论上海软土地基⑦⑧⑨层压缩模量Es的定值问题

上海地区深部土层⑦⑧⑨层埋深在30～70m。对其压缩模量Es的定值问题,现行《上海市地基基础设计规范》(DGJ08 11 1999)(后文中简称《规范》)长期以来确定室内试验E0 1～0 2值为沉降计算值,导致沉降计算值与建(构)筑物实际沉降量之间相差2～8倍。为符合规范的变形要求,设计人员不得不采取桩加粗、加长、加密的办法,从而造成桩基投资的极大浪费。为了正确认识深部土层的Es值,上海岩土工程界进行了多种形式的试验研究。近年来,笔者结合上海高、大、深、重建(构)筑物的工程实践,深入进行上海深部⑦⑧⑨层压缩模量Es的试验研究,获得许多新的认识,对其定值问题作了研究,提出⑦⑧⑨层的建议值,供同行参考研讨。     

Geoid determination using adapted reference field, seismic Moho depths and variable density contrast

 The traditional remove-restore technique for geoid computation suffers from two main drawbacks. The first is the assumption of an isostatic hypothesis to compute the compensation masses. The second is the double consideration of the effect of the topographic–isostatic masses within the data window through removing the reference field and the terrain reduction process. To overcome the first disadvantage, the seismic Moho depths, representing, more or less, the actual compensating masses, have been used with variable density anomalies computed by employing the topographic–isostatic mass balance principle. In order to avoid the double consideration of the effect of the topographic–isostatic masses within the data window, the effect of these masses for the used fixed data window, in terms of potential coefficients, has been subtracted from the reference field, yielding an adapted reference field. This adapted reference field has been used for the remove–restore technique. The necessary harmonic analysis of the topographic–isostatic potential using seismic Moho depths with variable density anomalies is given. A wide comparison among geoids computed by the adapted reference field with both the Airy–Heiskanen isostatic model and seismic Moho depths with variable density anomaly and a geoid computed by the traditional remove–restore technique is made. The results show that using seismic Moho depths with variable density anomaly along with the adapted reference field gives the best relative geoid accuracy compared to the GPS/levelling geoid. Received: 3 October 2001 / Accepted: 20 September 2002 Correspondence to: H.A. Abd-Elmotaal     

热液矿床石英铅同位素组成及其地质意义

作者以若尔盖铀矿床为例，研究了含矿热液形成的石英脉石英的铅同位素组成，并将其作为联系母源铅同位素组成的桥梁，判别铀的来源。结果表明，矿床中石英铅同位素组成与含矿黄铁矿和中酸性构造－岩浆成因的花岗岩铅同位素组成具线性演化关系。由此提出含矿热液中的铀来自中酸性构造－岩浆岩而不是地层岩石的新见解，同时提出利用热液石英铅同位素组成判别非放射性矿床成矿元素来源的可能性。     

微波焙烧炉在分析测试中的应用研究

本文详细论述了微波焙烧炉代替马弗炉应用于样品焙烧、熔融、活性炭灰化工作中的实际效果。结果表明：其应用不但可行，而且与马弗炉相比，微波焙烧炉具有更加优越的经济性与环保效果。     

SVLBI用于大地测量的卫星轨道及其跟踪网设计

SVLBI （space very long baseline interferometry） has some important potential applications in geodesy and geodynamics, for which one of the most difficult tasks is to precisely determine the orbit of an SVLBI satellite. This work studies several technologies that will possibly be able to determine the orbit of a space VLBI satellite. Then, according to the types and charac- teristics of the satellite and the requirements for geodetic study and the geometry of the GNSS （GPS, GALILEO） satellite to track the space VLBI satellite, the six Keplerian elements of the SVLBI satellite （TEST-SVLBI） are determined. A program is designed to analyze the coverage area of space of different altitudes by the stations of the network, with which the tracking network of TEST-SVLBI is designed. The efficiency of tracking TEST-SVLBI by the network is studied, and the results are presented.     

金川铜镍硫化物样品中锇同位素比值的高精度分析

采用两种独立的190Os稀释剂、4个不同的化学流程,用等离子体质谱仪、TRITON热表面电离质谱仪和MAT-262固体质谱仪3种质谱仪器,在4个实验室分别对采自金川铜镍硫化物样品的187Os/188Os同位素比值进行分析,样品分析数量达到56个。4个实验室获得的结果分别为0.3356±0.0018(n=12,2s)、0.3363±0.0008(n=6,2s)、0.3363±0.0010(n=18,2s)和0.3353±0.0034(n=20,2s)。采用ISOPLOT软件对所得56个数据进行加权平均计算,得到187Os/188Os同位素比值为0.33602±0.00022(置信度95%)。两台TRITON热表面电离质谱仪测量的结果几乎完全一致,且精度高于MAT-262固体质谱仪和等离子体质谱仪。比较了碱熔和Carius管两种溶样方法,结果表明,对于所研究的样品,用Carius管溶矿方式可以将含锇矿物完全溶解。     

The Influence of Chlorine on the Determination of Combined Water: An Investigation of a Correction Procedure

Differential thermal analysis, pH determination and ion chromatography were used to investigate the interference of chlorine in the determination of combined water (H₂O⁺) by the Penfield tube gravimetric method. The magnitude of the chlorine interference was quantified and a correction method was proposed to obtain accurate results for H₂O⁺. The method was applied to the determination of H₂O⁺ in deep sea sediments containing chlorine and certified reference materials of oceanic polymetallic nodules.     

电感耦合等离子体质谱法测定井间示踪剂中稀土元素

以甲醇为稀释剂,用电感耦合等离子体质谱法快速测定稀土示踪剂中17个稀土元素。研究表明,在优化的稀释剂甲醇浓度为2%(体积分数)、pH<2.47的条件下测定稀土元素,方法精密度(RSD)为1.23%~2.83%,日间6次测定的精密度为2.25%~4.76%,各稀土元素线性关系良好,检出限为2.0~9.0 ng/L;17个稀土元素的加标回收率为85%~108%,满足痕量元素分析要求。     

萃淋树脂吸附法测金

对萃淋树脂在酸性介质中吸附解脱金及相关体系的条件选择，以及萃淋树脂在生产方面的应用前景进行了实验研究。结果表明，萃淋树脂在稀王水介质中能较好地吸附金，用硫脲解脱金简便完全，检测限达0．002μg／g，吸附率达100％，解脱率99．8％。     

北斗卫星导航系统双差动力法精密定轨及其精度分析

针对GEO卫星切向轨道分量与双差模糊度强相关的问题,对经典双差动力法进行了改进,提出联合使用载波相位和相位平滑伪距实现北斗系统精密定轨,并从理论上分析了以上处理策略的可行性及对模糊度固定的影响,然后结合北斗系统精密定轨特点,推导给出了利用QIF方法实现北斗卫星双差模糊度固定的基本原理,实测数据分析表明:联合载波相位和相位平滑伪距,既可降低相关性,又可兼顾精度,定轨效果优于经典双差动力法;利用QIF方法能够取得一定的模糊度固定效果,但受观测条件限制,北斗卫星双差模糊度固定成功率整体不高,双差模糊度固定之后对轨道的改进作用有限。