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A three-dimensional x-ray analylsis of a crystallinie solid of Xe(+8) formed by the reaction of XeF(6) with sodium hydroxide solution indicates that it is sodium perxenate octahydrate, Na(4)XeO(6) * 8H(2)O. The perxenate ion, XeO(6)(-4), has approximately a regular octahedral configuration with a mean xenon-oxygen bond length of 1.875 A. 相似文献
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Borzi RA Grigera SA Farrell J Perry RS Lister SJ Lee SL Tennant DA Maeno Y Mackenzie AP 《Science (New York, N.Y.)》2007,315(5809):214-217
In principle, a complex assembly of strongly interacting electrons can self-organize into a wide variety of collective states, but relatively few such states have been identified in practice. We report that, in the close vicinity of a metamagnetic quantum critical point, high-purity strontium ruthenate Sr3Ru2O7 possesses a large magnetoresistive anisotropy, consistent with the existence of an electronic nematic fluid. We discuss a striking phenomenological similarity between our observations and those made in high-purity two-dimensional electron fluids in gallium arsenide devices. 相似文献
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H Thompson I A McCandlish H J Cornwell L Macartney N S Maxwell A F Weipers I R Wills J A Black A C Mackenzie 《The Veterinary record》1988,122(16):378-385
The performance of three live attenuated feline parvovirus vaccines licensed for use in the dog was studied. At the end of the primary vaccination course 67 per cent of dogs had inadequate antibody levels (less than or equal to 32) as measured by a haemagglutination inhibition test. Interference by maternal antibody accounted for some of the failures but the fact that there was no significant difference in performance between dogs vaccinated at 12 weeks or 16 weeks of age indicated that maternal antibody was not the only factor. 相似文献
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Transmission of Cowdria ruminantium (heartwater) by nymphs of Amblyomma sparsum has been demonstrated. Adults of the same tick species failed to transmit the disease after feeding on infected sheep in either the larval or the nymphal stage, and there was no transovarian transmission. A. sparsum seldom parasitizes domestic livestock but could be of importance in maintaining reservoirs of heartwater infection in wildlife populations. 相似文献
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The prevalence and severity of gastric ulcers were investigated in a sample of 50 slaughter pigs from each of 16 commercial farms in the uk. The mean prevalence of ulcers was 19.1 per cent and the mean (se) severity score on the 16 farms was 2.2 (0.15) on a scale from 0 (normal) to 6 (severe). Multivariate regression analysis showed that the type of lying surface provided for the pigs during the finishing phase was the most important factor associated with the occurrence of gastric ulcers in the farms studied. Finisher pigs housed on slatted floors had a significantly higher mean ulcer severity score (P<0.001) than pigs housed on solid concrete floors, which had a significantly higher score (P<0.01) than pigs housed on straw bedding. Feeding a pelleted finisher ration was also associated with significant increase in ulcer severity (P<0.01) compared with feeding an unpelleted ration, but was of less importance than the type of floor. The detrimental influence of feeding pellets was ameliorated by the provision of straw bedding. 相似文献
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