重力场匹配导航的全张量重力梯度基准图模拟

针对目前重力场匹配导航研究的需要,提出了一种计算机模拟全张量重力梯度基准图的方法,可利用地形高程数据模拟计算局部地区的重力梯度数字地图.该方法从扰动重力梯度的原理出发,分析了地形起伏对重力梯度场的影响,并提出以立方体为地形单元模型,积分计算测量点附近的地形对测量点重力梯度各个分量值的扰动影响.在此基础上模拟格网式测量,从而得到较高分辨率的全张量重力梯度数字地图.仿真实验表明,这种方法计算所得的重力梯度基准图可以精确到10-2～10-1E,相对误差为8.27%,并且存在大量的细节纹理,有着较好的导航应用前景.与实测数据的对比分析说明,所得的重力梯度基准图基本符合实测数据的特性,所提出的方法可以作为一种有效的全张量重力梯度基准图模拟的方法.     

ON THE EQUIVARIANT HARMONIC MAPS BETWEEN SURFACES IN R~3

In this paper,we study the existence and regularity of G-equivariantharmonic maps between surfaces with a finite group G(?)O(3)action.We discoverthat the energy level of compactness in the G-equivariant perturbed problems ishigher than that in general case.This implies the multiplicity of harmonic mapsfor some examples.     

某些耦合离散系统浑沌映射的同步性

研究了某些线性耦合浑沌映射的同步性的问题，给出了耦合线性浑沌映射的同步性的一些充分条件，同时介绍了一种证明耦合浑沌映射同步性的方法．针对Logistic映射xn 1=αxn(1-xn)和Henon映射的耦合浑沌映射进行了研究，耦合系数对线性耦合映射的同步性有着十分明显的影响．     

半严格伪上强制映射及其在变分不等式中的应用

该文在伪上强制映射的基础上,介绍了半严格伪上强制映射,讨论了这类映射的若干性质及其在变分不等式中的应用．     

A和B是k-集压缩映射方程x∈Ax+λBx在锥中的可解性

设X是一实Bomach空问,DX是含0点的一有界开集,KX是一个锥.在≠φ时=int K),我们证明了一个关于方程:x∈Ax十λBx可解的新结果(定理2),其中A和B是k-集压缩映射,这个结果的一个特别情形,即A≡0时回答了Petryshyn在提出的一个开问题.文中定理1和3分别是A+B和A在D∩K上的不动点指数为0新的结果.     

Hermite矩阵保秩1导出映射

设C是复数域,fij（i,j∈[n]△{1,3,…,n}）是从C到自身的映射,Hn（C）是C上n阶Hermite矩阵全体所成集合,f是Hn（C）上由{fij}n诱导的映射,在f（0）=0条件下给出了Hn（C）上保秩1的导出映射的形式。     

On the boundary value problem for harmonic maps of the Poincaré disc

The boundary value problem for harmonic maps of the Poincare disc is discussed. The emphasis is on the non-smoothness of the given boundary values in the problem. Let T . be a subspace of the universal Teichmüller space, defined as a set of normalized quasisymmetric homeomorphisms h of the unit circle S onto itself where h admits a quasiconformal extension to the unit disc D with a complex dilatation μ satisfying where ρ(z)|dz|2 is the Poincare metric of D. Let B . be a Banach space consisting of holomorphic quadratic differentials φ in D with norms It is shown that for any given quasisymmetric homeomorphism h : S1→S1∈ T . , there is a unique quasiconformal harmonic map of D with respect to the Poincare metric whose boundary corresponding is h and the Hopf differential of such a harmonic map belongs to B .     

挤压态CuCr25合金热变形行为及其加工图

在Gleeble-3500D热模拟试验机上,对挤压态CuCr25合金在应变速率为0.01~10s~(-1),变形温度为750~900℃的条件下进行恒温压缩模拟实验.结果表明:挤压态CuCr25合金在热变形过程中流变应力随变形温度升高和应变速率降低而减小;可用双曲正弦模型来描述合金的流变行为,其平均激活能为383.4kJ/mol;基于动态材料模型获得了挤压态CuCr25合金的热加工图,并结合金相显微组织分析得到了该合金在实验参数范围内较优的热加工工艺参数范围:加工温度830~900℃,应变速率为0.01~0.1s-1.     

Hot deformation behavior of uniform fine-grained GH4720Li alloy based on its processing map

The hot deformation behavior of uniform fine-grained GH4720Li alloy was studied in the temperature range from 1040 to 1130℃ and the strain-rate range from 0.005 to 0.5 s?1 using hot compression testing. Processing maps were constructed on the basis of compression data and a dynamic materials model. Considerable flow softening associated with superplasticity was observed at strain rates of 0.01 s?1 or lower. According to the processing map and observations of the microstructure, the uniform fine-grained microstructure remains intact at 1100℃ or lower because of easily activated dynamic recrystallization (DRX), whereas obvious grain growth is observed at 1130℃. Metallurgical instabilities in the form of non-uniform microstructures under higher and lower Zener–Hollomon parameters are induced by local plastic flow and primary γ′ local faster dissolution, respectively. The optimum processing conditions at all of the investigated strains are proposed as 1090–1130℃ with 0.08–0.5 s?1 and 0.005–0.008 s?1 and 1040–1085℃ with 0.005–0.06 s?1.     

Lorenz映射中的拓扑熵递减级联

利用推广的ＭｉｌｎｏｒＴｈｕｒｓｔｏｎ 揉理论和Ｓｔｅｆａｎ 转移矩阵，给出Ｌｏｒｅｎｚ 映射拓扑熵的２ 种计算方法；利用揉理论，研究复合词揉多项式的因子化、＊ 积对拓扑熵的变换及通向混沌的２ 类道路之一：拓扑熵递减并趋向零的道路．