نتایج جستجو برای: yttrium compounds

تعداد نتایج: 231289  

2003
M. A. Gusmão

With the aim of probing the effect of magnetic disorder in the low-temperature excitations of manganites, specific-heat measurements were performed in zero field, and in magnetic fields up to 9 T in polycrystalline samples of La0.7−xYxCa0.3MnO3, with Y concentrations x = 0, 0.10, and 0.15. Yttrium doping yielded the appearance of a cluster-glass state, giving rise to unusual low-temperature beh...

Journal: :Open Geosciences 2022

Abstract The Zhijin phosphorite (P)-bearing rare earth element (REE) deposit in Guizhou Province (China) hosts vast ore resources (P: 1.348 billion tonnes; REE: 1.44 Mt). Up to date, the resource has not been exploited because of uncertain occurrence associated REEs, which hampers mineral processing and extraction. In this study, structure, valence state, coordination position Y REE-yttrium-ric...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شهید چمران اهواز - دانشکده علوم 1370

1- in a search directed to the reaction of compound)23(the cycloaddition reaction of 1,3- diphenylisobenzofurane)14(with p-benzoquinone)19(,followed by addition of cyclopentadiene was carried out.the specific spacial stracture of its ir,nmr,mass spectra. 2- in another attempt the kinetic stability and behavior of compounds)20(and)23(was studied.the main subject of this study was the highly reve...

2010
Benjamin J. Hellmann Beate Neumann Norbert W. Mitzel

The three component reaction of LnCp3, LnCp2Cl (Ln = Nd, Y) and N,N-bis[2-(pyrid-2yl)ethyl]hydroxylamine [HON(C2H4-o-py)2] results in the formation of the [Nd(ON(C2H4-opy)2)2]+[NdCp3Cl]− salt in the case of neodymium and the [Y(ON(C2H4-o-py)2)2]+[YCp2Cl2]− salt if yttrium is used in the synthesis. The N,N-bis[2-(pyrid-2-yl)ethyl]hydroxylaminato ligand is able to coordinate doubly to the metal a...

Journal: :Chemistry 2013
Takanori Shima Zhaomin Hou

A new family of Y(4)/M(2) and Y(5)/M heterobimetallic rare-earth-metal/d-block-transition-metal-polyhydride complexes has been synthesized. The reactions of the tetranuclear yttrium-octahydride complex [{Cp''Y(μ-H)(2)}(4)(thf)(4)] (Cp'' = C(5)Me(4)H, 1-C(5)Me(4)H) with one equivalent of Group-6-metal-pentahydride complexes [Cp*M(PMe(3))H(5)] (M = Mo, W; Cp* = C(5)Me(5)) afforded pentanuclear he...

2016
P. Sarode A. Chetal C. Mande P. R. Sarode

— The K X-ray absorption discontinuity of cobalt in the compounds of the RCo5 family (R = rare earth or yttrium) has been measured with a bent crystal spectrograph. It is observed that the main discontinuity shifts to the low energy side, with respect to that in pure cobalt indicating a flow of charge from R to Co. The plot between the observed shifts and the number of covalently bonded electro...

Journal: :Biomedical and environmental sciences : BES 2015
Chen Xi Li Chuan Ma Hai Qin Fang Yuan Zhi Zhou Yu Hai Bin Xu Xu Dong Jia

OBJECTIVE The aim of this study was to assess the effects of yttrium nitrate on neurobehavioral development in Sprague-Dawley rats. METHODS Dams were orally exposed to 0, 5, 15, or 45 mg/kg daily of yttrium nitrate from gestation day (GD) 6 to postnatal day (PND) 21. Body weight and food consumption were monitored weekly. Neurobehavior was assessed by developmental landmarks and reflexes, mot...

Journal: :Dalton transactions 2013
Evgeny V Baranov Georgy K Fukin Tatyana V Balashova Anatoly P Pushkarev Ivan D Grishin Mikhail N Bochkarev

New 8-quinolinolate (Q) complexes of yttrium (1) and ytterbium (2) were synthesized by the reactions of Cp3Y and Yb[N(SiMe3)2]3 with 3 equiv. of 8-hydroxyquinoline in a DME solution. Single crystal X-ray analysis revealed the trinuclear molecular structure of the compounds Ln3Q9. The LDI-TOFMS investigation displayed that under the laser impact the compounds split off Q(-) anions to give Ln3Q8(...

Journal: :The Journal of organic chemistry 2007
Biswajit Saha Mei-Huey Lin T V RajanBabu

Halide or alkoxide free yttrium-salen complexes are excellent catalysts for the ring opening of epoxides mediated by TMSCN and TMSN3. Substrate to catalyst ratios up to 10000 have been realized in these potentially useful reactions, which can be run under solvent-free conditions. Even though the enantioselectivities for the TMSCN-mediated reaction remains modest (best 77% ee), these studies wit...

Journal: :Acta Crystallographica Section A Foundations of Crystallography 2008

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