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991.
Marie‐Christine Aquarone 《Ocean Development & International Law》2013,44(4):267-285
Abstract France, hitherto more “continental”; than “maritime,”; increasingly developed its ocean activities in the 1970s and 1980s. This article describes the different sectors of its marine activities and evolvement of a different outlook concerning the sea. Important events such as the 1976 Proclamation and subsequent implementation of the French 200‐nautical mile Exclusive Economic Zone, and 1981 formation of a new Socialist government in France after 23 years of uninterrupted “Gaullist”; rule, offered a unique opportunity to restructure marine policy. The new Ministry of the Sea was intended to integrate marine policy and cater to a developing ocean “constituency.”; It was eventually downgraded to a “Secrétariat d'Etat,”; but its impact was undeniably important. 相似文献
992.
993.
Randall E. Mielke John H. Priester Rebecca A. Werlin Jeff Gelb Allison M. Horst Eduardo Orias Patricia A. Holden 《Applied and environmental microbiology》2013,79(18):5616-5624
Nanoscale titanium dioxide (TiO2) is increasingly used in consumer goods and is entering waste streams, thereby exposing and potentially affecting environmental microbes. Protozoans could either take up TiO2 directly from water and sediments or acquire TiO2 during bactivory (ingestion of bacteria) of TiO2-encrusted bacteria. Here, the route of exposure of the ciliated protozoan Tetrahymena thermophila to TiO2 was varied and the growth of, and uptake and accumulation of TiO2 by, T. thermophila were measured. While TiO2 did not affect T. thermophila swimming or cellular morphology, direct TiO2 exposure in rich growth medium resulted in a lower population yield. When TiO2 exposure was by bactivory of Pseudomonas aeruginosa, the T. thermophila population yield and growth rate were lower than those that occurred during the bactivory of non-TiO2-encrusted bacteria. Regardless of the feeding mode, T. thermophila cells internalized TiO2 into their food vacuoles. Biomagnification of TiO2 was not observed; this was attributed to the observation that TiO2 appeared to be unable to cross the food vacuole membrane and enter the cytoplasm. Nevertheless, our findings imply that TiO2 could be transferred into higher trophic levels within food webs and that the food web could be affected by the decreased growth rate and yield of organisms near the base of the web. 相似文献
994.
José Ragusa‐Netto 《Studies on Neotropical Fauna and Environment》2013,48(2):99-105
I studied Brotogeris chiriri abundance and foraging activity at a dry forest of the Urucum mountains in western Mato Grosso do Sul, Brazil, to evaluate their relationships with food resource production. Brotogeris chiriri abundance sharply increased during the early wet season (mainly October 2001) when it mostly foraged for fleshy fruits. At that time Protium heptaphyllum, one of the most common tree species, bore a large crop of fruits, the arils of which were extensively consumed by B. chiriri. Conversely, only a few parakeets were recorded foraging from the late wet to the late dry season, when dry fruit production predominated. The monthly pattern of parakeet abundance paralleled both its monthly pattern of foraging activity and fleshy fruit availability. Moreover, the variations in foraging activity were highly correlated to fleshy fruit production. Thus, data presented here evidenced the effect of both fruiting pulses and a common tree species that produced a large and ephemeral fruit crop, on the dynamic of a small and mobile canopy forager at a primary dry forest. 相似文献
995.
Anna Barabasz Anna Wilkowska Katarzyna Tracz Anna Ruszczyńska Ewa Bulska Rebecca F. Mills Lorraine E. Williams Danuta Maria Antosiewicz 《Journal of plant physiology》2013
HvHMA2 is a plasma membrane P1B-ATPase from barley that functions in Zn/Cd root-to-shoot transport. To assess the usefulness of HvHMA2 for modifying the metal content in aerial plant parts, it was expressed in tobacco under the CaMV35S promoter. Transformation with HvHMA2 did not produce one unique pattern of Zn and Cd accumulation; instead it depended on external metal supply. Thus Zn and Cd root-to-shoot translocation was facilitated, but not at all applied Zn/Cd concentrations. Metal uptake was restricted in HvHMA2-transformed plants and the level in the shoot was not enhanced. It was shown that HvHMA2 localizes to the plasma membrane of tobacco cells, and overloads the apoplast with Zn, which could explain the overall decrease in metal uptake observed. Despite the lower levels in the shoot, HvHMA2 transformants showed increased Zn sensitivity. Moreover, introduction of HvHMA2 into tobacco interfered with Fe metabolism and Fe accumulation was modified in HvHMA2-transformants in a Zn- and Cd-concentration dependent manner. The results indicate that ectopic expression of the export protein HvHMA2 in tobacco interferes with tobacco metal Zn–Cd–Fe cross-homeostasis, inducing internal mechanisms regulating metal uptake and tolerance. 相似文献
996.
J. Zhang P.‐M. Chen G.‐B. Chen L.‐C. Fang Y. Tang 《Zeitschrift fur angewandte Ichthyologie》2013,29(6):1453-1455
997.
M. Suquet F. Rimond J. Cosson J. Wilson‐Leedy L. Lebrun I. Queau C. Mingant C. Fauvel 《Zeitschrift fur angewandte Ichthyologie》2013,29(5):1145-1148
The movement characteristics of Pacific oyster trochophores have received very little coverage in the scientific literature. Described here are not only changes in the swimming characteristics of Crassostrea gigas trochophores (size: 53–77 μm) in relation to time after fertilization and to inter‐female variation but also the effects of salinity and pH on movement characteristics. The percentage of motile trochophores was measured on images obtained through a dissecting microscope and the Velocity Average Path (VAP) was assessed using a Computer Assisted Sperm Analysis (CASA) system. At 20°C, the first movements of the trochophores were observed at 6.5 h post‐fertilization. The mean (± SD) percentage of swimming trochophores and the VAP observed in seawater at 11.5 h post‐fertilization were 85 ± 10% and 146 ± 75 μm s?1, respectively (n = 8 females). Significant inter‐female variation in the percentage of motile trochophores (range: 66 ± 16–93 ± 3%) and in the VAP (55 ± 47–180 ± 90 μm s?1) was detected. Most of the trochophores were motile in a 9‰ salinity solution. Adjusting the pH of the seawater to values from 5.10 to 9.08 had no effect on swimming characteristics. The present study shows that the movement of oyster trochophores exhibits high plasticity in relation to environmental conditions because the highest percentages of swimming trochophores and optimal velocity values were recorded within large ranges of salinity and pH. Further research is required to determine whether the swimming performances of trochophores can be used to assess embryo quality in commercial hatcheries. 相似文献
998.
Lola García‐López de Hierro Marcos Moleón Peter G. Ryan 《Ethology : formerly Zeitschrift fur Tierpsychologie》2013,119(3):199-211
Males in several avian groups carry specialised materials as part of their courtship display. Females may vary their investment in reproduction in relation to their mates' attractiveness. The house sparrow (Passer domesticus) population on Dassen Island, South Africa, builds domed nests in the branches of trees. These nests are more or less spherical structures with a deep cup lined largely with feathers. When males collect feathers, they call to females and display the feather before it is added to the nest. We examined whether carrying feathers provides females with an index of male quality, which correlates with their subsequent investment in parental care. Additionally, we studied the potential importance of feathers in nest insulation. Feathers were collected mainly by males. Males also brought larger feathers, and deposited more feathers in nests, than females. Number of trips with feathers – which increased after feathers were experimentally removed from nests – and number of feathers brought varied among males. Volume of feathers influenced females' investment in reproduction and positively correlated with clutch size and chick feeding rates. We found more feathers during incubation and immediately after chicks hatched, when nest heat requirements peak. Furthermore, number of trips with feathers and number and size of feathers were greater during incubation. Our results suggest that this feather‐carrying behaviour by male house sparrows influences maternal reproduction investment and could be a kind of parental care per se by supplementing nest insulation. 相似文献
999.
Leif Sönnichsen Matthijs Bokje Jessica Marchal Heribert Hofer Bogumiła Jędrzejewska Stephanie Kramer‐Schadt Sylvia Ortmann 《Ethology : formerly Zeitschrift fur Tierpsychologie》2013,119(3):233-243
In natural environments, predation risk varies over time. The risk allocation hypothesis predicts that prey is expected to adjust key anti‐predator behaviours such as vigilance to temporal variation in risk. We tested the predictions of the risk allocation hypothesis in a natural environment where both a species‐rich natural predator community and human hunters are abundant and where the differences in seasonal and circadian activity between natural and anthropogenic predators provided a unique opportunity to quantify the contributions of different predator classes to anti‐predator behaviour. Whereas natural predators were expected to show similar levels of activity throughout the seasons, hunter activity was high during the daytime during a clearly defined hunting season. According to the risk allocation hypothesis, vigilance should then be higher during the hunting season and during daytime hours than during the non‐hunting season and night‐time hours. Roe deer (Capreolus capreolus) on the edge of Bia?owie?a Primeval Forest in Eastern Poland displayed vigilance behaviour consistent with these predictions. The behavioural response of roe deer to temporarily varying predation risks emphasises the behavioural plasticity of this species and suggests that future studies of anti‐predator behaviour need to incorporate circadian variation in predation pressure as well as risk gradients of both natural and anthropogenic predators. 相似文献
1000.
Wei‐Chun Cheng Yi‐Huey Chen Hon‐Tsen Yu J. Dale Roberts Yeong‐Choy Kam 《Ethology : formerly Zeitschrift fur Tierpsychologie》2013,119(4):286-295
Sequential polygyny is a reproductive strategy that allows males to continue to mate and compensates for the loss of future breeding opportunities incurred by parental care (i.e. egg attendance). Using the frog Kurixalus eiffengeri, we tested predictions that (1) attending males fathered two, overlapping clutches; and (2) that double clutching leads to improved offspring numbers. Using five microsatellite DNA markers, we genotyped 15 pairs of overlapping clutches, which differed slightly in developmental stage at a single egg‐laying site. Parentage analyses showed at least 12 of 15 pairs of overlapping egg clutches were sired by the attending male mated with different females, providing the first genetic evidence to support an earlier prediction that attending males sired both egg clutches. Field surveys found a low incidence of overlapping clutches (4.9% of 263 egg‐occupied stumps), suggesting sequential polygyny is uncommon. Stumps with multiple clutches contained significantly more eggs than stumps with single clutches but hatched similar number of tadpoles. Results suggest that continuous calling that attracts females during egg attendance is a reproductive tactic that maximizes mating opportunities. However, adoption of the sequential polygyny tactic may only result in marginal fitness gains for males that are traded off against average higher egg mortality in larger egg clutches. 相似文献