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31.
Copper sulfide nanoparticles were synthesized and loaded on activated carbon (CuS-NPs-AC) for ternary dye removal. Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction spectroscopy (XRD) and scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDX) were used to characterize the synthesized materials. The performance of the materials was subsequently evaluated for simultaneous ultrasound assisted adsorption of Disulphine Blue (DB), Eosin Yellow (EY) and Safranin O (SO) dyes in ternary solution under different conditions that include variation in solution pH, initial concentrations of dyes, sonication time and adsorbent dosage. Response surface methodology (RSM) using central composite design (CCD) was employed to obtain the optimum experimental conditions. The maximum removal efficacies (88.39%, 68.49% and 55.69% for DB, EY and SO, respectively) were found at the optimum conditions: 3.63 min of sonication time, 0.02 g of CuS-NPs-AC, 7.76mg L-1 of DB, 8.89mg L-1 of EY, 9.87mg L-1 of SO and pH 6.5. Very high adsorbent capacities of 198.12, 165.0, 139.58mg g-1 for DB, EY and SO, respectively, were yielded from Langmuir isotherm as best fitted model. Kinetic study indicated that the pseudo-second-order kinetic model was well fitted to the experimental data of ternary adsorption process. The results of the study display very good adsorption efficiency of the synthesized adsorbent for dye removal with high adsorption capacity under optimum conditions.  相似文献   
32.
To process SiC/Ti filamentary composites using a liquid route method, it is first necessary to overcome various major difficulties such as, high speed filament/matrix coupling, liquid titanium wetting of filament surfaces, and reduction of filament/matrix interaction. All of these requirements depend mainly on the heat and mass transfer, which occurs as the filament runs through a liquid titanium bath. Consequently, these transfers were modeled and simulated numerically during the different processing steps, particularly the cooling step. The results describe the physical phenomena which occur during the process: the carbon transfer from the carbon coated SiC filament to the liquid titanium, heat exchanges, formation of the TiC interphase at the filament surface, and, finally, the solidification of the titanium coating. Numerical simulation has shown the strong influence of running speed which governs the wettability of the filament by the liquid metal. Furthermore, the effects of an additional specific cooling device have been highlighted.  相似文献   
33.
A procedure for near field microwave imaging of biological tissues is presented. A two-port microstrip test fixture mounted on a 2D translation stage is employed to capture the transmission images of 1 mm thick slices of rat brain. Spatial resolution and contrast of such images are discussed in terms of insertion loss and extracted tissue permittivity  相似文献   
34.
In an optically fed phased array antenna system, the microwave carrier signal is transmitted via a modulated lightwave to each active T/R (transmit/receive) module, where it must be converted back to the microwave domain. Currently, efficient optical-to-microwave conversion is extremely difficult, as the detected microwave signal is weak and noisy. A novel circuit, containing a high-gain/low-noise microwave injection-locked oscillator, has been developed to improve the interface between the optical and microwave components. The circuit utilizes two FETs and a dielectric resonator, which serves as a frequency-dependent feedback element. The circuit, designed to operate at about 8 GHz, provides significant amplitude and phase noise suppression. In addition, the circuit realization is compatible with MMIC technology  相似文献   
35.
Two correction methods are discussed in this paper to remove residual errors due to the lack of repeatability of coaxial-to-microstrip launchers as part of the TRL calibration procedure. These methods are applied for accurate insertion loss measurement of biological tissues embedded in a two-port microstrip test fixture, from which the tissues' complex permittivity values are extracted for frequencies between 15 and 50 GHz. In the first method, distilled water is used as a calibration standard as part of a two-port calibration procedure. The second method identifies an error transfer function using the difference between simulated and measured insertion loss for distilled water, and then applies it as a correction factor to the measurement results for biological tissues. Both methods are compared in terms of extracting the accurate complex permittivity of brain matter.  相似文献   
36.
ABSTRACT

Aim of this study is to investigate the influence of technological and social cognitive factors for the use of sensor-based technologies for active and healthy ageing (AHA) support by older adults. In a mixed methods approach, data was initially obtained from an online questionnaire completed by older health technology users and used in a regression analysis, where factors from the Technology Acceptance Model (TAM) and the Social Cognitive Theory (SCT) served as predictors for health technology use (HTU). Further, in-depth interviews were conducted with older adults to gain insights into technology use and physical activity behaviour of older adults. The regression analysis showed that the TAM and SCT factors accounted for a significant proportion of variance (39.5%) in HTU. Significant predictors of HTU were physical activity (.399**), social support (.287*), and expectations regarding individual health (.440*) and physical appearance (?.470**), indicating physical activity as mediator for HTU. The qualitative analysis indicated the conflation of technology support with social environments as key for physical activity behaviour in older adults. The findings indicate physical activity as a mediator in HTU by older adults and suggest that the consideration of social factors in health technology design may facilitate the uptake of AHA technologies.  相似文献   
37.
This paper develops an efficient energy management approach to increase the renewables share in energy provision of smart distribution grids (SDGs). Voltage violation ends in curtailment of renewables generations and, hence, decreases the economic success of distribution companies. To avert such deficits, this study fosters the collaboration of SDG components in an intelligent Volt/VAr control process. The investigated SDG is characterized with high penetration of photovoltaics (PVs), dispatchable distributed generations (DDGs), plug‐in hybrid electric vehicles (PHEVs), and infield control devices say as under‐load tap‐changing transformers (ULTCs). In charge stations, PHEVs are coupled to the SDG through bidirectional inverters which are offering simultaneous exchanges of active and reactive powers. Thus, regarding the PHEV aggregators, optimal schedules of active power charge/discharge signals with their inductive/capacitive reactive power provisions are determined. This notion effectively increases PV power injections and, consequently, provides significant monetary savings. Besides, this mechanism reduces ULTC tap operations in Volt/VAr control process maintaining its nominal lifetime. The proposed approach is formulated as a mixed‐integer non‐linear programming (MINLP) and solved based on DICOPT solvers in general algebraic modeling system (GAMS). Effectiveness of the proposed approach is explored on a typical distribution test system. The obtained results show 8.94% increment in harvested PVs power and hence 5.24% reduction on daily operation cost of SDG.  相似文献   
38.
In this paper, a SRAM cell structure which uses pMOS access transistors and predischarged bitlines is presented. By using the strained pMOS transistor technology, the degradation of the read static noise margin (SNM) at high supply voltages due to the aging, especially in the presence of symmetric stress, is suppressed. In contrast to conventional cell, the write margin of the proposed cell does not degrade considerably at low supply voltages. To assess the efficacy, the proposed cell is compared with conventional cell for two cases of unstrained and strained pMOS. A comparative study is performed using mixed mode device/circuit simulations for a gate length of 22 nm. The results show that the read SNM degradation due to the symmetric aging at the supply voltage of 1 V is about 6% after three years for the proposed strained structure, while degradations are 14%, 12%, and 11% for the unstrained proposed structure, unstrained, and strained conventional structures, respectively. In addition, the proposed cell has both read and write cell sigma yields higher than six for supply voltages ranging from 1 V down to 0.5 V while the other structures have read or write yields less than six at the minimum supply voltage. Through some work function tuning, the cell sigma yields of the other structures reach above six for both read and write while being still lower than those of the proposed structure. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
39.
Iranian Polymer Journal - Herein, a simple, rapid, cost-effective and sensitive poly(thionine)-based electrochemical sensor is described to determine trace amounts of tetracycline. In the present...  相似文献   
40.
The technique of delivering various nutrients, supplements, immunostimulants, vaccines, and drugs via the in ovo route is gaining wide attention among researchers worldwide for boosting production performance, immunity and safeguarding the health of poultry. It involves direct administration of the nutrients and biologics into poultry eggs during the incubation period and before the chicks hatch out. In ovo delivery of nutrients has been found to be more effective than post-hatch administration in poultry production. The supplementation of feed additives, nutrients, hormones, probiotics, prebiotics, or their combination via in ovo techniques has shown diverse advantages for poultry products, such as improved growth performance and feed conversion efficiency, optimum development of the gastrointestinal tract, enhancing carcass yield, decreased embryo mortality, and enhanced immunity of poultry. In ovo delivery of vaccination has yielded a better response against various poultry pathogens than vaccination after hatch. So, this review has aimed to provide an insight on in ovo technology and its potential applications in poultry production to deliver different nutrients, supplements, beneficial microbes, vaccines, and drugs directly into the developing embryo to achieve an improvement in post-hatch growth, immunity, and health of poultry. © 2019 Society of Chemical Industry  相似文献   
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