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21.
Synopsis Although hybridization of terrestrial and freshwater organisms has been well-studied, very little work has focused on hybridization among coral reef fish species. In the present paper, eleven examples of probable hybrids between marine angelfishes (Pomacanthidae) are reviewed. Evidence is presented which strongly suggests that the nominal speciesApolemichthys armitagei is invalid and that specimens previously identified as this species represent hybrids betweenA. trimaculatus andA. xanthurus. Of the remaining ten probable pomacanthid hybrids, five are inCentropyge (C. eibli x C. flavissimus, C. eibli x C. vrolikii, C. flavissimus x C. vrolikii, C. loricu0lus x C. potteri, andC. multifasciatus x C. venustus); one inHolacanthus (H. bermudensis x H. ciliaris), and four inPomacanthus (P. arcuatus x P. paru, P. chrysurus x P. maculosus, P. maculosus x P. semicirculatus, andP. sexstriatus x P. xanthometapon). An additional five examples of possible pomacanthid hybrids are described, two inCentropyge, two inChaetodontoplus and one inPomacanthus. Examination of hybrids may provide clues on reproductive behavior, dispersal capabilities, and phylogenetic relationships of species. More studies on hybridization in coral reef fish species, particularly those involving molecular techniques, are needed. 相似文献
22.
Jean-Fran ois Boe Philippe Goulas Jean-Louis Seris 《Biocatalysis and Biotransformation》1993,7(4):297-308
The effect of several organic acids on the oxidation of Mn(II) catalyzed by manganese peroxidase was studied. Reactivities of manganese peroxidase and chemically prepared Mn(III) organic acid complexes towards phenolic compounds were compared. If lactate appears to be the best complexant for manganese peroxidase activity, chemically prepared Mn(III)—lactate complex is a less effective oxidant towards phenolic compounds than other Mn(III)—complexes. Our results agree with the hypothesis that certain organic acids are involved in the catalytic cycle of manganese peroxidase. Malonate and lactate seem to be the most attractive complexants for practical applications of manganese peroxidase and were used in enzymatic treatment of hardwood kraft pulp. Bleaching of kraft pulp was studied and after alkaline extraction, a significant decrease of kappa number was measured. The bleaching was enhanced in lactate buffer. 相似文献
23.
Within estuarine and coastal ecosystems globally, extensive habitat degradation and loss threaten critical ecosystem functions and necessitate widescale restoration efforts. There is abundant evidence that ecological processes and species interactions can vary with habitat characteristics, which has important implications for the design and implementation of restoration efforts aimed at enhancing specific ecosystem functions and services. We conducted an experiment examining how habitat characteristics (presence; edge vs. interior) influence the communities of resident fish and mobile invertebrates on restored oyster (Crassostrea virginica) reefs. Similar to previous studies, we found that restored reefs altered community composition and augmented total abundance and biomass relative to unstructured sand habitat. Community composition and biomass also differed between the edge and interior of individual reefs as a result of species-specific patterns over small spatial scales. These patterns were only weakly linked to oyster density, suggesting that other factors that vary between edge and interior (e.g. predator access or species interactions) are likely more important for community structure on oyster reefs. Fine-scale information on resident species' use of oyster reefs will help facilitate restoration by allowing decision makers to optimize the amount of edge versus interior habitat. To improve the prediction of faunal use and benefits from habitat restoration, we recommend investigations into the mechanisms shaping edge and interior preferences on oyster reefs. 相似文献
24.
The efficiency and effectiveness of different sea urchin removal methods for kelp forest restoration
Sea urchin overgrazing has caused widespread phase shifts from kelp forests to “urchin barrens” on many temperate reefs, reducing habitat complexity, productivity, and biodiversity. Sea urchin removal is increasingly used for kelp restoration; however, few studies have quantified the efficiency and effectiveness of different removal methods, resulting in limited understanding of their practicality. In this study, the efficiency (removal rate) and effectiveness (proportion removed) of four removal methods were evaluated in northeastern New Zealand. We compared culling or collecting sea urchins by either SCUBA or freediving in 128 small-scale plots (25 m2). We also evaluated the efficiency and effectiveness of culling in four large (1.6–2 ha) barren areas, scales relevant for restoration. On average, culling sea urchins was 1.9–4.4 times faster than collecting, and SCUBA was 1.5–3.3 times faster than freediving. Removal rates increased with sea urchin density, especially for culling on SCUBA, while freediving removal rates increased with experience. Effectiveness was lower in large-scale removals (86–93% of sea urchins ≥40 mm removed) compared to small-scale removals (98–99%), but sufficient for restoration objectives. Estimated time per area (using SCUBA culling) was similar across large-scale removals (49–57 hours/ha), despite an almost 2-fold variation in initial sea urchin densities (approximately 4–8 urchins/m2), suggesting area may better predict total removal time than simply number of sea urchins across low-density ranges. While sea urchin removal provides a rapid, feasible, and effective approach to restoring kelp in urchin barrens, restoration plans need to also address the causes of sea urchin overpopulation to ensure long-term benefits. 相似文献
25.
海洋生物礁是由具有造礁能力的海洋生物聚集而成的一种三维礁体结构,其形成改变了海底地貌、增加了不同尺度上的地形复杂性,为其他海洋生物提供了栖息地并维持了生物多样性。近年来,由于自然因素和人为因素影响,海洋生物礁受到了严重威胁,已成为海洋生态保护和修复领域的重要研究对象。综述了海洋生物礁的类型、生态功能及其生态修复的研究进展。根据形成海洋生物礁的优势造礁生物种类,将海洋生物礁分为海藻礁、海绵礁、刺胞动物礁、贝类礁和多毛类礁,其优势造礁生物分别是珊瑚藻和仙掌藻、钙质海绵和硅质海绵、造礁珊瑚、牡蛎、龙介虫。目前国内对海洋生物礁的全面了解相对较少,主要集中在珊瑚礁和牡蛎礁。海洋生物礁的生态功能主要有海岸防护、提供栖息地、净化水体、固碳作用和能量耦合等。全球变暖和海洋酸化等全球气候变化以及海洋污染、破坏性渔业捕捞、海岸工程、水产养殖和敌害生物等自然和人为因素对海洋生物礁构成了严重威胁。海洋生物礁的生态修复方法分为两类:在退化生物礁区投放造礁生物逐渐成礁,投放人工礁体补充造礁生物逐渐成礁。针对海洋生物礁保护和修复的需要,提出下一步应加强海洋造礁生物生态特征、海洋造礁生物种群丧失因素和海洋生物礁保护与... 相似文献
26.
Jennifer L. Wright Heather A. Stewart Ivette Candanedo Evan D'Alessandro Maria Estevanez Rafael J. Araújo 《Biotropica》2023,55(2):299-305
We conducted visual fish surveys in coexisting mangrove-coral (CMC) habitats in Panama to analyze the effect of coral presence in mangrove habitats on the fish assemblage. Our study revealed that CMC habitats harbor distinct fish assemblages compared to mangrove habitats without coral, with greater species richness and increased herbivore abundance. Abstract in Spanish is available with online material. 相似文献
27.
【背景】海洋沉积物真菌富含生物活性天然产物,但珊瑚礁泥砂真菌及其天然产物的研究较少。【目的】分离珊瑚礁泥砂真菌及其天然产物,探究珊瑚礁泥砂来源真菌多样性,为海洋真菌天然产物开发奠定基础。【方法】采用稀释涂布平板法分离马来西亚热浪岛珊瑚礁泥砂真菌并基于ITSrDNA序列分析鉴定真菌;综合运用硅胶柱、反相柱和制备HPLC色谱技术分离枝孢属真菌(Cladosporium sp.) GXIMD02067的天然产物,通过核磁共振波谱技术和文献数据比对鉴定化合物结构。【结果】19株真菌被分离,隶属1纲4目4科6属,包括7株曲霉属(Aspergillus)、6株青霉属(Penicillium)、2株枝孢属(Cladosporium)、1株蜡蚧菌属(Lecanicillium)、2株路霉属(Lulworthia)和1株Parengyodontium。GXIMD02065和GXIMD02066 ITS rDNA序列的相似度小于87%,是潜在新菌种。7个化合物从Cladosporium sp. GXIMD02067中分离并鉴定为pyrenocine A (1)、pyrenocine B (2)、胸腺嘧啶脱... 相似文献
28.
John E. Randall Stephen M. Head Adrian P. L. Sanders 《Environmental Biology of Fishes》1978,3(2):235-238
Synopsis The giant humphead wrasse (Cheilinus undulatus), an inhabitant of coral reefs, is widely distributed in the tropical Indo-Pacific region. Stomach and intestinal contents of 72 specimens from the Pacific and the Red Sea revealed that this fish feeds primarily on mollusks, fishes, echinoids, and crustaceans.This article is one of several presented at the Second European Ichthyological Congress, Paris, 8-15 September 1976, to be published by Environmental Biology of Fishes. 相似文献
29.
Reproductive strategies of coastal marine fishes in the tropics 总被引:14,自引:0,他引:14
Robert E. Johannes 《Environmental Biology of Fishes》1978,3(1):65-84
Synopsis A synthesis of ethnobiological, behavioral and physical oceanographic information leads to the conclusion that temperate zone models of reproductive strategy are inapplicable to many fishes of the coastal tropics. Intense predation appears to exert heavy selection pressure on fishes that spend their adult lives in coral, mangrove or tropical seagrass communities. Many exhibit spawning behaviors and spawn at times and locations that favor the transport of their pelagic eggs and pelagic larvae offshore where predation is reduced. This creates a countervailing selection pressure — the need to return the larvae to shallow water once they are ready to colonize their post-larval habitats. Accordingly, spawning is often concentrated at times of the year when prevailing winds or currents are at their weakest, thereby reducing the transport of larvae long distances from where they originated. Spawning is also concentrated in the vicinity of nearshore gyres which similarly favor the ultimate return of the larvae to their natal area. Among these species, therefore, offshore larval dispersal does not seem to be an adaptation for dispersal of the species, but rather an evolutionary response to intense predation pressure in the adult habitats. Lunar reproductive periodicity is more common among these species than has previously been recognized, and is one of the strategies employed to enhance the offshore flushing of eggs and larvae.This paper forms part of the proceedings of a mini-symposium convened at Cornell University, Ithaca, N. Y. 18–19 May 1976, entitled Patterns of Community Structure in Fishes (G. S. Helfman, ed.).Contribution No. 524, Hawaii Institute of Marine Biology, University of Hawaii, Honolulu. 相似文献
30.
The question of the age of «Hauts de Meuse coral rag is studied again using new faunas of brachiopods and ammonites collected above, below and inside the coral rag. Ammonites fauna of the well known «Calcaires de Creuë is revised. Results obtained agree closely.The «Hauts de Meuse coral rag grew up during Middle Oxfordian time; and extend part of the Plicatilis zone (Antecedens Subzone) and the whole Transversarium Zone up to the basis of the Bifurcatus Zone, for the first time identified in Lorraine. So it span a short depositional time, about 1 MY, with a high deposition rate, the thickness of the coral rag being more than 100 meters, reaching 150 meters in Saint-Mihiel area. Towards SE, on the other side of the Marne Gap, the sudden change into basinal facies go with a reducing of thickness and deposition rate.Upper Oxfordian deposits show a relative uniformity of facies and thickness. At the top of Middle Oxfordian limestones, the age of the discontinuity and the Sequanian renewal of deposition is basal Bifurcatus Zone. Erosional renewal and terrigeneous deposits are a wide spread event by the beginning of Upper Oxfordian.In the paleontological part, species upon which are based new ages and interpretations are only figured, except the species new or with new paleontological data, which are described. Type specimen of Perisphinctes mosensisBayle, from the «Calcaires de Creuë, is described and photographically figured for the first time. 相似文献