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281.
Nitta  Yuriko 《Topics in Catalysis》2000,13(3):179-185
Both the enantioselectivity and activity of the hydrogenation of (E)-α-phenylcinnamic acid with cinchonidine-modified Pd catalysts are strongly solvent dependent; polar solvents with higher solubility for the substrate are preferable. The simultaneous increases in the enantioselectivity and activity, also induced by the addition of either a small amount of water to aprotic solvents or an amine such as benzylamine, indicate that preferential acceleration of the selective reaction has occurred, thus strongly suggesting the importance of the product desorption step on the modified sites. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   
282.
Co, Ni and Mn K-edge XAFS investigation of LiCo1/3Ni1/3Mn1/3O2 as alternative cathode material to commercially used LiCoO2 in lithium rechargeable battery has been performed. Parameters of a local atomic structure such as radii of metal-oxygen and metal-metal coordination shells and disorder in those shells have been determined. It has been found that the radius of the first coordination shell (metal-oxygen) as well as a local disorder in the second shell (metal-metal) around each of the 3d-metals are in a good agreement with obtained for superlattice model of [√3 × √3] R30° type in triangular lattice of sites by first principle calculation. Other parameters of the local atomic structure around Co, Ni and Mn atoms do not provide evidence for presence of superstructure in LiCo1/3Ni1/3Mn1/3O2.  相似文献   
283.
Effective life of electroless Co-P (2.5 wt%) thin films of about 100 nm in thickness was evaluated for both magnetic characteristics and corrosion. The Co-P films were grown on rigid Al substrates overcoated with nonmagnetic Ni-P thick films and were finally covered with electroplated Rh thin films of 120 nm - 180 nm in thickness. The life of the magnetic characteristics was defined as the time to reach 10% deviation from the initial values of Hc (coercive force), Br (remanence), and S (squareness of hysteresis loop). The life of the films for corrosion was defined as the induction period of corrosion. An increase of Hc was observed above 80°C for isothermal annealing, but Br and S were unchanged. The activation energy of the variation of Hc was approximately 0.7 eV below 144°C. The life of magnetic characteristics was estimated to be approximately 4.1 × 104 ? 2.3 × 105 hrs at 55°C corresponding to the allowable maximum temperature in field service. The life for corrosion was influenced by the quality of Rh films.  相似文献   
284.
This paper examines a detailed analysis by Shubnikov-de Haas measurements of the effective mass of two-dimensinal electron gas (2DEG) in an In0.52Al0.48As/ In0.53Ga0.47As modulation-doped (MD) structure with an InAs quantum well inserted into the InGaAs channel (InAs-inserted channel). The measured effec-tive mass of 2DEG in the InAs-inserted-channel MD structure is in good agreement with the calculated one of the strained InAs layer on In0.53Ga0.47As. This indicates that almost all of the 2DEG forms in the strained InAs quantum well. These results show that the InAs-inserted-channel MD structure improves the electron confinement, since the 2DEG is confined in the InAs quantum well with the thickness of 4 nm.  相似文献   
285.
Similarity of Legal Cases: From Temporal Relations of Affairs   总被引:1,自引:0,他引:1  
Case-based reasoning has played an important role in legal reasoning systems. As one criteria for similarity of cases, temporal relationsamong affairs in legal cases should be compared. Thus far in many legalreasoning systems, cases have been described as sequences of pointwiseevents, or at best, simple time intervals, and they have been related bypredicates such as before, after, while,and so on. However, such relations may depend on each implementer'spersonal view, and also require much labor to write down by hand. In this paper, we first propose a classification of affair types by their temporal features, and according to those types, we propose several assumption rules that prescribe the temporal relations between affair types. The temporal relations are automatically generated by these rules. Thereafter, we discuss how thesetemporal relations work in the comparison of similarity of cases. Inthe process of comparison, inadequate temporal relations need to beamended. For this purpose, we introduce revision rules, that refute theresults of assumption rules.  相似文献   
286.
The efficacy, safety and usefulness of balofloxacin (BLFX) for patients with acute infectious enteritis and the carriers mainly shigellosis, were investigated. The drug was administered at a daily dose of 200 mg twice a day for 3 days to patients with cholera, 7 days to patients with Salmonella enteritis and 5 days to patients with other conditions of infectious enteritis including shigellosis; 1. The efficacy was analyzed in 89 of the 135 patients who received the administration (43 patients with shigellosis, 14 with Salmonella enteritis, 8 with enteropathogenic/ enterotoxigenic Escherichia coli enteritis, 3 with cholera, 7 with enteritis with other pathogenic bacteria, 6 with polymicrobial infectious enteritis and 8 with acute enteritis that was pathogen-negative). 2. In patients bearing symptoms and who thus could be analyzed for drug efficacy, the drug was markedly effective or effective 50/52 (96.2%). 3. Bacteriologically, the drug was effective for Shigella spp. in 41 (100%) of 41, Salmonella spp. in 12 (85.7%) of 14, and enteropathogenic/enterotoxigenic Escherichia coli in 8 of 8 cases. 4. Adverse effects were seen in 5/133 patients (3.8%) receiving the drug, including two cases of skin eruption, one of the numbness of the hands, one of oral aphtha, and one of nausea. In patients for whom laboratory findings were available, 20/115 (17.4%) showed abnormalities, mainly elevations of GOT and/or GPT, but these were slight. 5. In terms of subjective reports of usefulness, 51/82 (62.2%) were markedly satisfied, and 73/82 (89.0%) were either satisfied or markedly satisfied. 6. The influence of administration of BLFX on fecal concentration and intestinal microbial flora was investigated in 2 patients with acute infectious enteritis. Results approximately equivalent to such flora levels in healthy subjects were obtained. These results suggest that BLFX is highly useful for infectious enteritis such as that caused by shigellosis.  相似文献   
287.
Nonlinear distortion and frequency response for light-emitting diodes in analogue video transmission are greatly improved by using a wideband optoelectronic feedback loop employing monolithically integrated PIN photodiodes. Large monitoring efficiency of more than 2% makes it easy to realise this wideband and high-gain feedback loop.  相似文献   
288.
Glass-forming regions, valence states, and viscosities in SiO2–PbO systems containing various transition-metal oxides as a third component were investigated. The glasses were prepared by melting in an open atmosphere. The glass-forming regions ranged as follows: MnO≡ZnO > FeO1.5>NiO. The ratios Fe2+/(Fe2++ Fe3+) and Mn3+/ (Mn3++ Mn2+) in the glasses were determined by chemical analysis. The Fe2+/ (Fe2++ Fe3+) ratio in SiO2–PbO–FeO1.5 glasses ranged from 0.016 to 0.050. The Mn3+/ (Mn3++ Mn2+) ratio in SiO2–PbO–MnO glasses ranged from 0.056 to 0.30. The fraction of manganese (III) ions in the glasses varies considerably with the glass composition. The effects of transitionmetal oxides on the viscosity are discussed.  相似文献   
289.
290.
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