白洋淀枝角类和桡足类调查及水环境因子分析

为了研究枝角类和桡足类的物种组成与分布以及与水环境因子的相关性,于2018年8月对白洋淀枝角类和桡足类及水环境因子进行了调查.基于DNA条形码技术对白洋淀的枝角类和桡足类种类进行鉴定,建立系统发育树,通过系统发育树鉴定物种种类并表明其遗传距离,共鉴定出枝角类3科5属8种,桡足类4科9属14种.采用典型相关分析(CCA)...     

环境因子对浮游动物休眠卵萌发的影响

目的:探讨不同环境因子对浮游动物休眠卵萌发的影响,为亚热带河口浮游动物的潜在补充机制和群落演替规律提供基础数据.方法:采集珠江口桂山岛海域表层沉积物,研究Cu、Zn、Cd、水温、盐度、酸碱度、冷藏时间和原位海区不同水深对休眠卵萌发的影响.结果:随着Cu、Zn、Cd浓度的增加和处理时间的延长,休眠卵死亡率呈明显上升趋势;桂山岛海域沉积物中休眠卵在较宽的水温、盐度、酸碱度范围均可孵化;冷藏10个月后孵化的桡足类幼体数量显著高于冷藏半个月;位于原位海区0. 5 m处沉积物中休眠卵的萌发量显著高于2 m处.结论:重金属对沉积物中休眠卵的孵化有较大影响,毒性效应由大到小依次为Cd Cu Zn;桂山岛海域沉积物中休眠卵最适孵化条件为:水温25℃、盐度30、酸碱度8;低温冷藏刺激有利于桡足类休眠卵孵化;原位海区休眠卵孵化数量与光照强度呈显著正相关.     

巴西沿岸浮游端足类锥科的种类与分布

浮游端足类是海洋浮游动物中的重要类群之一,其数量大,在浮游甲壳类中仅次于桡足类和磷虾类,居第三位,浮游端足类的分类系统,Pirlot等,Stephensen等已经做过研究,Bowman和Gruner在此分类系统基础上做了些修正,建立21科71属,共约500种,锥科的分类研究,包括种名修正、种类描述、种类索引等尚有其它报道。本文研究巴西沿岸     

海洋浮游桡足类滞育及其生理生态学研究进展

简述了海洋浮游桡足类滞育及其生理生态学的研究进展,总结了厦门大学海洋学系在这一研究领域的研究成果,包括滞育卵的形态与孵化、桡足类的季节演替以及桡足类滞育的生理生态学3个方面的研究.     

九龙江口低盐区桡足类种类多样性最小现象的初步研究

通过2003年5月至2004年2月间的4个调查航次，对沿九龙江口分布的桡足类种类数与盐度及盐度变化幅度的关系进行了初步研究．结果显示，该河口低盐区存在桡足类种类多样性最小现象，沿河口分布的桡足类种类数与所在水域的盐度变化幅度呈线性负相关，反映了剧烈的盐度变化对桡足类种类多样性的限制作用．桡足类有限的适盐能力和伴随潮汐垂直移动以借助水流迁移的行为则可能是形成在低盐区种类多样性最小现象的内因．     

海洋浮游桡足类滞育及其生理生态学研究进展

简述了海洋浮游桡足类滞育及其生理生态学的研究进展．总结了厦门大学海洋学系在这一研究领域的研究成果。包括滞育卵的形态与孵化、桡足类的季节演替以及桡足类滞育的生理生态学3个方面的研究．     

二氧化碳酸化和盐酸酸化对几种桡足类的急性毒性比较

利用实验生态学的方法研究了由二氧化碳和盐酸引起的海水酸化对几种桡足类的急性毒性,计算了24和48 hLC50(以pH值表示).结果表明:二氧化碳酸化条件下,几种桡足类的24和48 hLC50分别为pH 5.85~6.49和pH 5.93~6.69;盐酸酸化条件下,24和48 hLC50分别为pH 5.02~5.69和pH 5.25~6.12.裂区设计方差分析表明,二氧化碳酸化对桡足类的毒性显著高于盐酸酸化的毒性.此外,各种桡足类对海水酸化的耐受性具有高度的种类特异性:营底栖生活的日本虎斑猛水蚤的耐受性明显高于其他浮游性种类;在营浮游性生活的种类中,植食性种类(中华哲水蚤)对酸化的耐受性要高于杂食性和肉食性种类.本研究结果为进一步研究海水酸化对桡足类生理生化影响提供参考依据.     

我国海洋浮游桡足类的种类组成和地理分布

1:本文根据作者和过去有关我国海洋浮游桡足类的分类研究结果,将我国各海区的桡足类种类组成,特别是优势种,作了扼要介绍。从种类组成中,可以看出各海区桡足类的生态特点,而这些特点是和海流影响分不开的。作者认为,黑潮暖流和沿岸流在这方面起了决定性作用。 2.从各海区种类组成的比较中,可以看出有些广温性种类分布很广,遍及各海区;有些暖水性种类自南海向北分布到东海,甚至更远些分布到南黄海;而有些狭温性热带种类分布较狭,只局限于南海。这样,就可把我国海洋浮游桡足类的地理分布大体分为以上四类。这四类的划分仅是初步的。今后随着调查的扩展和深入,当会发现更多的种类;同时也会发现有些种类的划分可能是错误的。此外,也可能把上述划分法加以改变——合并或增加,本文仅就现有资料,对我国海洋浮游桡足类的地理分布作了初步探讨,并扼要地论述了地理分布和海流的关系,为将来进一步深入研究,特别是研究区系问题提供参考资料。     

海洋桡足类滞育卵在海水养殖业中的应用及其前景

海洋桡足类作为小型甲壳动物，是鱼虾类良好的天然饵料，其繁殖和培养将在现代海水养殖业中发挥重要的作用。本文就桡足类滞育卵的产生、控制条件和在养殖业上的潜在价值等进行了综述。     

西沙、中沙群岛海洋浮游桡足类的种类组成和分布

本文分析了1973—75年采集于西沙、中沙群岛周围海域的样品。初步鉴定浮游桡足类167种,其中19种(大多数是热带大洋深水种类)为我国首次记录。本海区具有热带太平洋浮游桡足类的区系特点。据其生态特点及分布范围,可分为广温广盐、高温低盐、高温高盐和深水四个生态类群。此水域的浮游桡足类的分布,主要受南海暖流和沿岸流及南海底层高盐冷水团的影响。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that