The numerical method of Fourier eigen transform and its application in seismicity analysis

ＴｈｅｎｕｍｅｒｉｃａｌｍｅｔｈｏｄｏｆＦｏｕｒｉｅｒｅｉｇｅｎｔｒａｎｓｆｏｒｍａｎｄｉｔｓａｐｐｌｉｃａｔｉｏｎｉｎｓｅｉｓｍｉｃｉｔｙａｎａｌｙｓｉｓＢＩＮＧＣＨＥＮ１）（陈兵）ＺＨＩ－ＺＨＥＮＺＨＥＮＧ２）（郑治真）ＺＡＩ－ＳＥＮＪＩＡＮＧ...     

利用共线方程对空间实验室影象进行数字几何纠正

本文论述了利用共线方程对空间实验室影象实施数字几何纠正的理论依据、数据准备、外方位元素解求过程中参量的确定及锚点纠正法的可行性和纠正精度,提出了纠正过程中几个必须注意的环节,以提高精度,缩短机时。同时还介绍了自编软件包的组成。     

点源三维地形视电阻率的计算

利用格林公式及点源场的边界条件,将地下半空间位函数的体积积分变为地面位函教的积分方程以后,用边界元方法解此积分方程便可得到地面各节点的电位值。其计算精度和速度取决于剖分方式和节点密度。本文采用变网格的剖分方式,用较少的点实现了计算,并兼顾了精度和速度。     

吉林中部环形构造及其控矿作用

吉林中部环形构造是中生代形成与演化的热点构造。这个环形构造主要由外环带的环形断陷火山含煤盆地,中心区的断焰火山含煤盆地和火山机构,以及呈现环带状分布的花岗岩成因系列等部分组成,其形态呈现圆形,直径270km。 吉林中部环形构造控制外生煤、油气矿床、内生多金属和金矿床的形成和分布规律,从而为这些矿产资源的预测提供了可靠的地质依据,并获得实际效果。     

GPS用于海上定位的模拟试验

文中给出了在海洋测量中用全球定位系统(GPS)伪距以及伪距和载波相位相结合进行定位的数学模型,并用这些模型分析了TL-4100接收机在地面点上70分钟的单点实测资料。分析指出,考虑高程先验信息时,消除了目前P-码三维单点定位特有的零定位现象,并使定位的平面精度优于±5米。P-码伪距和载波相位相结合的单点定位,可以达到优于±0.5米的重复精度。     

三组透镜组成的望远镜物镜系统

本文讨论了望远镜采用正或负透镜调焦的准距条件公式,得出它们可以用同一公式表达,并得出伪准距点与主物镜前焦点是焦距为(2e-L),且位于主物镜处的虚拟透镜的共轭点。由此说明了两组透镜组成的望远镜物镜系统后组到分划板的距离一般不够安放补偿器。 文中指出了三组透镜组成的望远镜物镜系统可以解决上述困难,并给出了全部参数的解算方法、程序和算例。这有助于我国目前自动安平水准仪的更新换代。     

岩浆岩的熔点、粘度及其与化学成分的关系

本文研究了我国中、新生代一些岩浆岩的化学成分、熔点、人工玻璃的折射率和比重以及它们在不同温度下的粘度。在常压下岩石酸度愈大,熔点愈高。熔点与岩石的Fe~(2+(+Fe~(3+)+Mn+Mg±Ca为反相关;与Si+Al+K+Na为正相关。计算粘度与温度的关系表明,酸度愈大,粘度愈大;碱度愈大,粘度愈小,温度愈高,粘度愈低;同一温差下,酸度愈大,粘度变化愈大。     

A three-dimensional model of the global ammonia cycle

Using a three-dimensional (3-D) transport model of the troposphere, we calculated the global distributions of ammonia (NH₃) and ammonium (NH ₄ ⁺ ), taking into account removal of NH₃ on acidic aerosols, in liquid water clouds and by reaction with OH. Our estimated global 10°×10° NH₃ emission inventory of 45 Tg N-NH₃ yr^– provides a reasonable agreement between calculated wet NH ₄ ⁺ deposition and measurements and of measured and modeled NH ₄ ⁺ in aerosols, although in Africa and Asia especially discrepancies exist.NH₃ emissions from natural continental ecosystems were calculated applying a canopy compensation point and oceanic NH₃ emissions were related to those of DMS (dimethylsulfide). In many regions of the earth, the pH found in rain and cloud water can be attributed to acidity derived from NO, SO₂ and DMS emissions and alkalinity from NH₃. In the remote lower troposphere, sulfate aerosols are calculated to be almost neutralized to ammonium sulfate (NH₄)₂SO₄, whereas in the middle and upper troposphere, according to our calculations, the aerosol should be more acidic, as a result of the oxidation of DMS and SO₂ throughout the troposphere and removal of NH₃ on acidic aerosols at lower heights. Although the removal of NH₃ by reaction with the OH radical is relatively slow, the intermediate NH₂ radical can provide a substantial annual N₂O source of 0.9 _–0.4 ^+0.9 Tg, thus contributing byca. 5% to estimated global N₂O production. The oxidation by OH of NH₃ from anthropogenic sources accounts for 10% of the estimated total anthropogenic sources of N₂O. This source was not accounted for in previous studies, and is mainly located in the tropics, which have high NH₃ and OH concentrations. Biomass burning plumes, containing high NO _x and NH₃ concentrations provide favourable conditions for gas phase N₂O production. This source is probably underestimated in this model study, due to the coarse resolution of the 3-D model, and the rather low biomass burning NH₃ and NO _x emissions adopted. The estimate depends heavily on poorly known concentrations of NH₃ (and NO _x ) in the tropics, and uncertainties in the rate constants of the reactions NH₂ + NO₂ N₂O + H₂O (R4), and NH₂ + O₃ NH₂O + O₂ (R7).     

Capacity evaluation of statnamic tested long piles

A procedure that uses the structural damping (SD) concept for estimating the capacity of a pile based on the Statnamic (STN) pile load test results, formerly used by the authors for short piles, is extended in this paper for the STN tested long piles. Similar to segmental unloading point method procedures for long piles, the shaft length is divided into several segments and each segment is assumed to behave as a mass of a single degree of freedom. The SD concept is then applied to each segment to consider the displacement related soil damping instead of the velocity dependent damping. Instrumented strain gauge data at different levels of the shaft are required for the interpretation method. Three case studies are presented in this paper to study the validity and applicability of the present method. The predicted results are also compared to the available test or analytical data.