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1.
2.
Summary The results of sorption measurements for gallium (III) and iodide ion traces onto tin(II) hydroxide from aqueous heterogeneous systems are given. Since only tagged sorbate was used (67Ga and 1311), in the determination of sorption by radioactive tracer method, it was necessary to establish the pH interval of tin(II) hydroxide in/stability. This was done by a turbidimetric method and the pH region of instability between 3 and 9 was found.The sorption results indicate a difference in sorption ability of gallium(III) and iodide as it appears from the dependence of the amount sorbed on contact time between heterogeneous reactants (sorbentsorbate). The amounts sorbed increase with increasing contact times at higher pH values for Ga(III) but remain unaffected for iodide sorption. Thus the sorption of iodide ions seems to be restricted to the solid surface while the sorption results for gallium(III) indicate the diffusion of sorbate into sorbent as a possible parallel mechanism. Those processes could be taken as compatible with the porous-double-layer mechanism which has been proposed in literature for aqueous heterogeneous oxide systems.
With 4 figures 相似文献
Zusammenfassung In der Arbeit werden Ergebnisse von Sorptionsmessungen für Ga3+- und j-Spuren an Zinn(II)-Hydroxid aus wäßrigen heterogenen Systemen berichtet. Zur analytischen Erfassung wurden radioaktives67Ga und 131 J verwendet. Die Stabilität von Zinn(II)-Hydroxid wurde durch Trübungsmessungen untersucht. Im pH-Bereich von 3–9 ist das Zinn(II)-Hydroxid als kolloide Suspension instabil.Ga3+ und J– verhalten sich bei der Adsorption unterschiedlich. Die adsorbierte Menge steigt mit zunehmender Kontaktzeit bei hohen pH-Werten von Gallium, bleibt jedoch für Jod unverändert. Die Unterschiede werden gedeutet durch die Annahme, daß Jod nur an der festen Oberfläche adsorbiert wird, während die Galliumionen auch in das Sorbens diffundieren können. Man könnte die Ergebnisse als verträglich mit einem porösen Doppelschichtmechanismus ansehen; ein solcher Mechanismus ist in der Literatur für wäßrige heterogene Oxidsysteme vorgeschlagen worden.
With 4 figures 相似文献
3.
Instrumental neutron activation was used for the determination of 23 trace and minor elements in 4 different samples of brewer's
yeast. Detection limits for these elements vary from 2 ppb to 100 ppm. The following average concentrations were found (ppm,
dry weight): Al 597, Br 0.36, Cl 1473, Co 0.21, Cu 19, Fe 285, K 16 400, Mg 1355, Mn 8.4, Na 2330, Rb 19, Sb 0.053, Se 1.2,
V 2.2 and Zn 80. NBS standard 1569 was also analyzed and the following concentrations (in ppm) were measured: Al 2300, Br
0.65, Ce 0.23, Cl 460, Co 0.26, Cr 2.12, Cu 11, Fe 707, Gd 7.1, Hf 0.13, K 15 500, Mg 1780, Mn 7, Na 510, Rb 16, Sb 0.075,
Sc 0.18, Se 0.92, Th 3.7, Ti 38, U 0.49, V 4.1 and Zn 70. 相似文献
4.
Jože Slivnik Mateja Žvanut Borka Sedej 《Monatshefte für Chemie / Chemical Monthly》1968,99(5):1713-1717
Zusammenfassung Die Reaktion zwischen MgCO3 und wässerigen Lösungen von Hydraziniumdifluorid und Flußsäure führt zum Hydraziniumfluoromagnesat. Diese Verbindung ist auch aus Magnesiumchlorid-und Hydraziniumdifluorid-Lösungen herstellbar. Es werden röntgenographische, IR-spektrographische und thermogravimetrische Untersuchungen dieser Verbindung angegeben.
Mit 3 Abbildungen 相似文献
Hydrazinium(+2) fluoromagnesate is formed in the reaction between MgCO3 and hydrazinium difluoride dissolved in hydrogen fluoride. The reaction of magnesium chloride and an aqueous solution of hydrazinium difluoride yields the same product. The results of X-ray diffraction studies, IR spectroscopical studies and thermogravimetrical investigation are given.
Mit 3 Abbildungen 相似文献
5.
The capabilities of reactor neutron and 12 MeV proton activation were evaluted on samples of orchard leaves, beef liver and
bovine liver. Based on γ-ray spectrometry, As, Ca, Cu, Fe, Mo, Pb, Sr, Ti, Zn and Zr at levels ranging from 2 to 20 900 ppm
were detected following proton activation of 1 hour. Al, Br, Ca, Cl, Cu, Mg, Mn, Rb and V (ranging from 0.4 to 20 900 ppm)
were measured by neutron activation (1 min irradiation). As, Ba, Br, Cr, Co, Fe, Hg, La, Na, Rb, Sb and Zn (ranging from 0.2
to 2400 ppm) were determined following a 14 h neutron irradiation. Although covering different elements, the two techniques
are comparable in their scope, i. e. detection limits that can be achieved and number of elements that can be detected simultaneously. 相似文献
6.
Analysing experimentally determined P, ?, T data of N2, ethylene, propene, CO2 and Xe by a new mathematical technique, we present evidence that their isothermal pressure-density dependence exhibits behaviour characteristic of a Riemann-Hugoniot catastrophe, in analogy to a van der Waals gas for above and sub critical isotherms. 相似文献
7.
J. Žofka 《Czechoslovak Journal of Physics》1982,32(3):321-325
Hypernuclear structure models are briefly reviewed. Phenomena related to hypernuclear polarization are displayed. A discussion is given of nuclear and hypernuclear neutron orbitals extraction. Preliminary results on
– angular distributions for the reaction6Li(K
–, –)
6
Li are presented.Presented at the symposium Mesons and Light Nuclei, Liblice, Czechoslovakia, June 1981.The collaboration of Dr. M. Sotona and Dr. L. Majling in the speedy preparation of the AD results and discussions with them and with Prof. B. Povh are greatly acknowledged. 相似文献
8.
Tomislav P. Živković 《Journal of mathematical chemistry》2002,32(1):39-71
Interaction of quantum system S
a
described by the generalised × eigenvalue equation A|
s
=E
s
S
a
|
s
(s=1,...,) with quantum system S
b
described by the generalised n×n eigenvalue equation B|
i
=
i
S
b
|
i
(i=1,...,n) is considered. With the system S
a
is associated -dimensional space X
a
and with the system S
b
is associated an n-dimensional space X
n
b
that is orthogonal to X
a
. Combined system S is described by the generalised (+n)×(+n) eigenvalue equation [A+B+V]|
k
=
k
[S
a
+S
b
+P]|
k
(k=1,...,n+) where operators V and P represent interaction between those two systems. All operators are Hermitian, while operators S
a
,S
b
and S=S
a
+S
b
+P are, in addition, positive definite. It is shown that each eigenvalue
k
i
of the combined system is the eigenvalue of the × eigenvalue equation
. Operator
in this equation is expressed in terms of the eigenvalues
i
of the system S
b
and in terms of matrix elements
s
|V|
i
and
s
|P|
i
where vectors |
s
form a base in X
a
. Eigenstate |
k
a
of this equation is the projection of the eigenstate |
k
of the combined system on the space X
a
. Projection |
k
b
of |
k
on the space X
n
b
is given by |
k
b
=(
k
S
b
–B)–1(V–
k
P})|
k
a
where (
k
S
b
–B)–1 is inverse of (
k
S
b
–B) in X
n
b
. Hence, if the solution to the system S
b
is known, one can obtain all eigenvalues
k
i
} and all the corresponding eigenstates |
k
of the combined system as a solution of the above × eigenvalue equation that refers to the system S
a
alone. Slightly more complicated expressions are obtained for the eigenvalues
k
i
} and the corresponding eigenstates, provided such eigenvalues and eigenstates exist. 相似文献
9.
Abstract A part of homotopy theory is applied to classify planar structures in chiral nematic liquid crystals confined to cylindrical cavities. The resulting classification is exact in the approximation of undeformed chiral nematic surfaces. Within this approach the relative stability of possible planar structures with surface and bulk disclination lines is discussed. The number and the shape of these disclinations, which in some cases form spiral structures, are predicted. Further approximate analytical expressions for non-singular director fields close to disclination lines with integral strength are introduced. Our predictions, which are also in agreement with some previously suggested pictures of such director fields, are used to improve stability considerations of the confined planar chiral nematic structures in tubes and droplets. 相似文献
10.
Žarko P. Barbarić Stojadin M. Manojlović Boban P. Bondžulić Milenko S. Andrić Srđan T. Mitrović 《Optik》2014
New relationship of displacement signal using opposite sectors on a quadrant photodiode is derived. Standard and new displacement signals are analyzed in details. Through MATLAB® laser tracking simulation models, based on common and suggested approaches, detailed analysis is performed, and it is shown that better results for the new relationship signal processing are obtained. Within new relationship of displacement signal, the sensitivity of the system to the displacement of the spot increases and, hence, provides better accuracy in positioning up to 30%. 相似文献