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21.
本研究针对黄海绿潮早期发生过程,以浒苔生殖细胞附着生长特征为切入点,以其主要原因藻种浒苔(Ulva prolifera)为材料,对比研究了不同材料附着基质对浒苔孢子附着萌发的影响。发现孢子在2—6h内的附着率达到80%,尤其是在前2h内的附着速率最快,而且在不同材料的基质上都能完成附着萌发,但萌发数量存在显著差异性,孢子在紫菜养殖筏架相关材料(塑料、竹片、尼龙网衣、塑料网衣)上的萌发率显著高于浅滩、礁石和养殖池相关材料(细砂、海泥、石块)。浒苔孢子还可以在藻段上完成附着萌发,而橡胶和鱼粉袋相关材料对浒苔孢子的萌发存在抑制作用。对比浒苔孢子和配子的萌发特性发现两者有异同点,两者在塑料、竹片等筏架相关材料上萌发率均较高,而孢子在藻段以及橡胶浸出液和鱼粉溶液中的萌发数均显著高于配子。本研究发现紫菜养殖筏架更有利于浒苔孢子的附着萌发,这进一步说明苏北浅滩数十万亩的紫菜养殖筏架在绿潮早期形成过程中为浒苔孢子提供了重要的附着基质。本研究结果将为探讨紫菜养殖筏架在绿潮早期发生过程中的重要作用,并为养殖筏架防附着材料的选用提供参考。  相似文献   
22.
The distribution of algae and insects was examined in two hot spring outflow channels at Waimangu in the Rotorua thermal district. The upper temperature limit for algal growth was 68°c, with maximum biomass occurring at 59–62°c. Two species of Diptera were present on the algal mat, Ephydrella thermarum Dumbleton at 34–43°c and Chironomus cylindricus Freeman at 39–41°c. The composition and temperature relations of the community are similar to those found in thermal regions in other parts of the world.  相似文献   
23.
On rocky shores, sewage discharges can modify natural distribution patterns of sessile organisms. The impact of sewage on shallow hard substrate assemblages has been assessed along SW Apulian coast (Ionian Sea, Italy), providing a framework to evaluate the benefits of future sewage displacement to deeper waters. Four locations (three controls and one putatively impacted) were selected and three sites were chosen at each location. Each site was sampled by 10 replicate photographic records. Univariate analyses revealed that the outfall did not affect the spatial distribution of number of taxa, total cover and abundance of some dominant taxa (mostly algae, sponges and bryozoans). The outfall negatively influenced the natural distribution pattern of filamentous green algae, whilst some algae (i.e. Gelidiales and Colpomenia sinuosa) were exclusively present at the impacted location. Multivariate analyses revealed that the outfall heavily modified the natural pattern of variability in the structure of the assemblage.  相似文献   
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25.
为探究冬季室温不同铁碳内电解基质下4种水生植物及其组合对人工湿地污水的净化效果,通过构建小试试验装置来探究冬季室温铁碳内电解质下菖蒲、鸢尾、金鱼藻、狐尾藻4种水生植物及菖蒲+鸢尾、金鱼藻+狐尾藻、菖蒲+鸢尾+金鱼藻+狐尾藻3种组合在不同试验时间内对污水中COD、NH_3+-N、TN、TP 4种污染物的净化效果。结果表明:冬季室温不同铁碳内电解基质下,4种植物及其组合对COD、TN、TP去除效果均较好,无显著性差异。NH3+-N净化效果较好的是菖蒲组和金鱼藻+狐尾藻组合。研究发现,铁碳内电解基质在COD、TN、TP的去除过程中发挥了主要作用。在TN去除方面,铁碳内电解质与植物的组合效果比单纯内电解质对污水的净化效果好。4种植物及其组合在NH_3+-N去除方面均发挥了重要作用,且不同处理间存在显著差异。  相似文献   
26.
为探究不同铁铜内电解基质在不同曝气条件下对人工湿地污水的净化效果,构建表流人工湿地床,以研究4种铁铜内电解基质(质量比1:0、1:0.05、1:0.1、1:0.2)在不同曝气条件下(气水比3:1、6:1、9:1、12:1、15:1)对人工湿地污水的COD、TN、TP去除率的影响。结果表明:不同铁铜内电解基质对COD、TN、TP的去除效果有显著差异。随着内电解基质中铜比例的提高,COD、TN、TP的去除率均有升高的趋势。随着气水比的提高,TP去除率呈先升后降的趋势。铁铜内电解基质与曝气条件之间的交互作用对COD、TN、TP去除效果影响不显著。研究发现,当气水比为9:1时,铁铜内电解基质(质量比1:0.2)的净污效果最好。  相似文献   
27.
The periphyton of acid, dystrophic bogs was investigated. Glass-slides were exposed in four different bog lakes about 100 km north of Berlin, Germany, in order to examine the species composition and the annual cycle of the protist community. The annual cycles of the periphyton in bog lakes were comparable to those in other mesotrophic lakes: During the winter months small heterotrophic flagellates (HF) dominated the periphyton community. Besides that bacterivorous ciliates were present as typical pioneer species. At the end of the ice covering, almost exclusively unicellular green algae colonized the slides. In May high abundances of ciliates and choanoflagellates were observed. At the same time, a maximum of species was reached. From August to October peritrich ciliates significantly contributed to the periphyton. Their number decreased when early frosts occurred.

The four investigated bog lakes exhibit very similar species compositions, almost all of the species were present in each of the four lakes. Differences were only distinct concerning the dominance of some protistan groups. The largest deflections, however, occurred not between two lakes, but between two habitats within one lake: The upper 30 cm of the Sphagnum mat comprise two very different protistan communities, determined by a strong vertical zoning. Due to the different light and nutrient conditions, the slides of the upper region exhibited a denser colonization, mainly consisting of autotrophic cryptomonads and vagile ciliates. In contrast to this, the slides of the deeper region were mainly colonized by heterotrophic flagellates and sessile peritrich ciliates.  相似文献   

28.
Glass-slides were exposed in four different bog lakes located in great forest areas in Northern Germany, about 100 km north of Berlin, in order to examine the protist community of these dystrophic, acid lakes. Species composition and succession of the periphyton were studied during one year. The four investigated bog lakes exhibit similar species compositions, most of the species were present in each of the four lakes. The periphyton was composed of a great variety of protist species. Specimens of all major flagellated protists and of most of the ciliate taxa were found on the slides. Many of these species are ubiquitous. Some species, however, like the flagellates Spongomonas sacculus, Rhipidodendron huxleyi, Cyathobodo sp., and Pseudodendromonas vlkii as well as the ciliates Ophrydium hyalinum, Leptopharynx costatus, Uroleptus caudatus, and Platyophrya sphagni are found more frequently in acid waters. A regular and common occurrence of these species partly characterizes the acid Sphagnum bogs. Besides that, common species like Bodo spp., Cryptomonas spp., Goniomonas truncata, Chilodonella uncinata, Vorticella sp., and Cyrtolophosis mucicola are represented in the periphyton. Examinations of the testate amoebae in the Sphagnum mats show a very different species composition compared to earlier studies.

The investigated bog lakes revealed mesotrophic conditions. In the upper regions of the Sphagnum mats and in the center of the larger bog lakes, oligotrophic conditions still prevail. The lower regions of the Sphagnum mat and the smaller lakes, however, are influenced by the partly degradation of plants and the run-off water from surrounding land. In comparison to earlier studies, the species composition indicates a beginning eutrophication of the bog lakes. A direct anthropogenic impact can be excluded.  相似文献   

29.
Seven subaerial, low energy beaches in the SE Mediterranean were surveyed biweekly for 13 months. Beach level data were computer-processed and plotted as time-series profile diagrams that differentiated the subaerial beach into three basic subenvironments: backshore, berm, and swash-zone. Heterogeneous seasonal trends in beach sand budget, erosion/accretion patterns, occurrence of ridges and berm-crests, and in pollution by seaborne tar were observed. The profile stations also showed very different degrees of seasonality, although located along similar beaches. Local beachrock protection, when evident, effectively masked seasonality by significantly lowering beach dynamics. Biweekly, seasonal, and annual fluctuations of the beach sand-budget were computed. Average annual net sand flux at the seven beaches was 66 m3/m of beach front, though wide variations occurred. Annual changes in the sand budget along the study area exceeded volumetric changes within the profile, indicating longshore sand transfer. Synchronism of beach behavior prevailed only at the seasonal level. However, intra-seasonal fluctuations for the different profile stations were out of phase, indicating poor synchronism of beach response due to longshore movement of rhythmic topography. Profile changes were thus often unrelated to concomitant wave-climate changes. The overall heterogeneous beach response was in sharp contrast to the identical wave climate, similar bathymetry, and sedimentology of the studied beaches.  相似文献   
30.
中华鲎(Tachypleus tridentatus)是保障我国医疗检测安全的重要战略生物资源,国内外中华鲎行为生态学相关研究极少。在实验室内模拟砾石底(NS)、细砂(SS)、中砂(MS)、粗砂(CS)、泥(AR)、泥沙1 (AA)、泥沙2 (AB)和沙泥(SA) 8种不同比例的泥沙类型对中华鲎行为特征的影响。结果表明,稚鲎较多时间潜藏于泥沙中,较少时间裸露于泥沙表面活动(如爬行、游泳等)。稚鲎偏好在含淤泥较多的泥沙类型中潜沙,且在泥质和泥沙质类型中埋栖时间较在沙质中埋栖时间长;在裸露于泥沙表面时,稚鲎相对偏好栖息于沙质底。泥沙环境下稚鲎用于游泳的时间比例高于砾石底。在凌晨、上午、中午、下午、夜晚5个时间段中,稚鲎在夜晚和凌晨活动较活跃。通过揭示不同比例的泥沙类型底质对中华鲎稚鲎行为特征的影响,为野外增殖放流计划的设计与实施、放流适宜地点的选择以及稚鲎人工养殖环境的优化提供科学理论依据。  相似文献   
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