A NEW RECEPTOR MODEL:A DIRECT TRILINEAR DECOMPOSITION FOLLOWED BY A MATRIX RECONSTRUCTION     

PHILIP K.HOPKE 《地理学报(英文版)》1992,(2)

In many cases,monitoring data for ambient airborne particles can be organized in the form of a three-way data table with one way for chemical species,one for sampling periods and one for sites.A directtrilinear decomposition followed by a matrix reconstruction(DTDMR)is developed to analyze such adata table as a whole.The three-way data set is composed into three two-way matrices by a direct trilineardecomposition(DTD).The column vectors of each of the matrices are called‘source profiles’,‘emissionpatterns’and‘site coefficients’respectively.Particulate sources are identified by examining both theirsource profiles and emission patterns.After the sources have been identified,emission patterns and sitecoefficients are used to produce a three-way matrix that gives estimates of mass contributions of sourcesto the samples collected at every site in every period.By simulation study,not only has the method beenverified,but a good indicator has been found that shows the number of factors(i.e.sources)in thesystem.Unlike other receptor models,DTDMR does not require source profile data and does not involvetrial-and-error procedures.Since DTDMR identifies sources based on variations in two dimensions,it hasa higher potential to distinguish two sources that have similar chemical compositions.The DTDMRmodel has provided excellent results with simulated data and has been applied in a real world three-waydata set.  相似文献   

Mapping runoff generating areas using AGNPS-VSA model     

Kishor Panjabi  Pradeep Goel  Prasad Daggupati  Narayan Kumar Shrestha  Rituraj Shukla 《水文科学杂志》2020,65(13):2224-2232

ABSTRACT

In humid regions, surface runoff is often generated by saturation-excess runoff mechanisms from relatively small variable source areas (VSAs). However, the majority of the current hydrologic models are based on infiltration-excess mechanisms. In this study, the AGricultural Non-Point Source Pollution (AGNPS) model was used to integrate the VSA concept using topographic wetness index (TWI). Both the original and AGNPS-VSA models were evaluated for a small agricultural field in Ontario, Canada. The results indicate that the AGNPS-VSA model performed better than original model. The AGNPS-VSA model predicted that only the saturated portion of the field with higher TWI values produced runoff, whereas the original AGNPS model showed uniform hydrologic response from the entire field. The results of this study are important for accurately mapping the locations of VSAs. This new model could be a powerful tool in identifying critical source areas for applying targeted best management practices to minimize pollutant loads to receiving waters.  相似文献   

酒泉、嘉峪关地域城镇系统的空间规模结构研究   总被引：6，自引：0，他引：6  

李志刚 《地理研究》1999,18(1):87-95

受干旱区自然地理、人口发展与分布等特殊条件的制约,酒泉、嘉峪关地域城镇系统的空间规模结构呈现“中小市镇、多中心”的特征。针对这种状况,空间规模结构的研究和规划,应注重建构多中心的地域城镇系统,带动地域整体发展要促进相邻城市间、城市与境内或周边单位间的空间关联及与近郊集镇的融合,推动城乡一体化应突出酒泉-嘉峪关复合城市的中心地位,强化敦煌市的规模和职能,保证玉门市区持续发展并尽快发展玉门镇,积极发展其他小城镇。  相似文献   

Estimation of Scalar Source/Sink Distributions in Plant Canopies Using Lagrangian Dispersion Analysis: Corrections for Atmospheric Stability and Comparison with a Multilayer Canopy Model   总被引：5，自引：0，他引：5  

R. Leuning 《Boundary-Layer Meteorology》2000,96(1-2):293-314

Source/sink distributions of heat, water vapour andCO₂ within a rice canopy were inferred using aninverse Lagrangian dispersion analysis and measuredmean profiles of temperature, specific humidity andCO₂ mixing ratio. Monin–Obukhov similarity theorywas used to account for the effects of atmosphericstability on _w(z), the standard deviation ofvertical velocity and _L(z), the Lagrangian timescale of the turbulence. Classical surface layer scaling was applied in the inertial sublayer (z > z_ruf)using the similarity parameter = (z - d)/L, where z is height above ground, d is the zero plane displacementheight for momentum, L is the Obukhov length,and z_ruf 2.3h_c, where h_c iscanopy height. A single length scale h_c, was usedfor the stability parameter 3 = h_c/L in the height range 0.25 < z/h_c < 2.5. This choice is justified by mixing layer theory, which shows that within the roughness sublayer there is one dominant turbulence length scaledetermined by the degree of inflection in the windprofile at the canopy top. In the absence of theoretical or experimental evidence for guidance,standard Monin–Obukhov similarity functions, with = h_c/L, were used to calculate the stabilitydependence of _w(z) and _L(z) in the roughness sublayer. For z/h_c < 0.25 the turbulence length and time scales are influenced by the presence of the lowersurface, and stability effects are minimal. With theseassumptions there was excellent agreement between eddycovariance flux measurements and deductions from theinverse Lagrangian analysis. Stability correctionswere particularly necessary for night time fluxes whenthe atmosphere was stably stratified.The inverse Lagrangian analysis provides a useful toolfor testing and refining multilayer canopy models usedto predict radiation absorption, energy partitioningand CO₂ exchanges within the canopy and at thesoil surface. Comparison of model predictions withsource strengths deduced from the inverse analysisgave good results. Observed discrepancies may be dueto incorrect specification of the turbulent timescales and vertical velocity fluctuations close to theground. Further investigation of turbulencecharacteristics within plant canopies is required toresolve these issues.  相似文献   

云南地热资源及其开发前景   总被引：1，自引：0，他引：1  

殷瑛  王明珠  何绕生 《云南地质》2006,25(1):70-75

云南地热异常多且显著。滇西高温水热活动区是藏滇水热带的南延，滇东断陷盆地中低温水热活动区的形成得益于独特的地质结构，滇西、滇南花岗岩地热系统则主要吸收地层中K^40同位索放射热而成。开发前景极为广阔。  相似文献   

钾盐矿床的物质来源和成矿机制   总被引：4，自引：0，他引：4  

郑大中  郑若锋 《云南地质》2006,25(2):125-142

讨论钾及其有关物质的理化性质和地化行为，钾盐的物质来源，盐卤的变质、结晶分异、成矿条件和机制。富钾热液是形成钾盐矿床的重要物质来源之一。矿物岩石流体包裹体的富钾成分、富钾热泉、富钾盐湖均是寻找钾盐矿床的重要指示。  相似文献   

2003年11月13日岷县ML5.5级地震震源机制的矩张量反演     

李亚荣  荣代潞  刘旭宙  韩晓明 《华南地震》2006,26(1):126-132

利用2003年11月13日岷县5.5级地震震中周围7个台站的数字记录反演了本次地震的矩张量,对所得结果与用P波初动符号的结果进行了比较,二者具有较好的一致性。结合该地区的地震分布和本次地震的余震分布,对可能的发震断层进行了讨论。  相似文献   

黔中降起的油气勘探壁垒——兼论海相碳酸盐岩烃源岩     

支家生 《海相油气地质》2006,11(3):15-18

黔中隆起在地质构造上属于扬子地块的滇黔隆褶带．南华纪晚期初现雏形，震旦纪—奥陶纪为水下隆起，燕山运动使其整体抬高，喜马拉雅运动时急剧隆升，构造地貌长期相对隆起。地表油苗油样分析结果显示，在红外吸收谱图中缩合芳烃结构及含氧基团吸收明显，有机质热成熟度高，且遭受了氧化蚀变：震旦系以上地层大量暴露，地表水溶蚀下渗深度在黔西南地区可达3000-4000m；作为长期存在的古隆起，经历了多次抬升，直至挽近仍处于严重剥蚀阶段。地腹可能存在酸性岩浆热源使有机质过度热演化、保存条件不佳以及缺少勘探目的层，是黔中隆起油气勘探的三大壁垒。兼谈了碳酸盐岩烃源岩问题．认为形成大油气田的烃源岩主要是泥质岩系，“碳酸盐岩烃源岩”只是从属性的．分布在泥质烃源岩系的边缘或局部范围。  相似文献   

Source parameters of intermediate-depth Vrancea (Romania) earthquakes from empirical Green's functions modeling     

Adrien Oth  Friedemann Wenzel  Mircea Radulian 《Tectonophysics》2007,438(1-4):33-56

Several source parameters (source dimensions, slip, particle velocity, static and dynamic stress drop) are determined for the moderate-size October 27th, 2004 (M_W = 5.8), and the large August 30th, 1986 (M_W = 7.1) and March 4th, 1977 (M_W = 7.4) Vrancea (Romania) intermediate-depth earthquakes. For this purpose, the empirical Green's functions method of Irikura [e.g. Irikura, K. (1983). Semi-Empirical Estimation of Strong Ground Motions during Large Earthquakes. Bull. Dis. Prev. Res. Inst., Kyoto Univ., 33, Part 2, No. 298, 63–104., Irikura, K. (1986). Prediction of strong acceleration motions using empirical Green's function, in Proceedings of the 7th Japan earthquake engineering symposium, 151–156., Irikura, K. (1999). Techniques for the simulation of strong ground motion and deterministic seismic hazard analysis, in Proceedings of the advanced study course seismotectonic and microzonation techniques in earthquake engineering: integrated training in earthquake risk reduction practices, Kefallinia, 453–554.] is used to generate synthetic time series from recordings of smaller events (with 4 ≤ M_W ≤ 5) in order to estimate several parameters characterizing the so-called strong motion generation area, which is defined as an extended area with homogeneous slip and rise time and, for crustal earthquakes, corresponds to an asperity of about 100 bar stress release [Miyake, H., T. Iwata and K. Irikura (2003). Source characterization for broadband ground-motion simulation: Kinematic heterogeneous source model and strong motion generation area. Bull. Seism. Soc. Am., 93, 2531–2545.] The parameters are obtained by acceleration envelope and displacement waveform inversion for the 2004 and 1986 events and MSK intensity pattern inversion for the 1977 event using a genetic algorithm. The strong motion recordings of the analyzed Vrancea earthquakes as well as the MSK intensity pattern of the 1977 earthquake can be well reproduced using relatively small strong motion generation areas, which corresponds to small asperities with high stress drops (300–1200 bar) and high particle velocities (3–5 m/s). These results imply a very efficient high-frequency radiation, which has to be taken into account for strong ground motion prediction, and indicate that the intermediate-depth Vrancea earthquakes are inherently different from crustal events.  相似文献   

节气气候变化与上消化道出血的关系研究     

吴荣娟  邱赠东林平 《广西气象》2007,28(3):47-49

通过对2000-2005年龙岩市第一医院上消化道出血（UGB）患者入院时的节气归属及当时气象资料的收集,分析不同节气气候变化与UGB的关系,运用最优子集回归方法建立关系模式进行综合分析,得出影响上消化道出血发病趋势的关键气象要素是节气最高气温、最低气温、平均水汽压;通过节气气候因素对UGB影响的认识,提出相应的预防保健措施。  相似文献