NONLINEAR GRAVITY-WAVES IN DEEP-WATER

In consideration of the problem on the boundary condition of nonlinear free water wave, coordinate transform is used to handle the free boundary. Supposing the solution form be the traveling wave, the ordinary differential equations of the one-order autonomous system with two variables are caused, then expanding the nonlinear terms at the equilibrium point with the Taylor expansion, we obtained the solution to traveling wave. The linear approximate equation near the equilibrium point is the small amplitude wave. A new nonlinear periodic traveling wave and nonlinear dispersion relation are shown when expanding to the second-order terms. A conclusion that the expansion of dispersion relation does not contain any odd-power terms of wave steepness and because of the nonlinear effort an oscillate structure is produced in the vertical direction is drawn.

Sources and preservation of organic matter in Plum Island salt marsh sediments (MA, USA): long-chain n-alkanes and stable carbon isotope compositions

Elemental (TOC, TN, C/N) and stable carbon isotopic (delta(13)C) compositions and n-alkane (nC(16-38)) concentrations were measured for Spartina alterniflora, a C-4 marsh grass, Typha latifolia, a C-3 marsh grass, and three sediment cores collected from middle and upper estuarine sites from the Plum Island salt marshes. Our results indicated that the organic matter preserved in the sediments was highly affected by the marsh plants that dominated the sampling sites. delta(13)C values of organic matter preserved in the upper fresh water site sediment were more negative (-23.0+/-0.3) as affected by the C-3 plants than the values of organic matter preserved in the sediments of middle (-18.9+/-0.8) and mud flat sites (-19.4+/-0.1) as influenced mainly by the C4 marsh plants. The distribution of n-alkanes measured in all sediments showed similar patterns as those determined in the marsh grasses S. alterniflora and T. latifolia, and nC(21) to nC(33) long-chain n-alkanes were the major compounds determined in all sediment samples. The strong odd-to-even carbon numbered n-alkane predominance was found in all three sediments and nC(29) was the most abundant homologue in all samples measured. Both delta(13)C compositions of organic matter and n-alkane distributions in these sediments indicate that the marsh plants could contribute significant amount of organic matter preserved in Plum Island salt marsh sediments. This suggests that salt marshes play an important role in the cycling of nutrients and organic carbon in the estuary and adjacent coastal waters. (C) 2003 Elsevier Ltd. All rights reserved.

H5N1 avian influenza re-emergence of Lake Communication Qinghai: phylogenetic and antigenic analyses of the newly isolated viruses and roles of migratory birds in virus circulation

Highly pathogenic avian influenza H5N1 virus has swept west across the globe and caused serious debates on the roles of migratory birds in virus circulation since the first large-scale outbreak in migratory birds of Lake Qinghai, 2005. In May 2006, another outbreak struck Lake Qinghai and six novel strains were isolated. To elucidate these QH06 viruses, the six isolates were subjected to whole-genome sequencing. Phylogenetic analyses show that QH06 viruses are derived from the lineages of Lake Qinghai, 2005. Five of the six novel isolates are adjacent to the strain A/Cygnus olor/Croatia/1/05, and the last one is related to the strain A/duck/Novosibirsk/ 02/05, an isolate of the flyway. Antigenic analyses suggest that QH06 and QH05 viruses are similar to each other. These findings implicate that QH06 viruses of Lake Qinghai may travel back via migratory birds, though not ruling out the possibility of local circulation of viruses of Lake Qinghai.

Cloning of hypoxia-inducible factor 1 alpha cDNA from a high hypoxia tolerant mammal - plateau pika (Ochotona curzoniae)

Hypoxia-inducible factor I is a transcription factor composed of HIF-1alpha and HIF-1beta. It plays an important role in the signal transduction of cell response to hypoxia. Plateau pika (Ochotona curzoniae) is a high hypoxia-tolerant and cold adaptation species livin only at 3000-5000m above sea level on the Qinghai-Tibet Plateau. In this study, HIF-1alpha cDNA of plateau pika was cloned and its expression in various tissues was studied. The results indicated that plateau pika HIF-1alpha cDNA was highly identical to those of the human (82%), bovine (89%), mouse (82%), and Norway rat (77%). The deduced amino acid sequence (822 bp) showed 90%, 92%, 86%, and 86% identities with those of the human, bovine, house mouse, and Norway rat, respectively. Northern blot analyses detected two isoforms named pLHIF-1alpha and pSHIF-1alpha. The HIF-1alpha mRNA was highly expressed in the brain and kidney, and much less in the heart, lung, liver, muscle, and spleen, which was quite different from the expression pattern of mouse mRNA. Meanwhile, a new variant of plateau pika HIF-1alpha mRNA was identified by RT-PCR and characterized. The deduced protein, composed of 536 amino acids, lacks a part of the oxygen-dependent degradation domain (ODD), both transactivation domains (TADs), and the nuclear localization signal motif (NLS). Our results suggest that HIF-1alpha may play an important role in the pika's adaptation to hypoxia, especially in brain and kidney, and pika HIF-1alpha function pattern may be different from that of mouse HIF-1alpha. Further-more, for the high ratio of HIF-1alpha homology among the animals, the HIF-1alpha gene may be a good phylogenetic performer in recovering the true phylogenetic relationships among taxa. (C) 2004 Elsevier Inc. All rights reserved.

力马河镍矿Re-Os同位素研究

四川力马河镍矿是峨眉山大火成岩省一个重要的岩浆硫化物矿床。本文通过对其主要岩、矿石类型Re、0s及其同位素组成的分析，综合探讨了成矿岩体原始岩浆性质、矿石硫化物成因、成矿机制及Re-Os同位素等时线年龄。结果表明，力马河镍不同类型岩矿石样品初始0s同位素组成是不均一的，富硫化物的网脉状矿石 及其选纯硫化物Os同位素组成初始值差异较小，其等时线年龄为265士35 Ma，与岩体错石SHRIMP年龄263士3Ma基本相当}硫化物含量较低的岩、矿石样品间初始Os同位素组成差异较大，其表观等时线年龄大于成矿年龄。分析认为。岩矿样品初始Os同位素组成的不均一是由含较高放射成因187Os丰度的硫化物熔体和含较低放射成因187Os丰度的硅酸盐熔体不同比例混合造成的。混合模型分析表明，硫化物含量超过3O％ 的矿石样品初始187 Os／188Os基本接近，硫化物含量低于3O ％的岩矿石样品初始 187Os／188Os随硫化物含量上的不同，差异很大，为岩浆硫化物矿床Re-Os等时线年龄出现多组年龄解的现象提供了一种可能的解释。成矿岩体中含放射成因187Os丰度最低的岩石样品 (t一260Ma)在5左右、Cu／Pd比值在7000左右，表明是基本没有受到地壳混染及硫化物熔离影响的原始岩浆结晶分异产物，估计原始岩浆Os含量在1×10 左右，为苦橄质岩浆。矿石硫化物Re／Os比值显著高于任何赋矿橄榄岩，7o,(￡一260Ma)高达110左右，综合分析揭示了力马河镍矿硫化物为二次熔离成因，模式分析认为，矿石硫化物是由原始岩浆经历R一2000左右的硫化物熔离后，其亏损岩浆再经R一200左右的硫化物熔离形成，与二次熔离相对应，成矿岩浆也经历了两次混染作用，分别为上、下地壳7％左右的混染。

粤北红岭钨矿中辉钼矿Re-Os同位素年代学及其地质意义

跃北红岭钨矿为产在热水复式岩体之中的中型钨多金属矿床, 矿化类型为石英脉型黑钨矿化和蚀变花岗岩型白钨矿化。对矿区含矿石英脉中8个辉钼矿样品进行Re-Os同位素测定, 获得等时线年龄及模式年龄的加权平均值分别为159.1±1.5Ma和158.8±0.88Ma. 等时线纵截距为-0.010±0.041, 说明样品中不存在可测定的初始187Os. 统计表明南岭地区中东段钨锡矿床的成矿年龄多集中在150~160Ma。粤北已有的几个钨矿成矿年龄与区域燕山期花岗岩大规模侵位时期一致，表明南岭地区花岗岩成岩成矿可能不存在明显的时差。