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21.
Xiang Rong Li Tiegang Yang Zuosheng Yan Jun Cao Qiyuan College of Marine Geosciences Ocean University of China 《海洋学报(英文版)》2003,(1)
Benthic foraminiferal analysis of 29 samples in surface sediments from the southern Okinawa Trough is carried out. The results indicate that benthic foraminiferal abundance decreases rapidly with increasing water depth. Percentage frequencies of agglutinated foraminifera further confirm the modern shallow carbonate lysocline in the southern Okinawa Trough. From continental shelf edge to the bottom of Okinawa Trough, benthic foraminiferal fauna in the surface sediments can be divided into 5 assemblages: (1) Continental shelf break assemblage, dominated by Cibicides pseudoungerianus, corresponds to subsurface water mass of the Kuroshio Current; (2) upper continental slope assemblage, dominated by Cassidulina carinata , Globocassidulina subglobosa, corresponds to intermediate water mass of the Kuroshio Current; (3) intermediate continental slope assemblage, dominated by Uvigerina hispi-da, corresponds to the Okinawa Trough deep water mass above the carbonate lysocline; (4) lower continental slope- trough b 相似文献
22.
Effect of oil pollution on gluthione and relative enzyme in oyster(Saccostrea cuculiata) 总被引:1,自引:0,他引:1
The oysters ( Saccostrea cuculiata ) were collected from four stations around Xiamen Island (Lundu Port, Xinglin Bay, Tong" an Bay, Huangcuo). The relation between the level of petroleum hydrocarbon in whole tissue and the contents of glutathione (GSH), the activity of selenium-dependent glutathione peroxidase (Se-GPx) and glutathione S-transferase (GST) in digestive gland and gill were investigated. The results showed: (1) The contents of petroleum hydrocarbon in oyster collected from four stations (Lundu Port, Xinglin Bay, Tong'an Bay, Huangcuo) were 380.68, 112.34, 27.31, 20.37μg/g wet weight, respectively; (2) the activity of Se-GPx and GST in digestive gland was lower than that in gill, and the content of GSH seemed reversibly; (3) among the four stations, both Se-GPx and GST activity of digestive gland and gill in Saccostrea cuculiata sampled from the four stations showed a good correlation with whole tissue petroleum hydrocarbon, could be as biomarkers of sea oil pollution. 相似文献
23.
ZHU Jun LIU Song QIN Yukun XING Rong’e YU Huahua CHEN Xiaolin LI Pengcheng 《海洋湖沼学报(英文)》2020,(3):841-850
Phytopathogenic fungi cause heavy negative impact on the agricultural economy,but most existing fungicides are toxic and pose a threat to both human health and environments.A green and efficient fungicide is urgently needed.Chitooligosaccharides(COSs),the degradation products of natural polysaccharide chitosan,are nontoxic and biodegradable antifungal substances.In this study,a novel type of aminourea chitooligosaccharide derivatives(AUCOS)was synthesized by successively grafting a hydrazine group and an amine-carbonyl group onto a chitooligosaccharide backbone to enhance the antifungal capability of COSs.The structures of the target compounds were identified by FTIR,1H NMR,and 13C NMR,and the degree of substitution of each product was calculated from the results of the elemental analysis.The antifungal activities of the prepared chitooligosaccharide derivatives against Fusarium solani,Verticillium albo-atrum and Phytophthora capsici were tested in vitro.The AUCOSs had better inhibitory efficiencies against the three plant pathogen fungi than that of chitooligosaccharide,of which aminourea chitooligosaccharide 2(AUCOS2)was the most promising antifungal compound,whose highest inhibition rates were 60.12%,82.95%,and 85.23%against F.solani,V.albo-atrum and P.capsici,respectively.The synthesized derivatives have good application prospects in crop protection and deserve further research. 相似文献
24.
Organic matter (OM) and minerals are major particle components of lacustrine shales. The influence of OM and minerals on pore space and structure in organic-rich oil-prone shales containing a large range of total organic carbon (TOC) contents is poorly understood. In this study, we investigated the variation in pore space and structure of low mature lacustrine shales in the Songliao Basin (NE China), based on a study of the mineralogy, petrography, geochemistry, and geophysical properties of shales. Different pore types make markedly different contributions to the mineral surface area (MSA) and pore volume (PV) of the shales. There exists a negative correlation between MSA/PV and TOC in mesopores (r2 = 0.75/0.65) and macropores (r2 = 0.74/0.68), and a positive correlation in micropores (r2 = 0.59/0.64), which are associated with the variation of mineral and TOC contents. A positive relationship between the throat/pore ratio and TOC (r2 = 0.82) shows an increase in throat radius and decrease in pore radius with increasing TOC content. This relationship is supported by the reduction in mean pore diameter (MPD) for large pores and increase in MPD for small pores. These variations are related to the decreased pores by quartz plus feldspar (Q + F) content, increased throats by clay minerals, and enhanced pore-fill by OM. We propose that the variation of OM and minerals is a key control on the pore space and structure of low mature organic-rich oil-prone shales. 相似文献
25.
Tl1eincreaseindomeSticmarkotalonecouldnotachieveeconon1icgrowthti1atChinaexpenencedinthel98os.Chinahasanaverageannualgrowthrateofl4.3perwtinthepenodofl978-l99o,whichisoneofthehighestinAsiaandtheworId.Sucl1highecononticgrowthhasbamachievedthrougheconon1icrefon11sandglobalizationofitseconomy.TheglobaliZationofitseconon1yisanintentionaleffortoftheopa1policyadoPtedinl978.BecauseofthelrlOCationaladvantage,itisnotsuI`Prisingtofindthateconomicgrowthofthecoastalprovincesisfasterthanililandprovince… 相似文献
26.
Mengting Ju Jun Yin Lei Hao Chenxu Liu Chao-Wei Tsai Junfeng Wang Zhengyi Shao Shuai Feng Yu Rong 《天文和天体物理学研究(英文版)》2024,(2):85-105
The star-forming clumps in star-bursting dwarf galaxies provide valuable insights into understanding the evolution of dwarf galaxies.In this paper,we focus on five star-bursting dwarf galaxies featuring off-centered clumps in the Mapping Nearby Galaxies at Apache Point Observatory survey.Using the stellar population synthesis software Fitting Analysis using Differential evolution Optimization,we obtain the spatially resolved distribution of the star formation history,which allows us to construct... 相似文献
27.
Volume 15,Number 235INTRODUCTIONEddhquake PrePrecursors and study dthelr卜atures filedsignificance to eal’thqu让e prediction.heanlsotroPyPyfeature Is one dthe nPnPortant aspects dprecursors,while its study Isdbenefit totheunderstandingdthe evolutiondstressfield andtothe deterrmnatlonJthe selsmopnlc fanfaut.S、wavespitting based on the EDA model Is。e Of the most popular。thods to study the preen。cry vanatlonof stress ield before earthquake and has made gnat。hleve。ms(Crampin,e… 相似文献
28.
Grain-size distribution data,as a substitute for measuring hydraulic conductivity(K),has often been used to get K value indirectly.With grain-size distribution data of 150 sets of samples being input data,this study combined the Artificial Neural Network technology(ANN)and Markov Chain Monte Carlo method(MCMC),which replaced the Monte Carlo method(MC)of Generalized Likelihood Uncertainty Estimation(GLUE),to establish the GLUE-ANN model for hydraulic conductivity prediction and uncertainty analysis.By means of applying the GLUE-ANN model to a typical piedmont region and central region of North China Plain,and being compared with actually measured values of hydraulic conductivity,the relative error ranges are between 1.55%and 23.53%and between 14.08%and 27.22%respectively,the accuracy of which can meet the requirements of groundwater resources assessment.The global best parameter gained through posterior distribution test indicates that the GLUEANN model,which has satisfying sampling efficiency and optimization capability,is able to reasonably reflect the uncertainty of hydrogeological parameters.Furthermore,the influence of stochastic observation error(SOE)in grain-size analysis upon prediction of hydraulic conductivity was discussed,and it is believed that the influence can not be neglected. 相似文献
29.
In the classic theory of plate tectonics, ophiolitic mantle peridotites (i.e., abyssal peridotite) are thought to originate in the shallow mantle beneath ocean spreading centers.Diamonds and other UHP minerals have been found in opholitic mantle peridotites and chromitites along the Neo-Tethyan Yarlung Zangbo suture of southern Tibet, and in a Paleozoic ophiolite in the Polar Urals of Russia,suggesting that UHP minerals may be widespread in ophiolitic peridotites.Diamonds from these different localities all have very similar features in C isotope and mineral inclusions,and are distinct from the other two well known types, i.e. kimberlitic diamonds and UHP metamorphicdiamonds. The occurrence of diamond in ophiolite indicate a completely new environment for diamond formation, which can be regarded as ophiolite-type diamond. These new findings indicate a need to reconsider the nature of the upper mantle and the conditions under which ophiolites form. 相似文献
30.
Cheng Zhou Yuanyuan Hu Jie Cao Liuxiong Xu Xuefang Wang Rong Wan Yu Xiao Jiangfeng Zhu Hao Tang 《海洋学报(英文版)》2022,41(3):1-2
In the western and central Pacific Ocean, upper strata waters exhibit highly dynamic oceanographic features under ENSO variability. This has been proved to be responsible for the dynamic change of both abundance and zonal distribution of skipjack tuna(Katsuwonus pelamis). Although causality has been suggested by researchers using physical–biological interaction models, cumulative evidence needs to be obtained and the tenability of assertion needs to be tested from an ecological habitat perspecti... 相似文献