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961.
A new molecule-based magnetic material [Mn2(Saloph)2(μ-OH)][Ni(bdt)2](CH3CN)2 was prepared by the metathesis of [Mn(Saloph)(H2O)(ClO4)] (S = 2) and TBA[Ni(bdt)2] (S = 1/2). In the crystal, [Ni(bdt)2]? anions form square lattices which are separated from each other by the layers of antiferromagnetically coupled binuclear cations [Mn2(Saloph)2(μ-OH)]+. The magnetic susceptibility of the material coincides with the sum of the S = 2 van Vleck dimer model and S = 1/2 Heisenberg ferromagnetic square lattice model with 2J = ?92.4 and +4.5 K, respectively. The origin of the ferromagnetic interaction can be explained by the T-shaped intermolecular overlap mode of SOMOs which spreads to the ends of [Ni(bdt)2]? molecules. 相似文献
962.
Polyethersulfone membranes are widely used for ultrafiltration and microfiltration especially in the dairy industry, but they are believed to degrade when exposed to the sodium hypochlorite solution that is used to sanitize the processing equipment. Such membranes were exposed to sodium hypochlorite for up to 25,000 ppm-day at 55 °C, and pH 9 and 12. Mechanical properties as measured by dynamic mechanical analysis and tensile strength did not change greatly, but surface properties measured by FTIR-ATR, field emission scanning electron microscopy and associated energy dispersive X-ray spectroscopy detected significant changes in the surface. Surface pitting was observed and was found to be most severe at pH 9. It was thought that pitting was the likely cause of degradation in performance of the membranes and that pits could act as stress raisers leading to cracking. 相似文献
963.
A thermal neutron-sensitive liposome has been developed focusing on irradiation site-specific-controlled release of a medicine. We recommended a 10B-borocaptate dimer as a detonator of liposome in expectation of effects of low-energy heavy ions produced by 10B(n, α)7Li reaction. As a result, an X-ray-sensitive liposome incorporating the detonator was vulnerable enough to release an anticancer agent, carboplatin, at a dose/dose–rate near clinical use. These results reveal, moreover, that the liposomes are also applicable to a heavy-ion beam. 相似文献
964.
Journal of Statistical Physics - The emergence of deterministic and irreversible macroscopic behavior from deterministic and reversible microscopic dynamics is understood as a result of the law of... 相似文献
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968.
Numerical Algorithms - We construct approximate Fekete point sets for kernel-based interpolation by maximising the determinant of a kernel Gram matrix obtained via truncation of an orthonormal... 相似文献
969.
We consider solving large sparse symmetric singular linear systems. We first introduce an algorithm for right preconditioned minimum residual (MINRES) and prove that its iterates converge to the preconditioner weighted least squares solution without breakdown for an arbitrary right‐hand‐side vector and an arbitrary initial vector even if the linear system is singular and inconsistent. For the special case when the system is consistent, we prove that the iterates converge to a min‐norm solution with respect to the preconditioner if the initial vector is in the range space of the right preconditioned coefficient matrix. Furthermore, we propose a right preconditioned MINRES using symmetric successive over‐relaxation (SSOR) with Eisenstat's trick. Some numerical experiments on semidefinite systems in electromagnetic analysis and so forth indicate that the method is efficient and robust. Finally, we show that the residual norm can be further reduced by restarting the iterations. 相似文献
970.
Motohiro Akazome Shusaku TomaTatsunori Horiguchi Ken MegumiShoji Matsumoto 《Tetrahedron》2011,67(16):2844-2848
Inclusion compounds of a dipeptide, (S)-threonyl-(S)-phenylglycine (Thr-Phg), with several aliphatic alcohols were easily prepared by grinding them in a mortar. Thr-Phg molecules arranged in antiparallel to construct a sheet, and guest alcohols were accommodated in a chiral pocket between the sheets. 3-Butyn-2-ol and 2-butanol were included with moderate enantioselectivity, 57% ee (R) and 49% ee (R), respectively. The role of the hydroxy group of Thr-Phg is not only to construct the unique pocket but also to capture guest alcohols by hydrogen bonding. 相似文献