Experiments sensitive to pp neutrinos from the Sun are very promising for precise measurement of the mixing angle ϑ12. A νe− scattering experiment (XMASS) and/or a charged-current experiment (indium detector) can measure the flux of electron pp neutrinos. One can find the total flux of pp neutrinos from a luminosity constraint after the contributions of 7Be and CNO neutrinos to the total luminosity of the Sun are measured. A radiochemical experiment utilizing a lithium target
has high sensitivity to the CNO neutrinos; thus, it has a good promise for precise measurement of the mixing angle and for
a test of the current theory of evolution of the stars.
The text was submitted by the authors in English. 相似文献
Russian Chemical Bulletin - A series of organosilicon rubbers of the addition-curable type containing dimethyland methylphenylsiloxy, or diphenylsiloxy units with terminal vinyl groups were... 相似文献
A synthesis of organosilicon 1,3-benzoxazines (BZ-Si) was accomplished by the reaction of organic phenols, paraformaldehyde and 3-aminopropyl(trialkoxy)silanes, as well as organosilicon phenols of the general formula R´[SiMe2O]n[SiMeRO]mSiMe2R´ (R´ is 4-hydroxy-3methoxyphenylpropyl-, R is methylor 4-hydroxy-3-methoxyphenylpropyl), paraformaldehyde, and aniline (or monoethanolamine). The structure of BZ-Si was confirmed by NMR and IR spectroscopy. The studies of BZ-Si by DSC showed that the benzoxazine ring opening takes place in the temperature range 130—265 °C. The temperature of 5% mass loss of BZ-Si in air is within 220—270 °C (TGA). 相似文献
The objective of the study is themass spectrometry analysis of the protein composition in blood plasma samples of large intestine cancer patients. Protein profiles of 58 blood plasma samples of large intestine cancer patients and healthy volunteers are analyzed using ultrahigh-resolution panoramic mass spectrometry. It is shown that the coincidence of identifications in the protein composition samples of intestine cancer patients and healthy men is 60–80%. Samples of intestines cancer patients contain proteins involved in the interaction with ribonucleic acid, proteins, and lowmolecular substrata. 相似文献
Folates have a pterine core structure and high metabolic activity due to their ability to accept electrons and react with O-, S-, N-, C-bounds. Folates play a role as cofactors in essential one-carbon pathways donating methyl-groups to choline phospholipids, creatine, epinephrine, DNA. Compounds similar to folates are ubiquitous and have been found in different animals, plants, and microorganisms. Folates enter the body from the diet and are also synthesized by intestinal bacteria with consequent adsorption from the colon. Three types of folate and antifolate cellular transporters have been found, differing in tissue localization, substrate affinity, type of transferring, and optimal pH for function. Laboratory criteria of folate deficiency are accepted by WHO. Severe folate deficiencies, manifesting in early life, are seen in hereditary folate malabsorption and cerebral folate deficiency. Acquired folate deficiency is quite common and is associated with poor diet and malabsorption, alcohol consumption, obesity, and kidney failure. Given the observational data that folates have a protective effect against neural tube defects, ischemic events, and cancer, food folic acid fortification was introduced in many countries. However, high physiological folate concentrations and folate overload may increase the risk of impaired brain development in embryogenesis and possess a growth advantage for precancerous altered cells. 相似文献
The effect of sintering aids of SiO2, ZrO2, B2O3, and MgO oxides on the optimum sintering temperature, ceramics grain growth, total volume of residual pores, and optical quality of obtained ceramics is studied. The best combinations of sintering aids are found; as a result, YAG:Nd (1 at%) samples of ceramics of high optical quality are obtained. An original method for characterizing laser properties of ceramics is developed. Comparative measurements of main laser characteristics of the obtained ceramics and ceramics of the Konoshima Chemical Corp. Ltd wellknown in the world practice, are performed. 相似文献
The influence of the size of Y2O3 powder particles on the structure formation and densification of Nd3+:Y3Al5O12 laser ceramics has been studied. It is shown that the use of 50- and 100-nm yttrium oxide particles makes it possible to synthesize single-phase yttrium aluminum garnet at temperatures of 1200 and 1500°C, respectively, whereas in the case of 5000-nm yttrium oxide particles 2-h exposure at a temperature of 1500°C yields only 80 wt % of the Nd3+:Y3Al5O12 phase. Bulk swelling of pressed samples during sintering of 2.94Y2O3-0.06Nd2O3-5Al2O3 powders with the size ratio of the initial particles R(Al2O3/Y2O3) ~ 5 is observed. The application of different-sized powders (R ~ 2.5) provides quantitative ratios between phases in the 3Y2O3-5Al2O3 system at which shrinkage in a temperature range of 20–1500°C is dominant. Laser ceramics 0–2 at % Nd3+:Y3Al5O12 have been obtained by the solid-phase sintering of oxide powders (R ~ 2.5). The slope efficiency for 1 at % Nd3+:Y3Al5O12 laser ceramics is found to be 33%.