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对“顿号的误用”和“选择问句中问号误用”的不同看法
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作者 邹哲承 《语文知识》 2002年第8期45-46,共2页
李思珩先生在贵刊2000年第3期上撰文,认为:“顿号常用在句内并列词语之间,如果句内并列的各项都带有‘啊’‘啦’等语气词的话,由于语气词的使用延长了停顿的时间,使这些并列成分之间的停顿加大,因此应该用逗号表示停顿,而不能用顿号。... 李思珩先生在贵刊2000年第3期上撰文,认为:“顿号常用在句内并列词语之间,如果句内并列的各项都带有‘啊’‘啦’等语气词的话,由于语气词的使用延长了停顿的时间,使这些并列成分之间的停顿加大,因此应该用逗号表示停顿,而不能用顿号。”李先生以此为依据,认为“ 展开更多
关键词 顿号 选择问句 问号 使用错 误气 语感 标点符号
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喉罩临床应用的几个问题 被引量:20
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作者 张燕 林成新 《广西医学》 CAS 2010年第3期359-361,共3页
关键词 喉罩 道密闭性 胃胀反流
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Analytical solution of coal-bed methane migration with slippage effects in hypotonic reservoir 被引量:1
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作者 XIAO Xiao-chun PAN Yi-shan YU Li-yan JIANG Chun-yu 《Journal of Coal Science & Engineering(China)》 2011年第2期137-141,共5页
Using theoretical analysis, the single-phase gas seepage mathematical model influenced by slippage effects was established. The results show that the pressure of producing wells attenuates more violently than the well... Using theoretical analysis, the single-phase gas seepage mathematical model influenced by slippage effects was established. The results show that the pressure of producing wells attenuates more violently than the wells without slippage effects. The decay rate of reservoir pressure is more violent as the Klinkenherg factor increases. The gas prediction output gradually increases as the Klinenberg factor increases when considering gas slippage effects. Through specific examples, analyzed the law of stope pore pressure and gas output forecast changing in a hypotonic reservoir with slippage effects. The results have great theoretical significance in the study of the law of coal-bed methane migration in hypotonic reservoirs and for the exploitation of coal-bed methane. 展开更多
关键词 slippage effect hypotonic reservoir Klinkenberg factor analysis solution
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The Soret and Dufour Effects in Non-thermal Equilibrium Packed Beds with Forced Convection and Endothermic Reactions* 被引量:1
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作者 李明春 赵中亮 +2 位作者 静宇 刘家涛 吴玉胜 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第8期867-875,共9页
To study the influence of the Soret and Dufour effects on the reactive characteristics of a porous packed bed with endothermic reactions and forced convection, a two-dimensional mathematical model considering the cros... To study the influence of the Soret and Dufour effects on the reactive characteristics of a porous packed bed with endothermic reactions and forced convection, a two-dimensional mathematical model considering the cross-diffusion effects was developed in accordance with the thermodynamics of irreversible processes and the local thermal non-equilibrium model. The simulation results were validated by comparing with experimental data. The influence of the Soret and Dufour effects on the heat transfer, mass transfer and endothermic chemical reaction in the non-thermal equilibrium packed bed is discussed. It was found that when the Peclet number reaches 1865, the maximum relative error of the concentration of gas product induced by the Soret effect is 34.7% and that of the solid fractional conversion caused by the Dufour effect is 10.8% at reaction time 160 s and initial temperature 1473 K. The differences induced by the Soret and Dufour effects are demonstrated numerically to increase gradually with the initial temperature of feeding gas and the Peclet number. 展开更多
关键词 heat and mass transfer thermal decomposition cross-diffusion effects porous packed bed
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Application of the Analogue-Based Correction of Errors Method in ENSO Prediction 被引量:9
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作者 REN Hong-Li LIU Ying +2 位作者 JIN Fei-Fei YAN Yu-Ping LIU Xiang-Wen 《Atmospheric and Oceanic Science Letters》 CSCD 2014年第2期157-161,共5页
In this study, a method of analogue-based correction of errors(ACE) was introduced to improve El Ni?o-Southern Oscillation(ENSO) prediction produced by climate models. The ACE method is based on the hypothesis that th... In this study, a method of analogue-based correction of errors(ACE) was introduced to improve El Ni?o-Southern Oscillation(ENSO) prediction produced by climate models. The ACE method is based on the hypothesis that the flow-dependent model prediction errors are to some degree similar under analogous historical climate states, and so the historical errors can be used to effectively reduce such flow-dependent errors. With this method, the unknown errors in current ENSO predictions can be empirically estimated by using the known prediction errors which are diagnosed by the same model based on historical analogue states. The authors first propose the basic idea for applying the ACE method to ENSO prediction and then establish an analogue-dynamical ENSO prediction system based on an operational climate prediction model. The authors present some experimental results which clearly show the possibility of correcting the flow-dependent errors in ENSO prediction, and thus the potential of applying the ACE method to operational ENSO prediction based on climate models. 展开更多
关键词 ENSO climatic prediction error correction
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Characteristics of pressure gradient force errors in a terrain-following coordinate 被引量:1
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作者 LI Jin-Xi LI Yi-Yuan WANG Bin 《Atmospheric and Oceanic Science Letters》 CSCD 2016年第3期211-218,共8页
A terrain-following coordinate (a-coordinate) in which the computational form of pressure gradient force (PGF) is two-term (the so-called classic method) has significant PGF errors near steep terrain. Using the ... A terrain-following coordinate (a-coordinate) in which the computational form of pressure gradient force (PGF) is two-term (the so-called classic method) has significant PGF errors near steep terrain. Using the covariant equations of the a-coordinate to create a one-term PGF (the covariant method) can reduce the PGF errors. This study investigates the factors inducing the PGF errors of these two methods, through geometric analysis and idealized experiments. The geometric analysis first demonstrates that the terrain slope and the vertical pressure gradient can induce the PGF errors of the classic method, and then generalize the effect of the terrain slope to the effect of the slope of each vertical layer (φ). More importantly, a new factor, the direction of PGF (a), is proposed by the geometric analysis, and the effects of φ and a are quantified by tan φ.tan a. When tan φ.tan a is greater than 1/9 or smaller than -10/9, the two terms of PGF of the classic method are of the same order but opposite in sign, and then the PGF errors of the classic method are large. Finally, the effects of three factors on inducing the PGF errors of the classic method are validated by a series of idealized experiments using various terrain types and pressure fields. The experimental results also demonstrate that the PGF errors of the covariant method are affected little by the three factors. 展开更多
关键词 Terrain-following coordinatepressure gradient forceerrors direction of pressuregradient slope of eachvertical layer nonlinearvertical pressure gradient pressure gradient alongvertical layer
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A neural network method for estimating weighted mean temperature over China and adjacent areas 被引量:3
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作者 Long Fengyang Hu Wusheng +1 位作者 Dong Yanfeng Yu Longfei 《Journal of Southeast University(English Edition)》 EI CAS 2021年第1期84-90,共7页
To improve the applicability of the global pressure and temperature 2 wet(GPT2w)model in estimating the weighted mean temperature in China and adjacent areas,the error compensation technology based on the neural netwo... To improve the applicability of the global pressure and temperature 2 wet(GPT2w)model in estimating the weighted mean temperature in China and adjacent areas,the error compensation technology based on the neural network was proposed,and a total of 374800 meteorological profiles measured from 2006 to 2015 of 100 radiosonde stations distributed in China and adjacent areas were used to establish an enhanced empirical model for estimating the weighted mean temperature in this region.The data from 2016 to 2018 of the remaining 92 stations in this region was used to test the performance of the proposed model.Results show that the proposed model is about 14.9%better than the GPT2w model and about 7.6%better than the Bevis model with measured surface temperature in accuracy.The performance of the proposed model is significantly improved compared with the GPT2w model not only at different height ranges,but also in different months throughout the year.Moreover,the accuracy of the weighted mean temperature estimation is greatly improved in the northwestern region of China where the radiosonde stations are very rarely distributed.The proposed model shows a great application potential in the nationwide real-time ground-based global navigation satellite system(GNSS)water vapor remote sensing. 展开更多
关键词 weighted mean temperature GPT2w model neural network error compensation GNSS meteorology
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ANALYSES OF ERRORS IN MEDIUM-TERM NUMERICAL FORECAST PRODUCTS FOR THE SUBTROPICAL HIGH 1998 被引量:1
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作者 王兴荣 姚叶青 +3 位作者 尚瑜 陈晓平 程小泉 率爱梅 《Journal of Tropical Meteorology》 SCIE 2003年第1期105-112,共8页
By statistic and dynamic analyses, we have come to the following conclusions: (1) The ECMWF medium-term numerical forecast can forecast medium-term activity of subtropical high, and the accuracy rate of forecast canno... By statistic and dynamic analyses, we have come to the following conclusions: (1) The ECMWF medium-term numerical forecast can forecast medium-term activity of subtropical high, and the accuracy rate of forecast cannot have large improvement by translational corrections. (2) The important cause for the ECMWF medium-term numerical forecast to have errors in 1998 is that the astronomical tide is not included in the model. (3) Two indexes are found from which it can be judged that ECMWF medium-term numerical forecast will have errors if the astronomical tide is ignored in the model : ① When the 54.7?line under the moon of the nodical month astronomical singularities coincides with the trough-line of the subtropical jet flow from 50癊 to 150癊 on the 500 hPa level at 2000 L.T. of the same day, and is approximately vertical (α>60? with the isotherm, then the day 0 2 days after the appearance of the nodical month astronomical singularities is defined as the initial day. Then in three successive days after the initial day, ECMWF medium-term numerical forecast of the northern latitude of the 588 line at 120 癊 will have continuous errors as large as two latitudes (7/9). Otherwise, it won’t have continuous errors (13/13). ② Otherwise, if the 54.7 ?line is in the range of a low pressure between two high pressures, then there is a dispersive error on the day of the nodical month astronomical singularities (5/7). There is not any error (6/6) otherwise. 展开更多
关键词 ECMWF medium-term numerical forecast subtropical high error analysis astronomical tide analysis of dynamics
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Chaos Particle Swarm Optimization Combined with Circular Median Filtering for Geophysical Parameters Retrieval from WindSat 被引量:2
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作者 ZHANG Lei WANG Zhenzhan +2 位作者 SHI Hanqing LONG Zhiyong DU Huadong 《Journal of Ocean University of China》 SCIE CAS 2016年第4期593-605,共13页
This paper established a geophysical retrieval algorithm for sea surface wind vector, sea surface temperature, columnar atmospheric water vapor, and columnar cloud liquid water from WindSat, using the measured brightn... This paper established a geophysical retrieval algorithm for sea surface wind vector, sea surface temperature, columnar atmospheric water vapor, and columnar cloud liquid water from WindSat, using the measured brightness temperatures and a matchup database. To retrieve the wind vector, a chaotic particle swarm approach was used to determine a set of possible wind vector solutions which minimize the difference between the forward model and the WindSat observations. An adjusted circular median filtering function was adopted to remove wind direction ambiguity. The validation of the wind speed, wind direction, sea surface temperature, columnar atmospheric water vapor, and columnar liquid cloud water indicates that this algorithm is feasible and reasonable and can be used to retrieve these atmospheric and oceanic parameters. Compared with moored buoy data, the RMS errors for wind speed and sea surface temperature were 0.92 m s^(-1) and 0.88℃, respectively. The RMS errors for columnar atmospheric water vapor and columnar liquid cloud water were 0.62 mm and 0.01 mm, respectively, compared with F17 SSMIS results. In addition, monthly average results indicated that these parameters are in good agreement with AMSR-E results. Wind direction retrieval was studied under various wind speed conditions and validated by comparing to the Quik SCAT measurements, and the RMS error was 13.3?. This paper offers a new approach to the study of ocean wind vector retrieval using a polarimetric microwave radiometer. 展开更多
关键词 Retrieval retrieval cloud Chaos columnar geophysical brightness retrieve validated swarm
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经方治疗急重症2则
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作者 吴培植 《实用中医内科杂志》 1996年第2期36-36,共1页
经方治疗急重症2则陕西省安康市第二医院(725021)吴培植一、经期感冒高热案史某,女,28岁,1992年8月14日诊。患者行经3日,因劳动时汗出淋雨,傍晚骤然寒战、壮热,体温达39.5℃,经当地卫生院消炎退热4日无... 经方治疗急重症2则陕西省安康市第二医院(725021)吴培植一、经期感冒高热案史某,女,28岁,1992年8月14日诊。患者行经3日,因劳动时汗出淋雨,傍晚骤然寒战、壮热,体温达39.5℃,经当地卫生院消炎退热4日无效。证见患者高热,眩晕心烦,间断不... 展开更多
关键词 月经期 感冒 哮喘
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Pairwise codeword error probability for coded atmospheric optical communication systems
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作者 HAN Jia-jia RONG Jian ZHONG Xiao-chun 《Optoelectronics Letters》 EI 2006年第3期203-205,共3页
To study the performance of various error-control coding schemes,exact expressions and upper bounds on the pairwise codeword error probability(PEP)for several modulation schemes(OOK,SC-BPSK,BPPM)used in atmospheric op... To study the performance of various error-control coding schemes,exact expressions and upper bounds on the pairwise codeword error probability(PEP)for several modulation schemes(OOK,SC-BPSK,BPPM)used in atmospheric optical communication systems are derived.To simplify the computation,this research was under the assumption of weak turbulence.Moreover,by simulation of expressions,the performances of PEP in different modulation schemes are compared and the best one of them is given. 展开更多
关键词 编码理论 差概率 光通信系统 调制系统
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A Potential High-Score Scheme for the Prediction of Atlantic Storm Activity 被引量:3
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作者 WANG Hui-Jun QIAN Zhuo-Lei 《Atmospheric and Oceanic Science Letters》 2010年第2期116-119,共4页
A new empirical approach for the seasonal prediction of annual Atlantic tropical storm number (ATSN) was developed using precipitation and 500 hPa geopotential height data from the preceding January February and April... A new empirical approach for the seasonal prediction of annual Atlantic tropical storm number (ATSN) was developed using precipitation and 500 hPa geopotential height data from the preceding January February and April May.The 2.5°×2.5° resolution reanalysis data from both the US National Center for Environmental Prediction/the National Center for Atmospheric Research (NCEP/NCAR) and the European Center for Medium-Range Weather Forecasting (ECMWF) were applied.The model was cross-validated using data from 1979 2002.The ATSN predictions from the two reanalysis models were correlated with the observations with the anomaly correlation coefficients (ACC) of 0.79 (NCEP/NCAR) and 0.78 (ECMWF) and the multi-year mean absolute prediction errors (MAE) of 1.85 and 1.76,respectively.When the predictions of the two models were averaged,the ACC increased to 0.90 and the MAE decreased to 1.18,an exceptionally high score.Therefore,this new empirical approach has the potential to improve the operational prediction of the annual tropical Atlantic storm frequency. 展开更多
关键词 tropical storm empirical prediction seasonal prediction
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Pressure gradient errors in a covariant method of implementing theσ-coordinate:idealized experiments and geometric analysis 被引量:1
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作者 LI Jin-Xi LI Yi-Yuan WANG Bin 《Atmospheric and Oceanic Science Letters》 CSCD 2016年第4期270-276,共7页
A new approach is proposed to use the covariant scalar equations of the a-coordinate (the covariant method), in which the pressure gradient force (PGF) has only one term in each horizontal momentum equation, and t... A new approach is proposed to use the covariant scalar equations of the a-coordinate (the covariant method), in which the pressure gradient force (PGF) has only one term in each horizontal momentum equation, and the PGF errors are much reduced in the computational space. In addition, the validity of reducing the PGF errors by this covariant method in the computational and physical space over steep terrain is investigated. First, the authors implement a set of idealized experiments of increasing terrain slope to compare the PGF errors of the covariant method and those of the classic method in the computational space. The results demonstrate that the PGF errors of the covariant method are consistently much-reduced, compared to those of the classic method. More importantly, the steeper the terrain, the greater the reduction in the ratio of the PGF errors via the covariant method. Next, the authors use geometric analysis to further investigate the PGF errors in the physical space, and the results illustrates that the PGF of the covariant method equals that of the classic method in the physical space; namely, the covariant method based on the non-orthogonal a-coordinate cannot reduce the PGF errors in the physical space. However, an orthogonal method can reduce the PGF errors in the physical space. Finally, a set of idealized experiments are carried out to validate the results obtained by the geometric analysis. These results indicate that the covariant method may improve the simulation of variables relevant to pressure, in addition to pressure itself, near steep terrain. 展开更多
关键词 Pressure gradient forceerrors covariant scalarequations of the o-coordinate steep terrain computational andphysical space geometricanalysis non-orthogonala-coordinate
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Quantifying the attribution of model bias in simulating summer hot days in China with IAP AGCM 4.1 被引量:4
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作者 LIN Zhao-Hui YU Zheng +1 位作者 ZHANG He WU Cheng-Lai 《Atmospheric and Oceanic Science Letters》 CSCD 2016年第6期436-442,共7页
Using lAP AGCM simulation results for the period 1961-2005, summer hot days in China were calculated and then compared with observations. Generally, the spatial pattern of hot days is reasonably reproduced, with more ... Using lAP AGCM simulation results for the period 1961-2005, summer hot days in China were calculated and then compared with observations. Generally, the spatial pattern of hot days is reasonably reproduced, with more hot days found in northern China, the Yangtze and Huaihe River basin, the Chuan-Yu region, and southern Xinjiang. However, the model tends to overestimate the number of hot days in the above-mentioned regions, particularly in the Yangtze and Huaihe River basin where the simulated summer-mean hot days is 13 days more than observed when averaged over the whole region, and the maximum overestimation of hot days can reach 23 days in the region. Analysis of the probability distribution of daily maximum temperature (Trnax) suggests that the warm bias in the model-simulated Tmax contributes largely to the overestimation of hot days in the model. Furthermore, the discrepancy in the simulated variance of the Tmax distribution also plays a non- negligible role in the overestimation of hot days. Indeed, the latter can even account for 22% of the total bias of simulated hot days in August in the Yangtze and Huaihe River basin. The quantification of model bias from the mean value and variability can provide more information for further model improvement. 展开更多
关键词 Hot days variance inprobability distribution bias attribution modelevaluation IAP AGCM
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STUDY OF THE EFFECTS OF REDUCING SYSTEMATIC ERRORS ON MONTHLY REGIONAL CLIMATE DYNAMICAL FORECAST
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作者 曾新民 席朝笠 《Journal of Tropical Meteorology》 SCIE 2009年第1期102-105,共4页
A nested-model system is constructed by embedding the regional climate model RegCM3 into a general circulation model for monthly-scale regional climate forecast over East China. The systematic errors are formulated fo... A nested-model system is constructed by embedding the regional climate model RegCM3 into a general circulation model for monthly-scale regional climate forecast over East China. The systematic errors are formulated for the region on the basis of 10-yr (1991-2000) results of the nested-model system, and of the datasets of the Climate Prediction Center (CPC) Merged Analysis of Precipitation (CMAP) and the temperature analysis of the National Meteorological Center (NMC), U.S.A., which are then used for correcting the original forecast by the system for the period 2001-2005. After the assessment of the original and corrected forecasts for monthly precipitation and surface air temperature, it is found that the corrected forecast is apparently better than the original, suggesting that the approach can be applied for improving monthly-scale regional climate dynamical forecast. 展开更多
关键词 climatology monthly regional climate dynamical forecast systematic errors
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The Spatial Patterns of Initial Errors Related to the “Winter Predictability Barrier” of the Indian Ocean Dipole 被引量:5
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作者 FENG Rong DUAN Wan-Suo 《Atmospheric and Oceanic Science Letters》 CSCD 2014年第5期406-410,共5页
In this study, using the Geophysical Fluid Dynamics Laboratory Climate Model version 2pl (GFDL CM2pl) coupled model, the winter predictability barrier (WPB) is found to exist in the model not only in the growing p... In this study, using the Geophysical Fluid Dynamics Laboratory Climate Model version 2pl (GFDL CM2pl) coupled model, the winter predictability barrier (WPB) is found to exist in the model not only in the growing phase but also the Indian Ocean dipole (IOD) decaying phase of positive events due to the effect of initial errors. In particular, the WPB is stronger in the growing phase than in the decaying phase. These results indicate that initial errors can cause the WPB. The domi- nant patterns of the initial errors that cause the occurrence of the WPB often present an eastern-western dipole both in the surface and subsurface temperature components. These initial errors tend to concentrate in a few areas, and these areas may represent the sensitive areas of the predictions of positive IOD events. By increasing observations over these areas and eliminating initial errors here, the WPB phenomenon may be largely weakened and the forecast skill greatly improved. 展开更多
关键词 Indian Ocean dipole winter predictabilitybarrier initial errors sensitive areas
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What Moved into the Lung?An Unusual Case of Foreign Body Migration
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作者 Yan-ting Wang Xiao-dong Yang +1 位作者 Shao-hua Liu Yan-hua Huang 《Chinese Medical Sciences Journal》 CAS CSCD 2013年第4期248-249,共2页
FOREIGN body migration into the lung is a rare complication that can cause various symptoms. In adults, however, foreign body deposited in the luna can be tolerated and remain undetected fora long time. Delayed diagno... FOREIGN body migration into the lung is a rare complication that can cause various symptoms. In adults, however, foreign body deposited in the luna can be tolerated and remain undetected fora long time. Delayed diagnosis and subsequent delayed treatment is usually associated with atypical complications. In this article, we describe a case of foreign body migration into the tracheobronchial tree. After a long time delay diagnosis, the foreign body was ultimately removed by operation. 展开更多
关键词 tracheobronchial foreign body MIGRATION
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Validation and intercomparison of HY-2A/MetOp-A/Oceansat-2 scatterometer wind products 被引量:5
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作者 吴庆 陈戈 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2015年第5期1181-1190,共10页
Sea surface winds are of great significance in scientific research. In the last few years,three series of scatterometers were launched to measure these winds,including the Advanced Scatterometer(ASCAT) aboard Meteorol... Sea surface winds are of great significance in scientific research. In the last few years,three series of scatterometers were launched to measure these winds,including the Advanced Scatterometer(ASCAT) aboard Meteorological Operational Satellite A(Met Op-A) and Met Op-B,Oceansat-2 Scatterometer(OSCAT),and HY-2A Scatterometer(HY-2A SCAT). Based on buoy wind data,validation and intercomparison of these scatterometers were performed. Scatterometer-derived wind and buoy wind data were collected only if the spatial difference was less than 0.1 degree and temporal difference less than 5 min. After discarding wind direction data outside five times the standard deviation,ASCAT wind products showed high accuracy in both wind speed and direction,with root-mean-square error(RMSE) 0.86 m/s and 17.97 degrees,respectively. HY-2A SCAT nearly meets the mission requirement,with RMSE for wind speed 1.23 m/s and 22.85 degrees for wind direction. OSCAT had poor performance when compared with the others. RMSE for wind speed was 1.54 m/s and 39.86 degrees for wind direction,which greatly exceeds the mission requirement of 20 degrees. In addition,the RMSE for wind direction shows a high-low pattern on buoy wind speed. However,a wind speed range from 14 to 15 m/s was found to be abnormal,and the reason remains unclear. There was no systematic dependency of both wind speed and direction residuals on buoy wind speed and cross-track location of the wind vector cells across the entire range. No seasonal variation was found for any scatterometer. 展开更多
关键词 SCATTEROMETER WIND VALIDATION intercomparison
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Extreme air pollution events:Modeling and prediction
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作者 周松梅 邓启红 刘蔚巍 《Journal of Central South University》 SCIE EI CAS 2012年第6期1668-1672,共5页
In order to get prepared for the coming extreme pollution events and minimize their harmful impacts, the first and most important step is to predict their possible intensity in the future. Firstly, the generalized Par... In order to get prepared for the coming extreme pollution events and minimize their harmful impacts, the first and most important step is to predict their possible intensity in the future. Firstly, the generalized Pareto distribution (GPD) in extreme value theory was used to fit the extreme pollution concentrations of three main pollutants: PM10, NO2 and SO:, from 2005 to 2010 in Changsha, China. Secondly, the prediction results were compared with actual data by a scatter plot. Four statistical indicators: EMA (mean absolute error), ERMS (root mean square error), IA (index of agreement) and R2 (coefficient of determination) were used to evaluate the goodness-of-fit as well. Thirdly, the return levels corresponding to different return periods were calculated by the fitted distributions. The fitting results show that the distribution of PM10 and SO2 belongs to exponential distribution with a short tail while that of the NOe belongs to beta distribution with a bounded tail. The scatter plot and four statistical indicators suggest that GPD agrees well with the actual data. Therefore, the fitted distribution is reliable to predict the return levels corresponding to different return periods. The predicted return levels suggest that the intensity of coming pollution events for PM10 and SO2 will be even worse in the future, which means people have to get enough preparation for them. 展开更多
关键词 extreme pollution event generalized Pareto distribution return level return period
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The Effect of Error Growth and Propagation on the Predictability of Quantitative Precipitation in a Cloud-Resolving Model 被引量:1
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作者 XU Jian-Yu ZHONG Qing 《Atmospheric and Oceanic Science Letters》 2009年第2期79-84,共6页
Limitations in the predictability of quantitative precipitation forecasting (QPF) that arise from initial errors of small amplitude and scale are investigated by means of real-case high-resolution (cloud-resolving) nu... Limitations in the predictability of quantitative precipitation forecasting (QPF) that arise from initial errors of small amplitude and scale are investigated by means of real-case high-resolution (cloud-resolving) numerical weather prediction (NWP) integrations. The case considered is the hail and wind disaster that occurred in Sichuan on 8 April 2005. A total of three distinct perturbation methods are used. The results suggest that a tiny initial error in the temperature field can amplify and influence the weather in a large domain, changing the 12-h forecasted rainfall by as much as one-third of the original magnitude. Furthermore, the comparison of the perturbation methods indicates that all of the methods pinpoint the same region (the heavy rainfall areas in the control experiment) as suffering from limitations in predictability. This result reveals the important role of nonlinearity in severe convective events. 展开更多
关键词 ERROR quantitative precipitation PREDICTABILITY
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