基于结构能量分析的抗震设计新方法的研究

概要介绍了多自由度结构能量分析方法，根据单自由度体系得到的输入能量谱，研究分析了多自由度与单自由度输入能量和耗能的等效性问题，并对一座钢筋混凝土框架结构算例进行了能量计算，对计算结果进行了分析，为能量分析设计方法应用于结构抗震设计进行有益的探索。     

改进的重力模拟退火反演研究

通过对模拟退火方法中常用的VFSA算法的分析，针对其在模型扰动及退火计划上存在的缺陷，针对性地作了更合理的改进VFSA算法，提高了VFSA算法的计算速度与稳健性，并结合重力反演过程中对模型的修正，克服了常规重力反演方法所存在的等值效应。研究中还把重力正演计算的单元体改为垂直侧边梯形单元，并合单同一层位的垂直侧边梯形单元成为一大单元再作计算，加快了正反演计算速度并提高了正反演精度。通过模型试验及实际资料的处理，验证了作者所提出的改进的模拟退火重力反演方法的有效性。     

Formal difference analysis and unification onp-norm distribution density functions

The cause of the formal difference ofp-norm distribution density functions is analyzed, two problems in the deduction ofp-norm formulating are improved, and it is proved that two different forms ofp-norm distribution density functions are equivalent. This work is useful for popularization and application of thep-norm theory to surveying and mapping. Supported by Scientific Research Fund of Human Province Education Department (No. 03C483).     

Equivalence of network-solution and PPP-solution

IntroductionIn GPS data-processing, the most accurate andpopular method is to solve the unknown parametersbased on a GPS network which includes many GPSsites. This mode is always called network-solution.The network-solution makes use of the spatial geom-e…     

Tight dual models of pore spaces

The pore throats in a porous medium control permeability, drainage, and straining through their pore scale geometry and through the way they are connected via pore bodies on the macroscale. Likewise, imbibition is controlled through the geometry of the pore bodies (pore scale) and through the way the pore bodies are connected via pore throats on the macroscale. In an effort to account for both scales at the same time we recently introduced an image-based model for pore spaces that consists of two parts related by duality: (1) a decomposition of a polyhedral pore space into polyhedral pore bodies separated by polygonal pore throats and (2) a polygonal pore network that is homotopy equivalent to the pore space. In this paper we stick to the dual concept while amending the definition of the pore throats and, as a consequence, the other elements of the dual model. Formerly, the pore throats consisted of single two-dimensional Delaunay cells, while they now usually consist of more than one two-dimensional Delaunay cell and extend all the way into the narrowing ends of the pore channel cross sections. This is the first reason for naming the amended dual model “tight”. The second reason is that the formation of the pore throats is now guided by an objective function that always attains its global optimum (tight optimization). At the end of the paper we report on simulations of drainage performed on tight dual models derived from simulated sphere packings and 3D gray-level images. The C-code for the generation of the tight dual model and the simulation of drainage is publicly available at https://jshare.johnshopkins.edu/mhilper1/public_html/tdm.html.     

等值化理念下中国城乡融合多维审视及影响因素

基于等值化理念采用全局主成分分析（GPCA）和空间自相关分析等方法,测度并审视中国城乡多维融合发展;选取空间计量模型探索推进城乡融合的体制机制。研究发现：① 中国城乡融合发展趋势向好且推进有序。社会和经济融合始终分列第一和第二主导位次,生态环境融合水平亦稳步提升。② 城乡融合热点和冷点区基本分列于“胡焕庸线”东南和西北两侧。人口融合沿东中西递减;空间融合形成“北上广”为主的“核心-边缘”区;东部沿海是经济融合扩散互溢区,而生态环境和经济融合存在空间“错位”;社会融合高值簇集中在中部。③ 破解人才瓶颈、夯实“三权分置”、健全财政体制并创新金融服务、调整产业结构和推动三产融合,打好人、地、钱、业组合拳同时规范政府行为、完善社会服务体系、构建小农户与现代农业有机衔接机制等均利于推进城乡融合。     

Research for time-temperature equivalence effect of rock(Ⅱ):Experimental research

With the creep test data of granite taken from Three Gorges,the existence of time-temperature equivalence effect(TTEE) of granite is investigated.Based on the creep test data at different temperatures,which are 20 ℃,60 ℃,80 ℃,100 ℃,200 ℃,300 ℃,four-component viscoelastic Burgers model is presented to characterize the creep curves.The parameters of elasticity modulus and viscosity coefficient in the constitutive model at different temperatures and their functional dependences on temperature are obtained.Then,according to the basic theory of TTEE presented in research(I),the TTEE of granite is investigated through modifying the compliance curves with vertical shift function and checking the coincidence of the modified curves with horizontal shift functions.It is concluded that:① Burgers model could appropriately characterize the creep property of granite in a short time scale.② Both elastic modulus and viscosity coefficient in the Burgers model decay exponentially with temperature.③ The coincidence of the curves at different temperatures after vertical shift modification and horizontal shift is fine,which indicates the existence of TTEE of granite.④The master curves which reflect the long time scale test data at temperatures 20 ℃,100 ℃,200 ℃ are obtained.     

Equivalence of network-solution and PPP-solution

The technique of precise point positioning (PPP) is gradually becoming a popular method in GPS data-processing. In GPS observation equation, the unknown parameters can be separated into two parts: global parameters and local parameters. The global parameters include orbit, satellite clock and geodynamic parameters. The local parameters are site-occupation-spectific, such as position, tropospheric delay, etc. The formulas of local parameters are firstly derived under the network-solution and the PPP-solution conditions respectively. If the weight matrix of global parameters in PPP-solution is small enough, the cofactor matrices of local parameters are the same as that in network-solution. Then, 16 daily solutions are obtained in both PPP mode and network mode. Three sites are selected to compare the solutions. The experimental results demonstrated that the difference between two solutions in coordinates and tropospheric delays are only few millimeters. This level of difference can be neglected so that the solutions from both PPP mode and network mode can be taken as the same in the actual application.     

基于递归学习的组合电路等价性检验方法研究

等价性检验方法通常包括功能性和结构性的验证方法。分析了等价性检验的一般方法；并讨论了基于递归学习的组合电路等价性检验方法；算法利用直接蕴含和间接蕴含的方法，解决了布尔可满足问题。实验结果表明了该方法的有效性和可行性。     

The Gravitational “Plane Waves” of Liu & Zhou and the Nonexistence of Dynamic Solutions for Einstein’s Equation

Although both the electromagnetic wave and the gravitational wave can be produced approximately from Maxwell-type equations, there are subtle differences in their respective exact equations. Since gravitational wave carries energy-momentum, the exact field equation of a gravitational wave must have a nonzero source term along its path, whereas a field equation for an electromagnetic wave does not. This explains that there is no weak wave solution of Einstein equation. Historically, neither Einstein & Rosen nor the Physical Review was aware that the nonexistence of gravitational wave solutions is due to a violation of the principle of causality. It is pointed out that the criterion of Liu & Zhou on plane-waves is valid since the principle of causality requires the existence of weak limits. However, due to the influence of the popular but unverified assumption of the existence of dynamic solutions, they made careless errors in their calculations and incorrectly concluded that their plane-waves have weak limits. It is shown that “plane-waves” of Liu & Zhou, is actually unbounded in amplitude, and have no weak limit. Therefore, Liu & Zhou provide additional evidence in supporting the nonexistence of dynamic solutions. PAC Number: 04.20.-q, 04.20.Cv, 04.30.-w