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51.
1 Introduction Microsatellites or simple sequence repeats (SSRs) are tandemly repeated motifs of one to six bases found in all prokaryotic and eukaryotic genomes analysed to date (Zane et al., 2002). Due to their hyper-variable and co-dominant nature, relatively high abundance and random distribution in the genome, microsatellites are among the most efficient class of molecular markers. Such repeats display high polymorphism because of variation in repeat length and can be rapidly analysed t…  相似文献   
52.
Although several studies have evaluated the genetic structure and phylogeographic patterns in many species of marine invertebrates, a general model that applies to all of them remains elusive. For example, some species present an admixture of populations with high gene flow, whereas others exhibit more complex patterns characterized by small‐scale unstructured genetic heterogeneity, even at a local scale. These differences are thought to be due to clear biological aspects such as direct versus indirect development, or the presence of lecithotrophic versus planktotrophic larvae, but few studies compare animals with similar distributions and life modes. Here, we explore the phylogeographic and genetic structure patterns in two chiton (Chiton olivaceus and Lepidopleurus cajetanus) and one abalone (Haliotis tuberculata) species co‐occurring in the same habitat. Samples were obtained from shallow rocky bottoms along the Iberian Peninsula (Atlantic and Mediterranean coasts), Italy, Croatia and Greece, and the mitochondrial markers COI and 16S rRNA gene were sequenced. Our data show evidence of admixture and population expansion in C. olivaceus and H. tuberculata, whereas L. cajetanus exhibited a ‘chaotic patchiness’ pattern defined by a high genetic variability with locality‐exclusive haplotypes, high genetic divergence, and a lack of geographic structure. Shared haplotypes were sampled in both coasts of Iberia (for H. tuberculata) and in the Western and Eastern Mediterranean (for C. olivaceus), potentially indicating high dispersal ability and a recent expansion. The processes underlying the fine‐scale structuring in L. cajetanus remain a mystery. These results are especially interesting because the reproductive mode of the two chitons is similar but differs from that of the abalone, with a veliger larva, while instead the genetic structure of C. olivaceus and H. tuberculata are similar, thus contrasting with predictions based on the life history of the three molluscs and showing that the genetic patterns of marine species may be shaped by many factors, including historical ones.  相似文献   
53.
1 Introduction Actinisanimportantcontractileproteinineukary oticcells .Itisoneofthetwomajorcomponentsin volvedinthecontractionofmusclecells .Innon mus clecells ,itisthemajorpartofcytoskeletoninvolvedinmanyprocessessuchascellmotility ,endocytosis ,exocyt…  相似文献   
54.
As the most widely used plasticizers in the world, phthalate esters (PAEs) are potential endocrine disruption compounds (EDCs). In the present study, the toxicity of dimethyl phthalate (DMP),diethyl phthalate (DEP), dibutyl phthalate (DBP), di (2-ethylhexyl) phthalate (DEHP) on embryogenesis and larvae development of the marine univalve Haliotis diversicolor supertexta was examined in laboratory. The results show that the malformation of embryos appeared during the experiment, such as embryos died or lysed, small transparent flocculent rings studded on the periphery of the embryo, and the larvae could failed to hatch. In embryo toxic test, embryos incubated at the highest concentration of DMP,DEP and DBP solutions showed significantly high abnormal rate compared with the control, while DEHP solutions displayed no significant difference. In larval toxic test, in all concentrations of DMP, DEP and DBP solutions, larval settlement rates were low significantly than that of the control. Similarly, DEHP solutions show nearly no effect on the larval settlement. The order of toxicity on embryos and larvae is DBP>DEP>DMP>DEHP. Being a simple and easy stimulation to indoor spawn, sensitive to environmental factors, and short culture time, the embryos of 1-1. diversicolor supertexta can be used to indicate toxicity of the PAEs.  相似文献   
55.
鲍藻混养模式的构建及其效益分析   总被引:3,自引:1,他引:2  
在福建省莆田市平海湾海区,利用现有海藻(海带)养殖设施,进行海藻与皱纹盘鲍和黑鲍混养。经150 d试验,皱纹盘鲍和黑鲍生长率分别为221.02%和187.70%,成活率都为94.00%,与室内单养、海区筏式单养无显著差异(P<0.05)。而3种模式鲍投入产出比分别为1∶1.84,1∶2.92,1∶1.41,即每万粒鲍鱼养殖可节约成本近万元。同时,鲍和海藻处在海洋生态系统的不同生态位,互利共生,促进海洋生态系统物质良性循环。  相似文献   
56.
研究了杂色鲍(Haliotis diversicolorReeve)鲍苗脱落死亡周期中水质、硅藻和细菌变化情况。结果显示,鲍苗脱落前各水质指标无明显变化,脱落前硅藻数量大幅度增加,以卵形藻(Cocconeisspp.)和舟形藻(Naviculaspp.)为主要种类。同时发现一株可疑致病菌,初步鉴定为溶藻弧菌(Vibrio alginolyticus)。实验表明水质等相关因子与鲍苗脱落无直接关系,而硅藻很可能是致病菌的“载体”,整个附着膜微环境与鲍苗存亡息息相关。  相似文献   
57.
Abalone Haliotis diversicolor supertexta is an important economic mollusk.The settlement and metamorphosis are two critical stages during its development period,which has direct influence on abalone survival and production.The influence of reactive oxygen species(hydrogen peroxide) on abalone embryo and juvenile development were examined in this study.Larvae of Haliotis diversicolor supertexta were induced to settlement and metamorphose by exposure to seawater supplemented with hydrogen peroxide.They had the best performance at 800 μmol/L.The concentration of 1 000 μmol/L or higher was toxic to the larvae,as the larvae could settle down only at benthic diatom plates without complete metamorphosis.In addition,H2O2 adding time was critical to the larval performance.24h after two-day post-fertilization was proved to be the optimal adding time.In this paper,two action mechanisms of hydrogen peroxide are discussed:(1) hydrogen peroxide has direct toxicity to ciliated cells,thus cause apoptosis;(2) hydrogen peroxide,as a product from catecholamines' autoxidation process in vivo,can reverse this process to produce neuro-transmitters to induce abalone metamorphosis.  相似文献   
58.
自2002年下半年开始,南方杂色鲍苗出现大规模死亡的问题,严重影响到南方鲍鱼产业的发展。从汕尾鲍鱼场发病杂色鲍苗中分离到一批菌株,本研究对16号优势菌株进行了比较深入的工作,回归感染试验证明其为病原菌,API 20E条带分析表明其为溶藻弧菌(Vib-rio alginolyticus),药敏试验揭示其对卡那霉素、氯霉素、氨苄西林、链霉素、四环素有抗药性,但对青霉素、复方新诺明、庆大霉素、多粘霉素敏感。本研究结果为我国南方杂色鲍苗掉板症的防治提供科学依据。  相似文献   
59.
饲料中维生素B6对皱纹盘鲍幼鲍蛋白质代谢的影响   总被引:4,自引:0,他引:4  
以皱纹盘鲍(Haliotis discus hannaiIno)幼鲍为研究对象,探讨维生素B6对其蛋白质代谢的影响。设计了3种维生素B6不同含量(0,40,4 000 mg/kg)的半精制饲料,在循环水养殖系统中养殖幼鲍240 d。结果表明,皱纹盘鲍内脏团和肌肉中磷酸吡哆醛(PLP)的含量随饲料中维生素B6的添加而显著升高(P<0.05)。饲料中不同维生素B6水平对肌肉组织中蛋白含量没有显著影响(P>0.05),而显著升高内脏团中蛋白质的含量(P<0.05)。内脏团和肌肉中的谷丙转氨酶(ALT)和谷草转氨酶(AST)活力随着饲料中维生素B6添加量的升高而显著增强,分别在维生素B6的添加量为4 000 mg/kg时取得最大值(P<0.05)。内脏团中所检测的各种氨基酸的含量与饲料中维生素B6添加量没有显著影响(P>0.05)。然而,肌肉中的天冬氨酸(Asp)、苏氨酸(Thr)、丝氨酸(Ser)、牛磺酸(Tau)的含量随着饲料中维生素B6添加量的升高而显著增加,并且分别在维生素B6添加量为4 000 mg/kg时取得最大值(P<0.05)。肌肉中甘氨酸(Gly)、丙氨酸(Ala)、缬氨酸(Val)、蛋氨酸(Met)的含量在两个维生素B6添加组(40 mg/kg和4 000 mg/kg)之间没有显著差异(P>0.05),但均显著高于维生素B6缺乏组(0 mg/kg)的值(P<0.05)。  相似文献   
60.
Neopeltopsis pectinipes gen. et sp. nov. is described and figured from sublittoral marine algae at Wellington, New Zealand; the genus is an addition to the Peltidiidae Sars. The genus is compared with the other genera of the family, and a revised key is given to the genera of the Peltidiidae.  相似文献   
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