房山花岗闪长岩体长石斑晶的数学特征及相带划分

对北京房山花岗闪长岩体中长石斑晶进行了系统测量,测点密度平均4.37个/km~2,测量标志为长石斑晶长轴长度和长石斑晶线含量等。对测得数据进行了分布统计、有序样品最优分割、和趋势变化分析等处理。揭示了长石斑晶在岩体中的分布规律和数学特征,划分了趋势岩相带,从而提出了较为合理的岩相带划分原则。     

镉—5—Br—PADAP—溴化十六烷基三甲基铵—十八醇聚氧乙烯(20)醚显色体系的研究及应用

本文研究了镉-5-Br-PADAP-溴化十六烷基三甲基铵-peregalo显色体系的光谱特征,显色条件,络合物的组成、干扰及其消除。实验证明该法灵敏度高,ε=1.3×10~5l·mol~(-1)·cm~(-1)。选择性较好,显色酸度范围较宽pH=8.0-9.5,络合物最大吸收波长为560nm,镉在0-10μg/25ml的含量范围内服从比尔定律。经标准水样、工业废水及生活用水验证,不经分离可测定水中PPb级的微量镉。     

~(218)Po法寻找隐伏铀矿体初见成效

本文介绍了一种寻找隐伏铀矿体的快速测氡方法,即~(218)Po法。作者叙述了该法的工作原理、特点以及找矿效果,并阐述了~(218)Po法寻找隐伏铀矿体的可能性。最后着重叙述了~(218)Po法测量结果的解释方法。通过野外试验,作者认为:~(218)Po法不仅可以寻找隐伏铀矿体,而且能够定量预测盲矿体的埋藏深度与规模。     

The piezomagnetic effect in rocks: a comparison of measurements in high and low fields

There are some puzzling features of the stress-dependence of magnetic susceptibility in rocks, although the behaviour in high fields appears to be well understood. As a test for the factors that cause low-field behaviour to differ from current theories we have made both high- and low-field torquemeter measurements of the stress-induced magnetic anisotropies of a number of rocks. Ratios of low- and high-field torques differing from expectation by factors up to 4 or so have been found in some rocks, although others conform well to expectation. A comprehensive study of magnetic and microscopic properties was undertaken to seek the cause(s) of the discrepancies. Stress sensitivity of susceptibility becomes particularly high in titanomagnetite with composition parameter x ≈ 0.6, at which the intrinsic anisotropy vanishes, and some other high values appear to be related to the presence of sulphide. It is concluded that current theory is satisfactory if but only if the magnetic minerals in a rock are simple titanomagnetites with x ? 0.4.     

Origin and distribution of tonsteins in late permian coal seams of Southwestern China

We have surveyed the areal and stratigraphic distribution of tonsteins in Late Permian coalfields of southwestern China over an area of several hundred thousand square kilometers. We studied the relationship between tonstein distribution and sedimentary environment. Based on mineralogical and petrographic data, we have concluded that these tonsteins originated as air-fall volcanic ashes. Following accumulation in the peat swamps, in situ alteration of the vitric and lithic components took place under acidic conditions, leading to the formation of kaolinite.Based on petrologic, mineralogic, and chemical analytical data, we have determined that the application of mineralogic and geochemical criteria for tonsteins may be useful in correlating coal beds, predicting coal qualities and reconstructing related sedimentary paleoenvironmental conditions.     

Simple-Shear Rheological Properties of Shallow Clay Layer in Shanghai

This paper presets the results of simple-shear rheological tests for the shallow clay layer in Shanghai and the rheological parameters of this clay layer, such as shear parameter, viscosity and long-term strength etc. , by using the obtained relationship among stress, strain and time. The test results show that with certain density and water content of the clay and shear stress less than the yield value, the relationship between shear stress and shear strain for the same shear duration can be obtained by superposition theorem. Because of its linearity, likewise, the relationship between long-term shear flow rate and shear stress also hold true thus, from the linear portion of the curves mentioned above the shear modulus G and viscosity η can be obtained . however , when shear stress is beyond a certain yield value, the curve becomes non-linear. This yield value can be regarded as long-term strength of the soil . In rheological experiments these parameters are all functions of time.     

向量场的经验正交展开及其应用

本文提出了一种向量场经验正交展开的方法。我们对N×T个离散点上的向量所构成的一个N×T维矩阵,设法寻找一组称为经验正交函数的向量,使其中每一个分量都在均方意义下最接近矩阵的每一列。这组向量可以从特征方程确定。对于有N列元素的矩阵(注意每一个元素都是一个向量),有不少于N个经验正交函数分量。用这些分量所作向量场的正交展开级数收敛很快。给出的展开实际例子说明:向量场经验正交展开,可以比一般标量场经验正交展开,取得更好的效果。     

方差分量估计方法在ERS—2卫星精密定轨中的应用

将方差分量估计（VCE）方法应用于ERS－2卫星的精密定轨,用SLR和PRARE资料计算了1998年前3个月的23个长度为5天的弧段（除了调整轨道的时段外,相邻弧段有两天的重叠）,从观测值残差分析和重叠弧段比较两个方面,考察VCE方法对定轨计算的影响,并给出了各组观测值的平均验后均方差,对观测值残差的分析表明,使用VCE方法明显地改善了观测值的拟合程度,但从阿卑（Abbey)标准对观测值残差的检验结果来看,使用VCE方法不能消除轨道中由力学模型和几何模型误差引入的系统差,重叠弧段比较的结果表明：（1）使用VCE方法缩小了重叠弧段的平均距离差,并改善了一部分权段明显不合理的偏离,使最后得到的轨道具有更均匀的精度,（2）相比较而言,VCE方法使相邻弧段靠拢的趋势在轨道切向体现得较为明显,由各组观测值的平均验后方差可见,说单个标准点观测值而言,部分SLR台站的观测资料在定轨计算中占有比其他观测资料更重的地位,纵观全文,使用VCE后得到的观测值的平衡验后均方差来确定资料的双重将比使用均方差更为合理。     

水稻时域散射特征分析及其应用研究

通过对肇庆试验区1996年和1997年获取的多时相、多模式雷达卫星（RADARSAT）数据分析,从图像上直接提取地物的后向散射系数,结合实地测量水稻的生长结构参数,建立了水稻生长模型,分析了不同生长周期（从80天到120－125天）4种类型水稻的时域散射特性。利用1997年4月至7月获取的7景标准模式雷达卫星数据,对试验区内三个县和两个行政区共5000km^2面积范围内的作物进行分类和水稻产量预估算,水稻类型分类及面积量算精度达91％。结果表明：利用雷达遥感数据进行水稻种植面积量算和估产需要水稻生长期间三个时相的数据,即插秧期、抽穗期、收割前期。若能够获得多参数雷达图像,可以用插秧期和收割前期的两个时相图像来代替上述的三个时相图像同样可以达到种植面积量算和估产的效果。这一结果充分说明多时相雷达卫星数据对我国南方水稻长势监测及估产具有明显优势和潜力。