酶解条件对条斑紫菜单细胞成活率影响的比较研究     

杨震  唐学玺  戴继勋  沈颂东  宫相忠  贾鹏举 《中国海洋大学学报(自然科学版)》2001,31(3):407-410

该文分别选用不同浓度的海螺酶 ;葡萄糖、蔗糖、甘露醇、山梨醇、氯化钠 5种渗透剂 ;维生素 C和甘露醇 2种抗氧化剂 ;对条斑紫菜酶解单细胞的成活率进行了研究。实验结果表明 :用浓度为 10 %的海螺酶酶解条斑紫菜 ,成活率最高 ;选用 2 mol/ L葡萄糖作渗透剂 ,效果最好 ,成活率达85.2 % ;加入抗氧化剂对细胞成活率没有影响  相似文献   

锌对虾夷扇贝和刺参幼体的毒性效应   总被引：11，自引：1，他引：11  

朱丽岩  吕建发  唐学玺  高象贤  徐怀恕 《海洋通报》1999,18(4):34-37

以虾夷扇贝和刺参幼体为材料,采用急性毒性试验和亚急性毒性试验的方法,研究了锌对虾夷扇贝稚贝及幼贝和刺参幼虫的毒性效应。结果显示,锌对虾夷扇贝稚贝的２４ｈＬＣ５０ ６．４０ｍｇ／Ｌ,４８ｈＬＣ５０为３．３１ｍｇ／Ｌ,７２ｈＬＣ５０为１．３９ｍｇ／Ｌ,９６ｈＬＣ５０为０．６１ｍｇ／Ｌ;而对幼贝的２４ｈＬＣ５０为３．３２ｍｇ／Ｌ,４８ｈＬＣ５０为２．６４ｍｇ／Ｌ。７２ｈＬＣ５０为１．７６ｍｇ／Ｌ,９６ｈ  相似文献   

Antioxidant system responses in two co-occurring green-tide algae under stress conditions     

王影  赵新宇  唐学玺 《中国海洋湖沼学报》2016,34(1):102-108

Green tides have occurred every year from 2007 to 2014 in the Yellow Sea. Ulva prolifera(Müller) J. Agardh has been identified as the bloom-forming alga,co-occurring with U. intestinalis. We observed distinct strategies for both algal species during green tides. U. prolifera exhibited a high abundance initially and then decreased dramatically,while U. intestinalis persisted throughout. The antioxidant system responses of these two macroalgae were compared in the late phase of a green tide(in-situ) and after laboratory acclimation. Lipid peroxidation and antioxidant system responses differed significantly between the two. Malondialdehyde and hydrogen peroxide contents increased significantly in-situ in U. prolifera,but not in U. intestinalis. In U. prolifera,we observed a significant decrease in total antioxidant ability(T-AOC),antioxidant enzymes(SOD and Apx),and non-enzyme antioxidants(GSH and As A) in-situ. U. intestinalis showed the same pattern of T-AOC and SOD,but its Gpx,Apx,and GSH responses did not differ significantly. The results suggest that U. prolifera was more susceptible than U. intestinalis to the harsh environmental changes during the late phase of a Yellow Sea green tide. The boom and bust strategy exhibited by U. prolifera and the persistence of U. intestinalis can be explained by differences in enzyme activity and antioxidant systems.  相似文献   

A density-based approach for detecting network-constrained clusters in spatial point events     

Min Deng  Xuexi Yang  Jianya Gong  Yang Liu  Huimin Liu 《International journal of geographical information science》2019,33(3):466-488

Existing spatial clustering methods primarily focus on points distributed in planar space. However, occurrence locations and background processes of most human mobility events within cities are constrained by the road network space. Here we describe a density-based clustering approach for objectively detecting clusters in network-constrained point events. First, the network-constrained Delaunay triangulation is constructed to facilitate the measurement of network distances between points. Then, a combination of network kernel density estimation and potential entropy is executed to determine the optimal neighbourhood size. Furthermore, all network-constrained events are tested under a null hypothesis to statistically identify core points with significantly high densities. Finally, spatial clusters can be formed by expanding from the identified core points. Experimental comparisons performed on the origin and destination points of taxis in Beijing demonstrate that the proposed method can ascertain network-constrained clusters precisely and significantly. The resulting time-dependent patterns of clusters will be informative for taxi route selections in the future.  相似文献   

Photosynthetic response of floating Ulva prolifera to diurnal changes of in-situ environments on the sea surface     

ZHAO Xinyu  TANG Xuexi  HU Shunxin  ZHONG Yi  QU Tongfei  WANG Ying 《海洋湖沼学报（英文）》2019,(2):589-599

During yellow sea green tide outbreak, the thalli of Ulva prolifera drifted more than 350 km on the sea surface from off shore of Jiangsu Province to Qingdao city, where they were exposed to complex changes of local environments. The purpose of this study is to investigate the response of the thalli to diurnal changes of environments on the sea surface, and a sea surface environment simulator (SSES) was designed to simulate the natural environment of floating U . prolifera mat. A control experiment is designed in the laboratory, which was processed under suitable conditions (20°C for temperature, 72 μmol photons/(m 2 ·s) for light intensity and 30 for salinity), and an in-situ research was conducted to study the photosynthetic responses of floating U . prolifera to diurnal changes of environments. The results show that the photosynthetic efficiency of the thalli decreased gradually with time, and decreased rapidly after 14:00 local time (LT). After exposed to the environment on the sea surface for 6 h, the photosynthetic activity of the thalli decreased significantly. Furthermore, physiological-level and molecular-level experiments revealed that non-photochemical quenching (NPQ), cyclic electron flow (CEF) and energy redistribution between PSI and PSII all played an important role in the strong photosynthetic plasticity of U . prolifera . NPQ is the most important photoprotective responses to environmental changes before 12:00 LT. The results also confirmed that the CEF and energy redistribution between PSI and PSII are the main synergistic eff ects for the thalli to adapt to the environmental changes when the process NPQ cannot work. And the result can further reveal the reason why U . prolifera can adapt to the living condition of long distance drift on the sea surface. The findings of this research could provide a theoretical basis for explaining outbreaks of the green tide and instructing the management of the problem.  相似文献   

苜蓿转化细胞系核酸和蛋白质合成的研究     

谢经良  唐学玺 《中国海洋大学学报(自然科学版)》2003,33(2):249-252

以苜蓿转化细胞系和对照细胞系为材料 ,利用同位素标志方法研究了 3种大分子物质——DNA、RNA和蛋白质的合成动态。结果表明 ,与对照细胞系相比 ,转化细胞系的生长速度明显加快 ,DNA、RNA和蛋白质的合成旺盛 ,合成速度显著提高。同时 ,转化细胞系 DNA、RNA和蛋白质出现最大合成速度的时间均相应地延迟。  相似文献   

蒽胁迫对2种海洋微藻的毒性效应     

田继远  唐学玺  于娟  王晨  刘文明 《中国海洋大学学报(自然科学版)》2002,32(6):919-925

采用水生毒理学方法以及通过分析蒽对 2种海洋微藻的几种生理生化指标的影响 ,初步研究了蒽胁迫对 2种海洋微藻的毒性效应。结果表明 :随着蒽浓度的不断增大 ,1 2种海洋微藻的相对增长率逐渐降低 ,叶绿素 a和类胡萝卜素含量稍有下降 ,蒽对小新月菱形藻生长的 72 h· EC50为 2 51μg· L-1 ,蒽对亚心形扁藻生长的 72 h· EC50 为 387μg· L-1 ;2还原型谷胱甘肽 (GSH)含量逐渐降低 ;3加入外源性抗氧化剂 (GSH和甘露醇 )可缓解蒽胁迫所造成的 2种海洋微藻的细胞密度的降低 ,即可缓解蒽胁迫对微藻的毒害作用  相似文献   

Ingestion of <Emphasis Type="Italic">Brachionus plicatilis</Emphasis> under different microalgae conditions     

周文礼  唐学玺  乔秀亭  王悠  王仁君  冯蕾 《中国海洋湖沼学报》2009,27(3):473-479

The effects of four microalgae,Chlorella vulgaris,Platymonas helgolandicavar,Isochrysis galbana,and Nitzschia closterium on the grazing and filtering rates of the marine rotifer,Brachionus plicatilis,were evaluated under laboratory conditions.The grazing rates in separate cultures of the four microalga were as follows:C.vulgaris > P.helgolandicavar > I.galbana > N.closterium.However,the filtering rates occurred in the following order:P.helgolandicavar > N.closterium > C.vulgaris > I.galbana.A mixed diets ex...  相似文献   

一种基于GTP的地下真3D集成表达的实体模型   总被引：5，自引：0，他引：5  

吴立新  陈学习  车德福  徐磊 《武汉大学学报(信息科学版)》2007,32(4):331-335

从建模对象、组成元素和拓扑描述三个方面对广义三棱柱（GTP）模型进行了修正和扩展。基于修正与扩展后的GTP模型，从地学、几何、拓扑三个层面对地下实体进行了提炼，抽象出8种空间构模几何元素，并将地下实体划分为点、线、面和体4类，体实体又进一步划分为简单体、复合体和复杂体，进而提出了一种基于GTP的地下真3D集成表这的实体模型（GTP—based entity model，GTP—EM）；采用面向对象的方法，通过构模元素之间拓扑关系的定义实现了地下实体的拓扑描述，并应用实例验证了GTP—EM的可行性。  相似文献   

褐藻纲海带目Laminaria属和Saccharina属基于三个分子标记的系统发育分析     

CHI Shan  QIAN Hao  LI Tianyong  WANG Xumin  LIU Cui  REN Lei  TANG Xuexi  LIU Tao 《海洋学报(英文版)》2014,33(9):139-151

In the past two decades, many studies have focused on the classification within genus Laminaria, ultimately trying to divide it into two subgroups or genera: Laminaria and Saccharina. A significant debate still surrounds the question of its division, as the conflicting phylogenetic hypotheses that have resulted from the classification studies are based on different taxon sampling, molecular markers, or analysis methods. It is aimed at elucidate the molecular phylogeny within Laminaria and Saccharina. The nine species of Laminariales are sampled from northern Asia and Europe, and 23 new sequences in the nuclear, plastid, and mitochondrial genomes are determined to identify their taxonomic status. The phylogenetic analyses of 71 species are performed, including representatives from six of the seven families of the order Laminariales, based on three separate data sets. An evidence is provided to strongly support a clear split that maintains the two recognized genera, Laminaria and Saccharina, with Laminaria appearing to be the ancestor group. Further, analyses indicate that all taxa in Saccharina and Laminaria did not form a monophyletic lineage, instead Laminariaceae and Lessoniaceae grouped together interlacedly, and Costariaceae appeared as the sister taxon of the Lessoniaceae–Laminariaceae clade. In the phylogenetic analysis, mitochondrial c oxidase I(COI) sequences appeared to be the most credible molecular marker which was more befitting than nuclear encoded internal transcribed spacer(ITS) and plastid encoded rbcL for establishment of Laminariales systematics. It is the most comprehensive phylogeny of the order Laminariales, and contributes to an enhanced understanding and estimation of the phylogenetic relationships for the economically important seaweeds, Laminaria and Saccharina.  相似文献