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981.
On the basis of the background field method, extended one-loop counterterm formulae are derived, and a method to get the two-loop double-pole counter lagrangian is given. As an example, the double-pole divergences of ξ2X3 counterterms are obtained.  相似文献   
982.
983.
In order to describe the kinematical behavior of the bimolecular chmical reaction in a dilute solution of species characterized by a single diffusion coefficient and by some nonuniform spatial distribution of the active site, a diffusion equation with a simple sink term is derived by reducing the many-body problem to a one-body problem. The equation is normalized with the concentration of unreacted particles. The so-called second-order reaction rate constant can be calculated from the solution of the equation. The equation is applied to the intermolecular termination reaction of polymer radicals on the assumption of free draining. The reaction rate constant gradually decreases with time.  相似文献   
984.
The title compound has been synthesized in enantiomerically pure form using diethyl L-tartrate as a chiral template.  相似文献   
985.
Phase equilibria of the Mn---Fe---O system (Fe/Mn = 2) were studied in the temperature range 1223–1393 K and in oxygen partial pressure from 10−1 to 105 Pa by measuring the electrical conductivity and the weight of the sample. The standard enthalpy and entropy changes per one mole oxygen for the phase boundary reaction between spinel and spinel + hematite were calculated from thermogravimetric data. A slight break in the plots between the oxygen partial pressure and weight change at constant temperature was observed in the single phase of manganese ferrite, where the lattice constant also showed a break in the plots of lattice constant against oxygen partial pressure. The oxygen potentials were calculated by assuming that the break point in the plots between the oxygen partial pressure and weight change is the stoichiometric composition of manganese ferrite.  相似文献   
986.
Summary A galvanic sensor for monitoring nitrogen dioxide was developed by using a poly(ethylene oxide) complex of silver trifluoromethanesulphonate electrolyte. The sensor, which is expressed as Au/P(EO)4.5 AgCF3SO3/Ag, is a small disk (i.d. 13 mm). The polymeric electrolyte film was made by casting the mixture of acetonitrile solutions of both P(EO) (MW 6×105) and AgCF3SO3. The working electrode was made by sputtering of gold in argon. The thicknesses of the desposited gold, polymeric electrolyte film and silver are 25 nm, 30 m and 1 mm, respectively. When the sample gas containing nitrogen dioxide impinges at 20 ml min–1 on the gold cathode, the current flowing in the external circuit was linearly related to the concentration of nitrogen dioxide from 20 ppb to about 10 ppm. The current efficiency of the cell was 0.051%. The cell's response time was about 2 min for 0.5 ppm of nitrogen dioxide.  相似文献   
987.
988.
[structure: see text] An O-glycosylated peptide carrying two core 2 sialopentasaccharides of different glycoform was synthesized as a model of the heterogeneous surface of mucin glycoprotein. Solid-phase synthesis and the subsequent enzymatic sialylation gave two segments, which were coupled by selective thioester activation to produce the title compound.  相似文献   
989.
990.
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