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31.
A careful analysis by 1H and 13C FT-NMR on the Cu(II) (L-histidine)2 complex was carried out which allows delineation of structure and dynamics in solution. A mixture of complexes was shown such that 24% of the Cu(II) (L-histidine)2 complex contains both histidines bound in the histaminelike way, while the remaining 76% contains one L-His molecule bound in the histaminelike way and the other L-His molecule bound in the glycinelike way. The motional correlation time and relevant features of the exchange process were also delineated.  相似文献   
32.
Rechargeable lithium–oxygen batteries (LOBs) are considered to be one of the most promising energy storage systems. However, the use of reactive lithium (Li) metal and the formation of Li dendrites during battery operation would lead to serious safety concerns, especially when flammable liquid electrolytes are utilized. Herein, superior metal–organic framework (MOF) glass-based solid-state electrolytes (SSEs) is developed for stable all-solid-state LOBs (SSLOBs). These non-flammable and boundary-free MOF glass SSEs are capable of suppressing the dendrite growth and exhibiting long-term Li stripping/plating stability, contributing to superior Li+ conductivity (5 × 10−4 S cm−1 at 20 °C), high Li+ transference number (0.86), and good electrochemical stability. It is discovered that discharge product deposition behavior in the solid-solid interface can be well regulated by the ion/electron mixed conducted cathode fabricated with MOF glass SSEs and electronic conductive polymers. As a result, the SSLOBs can be stably recharged for 400 cycles with a low polarization gap and deliver a high capacity of 13552 mAh g−1. The development of this proposed MOF glass displays great application potential in energy storage systems with good safety and high energy density.  相似文献   
33.
The feeding of spittlebug nymphs (Philaenus spumarius) from mature xylem vessels was studied by optical and cryo-analytical scanning electron microscopy. Feeding did not produce xylem embolisms and vessels remained liquid-filled during the day. Saliva secreted by the insect forms a hardened lining (salivary sheath) between the stylet bundle and the plant tissues. This sheath is continuous through the hole made by the stylets as they enter a vessel, and it extends into the vessel and along its periphery beyond the breach. The sheath is heterogeneous, with a thin outer layer adjoining the plant tissues and a thicker layer that contacts the stylet bundle. Both layers give positive histochemical reactions for proteins and, in fresh tissues, contain a red, strongly autofluorescent pigment, possibly condensed tannin derived from the plant (which is lost during tissue preparation), and other phenyl propanoid compounds, which are retained and which may produce the intense reaction of the periodic-acid-Schiff's-positive inner layer. It is concluded that the salivary sheath allows the insects to feed from functioning vessels without embolizing them or losing xylem fluid to the surrounding tissues. These findings and others in the entomological literature indicate low daytime tensions in the xylem conduits of the host plants.  相似文献   
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35.
Jerry H. Brown 《Proteins》2013,81(4):635-643
How local conformation is affected by local sequence is fairly well understood for alpha‐helical coiled‐coils, but less is known about how local conformation is influenced by distant features. Here, I describe an approach to detect such an effect, based on computing correlation coefficients of local out‐of‐register alignments, or so‐called “staggers” between the helices, as a function of the axial distance between the staggers. This approach requires parallel homodimers, in which each stagger can occur with two “signs,” where either one helix or the other is shifted towards the N terminus. The signs of such staggers separated by up to 12 residues are strongly correlated, indicating that the conformations of the ends of coiled‐coils are commonly influenced by attached structures. Thus, the structures of coiled‐coil residues aberrantly attached to alternative proteins, such as those resulting from leukemogenic chromosomal rearrangements, may be distinguishable from those in normal tissues, and in turn serve as targets of selective drug design. The signs of helical staggers separated by between 13 and 30 residues are moderately yet significantly correlated, indicating that some of the coiled‐coils transmit this conformational feature axially for at least 45 Å. A positive, albeit noisy, correlation also exists among tropomyosin coiled‐coils for signed staggers separated by the 40‐residue actin repeat distance, consistent with the semi‐flexible tropomyosin filament binding F‐actin and regulating skeletal muscle contraction in a partially cooperative manner. Communication of the signs of axial staggers is explained in part by minimization of main‐chain hydrogen bond deformations. © Proteins 2013. © 2012 Wiley Periodicals, Inc.  相似文献   
36.
Animals produce a wide array of sounds with highly variable acoustic structures. It is possible to understand the causes and consequences of this variation across taxa with phylogenetic comparative analyses. Acoustic and evolutionary analyses are rapidly increasing in sophistication such that choosing appropriate acoustic and evolutionary approaches is increasingly difficult. However, the correct choice of analysis can have profound effects on output and evolutionary inferences. Here, we identify and address some of the challenges for this growing field by providing a roadmap for quantifying and comparing sound in a phylogenetic context for researchers with a broad range of scientific backgrounds. Sound, as a continuous, multidimensional trait can be particularly challenging to measure because it can be hard to identify variables that can be compared across taxa and it is also no small feat to process and analyse the resulting high-dimensional acoustic data using approaches that are appropriate for subsequent evolutionary analysis. Additionally, terminological inconsistencies and the role of learning in the development of acoustic traits need to be considered. Phylogenetic comparative analyses also have their own sets of caveats to consider. We provide a set of recommendations for delimiting acoustic signals into discrete, comparable acoustic units. We also present a three-stage workflow for extracting relevant acoustic data, including options for multivariate analyses and dimensionality reduction that is compatible with phylogenetic comparative analysis. We then summarize available phylogenetic comparative approaches and how they have been used in comparative bioacoustics, and address the limitations of comparative analyses with behavioural data. Lastly, we recommend how to apply these methods to acoustic data across a range of study systems. In this way, we provide an integrated framework to aid in quantitative analysis of cross-taxa variation in animal sounds for comparative phylogenetic analysis. In addition, we advocate the standardization of acoustic terminology across disciplines and taxa, adoption of automated methods for acoustic feature extraction, and establishment of strong data archival practices for acoustic recordings and data analyses. Combining such practices with our proposed workflow will greatly advance the reproducibility, biological interpretation, and longevity of comparative bioacoustic studies.  相似文献   
37.
Acoustic signals consist of pressure changes over time and can thus be analyzed in the frequency- or in the time-domain. With behavioural experiments we investigated which frequency components (FC) are necessary for the recognition of the periodic envelope of the conspecific song by females of the grasshopper Chorthippus biguttulus. Further, we determined up to which frequency component phase information is required which would indicate processing in the time domain. Responses of females revealed that signals composed of FC between 10 and 50 Hz are sufficient for recognition of the song envelope. A systematic reduction in the number of FC showed that no single frequency component was required; signals without the fundamental frequency were still highly attractive and only three FC may be sufficient for song recognition. Phase changes for frequencies up to 40 Hz strongly changed the attractiveness of song signals but only little at 50 Hz. Females were also tested with rectangular signals in which pause duration was varied. Evidently, and despite the high attractiveness of song signals with a “missing fundamental”, females evaluated the attractiveness of signals in the time-domain, since the selectivity for pause duration predicted the responses to signals composed from FC well.  相似文献   
38.
The length–weight relationships (LWRs) for seven fish species belonging to five families in the Yangtze River Estuary and its adjacent waters are presented. Cynoglossus gracilis, Cynoglossus macrolepidotus, Ctenotrypauchen chinensis, Collichthys niveatus, Ophichthus apicalis and Erisphex potti were collected monthly in 2009 using trammel nets (the size of smaller mesh net was 1.5 m × 15 m × 4 panels with mesh sizes of 2.5, 3.4, 4.3 and 5.8 cm; the size of larger-mesh net was 2.4 m × 30 m × 4 panels with mesh sizes of 5.0, 6.0, 7.0 and 8.0 cm; soaking overnight). Lophiogobius ocellicauda were collected December in 2020 using shrimp trawl nets (mesh size 2.0 cm). The precision of measurement for the fish specimens is 0.1 cm total length and 0.1 g total weight. The estimated ranges of the parameters a and b for the seven fish species were from 0.0001 to 0.0289 and 2.718 to 3.541, respectively. Two new maximum total length were recorded for Ctenotrypauchen chinensis and Ophichthus apicalis.  相似文献   
39.
Parasitoid wasps are widely used as biocontrol agents. For successful deployment, it is important to know how they search for and recognize their hosts. They often use chemical cues in host searching and recognition. Little attention has been paid to the use of physical cues, particularly when combined with chemical cues, though a combination of cues may improve searching efficiency. Chelonus inanitus L. (Hymenoptera: Braconidae) is a solitary, egg–larval parasitoid wasp that parasitizes various lepidopteran species, including serious crop pests. In this study, effects of physical and/or chemical cues on host recognition were investigated in C. inanitus by observing its antennal searching, ovipositor probing, and the duration of arrestment. In a physical cue test, egg-mass models with glass beads differing in size were used, and a single-egg model with a specific size of bead. Egg-mass models with beads of 0.4–1.0 mm in diameter arrested C. inanitus, in accordance with egg size and arrangement of the host. In a chemical cue test, extract from egg masses of the host Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae), equivalent to half of a host egg mass and extract diluted 100-fold were used, and the undiluted extract stimulated C. inanitus. Untreated egg-mass models (0.2-mm-diameter glass beads) and diluted egg extract arrested C. inanitus less effectively; however, when glass beads were treated with the diluted extract, arrestment increased to the same degree as the undiluted extract. These results suggest that C. inanitus uses both physical and chemical cues to recognize eggs of its host, S. litura, and that these stimuli act synergistically.  相似文献   
40.
This article outlines the subsector of the information and communication technology (ICT) industry concerned with reducing the economy's environmental impact, dubbed ICT‐enabled low carbon technologies (ICTeLCTs). The article is based on a study funded by United Kingdom (UK) Trade and Investment, a division of the UK Department for Business, Innovation and Skills. ICTeLCTs can be segmented into specialist and generalist operators. Specialists focus on one or two ICT applications to monitor or reduce environmental issues, while generalists supply products and services enabling a firm or a private household to reduce the environmental impact of its activities. The subsector can be further segmented into green ICT, energy management, building management, carbon accounting, waste management, intelligent transport systems (ITSs), and water management. The main factors driving ICTeLCTs include legislation, voluntary environmental standards, corporate social responsibility (CSR) activities, customer demand, and competitive market factors. Policy makers should continue to drive the growth of ICTeLCTs with the introduction and refinement of environmental legislation regulating energy use and markets.  相似文献   
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