基于参数法的国内上市机场规模效率评估

本文构造了一个规模经济和机场行业特征作用于机场运营效率的理论框架,并以上市机场为例进行了实证研究,研究表明:首先,机场规模与机场效率存在一定关联,上市机场中规模较小的机场存在规模经济,此类机场规模仍然有拓展空间,而规模较大的三大枢纽门户机场效率则相对较低,出现了规模经济递减情况,另一方面,除机场规模外,存在其他效率影响因子,因为不同机场在同一规模截面,其效率迥异;其次,机场行业"双高双低"的特征显著影响了效率高低,使得各机场效率均呈周期性起落变化;最后,优质管理会有效提升机场效率,深圳宝安机场作为国内中型枢纽机场,以其优质资产管理和良好财务状况,在六大上市机场中持续高效运营。因此,大中型枢纽机场在不断追加设施投入的同时,须更加注重提升管理水平,通过内涵式发展推动机场高效运营。     

温泉旅游资源可持续利用评价研究——以广东龙门为例

结合旅游资源可持续发展理念和温泉旅游资源特点,制定出温泉旅游可持续发展水平评价指标体系,并在此基础上运用模糊判断方法和系统聚类方法,对龙门县温泉资源进行实证研究;通过对2种评价方法的结果分析与修正,将龙门县温泉旅游资源的可持续发展水平分为高、一般、低3类.     

-89G634.41H130;F085;17;46;F;H;F085_17;H130

试评价是英语新课程的重要组成部分,是实现新课程标准的重要保证。作为评价的试卷应该难度适中,充分体现教育、教学目标,并能对教学产生最大的正面导向作用,从而真正体现受测试者的英语水平和能力,准确反映教学情况和教学效果。在此问题上,命题者要从命题的方向、内容、原则与方法等几个方面去研究和把握。0山东师范大学外国语学院学报(基础英语教育)Journal of Basic English Education94-97G634.41H130;F085;17;46;F;H;     

Mineralogical characteristics of airborne particles collected in Beijing during a severe Asian dust storm period in spring 2002

Asian dust storm (ADS) samples were collected on March 20,2002 in Beijing,China. High-resolution field emission scanning electron microscopy with energy dispersive X-ray detector (FESEM-EDX) and X-ray diffraction (XRD) were used to study the morphology,chemical compositions,number-size dis-tributions and mineralogical compositions of ADS particles. The mineral particles were major compo-nents in the ADS samples,accounting for 94% by number. The XRD analysis indicated that the dust particles were dominated by clay (40.3%),and quartz (19.5%),followed by plagioclase (8.4%),calcite (7.5%),K-feldspar (1.5%),hematite (0.9%),pyrite (0.9%),hornblende (0.4%) and gypsum (0.3%),with a certain amount of noncrystalline materials (20.3%). Clay minerals were mainly illite/smectite mixed lay-ers (78%),followed by illite (9%),kaolinite (6%),and chlorite (7%). In addition to these main minerals,FESEM-EDX also detected some trace minerals,such as dolomite,pyrite,thenardite,as well as heavy minerals represented by rutile,ilmenite and apatite. The mineralogical compositions of the 2002-03-20 Asian dust storm and the Saharan dust plumes were similar but the clay mineralogy showed a great distinction,with the illite/smectite mixed layers being common in the Asian dust storm but illite being common in the Saharan dust plumes.     

一种显式四维变分资料同化方法

提出一种新的资料同化方法——显式变分四维同化方法, 该方法将奇异值分解(SVD)技术用于四维空间的预报集合提取正交基向量, 这些基向量不但能够表现分析变量的空间结构, 也能反映它的时间演变特征. 将分析变量依截断的基向量展开后, 控制变量会显式地出现在代价函数中, 避免了传统的变分四维同化方法所必需的伴随模式的运用, 使同化过程变得简单. 用浅水方程模式和人造资料进行的一系列数值试验对所提方法的有效性作了检验并和传统的变分四维同化方法进行比较. 结果表明, 在观测点很密集, 观测和模式都没有误差的情况下, 它不如传统的变分四维同化方法好. 但是当观测点稀疏时显式方法会好于传统的方法, 它对模式误差及观测误差的敏感性也远远小于传统的方法.     

THE DICHOTOMY OF ACTUAL TORRENT CATCHMENTS: IS THERE AN ALPINE DISEASE?

1 INTRODUCTIONDuring the last glaciation all large valleys along the northem tringe of the Bavarian Alps wereintensively influenced by the movement of huge glacial lobes into the forelands. During the glacialadvance of the combined Isar and Loisach glaciers in the Lainbach test basin, sitUated 6() kIn south ofMunich, the eastom rim of the geomorphological basin of Kochel was covered by a small secondare icelobe. In the KOchel basin the IsarLosach glacier developed to a maximum thickn…     

Grade-Tonnage, Ore Value-Tonnage, and Enrichment Ratio-Tonnage Models for Resource Assessment

I' Grade-tonnage diagrams are one of the most useful tools inthe resource assessment (e. g. St'nger, 1993). One' grade-tonnage diagram is well known as Laskys (1950) e\-7ation, whichdemonstrates the linear relation between average grade (x) andlOgarithms of cumulative ore tonnage (ac above a given gradex(0相似文献   

THE USE OF A RATIO METHOD AS AN ALTERNATIVE TO CONSTRAINED DECONVOLUTION

This paper will consider the use of an iterative ratio technique called Gold's ratio method as an alternativeto iterative constrained deconvolution methods for the restoration of overlapped and noisychromatograpic peaks.The study will consist of first describing the technique and then evaluating itsperformance with respect to Jansson's deconvolution procedure.A Hewlett-Packard 5890A gaschromatograph will be used to generate most of the test data.The evaluation criteria will includeconvergence rates,peak area errors and variances,retention time variances and noise performance.