The maximal Fejér operator on the spacesH p (R×···×R)

It is shown that the maximal operator of the Fejér means of a tempered distribution is bounded from thed-dimensional Hardy spaceH _p (R×···×R) toL _p (R ^d ) (1/2<p<∞) and is of weak type (H ₁ ^?i ,L ₁) (i=1,…,d), where the Hardy spaceH ₁ ^?i is defined by a hybrid maximal function. As a consequence, we obtain that the Fejér means of a functionf ∈H ₁ ^?i ?L(logL) ^d?1 converge a.e. to the function in question. Moreover, we prove that the Fejér means are uniformly bounded onH _p (R×···×R) whenever 1/2<p<∞. Thus, in casef ∈H _p (R×···×R) the Fejér means converge tof inH _p (R×···×R) norm. The same results are proved for the conjugate Fejér means, too.     

Использование изотопа N15 в изученпи усвояемости азотньіх минеральньіх удобрений

The effect of contamination of a cyanide, phosphate-buffered gold-plating bath with iron, cobalt, or nickel on the codeposition of these metals with gold, was investigated using ⁵⁹Fe, ⁵⁸Co and ⁶³Ni. It was shown that cobalt and nickel were practically not codeposited in gold if present in the solution in amounts up to 1000 or 2000 mg/dm³ respectively. Iron deposited in high amounts (up to 18%) depending on its concentration and the cathode current density. The diminishing in current efficiency of the plating process is proposed as an early signal of the contamination of gold deposit with iron.     

Direct and inverse theorems of approximation theory for a generalized modulus of smoothness

An asymmetric operator of generalized translation is introduced in this paper. Using this operator, we define a generalized modulus of smoothness and prove direct and inverse theorems of approximation theory for it.     

Исследование роли фосфиновых комплексов никеля различных степеней окисления в каталитической димеризации олефинов

Ni(II), Ni(I) Ni(O) . , , , Ni(O) Ni(I) - Ni(I) Ni(II) Ni(O).

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The interaction of organoaluminium compounds with phosphine complexes of Ni(II), Ni(I) and Ni(0) has been studied under the conditions of catalytic propylene dimerization. The active complexes are formed from Ni(II) compounds, the regeneration of the latter is ensured by repeated reduction, oxidation of Ni(0) to Ni(I), and by disproportionation of Ni(I) into Ni(II) and Ni(0).

     

Infinite matrices and Cesàro sequence spaces

Целяу даннои работы является введение пространства последователяностеиces[(p _n ), (q _n )] и характериэация классов матриц (ces[(p _n ), (q _n )],?_∞) и (ces[(p _n ), (q _n )],c), где ?_∞ и с — пространства ограниченных и, соответственно, сходяшихся комплексных последователяностеи. При специаляном выборе последователяностеи {p _n } и {q _n } получаутся некоторые иэвестные следствия.     

Enantioseparation of Novel Amino Analogs of Indole Phytoalexins on Macrocyclic Glycopeptide-Based Chiral Stationary Phase

Direct chiral separation of the enantiomers of spirobrassinin, 1-methoxyspirobrassinin and ten novel cis- and trans-diastereoisomers of 2-amino analogs of indole phytoalexin 1-methoxyspirobrassinol methyl ether on macrocyclic glycopeptide-based chiral stationary phase (CSP) with teicoplanin (Chirobiotic T) was studied. Normal phase eluents containing n-hexane with modifiers ethanol and 2-propanol were used. The effects of mobile phase composition, structure of the analytes and temperature were investigated. Chiral resolution on teicoplanin CSP was achieved only in the case of trans-diastereoisomers. The van??t Hoff plots were found to show linear behavior in all cases. It was found that studied normal phase enantioseparations were enthalpy driven. The elution order of the enantiomers was determined in some cases.     

在晶体和溶液中氟离子的核磁共振化学位移的研究

本文简单地描述了一种具有中等分辨本领的核磁共振波谱仪及测量固体中共振讯号化学位移的方法。对周期表中第一、二两族元素的氟化物晶体的F¹⁹共振的化学位移(δ)作了研究,发现除LiF以外,δ随着金属元素原子序数的增加而减少。用Yosida和Moriya的部分共价性理论以及Kondo和Yamashita电子壳层重迭理论讨论了实验结果,计算了碱金属氟化物相邻离子的重迭积分,用Kondo和Yamashita公式得到了与实验基本相符的磁屏蔽常数。根据这个符合,估计了氟的核磁屏蔽常数的绝对值σ,得到了合理的结果。研究了NH₄F盐类水溶液中F¹⁹共振位移的浓度效应,发现δ随浓度的增加而直线下降。把δ值和浓度关系的曲线外推到固体的克分子浓度值时,得到与直接测得的δ值相符的结果。其他碱金属氟化物水溶液的化学位移也有类似行为,表明溶液中离子间的相互作用对离子的电子结构的影响与固体中基本相同酸性氟化物盐类水溶液的研究确定了HF和HF₂^-的δ值。     

Finite pseudocomplemented lattices: The spectra and the Glivenko congruence

Recently, Gr?tzer, Gunderson and Quackenbush have characterized the spectra of finite pseudocomplemented lattices, solving a problem raised by G. Gr?tzer in his first monograph on lattice theory from 1971. In this note we discuss the tight connection between the spectra and the Glivenko congruence of finite pseudocomplemented lattices.