Thermal processing and crystallization of amorphous Mg‐Ca silicates     

Sarah J. Day  Stephen P. Thompson  Aneurin Evans  Julia E. Parker  Leigh D. Connor  Chiu C. Tang 《Meteoritics & planetary science》2013,48(8):1459-1471

The structural evolution of sol–gel‐produced amorphous Mg_(x)Ca_(1–x)SiO₃ silicates is investigated. Mid‐IR Fourier transform infrared spectroscopy and synchrotron X‐ray diffraction are used to confirm the amorphous nature of the as‐prepared silicates, while subsequent in situ synchrotron X‐ray powder diffraction measurements are used to study the evolution of crystalline mineral phases as a function of annealing temperature. Multiple silicate phases, including diopside, enstatite, forsterite, and SiO₂, are identified, while Rietveld (i.e., structure) refinement of the diffraction data is used to quantify phase change relationships. Investigated as possible analogs for the refractory dust grain materials likely to have been present in the early solar nebula, the likely relevance of these investigations to the observed silicate compositions of chondritic meteorites and cometary bodies and the processing of their precursor materials is discussed.  相似文献   

Hybrid-optimization algorithm for the management of a conjunctive-use project and well field design     

Chiu YC  Nishikawa T  Martin P 《Ground water》2012,50(1):103-117

Hi-Desert Water District (HDWD), the primary water-management agency in the Warren Groundwater Basin, California, plans to construct a waste water treatment plant to reduce future septic-tank effluent from reaching the groundwater system. The treated waste water will be reclaimed by recharging the groundwater basin via recharge ponds as part of a larger conjunctive-use strategy. HDWD wishes to identify the least-cost conjunctive-use strategies for managing imported surface water, reclaimed water, and local groundwater. As formulated, the mixed-integer nonlinear programming (MINLP) groundwater-management problem seeks to minimize water-delivery costs subject to constraints including potential locations of the new pumping wells, California State regulations, groundwater-level constraints, water-supply demand, available imported water, and pump/recharge capacities. In this study, a hybrid-optimization algorithm, which couples a genetic algorithm and successive-linear programming, is developed to solve the MINLP problem. The algorithm was tested by comparing results to the enumerative solution for a simplified version of the HDWD groundwater-management problem. The results indicate that the hybrid-optimization algorithm can identify the global optimum. The hybrid-optimization algorithm is then applied to solve a complex groundwater-management problem. Sensitivity analyses were also performed to assess the impact of varying the new recharge pond orientation, varying the mixing ratio of reclaimed water and pumped water, and varying the amount of imported water available. The developed conjunctive management model can provide HDWD water managers with information that will improve their ability to manage their surface water, reclaimed water, and groundwater resources.  相似文献   

Analysis of space–time patterns of rainfall events during 1996–2008 in Yilan County (Taiwan)     

Yu  Hwa-Lung  Chen  Bo-Lin  Chiu  Chuan-Hung  Lu  Mong-Ming  Tung  Ching-pin 《Stochastic Environmental Research and Risk Assessment (SERRA)》2015,29(3):929-945

Stochastic Environmental Research and Risk Assessment - Understanding local precipitation patterns is essential to water resource management and flood mitigation. Precipitation patterns can vary in...  相似文献   

Spatial and Temporal Changes of Groundwater Level Induced by Thrust Faulting     

Yeeping Chia  Jessie J. Chiu  Yi-Hsuan Chiang  Tsai-Ping Lee  Chen-Wuing Liu 《Pure and Applied Geophysics》2008,165(1):5-16

Changes of groundwater level, ranging from a fall of 11.10 m to a rise of 7.42 m, induced by thrust faulting during the 1999 M_w 7.6, Chi-Chi earthquake have been recorded in 276 monitoring wells in Taiwan. Most coseismic falls appeared near the seismogenic fault as well as other active faults, while coseismic rises prevailed away from the fault. Coseismic groundwater level rises and falls correlated fairly well with hypocentral distance in the vicinity of the thrust fault. We found a major difference of coseismic changes in wells of different depths at most multiple-well stations. The recovery process of coseismic groundwater level changes is associated with the confining condition of the aquifer. Cross-formational flow is likely to play an important role in groundwater level changes after the earthquake. In the hanging wall of the thrust fault, an abnormal decline of groundwater level was observed immediately before the earthquake. The underlying mechanism of the unique preseismic change warrants further investigation.  相似文献   

Comparison of TRMM and water district rain rates over New Mexico   总被引：10，自引：0，他引：10  

Long S. CHIU  Zhong LIU  Jearanai VONGSAARD  Stanley MORAIN  Amy BUDGE  Paul NEVILLE  Chandra BALES 《大气科学进展》2006,23(1):1-13

This paper compares monthly and seasonal rain rates derived from the Version 5 (V5) and Version 6 (V6) TRMM Precipitation Radar (TPR, TSDIS reference 2A25), TRMM Microwave Imager (TMI, 2A12), TRMM Combined Instrument (TCI, 2B31), TRMM calibrated IR rain estimates (3B42) and TRMM merged gauge and satellite analysis (3B43) algorithms over New Mexico (NM) with rain gauge analyses provided by the New Mexico water districts (WD). The average rain rates over the NM region for 1998–2002 are 0.91mmd?1 for WD and 0.75, 1.38, 1.49, 1.27, and 1.07mmd?1 for V5 3B43, 3B42, TMI, PR and TCA; and 0.74, 1.38, 0.87 and 0.97 mm d?1 for V6 3B43, TMI, TPR and TCA, respectively. Comparison of V5 3B43 with WD rain rates and the daily TRMM mission index (TPR and TMI) suggests that the low bias of V5 3B43 for the wet months (summer to early fall) may be due to the non-inclusion of some rain events in the operational gauge analyses that are used in the production of V5 3B43. Correlation analyses show that the WD rain rates vary in phase, with higher correlation between neighboring WDs. High temporal correlations (>0.8) exist between WD and the combined algorithms (3B42, 3B43 and TCA for both V5 and V6) while satellite instrument algorithms (PR, TMI and TCI) are correlated best among themselves at the monthly scale. Paired t-tests of the monthly time series show that V5 3B42 and TMI are statistically different from the WD rain rates while no significant difference exists between WD and the other products. The agreements between the TRMM satellite and WD gauge estimates are best for the spring and fall and worst for winter and summer. The reduction in V6 TMI (?7.4%) and TPR (?31%) rain rates (compared to V5) results in better agreement between WD estimates and TMI in winter and TPR during summer.  相似文献   

Navigating ethnicity: segregation,placemaking, and difference     

Francesca Chiu 《Urban geography》2019,40(4):582-583

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Marine 3D seismic volumes from 2D seismic survey with large streamer feathering     

Lin  Liang-Fu  Hsu  Ho-Han  Liu  Char-Shine  Chao  Kuo-Han  Ko  Chia-Chun  Chiu  Shye-Dong  Hsieh  Hsin-Sung  Ma  Yu-Fang  Chen  Song-Chuen 《Marine Geophysical Researches》2019,40(4):619-633

Marine Geophysical Research - Strong ocean current influences a marine seismic survey and forces the streamer off-course from the survey line. The sideway drift of the streamer results in that the...  相似文献   

The Driving Effect of Spatial Differences of Water Intensity in China     

Shi  Zhen  Huang  Huinan  Wu  Fengping  Chiu  Yung-ho  Zhang  Chenjun 《Natural Resources Research》2020,29(4):2397-2410

This paper adopts the logarithmic mean Divisia index in the family of spatial index decomposition analysis to decompose the driving effect of spatial differences of water intensity in China into intensity effect and structure effect employing data spanning 2000–2017. The results show that water use efficiency of the eastern provinces was always higher than that of the central provinces and western provinces except for Jiangsu and Hainan, and in the central and western regions, only Shanxi, Henan, Chongqing, and Shaanxi had higher efficiency levels than the national average level. Over that 17-year time period, the gap in water intensity exhibits a decreasing trend between the provincial level and average level (except for Heilongjiang and Chongqing). For industry water intensity, those provinces with a lower than average level were mainly in the eastern region. Except for Shanghai, Jiangsu, and Guangdong, the primary industry water intensity of the eastern provinces was always lower than the average level. Except for Fujian, Shanghai, Jiangsu, and Hainan, the secondary industry water intensity of the eastern provinces was always lower than the average level. Except for Guangdong, Fujian, and Hainan, the tertiary industry water intensity of the eastern provinces was always lower than average level. The water intensity of the secondary and tertiary industries in Shanxi and Inner Mongolia in the central and western regions was always lower than the average level. Lastly, the provinces in which the provincial proportion of the primary industry was lower than the average level were mainly in the eastern region, while conversely the same proportion of the primary industry among central and western provinces was generally high. Therefore, provinces should formulate and implement water resource policies that are different and pertinent to their own actual conditions.

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Laterally varying reflector at the top of D" beneath northern Siberia     

S. Houard  H-C. Nataf 《Geophysical Journal International》1993,115(1):168-182

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Space Telescope Astrometry from CCD images     

Liang-Tai George Chiu 《Celestial Mechanics and Dynamical Astronomy》1980,22(2):191-196

The astrometric application of the Wide Field Camera and the Planetary Camera is reviewed. It is shown that the digital image centering algorithms can yield a positional accuracy of 0.1 milli-arcsecond. Deconvolution of CCD's sensitivity, non-flatness of the filters, and crinkling of the CCD surface may limit the positional accuracy to 1 milli-arcsecond.Presented at the Symposium Star Catalogues, Positional Astronomy and Celestial Mechanics, held in honor of Paul Herget at the U.S. Naval Observatory, Washington, November 30, 1978.  相似文献