Compositional evidence regarding the influx of interplanetary materials onto the lunar surface

Siderophilic element/Ir ratios are higher in mature lunar soils from highlands sites than in those from mare sites. We infer that the population of materials responsible for the early intense bombardment of the Moon had high ratios, and that the population responsible for the essentially constant flux has low ratios. No group of chondrites has siderophile/Ir ratios identical to those in the mare or highlands soils; CM chondrites are the most similar, and CM-like materials may account for a major fraction of Earth-crossing materials during the past 3.7 b.y.Siderophile/Ir ratios may be used to determine the amount of highlands regolith in soils or breccias from the mare-highlands interface areas (Apollo 15 and 17), and to infer the time of formation of highlands breccias whose sideropbiles originated in mature soils. Arguments are summarized against the viewpoint that the siderophiles in most highlands breccias originated in basin-forming projectiles. Differences in mature soil siderophile concentrations at Apollo 14 and 16 indicate a substantially greater concentration at the latter site immediately following the Imbrium event.Siderophile concentrations are used to estimate mean regolith depths at the landing sites; as relative values these are more precise than estimates based on seismic or crater observations. The longlived flux is calculated to be 2.9 g cm^–2 b.y.^–1 averaged over the past 3.7 b.y. A consideration of the relationship between mass fluence and time indicates that the mass flux decreased with a half-life of about 40 m.y. immediately following the Imbrium event.     

The JPL deep-well mid-infrared array camera

We describe the development of a mid-infrared camera intended for use at the Palomar 5-m telescope and at the NASA Infrared Telescope Facility. The camera is based on Rockwell's HF-16 128×128 Si:As BIB array. This array is unusual in that it has a well depth of approximately 30 million electrons; this will allow the use of traditional broadband astronomical filters (N and Q) while keeping a reasonable field-of-view. Measured array performance indicates that it has a read noise of 1100 electrons and shows non-linearities of <1% up to 65% of full well. In this paper, we discuss the array and its operating characteristics and we give a brief overview of the camera design.National Research Council research associate at JPLSummer Undergraduate Research Fellow at JPL     

Evaluating performance of post‐tensioned steel connections with strands and reduced flange plates

The seismic performance of post‐tensioned steel connections for moment‐resisting frames was examined experimentally and analytically. Cyclic tests were conducted on three full‐scale subassemblies, which had two steel beams post‐tensioned to a concrete‐filled tube (CFT) column with high‐strength strands to provide recentring response. Reduced flange plates (RFPs) welded to the column and bolted to the beam flange were used to increase the dissipation of energy. Test results indicated that (1) the proposed buckling‐restrained RFP could dissipate energy in axial tension and compression, (2) the subassemblies could reach an interstorey drift of 4% without strength degradation, and (3) buckling of the beam occurred towards an interstorey drift of 5%, causing a loss of the strand force, the recentring response, and the moment capacity. A general‐purpose non‐linear finite element analysis program (ABAQUS) was used to perform a correlation study. The behaviour of the steel beam under both post‐tensioning and flexural loadings was compared to the test results and predictions. Copyright © 2006 John Wiley & Sons, Ltd.     

Mineralogy and geochemistry of the No. 6 Coal (Pennsylvanian) in the Junger Coalfield, Ordos Basin, China

This paper discusses the mineralogy and geochemistry of the No. 6 Coal (Pennsylvanian) in the Junger Coalfield, Ordos Basin, China. The results show that the vitrinite reflectance (0.58%) is lowest and the proportions of inertinite and liptinite (37.4% and 7.1%, respectively) in the No. 6 Coal of the Junger Coalfield are highest among all of the Late Paleozoic coals in the Ordos Basin. The No. 6 Coal may be divided vertically into four sections based on their mineral compositions and elemental concentrations. A high boehmite content (mean 6.1%) was identified in the No. 6 Coal. The minerals associated with the boehmite in the coal include goyazite, rutile, zircon, and Pb-bearing minerals (galena, clausthalite, and selenio-galena). The boehmite is derived from weathered and oxidized bauxite in the weathered crust of the underlying Benxi Formation (Pennsylvanian). A high Pb-bearing mineral content of samples ZG6-2 and ZG6-3 is likely of hydrothermal origin. The No. 6 coal is enriched in Ga (44.8 μg/g), Se (8.2 μg/g), Sr (423 μg/g), Zr (234 μg/g), REEs (193.3 μg/g), Hg (0.35 μg/g), Pb (35.7 μg/g), and Th (17.8 μg/g). Gallium and Th in the No. 6 Coal mainly occur in boehmite, and the Pb-bearing selenide and sulfide minerals contribute not only to Se and Pb contents in the coal, but also probably to Hg content. A high Zr content is attributed to the presence of zircon, and Sr is related to goyazite. The REEs in the coal are supplied from the sediment-source region, and the REEs leached from the adjacent partings by groundwater.     

油田污水中Fe2+,S2-,DO及pH值对无机交联体系HPAM-Cr3+CDG成胶性能影响的研究

在对河南油田下二门矿区油田污水进行全面分析的基础上，研究了污水中Fe^2 ，S^2-，溶解氧（DO）及污水的pH值对无机交联体系聚丙烯酰胺（HPAM）－Cr^3 胶成分散凝胶（CDG）成胶性能的影响。研究结果表明，对于HPAM－Cr^3 体系，污水中Fe^2 ，DO对其成胶性能没有影响；S^2-和污水的pH值对其成胶性能有影响。pH值增大，凝胶强度增强；S^2-浓度增加，则凝胶强度减弱。     

Existence of the atmosphere attractor

The global asymptotic behavior of solutions for the equations of large scale atmospheric motion with the non-stationary external forcing is studied in the infinite dimensional Hilbert space. Based on the properties of operators of the equations, some energy inequalities and the uniqueness theorem of solutions are obtained. On the assumption that external forces are bounded, the exsitence of the global absorbing set and the atmosphere attractor is proved, and the characteristics of the decay of effect of initial field and the adjustment to the external forcing are revealed. The physical sense of the results is discussed and some ideas about climatic numerical forecast are elucidated Work supported by the State Key Research Project on Dynamics and Predictive Theory of the Climate.     

依据控制致裂钻孔应力变化确定原岩应力的平行钻孔法的研究

为了寻求一种操作简单、低成本的岩体应力测试方法, 本文提出了一个依据控制致裂钻孔应力变化的量测推算原岩应力的改进平行钻孔法。本文阐明了平行钻孔法岩体应力量测的特点和控制致裂法的原理。介绍了依据控制致裂钻孔应力变化确定岩体应力的基本理论。     

The separation velocity of emerging magnetic flux

We measure the separation velocity of opposite poles from 24 new bipoles on the Sun. We find that the measured velocities range from about 0.2 to 1 km s^–1. The fluxes of the bipoles range over more than two orders of magnitude, and the mean field strength and the sizes range over one order of magnitude. The measured separation velocity is not correlated with the flux and the mean field strength of the bipole. The separation velocity predicted by the present theory of magnetic buoyancy is between 7.4Ba ^–1/4 cot and 13 cot km s^–1, where is the elevation angle of the flux tube at the photosphere (see Figure 9), B is the mean field strength, and a is the radius of the observed bipole. The rising velocity of the top of flux tubes predicted by the theory of magnetic buoyancy is between 3.7Ba ^–1/4 and 6.5 km s^–1. The predicted separation velocity is about one order of magnitude higher than those measured, or else the flux tubes are almost vertical at the photosphere. There is no correlation between the measured separation velocity and the theoretical value, 7.4Ba ^–1/4. The predicted rising velocity is also higher than the vertical velocity near the line of inversion in emerging flux regions observed by other authors.