A concentric ellipse multiple-arch system in the solar corona     

Kuniji Saito  Lewis L. House 《Solar physics》1968,5(1):61-86

A typical concentric ellipse multiple-arch system was observed in the solar corona during the February 4, 1962 eclipse in New Guinea. The following results have been obtained from analysis of a white-light photograph taken by N. Owaki (see Owaki and Saito, 1967a).

1. The arches are composed of four equidistant components, elliptical in shape, and almost concentric with a prominence at the common center of the ellipses.
2. The prominence and arch system appears to be the lower region of a helmet-shaped streamer.
3. The widths of the arches are observed to increase with height.
4. Analysis was made in the light of three models for the coronal structures that could lead to the observed arches: (a) rod-like concentrations of electrons; (b) tunnel-shaped elliptical shells of electrons; and (c) dome-like ellipsoidal shells of electrons. Electron densities are derived for the models, and the dome-like model is excluded as a possibility for arch systems exhibiting a coronal cavity.
5. The scale height in the arch-streamer region is found to be almost the same as that of the K-corona, suggesting equal temperatures, density distributions, etc. in each region.
6. There is a dark space (a coronal cavity) between the innermost arch and the prominence. The brightness of this cavity is 1/5 that of the adjacent arch. It is 3% brighter than the background corona of the arch-streamer system.
7. A comparison is made between the deficiency of electrons in the coronal cavity and the excess of electrons in the prominence. It is found that the ratio of the excess to the deficiency lies between 0.9 and 40.
8. A comparison between the electron efflux from the ‘leaky magnetic bottle’ possibly formed by rod-shaped coronal arches and the electron influx into those arches from the chromosphere leads us to the conclusion that the rod model is probably valid and that spicules appear to be an adequate supply for the electrons observed in the arches. The tunnel model may be valid, but in that case spicules are probably not the sources of the electrons observed in coronal arches.

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Numerical integration of stellar orbits     

F. House  G. Weiss  R. Wiegandt 《Celestial Mechanics and Dynamical Astronomy》1978,18(4):311-318

Five methods for numerically integrating stellar orbits in a time-independent, steady potential are compared in efficiency and accuracy. The methods are: Fehlberg's (1972) treatment of the Runge-Kutta method, Krogh's (1971) variable-order Adam's method, an extrapolation method described by Stoer (1974) and two orders of the implicit single-sequence method of Everhart (1974). It is found that Fehlberg's 6th-order Runge-Kutta is the fastest but also the least accurate. The new method of Everhart seems a good compromise between efficiency and accuracy in this problem.  相似文献   

Initial operation of a scanning stokes polarimeter     

Lewis L. House  Thomas G. Baur  Howard K. Hull 《Solar physics》1975,45(2):495-500

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Seismological Studies of a Fluid Injection in Sedimentary Rocks, East Texas     

L.S. House  R. Flores 《Pure and Applied Geophysics》2002,159(1-3):371-401

—?Induced microseismicity data from a large volume fluid injection into sedimentary rock was analyzed to study the fracture system, fluid pathways, and state of stress in the lower Frio formation in east Texas. Seismicity data are from two arrays of 25 3-component geophone packages sited in two monitoring boreholes. From a total of 2,894 event triggers, a subset of 54 microearthquakes was chosen for their high quality seismograms and clear P and S arrivals. Arrival times were picked with a precision of 0.5 to 1.0?ms, and microearthquakes were located with hypocentral uncertainties estimated as less than 10–20?m. Hypocenters farthest from the injection well define a nearly horizontal tube of seismicity approximately aligned in the direction of the injection well. A simultaneous inversion of arrival times for transverse isotropic velocity structure and hypocenters yielded P-wave anisotropy of ?14% and S-wave anisotropy of ?2%. Thus, velocities along vertical ray paths are higher than those along horizontal paths, probably because of lithologic differences. Single-event focal mechanisms were determined for 47 events, and many of them are normal fault type. The minimum principal stress derived from the focal mechanisms is nearly horizontal and trends approximately north-south, consistent with the regional stress state. An imaging analysis of the seismograms shows the presence of strong seismic scatterers at positions that correlate with boundaries seen in the hypocenters; both features probably result from a similar set of heterogeneities. This study demonstrates the abundance of information that can be extracted from induced seismicity data and underscores the value of induced seismicity monitoring for studying the fluid and fracture systems created by fluid injections.  相似文献   

内蒙东升庙硫化物多金属矿矿区同生断层的一些证据及矿床成因   总被引：2，自引：0，他引：2  

江晓庆 《矿床地质》1994,13(1):49-60

东升庙硫化物多金属矿矿床产于华北地台北缘狼山群细碎屑岩，碳酸盐岩中。矿区内发育大量沉积－重力构造，地层厚度及岩性变化甚大，表明矿区很可能存在同生断层。据同位素分析结果，包裹体测温及成分分析资料，成矿组分的空间分布特征以及围岩的地球化学特征等，认为矿床属弱变质喷气－沉积矿床。  相似文献   

Improving Cascadia subduction zone residents’ tsunami preparedness: quasi-experimental evaluation of an evacuation brochure     

Lindell  Michael K.  Jung  Meen Chel  Prater  Carla S.  House  Donald H. 《Natural Hazards》2022,114(1):849-881

Natural Hazards - This study surveyed 227 residents in three US Pacific Coast communities that are vulnerable to a Cascadia subduction zone tsunami. In the Brochure condition, information was...  相似文献   

统一数据底板建设及应用     

王斌  黄河  吴鉴清  周巍 《国土资源信息化》2010,(1):76-80

上海市规划和国土资源数据库是运用信息化手段,按照统一规划、统一标准、统一管理、资源共享的要求,集成覆盖全市的多尺度、多数据源、多分辨率、多时态基础测绘成果,打造成横向到边、纵向到底的规划和国土资源统一数据底板,广泛应用于土地、规划、资源行业的方方面面。  相似文献   

集聚信息 构建指挥监测中心     

任琳  宗臻铃 《国土资源信息化》2010,(1):24-28,34

本文对上海市规划和国土资源行业指挥监测中心的总体情况、系统框架、运行环境、特色功能等内容进行了简要的介绍,对指挥监测中心系统建设中的涉及数据仓库建设及更新机制、车辆实时指挥调度、海量数据存储、快速浏览展示等实现方式进行了详细的介绍。  相似文献   

上海市规划和国土资源信息化运维管理     

杨健  汪一琛  马卫平 《国土资源信息化》2010,(1):43-49

上海市规划和国土资源信息化运维团队从专注技术向运维管理转变。以优质服务,面向业务、面向客户来开展IT运维工作。  相似文献   

An empirical test of helium diffusion in apatite: borehole data from the Otway basin, Australia   总被引：5，自引：0，他引：5  

Martha A House  Kenneth A Farley  Barry P Kohn 《Earth and Planetary Science Letters》1999,170(4):543-474

We have analyzed helium ages of apatites from several boreholes in the Otway basin, Australia, to evaluate whether laboratory helium diffusivity can be accurately extrapolated to conditions relevant in nature. Downhole apatite helium ages define a broad swath of values from 78–71 Ma at the surface (15°C) to nearly zero at depths corresponding to ambient temperatures of 80°C. The width of the swath results from uncertainties in corrected borehole temperatures, differences in the thermal history experienced by the various boreholes, and possibly from slightly different helium diffusivities among the detrital apatite grains studied. In the eastern Otway basin, the shape and position of the helium age profile is in good agreement with predictions based on the extrapolation of laboratory diffusivity data for Durango apatite coupled with published thermal histories for this part of the basin. In contrast, helium ages are much younger than predicted in the western Otway basin. Based on measured ages from Otway sediments, which have been essentially isothermal over the last few million years, an empirical diffusivity (D/a²) of 2×10⁻¹⁵ s⁻¹ can be assigned to apatites residing at downhole temperatures of 67–97°C. This empirical diffusivity is consistent with laboratory diffusion measurements, demonstrating that such measurements are reasonably accurate and can be applied with confidence to natural geologic settings. Given this confirmation of the laboratory diffusivity data, the discrepancy between the observed and modeled helium age profiles in the western Otway basin suggests that these sediments recently experienced higher temperatures than presently supposed.  相似文献