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1.
Many models of spoken word recognition posit the existence of lexical and sublexical representations, with excitatory and inhibitory mechanisms used to affect the activation levels of such representations. Bottom-up evidence provides excitatory input, and inhibition from phonetically similar representations leads to lexical competition. In such a system, long words should produce stronger lexical activation than short words, for 2 reasons: Long words provide more bottom-up evidence than short words, and short words are subject to greater inhibition due to the existence of more similar words. Four experiments provide evidence for this view. In addition, reaction-time-based partitioning of the data shows that long words generate greater activation that is available both earlier and for a longer time than is the case for short words. As a result, lexical influences on phoneme identification are extremely robust for long words but are quite fragile and condition-dependent for short words. Models of word recognition must consider words of all lengths to capture the true dynamics of lexical activation. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
2.
Simple interconnection of high-speed local area networks (LAN's) can be accomplished without special technology through the use of table-free bridges. Self-guided frame routing allows frames to trace specific routes through bridged LAN's without requiring bridges to maintain address tables or perform table lookups. As a result, the technique applies to networks regardless of their operating speed or topological configuration and requires no interbridge protocols. The paper discusses a method known as source routing that provides tablefree bridging and self-guided frame routing for LAN's. Participation by the bridges that interconnect pairs of LAN's and by the stations whose frames they forward is described. Possible frame formats are shown as enhancements to the standard frame formats of the IEEE 802 and ISO 8802 local area networks. 相似文献
3.
Pre-/postconditions have been extensively used in program specification, e.g. Z [Spi89], VDM [Jon86], and proof, e.g. Hoare logic, Dijkstra's guarded commands [DiF88]. In [ScP86, SPB90] the authors introduced neutral and central relations to formalise the concept of the rest stays the same. In this paper we abstract away from the specific definition of neutral relation given in [SPB90], through the mechanism of relational boolean algebras. This leads to the definition of implicitly central relations which are easier for the user in practical examples and facilitate the use of pre-/postcondition reasoning about truly concurrent behaviour. 相似文献
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Software agents that are autonomous, communicative, and possibly intelligent processes raise new questions for developers of distributed systems. Specifically, what is responsible agent behavior, and who, as the owner, is legally responsible for it? The answers involve an understanding of human-agent interaction, agent-oriented middleware, and social behavior. Some software agents will have a sufficiently large number of internal states to be capable of seemingly intelligent behavior. Hence, an agent's future external behavior cannot be guaranteed on the basis of its past behavior, even if that behavior has been monitored over time. Complete compliance tests of intelligent agents, therefore, may not be achievable because of the (possibly) large number of internal states. Thus, the best we can say is that an agent has not exhibited noncompliant behavior yet. Communication between agents implies a contract between owners, and the complexity of agents implies possibly unpredictable behavior. Therefore, an appropriate legal framework is required to underwrite the consequences of communicative actions and to provide safeguards against unlawful activities. The legal implications of agent technology require new ways of thinking about working with an agent, new requirements for agent-oriented middleware, and additional types of social behavior to be considered when designing a multiagent system 相似文献
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Development of a disposable electrode modified with carbonized,graphene‐loaded nanofiber for the detection of dopamine in human serum 下载免费PDF全文
Pongpol Ekabutr Pakakrong Sangsanoh Poomrat Rattanarat Charles W. Monroe Orawon Chailapakul Pitt Supaphol 《应用聚合物科学杂志》2014,131(19)
A one‐step electrode surface modification is proposed in which a disposable, screen‐printed carbon electrode is functionalized with carbonized, electrospun polyacrylonitrile (PAN)‐loaded graphene (G) nanoparticles to form a composite, CPAN5G‐4x. The electrochemical behavior of the CPAN5G‐4x electrode was examined by cyclic voltammetry and electrochemical impedance spectroscopy. Scanning electron microscopy and X‐ray diffraction were used to characterize the surface morphology and physical properties of the carbonized composite nanofibers before and after modification. The modified electrode was found to be effective for the detection of dopamine (DA) using square‐wave voltammetry (SWV) in the presence of interfering substances such as ascorbic acid and uric acid. With the addition of sodium dodecyl sulfate (SDS) to an optimized solution of phosphate‐buffered saline (PBS) at a pH of 2, the fabricated electrode exhibited enhanced electrocatalytic activity toward the oxidation of DA relative to PBS without SDS at a pH of 7.4. The SWV current displayed a linear response to DA concentrations ranging from 0.5 to 100 μM, with a limit of detection of 70 nM (S/N = 3) and a sensitivity of 1.4258 μA μM?1 cm?2. Finally, the CPAN5G‐4x electrode was used to determine DA levels in human serum. The modified electrode can potentially be harnessed for further electrochemical biosensor applications. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40858. 相似文献
8.
Release characteristics of four model drugs from drug-loaded electrospun cellulose acetate fiber mats 总被引:1,自引:0,他引:1
Ultra-fine fiber mats of cellulose acetate (CA; Mw ≈ 30?000 Da; degree of acetyl substitution ≈ 2.4) containing four different types of model drugs, i.e., naproxen (NAP), indomethacin (IND), ibuprofen (IBU), and sulindac (SUL), were successfully prepared by electrospinning from 16% w/v CA solutions in 2:1 v/v acetone/N,N-dimethylacetamide (DMAc). The amount of the drugs in the solutions was fixed at 20 wt.% based on the weight of CA powder. The morphology of the drug-loaded electrospun (e-spun) CA fiber mats was smooth, with the average diameters of these fibers ranging between 263 and 297 nm. No presence of the drug aggregates of any kind was observed on the surfaces of these fibers, suggesting that the drugs were encapsulated well within the fibers. After submersion in the acetate buffer solution at 37 °C for 24 h, the drug-loaded e-spun CA fiber mats swelled particularly well (i.e., 570-630%), while the corresponding solvent-cast film counterparts did not. The release characteristics of the model drugs from both the drug-loaded CA fiber mats and the drug-loaded as-cast CA films were carried out by the total immersion method in the acetate buffer solution at 37 °C. At any given immersion time point, the release of the drugs from the drug-loaded e-spun CA fiber mats was greater than that from the corresponding as-cast films. The maximum release of the drugs from both the drug-loaded fiber mats and films could be ranked as follows: NAP > IBU > IND > SUL. 相似文献
9.
Organic nitrogen transformations in a 4-stage Bardenpho nitrogen removal plant and bioavailability/biodegradability of effluent DON 总被引:2,自引:0,他引:2
Chakkrid Sattayatewa Krishna Pagilla Paul Pitt Kevin Selock Theresa Bruton 《Water research》2009,43(18):4507-4516
Nitrogen species, specifically, the fate and occurrence of organic nitrogen (ON) within a 4-stage Bardenpho process bioreactor producing low total nitrogen (TN) effluents were investigated in this study. The results showed release of ON in primary anoxic zone and no ON release in the first aerobic zone of the process. The research included investigation of biodegradability/bioavailability of wastewater-derived effluent dissolved ON (DON). The final-effluent DON utilization was evaluated by two different bioassay protocols in the presence and absence of nitrate. About 28–57% of the effluent DON was bioavailable/biodegradable. Bioavailable (to algae and bacteria) DON (ABDON) and biodegradable (to bacteria) DON (BDON) results did not show significant differences in terms of quantity, but DON utilization rates by ABDON (0.13 day−1) protocol were higher than that of the BDON (0.04 day−1) protocol in the nitrate-removal samples. As a result, ABDON requires a shorter time to exert the bioavailable fraction due to symbiotic relationship between algae and bacteria. In the nitrate-containing samples, it appears that nitrate competes with labile DON as a nitrogen source to microorganisms in both ABDON and BDON protocols. The first order decay rate of DON in the presence of nitrate was 0.11 day−1 and 0.02 day−1 for ABDON and BDON, respectively. 相似文献
10.
T Pitt 《Canadian Metallurgical Quarterly》1995,29(4):199-207
Rota Viral infection is recognised as a significant global public health concern causing large numbers of potentially preventable illnesses and deaths, especially among young ones of man and animals. The paper presents an overview of the epidemiology, control, treatment, virology, diagnosis and the zoonotic aspects of the problem. Problems for further research are identified. 相似文献