Validation of a Crop Yield and CO<Subscript>2</Subscript> Fixation Model over Southeast Asia by Carbon Partitioning in Grain Plants     

Daijiro Kaneko  Peng Yang  Toshiro Kumakura 《Journal of the Indian Society of Remote Sensing》2011,39(3):297-306

A photosynthetic-sterility model for grain production monitoring has been developed and validated under the background of climate change and Asian economic growth in developing countries. This paper presents an application of the model to evaluate carbon-fixation rates in yields of paddy rice, winter wheat, and maize in Asia. The validation of the model is based on carbon partitioning in grain plants. The carbon hydrate in grains has the same chemical formula as that of cellulose in grain vegetation. The partitioning of carbon in plants can validate fixation amounts of computed carbon using a satellite-based photosynthesis model. The model estimates the photosynthesis fixation of rice reasonably in Japan and China. Results were validated through examination of carbon in grains, but the model tends to underestimate results for winter wheat and maize. This study also provides daily distributions of the PSN, which is the CO₂ fixation in Asian areas combined with a land-cover distribution classified from MODIS data, NDVI from SPOT VEGETATION, and meteorological re-analysis data by European Centre for Medium-Range Forecasts (ECMWF). The mean CO₂ and carbon fixation rates in paddy areas were 25.92 (t CO₂/ha) and 5.28 (t C/ha) in Japan, respectively. Comparisons between the model’s values and MODIS seasonal PSNs show similar trends. The writers are preparing to compare computed photosynthesis rates with observed AsiaFlux data for the validation of this model at field sites of paddy, grassland and forests in Japan and Asian countries.  相似文献   

Ground motion spatial variability effects on seismic response control of cable-stayed bridges     

Shehata E. Abdel Raheem  Toshiro Hayashikawa  Uwe Dorka 《地震工程与工程振动(英文版)》2011,10(1):37-49

The spatial variability of input ground motion at supporting foundations plays a key role in the structural response of cable-stayed bridges (CSBs); therefore, spatial variation effects should be included in the analysis and design of effective vibration control systems. The control of CSBs represents a challenging and unique problem, with many complexities in modeling, control design and implementation, since the control system should be designed not only to mitigate the dynamic component of the structural response but also to counteract the effects of the pseudo-static component of the response. The spatial variability effects on the feasibility and efficiency of seismic control systems for the vibration control of CSBs are investigated in this paper. The assumption of uniform earthquake motion along the entire bridge may result in quantitative and qualitative differences in seismic response as compared with those produced by uniform motion at all supports. A systematic comparison of passive and active system performance in reducing the structural responses is performed, focusing on the effect of the spatially varying earthquake ground motion on the seismic response of a benchmark CSB model with different control strategies, and demonstrates the importance of accounting for the spatial variability of excitations.  相似文献   

Free oscillations of a slightly anisotropic earth     

Toshiro Tanimoto 《Geophysical Journal International》1986,87(2):493-517

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Cagniard de-Hoop method for a Haskell type vertical fault     

Toshiro Tanimoto 《Geophysical Journal International》1982,70(3):639-646

Summary. There are two ways to apply the Cagniard de-Hoop method when generating synthetic seismograms due to a source in a three-dimensional medium. One is the Hankel transform method (hereafter called 'the cylindrical wave representation method'), which utilizes the property of the modified Bessel function. The other is 'the plane wave representation method', which replaces the Bessel function by a superposition of plane waves. In extending a point source to a finite dimensional source, the latter method is extremely useful, because it enables the integrations on the fault surface to be performed analytically.
Using the latter method, expressions for displacements due to a Haskell type vertical fault in a uniform half-space are obtained. A solution is given as a sum of four quadrantal source contributions, which is similar to Madariaga's solution for a source in the whole space. Each contribution consists of a single finite range integration or a single integration plus a pole contribution, depending on the location of the observation point with respect to the source. The procedure can be extended to other fault types.  相似文献   

Distribution of gold and silver and its relation with hypogene ore minerals in the Esperanza porphyry deposit,Antofagasta Region,Chile     

Shoji Kojima  María Constanza San Martín  Toshiro Nagase  Daisuke Nakashima  Claudio Bisso  Andrew Menzies 《Resource Geology》2021,71(1):80-90

Modes of occurrence of Au‐ and Ag‐bearing phases and their relation with associated hypogene ore minerals were examined with the objective to elucidate Au‐Ag distribution at the Esperanza porphyry deposit in the Eocene Centinela copper belt, using ore‐microscope modal analysis, semi‐quantitative analyses by automated mineralogy, electron probe microanalysis, and secondary ion mass spectrometer. The Esperanza hypogene mineralization is characterized by early‐stage chalcopyrite‐rich veinlets in the potassic alteration zone and later polymetallic stage with tennantite and galena in the chlorite‐sericitic alteration zone. Only the early‐stage chalcopyrite contains fine‐grained electrum (Au₆₈Ag₃₂ ‐ Au₈₁Ag₁₉) and hessite (Ag₂Te), and thus yields positive correlations in Cu vs. Au and Cu vs. Ag grades that are clearly recognized in the hypogene sulfide zone. The early‐stage chalcopyrite grains frequently exhibit polysynthetic twinning suggestive of inversion from intermediate solid solution. These features suggest that the fine‐grained electrum and hessite are products exsolved in the cooling process with the intermediate solid solution to chalcopyrite inversion. In contrast, tennantite and galena of the later‐stage mineralization contain no detectable Ag, and it is thus proposed that the early‐stage inverted chalcopyrite is the principal storage of economically important precious metals.  相似文献   

Influence of vegetation factors on biological soil crust cover on rehabilitated grassland in the hilly Loess Plateau, China   总被引：1，自引：0，他引：1  

Jian Zhang  Guobin Liu  Mingxiang Xu  Ming Xu  Norikazu Yamanaka 《Environmental Earth Sciences》2013,68(4):1099-1105

Biological soil crusts (BSCs) perform essential ecosystem functions in arid and semi-arid ecosystems worldwide. The formation, development, and distribution of BSCs are influenced by changes in multiple environmental factors, including changes in the vascular plant community. The influence of changes in vegetation factors on BSC cover in 8-, 12-, and 16-year-old rehabilitated grasslands were studied in the hilly area of the Chinese Loess Plateau. The rate of degradation of BSCs underneath litter (P < 0.01) and the degradation cover of BSCs (P < 0.05) differed significantly between the 8- and 16-year-old successions. Stepwise multiple linear regression analysis showed that the main vegetation factors influencing the dynamics of BSC cover differed among the 8-, 12-, and 16-year-old rehabilitated grasslands. Basal cover, phytomass, and litter cover were the main vegetation factors influencing the dynamics of BSC cover on 8-year-old rehabilitated grassland. Phytomass, litter thickness, and litter cover were the main factors influencing the dynamics of BSC cover on 12-year-old rehabilitated grassland. On 16-year-old rehabilitated grassland, Pielou evenness index, litter thickness, and litter biomass were the main vegetation factors influencing degradation of BSC cover underneath litter, whereas basal cover, litter thickness, and litter biomass were the main vegetation factors influencing the degradation cover of BSCs. At particular stages of herbaceous succession, vegetation factors can have a large influence on changes in the community’s basal cover and litter, which are key factors influencing changes in BSC cover. The degradation of BSCs underneath litter may be a result of complicated eco-physiological processes.  相似文献   

An evaluation of 3-D velocity models of the Kanto basin for long-period ground motion simulations     

Yadab P. Dhakal  Hiroaki Yamanaka 《Journal of Seismology》2013,17(3):1073-1102

We performed three-dimensional (3-D) finite difference simulations of long-period ground motions (2–10 s) in the Kanto basin using the Japan Seismic Hazard Information Station (J-SHIS 2009), Yamada and Yamanaka (Exploration Geophysics 65(3):139–150, 2012) (YY), and Head Quarter for Earthquake Research Promotion (HERP 2012) velocity models for two intermediate depth (68–80 km) moderate earthquakes (Mw 5.8–5.9), which occurred beneath the Kanto basin. The models primarily differ in the basic data set used in the construction of the velocity models. The J-SHIS and HERP models are the results of integration of mainly geological, geophysical, and earthquake data. On the other hand, the YY model is oriented towards the microtremor-array-observation data. We obtained a goodness of fit between the observed and synthetic data based on three parameters, peak ground velocities (PGVs), smoothed Fourier spectra (FFT), and cross-correlations, using an algorithm proposed by Olsen and Mayhew (Seism Res Lett 81:715–723, 2010). We found that the three models reproduced the PGVs and FFT satisfactorily at most sites. However, the models performed poorly in terms of cross-correlations especially at the basin edges. We found that the synthetics using the YY model overestimate the observed waveforms at several sites located in the areas having V _s 0.3 km/s in the top layer; on the other hand, the J-SHIS and HERP models explain the waveforms better at the sites and perform similarly at most sites. We also found that the J-SHIS and HERP models consist of thick sediments beneath some sites, where the YY model is preferable. Thus, we have concluded that the models require revisions for the reliable prediction of long-period ground motions from future large earthquakes.  相似文献   

Petrogenesis of the Kaikomagatake granitoid pluton in the Izu Collision Zone, central Japan: implications for transformation of juvenile oceanic arc into mature continental crust   总被引：1，自引：0，他引：1  

Satoshi Saito  Makoto Arima  Takashi Nakajima  Kenichiro Tani  Takashi Miyazaki  Ryoko Senda  Qing Chang  Toshiro Takahashi  Yuka Hirahara  Jun-Ichi Kimura 《Contributions to Mineralogy and Petrology》2012,163(4):611-629

The Miocene Kaikomagatake pluton is one of the Neogene granitoid plutons exposed in the Izu Collision Zone, which is where the juvenile Izu-Bonin oceanic arc is colliding against the mature Honshu arc. The pluton intrudes into the Cretaceous to Paleogene Shimanto accretionary complex of the Honshu arc along the Itoigawa-Shizuoka Tectonic Line, which is the collisional boundary between the two arcs. The pluton consists of hornblende–biotite granodiorite and biotite monzogranite, and has SiO₂ contents of 68–75 wt%. It has high-K series compositions, and its incompatible element abundances are comparable to the average upper continental crust. Major and trace element compositions of the pluton show well-defined chemical trends. The trends can be interpreted with a crystal fractionation model involving the removal of plagioclase, biotite, hornblende, quartz, apatite, and zircon from a potential parent magma with a composition of ~68 wt% SiO₂. The Sr isotopic compositions, together with the partial melting modeling results, suggest that the parent magma is derived by ~53% melting of a hybrid lower crustal source comprising ~30% Shimanto metasedimentary rocks of the Honshu arc and ~70% K-enriched basaltic rocks of the Izu-Bonin rear-arc region. Together with previous studies on the Izu Collision Zone granitoid plutons, the results of this study suggest that the chemical diversity within the parental magmas of the granitoid plutons reflects the chemical variation of basaltic sources (i.e., across-arc chemical variation in the Izu-Bonin arc), as well as a variable contribution of the metasedimentary component in the lower crustal source regions. In addition, the petrogenetic models of the Izu Collision Zone granitoid plutons collectively suggest that the contribution of the metasedimentary component is required to produce granitoid magma with compositions comparable to the average upper continental crust. The Izu Collision Zone plutons provide an exceptional example of the transformation of a juvenile oceanic arc into mature continental crust.  相似文献   

ICT-Based Remediation with Knowledge Information Management for Contaminated Groundwater     

Yoshihisa Miyata  Toshiro Hata 《Geotechnical and Geological Engineering》2013,31(3):911-926

ICT-based remediation with knowledge information management is presented for the pump-and-treat method of contaminated groundwater. The usefulness of ICT is discussed for monitoring contaminants and groundwater level, transferring data between the remediation well and the remote remediation center, and decision support analysis for controlling the remediation well. A prototype system was developed and applied to field measurement. The prototype system performed reliably for ~600 days. As a decision support analysis, a fuzzy inference model is discussed. The membership functions were determined based on simple reliability theory. The effectiveness of the proposed method was assessed by numerical simulations. The simulation results suggest that the proposed method is likely to reduce the pumped quantity compared to PID control or an engineer’s empirical knowledge. Analysis results are also shown for cancer risks from contaminants and ground settlement risks due to excess pumping up of groundwater.  相似文献   

Prediction and mitigation analysis of ground vibration caused by running high-speed trains on rigid-frame viaducts     

Liangming Sun  Weiping Xie  Xingwen He  Toshiro Hayashikawa 《地震工程与工程振动(英文版)》2016,15(1):31-47

In this study a 3D numerical analysis approach is developed to predict the ground vibration around rigid-frame viaducts induced by running high-speed trains. The train-bridge-ground interaction system is divided into two subsystems: the train-bridge interaction and the soil-structure interaction. First, the analytical program to simulate bridge vibration with consideration of train-bridge interaction is developed to obtain the vibration reaction forces at the pier bottoms. The highspeed train is described by a multi-DOFs vibration system and the rigid-frame viaduct is modeled with 3D beam elements. Second, applying these vibration reaction forces as input external excitations, the ground vibration is simulated by using a general-purpose program that includes soil-structure interaction effects. The validity of the analytical procedure is confirmed by comparing analytical and experimental results. The characteristics of high-speed train-induced vibrations, including the location of predominant vibration, are clarified. Based on this information a proposed vibration countermeasure using steel strut and new barrier is found effective in reducing train-induced vibrations and it satisfies environmental vibration requirements. The vibration screening efficiency is evaluated by reduction VAL based on 1/3 octave band spectral analysis.  相似文献