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The technique of ferromagnetic resonance at 23 GHz has been used to determine the first three anisotropy constants of pure Ni down to 4.2K. A temperature and orientation dependent linewidth has also been observed. 相似文献
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L.N Carling 《Journal of Functional Analysis》1977,25(3):236-243
G is a locally compact group that contains the semidirect product J of a closed normal subgroup H and a closed connected subgroup K. Conditions on J are given that imply that the restriction map Bp(G) → Bp(H) (1 < p < ∞; G amenable if p ≠ 2) of the Fourier-Stieltjes algebras is not surjective. It is also shown that if the restriction map B(J) → B(H) is surjective, J need not be a direct product, even if H is nilpotent. 相似文献
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Robert W. Carling 《Journal of Physics and Chemistry of Solids》1979,40(12):1051-1056
The heat capacities of ZnFe2O4, Zn0.005Fe2.995O4, Zn0.066Fe2.934O4, and Cd0.010Fe2.990O4 were measured over the temperature range of 350–1000 K by means of differential scanning calorimetry. The temperatures at which the maximum in heat capacity occurs due to the ferrimagnetic anomaly in the doped-Fe3O4 samples were found to decrease with increasing dopant. The excess entropy associated with the ferrimagnetic anomaly was estimated using three methods. One method, used previously for Fe3O4, employed a calculated lattice contribution for Fe3O4. The other two methods used the experimentally determined heat capacity of ZnFe2O4, either unmodified or mass adjusted, to approximate contributions from lattice vibrations. 相似文献
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The structural and magnetic properties of the tris-dithiooxalato salts, A[M(II)Cr(C(2)S(2)O(2))(3)], have been investigated with A(+) = PPh(4)(+), N(n-C(n)()H(2)(n)()(+1))(4)(+), with n = 3-5, where M(II) is Mn, Fe, Co, and Ni. With the exception of A[MnCr(C(2)S(2)O(2))(3)], all the salts are ferromagnets with Curie temperatures, T(c), between 5 and 16 K. In contrast to the corresponding oxalates which are ferromagnetic, the A[MnCr(C(2)S(2)O(2))(3)] compounds are paramagnetic above 2 K. Powder neutron diffraction studies of d(20)-PPh(4)[FeCr(C(2)S(2)O(2))(3)] indicate that no structural phase transitions occur between 2.4 and 285 K and that the coefficient of linear expansion is four times larger for the c-axis than for the a-axis. The crystal structure refined from powder neutron diffraction data confirms the honeycomb layer arrangement observed in the related bimetallic tris-oxalate salts. The M?ssbauer spectra reveal that the iron(II) in PPh(4)[FeCr(C(2)S(2)O(2))(3)] is coordinated mainly to six oxygen atoms of the dithiooxalato ligand but with a minor component of sulfur coordination that increases with aging of the sample; the iron(II) is high-spin in both cases. Powder neutron diffraction profiles of d(20)-PPh(4)[FeCr(C(2)S(2)O(2))(3)] below T(c) show magnetic intensity with a q = 0 propagation vector, confirming the presence of ferromagnetic order. 相似文献
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Carl-Johan Carling Jason Olejniczak Alexandra Foucault-Collet Guillaume Collet Mathieu L. Viger Viet Anh Nguyen Huu Brendan M. Duggan Adah Almutairi 《Chemical science》2016,7(3):2392-2398
We introduce a means of efficiently photo-uncaging active compounds from amino-1,4-benzoquinone in aqueous environments. Aqueous photochemistry of this photocage with one-photon red light is typically not efficient unless the photocaged molecules are allowed to assemble into nanoparticles. A variety of biologically active molecules were functionalized with the photocage and subsequently formulated into water-dispersible nanoparticles. Red light irradiation through various mammalian tissues achieved efficient photo-uncaging. Co-encapsulation of NIR fluorescent dyes and subsequent photomodulation provides a NIR fluorescent tool to assess both particle location and successful photorelease. 相似文献
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