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991.
热带太平洋海温等20 ℃深度面的演变规律及其与ENSO循环的联系 总被引:2,自引:0,他引:2
利用美国Scripps海洋研究所联合环境数据分析中心(JEDAC)提供的120 ?E~80 ?W,20 ?N~20 ?S范围的太平洋次表层海温资料,插值获得热带太平洋地区的等20 ℃海温面深度资料。分析发现,就全年及四季而言,太平洋的等20 ℃海温面呈西深东浅的纬向分布,在西太平洋地区呈深-浅-深的经向分布,在东太平洋地区呈浅-深-浅的经向分布。太平洋等20 ℃海温面的方差变化存在三个大值区,分别位于暖池、赤道附近及其东南太平洋海域。等20 ℃海温深度面的准3~7年振荡是除去年循环之外的最显著振荡周期。等20 ℃海温深度距平信号的准3~7年振荡传播的回路,很好地反映了El Ni?o和La Ni?a事件循环的特征,从而从观测事实方面支持了ENSO循环概念模式图。 相似文献
992.
993.
EmpA is an extracellular metalloprotease secreted by Vibrio anguillarum.For better understanding its role in the patho-genicity of V.anguillarum strain M3,empA insertion mutant was constructed.In the mutant it decreased in extracellular proteolytic activity,swarming motility,hemolytic activity and virulence on turbot(Scophthalmus maximus).Significant decline(by 5-fold)of extracellular proteolytic activity and similar growth curve between mutant and wild type strains indicated that EmpA was the major extracellular protease of M3.LD50 of mutant increased by 38-fold compared with wild type.No pro-EmpA was detected in the su-pernatant of culture,indicating that EmpA autolyzed to mature protein after 24 h.Secretion of EmpA in M3 was similar to that in NB10 strain.Attenuated virulence of mutant was similar to that of M93Sm strain.It was demonstrated that specific operation of EmpA was different from that in previous studies and EmpA contributed to the swarming motility and hemolytic activity in V.an-guillarum strain M3.The results provides insight into understanding the function of EmpA and its potential application in vaccine development. 相似文献
994.
优化、高效的区域产业结构是区域社会经济发展的必备条件.本研究基于传统偏离-份额分析法(SSM)以及动态偏离-份额分析法对区域产业结构进行横向对比与纵向测度,从福建省的视角进行实证分析,旨在为区域产业结构优化升级、经济发展方式转变提供科学指导.研究表明:1)中国沿海地区的产业结构份额和产业竞争份额大部分大于全国平均水平,... 相似文献
995.
微型桩技术广泛应用于地质灾害应急抢险治理工程中.凤凰山公园滑坡应急治理工程中,在调查滑坡地理条件、地质条件和基本特征的基础上,采用潜孔锤微型钻孔灌注桩技术,辅以挡土板和格构砼的综合治理方案.结果表明工程安全、快速、高效、造价低、质量高,治理效果明显. 相似文献
996.
王孝平 《地质灾害与环境保护》2011,22(4):78-82
在探讨6种隧道地质超前预报方法的基础上,综合应用TGP206、地质雷达和红外探水法,预报岚谷斜井隧道工程中的不良地质.结果表明,综合隧道地质预报方法,能提高预测的准确性和精度,能有效地减少事故,确保施工安全. 相似文献
997.
998.
A new ketosteroid, along with six known steroids, was isolated from the ethanolic extracts of red alga Acanthophora spicifera (Vahl.) Boergesen. The structures, identified using chemical and spectroscopic methods including 2D NMR, were: (1) 22-hydroxy-5α-cholest-3,6-dione, (2) 6-hydroxycholest-4-ene-3-one, (3) cholest-4-ene-3,6-dione, (4) cholest-5-ene-3β-ol, (5) 5α-cholestane-3,6-dione, (6) β-Sitosterol and (7) Saringosterol. The MTT method was used to test the cytotoxicity of the compounds against the human cancer cell lines, HCT-8, Bel-7402, BGC-823, A549 and HELA. Compounds 1, 2, 3 and 5 showed moderate cytotoxic activity against human cancer cell lines. 相似文献
999.
基于小波变换的稳定性函数来研究尺度进制的算法。用母波的频谱函数来构造出尺度进制为任意进制时的稳定性函数,根据稳定性函数计算小波框架的边界、紧致度和收敛因子,最后由框架参数值进一步计算得到尺度进制范围。结果表明,此范围有效地缓解了小波变换的稳定性和冗余性之间的矛盾。 相似文献
1000.
Correlation between incompetent beds and slope deformation at Badong town in the Three Gorges reservoir, China 总被引:2,自引:0,他引:2
Badong town is a new immigration area in the Three Gorges reservoir, China, which is built on many giant deep-seated landslides. In this region, the slope deformation is very severe and it is strongly correlated with the incompetent beds, which are distributed widely in the rock mass. In this paper, two giant deep-seated translational rock landslides used as study cases are Huangtupo landslide and Zhaoshuling landslide. Firstly, the composition materials, structures and deformation characteristics of the two landslides are analyzed. Then, the position, structure, mineral composition and the formation mechanism of the incompetent beds are studied in detail. Finally, based on the comparison of the position, mineral and structure between incompetent beds and sliding zones of the landslides, the correlations between incompetent beds and giant landslide are discussed. The results indicate that 13 large incompetent beds exist in the middle Triassic Badong Formation strata, which can be divided into three types as weak interlayers, crushed beds and groundwater corrosion zones. The dominant minerals in the incompetent beds are illite, chlorite, quartz and calcite. The contents of the clay minerals in different positions are quite distinct, and the maximum difference of clay content exceeds 70 %. In addition, it is found that the contents of minerals in incompetent beds are similar to the slide zones of the landslides. The initial deformation of slopes normally developed along the incompetent beds, which induced subsequent shear displacement easily. Under the effect of gravity, the deep slip zones were generated mainly along the incompetent beds and the failure mode evolved from creep to integral slide gradually. The results can provide an important reference for the mechanism analysis and prevention of landslides in Badong town. 相似文献