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PENG Zicheng LEUNG Po Lau YU Peter CHENG Peikai LI Mai 《《地质学报》英文版》2006,80(5):759-762
The microprobe EDXRF equipment was used for analysis of the major and trace elements in glaze layer-transitive layer-body layer of the celadon from the Altar Yao （Kiln） and Laohudong Yao in the Southern Song Dynasty （1127-1279 A.D.）, Zhejiang, China. The K values of the discriminant factor for the celadon wares are larger than 8, which means the celadon of the Altar Yao and Laohudong Yao are different from that of the Longquan Yao. The former two belong to the Guan Yao system （the Chinese imperial kilns）, but the latter to the Min Yao system （the Chinese popular kilns）. The principle component analysis shows their relationship between the Altar and Laohudong wares with provenance postulation. The thickness of the transitive layer in the Altar and Laohudong wares is obviously different, which reveals the microstructure characteristics of the celadon even though both kinds of wares belong to the imperial kiln system. 相似文献
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黄河流域未来气候-水文变化的模拟研究 总被引：3，自引：0，他引：3
将大尺度半分布式水文模型VIC应用到黄河上中游流域(花园口水文断面以上),并利用区域气候模式RegCM4.0单向嵌套全球气候模式BCC_CSM1.1,动力降尺度到黄河流域的模拟结果驱动VIC模型,开展在新的典型浓度路径下(RCP4.5和RCP8.5)黄河流域未来气候和水文变化的离线模拟。模拟结果显示,在RCP4.5和RCP8.5排放情景下,黄河流域21世纪平均地表气温相对于1971—2000年均呈显著上升趋势,2019—2048年上升1.2—1.5℃,2069—2098年上升2.19—3.9℃。未来年平均降水量有微弱的增大,2019—2048年增幅为6%左右,2069—2098年增幅为1.4%—5.6%。未来蒸发量增大明显,2069—2098年年平均蒸发量最大可增加9.6%。2019—2048年花园口水文站的年平均径流量增大3.4%—7.4%,2069—2098年年平均径流量转为减少,减幅为3.3%—5.3%。黄河上游地区未来气候和水文变化趋势与黄河流域基本一致,但未来年径流量变幅低于黄河流域,相对比较稳定。 相似文献
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A Study on the Relationship Among Visibility, Atmospheric
Suspended Particulate Concentration, and Meteorological
Conditions in Hong Kong 
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下载免费PDF全文 By making use of the 2005 hourly data of visibility at Chek Lap Kok and suspended particulate (PM2.5) at Tung Chung,PM2.5 concentration and visibility (excluding cases with mist,fog, rain, or relative humidity≥95%) are found to have a reciprocal relationship with correlation coefficient about 0.8.
Besides, similar seasonal trends are exhibited in both the number of hours of reduced visibility (visibility below 8 km and excluding cases with mist, fog, rain, or relative humidity≥95%) and PM2.5 concentration, i.e., with higher value attained in winter and lower value in summer.Backward trajectory analysis using HYSPLIT indicates that this phenomenon is related to the source of air mass affecting Hong Kong. For continental trajectories, the average daily occurrence of reduced visibility and the daily mean PM2.5 concentration were much higher than the corresponding occurrence of reduced visibility and mean PM2.5 concentration for maritime trajectories.A case study on an event with a tropical cyclone approaching Hong Kong is included in this paper to demonstrate the significance of meteorological conditions in determining the visibility and PM2.5
concentration. 相似文献
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遥感影像配准误差传递模型及模拟分析 总被引：3，自引：0，他引：3
在遥感影像配准过程中,通常假设控制点是“完美的”。然而,在实际情况中,由于控制点本身不可避免的带有一定的误差导致这种假设在一定情况下并不成立,并且将会影响遥感影像几何校正的精度。普通最小二乘方法OLS(O rd inary Least Square)是遥感影像配准常用的校正估计模型,令人遗憾的是,在控制点存在误差的情况下,它的估计是有偏的,并且不能够正确传递和估计校正影像的误差大小。引入一致校正最小二乘方法CALS(ConsistentAd justed Least Squares),在此基础上提出的一个改进的方法,称之为松弛一致校正最小二乘方法RCALS(Relaxed ConsistentAd justed Least Squares)。这类回归模型具有改正控制点(解释变量)中的误差和跟踪回归模型中的误差传递的能力。为了验证CALS和RCALS模型的有效性,本文利用模拟影像进行分析。这里着重分析OLS,CALS和RCALS模型在几何校正过程中的比较。结果表明,RCALS和CALS的结果优于OLS估计结果。 相似文献
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WANG Shourong HUANG Ronghui DING Yihui LEUNG. L. R WIGMOSTA M. S. VAIL. L. W. 《Acta Meteorologica Sinica》2002,16(3):374-387
The advanced distributed hydrology-soil-vegetation model DHSVM,developed by Wigmostaet al.(1994)is introduced from US Pacific Northwest National Laboratory.To apply DHSVM inChina for the first time some improvements have been made in terms of the basin characteristics:1)to change evapotranspiration model,using the improved Penman-Monteith approach in place ofthe original one;2)to change the model structure,inserting datasets from 4 stations to grid cellsfor each river basin,instead of datasets from one or two stations;3)to develop new hydrology,vegetation and soil parameterization schemes for improving the simulated results,with focus oncalculation and adjustment of 11 parameters,such as soil porosity (?),field capacity θ_(fc),leaf areaindex LAI,stochastic resistance γ_s,among the total 33 parameters.Then the improved DHSVM isdriven by observed datasets for Luanhe River Basin and Sanggan River Basin,respectively.Thesimulated evapotranspiration(ET),runoff,snow water equivalent,water table,soil moisture andpercolation are then gained as DHSVM outputs.The simulated ET shows that the highest peakappears in May or June instead of July or August.This is consistent with the real situations,owing to the improvement of ET model.The simulated runoff process and flood peak are quiteconsistent with the observed ones.The model efficiency values for Luanhe River and SangganRiver Basins are 0.89 and 0.82,respectively,which shows high simulating ability of the modelsystem for both relatively humid and dry basins. 相似文献
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Based on improvement of a distributed hydrology-soil-vegetation model (DHSVM for short)and its application to North China,a nested regional climatic-hydrologic model system is developedby connecting DHSVM with RegCM2/China.The simulated climate scenarios,including controland 2×CO_2 outputs,are downscaled to 8 stations in Luanhe River and Sanggan River Basins todrive the hydrology model.According to simulation results,under double CO_2 scenarios,annualmean temperature and evapotranspiration will increase 2.8C and 29 mm,respectively;precipitation also increase but with different value for each basin,6 mm for Luanhe River Basinwhile 46 mm for Sanggan River Basin;runoff change for the two basins is different too,27 mmdecrease for Luanhe River Basin while 26 mm increase for Sanggan River Basin.As a result,therunoff in future for Luanhe River Basin and Sanggan River Basin will be 74 mm and 71 mm,respectively,which is approximately a quarter of annual mean runoff(284 mm)of the wholecountry.Total streamflow for the two basins will decrease about 2.5×10~8m~3.All these indicatethat the warm and dry trend will continue in the two river basins under double CO_2 scenarios.Thenested model system,with both climatic and hydrologic prediction ability,could also be applied toother basins in China by parameter adjustment. 相似文献
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全球化与城市国际化:国际城市的一项实证研究 总被引：3，自引：0，他引：3
在当今全球化时代，许多城市被确认为世界城市或全球城市，但本文认为世界上只有少数一些城市真正达到“世界城市”的标准，具有控制世界经济的功能。而许多其他城市，无论是支配或被支配的城市，只显示出国际化的若干特征。本文利用全球264个城市与69家高级生产者服务公司的资料，从国际城市的角度研究世界上的重要城市。研究发现不同的城市有不同的国际化水平，除了少数高度国际化的一流城市达到世界城市的标准，许多其他城市只达到局部国际化，且他们的分布在地域上并无集中的趋势。同时研究发现世界上只有少数高级服务公司拥有全球城市服务网络，大部分公司的服务网络只集中在部分地区。 相似文献
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Traditionally,a delayed(early)onset of the South China Sea summer monsoon(SCSSM)has been observed to follow a warm(cold)El Ni?o-Southern Oscillation(ENSO)event in winter,supporting high seasonal predictability of SCSSM onset.However,the empirical seasonal forecasting skill of the SCSSM onset,solely based on ENSO,has deteriorated since 2010.Meanwhile,unexpected delayed onsets of the SCSSM have also occurred in the past decade.We attribute these changes to the Northwest Indian Ocean(NWIO)warming of the sea surface.The NWIO warming has teleconnections related to(1)suppressing the seasonal convection over the South China Sea,which weakens the impacts of ENSO on SCSSM onset and delays the start of SCSSM,and(2)favoring more high-frequency,propagating moist convective activities,which enhances the uncertainty of the seasonal prediction of SCSSM onset date.Our results yield insight into the predictability of the SCSSM onset under the context of uneven ocean warming operating within the larger-scale background state of global climate change. 相似文献