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排序方式: 共有1314条查询结果,搜索用时 19 毫秒
1.
In recent years, we have experienced mega‐flood disasters in Japan due to climate change. In the last century, we have been building disaster prevention infrastructure (artificial levees and dams, referred to as “grey infrastructure”) to protect human lives and assets from floods, but these hard protective measures will not function against mega‐floods. Moreover, in a drastically depopulating society such as that in Japan, farmland abandonment prevails, and it will be more difficult to maintain grey infrastructure with a limited tax income. In this study, we propose the introduction of green infrastructure (GI) as an adaptation strategy for climate change. If we can use abandoned farmlands as GI, they may function to reduce disaster risks and provide habitats for various organisms that are adapted to wetland environments. First, we present a conceptual framework for disaster prevention using a hybrid of GI and conventional grey infrastructure. In this combination, the fundamental GI, composed of forests and wetlands in the catchment (GI‐1) and additional multilevel GIs such as flood control basins that function when floodwater exceeds the planning level (GI‐2) are introduced. We evaluated the flood attenuation function (GI‐1) of the Kushiro Wetland using a hydrological model and developed a methodology for selecting suitable locations of GI‐2, considering flood risk, biodiversity and the distribution of abandoned farmlands, which represent social and economic costs. The results indicated that the Kushiro Wetland acts as a large natural reservoir that attenuates the hydrological peak discharge during floods and suitable locations for introducing GI‐2 are concentrated in floodplain areas developing in the downstream reaches of large rivers. Finally, we discussed the network structure of GI‐1 as a hub and GI‐2 as a dispersal site for conservation of the Red‐crowned Crane, one of the symbolic species of Japan.  相似文献   
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A novel vinyl ether-type RAFT agent, benzyl 2-(vinyloxy)ethyl carbonotrithioate (BVCT) was synthesized for various block copolymers via the combination of living cationic polymerization of vinyl ethers and reversible addition−fragmentation chain transfer (RAFT) polymerization. The novel BVCT–trifluoroacetic acid adduct play an important role to produce well-defined block copolymers, which is both as a cationogen under EtAlCl2 initiation system in the presence of ethyl acetate for living cationic polymerization and a RAFT agent for blocks by RAFT polymerization. The resulting polymer, poly(vinyl ether)s, by living cationic polymerization had a high number average α-end functionality (≥0.9) as determined by both 1H NMR and MALDI-TOF-MS spectrometry. In addition, this poly(vinyl ether)s worked well as a macromolecular chain transfer agent for RAFT polymerization. The RAFT polymerization of radically polymerizable monomers was conducted in toluene using 2,2′-azobis(isobutyronitrile) at 70 °C. For example, a double thermoresponsive block copolymer (MOVE61-b-NIPAM150) consisting of 2-methoxyethyl vinyl ether (MOVE) and N-isopropylacrylamide (NIPAM) was prepared via the combination of living cationic polymerization and RAFT polymerization. The block copolymer reversibly formed and deformed micellar assemblies above the phase separation temperature (Tps) of poly(NIPAM) block in water. This BVCT is not only functioned as an initiator, but also acted as a monomer. When BVCT was copolymerized with MOVE by living cationic polymerization, followed by graft copolymerization with NIPAM via RAFT polymerization, well-defined graft copolymers (MOVEn-co-BVCTm)-g-NIPAMx (n = 62–73, m = 1–9, x = 19–214) were successfully obtained. However, no micelle formed in water above Tps of poly(NIPAM) graft chain unlike the case of block copolymers.  相似文献   
4.
In vitro mammalian cytogenetic tests detect chromosomal aberrations and are used for testing the genotoxicity of compounds. This study aimed to identify a supportive genomic biomarker could minimize the risk of misjudgments and aid appropriate decision making in genotoxicity testing. Human lymphoblastoid TK6 cells were treated with each of six DNA damage-inducing genotoxins (clastogens) or two genotoxins that do not cause DNA damage. Cells were exposed to each compound for 4 h, and gene expression was comprehensively examined using Affymetrix U133A microarrays. Toxicogenomic analysis revealed characteristic alterations in the expression of genes included in cyclin-dependent kinase inhibitor 1A (CDKN1A/p21)-centered network. The majority of genes included in this network were upregulated on treatment with DNA damage-inducing clastogens. The network, however, also included kinesin family member 20A (KIF20A) downregulated by treatment with all the DNA damage-inducing clastogens. Downregulation of KIF20A expression was successfully confirmed using additional DNA damage-inducing clastogens. Our analysis also demonstrated that nucleic acid constituents falsely downregulated the expression of KIF20A, possibly via p16 activation, independently of the CDKN1A signaling pathway. Our results indicate the potential of KIF20A as a supportive biomarker for clastogenicity judgment and possible mechanisms involved in KIF20A downregulation in DNA damage and non-DNA damage signaling networks.  相似文献   
5.

This review paper summarizes early Mössbauer and DTA studies of different oxide glasses containing small amounts of iron (III) or tin (IV) as the probe. A lot of valuable information of the atomic level has been obtained about the role of nonbridging oxygen (NBO), network former (NWF), network modifier (NWM), local network structure, glass transition, structural relaxation, crystallization, etc. Introduction of alkali oxide into iron (III)-containing oxide glass causes a marked decrease in glass transition temperature (Tg) amounting to 100 °C and a concordant decrease in quadrupole splitting (Δ) of FeIII, which reflects decreased distortion of NWF–oxygen polyhedra and formation of NBO. By contrast, introduction of non-alkali oxide into oxide glass causes an increase in Tg amounting to more than 100 °C and a concordant increase in Δ, reflecting increased distortion of NWF–oxygen polyhedra in highly cross-linked network. These experimental results led to a discovery of “Tg-Δ rule”, which was consistent with the “conformer model” proposed for polymers by Matsuoka and Quan. Debye temperatures (θD) obtained by low-temperature Mössbauer measurements proved to be useful to determine short- and long-range structures of glass and glass ceramics. Isothermal annealing of vanadate glasses at temperatures higher than Tg or crystallization temperature (Tc) causes a “tunable” decrease in DC-resistivity from the order of MΩ cm to Ω cm. Introduction of metal oxide with a narrow bandgap (Eg) is highly effective to increase the conductivity after the annealing. It was proved that “structural relaxation” of NWF–oxygen polyhedra and resultant decrease in the activation energy (Ea) for conduction are responsible for the improved conductivity. Heat treatment of IR-transmitting aluminate, gallate, and tellurite glasses at temperatures higher than Tg or Tc revealed that crystallization was triggered by the cleavage of NWF–oxygen bonds. These findings will contribute to the development of functional glass and glass ceramics such as smart glass and eco-friendly glass.

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6.
A platform of high accuracy and reliability is crucial for power amplifier (PA) designers to assess the characteristics of the PA prototype, and for the digital predistorter engineers to validate their models and algorithms. Digital processing techniques for building a test bed of high performance for PA characterization and predistortion (PD) are discussed in this article. We also proposed a novel technique to characterize the frequency responses of the vector signal generator and vector signal analyzer independently without using any other instrument. The techniques described in this article are quite useful, especially for narrowband vector transmitters and receivers, to improve their performance. These techniques were experimentally evaluated, both for characterization and PD of a class‐F PA. Test results show that using such techniques can successfully build a test bed of high accuracy and wide bandwidth. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2013.  相似文献   
7.
Li  Xiang  Makihara  Yasushi  Xu  Chi  Yagi  Yasushi  Ren  Mingwu 《Multimedia Tools and Applications》2018,77(21):28333-28354
Multimedia Tools and Applications - Human age estimation from gait is expected to be an important technology for a variety of applications such as automatic customer counting for marketing research...  相似文献   
8.
The graded energy deposition of heavy ion beam irradiation to polymeric materials was utilized to synthesize a novel proton exchange membrane (PEM) with the graded density of sulfonic acid groups toward the thickness direction. Stacked Poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP) films were irradiated by Xe54+ ion beam with the energy of 6 MeV/u under a vacuum condition. The induced trapped radicals by the irradiation were measured by electron spin resonance (ESR) spectroscopy. Irradiated films were grafted with styrene monomer and then sulfonated. X-ray photo-electron spectroscopy (XPS) spectra showed that the densities of sulfonic acid groups were controlled for injection “Surface” and transmit “Back” sides of the fabricated PEM. The membrane electrode assembly (MEA) fabricated by the function-graded PEM showed improved fuel cell performance in terms of voltage stability. It was expected that the function-graded PEM could control the graded concentration of sulfonic acid groups in PEM.  相似文献   
9.
We investigated the characteristics of highly transparent conductive Ga-doped ZnO (GZO) polycrystalline films of 100 nm thickness deposited on glass and polymer substrates. GZO films were deposited by ion plating with dc-arc discharge. We developed multiple-deposition method to obtain various deposition process temperatures lower than 100 °C. Cross-sectional SEM images show that all the GZO films have columnar structure. Analysis of data obtained by XRD measurements shows that all the GZO films with wurtzite structure exhibit highly (002) orientation perpendicular to the substrate. The resistivity of the GZO films deposited on polyester and glass substrates were 5.0 × 10-4 Ω · cm. The mechanical bending properties of the GZO films were investigated by comparing the sheet resistance determined before and after a bending test with various bending diameters. For the bending diameter of more than 30 mm, all the GZO films exhibited excellent bending properties with no change in sheet resistance. For the bending diameter of less than 20 mm, we found the sheet resistance affected by the bending. We demonstrated that our multiple-deposition method to achieve different controllable polyester substrate temperatures is highly suitable for improving the bending properties of GZO films.  相似文献   
10.
When using multiple Kinects, there must be enough distances among neighboring Kinects to avoid spoiled range data caused by the interference of their infrared speckle patterns. In the arrangement, their overlapped regions are too small to apply existing calibration methods using correspondences between their observations straightforwardly. Therefore, we propose a method to calibrate Kinects without large overlapped regions. In our method, first, we add extra RGB cameras in an environment to compensate overlapped regions. Thanks to them, we can estimate their camera parameters by obtaining correspondences between color images. Next, for accurate calibration, which considers range data as well as color images of Kinects, we optimize the estimated parameters by minimizing both the errors of correspondences between color images and those of range data of planar regions, which exist in a general environment such as walls and floors. Although our method consists of conventional techniques, its combination is optimized to achieve the calibration. © 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.  相似文献   
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