鄱阳湖桡足类的群落组成与现存量季节变化的初步研究

根据１９８７￣１９８９年在鄱阳湖进行的６个采样站的调查资料,共获得２３种浮游桡足类,隶属３目６科１６属。新记录１０种。根据各种类出现的月份,把２３种桡足类分成终年出现型,夏秋季型、冬春季型和畏严冬型;并据出现的区域,归成沿岸型,敞水型和广布型。年数量变动曲线与生物量变动曲线有春、夏和秋季三次高峰。秋季高峰比春,夏季高峰更突出,持续时间约两个月,但生物量与数量三次高峰出现的时间并不完全一致。笔者还初     

鄱阳湖原生动物群落生态的初步研究

报道了１９８７～１９８９年鄱阳湖６个采样站原生动物的种类组成和现存量季节性变化的调查结果。共观察到８３种原生动物（仅包括肉足虫类和纤毛虫类）,隶属于５３属３１科１２目。原生动物数量变动曲线一般有春末和仲秋两个高峰,秋季高峰远大于春末高峰。原生动物年生物量变动曲线与数量变动曲线基本上一致。还用原生动物群落的多样性指数、相似系数与优势种群对鄱阳湖各站的水质进行了评价。     

鄱阳湖轮虫种类组成与现存量季节变动的初步研究

根据Ｋｏｓｔｅ提出的轮虫分类系统对鄱阳湖１９８７－１９８９年６个采样站的轮虫调查资料进行了分类，并报道了其现存量的调查结果。笔者共观察到轮虫８５种，隶属于３３个属，２０个科。鄱阳湖轮虫新记录２８种。翻阳湖轮虫的数量变动曲线与生物变动曲线都呈现夏，秋季两个高峰，冬，春季为低贬期。     

赣江中下游浮游动物时空分布特征及水质综合评价

对2010年12月与2011年7月赣江中下游各监测断面中浮游动物类群的结构组成、优势类群进行调查,结果表明:赣江中下游浮游动物有4类41种;种类最多的是轮虫类,共计7科15属25种,占总数的60.98%;枝角类5科6属7种,占17.07%;桡足类与原生动物占21.95%。时间分布上浮游动物丰度丰水期大于枯水期,密度变动范围为100~522个/L,其中丰水期轮虫、枝角类、桡足类与原生动物密度分别占浮游动物密度的61.7%,11.4%,18.9%与7.8%;枯水期轮虫、枝角类、桡足类与原生动物密度分别占浮游动物密度的65.3%,9.5%,16.0%与9.1%。浮游动物密度空间分布上呈现中间大、两端小的特点,最大值出现在4号监测点新干,最小值出现在10号监测点赣州。赣江中下游浮游动物数量结构主要由轮虫和桡足类组成,生物量结构则主要由桡足类和枝角类组成。生物多样性及水质综合评价为轻度污染至中度污染。     

鄱阳湖保护区碟形子湖浮游动物群落季节动态研究

为了解鄱阳湖保护区子湖内浮游动物群落的季节动态变化，分别于2020年7月、10月和11月在江西鄱阳湖国家级自然保护区内的1个碟形子湖——沙湖进行了浮游动物定量采样调查. 3个季节调查共采集到浮游动物77种，其中轮虫62种、枝角类9种、桡足类6种.浮游动物密度的季节变化为夏季高于秋季，秋季高于冬季；浮游动物生物量的季节变化为夏季高于冬季，冬季高于秋季.无度量多维排序(NMDS)和群落聚类分析显示，2020年沙湖浮游动物的群落结构可以明显区分为3个：夏季群落、秋季群落和冬季群落.与前期研究结果进行对比分析发现：长江流域的十年禁渔措施促使了鱼类种群数量的恢复，间接影响了浮游动物的组成和数量.     

鱼池浮游动物变动规律与鱼产力的关系

在北京双桥鱼场,经三年来研究,鉴定出浮游动物84种,其中轮虫29种。虽然轮虫仅占浮游动物数量的16.87％,但在生物量上,却要占到浮游动物生物量的72.80％,说明轮虫明显地左右着浮游动物生物量的变动。从浮游动物年变动规律分析,一年有1～2次高峰,生物量的高峰多出现在6～7月,占总调查高峰次数的60％。本文还从水质、水温、饵料等因素,分析了对轮虫生物学上的影响,探讨了轮虫和浮游动物生物量之间的相关性,最后对浮游动物等转化鳙鱼鱼产力的估算值与其实际产量进行了比较与分析。     

虾池小型底栖动物类群组成和数量分布

2002-09-10-2003-02-26期间6次采样,对厦门高崎3口虾池小型底栖动物的数量变动、生物量变化及水平分布进行了初步研究,结果表明:自由生活海洋线虫和桡足类是虾池中小型底栖动物的主要类群.实验期间养殖区和对照区中,线虫的平均密度基本相同,分别为(59.0±26.1)(个·cm-2)和(51.1±31.8)(个·cm-2);桡足类的平均密度分别为(6.0±6.2)(个·cm-2)和(1.5±1.0)(个·cm-2).整个实验期间2个类群的数量,养殖区表现为养殖前期(大约2个月内)激增,之后在一定的范围内上下波动;对照区表现为比养殖前期更长的期间内增长,特别是桡足类,在整个养殖期间近乎呈现为逐步增长的趋势.养殖区和对照区中,线虫的生物量干重分别为(9.43±4.18)(μg·cm-2)和(8.17±5.09)(μg·cm-2);桡足类的分别为(11.93±12.36)(μg·cm-2) 和(2.93±2.07)(μg·cm-2).两大类群的水平分布规律不同.     

珠江口枯水期和丰水期中小型桡足类种类组成、丰度分布及其与环境因子的关系

中小型桡足类是河口区浮游动物的重要组成部分.根据珠江口枯水期(2013年11月)和丰水期(2014年8月)24个站位的调查资料,对中小型桡足类种类组成、丰度分布和优势种等特征进行了研究.枯水期和丰水期中小型桡足类分别出现60和40种,以河口和近岸类群为主.根据表层盐度变化将珠江口分为Ⅰ、Ⅱ、Ⅲ区,桡足类种类分布具有显著的河口特征,枯水期和丰水期盐度均为Ⅲ区Ⅱ区Ⅰ区.相关性分析结果显示,桡足类种类数与盐度呈极显著正相关.桡足类丰度时空分布差异显著,丰水期(10 809.05ind/m3)显著高于枯水期(1 371.20ind/m3),且在2个水期均以Ⅰ区丰度最高.强额孔雀哲水蚤(Parvocalanus crassirostris)和中华异水蚤(Acartiella sinensis)在2个水期均为主要优势种,其空间分布亦与盐度密切相关.研究结果表明盐度是影响珠江口中小型桡足类种群结构的关键非生物环境因子.     

舟山黄大洋海域春夏季鱼类种类组成和分布特征

根据2010年5月、11月对黄大洋进行的2次拖网调查所获鱼类资料,分析了该海域鱼类种类组成、数量分布和多样性特征。结果表明:黄大洋春秋两季共出现鱼类48种,隶属于13目、28科,其中春季出现鱼类28种,秋季35种。春季优势种主要为六丝钝尾虾虎鱼、龙头鱼、棘头梅童鱼等,秋季龙头鱼和黄鲫在尾数和生物量上都占绝对优势。根据不同季节ABC曲线变化,黄大洋春秋季鱼类的丰度曲线均在生物量曲线之上,说明其鱼类群落处于不稳定的状态。秋季鱼类渔获率普遍高于春季,这主要与鱼类的生态习性有关,水平分布上黄大洋东面站位的渔获率两个季节均高于西面站位渔获率,其主要受水文环境影响。     

厦门及其附近沿海橈足类生态的初步研究

厦门内港桡足类种类与数量春季开始增加,形成全年次高峯,秋季达到全年最高峯,种类的季节变化有二种类型:(1)季节变化显著的,暖水性或暖流种类,(2)季节变化不很显著的,少数四季常见的种类,根据种类的季节变化看来,厦门内港在9—10月间受黑潮暖流的影响较大。 根据昼夜垂直移动的幅度,厦门内港桡足类可分为二大类型:(1)有显著昼夜直垂移动的种类,(2)没有显著昼夜垂直移动的种类,但幼体与成体的昼夜垂直移动则并不完全一致,这随种类而巽,“午夜下降,黎明上升”的现象在桡足类中并不普遍。     

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.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

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