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71.
ABSTRACT

Fully autonomous or “self-driving” vehicles are an emerging technology that may hold tremendous mobility potential for individuals who are visually impaired who have been previously disadvantaged by an inability to operate conventional motor vehicles. Prior studies however, have suggested that these consumers have significant concerns regarding the accessibility of this technology and their ability to effectively interact with it. We present the results of a quasi-naturalistic study, conducted on public roads with 20 visually impaired users, designed to test a self-driving vehicle human–machine interface. This prototype system, ATLAS, was designed in participatory workshops in collaboration with visually impaired persons with the intent of satisfying the experiential needs of blind and low vision users. Our results show that following interaction with the prototype, participants expressed an increased trust in self-driving vehicle technology, an increased belief in its likely usability, an increased desire to purchase it and a reduced fear of operational failures. These findings suggest that interaction with even a simulated self-driving vehicle may be sufficient to ameliorate feelings of distrust regarding the technology and that existing technologies, properly combined, are promising solutions in addressing the experiential needs of visually impaired persons in similar contexts.  相似文献   
72.
In this study we prepare a nanocomposite substrate from poly lactic acid (PLA) and graphene oxide (GO) using electrospinning. Determining the possible placement of graphene oxide nano-sheets in the electrospun fiber mats is the main goal of this work. The investigative methods employed include scanning electron microscopy (SEM), atomic force microscopy (AFM) micrographs, tensile modulus and attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR). It is shown that the localization of nanoparticle by different methods controls different final properties. We performed the study of the mechanical properties, surface chemical structure and topology of obtaining nanofiber mats. Studies showed that the location of GO sheets depends on the lateral size of them and based on this claim we estimated three possible locations for them: (1) small GO sheets (less than 200 nm) fully or partially inside the electrospun fibers, (2) some larger ones rolling around and on the fibers surface under the high applied voltage, and (3) parts of large sheets bridging between the fibers.  相似文献   
73.
Image edge detection based on low-level feature is usually performed on gray-scale images. Some methods have been developed for edge detection on colour images based on low-level feature, but they are not consistent with human colour perception. This research provides a new algorithm for edge detection based on the “HyAB” large-colour-difference formula. This algorithm uses Sobel operators for gradient-magnitude calculations and Canny methods for localizing edge points. The performance of the new algorithm is qualitatively compared with Sobal and Canny methods using some challenging colour images. The results indicate that gradient magnitudes are best calculated using the HyAB colour-difference formula, and that CIELAB and CIEDE2000 differences are not suitable for this purpose. Definition of gradient magnitudes according human perception is essential in applications such as quality control of fabric printing, calculation of disruptive colouration, and so on. The new algorithm is successful in accuracy and fine edge detection in comparison with the Sobel and Canny methods. The new method is quantitatively compared with state-of-the-art methods using three datasets including BSDS500, MBDD, and BIPED. The correctness and accuracy of annotations of images in datasets have an important effect on results. The new method does not reach scores better than deep-learning-based methods, but it is simple and does not need training. It could probably have better results with improving noise-suppression.  相似文献   
74.
High-efficiency thermal management subsystem has a key role on the PEM fuel cell performance and durability. In this study, design of thermal management subsystem for a 5 kW PEM fuel cell system is investigated. A numerical model is presented to study the cooling flow field performance. The number of parallel channels in parallel serpentine flow field is selected as the design parameter of the flow field and its optimum value is obtained by compromising between the minimum pressure drop of coolant across the flow field and maximum temperature uniformity within the bipolar plate criteria. The optimum coolant flow rate is also determined by compromising between different criteria. Test results of a 5-cells short stack are presented to verify the numerical simulation results.  相似文献   
75.
As most of the undernourished people in the world live in developing countries, achieving food security plays a major role on the daily agenda of policy makers. For achieving food security, there exist various strategies such as supply management, demand management, or better food distribution. This article aims to analyze different scenarios in a developing country context and seeks to provide an overview that could be the most suitable approach to achieve food security. In this context, not only producing more food is considered but also the environmental and social implications that come along with a higher production. Some of the existing options for achieving food security seem not to be appropriate anymore; for instance, cultivation expansion, as this can only be achieved at high social and environmental costs. Other options, such as sustainable intensification or waste management, seem to be more appropriate. The article concludes that there exists no stand-alone solution to the food security problem. Instead, an integrated approach that combines different options might rather be the key to sustainable food security.  相似文献   
76.
Metals and Materials International - It is requisite in laser-aided direct metal deposition (LADMD) to investigate the influence of three key process parameters (laser power, scanning speed, and...  相似文献   
77.
Hybridization‐based methods for the detection of nucleic acid sequences are important in research and medicine. Short probes provide sequence specificity, but do not always provide a durable signal. Sequence‐specific covalent crosslink formation can anchor probes to target DNA and might also provide an additional layer of target selectivity. Here, we developed a new crosslinking reaction for the covalent capture of specific nucleic acid sequences. This process involved reaction of an abasic (Ap) site in a probe strand with an adenine residue in the target strand and was used for the detection of a disease‐relevant T→A mutation at position 1799 of the human BRAF kinase gene sequence. Ap‐containing probes were easily prepared and displayed excellent specificity for the mutant sequence under isothermal assay conditions. It was further shown that nanopore technology provides a high contrast—in essence, digital—signal that enables sensitive, single‐molecule sensing of the cross‐linked duplexes.  相似文献   
78.
Core-sheath nanofibrous yarns were obtained through electrospinning of polyamide 6 (PA6) solution containing different concentrations of multi-wall carbon nanotubes (MWNTs) as sheath and PVA multifilament as the yarn core. By dissolving PVA, for obtaining conductive hollow nanofibrous PA6/MWNTs yarn, two types of porosity could be obtained including hollow central tube due to the structure of hollow yarn and nano-porous areas embedded in electrospun nanofibers. SEM results showed that the diameters of nanofibers were varying in the range of 103–145 nm obeying MWNTs concentrations and TEM results revealed that the MWNTs were embedded in nanofiber matrix as straight and aligned form. DSC analysis showed that electrospinning process caused the formation of less-ordered γ phase in nanofibers. The electrical conductivity of yarns increased from 10?13 S m?1 to 2.4?×?10?6 S m?1 with increasing the concentration of nanotubes from 0 wt.% to 7 wt.%.  相似文献   
79.
The aim of this study was to develop the water flux and antifouling properties of a polyamide (PA) nanofiltration membrane. A nascent PA membrane was prepared with an interfacial polymerization technique and modified with 2,5‐diaminobenzene sulfonic acid (2,5‐DABSA) as a second modification. The effects of the 2,5‐DABSA monomer concentration and the modification time on the membrane performance were investigated. The chemical structure, morphology, roughness, hydrophilicity, molecular weight cutoff, and antifouling properties of the membranes were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, atomic force spectroscopy, contact angle measurement, poly(ethylene glycol) tracers, and cetyl trimethyl ammonium bromide filtration, respectively. The PA membrane with optimized performance was shown to have a greater than 44% higher water permeate flux with a change in the salt rejection in the order RNa2SO4 > RCaCl2 > RNaCl to RNa2SO4 > RNaCl > RCaCl2. The improvement of the hydrophilicity led to excellent antifouling properties in the new PA membranes and illustrated a promising and simple method for the fabrication of high‐performance PA membranes. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43583.  相似文献   
80.
Several N,N′‐bis(n‐alkyl‐4,13‐diaza[18]crown‐6) lariat ethers were found to significantly enhance the potency of rifampicin and tetracycline, but not erythromycin and kanamycin, against the non‐pathogenic DH5α and K‐12 strains of Escherichia coli when administered at levels below their minimum inhibitory concentrations (MICs). The enhancements in antibiotic potency observed for the lariat ethers ranged from three‐ to 20‐fold, depending on the strain of E. coli, the antibiotic, and the lengths of the alkyl chains attached at the macroring nitrogen atoms. The dialkyl lariat ethers, previously thought to only be cation carriers, formed well‐behaved, ion‐conducting pores in soybean asolectin membranes, as judged by planar bilayer conductance measurements. The ability of lariat ethers to form stable pores, which appeared to be aggregated, depended in part on alkyl chain length and in part on the composition of the bilayer membrane in which they were studied.  相似文献   
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