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51.
Michael A. Noble 《Accreditation and quality assurance》2002,7(8-9):341-344
External quality assessment for microbiology laboratories has seen many changes over the past ten years. EQA is much less
focused on the pure analytic process of identifying single organisms submitted in an artificial medium. Samples are more realistic,
and can be used to address clinical relevancy. Samples can be supplemented with a variety of non-traditional challenges to
extend testing to include a wider range of the pre- and post-analytic aspects of the laboratory cycle. A look to the future
sees a broad range of newer targets, with increasing interest in virology and point-of-care testing.
Received: 13 April 2002 Accepted: 24 June 2002 相似文献
52.
K. J. Albutt 《Accreditation and quality assurance》1998,3(7):279-280
Accredited laboratories are the accreditation bodies customers – all other interested parties are stakeholders. The ultimate
consumer expects his product to be safe, reliable and good value for money. All other expectations in the supply chain relate
to the consumer's expectations. 相似文献
53.
Amperometric oxygen electrodes are useful transducers for enzymatic analyses. One must, however, account for contributions from oxygen incorporation or depletion caused by sample introduction, stirring and diffusion, or non-enzymatic reactions, as well as for instrumental response time. Examples of various characteristics of these contributions are shown and discussed from a theoretical basis. 相似文献
54.
G. Hadjipanaysis S.C. Cornelison J.A. Gerber D.J. Sellmyer 《Journal of magnetism and magnetic materials》1980,21(1):101-107
We have studied the magnetic and electrical properties of several amorphous rare-earth—transition-metal alloys obtained by splat cooling. Low-field susceptibility, high-field magnetization and electrical resistivity measurements were made between 1.6 and 300 K. Mössbauer results are reported for (Gd65Fe35)90B10 at the temperatures of 80 and 300 K. Resistivity measurements show both positive and negative coefficients and in some cases maxima or minima that are associated with magnetic ordering or Kondo-type scattering, respectively. 相似文献
55.
F.W. Büsser L. Canilleri L. Di Lella B.G. Pope A.M. Smith B.J. Blumenfeld S.N. White A.F. Rothenberg S.L. Segler M.J. Tannenbaum M. Banner J.B. Chèze H. Kasha J.P. Pansart G. Smadja J. Teiger H. Zaccone A. Zylberstejn 《Nuclear Physics B》1976,113(2):189-245
Measurements of single-electron production in proton-proton collisions at the CERN ISR are presented for five centre-of-mass energies √s = 23.5, 30.6, 44.8, 52.7, and 62.4 GeV. The invariant cross sections for single electrons with transverse momenta of 0.60 to 4.7 GeV/c are given. Measurements of electron-positron pairs and measurements of charged hadrons produced in association with the single electrons, are also reported. 相似文献
56.
M.H. Hecht A.J. Viescas I. Lindau J.W. Allen L.I. Johansson 《Journal of Electron Spectroscopy and Related Phenomena》1984,34(4):343-353
We report on the four-peak structure observed in the region of 4f photoemission in Yb metal, using synchrotron radiation in the energy range 70–200 eV. We conclude, contrary to previous reports, that the doublet associated with surface emissions results from an intrinsic surface shift on clean regions of the surface. We also demonstrate that the observed structure is consistent with earlier XPS measurements, and we set an upper limit on the width of the bulk peaks. 相似文献
57.
A carefully controlled interlaboratory comparison of analyses by size exclusion chromatography of a poly(vinyl acetate) whole polymer showed that compatible measurements could be made of the molar mass distribution. The characterized sample is available as a Community Bureau of Reference (BCR) test material. 相似文献
58.
Densities of water—glycol (mono- di-, tri- and tetraethyleneglycol) mixtures have been measured over the entire composition range at 298. 15 K. Mixtures involving monoethyleneglycol (MEG) have also been studied at different temperatures from 308.15 to 288.15 K. Deviations, VE, from ideal volumes of mixing have been calculated: negative values are observed for all systems. They increase with the number of ether functions present in the organic molecule; a slight dependence of VE towards temperature has been shown in the water—MEG mixtures. Partial molal volumes have also been calculated for both components of each system; they exhibit an extremum in the water-rich region. 相似文献
59.
The determination of manganese in iron and steels by u.h.f. plasma torch spectrometry is described. The intensity of the Mn II 257.16-nm ion line decreased with increasing concentration of iron, whereas the intensity of the Mn I 403.07-nm atom line increased; only the Mn I 279.48-nm atom line showed constant intensity as the concentration of iron increased. This behavior can be explained in terms of plasma temperature. The effects of acids were examined; the influence of small amounts of diverse elements was depressed by a large amount of iron. A simple and rapid method for the determination of manganese in iron and steels was established, the relative standard deviation being 2.6 % for 0.10 % Mn. 相似文献
60.
James Kao 《Journal of Molecular Structure》1980,63(2):293-300
The structures of S42+ and S42? have been investigated by ab initio calculations using the GAUSSIAN 70 system of programs and the 44-31G basis set. Electronic singlet states of the square form and three possible conformations of the chain structure were examined for both ions, and the singlet rectangle form of S42? was also investigated. The anti chain form of S42+ was found to be 78.3 kJ mol? more stable than the square form, in contrast to previous experimental data. S42?is predicted to adopt the chain structure with the anti conformation. 相似文献