氮浓度、温度和照度对波吉卵囊藻繁殖模式的影响     

杨敏志  李长玲  黄翔鹄  王清珍  陈爱珊 《广东海洋大学学报》2019,(5)

【目的】探索波吉卵囊藻(Oocystisborgei)的繁殖模式,调控其生殖过程以实现藻生物质稳定增长。【方法】在荧光显微镜下观察波吉卵囊藻似亲孢子形成过程,探究温度、照度、氮浓度对其繁殖模式的影响。【结果】波吉卵囊藻以2、4和8似亲孢子型模式繁殖,在藻细胞第二轮分裂过程中因分裂不同步,有时也形成3个似亲孢子。氮限制和弱光显著影响波吉卵囊藻繁殖模式(P 0.05)。通常情况下,波吉卵囊藻以4似亲孢子型繁殖模式繁殖,但在缺氮和弱光下2和3似亲孢子型模式的频率上升。在15～35℃温度范围内,波吉卵囊藻繁殖模式变化不大。【结论】波吉卵囊藻有4种繁殖模式。在不良环境中,2和3似亲孢子型模式频率上升。  相似文献   

发头裸腹溞休眠卵发育的温度因子分析   总被引：2，自引：0，他引：2  

黄诚  葛家春  孟文新  陈建秀  周婷 《湖泊科学》1996,8(2):151-155

测定了不同温度下发头裸腹溞(Moina irrasa)体眠卵的孵化时间及孵化率;取最先孵出和过半数孵出的两组数据依莱奥姆积温法则求得种群休眠卵最低临界温度为12.00℃,最低有效积温为441.61℃·h;最低亚致死高温点(即最适温度)为35.16℃,以及最低死亡高温点39.44℃。种群中过半数的临界温度为12.88℃,过半数有效积温为557.10℃·h,过半数的亚致死高温点为35.56℃以及过半数死亡高温点为39.49℃。讨论了这些参数在枝角类集约化培养中休眠卵的有效保存与启用所具有的实践意义。  相似文献   

西藏许如错地区中全新世地震触发软沉积物变形构造及其地质意义   总被引：1，自引：0，他引：1       下载免费PDF全文

秦雅东  张士贞  刘函  李勇 《地球科学》2020,45(8):2945-2956

湖相沉积古地震研究是对地表破裂古地震研究的重要补充.通过详细的野外地质调查,在西藏许如错地区全新统湖相地层内新发现大量地震触发软沉积物变形构造(震积岩),层内发育液化脉、液化曲卷变形、液化角砾岩、液化水压构造、滴状体与锥状体、砾石丘、负载构造和火焰构造等软沉积变形标志,还发育同震断层、震裂缝和同震褶皱等同震构造标志.根据软沉积变形标志与震级之间的关系,结合历史地震统计液化颗粒范围,通过C14和光释光年龄测定,推测古地震事件发生在±7.5 ka,M_S>7.5级;填补了该区历史地震的空缺,为恢复青藏高原南北向地堑地震活动历史及迁移规律提供了素材.震积岩中见大量砾石液化现象,这对现阶段以砂土-粉砂土研究为主的砂土液化调查工作提出了新挑战.   相似文献   

砂砾岩储层中岩屑含量统计方法及应用:以东营凹陷北带盐家-永安地区沙四段上亚段为例北大核心CSCD     

王军  曲希玉  陈思芮  郭长春  邱隆伟  张习武 《矿物岩石地球化学通报》2020,(1):51-58

岩屑的类型与含量对于储集层的研究具有重要意义,但是现有的统计方法通常是针对砂级大小的岩屑颗粒,这对于以砂砾混杂为主的砂砾岩储层研究来说会忽视对砾石级大小岩屑的含量统计,进而导致岩屑的统计结果偏差。为了建立适用于砂砾岩储层的岩屑含量统计方法,综合应用FMI成像测井、岩芯观察及薄片鉴定等手段,将宏观砾石级岩屑统计结果和微观砂级岩屑统计结果结合起来,对砂砾岩储层中的岩屑类型与含量进行定量表征,从而在一定程度上降低薄片观察与统计带来的统计学误差。将该方法应用于东营凹陷北带盐家-永安区块沙四段上亚段储层中得到的认识为:盐家区块以碳酸岩岩屑与花岗片麻质岩屑为主,永安区块以硅质岩屑与花岗片麻质岩屑为主;岩屑类型与含量的差异是导致两区块储层物性差异的主要原因之一。  相似文献   

Oomycetes and fungi: important parasites on marine algae     

LI Wei  ZHANG Tianyu  TANG Xuexi  WANG Bingyao 《海洋学报(英文版)》2010,29(5):74-81

Considering that the field is largely unexplored and its importance to aquaculture, outline of oomycetes and fungi parasiting on marine algae was provided in this paper, including 15 species of oomycetes, six species of chytrids, 31 Ascomycota species and one species of mitosporic fungi. In natrue, both the oomycetes and chytrids frequently occurred and induced prevalences of disease which could destroy the populations of host plants greatly. However, the parasites in Ascomycota on algae have never occurred as epidemics so far. Some issues relating to the field were discussed such as performing tests to satisfy Koch''s postulates, investigations of host specificity, interactions between host and parasite and the potential effects of environmental factors on occurrence of a disease, which are urgent in need of further investigations.  相似文献   

A Multi-Generation Schmakeria poplesia Culturing System for Use in Ecotoxicological Study     

HUANG Ying  ZHU Liyan  QIU Xuchun  QI Benjin  ZHANG Tianwen 《中国海洋大学学报(英文版)》2009,8(1)

Crustacean zooplankton form the keystone link between primary producers and fish stocks in marine and estuary ecosys-tems. We have established a multi-generation cultivation system for zooplankton with which future experiments on the biological effects of pollutants in marine and estuary environments can be better performed. A population of calanoid copepod, Schmakeria poplesia, was collected in December 2003 and maintained in a static system through all stages (eggs to adults). The population ex-hibited an average developmental time of 13.6d in conditions corresponding to the natural enwronment (water temperature 20℃ salinity 15). A series of experiments were performed to examine copepod egg production and hatching success as functions of food type and feeding concentration. Results in our study showed that Isochrysis galbana was more favored for the reproduction of cope-pods than Phaeodactylum tricornutum, and 10×104cellsmL-1 was the most practical algae concentration. We have demonstrated that the Schmakeria poplesia population can be maintained in the laboratory through multiple generations. In addition, methods to control egg production through changes in food concentration have been established, making it feasible to control the start date of exposure experiments or the timing of the collection of offspring to initiate a new generation.  相似文献   

Gravel accumulation in deposits of viscous debris flows with hyper-concentration   总被引：1，自引：1，他引：0  

Yuyi Wang  Rongzhi Tan  Chyandeng Jan  Bing Tian 《山地科学学报》2009,6(1):88-95

According to the observational data of viscous debris flows with hyper-concentration, debris flows can be classified into three types： high-viscous, viscous, and sub-viscous debris flows. Distinct formation mechanism of different graded bedding structures in deposits of viscous debris flows was analyzed in this paper by using their yield-stress ratio and flow plug ratio. This paper specially analyzed the effect of Weissenberg which the gravels in squirm condition of hyper-concentration viscous flows would tend to move vertically, and the formation mechanism of the gravels accumulated at surface was also studied. The analysis in this paper can establish a foundation for the studies on differentiation of bedding structures of debris flow deposits and studies on dynamic parameters of debris flows.  相似文献   

凤鲚、湖鲚和刀鲚卵巢氨基酸、脂肪酸及矿物元素分析     

王桂学  刘凯  徐东坡  段金荣  张敏莹  施炜纲 《广东海洋大学学报》2009,29(3):86-89

对长江下游凤鲚、湖鲚和刀鲚卵巢氨基酸、脂肪酸和矿物元素组成及含量进行了测定分析。结果表明:三种鲚属鱼类卵巢鲜样中总氨基酸、必需氨基酸、呈味氨基酸含量差异不显著;必需氨基酸含量(w)为5.36%～6.32%,占总氨基酸含量为:0.43%、0.41%和0.43%,均以亮氨酸含量最高而色氨酸最低,赖氨酸含量(w)为0.96%～1.04%;饱和脂肪酸、单不饱和脂肪酸和多不饱和脂肪酸差异较显著,脂肪酸组成均以油酸含量最高,EPA和DHA总量(w)为8.00%～11.81%;矿物质含量大多也存在显著差异,常量元素含量最高的为钾(16970～22220mg/kg),微量元素则为锌(262.0～277.0mg/kg);不同水域生长环境对鲚属鱼类卵巢氨基酸含量影响不显著,而对脂肪酸和矿物质含量影响较显著。  相似文献   

雨花台砾石层内含辉木砾石的发现及其意义   总被引：1，自引：1，他引：0  

李立文 《江苏地质》1999,23(3):151-155

通过雨花台砾石层内含辉木雨花石的发现,分析了其重要的科研意义和实用价值。指出对雨花石、辉木化石和树蕨三者的深入研究,将有助于全面探讨古长江流域的发育史,进一步弄清地层进代、研究古生侯和古环境  相似文献   

基于数字图像的山东长山岛砾石海滩表层砾石形貌特征研究     

王兴  王永红  徐杨杨  向亚武 《海洋学报》2021,43(1):110-121

天然砾石海滩作为一种高能环境下的海岸堆积体,因其粒径粗、孔隙度大等特征,是良好的海岸防护屏障.了解砾石海滩形成过程离不开砾石形貌这一重要参数,但要快速、准确获得大量砾石的定量参数比较困难.本文对山东北长山岛3个砾石海滩(九丈崖、月牙湾、长滩)、南长山岛的4个砾石海滩(仙境源、林海、长山尾和明珠广场)进行现场剖面测量并采...  相似文献