共查询到20条相似文献,搜索用时 15 毫秒
1.
Q-mode factor analysis was applied to 99 surface samples from the South China Sea to define four planktonic foraminiferal assemblages: tropical-subtropical assemblage, high-salinity assemblage, transitional assemblage and dissolution resistant assemblage. The tropical-subtropical assemblage is a dominant assemblage. The variation of the planktonic foraminifera of this assemblage reflects the changes of tropical surface water from the west Pacific to South China Sea. These four assemblages reveal that different planktonic foraminiferal assemblages are controlled by different factors in the South China Sea, such as tropical-subtropical assemblage controlled by sea surface temperature (SST), high-sallnity assemblage mainly by salinity besides SST, transitional assemblage by SST and dissolution resistant assemblage by water depth. 相似文献
2.
3.
4.
5.
The South China Sea is the westernmost marginal sea in the west Pacific Ocean. On thebasis of the analyses of sedimentary components, biofossils, oxygen-carbon isotopes and theirdatings in four seafloor cores which were collected from the deep sea plain to continentalslope in the northern South China Sea, the environmental variations were basically similarto other tropical ocean areas, and their cycle changes in about the ages of 40 ka and 20 kawere more apparent since the late Pleistocene. During the warm climates, the depositionrate on the continental slope was about 2.6 times as rapid as on the deep sea plain margin.The seafloor in the deep sea plain was below the CaCO_3 compensation depth. During thecold periods, however, the deposition rate on the deep sea plain margin was slightly quickerthan on the continental slope due to the sea level reduction on a larger scale and moresupply of the terrigenous clastics. 相似文献
6.
7.
SU Jing-Yu ZHONG Yong-Li ZENG Long-MeiDepartment of Chemistry Zhongshan University Guangzhou Guangdong China WU Hou-Ming MA KanState Key Laboratory of Bioorganic Natural Products Chemistry Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai China 《中国化学》1995,13(5):460-463
A new sesquiterpene, ent-furodysin (1), has been isolated from the South China Sea Sponge Dysidea fragilis, along with a known sesqui-terpene, ent-furodysinin (2). The structure and relative stereochemistry of 1 and 2 were established by spectral analysis. 相似文献
8.
9.
10.
南海海绵Rhabdastrella属中新胆甾醇Rhabdasterol 总被引:5,自引:0,他引:5
人们已从海绵生物中发现了许多结构独特的有机化合物,如萜类、甾醇、苷类、生物碱、多肽和聚醚等,其中许多具有广谱抗菌、抗病毒、抗心血管病和抗肿瘤等生理活性.本文报道从我国南海海绵Rhabdastrelasp.中分离出一个具有新型侧链的胆甾醇:25(29)... 相似文献
11.
The monthly mean circulations in the whole Pacific Ocean are investigated numerically by using a barotropic ocean model with finer horizontal resolutions. The current system in the China Sea and its adjacent areas has been well reproduced. Especially, some warm currents moving windward in winter, such as the South China Sea Warm Current (SCSWC), Taiwan Warm Current (TWO, Yellow Sea Warm Current (YSWC) and Tsushima Warm Current (TsWC) are simulated very well. Numerical results of January show that there exists indeed a so-called "Taiwan-Tsushima-Tsugaru Warm Current System" (TTTWCS) which originates from the area off the southeastern Hainan Island and enters the Pacific Ocean mainly through the Tsugaru Strait in January. 相似文献
12.
13.
14.
Thealgaeproducedmanyinterestingpharmacologicalandbiologicalactivitymetabolitessuchasantibacterium.antineoplastic.anticancerandantimicrobialactivitiescompound'-'.Moreandmorechemistandbiologistpayattentiontothecollstituentsofthealgae.ThealgaSal'gassunl1)achedcollectedfromtheSouthChinaSeahasbeenstudiedandcompoundIwasisolated.FigureI-shestructureof1Theethanole\tractofalgaSul'gassll))]1)uk'hel/waselutedb}'silicagelusingpetroleunletherx"itllincreasingamountsofethy'lacetateaseluent.Thefractionobt… 相似文献
15.
Carmen Varlam V. Patrascu R. M. Margineanu I. Faurescu Irina Vagner Denisa Faurescu O. G. Duliu 《Journal of Radioanalytical and Nuclear Chemistry》2013,298(3):1679-1683
The Black Sea tritium level was investigated in 33 places southward the Danube Delta covering about 360 km of the Black Sea Western Shore. Both surface (10 cm depth) and bottom (up to 20 m depth) water samples were collected. In the close vicinity of Danube Delta, the tritium activity concentration in the surface water was around 28 TU, which is almost the same as that of the Danube River waters, but it decreased to about 5 TU in the bottom water. This discrepancy slowly diminished wherein at about 120 km southward, the tritium content in both surface and bottom water reached almost the same constant value of 6.5 ± 2.3 TU. This value, about two and a half times smaller than that reported 17 years ago, remained almost unchanged for the last 240 km of shore up to the Turkish border. 相似文献
16.
具有Scalarane碳架的二倍半萜以及C-20甲基化或C-20和C-24双甲基化的Scalarane型高二萜半萜是Dictyoceratida科海绵的典型代谢产物。海绵Phyllospongia foliascens属Dictyoceratida科,从这种海绵中我们已分离和测定了7种双高二倍半萜的结构,作为对这种海绵深入研究的一部分,我们对采自西沙和南沙群岛的同种海绵进行了研究,从中得到Acetoxy phyllofoldctone A(1).本文报道(1)的分离及结构测定. 相似文献
17.
大亚湾沉积物中氨基酸的垂直分布——沉积物柱样W0中的水解氨基酸 总被引:2,自引:0,他引:2
测定了采自大亚湾近岸海域的一个长60cm的沉积物柱样W0中15种水解氨基酸的含量;结果表明,15种水解氨基酸含量均随深度而下降,其中苏氨酸、丝氨酸、甘氨酸、丙氨酸、精氨酸、缬氨酸、苯丙氨酸、亮氨酸、异亮氨酸的含量以及水解氨基酸总量随深度的变化可用指数方程c=c0e^-kx加以描述;天冬氨酸、谷氨酸、丝氨酸、甘氨酸、丙氨酸和缬氨酸是大亚湾沉积物中最丰富的氨基酸。 相似文献
18.
19.
20.
Menverins H–L,New Highly Oxygenated Guaiane Lactones from the Gorgonian Coral Menella kanisa
下载免费PDF全文
![点击此处可从《Helvetica chimica acta》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Lian Yu Lin Lin Bin Long Yinning Chen Fu Lei Liangjuan Wen Haiyan Sun Chenghai Gao Riming Huang 《Helvetica chimica acta》2015,98(5):710-718
By further chemical investigation of South China Sea gorgonian Menella kanisa, five new highly oxygenated guaiane lactones, menverins H–L ( 1 – 5 , resp.), were obtained. Their structures were established by employing spectroscopic methods, computer modeling, and comparison of their data with those of related metabolites. 相似文献