Baroclinic Buoyancy-Inertia Joint Stability Parameter

At present, the barotropic buoyant stability parameter has been derived from a vertical virtual displacement of a water parcel. The barotropic inertial stability parameter in the eccentrically cyclogeostrophic, basic current field was derived in 2003 from a horizontal cross-stream virtual displacement of a parcel. By expressing acceleration of a parcel due to a virtual displacement, which is arbitrarily sloping within a vertical section across the basic current, in terms of natural coordinates, we derived the vertical component of baroclinic buoyant stability parameter B ₂ ², the horizontal component of baroclinic inertial stability parameter I ₂ ², the baroclinic joint stability parameter J ², its buoyant component B ² and its inertial component I ². B ² is far greater than I ₂ ², and when neglecting relative vorticity except for vertical shear, a downward convex curve of J ² plotted against the slope of a virtual displacement follows a trend of B ² curve. If a parcel displaces along a horizontal surface or an isopycnal surface, however, B ² vanishes, and J ² becomes equal to I ². Actual parcel is apt to displace not only along the bottom slope, but also along the sea surface and an isopycnal interfacial surface, which is approximately equivalent to an isentropic surface, preferred by lateral mixing and exchange of momentum. Such actual displacement makes B ² vanishing, and grants I ² an important role. The present analysis of I ² examining effects due to curvature and horizontal and vertical shear vorticities are useful in deepening our understanding of baroclinic instability in actual oceanic streams.     

投喂频率对南美白对虾(Penaeus vannamei Boone)生长、饲料利用及虾体组成影响的初步研究

本实验选用商品饲料饲养平均初体重为0．09g的南美白对虾，经过30d的生长实验，研究不同投喂频率对南美白对虾生长、成活以及饲料利用的影响。结果表明，随着投喂频率由3次／天增加到5次／天，南美白对虾的增重率、特定生长率和蛋白质效率显著提高，而饲料系数则显著降低，但当投喂频率由5次／天增加到7次／天时，南美白对虾增重率、特定生长率和蛋白质效率并无显著提高。对对虾全虾体主要组成成分的分析表明南美白对虾体主要组成成分并不受投喂频率增加的影响。     

GPS单频精密单点定位方法与实践

讨论了单频精密单点定位的解算方法与思路,编写了单频精密动态单点定位的程序,实现了事后动态单频精密单点定位.     

小波变换在遥感图像上矿区空间定位方面的分析与应用——以鄂东南铁矿矿区为例

随着社会的发展,人们对自然地物的影响越来越显著,大量地改变了地表的状况,在遥感图像上则表现为灰度值变化剧烈,其中的纹理信息发生改变.在频率域上说,人工改变的区域部分的高频成分比其他区域部分要丰富很多,小波变换能够有效地将其中的高频信息提取出来,用假彩色分割图将其中的异常值明显地表示出来.湖北大冶的铁山矿区分布着六大露天矿区,地表开挖范围广,影响程度大,以该地区为例,分析小波变换在遥感图像上矿区空间定位方面的应用.使用本文介绍的方法处理效果比较明显.矿区位置的确定还需要参考断层分布信息,这意味着使用小波变换进行处理的方法具有一定的局限性.     

Multi-Scale Texture Modeling

Patterns of crystallographic preferred orientation are referred to as texture. The specific subject of texture analysis is the experimental determination and interpretation of the statistical distribution of orientations of crystals within a specimen of polycrystalline material, which could be metals or rocks. The objective is to relate an observed pattern of preferred orientation to its generating processes and vice versa. In geosciences, texture of minerals in rocks is used to infer constraints on their tectono-metamorphic history. Since most physical properties of crystals, such as elastic moduli, the coefficients of thermal expansion, or chemical resistance to etching depends on crystal symmetry and orientation, the presence of texture imparts directional properties to the polycrystalline material. A major issue of mathematical texture analysis is the resolution of the inverse problem to determine a reasonable orientation density function on SO(3) from measured pole intensities on , which relates to the inverse of the totally geodesic Radon transform. This communication introduces a wavelet approach into mathematical texture analysis. Wavelets on the two-dimensional sphere and on the rotational group SO(3) are discussed, and an algorithms for a wavelet decomposition on both domains following the ideas of Ta-Hsin Li is given. The relationship of these wavelets on both domains with respect to the totally geodesic Radon transform is investigated. In particular, it is shown that the Radon transform of these wavelets on SO(3) are again wavelets on . A novel algorithm for the inversion of experimental pole intensities to an orientation density function based on this relationship is developed.     

Latitudinal variation of measured O3 photolysis frequencies J(O1D) and primary OH production rates over the Atlantic Ocean between 50° N and 30° S

The latitudinal variation of the photolysis frequency of ozone to O(¹D) atoms, J(O¹D), was measured using a filter radiometer during the cruise ANT VII/1 of the research vessel Polarstern in September/October 1988. The J(O¹D) noon values exhibited a maximum of 3.6×10^-5 s^-1 (2 sr) at the equator and decreased strongly towards higher latitudes. J(O¹D) reached highest values for clean marine background air with low aerosol load and almost cloudless sky. The J(O¹D) data, measured under these conditions and a temperature of 295 K, can be expressed by: % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOsaiaacI% cacaqGpbWaaWbaaSqabeaaiiaacqWF8baFaaGccaqGebGaaeykaiaa% bccacqWF9aqpcaqGGaGaaeyzaiaabIhacaqGWbGaaeiiaiaabUhacq% GHsislcaaI4aGaaiOlaiaaicdacaaIYaGaeyOeI0IaaGioaiaac6ca% caaI4aGaaiiEaiaaigdacaaIWaWaaWbaaSqabeaacqGHsislcaaIZa% aaaOGaaeiiaiaabIhacaqGGaGaam4uaiabgUcaRiaaiodacaGGUaGa% aGinaiaacIhacaaIXaGaaGimamaaCaaaleqabaGaeyOeI0IaaGOnaa% aakiaadofadaahaaWcbeqaaiaaikdaaaGccaGG9bGaaeikaiaaboha% daahaaWcbeqaaiabgkHiTiaaigdaaaGccaGGPaaaaa!5EE9!\[J({\text{O}}^| {\text{D) }} = {\text{ exp \{ }} - 8.02 - 8.8x10^{ - 3} {\text{ x }}S + 3.4x10^{ - 6} S^2 \} {\text{(s}}^{ - 1} )\] where S represents the product of the overhead ozone column (DU) and the secant of the solar zenith angle. The meridional profile of the primary OH radical production rate P(OH) was calculated from the J(O¹D) measurements and simultaneously recorded O₃ and H₂O mixing ratios. While the latitudinal distribution of J(O¹D) and water vapour was nearly symmetric to the equator, high tropospheric ozone levels up to 40 ppb were observed in the Southern Hemisphere, SH, resulting in higher P(OH) in the SH.     

青藏高原腹地湖泊沉积对第四纪晚期古季风变化的响应

通过对青藏高原腹地的综合科学考察和对中心钻孔岩芯剖面的最新研究,用层序地层学与年代地层学和气候地层学相结合的方法,分辨出可可西里地区湖泊沉积记录(孔深7.25 m)的第四纪晚期距今3万余年以来的古气候变化,沉积物磁化率等因子综合表征的高原古季风变化是波动发展的,发生在仙女木期地质环境事件中的季风活动具有强烈暴发的特点,是高原季风发展中的突变事件,而且地表热点效应对其起到了激发作用。综合分析的研究成果表明,它的变化频谱与激变因子及其运行机制是伴随着青藏高原地质效应的演变而发展的,为研究第四纪冰消期以来的气候变化提供了新的信息。     

Sequence stratigraphy of a Late Devonian ramp-situated reef system in the Western Canada Sedimentary Basin: dynamic responses to sea-level change and regressive reef development

The Alexandra Formation, located in the Northwest Territories of Canada, is formed of a Late Devonian (Frasnian) reef system that developed on a gently sloping, epicontinental ramp in the Western Canada Sedimentary Basin. High‐resolution sequence stratigraphic analysis of its deposits delineates two reef complexes that are separated by a Type I sequence boundary. The second reef complex developed on the outer ramp, basinward of the first, after sea‐level fell ≈17 m. Stratigraphic complexity of the second reef complex was a result of its initiation during forced regression, and its development through an entire cycle of sea‐level rise followed by sea‐level fall. Its highstand systems tract was not characterized by high rates of carbonate production or sediment shedding. Rather, these features took place as sea‐level fell, after its highstand systems tract. The sequence stratigraphic framework of this regressive reef system highlights a number of depositional parameters that differ from high‐relief, shelf‐situated reef systems with steep, narrow margins. These have implications for understanding the controls on the development of ramp‐situated reef systems, and the nature of reef systems with gently sloping profiles. This study demonstrates that the development of stromatoporoid reef systems may be far more complex than generally realized, and that high‐resolution sequence stratigraphy may provide the tools for better understanding of complex, often enigmatic, aspects of these systems.