Intrinsic viscosity of polyelectrolytes in salt solutions

The dependence of the intrinsic viscosity of polyelectrolytes on the concentration of added salt is given satisfactorily by a formula obtained recently. A new viscosity—molecular weight relation gives satisfactory agreement with experiments.     

Wendroff's inequality in n independent variables

The present note obtains some generalizations of Wendroff's integral inequality. These inequalities can be used in the study of the theory of partial differential and integral equations.     

Instant capture of recoil51Cr(III) from neutron activated K2CrO4

We have recently developed a new method of measuring the initial⁵¹Cr(III) produced from nuclear recoil of K₂CrO₄. In our method, K₂CrO₄ was mixed with MgO in the presence of a small amount of water, and the mixture was irradiated in a nuclear reactor. After irradiation, the mixture was dissolved in water, and MgO precipitate was separated from the solution. The yield of recoil⁵¹Cr(III) could be calculated from the⁵¹Cr activity in the precipitate measured. On the other hand, the yield of retention of⁵¹Cr as chromate could be calcualted from the activity found in the supernatant. The⁵¹Cr(III) yield thus obtained is almost a factor of 2 higher than observed in pure K₂CrO₄ without mixing with MgO, irradiated under the same condition. Another important observation is that the⁵¹Cr(III) yield is independent of irradiation time in the presence of MgO. Without MgO, the observed⁵¹Cr(III) yield decreases with increasing irradiation time, suggesting possible oxidation of Cr(III) to chromate during irradiation. This variation is not observed in the system of K₂CrO₄ containing MgO, indicating that the initial Cr(III) is adsorbed immediately after nuclear recoil by MgO and is protected from oxidation by gamma radiation.     

应用双面电极的PLZT横向电光调制器电场的精确解

使用保角变换方法导出了横向电光调制器中双面电极结构的电场和电容的解析表达式，给出了用于ＰＬＺＴ电光陶瓷介质中二次电光效应分析的电场分布的物理图像。通过计算对比表明，双面电极结构电极边级区域由于过剩双折射引起的强度调制非均匀性较单面电极有所改善。     

Scalar phase conjugator for polarization correction

The concept of a scalar phase-conjugator is proposed and investigated. It is shown that only a scalar phase-conjugator can correct for polarization distortion and restore the original polarization state. The tensor property of a phase-conjugate reflector is investigated. An example to achieve such a scalar phase conjugation is discussed.     

Substituent effects on one-bond 15N?13C couplings in N,N-dimethylanilines and nitrobenzenes. Effect of steric inhibition of conjugation

The ¹J(¹⁵N¹³C) values for a series of ring-substituted N,N-dimethylaniline-¹⁵N derivatives and a series of nitrobenzene-¹⁵N derivatives were measured from the ¹³C spectra. In the nitrobenzenes, small changes in ¹J(¹⁵N¹³C) are attributed to the inductive effect of the substituents, since steric inhibition of conjugation has little effect on the magnitude of the coupling. In contrast, steric inhibition of nitrogen lone-pair delocalization in N,N-dimethylaniline derivatives markedly reduces the value of ¹J(¹⁵N¹³C). Theoretical calculations of ¹J(¹⁵N¹³C) values for the two series of compounds were made using standard INDO parameters and a ‘sum-over-states’ perturbation approach. Fair agreement between the calculated and experimental values is found.     

Determination of Metal Ions by High Performance Liquid Chromatography

The mixture of metal ions [Bi(III), Fe(III), Fe(II), Cu(II), Zn(II), Ni(II), Co(II), Pb(II), Cd(II), Mn(II)] were separated in the bonded-phase strong cation exchange column (Vydac-401 SA) and monitored at 540 nm after a postcolumn reaction with 4-(2-pyridylazo)-resorcinol (PAR). Citrate, tartrate, lactate and α-hydroxyisobutyrate buffer were used as eluent and it has been found that the elution order of some metal ions were changed with different eluents. The detection limits and the calibration curves of metal ions were also studied.     

Syntheses of Bissydnone Derivatives and Studies of Their Biological Activities

A new method to prepare 3,3′-ethylenebissydnone (40%), 3,3′-tetramethylenebissydnone (37%) and 3,3′-hexamethylenebissydnone (43%) from the corresponding alkylene diamine with paraformaldehyde and potassium cyanide were investigated. Some new bissydone: ?3,3′-trimethylenebissydnone (6%), 3,3′-(4,4′-diphenyl)bissydnonylmethane (9%) and 3,3′-(4,4′-diphenyi)bissydnonyl ether (28%) were synthesized from the corresponding diamine, paraformaldehyde, sodium bisulfite and potassium cyanide. Biological test of 3,3′-(4,4′-diphenyl)bissydnonylmethane shows significant response for coronary dilgtion test, inhibition of collagen induced platelet aggregation and moderate carditropic response. 3,3′-(4,4′-Diphenyl)bissydnonyl ether also shows inhibition of collagen induced platelet aggregation and moderate carditropic response.     

Bellman-Bihari integral inequalities in several independent variables

In this paper we unify certain types of integral inequalities which are established by Bellman, Bihari, Deo and Dhongade.