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Journal of Materials Science & Technology 2020年第15期47卷 162-170页

作者： Yufan Zhao Yuichiro Koizumi kenta Aoyagi kenta yamanaka Akihiko Chiba Department of Materials Processing Graduate School of EngineeringTohoku UniversityAoba-yama 02Aoba-kuSendai980-8579Japan Institute for Materials Research Tohoku University2-1-J KatahiraAoba-kuSendai980-8577Japan

Powder bed fusion with electron beam(PBF-EB),allows Co-Cr-Mo(CCM) implants with patientcustomization to be fabricated with high quality and complex ***,the variability in the properties of PBF-EB-built CCM alloy,mainly due to the lack of understanding of the mechanisms that govern microstructural heterogeneity,brings limitations in extensive *** this study,the microstructural heterogeneity regarding the γ-fcc→ε-hcp phase transformation was *** phase transformation during PBF-EB was analyzed depending on the thermal history that was elucidated by the numerical *** revealed that isothermal γ→ε transformation occurred during the ***,the difference in γ/ε phase distribution was a result of the thermal history determining which method phase transformation was taking place,which can be influenced by the PBF-EB process *** the sample with a low energy input(Earea=2.6 J/mm2),the martensitic transformation was *** the building height increased from the bottom,the e phase fraction *** the other hand,in the sample with a higher energy input(Earea=4.4 J/mm2),the ε phase fo rmed via diffusional-massive transformation and only appea red in a short range of the lower part away from the bottom.

关键词： Powder bed fusion with electron beam Phase transformation Thermal history Numerical simulation

Microstructure and mechanical properties of Ti−Nb−Fe−Zr alloys with high strength and low elastic modulus

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Transactions of Nonferrous Metals Society of China 2022年第2期32卷 503-512页

作者： Qiang LI Qi HUANG Jun-jie LI Qian-feng HE Masaaki NAKAI Ke ZHANG Mitsuo NIINOMI kenta yamanaka Akihiko CHIBA Takayoshi NAKANO School of Mechanical Engineering University of Shanghai for Science and TechnologyShanghai 200093China CAS Key Laboratory of Functional Materials and Devices for Special Environments Xinjiang Technical Institute of Physics&ChemistryCASUrumqi 830011China Division of Mechanical Engineering Faculty of Science and EngineeringKindai University3-4-1 KowakaeHigashiosakaOsaka 577-8502Japan School of Materials Science and Engineering University of Shanghai for Science and TechnologyShanghai 200093China Institute for Materials Research Tohoku University2-1-1 KatahiraAoba-kuSendai 980-8577Japan Division of Materials and Manufacturing Science Graduate School of EngineeringOsaka University2-1 Yamada-OkaSuitaOsaka 565-0871Japan Department of Materials Science and Engineering Graduate School of Science and TechnologyMeijo University1-501 ShiogamaguchiTempaku-kuNagoya 468-8502Japan

Zr was added to Ti−Nb−Fe alloys to develop low elastic modulus and high strengthβ-Ti alloys for biomedical *** of Ti−12Nb−2Fe−(2,4,6,8,10)Zr(at.%)were prepared by arc melting and then subjected to homogenization,cold rolling,and solution *** phases and microstructures of the alloys were analyzed by optical microscopy,X-ray diffraction,and transmission electron *** mechanical properties were measured by tensile *** results indicate that Zr and Fe cause a remarkable solid-solution strengthening effect on the alloys;thus,all the alloys show yield and ultimate tensile strengths higher than 510 MPa and 730 MPa,*** plays a weak role in the deformation ***,twinning occurs in all the deformed alloys and is beneficial to both strength and ***−12Nb−2Fe−(8,10)Zr alloys with metastableβphases show low elastic modulus,high tensile strength,and good plasticity and are suitable candidate materials for biomedical implants.

关键词： biomedical Ti alloy mechanical properties solid-solution strengthening work hardening twinninginduced plasticity

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未来气候条件下蒙古草原植被的预测分布

Journal of Plant Ecology 2024年第3期17卷 16-27页

作者： Kohei Suzuki Ikutaro Tsuyama Radnaakhand Tungalag Amartuvshin Narantsetseg Tsagaanbandi Tsendeekhuu Masato Shinoda Norikazu yamanaka Takashi Kamijo Department of Regional Regeneration Science Faculty of Regional Environment ScienceTokyo University of AgricultureTokyo 156-8502Japan Hokkaido Research Center Forestry and Forest Products Research InstituteHokkaido 062-8516Japan Department ofBiology School of Arts and SciencesNational University of MongoliaUlaanbaatar 210646Mongolia Botanic Garden and ResearchInstitute Mongolian Academy of ScienceUlaanbaatar 51Mongolia Department of Earth and Environmental Sciences GraduateSchool of Environmental StudiesNagoya UniversityNagoya 464-8601Japan Arid Land Research Center Tottori UniversityTottori680-0001Japan Faculty of Life and Environmental Sciences University of TsukubaIbaraki 305-8572Japan

蒙古牧民家庭通过适应当地植被分布的特点来维持牲畜的健康状况。因此,预测未来植被变化对于稳定的牲畜放牧和可持续的草原利用至关重要。本研究基于前期研究获得的植被数据预测了2081年至2100年间草原植被,尤其是沙漠草原、草原和草甸... 详细信息

蒙古牧民家庭通过适应当地植被分布的特点来维持牲畜的健康状况。因此,预测未来植被变化对于稳定的牲畜放牧和可持续的草原利用至关重要。本研究基于前期研究获得的植被数据预测了2081年至2100年间草原植被,尤其是沙漠草原、草原和草甸草原的分布范围。我们首先基于在蒙古(43–50°N,87–119°E)收集的草原植被数据(2012至2016年,278个样地)划分了不同的群落类型。其次,采用最大熵(MaxEnt)模型进行物种分布建模,其中以荒漠草原、草原和草甸草原的分布数据作为目标变量,使用WorldClim的生物气候数据作为解释变量。最后,采用WorldClim提供的CMIP6下缩放的未来气候预测数据进行未来预测。结果发现,荒漠草原、草原和草甸草原模型的曲线下面积值分别为0.850、0.847和0.873。根据所有情景和所有群落的气候变化,适宜栖息地预计将缩小。潜在适宜区域减少的程度在草甸草原群落中最为显著。上述结果表明,未来气候变化情景下草甸草原群落将转变为草原群落。

关键词：气候变化群落最大熵物种分布建模草原 WorldClim

Influence of image classification accuracy on saliency map estimation

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CAAI Transactions on Intelligence Technology 2018年第3期3卷 140-152页

作者： Taiki Oyama Takao yamanaka Department of Information and Communication Sciences Sophia University 7-1 Kioi-cho Chiyoda-ku Tokyo 102-0094 Japan

Saliency map estimation in computer vision aims to estimate the locations where people gaze in images. Since people tend to look at objects in images, the parameters of the model pre-trained on ImageNet for image classification are useful for the saliency map estimation. However, there is no research on the relationship between the image classification accuracy and the performance of the saliency map estimation. In this study, it is shown that there is a strong correlation between image classification accuracy and saliency map estimation accuracy. The authors also investigated the effective architecture based on multi-scale images and the up-sampling layers to refine the saliencymap resolution. The model achieved the state-of-the-art accuracy on the PASCAL-S, OSIE, and MIT1003 datasets. In the MIT saliency benchmark, the model achieved the best performance in some metrics and competitive results in the other metrics.

关键词：计算机视觉图像处理发展现状计算机技术

Site effects by generalized inversion technique using strong motion recordings of the 2008 Wenchuan earthquake

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Earthquake Engineering and Engineering Vibration 2013年第2期12卷 165-184页

作者： Ren Yefei Wen Ruizhi Hiroaki yamanaka Toshihide Kashima Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake Administration Tokyo Institute of Technology Building Research Institute

The generalized inversion of S-wave amplitude spectra from the free-field strong motion recordings of the China National Strong Motion Observation Network System （NSMONS） are used to evaluate the site effects in the Wenchuan area. In this regard, a total of 602 recordings from 96 aftershocks of the Wenchuan earthquake with magnitudes of M3.7-M6.5 were selected as a dataset. These recordings were obtained from 28 stations at a hypocenter distance ranging from 30 km to 150 km. The inversion results have been verified as reliable by comparing the site response at station 62WUD using the Generalized Inversion Technique （GIT） and the Standard Spectral Ratio method （SSR）. For all 28 stations, the site predominant frequency F and the average site amplification in different frequency bands of 1.0-5.0 Hz, 5.0-10.0 Hz and 1.0-10.0 Hz have been calculated based on the inversion results. Compared with the results from the horizontal-to-vertical spectral ratio （HVSR） method, it shows that the HVSR method can reasonably estimate the site predominant frequency but underestimates the site amplification. The linear fitting between the average site amplification for each frequency band and the V20 （the average uppermost-20 m shear wave velocity） shows good correlation. A distance measurement called the asperity distance DAspt is proposed to reasonably characterize the source-to-site distance for large earthquakes. Finally, the inversed site response is used to identify the soil nonlinearity in the main shock and aftershocks of Wenchuan earthquake. In ten of the 28 stations analyzed in the main shock, the soil behaved nonlinearly, where the ground motion level is apparently beyond a threshold ofPGA 〉 300 cm/s^2 or PGV 〉 20 cm/s, and only one station coded 51SFB has evidence of soil nonlinear behavior in the aftershocks.

关键词： generalized inversion technique site effect Wenchuan earthquake soil nonlinearity predominant frequency site amplification

Duodenal intussusception secondary to ampullary adenoma: A case report

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World Journal of Clinical Cases 2019年第14期7卷 1857-1864页

作者： Masaaki Hirata Yoshiharu Shirakata Kenya yamanaka Department of Surgery Hyogo Prefectural Amagasaki General Medical CenterAmagasakiHyogo 660-0892Japan

BACKGROUND Because the duodenum is fixed onto the retroperitoneum, duodenal intussusception is usually impossible except in cases of malrotational abnormality. Although cases of duodenal intussusception without malrotational abnormalities have been reported, it is unclear whether they constitute true intussusception or simple mucosal prolapse. CASE SUMMARY A 66-year-old woman presented with whole-body edema and malaise. Blood analysis indicated severe anemia and cholestasis. Endoscopic examination revealed a pedunculate polyp on the second part of the duodenum that migrated distally with mucosal elongation. Computed tomography showed duodenal intussusception. A tumor as the lead point and retroperitoneal structure, including the head of the pancreas and fat, invaginated beyond the duodenojejunal flexure. She was diagnosed with ampullary adenoma caused repeated intussusception that reduced spontaneously and underwent pancreaticoduodenectomy. Laparotomy showed tumor prolapse beyond the duodenojejunal flexure without intussusception. There was no evidence of malrotational abnormality. She was discharged with no complications. CONCLUSION We report true duodenal intussusception without malrotational abnormality. This phenomenon was also associated with mucosal prolapse.

关键词： Duodenal intussusception Mucosal prolapse Ampullary adenoma Case report

Effectiveness of impedance monitoring during radiofrequency ablation for predicting popping

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World Journal of Gastroenterology 2012年第41期18卷 5870-5878页

作者： Hiroya Iida Tsukasa Aihara Shinichi Ikuta Naoki yamanaka Department of Surgery Meiwa Hospital4-31 Agenaruo-choNishinomiyaHyogo 663-8186Japan

AIM： To retrospectively evaluate the effectiveness of impedance monitoring for predicting popping during radiofrequency ablation （RFA） using internally cooled electrodes. METHODS： We reviewed 140 patients （94 males, 46 females; age range 73.0 ＋ 11.1 year） who underwent RFA between February 2006 and November 2008 with a modified protocol using a limited power delivery rather than a conventional one to avoid popping. All the patients provided their written informed consent, and the study was approved by the institutional review board. Intraprocedural impedances were measured for the study subjects, and the tumors were classified into three types according to the characteristics of their impedance curves： increasing, flat, or decreasing. The tumors were further sorted into seven subtypes （A-G） depending on the curvature of the impedance curve＇ s increase or decrease. Relative popping rates were determined for the three types and seven subtypes. A chi-square test was performed to estimate statistical ***： A total of 148 nodules treated by RFA were analyzed. The study samples included 132 nodules of hepatocellular carcinoma, 14 nodules of metastatic liver cancer, and two nodules of intrahepatic cholangio- carcinoma. The numbers of nodules with each imped- ance curve type were as follows： 37 increasing-type nodules, 43 fiat-type nodules, and 68 decreasing-type nodules. Popping occurrence rates were 24.3%, 46.5% and 64.7%, respectively. Flat-type nodules exhibited a significantly higher rate of popping compared to increasing-type nodules （P = 0.039）. Decreasing-type nodules exhibited a significantly higher rate of popping compared to increasing-type nodules （P 〈 0.0001）. No- tably, nodules that showed a sharp decrease in imped- ance in the latter ablation period （subtype E） exhibited a significantly higher rate of popping compared to other subtypes. CONCLUSION： Intraprocedural impedance monitoring can be a useful tool to predict the occurrence of pop- ping

关键词： Radiofrequency ablation Internally cooledelectrode Popping Liver Complication

Chemically oligomerizable TDP-43:a novel chemogenetic tool for studying the pathophysiology of amyotrophic lateral sclerosis

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Neural Regeneration Research 2022年第11期17卷 2434-2436页

作者： Kohsuke Kanekura Yoshiaki yamanaka Tamami Miyagi Masahiko Kuroda Department of Molecular Pathology Tokyo Medical University

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease characterized by the progressive loss of both upper and lower motor *** ALS cases are sporadic,but approximately 5-10%of patients have a f... 详细信息

关键词： sclerosis familial

Long Gap Discharge Guiding Experiments Using Strongly and Weakly Ionized Plasma Channels for Laser Triggered Lightning

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Plasma Science and Technology 2007年第6期9卷 740-742页

作者： Y.SHIMADA M.YAMAURA C.yamanaka Institute for Laser Technology OsakaJapan

A study to generate longer plasma channel was conucted to improve probability of triggered lightning. To generate the long laser plasma channel, a strongly and a weakly ionized plasma channels were used in series, a scheme called hybrid method. The strongly and the weakly ionized plasma channels were used for triggering an electrical leader and guiding the leader. The electrical leader propagated through the weakly ionized plasma. Then main discharge occurred between the electrodes. It is found that the streamer was accelerated with both the increase in the plasma density and the increase in an ambient electric field close to the plane electrode.

关键词： laser plasma channel lightning velocity of streamer

Presence of a cerebral factor showing summer-morph- producing hormone activity in the brain of the seasonal non- polyphenic butterflies Vanessa cardui, V. indica and Nymphalis xanthomelas japonica （Lepidoptera： Nymphalidae）

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Insect Science 2009年第2期16卷 125-130页

作者： Ayuki Tanaka Moeko Inoue Katsuhiko Endo Chisato Kitazawa Akira yamanaka Laboratory of Environmental Biology Department of Physics Biology and Informatics Faculty of Science Yamaguchi University Yamaguchi Laboratory of Environmental Biology Graduate School of Medicine Yamaguchi University Yamaguchi 753-8512 Biological Institute Faculty of Education Yamaguchi University Yamaguchi 753-8513 Japan

Three species ofnymphalid butterflies, Vanessa cardui, V. indica and Nymphalis xanthomelasjaponica, do not exhibit seasonal polyphenism in wing coloration. To deter-mine whether seasonal non-polyphenic butterflies possess a cerebral factor affecting wing coloration, we used a Polygonia c-aureurn female short-day pupal assay for detection of summer-morph-producing hormone （SMPH） activity in P. c-aureum. When 2% NaCl extracts of 25 brain-equivalents prepared from the pupal brains of V. cardui, V. indica or N. xanthomelasjaponica were injected into Polygonia female short-day pupae, all recipients developed into summer-morph adults with dark-yellow wings, and the average grade score （AGS） of summer morphs showing SMPH activity was 3.8, 3.7 and 4.0, respectively. In contrast, when acetone or 80% ethanol extracts prepared from pupal brains were injected into Polygonia pupae, all recipients developed into autumn-morph adults with a dark-brown coloration and each exhibited an AGS of less than 0.5. Our results indicate that a cerebral factor showing SMPH activity is present in the pupal brain of seasonal non-polyphenic nymphalid butterflies, suggesting that a SMPH and cerebral factor showing SMPH activity occur widely among butterfly species. This finding will improve our understanding of the presence of cerebral factors showing interspecific actions of SHPH.

关键词： Key words Nymphalis xanthomelasjaponica seasonal non-polyphenic butterfly seasonalpolyphenism summer-morph-producing hormone Vanessa cardui wing coloration