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Quantitative Estimation of the Changes in Soil CEC after the Removal of Organic Matter and Iron Oxides 被引量:1
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作者 Xiangzheng Kong Decheng Li +1 位作者 Xiaodong Song Ganlin Zhang 《Agricultural Sciences》 2021年第11期1244-1254,共11页
The removal of organic matter and iron oxides could increase and decrease soil CEC in tropical and subtropical regions, but the quantitative information is insufficient so far about the change of soil CEC, the influen... The removal of organic matter and iron oxides could increase and decrease soil CEC in tropical and subtropical regions, but the quantitative information is insufficient so far about the change of soil CEC, the influence factors and their contribution. In this study, the subhorizon soils of 24 soil series in the tropical and subtropical China were used, pH, particle size composition, organic matter, iron oxides of these samples were measured, and also CECs were measured and compared for the original soils and after the removal of organic matter and iron oxides. The results showed that, compared with CEC of the original soil, the eliminating organic matter increased soil CEC significantly by 2.28% - 56.50% with a mean of 24.02%, but the further obliterating iron oxides decreased soil CEC significantly by 0.75% - 20.30% with a mean of 7.73%. CEC after the removal of organic matter and iron oxides had positive correlation with iron oxides (p < 0.01) and negative correlation with sand content (p < 0.01 and p < 0.05). CEC after organic matter eliminated was mainly decided by iron oxides (51.68%), followed by silt content (22.19%);while CEC after iron oxides obliterated was mainly determined by iron oxides (50.55%). The increase of CEC after organic matter eliminated was co-affected by the contents of clays, slits, iron oxides and pH (22.00% - 27.34%), while the decrease of CEC after iron oxides obliterated further was dominated by the content of organic matter (66.92%). More other soil parameters should be considered for higher predicting accuracy in the regression model of soil CEC after the removal of organic matter and iron oxides, and the recommended optimal models obtained in this study were as follows: for soil CEC after organic matter eliminated, CEC = 1.665 <span style="white-space:nowrap;">&#8722;</span> 0.546pH <span style="white-space:nowrap;">&#8722;</span> 0.024OM + 0.053Fe<sub>x</sub>O<sub>y</sub> <span style="white-space:nowrap;">&#8722;</span> 0.001Silt + 0.007Clay + 0.972CEC<sub>original</sub> (R<sup>2</sup> was 0.923, RSME was 1.55 cmol(+)<span style="white-space:nowrap;"><span style="white-space:nowrap;">&#8729;</span></span>kg<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">&#8722;</span></span>1</sup>, p < 0.01), while for soil CEC after iron oxides further obliterated, CEC = 1.665 <span style="white-space:nowrap;">&#8722;</span> 0.546pH <span style="white-space:nowrap;">&#8722;</span> 0.024OM + 0.053Fe<sub>x</sub>O<sub>y</sub> <span style="white-space:nowrap;">&#8722;</span> 0.001Silt + 0.007Clay + 0.972CEC<sub>original</sub> (R<sup>2</sup> was 0.923, RMSE was 1.55 cmol(+)<span style="white-space:nowrap;"><span style="white-space:nowrap;">&#8729;</span></span>kg<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">&#8722;</span></span>1</sup>, p < 0.01). Further research is needed in the future as for exploring internal functional mechanism in view of soil electrochemistry and mineralogy. 展开更多
关键词 Soil CEC quantitative estimation REMOVAL Organic Matter Iron Oxides
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Quantitative Estimation of Air Mass Exchange by Along-Valley Wind in the Rongbuk Valley 被引量:1
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作者 Zhou Li-Bo Zou Han +3 位作者 Ma Shu-Po Zhu Jin-Huan Li Peng Huo Cui-Ping 《Atmospheric and Oceanic Science Letters》 2009年第1期29-34,共6页
For a better understanding of the air mass exchange processes between the surface and free atmos-phere in the Himalayas,a Himalayan exchange between the surface and troposphere 2007 (HEST2007) campaign was carried out... For a better understanding of the air mass exchange processes between the surface and free atmos-phere in the Himalayas,a Himalayan exchange between the surface and troposphere 2007 (HEST2007) campaign was carried out in the Rongbuk Valley,on the northern slope of Mt.Qomolangma,in June 2007.The wind,tem-perature and radiation conditions were measured during the campaign.Using these observation data,together with the National Centers for Environmental Prediction/the National Center for Atmospheric Research (NCEP/NCAR) reanalysis data,the air mass exchange between the inside of the valley and the outside of the valley is quantitatively estimated,based on a closed-valley method.The air mass is strongly injected into the Rongbuk Valley in the after-noon,which dominates the diurnal cycle,by a strong downward along-valley wind,with a maximum down-ward transfer rate of 9.4 cm s?1.The total air volume flux injected into the valley was 2.6×1011 m3 d?1 in 24 hours in June 2007,which is 15 times the total volume of the val-ley.The air mass transfer into the valley also exhibited a clear daily variation during the HEST2007 campaign,which can be affected by the synoptic situations through the adjustment of local radiation conditions. 展开更多
关键词 air mass exchange quantitative estimation along-valley wind the Himalayas
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Quantitative Estimation of Groundwater Leakage from Namco Lake by SAR Monitoring
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作者 CHEN Jiaqi DENG Yunkai +3 位作者 LI Ning WANG Yu LIU Zhongling ZHANG Shilin 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第4期1555-1556,共2页
Objective This study focused on the Namco, the largest lake on the Tibet plateau as well as the highest large lake in the world. A large imbalance between water input and output of this lake has attracted great atten... Objective This study focused on the Namco, the largest lake on the Tibet plateau as well as the highest large lake in the world. A large imbalance between water input and output of this lake has attracted great attention in the field of hydrogeology during recent years. As there is no surface outflow from Namco, the large water imbalance can only be explained by water seepage. Synthetic aperture radar (SAR) image data were used for the first time in combination with hydrological data actually measured in the field and meteorological station data, to quantitatively acquire the information of surface fluctuation, water storage variation, and to estimate groundwater leakage from Namco Lake. The results provide theoretical support and data for further understanding the processes and extent of water resource response to global climate change, and also provide a scientific basis for rational development and utilization of water resource in the Tibetan Plateau. 展开更多
关键词 LAKE quantitative estimation of Groundwater Leakage from Namco Lake by SAR Monitoring SAR
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Quantitative estimation presort of glacier lake outburst debris flow based on bucket effect
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作者 ZHANG Li YANG Zhaohua LI Guogang 《Global Geology》 2012年第1期48-52,共5页
Glacier-lake outburst debris flow(GLODF),unique in high altitude mountains where modern glacier is active,is significantly large in its scale of time and space,and strong in power of destroy.Following the world's ... Glacier-lake outburst debris flow(GLODF),unique in high altitude mountains where modern glacier is active,is significantly large in its scale of time and space,and strong in power of destroy.Following the world's becoming warmer,GLODF frequency gradually rises.In late years,quantitative estimation methodologies has been put into use of mass GLODF estimations.To improve former methodologies,this article suggests that the glacier(or the massif)on the trailing edge and the moraine dam are the two major systems providing independent glacier lake outburst possibilities.Bucket Effect exists in GLODF issues.Therefore focusing on the relatively unstable one of the above two provides better accuracy in estimation on GLODF possibility.Thus,this article summarizes method of presort through specific GLODF evaluation. 展开更多
关键词 GLODF quantitative estimation outburst modes catastrophe mechanism bucket effect
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Study on Quantitative Precipitation Estimation by Polarimetric Radar Using Deep Learning
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作者 Jiang HUANGFU Zhiqun HU +2 位作者 Jiafeng ZHENG Lirong WANG Yongjie ZHU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第6期1147-1160,共14页
Accurate radar quantitative precipitation estimation(QPE)plays an essential role in disaster prevention and mitigation.In this paper,two deep learning-based QPE networks including a single-parameter network and a mult... Accurate radar quantitative precipitation estimation(QPE)plays an essential role in disaster prevention and mitigation.In this paper,two deep learning-based QPE networks including a single-parameter network and a multi-parameter network are designed.Meanwhile,a self-defined loss function(SLF)is proposed during modeling.The dataset includes Shijiazhuang S-band dual polarimetric radar(CINRAD/SAD)data and rain gauge data within the radar’s 100-km detection range during the flood season of 2021 in North China.Considering that the specific propagation phase shift(KDP)has a roughly linear relationship with the precipitation intensity,KDP is set to 0.5°km^(-1 )as a threshold value to divide all the rain data(AR)into a heavy rain(HR)and light rain(LR)dataset.Subsequently,12 deep learning-based QPE models are trained according to the input radar parameters,the precipitation datasets,and whether an SLF was adopted,respectively.The results suggest that the effects of QPE after distinguishing rainfall intensity are better than those without distinguishing,and the effects of using SLF are better than those that used MSE as a loss function.A Z-R relationship and a ZH-KDP-R synthesis method are compared with deep learning-based QPE.The mean relative errors(MRE)of AR models using SLF are improved by 61.90%,51.21%,and 56.34%compared with the Z-R relational method,and by 38.63%,42.55%,and 47.49%compared with the synthesis method.Finally,the models are further evaluated in three precipitation processes,which manifest that the deep learning-based models have significant advantages over the traditional empirical formula methods. 展开更多
关键词 polarimetric radar quantitative precipitation estimation deep learning single-parameter network multi-parameter network
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Quantitative Precipitation Estimation Using X-band Phased Array Weather Radar
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作者 Shaoyu HOU Xuejiao CHEN +1 位作者 Chunnan SUO Xiangfeng HU 《Meteorological and Environmental Research》 2024年第4期29-31,共3页
This study utilized data from an X-band phased array weather radar and ground-based rain gauge observations to conduct a quantitative precipitation estimation(QPE)analysis of a heavy rainfall event in Xiong an New Are... This study utilized data from an X-band phased array weather radar and ground-based rain gauge observations to conduct a quantitative precipitation estimation(QPE)analysis of a heavy rainfall event in Xiong an New Area from 20:00 on August 21 to 07:00 on August 22,2022.The analysis applied the Z-R relationship method for radar-based precipitation estimation and evaluated the QPE algorithm s performance using scatter density plots and binary classification scores.The results indicated that the QPE algorithm accurately estimates light to moderate rainfall but significantly underestimates heavy rainfall.The study identified disparities in the predictive accuracy of the QPE algorithm across various precipitation intensity ranges,offering essential insights for the further refinement of QPE techniques. 展开更多
关键词 X-band phased array radar quantitative precipitation estimation
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Radar Quantitative Precipitation Estimation Based on the Gated Recurrent Unit Neural Network and Echo-Top Data 被引量:2
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作者 Haibo ZOU Shanshan WU Miaoxia TIAN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2023年第6期1043-1057,共15页
The Gated Recurrent Unit(GRU) neural network has great potential in estimating and predicting a variable. In addition to radar reflectivity(Z), radar echo-top height(ET) is also a good indicator of rainfall rate(R). I... The Gated Recurrent Unit(GRU) neural network has great potential in estimating and predicting a variable. In addition to radar reflectivity(Z), radar echo-top height(ET) is also a good indicator of rainfall rate(R). In this study, we propose a new method, GRU_Z-ET, by introducing Z and ET as two independent variables into the GRU neural network to conduct the quantitative single-polarization radar precipitation estimation. The performance of GRU_Z-ET is compared with that of the other three methods in three heavy rainfall cases in China during 2018, namely, the traditional Z-R relationship(Z=300R1.4), the optimal Z-R relationship(Z=79R1.68) and the GRU neural network with only Z as the independent input variable(GRU_Z). The results indicate that the GRU_Z-ET performs the best, while the traditional Z-R relationship performs the worst. The performances of the rest two methods are similar.To further evaluate the performance of the GRU_Z-ET, 200 rainfall events with 21882 total samples during May–July of 2018 are used for statistical analysis. Results demonstrate that the spatial correlation coefficients, threat scores and probability of detection between the observed and estimated precipitation are the largest for the GRU_Z-ET and the smallest for the traditional Z-R relationship, and the root mean square error is just the opposite. In addition, these statistics of GRU_Z are similar to those of optimal Z-R relationship. Thus, it can be concluded that the performance of the GRU_ZET is the best in the four methods for the quantitative precipitation estimation. 展开更多
关键词 quantitative precipitation estimation Gated Recurrent Unit neural network Z-R relationship echo-top height
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Application of X-band Polarimetric Phased-array Radars in Quantitative Precipitation Estimation 被引量:1
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作者 张羽 刘显通 +3 位作者 陈炳洪 冯嘉宝 曾琳 田聪聪 《Journal of Tropical Meteorology》 SCIE 2023年第1期142-152,共11页
The performance of different quantitative precipitation estimation(QPE) relationships is examined using the polarimetric variables from the X-band polarimetric phased-array radars in Guangzhou,China.Three QPE approach... The performance of different quantitative precipitation estimation(QPE) relationships is examined using the polarimetric variables from the X-band polarimetric phased-array radars in Guangzhou,China.Three QPE approaches,namely,R(ZH),R(ZH,ZDR) and R(KDP),are developed for horizontal reflectivity,differential reflectivity and specific phase shift rate,respectively.The estimation parameters are determined by fitting the relationships to the observed radar variables using the T-matrix method.The QPE relationships were examined using the data of four heavy precipitation events in southern China.The examination shows that the R(ZH) approach performs better for the precipitation rate less than 5 mm h-1, and R(KDP) is better for the rate higher than 5 mm h-1, while R(ZH,ZDR) has the worst performance.An adaptive approach is developed by taking the advantages of both R(ZH) and R(KDP) approaches to improve the QPE accuracy. 展开更多
关键词 X-band polarimetric phased-array radar raindrop spectrum quantitative precipitation estimation
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Quantitative Estimation of Experts’Judgments on Petroleum Exploration
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作者 Zhang Zaixu University of Petroleum, Dongying, Shandong 257062, P. R. China 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1997年第4期61-66,共6页
A new method in making judgment matrix is proposed based on a basic value of “importance” and a relative measure level of “importance”. Factors affecting petroleum exploration are analyzed and Experts’ judgment m... A new method in making judgment matrix is proposed based on a basic value of “importance” and a relative measure level of “importance”. Factors affecting petroleum exploration are analyzed and Experts’ judgment matrix on a geologic formation is given. Expected value of each factor is computed and the volume of recoverable oil is estimated. 展开更多
关键词 Judgment matrix Analytic hierarchy process Petroleum exploration quantitative estimation Expected value.
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An analytical method for quantitative estimation of the cytotoxicity of dental alloys using MTT assay,ICP analysis and effective cytotoxicity calculation
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作者 Lü Xiao Ying and H.F.Kappert 《Chinese Medical Journal》 SCIE CAS CSCD 1997年第12期47-47,共1页
The two most important criteria for dental materials are their biofunctional and biocompatible endurance within the anticipated life-span of the dental restoration in the mouth. Biocompatibility relates mainly to the ... The two most important criteria for dental materials are their biofunctional and biocompatible endurance within the anticipated life-span of the dental restoration in the mouth. Biocompatibility relates mainly to the allergenicity and the toxicity of the material. To test the non-specific toxicity of dental materials, in vitro cell culture assays have been developed. For in vitro screening, such tests are recommended to check the cytotoxicity of dental materials (ISO 10993 5). Various studies have already been performed to quantitatively determine the cytotoxicity level of dental alloys. However, as long as only dental alloys and the cell culture technique are applied, it is not possible to determine which of the alloying elements cause the cytotoxicity. Therefore, an analytical method is needed. Wataha et al determined in 1991 the TC50 values of 9 metal cations of various dental casting alloys, using cell culture methods. Kapert et al reported in 1994 a complex in vitro test concept, where the ICP analysis (inductively coupled plasma emission spectroscopy) was introduced to measure the trace elements extracted from various alloys. Experimentelle Zahnheilkunde, Universitts ZMK Klinik Freiburg, Germany (Lü XY and Kappert HF) The aim of the present study was to find a relation between the ICP results, the TC50 value of metal cations, and the cytotoxicity of dental alloys. The cytotoxicity levels of various dental alloys and the TC50 values of 10 metal cations were established using the MTT assay, an effective cell culture of method. Then, the concentrations of the corrosively soluted metal cations in the extracts of the alloys were measured using the ICP method. From all these experimental results it was found that the relation between the effective cytotoxicity Z eff of an alloy, the concentrations C i of i th trace element and the TC50 values T Ci of the i th metal cation can approximately be expressed by Z eff =∑iC i2·T Ci . Two significant applications of this expression are a) The cytotoxicity of an alloy can be estimated by ICP analysis of the extract if the TC50 values of the trace elements are know. b) The cytotoxicity of a new-developed-alloy can be estimated in advance, according to the alloying components. 展开更多
关键词 MTT ICP An analytical method for quantitative estimation of the cytotoxicity of dental alloys using MTT assay ICP analysis and effective cytotoxicity calculation
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Operational Evaluation of the Quantitative Precipitation Estimation by a CINRAD-SA Dual Polarization Radar System 被引量:6
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作者 CHEN Chao LIU Li-ping +3 位作者 HU Sheng WU Zhi-fang WU Chong ZHANG Yang 《Journal of Tropical Meteorology》 SCIE 2020年第2期176-187,共12页
In this paper,a quantitative precipitation estimation based on the hydrometeor classification(HCA-QPE)algorithm was proposed for the first operational S band dual-polarization radar upgraded from the CINRAD/SA radar o... In this paper,a quantitative precipitation estimation based on the hydrometeor classification(HCA-QPE)algorithm was proposed for the first operational S band dual-polarization radar upgraded from the CINRAD/SA radar of China.The HCA-QPE algorithm,localized Colorado State University-Hydrometeor Identification of Rainfall(CSUHIDRO)algorithm,the Joint Polarization Experiment(JPOLE)algorithm,and the dynamic Z-R relationships based on variational correction QPE(DRVC-QPE)algorithm were evaluated with the rainfall events from March 1 to October 30,2017 in Guangdong Province.The results indicated that even though the HCA-QPE algorithm did not use the observed rainfall data for correction,its estimation accuracy was better than that of the DRVC-QPE algorithm when the rainfall rate was greater than 5 mm h-1;and the stronger the rainfall intensity,the greater the QPE improvement.Besides,the HCA-QPE algorithm worked better than the localized CSU-HIDRO and JPOLE algorithms.This study preliminarily evaluated the improved accuracy of QPE by a dual-polarization radar system modified from CINRAD-SA radar. 展开更多
关键词 quantitative precipitation estimation operational QPE evaluation with dual-polarization radar optimization algorithm dual-polarization radar hydrometeor classification dynamic Z-R relations algorithm
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A STUDY ON VARIABLE QUANTITATIVE PRECIPITATION ESTIMATION USING DOPPLER RADAR DATA
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作者 冀春晓 陈联寿 +2 位作者 徐祥德 赵放 吴孟春 《Journal of Tropical Meteorology》 SCIE 2008年第2期109-112,共4页
With the pros and cons of the traditional optimization and probability pairing methods thoroughly considered, an improved optimal pairing window probability technique is developed using a dynamic relationship between ... With the pros and cons of the traditional optimization and probability pairing methods thoroughly considered, an improved optimal pairing window probability technique is developed using a dynamic relationship between the base reflectivity Z observed by radar and real time precipitation I by rain gauge. Then, the Doppler radar observations of base reflectivity for typhoons Haitang and Matsa in Wenzhou are employed to establish various Z-I relationships, which are subsequently used to estimate hourly precipitation of the two typhoons. Such estimations are calibrated by variational techniques. The results show that there exist significant differences in the Z-I relationships for the typhoons, leading to different typhoon precipitation efficiencies. The typhoon precipitation estimated by applying radar base reflectivity is capable of exhibiting clearly the spiral rain belts and mesoscale cells, and well matches the observed rainfall. Error statistical analyses indicate that the estimated typhoon precipitation is better with variational calibration than the one without. The variational calibration technique is able to maintain the characteristics of the distribution of radar-estimated typhoon precipitation, and to significantly reduce the error of the estimated precipitation in comparison with the observed rainfall. 展开更多
关键词 TYPHOON radar quantitative precipitation estimation variational calibration verification
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The First Quantitative Slip-Rate Estimated Along the Ashikule Fault at the Western Segment of the Altyn Tagh Fault System 被引量:5
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作者 PAN Jiawei LI Haibing +5 位作者 VAN DER WOERD Jerome SUN Zhiming SI Jialiang PEI Junling WU Fuyao CHEVALIER Marie-Luce 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2015年第6期2088-2089,共2页
As one of the longest strike-slip fault in Asia,the Altyn Tagh Fault(ATF)defines the northern boundary of the Tibetan Plateau and plays a significant role inaccommodating the deformation resulting from the IndiaAsia... As one of the longest strike-slip fault in Asia,the Altyn Tagh Fault(ATF)defines the northern boundary of the Tibetan Plateau and plays a significant role inaccommodating the deformation resulting from the IndiaAsia convergence. 展开更多
关键词 Asia Co The First quantitative Slip-Rate Estimated Along the Ashikule Fault at the Western Segment of the Altyn Tagh Fault System ATF rate
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Application of the Attenuation Correction Technology in C-band Radar Precipitation Estimation
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作者 WANG Nan 《Meteorological and Environmental Research》 2012年第1期51-54,共4页
[ Objective] The research aimed to study application of the attenuation correction technology in C-band radar precipitation estimation. [ Method~ Based on CINRAD-CB radar data in Shaanxi, we conducted the attenuation ... [ Objective] The research aimed to study application of the attenuation correction technology in C-band radar precipitation estimation. [ Method~ Based on CINRAD-CB radar data in Shaanxi, we conducted the attenuation correction experiment by using iteration method and Kufa method respectively. Moreover, we conducted application expedment of the Kufa attenuation correction method in the quantitative precipitation esti- mation. [ Result~ Attenuation correction technology could compensate for attenuation problem of the echo at the distant range. Calculation result of the iteration method finally tended to that of the Kufa method. Moreover, iteration method spent more time. Therefore, Kufa attenuation correction technology was more suitable for business operation. When strong echo was near radar, generated attenuation was more obvious, and application value of the attenuation correction was bigger. Attenuation correction technology was used for quantitative precipitation estimation, which was favor- able for improving accuracy of the precipitation estimation. But we should conduct detailed planning on calculation scheme of the precipitation esti- mation because that different calculation schemes had great influences on accuracy of the quantitative precipitation estimation. [ Cendusien] This research provided a basis for improving accuracy of the quantitative precipitation estimation in Shaanxi. Key words Attenuation correction 展开更多
关键词 Attenuation correction K-ufa methyl Iteration method i quantitative precipitation estimation China
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Quantitative Green's function estimates for lattice quasi-periodic Schrodinger operators
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作者 Hongyi Cao Yunfeng Shi Zhifei Zhang 《Science China Mathematics》 SCIE CSCD 2024年第5期1011-1058,共48页
In this paper,we establish quantitative Green’s function estimates for some higher-dimensional lattice quasi-periodic(QP)Schrodinger operators.The resonances in the estimates can be described via a pair of symmetric ... In this paper,we establish quantitative Green’s function estimates for some higher-dimensional lattice quasi-periodic(QP)Schrodinger operators.The resonances in the estimates can be described via a pair of symmetric zeros of certain functions,and the estimates apply to the sub-exponential-type non-resonance conditions.As the application of quantitative Green’s function estimates,we prove both the arithmetic version of Anderson localization and the finite volume version of(1/2-)-Holder continuity of the integrated density of states(IDS)for such QP Schrodinger operators.This gives an affirmative answer to Bourgain’s problem in Bourgain(2000). 展开更多
关键词 Holder continuity of the IDS quantitative Green's function estimates quasi-periodic Schrodinger operators arithmetic Anderson localization multi-scale analysis
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Relative Peak Frequency Increment Method for Quantitative Thin-Layer Thickness Estimation
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作者 孙鲁平 郑晓东 首皓 《Journal of Earth Science》 SCIE CAS CSCD 2013年第6期1068-1078,共11页
Quantitative thickness estimation of thin-layer is a great challenge in seismic exploration, especially for thin-layer below tuning thickness. In this article, we analyzed the seismic response cha- racteristics of rhy... Quantitative thickness estimation of thin-layer is a great challenge in seismic exploration, especially for thin-layer below tuning thickness. In this article, we analyzed the seismic response cha- racteristics of rhythm and gradual type of thin-layer wedge models and presented a new method for thin-layer thickness estimation which uses relative peak frequency increment. This method can de- scribe the peak frequency to thickness relationship of rhythm and gradual thin-layers in unified equa- tion while the traditional methods using amplitude information cannot. What's more, it won't be in- fluenced by the absolute value of thin-layer reflection coefficient and peak frequency of wavelet. The unified equations were presented which can be used for rhythm and gradual thin-layer thickness cal- culation. Model tests showed that the method we introduced has a high precision and it doesn't need to determine the value of top or bottom reflection coefficient, so it has a more wide application in practice. The application of real data demonstrated that the relative peak frequency increment attribute can character the plane distribution feature and thickness characteristic of channel sand bodies very well. 展开更多
关键词 THIN-LAYER quantitative estimation relative peak frequency increment Ricker wavelet.
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Regional Study on Economical Supporting Capacity of Land Resources in Shandong Province
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作者 Li Yujiang Chen Pei'an 《Chinese Journal of Population,Resources and Environment》 北大核心 2007年第1期68-73,共6页
Taking the land resources of 17 cities in Shandong Province as the basic data, the article studied on the economical supporting capacity of land resources in terms of the effect of land on economy. The author classifi... Taking the land resources of 17 cities in Shandong Province as the basic data, the article studied on the economical supporting capacity of land resources in terms of the effect of land on economy. The author classified 17 cities of Shandong Province into four types according to the economical supporting capacity of land resources by quantitatively estimating the evaluation indices of the total amount of land resources, the potential of urban and other nonagricultural land, and the integrated economical sup- porting capacity of land resources, etc. The author proposes the questions requiring further study at the end of this article. 展开更多
关键词 land resources economical supporting capacity quantitative estimation Shandong Province
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Mathematical Modeling of Landfill Gas (MSW)—Production of Gas with Methane Gas Content from Landfills (MSW)
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作者 Danila Vieru 《Journal of Geoscience and Environment Protection》 2020年第12期36-62,共27页
The municipal solid waste (msw) is a source of landfill gas (msw)—with methane gas content. Preoccupations for landfill gas (msw) management date back since 1976 when, at a landfill (msw) in California (USA), it turn... The municipal solid waste (msw) is a source of landfill gas (msw)—with methane gas content. Preoccupations for landfill gas (msw) management date back since 1976 when, at a landfill (msw) in California (USA), it turned out practically that the landfill gas (msw) with methane gas content contains a gas with high caloric value that can be collected and used for economic purposes. The landfill gas (msw) contains methane gas (30% - 60% volume), carbon dioxide (45% - 50% volume), hydrogen sulfide and other gases. Methane gas, carbon dioxide, nitrous oxide and other gases are listed in Kyoto Protocol as high greenhouse gases. Their ecological-rational management is both a national and global preoccupation. In terms of greenhouse gases, especially methane gas, the landfill (msw) is held responsible for 3.5% - 5% of the total global greenhouse gases. Practically, the quantitative estimation of the methane gas in a municipal solid waste landfill can be done by measuring the landfill gas (msw) flow in an extraction-collection well. In Romania, a quantitative estimation relationship of methane gas from deposits (msw) was made, approaching the problem in a different way. This paper presents the calculation formula, the working algorithm, the municipal waste landfill equation and the NOMOGRAMA of a municipal solid waste landfill (msw). The NOMOGRAMA allows us to define the values for parameter -m- (number of months needed for an amount of municipal solid waste (msw) to degrade, starting with the year from which the landfill gas (msw) emission with methane gas content is calculated). Taking into account the environmental conditions for each location of municipal solid waste landfill, the calculation uses various indexes and approximations, while the fundamental parameter remains -m- defined by the NOMOGRAMA of the municipal solid waste landfill (msw). A municipal solid waste landfill (msw) is a conglomerate of waste with various biodegradation periods between 2 - 3 years and 5 - 10 - 30 years. Degradation of waste (msw) in to dissolved organic carbon will take place in a number of months defined -m- starting with the year from which the methane gas emission with the NOMOGRAMA of the municipal solid waste landfill (msw) is calculated. The -m- values for the year of the quantitative emission of methane gas can be also done analytically, which requires good experience in the ecologic-rational management of the municipal solid waste (msw). 展开更多
关键词 Municipal Solid Waste (MSW) NOMOGRAMA Calculation Formula Parameter -m- quantitative estimation of Methane Gas
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A Strategy for Merging Objective Estimates of Global Daily Precipitation from Gauge Observations, Satellite Estimates, and Numerical Predictions 被引量:3
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作者 Suping NIE Tongwen WU +5 位作者 Yong LUO Xueliang DENG Xueli SHI Zaizhi WANG Xiangwen LIU Jianbin HUANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2016年第7期889-904,共16页
This paper describes a strategy for merging daily precipitation information from gauge observations, satellite estimates (SEs), and numerical predictions at the global scale. The strategy is designed to remove syste... This paper describes a strategy for merging daily precipitation information from gauge observations, satellite estimates (SEs), and numerical predictions at the global scale. The strategy is designed to remove systemic bias and random error from each individual daily precipitation source to produce a better gridded global daily precipitation product through three steps. First, a cumulative distribution function matching procedure is performed to remove systemic bias over gauge-located land areas. Then, the overall biases in SEs and model predictions (MPs) over ocean areas are corrected using a rescaled strategy based on monthly precipitation. Third, an optimal interpolation (OI)-based merging scheme (referred as the HL-OI scheme) is used to combine unbiased gahge observations, SEs, and MPs to reduce random error from each source and to produce a gauge--satellite-model merged daily precipitation analysis, called BMEP-d (Beijing Climate Center Merged Estimation of Precipitation with daily resolution), with complete global coverage. The BMEP-d data from a four-year period (2011- 14) demonstrate the ability of the merging strategy to provide global daily precipitation of substantially improved quality. Benefiting from the advantages of the HL-OI scheme for quantitative error estimates, the better source data can obtain more weights during the merging processes. The BMEP-d data exhibit higher consistency with satellite and gauge source data at middle and low latitudes, and with model source data at high latitudes. Overall, independent validations against GPCP-1DD (GPCP one-degree daily) show that the consistencies between B MEP-d and GPCP-1DD are higher than those of each source dataset in terms of spatial pattern, temporal variability, probability distribution, and statistical precipitation events. 展开更多
关键词 global daily precipitation multi-source merging strategy bias correction quantitative error estimation
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NUMERICAL STUDY OF THE INFLUENCE OF WAVES AND TIDE-SURGE INTERACTION ON TIDE-SURGES IN THE BOHAI SEA 被引量:3
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作者 尹宝树 侯一筠 +4 位作者 程明华 苏京志 林明祥 李明悝 M.I.El-Sabh 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2001年第2期97-102,共6页
The author’s combined numerical model consisting of a third generation shallow water wave model and a 3 D tide surge model with wave dependent surface wind stress were used to study the influence of waves on tide sur... The author’s combined numerical model consisting of a third generation shallow water wave model and a 3 D tide surge model with wave dependent surface wind stress were used to study the influence of waves on tide surge motion. For the typical weather case, in this study, the magnitude and mechanism of the influence of waves on tide surges in the Bohai Sea were revealed for the first time. The results showed that although consideration of the wave dependent surface wind stresses raise slightly the traditional surface wind stress, due to the accumulated effects, the computed results are improved on the whole. Storm level maximum modulation can reach 0.4 m. The results computed by the combined model agreed well with the measured data. 展开更多
关键词 combined wave and tide surges numerical model influence mechanisms quantitative estimate
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