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991.
Alien invasive pathogens have caused numerous disastrous epidemics around the globe during the last two centuries. The frequency of these catastrophes has increased in parallel with the increase of international plant trade. Effective control of the risks requires understanding of factors governing vulnerability of indigenous plants. We tested whether the threat caused by alien pathogens of Asian origin is random among various tree species in Europe or whether it relates to their distribution range. A database including distribution ranges of 75 European tree species and literature-derived information on their susceptibility to invasive forest pathogens (IFPs) of Asian origin was compiled. Analysis on this database indicated that the susceptibility to Asian pathogens is significantly more common among tree species that occur only within Europe than among species with distributional ranges from Europe to Siberia (disease susceptibility percentage, DSP, 52 and 19 %, respectively). Notably, all severely attacked tree species are strictly European while tree species with distribution ranges extending from Europe to Siberia show at most only mild or moderate symptoms of Asian IFPs. Furthermore, the proportion of European broadleaf tree species susceptible to Asian IFPs is significantly higher than that of conifer species. Our results suggest that in Europe, Asian pathogens cause a higher risk to temperate and Mediterranean forests, largely composed of broadleaved species with distributional ranges restricted to Europe, than to boreal forests dominated by conifers distributed to Siberia.  相似文献   
992.
A particularly vexing phenomenon within invasion ecology is the occurrence of spontaneous collapses within seemingly well-established exotic populations. Here, we assess the frequency of collapses among 68 exotic bird populations established in Hawaii, Puerto Rico, Los Angeles and Miami. Following other published definitions, we define a ‘collapse’ as a decline in abundance of ≥90 % within ≤10 years that lasts for at least 3 years. We show that 44 of the 68 exotic bird populations have exhibited declines at some point within their time series. Sixteen of the populations declined sufficiently to be defined as collapsed. It took on average 3.8 ± 1.8 years for populations to decline into a collapsed state, and this state persisted on average for 7.1 ± 6.3 years across (collapsed) populations. We compared the severity and duration of declines across all 44 declining populations according to taxonomic Order and geographic region. Neither variable explained substantial variation in the metrics of collapse. Our results indicate that severe, rapid, and persistent population declines may be common among exotic populations. We suggest that incorporating the probability and persistence of collapses into management decisions can inform efforts to enact control or eradication measures. We also suggest that applying our approach to other taxa and locations is crucial for improving our understanding of when and where collapses are likely to occur.  相似文献   
993.
Many biological invasions result in negative impacts on the environment and human livelihoods, but simultaneously some also provide benefits that are valued differently by various stakeholders. To inform policy and management of invasive species it is important to assess landowners’ and broader society’s knowledge and perceptions of invasive species, something which is lacking in many contexts, especially in urban settings. In this study we interviewed 153 householders living in a medium-sized South African town who had declared invasive alien trees in their gardens. Less than half of the respondents could identify the invasive tree on their property and only one-third knew that it was an invasive alien species. There was a positive association between income and education levels with exposure to media about invasive alien species and respondents’ ability to identify the species and name any other invasive alien tree species. Knowledge levels were unequal across species. Amongst those who knew the tree was an invasive alien species, reasons why they retained it in their gardens included that it would be costly or too much effort to remove, they liked the tree, that it was not causing any harm and that the property was rented and so its removal was not their responsibility. However, the majority of people (83 %) were willing to have it removed from their garden if done for free by appropriate agencies, which is promising for compliance with new regulations on invasive species implemented at the end of 2014 in South Africa. The results also highlight the need for targeted and appropriate education and awareness programs amongst urban householders on invasive alien species, relevant legislation and their obligations.  相似文献   
994.
Both the size of founding populations (propagule size) and environmental suitability are known to influence whether a species newly introduced to a location will establish a self-sustaining population. However, these two factors do not operate independently: it is the interaction between propagule size and environmental suitability that determines the probability an introduced population will establish. Here I use the example of dung beetle introductions to Australia to illustrate the importance of this interaction. I first describe equations that model establishment success jointly as a function of propagule size and environmental suitability. I then show how these equations provide insight into the different outcomes observed in two dung beetle species widely introduced to Australia. In one species, variation in propagule size had relatively little influence on establishment success due to large variation in environmental suitability, leading to an essentially bimodal outcome: sites were either very suitable for establishment and introductions succeeded, or sites were unsuitable and introductions failed regardless of propagule size. For the second species, there was much less variation among locations in environmental suitability, leading to propagule size having a strong influence on establishment success. These examples highlight how the interplay between environmental suitability and founding population size is central to determining the probability an introduced species will establish.  相似文献   
995.
The synthesis of four novel analogues of metoprolol, a well-known beta1-blocker used to reduce arterial blood pressure, is described. The preparation of (2S,2'S)-7, (2R,2'S)-7, (2R,2'R)-8, and (2S,2'R)-8 was based on the reaction of racemic 2-[4-(2'-methoxyethyl)-phenoxymethyl]-oxirane (4) with (R)- or (S)-2-amino-1-butanol. Salient characteristics of analogues 7 and 8 relative to metoprolol are the incorporation of an additional stereogenic center, as well as a methyl group and a hydroxyl function on the nitrogen-containing chain. These novel derivatives present significant hypotensive and bradycardiac activity, although no blocking action toward beta1 and beta2 adrenergic receptor.  相似文献   
996.
Polyamines are ubiquitous polycationic compounds that mediate fundamental aspects of cell growth, differentiation, and cell death in eukaryotic and prokaryotic organisms. In plants, polyamines are implicated in a variety of growth and developmental processes, in addition to abiotic and biotic stress responses. In the last decade, mutant studies conducted predominantly in Arabidopsis thaliana revealed an obligatory requirement for polyamines in zygotic and somatic embryogenesis. Moreover, our appreciation for the intricate spatial and temporal regulation of intracellular polyamine levels has advanced considerably. The exact molecular mechanism(s) through which polyamines exert their physiological response remains somewhat enigmatic and likely serves as a major area for future research efforts. In the following review, we discuss recent advances in the plant polyamine field, which range from metabolism and mutant characterization to molecular genetics and potential mode(s) of polyamine action during growth and development in vitro and in vivo. This review will also focus on the specific role of polyamines during embryogenesis and organogenesis.  相似文献   
997.
Genomic selection (GS) is an effective method to improve predictive accuracies of genetic values. However, high cost in genotyping will limit the application of this technology in some species. Therefore, it is necessary to find some methods to reduce the genotyping costs in genomic selection. Large yellow croaker is one of the most commercially important marine fish species in southeast China and Eastern Asia. In this study, genotyping-by-sequencing was used to construct the libraries for the NGS sequencing and find 29,748 SNPs in the genome. Two traits, eviscerated weight (EW) and the ratio between eviscerated weight and whole body weight (REW), were chosen to study. Two strategies to reduce the costs were proposed as follows: selecting extreme phenotypes (EP) for genotyping in reference population or pre-selecting SNPs to construct low-density marker panels in candidates. Three methods of pre-selection of SNPs, i.e., pre-selecting SNPs by absolute effects (SE), by single marker analysis (SMA), and by fixed intervals of sequence number (EL), were studied. The results showed that using EP was a feasible method to save the genotyping costs in reference population. Heritability did not seem to have obvious influences on the predictive abilities estimated by EP. Using SMA was the most feasible method to save the genotyping costs in candidates. In addition, the combination of EP and SMA in genomic selection also showed good results, especially for trait of REW. We also described how to apply the new methods in genomic selection and compared the genotyping costs before and after using the new methods. Our study may not only offer a reference for aquatic genomic breeding but also offer a reference for genomic prediction in other species including livestock and plants, etc.  相似文献   
998.
Evolutionary anthropology has traditionally focused on the study of small-scale, largely self-sufficient societies. The increasing rarity of these societies underscores the importance of such research yet also suggests the need to understand the processes by which such societies are being lost—what we call “modernization”—and the effects of these processes on human behavior and biology. In this article, we discuss recent efforts by evolutionary anthropologists to incorporate modernization into their research and the challenges and rewards that follow. Advantages include that these studies allow for explicit testing of hypotheses that explore how behavior and biology change in conjunction with changes in social, economic, and ecological factors. In addition, modernization often provides a source of “natural experiments” since it may proceed in a piecemeal fashion through a population. Challenges arise, however, in association with reduced variability in fitness proxies such as fertility, and with the increasing use of relatively novel methodologies in evolutionary anthropology, such as the analysis of secondary data. Confronting these challenges will require careful consideration but will lead to an improved understanding of humanity. We conclude that the study of modernization offers the prospect of developing a richer evolutionary anthropology, by encompassing ultimate and proximate explanations for behavior expressed across the full range of human societies.  相似文献   
999.
The God Allusion     
It has previously been suggested that the historically and geographically widespread persistence of religious beliefs occurs because it is a by-product of normal cognitive processes, ones which first evolved to confer survival advantages in the social domain. If this theory holds, then it is likely that inter-individual variation in the same biases may predict corresponding variation in religious thoughts and behaviors. Using an online questionnaire, 298 participants answered questions regarding their tendency to detect agency, the degree to which they displayed schizotypal traits, their ability to understand the emotions and motivations of others (“mentalizing”), and their religious beliefs and behaviors. Path analysis suggests that mentalizing, agency detection, and schizotypal thinking were each independently related to religiosity. Furthermore, schizotypal thinking and agency detection were highly interrelated with one another, whereas mentalizing was not. Although the degree to which an individual engages with religious or spiritual beliefs will be influenced by their cultural and historical context, this paper helps to elucidate the interplay between various cognitive processes that might predispose some individuals but not others toward holding such beliefs in the first place.  相似文献   
1000.
Venturing into novel terrain poses physical risks to a female and her offspring. Females have a greater tendency to avoid physical harm, while males tend to have larger range sizes and often outperform females in navigation-related tasks. Given this backdrop, we expected that females would explore a novel environment with more caution than males, and that more-cautious exploration would negatively affect navigation performance. Participants explored a novel, large-scale, virtual environment in search of five objects, pointed in the direction of each object from the origin, and then navigated back to the objects. We found that females demonstrated more caution while exploring as reflected in the increased amounts of pausing and revisiting of previously traversed locations. In addition, more pausing and revisiting behaviors led to degradation in navigation performance. Finally, individual levels of trait harm avoidance were positively associated with the amount of revisiting behavior during exploration. These findings support the idea that the fitness costs associated with long-distance travel may encourage females to take a more cautious approach to spatial exploration, and that this caution may partially explain the sex differences in navigation performance.  相似文献   
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