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991.
Acta Geotechnica - Soil bio-cementation via microbially induced carbonate precipitation (MICP) has been extensively studied as a promising alternative technique to traditional chemical cementing... 相似文献
992.
ShuiYong Fan Y.R. Guo Ming Chen JiQin Zhong YanLi Chu W. Wang X.Y. Huang YingChun Wang Y.H. Kuo 《寒旱区科学》2009,1(2):0135-0142
To improve the weather forecasting over the Beijing area for the 2008 Olympic Games,a triple-nested(27/9/3km) WRFVar/WRF system with 3-h update cycle was established.Experiments have been done for a convective event that occurred on August 1,2006.The results showed that the high-resolution rapid update cycle gave a good precipitation forecast;the tunings of background error statistics(BES) and observation-error statistics in WRFVar improved the skill of the precipitation forecast;the BES for the fine domain(3 km) obtained by interpolation from its parent domain(9 km) can be used in 3 km WRFVar as a reasonable approximation.The user can now save a great deal of work related to the derivation of the fine mesh BES from the forecast over a period of time;the rapid update cycle with 3-h frequency has satisfied the forecast,and the update cycle with 1-h frequency was not necessary. 相似文献
993.
The mixing of seawater/hydrothermal fluid within the large seafloor hydrothermal sulfide deposits plays a key role in the
formation processes of the sulfide deposits. Some issues attract considerable attentions in the study of seafloor hydrothermal
system in recent years, such as the relationships among different types of vent fluids, the characteristics of chemical compositions
and mineral assemblages of the hydrothermal deposits and their governing factors. Combined with the measured data of hydrothermal
fluid in the TAG field, the thermodynamic model of mixing processes of the heated seawater at different temperatures and the
hydrothermal fluid is calculated to understand the precipitation mechanism of anhydrite and the genetic relationships between
the black and white smoker fluids within the TAG mound. The results indicate that the heating of seawater and the mixing of
hydrothermal fluid/seawater are largely responsible for anhydrite precipitation and the temperature of the heated seawater
is not higher than 150°C and the temperature of the end-member hydrothermal fluid is not lower than 400°C. Based on the simulated
results, the evolving patterns of fluids within the TAG deposit are discussed. The mixed fluid of the end-member hydrothermal
fluid and the seawater heated by wall rock undergoes conductive cooling during upflowing within the deposit and forms “White
Smoker” eventually. In addition, the end-member hydrothermal fluid without mixed with seawater, but undergoing conductive
cooling, vents out of the deposit and forms “Black Smoker”.
Supported by China Ocean Mineral Resources Research and Development Association Program (Grant No. DY115-02-1-01) and National
Basic Research Program of China (Grant No. G2000078503) 相似文献
994.
Recent declines in Chesapeake Bay oyster populations have been attributed to disease, and reduced water quality from pollution. The stress associated with pollutant exposure may reduce energy available for growth and reproduction. Polychlorinated biphenyls (PCBs) are lipophilic contaminants that may potentially affect mobilization of lipid reserves, increasing reliance on glycogen stores, which could otherwise be utilized to supply energy for gametogenesis. Thus, PCBs may indirectly affect glycogen stores in oysters in a deleterious manner. To test for this effect, reproductively inactive oysters were exposed to PCBs by feeding individuals 0.7 g of algal paste containing 0, 0.35, or 3.5 micrograms PCBs daily for 8 weeks. Additionally, a group of oysters was exposed to PCBs (0, 0.35, and 3.5 micrograms) plus 0.3 g of non-toxic artificial sediment to examine interactive effects of sediment particles and PCBs. Adductor muscle, mantle, and gonadal tissues were analyzed for glycogen content. Results suggest that glycogen content is reduced in the adductor muscle with increasing PCB exposure, but there are no effects of PCBs in the mantle and gonadal tissues. 相似文献
995.
Recent declines in Chesapeake Bay oyster populations have been attributed to disease, and reduced water quality from pollution. The stress associated with pollutant exposure may reduce energy available for growth and reproduction. Polychlorinated biphenyls (PCBs) are lipophilic contaminants that may potentially affect mobilization of lipid reserves, increasing reliance on glycogen stores, which could otherwise be utilized to supply energy for gametogenesis. Thus, PCBs may indirectly affect glycogen stores in oysters in a deleterious manner. To test for this effect, reproductively inactive oysters were exposed to PCBs by feeding individuals 0.7 g of algal paste containing 0, 0.35, or 3.5 μg PCBs daily for 8 weeks. Additionally, a group of oysters was exposed to PCBs (0, 0.35, and 3.5 μg) plus 0.3 g of non-toxic artificial sediment to examine interactive effects of sediment particles and PCBs. Adductor muscle, mantle, and gonadal tissues were analyzed for glycogen content. Results suggest that glycogen content is reduced in the adductor muscle with increasing PCB exposure, but there are no effects of PCBs in the mantle and gonadal tissues. 相似文献
996.
George Galanis Peter C. Chu George Kallos Yu-Heng Kuo C. T. J. Dodson 《Stochastic Environmental Research and Risk Assessment (SERRA)》2012,26(1):83-103
The main characteristics of the significant wave height in an area of increased interest, the north Atlantic ocean, are studied
based on satellite records and corresponding simulations obtained from the numerical wave prediction model WAM. The two data
sets are analyzed by means of a variety of statistical measures mainly focusing on the distributions that they form. Moreover,
new techniques for the estimation and minimization of the discrepancies between the observed and modeled values are proposed
based on ideas and methodologies from a relatively new branch of mathematics, information geometry. The results obtained prove
that the modeled values overestimate the corresponding observations through the whole study period. On the other hand, 2-parameter
Weibull distributions fit well the data in the study. However, one cannot use the same probability density function for describing
the whole study area since the corresponding scale and shape parameters deviate significantly for points belonging to different
regions. This variation should be taken into account in optimization or assimilation procedures, which is possible by means
of information geometry techniques. 相似文献
997.
998.
The sediment content of the Yellow River is resulted from the interactions of natural, economic,and social factors,so it includes some evolutive information of the Yellow River Basin system.Sediment contents from 1952 to 2007 on Toudaoguai,Tongguan,Huayuankou and Lijin sections along the river are chosen as the study time series,and correlation dimensions(D2),Kolmogorov entropies(K2),and Hurst indexes(H)of the time series were calculated.Correlation dimensions on Toudaoguai,Tongguan,Huayuankou,and Lijin sec... 相似文献
999.
1000.