专业标准的一根支柱——实用性

地学标准,不同于机械制造、医药卫生、食品加工等行业的标准。因为地学标准中有很多属于文字描述性的内容,它不能用几个表格、几行列式去简化、去处理。譬如,野外地质规范,对一些地质现象、

Application of the Wavelet Packet Method in Discrimination Between Nuclear Explosion and Earthquake

Although the CTBT (Comprehensive Nuclear Test Ban Treaty) was passed in 1996, it is still necessary to develop new and highly efficient methods (Wu Zhongliang, Chen Yuntai, et al., 1993; Xu Shaoxie, et al.1994; Richard L. Garwin, 1994) to monitor possible events. Many discrimination criteria (Xu Shaoxie, et al.,1994; Institute of Geophysics, Chinese Academy of Sciences, 1976; Richard L. Garwin, 1994) have been put forward since the 1950s. The results show that each of the existing criteria has its own limitation, but the seismological method is an important and efficient method in the discrimination between nuclear explosion and earthquake. Especially in recent years, because of the little and little equivalent as well as the increasing hiding steps used in the test, a number of more efficient seismological methods have been worked out. In this paper, a new discrimination method, the Wavelet Packet Component Ratio (WPCR) method, is put forward. This method makes full use of the difference in variation with time between the spectra of nuclear explosions and earthquakes. Its discrimination efficiency is rather high.

Calculation of Calibration Functions and Explosive Aftershock Magnitudes in the Near Field

The current calibration function used in calculating the magnitude of natural earthquakes within 5km is a constant; a fact that causes several serious difficulties for the calculation of the magnitude of small and shallow-focus earthquakes. According to the attenuation law of explosions and the propagation theory of elastic waves, the calibration function is calculated for near field quakes from 0km to 5km. Magnitudes of two aftershock sequences are calculated. The magnitudes of most explosion earthquakes are small, ranging mainly from magnitude -0.5 to 1.0. The M-t chart of the explosive aftershocks is completely different from that of strong earthquake aftershocks. It not only shows positive columnar lines indicating large magnitudes but also short negative columnar lines indicating small magnitudes.

Definition of Standard English and its enlightenment on English teaching

Standard English is defined not as a language, a style, an accent, but as standardized grammar and vocabulary with different accents. And from a linguistic point of view, Standard English is no more correct than any other form of English. Yet it is most prestigious, and a desirable educational target. However, different varieties of English should also be taught for international communication.

Logging data representation based on XML

As an open standard of data representation,XML breathes new energy to the Web application and the network computing.The development,advantage and status of XML and some standards relating to XML are reviewed.In addition,the authors put forward a method representing logging data and using UML language to establish the conceptual and logical model of logging data;using a logging data,explain how to establish the model as well as how to use XML to display and process geology data.

Physico-chemical and Bacteriological Specification Groundwater of Tangier

The drinking water for all the inhabitants of Tangier is still an aim far from being achieved. Therefore, all rural areas and some urban areas feed water wells and springs whose composition and safety are unknown. In the absence of data on water and ignorance of consumers towards the risk of poisoning and waterborne diseases transmitted by these waters, the authors conducted a study to determine the composition, physico-chemical quality and bacteriological these waters. This study is to provide a basic physico-chemical and bacteriological data from these waters in some urban areas of old or missing infrastructure in some sites in the province of Tangier. Such as Ziatine sites, Gzenaya, Rmilate, Malabata ＋ Mnar, Mghoura ＋ Aouama and Downtown. Analyzes are performed according to AFNOR methods （AFNOR： French Standards Association）. The results indicate that these waters are generally mild and are experiencing significant geochemical imbalance. Moreover, these waters also have a significant organic and bacteriological pollution. It is concluded that the waters of these sites are of poor quality, unfit for human consumption.

A COMPLETE METRIC OF POSITIVE CURVATURE ON R^n AND EXISTENCE OF CLOSED GEODESICS

An example of complete Riemannian metric of positive (or nonnagative) curvature on Resuch as aam = a(x)dx' is obtained by direct caculations. Furthermore, by using a geodesic convex condition and a theorem for complete noncompact Riemannian manifold, an existence resultof periodic solution of prescribed energy for a singular Handltonian system is also obtained.

Application of superconductive gravity technique on the constraints of core-mantle coupling parameters

The parameters, i.e. the Period and the Quality factor, of the Earth's free core nutation (FCN) are closely related to the dissipative coupling between the core and the mantle. Based on the FCN parameters obtained from the actual observations and theoretical simulation, significantly constrained in this study were several key parameters near the core-mantle boundary (CMB), related to the core and mantle coupling, including viscosity at the top of liquid core, conductivity at the bottom of the mantle, and dynamic ellipticity of the CMB. In order to choose high quality observations from global stations of the superconducting gravimeters (SG) on the Global Geodynamics Project (GGP) network, we adopted two criteria, the standard deviations of harmonic analysis on tidal observations and the quality of the FCN parameters calculated with the observations from single station. After the mean ocean tidal effects of the recent ocean tidal models were removed, the FCN parameters were retrieved by stacking the tidal gravity observations from the GGP network. The results were in a good agreement with those in the recent research by using the SG and/or the VLBI observations. Combined with an FCN theoretical model deduced by angular momentum method, the viscous and electromagnetic coupling parameters near the CMB were evaluated. Numerical results indicated that the viscosity at the top of the liquid core was in the range from 6.6×102 to 2.6×103 Pa·s, which was in good agreement with those obtained from the Earth's nutation, the FCN and variations in the length of day (LOD). The conductivity at the bottom of the mantle should be as large as 2.6×106-1.0×107 S m-1 to match the FCN quality factors from the actual observations. The dissipative coupling had a little influence of 1-2 sidereal days for the FCN period.