タングステン及びモリブデンを含む規則化ペロブスカイト型酸化物の合成、結晶構造と触媒特性

長崎大学学位論文 学位記番号:博(海)甲第182号 学位授与年月日:平成12年3月31

Low-voltage, low-power circuits for data communication systems

There are growing industrial demands for low-voltage supply and low-power consumption circuits and systems. This is especially true for very high integration level and very large scale integrated (VLSI) mixed-signal chips and system-on-a-chip. It is mainly due to the limited power dissipation within a small area and the costs related to the packaging and thermal management. In this research work, two low-voltage, low-power integrated circuits used for data communication systems are introduced. The first one is a high performance continuous-time linear phase filter with automatic frequency tuning. The filter can be used in hard disk driver systems and wired communication systems such as 1000Base-T transceivers. A pseudo-differential operational transconductance amplifier (OTA) based on transistors operating in triode region is used to achieve a large linear signal swing with low-voltage supplies. A common-mode (CM) control circuit that combines common-mode feedback (CMFB), common-mode feedforward (CMFF), and adaptive-bias has been proposed. With a 2.3V single supply, the filters total harmonic distortion is less than 44dB for a 2VPP differential input, which is due to the well controlled CM behavior. The ratio of the root mean square value of the ac signal to the power supply voltage is around 31%, which is much better than previous realizations. The second integrated circuit includes two LVDS drivers used for high-speed point-to-point links. By removing the stacked switches used in the conventional structures, both LVDS drivers can operate with ultra low-voltage supplies. Although the Double Current Sources (DCS) LVDS driver draws twice minimum static current as required by the signal swing, it is quite simple and achieves very high speed operation. The Switchable Current Sources (SCS) LVDS driver, by dynamically switching the current sources, draws minimum static current and reduces the power consumption by 60% compared to the previously reported LVDS drivers. Both LVDS drivers are compliant to the standards and operate at data rates up to gigabits-per-second

Some Conclusions on Markov Matrices and Transformations

Markov matrices have an important role in the filed of stochastic processes. In this paper, we will show and prove a series of conclusions on Markov matrices and transformations rather than pay attention to stochastic processes although these conclusions are useful for studying stochastic processes. These conclusions we come to, which will make us have a deeper understanding of Markov matrices and transformations, refer to eigenvalues, eigenvectors and the structure of invariant subspaces. At the same time, we account for the corresponding significances of the conclusions. For any Markov matrix and the corresponding transformation, we decompose the space as a direct sum of an eigenvector and an invariant subspace. Enlightened by this, we achieve two theorems about Markov matrices and transformations inspired by which we conclude that Markov transformations may be a defective matrix--in other words, may be a nondiagonalizable one. Specifically, we construct a nondiagonalizable Markov matrix to exhibit our train of thought.Comment: 10 pages, 1 .bbl fil

Blur Interpolation Transformer for Real-World Motion from Blur

This paper studies the challenging problem of recovering motion from blur, also known as joint deblurring and interpolation or blur temporal super-resolution. The remaining challenges are twofold: 1) the current methods still leave considerable room for improvement in terms of visual quality even on the synthetic dataset, and 2) poor generalization to real-world data. To this end, we propose a blur interpolation transformer (BiT) to effectively unravel the underlying temporal correlation encoded in blur. Based on multi-scale residual Swin transformer blocks, we introduce dual-end temporal supervision and temporally symmetric ensembling strategies to generate effective features for time-varying motion rendering. In addition, we design a hybrid camera system to collect the first real-world dataset of one-to-many blur-sharp video pairs. Experimental results show that BiT has a significant gain over the state-of-the-art methods on the public dataset Adobe240. Besides, the proposed real-world dataset effectively helps the model generalize well to real blurry scenarios

Metal-organic framework derived hierarchical porous TiO2 nanopills as a super stable anode for Na-ion batteries

Hierarchical porous TiO2 nanopills were synthesized using a titanium metal-organic framework MIL-125(Ti) as precursor. The as-synthesized TiO2 nanopills owned a large specific surface area of 102 m2/g and unique porous structure. Furthermore, the obtained TiO2 nanopills were applied as anode materials for Na-ion batteries for the first time. The as-synthesized TiO2 nanopills achieved a high discharge capacity of 196.4 mAh/g at a current density of 0.1 A/g. A discharge capacity of 115.9 mAh/g was obtained at a high current density of 0.5 A/g and the capacity retention was remained as high as 90% even after 3000 cycles. The excellent electrochemical performance can be attributed to its unique hierarchical porous feature

Mesoporous titania nanotubes: their preparation and application as electrode materials for rechargeable lithium batteries

Mesoporous titania nanotubes with tunable dimension have been fabricated within the pores of alumina membranes by a simple sol‐gel templating method. The 3D network structures of these mesoporous nanotubes (see figure) can provide both electron pathway and lithium ion pathway which benefit their applications in a high rate rechargeable lithium battery

Supercritical fluid processing of mesoporous crystalline TiO2 thin films for highly efficient dye-sensitized solar cells

In this study, a high light-to-electricity conversion efficiency of 5.14% was achieved by applying a TiO2 thin film with a thickness of 1.87 µm as an electrode material under an AM 1.5 solar light (100 mW cm−2). This high efficiency can be attributed to post-treatment by the supercritical fluid process and the addition of nanoparticles to the thin film. Supercritical fluid treatment is shown to significantly enhance the thermal stability of these thin films. Thus, the high porosity of the treated films was maintained even upon calcination at a high temperature. Additionally, the addition of crystalline light scattering nanoparticles in the thin film not only increases the crystallinity of the thin films but also ensures capture of the incident light and increases the efficiency of light harvesting. The thin film with well-preserved mesopores among the nanoparticles can capture the incident light efficiently and further increase efficiency of light harvesting, which leads to the remarkably high light-to-electricity conversion efficiency

Influence of lumping properties of coking coal by pyrolysis shrinkage

The performance of coke in blast furnace has higher requirement under the carbon emission peak & carbon neutrality goal and hydrogen-rich blast furnace development in China. Except for the thermal performance, the lump size of coke gets more attention. The pyrolysis shrinkage of coking coal is an important factor to determine the lumping performance of coke. The coking tests of coal with different deterioration were carried out with 2 kg coke oven, the effect of fineness of coal on coke lumping property was analyzed. An improved Audibert-Arnu dilatometer was used to study the shrinkage performance of eight kinds of coking coals with different degrees of metamorphism during the pyrolysis process at 300 ℃ to 900 ℃. The influence of the shrinkage coefficient of coal pyrolysis and its shrinkage dynamic characteristics on the caking performance of coke was discussed, and the mathematical relationship between the shrinkage coefficient of pyrolysis and the activation energy of pyrolysis of the average caking size of coke was established. It attempts to predict the average lumpiness of coking coal by its pyrolysis shrinkage characteristics. The results show that the average lumpiness of coke is increased with the increase of coking coal metamorphism. The average lumpiness of YK gas coal is only 38.9 mm, while the SAJ coking coal and BBG lean coal are 50.5 mm and 48.5 mm respectively. Among the eight kinds of coking coals, except for BBG lean coal, the average lumpiness of coke formed is the largest when the fineness of coal into furnace is 75%. The average lumpiness of coke is the best when BBG lean coal is 85% in fineness. On the pyrolysis process, the shrinkage coefficient and activation energy of the first shrinkage peak of coking coal with different metamorphic degrees are obviously different. The pyrolysis shrinkage coefficient of low-metamorphic YK gas coal and SYS1/3 coking coal is higher than 8.33×10−4 ℃−1, and the pyrolysis activation energy is lower than 77 kJ/mol. The pyrolysis shrinkage coefficient of LH coking coal, SAJ coking coal and BBG lean coal is lower than 4.55×10−4 ℃−1, but the activation energy required for pyrolysis is all higher than 106.1 kJ/mol. It indicates that the coking coal with high metamorphism requires higher energy to complete the shrinkage process during pyrolysis. The larger the shrinkage coefficient of coking coal, the smaller the average lumpiness of coke, and the pyrolysis shrinkage coefficient has a good linear relationship with the average lumpiness of coke, the correlation coefficient is 0.90. At the same time, the activation energy of pyrolysis shrinkage is also closely related with the average lumpiness of coke. Therefore, pyrolysis shrinkage coefficient and shrinkage activation energy can be used to effectively predict the average lumpiness of coke generated from coking coal with different metamorphic degrees