简单体系水溶液包裹体pH和Eh的计算

流体包裹体pH和Eh参数的计算一直处于探索阶段。已经发表的计算公式,由于缺少高压(＞1bar)环境下化学组分反应平衡常数,常常利用常压(1大气压)下化学组分反应平衡常数代替而推导出的,对于大多数自然界捕获的包裹体,不可避免地产生较大计算误差。根据水溶液包裹体中离子反应热力学特征,结合前人推导的计算公式,我们分别建立简单体系水溶液包裹体pH和Eh计算公式。由于利用较高压(＞1bar)化学反应平衡常数,基本上解决不同条件下、特别在较高温度、压力下捕获的水溶液包裹体pH和Eh的计算难题。4种简单体系水溶液包裹体pH计算公式:① H₂O包裹体:pH=pK_w② CO₂-H₂O包裹体: ³－(m_CO2K_a,1+K_W)· －2mCO₂K_a,1K_a,2=0③ NaCl-H₂O包裹体: ²= ④ CO₂-H₂O-NaCl包裹体: ³+ ²－(m_CO2·K_a,1+K_w)· －2mCO₂·K_a,1·K_a,2－ =0计算数值精度分析表明:CO₂-H₂O和NaCl-H₂O包裹体的pH值按照公式计算,相同或接近于实际测定的天然酸雨、海水pH数值范围。CO₂-H₂O-NaCl包裹体与Crerar(1978)公式计算误差不超过10%。4种简单体系水溶液包裹体Eh的计算,引用Ryzhenko and Bryzgalin (1984)年推导的Eh公式。文中列举了3个实例,详细叙述不同类型包裹体捕获温度、压力下pH和Eh计算过程。自然界中水溶液包裹体成分十分复杂,本文涉及的只是自然界几种简单体系水溶液包裹体,给出的pH和Eh公式只对特定组分组合反应平衡条件有效,它不适合另外一种组分组合平衡条件下的关系,因此使用时务必注意平衡的组分组合条件。     

Petrological consequences of variations in metamorphic reaction affinity

The extent to which kinetic barriers to nucleation and growth delay the onset of prograde metamorphic reaction, commonly known as overstepping, is related to the macroscopic driving force for reaction, termed reaction affinity. Reaction affinity is defined in the context of overstepping as the Gibbs free‐energy difference between the thermodynamically stable, but not‐yet‐crystallized, products and the metastable reactants. Mineral reactions which release large quantities of H₂O, such as chlorite‐consuming reactions, have a higher entropy/volume change, and therefore a higher reaction affinity per unit of temperature/pressure overstep, than those which release little or no H₂O. The former are expected to be overstepped in temperature or pressure less than the latter. Different methods of calculating reaction affinity are discussed. Reaction affinity ‘maps’ are calculated that graphically portray variations in reaction affinity on equilibrium phase diagrams, allowing predictions to be made about expected degrees of overstepping. Petrological consequences of variations in reaction affinity include: (i) metamorphic reaction intervals may be discrete rather than continuous, especially in broad multivariant domains across which reaction affinity builds slowly; (ii) reaction intervals may not correspond in a simple way to reaction boundaries and domains in an equilibrium phase diagram, and may involve metastable reactions; (iii) overstepping can lead to a ‘cascade effect’, in which several stable and metastable reactions involving the same reactant phases proceed simultaneously; (iv) fluid generation, and possibly fluid presence in general, may be episodic rather than continuous, corresponding to discrete intervals of reaction; (v) overstepping related to slowly building reaction affinity in multivariant reaction intervals may account for the commonly abrupt development in the field of certain index mineral isograds; and (vi) P–T estimation based on combined use of phase diagram sections and mineral modes/compositions on the one hand, and classical thermobarometry methods on the other, may not agree even if the same thermodynamic data are used. Natural examples of the above, both contact and regional, are provided. The success of the metamorphic facies principle suggests that these kinetic effects are second‐order features that operate within a broadly equilibrium approach to metamorphism. However, it may be that the close approach to equilibrium occurs primarily at the boundaries between the metamorphic facies, corresponding to discrete intervals of high entropy, dehydration reaction involving consumption of hydrous phases like chlorite (greenschist–amphibolite facies boundary) and mica (amphibolite–granulite facies boundary), and less so within the facies themselves. The results of this study suggest that it is important to consider the possibility of reactions removed from equilibrium when inferring the P–T–t evolution of metamorphic rocks.     

Estimating Synaphobranchus kaupii densities: Contribution of fish behaviour to differences between bait experiments and visual strip transects

Kaup's arrowtooth eel Synaphobranchus kaupii is a small-bodied fish and an abundant inhabitant of the European continental slope. To estimate its local density video information using the remotely operated vehicle (ROV) Victor 6000 were collected at three locations in the Bay of Biscay slope. Two methods for estimating local densities were tested: strip transect counts and bait experiments. For bait experiments three behaviour types were observed in about equal proportions for individuals arriving near the seafloor: moving up the current towards the ROV, moving across the current and drifting with the current. Visible attraction towards the bait was the highest for individuals swimming against the current (80%) and about equally low for the other two types (around 30%); it did not depend on current speed nor temperature. Three main innovations were introduced for estimating population densities from bait experiments: (i) inclusion of an additional behaviour category—that of passively drifting individuals, (ii) inclusion of reaction behaviour for actively swimming individuals and (iii) a hierarchical Bayesian estimation framework. The results indicated that about half of individuals were foraging actively of which less than one third reacted on encountering the bait plume and the other half were drifting with the current. Taking account of drifting individuals and the reaction probability made density estimates from bait experiments and strip transects more similar.     

Neutron-induced nucleosynthesis

Neutron-induced nucleosynthesis plays an important role in astrophysical scenarios like in primordial nucleosynthesis in the early universe, in the s-process occurring in Red Giants, and in the -rich freeze-out and r-process taking place in supernovae of type II. A review of the three important aspects of neutron-induced nucleosynthesis is given: astrophysical background, experimental methods and theoretical models for determining reaction cross sections and reaction rates at thermonuclear energies. Three specific examples of neutron capture at thermal and thermonuclear energies are discussed in some detail.     

不变量方法

不变量方法是一种数字技术，该方法对给定长度有限的时间序列，可以构造出一个常微分方程组。该方程组的解在有限时段上的采样值与给定序列重合。观测研究是对无法确定其方程的动力系统进行的研究；不变量方法提出了动力数值试验的可能性。     

大气中的水汽对太阳紫外辐射消光的可能机制分析

本文给出了北京地区晴天和实际天气条件下到达地面太阳紫外总辐射的一种计算方法，分析了影响到达地面太阳紫外总辐射的各主要因子的主次贡献，重点讨论了水汽在参与大气中的光化学反应过程中，对到达地面的太阳紫外总辐射消光的可能机制。     

变质流体对变质反应平衡温度的控制作用研究──以内蒙古东南部孔兹岩系为例

根据内蒙古东南部早前寒武纪孔兹岩系研究，指出变质流体在变质作用过程中对脱水变质反应的平衡温度具有明显的控制作用，并以热力学理论对这种控制作用的机制和程度加以解释和计算，据此阐明变质流体在划分变质相等方面的重要意义。     

极化曲线反应极限电流强度确定矿体表面积的实验研究

本文简单了极化曲线反应极限电流强度确定矿体表面积的基本原理，阐述了单矿体和多矿物极化曲线反应极限电流强度确定矿体表面积的实验研究方法和结果，并说明极化曲线反应极限电流强度确定矿体表面积是有可能的。     

海泡石对碱金属离子的吸附性能研究

本文对湖南浏阳、北京延庆地区热液型海泡石的物化性能、活化处理工艺条件及其对Na^ ,K^ ,Ca^2 离子的吸附作用进行了研究。实验表明，酸处理的方法可以有效地提高海泡石对Na^ ,K^ ,Ca^2 离子的吸附能力，并且通过正交实验得到最佳酸化工艺条件为：酸化时间为2h，酸的浓度为5％，液固比为35：1，经酸处理的海泡石可以有效地降低饱和Ca(OH)2溶液中Na^ 含量，这为海泡石作为掺和料吸附混凝土细孔中游离的碱性阳离子，抑制混凝土的碱－骨料不良反应的发生提供了实验依据。     

中国大地构造的动力学新理论

在全球范围内流行的按密度差、温度差建立的地幔对流、拆沉作用和地幔柱（羽）理论，阐明不了中国大陆岩石圈、大陆造山带的组成、结构与演化。从我们对中国秦岭及西部造山带的研究中，发现和提出的在地球自转速度变化制约下的多层扭动涡旋甩出说－核幔壳“风暴”所引发的热核反应是地球发展与演化唯一的、统一的“动力”来源，是中国大陆岩石圈、大陆造山带形成、发展与演化的动力学理论。