Singularity attenuation with quantum-mechanically revisited metric tensor

The space and initial singularities are reexamined in the most reliable solutions to the Einstein's field equations (EFE), that is, the Einstein–Gilbert–Straus (EGS) metric. In discretized Finsler geometry, additional curvatures and thereby geometric structures likely emerge, which are distinct from the conventional spacetime curvatures and geometric structures that the Einstein's theory of general relativity introduced. The generalized fundamental tensor, which is obtained in the Fisleriean geometry, imposes quantum-mechanically revisions on the Landau–Raychaudhuri evolution equations. The time-like geodesic congruence in EGS metric is then analyzed, analytically and numerically. The evolution of a family of trajectories whose congruence is defined by the flow lines generated by velocity fields is determined. We conclude that both two types of singularities seem to be attenuated or even regulate. With the singularity attenuation, we refer to the fundamental nature of the additional curvatures at quantum relativistic scales.     

中国名山的历史保护与启示——以中华五岳为例

中国山岳的开发历史悠久,中国名山在当前多作为国家风景名胜区,其中部分还进入了世界遗产名录.这些宝贵的自然和文化遗产历经数千年仍能较好得到保留,对其认识和保护的历史经验值得探究.五岳作为东南西北中不同地域的代表性名山,开发利用和保护历史悠久,是研究中国名山历史保护的良好范例.通过对五岳的文献资料与历史遗迹的研究发现,古人...     

基于空间句法的泉州城区道路网形态研究

根据空间句法理论对泉州城区道路网进行量化描述,并利用量化后的泉州城区道路网的形态变量对其空间特征形态进行研究分析.结果表明,泉州中心城区总体呈格网状特征,空间智能性较高,道路网形态较合理,同时也存在智能值与集成度均与交通实际不符的道路空间.最后在此形态基础上提出泉州道路网的优化建议,为城市的空间扩展、规划建设提供参考依...     

Home-range sizes of social groups of Mongolian gerbils Meriones unguiculatus

Spacing behavior is important to the population regulation and social organization of rodents. However, little is known regarding the factors influencing space use by rodent social groups. We tested the hypotheses that food resources in the typical steppe would be so abundant that food availability would not be a limiting factor of home-range sizes of social groups of Mongolian gerbils (Meriones unguiculatus). We also assessed the effects of social organization on the home-range size of social groups of gerbils, using capture-recapture methods. Home ranges of social groups of Mongolian gerbils did not differ in size between the breeding and non-breeding periods; however, home ranges overlapped more during the breeding period than during the non-breeding period. Overlap of home ranges might allow male gerbils to access female mates of neighboring colonies during the breeding period. Home-range sizes of social groups were positively related to number of males during the breeding period, but positively related to group size and number of females during the non-breeding period. Therefore, social organization influenced home-range sizes of social groups. Our hypothesis that food availability is not a limiting factor of space use by social groups of Mongolian gerbils from spring through autumn was supported.     

Provisioning systems for a good life within planetary boundaries

The concept of provisioning systems has recently emerged as a promising way to understand the differences between levels of resource use and social outcomes observed across societies. However, the characteristics of provisioning systems remain poorly understood. Here, we make a new contribution to conceptualising provisioning systems and to understanding differences in the resource efficiency with which they achieve social outcomes. We define a provisioning system as a set of related elements that work together in the transformation of resources to satisfy a foreseen human need. We analyse six theories in terms of their contribution to understanding provisioning systems within the biophysical and social constraints of Raworth’s “Safe and Just Space” framework. We find that most of these theories fail to prioritise human needs and well-being, and do not incorporate explicit environmental limits. However, they provide important insights that we draw upon to identify six important provisioning system elements (households, markets, the commons, the state, techniques, and material stocks). Based on the theories, we also identify two important relationships between elements, namely feedbacks and power relations. We further propose the concept of “appropriating systems” as a component of provisioning systems. Appropriating systems reduce the resource efficiency of human well-being via rent extraction, and act as a barrier to meeting human needs at a sustainable level of resource use. We combine these concepts into a new framework, and discuss applications to energy systems.     

月壤中纳米金属铁的太空风化成因及模拟方法分析

月壤中普遍存在着大量由太空风化作用产生的纳米金属铁,这些纳米金属铁在一定程度上改变了月球表面的物理、化学和光学特征.纳米金属铁在月壤中主要赋存于胶结质玻璃相中和月壤颗粒的表面,胶结质玻璃相的纳米金属铁起源于微陨石轰击富含太阳风氢粒子的月壤产生的高温熔融还原作用,颗粒表面的纳米金属铁来自微陨石轰击引起的蒸发沉积作用和太阳...     

Sensitivity to space and time resolution of a hydrological model using digital elevation data

The space and time resolutions used for the input variables of a distributed hydrological model have a sufficient impact on the model results. This resolution depends on the required accuracy, experimental site and the processes and variables taken into account in the hydrological model. The influence of space and time resolution is studied here for the case of TOPMODEL, a model based on the variable contributing area concept, applied to an experimental 12 km² catchment (Coët-Dan, Brittany, France) during a two month winter period. A sensitivity analysis to space and time resolution is performed first for input variables derived from the digital elevation data, secondly for the optimized values of the TOPMODEL parameters and finally for modelling efficiency. This analysis clearly shows that a relevant domain of space and time resolutions where efficiency is fairly constant can be defined for the input topographic variables, as opposed to another domain of larger resolutions that induces a strong decrease of modelling efficiency. It also shows that the use of a single set of parameters, defined as mean values of parameters on this relevant domain of resolution, does not modify the accuracy of modelling. The sensitivity of the parameters to space and time resolution allows the physical significance of the parameter values to be discussed.     

地震非均匀度在华北地震中期预报中的应用

使用华北地区地震资料进行地震非均匀度GL值空间扫描。结果表明，中强地震前1－3年，未来震中周围通常开始出现明显的GL值中期异常区，此方法具有很好的中期预报效果。文中还就GL值进行中期预报的有关问题进行了讨论。     

地震调制比及其在华北地震中期预报中的应用

通过对调制比预报地震方法进行改进，并使用改进后的地震调制比Rm10对华北地区进行空间扫描。结果表明，中强地震前1～3年，未来震中周围通常出现Rm10中期异常区，具有较好的中期预报效果。     

空间斜墨卡托投影及其在遥感图象处理中的应用

本文推导了球体、椭球体空间斜墨卡托(SOM)投影公式;指出了空间投影的特点和用途,给出了可实际应用的SOM投影正反解公式计算程序包;分析了真(垂直)卫星地面轨迹投影线附近的变形情况,提出了一种正形多项式快速算法,提高了SOM投影正反解计算速度;最后给出了SOM投影与传统地图投影(例如高斯、等角园锥投影)的转换程序包。