月球地形测绘和月球大地测量(2)

本文主要概要介绍前苏联在探月航天器方面,探测号(Zond)和月亮号(Luna)的主要历程和在月球上的地形测绘及大地测量等地学方面的成绩。     

科尔沁沙地植被恢复过程中群落组成及多样性演变特征

流动沙丘、固定沙丘和沙质草地均是科尔沁沙地土地沙化的产物,植被恢复重建则是该区域流沙治理的主要措施,理解植被恢复过程中群落组成及植物多样性演变特征有利于沙地植被恢复和生态重建.本研究基于连续15年对科尔沁沙地流动沙丘、固定沙丘和沙质草地长期植物群落结构调查数据,分析了 3种沙地类型植物群落年际变化特征及不同生活型植物年...     

Non—integrability of Hill's lunar problem

We prove that Hill's lunar problem does not possess a second analytic integral of motion, independent of the Hamiltonian. In order to obtain this result, we avoid the usual normalization in which the angular velocity of the rotating reference frame is put equal to unit. We construct an artificial Hamiltonian that includes an arbitrary parameter b and show that this Hamiltonian does not possess an analytic integral of motion for in an open interval around zero. Then, by selecting suitable values of , b and using the invariance of the Hamiltonian under scaling in the units of length and time, we show that the Hamiltonian of Hill's problem does not possess an integral of motion, analytically continued from the integrable two–body problem in a rotating frame.     

MORICE--new technology for mechanical oil recovery in ice infested waters

Mechanical oil recovery in ice infested waters (MORICE) was initiated in 1995 to develop technology for the recovery of oil spills in ice. It has been a multinational effort involving Norwegian, Canadian, American and German organizations and researchers. Through a stepwise approach with the development organized in six separate phases, laboratory tests and field experiments have been conducted to study various ideas and concepts, and to refine the ideas that were considered to have the best potential for removing oil in ice. Put together in one unit, these concepts included ice processing equipment and two alternative oil recovery units installed on a work platform. In January 2002, the final oil and ice testing with MORICE concepts was conducted at the Ohmsett test facility in Leonardo, New Jersey. The unit has been referred to as a harbor version to indicate the size and operating conditions, but the concepts could be scaled up to increase the capacity of oil and ice processing. For heavier ice conditions it would also be necessary to increase the overall strength.     

Heavy metal pollution and lake acidity changes caused by one thousand years of copper mining at Falun, central Sweden

One thousand years of mining of sulfurous ores at the Falun copper mine, central Sweden, and the resulting atmospheric emissions of metals and sulfur dioxide, gives a unique opportunity to study long-term responses to acid deposition. Copper production peaked in the 17^th century, when Falun supplied 2/3 of the world's copper production. Thereafter production and associated emissions have declined, and the mine was closed in the 1990's. Sediment cores from 14 lakes situated between 3-27 km from the mine have been analyzed for Cu, Pb, Zn, Cd, S and ²⁰⁶Pb/²⁰⁷Pb isotope ratios to study the historical and geographical distribution of airborne pollutants. Diatoms have been analyzed to infer past lake acidity and to assess whether lake acidification has occurred and, if so, whether any recovery from acidification has occurred following the reduction in sulfur emissions. Eight of the fourteen lakes have acidified, beginning as early as the late 17^th century, when the estimated annual emissions of SO₂ amounted to 40,000 tons. This is perhaps the earliest known record of anthropogenic lake acidification. Despite the large historical deposition of sulfur, the pH has only decreased by 0.4–0.8 units, with the lowest diatom-inferred pH being 5.8. Effects of agriculture and forestry following the expanding mining industry may have counteracted acidification. Despite the 300 yrs of lowered emissions the diatom record shows no recovery in pH. There are still large amounts of sulfur accumulated in the soils in the area that may delay recovery from lake acidification. Afforestation in the area over the last 100 yrs may also play an important role in delaying the recovery process.     

贵州工业固体废物资源化探讨

分析了贵州工业固体废物的现状、主要特点和发展趋势，探讨了资源化的主要途径和具体措施。     

潞安—晋城矿区煤层气采收率分析

根据煤田地质瓦斯资料和煤层气参数井测试成果，分析了潞安－晋城（新区）矿区主煤储层的平均含气量、饱和度、临界解吸压力、理论采收率以及煤层甲烷解吸率、可解吸量等数据，得出本区主煤储层平均解吸率约为38％，高于全国其它地区。     

Targeting the impactors: siderophile element signatures of lunar impact melts from Serenitatis

Highly siderophile element compositions of lunar impact melt breccias provide a unique record of the asteroid population responsible for large cratering events in the inner Solar System. Melt breccias associated with the 3.89 Ga Serenitatis impact basin resolve at least two separate impact events. KREEP-rich melt breccias representing the Apollo 17 poikilitic suite are enriched in highly siderophile elements (3.6-15.8 ppb Ir) with CI-normalized patterns that are elevated in Re, Ru and Pd relative to Ir and Pt. The restricted range of lithophile element compositions combined with the coherent siderophile element signatures indicate formation of these breccias in a single impact event involving an EH chondrite asteroid, probably as melt sheet deposits from the Serenitatis Basin. One exceptional sample, a split from melt breccia 77035, has a distinctive lithophile element composition and a siderophile element signature more like that of ordinary chondrites, indicating a discrete impact event. The recognition of multiple impact events, and the clear signatures of specific types of meteoritic impactors in the Apollo 17 melt breccias, shows that the lunar crust was not comprehensively reworked by prior impacts from 3.9 to 4.5 Ga, an observation more consistent with a late cataclysm than a smoothly declining accretionary flux. Late accretion of enstatite chondrites during a 3.8-4.0 Ga cataclysm may have contributed to siderophile element heterogeneity on the Earth, but would not have made a significant contribution to the volatile budget of the Earth or oxidation of the terrestrial mantle. Siderophile element patterns of Apollo 17 poikilitic breccias become more fractionated with decreasing concentrations, trending away from known meteorite compositions to higher Re/Ir and Pd/Pt ratios. The compositions of these breccias may be explained by a two-stage impact melting process involving: (1) deep penetration of the Serenitatis impactor into meteorite-free lower crust, followed by (2) incorporation of upper crustal lithologies moderately contaminated by prior meteoritic infall into the melt sheet. Trends to higher Re/Ir with decreasing siderophile element concentrations may indicate an endogenous lunar crustal component, or a non-chondritic late accretionary veneer in the pre-Serenitatis upper crust.     

聚合物驱油含水率变化及增加可采储量预测

根据试验区开发数据总结注聚合物驱油含水率变化规律。找到描述聚合物驱油见效后含水变化规律的数学模型。并根据该模型推导出预测和评价注聚合物驱油效果的方法，利用该方法得到的预测结果同后期实际生产数据之间误差很小，在对达到高含水期后的大庆油田进行提高剩余油采收率试验获得到成功，并在其他地区得到大规模地推广应用。     

Diatom and chrysophyte functions and inferences of post-industrial acidification and recent recovery trends in Killarney lakes (Ontario, Canada)

The surface sediment diatom and chrysophyte assemblages from 33 Sudbury lakes were added to our published 72 lake data set to expand and refine the diatom and chrysophyte-based inference models that we had earlier developed for this region. Our calibration data set now includes 105 lakes, representing gradients for multiple environmental variables (e.g., lakewater pH, metals, and transparency). The revised models are based on the weighted averaging calibration and regression approach and include bootstrap error estimates. The pH model was the strongest (r² _boot = 0.75, RMSE _boot = 0.50). The chrysophyte-inferred pH model (r² _boot = 0.79, RMSE _boot = 0.48) that we developed was as robust as the diatom pH model. Diatom and chrysophyte inferred pH models were then applied to top (surface sediments representing current conditions) and bottom (generally from > 30 cm deep representing pre-industrial conditions) sediment diatom and chrysophyte assemblages of 19 Killarney area lakes near Sudbury. The top and bottom inferred pH results were compared to early-1970s measured pH data. These data suggest that, although many of the poorly buffered Killarney lakes had experienced acidification, marked pH recovery has occurred in many lakes within the last 25 years. Despite the stunning pH recovery, the present-day diatom and chrysophyte assemblages are significantly different from assemblages present during pre-industrial times. Our results suggest that biological recovery may require more time than chemical recovery. It is also likely that these lakes may never recover biologically because other anthropogenic stressors (e.g., climate warming and increased exposure to UV-B radiation) may now have greater influence on biological communities in Killarney/Sudbury area lakes than acidification.