基于TOPEX/Poseidon资料的南海海面高度场的时空特征分析

采用经验正交函数(EOF)分解方法，对TOPEX／Poseidon卫星高度计在南海获得的1992年10月到1999年9月约7a的海面高度观测资料进行分析，从而获得南海海面高度距平场典型的空间分布型态及其对应的时间变化特征。结果表明，南海海面高度距平场在空间上主要表现为两种典型的分布结构：(1)由于冬、夏季风反转造成海盆尺度的涡旋结构，这种分布结构对南海海面高度距平场的方差贡献达27．46％；(2)NE—SW即吕宋—越南反相双涡结构，其方差贡献达20．37％。这两个模态都明显反映了季风的反转以及季风结构所造成的影响。同时，对各空间典型场所对应的时间系数序列进行了傅立叶谱分析，结果表明南海海面高度距平场存在多种时间尺度的变化。     

运用正交函数拟合预测新疆阿舍勒地区块状硫化物矿床

新疆阿舍勒块状硫化物铜锌矿床,是一个正在勘探的大型富铜矿床,矿体呈厚大透镜状,具层控特征,矿体和围岩之间密度差较大。地面重力方法,理应是最有效的勘探方法,但是,由于阿舍勒矿区地质构造过分复杂,地下不同深度的多种密度体叠合在一起,往往掩盖了矿体所产生的重力异常。为了解决这个疑难问题,通过研究,选择适当的正交函数去进行拟合,实现目标信息分离,将成矿层位的重力异常从实测重力异常值中分离出来,勾绘出了矿区线状构造成矿带的轮廓,揭示了矿区构造;指出找矿方向,圈出１１个重力异常,根据矿区矿石的最低密度大于围岩最高密度的实事,可以说：“凡有矿的地方必然显示出重力异常”。故使用本方法处理重力资料,在阿舍勒这类矿区,可具直接找矿效果。     

用ECMWF数值预报产品作热带气旋路径预报的业务系统

以欧洲中心数值预报产品为基础,采用ＥＥＯＦＳ展开选取“典型场”作为数值预报产品的信息,以统计释用方法研究建立的,可以应用于南海区的热旋路径业务预报方法。该方法于１９９４年台汛期参加由广东省气象主持的“关于热带气旋预报业务试验项目”,进行了９个台风的共１４次预报试验,平均误差２４ｈ为１８７ｋｍ,４８ｈ为２５２ｋｍ。     

Seismic response of multi‐supported structures by proper orthogonal decomposition

The seismic analysis of structures is usually carried out considering the ground motion as fully‐correlated in space and determining the structural response by pseudo‐deterministic methods such as the response spectrum technique. Actually, the partial correlation of the seismic acceleration may influence heavily the behaviour of spatially extended structures, such as bridges, viaducts or pipelines. In order to take its partial correlation into account, the seismic ground motion is schematized as a stochastic process dependent on time and on space; the hypotheses of stationarity and homogeneity are used to obtain simple and general results. The influence of the partial correlation of the seismic ground motion on the structural response is investigated by introducing suitable Equivalent Spectra. The acceleration of the support‐points of the structure is represented by the Proper Orthogonal Decomposition (POD), defining the modes of the earthquake. The method is formulated for any kind of multi‐degree‐of‐freedom system and is applied, as a case study, to an ideal single‐storey multi‐supported frame with an axially rigid beam. In the case of two supports, the POD decouples the pseudo‐static and the dynamic contributions to the structural response. This property is preserved for structural systems with many supports, where only the lower modes of the earthquake, usually the first two POD modes, are responsible for the structural response. Copyright © 2003 John Wiley & Sons, Ltd.     

在线双管氢化AAS测定As,Sb和Bi的最佳条件

在线双管氢化AAS法是一种新的原子吸收氢化光谱法 ,具有简便、快速、灵敏度高和硼氢化钾用量少的优点。采用正交试验设计法对在线双管氢化AAS法测定低含量As、Sb和Bi的测定条件进行了系统的研究 ,确定了乙炔流量、燃烧器高度、硼氢化钾浓度和溶液酸度的最佳测定条件。在最佳条件下对实际样品土壤GSS -5、水系沉积物GSD -11、钨矿石GSO -W -1和GSO -W -2中As ,Sb ,Bi的含量进行了测定 ,测定的结果较准确 ,RSD <3 .2 6%。     

Response to orthogonal components of ground motion and assessment of percentage combination rules

The effects of horizontal components of ground motion on the linear response of torsionally stiff and torsionally flexible systems, on soft and firm soil conditions, are examined. A one‐story, two‐way asymmetric structural system is used, subjected to uncorrelated ground motion components along their principal directions. Spectral densities for ground accelerations in firm and soft soils are modeled based on recorded data from large intensity Mexican earthquakes. It is shown that for firm soils, in general, these effects are important in the case of torsionally flexible systems that are stiff under translation, or for torsionally stiff systems that are flexible in translation. The percentage combination rules usually specified in seismic design codes are assessed against the dynamic response. Such combination rules can result in overly conservative design forces or underestimated design forces, particularly for torsionally flexible structures. Given the relative magnitude of the response to each ground motion component, it was found that using different percentage values in the combination rules has no significant effect on improving the estimation of the total response. Copyright © 2003 John Wiley & Sons, Ltd.     

粉煤灰处理含氟废水的正交试验研究

对粉煤灰处理含氟废水进行了正交试验研究。结果表明各因素对F-去除率的影响顺序为:pH>V/M>T>CF-,极差R分别为49.6、9.1、4.9和3.6;在pH=5、V/M=10、T=3h时,粉煤灰对于CF-<500 mg/L的废水具有较好的去除效果;粉煤灰吸附F-的行为符合Langmuir等温方程,方程为Ce/qe=0.251 8Ce+6.087 3。     

Statistical analysis on energy field of seismicity in Ningxia and its neighborhood region

IntroductionOneofnotablefeaturesofseismicityistherandomoccurrenceofearthquakesinspaceandtime.Oneessentialelementofseismicityisthatearthquakereleasedenergycanbetakenastherandomfunctionsofspatialandtemporalcoordinates.Therandomfunctioncanbecalledseismicityenergystochasticfieldorearthquakeenergyfield.Sincetheseismicityisrelatedinspaceandtime,usingtheconceptofstochasticfield,thetotalfeatureofregionalseismicactivitycanbeconsidered,ratherthanthestatisticsofasingleearthquakeinthepast.Therefore,thefe…     

Spatio-temporal filtering using wavelets

 In this paper, a class of spatio-temporal processes with first-order autoregressive temporal structure and functional spatio-temporal interaction is introduced. The spatial second-order regularity is allowed to change over time and is characterized in terms of fractional Sobolev spaces. The associated filtering problem is considered, assuming that observations are defined by spatial linear functionals of the process of interest, being affected by additive noise. Conditions under which a stable solution to this problem is obtained are studied. A functional least-squares linear estimate fusion method is derived to calculate this solution A multiscale finite-dimensional approximation to the problem is obtained from the wavelet-based orthogonal expansions of the time cross-section spatial processes, which allows the numerical inversion of the linear operator involved.     

EFFECT OF ARCTIC ICE COVER ON THE MONTHLY TEMPERATURE AND PRECIPITATION IN CHINA

Filtering technique, extended empirical orthogonal function (EEOF), spectrum distribution function and correla-tion analysis have been employed to study the relationship between arctic ice cover (AIC) and monthly mean tempera-ture and precipitation in China. The function of power spectrum density shows that not only a semi-annual and an an-nual oscillation but also a quasi-biennial oscillation can be found in AIC area index series, especially in June, Septemberand November. During the period of analysis, it can also be found that there exists a good correlation between the ElNino events and the AIC area index. An analysis on the EEOF of AIC and the temperature over China exhibits somesignificant temporal-spatial patterns and a better time-lag interrelationship between them. The results from the correla-tion analysis indicate that the variation of AIC area has a significant influence on the temperature and precipitation insubsequent months over China. In addition, it experiences a quasi-biennial low-frequency oscillation and displays tocertain extent some features of propagation.