检索结果-南通市图书馆

A case study of seismic response of earth embankment foundation on liquefiable soils

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2009年第6期16卷 994-1000页

作者：黄雨 YASHIMA A sawada K 张锋 Department of Geotechnical Engineering Tongji University Key Laboratory of Geotechnical and Underground Engineering Ministry of EducationTongji University Department of Civil Engineering Gifu University Department of Civil Engineering Nagoya Institute of Technology

A case study of seismic response of an earth embankment foundation on liquefiable soils in Kansai area,western Japan was presented. Based on a calibrated cyclic elasto-plastic constitutive model for liquefiable sand and Biot dynamic coupled theory,the seismic analysis was carried out by using a dynamic effective stress finite element method under plane strain condition. A recent design study was illustrated in detail for a river earth embankment subjected to seismic excitation on the saturated deposits with liquefiable sands. Simulated results of the embankment foundation during liquefaction were obtained for acceleration,displacement,and excess pore water pressures,which were considered to yield useful results for earthquake geotechnical design. The results show that the foundation soil reaches a fully liquefied state with high excess pore pressure ratios approaching to 1.0 due to the earthquake shaking. At the end of the earthquake,the extensive liquefaction causes about 1.0 m lateral spreading at the toe and 60 cm settlement at the crest of the earth embankment.

关键词： earth embankment earthquake liquefaction cyclic plasticity finite element method case study

Full polarimetric PALSAR-based land cover monitoring in Cambodia for implementation of REDD policies

在线全文

学校读者我要写书评

暂无评论

International Journal of Digital Earth 2013年第3期6卷 255-275页

作者： Ram Avtar Wataru Takeuchi Haruo sawada Institute of Industrial Science The University of TokyoTokyoJapan

Forest cover monitoring plays an important role in the implementation of climate change mitigation policies such as Kyoto protocol and Reducing Emissions from Deforestation and Forest Degradation(REDD).In this study,we have monitored land cover using the PALSAR(Phased Array type L-band Synthetic Aperture Radar)full polarimetric data based on incoherent target *** classification technique has been applied on CloudePottier decomposition,FreemanDurden three component,and Yamaguchi four component decomposition for accurate mapping of different types of land cover *** on confusion matrix derived from the predicted and defined pixels,the evergreen and sparsely deciduous forests have shown high producer’s accuracy by FreemanDurden three component and Yamaguchi four component classifica*** overall accuracy of Maximum Likelihood Classification by Yamaguchi four component is 94.1%with 0.93 kappa coefficient as compared to the 90.3%with 0.88 kappa coefficient by FreemanDurden three component and 89.7%with 0.88 kappa coefficient by CloudePottier *** accuracy of classification in a forested area using full polarimetric PALSAR data may have been because of high penetration of L-band *** content of this study could be useful for the forest cover mapping during cloudy days needed for proper implementation of REDD policies in Cambodia.

关键词： global climate change REDD PALSAR forest cover mapping

Dynamic pressure change in a rotating, laterally oscillating cylindrical container

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Ocean Engineering and Science 2018年第2期3卷 91-95页

作者： Yusuke Saito Tatsuo sawada Department of Mechanical Engineering Keio University3-14-1 HiyoshiKohoku-kuYokohama 223-8522Japan

We examined wave phenomena pertinent to water in a rotating,laterally oscillating cylindrical *** particular,we measured the time-dependent dynamic water pressure and pressure change by fast Fourier transform *** swirling of water in the container had three frequency components;the frequency responses of each frequency component are reported *** swirling occurs in a rotating cylindrical container,it was found that the wave rotating in the same direction as the rotation of the cylindrical container and the wave rotating in the opposite direction to the cylindrical container exist at the same *** swirling direction was determined by the relationship of these magnitude.

关键词： Sloshing Dynamic pressure Cylindrical container Rotation Oscillation Swirling

Synchrotron X-ray diagnostics of cutoff shape of nonthermal electron spectrum at young supernova remnants

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2014年第2期14卷 165-178页

作者： Ryo Yamazaki Yutaka Ohira Makoto sawada Aya Bamba Department of Physics and Mathematics Aoyama Gakuin University5-10-1 FuchinobeSagamihara 252-5258Japan

Synchrotron X-rays can be a useful tool to investigate electron accelera- tion at young supemova remnants （SNRs）. At present, since the magnetic field con- figuration around the shocks of SNRs is uncertain, it is not clear whether electron acceleration is limited by SNR age, synchrotron cooling, or even escape from the ac- celeration region. We study whether the acceleration mechanism can be constrained by the cutoff shape of the electron spectrum around the maximum energy. We derive analytical formulae of the cutoff shape in each case where the maximum electron en- ergy is determined by SNR age, synchrotron cooling and escape from the shock. They are related to the energy dependence of the electron diffusion coefficient. Next, we discuss whether information on the cutoff shape can be provided by observations in the near future which will simply give the photon indices and the flux ratios in the soft and hard X-ray bands. We find that if the power-law index of the electron spectrum is independently determined by other observations, then we can constrain the cutoff shape by comparing theoretical predictions of the photon indices and/or the flux ratios with observed data which will be measured by NuSTAR and/or ASTRO-H. Such study is helpful in understanding the acceleration mechanism. In particular, it will supply another independent constraint on the magnetic field strength around the shocks of SNRs.

关键词： acceleration of particles -- ISM: cosmic rays -- ISM: supernova rem-nants -- turbulence -- X-rays: ISM

Erythropoietin ameliorates early ischemia-reperfusion injury following the Pringle maneuver

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2010年第38期16卷 4838-4845页

作者： Masato Kato Tokihiko sawada Junji Kita Mitsugi Shimoda Keiichi Kubota Second Department of Surgery Dokkyo Medical UniversityKitakobayash 880

AIM:To investigate the protective effect of erythropoietin (Epo) against ischemia-reperfusion injury (IR/I) following the Pringle maneuver (PM),in comparison with conventional steroid administration in a prospective randomized trial. METHODS:Patients were randomized by age, sex, diagnosis, and surgical method, and assigned to three groups:(1) A steroid group (STRD, n= 9) who received 100 mg of hydrocortisone before PM, and on postoperative days 1, 2 and 3, followed by tapering until postoperative day 7; (2) An EPO1 group (n=10) who received 30 000 U of Epo before the PM and at the end of surgery; and (3) An EPO2 group (n=8) who received 60 000 U of Epo before the PM. Hemoglobin (Hb), hematocrit (Ht), aspartate aminotransferase (AST), alanine transaminase (ALT),lactate dehydrogenase (LDH), lactate, interleukin-6 (IL-6),and tumor necrosis factor(TNF)-α were measured before and just after (Day 0) surgery, and on postoperative days 1, 3, 7 and 14. RESULTS: There were no increases in Hb and Ht in the EPO1 and EPO2 groups. AST was signif icantly lower in EPO1 than in STRD on Day 0 (P=0.041), and lower in EPO1 than in STRD and EPO2 on Day 1 (P=0.018). ALT was signif icantly lower in EPO1 than in STRD and EPO2 on Day 0 (P=0.020) and Day 1 (P=0.004). There were no signif icant inter-group differences in the levels of LDH and lactate. IL-6 was signif icantly lower in EPO1 than in STRD and EPO2 on Day 0 (P=0.0036) and Day 1 (P=0.0451). TNF-α was signif icantly lower in EPO1 than in STRD and EPO2 on Day 0 (P=0.0006) and Day 1 (P<0.0001). Furthermore, hospitalization was signif icantly shorter in EPO1 and EPO2 than in ***:Epo has greater potential than steroids to ameliorate IR/I after the PM. Epo at a dose of 30000 U, administered before PM and just after surgery, yields better results.

关键词： Erythropoietin Hepatic resection Pringle maneuver Steroid Prospective randomized study

Implicit Discontinuous Galerkin Method for RANS Simulation Utilizing Pointwise Relaxation Algorithm

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Computational Physics 2010年第3期7卷 510-533页

作者： Kanako Yasue Michiko Furudate Naofumi Ohnishi Keisuke sawada Department of Aerospace Engineering Graduate School of EngineeringTohoku UniversitySendai 980-8579Japan

An efficient implicit procedure for the Discontinuous Galerkin (DG) methodis developed utilizing a pointwise relaxation algorithm. In the pointwise relaxation,those contributions from the degrees of freedom in own computational cell are accounted for in the implicit matrix inversion. The resulting scheme is shown to be stablewith very large CFL numbers for both the Euler and the Navier-Stokes equations fortypical test problems. In order to achieve a faster convergence, efforts are also madeto reduce computing time of the present method by utilizing a p-multigrid schemeand also by solving a simplified matrix instead of a fully loaded dense matrix in theimplicit matrix inversion. A superior performance of the present implicit DG methodon the parallel computer using up to 128 PEs is shown in terms of readily achievablescalability and high parallel efficiency. The RANS simulation of turbulent flowfieldover AGARD-B model is carried out to show the convergence property and numericalstability of the present implicit DG method for engineering applications.

关键词： Discontinuous Galerkin method pointwise relaxation implicit scheme viscous compressible flow

An Implicit LU-SGS Scheme for the Spectral Volume Method on Unstructured Tetrahedral Grids

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Computational Physics 2009年第10期6卷 978-996页

作者： Takanori Haga Keisuke sawada Z.J.Wang Department of Aerospace Engineering Tohoku UniversitySendai 980-8579Japan Department of Aerospace Engineering Iowa State UniversityAmesIA 50011USA

An efficient implicit lower-upper symmetric Gauss-Seidel(LU-SGS)solution approach has been applied to a high order spectral volume(SV)method for unstructured tetrahedral *** LU-SGS solver is preconditioned by the block element matrix,and the system of equations is then solved with a LU *** compact feature of SV reconstruction facilitates the efficient solution algorithm even for high order *** developed implicit solver has shown more than an order of magnitude of speed-up relative to the Runge-Kutta explicit scheme for typical inviscid and viscous problems.A convergence to a high order solution for high Reynolds number transonic flow over a 3D wing with a one equation turbulence model is also indicated.

关键词： High-order unstructured grid spectral volume implicit method

Secular change in lifetime of granitic crust and the continental growth: A new view from detrital zircon ages of sandstones

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geoscience Frontiers 2018年第4期9卷 1099-1115页

作者： Hikaru sawada Yukio Isozaki Shuhei Sakata Takafumi Hirata Shigenori Maruyama Department of General System Studies The University of Tokyo Earth-Life Science Institute(ELSI) Tokyo Institute of Technology Department of Chemistry Gakushuin University Geochemical Research Center The University of Tokyo

U-Pb ages of detrital zircons were newly dated for 4 Archean sandstones from the Pilbara craton in Australia, Wyoming craton in North America, and Kaapvaal craton in Africa. By using the present results with previously published data, we compiled the age spectra of detrital zircons for 2.9, 2.6, 2.3,1.0, and0.6 Ga sandstones and modern river sands in order to document the secular change in age structure of continental crusts through time. The results demonstrated the following episodes in the history of continental crust：（1） low growth rate of the continents due to the short cycle in production/destruction of granitic crust during the Neoarchean to Paleoproterozoic（2.9-23 Ga）,（2） net increase in volume of the continents during Paleo-to Mesoproterozoic（2.3-1.0 Ga）, and（3） net decrease in volume of the continents during the Neoproterozoic and Phanerozoic（after 1.0 Ga）. In the Archean and Paleoproterozoic, the embryonic continents were smaller than the modern continents, probably owing to the relatively rapid production and destruction of continental crust. This is indeed reflected in the heterogeneous crustal age structure of modern continents that usually have relatively small amount of Archean crusts with respect to the post-Archean ones. During the Mesoproterozoic, plural continents amalgamated into larger ones comparable to modern continental blocks in size. Relatively older crusts were preserved in continental interiors, whereas younger crusts were accreted along continental *** addition to continental arc magmatism, the direct accretion of intra-oceanic island arc around continental peripheries also became important for net continental growth. Since 1.0 Ga, total volume of continents has decreased, and this appears consistent with on-going phenomena along modern active arc-trench system with dominant tectonic erosion and/or arc subduction. Subduction of a huge amount of granitic crusts into the mantle through time is suggested, and this requires re-co

关键词： Detrital zircon U-Pb age Continental growth Subduction erosion Preservation bias

MK615 inhibits pancreatic cancer cell growth by dual inhibition of Aurora A and B kinases

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2008年第9期14卷 1378-1382页

作者： Toshie Okada Tokihiko sawada Tatsushi Osawa Masakazu Adachi Keiichi Kubota Second Department of Surgery Dokkyo University School of Medicine Kitakobayashi 880MibuShimotsugaTochigi 321-0293Japan Second Department of Surgery Dokkyo University School of Medicine Kitakobayashi 880MibuShimotsuga Tochigi 321-0293Japan Japan Apricot Co.Ltd.1-11-7 MidorichoTakasakiGunma 370-0073 Japan Japan Apricot Co. Ltd.1-11-7 MidorichoTakasakiGunma 370-0073 Japan Second Department of Surgery Dokkyo University School of MedicineKitakobayashi 880Mibu ShimotsugaTochigi 321-0293Japan

AIM:To investigate the anti-neoplastic effect of MK615, an anti-neoplastic compound isolated from Japanese apricot, against human pancreatic cancer cells in vitro. METHODS: Three human pancreatic cancer cell lines PANC-1, PK-1, and PK45H were cultured with MK615 at concentrations of 600, 300, 150, and 0 μg/mL. Growth inhibition was evaluated by cell proliferation assay, and killing activity was determined by lactate dehydrogenase (LDH) assay. Expression of Aurora A and B kinases was detected by real-time polymerase chain reaction (PCR) and Western blotting. Cell cycle stages were evaluated by flow cytometry. RESULTS: The growth inhibitory rates of MK615 at 150, 300, and 600 μg/mL were 2.3% ± 0.9%, 8.9% ± 3.2% and 67.1% ± 8.1% on PANC1 cells, 1.3% ± 0.3%, 8.7% ± 4.1% and 45.7 ± 7.6% on PK1 cells, and 1.2 ± 0.8%, 9.1% ± 2.1% and 52.1% ± 5.5% on PK45H cells, respectively (P <0.05). The percentage cytotoxicities of MK615 at 0, 150, 300, and 600 μg/mL were 19.6% ± 1.3%, 26.7% ± 1.8%, 25.5% ± 0.9% and 26.4% ± 0.9% in PANC1 cells, 19.7% ± 1.3%, 24.7% ± 0.8%, 25.9% ± 0.9% and 29.9% ± 1.1% in PK1 cells, and 28.0% ± 0.9%, 31.2% ± 0.9%, 30.4% ± 1.1% and 35.3 ± 1.0% in PK45H cells, respectively (P < 0.05). Real-time PCR and Western blotting showed that MK615 dually inhibited the expression of Aurora A and B kinases. Cell cycle analysis revealed that MK615 increased the population of cells in G2/M phase. CONCLUSION: MK615 exerts an anti-neoplastic effect on human pancreatic cancer cells in vitro by dual inhibition of Aurora A and B kinases.

关键词： Japanese apricot Aurora kinases Pancreatic cancer Cell cycle