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171.
172.
Landscape of transcription in human cells 总被引:3,自引:0,他引:3
S Djebali CA Davis A Merkel A Dobin T Lassmann A Mortazavi A Tanzer J Lagarde W Lin F Schlesinger C Xue GK Marinov J Khatun BA Williams C Zaleski J Rozowsky M Röder F Kokocinski RF Abdelhamid T Alioto I Antoshechkin MT Baer NS Bar P Batut K Bell I Bell S Chakrabortty X Chen J Chrast J Curado T Derrien J Drenkow E Dumais J Dumais R Duttagupta E Falconnet M Fastuca K Fejes-Toth P Ferreira S Foissac MJ Fullwood H Gao D Gonzalez A Gordon H Gunawardena C Howald S Jha R Johnson P Kapranov B King 《Nature》2012,489(7414):101-108
Eukaryotic cells make many types of primary and processed RNAs that are found either in specific subcellular compartments or throughout the cells. A complete catalogue of these RNAs is not yet available and their characteristic subcellular localizations are also poorly understood. Because RNA represents the direct output of the genetic information encoded by genomes and a significant proportion of a cell's regulatory capabilities are focused on its synthesis, processing, transport, modification and translation, the generation of such a catalogue is crucial for understanding genome function. Here we report evidence that three-quarters of the human genome is capable of being transcribed, as well as observations about the range and levels of expression, localization, processing fates, regulatory regions and modifications of almost all currently annotated and thousands of previously unannotated RNAs. These observations, taken together, prompt a redefinition of the concept of a gene. 相似文献
173.
The ability to deposit and tailor reliable semiconducting films (with a particular recent emphasis on ultrathin systems) is indispensable for contemporary solid-state electronics. The search for thin-film semiconductors that provide simultaneously high carrier mobility and convenient solution-based deposition is also an important research direction, with the resulting expectations of new technologies (such as flexible or wearable computers, large-area high-resolution displays and electronic paper) and lower-cost device fabrication. Here we demonstrate a technique for spin coating ultrathin (approximately 50 A), crystalline and continuous metal chalcogenide films, based on the low-temperature decomposition of highly soluble hydrazinium precursors. We fabricate thin-film field-effect transistors (TFTs) based on semiconducting SnS(2-x)Se(x) films, which exhibit n-type transport, large current densities (>10(5) A cm(-2)) and mobilities greater than 10 cm2 V(-1) s(-1)--an order of magnitude higher than previously reported values for spin-coated semiconductors. The spin-coating technique is expected to be applicable to a range of metal chalcogenides, particularly those based on main group metals, as well as for the fabrication of a variety of thin-film-based devices (for example, solar cells, thermoelectrics and memory devices). 相似文献
174.
Most biological catalysts are made of protein; however, eight classes of natural ribozymes have been discovered that catalyse fundamental biochemical reactions. The central functions of ribozymes in modern organisms support the hypothesis that life passed through an 'RNA world' before the emergence of proteins and DNA. We have identified a new class of ribozymes that cleaves the messenger RNA of the glmS gene in Gram-positive bacteria. The ribozyme is activated by glucosamine-6-phosphate (GlcN6P), which is the metabolic product of the GlmS enzyme. Additional data indicate that the ribozyme serves as a metabolite-responsive genetic switch that represses the glmS gene in response to rising GlcN6P concentrations. These findings demonstrate that ribozyme switches may have functioned as metabolite sensors in primitive organisms, and further suggest that modern cells retain some of these ancient genetic control systems. 相似文献
175.
176.
Discovery of deep-level foreland thrust-fold structures in Taihang Mt. and its implication for early tectonic evolution of North China 总被引:5,自引:0,他引:5
Delineation and correlation of Dragon Spring Shear Zone with its deep-level structures at foreland have been studied by field work. This paper reports our new findings of thrust-fold structures within Taihang Neoarchean basement, which include flat thrusts,large-scale recumbent folds, subhorizontal foliation patterns, etc. It reveals that early tectonic evolution of North China clearly involves the horizontal contraction on a large scale, comparable to those of foreland of classical collisional orogenic belts. The vertical variation of structural patterns with foreland fold-thrust belt from shallow to deep levels has been documented for Taihang Mt. by structural correlation,which is associated with tectonic transposition and imbrication of basement complex with supracrustal sequences in the Neoarchean. 相似文献
177.
Orme CD Davies RG Burgess M Eigenbrod F Pickup N Olson VA Webster AJ Ding TS Rasmussen PC Ridgely RS Stattersfield AJ Bennett PM Blackburn TM Gaston KJ Owens IP 《Nature》2005,436(7053):1016-1019
Biodiversity hotspots have a prominent role in conservation biology, but it remains controversial to what extent different types of hotspot are congruent. Previous studies were unable to provide a general answer because they used a single biodiversity index, were geographically restricted, compared areas of unequal size or did not quantitatively compare hotspot types. Here we use a new global database on the breeding distribution of all known extant bird species to test for congruence across three types of hotspot. We demonstrate that hotspots of species richness, threat and endemism do not show the same geographical distribution. Only 2.5% of hotspot areas are common to all three aspects of diversity, with over 80% of hotspots being idiosyncratic. More generally, there is a surprisingly low overall congruence of biodiversity indices, with any one index explaining less than 24% of variation in the other indices. These results suggest that, even within a single taxonomic class, different mechanisms are responsible for the origin and maintenance of different aspects of diversity. Consequently, the different types of hotspots also vary greatly in their utility as conservation tools. 相似文献
178.
Restoration of photoreceptor ultrastructure and function in retinal degeneration slow mice by gene therapy 总被引:17,自引:0,他引:17
Ali RR Sarra GM Stephens C Alwis MD Bainbridge JW Munro PM Fauser S Reichel MB Kinnon C Hunt DM Bhattacharya SS Thrasher AJ 《Nature genetics》2000,25(3):306-310
The gene Prph2 encodes a photoreceptor-specific membrane glycoprotein, peripherin-2 (also known as peripherin/rds), which is inserted into the rims of photoreceptor outer segment discs in a complex with rom-1 (ref. 2). The complex is necessary for the stabilization of the discs, which are renewed constantly throughout life, and which contain the visual pigments necessary for photon capture. Mutations in Prph2 have been shown to result in a variety of photoreceptor dystrophies, including autosomal dominant retinitis pigmentosa and macular dystrophy. A common feature of these diseases is the loss of photoreceptor function, also seen in the retinal degeneration slow (rds or Prph2 Rd2/Rd2) mouse, which is homozygous for a null mutation in Prph2. It is characterized by a complete failure to develop photoreceptor discs and outer segments, downregulation of rhodopsin and apoptotic loss of photoreceptor cells. The electroretinograms (ERGs) of Prph2Rd2/Rd2 mice have greatly diminished a-wave and b-wave amplitudes, which decline to virtually undetectable concentrations by two months. Subretinal injection of recombinant adeno-associated virus (AAV) encoding a Prph2 transgene results in stable generation of outer segment structures and formation of new stacks of discs containing both perpherin-2 and rhodopsin, which in many cases are morphologically similar to normal outer segments. Moreover, the re-establishment of the structural integrity of the photoreceptor layer also results in electrophysiological correction. These studies demonstrate for the first time that a complex ultrastructural cell defect can be corrected both morphologically and functionally by in vivo gene transfer. 相似文献
179.
Mutations in SPINK5, encoding a serine protease inhibitor, cause Netherton syndrome 总被引:23,自引:0,他引:23
Chavanas S Bodemer C Rochat A Hamel-Teillac D Ali M Irvine AD Bonafé JL Wilkinson J Taïeb A Barrandon Y Harper JI de Prost Y Hovnanian A 《Nature genetics》2000,25(2):141-142
We describe here eleven different mutations in SPINK5, encoding the serine protease inhibitor LEKTI, in 13 families with Netherton syndrome (NS, MIM256500). Most of these mutations predict premature termination codons. These results disclose a critical role of SPINK5 in epidermal barrier function and immunity, and suggest a new pathway for high serum IgE levels and atopic manifestations. 相似文献
180.
Hillier LW Fulton RS Fulton LA Graves TA Pepin KH Wagner-McPherson C Layman D Maas J Jaeger S Walker R Wylie K Sekhon M Becker MC O'Laughlin MD Schaller ME Fewell GA Delehaunty KD Miner TL Nash WE Cordes M Du H Sun H Edwards J Bradshaw-Cordum H Ali J Andrews S Isak A Vanbrunt A Nguyen C Du F Lamar B Courtney L Kalicki J Ozersky P Bielicki L Scott K Holmes A Harkins R Harris A Strong CM Hou S Tomlinson C Dauphin-Kohlberg S Kozlowicz-Reilly A Leonard S Rohlfing T Rock SM Tin-Wollam AM Abbott A 《Nature》2003,424(6945):157-164