Comment on ‘The residence time of aerosols and SO2 in the long-range transport over the Ocean’, by Ito et al.     

B. Bonsang  B. C. Nguyen  G. Lambert 《Journal of Atmospheric Chemistry》1987,5(3):367-369

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河北大湾锌矿中硫锰矿与闪锌矿的成因关系     

魏绮英  涂勘 《矿物学报》1987,(1)

本文研究了产于河北大湾锌矿床中的硫锰矿,探讨了硫锰矿与闪锌矿的成因关系。由实验结果而认为大湾硫锰矿是从深色高锰闪锌矿中出溶而成的。  相似文献   

Derivation of the Pearson type (PT) III distribution by using the principle of maximum entropy (POME) — Comment     

Huynh Ngoc Phien  Van-Thanh-Van Nguyen 《Journal of Hydrology》1987,90(3-4):351-355

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大气边界层的数值模式   总被引：3，自引：4，他引：3  

吴辉碇  张兴旺  屠伟铭  朱宗申 《气象学报》1984,42(3):290-300

从大气边界层温湿特征的模拟,讨论模式的设计和处理。模式计算所得位温,混合比垂直廓线和混合层厚度等随时间变化基本反映实际大气边界层的一些特点。并从地气之间热量收支、土壤热传导方程出发计算地面温度日变化。利用Clarke的Wangara资料计算了24小时内它们的变化,并与观测值进行比较。本文还对温湿预报方程的数值解的稳定性进行了讨论。  相似文献   

Explicit expression and regularization of the harmonic reproducing kernels for the earth's ellipsoid     

Nguyen Chí Thông 《Journal of Geodesy》1996,70(9):533-538

The reproducing kernel functions and the integral formulae involving the solutions of the fixed gravimetric boundary value problems for the earth's ellipsoid are investigated in a suitable polar coordinate system defined on the boundary ellipsoid. The infinite series expressions of the reproducing kernel functions are represented explicitly up to the square of the first excentricity of the boundary surface. The obtained results show that the reproducing kernel functions for the earth's ellipsoid are, in contrast to the case of the spherical boundary, inhomogeneous and anisotropic. Moreover, the anisotropy is stronger near the pole. Subsequently the kernel functions are regularized in order to overcome the weak singularity of the integrals.  相似文献   

泡沫钻进流体压力损失的研究     

杨世忠  陈惟明 《地质与勘探》1996,32(3):61-64,F003

为了研究泡沫钻进中泡沫流休压力损失的变化规律，建立室内模拟试验台，通过大量实验，得出结论。  相似文献   

聚晶立方氮化硼刀具及其制造技术综述   总被引：2，自引：0，他引：2  

刘一波  屠厚泽 《地质与勘探》1996,32(4):59-64

首先介绍了聚晶立氮化硼刀具的优异性能及其应用领域。然后从几个方面综述了ＰＣＢＮ刀具制造的关键技术及其发展现状。  相似文献   

Subduction—Modified Subcontinental Mantle in South China：Trace Element and Isotope Evidence in Basalts from Hainan Island     

张明  解广轰等 《中国地球化学学报》1996,15(1):1-19

Cenozoic lavas from Hainan Island,South China,comprise quartz tholeiite,olivine tholeiite,alkali basalt,and basanite and form a continuous,tholeiite-dominated,compositional spectrum.Highly incompatible elements and their relationships with isotopes in these lavas are shown to be useful in evaluating mantle-source composition,whereas modeling suggests that ratios of elements with bulk partition coefficients significantly larger than those of Nb and Ta may be sensitive to partial melting.Th/Ta and La/Nb ratios of alkali basalts are lower than those of tholeiites,and they are all lower than those of the primitive mantle,These ratios correlate positively with ^207Pb/^204Pb and ^87Sr/^86Sr ratios.Such relationships can be explained by mixing of depleted and enriched source components.A depleted component is indicated by alkali basalt compositions and is similar to some depleted OIB (PREMA).The enriched component,similar to sediment compositions,is indicated by tholeiites with high LILE/HFSE,^207Pb/^204Pb,and ^87Sr/^86Sr ratios.In general,basalts from Hainan and the South China Basin(SCB)share common geochemical characters.e.g.high Rb/Sr,Th/Ta,^207Pb/^206Pb,and low Ba/Th ratios.Such a geochemical trend is comparable to that of EMII-type OIB and best explained as the result of subduction.Occurrence of these characteristics in both continental Hainan basalts and SCB seamout basalts indicates the presence of a South China geochemical domain that exists in the mantle region below the lithosphere.  相似文献   

九十年代固体地球科学及超大型矿床研究若干进展   总被引：7，自引：0，他引：7  

涂光炽 《矿物学报》1997,17(4):357-363

90年代，国内外地学工作者将现代科学的新方法、新技术应用于地球科学研究中，通过深海钻探、高温高压技术与地球物理手段等多种方法综合研究，致使在：地球的核-幔组分；CO2的起源、全球变化及其与成矿的关系；岩石圈的演化与缺氧事件、生物灭绝、海底扩张及成矿的相关性等诸多固体地球科学研究领域，均取得了若干最新的认识和重要进展。本文还对超大型矿床及分散元素成矿机制等的研究新进展分别作了阐述，并提出在华南和西南地区要重视晋宁期和喜山期成矿作用的研究。  相似文献   

The Brittlestar Amphiodia urtica; A Candidate Bioindicator?     

D. Maurer  H. Nguyen 《Marine Ecology》1996,17(4):617-636

Abstract. The ophiuroid Amphiiodia urtica L yman is presently under study as a potential wastewater discharge indicator species from ocean outfalls in the Southern California Bight. On the San Pedro Shelf, the maximum abundance of A. urtica was found at depths from 30 to 100 m, and in sediment with a median grain size of 0.085 nim, 60–80% sand. 15–30% silt, 0–37% clay, and 0.2–0.5% TOC. The mean abundance of A. urtica fluctuated annually with a slight increase from 1977 through 1993.
The hypothesis was posed that the distribution and abundance of A. urtica is not influenced by an ocean outfall and its operation on the San Pedro Shelf. Based on long-term (1977–1994) and intensive (2860 samples) sampling. the hypothesis was rejected. However, the effect of the outfall is not clear because sediment bioassays from test stations and controls produced no significant differences in survivorship and growth of juveniles. Amphiodia presently occupies areas within the Zone of Initial Dilution (ZID) where it was not found during the mid-1970s and early 1980s. While recognizing that A. urtica abundance responds to proximity to the outfall, the mechanism for this response is still unclear. The application of a single species as a bioindicator is not recommended, and most certainly not without fully essing its role in community structure and function.  相似文献