On the system of functional equationsf(x + y) = f(x) + f(y) andf(xy) = p (x)f(y) + q(y)f(x)

Aequationes mathematicae -     

Radiation effects of poly(vinylidene fluoride) (PVDF) (I)

The relationship between the crystallinity of poly (vinylidene fluoride) (PVDF) and electron radiation effects is studied with differential scanning calorimeter and X-ray diffraction. The form of crystal of PVDF is not changed. In the low dose zone (lower than 400 kGy), the crystallinity of PVDF increases slightly with the increase of absorbed dose, and then decreases slowly, whereas the decrease of the crystallinity is accelerated with the increase of the absorbed dose in high dose zone. Gel and Sol properties of irradiated samples of PVDF are also studied with extraction of N, N-dimethyl formamide. In a low dose range, it fits Charlesby-Pinner formula very well; however, with the increase of the dose, it begins to deviate from this formula because of the obstruction of the crystalline region of PVDF.     

Autour def(x)f(y) −f(xy)

Sans résumé

---

     

Некоторые вопросы теории приближения в пространствах L p(x) (E)

Some aspects of approximation theory are studied in the paper for the spaces of integrable functions with variable exponent. In particular, necessary and suffcient conditions on the variable exponent are established that guarantee the basis property of the trigonometric system in the corresponding normed spaces. Namely, these conditions require that the periodic variable exponent p(x) > 1 satisfy the Dini-Lipschitz condition.     

(IC)式Stone-(C)ech紧化

以Hutton单位区间I(L)的外(IC)化空间(L)作为标准单位区间,引入了相应的(IC)完全正则分离性,建立了这类空间的嵌入理论并给出了(IC)式Stone-(C)ech紧化定理.     

(NCI)算子与(NFI)算子

引入两类与不变子空间密切相关的算子,即(NCI)算子与(NFI)算子.考虑这两类算子的性质,例如存在性,相似不变性,以及与强不可约算子的关系等.并在可分Banach空间上讨论谱为单点集{0}的算子能否小紧摄动成为(NFI)算子.     

Bounds on the solution of the time-varying linear matrix differential equation P(t) = AH(t) P(t) + P(t) A(t) + Q(t)

^** Email: pagilla{at}ceat.okstate.edu We derive upper and lower bounds for the trace of the solutionof the time-varying linear matrix differential equation (t)= A^H(t) P(t) + P(t) A(t) + Q(t). A practical numerical exampleis given to verify the bounds. The bounds obtained are usefulsince the considered equation is encountered in a number ofapplications in systems and control theory.     

关于φ（z）f（z）f＇（z）的值分布

本文研究有穷圆内的值分布，其中ｆ（２）为非常数亚纯函数，为非零亚纯函数，并对平面上这样的函数，若，得到     

On the functional equationf(x) g(y) = p(x + y) q(x/y)

Aequationes mathematicae -     

Remarks onB(H) ⊗B(H)

We review the existing proofs that the min and max norms are different onB(H) ⊗B(H) and give a shortcut avoiding the consideration of non-separable families of operator spaces.     

L^∞（G）中的一个闭凸不变集

设G是局部紧群,f是G上的右一致连续函数.本文讨论L(G)中一个闭凸不变集的关系式Co{Lxfx∈G}11@11={φ*fφ∈P＇(G)}11@11(f∈R∪C(G)).由此式易得出RUC(G)上的左不变平均与拓扑左不变平均的等价关系.