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561.
亚洲是世界著名的季风区,我国降水分布特征与东亚行星尺度环流型背景以及大地形结构有密切关系。本文采用p-σ坐标原始方程模式,着眼于西太平洋副热带高压与大陆热低压系统强度及其相互配置关系,即相应于东亚夏季风不同强度,与东亚海陆热状况密切相关的“纬向驻波”特征,研究夏季风流型与中国东部降水分布的相关。本文数值试验研究了东亚夏季风基本气流汇合特征与海陆纬向驻波环流型的相关;夏季暖湿区分布,暖湿舌形成与中国东部降水关系。还研究了我国东部雨带形成的高、低层流场的动力结构以及南亚高压活动特点。 相似文献
562.
粒度分组:提取古环境变化信息的一种有效方法 总被引:3,自引:0,他引:3
对南京老虎山黄土-古土壤剖面全样和三个粒级组分(《2 μm、2~45μm和》45 μm)的Rb/Sr比值进行了系统研究.结果表明,Rb/Sr比值是衡量黄土和古土壤化学风化强度的良好地球化学指标;粒度分组是利用Rb/Sr比值研究古环境变化的有效方法.通过粒度分组,可以排除不同粒度组分之间由于Rb/Sr初始比值不同造成的互相干扰.《2 μm粒级的(Rb/Sr)-Sr反相关图的R2值最大(达0.97),说明该粒级指示化学风化作用的灵敏度最高,研究Rb/Sr比值这一地球化学指标最理想. 相似文献
563.
稀土元素:海相硅岩沉积环境的有效指标 总被引:2,自引:3,他引:2
世界范围内海水的REE研究表明,不同环境海水的REE有一定的差异.海相硅质沉积也显示出与周围海水相似的REE特征,其中最明显的是Ce异常。对已知沉积环境的硅岩所作REE研究说明,利用硅岩的REE特征可以帮助判别海相沉积环境。江西南部寒武—奥陶系中广泛产出厚层的层状硅岩,根据Ce的异常,推测此区硅岩形成于大陆边缘—大洋盆地的过渡地区。 相似文献
564.
PAN Shaohua XIAQiyi LIN Shiqing XU Lunhuan
Professor Dept. of Coastal Engineering College of Harbour Waterway Coastal Engineering Hohai University Nanjing P. R. China.
Senior Engineer Dept. of Coastal Engineering College of Harbour Waterway Coastal Engineering Hohai University Nanjing P. R. China.
Senior Engineer Fujian Province Ports Shipping Administration Bureau Fuzhou P. R. China. 《中国海洋工程》1999,(2)
Test studies on the wave pressure on a breakwater pier show that the influence of transmissivewave pressure on the outside wall of the breakwater pier is considerable,when the width of the pier is notvery large.The variations of transmissive wave pressure on the breakwater pier with different widths arecompared and the relationship is obtained between relative transmitting distance b/L and wave pressurereduction factor K,which may be used in the design of similar breakwater piers. 相似文献
565.
Conodont samples were collected from three localities in the Onoo Tolgoi area, Mongolia, and many conodonts have been found. Conodonts from the Onoo Tolgoi Formation (M288-M294) lack index fossils; its age could be Late Silurian. Samples from the Hutul us hudag Formation (M295-M299) contain Ozarkodina pandora alpha Morph. ( P element), clearly indicating that this formation is Early Devonian late Lochkovian in age. Samples collected from so-called Silurian Onoo Tolgoi Formation at other localities (M300-M303) yield many Ordovician conodonts, including Icriodella baotaensis, Icriodella cf. baotaensis, Eoplacognathus fianyeen- sis, Eoplacognathus protoramosus ; Baltoniodus alobatus ; and ? Ambalodus triangularis ; the age is Late Ordovician, more precisely, early-middle Late Ordovician. 相似文献
566.
Wave-Current Propagation over a Frictional Topography 总被引:1,自引:0,他引:1
ZUO Qihua DING Bingcan Prof. Senior Engineer River Harbour Department Nanjing Hydraulic Research Institute 《中国海洋工程》1998,(4)
—In this paper the parabolic approximation model based on mild-slope equation is used tostudy wave propagation over a slowly varying and frictional topography under wave-current interaction.A governing equation considering the friction effects is derived by the authors for the first time.A simpli-fied form for the rate of wave energy dissipation is presented on the basis of the wave-current action conser-vation equation and the bottom friction model given by Yoo and O'connor(1987).Examples reveal thatthe present computational method can be used for the calculation of wave elements for actual engineeringprojects with large water areas. 相似文献
567.
PAN Junning WANG Hongchuan YAO Guoquan Graduate Student River Harbour Department Nanjing Hydraulic Research Institute Nanjing P. R. China.Engineer River Harbour Department Nanjing Hydraulic Research Institute Nanjing P. R. China. Professor River Harbour Department Nanjing Hydarulic Research Institute Nanjing P. R. China. 《中国海洋工程》1998,(2)
-In this paper a simple and efficient implicit finite-difference scheme is used for depth-averagedtwo-dimensional storm surge model.This finite-difference scheme is simpler and more efficient than the wi-dely-used ADI scheme.Accuracy analysis and stability analysis indicate that the scheme has two-order ac-curacy and is unconditionally stable when the grid size is constant.The present analysis results show thatthe scheme is of higher numerical accuracy than that introduced by Maa(1990).After tested by ideal mod-els,a calculation example of a real typhoon surge is carried out,the results of the numerical simulation co-incide well with the observed data and the accuracy is sufficient for engineering applications. 相似文献
568.
为促进浙江省渔业产业的转型升级和渔业经济的可持续发展,文章以我国实施乡村振兴战略为背景,对浙江省休闲渔业发展进行SWOT分析,并提出对策建议。研究结果表明:浙江省是渔业大省,休闲渔业发展时间较短,但发展势头良好;浙江省发展休闲渔业的优势包括地理区位优越、渔业资源丰富、旅游资源丰富和经济实力强大,劣势包括管理、规划、资金和从业者等方面,机会包括政府政策支持和公众需求旺盛,威胁包括市场竞争激烈、资源环境被破坏以及科研投入和转化率不足;浙江省休闲渔业发展应明确管理部门职责、加快制定整体规划、解决融资难问题以及培养和引进专业人员。 相似文献
569.
CHEN Hui'e WANG Qing CAI Keyi.College of Construction Engineering Jilin University Changchun China .Highway Management Station of Jiangning District in Nanjing City Nanjing China 《东北亚地学研究》2009,12(1):17-21
On the basis of elastic-plastic damage model of cement consolidated soil, the authors took organic contents into reasonable damage variable evolution equation in order to seek relation between the organic contents and parameters in the equation, and established the elastic-plastic damage model of cement consolidated soil considering organic contents. The results show that the parameters change correspondingly with difference of the organic contents. The higher the organic contents are, the less the valves of the parameters such as elastic modulus (E), material parameters (K, n) and damage evolution parameter (ε) become, but the larger strain damage threshold value (εd) of the sample is. Meanwhile, the calculation results obtained from established model are compared with the test data in the condition of common indoors test, which is testified with reliability. 相似文献
570.