Experimental investigations of changes in the rate of beta decay of radioactive elements

Changes in the rate of the beta decay of radioactive elements whose periods are about 24 h and 27 d are detected on the basis of long-term investigations performed with the aid of scintillation and germanium-lithium gamma detectors. The use of the scintillation procedure yields results whose level of significance is much higher than 5%, while the procedure based on germanium—lithium detectors gives a more than 1% deviation from the average value of fluxes of gamma rays accompanying, for example, ⁶⁰Co beta decay. With allowance for the rotation of the laboratory frame together with the Earth, deviations of the change in the rate of beta decay of radioactive elements single out three directions in the physical space.     

A New Flavone Glycoside from Isodon enanderianus

Isodon enanderianus (Hand.-Mazz.) H. W. Li, a perennial shrub plant of Labiatae family, is widely distributed in the southern part of Yunnan province. It has long been used as folk medicine to diminish inflammation and detoxify1. The Isodon genus is known to be rich in ent-kaurane diterpenoids, a series of new ent-kaurane diterpenoids have been isolated from the dried leaves of I. enanderianus2-4. During the course on a re-investigation of the chemical constituents of I. enanderianus, four…     

Diamagnetic probe atoms of Tin-119 in magnetically ordered ferrites with a brownmillerite-type structure

The method of Mossbauer probe spectroscopy on ¹¹⁹Sn nuclei was used applied to study the influence of the nature of the alkali-earth cation A²⁺ = (Ca, Sr) in A₂Fe₂O₅ ferrites with an ordered brownmillerite-type structure on the formation of the local environment and magnetic hyperfine interactions of probe tin atoms.     

Wisdom of symbols

This is an overview of the origins and vistas of mathematics.     

A simulation study of scheduling clinic appointments in surgical care: individual surgeon <Emphasis Type="Italic">versus</Emphasis> pooled lists

The purpose of this paper is to compare two methods of scheduling outpatient clinic appointments in the setting where the availability of surgeons for appointments depends on other clinical activities. We used discrete-event simulation to evaluate the likely impact of the scheduling methods on the number of patients waiting for appointments, and the times to appointment and to surgery. The progression of individual patients in a surgical service was modelled as a series of updates in patient records in reaction to events generated by care delivery processes in an asynchronous fashion. We used the Statecharts visual formalism to define states and transitions within each care delivery process, based on detailed functional and behavioural specifications. Our results suggest that pooling referrals, so that clinic appointments are scheduled with the first available surgeon, has a differential impact on different segments of patient flow and across surgical priority groups.     

CFBC混烧城市污泥与煤:N2O和NO的排放

在0.15MWth CFBC试验台上混烧城市污泥与煤,当城市污泥的含水率和混烧率分别变化在30％～60％和25％～100％之间时,可以实现稳定燃烧。分析了炉膛温度和城市污泥混烧率对NO和N_oO生成浓度的影响。结果显示,在焚烧氮含量很高的城市污泥过程中,通过适当提高炉膛温度,可以控制N_2O的生成,但是NO的生成浓度主要与混烧率有关。     

Peculiarities in total cross sections of reactions with weakly bound nuclei <Superscript>6</Superscript>He, <Superscript>9</Superscript>Li

The energy dependence of the total cross sections for the ⁶He + Si and ⁹Li + Si reactions was measured at beam energies between 5 and 20 MeV per nucleon. The results agree with experimental data published for the ⁶He + Si reaction. New data are obtained for the ⁹Li + Si reaction in the vicinity of a local enhancement of the total cross section. A theoretical analysis of the possible reasons behind the appearance of this peculiarity in the case of collisions of ⁶He and ⁹Li nuclei with silicon target nuclei is performed. In particular, the enhancement may owe its origin to the effect of loosely bound projectile nucleons.     

Investigation of total cross sections for reactions induced by <Superscript>6</Superscript>He interaction with silicon nuclei at energies between 5 and 50 MeV/<Emphasis Type="Italic">А</Emphasis>

Experimental excitation functions in terms of the total cross sections for ⁶He + Si nuclear reactions are analyzed in the energy range between 5 and 50 MeV/А, and a brief survey of the procedures used to obtain experimental data is given. Particular attention is given to describing experiments performed in beams of radioactive nuclei from the accelerators of the Laboratory of Nuclear Reactions at the Joint Institute for Nuclear Research (JINR, Dubna). The experimental data in question are analyzed on the basis of a semimicroscopic optical model.