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Ductility improvement methods for commercial AZ31B magnesium alloy in cold forging

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Transactions of Nonferrous Metals Society of China 2010年第7期20卷 1275-1281页

作者： Ryo matsumoto Division of Mechanical Engineering Graduate School of Engineering ScienceOsaka University1-3 MachikaneyamaToyonakaOsaka 560-8531Japan

In order to realize cold forging of magnesium alloys in practical application,some methods for ductility improvement of a commercial wrought AZ31B magnesium alloy(Mg-3%Al-1%Zn,mass fraction) at room temperature were *** effects of heat treatment before forging and hydrostatic pressure during forging on the ductility were investigated in cold upsetting and cup ***-temperature annealing was effective to reduce the degree of the texture anisotropy of the specimen,and it was found that the forging limit of the annealed specimen was improved in cold *** the other hand,cold cup forging of the annealed specimen was carried out with applying counter *** applying counter pressures of 100-200 MPa during forging,the critical punch stroke for forging limit of the specimen without crack was improved by 25%in punch stroke.

关键词： magnesium alloy forging forgeability heat treatment counter force finite element simulation

A high-resolution climatic change since the Late Glacial Age inferred from multi-proxy of sediments in Qinghai Lake

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Science China Earth Sciences 2005年第6期48卷 742-751页

作者： Ryo matsumoto Geology Institute Tokyo University Tokyo 113 Japan

Based on multi-proxy analysis of pollen, carbonate, TOC, TN and δ13C of organic matters, a high-resolution climatic evolution of Qinghai Lake since the Late Glacial Age is recon-structed. The results indicate that the boundary between the Last Glacial Maximum and the Late Glacial Age is at about 18.2 *** BP. The warm and wet period, which began at about 15.4 *** BP, culminated at 7.4 *** BP and came to its end at about 4.5 *** BP. After that, the climate gradually became cold and dry. The multi-proxy analysis indicates that the climate fluc-tuated greatly during the transitional period from the Late glacial Age to the Holocene, and this is in good accordance with that reflected by deep sea cores of North Atlantic, ice cores of Greenland, lake sediments in Europe, loess sequences and Guliya ice core in China. The cli-matic evolutional characteristic of the Qinghai Lake since the Late Glacial Age shows that the driving force of the East-Asia Monsoon correlates with solar radiation on the ten-thousand-year scale.

关键词： Qinghai Lake, Late-Glacial Age to Holocene, multi-proxy analysis, high-resolution, palaeoclimate.

Adenocarcinoma arising from heterotopic pancreas at the third portion of the duodenum

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World Journal of Gastroenterology 2015年第13期21卷 4082-4088页

作者： Nobutada Fukino takatsugu Oida Kenji Mimatsu Youichi Kuboi Kazutoshi Kida Department of Surgery Japan Community Healthcare Organization Yokohama Central HospitalKanagawa 231-8553Japan Department of General Surgical Science Nihon University HospitalTokyo 101-8309Japan

A 62-year-old Japanese man presented to our hospital with a history of weight loss of 6 kg in 4 mo. Imaging examinations revealed a tumor located on the third portion of the duodenum with stenosis. We suspected duodenal carcinoma and performed pancreas-preserving segmental duodenectomy. Adenocarcinoma arising from a heterotopic pancreas at the third portion of the duodenum was finally diagnosed by immunohistochemical staining. Malignant transformation in the duodenum arising from a heterotopic pancreas is extremely rare; to our knowledge, only 13 cases have been reported worldwide, including the present case. The most common location of malignancy is the proximal duodenum at the first and descending portion. Herein, we describe the first case of adenocarcinoma arising from a heterotopic pancreas, which was located in the third portion of the duodenum, with a review of the literature.

关键词： Adenocarcinoma Heterotopic pancreas Duodenum Segme

Implications of excess ^(210)Pb and ^(137)Cs in sediment cores from Mikawa Bay, Japan

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Journal of Environmental Sciences 2009年第5期21卷 707-712页

作者： LU Xueqiang matsumoto Eiji Tianjin Academy of Environmental Sciences Tianjin 300191 China Graduate School of Environmental Studies Nagoya University Nagoya 464-8601 Japan

Four sediment cores were collected from Mikawa Bay, Japan, and excess ^210pb and ^137Cs were measured by gamma spectrometry. Sedimentation rates for the four cores were determined by ^210Pb method. The sedimentation rate range is 0.10-0.70 g/（cm^***）. The bio-mixing depth for each core is less than 7.0 cm, and was determined by the excess 210^pb profiles as well. Therefore, the bioturbation is slight. The 210^pb-derived dates coincided with the results from ^137Cs geochronology. Acceleration in sedimentation rate due to environmental alteration has been found in cores A2.5 and 05AS8, representing two depocenters due to their topography. Evidence of the Tokal Flood in 2000 was found in core 05AS8 according to the profiles of both radioisotopes and trace metals.

关键词： ^210pb ^137Cs sedimentation rate Mikawa Bay

Lake sediment records on climate change and human activities since the Holocene in Erhai catchment, Yunnan Province, China

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Science China Earth Sciences 2005年第3期48卷 353-363页

作者： R. matsumoto Geology Institute Tokyo University Tokyo 113 Japan

According to high-resolution analyses on multi-proxy of sediment core from the Er- hai Lake, Yunnan Province, the sequence of climatic and environmental change since the Holo- cene has been reconstructed based on accurate dating. The results show that climate had tran- sited from cold-wet to warm-wet during ca. 12950-8399 aBP in this area, and the transition happened in ca. 10329 aBP. Due to the enhancing southwest Asian monsoon and increasing precipitation, the lake-level of the Erhai Lake began to rise after ca. 10329 a BP. Climate in the catchment was warm and wet during the mid-Holocene, and the warmest stage appeared in ca. 8399-6371 a BP. The lake-level descended in the mid-Holocene because of the decrease of effective moisture in the basin. Human activities appeared in ca. 6371 a BP, and the initial man- ner mainly focused on deforestation. Up to ca. 2139 a BP, due to the amount of immigration into this area, the cultivation was developed widely, which was followed by mining (coal mine).

关键词： climate change, human activity, Holocene, lake sediment, Erhai Lake in Yunnan Province.

Growth promotion of interspecific hybrid embryos between Cucumis anguria and Melon(C. melo) by fruit heating

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Horticultural Plant Journal 2022年第2期8卷 215-220页

作者： Yuichi matsumoto Mako Tsunamoto Center for Education and Research in Agricultural Innovation Faculty of AgricultureSaga UniversitySaga 8470021Japan

Wild species of the genus Cucumis, such as C. anguria, are resistant to various melon(C. melo) diseases such as Fusarium wilt race 1.2 and are anticipated as genetic resources of melon. However, in the interspecific crosses between C. anguria and melon, the abortion of the embryos was observed in the early growth stage and could not be regenerated even when cultured. Therefore, for embryo rescue, it is necessary to promote embryo growth during abortion occurrence. This study investigated the effects of fruit heating on embryo growth in interspecific hybrids of C. anguria and melon. In the heating device, the minimum night temperature around the fruit was maintained above 21.5 °C. The ovule grain area of C. anguria × MR-1 with fruit heating was significantly enlarged compared to that without fruit-heating. It was also significantly enlarged compared with the ovule grain area of C. anguria self-pollination. Although, in C. anguria × MR-1 without fruit-heating, no embryo was observed until 10 days after pollination(DAP), and pre-embryos were observed at 13 DAP. Conversely, in C. anguria × MR-1 with fruit-heating, pre-embryos were even observed at 10 DAP. These results suggest that the possibility of embryo or ovule culture regeneration has increased due to embryo growth promotion.

关键词： Cucumis anguria L. Interspecific cross Melon Night temperature Ovule area

Research　on　the　Conditions　of　Enzymatic　Saccharification　for　Sugarcane　Bagasse

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Chemical Research in Chinese Universities 1998年第1期14卷 46-52页

作者： Zheng, C matsumoto, K Guangzhou Univ Dept Light Chem Engn Guangzhou 510091 Peoples R China Yokohama Natl Univ Dept Mat Sci & Chem Engn Yokohama Kanagawa Japan

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ＲｅｓｅａｒｃｈｏｎｔｈｅＣｏｎｄｉｔｉｏｎｓｏｆＥｎｚｙｍａｔｉｃＳａｃｃｈａｒｉｆｉｃａｔｉｏｎｆｏｒＳｕｇａｒｃａｎｅＢａｇａｓｓｅＺＨＥＮＧＣｈｅｎｇ（Ｄｅｐｔ，ｏｆＬｉｇｈｔＣｈｅｍ．Ｅｎｇ．，ＣｕａｎｇｚｈｏｕＵｎｉｖｅｒｓｉｔｙ，Ｇｕａ...

关键词： Conditions Enzymatic Sugarcane Saccharification

Effects of bottom bracings on torsional dynamic characteristics of horizontally curved twin I-girder bridges with different curvatures

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Earthquake Engineering and Engineering Vibration 2012年第2期11卷 149-162页

作者： Robiul Awall Toshiro Hayashikawa Takashi matsumoto Graduate School of Engineering Hokkaido University Faculty of Engineering Hokkaido University

Curved twin I-girder bridges (CTIGBs) have low torsional stiffness that makes them vulnerable to dynamic loads. This study investigates the effects of bottom bracings on the torsional dynamic characteristics of CTIGBs. Five types of bottom bracings are designed to investigate their effects on the dynamic characteristics of CTIGBs with different curvatures under free and forced vibrations. To perform numerical investigations, three-dimensional (3-D) finite element (FE) bridge and vehicle models are established using commercial ANSYS code, and then a vehicle-bridge interaction analysis approach is proposed. Road roughness profiles generated from power spectral density and cross spectral functions are also taken into account in the analyses. The numerical results show that torsional frequencies increase significantly after providing bottom bracings, and the increasing rate depends on the type of bottom bracings and their locations of installation. Bottom bracings can act as load transmitting members from one main girder to the others. Large negative bearing forces that have occurred in bridges with small radii of curvatures can be remarkably reduced by providing bottom bracing systems. It is found that the performances of several bottom bracing systems are effective in improving the torsional dynamic characteristics of the bridges in this study.

关键词： bottom bracing CTIGB FE model torsional stiffness dynamic response negative bearing force

Urban climate in the Tokyo metropolitan area in Japan

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Journal of Environmental Sciences 2017年第9期29卷 54-62页

作者： Jun matsumoto Fumiaki Fujibe Hideo Takahashi Research Center for Climatology Department of Geography Tokyo Metropolitan University Department of Coupled Ocean-Atmosphere-Land Processes Research JAMSTEC

Long-term climate changes related with urbanization in Tokyo, Japan, and recent temperature and heavy rainfall distribution in the Tokyo metropolitan area are reviewed. A relatively high temperature increase in annual mean temperature at the rate of 3.0°C/century was detected in Tokyo for the period 1901–2015. Some observational evidence showed the existence of both thermal and mechanical effects of urbanization on recent heavy rainfall occurrences, and modeling studies also support precipitation enhancement. Urban influences were recognized in other climatological elements, such as number of fog days, relative humidity, and wind circulation.

关键词： Heat island Cool island Heavy rainfall Fog Humidity Sea breeze