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61.
62.
The aim of this paper is to find the global solutions of uncertain optimization problems having a quadratic objective function and quadratic inequality constraints. The bounded epistemic uncertainties in the constraint coefficients are represented using either universal or existential quantified parameters and interval parameter domains. This approach allows to model non-controlled uncertainties by using universally quantified parameters and controlled uncertainties by using existentially quantified ones. While existentially quantified parameters could be equivalently considered as additional variables, keeping them as parameters allows maintaining the quadratic problem structure, which is essential for the proposed algorithm. The branch and bound algorithm presented in the paper handles both universally and existentially quantified parameters in a homogeneous way, without branching on their domains, and uses some dedicated numerical constraint programming techniques for finding a robust, global solution. Several examples clarify the theoretical parts and the tests demonstrate the usefulness of the proposed method. 相似文献
63.
Marcin Konkol Tetsuya Kohno Tatsuya Miyatake 《Journal of organometallic chemistry》2011,696(9):1792-2956
The tetradentate [OSSO]-type bis(phenol) ligands, [{2,2′-(HOC6H2-4,6-R2)2CH2SCH2CH2SCH2}] (R = tBu, 2; Br, 3) react with MBz4 (M = Zr, Hf) to yield the corresponding dibenzyl complexes, [M{2,2′-(OC6H2-4,6-R2)2CH2SCH2CH2SCH2}Bz2] (R = Br, M = Zr, 4Br; Hf, 5Br; R = tBu, M = Hf, 5) in a good to very good yield. Zirconium diamido complexes, [Zr{2,2′-(OC6H2-4,6-R2)2CH2SCH2CH2SCH2}(NMe2)2] (R = tBu, 6; Br, 6Br) were prepared in a reaction of the corresponding disodium salt of 2 or 3 generated in situ with ZrCl2(NMe2)2(THF)2. Heating of 6 with TMSCl at 35 °C afforded zirconium dichloro complex, [Zr{2,2′-(OC6H2-4,6-tBu2)2CH2SCH2CH2SCH2}Cl2] (7), whereas the titanium analog 8 was prepared in a direct reaction with TiCl4. While for complexes 4Br, 5, 5Br, 6, 6Br and 7 single C2-symmetric isomers were observed in solution at room temperature, as revealed by the NMR spectroscopic data, titanium complex 8 formed as a mixture of cis-α (8a) and cis-β (8b) isomers in a ratio of approx. 20:80% (measured in CD2Cl2). The VT NMR studies revealed a reversible conversion of 8a into 8b above 60 °C. The X-ray crystal structure determination of complexes 4Br, 5Br and 7 confirmed their C2-symmetrical configuration in the solid state with cis-arranged benzyl/chloro groups and the trans-coordination of two bulky phenolato moieties. The zirconium dibenzyl complexes exhibit good catalytic activities in homopolymerization of 1-hexene (atactic poly(1-hexene), PDI = 1.5-1.7) and vinylcyclohexane (isotactic poly(vinylcyclohexane), PDI = 1.2-1.8) upon activation with a co-catalyst. In both polymerizations no increase of activity was observed for the complex 4Br with electron-withdrawing substituents on phenolate rings. Moreover, polymerization of liquid propylene catalyzed by the titanium dichloro isomeric mixture 8 afforded at 5 °C ultrahigh molecular weight atactic/isotactic polypropylene mixtures. 相似文献
64.
Contamination of the exterior surface of vials of cytostatic drugs by the drugs themselves is a potential hazard to human health. This study developed a validated method using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) for the determination of contamination of the exteriors of vials of cisplatin and carboplatin. Large Alpha® sampling swabs were employed to wipe the vial exterior. Cisplatin or carboplatin and gold(III) as an internal standard were derivatized by N,N-diethyldithiocarbamate (DDTC). Pt(DDTC)3+ and Au(DDTC)2+ were monitored by the respective transitions of m/z 639.3-490.9 and 493.0-345.0, respectively. Each separation was completed within 9 min using a 3 μm particle ODS-column. Calibration curves for cisplatin and carboplatin were linear over concentration ranges of 30-10,000 and 30-30,000 pg vial−1, respectively. The accuracies and precisions were 96.1-102.5% and within 8.2% for intra-assay and 99.6-103.3% and within 7.6% for inter-assay, respectively. Their lower limit of quantification was 30 pg vial−1. Amounts of 0.17-17.0 ng vial−1 as cisplatin and 0.48-794 ng vial−1 as carboplatin were detected from the exterior surface of the vials. This validated method using LC-ESI-MS/MS for the determination of platinum anticancer drugs is helpful for monitoring contamination of the exterior surface of drug vials. 相似文献
65.
Koichi Kan Jinfeng Yang Kimihiro Norizawa Takafumi Kondoh Yoichi Yoshida Atsushi Ogata 《Radiation Physics and Chemistry》2011,80(12):1323-1326
A novel method to generate high-power THz radiation is proposed. If a beam with a bunch length on the order of 100 fs is injected into an electron–hole plasma of a semiconductor with a plasma frequency on the order of THz, THz wake fields are coherently generated. If the beam moves on the axis of a hollow tube covered by a metal, the frequency spectrum of the radiation is composed of discrete components. Monochromatic radiation is obtained by making only the lowest frequency component coherent. 相似文献
66.
Takafumi Shibuta 《Journal of Pure and Applied Algebra》2011,215(12):2829-2842
We give algorithms for computing multiplier ideals using Gröbner bases in Weyl algebras. To this end, we define a modification of Budur-Musta?aˇ-Saito’s generalized Bernstein-Sato polynomial. We present several examples computed by our algorithm. 相似文献
67.
The collision complex formed from a vibrationally excited reactant undergoes redissociation to the reactant, intramolecular vibrational relaxation (randomization of vibrational energy), or chemical reaction to the products. If attractive interaction between the reactants is large, efficient vibrational relaxation in the complex prevents redissociation to the reactants with the initial vibrational energy, and the complex decomposes to the reactants with low vibrational energy or converts to the products. In this paper, we have studied the branching ratios between the intramolecular vibrational relaxation and chemical reaction of an adduct HO(v)-CO formed from OH(X(2)Π(i)) in different vibrational levels v = 0-4 and CO. OH(v = 0-4) generated in a gaseous mixture of O(3)/H(2)/CO/He irradiated at 266 nm was detected with laser-induced fluorescence (LIF) via the A(2)Σ(+)-X(2)Π(i) transition, and H atoms were probed by the two-photon excited LIF technique. From the kinetic analysis of the time-resolved LIF intensities of OH(v) and H, we have found that the intramolecular vibrational relaxation is mainly governed by a single quantum change, HO(v)-CO → HO(v-1)-CO, followed by redissociation to OH(v-1) and CO. With the vibrational quantum number v, chemical process from the adduct to H + CO(2) is accelerated, and vibrational relaxation is decelerated. The countertrend is elucidated by the competition between chemical reaction and vibrational relaxation in the adduct HOCO. 相似文献
68.
Noriaki Nishiguchi Takafumi Kinuta Yoko Nakano Dr. Takunori Harada Dr. Nobuo Tajima Tomohiro Sato Prof. Dr. Michiya Fujiki Prof. Dr. Reiko Kuroda Prof. Dr. Yoshio Matsubara Dr. Yoshitane Imai 《化学:亚洲杂志》2011,6(4):1092-1098
The solid‐state chiral optical properties of a 4‐(2‐arylethynyl)‐benzoic acid/amine supramolecular organic fluorophore can be controlled by changing the arylethynyl group of the achiral 4‐(2‐arylethynyl)‐benzoic acid component molecule rather than the chirality of the amine component molecule. 相似文献
69.
Hiroshi Sugaya Takafumi Arai Youichi Ueda 《Journal of magnetism and magnetic materials》1993,120(1-3):106-111
A contact printing model is introduced to explain the re-recording dip in overwrite recording. The first signal on a recording medium is transferred to the medium surface, where the second signal increases the susceptibility to transfer the S-1 signal magnetically with opposite phase. The output signal of S-1 will be compensated by the transferred signal, and will be zero, which is supposed to be the re-recording dip. The contact printing model is confirmed by experiments. 相似文献
70.
Takafumi Seto Kenji Koga Hiroyuki Akinaga Fumiyoshi Takano Takaaki Orii Makoto Hirasawa 《Journal of nanoparticle research》2006,8(3-4):371-378
Monodispersed CoPt alloy nanoparticles were synthesized by a pulsed laser ablation (PLA) technique coupled with a low-pressure operating differential mobility analyzer (LP-DMA). The CoPt alloy nanoparticles were generated by laser ablating a solid Co–Pt target. In CoPt alloy nanoparticles synthesized from a target with a Co composition of 75 at%, the nanoparticle surfaces were covered by an oxide layer and exhibited a core-shell structure. In contrast, no shell was observed in particles generated from a target with a Co:Pt ratio of 50:50 at%. According to an EDX analysis, the compositions of the individual nanoparticles were almost the same as that of the target material. Finally, the magnetic hysteresis loops of the CoPt alloy nanoparticles exhibited ferromagnetism. 相似文献