幂律度与成矿预测

分形理论的引入极大地促进了现代定量地学的发展。在成矿预测的科研和实践中,人们曾先后建立了多种分形预测模型,并取得较好的效果。作者另辟蹊径,通过引入新的分形变量幂律度(power-law),建立地质-分形联合预测模型,在理论上进行了初步探索;并以云南省宁蒗—永胜地区铜矿成矿预测为例,圈定A级找矿靶区1处、C级找矿靶区2处,已知矿点的误判率较单一地质预测模型明显降低,体现了幂律度这一分形变量在成矿预测中的优越性。

连接分形的城市

和所有生命系统一样,有活力的城市本质上都具有分形特征。汽车和人口增长带来的压力迫使20世纪的城市规划者推行反分形的几何类型,传统城市的分形特征被去除,给城市肌理造成灾难性的影响。要消除这种破坏,必须深入细致地理解一些问题:(1)分形特征都有哪些;(2)有活力的城市肌理中错综复杂的相互连接;(3)连接和修补城市空间的方法;(4)整合行人、汽车和公共交通的有效方式;(5)如何将实体联系与电子联系结合起来。首先,我们应该消除对分形结构的一些基本误解,然后我会强调层级一致性的本质和重要性。我们可以用分形标度来检验城市形体——作为城市成功的一个前提;另一个独立标度是连通性,应当从拓扑学角度进行研究。用生物系统进化和因特网的知识来讨论尺度分布、逆幂律度尺度法则和"小世界"网络。这些概念表明当代都市一方面向郊区化蔓延发展,另一方面是摩天楼式发展——这种对极端密度的偏好都是病态的。当代都市面临的挑战是如何用最佳方式实现竞争性连接网络的融合。

基于品牌效应与竞争力的复杂供应链网络演化模型及仿真

运用复杂网络理论和分析方法,根据供应链网络演化的基本特征,提出基于品牌效应与竞争力的复杂供应链网络演化模型,刻画供应链网络形成和演化机理。通过计算机仿真,计算不同非线性择优指数下的供应链网络的度分布和聚集系数,分析这个复杂网络的拓扑结构。仿真结果表明,随着非线性择优指数增大网络出现凝聚,说明在供应链网络中出现巨型核心企业,为认识、控制和协调供应链提供理论参考。

Depinning Dynamics of Fluid Monolayer on a Quenched Substrate

Langevin simulations are preformed on the depinning dynamics of fluid monolayer on a quenched substrate. With increase in the strength of the substrate, we find for the first time a crossover from elastic crystal to smectic flows as well as a crossover from smectic to plastic flows above the depinning. A power-law scaling relationship can be derived between the drift velocity and the driving force for both the elastic crystal and smectic flows, but fails to be obtained for the plastic flow. The power-law exponents are found to be no larger than 1 for the elastic crystal flow and larger than 1 for the smeetic flow. The critical driving force and the averaged intensity of Bragg peaks remain invariant basically in the regime of smectic flow. A sudden increase in the critical driving force is observed within the crossover from the smeetic to plastic flows, and the averaged intensity of Bragg peaks shows sudden decreases within the crossovers both from the elastic crystal to smectic flows and from the smectic to plastic flows. The results are helpful for understanding the slip dynamics of fluids on a molecular level.

Concentration–discharge patterns of weathering products from global rivers

Quantifying the functional relationships relating river discharge and weathering products places key constraints on the negative feedback between the silicate weathering and climate. In this study we analyze the concentration–discharge relationships of weathering products from global rivers using previously compiled time-series datasets for concentrations and discharge from global rivers. To analyze the nature of the covariation between specific discharge and concentrations, we use both a power law equation and a recently developed solute production equation. The solute production equation allows us to quantify weathering efficiency, or the resistance to dilution at high runoff, via the Damkohler coefficient. These results are also compared to those derived using average concentration–discharge pairs.Both the power law exponent and the Damkohler coefficient increase and asymptote as catchments exhibit increasingly chemostatic behavior, resulting in an inverse relationship between the two parameters. We also show that using thedistribution of average concentration–discharge pairs from global rivers, rather than fitting concentration–discharge relationships for each individual river, underestimates global median weathering efficiency by up to a factor of ～10. This study demonstrates the utility of long time-series sampling of global rivers to elucidate controlling processes needed to quantify patterns in global silicate weathering rates.

Double Reduction and Exact Solutions of Zakharov–Kuznetsov Modified Equal width Equation with Power Law Nonlinearity via Conservation Laws

The conservation laws for the （1＋2）-dimensional Zakharov-Kuznetsov modified equal width （ZK-MEW） equation with power law nonlinearity are constructed by using Noether＇s approach through an interesting method of increasing the order of this equation. With the aid of an obtained conservation law, the generalized double reduction theorem is applied to this equation. It can be shown that the reduced equation is a second order nonlinear ODE. FinaJ1y, some exact solutions for a particular case of this equation are obtained after solving the reduced equation.

No evidence for the evolution of mass density power-law index γ from strong gravitational lensing observation

In this paper, we consider the singular isothermal sphere lensing model that has a spherically symmetric power-law mass dis- tribution ρtot（r） - r-γ. We investigate whether the mass density power-law index y is cosmologically evolutionary by using the strong gravitational lensing （SGL） observation, in combination with other cosmological observations. We also check whether the constraint result of y is affected by the cosmological model, by considering several simple dynamical dark energy models. We find that the constraint on y is mainly decided by the SGL observation and independent of the cosmological model, and we find no evidence for the evolution of y from the SGL observation.

Experimental Investigation of Dimensionless Velocity and Shearing Stress in Boundary Layer Flow on Continuous Moving Surface in Power Law Fluids

An analysis is carried out to study the steady flow characteristics from a continuous flat surface moving in a parallel free stream of non-Newtonian power law fluid. The constitutive equations of the fluid are transformed into dimensionless ones. The velocity field is measured by Particle Image Velocimetry. Experimental results are obtained for the distribution of velocity. The influence of wall velocity ratio parameter on boundary layer flow field is observed in the experiment. Dimensionless velocity distribution and shearing stress distribution are obtained by post-processing experimental results. The effects of various physical parameters like velocity ratio parameter and similarity variable on various momentum transfer characteristics are discussed in detail and shown graphically. It is indicated that dimensionless velocity increases with velocity ratio parameter and similarity variable, and that dimensionless shearing stress decreases with velocity ratio parameter and similarity variable.