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1.
Most models of visual word recognition in alphabetic orthographies assume that words are lexically organized according to orthographic similarity. Support for this is provided by form-priming experiments that demonstrate robust facilitation when primes and targets share similar sequences of letters. The authors examined form-orthographic priming effects in Hebrew, Arabic, and English. Hebrew and Arabic have an alphabetic writing system but a Semitic morphological structure. Hebrew morphemic units are composed of noncontiguous phonemic (and letter) sequences in a given word. Results demonstrate that form-priming effects in Hebrew or Arabic are unreliable, whereas morphological priming effects with minimal letter overlap are robust. Hebrew bilingual subjects, by contrast, showed robust form-priming effects with English material, suggesting that Semitic words are lexically organized by morphological rather than orthographic principles. The authors conclude that morphology can constrain lexical organization even in alphabetic orthographies and that visual processing of words is first determined by morphological characteristics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
2.
The low-temperature performance of vertical cavity lasers (VCL's) is of interest for high-speed data transmission from superconducting and cryogenic semiconductor circuits. Our double-fused 1.5 μm lasers employ a strain-compensated InGaAsP-InP multiquantum-well (MQW) active region that is sandwiched between two AlGaAs-GaAs distributed Bragg reflectors. Continuous wave (CW) lasing at ambient temperature as low as 7 K is measured on the same type of top-emitting devices that previously lased at a record-high temperature of 337 K. The optimum temperature is found at 180 K giving minimum threshold current, maximum modulation bandwidth of 5 GHz, and more than 3 GHz/mA1/2 modulation current efficiency. The optimum temperature agrees very well with the theoretical prediction. Further device optimization for cryogenic high-speed applications is discussed in detail  相似文献   
3.
Crowdwork, a new form of digitally mediated employment and part of the so-called gig economy, has the capacity to change the nature of work organization and to provide strategic value to workers, job providers, and intermediary platform owners. However, because crowdwork is temporary, large-scale, distributed, and mediated, its governance remains a challenge that often casts a shadow over its strategic value. The objective of this paper is to shed light on the making of value-adding crowdwork arrangements. Specifically, the paper explores crowdwork platform governance mechanisms and the relationships between these mechanisms and organizational value creation. Building on a comprehensive review of the extant literature on governance and crowdwork, we construct an overarching conceptual model that integrates control system and coordination system as two complementary mechanisms that drive crowdwork platform governance effectiveness and the consequent job provider benefits. Furthermore, the model accentuates the role of the degree of centralization and the degree of routinization as critical moderators in crowdwork platform governance. Overall, the paper highlights the potential of crowdwork to contribute not only to inclusion, fair wages and flexible work arrangements for workers but also to organizations’ value and competitive edge.  相似文献   
4.
5-Methylcytosine and 5-hydroxymethylcytosine are epigenetic modifications involved in gene regulation and cancer. We present a new, simple, and high-throughput platform for multi-color epigenetic analysis. The novelty of our approach is the ability to multiplex methylation and de-methylation signals in the same assay. We utilize an engineered methyltransferase enzyme that recognizes and labels all unmodified CpG sites with a fluorescent cofactor. In combination with the already established labeling of the de-methylation mark 5-hydroxymethylcytosine via enzymatic glycosylation, we obtained a robust platform for simultaneous epigenetic analysis of these marks. We assessed the global epigenetic levels in multiple samples of colorectal cancer and observed a 3.5-fold reduction in 5hmC levels but no change in DNA methylation levels between sick and healthy individuals. We also measured epigenetic modifications in chronic lymphocytic leukemia and observed a decrease in both modification levels (5-hydroxymethylcytosine: whole blood 30 %; peripheral blood mononuclear cells (PBMCs) 40 %. 5-methylcytosine: whole blood 53 %; PBMCs 48 %). Our findings propose using a simple blood test as a viable method for analysis, simplifying sample handling in diagnostics. Importantly, our results highlight the assay‘s potential for epigenetic evaluation of clinical samples, benefiting research and patient management.  相似文献   
5.
TENT4A (PAPD7) is a non-canonical poly(A) polymerase, of which little is known. Here, we show that TENT4A regulates multiple biological pathways and focuses on its multilayer regulation of translesion DNA synthesis (TLS), in which error-prone DNA polymerases bypass unrepaired DNA lesions. We show that TENT4A regulates mRNA stability and/or translation of DNA polymerase η and RAD18 E3 ligase, which guides the polymerase to replication stalling sites and monoubiquitinates PCNA, thereby enabling recruitment of error-prone DNA polymerases to damaged DNA sites. Remarkably, in addition to the effect on RAD18 mRNA stability via controlling its poly(A) tail, TENT4A indirectly regulates RAD18 via the tumor suppressor CYLD and via the long non-coding antisense RNA PAXIP1-AS2, which had no known function. Knocking down the expression of TENT4A or CYLD, or overexpression of PAXIP1-AS2 led each to reduced amounts of the RAD18 protein and DNA polymerase η, leading to reduced TLS, highlighting PAXIP1-AS2 as a new TLS regulator. Bioinformatics analysis revealed that TLS error-prone DNA polymerase genes and their TENT4A-related regulators are frequently mutated in endometrial cancer genomes, suggesting that TLS is dysregulated in this cancer.  相似文献   
6.
Doped transparent ceramics with high optical quality can serve as materials for photonic applications such as laser gain media. In that regard, transparent polycrystalline alumina has potential for high-power applications due to its excellent physical and chemical properties, combined with unique doping possibilities. However, optical birefringence of Al2O3 crystals make achieving sufficiently high optical transmittance a processing challenge. In the present study, we demonstrated fabrication of highly transparent 0.5 at.% Cr:Al2O3 ceramics by high-pressure spark plasma sintering (HPSPS). The optical properties of these polycrystalline ruby ceramics were analyzed in order to assess possible laser operation (at 694.3 nm). The obtained ceramics exhibit high in-line transmittance (~72.5 % at 700 nm), equivalent to a scattering coefficient of 2.15 cm?1, and characteristic ruby photoluminescence. The theoretically estimated lasing threshold and percentage of absorbed pump power indicate that such ruby ceramic lasers could operate at reasonable thresholds of 80?225 mW with short lengths of 0.5?5 mm. Thus, HPSPS is a promising method for producing laser-quality doped transparent ceramics for compact laser systems.  相似文献   
7.
Inspection of the amino acid-base interactions in protein-DNA complexes is essential to the understanding of specific recognition of DNA target sites by regulatory proteins. The accumulation of information on protein-DNA co-crystals challenges the derivation of quantitative parameters for amino acid-base interaction based on these data. Here we use the coordinates of 53 solved protein-DNA complexes to extract all non-homologous pairs of amino acid-base that are in close contact, including hydrogen bonds and hydrophobic interactions. By comparing the frequency distribution of the different pairs to a theoretical distribution and calculating the log odds, a quantitative measure that expresses the likelihood of interaction for each pair of amino acid-base could be extracted. A score that reflects the compatibility between a protein and its DNA target can be calculated by summing up the individual measures of the pairs of amino acid-base involved in the complex, assuming additivity in their contributions to binding. This score enables ranking of different DNA binding sites given a protein binding site and vice versa and can be used in molecular design protocols. We demonstrate its validity by comparing the predictions using this score with experimental binding results of sequence variants of zif268 zinc fingers and their DNA binding sites.  相似文献   
8.
Most Hebrew words are composed of 2 intertwined morphemes: a triconsonantal root and a phonological word pattern. Previous research with conjugated verb forms has shown consistent priming from the verbal patterns, suggesting that verbal forms are automatically parsed by native speakers into their morphemic constituents. The authors investigated the decomposition process, focusing on the structural properties of verbal forms that are perceived and extracted during word recognition. The manipulations consisted of using verbal forms derived from "weak" roots that have one consonant missing in some of the forms. The results demonstrated that if 1 consonant is missing, the parsing system collapses, and there is no evidence for morphological priming. In contrast, when a random consonant is inserted into the weak form, the verbal-pattern priming re-emerges. This outcome suggests that the constraint imposed on the decomposition process is primarily structural and abstract. Moreover, the all-or-none pattern of results is characteristic of rule-based behavior and not of simple correlational systems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
9.
Dietary unsaturated fatty acids, such as oleic acid, have been shown to be covalently incorporated into a small subset of proteins, but the generality and diversity of this protein modification has not been studied. We synthesized unsaturated fatty‐acid chemical reporters and determined their protein targets in mammalian cells. The reporters can induce the formation of lipid droplets and be incorporated site‐specifically onto known fatty‐acylated proteins and label many proteins in mammalian cells. Quantitative proteomics analysis revealed that unsaturated fatty acids modify similar protein targets to saturated fatty acids, including several immunity‐associated proteins. This demonstrates that unsaturated fatty acids can directly modify many proteins to exert their unique and often beneficial physiological effects in vivo.  相似文献   
10.
The mass and complexity of biological information requires computer-aided simulation and analysis to help scientists achieve understanding and guide experimentation. Although living organisms are composed of cells, actual genomic and proteomic data have not yet led to a satisfactory model of working cell in silico. We have set out to devise a user-friendly generic platform, GemCell, for Generic Executable Modeling of Cells, based on whole, functioning cells. Starting with the cell simplifies life, because all cells expresses essentially five generic types of behavior: replication, death, movement (including change of shape and adherence), export (secretion, signaling, etc.) and import (receiving signals, metabolites, phagocytosis, etc.). The details of these behaviors are specified in GemCell for particular kinds of cells as part of a database of biological specifics (the DBS), which specifies the cell properties and functions that depend on the cell’s history, state, environment, etc. The DBS is designed in an intuitive fashion, so users are able to easily insert their data of interest. The generic part of GemCell, built using Statecharts, is a fully dynamic model of a cell, its interactions with the environment and its resulting behavior, individually and collectively. Model specificity emerges from the DBS, so that model execution is carried out by the statecharts executing with the aid of specific data extracted from the DBS dynamically. Our long term goal is for GemCell to serve as a broadly applicable platform for biological modeling and analysis, supporting user-friendly in silico experimentation, animation, discovery of emergent properties, and hypothesis testing, for a wide variety of biological systems.  相似文献   
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