季风指数及其年际变化Ⅱ.南海夏季风分量动能强度指数及其年际变化     

张东凌  何卷雄  左瑞亭  曾庆存 《气候与环境研究》2005,10(3):333-341

计算了各年南海夏季风建立前后流场的场相似度、场比幅、季风分量动能强度指数和突变度.指出按变差度最大或相似度绝对值最小及其变化最陡以及比幅最小,可客观定量地定出季风来临的预兆日期,在大多年份该日期比用天气气候学方法得到的季风来临(爆发)日期要早些,且两者有较好正相关.绝大多数年份季风建立时有环流突变发生,但也有少数年份呈调和变化或二次突变.季风分量动能强度指数能够反映各年南海夏季风建立后的强度.最后分析指出,南海850hPa夏季风的前兆日期,突变度和强度指数都有明显的年际和年代际变化.  相似文献   

Comparative Analysis of Mitochondrial Control Region Sequence from Three Flatfish Species （Pleuronectidae）     

YUJianzhong KONGXiaoyu YUZiniu ZHOULishi 《中国海洋大学学报(英文版)》2005,4(1):80-84

The 5‘-end of the mitochondrial control region sequences of three flatfishes (Pleuronectiformes: Pleuronectidae) were amplified and sequenced. These sequences were compared with those of other three Pleuronectids species retrieved from GenBank. A phylogenetic tree was constructed based on the partial control region sequences. The results of phylogenetic analysis are consistent with those of conventional systematics. Compared to previous studies, the structure of the 5‘-end of mitochondrial control region was analyzed. The terminal associated sequence motif and its complementary motif were identified at the 5‘-end of the sequences. A conserved sequence block, named as CM5‘ d, was identified in the 5‘-end of control region sequences in all Pleuronectids. Another central conserved sequence block, named as CSB-F, was detected in the central conserved blocks.  相似文献   

Seismic inversion modeling method for faulted basins:a case study of Liaohe Beach in Bijialing region     

JING Siliang  LU Qi  WANG Dian 《世界地质(英文版)》2017,20(4)

There is not much correlation between sand content and P-wave impedance in faulted basins , and the prediction results cannot be guaranteed .Due to sedimentary facies control , there is inconsistency between sand content and low frequency trend of P-wave impedance , causing problems for seismic inversion modeling , which directly affects final seismic inversion results .The acoustic impedance increases with burial depth .When the same layers of sand and shale formation endure different compaction , the acoustic impedance values will be dif-ferent .Therefore , The seismic inversion modeling of faulted basin is different from that of conventional basins . The authors built an inversion model using uncompact sandstone percentage , directly compensating for the low frequency trend of the inversion model .In addition, the model's intermediate frequency is similar to P-wave im-pedance , ensuring that the inversion results are converged correctly .The final results of the inversion can be used directly as sandstone percentage .The aforementioned method was applied to Liaohe Beach in the Bijialing region and obtained optimistic lithology inversion effects:the results were correlated well with the depositional facies map and with lithology in the well borehole .The inversion results can be used to define the sand body horizontally and can separate sand bodies vertically , which is very difficult on conventional seismic section . Therefore the inversion results played an important role in reservoir prediction .  相似文献   

Untersuchungen zum Abbau von Pharmaka in kommunalen Kläranlagen mit HPLC-Electrospray-Massenspektrometrie     

E. Mhle  C. Kempter  A. Kern  J. W. Metzger 《洁净——土壤、空气、水》1999,27(6):430-436

Examination of the Degradation of Drugs in Municipal Sewage Plants Using Liquid Chromatography-Electrospray Mass Spectrometry Numerous drugs can be identified in the secondary effluent of municipal sewage plants. In order to obtain information about the degree of elimination (adsorption, aerobic degradation) of these compounds, a batch reactor containing different drugs in environmentally relevant concentrations and a suspension of activated sludge was coupled to a HPLC-MS-MS system. During a testing period of three days concentration-time-curves were recorded. For most of the examined drugs (acetamidoantipyrine, crotamiton, diclofenac, primidone, propyphenazone) solely a strong decrease of the initial concentration within the first 15 minutes was observed, which was interpreted primarily as adsorption to the activated sludge. For acetaminophenol and pentoxifyllin an additional slower decrease in concentration within several hours was observed. This slower elimination was interpreted to be caused mainly by primary degradation. It could be shown that dihydrocodeine is oxidized to hydrocodone in the batch reactor. The conjugate acetaminophen glucuronide was cleaved.  相似文献   

Occurrence and Distribution of Organic Contaminants in the Aquatic System in Berlin.Part II: Substituted Phenols in Berlin Surface Water     

K. Schmidt-Bumler  Th. Heberer  H.-J. Stan 《洁净——土壤、空气、水》1999,27(3):143-149

In a surface water screening, 30 representative surface water samples collected from rivers, canals, and lakes in Berlin were investigated for the presence of 22 substituted phenols. The phenols selected include the 11 phenols considered as “priority pollutants” by the US Environmental Protection Agency (US-EPA). Surface water samples were extracted applying solid-phase extraction with styrenedivinylbenzene adsorbent. The recoveries, determined in spiking experiments, were between 80 % and 103 %. After derivatization with N-(tert-butyldimethylsilyl)-N-methyl-trifluoroacetamide (MTBSTFA) the samples were analyzed by capillary gas chromatography-mass spectrometry (GC-MS). Phenol, cresols, 2-ethylphenol, 2-chlorophenol, 4-chloro-3-methylphenol, pentachlorophenol, 2-nitrophenol, and 4-nitrophenol were detected in the surface water samples at concentrations between 0.02 μg/L and 7.8 μg/L, respectively. The distribution of these residues in the Berlin surface waters showed that the phenolic residues, with the exception of pentachlorophenol and 2-ethylphenol, do not originate primarily from municipal sewage treatment plants discharges. Some of the phenols are formed naturally or occur as ubiquitous anthropogenic contaminants in the aquatic system.  相似文献   

Ree geochemistry characteristics of stratigraphic samples in the abalieke region,Western Kunlun北大核心     

Shen N.-P.  Zhang Z.-W.  Peng J.-T.  Xiao J.-F.  Zhu X.-Q.  You F.-H.  Zhang Z.-S.  Wang F.-D. 《矿物岩石地球化学通报》2010,(4):388-399

The Abalieke region locats in the central section of the western Kunlun polymetallic (Pb, Zn, Cu, etc) ore belt, an area with major potential for further base metal deposit discoveries. This paper reports REE data for 82 samples from 8 stratigraphic sections for Huoshilafu formation in the Abalieke region. To attempt to solve the origin of ore-forming materials using REE geochemistry. Although total REE contents are quite variable ( Σ REE = 7. 52 × 10-6-220. 70 × 10-6, ΣLREE = 5. 82 × 10-6-198. 46 × 10-6, ΣHREE = 1. 49 × 10-6- 32. 74 × 10-6 and Y = 4. 77 × 10-6-91. 30 × 10-6) , chondrite-normalized REE patterns of the majority of samples are uniformly LREE-enriched (averaging ΣLREE/ΣHREE = 6. 57), with remarkably fractionation of LREE and HREE [averaging (La/Yb)N = 8. 20], slightly negative Eu anomalies (averaging δEu = 0. 77) and insignificant Ce anomalies (averaging δCe = 0. 88). The results demonstrate that REE characteristics of stratigraphic samples from Abalieke region are similar to those of rock and ore samples from other representative deposits (Tiekelike, Tamu, Kalangu, Tuokuziate) in the western Kunlun polymetallic ore belt, which indicate a close genetic relationship between the ore-forming materials and the host strata for the majority of deposits in this belt.  相似文献   

基于形态学灰度重构的乳腺微钙化点提取     

文浩  马金盛  王玉慧  庄达民 《CT理论与应用研究》2006,15(2):33-37

针对乳腺X线摄片,提出了一种计算机辅助检测乳腺微钙化点的方法:首先利用灰度形态重构完成穹顶提取,除去乳腺背景结构同时又能很好地保留微钙化点;其次运用拉普拉斯算子在空间域内对图像进行锐化以增强微钙化点;然后在频率域内利用巴特沃思高通滤波器对图像进行高通滤波;最后利用二维最大熵阈值分割对图像二值化,从而检测出微钙化点并在图像上标识出来。计算机辅助诊断的方法不仅避免了医生因大量阅片引起疲劳而造成误诊,起到了协助医生诊断的作用,而且提高了诊断的效率和准确率。  相似文献   

下扬子区新生代断陷盆地的断裂构造特征与活动规律   总被引：1，自引：0，他引：1       下载免费PDF全文

徐曦  孙连浦  肖梦楚  李筱  朱晓颖  高顺莉 《高校地质学报》2018,24(5):723

下扬子海陆域新生代沉积盆地是中国东部主要含油气盆地之一,成盆断裂特征与活动规律是该区油气勘探研究的基 础。文章基于高覆盖率的地震勘探测线,以构造断裂解析为突破口,探究盆地断裂的变形特征与活动规律。依据断裂组合 样式与构造活动特征,断裂可分为伸展、走滑、挤压-反转三种样式,构造活动分为伸展断裂与伸展-走滑断裂两种构造 体系。成盆断裂显著受控于郯庐断裂右行走滑变形,主要与郯庐断裂带不同构造走向的区段位置和与郯庐断裂带的距离这 两个因素或变量有关,盆地断裂呈现了“东西有别,中部不同”的特点。下扬子区新生代多变应力场,控制着作为油气运 移通道断裂的开闭状态,是油气资源评价的重要依据。  相似文献   

The Baltic Sea environment and the European Union: Analysis of governance barriers     

《Marine Policy》2017

The EU enlargement brought the Baltic Sea into the sphere of EU environmental policymaking, making the sea, with the exception of Russia, an EU inland sea. Yet, the state of the Baltic Sea environment is deteriorating at an alarming pace. This paper describes the evolution of the EU governance of the Baltic Sea environment, focussing on governance barriers. The findings demonstrate how the choice of analytical lens influences the construction of governance barriers and the respective intervention strategies. Such understanding can help policy practitioners in their search for successful measures to improve the governance situation in the Baltic Sea region.  相似文献   

基于COI基因和D-loop区部分序列比较雷州半岛东、西岸湖栖鳍虾虎鱼群体的遗传多样性     

廖健  龙水生  贺亮  郭昱嵩  刘楚吾  刘丽  王中铎 《海洋科学》2017,41(2):103-110

为比较分析雷州半岛东、西两岸湖栖鳍虾虎鱼(Gobiopterus lacustris)遗传差异,以COI基因和D-loop区部分序列为分子标记,获取雷州半岛湖栖鳍虾虎鱼群体COI序列44条(九龙山群体21条,高桥群体23条)、D-loop序列53条(九龙山群体25条,高桥群体28条)。基于COI基因部分序列分析结果显示:619 bp的44条序列中,统计的变异位点29个;T、C、A、G碱基组成分别为:27.8%、31.0%、23.7%、17.5%,且A+T(51.5%)高于C+G(48.5%);单倍型多样性比较,九龙山群体(0.695)高桥群体(0.324);遗传分化分析表明东、西群体分化显著(Snn=0.0.591,0.01P0.05),基因流(Nm)为5.37,遗传分化系数(Gst)为0.147,固定指数(Fst)为0.042(0.001P0.01),核苷酸差异数(Kxy)为2.547,核苷酸歧义度(Dxy)为0.004。而基于D-loop区部分序列分析结果表明:563 bp的53条序列中,变异位点133个;T、C、A、G碱基组成分别为:32.3%、14.8%、35.5%、17.4%,A+T(67.8%)明显高于C+G(32.2%);单倍型多样性与COI分析结果类似,九龙山群体(0.797)高桥群体(0.661);遗传分化分析表明东、西群体分化极显著(Snn=0.970,P0.001),Fst为0.315(P0.001),Nm值为0.55,Gst、Kxy、Dxy分别为:0.157、3.506、0.006;AMOVA分析揭示群体内变异程度高于群体间;聚类分析表明,基于COI基因与D-loop区部分序列构建的邻位链接法聚类树(NJ树)均存在按照采样点聚类的现象,但D-loop更为明显。综上,雷州半岛东、西两岸湖栖鳍虾虎鱼群体出现较为明显的分化现象。  相似文献