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951.
漳浦复式岩体位于长乐一南澳断裂带南段,是一个大型的燕山期复式岩体。前人将该复式岩体划分为早侏罗世、晚侏罗世、早白垩世早期、早白垩世晚期、晚白垩世等5期侵入岩。其中,早侏罗世、晚侏罗世、早白垩世早期侵入岩都具有韧性变形、变质的特征,而早白垩世晚期、晚白垩世侵人岩则未发生韧性变形、变质作用。通过对变质侵入岩锆石微区(LA—... 相似文献
952.
在能量平衡方程中引入气溶胶的吸收和散射作用,并与三维行星边界层运动方程组相耦合,根据温度分布显式求解运动场,探讨三维行星边界层内温度、运动、气溶胶浓度分布特征.结果表明,城市人为热释放直接决定了城市热岛效应的强度,城市面积越大,城市热岛效应的强度也越强,城市面积固定时,城市越分散,城市热岛效应的强度越弱,这为城市建设多采取卫星城的方式提供了一定的理论支撑.气溶胶的散射作用要大于吸收作用,其对城市热岛效应的强度主要起削弱作用,当气溶胶浓度较大时,吸收作用更显著一些,此时城市热岛效应的强度会有一定的增强,但是幅度不大.当城市热岛效应的强度增强时,其所驱动的环流也会增强,造成城区中心气溶胶浓度略有下降. 相似文献
953.
954.
Numerical simulations, based on the core-nucleated accretion model, are presented for the formation of Jupiter at 5.2 AU in three primordial disks with three different assumed values of the surface density of solid particles. The grain opacities in the envelope of the protoplanet are computed using a detailed model that includes settling and coagulation of grains and that incorporates a recalculation of the grain size distribution at each point in time and space. We generally find lower opacities than the 2% of interstellar values used in previous calculations (Hubickyj, O., Bodenheimer, P., Lissauer, J.J. [2005]. Icarus 179, 415-431; Lissauer, J.J., Hubickyj, O., D’Angelo, G., Bodenheimer, P. [2009]. Icarus 199, 338-350). These lower opacities result in more rapid heat loss from and more rapid contraction of the protoplanetary envelope. For a given surface density of solids, the new calculations result in a substantial speedup in formation time as compared with those previous calculations. Formation times are calculated to be 1.0, 1.9, and 4.0 Myr, and solid core masses are found to be 16.8, 8.9, and 4.7 M⊕, for solid surface densities, σ, of 10, 6, and 4 g cm−2, respectively. For σ = 10 and σ = 6 g cm−2, respectively, these formation times are reduced by more than 50% and more than 80% compared with those in a previously published calculation with the old approximation to the opacity. 相似文献
955.
R. S. Quiroz 《Pure and Applied Geophysics》1980,118(1):416-427
Zonal mean data and amplitudes and phases of planetary zonal waves were derived from daily hemispheric maps for tropospheric and stratospheric levels, for the four winters 1975–76 to 1978–79. Important year-to-year fluctuation in zonal means and wave activity are described, most notable of which are the changes from 1975–76 to 1976–77. Comparison of the relative strengths of the stratospheric and tropospheric jet streams shows a strong negative correlation (–0.8) between monthly mean zonal stratospheric winds (at 10 mb, 65°N) and zonal tropospheric winds (at 200 mb, 32.5°N, in the jet core) and a positive correlation (+0.7) between the stratospheric 10 mb winds and the tropospheric 200 mb winds at 65°N. Parameters correlated were the departures from the climatological mean zonal winds. The structure of correlation between wave amplitudes in the same wave number (1, 2) at different altitudes and between wave numbers 1 and 2 is investigated. We find a high correlation (+0.93) between wave 1 in the stratosphere (10 mb height) and wave 2 (height) in the troposphere at 65°N; but only a weak correlation (+0.2) between wave 1 amplitudes in the stratosphere and troposphere. These results suggest the possible importance of wave-wave interactions in processes linking the stratosphere and troposphere. The wave correlations presented here are based on comparisons of monthly means of daily amplitudes; the correlation structure in individual wave developments may differ, in view of the likelihood of altitudinal lags in wave amplification. 相似文献
956.
A global solution for the Mars static and seasonal gravity, Mars orientation, Phobos and Deimos masses, and Mars ephemeris 总被引:2,自引:0,他引:2
Alex S. Konopliv Charles F. Yoder E. Myles Standish Dah-Ning Yuan William L. Sjogren 《Icarus》2006,182(1):23-50
With the collection of six years of MGS tracking data and three years of Mars Odyssey tracking data, there has been a continual improvement in the JPL Mars gravity field determination. This includes the measurement of the seasonal changes in the gravity coefficients (e.g., , , , , , ) caused by the mass exchange between the polar ice caps and atmosphere. This paper describes the latest gravity field MGS95J to degree and order 95. The improvement comes from additional tracking data and the adoption of a more complete Mars orientation model with nutation, instead of the IAU 2000 model. Free wobble of the Mars' spin axis, i.e. polar motion, has been constrained to be less than 10 mas by looking at the temporal history of and . A strong annual signature is observed in , and this is a mixture of polar motion and ice mass redistribution. The Love number solution with a subset of Odyssey tracking data is consistent with the previous liquid outer core determination from MGS tracking data [Yoder et al., 2003. Science 300, 299-303], giving a combined solution of k2=0.152±0.009 using MGS and Odyssey tracking data. The solutions for the masses of the Mars' moons show consistency between MGS, Odyssey, and Viking data sets; Phobos GM=(7.16±0.005)×10−4 km3/s2 and Deimos GM=(0.98±0.07)×10−4 km3/s2. Average MGS orbit errors, determined from differences in the overlaps of orbit solutions, have been reduced to 10-cm in the radial direction and 1.5 m along the spacecraft velocity and normal to the orbit plane. Hence, the ranging to the MGS and Odyssey spacecraft has resulted in position measurements of the Mars system center-of-mass relative to the Earth to an accuracy of one meter, greatly reducing the Mars ephemeris errors by several orders of magnitude, and providing mass estimates for Asteroids 1 Ceres, 2 Pallas, 3 Juno, 4 Vesta, and 324 Bamberga. 相似文献
957.
赤峰地区金矿床类型及地质特征 总被引:2,自引:0,他引:2
赤峰地区的金矿床依据金矿成矿物质来源、成矿作用和矿床地质特征,划分为混合岩化热液金矿床、岩浆热液金矿床、火山热液金矿床和伴生金矿床四个类型。叙述了每一类型金矿床矿体地质、矿石矿物、矿床同位素等特征。并指出混合岩化热液金矿床是赤峰地区找金矿的重要类型。 相似文献
958.
地质学的若干问题 总被引:19,自引:0,他引:19
对地质学几个领域近几十年的发展做了扼要的总结,指出了一些有突破性的进展,并提出了这些学科今后若干年可能的发展展望,论文涉及的学科包括矿物学、花岗岩、铁镁-超铁镁岩、变质岩、沉积学、多重地层分类与地质年代学、构造这以及板块构造学与大陆动力学。对于各学科并非全面的论述,而是指出其有重大意义的突破性进展,在矿物学方面强调了由于新技术的运用而大大地促进了矿物学的进展,矿物材料学和环境矿物学都是今后着重发展的方向。总结了当前对花岗岩的基本认识,指出应开展“岩浆系统”与“火山系统”的深层次研究;对于铁镁-超铁镁岩今后要加强壳幔物质的相互作用与深部过程的研究;总结了变质岩研究的三个阶段,今后要在重点地质区坚持长期深入系统的研究,特别是前寒武纪麻粒岩区和造山带。沉积学最近有较大发展,有三方面的意义;在构造地质学方面指出在大陆造山带伸展构造、韧性剪切等研究热点以及从定性到定量的研究趋势;板块构造学是地球科学有史以来最伟大的成就,90年代是大陆构造研究的大发展时期。 相似文献
959.
1∶150万山东省地下水资源评价空间数据库,是全国地下水资源评价空间数据库的重要组成部分,是在新一轮山东省地下水资源评价的基础上建立的。本文简要论述了建库的准备、图形数据采集、属性数据采集、数据的集成4个阶段的工作方法流程。该库的建立,实现了山东省地下水资源评价空间信息的集中管理、数据的网络查询、统计分析及全国范围内的信息共享。 相似文献
960.
Land-use activities are increasingly globalized and industrialized. While this contributes to a reduction of pressure on domestic ecosystems in some regions, spillover effects from these processes represent potential obstacles for global sustainable land-use. This contribution scrutinizes the complex global resource nexus of national land-use intensity, international trade of biomass goods, and resource footprints in land-use systems. Via a systematic account of the global human appropriation of net primary production (HANPP) and input–output modelling, we demonstrate that with growing income countries reduce their reliance on local renewable resources, while simultaneously consuming more biomass goods produced in other countries requiring higher energy and material inputs. The characteristic 'outsourcing' country appropriates 43% of its domestic net primary production, but net-imports a similar amount (64 gigajoules per capita and year) from other countries and requires energy (11 GJ/cap/yr) and material (~400 kg/cap/yr) inputs four to five times higher as the majority of the global population to sustain domestic land-use intensification. This growing societal disconnect from domestic ecological productivity enables a domestic conservation of ecosystems while satisfying growing demand. However, it does not imply a global decoupling of biomass consumption from resource and land requirements. 相似文献