Dynamic Molecular Metamorphism Involving Palladium-Assisted Dimerization of π-Cation Radicals

A dynamic supramolecular approach is developed to promote the π-dimerization of viologen radicals at room temperature and in standard concentration ranges. The approach involves cis- or trans-protected palladium centers serving as inorganic hinges linking two functionalized viologens endowed with metal-ion coordinating properties. Based on detailed spectroscopic, electrochemical and computational data, we show that the one-electron electrochemical reduction of the viologen units in different dynamic metal/ligand mixtures leads to the formation of the same intramolecular π-dimer, regardless of the initial environment around the metallic precursor and of the relative ratio between metal and ligand initially introduced in solution. The large-scale electron-triggered reorganization of the building blocks introduced in solution thus involves drastic changes in the stoichiometry and stereochemistry of the palladium/viologen complexes proceeding in some cases through a palladium centered trans→cis isomerization of the coordinated ligands.     

The Transformation of Clay Minerals in Triassic Mudstone of North Shaanxi Province During Burial Metamorphism

According to the analysis of X-ray diffraction and the investigation under electron microscope (SEM, TEM) of clay minerals, the transformation of clay minerals in Triassic mudstone during burial metamorphism has been studied in detail. Berthierine, the mixed layer of illite and chlorite, and the changeable texture from berthierine to chlorite have been first discovered in the paper; and then it is considered that the transformation of clay minerals during burial metamorphism is shown in the following reaction: Smectite+ Kaolinite + K~+ = lllite + Chlorite + Quartz. The metamorphic temperature of the above reaction is about 160—220℃, according to the calculation of oxygen isotope geothermometry of illite and quartz. The study of crystallinity and polytype of illite and chlorite shows that the different indexes have varied in regular way, and have certain functional relationship between them.     

Study of oxidative desulphurization process of coal with different metamorphism degrees

The oxidative desulphurization process of coal with different metamorphism degrees treated by an air-steam mixture has been studied.It has been shown that the pyrite present in black coal and anthracite is oxidized with the sulphur dioxide formation,and the process chemical mechanism does not depend on the quality of organic matter.The medium-metamorphized coal,capable of turning into a plastic state and cake in the range of investigated temperatures(350～450 ℃),is desulphurized with the greatest difficulty.The chemical mechanism dealing with the transformations of pyritic sulphur present in brown coal differs from similar processes taking place in black coal and anthracite,because FeS2 is converted with hydrogen sulphide formation at desulphurization.     

变质性商品一次性订购的PEOQ模型

提出一类变质性商品有价格折扣的利润性经济订购批量（ＰＥＯＱ）模型，所给出的算法便于在商业管理上的应用．     

榴辉岩形成过程中石榴石生长的实验研究

 在2.0～3.0 GPa、860～980 ℃、加温时间0.57～13.07 h的条件下,研究了粗面玄武岩、安山岩—榴辉岩相变过程中的石榴石生长。这一过程中的石榴生长为正常晶体生长。石榴石粒径随时间而增大,其生长速率随粒径增大而减小。粗面玄武岩—榴辉岩相变过程中的石榴石生长速率大于安山岩—榴辉岩相变过程中的石榴石生长速率,实验样品的初始化学成分及挥发份含量的不同造成了这一差别。在变质作用初期,界面是控制晶体生长的主要因素。     

The Discovery and Geological Feature of Kyanite-Topazite in High-Pressure Belt From Central China

For the first time, we find kyanite-topazite which is similar to the white schist from abroad, in Jiangsu, Anhui, Henan of China. Because of intercontinental obduction and collision, the kyanite-topazite is formed from the superhigh-pressure metamorphism of sedimentary rock in continental crust, at the depth of mantle. Kyanite-topazite runs parallel to blue schist, eclogite and constitutes the high-pressure metamorphic belt in Central China. Its original rocks are a set of sedimentary rock series which is mainly composed of marginal shallow marine facies to continental facies pelitic to magnesium carbonatite, both rocks exist in Precambrian Middle-Upper Proterozoic metamorphic strata.     

Shock metamorphism on the surface of the Moon

The material characteristics of lunar materials are discussed as indicators of shock metamorphism. As lunar materials are subjected to both impact shock modification due to energetic particles formed at locations of collisionless plasma shocks in cosmic space, it is necessary to identify specific features of each process. All types of lunar glasses formed by various impacts under high pressure ( 90 GPa) are found as impact glass, ropy glass, agglutinates and brecciated rocks. The agglutinates and iron particles are identified from X-ray diffraction measurements. Fine-grained lunar materials, including the agglutinates and breccias bonded by crystals and glasses due to impact shocks, contain hydrogen and helium from the energetic particles of collisionless shocks. Lunar shocked minerals of plagioclase and silica show anomalous compositions and densities. The shock metamorphism shows evidence for two major impact processes on evolved and primordial lunar surfaces: (1) shocked silica phases with minor Al contents formed from plagioclase-rich primordial crusts of the Moon, and (2) shocked quartz formed by silica-rich target rocks, especially on evolved parts of the Moon. Silica subjected to both impact and energetic particle modification can grow to coarse-grained normal crystals by long existence in vapor plume under high-temperature or after gradual high-temperature evolution, with the result that original effects of the impact process cannot be distinguished.This article was processed using Springer-Verlag T_EX Shock Waves macro package 1.0 and the AMS fonts, developed by the American Mathematical Society.