The Ushnus in the astronomy of the Inca culture

Inferences are made about the relationship that existed between the Ushnus, pyramid-shaped, terraced structures used by the Incas in the most important ceremonies of the Tawantinsuyo, and Inka Astronomy. We draw attention to Ayni, Kawsaypacha, Duality, and Tinkuy principles, multidimensional codes of conduct and wisdom that are at the root of the Andean cosmovision and on their perception of the world and the Cosmos. These principles, examined as postulates, allow to elaborate axiomatic propositions to identify the Ushnus with ancient Astronomy practices. In a complementary statement, starting from a bi-conditional proposition, we may infer through reciprocal corollaries that the Inka earliest roots to a holistic learning and educational ambient in the Tawantinsuyo was not elitist, instead it was based on a epistemological construct that differs from the corresponding Western educational ambients. An epistemological and cognitive approach allows to identify an ancient elaborate process of knowledge construction, based on the four fundamental principles, corresponding to different levels of assimilation and comprehension. As a complementary aspect, we identify some of the most preserved Ushnus of the Inka “Empire.” Then we complement this contribution with a broader interpretation for the Ushnus.     

厦门同安西柯对虾养殖池的细菌数量动态

本文研究了对虾养成期间养殖池生态系中细菌的数量动态,探讨其变化规律与虾病的关系。结果表明,总细菌、弧菌和发光细菌在水体、底质和虾体中的数量变化各异。在水体各菌数与其环境因子的关系中,除了总菌数与COD存在着正相关外,其它的不存在相关性。虾体的总细菌、弧菌和发光细菌的数量（以细胞计）可以用来预报虾病,三者的阅值分别为107个　／g（湿重）、105个／g（湿重）和104介／g（湿重）。通过对对虾的细菌学跟踪监测,可以及时采取有效的应急防治措施。     

Pc3 pulsations during variable IMF conditions

Pc3 geomagnetic field fluctuations detected at low latitude (L’Aquila, Italy) during the passage of a high velocity solar wind stream, characterized by variable interplanetary magnetic field conditions, are analyzed. Higher frequency resonant fluctuations and lower frequency phenomena are simultaneously observed; the intermittent appearance and the variable frequency of the longer period modes can be well interpreted in terms of the variable IMF elements; moreover their polarization characteristics are consistent with an origin related to external waves propagating in antisunward direction. A comparison with simultaneous observations performed at Terra Nova Bay (Antarctica) provides additional evidence for a clear relationship between the IMF and Pc3 pulsations also at very high latitudes.     

Lattice distortion in a zircon population and its effects on trace element mobility and U–Th–Pb isotope systematics: examples from the Lewisian Gneiss Complex, northwest Scotland

Zircon is a key mineral in geochemical and geochronological studies in a range of geological settings as it is mechanically and chemically robust. However, distortion of its crystal lattice can facilitate enhanced diffusion of key elements such as U and Pb. Electron backscatter diffraction (EBSD) analysis of ninety-nine zircons from the Lewisian Gneiss Complex (LGC) of northwest Scotland has revealed five zircons with lattice distortion. The distortion can take the form of gradual bending of the lattice or division of the crystal into subgrains. Zircon lattices are distorted because of either post-crystallisation plastic distortion or growth defects. Three of the five distorted zircons, along with many of the undistorted zircons in the population, were analysed by ion microprobe to measure U and Pb isotopes, Ti and REEs. Comparison of Th/U ratio, ²⁰⁷Pb/²⁰⁶Pb age, REE profile and Ti concentration between zircons with and without lattice distortion suggests that the distortion is variably affecting the concentration of these trace elements and isotopes within single crystals, within samples and between localities. REE patterns vary heterogeneously, sometimes relatively depleted in heavy REEs or lacking a Eu anomaly. Ti-in-zircon thermometry records temperatures that were either low (~700 °C) or high (>900 °C) relative to undistorted zircons. One distorted zircon records apparent ²⁰⁷Pb/²⁰⁶Pb isotopic ages (?3.0 to +0.3 % discordance) in the range of ~2,420–2,450 Ma but this does not correlate with any previously dated tectonothermal event in the LGC. Two other distorted zircons give discordant ages of 2,331 ± 22 and 2,266 ± 40 Ma, defining a discordia lower intercept within error of a late amphibolite-facies tectonothermal event. This illustrates that Pb may be mobilised in distorted zircons at lower metamorphic grade than in undistorted zircons. These differences in trace element abundances and isotope systematics in distorted zircons relative to undistorted zircons are generally interpreted to have been facilitated by subgrain walls. Trace elements and isotopes would have moved from undistorted lattice into these subgrain walls as their chemical potential is modified due to the presence of the dislocations which make up the subgrain wall. Subgrain walls provided pathways for chemical exchange between crystal and surroundings. Only five per cent of zircons in this population have lattice distortion suggesting it will not have a major impact on zircon geochronology studies, particularly as three of the five distorted zircons are from strongly deformed rocks not normally sampled in such studies. However, this does suggest there may be a case for EBSD analysis of zircons prior to geochemical analysis when zircons from highly deformed rocks are to be investigated.     

Population synthesis of cataclysmic variable star: I. A new methodology and initial study on the post common-envelope stage

We report the results of our population synthesis for post common-envelope binaries by following the evolution of each system in detail. Our main focus is a comparison with the white dwarf mass distribution of post common-envelope systems from the Sloan Digital Sky Survey. We employ a Monte Carlo method to choose the initial parameters of the progenitors (primary mass, mass ratio and orbital period). Then the evolution of the progenitor binary system is followed up to the onset of the common-envelope phase, which usually occurs near the tip of the giant branch or asymptotic giant branch. An approximate post-Helium flash evolution for primary masses ${\leq}2.25 \mathrm{M_{\odot}}$ is included. The binary parameters before and after common-envelope phase are calculated using the energy budget argument. In this paper we address the case of α _CE=1.0, which is the commonly adopted value to calculate the common-envelope ejection. We consider a hydrogen-exhausted core to define the core mass of the primary (white dwarf mass, M _WD) at the onset of common envelope phase. To obtain the present-day M _WD distributions, we assumed a constant star formation rate. The distribution resulting from our population synthesis shows a double peak profile for M _WD, similar to previous population syntheses and recent observational data. Our present synthesis result could not reproduce the location of the low and high mass peaks from the observations, but shows how a future synthesis can be made to produce an M _WD distribution which is closer to observational data.     

Fractal analysis of the Oyo River, cave systems, and topography of the Gunungsewu karst area, central Java, Indonesia

Gunungsewu, the southernmost subzone of the Southern Mountains, central Java, is a classic karst terrain, bounded by the Oyo River on the north and the Indian Ocean on the south. In this study, the Oyo River, the main drainage in the area, is divided into 14 segments, and the fractal dimension of each segment is determined by the box-counting method. The 14 segments show various values of fractal dimensions, which are controlled by lithology and geologic structures of the area that is being dissected by the river. Easily eroded lithologies have larger fractal dimensions, and the value changes abruptly when the river crosses faults. Fractal dimensions of six underground rivers in the Bribin, Sodong, Semuluh, Jomblang, Soga, and Sumurup caves, and the surface topography above the caves were also determined. The caves have fractal dimensions that range from 1.043 ±0.01 to 1.08±0.01; the surface topography has fractal dimensions that range from 1.49±0.01 to 1.732±0.01. The fractal dimension of an underground river is proportional to the fractal dimension of the surface topography over the passage. Larger fractal dimensions of underground rivers are associated with smaller flow rates of the rivers. Received, June 1998Revised, March 1999, August 1999, February 2000Accepted, February 2000     

地电化学参数法在金矿深部定位预测中的应用

介绍了地电化学参数法的基本原理和工作方法 ,通过在不同地区、不同金矿类型中进行的试验和应用结果表明 ,与其它一系列寻找隐伏矿的方法相比 ,该方法在寻找隐伏矿体方面具有快速、有效、低成本、高精度的特点。