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121.
Chung-Ming Liu Ming-Chin Wu Sahana Paul Ying-Chen Chen Shu-Hua Lin Wei-Shiang Lin Yen-Chih Lee Huang-Hsung Hsu Ren-Yow Tseng Cheng-Ta Chen 《Theoretical and Applied Climatology》2011,103(1-2):265-278
Runs of three regional climate models (RCMs) dynamically downscaling the outputs of atmosphere?Cocean coupling general circulation models (AOGCMs) are studied. These RCMs are NCAR-MM5, NCEP-RSM (Regional Spectral Model), and Purdue-PRM (Purdue Regional Model). A useful approach is developed to compare the variability, error, and spatial distribution of model-simulated results with respect to the Climatic Research Unit (CRU) datasets over East Asia and seven sub-regions during the 1990s. The results show that NCEP-RSM outperforms the other two in meeting criteria selected on evaluating the model performance. Furthermore, three super-ensemble approaches are tested on merging RCMs?? outputs. The inverse of the square error summation (ISES) method is selected as a suitable method with a generally good performance during the verification period. The projected future climate changes by ISES indicate larger temperature increases over high-latitude continent and smaller over low-latitude maritime areas. Rainfall will increase in summer over the central simulation domain, i.e. the eastern China, but decrease in winter, which are clearly linked to the variation in the synoptic airflows. Also, a more frequent occurrence of extreme rainfall events than what happened in the 1990s is projected. The projection over Taiwan suggests strong warming in summer, followed by autumn, winter, and spring. The interaction between the synoptic flow and the local terrain affects significantly the changes in precipitation. In general, larger change of the variability of rainfall will be over areas with lesser rainfall in the future, while lesser change will be over areas with more projected rainfall. 相似文献
122.
SPT-N-based methods have been adopted for liquefaction assessment of soils during earthquakes for decades. However, there has not been a consistent way of assessing the accuracy and applicability of these methods. The Chi-chi earthquake of 1999, which has been the most serious ground shaking in Taiwan within the century, caused extensive liquefactions in mid-west alluvial deposits of the island. This paper assesses the prediction accuracy of several SPT-N-based methods using liquefaction and non-liquefaction incidents observed during the earthquake. A sensitivity study on commonly adopted parameters shows that the SPT blow count and peak ground acceleration are most sensitive in computing liquefaction potential. By comparing the error in predicting liquefaction and non-liquefaction incidents, this study concludes that Tokimatsu and Yoshimi’s method is more accurate than the other methods. However, the differences between prediction errors of various methods are minimal, indicating all of the methods examined are applicable for the 1999 earthquake in Taiwan. 相似文献
123.
Based on the extended mild-slope equation, the wind wave model (WWM; Hsu et al., 2005) is modified to account for wave refraction, diffraction and reflection for wind waves propagating over a rapidly varying seabed in the presence of current. The combined effect of the higher-order bottom effect terms is incorporated into the wave action balance equation through the correction of the wavenumber and propagation velocities using a refraction–diffraction correction parameter. The relative importance of additional terms including higher-order bottom components, the wave–bottom interaction source term and wave–current interaction that influence the refraction–diffraction correction parameter is discussed. The applicability of the proposed model to calculate a wave transformation over an elliptic shoal, a series of parallel submerged breakwater induced Bragg scattering and wave–current interaction is evaluated. Numerical results show that the present model provides better predictions of the wave amplitude as compared with the phase-decoupled model of Holthuijsen et al. (2003). 相似文献
124.
地球各圈层相互作用的大地测量研究和检测 总被引:3,自引:0,他引:3
许厚泽 《大地测量与地球动力学》2002,22(4):1-5
大地测量资料,包括在球表面运动,地球引力场及地球整体自转运动的观测资料,是研究地球各圈层相互作用的重要地表约束,探讨了大地测量用于这一研究领域中的几个重要科学前沿问题。 相似文献
125.
126.
Ai‐Cheng Zhang Shoichi Itoh Hisayoshi Yurimoto Wei‐Biao Hsu Ru‐Cheng Wang Lawrence A. Taylor 《Meteoritics & planetary science》2016,51(1):56-69
CM chondrites are a group of primitive meteorites that have recorded the alteration history of the early solar system. We report the occurrence, chemistry, and oxygen isotopic compositions of P‐O‐rich sulfide phase in two CM chondrites (Grove Mountains [GRV] 021536 and Murchison). This P‐O‐rich sulfide is a polycrystalline aggregate of nanometer‐size grains. It occurs as isolated particles or aggregates in both CM chondrites. These grains, in the matrix and in type‐I chondrules from Murchison, were partially altered into tochilinite; however, grains enclosed by Ca‐carbonate are much less altered. This P‐O‐rich sulfide in Murchison is closely associated with magnetite, FeNi phosphide, brezinaite (Cr3S4), and eskolaite (Cr2O3). In addition to sulfur as the major component, this sulfide contains ~6.3 wt% O, ~5.4 wt% P, and minor amounts of hydrogen. Analyses of oxygen isotopes by SIMS resulted in an average δ18O value of ?22.5 ‰ and an average Δ17O value of 0.2 ± 9.2 ‰ (2σ). Limited variations in both chemical compositions and electron‐diffraction patterns imply that the P‐O‐rich sulfide may be a single phase rather than a polyphase mixture. Several features indicate that this P‐O‐rich sulfide phase formed at low temperature on the parent body, most likely through the alteration of FeNi metal (a) close association with other low‐temperature alteration products, (b) the presence of hydrogen, (c) high Δ17O values and the presence in altered mesostasis of type‐I chondrules and absence in type‐II chondrules. The textural relations of the P‐O‐rich sulfide and other low‐temperature minerals reveal at least three episodic‐alteration events on the parent body of CM chondrites (1) formation of P‐O‐rich sulfide during sulfur‐rich aqueous alteration of P‐rich FeNi metal, (2) formation of Ca‐carbonate during local carbonation, and (3) alteration of P‐O‐rich sulfide and formation of tochilinite during a period of late‐stage intensive aqueous alteration. 相似文献
127.
Alexandre Canitano Ya-Ju Hsu Hsin-Ming Lee Alan T. Linde Selwyn Sacks 《Journal of Geodesy》2018,92(3):223-240
We propose an approach for calibrating the horizontal tidal shear components [(differential extension (\(\gamma _1\)) and engineering shear (\(\gamma _2\))] of two Sacks–Evertson (in Pap Meteorol Geophys 22:195–208, 1971) SES-3 borehole strainmeters installed in the Longitudinal Valley in eastern Taiwan. The method is based on the waveform reconstruction of the Earth and ocean tidal shear signals through linear regressions on strain gauge signals, with variable sensor azimuth. This method allows us to derive the orientation of the sensor without any initial constraints and to calibrate the shear strain components \(\gamma _1\) and \(\gamma _2\) against \(M_2\) tidal constituent. The results illustrate the potential of tensor strainmeters for recording horizontal tidal shear strain. 相似文献
128.
Yu-Fang Chiu Samkele S. Tfwala Yung-Ching Hsu Yen-Yu Chiu Chen-Yang Lee Su-Chin Chen 《地球表面变化过程与地形》2021,46(13):2527-2539
Sediment flushing and the morphological responses to the procedure of check dam removal are still unclear. Following laboratory experiments that revealed three stages (deepening, widening, and volume release) of check dam adjustment, a check dam built in 2007 at Landao Creek in central Taiwan was adjusted in 2015 by removing central bars and cutting 2.5 m from the middle two piers (stage 1 + 2), with the purpose of regulating sediment transfer and keeping the thalweg at the center of the channel, while also preventing hill slope toe erosion. In 2019, four central piers were removed (stage 3) to increase the volume of sediment released. Annual surveys were conducted after the initial adjustment in 2015 through to 2020 using unmanned aerial vehicles (UAVs). The check dam adjustments revealed that the channel had narrowed and stabilized as indicated by regenerating riparian vegetation. Additionally, distinct terraces had formed on the hill slope toes of the creek channel in proximity to the check dam. The meander upstream weakened following the dam adjustments. This study combining laboratory experiments with actual field observation contributed immensely to check dam decommissioning. Additionally, this study illustrated how an adjustable check dam may aid regulation of sediment transport and thereby sediment balance. It can be adjusted accordingly based on the prevailing channel condition. 相似文献
129.
Chia-Chang Lin Li-Ting Lee Ling-Jung Hsu 《International Journal of Environmental Science and Technology》2014,11(3):831-838
This investigation evaluates the effectiveness of UV-365 nm/S2O8 2? process in degrading polyvinyl alcohol in aqueous solutions. The effects of pH, Na2S2O8 dosage, and temperature on the degradation efficiency of polyvinyl alcohol were studied. Under acidic conditions, the degradation efficiency of polyvinyl alcohol exceeded that under alkaline conditions. Additionally, a higher Na2S2O8 dosage and a higher temperature were associated with a higher degradation efficiency of polyvinyl alcohol. The degradation rates of polyvinyl alcohol followed a pseudo-first-order kinetic model. Moreover, the observed degradation rate coefficient increased from 0.0078 to 0.4081 min?1 when the temperature was increased from 10 to 55 °C. Also, the activation energy estimated using the observed degradation rate coefficients and the Arrhenius equation was 64 kJ/mol. At UV-365 nm, pH 3, an Na2S2O8 dosage of 0.06 g/L, a temperature of 55 °C, and an initial polyvinyl alcohol concentration of 20 mg/L, around 100 % of polyvinyl alcohol was degraded, indicating that UV-365 nm/S2O8 2? process has great potential in degrading polyvinyl alcohol in aqueous solutions. 相似文献
130.
Po-Yi Chou Hung-Chieh Lo Shih-Meng Hsu Yen-Tsu Lin Chi-Chao Huang 《Hydrogeology Journal》2012,20(6):1101-1116
The feasibility of using geological and geophysical well-log and borehole-televiewer data for the identification of hydraulically transmissive fractures is evaluated. Twenty-nine boreholes were drilled to a depth of 100?m in the middle-stream basin of Jhuoshuei River, Taiwan. Four criteria that assist in indicating the potential presence of permeable zones are proposed, including: lower gamma-ray response compared with the average response, divergence of the short normal-resistivity log relative to that of the long one, longer sonic travel time, and the appearance of discernible openings detected with the televiewer. With these, the transmissivities at the predetermined depths were estimated and verified by an in-situ hydraulic test. The statistical results indicate that, particularly in the mountainous area where a complex folded structure with a succession of synclines and anticlines is shown, the interpretation of lithologic conditions is not necessary to identify the presence of a relatively higher-permeability zone. Comparatively, the estimates of porosity and fracture aperture are the necessary premises to the prediction of hydraulically transmissive fractures. A joint consideration of all four criteria is found, allowing a less biased evaluation of the fracture transmissivity. 相似文献