Cyclotella-taxa (Bacillariophyceae) in lakes of the Alpine region and their relationship to environmental variables     

Sybille Wunsam  Roland Schmidt  Rolf Klee 《Aquatic Sciences - Research Across Boundaries》1995,57(4):360-386

Surface sediment diatom assemblages for 86 Alpine lakes were analysed focusing on the dominant genusCyclotella and corresponding environmental data. The range of morphological variability of theCyclotella bodanica/radiosa, C. distinguenda, C. ocellata, C. comensis andC. stelligera complexes was documented. Significance tests included in the canonical correspondence analysis (CCA) indicated that total phosphorus, conductivity and surface water temperature were significantly correlated withCyclotella taxa assemblage distribution. Numerical species optima and tolerances were calculated in respect to these significant variables using weighted averaging (WA) regression and calibration. CCA and WA were able to provide information about the environmental preferences of the various morphotypes observed.  相似文献   

A potential model for fluorapatite     

V. Devarajan  W. E. Klee 《Physics and Chemistry of Minerals》1981,7(1):35-42

For the mineral fluorapatite, Ca₁₀(PO₄)₆F₂, a potential model of the polarizable ion type has been developed in order to reproduce the following physical constants: the vibrational frequencies (transverse and longitudinal), the elastic constants and the static and high frequency dielectric constants. The parameters of the model are short range force constants, ionic charges and ionic polarizabilities. The polarizable ion model was built up in three stages in order to facilitate comparison with simpler models. In the first stage a short range valence type model was set up, assuming interaction up to a distance of 3.5 Å. In the second stage this model was extended to a rigid ion model by the addition of long range Coulomb forces. In the third stage, which resulted in the polarizable ion model, the polarizabilities of the ions were also taken into account. There was good agreement between calculated and observed data. This demonstrates that even for a crystal structure as complicated as that of fluorapatite with 42 atoms per unit cell a potential model can be constructed which reproduces in a satisfactory way the above-mentioned physical constants.  相似文献   

In Situ Stresses in Borehole Blanche-1/South Australia Derived from Breakouts,Core Discing and Hydraulic Fracturing to 2 km Depth     

G. Klee  A. Bunger  G. Meyer  F. Rummel  B. Shen 《Rock Mechanics and Rock Engineering》2011,44(5):531-540

The development of Hot-Dry Rock (HDR) geothermal energy in Australia with drillings to some kilometres depth yields an impetus for deep stress logging. For the Olympic Dam HDR-project, borehole Blanche-1 was drilled to almost 2 km depth and provided the possibility to estimate the in situ stresses within the granitic borehole section by the analysis of borehole breakouts and core discing, as well as by hydraulic fracturing combined with acoustic borehole televiewer logging for fracture orientation determination. Although the stress magnitudes derived by the different methods deviate significantly, they clearly indicate for the depth range between 800 and 1,740 m a compressional stress regime of S _v ≤ S _h < S _H and a consistent East–West orientation of maximum horizontal compression in agreement with existing stress data for Australia. The minor horizontal stress S _h derived from the hydraulic fracturing closure pressure values is about equal to the overburden stress and may be regarded as most reliable.  相似文献