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91.
Aud H. Halbritter Simone Fior Irene Keller Regula Billeter Peter J. Edwards Rolf Holderegger Sophie Karrenberg Andrea R. Pluess Alex Widmer Jake M. Alexander 《Journal of evolutionary biology》2018,31(6):784-800
Studies of genetic adaptation in plant populations along elevation gradients in mountains have a long history, but there has until now been neither a synthesis of how frequently plant populations exhibit adaptation to elevation nor an evaluation of how consistent underlying trait differences across species are. We reviewed studies of adaptation along elevation gradients (i) from a meta‐analysis of phenotypic differentiation of three traits (height, biomass and phenology) from plants growing in 70 common garden experiments; (ii) by testing elevation adaptation using three fitness proxies (survival, reproductive output and biomass) from 14 reciprocal transplant experiments; (iii) by qualitatively assessing information at the molecular level, from 10 genomewide surveys and candidate gene approaches. We found that plants originating from high elevations were generally shorter and produced less biomass, but phenology did not vary consistently. We found significant evidence for elevation adaptation in terms of survival and biomass, but not for reproductive output. Variation in phenotypic and fitness responses to elevation across species was not related to life history traits or to environmental conditions. Molecular studies, which have focussed mainly on loci related to plant physiology and phenology, also provide evidence for adaptation along elevation gradients. Together, these studies indicate that genetically based trait differentiation and adaptation to elevation are widespread in plants. We conclude that a better understanding of the mechanisms underlying adaptation, not only to elevation but also to environmental change, will require more studies combining the ecological and molecular approaches. 相似文献
92.
Kaitlin R.Wright Jessica A.Mayhew Lori K.Sheeran Jake A.Funkhouser Ronald.S.Wagner Li-Xing Sun Jin-Hua Li 《动物学研究》2018,(4)
Play behaviors and signals during playful interactions with juvenile conspecifics are important for both the social and cognitive development of young animals.The social organization of a species can also influence juvenile social play. We examined the relationships among play behaviors, candidate play signals, and play bout termination in Tibetan macaques(Macaca thibetana) during juvenile and infant social play to characterize the species play style. As Tibetan macaques are despotic and live in groups with strict linear dominance hierarchies and infrequent reconciliation, we predicted that play would be at risk of misinterpretation by both the individuals engaged in the play bout and by those watching, possibly leading to injury of the players. Animals living in such societies might need to frequently and clearly signal playful intent to play partners and other group members to avoid aggressive outcomes. We gathered video data on 21 individually-identified juvenile and infant macaques(one month to five years of age)from the Valley of the Wild Monkeys, Mt. Huangshan,China. We used all-occurrence sampling to record play behaviors and candidate play signals based on an ethogram. We predicted that play groups would use multiple candidate play signals in a variety of contexts and in association with the number of audience members in proximity to the players and play bout length. In the 283 playful interactions we scored,juvenile and infant macaques used multiple body and facial candidate play signals. Our data showed that juvenile and infant Tibetan macaques use a versatile repertoire of play behaviors and signals to sustain play. 相似文献
93.
Yves T. Prairie Jukka Alm Jake Beaulieu Nathan Barros Tom Battin Jonathan Cole Paul del Giorgio Tonya DelSontro Frédéric Guérin Atle Harby John Harrison Sara Mercier-Blais Dominique Serça Sebastian Sobek Dominic Vachon 《Ecosystems》2018,21(5):1058-1071
Freshwater reservoirs are a known source of greenhouse gas (GHG) to the atmosphere, but their quantitative significance is still only loosely constrained. Although part of this uncertainty can be attributed to the difficulties in measuring highly variable fluxes, it is also the result of a lack of a clear accounting methodology, particularly about what constitutes new emissions and potential new sinks. In this paper, we review the main processes involved in the generation of GHG in reservoir systems and propose a simple approach to quantify the reservoir GHG footprint in terms of the net changes in GHG fluxes to the atmosphere induced by damming, that is, ‘what the atmosphere sees.’ The approach takes into account the pre-impoundment GHG balance of the landscape, the temporal evolution of reservoir GHG emission profile as well as the natural emissions that are displaced to or away from the reservoir site resulting from hydrological and other changes. It also clarifies the portion of the reservoir carbon burial that can potentially be considered an offset to GHG emissions. 相似文献
94.
Simplifying understory complexity in oil palm plantations is associated with a reduction in the density of a cleptoparasitic spider,Argyrodes miniaceus (Araneae: Theridiidae), in host (Araneae: Nephilinae) webs 下载免费PDF全文
Dakota M. Spear William A. Foster Andreas Dwi Advento Mohammad Naim Jean‐Pierre Caliman Sarah H. Luke Jake L. Snaddon Sudharto Ps Edgar C. Turner 《Ecology and evolution》2018,8(3):1595-1603
Expansion of oil palm agriculture is currently one of the main drivers of habitat modification in Southeast Asia. Habitat modification can have significant effects on biodiversity, ecosystem function, and interactions between species by altering species abundances or the available resources in an ecosystem. Increasing complexity within modified habitats has the potential to maintain biodiversity and preserve species interactions. We investigated trophic interactions between Argyrodes miniaceus, a cleptoparasitic spider, and its Nephila spp. spider hosts in mature oil palm plantations in Sumatra, Indonesia. A. miniaceus co‐occupy the webs of Nephila spp. females and survive by stealing prey items caught in the web. We examined the effects of experimentally manipulated understory vegetation complexity on the density and abundance of A. miniaceus in Nephila spp. webs. Experimental understory treatments included enhanced complexity, standard complexity, and reduced complexity understory vegetation, which had been established as part of the ongoing Biodiversity and Ecosystem Function in Tropical Agriculture (BEFTA) Project. A. miniaceus density ranged from 14.4 to 31.4 spiders per square meter of web, with significantly lower densities found in reduced vegetation complexity treatments compared with both enhanced and standard treatment plots. A. miniaceus abundance per plot was also significantly lower in reduced complexity than in standard and enhanced complexity plots. Synthesis and applications: Maintenance of understory vegetation complexity contributes to the preservation of spider host–cleptoparasite relationships in oil palm plantations. Understory structural complexity in these simplified agroecosystems therefore helps to support abundant spider populations, a functionally important taxon in agricultural landscapes. In addition, management for more structurally complex agricultural habitats can support more complex trophic interactions in tropical agroecosystems. 相似文献
95.
High levels of genetic structure and striking phenotypic variability in a sexually dimorphic suckermouth catfish from the African Highveld 下载免费PDF全文
Jake Morris Antonia G. P. Ford Jarome R. Ali Claire R. Peart Roger Bills Julia J. Day 《Biological journal of the Linnean Society. Linnean Society of London》2016,117(3):528-546
Uncovering biological diversity to more accurately understand diversity patterns, and ultimately the processes driving diversification, is important not only from an evolutionary perspective but also a conservation perspective. This is particularly pertinent in Africa's rivers in which overall diversity, as well as how it arose, is poorly understood in comparison with lacustrine environments. Here we investigate population divergence in the sexually dimorphic suckermouth catfish species Chiloglanis anoterus (Crass, 1960) from the African Highveld, in which we observe striking variability in exaggerated male caudal fins across its range. As this trait is likely to be indirect evidence for sexual selection by female choice, a mechanism that has been shown to increase species diversity in different taxa, we used an integrated approach to test if current diversity in this species is underestimated. Results based on phylogenetic inference, population genetics and geometric morphometrics indicate that the recognized species C. anoterus represents five distinct lineages that may be considered confirmed candidate species. We suggest that diversification in these highland catfish has been facilitated through geographical isolation in upper river catchments, and that sexual selection through female choice has probably driven variation in male caudal fin morphology. In contrast to the relatively large range size of the currently recognized species (C. anoterus), our findings highlight highly restricted ranges of the lineages identified here, indicating that these highland habitats may harbour higher levels of endemic diversity than previously thought. 相似文献
96.
Leah Edwards Jake Knight Robert Handler Joseph Abraham Paul Blowers 《The International Journal of Life Cycle Assessment》2016,21(4):536-554
Purpose
In 2012 and 2013, the University of Arizona’s Office of Sustainability conducted environmental life cycle assessments of two Homecoming events that drew 60,000 attendees each. Based on reviews of published literature, this is the first time that a process-based life cycle assessment has been conducted for an event of this size. This study contributes to the small but growing field of research using life cycle assessment to track the environmental impacts of events.Methods
The assessments at The University of Arizona considered the environmental impact of food, materials, waste, travel, and lodging. The effects of these components of Homecoming weekend were evaluated in terms of nine different categories. However, this paper focuses on greenhouse gas emissions. The data collection process for these assessments was completed by student observers and supplemented with information provided by university departments, event organizers, and survey responses from attendees. Data were analyzed using SimaPro Life Cycle Assessment software and using data from the EcoInvent database. Based on the results of the 2012 study, initiatives were put into place for 2013 that were designed to reduce the environmental impact of the subsequent Homecoming event.Results and discussion
The results show that the total impact of Homecoming 2012 was an estimated 2400 metric tons of CO2-eq, whereas the impact of Homecoming 2013 was an estimated 1900 metric tons of CO2-eq, a 19 % decrease year over year. Data were analyzed in terms of carbon dioxide emissions in both years. Travel made up the majority of the environmental impact (82.04 % in 2012 and 77.77 % in 2013), followed by accommodations (17.5 % in 2012 and 19.31 % in 2013), with energy, materials, and food having almost negligible impacts (0.46 % in 2012 and 2.92 % in 2013). While there had been noticeable changes in the measured impact of food and energy between 2012 and 2013, the significant impact of travel overshadowed all other impact categories in terms of greenhouse gas emissions, making these changes less noticeable. Analysis of each of these categories of impact helped to establish best practices for mitigating the impact of events on a category-by-category basis.Conclusions
This study introduces a framework for assessing impacts of a large university event while also highlighting ways to reduce impacts. The initiatives implemented in 2013 to reduce impacts of large-scale events can be informative to others working to reduce emissions at large events. Additional recommendations to reduce impacts of large events are provided.97.
Limited Protection from a Pathogenic Chimeric Simian-Human Immunodeficiency Virus Challenge following Immunization with Attenuated Simian Immunodeficiency Virus 总被引:1,自引:1,他引:0 下载免费PDF全文
Mark G. Lewis Jake Yalley-Ogunro Jack J. Greenhouse Terry P. Brennan Jennifer Bo Jiang Thomas C. VanCott Yichen Lu Gerald A. Eddy Deborah L. Birx 《Journal of virology》1999,73(2):1262-1270
Two live attenuated single-deletion mutant simian immunodeficiency virus (SIV) constructs, SIV239Δnef and SIVPBj6.6Δnef, were tested for their abilities to stimulate protective immunity in macaques. During the immunization period the animals were examined for specific immune responses and virus growth. Each construct generated high levels of specific immunity in all of the immunized animals. The SIV239Δnef construct was found to grow to high levels in all immunized animals, with some animals remaining positive for virus isolation and plasma RNA throughout the immunization period. The SIVPBj6.6Δnef was effectively controlled by all of the immunized animals, with virus mostly isolated only during the first few months following immunization and plasma RNA never detected. Following an extended period of immunization of over 80 weeks, the animals were challenged with a pathogenic simian-human immunodeficiency virus (SHIV) isolate, SIV89.6PD, by intravenous injection. All of the SIV239Δnef-immunized animals became infected with the SHIV isolate; two of five animals eventually controlled the challenge and three of five animals, which failed to check the immunizing virus, progressed to disease state before the unvaccinated controls. One of five animals immunized with SIVPBj6.6Δnef totally resisted infection by the challenge virus, while three others limited its growth and the remaining animal became persistently infected and eventually died of a pulmonary thrombus. These data indicate that vaccination with attenuated SIV can protect macaques from disease and in some cases from infection by a divergent SHIV. However, if animals are unable to control the immunizing virus, potential damage that can accelerate the disease course of a pathogenic challenge virus may occur. 相似文献
98.
99.
Positive Maternal Attitude to the Family Eating Together Decreases the Risk of Adolescent Overweight
Abdullah A. Mamun Debbie A. Lawlor Michael J. O'Callaghan Gail M. Williams Jake M. Najman 《Obesity (Silver Spring, Md.)》2005,13(8):1422-1430
Objectives: To determine whether maternal attitude towards the family regularly eating together and maternal report of how often the family eat together are associated with adolescent offspring overweight. Research Methods and Procedures: A cross‐sectional mother‐child‐linked analysis was carried out using 14‐year follow‐up data from a population‐based prospective birth cohort of 3795 children (52% males) who were participants in the Mater‐University study of pregnancy, Brisbane, Australia. Maternal reports on family eating pattern reported at age 14 were used. Results: The prevalence of overweight at age 14 was 24.1% (95% confidence interval (CI), 22.3, 26.1) for males and 27.1% (CI, 25.1, 29.2) for females. The majority of mothers (78%) reported that the family ate together at least once a day, but only 43% reported that they felt that family eating together was important. The offspring of women who felt that the family eating together was not important had increased odds of being overweight at age 14 (odds ratio, 1.27; 95% CI, 1.05, 1.53) in age‐ and sex‐adjusted models. Adjustment for potential confounding factors had no substantive effect on the association. There was no association between maternal reports of how often the family actually did eat together and overweight at age 14 in the offspring. Discussion: These findings suggest that maternal attitude towards family eating patterns, but not maternal report of how often the family do eat together, are associated with childhood overweight status. Maternal attitude towards family eating (as opposed to a report of actual frequency at one time‐point) may reflect broader maternal influences (beyond family eating pattern) on their child's diet and eating patterns over a long time course. 相似文献
100.
Meng QJ Logunova L Maywood ES Gallego M Lebiecki J Brown TM Sládek M Semikhodskii AS Glossop NR Piggins HD Chesham JE Bechtold DA Yoo SH Takahashi JS Virshup DM Boot-Handford RP Hastings MH Loudon AS 《Neuron》2008,58(1):78-88
The intrinsic period of circadian clocks is their defining adaptive property. To identify the biochemical mechanisms whereby casein kinase1 (CK1) determines circadian period in mammals, we created mouse null and tau mutants of Ck1 epsilon. Circadian period lengthened in CK1epsilon-/-, whereas CK1epsilon(tau/tau) shortened circadian period of behavior in vivo and suprachiasmatic nucleus firing rates in vitro, by accelerating PERIOD-dependent molecular feedback loops. CK1epsilon(tau/tau) also accelerated molecular oscillations in peripheral tissues, revealing its global role in circadian pacemaking. CK1epsilon(tau) acted by promoting degradation of both nuclear and cytoplasmic PERIOD, but not CRYPTOCHROME, proteins. Together, these whole-animal and biochemical studies explain how tau, as a gain-of-function mutation, acts at a specific circadian phase to promote degradation of PERIOD proteins and thereby accelerate the mammalian clockwork in brain and periphery. 相似文献