Experiments on channel evolution caused by check-dam failure     

Wen-Hsiao TSENG  Hsiao-Wen WANG  Shih-Chieh CHOU  Yu-Lin KAO  Chjeng-Lun Shieh 《山地科学学报》2012,9(2):175-184

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Slip monitoring of a dip-slope and runout simulation by the discrete element method: a case study at the Huafan University campus in northern Taiwan     

Chia-Han Tseng  Yu-Chang Chan  Ching-Jiang Jeng  Yu-Chung Hsieh 《Natural Hazards》2017,89(3):1205-1225

Slope failure is a widely observed phenomenon in the mountainous areas in Taiwan due to rainy climatic and fragile geological conditions. Landslides easily occur after intense rainfall, especially from typhoons, and, accordingly, cause a great loss of human life and property. At the northern end of the Western Foothill belt in northern Taiwan, Huafan University is founded on a dip-slope about 20° toward the southwest composed of early Miocene alternations of sandstone and shale. Data from continuous monitoring using inclinometers and groundwater gauges reveal that 6–10 mm/month of slope creeping occurs, and a potential sliding surface is then detected about 10–40 m beneath the slope surface. To understand the potential runout process of the dip-slope failure at the campus, particle flow code 3D models based on a discrete element method are applied in this study. Results of the simulation reveal a critical value of the friction coefficient to be 0.13 and that more than 90% of the campus buildings will slide down in 100 s when the friction coefficient is reduced to half the critical value. The weakening of the shear zone due to the rise of groundwater during rainstorms is assumed to be the main factor. Some suggestions for preventing landslide disasters are to construct catchpits to drain runoff and lower the groundwater table and to install a sufficient number of ground anchors and retaining walls to stabilize the slope.  相似文献   

A multi‐azimuth seismic refraction study for a horizontal transverse isotropic medium: physical modelling results          下载免费PDF全文

Cheng‐Wei Tseng  Young‐Fo Chang  Jia‐Wei Liu  Chao‐Ming Lin 《Geophysical Prospecting》2018,66(1):13-25

To investigate the characteristics of the anisotropic stratum, a multi‐azimuth seismic refraction technique is proposed in this study since the travel time anomaly of the refraction wave induced by this anisotropic stratum will be large for a far offset receiver. To simplify the problem, a two‐layer (isotropy–horizontal transverse isotropy) model is considered. A new travel time equation of the refracted P‐wave propagation in this two‐layer model is derived, which is the function of the phase and group velocities of the horizontal transverse isotropic stratum. In addition, the measured refraction wave velocity in the physical model experiment is the group velocity. The isotropic intercept time equation of a refraction wave can be directly used to estimate the thickness of the top (isotropic) layer of the two‐layer model because the contrast between the phase and group velocities of the horizontal transverse isotropic medium is seldom greater than 10% in the Earth. If the contrast between the phase and group velocities of an anisotropic medium is small, the approximated travel time equation of a refraction wave is obtained. This equation is only dependent on the group velocity of the horizontal transverse isotropic stratum. The elastic constants A₁₁, A₁₃, and A₃₃ and the Thomsen anisotropic parameter ε of the horizontal transverse isotropic stratum can be estimated using this multi‐azimuth seismic refraction technique. Furthermore, under a condition of weak anisotropy, the Thomsen anisotropic parameter δ of the horizontal transverse isotropic stratum can be estimated by this technique as well.  相似文献   

钝顶螺旋藻C-藻蓝蛋白分子内不同基团间能量传递的研究   总被引：3，自引：2，他引：1  

王广策; 曾呈奎  王广策; 曾呈奎 《海洋与湖沼》1998,29(5):471-476

于１９９６年８－１２月,从钝顶螺旋藻中分离纯化Ｃ－藻蓝蛋白,并用荧光光谱法对Ｃ－藻蓝蛋白分子内不同基团间的能量传递进行研究,结果表明,Ｃ－藻蓝蛋白分子内芳香族氨基酸残基能将能量传至与脱辅基蛋白共价结合的色基,从而使色基产生相应的荧光,Ｃ－藻蓝蛋白分子２４０－２４５ｎｍ的荧光激发峰产生于二硫键,它也能将吸收的能量传至色基;同时还发现,溶液状态下的Ｃ－藻蓝蛋白分子内,色氨酸残基可能位于分子内部的疏水区  相似文献   

Estimating the economic impacts of climate change on infectious diseases: a case study on dengue fever in Taiwan     

Wei-Chun Tseng  Chi-Chung Chen  Ching-Cheng Chang  Yu-Hsien Chu 《Climatic change》2009,92(1-2):123-140

Researchers of climate change have suggested that climate change and variability has a significant influence on the epidemiology of infectious diseases, particularly vector-borne diseases. The purpose of this study is to explore how climate conditions and the dengue fever epidemic in Taiwan are related and to estimate the economic impact of climate change on infectious diseases. To achieve these objectives, two different methods, one involving the Panel data model and the other the Contingent Valuation Method (CVM), are applied in this study. At first, we use the Panel data model to assess the relationship between climate conditions and the number of people infected by dengue fever during the period from January 2000 to February 2006 in 308 cities and townships in the Taiwan. The results of the empirical estimation indicate that climate conditions have an increasingly significant impact on the probability of people being infected by dengue fever. The probability of being infected by dengue fever due to climate change is then calculated and is found to range from 12% to 43% to 87% which represent low, mid, and high probabilities of infection caused by climate change when the temperature is increased by 1.8°C. The respondent’s willingness to pay (WTP) is also investigated in the survey using the single-bounded dichotomous choice (SBDC) approach, and the results show that people would pay NT$724, NT$3,223 and NT$5,114 per year in order to avoid the increased probabilities of 12%, 43%, and 87%, respectively, of their being infected with dengue fever.  相似文献   

Resolving the upper-ocean warm layer improves the simulation of the Madden–Julian oscillation     

Wan-Ling Tseng  Ben-Jei Tsuang  Noel S. Keenlyside  Huang-Hsiung Hsu  Chia-Ying Tu 《Climate Dynamics》2015,44(5-6):1487-1503

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Behavioral effects of titanium dioxide nanoparticles on larval zebrafish (Danio rerio)     

Chen TH  Lin CY  Tseng MC 《Marine pollution bulletin》2011,63(5-12):303-308

In this study, zebrafish embryos were exposed to titanium dioxide nanoparticles (TiO2 NPs at 0.1, 0.5, 1, 5, 10 mg/L or control) from fertilization to free swimming stage. Hatchability, survival, and malformation rate were not affected by TiO2 NPs at these exposure levels. However, larval swimming parameters, including average and maximum velocity and activity level were significantly affected by TiO2 NPs. Co-exposure to either the glutathione precursor, N-acetylcysteine (NAC), or the glutathione synthesis inhibitor, buthionine sulfoximine (BSO), did not significantly alter the behavioral effects resulting from TiO2 NPs, suggesting that other factor(s) besides oxidative stress may contribute to the behavioral toxicity of TiO2 NPs. Our study also demonstrated that the behavioral endpoints were more sensitive than the others (e.g., hatchability and survival) to detect toxicity of TiO2 NPs on developing fish.  相似文献   

A preliminary study on Typhoon Tim induced resonance at Hualien Harbor,Taiwan   总被引：1，自引：1，他引：0  

Jerome Peng-Yea Maa  Cheng-Han Tsai  Wen-Jye Juang  Hsiang-Maw Tseng 《Ocean Dynamics》2011,61(4):411-423

New analysis of wave records at Hualien Harbor during Typhoon Tim in 1994 reveals that for certain wave periods, the ratios of measured wave heights among three available wave stations inside the harbor are unique and roughly remain the same during the severest period of resonance. Since there is no incident infragravity wave (period from 80 to 220 s) information at offshore boundaries, these unique ratios become the surrogate of background truth for checking the performance of numerical simulations. A new simulation effort using a large (45 × 17 km) modeling domain, high-resolution (20 × 20 m) grid and the RIDE wave transformation model were conducted to simulate the observed responses. Comparison of the modeling results with the observations showed reasonable agreement. Additional model studies using ideal bathymetries with the same grid domain and resolution were also conducted to help interpret the prototype modeling results. The effects of two types of commonly used remedies were first examined by using the ideal bathymetry, and then, the prototype bathymetry. The results demonstrated that a single 1-km long, shore-parallel breakwater could significantly reduce the resonance. The results of using three shore-parallel breakwaters, however, are no better. More studies to identify the optimum design associated with the shore-parallel breakwater (location, length, etc.) are necessary for the optimum reduction of resonance at Hualien Harbor.  相似文献   

A new viewpoint on risk control decision models for natural disasters   总被引：8，自引：8，他引：0  

Chun-Pin Tseng  Cheng-Wu Chen  Yu-Ping Tu 《Natural Hazards》2011,59(3):1715-1733

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Sea level variations in the regional seas around Taiwan   总被引：2，自引：0，他引：2  

Yu-Heng Tseng  Larry C. Breaker  Emmy T. -Y. Chang 《Journal of Oceanography》2010,66(1):27-39

The patterns and trends of sea level rise in the regional seas around Taiwan have been investigated through the analyses of long-term tide-gauge and satellite altimetry data. Series of tide-gauge data extending over 50 years reveal decadal and interannual variations and spatially-inhomogeneous patterns of generally rising sea level. The East Asia tide-gauge stations around Taiwan show an average trend of +2.4 mm/yr from 1961–2003, which is larger than the reported global rate of +1.8 mm/yr for the same period. These stations also show significantly larger sea level rise rates (+5.7 mm/yr) than global values (+3.1 mm/yr) during the period from 1993–2003. Consistent with the coastal tide-gauge records, satellite altimetry data show similar increasing rates (+5.3 mm/yr) around Taiwan during the same period. Comparisons with temperature anomalies in the upper ocean suggest that thermal expansion and heat advection in the upper layer contribute significantly to the long-term sea level variations in this area with correlations >0.9 for observations after 1992. Thermosteric sea level variations may also explain the interannual and decadal variations of the observed sea level rises around Taiwan. Our analysis also indicates that the altimetry data are only part of a long-term, larger-scale signal. Finally, we have found that a non-linear smoother, LOESS, is more suitable for extracting long-term trends in sea level than the traditional linear regression approach.  相似文献