Corrigendum to “Effects of salinity on the growth,Na partitioning,and Na dynamics of a salt-tolerant tree,Populus alba L.” [Journal of Arid Environments 73 (2009) 245–251]     

S. Imada  N. Yamanaka  S. Tamai 《Journal of Arid Environments》2009,73(6-7):693

  相似文献   

Diel tuning of photosynthetic systems in ice algae at Saroma-ko Lagoon, Hokkaido, Japan   总被引：1，自引：0，他引：1  

Shimpei Aikawa  Hiroshi Hattori  Yasushi Gomi  Kentaro Watanabe  Sakae Kudoh  Yasuhiro Kashino  Kazuhiko Satoh 《Polar Science》2009,3(1):57-72

Ice algae are the major primary producers in seasonally ice-covered oceans during the cold season. Diurnal change in solar radiation is inevitable for ice algae, even beneath seasonal sea ice in lower-latitude regions. In this work, we focused on the photosynthetic response of ice algae under diurnally changing irradiance in Saroma-ko Lagoon, Japan. Photosynthetic properties were assessed by pulse-amplitude modulation (PAM) fluorometry. The species composition remained almost the same throughout the investigation. The maximum electron transport rate (rETR_max), which indicates the capacity of photosynthetic electron transport, increased from sunrise until around noon and decreased toward sunset, with no sign of the afternoon depression commonly observed in other photosynthetic organisms. The level of non-photochemical quenching, which indicates photoprotection activity by dissipating excess light energy via thermal processes, changed with diurnal variations in irradiance. The pigment composition appeared constant, except for xanthophyll cycle pigments, which changed irrespective of irradiance. These results indicate that ice algae tune their photosynthetic system harmonically to achieve efficient photosynthesis under diurnally changing irradiance, while avoiding damage to photosystems. This regulation system may be essential for productive photosynthesis in ice algae.  相似文献   

泥石流的二维数学模型   总被引：5，自引：2，他引：3  

王纯祥  白世伟  江崎哲郎  三谷泰浩 《岩土力学》2007,28(6):1237-1241

泥石流是在重力作用下,由砂粒石块和水等组成的固液混合物,是一种发生于山区的复杂的地质灾害现象。泥石流主要是由暴雨诱发引起的,它沿着复杂的三维地形高速流动,具有流体流动的特性。为了模拟泥石流的运动规律,预测降雨诱发的泥石流的到达距离和泛滥范围,减少和避免泥石流引起的灾害,把泥石和雨水组成的固液混合物假定为遵循均匀、连续、不可压缩的、非定常的牛顿流体运动规律。基于质量守恒方程和Naiver-stokes方程,采用深度积分方法,推导出了一个模拟泥石流运动的二维数学模型。所有方程式可用有限差分法来求解。结合GIS,该模型可用于预测泥石流的流动距离和泛滥范围,以及泛滥范围内的危险房屋和路段,也可以用于泥石流灾害的风险性分析。  相似文献   

Photocatalytic degradation of spill oils on TiO₂ nanotube thin films     

Ying-Ya Hsu  Tung-Li Hsiung  H. Paul Wang  Yasuhiro Fukushima  Yu-Ling Wei  Juu-En Chang   《Marine pollution bulletin》2008,57(6-12):873

The nitrogen-doped TiO₂ nanotube (N-TNT) thin films were synthesized using ZnO nanorods as the template and doped with urea at 623 K. Under ultraviolet (UV) and visible light irradiation, the efficiencies for photocatalytic degradation of methylene blue is as high as 30%. About 10% of toluene (representing aromatics in the spill oils) in sea water can be photocatalytically degraded under visible light radiation for 120 min. The aliphatic model compound (1-hexadecene) has, on the contrary, a less efficiency (8%) on the N-TNT photocatalyst. On the average, under visible light radiation, the effectnesses of the N-TNT for photocatalytic degradation of model compounds in the spill oils in sea water are 0.38 mg toluene/gN-TNT h and 0.25 mg 1-hexadecene/gN-TNT h. It is expected that spill oils in the harbors or seashores can be adsorbed and photocatalytically degraded on the N-TNT thin films that are coated onto levee at the sea water surface level.  相似文献   

Molecular dynamics study of pressure-induced transformation of quartz-type GeO2     

T. Tsuchiya  T. Yamanaka  M. Matsui 《Physics and Chemistry of Minerals》2000,27(3):149-155

We simulated quartz-type GeO₂ and investigated its high-pressure transformation using the molecular dynamics (MD) simulation method with a model potential. The calculated results under hydrostatic compression indicated that a pressure-induced amorphization of quartz-type GeO₂ originated from the mechanical instability of the quartz lattice as, in previous theoretical studies of SiO₂. Furthermore, quartz-type GeO₂ directly transformed to a rutile-like structure with only subtle displacements of ions under σ _{x y} imposed shear stressed decompression. This is the first reproduction of the quartz-to-rutile transformation. A possible pathway of this transition is proposed in this study. Received: 14 April 1999 / Revised, accepted: 11 August 1999  相似文献   

Low-frequency variations of the Eastern Subtropical Front in the North Pacific in an eddy-resolving ocean general circulation model: roles of central mode water in the formation and maintenance     

Shusaku Sugimoto  Kimio Hanawa  Tamaki Yasuda  Goro Yamanaka 《Journal of Oceanography》2012,68(4):521-531

Temporal variations (1960–2005) of the Eastern Subtropical Front (ESTF) in the North Pacific are investigated using historical-run output data of the eddy-resolving Meteorological Research Institute Community Ocean Model, forced by atmospheric reanalysis dataset. Simulated ESTF is distributed in a region of zonal band of 24°N–30°N east of the International Date Line, and is located at the southern boundary of the central mode water (CMW) north of the front. The ESTF intensity clearly shows an interdecadal variation with a timescale of about 20?years. This variation is associated with that in the potential vorticity of CMW, which originates in the CMW formation region farther north about 3?years earlier due to changes in the surface wind forcing.  相似文献   

Development of an operational coastal model of the Seto Inland Sea,Japan     

Kei Sakamoto  Goro Yamanaka  Hiroyuki Tsujino  Hideyuki Nakano  Shogo Urakawa  Norihisa Usui  Mikitoshi Hirabara  Koji Ogawa 《Ocean Dynamics》2016,66(1):77-97

  相似文献   

Seismic response estimation method for earthquake‐damaged RC buildings          下载免费PDF全文

Ho Choi  Yasushi Sanada  Hisatoshi Kashiwa  Yasuhiro Watanabe  Jafril Tanjung  Huanjun Jiang 《地震工程与结构动力学》2016,45(6):999-1018

This study proposes a procedure for identifying spectral response curves for earthquake‐damaged areas in developing countries without seismic records. An earthquake‐damaged reinforced concrete building located in Padang, Indonesia was selected to illustrate the identification of the maximum seismic response during the 2009 West Sumatra earthquake. This paper summarizes the damage incurred by the building; the majority of the damage was observed in the third story in the span direction. The damage was quantitatively evaluated using the damage index R according to the Japanese guidelines for post‐earthquake damage evaluation. The damage index was also applied to the proposed spectral response identification method. The seismic performance of the building was evaluated by a nonlinear static analysis. The analytical results reproduced a drift concentration in the third story. The R‐index decreased with an increase in the story drift, which provided an estimation of the maximum response of the building during the earthquake. The estimation was verified via an earthquake response analysis of the building using ground acceleration data, which were simulated based on acceleration records of engineering bedrock that considered site amplification. The maximum response estimated by the R‐index was consistent with the maximum response obtained from the earthquake response analysis. Therefore, the proposed method enables the construction of spectral response curves by integrating the identification results for the maximum responses in a number of earthquake‐damaged buildings despite a lack of seismic records. Copyright © 2016 The Authors. Earthquake Engineering & Structural Dynamics published by John Wiley & Sons Ltd.  相似文献   

Improving GPS positioning estimates during extreme weather situations by the help of fine-mesh numerical weather models     

Thomas Hobiger  Seiichi Shimada  Shingo Shimizu  Ryuichi Ichikawa  Yasuhiro Koyama  Tetsuro Kondo 《Journal of Atmospheric and Solar》2010,72(2-3):262-270

Space geodetic applications require to model troposphere delays as good as possible in order to achieve highly accurate positioning estimates. However, these models are not capable to consider complex refractivity fields which are likely to occur during extreme weather situations like typhoons, storms, heavy rain-fall, etc. Thus it has been investigated how positioning results can be improved if information from numerical weather models is taken into account. It will be demonstrated that positioning errors can be significantly reduced by the usage of ray-traced slant delays. Therefore, meso-scale and fine-mesh numerical weather models are utilized and their impact on the positioning results will be measured. The approach has been evaluated during a typhoon passage using global positioning service (GPS) observations of 72 receivers located around Tokyo, proving the usefulness of ray-traced slant delays for positioning applications. Thereby, it is possible reduce virtual station movements as well as improve station height repeatabilities by up to 30% w.r.t. standard processing techniques. Additionally the advantages and caveats of numerical weather models will be discussed and it will be shown how fine-mesh numerical weather models, which are restricted in their spatial extent, have to be handled in order to provide useful corrections.  相似文献   

Livestock wastes as a source of estrogens and their effects on wildlife of Manko tidal flat,Okinawa   总被引：9，自引：0，他引：9  

Tashiro Y  Takemura A  Fujii H  Takahira K  Nakanishi Y 《Marine pollution bulletin》2003,47(1-6):143-147

The Manko tidal flat in the southern part of Okinawa Island is an important visiting and wintering area for migratory birds and was added to the Ramsar Convention Register of Wetlands in 1999. This area used to be an inlet extending to the inner part of Naha Port, but recent reclamation projects have restricted its connection to the East China Sea. As is typical in rural regions of subtropical islands, the inhabitants in the Manko basin raise livestock, especially pigs, without employing sufficient waste treatment methods. As sewage treatment works are considered to be one of the main sources of environmental estrogens in urban areas, the significance of livestock farming as a source of estrogens in rural area is examined in this study. In the present study, total estrogenic activities in water and sediment samples from the Manko tidal flat and its basin were measured using a recombinant yeast screen method. Estrogenic activities (equivalent to 17beta-estradiol, E2) were around 10 ng l(-1) in water samples and more than 10 microg kg(-1) in some sediment samples. In addition, the concentrations of estrone (E1) and E2 in water samples measured using LC/MS/MS indicated a high contribution of environmental estrogens from livestock wastes.  相似文献