扬子地台钾镁煌斑岩 Nd、Sr、Pb 同位素特征

扬子地台周缘钾镁煌斑岩 Nd、Sr同位素特征介于南非Ⅰ、Ⅱ型金伯利岩和西澳与北美钾镁煌斑岩两种变化趋势之间，不同岩区间同位素组成差异反映地台周边构造性质不同，Pb同位素特征表明晚太古代地幔岩石圈具U亏损特征。     

The construction of self-consistent models for outflowing stellar envelopes

The article presents self-consistent computations of the spherically symmetric envelope of a massive (M=20M _⊙) star whose envelope is flowing outward under the action of continuum radiation pressure. A system of equations describing the out flow for arbitrary optical depth, degree of ionization, and opacity κ are obtained. A numerical solution is obtained for the case of constant κ and degree of ionization via approaching integrations from the singularities and smooth joining in the intermediate region. Asymptotic solutions are found in the vicinity of the sonic point and the singularity at infinity.     

Morphotectonics of the Mongolia-Siberian mountain belt

The mountains of north-eastern Inner Asia comprise the Mongolia-Siberian orogenic belt which has a complex structure. The southern flank of the belt consists of a chain of large domal uplifts. The Baikal rift zone is located on the northern flank. The central segment is composed of zones of linear warping. The tectonic landforms rest on a large domal basement uplift. The morphology of the latter is paragenetically connected with the shape of the asthenolith underlying the belt. The neotectonic zones are also connected with the deep structure elements.The Mongolia-Siberian mountain belt is a group of orogenic forms typical of intracontinental mountain areas.     

Sr isotope evolution during chemical weathering of granites —Impact of relative weathering rates of minerals

The Sr isotopic systematics in the weathering profiles of biotite granite and granite porphyry in southern Jiangxi Province were investigated. The results showed that during the chemical weathering of granites, remarked fractionation occurred between Rb and Sr. During the early stages of chemical weathering of granites, the released Sr/Si and Sr/Ca ratios are larger than those of the parent rocks, and the leaching rate of Sr is higher than those of Si, Ca, K, Rb, etc. Dynamic variations in relative weathering rates of the main Sr-contributing minerals led to fluctuation with time in⁸⁷Sr/⁸⁶Sr ratios of inherent and released Sr in the weathering crust of granite. Successive weathering of biotite, plagioclase and K-feldspar made⁸⁷Sr/⁸⁶Sr ratios in the weathering residues show such a fluctuation trend as to decrease first, increase, and then decrease again till they maintain stable. This work further indicates that when Sr isotopes are used to trace biogeochemical processes on both the catchment and global scales, one must seriously take account of the preferential release of Sr from dissolving solid phase and the fluctuation of⁸⁷Sr/⁸⁶Sr ratios caused by the variations of relative weathering rates of Sr-contributing minerals.     

Physiologie des Phenolabbaus bei Rhodococcus spec. P1. Teil 2: Untersuchungen zur Regulation des Phenolabbaus

The phenol-degrading system which can be induced in Rhodococcus spec. P 1 brings about the metabolization of phenol via the β-ketoadipate path (ortho-cleavage of catechol). For the more precise characterization of the degradation performance investigations were made into the influences of different carbon sources: glucose, galactose, ribose, arabinose, xylose, acetate, citricacid, mandelic acid, protocatechoic acid, glycerol, tryptophane, phenylalanine and the complex substrate of nutrient broth as well as succinate, catechol and benzoate. Only the three last-named substances show an influence: succinate inhibits only the synthesis of phenol hydroxylase, catechol and benzoate inhibit the synthesis and activity of phenol hydroxylase. As a comparison of the results with literature shows, even at the same path of degradation there are different regulating mechanismus in the different microorganisms.     

Profile measurements in the atmospheric near-surface layer and the use of suitable universal functions for the determination of the turbulent energy exchange

The authors summarize their recent published studies on profile measurements including new universal functions and an error analysis with a particular view to parameterisation above soil and water. Verification of the theoretical results is given using new data of the MESP-81 Tsimlyansk experiment.     

电热石墨炉原子吸收法测定贵金属(四)岩石矿物中超痕量钯的测定

本文提出了用0.5mlN-正辛基苯胺-间二甲苯萃取测定岩石矿物中超痕量钯的电热石墨炉原子吸收分析方法。对萃取剂的性能、萃取钯的条件,其它离子的干扰情况以及在HGA-500型石墨炉中测定钯的最佳条件进行了研究。样品用盐酸、过氧化氢分解后,溶液进行萃取,直接测定有机相。大量的其它离子不干扰测定,为钯的定量测试提供了简便、高灵敏的方法。灵敏度为5.5pg,可检测0.0001g/t的钯。对含钯量为0.002g/t的矿物重复溶样测定11次,其标准偏差为4.9％。     

Asthenospheric parameters of dipping plate regions by magnetotelluric investigations

The multifrequency resolving capability of the electromagnetic surface impedance parameter, employed in magnetotelluric investigations, has been examined for an upper mantle model incorporating (1) a deep-seated lithosphere-asthenosphere boundary and (2) preferred orientations of olivine crystals in the lithosphere, usually associated with the subducting plate boundary zones. Numerical results display the quantitative errors in the resolution of various anisotropic and dipping plate conditions. It is found that (1) conductivity anisotropy, particularly with higher dips, causes a significant dispersion in the impedance values and higher resolving power, and (2) variations in the geometrical/physical parameters are reflected predominantly in the phase component of the surface impedance. The study has relevance to the understanding of the electrical nature of materials, its relationship with physical properties and associated geothermal and seismic activities in the dipping plate regions.