阴极保护时碳钢的交流阻抗特性和最佳防蚀电位   总被引：2，自引：0，他引：2       下载免费PDF全文

侯保荣  西方笃  水流徹  春山志郎 《海洋与湖沼》1993,24(3):272-278

测定了在3.5％食盐水中碳钢的法拉第交流阻抗,其结果与理论解析结果一致。阴极保护的实际效率(保护效率p和保护电流利用率q的乘积即r=p×q)在腐蚀电位E′_(cor)附近表现出最大值,这个电位可以认为是阴极保护的最佳保护电位。由于法拉第交流阻抗值容易被测得,为此提出了一种对阴极保护系统进行监测管理的一种新方法。  相似文献   

Notes on linear and nonlinear barotropic flows in a polar circular basin     

Satoshi Sakai  Shiro Imawaki 《Journal of Oceanography》1981,37(5):287-293

Barotropic flows in a circular ocean are studied. Flows are driven by an inflow and an outflow through openings at the circumference. A linear, steady state solution is interpreted in terms of dissipating planetary waves. A weakly nonlinear, steady state solution is obtained numerically. It differs remarkably from the linear solution; an intense anticyclonic polar gyre extending over the whole basin is formed. The nonlinear term is essential to the gyre and can not be neglected, although the Rossby number is small.  相似文献   

Chemical modification of sea water by submarine volcanism at Nishinoshima-Shintô Island     

Yoshimasa Toyota  Satoru Kanamori  Michihiko Kodama  Masahiro Furukawa  Shiro Okabe 《Journal of Oceanography》1982,38(5):307-312

Sea water samples, still hot from volcanic emanations were taken in a bay of Nishinoshima-Shintô Island just after volcanic activity had ceased and were analysed for borate-B, fluoride-F and bromide-Br. The hot water is considered to be formed by the conservative mixing of volcanic emanations with sea water, and the emanations containedCl, B, F andBr in the ratio of 1∶1.84×10^?3∶0.474×10^?3∶6.47×10^?3 by weight. RatiosB/Cl andF/Cl can be used as effective measures of the contribution of volcanic emanations to sea water.  相似文献   

Effective Emergency Transportation for Saving Human Lives     

Yasuko Kuwata  Shiro Takada 《Natural Hazards》2004,33(1):23-46

To save lives immediately after a catastrophic earthquake occurs, it is essential for an urban transportation system to retain its functional performance in order to carry injured people to hospitals. Recent seismic assessment studies have mostly been based on cost-benefit analyses, carried out in monetary terms that are reasonable for long-term considerations. However, many problems of seismic risk management still remain. For example, attributing a monetary value to a human life is considered impossible. Also, requirements for functioning of a transportation system are different in the period immediately after an earthquake. This paper concentrates on how to assess the importance of an urban transportation system as it relates to saving human life, and what system enhancements should be made to improve performance. This paper proposes a risk assessment method for the functional reliability of a transportation system immediately after an earthquake. In that period, system malfunction adversely affects the saving of lives as a result of time delays when moving injured people to medical facilities. A system dynamics simulation of transporting injured people is incorporated in the method, which uses two assessment approaches to evaluate the differences of cumulative injured people who receive medical care. In deciding on the destination of medical facility in the simulation, two ways of deciding are addressed; one uses information only on the road network, and the other uses information on both road network and hospital availability. Results of an application to an actual target area show the most vulnerable road links and differences of the two decision-making processes. A way to mitigate the loss due to damage to road links is examined. The paper also summarizes future developments in advanced information technology for emergency transportation systems.  相似文献   

An equivalent-boundary method for the shell analysis of buried pipelines under fault movement   总被引：2，自引：0，他引：2  

刘爱文  胡聿贤  赵凤新  李小军  高田至郎  赵雷 《地震学报(英文版)》2004,17(Z1)

Introduction The history of research work on the response of buried pipeline under the fault movement hasbeen about 30 years. Several simplified design methods have been proposed to obtain the maxi-mum stress or strain in pipe. These methods include the theoretical method and the finite elementmethod (FEM). In the theoretical method, the pipe is usually modeled as a cable (Newmark, Hall1975; Kennedy, et al, 1977) or a beam (Wang, Wang, 1995; LIU, ZHANG, 2002). These theoreti-cal me…  相似文献   

Large-scale freezing work for subway construction in Japan     

Michio Miyoshi  Tsuneo Tsukamoto  Shiro Kiriyama   《Engineering Geology》1979,13(1-4):397-415

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Phengite K-Ar ages of schists from the Sanbagawa southern marginal belt, central Shikoku, southwest Japan: Influence of detrital mica and deformation on age     

Tetsumaru  Itaya Shiro  Fukui 《Island Arc》1994,3(1):48-58

Abstract K–Ar age determinations were carried out on phengite separates from pelitic schists collected systematically from the Sanbagawa southern marginal belt and the associated area. The petrography and phengite chemistry by electron probe micro-analyzer (EPMA) revealed the existence of detrital white micas in the schist that have an extremely older age (108 Ma) in comparison with the neighboring schists (88 Ma) without any detrital mica. The ages become gradually older from the north ( ca 78 Ma) to the south ( ca 90 Ma) except for some samples that contain detrital micas and/or have been reactivated thermally by intrusives. The age is interpreted as an exhumation-cooling age that has been controlled by the ductile deformation of the host rocks that have never experienced a culmination temperature higher than 350°C which corresponds to the closure temperature of the K–Ar phengite system. The southward aging of the recorded ages in the extensive chlorite zone of the central Shikoku, from the Dozan river area of the north ( ca 65 Ma) to the study area of the south ( ca 85 Ma) through the Asemi river area ( ca 75 Ma), is explained in terms of increasing exhumation/cooling rates of the host rocks from north to south. The phengite K–Ar ages in the pelitic schists from the Kyomizu tectonic zone, which is classically considered as a remarkable thrusting shear zone, have no significant difference in comparison with that of the neighboring schists. This fact suggests that the latest stage of brittle deformation during exhumation/uplift has not significantly affected the ages of phengite in the schists.  相似文献   

Geostrophy in the Intermediate and Deep Layers of the Kuroshio and Its Recirculation Regions South of Japan     

Motohiko Kashima  Shiro Imawaki  Shin-Ichiro Umatani  Hiroshi Uchida  Yuji Hashibe  Hiroshi Ichikawa  Masao Fukasawa 《Journal of Oceanography》2003,59(3):291-301

Theoretically, the geostrophic approximation holds for the low-frequency flow field, but no detailed examination has been done on how well the estimated geostrophic velocity corresponds with the observed velocity. Intensive surveys were carried out during 1993–1995 in the Kuroshio and its recirculation regions south of Shikoku, Japan, including repeated hydrographic surveys and direct current measurements at nominal depths of 700, 1500 and 3000 m. For these depth intervals, vertical differences of estimated geostrophic velocity are compared with those of observed velocity. For the intermediate layer (between 700 and 1500 m depths), the slope of the regression line is 0.99, correlation coefficient is 0.98, and the root-mean-square of difference from geostrophic balance is 2.8 cm/s which is close to the estimated error of 2.1 cm/s. For the deep layer (between 1500 and 3000 m depths), the corresponding values are 0.82, 0.93, 1.2 cm/s and 2.0 cm/s, respectively. The results indicate that the estimated geostrophic velocity compares well with the observed velocity in these regions. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

Peroxy Radical Concentrations Measured at a Forest Canopy in Nikko,Japan, in Summer 2002     

Bin?Qi  Akinori?Takami  Shiro?HatakeyamaEmail author 《Journal of Atmospheric Chemistry》2005,52(1):63-79

Concentrations of peroxy radicals were measured by a chemical amplification technique at a remote forested site as part of the Program for Research on Oxidants in a Forested Region in Nikko (PROFRN). During the measurement period of 22–27 July 2002, the mixing ratios of peroxy radicals averaged for 3 min at midday ranged from 109 to 134 pptv at a height approximately 5 m above the forest canopy. Significant diurnal variation in concentrations of peroxy radicals was observed, with the maximum usually occurring around noon. Most of the variation was driven by changes in the intensity of solar radiation. However, it was found that the peroxy radical concentration reached its peak about 3-h later than that of solar radiation on 24 and 26 July. The origins of this delay are discussed based on an analysis of the total radical budget in that period. A transport of polluted air masses to the site was one of possible causes for the inconsistency. In addition, the measured peroxy radical concentrations were compared with those derived from the deviations of NO-NO₂-O₃ photo-stationary state (PSSD) for clear days. The estimated half-hour-average concentrations of peroxy radical were in agreement with the PERCA measured in the morning and late afternoon. However the two techniques differed by as much as a factor of two during the time of near midday.  相似文献   

The effect of the stellar wind velocity on the eccentric-orbit binary model     

Toru Okuda  Shiro Sakashita 《Astrophysics and Space Science》1982,83(1-2):441-444

The previous eccentric-orbit binary model for the recurrent X-ray sources is modified by taking account of the velocity field of the stellar wind. The resultant formula of the light curves for the X-ray sources may have an useful application to the observed X-ray sources.  相似文献