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241.
As the most famous woman scientist of the twentieth century, there has been no shortage of books and articles on the life and career of Marie Curie (1867–1934). Her role as a director of a laboratory-based research school in the new scientific field of radioactivity, a field which embraced both chemistry and physics, however, has never been examined. In recent years, there has been a growing interest in the question of research schools, and Morrell, Ravetz, Geison, and Klosterman, amongst others, have written on this subject. Using, in part, the methodology of Morrell, this paper investigates the role of Marie Curie as a school director in the Paris Faculty in the years 1907–14, examining the work and characteristics of her school and assessing her effectiveness as a director.  相似文献   
242.
Pest insect species are a burden to humans as they destroy crops and serve as vectors for a wide range of diseases including malaria and dengue. Chemical insecticides are currently the dominant approach for combating these pests. However, the de-registration of key classes of chemical insecticides due to their perceived ecological and human health risks in combination with the development of insecticide resistance in many pest insect populations has created an urgent need for improved methods of insect pest control. The venoms of arthropod predators such as spiders and scorpions are a promising source of novel insecticidal peptides that often have different modes of action to extant chemical insecticides. These peptides have been optimized via a prey–predator arms race spanning hundreds of millions of years to target specific types of insect ion channels and receptors. Here we review the current literature on insecticidal venom peptides, with a particular focus on their structural and pharmacological diversity, and discuss their potential for deployment as insecticides.  相似文献   
243.
We consider the problem of online prediction when it is uncertain what the best prediction model to use is. We develop a method called dynamic latent class model averaging, which combines a state‐space model for the parameters of each of the candidate models of the system with a Markov chain model for the best model. We propose a polychotomous regression model for the transition weights to assume that the probability of a change in time depends on the past through the values of the most recent time periods and spatial correlation among the regions. The evolution of the parameters in each submodel is defined by exponential forgetting. This structure allows the ‘correct’ model to vary over both time and regions. In contrast to existing methods, the proposed model naturally incorporates clustering and prediction analysis in a single unified framework. We develop an efficient Gibbs algorithm for computation, and we demonstrate the value of our framework on simulated experiments and on a real‐world problem: forecasting IBM's corporate revenue. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
244.
Two new species of tarantulas from Mexico are described and illustrated: Bonnetina tenuiverpis and Bonnetina juxtantricola, from the states of Mexico and Guerrero, respectively. Male palpal bulbs, tibial apophyses and spermatheca are among the most taxonomically informative characters. Male bulb microstructure is revealed from scanning electron microscopy; both new and homologous structures to other Theraphosinae genera are identified and described. Nomenclatural changes for male tibial apophyses are also proposed. The holotype male and allotype female of one of the species are molecularly characterized and matched from CO1 partial sequence.

http://zoobank.org/urn:lsid:zoobank.org:pub:BBDBBEDE-6983-4F5C-B34C-4622DF494C84  相似文献   
245.
Neutrophils are being increasingly recognized as an important element in tumor progression. They have been shown to exert important effects at nearly every stage of tumor progression with a number of studies demonstrating that their presence is critical to tumor development. Novel aspects of neutrophil biology have recently been elucidated and its contribution to tumorigenesis is only beginning to be appreciated. Neutrophil extracellular traps (NETs) are neutrophil-derived structures composed of DNA decorated with antimicrobial peptides. They have been shown to trap and kill microorganisms, playing a critical role in host defense. However, their contribution to tumor development and metastasis has recently been demonstrated in a number of studies highlighting NETs as a potentially important therapeutic target. Here, studies implicating NETs as facilitators of tumor progression and metastasis are reviewed. In addition, potential mechanisms by which NETs may exert these effects are explored. Finally, the ability to target NETs therapeutically in human neoplastic disease is highlighted.  相似文献   
246.
Expression of the glycosylphosphatidylinositol-anchored membrane protein CD24 correlates with a poor prognosis for many human cancers, and in experimental tumors can promote metastasis. However, the mechanism by which CD24 contributes to tumor progression remains unclear. Here we report that in MTLy breast cancer cells CD24 interacts with and augments the kinase activity of c-src, a protein strongly implicated in promoting invasion and metastasis. This occurs within and is dependent upon intact lipid rafts. CD24-augmented c-src kinase activity increased formation of focal adhesion complexes, accelerated phosphorylation of FAK and paxillin and consequently enhanced integrin-mediated adhesion. Loss and gain of function approaches showed that c-src activity is necessary and sufficient to mediate the effects of CD24 on integrin-dependent adhesion and cell spreading, as well as on invasion. Together these results indicate that c-src is a CD24-activated mediator that promotes integrin-mediated adhesion and invasion, and suggest a mechanism by which CD24 might contribute to tumor progression through stimulating the activity of c-src or another member of the Src family.  相似文献   
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This review focuses on the recent advances in functions of spectrins in non-erythroid cells. We discuss new data concerning the commonly known role of the spectrin-based skeleton in control of membrane organization, stability and shape, and tethering protein mosaics to the cellular motors and to all major filament systems. Particular effort has been undertaken to highlight recent advances linking spectrin to cell signaling phenomena and its participation in signal transduction pathways in many cell types.  相似文献   
250.
IMAGe syndrome (intrauterine growth restriction, metaphyseal dysplasia, adrenal hypoplasia congenita and genital anomalies) is an undergrowth developmental disorder with life-threatening consequences. An identity-by-descent analysis in a family with IMAGe syndrome identified a 17.2-Mb locus on chromosome 11p15 that segregated in the affected family members. Targeted exon array capture of the disease locus, followed by high-throughput genomic sequencing and validation by dideoxy sequencing, identified missense mutations in the imprinted gene CDKN1C (also known as P57KIP2) in two familial and four unrelated patients. A familial analysis showed an imprinted mode of inheritance in which only maternal transmission of the mutation resulted in IMAGe syndrome. CDKN1C inhibits cell-cycle progression, and we found that targeted expression of IMAGe-associated CDKN1C mutations in Drosophila caused severe eye growth defects compared to wild-type CDKN1C, suggesting a gain-of-function mechanism. All IMAGe-associated mutations clustered in the PCNA-binding domain of CDKN1C and resulted in loss of PCNA binding, distinguishing them from the mutations of CDKN1C that cause Beckwith-Wiedemann syndrome, an overgrowth syndrome.  相似文献   
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