The redshift dependence of spectral index in powerful radio galaxies

We present and discuss in this paper the rest frame radio spectra (1–25 GHz) of a sample of fourteen radio galaxies atz >2 from the newly defined MRC/1Jy complete sample of 558 radio sources. These galaxies are among the most powerful radio sources known and range in luminosity from 1028-1028·8 watt Hz-1 at 1 GHz. We find that the median rest frame spectral index of this sample of galaxies atz >2 is significantly steeper than that of a matched luminosity sample of 3CRR galaxies which are at a much lower redshift (0.85 <z < 1.7). This indicates that spectral index correlates primarily with redshift, at least in the luminosity range considered here. The difference between the distributions of rest frame spectral curvatures for the two samples does not appear to be statistically significant. We suggest a new explanation for the steeper spectra of radio galaxies at high redshift involving steeper electron energy spectra at injection. Electron energy spectra are expected to steepen in a first-order Fermi acceleration process, at both non-relativistic and relativistic shock fronts, as the upstream fluid velocity decreases. This may well be the case at high redshifts: the hotter and denser circum-galactic medium at high redshifts could result in slower speeds for the hotspot and the jet material behind it. The smaller sizes of radio sources at higher redshifts provide support to this scenario. Since deceased.     

东太平洋海盆内多金属结核中的铁矿物

东太平洋海盆内多金属结核中的铁矿物萧绪琦郭立鹤（中国地质科学院矿床地质研究所，北京１０００３７）１前言早在五十年代人们就已注意到，大洋多金属结核含铁量较高，由于结核中矿物颗粒细小，结晶程度低，使得铁矿物的确定很困难，通常称之为铁的氧化物和氢氧化物。在...     

铁辉砷镍矿的电子探针研究

借助电子探针、扫描电镜、Ｘ射线衍射等手段，研究了中、低温热液型金铜矿床中的铁辉砷镍矿。结果表明，该矿物由Ｎｉ、Ａｓ、Ｆｅ、Ｃｏ和Ｓ等元素组成。矿物的物理性质、光学性质和晶胞参数与辉砷镍矿相似或相近。     

岩土工程勘察计算机数据共享处理技术

通过对工程地质平面图、剖面图、土工试验数据的共享处理,快速得到美观、准确的图表,而且数据文件又可供资料归档享用。     

原油中镜质体碎屑的检出及其地质意义

应用共聚焦激光扫描显微镜观察和分析了准噶尔盆地侏罗系原油，在国内首次发现这些原油中存在镜质体碎屑。这些镜质体碎屑均具有明显的棱角，其反射率值和侏罗纪煤的反射率值相近，且产出镜质体碎屑的原油均普遍检出了具有高等植物为母质输入的生物标志化合物。因此原油中镜质体碎届的检出为确认准噶尔盆地煤成油的存在提供了可靠的依据。     

钙稀土氟碳酸盐中四种B10S8新规则混层矿物的透射电镜研究

根据HRTEM研究，在四川西昌地区的钙稀土氟碳酸盐矿物衍生多晶体中发现了四种不同的B10S8型[即氟碳怖矿（B）／直氟碳钙铈矿（S）为10：8]新规则混层矿物（B10S8－I，B10S8－Ⅱ，B10S8-Ⅱ和B10S8－Ⅳ）。用SAED和HREM方法确定了四种新规则混层矿物的晶体结构对称性、晶胞参数、结构堆垛模式及晶体化学式等。四种B10S8新规则混层矿物结构中，Ce－F离子层的堆垛层序以及两个Ce－F离子层之间的碳酸根离子层的排列方式均不同。同时还观察到该类矿物中的畸结构及堆垛层错等。     

Newly Discovered Submicron-Scale Weathering in Quartz: Geographical Implications*

Quartz is regarded as one of the minerals most resistant to chemical weathering. Nevertheless, quartz does weather under certain conditions. Several geographic phenomena, including downstream sorting of fluvial sediments, the distribution of loess, and the absence of silica in tropical soils, may be directly or indirectly related to quartz weathering. Weathering may impact the use of quartz in geographic applications of geochronology and paleoenvironmental analysis. This paper defines the molecular-scale mechanisms of chemical weathering in quartz, and presents the first examination of quartz weathering in the terrestrial environment using high resolution transmission electron microscopy (HRTEM). HRTEM images illustrate crystalline disintegration, or amorphization, of exterior surfaces and internal fractures of quartz sand grains collected from tills of the Eastern Sierra Nevada, California. Of several alternative mechanisms, in situ hydration of the crystalline matrix is the most plausible for quartz amorphization. Scale and mineral structure appear to be prominent factors in quartz amorphization; microenvironment and weathering rates may also be significant, but data are insufficient to make more precise generalizations.     

1980年代中国地磁正常场图及其数学模式

本文介绍了1980.0年中国地磁正常场图的编绘和地磁正常场数学模式的建立使用不同年代观测的地磁三要素资料2000余个,经过通化改正,统统改正到1980.0这个特定年代。采用泰勒多项式和最小二乘法,分别建立1980.0年中国地磁正常场和地磁场长期变化数学模式,并计算其网格值,用于编绘1980.0年中国地磁正常场图。本文在建立地磁正常场数学模式时,采用三个独立的地磁要素建立模式的方法,解决了地磁场模式在地磁倾角为零的地方、而垂直强度不为零的问题。     

辉石相变的矿物物理特征及滑石瓷老化机理的探讨

本文采用X射线衍射物相定量分析,透射电子显微镜及X射线电子能谱分析研究了原顽辉石→斜顽辉石的相变特征,提出了滑石瓷老化的实质是当原顽辉石Pbcn相向斜顽辉石P2_1/c相转变时,由于体积缩小和钡玻璃相拉应力的减少,导致滑石瓷表面产生微裂缝,从而加剧老化的过程。     

Electron spin resonance of stabilized free radicals in sedimentary organic matter

Electron spin resonance (ESR) is evaluated as a method to study the thermal degradation of sedimentary organic matter which consists mainly of kerogen. Whole rock and separated kerogen samples were pyrolysed stepwise (ambient to 700°C at 50°C increments), extracted and analysed for elemental composition and ESR spectra at each step. Whole rock samples give rise to complex spectra which include those of paramagnetic metals and are therefore unsuitable in most cases for this purpose.The ESR parameters g value, ΔH and N_g differ for different types of immature organic matter. An increase in N_g,shift of g value to 2.0026–2.0028 and reduction in h are the main trends during pyrolysis and in natural heating of sedimentary organic matter.The peak generations of liquid and gaseous hydrocarbons coincide with maxima of free radical density. ESR spectroscopy in combination with complementary geochemical characterization of the sedimentary organic matter can serve to indicate maturity with respect to peak oil-gas generation.