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161.
Summary An X-ray fluorescence method is described for the determination of Sm, Eu, Tb, Dy, Ho, Yb and Y in gadolinium oxide. Samples are taken in oxalate form and mixed with boric acid in the ratio 31. The mixture is pressed as a double-layer pellet. Selection of experimental parameters and choice of analysis lines is discussed. The estimation limit ranges from 0.005–1% for most of the elements.
Röntgenfluorescenz-spektrometrische Bestimmung von Sm, Eu, Tb, Dy, Ho, Yb und Y in hochreinem Gadoliniumoxid
Zusammenfassung Bei dem vorgeschlagenen Verfahren werden die Proben in die Oxalatform übergeführt und mit Borsäure im Verhältnis 31 gemischt. Die Mischung wird zu einer Doppelschicht-Tablette gepreßt. Die Auswahl der geeigneten experimentellen Parameter sowie der Analysenlinien wird diskutiert. Die Bestimmungs-grenzen liegen für die meisten Elemente im Bereich 0,005–1%.相似文献
162.
S. Mahendra Kumar Parag A. Deshpande M. Krishna M. S. Krupashankara Giridhar Madras 《Plasma Chemistry and Plasma Processing》2010,30(4):461-470
Nanocrystalline TiO2 was synthesized using the microwave plasma technique and characterized using X-ray diffraction, transmission electron microscopy, scanning electron microscopy, laser particle size analyzer, UV–vis spectroscopy and BET surface area analyzer. The synthesized TiO2 powder crystallized in anatase phase and the crystallite sizes were in nanometers. The photocatalytic activity of the compound was determined and compared against the activity of the commercial Degussa P-25 TiO2 catalyst. The degradation rates of the dyes were found to be higher over the synthesized TiO2 as compared to that over commercial Degussa P-25 TiO2. 相似文献
163.
The effect of addition of LiX (X = F, Cl, Br, I) and Na2SO4 on the electrical conductivity of the eutectic composition of Li2SO4 and Li2CO3 has been studied. The eutectic composition with 10 mol% Na2SO4 gives high conductivity and this could be applied in power sources. 相似文献
164.
J. C. D. Brand U. D. Deshpande A. R. Hoy S. M. Jaywant 《Journal of Molecular Spectroscopy》1983,100(2)
Molecular constants for the E0+(3P2) and 1(3P2) ion-pair states of ICl vapor have been determined using sequential two-photon polarization-labeling spectroscopy. The two states are coupled by a heterogeneous perturbation which is analyzed in some detail for low-lying vibrational levels of 1(3P2). The I35Cl potential constants for the 1(3P2) state and the rotation-vibration constants for the set of f sublevels—i.e., the constants unaffected by coupling with the E state—are (in cm−1) 1(3P2): Y0,0= 39103.814(32), Y1,0= 170.213(15), Y2,0= −0.4528(22), Y3,0= −7.0(12) × 10−4, Y4,0= −1.48(24) × 10−5 and Y5,0= −6.6(19) × 10−8, Y(f)0,1= 5.6878(17) × 10−2 Y(f)1,1= −2.110(24) × 10−4, Y(f)2,1= −1.23(62) × 10−7, and Y(f)0,1= −3.08(22) × 10−8Likewise, the I35Cl constants determined for the E 0+(3P2) state are E 0+(3P2: Y0,0= 39054.38(61), Y1,0= 166.96(10), Y2,0 = −0.3995(42), Y0,1= 5.738(31) × 10−2, and Y1,1= −1.67(26) × 10−4Practical constraints in pumping the sequence E 0+ ← B 0+ ← × 0+ restrict the analysis of the E state to levels v = 9–15. Given the long extrapolation to the equilibrium state the 3σ statistical uncertainties quoted for these constants should be treated with caution. 相似文献
165.
Tanmay Deshpande 《Selecta Mathematica, New Series》2014,20(1):285-313
Let $G$ be a unipotent algebraic group over an algebraically closed field $\mathtt{k }$ of characteristic $p>0$ and let $l\ne p$ be another prime. Let $e$ be a minimal idempotent in $\mathcal{D }_G(G)$ , the $\overline{\mathbb{Q }}_l$ -linear triangulated braided monoidal category of $G$ -equivariant (for the conjugation action) $\overline{\mathbb{Q }}_l$ -complexes on $G$ under convolution (with compact support) of complexes. Then, by a construction due to Boyarchenko and Drinfeld, we can associate to $G$ and $e$ a modular category $\mathcal{M }_{G,e}$ . In this paper, we prove that the modular categories that arise in this way from unipotent groups are precisely those in the class $\mathfrak{C }_p^{\pm }$ . 相似文献
166.
Mechanistic insights into Heck and Suzuki‐Miyaura cross coupling reactions with C59M (M = Pd/Ni) catalysts were developed. Density functional theory was used for the analysis of all the intermediates and transition states possible during C‐C cross coupling reactions over the catalysts under study. Oxidative addition, a step common to both Heck and Suzuki‐Miyaura cross coupling reactions, was observed to proceed with smaller activation barriers over C59Pd. Heck coupling of iodobenzene with styrene was observed to proceed via oxidative addition, migratory insertion, and reductive elimination steps. The free energy barriers for oxidative addition, migratory insertion, and reductive elimination steps were 14.8, 11.6, and 4.8 kcal/mol, respectively, over C59Pd, and 17.4, 79.3, and 17.4 kcal/mol, respectively, over C59Ni, indicating oxidative addition and migratory insertion to be the rate‐determining steps over C59Pd and C59Ni, respectively. Similarly for Suzuki‐Miyaura coupling reaction, activation barriers for oxidative addition, transmetalation, and reductive elimination steps were 14.8, 52.4, and 7.9 kcal/mol, respectively, over C59Pd, and 17.4, 64.7, and 60.2 kcal/mol, respectively, over C59Ni, indicating transmetalation step to be the rate‐determining step over both the heterofullerenes. 相似文献
167.
168.
169.
K. Danas V.S. Deshpande N.A. Fleck 《Journal of the mechanics and physics of solids》2012,60(9):1605-1625
The size effect in conical indentation of an elasto-plastic solid is predicted via the Fleck and Willis formulation of strain gradient plasticity (Fleck, N.A. and Willis, J.R., 2009, A mathematical basis for strain gradient plasticity theory. Part II: tensorial plastic multiplier, J. Mech. Phys. Solids, 57, 1045–1057). The rate-dependent formulation is implemented numerically and the full-field indentation problem is analyzed via finite element calculations, for both ideally plastic behavior and dissipative hardening. The isotropic strain-gradient theory involves three material length scales, and the relative significance of these length scales upon the degree of size effect is assessed. Indentation maps are generated to summarize the sensitivity of indentation hardness to indent size, indenter geometry and material properties (such as yield strain and strain hardening index). The finite element model is also used to evaluate the pertinence of the Johnson cavity expansion model and of the Nix–Gao model, which have been extensively used to predict size effects in indentation hardness. 相似文献
170.
Efficient Microwave‐assisted One‐pot Synthesis of Novel Spironaphthopyrano‐one Derivatives 下载免费PDF全文
Rapid and efficient one‐pot three‐component synthesis of new spironaphthopyrano‐one derivatives by cyclocondensation reaction in aqueous media is achieved under microwave irradiation conditions. This protocol has the advantages of higher yield, lower cost, reduced time, environmental impact, and convenient procedure. 相似文献