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121.
122.
Matsushima T. Inazumi H. Hirasawa S. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》1991,37(5):1288-1293
The problem of distortionless encoding when the parameters of the probabilistic model of a source are unknown is considered from a statistical decision theory point of view. A class of predictive and nonpredictive codes is proposed that are optimal within this framework. Specifically, it is shown that the codeword length of the proposed predictive code coincides with that of the proposed nonpredictive code for any source sequence. A bound for the redundancy for universal coding is given in terms of the supremum of the Bayes risk. If this supremum exists, then there exists a minimax code whose mean code length approaches it in the proposed class of codes, and the minimax code is given by the Bayes solution relative to the prior distribution of the source parameters that maximizes the Bayes risk 相似文献
123.
Solid-liquid equilibria in the Sn-rich region of quaternary Cu-Ga-S-Sn system have been investigated experimentally. Solidus
compositions corresponding to Cu-Ga-S-Sn liquidus points were determined using the crystals self-nucleated from solutions
composed of Sn solvent and Cu-Ga-S solute. It has been found that, in the isothermal liquidus surface at 780°C, there exist
at least four regions corresponding to different crystalline solids, having compositions of CuGaS2, SnS, CuGa3S5 and Ga4SnSx (x=7∼8), respectively. The conditions of the solution growth of single-phase CuGaS2 crystals using Sn solvent have been also discussed. 相似文献
124.
Fluid-rock interaction processes in the Te Kopia geothermal field (New Zealand) revealed by SEM-CL imaging 总被引:1,自引:0,他引:1
Scanning electron microscopy-cathodoluminescence (SEM-CL) imaging of hydrothermal quartz exposed by weathering in the Te Kopia geothermal field (New Zealand) has revealed a history of crystal growth, dissolution, overprinting and fracturing that cannot be detected using other observational techniques (e.g. transmitted or reflected light microscopy, back-scattered electron imaging or secondary electron imaging). The crystals initially grew as CL-dark quartz, at least 350 m below their present location on the Paeroa Fault scarp, in a neutral pH, 215±10 °C liquid reservoir (inferred from the analysis of primary liquid fluid inclusions: mean Th of 213 °C; 0.2–0.4 wt.% NaCleq.). Relict quartz–adularia–illite alteration occurs at the surface, in the vicinity of the quartz crystals, and in drillcores from the nearby TK-1 exploration well. Repeated movement on the Paeroa Fault uplifted pyroclastic rocks hosting the quartz crystals, but also provided pathways for “pulses” of hot fluids to move through the system. Quartz precipitation occurred at the edge of the crystals as the reservoir fluids cooled, as indicated by micron-scale alternating CL-dark/CL-bright quartz growth bands, which contain fluid inclusions with Th values of 210±40 °C. Pressure fluctuations were the likely cause of dissolution, marked by corroded crystal edges, with subsequent precipitation of quartz into open space. SEM-CL imaging shows that the quartz crystals contain healed fractures, which trapped low salinity fluids with Th values of 201±6 °C. Low-pH fluids in the near-surface setting also rounded the quartz crystals, and coated them with kaolinite and CL-grey amorphous “silica residue”. 相似文献
125.
Kuboyama H. Tanaka Y. Sato K. Fujimoto K. Hirasawa K. 《Vehicular Technology, IEEE Transactions on》1990,39(2):150-160
The receiving performance of mobile antenna systems that have vertical and horizontal elements at the 920-MHz band has been investigated by measurements in both rural and urban areas in Japan. Three types of inverted-F antennas for a car and three types of antenna elements, a monopole, a bent-slot and an inverted-F antenna, for portable equipment were used in the experiments. The average received power and its probability density function are obtained as the parameter to evaluate the performance of antenna systems. The performances of the bent-slot antenna system for portable equipment and the inverted-F antenna system mounted on a car are compared with those of the monopole or dipole antenna systems used as reference antennas. A notable increase in the average received power has been observed in operation in an urban area where the field distributes randomly and consists of cross-polarized components 相似文献
126.
The effects of tungstate, molybdate and chromate ions on the passivation of iron were investigated, and these oxyanions stimulated the passivation especially at lower pH.The results were rationalized by the dissolution-precipitation mechanism of iron passivation.In order to bring about the passivity of iron, it was required that iron first dissolves into solution, and then a ferric hydroxide or a ferric complex with oxyanion should be produced on the metal surface, which was followed by the dyhydration or the condensation reaction of these compounds to form ferric oxide. 相似文献
127.
Tanaka T Hijioka H Fujita K Usuki Y Taniguchi M Hirasawa E 《Journal of Bioscience and Bioengineering》2004,98(6):470-476
Among various analogs of the isoprenoid farnesol (FOH), farnesylamine (FNH2) inhibited the growth of the budding yeast Saccharomyces cerevisiae by accelerating cellular reactive oxygen species (ROS) generation. Unlike the case with FOH, however, FNH2 did not cause mitochondrial transmembrane potential (mtDeltaPsi) hyperpolarization so that FNH2-treated cells were not protected against ROS production by inhibiting the proton pumping function of mitochondrial F(O)F1-ATPase. FNH2 promoted ROS generation even in cells of a respiration-deficient mutant, indicating a yeast metabolic pathway other than mitochondrial electron transport as the origin of ROS. FNH2 oxidase activity was detected in the yeast mitochondrial fraction, which produces hydrogen peroxide (H2O2) in the reaction with either FNH2 or geranylgeranylamine (GGNH2), in addition to polyamine oxidase activity specific for spermine. GGNH2 also exhibited the growth inhibitory effect with the accompanying induction of ROS generation, while such an activity was not detected with any of the polyamines tested or geranylamine. FNH2 oxidase, which was sensitive to a typical copper-chelating agent, diethyldithiocarbamic acid (DDC), could be solubilized with Triton X-100, and detected as a single band upon activity staining with FNH2 but not with spermine in polyacrylamide gel electrophoresis. FNH2-treated cells were partly protected against ROS production by the additional supplementation of DDC in the medium. Our results suggest the involvement of H2O2 production due to direct oxidation of FNH2 by copper amine oxidase in oxidative stress-dependent inhibition of yeast cell growth. 相似文献
128.
Size and crystallinity controlled silicon nanoparticles were prepared by a laser ablation, in situ annealing and mobility size-selection with a differential mobility analyzer (DMA). The shape and crystal structure of generated particles were observed by a transmission electron microscopy (TEM). Both densification of agglomerates and crystal growth of the particles were observed. The size of silicon primary particle was increased by the annealing, and the uniformity of the particle classified at 10 nm was improved as a result. 相似文献
129.
The task of rats (Rattus norvegicus) was to enter 1 box of a defined ordinal number among an array of boxes. In Experiments 1 and 2, the rats correctly chose the 4th box from arrays of 6 and 12 boxes, respectively. In Experiments 3 and 4, in which the ordinal number of the correct box was increased in a graduated fashion, they were able to select the correct box even when its position was higher than 10th among 12 and 18 boxes, respectively. In Experiment 5, the possibility that the rats had used cues to the openability of the box doors was ruled out. In Experiments 6 and 7, the rats succeeded in the task even when the total number of boxes was varied from trial to trial. In Experiment 8, both small- and large-sized boxes were used to control for the possibility of using the cumulative length of the boxes as a cue. Overall, the results suggest that performance was based on numerical cues. Intentional acts were occasionally observed but appeared not to be essential for solving the task. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
130.
Wastewater treatment after electroless nickel plating runs has been known to be difficult and this has been a subject of worldwide
concern. Discarding wastewater of electroless nickel plating into sea was prohibited under the London Dumping Treaty since
1996. We have studied on recovering nickel from wastewater by reduction crystallization. In this study, the characteristics
of nickel ion removal and recovery were investigated in the process of reduction crystallization using a laboratory scale
batch crystallizer (500 ml), in order to propose a new process for wastewater treatment from nickel plating. In the reduction
crystallization, which can use hypophosphite ion as a reducing agent for nickel ion in the wastewater, nickel ion could be
recovered as a form of nickel metal by seeding nickel powder having large specific surface area. 相似文献