关于Gr(u)nwald插值算子的Lp收敛速度

本文给出了以第二类Tchebyshev多项式的零点为插值结点的Gr(u)nwald捅值多项式Lp范数下的收敛速度估计,并证明了该估计在1≤p＜2时是精确的.     

关于Grünwald插值算子的L_p收敛速度

本文给出了以第二类Tchebyshev多项式的零点为插值结点的Grunwald插值多项式在Lp范数下的收敛速度估计,并证明了该估计在1≤p<2时是精确的。     

一种拟Grünwald插值算子的加权L2收敛速度

证明了以第二类Tchebycheff多项式的零点为插值结点组的Grünwald插值算子列于L2下不是收敛算子列,后给出了一种于L2下收敛的拟Grünwald插值多项式,得到了基于加权L2下的收敛速度.     

Grnwald插值算子于加权L_2下的收敛速度

得到了Ｇｒ汃ｎｗ ａｌｄ 插值算子于加权Ｌ２ 下收敛于ｆ ∈Ｃ［－ １,１］ 的两个速度估计。     

插值算子的加权Lp收敛速度

本文讨论了以第二类Tchebycheff多项式的零点为插值结点组的Hermite-Fejer插值多项式和Grünwald插值多项式在加权L_p范数下的收敛速度。     

关于Grünwald型多项式算子的线性组合

研究了Grünwald型多项式算子Hn(f;x,r)对f(x)∈Cj[-1,1],1≤j≤r的逼近阶,在连续状态下给出了点态的逼近阶.     

两种Hermite—Fejer插值的加权Lp收敛速度

讨论了两种Ｈｅｒｍｉｔｅ－Ｆｅｊｅｒ插值算子于加权Ｌｐ下收敛于连续函数的收敛速度，证明了在估计其收敛速度时不能用光滑膜ｗｐ（ｆ，δ）代替连续续ｗ（ｆ，δ）。     

Gruenwald插值算子于加权L2下的收敛速度

得到了Ｇｒｕｅｎｗａｌｄ插值算子于加权Ｌ２下收敛于ｆ∈Ｃ〔－１，１〕的两个速度估计。     

一种拟Crunwald插值算子的加权L2收敛速度

证明了以第二类Ｔｃｈｅｂｙｃｈｅｆｆ多项式的零点为插值结点组的Ｇｒｕｎｗａｌｄ插值算子列于Ｌ２下不是收敛算子列,后给出了一种于Ｌ２下收敛的拟Ｇｒｕｎｗａｌｄ插值多项式,得到了基于加权Ｌ２下的收敛速度。     

关于一类插值多项式的最高收敛阶

以第一类Tchebyshev多项式的零点作为插值节点，推广了伯恩斯坦提出的一个问题，构造了插值多项式算子Gn,b(f;x)，它不仅对f(x)∈C^a[-1,1](p≤a≤b-1，其中b为自然数）一致收敛，而且收剑阶达到了最佳。对算子Gn,b(f;x)，最高收敛阶不会超过1/n^6，这是对伯恩斯坦所提出问题的一个圆满的回答。     

有理插值算子对连续函数的逼近

本文给出了有理插值算子当1＜S＜Z及S＞2时的Timan型逼近阶，从而推广了已有的S＞3的结果．     

M-带正交插值小波的构造

考虑由M-带正交插值函数构造相应小波函数的矩阵扩充问题。利用插值特性,给出插值函数相应正交小波符号函数的显式构造公式。最后以算例说明该算法。     

Syntactic Iron Foams – On Deformation Mechanisms and Strain‐Rate Dependence of Compressive Properties

Syntactic iron foams are produced by metal injection moulding from pure Fe powder and two grades of commercial glass microspheres. Mechanical performance of samples containing 5/10/13 wt% of microspheres is compared to unfilled reference material properties at strain‐rates covering 6 orders of magnitude, including Split Hopkinson Pressure Bar (SHPB) experiments. Complex mechanical behavior including strengthening effects of microspheres leading to a plateau strength level which is nearly independent of porosity as well as strain‐rate sensitivity of compressive properties are observed. Typical plateau onset stress levels exceed equivalent characteristics of most comparable cellular metallic materials, reaching between approximately 220 and 270 MPa under quasi‐static conditions, depending on amount and type of added microspheres. A qualitative explanation of significant events in the deformation sequence as reflected in the stress–strain‐curve is offered and discussed in the context of existing studies on syntactic foams. A course for further investigations to verify this hypothesis is suggested.     

On Grain Size Dependence of Minimum Creep Rate

The available experimental results have beensummarized concerning the effect of grain size onminimum creep rate.There are two types of creeprate-grain size relations.One is that there is a criti-cal grain size above which creep rate is independentof grain size,below which creep rate increases withthe decrease of grain size.The other is that there isan intermediate grain size at which creep resistanceis optimum.The first relation usually occurs athigher temperatures(>0.5 T_m),and intermediatestress ranges,while the second relation at interme-diate temperature ranges(0.4-0.5 T_m)and higherstresses.For the two types of creep rate-grain sizerelations,the increase of the creep rates with the de-crease of grain size for small grain sizes is all due tograin boundary sliding.For large grain sizes,a dis-location climb mechanism is dominant in creepdeformation for the first relation,while aHall-Perch grain boundary strengthening effect isbelieved to play an important role by dislocationglide mechanism for the second relation.