海洋沉积物中氮的形态及其生态学意义

海洋沉积物作为生源要素氮的重要源与汇，在其生物地球化学循环中起着至关重要的作用。该项研究旨在查清海洋沉积物中氮的存在形态及其生态学意义。氮是生物生命活动必需的营养要素，海洋中的氮往往是海洋初级生产力的限制因子，氮的吸收与再生释放在估算海洋新生产力和生源要素的生物地球化学循环率上也有重要贡献。海洋沉积物中的氮作为海水中氮的重要供给源是海洋生物赖以生存的重要物质基础，对维持海洋生态平衡、修复失衡的海洋生态环境具有重要意义。但由于不同海区海洋沉积物的来源和环境不同，氮的形态和含量亦不相同，可被生物吸收和利用的数量就不相同，因此造成了不同海区生物种群和环境不同，进而影响生态环境。因此，研究海洋沉积物中氮的形态，了解各个形态与沉积物中生物种群及与环境的关系，确定其生物和化学活性，査清氮不同形态的生态学功能，对于深入探讨海洋生物资源可持续利用的方法和策略具有重要意义。本文主要阐述海洋沉积物中氮的存在形式与分布、氮的早期成岩和去营养化作用、硝化和反硝化作用以及氮与生物特定种群的关系等，探讨了影响海洋沉积物中的氮循环的主要因素，并分析了海洋沉积物中的氮与生态系的关系，以期对研究氮的海洋生物地球化学过程有所帮助。     

金的活动态分析方法及其应用

在金相态分析方法的基础上,对金活动态分析方法进行了如下改进:用5 μm孔径的滤膜取代2 μm孔径的滤膜抽滤;将加入提取剂溶液提取黏土吸附相、有机结合相和铁锰氧化物相改为直接加入固体提取剂;将泡沫塑料吸附-原子吸收法改为甲基异丁基酮(MIBK)萃取-原子吸收法测定金。介绍了改进后的金活动态分析方法及其在东北高寒森林覆盖景观某金矿区的一个应用实例。结果表明,除水提取相异常相对不明显外,其余3个相在矿体上方均有清晰、明显的异常指示。其中有机结合相的异常强度最大,是在该景观条件下寻找隐伏矿的最有利相态。重复样分析的相对误差小于50%,满足金的活动态分析要求。     

Nekhoroshev estimate for isochronous non resonant symplectic maps

We prove that non resonant isochronous symplectic maps in a neighborhood of an elliptic fixed point are stable for exponentially long times with the inverse of the distance from the fixed point. In the proof we make use of the majorant series method together with an idea for optimizing remainder estimates first applied to Hamiltonian problems by Nekhoroshev.     

Overall stability performance of alternative hull forms

In this paper, two alternative corvette hull forms namely, the round bottom and deep V have been comparatively analyzed in terms of intact and damaged stability and roll performance in beam waves. The boat is planned to operate in the Navy's coastal water missions. Even though both forms are considered to comply with the design requirements, slight differences in displacement and principal dimensions are found to be inevitable due to the intrinsic characteristics of the specific forms. First part of the study concentrated on determining the conventional intact and damaged stability qualities whereas the second part was devoted to nonlinear rolling behavior of the vessels in synchronous beam waves. Nonlinear rolling amplitudes are thought to be quite important especially for resonance condition since they tend to peak in capsize conditions. Various combinations of loading conditions and damaged cases are taken into account to analyze the effects of them. Comparative results are presented graphically depicting the advantages/disadvantages of the selected forms over each other.     

Biogeography, Taxonomical Status and Ecology of Alcyonium (Parerythropodium) coralloides (PALLAS, 1766)

Abstract. Ecology and morphology of Alcyonium (Parerythropodium) coralloides were studied in different sites of the Eastern Atlantic and the Mediterranean. The species is extremely variable in size, colony shape and colour. In the Mediterranean population, encrusting red colonies are mostly encountered, although lobate colonies also exist. White and pink colonies are considered mutants, which tolerate the stable environment of deeper habitats better than the conditions encountered in shallow biotopes. Mediterranean colonies are dioecious and reproduce sexually. In the Eastern Atlantic, lobate pink colonies are the most common form, and show little variability. These (at least partly) parthenogenic populations are considered offspring from stray larvae from more southern regions. This explains the rather patchy distribution of the Atlantic populations, as compared to the widespread distribution throughout the entire Western Basin of the Mediterranean and the Adriatic Sea. A study of the most important systematic characters of the species (growth form, sclerites and solenial network) leads to the conclusion that coralloides belongs to the genus Alcyonium. As a result, coralloides being its type-species, the genus Parerythropodium will have to be suppressed.     

全数字摄影测量系统与MicroStation联机测图

论述了全数字摄影测量系统(DPS)与MicroStation联机测图的方法,以及与此相关的层控对应表的制作.以实际生产作业为例,有效地提高了工作效率,降低内耗,减少了作业中间数据的相互转换,避免了有效数据的丢失,很好地保证了产品的质量.     

向海湿地沉积剖面化学元素相对迁移特征分析

旨于探索沉积剖面元素迁移强度的描述方法,讨论向海沼泽湿地沉积物化学元素的迁移积聚等基本地球化学特征,以深化对沼泽湿地沉积化学行为的某些认识。冬季在向海两处沼泽采集了代表一定范围汇水区与人类活动影响的沉积芯。利用Tessier等(1979)提出的连续提取法对沉积物中多种常量与微量元素地球化学相进行分离。可迁移系数、潜在迁移系数、非迁移系数的计算结果表明,在向海沼泽沉积剖面中,化学元素相对迁移强度为:Ca、Sr、Mn、Pb潜在活性最大,Ti、Al、K、Rb潜在活性最小,以此为依据,Ti、Al、K、Rb等元素适宜作为示踪元素。为消除沉积物构成组织的影响,以Al为参考元素对重金属元素形态两种分量进行归一化后,重金属环境非迁移分量与相对迁移分量均表现出在表层的富集,尤其表现在上游霍林河煤矿开发后20余年这一时期,人类活动的介入加速了重金属元素通过河流搬运向下游湿地的输入。     

元素活动态测量法在鄂尔多斯盆地砂岩型铀矿勘查中的应用

常规化探方法勘查砂岩型铀矿难以奏效。应用深穿透地球化学方法系列中的元素活动态测量法在鄂尔多斯盆地砂岩型铀矿上的试验结果表明,几种U元素活动态在矿体上方都有异常出现,特别是其中的粘土吸附态U含量级别高、异常衬度大。因此,土壤粘土吸附态U测量法是本区化探找铀矿的有效方法;取样深度和取样粒级分别以60～90cm和-120目为宜;采用400m的取样点距基本不影响本区砂岩型铀矿的找矿效果。在盆地东北部应用土壤粘土吸附态U测量法预测了3个有利地段,并在其中1个地段的深部发现了较好的铀矿化。     

地貌基本形态的主客分类法

针对现有地貌基本形态分类法的欠缺，提出了“地貌基本形态的主客分类法”。本分类法是一种以相对高度为主，绝对高度为辐的地貌分类法。它首先根据相对高度将地貌基本形态划分为平原、丘陵、低山，中山和高山等，然后再按绝对高度把这些形态再分别划分为低位、中位、高位三种类型。该地貌分类法的优点在于①符合人们对于山地的高、中、低的观念，避免了现有地貌分类法中出现的那种与人们固有观念相冲突的高山不高、低山不低的现象；②统一了地貌基本形态的划分标准，避免了平原、丘陵按相对高度划分，而山地按绝对高度划分的不一致性；③有利于地貌知识的科学普及和地貌的利用。     

The hydrogeochemistry of the Kärkevagge Valley, Lapland, Sweden

The Kärkejokk (jokk = Lappish for brook) is rich in sulfate and calcium, both elements having been considered enigmatic. To resolve these problems we collected waters at 13 sites during 27 June to 1 September 1996. Nine sites were in the Kärkevagge, and the others in the drainage towards lake Torne Träsk. Rain waters were collected the same period. Conductivity, pH, and temperature were measured in the field, whereas salt load and the elements Na, K, Ca, Mg, S, Si, Fe, Al, Mn, Zn, Sr, and Ba were determined in the laboratory.
Mixing models based on rain water and leaching products of the major bedrocks do not explain observed element patterns except in the lower parts of the jokk. However, oxidation of pyrite has formed acid, sulfate–rich solutions that released Ca and Mg from limestones, and Fe, Mn, Al, and Si, from black shales (Malmsten 1998; Malmsten et al. 2000). Conservative mixing models, using rain water, leached bedrock and pyrite, match the jokk waters quite well, and sulfur isotope data corroborate these findings. The nearby Låktajokk, and Vassijokk also contain much S.
Where these waters debouch they may deposit Si, Al, and Ca, but only little S on various rocks. Total rock analyses, thermodynamic and X–ray data suggest that gypsum, barite, or alunite are not formed in major quantities.
These models show that the hydrogeochemistry of the Kärkejokk may be less enigmatic than often assumed.