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In this study, five different algorithms are provided for tracking targets that move very fast in wireless sensor networks. The first algorithm is static and clusters are formed initially at the time of network deployment. In the second algorithm, clusters that have members at one hop distance from the cluster head are provided dynamically. In the third algorithm, clustered trees where members of a cluster may be more than one hop distance from the cluster head are provided dynamically. In the fourth, algorithm lookahead trees are formed along the predicted trajectory of the target dynamically. Linear, Kalman and particle filtering techniques are used to predict the target’s next state. The algorithms are compared for linear and nonlinear motions of the target against tracking accuracy, energy consumption and missing ratio parameters. Simulation results show that, for all cases, better performance results are obtained in the dynamic lookahead tree based tracking approach.  相似文献   
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Monitoring and control of dangerous substances discharged into receiving waters have attracted more attention lately. Since it is not possible to analyze every single substance, a prioritization methodology is needed for the selection of those to be monitored. Existing well-developed models require significant amount of data for reliable outcomes. This paper presents a methodology to prioritize the dangerous substances having adverse effects on freshwaters in Turkey, where data are scarce. Such a methodology will also serve as a solid model for other countries with limited background data. The adopted methodology enabled the elimination of chemicals to generate a candidate list composed of 608 substances among more than 5000 substances. Further screening and prioritization were conducted using different assessment methods (i.e., Total Hazard Value, Total Impact Value, Combined Monitoring-based, and Modelling-based Priority Setting) to obtain a proposed Final Candidate Specific Pollutants List of 150 dangerous substances. The proposed Candidate National Pollutant List of Turkey was established by combining 45 priority pollutants of the European Union with a list of candidate specific pollutants. According to the outcomes of this study, monitoring and controlling of 195 dangerous substances in freshwaters are recommended. Further detailed studies should be conducted in order to observe the actual levels of these dangerous substances in freshwaters followed by a review of the monitoring list accordingly. Moreover, further revisions might be required in the proposed list due to some possible versatile conditions in terms of sampling points (i.e., change in the location of industries).  相似文献   
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The surfaces of pencil graphite electrodes (PGEs) were decorated with zinc oxide nanowires (ZnO NWs) for the electrochemical detection of nucleic acids. ZnO NWs were synthesized through simple hydrothermal method. PGEs decorated with ZnO NWs (ZnO NW/PGEs) were electrochemically characterized through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) following morphological characterization through transmission (TEM) and scanning electron microscopy (SEM). Enhanced sensor response obtained using ZnO NW/PGEs contrary to the bare PGE (control) samples. Our preliminary results simply reveal the potential of combining ZnO NWs with disposable sensor technology for the electrochemical detection of DNA.  相似文献   
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Airborne sand particles that deposit on thermal barrier coatings (TBCs) in gas-turbine engines melt and form calcium–magnesium–aluminosilicate (CMAS) glass, which attacks the TBCs. A new approach for mitigating CMAS attack on TBCs is presented, where up to 20 mol.% Al2O3 and 5 mol.% TiO2 in the form of a solid solution is incorporated into Y2O3-stabilized ZrO2 (YSZ) TBCs. The fabrication of such TBCs with engineered chemistries is made possible by the solution-precursor plasma spray (SPPS) process, which is uniquely suited for depositing coatings of metastable ceramics with extended solid-solubilities. Here, the TBC serves as a reservoir of Al and Ti solutes, which are incorporated into the molten CMAS glass that is in contact with the TBC. This results in the crystallization of the CMAS glass and the attendant arrest of the penetrating CMAS front. This approach could also be used to mitigate attack by other types of foreign deposits (salt, ash, and contaminants) on TBCs.  相似文献   
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The study examines consumer responses to SMS-based mobile advertising campaigns using a field experiment with actual behavioral responses. Specifically, the effects of message characteristics (i.e., incentives and prior permission) and individual differences of message recipients (i.e., content involvement, prior experience with the mobile medium, and medium-fit perceptions) on the attitudinal and behavioral outcomes of such campaigns are investigated. Perceived intrusiveness of the message and attitude toward the campaign are conceptualized as key attitudinal reactions triggered by a mobile advertising message, which in turn influence the behavioral responses generated by the campaign. Findings suggest that, in comparison to permission and incentive, individual differences are stronger determinants of responses to mobile advertising campaigns. Additionally, intriguing insights with respect to the effectiveness of different types of incentives are provided.  相似文献   
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In mixed-line-rate (MLR) networks, different line rates on different wavelengths can coexist on the same fiber. MLR architectures can be built over transparent optical networks, where the transmitted signals remain in the optical domain along the entire path. Along the transparent optical path, a signal experiences various physical layer impairments (PLIs), and its quality degrades as it travels through each optical component. One of the major factors that affect the transmission quality is the launch power of the optical signal. The power must be large enough to ensure noise resiliency at the receiver, but it must be below the limit where fiber nonlinearities distort the signal. Moreover, high launch power is disruptive not only for the actual lightpath itself but also for neighboring lightpaths, and this effect is particularly critical in MLR networks since advanced modulation techniques used for high line rates are highly susceptible to PLIs. In this study, we investigate the problem of determining the appropriate launch power for provisioning of dynamic connection requests in MLR networks. By setting the appropriate launch power for each connection, we aim to maximize the number of established connections. We propose two different heuristics to determine the appropriate launch power of a lightpath. Worst-case best-case average (WBA) is based on optical reach of signal in a transparent optical network. In impairment-aware launch power determination (I-ALPD), current state of the network and impairments are evaluated to determine the launch power. The proposed approaches are practical and can adapt to the needs of network operators. Simulation results show that the performances of the proposed approaches show better results than the existing schemes in terms of blocking probability and bandwidth blocking ratio.  相似文献   
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The purpose of this study is to understand the effects of substrate temperature (ST) and post deposition annealing (PDA) on the structural-electrical properties of Gd2O3 film and to evaluate the electrical performances of the MOS based devices formed with this dielectric. The Gd2O3/Si structures were annealed at 500, 600, 700, and 800 °C under N2 ambient after the films were grown on heated p-Si substrate at various temperatures ranged from 20 to 300 °C by RF magnetron sputtering. For any given ST, the crystallization/grain size increased with increasing PDA temperature. The bump in the accumulation region or continuous decrease in the capacitance values of the inversion region of the C–V curves for 800 °C PDA was not observed. The lowest effective oxide charge density (Q eff ) value was obtained to be ??1.13?×?1011 cm?2 from the MOS capacitor with Gd2O3, which is grown on heated Si at 300 °C and annealed at 800 °C. The density of the interface states (D it ) was found to be in the range of 0.84?×?1011 to 1.50?×?1011 eV?1 cm?2. The highest dielectric constant (ε) and barrier height \(({\Phi _B})\) values were found to be 14.46 and 3.68, which are obtained for 20 °C ST and 800 °C PDA. The results show that the negative charge trapping in the oxide layer is generally more than that of the positive, but, it is reverse of this situation at the interface. The leakage current density decreased after 20 °C ST, but no significant change was observed for other ST values.  相似文献   
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