Pulsar magnetic field for an infinitely conductive accretion disk

The magnetic-field distribution outside a flat, infinitely conductive unbounded disk in the field of a point magnetic dipole is determined. A relationship is established between the problem of magnetic-field determination and the problem of the flow of an ideal incompressible fluid around an infinitely thin disk.     

The SFR and IMF of the galactic disk

There is a long term dynamical heating of stellar populations with age observed in the age – velocity dispersion – relation (AVR). This effect allows a determination of the star formation history SFR(t) from local kinematical data of main sequence stars. Using a self-consistent disk model for the vertical structure of the disk, we find from the kinematics of the stars in the solar neighbourhood that the SFR shows a moderate star burst about 10 Gyr ago followed by a continuous decline to the present day value consistent with the observed number of OB stars. The gravitational potential of the gas component and of the Dark Matter Halo is included and the effect of chemical enrichment, finite lifetime of the stars and mass loss of the stellar component are taken into account. The scale heights for main sequence stars together with the SFR is then used to determine constistently the IMF from the observed local luminosity function. The main new result is that the power law break in the present day mass function (PDMF) around 1 M _⊙ is entirely due to evolutionary effects of the disk and does not appear in the IMF. This revised version was published online in August 2006 with corrections to the Cover Date.     

激变变星中的快速光变

文中综述了激变变星中快速光变的研究进展，讨论了闪变，相干振荡和准周期振荡的观测特征和可能的产生机制。     

圆盘固相萃取富集-气相色谱法测定地表水中有机氯和有机磷农药

采用环境友好的圆盘固相萃取新技术富集水体中有机氯农药和有机磷农药,分别用微池电子捕获检测器(μECD)和火焰光度检测器(FPD)气相色谱法检测,实现了水中有机氯和有机磷农药残留物的测定。结果表明,16种有机氯农药的平均回收率为64.7%~102%,精密度(RSD,n=6)为2.9%~15%;13种有机磷农药的平均回收率为65.9%~104%,精密度(RSD,n=6)为1.7%~17%。方法快速、灵敏、低污染,可用于水体中多种有机氯农药和有机磷农药的残留分析。     

Interpolation by regularized spline with tension: I. Theory and implementation

Bivariate and trivariate functions for interpolation from scattered data are derived. They are constructed by explicit minimization of a general smoothness functional, and they include a tension parameter that controls the character of the interpolation function (e.g., for bivariate case the surface can be tuned from a membrane to a thin steel plate), Tension can be applied also in a chosen direction, for modeling of phenomena with a simple type of anisotropy. The functions have regular derivatives of all orders everywhere. This makes them suitable for analysis of surface geometry and for direct application in models where derivatives are necessary. For processing of large datasets (thousands of data points), which are now common in geosciences, a segmentation algorithm with a flexible size of overlapping neighborhood is presented. Simple examples demonstrating flexibility and accuracy of the functions are presented.On leave from the Department of Physical Geography and Cartography, Comenius University, Mlynská dolina, Bratislava, Czechoslovakia.On leave from the Institute of Physics, Dúbravská cesta 9, Bratislava, Czechoslovakia.     

变参考慢度Born近似傅氏偏移

针对常规Born近似傅氏偏移方法对于剧烈横向变速介质不能精确成像的状况而提出了变参考慢度Born近似傅氏偏移，理论上解决了任意速度变化地质模型的偏移成像问题。此外，为进一步提高复杂地层的成像精度和波场延拓算子的稳定性，对散射波场的计算公式作了改进。将改进的方法运用于盐丘模型的正演和偏移试验，并与常规Born近似偏移方法相比较，可明显看出变参考慢度Born近似傅氏偏移方法在效果上要优于后者，其处理速度横向变化的能力大大增强。     

陕西气象信息数据库应用平台综合设计

硬盘一旦出现故障，对每一个使用电脑的人来说简直就是一场灾难，因为硬盘里的数据比硬盘本身的价值更大，如何将其损失降到最低限度，这是非常值得研究的。     

碟形弹簧竖向减震体系的分析与研究

对碟形弹簧竖向减震体系利用时程分析方法对其进行动力分析，并输入不同场地、不同频谱的地震波考察其减震效果，验证了碟形弹簧在合理控制其刚度的前提下可以起到有效减小竖向地震的作用。     

济宁许厂煤矿伴生分散元素铼的富集成矿探析

铼是一种分散金属,目前尚没有在煤层中富集成矿的案例。该文依据山东省济宁煤田许厂煤矿16上、17煤层光谱分析成果,结合铼元素的性质、物质来源和石炭-二叠纪太原组的聚煤环境等因素进行综合分析,论证了其富集可能性。简要阐述了铼富集成矿的意义,建议煤田地质勘查工作中加强对煤中伴生铼元素的分析和研究。     

迭代法井间地震衍射层析成像

从各向同性非均匀介质中弹性波波动方程出发，导出了在弱不均匀条件下，频率－波数域衍射场方程，给出了格林函数解析解。在电磁波地球物理层析成像数据合成的基础上，用类“体电流法（ＶＣＭ）”，将解析解线性化，得到未作Ｂｏｒｎ近似或Ｒｙｔｏｖ近似的衍射场数值解，便于计算合成数据。采用迭代法进行反演，每步迭代中，采用等比Ｎｅｕｍａｎｎ级数解；反问题用ＳＶＤ法求解，探讨了阻尼因子的取法。数值模型试验表明，这种算法是有效和成功的，成像的分辨率较高，对介质的均匀性要求有所降低，为实际应用创造了进一步条件。