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- Author or Editor: B. Wang x
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Invariant results are established for a considerably general multiplier convergence of operator series where the operators are defined on arbitrary topological vector spaces and valued in arbitrary locally convex spaces.
Abstract
The recent progress of positron studies on polymers are briefly reviewed. The correlation between free-volume holes and mechanical properties are discussed. The results indicate that the positron spectroscopy is a potential tool to characterize the microstructure and mechanical properties of polymeric materials.
Abstract
This paper is concerned with the divergence points with fast growth orders of the partial quotients in continued fractions.
Let S be a nonempty interval. We are interested in the size of the set of divergence points
Abstract
The influence of solution composition (pH, salts, and chelant) on the thermostability of horse liver alcohol dehydrogenase was studied by differential scanning calorimetry (DSC) in the pH range from7.51 to 9.50 and showing the enzyme catalytic activity. The experiments demonstrated that the effect of increasing pH on the heat denaturation temperature of the enzyme was slight, but the denaturation enthalpy was considerably increased, indicating the enzyme conformation alteration by changing pH and the presence of enthalpy-entropy compensation. The effect of ionic strength on thermostability was not noticeable, i.e., the electrostatic interactions were not a dominant factor for the thermostability. The anions Cl− and SCN− imposed diverse influence upon the enzyme thermostability, and SCN−can reduce the thermostability considerably. The chelant 1,10-phenanthroline, which can reversibly bind together with the zinc ions functioning the catalytic action in the enzyme molecules, increases the thermostability considerably. The hydration of the enzyme plays an important role to the thermostability.
Abstract
Positron annihilation lifetime spectra and ionic conductivity have been measured for poly(etherurethane)-LiClO4 as a function of temperature. The effects of Li salt on glas transition free volume and ionic conductivity have been discussed. A correlation between fractional free volume and ionic conductivity was first experimentally confirmed by using the free volume theory.
Abstract
Let X,X 1,X 2,… be a sequence of non-degenerate i.i.d. random variables with mean zero. The best possible weighted approximations are investigated in D[0, 1] for the partial sum processes {S [nt], 0 ≦ t ≦ 1} where S n = Σ j=1 n X j , under the assumption that X belongs to the domain of attraction of the normal law. The conclusions then are used to establish similar results for the sequence of self-normalized partial sum processes {S [nt]=V n , 0 ≦ t ≦ 1}, where V n 2 = Σ j=1 n X j 2. L p approximations of self-normalized partial sum processes are also discussed.
Abstract
This paper investigates weighted approximations for Studentized U-statistics type processes, both with symmetric and antisymmetric kernels, only under the assumption that the distribution of the projection variate is in the domain of attraction of the normal law. The classical second moment condition E|h(X 1, X 2)|2 < ∞ is also relaxed in both cases. The results can be used for testing the null assumption of having a random sample versus the alternative that there is a change in distribution in the sequence.
Abstract
N,N,N
,N-tetrabutylmalonamide (TBMA) was synthesized and used for extraction of uranyl(II) ion from nitric acid media in toluene. The effects of nitric acid concentration, extractant concentration, temperature and salting-out agent (LiNO3) on distribution coefficients of uranyl(II) ion have been studied. The extraction of nitric acid is also studied. The main adduct of TBMA and HNO3 is HNO3. TBMA in 1.0 mol/l nitric acid solution. The 1:2:3 complex of uranyl(II) ion, nitrate ion and TBMA as extracted species is further confirmed by IR spectra of the extraction of uranyl(II) ion with TBMA, and found that the NO
3
–
in the extraction species UO2(NO3)2·3TBMA did not participate in coordination of uranyl(II) ion. The values of thermodynamic parameters have also been calculated.
Abstract
N,N,N
,N-tetrabutylsuccinylamide (TBSA) was synthesized, characterised and used for the extraction of U(VI) and Th(IV) from nitric acid solutions into n-dodecane. Extraction distribution coefficients of U(VI) and Th(IV) as a function of aqueous nitric acid concentration, extractant concentration and temperature have been measured and found that n-dodecane as diluent was superior to 50% 1,2,4-trimethyl benzene (TMB) and 50% kerosene, (OK) system for extraction of U(VI) and Th(IV). The compositions of extracted species, equilibrium constants and enthalpies of extraction reactions have also been calculated. The formation of the 1
21 complex of uranyl(II) ion or the 141 complex of thorium(IV) ion, nitrate ion and TBSA and extracted species was further confirmed by the IR spectra of saturated extract of U(IV) and Th(IV).
Abstract
The extraction of U(VI) with newly synthesized long chain alkyl amide, N,N-dibutyldodecanamide (DBDA), in toluene has been studied. The dependence of the extraction on nitric acid and DBDA concentrations and temperature from nitric acid solution has been considered. The extracted species has also been investigated using FT-IR spectrometry. The related thermodynamic functions were calculated. The separation factor between U(VI) and Th(IV) is higher and there is no third phase formation under the conditions studied.
