羟基磷灰石吸附剂去除铬黄工业废水中铅离子的研究

羟基磷灰石吸附剂对铬黄废水中Pb^2 吸附的间歇实验结果表明：当每吨废水中吸附剂用量为200～400g时，常温搅拌60min后，在弱酸性或中性废水中，铅离子质量浓度由2.74mg/L降至0.5mg/L以下，完全符合GB8978-1996工业废水排放标准1.0mg/L。     

Modeling of dioctahedral 2:1 phyllosilicates by means of transferable empirical potentials

 Dioctahedral 2:1 phyllosilicates with different interlayer charge have been studied theoretically by using transferable empirical interatomic potentials. The crystal structures of pyrophyllite, muscovite, margarite, beidellite, montmorillonite, and different smectites and illites have been simulated. The interatomic potentials were able to reproduce the experimental structure of phyllosilicates with high, medium and low interlayer charge. The calculated structures are in agreement with experiment for the main structural features of the crystal lattice. The effect of the cation substitution in the octahedral and tetrahedral sheets on the structural features has been also studied. Good linear relationships have been found, and the calculated effects are consistent with experimental results. Some unknown structural features of the crystal structures of clays are predicted in this work. Received: 8 March 2000 / Accepted: 19 September 2000     

Electronic absorption spectra of Fe2+ ions in oxygen-based rock-forming minerals at temperatures between 297 and 600 K

 Polarized electronic single crystal spectra of natural Fe²⁺ ion-bearing oxygen-based minerals, in which ferrous ions enter octahedral sites of different symmetry and distortion (olivine, cordierite, ortho- and clinopyroxene, amphibole), eightfold sites in garnet (almandine) and clinopyroxene (M2), and tetrahedral sites in spinel, were studied at temperatures from 300 to ca. 600 K. In the minerals studied, the spin-allowed bands of Fe²⁺ display rather variable temperature behaviour. In most cases, due to the thermal expansion of the Fe²⁺-bearing polyhedra, bands shift to lower energies upon increasing temperature, though there are some exceptions to this rule: in cases of other than sixfold octahedral or close to octahedral coordination, in almandine and spinel the bands shift to higher energies, which can be explained by an increase in distortions of the Fe²⁺-bearing polyhedra. Splitting of the excited ⁵ E _g-level of Fe²⁺ ions usually, but not always, increases with temperature, reflecting thermally induced increase in distortion of the Fe²⁺-bearing sites in the minerals studied. Integral intensities of the bands in question do not always obey the general rule, according to which intensity should increase with temperature, when the 3d ^N-centred site is centrosymmetric, or should remain unchanged when the 3d ^N site lacks an inversion centre. The experimental results show that the response of the characteristics of absorption bands such as width, intensity and energy caused by dd transitions of Fe²⁺ in oxygen-based minerals to increasing temperature is not always uniform and is at variance with expectation. This temperature dependence cannot be used directly to solve band assignment problems, as earlier proposed in the literature. Received: 22 December 1999 / Accepted: 30 October 2000     

广西巴里—龙头山100号锡多金属矿床成矿物理化学环境研究——氧逸度(f_(o_2))、CO_2逸度(f_(co_2))、硫逸度(f_(s_2))、mΣs

根据已知的 10 0号矿体的成矿温度及成矿压力 ,并结合矿体的矿物组合推算出10 0号矿体是在相对低硫、氧和二氧化碳逸度 ,溶液为酸性至弱碱性的物理化学环境下形成的。     

Free cupric ion concentrations and Cu complexation in selected Swiss lakes and rivers

[Cu²⁺] and Cu complexation parameters in some selected freshwater systems in Switzerland were determined by the technique of ligand-exchange and DPCSV. Results from the water columns of some eutrophic and oligotrophic lakes are presented and compared to small acid lakes. Cu is strongly complexed by organic ligands which with very high stability constants at low concentrations are probably biologically produced, as indicated by the seasonal variations in the eutrophic lakes and by the relationship between Cu complexation and algal activity in the eutrophic (pCu=15–16), oligotrophic (pCu=13–14) and acidic (pCu=9–10) lakes. The extent of Cu complexation in river waters was generally lower than in the eutrophic lakes, at similar DOC levels. No obvious correlation between Cu complexation and DOC was observed, indicating that Cu complexing ligands are specific organic compounds.     

Processing of oxidised nitrogen compounds by passage through winter-time orographic cloud

Four case studies are described, from a three-site field experiment in October/November 1991 using the Great Dun Fell flow-through reactor hill cap cloud in rural Northern England. Measurements of total odd-nitrogen nitrogen oxides (NO _y ) made on either side of the hill, before and after the air flowed through the cloud, showed that 10 to 50% of the NO _y , called NO _z , was neither NO nor NO₂. This NO _z failed to exhibit a diurnal variation and was often higher after passage through cloud than before. No evidence of conversion of NO _z to NO₃ ^- in cloud was found. A simple box model of gas-phase chemistry in air before it reached the cloud, including scavenging of NO₃ and N₂O₅ by aerosol of surface area proportional to the NO₂ mixing ratio, shows that NO₃ and N₂O₅ may build up in the boundary layer by night only if stable stratification insulates the air from emissions of NO. This may explain the lack of evidence for N₂O₅ forming NO₃ ^- in cloud under well-mixed conditions in 1991, in contrast with observations under stably stratified conditions during previous experiments when evidence of N₂O₅ was found. Inside the cloud, some variations in the calculated total atmospheric loading of HNO₂ and the cloud liquid water content were related to each other. Also, indications of conversion of NO _x to NO _z were found. To explain these observations, scavenging of NO _x and HNO₂ by cloud droplets and/or aqueous-phase oxidation of NO₂ ^- by nitrate radicals are considered. When cloud acidity was being produced by aqueous-phase oxidation of NO _x or SO₂, NO₃ ^- which had entered the cloud as aerosol particles was liberated as HNO₃ vapour. When no aqueous-phase production of acidity was occurring, the reverse, conversion of scavenged HNO₃ to particulate NO₃ ^-, was observed.     

The NO2 absorption spectrum. III: The 200–300 nm region at ambient temperature

Absorption cross-section measurements of NO₂ performed in our laboratory have been extended to the 200–300 nm region at ambient temperature. Low pressures have been used, limiting the effects of the dimer N₂O₄ which has an absorption cross-section from one to two orders of magnitude larger than that of NO₂ in this region. The results have been compared to those of previous authors and are now available for atmospheric purposes at 0.01 nm intervals.Unité de Recherche Associée au CNRS.     

NO2 total column evolution during the 1989 spring at Antarctica Peninsula

Ground-based visible differential absorption spectrometry during twilight has been used for NO₂ total column observations at the Antarctica Peninsula, Marambio Base (64S, 56W), during the austral spring of 1989 (9 September to 25 November).Results show moderate NO₂ vertical column levels of 1.5 to 2.5×10¹⁵ molec cm^-2 in the morning and 2 to 3×10¹⁵ molec cm^-2 in the evening until middle October, highly modulated by planetary wave activity. From that date until the end of the period, a steady increase occurs which is associated with the rising of lower stratosphere temperature as the vortex weakens, reaching values of 5×10¹⁵ molec cm^-2 in late November, with small a.m.-p.m. differences. NO₂ is found to be positively correlated to both total ozone and 50 hPa temperature during the entire spring. However, when analyzing the departures from linear trends, a highly negative correlation has been observed from day 301 onwards.     

低纬Pi2地磁脉动和亚暴电流体系

本文试图建立一个产生低纬Pi2 脉动的亚暴三维电流体系模型.用这个模型可以模拟地球表面不同纬度和经度上记录的Pi2脉动的波形和偏振图,与低纬Pi2脉动的多台观测结果基本相符.从而定量地解释了Pi2脉动和亚暴电流体系的关系.     

中低纬地区地磁脉动的研究

近年来我们对中低纬地区地磁脉动进行了大量的观测和研究。本文不仅介绍了观测仪器的设计、台网设置及数据处理方法。而且还简要地介绍了一些主要科研成果,如低纬Pc3脉动特点,低纬Pi2脉动偏振特性。南极地区的地磁脉动观测结果,以及在磁暴和太阳耀斑期间在低纬地区观测的地磁脉动。这对于进一步认识中低纬地区地磁脉动是十分有益的。