Energy Distribution of a Gödel-Type Space–Time

We calculate the energy and momentum distributions associated with a Gödel-type space–time, using the well-known energy–momentum complexes of Landau–Lifshitz and Møller. We show that the definitions of Landau–Lifshitz and Møller do not furnish a consistent result.     

Characterization of a chalcopyrite from Brazil by Mössbauer spectroscopy and other physicochemical techniques

We studied a chalcopyrite from a Cu ore deposit in Rio Grande do Sul, Brazil, by Mössbauer spectroscopy at room temperature and 110 K. Supporting methods to check for sample purity and to characterize further sample properties were slow-scanning X-ray powder diffraction and optical and microprobe analyses of polished sections of selected grains. Chemical analyses obtained using a scanning electron microscope equipped with an energy-dispersive X-ray spectrometer showed the sample to consist of homogeneous and essentially stoichiometric chalcopyrite (CuFeS₂). Mössbauer spectra taken at both the above temperatures consist of asymmetric magnetically ordered patterns with unequal intensities of the line pairs 1–6 and 2–5, pointing to the existence of non-equivalent or multiple Fe sites. Least-squares fittings evidenced that the resonance intensity ratio of subspectrum with lower quadrupole shift (indicative of a more symmetric environment) to that with higher shift is 69:31, at room temperature, and 68:32, at 110 K. Rietveld refinement of the XRD data indicates the existence of tetragonal [a = 0.52855(1) and c = 1.0412(1) nm] and cubic [a ₀ = 0.5273(2) nm] modifications in a proportion of 74:26, in good agreement with the Mössbauer data. The saturation magnetization of the sample was 32.7 J/(T kg), confirming the oxidation state of Fe as trivalent and pointing to little to no spin canting.     

自定义坐标系的建立及其坐标变换实现

大地基准(含数学椭球体)和投影方式的组合形成多种投影坐标系。地质勘查工作者常遇到坐标转换问题和建立自定义坐标问题,尤其是当我国北京54坐标系和西安80坐标系地质数据的GIS化时。GIS软件已经成为地质勘查的基本工具,而地质数据GIS化的第一步就是建立坐标系统。本文论述了如何使用Map Info和GeosoftOasis MontajTM两种常见地质勘查GIS软件建立自定义坐标,主要是如何在该两个软件中构建自定义大地基准(datum),并且给出了如何使用两个软件进行坐标变换的步骤。     

塔北西部一间房组碳酸盐岩礁滩体同生期暴露溶蚀作用模式

在详细的钻井资料和岩心的宏观及微观特征研究的基础上,通过对塔北隆起西部奥陶系中统一间房组礁滩体沉积相特征及展布规律的分析,结合礁滩体储层同生期溶蚀作用特征研究,按照古沉积地貌单元结合岩相的方法建立了一间房组礁滩体同生期溶蚀作用模式。研究认为一间房组开阔台地相包括台内滩、滩间海和台内点礁3个亚相,沉积相平面分布稳定;一间房组的同生期暴露溶蚀作用明显,普遍反映出滩体的间歇性暴露的特征:生物钻孔和溶蚀孔洞内充填礁滩体暴露形成的古土壤泥;发育潮间带的化石碎片堆积和软体生物活动遗迹;岩心观察和成像测井可以识别出渗流-潜流带溶蚀作用旋回。按照礁滩相沉积地貌结合岩相的模式,将一间房组开阔台地的浅滩和点礁沉积划分出潮上长期暴露滩、潮间间歇暴露滩、潮下高能滩、瓶筐石障积礁、潮汐水道等地貌单元。     

非火山地热区玛旁雍热田土壤CO_2脱气研究

地热活动是地球脱气的重要形式之一,其过程常伴随大量温室气体排放。选取非火山地热区西藏玛旁雍热田作为研究对象,基于菲克扩散定律对地热田区土壤CO_2脱气量进行评估。结果表明:该区一般土壤CO_2脱气通量为0.167~0.771 kg/(m2·a),含喷气孔区域土壤CO_2脱气通量为2.054~7.877 kg/(m2·a),含喷气孔地区的土壤CO_2脱气通量是一般土壤脱气量的18.9倍;与全球火山区土壤脱气量(0.001~2.25 Mt/(m2·a))相比,其值显著偏低;但比青藏高原高寒草原生态系统土壤的CO_2排放量(187.46 g/(m2·a))大。结合区域地质背景推测地热系统中的CO_2含量主要来源于岩浆脱气和热液同长石等围岩矿物的蚀变反应。区内土壤CO_2的低脱气通量受透水性较差的碎屑岩沉积盖层约束。     

Implications of early action for JI baselines

Abstract

This article discusses possible implications of early Joint Implementation (JI) action. Some projects which would otherwise be non-additional during the first commitment period, can become additional by implementing them before 2008 through early JI. For example, several environmental investments that will be mandatory under the European Union (EU) Acquis Communautaire as of, e.g. 2008 or 2010 could be carried out earlier than that with early JI action. As such, candidate countries could partly finance the accession process through JI credits and their environmental standards would earlier be in line with the Acquis. The theoretical risk that projects would have to follow a slow track if JI parties are not eligible for the fast track is not large for JI hosts that are candidate for EU membership.     

RELATION BETWEEN δ~（18）O IN ATMOSPHERIC PRECIPITATION AND TEMPERATURE AND PRECIPITATION

ＲＥＬＡＴＩＯＮＢＥＴＷＥＥＮδ~（１８）ＯＩＮＡＴＭＯＳＰＨＥＲＩＣＰＲＥＣＩＰＩＴＡＴＩＯＮＡＮＤＴＥＭＰＥＲＡＴＵＲＥＡＮＤＰＲＥＣＩＰＩＴＡＴＩＯＮＺｈａｎｇＸｉｎｐｉｎｇ（章新平）（ＤｅｐａｒｔｍｅｎｔｏｆＧｅｏｇｒａｐｈｙ，ＨｕｎａｎＮｏ?..     

Energy Of The Universe In Bianchi-Type I Models In MØLler’S Tetrad Theory Of Gravity

In this paper, using the energy definition in MØller’s tetrad theory of gravity we calculate the total energy of the universe in Bianchi-type I cosmological models which includes both the matter and gravitational fields. The total energy is found to be zero and this result agrees with a previous works of Banerjee and Sen who investigated this problem using the general relativity version of the Einstein energy-momentum complex and Xulu who investigated same problem using the general relativity versions of the Landau and lifshitz, Papapetrou and Weinberg’s energy-momentum complexes. The result that total energy of the universe in Bianchi-type I universes is zero supports the viewpoint of Tryon.     

Effects of the number of stations and time resolution on derivation

For at least 30 years now it has been well known that the Dst index can be modelled using the solar wind as input. Since then, many attempts have been made to improve the predictability of Dst using different approaches. These attempts are useful, for instance, to understand which features of the solar wind–magnetosphere interactions are most important in producing magnetospheric activity and how the Dst index would improve the space weather forecast. The Dst index is by far the most reliable and simple indication that a magnetic storm is in progress. In this work, the effect of using more than four magnetic stations and shorter time intervals than the hourly averages used in Sugiura's procedures is evaluated. The discussion is based on the results presented by Burton in 1975 and Feldstein in 1984 considering 4 or 12 magnetic stations and time averages of 2.5 min for a magnetic disturbed period that occurred from February 7–28, 1967, including two geomagnetic storms. The analysis has shown that the global representation of a magnetic storm by the standard Dst (Sugiura) is well preserved either using 4, 6, 12 magnetic stations or using 1 h, 2.5 min 1 min averages. A brief review of the current understanding of Dst has been included to support the discussions. The analysis performed has shown that a more refined Dst index (time and number of stations>4) would be useful to investigate the intrinsic processes and the different current systems involved in the ring current development during magnetic storms; the standard Dst, as it is conceived, is quite adequate to monitor geomagnetic storms and identify their overall features; concerning the magnetic stations normally considered, the inclusion of higher magnetic latitude stations (>35) may underestimate the observed Dst.     

Unstable kinetic Alfvén wave in partially ionized plasma

The stability of kinetic Alfven waves is discussed for a partially ionized plasma with a flux of ionizing electrons which balance the plasma particle losses. Accidental electromagnetic perturbations are shown to be unstable due to the energy change of ionizing electrons.