In situ infrared spectroscopic study of brucite carbonation in dry to water-saturated supercritical carbon dioxide

In geologic carbon sequestration, whereas part of the injected carbon dioxide will dissolve into host brine, some will remain as neat to water saturated supercritical CO(2) (scCO(2)) near the well bore and at the caprock, especially in the short term life cycle of the sequestration site. Little is known about the reactivity of minerals with scCO(2) containing variable concentrations of water. In this study, we used high-pressure infrared spectroscopy to examine the carbonation of brucite (Mg(OH)(2)) in situ over a 24 h reaction period with scCO(2) containing water concentrations between 0% and 100% saturation, at temperatures of 35, 50, and 70 °C, and at a pressure of 100 bar. Little or no detectable carbonation was observed when brucite was reacted with neat scCO(2). Higher water concentrations and higher temperatures led to greater brucite carbonation rates and larger extents of conversion to magnesium carbonate products. The only observed carbonation product at 35 °C was nesquehonite (MgCO(3)·3H(2)O). Mixtures of nesquehonite and magnesite (MgCO(3)) were detected at 50 °C, but magnesite was more prevalent with increasing water concentration. Both an amorphous hydrated magnesium carbonate solid and magnesite were detected at 70 °C, but magnesite predominated with increasing water concentration. The identity of the magnesium carbonate products appears strongly linked to magnesium water exchange kinetics through temperature and water availability effects.     

n维理想玻色气体性质的普遍描述

给出了在Ｔ＞Ｔｃ和Ｔ＜Ｔｃ情况下能谱为ε＝ａｐ＾ｓ的ｎ维简并理想玻色色体的内能、熵、状态程和热容量和普遍表达式。指出存在两种类型的玻以－爱因斯坦凝聚。     

A NOTE TO THE NEVANJUNNA''S FUNDAMENTAL THEOREM

In this paper, the author extends Nevanlinna's second fundamental theorem and establishes the following inequality: Let $\[p(s,u) = {A_v}(s){u^v} + {A_1}(s){u^{v - 1}} + \cdots + {A_0}(s)\]$ be an irreducible two-variable polynomial and $f(s)$ a transcendental entire function, then $$\[(\nu - 1)T(r,f) < N(r,\frac{1}{{p(z,f(z))}}) + S(r,f)\]$$ with $$\[S(r,f) = O(\log (rT(r,f)))n.e\]$$ where an. "n.e" means that the estimation holds for all large r with possibly an exceptional of finite measure when f is of infinite order.     

土壤－水稻系统中砷污染表征与相关性校验

研究了青紫泥田、黄筋泥田和红砂田中水溶性砷、酸溶性砷和总砷与水稻生物产量和砷积累的关系，探讨了它们之间的相关性，为表征和校验土壤水稻系统中砷污染提供依据。     

Pulsed-laser Pumped Photothermal Deflection Spectroscopy for Liquid Thermal Diffusivity Measurement

The pulsed-laser pumped photothermal deflection spectroscopy (PPDS) is applied to measure liquid thermal diffusivity in a modified collinear configuration. Here the pulsed beam is regarded as in the form of a Dirac delta function. The experiment setup used is described. Measurement result for the thermal diffusivity of a liquid sample(magnta/ethanol saturated solution) is reported. The measurement error is less than 3%.     

Zn/H-ZSM-5催化剂上的二甲醚芳构化反应

 考察了 H-ZSM-5 和 Zn/H-ZSM-5 催化剂的二甲醚芳构化性能. 结果表明, H-ZSM-5 分子筛催化剂酸性的增强和酸中心的增多有利于二甲醚芳构化. 当在 H-ZSM-5 催化剂中加入 2% Zn 时, 在 360 oC 下反应时总芳烃收率从 50.0% 增加至 66.2%, C8 芳烃收率从 28.6% 增加到 39.0%. 反应温度升高到 480 oC 时, 总芳烃收率增加至 78.0%.     

热效应对克尔自锁模激光腔的影响

讨论了克尔透镜锁模激光腔中热效应对锁模的影响，用数值解法给出了存在热效应时腔中光斑半径随归一化功率的变化曲线。同时给出了存在热效应时光斑半径对归一化功率的相对敏感度参数。     

BOUNDED COMPOSITION OPERATORS ON HARDY SPACES (II)

In this paper, the characterization of semi-Fredholm composition operators from H2(Bm) to H2(Bn) is given. As an application of the composition operators, the extension properties of analytic maps are discussed.     

钾原子的双光子共振三光子电离

在钾蒸气中用双光子共振三光子电离法测出了钾原子６Ｓ态的电离流随时间的衰减曲线。由电离流和多光子动力学参数的关系计算了６Ｓ态的光电离截面。当用７６６．４ｎｍ和７６９．８ｎｍ单光子激发时,通过能量积聚效应也可诱导钾原子得以电离。