智能潜器控制系统的实航验证

本文介绍了某智能潜器的系统概要及其使命规划系统和使命控制系统的结构,并通过对其实航试验结果的分析,证明了本系统能够实现自主导航、自主避障等功能。特别是,本系统对潜器的位置和艏向具有优良的控制特性,达到了预定的研究目标。     

动力定位系统的模糊自适应控制

本文设计了一个用于海洋动力定位系统运动控制的模糊自适应控制器。文中提出了一种优化设计方法,使模糊控制性能接近最优,并保证了自适应控制的稳定性。仿真结果表明：该控制器有效、实用,在各种环境下都能取得满意的控制效果。该方法对于海上平台、动力定位船舶及潜器等控制系统都是适用的。     

太湖、琵琶湖中水平扩散系数的探讨

根据１９９２年和１９９３年在太湖和日本琵琶湖观测到的长序列湖流资料,依据Ｔａｙｌｏｒ扩散理论计算了太湖和琵琶湖中的水平扩散系数,计算结果与通过浓度扩散方程计算基本一致。     

Molecular identification,expression pattern,and in-vitro bioactivity analysis of insulin-like growth factor 2 in olive flounder Paralichthys olivaceus

Insulin-like growth factors (IGFs) are key regulators of development and growth. Here, we characterized the igf2 gene from olive flounder (Paralichthys olivaceus) and determined its temporal and spatial expression. We set up an in-vitro protein expression system in eukaryotic human embryonic kidney (HEK293T) cells and explored its effects on cell proliferation. The flounder igf2 cDNA contained a 648-bp open reading frame (ORF) encoding a protein of 215 amino acids (aa), which spanned the complete signal peptide (47 aa), mature peptide (70 aa), and E domain (98 aa). In adult flounder, igf2 mRNA was detected in all selected tissues. In early development, igf2 mRNA was detected throughout development from unfertilized eggs to hatching-stage embryos. In-situ hybridization analysis indicated that igf2 mRNA was specially expressed in the brain region, floor plate, hypochord, otic vesicle, and pectoral fin during embryogenesis. Western blotting analysis indicated that the soluble recombinant flounder IGF2 protein was successfully produced through eukaryotic expression in HEK293T cells. In addition, the recombinant IGF2 protein significantly promoted the proliferation of human cervical carcinoma (HeLa) and HEK293T cells. These results provide new information about the structural and functional conservation, expression patterns, and biological activity of the igf2 in teleosts.

     

Mercury speciation,bioavailability and risk assessment on soil–rice systems from a watershed impacted by abandoned Hg mine-waste tailings

Acta Geochimica - Mercury (Hg) is a global pollutant and can be accumulated in the food chain, posing exposure risks to humans. In this study, rice plants and corresponding rhizosphere soil samples...     

Iron Isotopic Compositions of Forearc Mantle Peridotites Constrained by Ophiolites from the North Qilian Orogen,Northern Tibet

Previous studies on iron isotope compositions of subduction zone magmas have revealed significant and complex variations that have great bearings on petrogenetic processes in the mantle wedge, e.g., partial melting, fluid metasomatism and redox state. However, interpretations for the fractionations are highly debatable and lack direct constraints from mantle wedge peridotites. This study presents iron isotope compositions for whole rocks and mineral separates in fresh forearc peridotites from the Yushigou ophiolite, North Qilian orogen in northern Tibet. Major and trace element compositions of whole rock and mineral indicate that the peridotites are highly depleted forearc peridotites overprinted by melt metasomatism, in contrast to the long‐holding opinion that the peridotites are derived from mid‐oceanic ridges. The minerals fall on a line with a slope of ～1 on the plot of δ⁵⁶Fe vs. δ⁵⁶Fe, indicating isotope equilibrium between minerals. δ⁵⁶Fe fractionation between olivine and orthopyroxene is within the range of 0～0.05, while fractionation between olivine and spinel is about 0.05～0.10. The fractionation trend between olivine and spinel is opposite to previous theoretical and experimental constraints, which may be due to substantial Cr substitution into the spinel. This indicates that negative correlations between spinel Cr#, fO₂ and spinel δ⁵⁶Fe in previous studies are probably a reflection of gradual Cr enrichment in spinel during melt extraction, and spinel δ⁵⁶Fe values are not a proxy for oxygen fugacity. Whole rock δ⁵⁶Fe values are well correlated with mineral δ⁵⁶Fe values, varying from overlapping with depleted mantle to slightly lower than depleted mantle. Therefore, variations in iron isotope compositions of subduction zone magmas are probably due to combined effect of source heterogeneity and partial melting fractionation.     

渭河流域全新世以来野火历史与人类土地利用的炭屑记录

全新世黄土沉积中的炭屑通常用来重建野火历史及其演变的过程。通过野外考察和对炭屑以及磁化率等指标的分析,获得全新世野火景观演变过程的地球生物沉积证据。参照OSL/TL、¹⁴C测年和考古学断代数据,重建渭河流域黄土高原全新世以来野火历史以及景观演变过程。结果表明：末次冰期到全新世中期阶段(12 000~3 100 a B.P.),渭河流域黄土高原地区野火事件变化主要与区域季节性气候差异密切相关,其中千年-百年尺度有效湿度和燃料供给区域变化是野火发生的主控因素;全新世晚期,随着气候进一步干旱,加之人类耕作活动加剧,人类土地利用强度与时空分布已成为影响生物量燃烧规模的重要驱动力。距今3 100 a以来,渭河流域南部地区农田景观已初具规模;而距今约2 170 a,大规模土地开垦已扩展到渭河北部黄土台塬地区;直到距今1 500 a,渭河北部黄土高阶台塬地区旱作农业景观已基本形成。利用多项古生态记录和区域角度综合分析,有助于深入理解该区域野火历史和人类土地利用变化以及社会结构演变过程。     

随钻电磁波测井数据处理新方法

在有限元素法分析的基础上,根据图版中数据对(地层视电阻率,介电常数)和(幅度衰减,相位差)之间的对应关系,给出了一种采用交汇解释图版的方法,可把随钻电磁测量的相位差和幅度衰减同时转换为地层视电阻率和地层介电常数。同时,通过三维数值模拟不同地层模型的仪器响应,系统地分析了地层各向异性、地层倾角和地层厚度等环境因素对随钻电磁测量视电阻率的影响,结果表明,地层倾角越小,地层厚度越大,测量结果也就越准确。同时绘制了相应的校正解释图版。     

西秦岭造山带东段喷流沉积型铅锌矿床特征及其成矿模式——以徽县洛坝矿床为例

西秦岭造山带东段西成矿田内发育一系列泥盆纪的喷流沉积型（SEDEX）铅锌矿床,甘肃徽县洛坝铅锌矿床就是其中的代表型矿床之一。它产于中泥盆统安家岔组焦沟层上部,矿体分布受洛坝背斜和南、北两翼断裂控制,与地层产状基本一致,矿石主要为纹层状、层状、浸染状、块状构造。经过详细的显微构造和SEM扫描电镜分析,鉴定出与喷流沉积有关的通道构造、淬火构造等。矿床地球化学分析显示,该矿床赋矿围岩的Ba、As、Sb、B、Ag、Hg等喷流沉积指示元素值均较高,且两者均具有LREE相对富集、明显的Eu正异常和中等Ce正异常特征,对比表明,成矿流体中的REE主要继承赋矿围岩（硅质岩）。矿床包裹体及硫同位素分析表明：成矿温度为168~350℃,以中、高温为主;早期矿化硫化物的δ³⁴S值（平均9.8‰）明显大于晚期矿化硫化物的δ³⁴S值（平均5.6‰）,说明后期改造作用中有地层硫的参与。综合研究表明,该矿床为热水喷流沉积型铅锌矿床,后期又受到海西期-印支期的叠加改造,并确定该矿床为秦岭后造山期板内伸展热水喷流的产物,最后建立了洛坝铅锌矿床热水喷流沉积成矿模式。     

郑州市河道沉积物中微塑料的污染特征

本文以郑州市主要河道沉积物为研究对象,利用密度浮选法分离提取沉积物中的微塑料,采用显微镜及傅里叶变换显微红外光谱仪(μ-FTIR)分析微塑料的丰度、组成、形状、尺寸分布特征.结果表明:郑州市7条主要河道沉积物中微塑料丰度为(以干重计):(2412±188)～(7638±1312)个·kg-1,平均丰度为(以干重计):(...