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31.
This paper discusses numerical results from three-dimensional large eddy simulations of an oscillating cylinder under prescribed movements in uniform flow. Six cases,namely pure in-line,pure cross-flow and two groups of 'Figure of Eight' oscillation patterns are under investigation at Reynolds number Re=24000. The 'Figure of Eight' pattern in each group is with identical shape but opposite orbital directions. The numerical results on hydrodynamic forces,higher order force components,and vortex shedding mode... 相似文献
32.
四川会理大岩子铂钯矿的地质地球化学特征及找矿前景浅析 总被引:5,自引:0,他引:5
四川会理县大岩子铂钯矿床是目前国内品位最高的独立铂族元素矿床之一,也是一个独特的热液成因矿床。矿区及区域上的镁铁质岩浆岩可能是铂族元素的初始来源,震旦系白云岩是其有利的容矿围岩,构造控制下的热液活动促使了铂族元素的迁移富集。地表氧化带蓝铜矿化白云岩矿石的PGE含量最高可达27.13×10-6,坑道中相对新鲜橄辉岩的PGE含量为1.068×10-6,强烈蚀变橄辉岩含PGE0.528×10-6,地表蚀变后橄辉岩的PGE含量为0.435×10-6,表明铂族元素可能发生了活化转移。整个攀西地区基性超基性岩发育,后期构造活动强烈,有利的围岩广泛分布,因而具备形成热液型铂族元素矿床的条件,找矿前景看好。 相似文献
33.
34.
基于OFDM核心技术的WiMAX(全球微波接入互操作性)具有4G技术的特点。与3G和WiFi无线通讯技术相比具有明显的高速率、大容量数据传输优势。本文就基于WiMAX的地质灾害应急通讯系统的几种技术方案加以详细论述,说明WiMAX在地质灾害应急指挥中具有广阔前景。 相似文献
35.
YONGDONG WANG ODD S.BORGEN BRUCE R.KOWALSKI Laboratory for Chemometrics Center for Process Analytical Chemistry Department of Chemistry BG- University of Washington Seattle WA U.S.A. Present address:Perkin-Elmer Corporation Main Avenue Norwalk CT - U.S.A. 《地理学报(英文版)》1993,(5)
Through theoretical analysis and computer simulation,this short communication comments on theresidual bilinearization(RBL)method and compares it with non-bilinear rank annihilation(NBRA)forthe treatment of second-order calibration with non-bilinear data.It is found that these two methods aremathematically equivalent but have different noise propagation properties.The second-order advantage,namely quantitation in the presence of unknown interferences,can be carried over to non-bilinear dataonly if there exists a net analyte rank(NAR)for the analyte of interest. 相似文献
36.
This is a first foray into the historical start and early years of chemometrics from about 1972 onwards.We have gathered interviews with three originators(Kowalski,Wold and Massart)as well as with aselected group of six other well-known chemometricians who gradually became active in the 1970s(Christie,Clementi,Hopke,Martens,Brown and Deming).The interviews include amongst a host ofsubjective recollections a succinct record of the key historical literature as highlighted by the interviewees'own rankings of‘earliest’and‘best’.A discussion of the most general commonalities in these interviews together with other historicalmaterial is presented in the second part of the paper. 相似文献
37.
In this paper,a tropical atmospheric model of relevance to shorts-term climate variations(Wang and Li 1993)is util-ized for study of the development of Madden-Julian oscillation.The model contains an interactive process ofboundary-layer Ekman convergence and precipitation heating.The model is solved by expanding dependent variables interms of parabolic cylindrical functions in the meridional direction and truncating three meridional modes n=0,2,4 forequatorial symmetric solutions.The free wave solutions obtained under long-wave approximation are induced as aKelvin wave and two Rossby waves.After considering the effect of boundary-layer dynamic process,the modifiedKelvin wave becomes unstable in long-wave bands with a typical growth rate on an order of 10~(-6) s~(-1)and an eastwardphase speed of 10 m s~(-1);the most unstable mode is wavenumber one.These theoretical results are consistent with the ob-served Madden-Julian oscillation in equatorial area.For the two modified Rossby waves,one with a smaller meridionalscale(n=4)decays except for extra long-waves;the other with a larger meridional scale(n=2)grows in short-wavebands.This may be relevant to explaining the westward propagation of super cloud clusters in the Madden-Julianoscillation.The theory suggests that the boundary-layer dynamic process is an important mechanism in the develop-ment of the Madden-Julian oscillation. 相似文献
38.
SIMULATION OF HEAVY RAINFALL IN THE SUMMER OF 1998 OVER CHINA WITH REGIONAL CLIMATE MODEL 总被引:11,自引:0,他引:11
The heavy rainfall in the summer of 1998 over China has been simulated with the NCCRegional Climate Model(RegCM_NCC).It was successful for RegCM_NCC to reproduce thelocation and seasonal shift of the seasonal rain belt in the summer of 1998 over China.The rainyseason in the summer of 1998 over China can be divided into 7 episodes,including the pre-summerrainy season in South China.the Meiyu onset over the Yangtze-Huaihe River Basin,shortappearance of North China rain season and the retreat of seasonal rain belt,the second Meiyuseason over the Yangtze River Valley,the rainy period over the Yellow and Huaihe River Valleyand the seasonal retreat of rain belt over North China.The shortcoming of the RegCM_NCC isover-estimation of precipitation amounts.The regions with large latent heat flux,upper soilmoisture and total runoff are located in the rainy area and move with the simulated rain belt duringthe different episodes.On the contrary,the regions with small sensible heat flux are located in thesimulated rainy area and move with the simulated rain belt during the different episodes. 相似文献
39.
In the context of tower measured radiation datasets.following the correction principle meetinga diagnostic equation in data quality control and in terms of a technique for model construction ondata and ANN(artificial neural network)retrieval for BP correction of radiation measurementswith rough errors available,a BP model is presented.Evidence suggests that the developed modelworks well and is superior to a convenient multivariate linear regression model,indicating its wideapplications. 相似文献
40.
华创升达 《中国气象科学研究院年报》2006,(1):33
FNP-1新型净全辐射表,用来测量太阳短波辐射和地球辐射的净差值,采用了国外先进技术,改善了以前的制作工艺,该表测量精度高、稳定性好,广泛应用于气象自动站、农业、林业气象监测系统.专利号为ZL03206191.9. 相似文献