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論文

A Study on the effects of photogrammetry by the camera angle of view using computer simulation

中村 啓太; 羽成 敏秀; 松本 拓; 川端 邦明; 八代 大*

Journal of Robotics and Mechatronics, 36(1), p.115 - 124, 2024/02

During the decommissioning activities, a movie was shot inside the reactor building during the investigation of the primary containment vessel by applying photogrammetry, which is one of the methods for three-dimensional (3D) reconstruction from images, to the images from this movie, it is feasible to perform 3D reconstruction of the environment around the primary containment vessel. However, the images from this movie may not be suitable for 3D reconstruction because they were shot remotely by robots owing to limited illumination, high-dose environments, etc. Moreover, photogrammetry has the disadvantage of easily changing 3D reconstruction results by simply changing the shooting conditions. Therefore, this study investigated the accuracy of the 3D reconstruction results obtained by photogrammetry with changes in the camera angle of view under shooting conditions. In particular, we adopted 3D computer graphics software to simulate shooting target objects for 3D reconstruction in a dark environment while illuminating them with light for application in decommissioning activities. The experimental results obtained by applying artificial images generated by simulation to the photogrammetry method showed that more accurate 3D reconstruction results can be obtained when the camera angle of view is neither too wide nor too narrow when the target objects are shot and surrounded. However, the results showed that the accuracy of the obtained results is low during linear trajectory shooting when the camera angle of view is wide.

論文

Integration of multiple partial point clouds based on estimated parameters in photogrammetry with QR codes

馬場 啓多*; 渡部 有隆*; 中村 啓太*; 松本 拓; 羽成 敏秀; 川端 邦明

Proceedings of 29th International Symposium on Artificial Life and Robotics (AROB 2024) (Internet), p.751 - 756, 2024/01

This study proposes a partial-to-partial point cloud registration method based on estimated parameters in photogrammetry and QR code. Some research and development on Generating a 3D map of the workspace by photogrammetric methods have been proposed for the decommissioning work at the Fukushima Daiichi Nuclear Power Plant. Photogrammetry is a method for 3D reconstruction of the location and shape of target objects from many images, and the processing time depends on the number of images. Considering the reconstruction of a large area, the number of images increases, and processing time also increases significantly. To reduce such computational time, this study considers applying SfM-MVS (Structure from Motion and Multi-View Stereo), which is one of the photogrammetry methods, to each segmented image group, aligning each obtained result, integrating them, and creating a model of the entire space. This alignment is called partial-to-partial registration and it is difficult to find the correspondence points for registration. Therefore, we place markers such as QR codes in the target reconstruction space to make it easy to find the correspondence points. We adopt the QR code as a 2D code because it is easy to reconstruct by photogrammetry. In this paper, we discuss the validity of this approach by comparing it with the integrated model using all images applying SfM-MVS. We verify the validation of the proposed method by simulation due to the large number of images and the ease of modifying the environment. The experiment about varying the number of image divisions shows that the reconstruction result from all images is more accurate than the integrated result. However, all of these models have high reconstruction accuracy. Moreover, the accuracy of the integrated model does not depend on the number of divisions.

論文

Automatic system for sequential reconstruction from image sequences acquired from a camera by SfM-MVS

松本 拓; 羽成 敏秀; 川端 邦明; 八代 大*; 中村 啓太*

Proceedings of 2023 IEEE International Conference on Robotics and Biomimetics (IEEE ROBIO 2023) (Internet), 7 Pages, 2023/12

This paper describes an automatic system that performs three-dimensional (3D) modeling from image sequences acquired from a camera during a survey to understand the state of the environment sequentially. The developed system sequentially generates local 3D models from image sequences acquired from a camera by the Structure from Motion and Multi-View Stereo (SfM-MVS) and integrates the models. This system, consisting of a camera, a computer, and storage, handles streaming, image acquisition, 3D modeling, and integration processes. The system is designed to perform each process in parallel while performing image acquisition. Local 3D models are integrated based on the similarity of camera trajectories, which correspond to overlapped images in each sequence, estimated from SfM. Our experiments verified the operation of the developed system from the image acquisition to the integration of local 3D models in two cases. Consequently, we confirmed that an integrated model could be generated by automatically executing each process in the system through experiments.

論文

Compact moving particle semi-implicit method for incompressible free-surface flow

Wang, Z.; 松本 俊慶; Duan, G.*; 松永 拓也*

Computer Methods in Applied Mechanics and Engineering, 414, p.116168_1 - 116168_49, 2023/09

 被引用回数:3 パーセンタイル:86.6(Engineering, Multidisciplinary)

Recently, consistent meshfree particle methods have been intensively studied. It has been pointed out that numerical inaccuracy or instability could easily occur with incomplete or biased neighbor support. This study proposes a new meshfree particle method called the compact moving particle semi-implicit (CMPS) method to decrease the condition number. In the proposed CMPS, the first-order and second-order derivatives are discretized separately, enhancing the numerical stability significantly. By adopting a small dilation parameter of the compact support, the CMPS can remarkably improve accuracy and reduce computational costs. Formulations for zeroth-order, first-order, and second-order derivatives are derived, and various boundary conditions, e.g., Dirichlet and Neumann, are discussed. In order to better deal with complex free-surface flows using the CMPS, some new numerical techniques, i.e., optimized regularization and reconstructed particle shifting schemes, are also developed. Furthermore, the surface fitting method is extended to address the surface tension. A convergence study is conducted in complex geometry to verify the stability, accuracy, and efficiency of the CMPS. Then, second-order accuracy is confirmed using the Taylor-Green vortex problem. After that, numerical examples concerning various free-surface flows, including square patch, hydrostatic pressure, dam break, droplet oscillation, and droplet coalescence, are calculated to demonstrate the potential of the CMPS.

論文

Integration of 3D environment models generated from the sections of the image sequence based on the consistency of the estimated camera trajectories

松本 拓; 羽成 敏秀; 川端 邦明; 八代 大*; 中村 啓太*

Proceedings of 22nd World Congress of the International Federation of Automatic Control (IFAC 2023) (Internet), p.12107 - 12112, 2023/07

This paper describes a method that integrates Three-Dimensional (3D) environment models reconstructed from image sequences to reduce the computation time of 3D environment modeling that estimates camera poses and simultaneously reconstructs a 3D environment model from images based on photogrammetry. However, 3D environment modeling is time-consuming when using many images because it finds correspondence points between them by feature matching. Therefore, we assume that the computation time is reduced by reconstructing 3D environment models from image sequences divided from an image sequence because the number of images used in 3D environment modeling becomes less. However, it is difficult to integrate the 3D environment models because the scale between them may not be the same, and overlapping regions between 3D environment models are small for integrating the models. In this paper, we propose a method that integrates 3D environment models based on camera trajectories corresponding to overlapped images between image sequences used in 3D environment modeling. To integrate them, transformation parameters are calculated from poses of camera trajectories between 3D environment models. After that, the transformed camera trajectory is aligned using coarse and fine registration. Consequently, compared with 3D environment modeling that processes an image sequence in batch, the proposed method could reduce the computation time and reconstruct a comparable integrated model.

論文

Automatic process for 3D environment modeling from acquired image sequences

松本 拓; 羽成 敏秀; 川端 邦明; 八代 大*; 中村 啓太*

Proceedings of 28th International Symposium on Artificial Life and Robotics (AROB 28th 2023) (Internet), p.768 - 773, 2023/01

This paper reports on an automatic process for 3D environmental modeling from acquired image sequences. We have studied methods of 3D environment modeling to understand unknown environments. However, 3D environment modeling using acquired image sequences is a time-consuming task. When 3D environment modeling is performed using image sequences acquired in an unknown environment, the generated models do not always produce the expected result. Therefore, we consider that the quality of the generated 3D environment models could be quickly verified by realizing the sequential presentation of the generated models. To verify the effectiveness of the automatic process, we implemented it under different execution environments. Consequently, the automatic process could generate a 3D environment model from acquired image sequences.

論文

Advanced gel electrophoresis techniques reveal heterogeneity of humic acids based on molecular weight distributions of kinetically inert Cu$$^{2+}$$-humate complexes

丸茂 和樹*; 松本 篤正*; 中野 純佳*; 渋川 雅美*; 斉藤 拓巳*; 原賀 智子; 齋藤 伸吾*

Environmental Science & Technology, 53(24), p.14507 - 14515, 2019/12

 被引用回数:7 パーセンタイル:28.45(Engineering, Environmental)

フミン酸(HA)は環境中に存在する不定形有機高分子であり、環境中の有害重金属や放射性金属イオンと錯形成し、それらの動態を制御している。そのため、土壌や河川の環境評価や放射性廃棄物処分の安全評価において、HAによる金属イオンの保持挙動を解明することが重要である。本研究では、HAに保持された銅イオンの分子量分布を評価するため、ポリアクリルアミドゲル電気泳動法(PAGE)を基盤とした新規分析法を開発した。本法により、HAに対して高い分離能を有し、かつ泳動場の汚染金属イオンを抑制することが可能となり、HAの分子量に対する精確な金属イオン分布を得ることに成功した。また、PAGE, UV-Vis測定および励起蛍光マトリクス-平行因子分析を組み合わせることにより、HAの分子量,金属イオン分布およびHA蛍光成分分布の相関を評価することにも成功した。本研究により、HA中の金属イオン配位サイトやHA蛍光成分はHAの分子量に対して不均一に分布しており、HAによる金属イオンの保持挙動は金属イオンの電荷や立体配位座によって大きく異なることを明らかにした。

論文

Implementation and performance evaluation of a communication-avoiding GMRES method for stencil-based code on GPU cluster

松本 和也*; 井戸村 泰宏; 伊奈 拓也*; 真弓 明恵; 山田 進

Journal of Supercomputing, 75(12), p.8115 - 8146, 2019/12

 被引用回数:2 パーセンタイル:24.35(Computer Science, Hardware & Architecture)

ジャイロ運動論的トロイダル5次元オイラーコードGT5Dにおける反復法線形ソルバの性能向上に向けて省通信一般化最小残差法(CA-GMRES)をCPU-GPUハイブリッドクラスタで実装した。CA-GMRESに加え、計算量を削減するために我々が提案した修正版CA-GMRES(M-CA-GMRES)の実装と評価も行った。本研究から、集団通信回数の最小化と密行列積演算による高効率演算というCA-GMRESの利点が実証された。性能評価は1ノードあたりNVIDIA Tesla P100 GPU4台を搭載したReedbush-L GPUクラスタで実施した。この結果、M-CA-GMRESによりCA-GMRES, 一般化共役残差法(GCR), GMRESに比べてそれぞれ1.09x, 1.22x, 1.50xの高速化が示された。

論文

Degassing behavior of noble gases from groundwater during groundwater sampling

中田 弘太郎*; 長谷川 琢磨*; Solomon, D. K.*; 宮川 和也; 富岡 祐一*; 太田 朋子*; 松本 拓也*; 濱 克宏; 岩月 輝希; 小野 昌彦*; et al.

Applied Geochemistry, 104, p.60 - 70, 2019/05

 被引用回数:8 パーセンタイル:46.78(Geochemistry & Geophysics)

地下水に溶存している希ガス(He, Ne, Ar, Kr, Xe)は、地下水の起源や滞留時間、涵養温度などの推定に使われる。地下水に溶存しているガスを全て定量することが望ましいが、一方で、地下水の採取に伴う溶存ガスの脱ガスを避けることは難しい。本研究は、地下水の採取に伴う溶存希ガスの脱ガス挙動について調べ、その補正方法を提案するものである。地下施設及び深層ボーリングから地下水試料を採取し、原位置の圧力を維持した状態で採取した試料と、圧力を低下させて脱ガスさせた試料との比較を行った。その結果、溶存ガス圧が低い試料(約4.6気圧以下)については、大気圧下で脱ガスさせた場合、気液平衡が成り立つことが分かった。一方で、溶存ガス圧が高い試料(約32気圧)については、気液平衡が成り立たないことが分かった。気液平衡が成り立つ試料については、脱ガスの影響を補正することが可能であるが、気液平衡が成り立たない試料については、補正が困難であり、さらなる検討が必要である。

論文

Deformation analysis of reinforced concrete using neutron imaging technique

小山 拓*; 上野 一貴*; 関根 麻里子*; 松本 吉弘*; 甲斐 哲也; 篠原 武尚; 飯倉 寛; 鈴木 裕士; 兼松 学*

Materials Research Proceedings, Vol.4, p.155 - 160, 2018/05

 被引用回数:0 パーセンタイル:0.18(Materials Science, Characterization & Testing)

We developed, in this study, a novel method to observe internal deformation of concrete by the neutron transmission imaging technique. In order to visualize the internal deformation of concrete, the cement paste markers containing Gd$$_{2}$$O$$_{3}$$ powder were two-dimensionally dispersed around the ferritic deformed rebar in the reinforced concrete. This experiment was conducted using BL22, RADEN, in the Material and Life Science Experimental Facility of the Japan Proton Accelerator Research Complex. The transmission images of the reinforced concrete sample were taken at several positions on the vertical sample stage, and the displacement of the marker from the initial position was successfully evaluated within approximately $$pm$$0.1 mm accuracy by image analysis for selected markers with higher contrast and circularity. Furthermore, concrete deformation under pull-out loading to the embedded rebar was evaluated by the same way, and its reaction compressive deformation was successfully observed by analyzing the displacement of the markers. The results obtained in this study bring beneficial knowledge that the measurement accuracy of the marker displacement can be improved more by choosing a spherical shape of the marker and by increasing the contrast of the marker.

論文

Application of a communication-avoiding generalized minimal residual method to a gyrokinetic five dimensional Eulerian code on many core platforms

井戸村 泰宏; 伊奈 拓也*; 真弓 明恵; 山田 進; 松本 和也*; 朝比 祐一*; 今村 俊幸*

Proceedings of 8th Workshop on Latest Advances in Scalable Algorithms for Large-Scale Systems (ScalA 2017), p.7_1 - 7_8, 2017/11

ジャイロ運動論的5次元オイラーコードGT5Dに省通信一般化最小残差(CA-GMRES)法を適用し、一般化共役残差(GCR)法を用いたオリジナルコードとの性能比較をJAEA ICEX(Haswell)、Plasma Simulator(FX100)、Oakforest-PACS(KNL)において実施した。CA-GMRES法はGCR法に比べて約3.8倍の演算密度となることから、メモリとネットワークの帯域が制限された将来のエクサスケールアーキテクチャに適合する。性能評価の結果、GCR法に比べて計算カーネルは1.47$$sim$$2.39倍加速され、1,280ノード処理におけるデータ縮約通信は全体コストの5$$sim$$13%から約1%に削減された。

論文

X-ray absorption spectroscopy in the heavy Fermion compound $$alpha$$-YbAlB$$_4$$ at high magnetic fields

寺島 拓*; 松田 康弘*; 久我 健太郎*; 鈴木 慎太郎*; 松本 洋介*; 中辻 知*; 近藤 晃弘*; 金道 浩一*; 河村 直己*; 水牧 仁一朗*; et al.

Journal of the Physical Society of Japan, 84(11), p.114715_1 - 114715_4, 2015/11

 被引用回数:4 パーセンタイル:34.72(Physics, Multidisciplinary)

$$alpha$$-YbAlB$$_4$$ shows strong valence fluctuation as well as heavy fermion behavior at low temperatures. It has been theoretically suggested that the quantum criticality owing to the valence fluctuation found in Yb ions plays an important role in the peculiar properties of this material. In this work, we measured the X-ray absorption spectra (XAS) and X-ray magnetic circular dichroism (XMCD) at the L3 edge of Yb ions in high magnetic fields of up to 40 T. It is found that the XAS are almost independent of the magnetic field at 2 K, which proves that there is no significant valence change in this field range. The XMCD spectrum exhibits a distinct negative peak at the low-energy side of the L3 edge as well as the main positive peak near the white line. The negative XMCD peak is attributed to the quadrupole transition between the 2p and 4f states, and gives us microscopic information on the 4f state. This finding supports the recent theoretical proposal that $$|J_Z=pm5/2rangle$$ is the ground state of the localized Yb magnetic moment, where $$J_Z$$ is the z-component of the total angular momentum of Yb$$^{3+}$$.

論文

Synchrotron X-ray spectroscopy study on the valence state and magnetization in $$alpha$$-YbAl$$_{1-x}$$Fe$$_x$$B$$_4$$ ($$x=0.115$$) at low temperatures and high magnetic fields

寺島 拓*; 松田 康弘*; 久我 健太郎*; 鈴木 慎太郎*; 松本 洋介*; 中辻 知*; 近藤 晃弘*; 金道 浩一*; 河村 直己*; 水牧 仁一朗*; et al.

Journal of Physics; Conference Series, 592(1), p.012020_1 - 012020_6, 2015/03

 被引用回数:1 パーセンタイル:43.09(Physics, Atomic, Molecular & Chemical)

価数転移に伴う量子臨界現象が理論的に提案され、希土類金属間化合物における価数揺動現象が注目を集めている。最近、$$beta$$-YbAlB$$_4$$がチューニングなしで量子臨界を示すことと強い混合原子価状態にあることが見出された。この研究では我々は$$alpha$$-YbAl$$_{1-x}$$Fe$$_x$$B$$_4$$ ($$x=0.115$$)について磁化曲線とX線吸収を測定した。この物質は、局所的には$$beta$$-YbAlB$$_4$$と同一構造をもつ多形である。磁化測定とX線測定はそれぞれ55Tと40Tまで行った。Yb価数のわずかな上昇が磁化曲線が傾きの変化を示す磁場で観測された。

論文

Giant cadherins Fat and Dachsous self-bend to organize properly spaced intercellular junctions

塚崎 克和*; 宮崎 直幸*; 松本 淳; 長江 成典*; 米村 重信*; 田ノ上 拓自*; 岩崎 憲治*; 竹市 雅俊*

Proceedings of the National Academy of Sciences of the United States of America, 111(45), p.16011 - 16016, 2014/11

 被引用回数:38 パーセンタイル:63.49(Multidisciplinary Sciences)

Fat and Dachsous cadherins regulate cell polarity and proliferation via their heterophilic interactions at intercellular junctions. Their ectodomains are unusually large because of the repetitive EC domains, which raises questions of how they fit in regular intercellular spaces. Cadherins typically exhibit a linear topology through the binding of Ca$$^{2+}$$ to the linker between the EC domains. Our electron microscopic observations of mammalian Fat4 and Dachsous1 ectodomains, however, revealed that, while their N-terminal regions exhibit a linear configuration, the C-terminal regions are kinked with multiple hairpin-like bends. Notably, certain EC-EC linkers in Fat4 and Dachsous1 lost Ca$$^{2+}$$-binding amino acids. When such non-Ca$$^{2+}$$-binding linkers were substituted for a normal linker in E-cadherin, the mutant E-cadherins deformed more extensively than the wild-type molecule. To simulate cadherin structures with non-Ca$$^{2+}$$-binding linkers, we used the elastic network model and confirmed that bent configurations can be generated by deformation of the non-Ca$$^{2+}$$-binding linkers. These findings suggest that Fat and Dachsous self-bend due to the loss of Ca$$^{2+}$$-binding amino acids from specific EC-EC linkers, and therefore adapt to confined spaces.

論文

Elucidations of the catalytic cycle of NADH-cytochrome $$b$$$$_{5}$$ reductase by X-ray crystallography; New insights into regulation of efficient electron transfer

山田 貢*; 玉田 太郎; 竹田 一旗*; 松本 富美子*; 大野 拓*; 小杉 正幸*; 高場 圭章*; 正山 祥生*; 木村 成伸*; 黒木 良太; et al.

Journal of Molecular Biology, 425(22), p.4295 - 4306, 2013/11

 被引用回数:21 パーセンタイル:50.49(Biochemistry & Molecular Biology)

NADHシトクロム$$b$$$$_{5}$$還元酵素(b5R)はNADHドメインとFADドメインの2つのドメインからなるフラボタンパク質で、NADHから二個の電子を受け取り、二分子のシトクロム$$b$$$$_{5}$$(Cb5)に一電子ずつ伝達する反応を触媒する。今回、ブタ肝臓由来b5Rの還元型および酸化型の両状態における結晶構造解析に成功した。嫌気環境下で作製した結晶を用いて1.68${AA}$分解能で解析した二電子還元型b5Rの構造は、酸化型と比較して2つのドメインの相対配置がわずかに変化しており、その結果、FADの溶媒露出面積が増大し、FADのイソアロキサジン環のN5原子と、FADからのプロトン放出に関わっていると考えられているThr66の側鎖の水酸基間に水素結合が形成していた。一方、イソアロキサジン環の平面性は、還元型においても酸化型と変わらず保持されており、NAD$$^{+}$$のニコチンアミド環とスタッキングしていた。また、0.78${AA}$分解能で解析した酸化型b5Rの構造から、Thr66を介したFADとHis49間の水素結合ネットワークが水素原子の位置情報と共に明らかになった。これらの構造的特徴は、b5Rの触媒サイクルにおいて、電子の逆流を防ぎ、Cb5のような電子受容体への電子移動を促進するものであった。さらに、クライオトラップ法により還元型結晶の大気暴露時間を制御し作製した結晶を用いた解析により、還元型から酸化型への再酸化反応は二段階を経ることが示唆された。

論文

Resonant angle-resolved photoelectron spectroscopy of substitutional solid solutions of CeRu$$_2$$Si$$_2$$

岡根 哲夫; 川崎 郁斗; 保井 晃; 大河内 拓雄*; 竹田 幸治; 藤森 伸一; 斎藤 祐児; 山上 浩志; 藤森 淳; 松本 裕司*; et al.

Journal of the Physical Society of Japan, 80(Suppl.A), p.SA060_1 - SA060_3, 2011/07

 被引用回数:1 パーセンタイル:11.3(Physics, Multidisciplinary)

Angle-resolved photoelectron spectroscopy was measured in the Ce 3$$d$$$$rightarrow$$4$$f$$ resonance energy region for the paramagnetic state of CeRu$$_2$$Si$$_2$$, Ce$$_{0.84}$$La$$_{0.16}$$Ru$$_2$$Si$$_2$$ and LaRu$$_2$$Si$$_2$$ to investigate a variation of band structures around the quantum critical point (QCP). While the results clearly demonstrate the difference of the band structures between CeRu$$_2$$Si$$_2$$ and LaRu$$_2$$Si$$_2$$, the observed band structures of CeRu$$_2$$Si$$_2$$ and Ce$$_{0.84}$$La$$_{0.16}$$Ru$$_2$$Si$$_2$$ resemble each other. The results indicate that the Ce $$4f$$ electrons in the paramagnetic state have an itinerant character in either side of the critical composition, and Ce$$_{1-x}$$La$$_{x}$$Ru$$_2$$Si$$_2$$ near QCP is similar to CeRu$$_2$$(Si$$_{1-x}$$Ge$$_{x}$$)$$_2$$.

論文

Band structures of CeRu$$_2$$(Si$$_{1-x}$$Ge$$_{x}$$)$$_2$$ studied by resonant soft X-ray ARPES

岡根 哲夫; 大河内 拓雄*; 竹田 幸治; 藤森 伸一; 保井 晃; 斎藤 祐児; 山上 浩志; 藤森 淳; 松本 裕司*; 杉 基紀*; et al.

Physica Status Solidi (B), 247(3), p.397 - 399, 2010/03

Angle-resolved photoelectron spectroscopy measurements were made in the Ce $$3d$$$$rightarrow$$4$$f$$ resonance energy region for the paramagnetic state of CeRu$$_2$$Si$$_2$$, CeRu$$_2$$(Si$$_{0.82}$$Ge$$_{0.18}$$)$$_2$$ and LaRu$$_2$$Si$$_2$$ to investigate a variation of band structures around the quantum critical point. The results indicate that the Ce $$4f$$ electrons in the paramagnetic state have an itinerant character and participate in the formation of energy bands both in CeRu$$_2$$Si$$_2$$ and CeRu$$_2$$(Si$$_{0.82}$$Ge$$_{0.18}$$)$$_2$$, and the change of the band structures in the paramagnetic states should be continuous around the quantum critical point of the CeRu$$_2$$(Si$$_{1-x}$$Ge$$_{x}$$)$$_2$$ system.

論文

4$$f$$-derived Fermi surfaces of CeRu$$_2$$(Si$$_{1-x}$$Ge$$_{x}$$)$$_2$$ near the quantum critical point; Resonant soft-X-ray ARPES study

岡根 哲夫; 大河内 拓雄*; 竹田 幸治; 藤森 伸一; 保井 晃; 斎藤 祐児; 山上 浩志; 藤森 淳; 松本 裕司*; 杉 基紀*; et al.

Physical Review Letters, 102(21), p.216401_1 - 216401_4, 2009/05

 被引用回数:28 パーセンタイル:77.03(Physics, Multidisciplinary)

Angle-resolved photoelectron spectroscopy in the Ce $$3d$$$$rightarrow$$4$$f$$ excitation region was measured for the paramagnetic state of CeRu$$_2$$Si$$_2$$, CeRu$$_2$$(Si$$_{0.82}$$Ge$$_{0.18}$$)$$_2$$, and LaRu$$_2$$Si$$_2$$ to investigate the changes of the 4$$f$$ electron Fermi surfaces around the quantum critical point. While the difference of the Fermi surfaces between CeRu$$_2$$Si$$_2$$ and LaRu$$_2$$Si$$_2$$ was experimentally confirmed, a strong 4$$f$$-electron character was observed in the band structures and the Fermi surfaces of CeRu$$_2$$Si$$_2$$ and CeRu$$_2$$(Si$$_{0.82}$$Ge$$_{0.18}$$)$$_2$$, consequently indicating a delocalized nature of the 4$$f$$ electrons in both compounds. The absence of Fermi surface reconstruction across the critical composition suggests that SDW quantum criticality is more appropriate than local quantum criticality in CeRu$$_2$$(Si$$_{1-x}$$Ge$$_{x}$$)$$_2$$.

論文

Oxidation process of xylene in air using Ag/TiO$$_{2}$$ under electron beam irradiation

箱田 照幸; 松本 加奈江; 水野 彰*; 成田 正*; 小嶋 拓治; 広田 耕一

IEEE Transactions on Industry Applications, 44(6), p.1950 - 1956, 2008/11

 被引用回数:3 パーセンタイル:34.14(Engineering, Multidisciplinary)

塗料工場からの換気ガス中に含まれるキシレンなどの電子ビーム(EB)照射による分解処理技術の開発のために、EB照射と触媒であるAg担持TiO$$_{2}$$を併用して、キシレンやその照射副生成物の分解を促進する触媒設置条件を明らかにするととともに、触媒表面上の酸化反応を定量した。その結果、照射空間の下流への触媒導入により、照射副生成物のCO$$_{2}$$への選択的な酸化が認められ、特にAg担持量が5wt%以上の場合に最大のCO$$_{2}$$生成量が得られることがわかった。さらに、非照射空間における副生成物の酸化反応では照射由来のO$$_{3}$$から解離した活性酸素が照射副生成物の酸化分解に関与している可能性があることを明らかにした。

論文

Application of ozone decomposition catalysts to electron-beam irradiated xylene/air mixtures for enhancing carbon dioxide production

箱田 照幸; 松本 加奈江; 島田 明彦; 成田 正*; 小嶋 拓治; 広田 耕一

Radiation Physics and Chemistry, 77(5), p.585 - 590, 2008/05

 被引用回数:8 パーセンタイル:48.87(Chemistry, Physical)

当グループでは、塗料工場からの換気ガスに含まれる芳香族有機物を電子ビーム照射により分解除去する技術の開発を進めている。電子ビーム照射した汚染空気には、ガス中では有機物とほとんど反応しないオゾンが残存していることから、本研究では、このオゾンを活性化するとともに、この活性酸素により芳香族有機化合物やその照射生成物を酸化分解する技術の開発に着手した。具体的には、オゾンを活性化する方法としてオゾンの分解能力の高い二酸化マンガンを選定し、電子ビーム照射したキシレン含有空気をこの触媒に通じることにより、キシレン及び照射生成物の触媒酸化反応について調べた。その結果、触媒上でオゾンが解離して生じた活性酸素により、照射生成物のみを選択的に二酸化炭素にまで分解でき、またオゾンの分解量と同量の二酸化炭素が生成することがわかった。さらに、二酸化炭素となる照射生成物は、ギ酸などの低級な有機物であることを明らかにした。

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