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21.
Sponge endemic species inhabit the Lake Baikal from the ancient times. Because the sponges are the biological filters of the Baikal water and they contribute greatly to silicon circulation in the lake, it is crucial to analyze their composition. Only a few publications report the analytical data concerning the element composition of Lake Baikal sponges. However, the analytical data were mainly obtained by destructive methods. No data on the concentrations of some alkaline and volatile elements are available so far. This article describes the application of wavelength dispersive X‐ray fluorescence spectrometry to study the sponges of Lubomirskia baicalensis, Baikalospongia bacillifera, and Baikalospongia recta species collected at the littoral part of the Beryozovy Cape in the Southern Baikal. The concentrations of 19 elements Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr, and Ba have been determined. In this article, we discuss the problem of selecting calibration samples for wavelength dispersive X‐ray fluorescence spectrometry, because appropriate reference samples are not available. The synthetic specimens, prepared by mixing plant certified reference materials and silicon dioxide in certain proportions, were proposed for calibration. The compositions of sponges cleaned from mineral particles and symbiotic organisms, as well as unwashed sponges, have been compared. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
22.
Much of the in vivo research that has been conducted on the health effects of pollutants such as SO2 and NO2 has been concerned with their effects upon lung defense systems, with particular reference to their effect on functional properties of the alveolar macrophage (AM). The lungs are constantly exposed to the external environment with its variable content of irritants and infectious agents. Agents deposited in or below the region of the respiratory bronchioles are phagocytized by the AM. The specific capacity of the AM to perform its task is subject to many factors. Gaseous air pollutants have been shown to affect the functional state of the cells(1). Phagocytosis is an energy dependent process and plasma membrane ATPase has been suggested to act as a mechanoenzyme making phagocytosis possible through the conversion of chemical energy in the form of ATPase to the mechanical energky required for attachement and ingestion (2). Since the bulk of the cellular ATPase activity is located in the plasma membrane of the AM(3) the enzyme is easily accessible to inhaled pollutants. Furthermome, the activity of ATPase and other membrane bound enzymes is well know to be dependent upon the fluidity of membrane lipids.  相似文献   
23.
Ph. Pruzan  N. Dahan 《高压研究》2013,33(1-6):546-548
Abstract

The expansivity of n-hexane was measured through the heat of compression up to 500 MPa in the 243–473 K temperature range. Details about the experiment are given. From the fit to our data, the pressure variation of the specific heat Cp, in the same pressure-temperature domain, is computed; good agreement is obtained with available high pressure data.  相似文献   
24.
Specific properties of the hydrogen bond and protons appear to be responsible for the formation of the quasi-liquid state of conducting ions and the resulting superionic behaviour. This state is reached by successive phase transitions involving the mobile species and their interactions with a more or less rigid framework. H3OUO2PO4 · 3H2O (HUP) and CsHSO4 can be considered as models of wet and dry superionic conduction, respectively. Interactions between static effects and dynamical disorder as well as the coupling between sublattices are discussed in relation to results obtained by calorimetry, impedance spectroscopy (up to 10 GHz), vibrational spectroscopy and quasi-elastic neutron scattering.  相似文献   
25.
26.
The chemical state of gold in gold ores, mattes and roaster products has been studied by197Au Mössbauer spectroscopy. Gold minerals were studied in order to provide reference data for the ore spectra.57Fe Mössbauer spectroscopy was used to monitor the iron compounds always present in gold ores and to follow their transformations caused by smelting and roasting.  相似文献   
27.
Thee + e ?K + K ? cross section has been measured from about 750 events in the energy interval \(1350 \leqq \sqrt s \leqq 2400 MeV\) with the DM2 detector at DCI. TheK ± form factor |F F ±| cannot be explained by the ρ, ω, ? and ρ′(1600). An additional resonant amplitude at 1650 MeV has to be added as suggested by a previous experiment.  相似文献   
28.
The wavenumbers of the vibration rotation band lines of 14N16O are reported for the 2Π12-2Π12, 2Π12-2Π12 and 2Π12-2Π12 subbands of the 1-0 transition in the infrared. The full set of spectroscopic constants for this band has been determined by direct approach using the analysis of Zare, Schmeltekopf, Harrop, and Albritton. In addition to the band origin ν0 and the B, D, H constants for the lower and upper vibrational levels, the following spin-orbit coupling constants have been derived: A?0 = 123.02772 ± 0.00011 and A?1 = 122.78248 ± 0.00011 (in cm?1). Apparent centrifugal corrections to these constants have been determined and the values obtained for them are A?D0 = (0.347573 ± 0.00051) × 10?3 and A?D1 = (0.337135 ± 0.00050) × 10?3cm?1. Λ-Type doubling constants evaluated by using both grating and tunable laser data are also reported.  相似文献   
29.
We have measured the far-i.r. reflectivity spectrum of the layer crystal PbI2 for the in-plane polarization. A strong reststrahlen band is observed, with TO and LO phonon frequencies located at 52 and 108 cm?1. The large lattice contribution accounts for three-quarters of the low-frequency dielectric constant of 26. The deduced infrared effective charge and electronic polarizability of PbI2 indicates that the intralayer bonding is closely related to the chemical bonding in the IV–VI rocksalt-structure crystals.  相似文献   
30.
The radiative decayJ/ψ → γ π+ π? has been studied using the 8.6 millionJ/ψ produced in the DM2 experiment at the DCIe +e? storage rings at Orsay. The π+ π? mass spectrum shows a cleanf 2 (1270) signal, and the possible presence of two other states at thef 2 (1720) andf 4 (2030) masses. For thef 2 (1270), the branching ratio BR(J/ψ →γf)xBR(f→π+ π?) is measured to be (7.50±0.30±1.12)×10?4, and the spin analysis prefers theJ=2 assignment, with helicity parametersx=0.83±0.06 andy=0.01±0.06. The existence of higher mass states is discussed.  相似文献   
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