名义上无水矿物中"水"的原位变温红外光谱研究

名义上无水矿物(nominally anhydrous minerals, 简称NAMs, 如橄榄石、辉石、石榴石、长石等)中以缺陷形式存在的结构水的重要性已经被地球科学界广泛认同,并得到了越来越多的关注。由于对OH振动的高度敏感性,红外光谱方法被广泛用来测量NAMs中"水"的赋存状态、含量以及在晶体结构中的位置。随着傅立叶变换红外光谱仪的不断发展及分析技术的提高,以及红外附件的更新换代,出现了一些新的分析方法。原位变温红外光谱实验就是利用变温红外附件测量样品在不同温度下的红外光谱,通过研究不同温度下红外光谱图的峰形、峰位、峰数等参数的变化,了解温度改变过程中样品所发生的物理、化学变化,且具有实时监测的优点,因此广泛用于含水矿物和玻璃中OH和H₂O的研究。主要包括含水矿物和玻璃的脱水机理及脱水动力学研究,OH和H₂O的红外吸收系数的温度依赖性及不同温度下红外吸收系数的校正等方面。虽然原位变温红外光谱广泛应用于含水矿物和玻璃中水的研究,但是应用于名义上无水矿物还是刚刚起步。NAMs中的H是活动的,高温下H的赋存状态及其在晶体中的位置可能会不同于室温,而地质过程往往都在高温下进行,研究高温下NAMs中的水具有重要的地质学意义。因此,有必要利用原位变温红外光谱实时监测不同温度下NAMs中水的变化。有关NAMs中水的原位变温红外光谱实验早期工作只是观察不同温度下谱图参数的变化并给予一定的解释,以及用此法来确定NAMs中水的赋存状态。受含水矿物和玻璃的研究结果的启发,原位变温红外光谱实验目前也开始用来研究NAMs中水的脱水机理和扩散动力学。此外,利用原位变温红外光谱技术,通过研究不同温度下OH的积分吸收面积可探索NAMs中OH红外吸收系数温度依赖性;通过研究OH峰位随温度移动的幅度与某些化学成分的关系,可给出NAMs中OH的结合机理方面的有用信息。虽然近些年来已经开展了一些工作,取得了一些新的成果,但是总的说来还处在起步阶段,今后针对NAMs的研究重点应该集中在以下三个方面:(1)吸收系数温度依赖性的定量化,(2)脱水机理和动力学的扩展,(3) OH结合机理研究的深入。     

锆石中钛温度计在鲁西—苏北地区中生代侵入杂岩中的应用

利用锆石中钛地质温度计对鲁西—苏北地区出露的8个中生代侵入杂岩的岩浆岩结晶温度进行计算,结果表明研究区斑井岩体的平均岩浆结晶温度为715~716℃,蔡山岩体为653℃,丰山岩体为697℃,夹沟岩体为711℃,利国岩体为737℃,铁铜沟岩体为766℃,上峪岩体为889℃,金岭岩体为770℃。岩体的岩浆结晶温度沿侵入杂岩带展布方向,从S到N依次增高,暗示其岩浆起源深度逐渐加大。岩浆结晶温度计算结果大致限定了各岩体的岩浆源区深度范围,结合锆石寄主岩石和寄主岩石中的深源包体的研究表明研究区中生代侵入杂岩体的母岩浆起源于上地幔和/或下地壳。     

氧化锰、氧化铁、氧化铝对砷(Ⅲ)的吸附行为研究

合成了氧化锰、氧化铁、氧化铝三种矿物,以氧化铁、氧化锰为吸附剂研究了pH值、离子强度和时间等因素对吸附As(Ⅲ)的影响,并讨论了氧化锰、氧化铁、氧化铝三种矿物对As(Ⅲ)的饱和吸附容量及等温吸附实验。pH值对氧化锰吸附As(Ⅲ)几乎不影响,对氧化铁吸附As(Ⅲ)在很大的范围内(pH为3.5~8.5)影响不大,离子强度对二者吸附As(Ⅲ)的影响不大,吸附反应在0.5 h左右达到吸附平衡。在优化吸附条件下氧化锰、氧化铁、氧化铝对As(Ⅲ)的饱和吸附容量分别为48.38 mg/g、23.70 mg/g、3.52mg/g,三种合成矿物对As(Ⅲ)的饱和吸附容量:氧化锰氧化铁氧化铝。对实验数据进行Freundlich和Langmuir拟合,相关系数R均在0.98以上,吸附动力学符合Lagergren二级速率方程。     

Nonstationary analysis of the extreme temperatures in Turkey

Record-breaking extreme temperatures have been measured in the last two decades all over Turkey, with recent studies detecting positive trends in extreme temperature time series. In this study, nonstationary extreme value analysis was performed on extreme temperature time series obtained from fifty stations scattered over the seven geographical regions of Turkey. Basic characterization of the data set was defined through outlier detection, homogeneity, trend detection, and stationarity tests. Trend-including non-stationary extreme temperature time series were analyzed with non-stationary Generalized Extreme Value distribution. Three main physical drivers were considered as the leading causes that trigger the observed trends in extreme temperatures over Turkey: time, teleconnection patterns of the Arctic Oscillations, and those of the North Atlantic Oscillations. The results showed that most of the absolute annual minimum and maximum temperature time series are inhomogeneous while the possible breakpoints date back to the1970s and 1990s, respectively. More than half of the absolute annual maximum time series (26/50 and many of the absolute annual minimum time series (21/50) showed a positive trend. No negative trend was detected in the extreme temperature time series. Based on the frequency analysis of the 21 annual maximum time series, the non-stationary estimations of 50-year return levels were detected to be higher than in the stationary model (between 0.44 °C and 3.73 °C). The return levels in 15 of the 20 minimum temperature time series increased from 0.11 °C up to 12.28 °C. Elevation increases the nonstationarity impact on absolute minimum temperatures and decreases it on absolute maximums. The findings in this study indicate that the consideration of non-stationarity in extreme temperature time series is a necessity during return level estimations over the study area.     

污染源、气象条件变化对我国SO2浓度及硫沉降量分布的影响

用三维欧拉型污染物长距离输送模式,模拟了中国大陆SOx的分布,并采用不同时期(1975、1980、1987年)的污染源与气象场资料,分析了污染源与气象条件变化对SOx分布产生的影响.研究表明,在该期间中国SOx污染比较严重的地区,气象条件变化导致SO2浓度和硫沉降量的相对变化通常在20%左右;污染源对SO2浓度与硫沉降量的作用通常大于气象条件,污染源变化产生的SO2浓度与硫沉降量的相对变化率为气象条件变化的几倍,甚至1～2个量级,尤其SOx污染比较严重的地区更为明显;但对西北及青藏高原地区,在源排放量变化不大,而气象条件变化较显著时,气象条件的作用通常大于排放源的影响.     

Compressional elastic wave velocities of serpentinized pyroxenite at high pressures and high temperatures and its geological significance

Elastic wave velocity measurement in rocks at high pressures and high temperatures plays a key role in researching the state, properties and movement of the earth interior materials. Nowadays dehydration is believed to be as one of the most important reasons responsible for the abnormality of seismic velocity (Kern, 1982; Ito, 1990; Christensen, 1989; Popp, Kern, 1993; SONG, et al, 1996; ZHOU, 1998; ZHAO, et al, 1996). Geophysical, geochemical and mineralogical data have revealed that on…     

Enzyme leach anomalies associated with deep Mississippi Valley-type zinc ore bodies at the Elmwood Mine, Tennessee

Deeply buried Mississippi Valley-type deposits that have been or are currently being mined in North America were initially discovered by drilling. Conventional geochemical methods are ineffective for detecting these ‘blind' deposits when they occur deep within sequences of stable-platform carbonates and shales. The ‘enzyme' leach is a selective analytical technique for determining trace elements associated with amorphous Mn oxide coatings in soils. In many areas of the world, the enzyme leach method is useful for detecting low-level geochemical anomalies in soils, which are associated with blind mineral deposits. Enzyme leach analysis of soils, collected at the Elmwood Mine, Tennessee, revealed high-contrast anomalies over ore bodies 370 m below the surface. In areas where the soils are in chemical equilibrium, ‘combination' anomalies occur over Zn ore bodies. These are characterized by asymmetrical halogen halos which occur around a halogen ‘central low'. Commodity metals (Zn and Pb) and trace elements associated with the ore (Cd, Ba, and Mn) form apical anomalies, which occur over the ore bodies and within the halogen halo. Under most circumstances, agricultural practices do not affect enzyme leach results. However, agricultural activity in central Tennessee appears to have altered the proportion of amorphous Mn oxides in the soils in some locations. Where the MnO₂-form equilibrium of the soil has been disturbed, enzyme leach data are erratic. In the one instance where this was encountered, ratioing the data to Mn reveals anomalies which bracket the blind ore bodies.     

紫金山铜矿原地破碎细菌浸出工艺的可行性分析

根据紫金山铜矿的实际情况，分析采用原地破碎细菌浸出工艺回收紫金山铜矿资源的工程技术可行性，在此基础上进行经济方面的讨论。     

ON CHANGES OF CHINA'S MAXIMUM AND MINIMUM TEMPERATURES IN 1951——1990

Based on China's observational data in 1951-1990,after minimizing the possible biasescaused by station relocation and urban heat island,the spatial and temporal distributions of trendsfor maximum and minimum temperatures are studied.The results show that increasing trends ofmaximum temperatures are in the areas west to 95°E,and north to the Huanghe(Yellow)River,while decreasing trends exist in eastern China south to the Yellow River.Minimum temperaturesare generally increasing throughout China,with dominant warming trends at the higher latitudes.This resulted in very obvious decreasing trends in diurnal temperature ranges.The periodic cycles are consistent between the maximum and minimum temperatures,butasymmetric trends are very obvious.The significant increase of minimum(nighttime)temperaturesreflects the evidence of enhancement of greenhouse effect.Further analysis shows that the changesof maximum and minimum temperatures are mainly related to sunshine duration and atmosphericwater vapor content.     

Warming permafrost in European mountains

Here we present the first systematic measurements of European mountain permafrost temperatures from a latitudinal transect of six boreholes extending from the Alps, through Scandinavia to Svalbard. Boreholes were drilled in bedrock to depths of at least 100 m between May 1998 and September 2000. Geothermal profiles provide evidence for regional-scale secular warming, since all are nonlinear, with near-surface warm-side temperature deviations from the deeper thermal gradient. Topographic effects lead to variability between Alpine sites. First approximation estimates, based on curvature within the borehole thermal profiles, indicate a maximum ground surface warming of +1 °C in Svalbard, considered to relate to thermal changes in the last 100 years. In addition, a 15-year time series of thermal data from the 58-m-deep Murtèl–Corvatsch permafrost borehole in Switzerland, drilled in creeping frozen ice-rich rock debris, shows an overall warming trend, but with high-amplitude interannual fluctuations that reflect early winter snow cover more strongly than air temperatures. Thus interpretation of the deeper borehole thermal histories must clearly take account of the potential effects of changing snow cover in addition to atmospheric temperatures.