CĂRȚI ÎN ENGLEZĂ ÎN LEGĂTURĂ CU «NIOBIC»
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niobic în următoarea selecție bibliografică. Cărți în legătură cu
niobic și extrase din aceasta pentru a furniza contextul de întrebuințare al acestuia în literatura Engleză.
1
A Dictionary of Chemistry and the Allied Branches of Other ...
According to Blomstrand, pure niobic chloride is reduced by hydrogen, at a red
heat, to iridescent steel-grey metallic niobium. NIOBIUM, BROMIDE OF. Niobic
bromide and oxybromide are analogous in composition to the chloride and ...
2
Notes on Qualitative Analysis
\ A solution of niobic acid in excess of HF gives with potassium salts a crystalline
ppt. of K2NbF7. This is more soluble than the corresponding Ta compound. On
boiling, it gives an oxyfluoride which is still more soluble. Solutions of K6Nb6O19
...
3
Science and Technology in Catalysis 2006: Proceedings of the ...
As a solid acid catalyst niobic acid was very effective, presenting superior
performance to commercial acid zeolites. The Agropalma plant started its
operation in April 2005 and since then they are continuously producing biodiesel,
branded as ...
Koichi Eguchi, Masato Machida, Ichiro Yamanaka, 2007
4
New Solid Acids and Bases: Their Catalytic Properties
In the case of dehydration of 2-butanol, the activity of niobic acid was high and
competed with that of SiO2 — A1203 when evacuated at 423 K, but markedly
decreased when evacuated at 573 K.” Thus, the active sites are considered to be
...
K. Tanabe, M. Misono, H. Hattori, 1990
5
Heterogeneous Catalysts for Clean Technology: Spectroscopy, ...
Even at room temperature (300K), 90% of benzyl toluene was formed over titania
nanotubes, much higher than for H-β-zeolite ( about 30%), sulfated zirconia (
about 15%), and other solid acids such as TiO2, niobic acid, H-ZSM-5, Nafion,
and ...
Karen Wilson, Adam F. Lee, 2013
6
Progress in Solid State Chemistry Research
The source of niobium used is obtained from the dissolution of niobic acid, freshly
precipitated from NbCl5, in aqueous oxalic acid. The solid mixed precursor is
obtained either by a freeze-drying process [27] or by slow evaporation of water at
...
7
New Frontiers in Catalysis, Parts A-C
Using the niobic acid catalyst these drawbacks could be avoided and yields of
about 60 % could be achieved at 250°C. Furthermore this catalyst is superior to
other solid acid catalyst as shown in table 2. Table 2 Production of 2,5-dimethyl-2
...
L. Guczi, F. Solymosi, P. Tétényi, 1993
8
Phosphorus Acids—Advances in Research and Application: 2013 ...
In an exemplary embodiment, the phosphorus source comprises phosphoric acid
, the silicon source comprises diatomaceous earth, and the promoter comprises
niobic acid. “It is also an object of the present invention to provide processes for ...
9
Heterogeneous Catalytic Materials: Solid State Chemistry, ...
This material displays both Lewis and Brønsted acidity, which can be utilized also
in the presence of liquid water.347 Proton NMR data indi- cate that Brønsted
acidity of niobic acid is very high, possibly comparable with that of protonic ...
10
Manual of qualitative chemical analysis
Niobic acid (anhydride). NbjO« , is white, can be obtained in a crystallized
condition (Ebelmen, A. Knop), and turns transiently yellow when ignited (
difference from tantalic acid). Its specific gravity lies between 4.37 and 4.53 (
difference from ...
Karl Remigius Fresenius, 1897
ȘTIRI NOI CARE INCLUD TERMENUL «NIOBIC»
Află ce ziare naționale și internaționale au scris despre și cum este întrebuințat termenul
niobic în contextul următoarelor știri.
Facts About Niobium
... which he named niobic acid and pelopic acid. He renamed the element niobium. Twenty years later, Swiss chemist Jean Charles Galissard ... «LiveScience.com, Mai 13»
