地球物质科学研究的新进展--第13届V.M.Goldschmidt国际地球化学会议一瞥

第13届V.M.Goldschmidt国际地球化学会议(简称Goldschmidt 2003)于2003年9月7～12日在日本仓敷(Kurashiki)召开.会议内容反映了当前地球物质科学研究的前沿,从地球的圈层到行星宇宙、从生命的起源到岩浆和变质作用地球化学、从宏观到纳米物质举凡地球科学的重大课题均有涉及;从会议的内容看出:①学科间的融合是地球物质科学研究的主流方向;②对行星和陨石等天体物质的研究是当前地球物质科学研究的一大亮点;③矿物的晶内扩散是了解变质过程中物质迁移规律的新手段;④生命的起源和早期地球演化仍是当前地球科学讨论的热门课题;⑤非传统稳定同位素已得到了广泛的应用.从学科发展的历史角度看,地球物质科学的新生长点存在于学科本身,学科间的融合交叉是学科得以发展的原动力.     

A benthic mucilage event in North-Western Mediterranean Sea and its possible relationships with the summer 2003 European heatwave: short term effects on littoral rocky assemblages

In this contribution we document an anomalous mucilage growth which occurred in June 2003 along the rocky cliffs of the Portofino Promontory (Ligurian Sea, NW Mediterranean Sea), and we describe its dynamics and its negative effects on many benthic taxa. The zooxanthellate scleractinian Cladocora caespitosa underwent ‘bleaching’ and about 40% of biomass of the erect algae was detached by mucilage ‘lianas’ created and strengthened by bottom currents. The 2003 event differed from any other previously occurred in the northern Tyrrhenian Sea, in that the mucilage aggregates were formed by the free‐living form of the Phaeophyceae Acinetospora crinita (Harvey) Kornmann, a not usually dominant species in mucilage aggregates from the north Tyrrhenian Sea. The damage suffered by the benthic organisms living in this area was curtailed by a severe storm, occurred in July, which removed the mucilage to deeper depths, preventing irreversible damages. Only slow growing, perennant organisms, such as corallinales or scleractinians, were seriously affected, but a survey carried out 1 year later, in June 2004, allowed to appreciate a complete recovery of those organisms. This anomalous mucilage event occurred in coincidence of the 2003 European heatwave, and the anomalous temperature increase of seawater has to be regarded as the major contributing event that led to the mucilage outbreak.     

Excel 2003在高斯投影坐标换算中的应用

对Excel 2003函数功能进行充分的应用,使其成为批量坐标换算的一个真实有效的工具.针对坐标换算处理的整个过程,给出坐标换算的新方法.重点论述运用Excel 2003函数功能实现高斯投影坐标变换,可正算、反算、换带、求面积.同时结合实例体现Excel 2003处理数据的特点,给出一个批量坐标换算的高效率、便捷和直观的方法.     

Influence of ferric iron on the stability of mineral assemblages

Ferric iron is present in all metamorphic rocks and has the ability to significantly affect their phase relations. However, the influence of ferric iron has commonly been ignored, or at least not been considered quantitatively, mainly because its abundance in rocks and minerals is not determined by routine analytical techniques. Mineral equilibria calculations that explicitly account for ferric iron can be used to examine its effect on the phase relations in rocks and, in principle, allow the estimation of the oxidation state of rocks. This is illustrated with calculated pseudosections in NCKFMASHTO for mafic and pelitic rock compositions. In addition, it is shown that ferric iron has the capacity to significantly increase the stability of the corundum + quartz assemblage, making it possible for this assemblage to exist at crustal P–T conditions in oxidized rocks of appropriate composition.     

Lessons from the 2003 Tokachi-oki, Japan, earthquake for prediction of long-period strong ground motions and sloshing damage to oil storage tanks

The 2003 Tokachi-oki earthquake (M _w 8.0) in northern Japan generated large-amplitude long-period (4–8 s) ground motions in the Yufutsu sedimentary basin, causing severe damage to seven large oil storage tanks with floating roof structures because of severe sloshing of oil. The 30,000–40,000-m³ tanks having suffered the severe damage such as fires and sinking of floating roofs experienced the sloshing with large amplitudes exceeding 3 m in which the fundamental mode was predominant. The second mode of sloshing was also excited in the 110,000-m³ tanks in which their floating roofs sank into oil, indicating that the higher modes of sloshing as well as the fundamental mode should be considered in damage prediction. The strong ground motion recordings demonstrated the earthquake dependency of predominant periods and the substantial spatial variation of the long-period shaking observed within the Yufutsu basin, meaning the necessity of source- and site-specific prediction of long-period strong ground motions. The two-dimensional numerical modeling suggested the importance of detailed structures of soft near-surface sediments as well as deep basin structure for accurate prediction of long-period strong ground motions in deep sedimentary basins.     

SN 2005cs in M51 – I. The first month of evolution of a subluminous SN II plateau

Early-time optical observations of supernova (SN) 2005cs in the Whirlpool Galaxy (M51) are reported. Photometric data suggest that SN 2005cs is a moderately underluminous Type II plateau SN (SN IIP). The SN was unusually blue at early epochs (   U − B ≈−0.9  about three days after explosion) which indicates very high continuum temperatures. The spectra show relatively narrow P Cygni features, suggesting ejecta velocities lower than observed in more typical SNe IIP. The earliest spectra show weak absorption features in the blue wing of the He  i 5876-Å absorption component and, less clearly, of Hβ and Hα. Based on spectral modelling, two different interpretations can be proposed: these features may either be due to high-velocity H and He  i components, or (more likely) be produced by different ions (N  ii , Si  ii ). Analogies with the low-luminosity, ⁵⁶Ni-poor, low-velocity SNe IIP are also discussed. While a more extended spectral coverage is necessary in order to determine accurately the properties of the progenitor star, published estimates of the progenitor mass seem not to be consistent with stellar evolution models.     

突出重点改进方法扎实做好新形势下国土资源工作

在全面推进国土资源各项工作的同时，从当前实际出发，提出了重点要在资源集约利用上下功夫、见成效；要在创新土地制度、为农民建立保障机制上下功夫、见成效；要在抓好队伍思想作风建设的同时，努力在增强自身实力上下功夫、见成效；要在以信息化提升整个基础业务建设水平上下功夫、见成效。强调了做好新形势下国土资源工作的4个“一定要”，即：一定要始终服从大局，服务中心；一定要不断解放思想，改革创新；一定要实行上下联动，共同发展；一定要注意调查研究，以点带面；一定要坚持物质文明、政治文明、精神文明协调发展。     

地面雷达的位移监测试验研究

地面雷达是一种基于微波干涉测量的变形监测设备,具有高精度、高分辨率的监测优势,本文讨论了地面雷达的技术原理和数据处理流程,介绍了微变形监测系统,并进行了位移监测的对比试验,将微变形监测系统与TCA 2003、千分表的位移监测数据进行对比.试验数据分析结果证明:地面雷达具有高精度的位移监测能力.     

SN 2005cs in M51 – II. Complete evolution in the optical and the near-infrared

We present the results of the one-year long observational campaign of the type II plateau SN 2005cs, which exploded in the nearby spiral galaxy M51 (the Whirlpool galaxy). This extensive data set makes SN 2005cs the best observed low-luminosity, ⁵⁶Ni-poor type II plateau event so far and one of the best core-collapse supernovae ever. The optical and near-infrared spectra show narrow P-Cygni lines characteristic of this SN family, which are indicative of a very low expansion velocity (about  1000 km s⁻¹  ) of the ejected material. The optical light curves cover both the plateau phase and the late-time radioactive tail, until about 380 d after core-collapse. Numerous unfiltered observations obtained by amateur astronomers give us the rare opportunity to monitor the fast rise to maximum light, lasting about 2 d. In addition to optical observations, we also present near-infrared light curves that (together with already published ultraviolet observations) allow us to construct for the first time a reliable bolometric light curve for an object of this class. Finally, comparing the observed data with those derived from a semi-analytic model, we infer for SN 2005cs a ⁵⁶Ni mass of about  3 × 10⁻³ M_⊙  , a total ejected mass of  8–13 M_⊙  and an explosion energy of about  3 × 10⁵⁰ erg  .