大别山碧溪岭榴辉岩的K-Ca同位素定年:多硅白云母含过剩氩的新证据

40K可以进行分支衰变成40 Ar和40 Ca。在正常情况下 ,这对40 K 40 Ar或3 9Ar 40 Ar年龄与40 K 40 Ca年龄在误差范围内应该一致。测定了国家钾标样的含量、国家钾长石 (W 0 3116 )和球团矿 (W 72 0 0 )的钾钙含量、国内K Ar法标准矿物黑云母 (ZBH 2 5 )和角闪石 (ZBJ)的钾钙含量以及Tachiti标样的 (40 Ca/42 Ca)比值和含量 ,结果实测值与标称值在误差范围内一致。对大别山碧溪岭超高压变质榴辉岩的多硅白云母、绿辉石和石榴子石进行了 (40 Ca/42 Ca)和 (40 K/42 Ca)的测定。由15组数据构成的等时线斜率S =0 .12 0 8± 0 .0 4 2 3,相应的K Ca年龄为 2 2 8± 75Ma。然而多硅白云母和绿辉石的3 9Ar 40 Ar等时线年龄分别为 80 7.1± 32 .6Ma和 4 5 6 .7± 2 7.2Ma ,在误差范围内明显地高于40 K 40 Ca等时线年龄 ,这给出了前者存在过剩氩的直接证椐。此外 ,K Ca等时线的初始值 (40 Ca/42 Ca) i 为 15 1.4 2 4± 0 .0 13,相应的 ξCa为 +2 7。由于地幔岩的 ξCa≈ 0 ,所以前者表明榴辉岩的原岩具有典型的大陆地壳性质 ,这为大别山超高压变质岩体是由大陆物质俯冲至上地幔的深度 ,然后折返至大陆的形成过程提出了又一个判据     

弹性波逆时偏移及其成像条件

从弹性波动方程出发,推导了二维各向同性介质情况下弹性波逆时传播的高阶差分格式,实现了弹性波在数值空间中的逆时延拓。从程函方程出发,采用逆时差分格式求取网格空间中各点的直达波旅行时,以此作为弹性波逆时偏移的成像条件(激发时间成像条件),实现多波多分量资料的逆时偏移。文中给出了几个典型模型的理论记录的偏移结果,数值试验表明,逆时偏移能够使地表接收到的波场准确归位,提高资料处理的精度。     

In situ trace metal speciation in a eutrophic lake using the technique of diffusion gradients in thin films (DGT)

We evaluated the application of DGT (diffusion gradients in thin films) as a tool to determine Cu, Zn, Ni, Cd, Pb and Mn concentrations and speciation in a hardwater eutrophic lake. This technique was used in situ during six sampling periods over one year in Lake Greifen. The DGT-labile species of Cu and Ni amounted to 15-25% of the total dissolved concentrations. Speciation by ligand-exchange/DPCSV indicated that Cu and Ni were predominantly organically complexed (>99%). Thus, the DGT-labile species for Cu and Ni were much more abundant than the free ionic and inorganic species determined by ligand-exchange/DPCSV. The results can be explained by incomplete metal exchange of very strong complexes with the chelating resin in the DGT devices, metal exchange of less abundant weaker complexes, and by slow diffusion of exchangeable organic complexes. For Zn (36 to >90% DGT-labile) and Mn (50 to 100% DGT-labile), the results indicated that these metals are less strongly organically complexed. A larger fraction of Zn occurred in DGT-labile species in the hypolimnion than it did in the surface water, probably due to a larger concentration of strong ligands in the productive surface water. DGT-labile Cd- (0.01-0.02 nM) and Pb-species (0.03-0.06 nM) were detected at very low levels. The combination of measurements of dissolved and DGT-labile species showed a decrease of Cu, Zn, Cd and Mn concentration at 2.5 m from June to August, which was probably linked to intensive sedimentation of organic matter during summer stagnation. Mixing and oxygenation of the lake in winter-spring led to an increase in dissolved and DGT-labile Ni, Zn and Cd, whereas Mn decreased in the hypolimnion.     

Sedimentary records of environmental evolution in the Sanmen Lake Basin and the Yellow River running through the Sanmenxia Gorge eastward into the sea

A series of independent faulted basins developed in the present middle reaches of the Yellow River during late Cenozoic, among which the Sanmen Lake Basin is located in the east edge of the Loess Plateau, a transitional zone between the second and third macromorphological step of China. The thick strata of the Sanmen Group deposited in the large basin. The Sanmen Group is a perfect place for the study on paleoenvironmental change, tectono-climatic cycles as well as the formation and evolution of the Yellow River. In this paper, the paleoenvironmental changes, regional tectonic movement and the evolutionary process of the Sanmen Lake Basin during the past 5 Ma were reconstructed based on the analysis of paleomagnetic stratigraphy, pollen, TOC and carbonate content from the Huangdigou outcrop near the Sanmenxia Reservoir, Pinglu County, Shanxi Province. The sedimentary records from the outcrop indicate that the basin was first formated by fault activity at about 5.4 MaBP, and after the strong tectonic movement at 3.6 MaBP the lake enlarged and the rainfall of summer monsoon increased. There was no great climatic transition near 2.6 MaBP, corresponding to the bottom age of loess in the Loess Plateau. After Olduvai event (about 1.77 MaBP) the Picea and Abies were presented in the sediments, which indicates a colder climate. The tectonic movement at 1.2 MaBP caused the light angular discordance between the upper and lower Sanmen Group. The sedimentary records show a cold and wet climate during the prosperous periods of loess accumulation such as L15, L9, L6. The tectonic intensification periods of the Sanmen Basin correspond with the tectonic movements in the Qinghai-Xizang Plateau chronologically. The earliest age of the outflow from the Paleo-Sanmen Lake or the partly cutting off of the Sanmenxia Gorge was about 0.41- 0.35 MaBP. The age of cutting thoroughly the Sanmenxia Gorge by the Yellow River and the disappearance of the Paleo-Sanmen Lake was about 0.15 MaBP, which symbolized the formation of the present Yellow River and had an important influence on the environmental and morphological evolution in the middle and lower reaches of the Yellow River.     

试论黑龙江省地质环境的保护

首先在引言中提出了地质环境的涵义，并回顾了人类对地质环境的认识和保护的历史，分析了当前地质环境保护的重要性和紧迫性。接着研究了黑龙江省在地质环境保护中所存在的一系列问题，最后具体提出了地质环境保护的措施和对策。期望有关部门和领导的地质环境的保护和管理工作能提供一个典型实例及一种积极的探索经验。同时还具有现实意义和历史意义。     

黑河流域TM/ETM+影像数字镶嵌图的制作与应用研究

对研究区内两个时期(1986-1990年和1999-2000年)20景Landsat TM5或Landsat ETM7影像图进行多波段合成、色彩优化、几何配准和数字镶嵌等预处理工作,生成试验区两个时期的TM/ETM+影像数字镶嵌图,并利用均方根(Root mean square, RMS)误差法评价几何配准的精度,用采样法评价数字镶嵌的精度. 结果表明,单景TM/ETM+影像图几何配准的精度可以控制在1个像元以内. 多景数字镶嵌时多数点的RMS误差小于2个像元,总的RMS误差在1.3～1.5之间. 利用影像图作为几何配准的数据源的方法要优于利用地形图作为几何配准的数据源的方法.     

冻结粉质粘土中锥形桩弹性阶段挤扩效应的研究

20世纪70年代, 在原苏联的乌克兰地区, 用锥形桩作基础建造了大量的多层或高层住宅, 取得了显著的经济效益. 我国的科技人员于20世纪80年代初期也开始了这方面的研究, 并于河北省的保定地区进行了试点工作. 但在冻土中采用锥形桩作基础, 迄今为止还未有报道. 通过对冻结条件下粉质粘土中锥形桩在竖向荷载作用下弹性阶段挤扩效应的分析, 根据厚壁圆筒受均匀内压时的弹性理论解答, 计算出了冻结条件下粉质粘土中锥形桩侧表面在弹性阶段末期的挤扩应力值, 并根据锥形桩模型在竖向快速加荷条件下的试验资料, 验证了公式的正确性, 结果令人满意.     

固定源建场测深在地形复杂区的勘探试验研究

固定源建场测深是一种时间域电磁测深方法，其具资料信噪比高，数据精度高，可避免地表电性不均匀引起的静态位移等优点。但用线圈作为磁探头的传统方法只能适用于地形平坦区，在地形复杂的勘探高难地区无法应用。采用磁棒代替线圈作磁探头，进行了固定源建场测深在地形复杂区的勘探试验。结果表明，改进后的固定源建场测深能适用于地形复杂区的勘探，其成果可弥补该类地区地震勘探资料的不足。     

小波神经网络在测井油水解释中的应用

作者在本文中讨论了小波神经网络概念和油水测井曲线段的频率特性。以小波分析为数据预处理工具，首先用小波分解高频成分对测井曲线进行分段，然后应用小波分析提取出测井段的分频能量特征向量，以此向量代表井段的信息，并作为神经网络的输入，进行神经网络的测井解释，实现了小波神经网络的测井分段油水解释。     

"中国气象数值预报系统技术创新研究"业务化试验

由于一部分成果已经可以进行业务化试验,为了促进科研成果及时转化为业务能力,同时也为了通过业务试验来促进科研成果的进一步优化,并帮助业务部门应用最新科技成果,项目及时组织阶段成果的业务试验.一方面项目研发人员与国家气象中心联合组织成果业务试验小组,并在各区域数值预报中心建立了多个业务试验基地,另一方面又及时召开阶段成果的推广应用会.目前项目开发的变分同化系统已建立了国家级的并行试验系统,并在广州、辽宁等区域气象中心实现了实时运行试验,这些试验的结果又及时反馈给课题研究开发组,对研究开发成果的进一步优化提供了线索与依据.