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31.
This paper introduces a method for optimizing sewer networks using the mixed-integer linear programming (MILP) for a given layout. The objective function is defined as the sum of the costs for pipe purchase, pipe-laying, and manhole construction expressed in linear terms and subject to minimum and maximum allowable slopes, velocities, and relative depths for both minimum and maximum sewage discharge rates in each pipe. Additionally, provisions are made as constraints or conditions to ensure that a minimum pipe cover is required, that pipe diameters do not decrease in the flow direction, and that pipes maintain a steady elevation at each manhole. All the non-linear constraints are transformed into the linear format. Pipe slope, binary variables accounting for commercial pipe diameters and average implemented depths have also been considered as decision variables. Finally, the performance of the proposed optimization method is evaluated in a benchmark sewer network from the literature.  相似文献   
32.
The electrocatalytic oxidation of ethanol in alkaline medium has been studied using Ag/Pd bimetallic nanoparticles modified carbon ionic liquid electrode (Ag/PdCILE). The electrochemical characterizations were performed using cyclic voltammetry (CV), chronoamperometry and electrochemical impedance spectroscopy (EIS). The results show that the electrode reveals excellent characteristics such as high catalytic activity, stability, tolerance toward poisoning effects (even at very high ethanol concentrations) and capacity for electrooxidation of ethanol in alkaline medium. The results show that this electrode is very attractive for application in direct ethanol fuel cells.  相似文献   
33.
34.
Till date, a variety of efforts have been made to develop the essential properties of hydroxyapatite as the most promising bioactive ceramic used in a broad spectrum of clinical applications from bone-tissue engineering to the bio-coatings applied on the implants. Radio frequency magnetron sputtering provides multiple advantages including high efficiency, favorable bonding strength, and controllable properties, therefore an increasing tendency has been emerged for exploiting its benefits in fabrication of HAp bio-coatings. The present review strives to systematically address all of the reported results in the field of RFMS'ed HAp-based composite and multilayer bio-coatings with putting the stress on drawing a clear correlation between the assessed variables, e.g. chemical composition and content of reinforcing phase(s) and interlayer(s), operating conditions, pre/post treatments, and the final characteristics of the bio-coatings. The facing challenges and future horizons of these systems are also treated in detail.  相似文献   
35.
In this study acidic sludge was refined by a novel method that involves neutralization and extraction of organic compound by a waste solvent. Study on refined sludge indicated that sulfuric acid and major of impurities were removed from sludge. Moreover, resin and asphaltene and accordingly ductility of sludge increased. In continue, different amounts of sludge residue were added to vacuum bottom for bitumen preparation. Test results indicated that sludge residue improved mechanical property and elastic modulus of bitumen. Thermal tests illustrated fine thermal stability of blends at production temperature. Also, aging data described reasonable durability for samples. Consequently, by this approach not only hazardous acidic sludge was eliminated from environment but also it improved mechanical properties of bitumen.  相似文献   
36.
The experimental solubility of tadalafil in binary mixtures of ethanol (EtOH) + water, propylene glycol (PG) + water, polyethylene glycol 200 (PEG 200) + water, polyethylene glycol 400 (PEG 400) + water, and ternary mixtures of PEG 200 + PG + EtOH at 298.2 K were assessed. The experimental data were fitted to the Jouyban–Acree model. The mean percent deviations (MPD) of the back-calculated solubilities for EtOH + water, PG +water, PEG 200 + water, PEG 400 + water, and PEG 200 + PG + EtOH mixtures were 7.4%, 11.3%, 14.0%, 18.5%, and 5.6%, respectively and the overall MPD was 11.0%.  相似文献   
37.
Biosynthesis of nanoparticles (NPs) using biomass is now one of the best methods for synthesising NPs due to their nontoxic and biocompatibility. Plants are the best choice among all biomass to synthesise large‐scale NPs. The objectives of this study were to synthesise zinc oxide nanoparticles (ZnO‐NPs) using Anjbar (root of Persicaria bistorta) [An/ZnO‐NPs] and investigate the cytotoxic and anti‐oxidant effects. For this purpose, the An/ZnO‐NPs were synthesised by using Bistort extract and characterised using UV–Visible spectroscopy, transmission electron microscope, field emission scanning electron microscope, x‐ray diffraction and Fourier‐transform infrared spectroscopy. The cytotoxic effects of the An/ZnO‐NPs on MCF‐7 cells were followed by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assays at 24, 48, and 72 h. Nuclear morphology changed and apoptosis in cells was investigated using acridine orange/propodium iodide (AO/PI) staining and flow cytometry analysis. The pure biosynthesised ZnO‐NPs were spherical in shape and particles sizes ranged from 1 to 50 nm. Treated MCF‐7 cells with different concentrations of ZnO‐NPs inhibited cell viability in a time‐ and dose‐dependent manner with IC50 about 32 μg/ml after 48 h of incubation. In flow cytometry analysis the sub‐G1 population, which indicated apoptotic cells, increased from 12.6% at 0 μg/ml (control) to 92.8% at 60 μg/ml, 48 h after exposure. AO/PI staining showed that the treated cells displayed morphologic evidence of apoptosis, compared to untreated groups. Inspec keywords: cancer, cellular biophysics, toxicology, particle size, nanofabrication, X‐ray diffraction, nanomedicine, nanoparticles, ultraviolet spectra, scanning electron microscopy, visible spectra, transmission electron microscopy, patient treatment, field emission electron microscopy, Fourier transform infrared spectra, drug delivery systemsOther keywords: anjbar, cytotoxic effects, human breast cancer cell line, biomass, transmission electron microscope, field emission scanning electron microscope, Fourier‐transform infrared spectroscopy, flow cytometry analysis, ZnO‐NPs inhibited cell viability, antioxidant effects, MCF‐7 cells, biosynthesised ZnO‐NP, biosynthesised ZnO‐NP, acridine orange‐propodium iodide staining, An‐ZnO‐NP, Persicaria bistorta, zinc oxide nanoparticle biosynthesis, 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide  相似文献   
38.
Safavi  S. Lopes  L.B. 《Electronics letters》1996,32(11):966-968
A simple and effective metric for antenna diversity in DECT is introduced. Using a segment of only 2 to 4 bit periods, this metric provides a reliable estimation of the received signal quality. To emulate ideal selection diversity in a single receiver, this metric is calculated by performing two successive measurements on each antenna during the DECT preamble. When using a correlative clock timing, this diversity provides a performance improvement similar to an ideal CRC-driven selection diversity employing two parallel receivers. This offers a cheap and simple solution to DECT outdoor applications such as PCS  相似文献   
39.
Combined simulation-optimization models have been widely used to address the management of water resources issues. This paper presents a simulation-optimization model for conjunctive use of surface water and groundwater at a basin-wide scale, the Zayandehrood river basin in west central Iran. In the Zayandehrood basin, in the past 10 years, a historical low rainfall in the head of the basin, combined with growing demand for water, has triggered great changes in water management at basin and irrigation system level. The conjunctive use model that coupled numerical simulation with nonlinear optimization is used to minimize shortages of water in meeting irrigation demands for four irrigation systems. Constraints guarantee the maximum/minimum cumulative groundwater drawdown and maximum capacity of irrigation systems. A support vector machines (SVMs) model is developed as a simulator of surface water and groundwater interaction model while a genetic algorithm (GA) is used as the optimization model. Conjunctive use model runs for three scenarios. Results show that the accuracy of SVMs as a simulator for surface water and groundwater interaction model is good and that it is possible to decrease the water shortage for irrigation systems with application of proposed SVMs-GA model.  相似文献   
40.
The fumonisin B(1) (FB(1)) contamination of maize collected in two areas of Iran during 1999 was determined. The 20 maize samples from Mazandaran Province, situated on the Caspian littoral of Iran, consisted of random samples of farmers' lots and were all contaminated with FB(1) at a mean level of 3.18 mg kg(-1) (range 0.68-7.66 mg kg(-1)). The 10 samples (of the same maize cultivar) from Isfahan Province in central Iran were purchased as maize cobs in local retail markets and had mean FB levels of 0.22 mg kg(-1) (mean of all samples, 6/10 samples positive, range <0.01-0.88 mg kg(-1)). The FB levels in Mazandaran, an area of high oesophageal cancer, were significantly (p < 0.0001) higher than the FB levels found in maize from Isfahan, an area of low oesophageal cancer in Iran.  相似文献   
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