pH (r = −0.9), both at greater than the 99% confidence level. Arsenate is weakly related to pH and DOC (r = 0.4 and −0.37, respectively), and neither relationship is statistically significant. No statistical relationships exist between As(V) or As(III) and PO₄ concentrations. The predominance of As(III) and its strong correlation with DOC in Great Dismal Swamp waters suggest that DOC may inhibit As(III) adsorption or form stable aqueous complexes with As(III) in these waters. Alternatively, phytoplankton and/or bacterially mediated reduction of As(V) may be important processes in the organic-rich blackwaters and/or sediment porewaters of the swamp, leading to the prevalence of As(III) in the water column.     

淮阴市冷热指数预报及应用

本文探讨了体感温度与气温、风速、相对湿度的关系，得出冷热指数经验公式，并从人体感受、着装、气象保健等方面，确定冷热指数等级。根据不同冷热等级提出相应的服务建议。     

我国东南地区πg波的频散特征

本文利用1987年8月在江西省寻乌发生的三次5.0级以上地震的记录资料,讨论了我国东南地区π_g波的传播特征。结果表明:π_g波的初至波速为6.00km/s,与Press的结果相近;π_g波有明显的频散特征,其卓越周期为0.6—0.8秒,较多表现为正常频散,同时也有少量表现为反常频散,由π_g波的波数及波峰的水平合成矢量得到的振幅辐射图象,基本上与弱非均匀介质辐射图象相近;π_g波各波数水平到时与垂直到时存在明显的到时差。     

Oil geologic anomaly in the north edge of the Middle and Lower Yangtze areas based on the evidence weight method

The study of oil geologic anomalies is a new area of petroleum geology. Using the evidence weight method, we selected tectonic, hydrocarbon abundance of source rock, thickness of source rock, level of reservoir, complexity of reservoir, degree of mineralization of formation water as the evidence layer to evaluate the favorable zones of pool forming in the Lower Paleozoic in the north edge of the Middle and Lower Yangtze areas. Finally, we integrated our results with the petroleum geology of this area and concluded that the North Sichuan basin, the western area of Hubei and the eastern area of Chongqing and parts of the Lower Yangtze are the most profitable areas for exploration in the north edge of the Lower and Middle Yangtze areas. __________ Translated from Journal of Jilin University (Earth Science Edition), 2007, 37(3): 458–462 [译自: 吉林大学学报(地球科学版)]     

鄂尔多斯盆地四大古隆起演化及其油气控藏意义的差异*

鄂尔多斯盆地在地质历史上曾存在中央古隆起、乌兰格尔古隆起、渭河古隆起及乌审旗古隆起4个主要的隆起构造。作者通过沉积地层分布及构造演化过程剖析等方法,系统分析了4大古隆起构造演化的差异性及其对油气成藏控制作用的差异,并首次提出“渭河古隆起”的概念。研究表明,4大古隆起分别形成于不同的地质时代和区域构造环境,并经历了不同的演化过程: 中央古隆起形成于早古生代拉伸构造环境,在印支期发生构造反转而转化为坳陷沉降区; 乌兰格尔古隆起则是自盆地基底形成以来就已存在的长期继承性隆起,但在白垩纪及新生代发生差异隆升—沉降而分化为现今构造的不同单元; 渭河古隆起形成于白垩纪的区域挤压构造环境,也是在新生代发生差异隆升—沉降而分化为今构造的不同单元; 乌审旗古隆起是前寒武纪即已存在的古地形高地,早古生代并无进一步的发展,因而仅是在寒武纪海侵沉积时突显、奥陶纪开始沉积后即快速消隐。古隆起的控藏差异主要表现为: (1)古生代及之前形成的古隆起对盆地油气成藏多具有控相、控储及控制源—储配置等积极作用,且后期“由隆转坳”的古隆起对油气的成藏演化极为有利; (2)白垩纪以来的较晚期隆起对油气成藏总体以破坏性作用为主,尤以对古生界天然气藏的影响最为显著。     

四川汶川8．0级地震前后中国大陆西部地震活动特征及震后趋势分析

通过对汶川8．0级地震前后中国大陆地震活动特征的分析,探讨了汶川8．0级地震的地震活动背景．重新划分了中国大陆7级以上地震的活动周期,并根据汶川地震发生的构造背景分析了汶川地震对中国大陆活动趋势的影响和西部大三角与中国大陆强震活动趋势的关系。分析结果表明：在未来1-3年中国大陆特别是西部强震活动仍然处于活跃状态,有可能再次发生7级以上地震。     

中国荒漠类自然保护区保护成效评估指标及其应用

自然保护区的保护成效是近年来一个重要科学问题。中国荒漠类自然保护区面积比例较高,而针对其保护成效问题的研究较少。本文以中国荒漠类自然保护区为研究对象,结合国内外自然保护区保护成效的相关研究,构建了荒漠类自然保护区保护成效评估指标体系,包括5个因素层共计20个评估指标,并在安西极旱荒漠国家级自然保护区进行了示范应用。结果表明:本研究构建的指标体系能够反映荒漠类自然保护区主要保护对象的动态变化,从而为科学客观评估荒漠类自然保护区保护成效、提升管理水平提供重要参考依据。此外,通过示范评估可以看出,安西保护区在物种及珍稀濒危生物保护方面取得了一定成效,但在珍稀濒危及特有物种和生态系统服务功能等方面的科研监测尚有待加强。