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41.
42.
With the explosion of the Internet many firms are incorporating technology into their marketing and operations and are adopting a multichannel strategy. The impact of this strategy has been especially high in the services area, which has traditionally relied on close, personal contact between customers and employees. This study explores how overall customer loyalty is built as a consequence of the value provided by each channel (offline and online). It also analyzes the moderating role of complexity of services used and customers’ Internet access in the service value–loyalty link. The model is tested with a sample of 302 multichannel financial services customers who use both the offline (traditional) and the online channel. Results show that offline perceived service value increases online perceived value; offline value has a stronger effect on overall loyalty than online value; and online service complexity and Internet adoption moderate the influence of service value on overall loyalty. Implications for management and theory are discussed.  相似文献   
43.
In this paper, a novel flowing stream scheme based upon the multisyringe flow injection (MSFI) technique is presented as a powerful tool to perform automated enzymatic assays. The exploitation of enzymes in homogeneous phase circumvents typical drawbacks associated with the commonly used packed-bead or open tubular permanent columns, namely, malfunctions of the reactor, carryover effects, flow resistance, loss of binding sites, large reagent consumption, and use of harmful organic solvents during immobilization procedures.The proposed MSFI system is able to handle minute volumes of soluble enzymes and accommodate reactions with divergent kinetic and pH demands, as demonstrated via the indirect chemiluminescence determination of trace levels of glucose. The procedure is based on the on-line glucose oxidase-catalyzed oxidation of beta-glucose in homogeneous phase to beta-glucono-delta-lactone and hydrogen peroxide. Subsequently, the generated oxidant merges downstream with an alkaline slug of 3-aminopthalhydrazide and a metal-catalyst zone (viz., Co(II)) at a total flow rate as high as 72 mL/min aiming to warrant maximum light collection from the fast CL reaction. Under optimum conditions for both sequentially occurring reactions, a glucose concentration as low as 90 microg/L may be easily detected at a 1000-fold photomultiplier gain. A second-order polynomial regression equation of light emission versus substrate concentration is found over the range 90 microg/L-2.7 mg/L glucose, although a maximum concentration of 180 mg/L may be determined by suitable gain selection without requiring manifold reconfiguration. An injection throughput of 20 h(-1), a repeatability better than 2.5% at the 1 mg/L level, and a 3sigma detection limit of 72 microg/L are the analytical features of the designed analyzer. The proposed approach was applied to the analysis of ultralow glucose content soft drinks as well as fruit juices suitable for diabetic consumers. The accuracy was assessed using the spectrophotometric batch glucose-Trinder method as an external reference methodology for the determination of the target species in parenteral solutions.  相似文献   
44.
The process of expansion of urban centers in Brazil has been distinguished by the complete absence of planning. As a result, urban environments lead to land uses encroaching on, defacing and destroying landmarks. Attention is given to the Morro da Queimada Archaelogical Site. This represents an important cultural heritage of the 1720 movement of secession during the gold rush. Several ruins of mining equipments such as houses, wells, shafts and galleries have been gradually destroyed. The process of the site's loss of distinct character has been monitored since 1950 using aerial photographs and cartography. Collected data indicate a conservative annual land-use change rate of about 1.5%. This rate points to the complete destruction of the site in 2008. This paper proposes the creation of the Morro da Queimada Historical Park, within the limits of the remaining set of ruins.  相似文献   
45.
Lately, modern hardfacing tubular wires for semiautomatic welding with gas protection and without it have been developed. These wires deposit Fe-based nanostructured alloys with high abrasive wear resistance. The information on these new consumables is scarce, especially about the effect that the welding parameters (heat input, shielding gas, arc voltage, current intensity, etc.) have on the deposit, its microstructure and, consequently, its wear behaviour. For this reason, in this article, we study the effect of heat input (voltage, intensity of current and welding velocity) on the properties of a flux-cored arc welding Fe-based nanostructured deposit obtained without gas protection. This study is a continuation of a previous one in which the same consumable was used under shielding gas. Bead on plate samples were welded using heat inputs between 0.5 and 3.5 k/mm. The dimensional study was performed on the beads, chemical composition was determined and the microstructure was analysed using optical and electronic microscopy and X-ray diffraction. Microhardness, crystallite size and dilution percentage were also measured. An important influence of the welding parameters on the bead geometry and the microstructure was observed. The operational behaviour of this wire, welded without shielding gas, was very good.  相似文献   
46.
Nowadays, the automatic processing of digitalized documents is crucial to cope with the increasing amount of information available. This issue is addressed from the natural language processing (NLP) research field. One of the tasks required for many NLP applications is temporal information processing. It involves the automatic extraction and interpretation of temporal expressions, events, and their relations. Specifically, the identification and the categorization of temporal relations are the most complex subtasks yet to solve, judging from the results reported in the latest international evaluation exercise. Temporal relation identification has been addressed by very few approaches, and the current categorization approaches are still not a definitive solution. This paper presents a system that approaches temporal relation identification and categorization. The former is approached with a knowledge‐driven strategy and the later with data‐driven strategy based on different machine‐learning techniques. Our proposal has been empirically evaluated over the currently available English data sets annotated with temporal information (TimeBank and AQUAINT) in a 10‐fold cross‐validated experiment. The results obtained support that the presented approach achieves a high performance. It improves the baseline F1 by 46% and outperforms the state of the art. © 2012 Wiley Periodicals, Inc.  相似文献   
47.
An automatic system for the determination of Zn, Cd, Pb and Cu by anodic stripping potentiometry using the oxygen dissolved in the sample as oxidant is reported. The system relies on the use of a PC-compatible computer for instrumental control and data acquisition and processing.  相似文献   
48.
CuInSe2 (CIS) thin films were deposited on Mo/glass substrates by one-step electrodeposition from aqueous baths containing CuSO4, In2(SO4)3 and SeO2 with Li2SO4 electrolyte. The quality of the electrodeposited films depended on the presence of pH buffer in the bath. CIS films deposited from non-pH buffered baths showed pronounced (112) orientation, while films exhibiting more random orientation were obtained from pH buffered baths. Denser, smoother samples were obtained from non-pH buffered baths, though with no difference in film composition. As-deposited films exhibit low crystallinity and require recrystallization by annealing in H2Se. Best devices, ∼ 9%, were obtained with CuInSe2 films deposited from non-pH buffered baths.  相似文献   
49.
Several Enterococci were isolated from Cotija cheese, which is a Mexican farmhouse-made product prepared from whole raw milk. No thermal step, neither starter cultures, are used in its manufacturing process. From the isolated strains two were outstanding for their extracellular lytic activity against Staphylococcus aureus, and were identified by 16S rDNA sequencing as Enterococcus faecalis and Enterococcus faecium, respectively. They also showed bacteriolytic activity against other pathogenic bacteria, such as Yersinia enterocolitica, Salmonella enterica Typhimurium and Pseudomonas aeruginosa, as demonstrated by agar diffusion tests. By zymography it was shown that they produced proteins with bacteriolytic activity with molecular masses of 95 and 81 kDa, respectively. Protein identification by LC/ESI–MS/MS showed that they correspond to different enzymes with peptidoglycan hydrolase (PGH) activity of N-acetylglucosaminidase. Two of them were considered as putative enzymes and had not been studied before. Concentrated protein preparations from both strains showed lytic activity on S. aureus growth in liquid culture, as well. Considering that the PGHs studied are produced by lactic bacteria isolated from a dairy product and their spectrum of bacterial inhibition, these enzymes have a potential use in food preservation.  相似文献   
50.
In this paper we show how non-linear attractor dynamics can be used as a framework to control teams of autonomous mobile robots that should navigate according to a predefined geometric formation. The environment does not need to be known a priori and may change over time. Implicit to the control architecture are some important features such as establishing and moving the formation, split and join of formations (when necessary to avoid obstacles). Formations are defined by a formation matrix. By manipulating this formation matrix it is also possible to switch formations at run time. Examples of simulation results and implementations with real robots (teams of Khepera robots and medium size mobile robots), demonstrate formation switch, static and dynamic obstacle avoidance and split and join formations without the need for any explicit coordination scheme. Robustness against environmental perturbations is intrinsically achieved because the behaviour of each robot is generated as a time series of asymptotically stable states, which contribute to the asymptotic stability of the overall control system.  相似文献   
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