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排序方式: 共有624条查询结果,搜索用时 343 毫秒
81.
Neural Processing Letters - We propose a multi-step training method for designing generalized linear classifiers. First, an initial multi-class linear classifier is found through regression. Then... 相似文献
82.
Polycaprolactone (PCL) was reinforced with natural fibres as they not only permit a substantial reduction of the material costs, but also play a role as reinforcement in mechanical properties. This work was focused on the estimation of mechanical and thermal behaviour based on PCL and Pine Cone particles (PCP) filler at different weight percentages (0, 5, 10, 15, 30 and 45 wt%). Tests results indicated considerable improvement in mechanical properties, corresponding to a gain in impact strength and % elongation of 6 and 9.2% at 15 wt% particle loading, respectively. Some decrease in thermal stability was observed for composites with increasing filler content where as composite at 15% PCP was not significantly affected. Lower melting and crystallization enthalpies and higher crystallinity values were obtained for bio-composites compared with neat PCL. Some decrease in thermal stability and increase in oxygen and water vapour barrier properties were also observed for composites with increasing filler content. 相似文献
83.
Pallavi Rana Chetna Narula Anita Rani R. P. Chauhan Rashi Gupta Rajesh Kumar 《Journal of Materials Science: Materials in Electronics》2017,28(14):9998-10006
Copper nanowires of diameter 80 nm were synthesized in polycarbonate membrane using template technique. Samples were then implanted with 160 keV O?1 ion beam with varying particle fluence of 1?×?1012, 5?×?1012 and 1?×?1013 ions/cm2. The SRIM (Stopping and range of ions in matter) software was used to study the processes involved. Compositional analysis confirms implantation of oxygen ions and the stoichiometry of Cu:O was found to be 6:1 by weight % when implanted at 1?×?1013 ions/cm2. Scanning electron microscopy reveals no changes in morphology of nanowires on implantation. X-ray diffraction analysis showed no shifting in the ‘2θ’ position of diffraction peaks however some new diffraction peaks of oxygen were seen. Implantation with oxygen ion led to the increased crystallite size and reduced strain. The conductivity of the nanowires was found to increase linearly with the ion fluence presenting constructive effect of negative ion implantation on copper nanowires. 相似文献
84.
Kun Liang Ray A. Matsumoto Wei Zhao Naresh C. Osti Ivan Popov Bishnu P. Thapaliya Simon Fleischmann Sudhajit Misra Kaitlyn Prenger Madhusudan Tyagi Eugene Mamontov Veronica Augustyn Raymond R. Unocic Alexei P. Sokolov Sheng Dai Peter T. Cummings Michael Naguib 《Advanced functional materials》2021,31(33):2104007
MXenes exhibit excellent capacitance at high scan rates in sulfuric acid aqueous electrolytes, but the narrow potential window of aqueous electrolytes limits the energy density. Organic electrolytes and room-temperature ionic liquids (RTILs) can provide higher potential windows, leading to higher energy density. The large cation size of RTIL hinders its intercalation in-between the layers of MXene limiting the specific capacitance in comparison to aqueous electrolytes. In this work, different chain lengths alkylammonium (AA) cations are intercalated into Ti3C2Tx, producing variation of MXene interlayer spacings (d-spacing). AA-cation-intercalated Ti3C2Tx (AA-Ti3C2), exhibits higher specific capacitances, and cycling stabilities than pristine Ti3C2Tx in 1 m 1-ethly-3-methylimidazolium bis-(trifluoromethylsulfonyl)-imide (EMIMTFSI) in acetonitrile and neat EMIMTFSI RTIL electrolytes. Pre-intercalated MXene with an interlayer spacing of ≈2.2 nm, can deliver a large specific capacitance of 257 F g−1 (1428 mF cm−2 and 492 F cm−3) in neat EMIMTFSI electrolyte leading to high energy density. Quasi elastic neutron scattering and electrochemical impedance spectroscopy are used to study the dynamics of confined RTIL in pre-intercalated MXene. Molecular dynamics simulations suggest significant differences in the structures of RTIL ions and AA cations inside the Ti3C2Tx interlayer, providing insights into the differences in the observed electrochemical behavior. 相似文献
85.
Sunil Tyagi 《Applied Artificial Intelligence》2017,31(7-8):593-612
An Artificial Neural Network (ANN) classifier trained by a hybrid GA-BP method for diagnosis of gear faults is presented here that can be incorporated in an online fault diagnostic system of vital gearboxes. The distinctive features obtained from vibration signals of a running gearbox; that was operated in normal and with faults induced conditions were used to feed the GA-BP hybrid classifier. Time domain vibration signals were divided in 40segments. From each segment features such as magnitude of peaks in time domain and spectrum along with statistical features such as central moments and standard deviations were extracted to feed the classifier. Based on the experimental results it was shown that the GA-BP hybrid classifier can successfully identify gear condition. It was also shown that the network trained by GA-BP hybrid method performs much better than ANN that is trained by standard BP or GA individually. Further, it was also shown that if prior to extraction of features; the vibration signals are pre-processed by Discrete Wavelet Transform (DWT) then efficacy of the GA-BP hybrid is significantly enhanced. 相似文献
86.
Phase‐dependent radiation‐resistant behavior of BaTiO3: An in situ X‐ray diffraction study
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Renu Kumari Pawan Kumar Kulriya Surubala Mishra Vasundhara Kotari Srungarpu N. Achary Avesh K. Tyagi Devesh K. Avasthi 《Journal of the American Ceramic Society》2017,100(9):4263-4269
The radiation‐resistant response of BaTiO3 in the tetragonal and rhombohedral phases on exposure to 100 MeV Ag7+ ion irradiation was investigated by in situ X‐ray diffraction (XRD) at room temperature (300 K) and low temperature (25 K), respectively. This study revealed that the BaTiO3 in rhombohedral phase retained crystallinity up to an ion fluence of 1×1014 ions/cm2, whereas tetragonal phase amorphized at much lower fluence viz. 1×1013 ions/cm2. The in situ XRD along with Raman spectroscopy studies revealed that BaTiO3 in rhombohedral phase is more radiation resistant than that of tetragonal phase. The density functional theory (DFT) calculations confirmed higher bond strength of rhombohedral phase as compared to tetragonal phase, which supported the experimental result of higher radiation stability of rhombohedral phase. The theoretical predictions on high‐temperature phase will be of relevance to the nuclear waste applications. 相似文献
87.
Microbial leaching is one of the advantageous methods of removing heavy metals from sewage sludge, however, the microbiological aspects of this technology have not been studied. This study presents the characterization of the naturally occurring microorganisms, responsible for the metal leaching activity, in 21 different sewage sludges. The results obtained indicate that the bioleaching of metals is carried out by successive growth of less-acidophilic and acidophilic thiobacilli. Several species of less-acidophilic thiobacilli participate in the sludge acidification, but Thiobacillus thioparus is the most important species. In contrast, Thiobacillus thiooxidans seems to be the only species involved in the acidophilic group of thiobacilli. The growth kinetics of the two groups of thiobaciili was followed in five different sewage sludges. After 5 days of incubation in shake flasks, the pH of the sludge was decreased to about 2.0 and this pH decrease solubilized the toxic metals (Cd: 83–90%; Cr: 19–41%; Cu: 69–92%; Mn: 88–99%; Ni: 77–88%; Pb: 10–54%; Zn: 88–97%). The maximum specific growth rate (μmax) for the less-acidophilic thiobacilli varied between 0.079 and 0.104 h−1 and that for the acidophilic thiobacilli varied between 0.067 and 0.079 h−1. 相似文献
88.
Fire losses due to cable fire in thermal power plants and industrial units are mounting. Fire in cable galleries is caused either by an external source or internal heating due to overloading or poor cable insulation. Most of the power cables are laid in groups that run on trays. In the event of fire, cable insulation melts and cable conductors come into contact and generate sparks. The resulting flame spreads through cables and engulf other groups of cables. This leads to damage in control rooms and distribution units that causes power generation disruption and plant shutdown.To minimize the damage and system disturbance due to fire, a new system for cable installation has been developed. The system involves construction of fire stop walls using fire-resistant cavity blocks, heat-resistant wool, and fire-resistant sealant. 相似文献
89.
A conceptual model of the overall process of metal bioleaching from sewage sludge has been developed on the basis of experimental observations. Sludge pH was identified as the parameter which controls bacterial growth and thus the overall process. Quantitative relationships among the various process parameters were incorporated in the conceptual model, giving a mathematical model for the process. Bacterial growth, sulfate concentration and pH profiles simulated using the model were found to match experimental observations. The degree of solubilization of each metal was found to depend on the sludge pH and the type of the sludge and is given as a set of solubilization curves. 相似文献
90.
Optical and mechanical properties of diamond like carbon films deposited by microwave ECR plasma CVD
S. B. Singh M. Pandey N. Chand A. Biswas D. Bhattacharya S. Dash A. K. Tyagi R. M. Dey S. K. Kulkarni D. S. Patil 《Bulletin of Materials Science》2008,31(5):813-818
Diamond like carbon (DLC) films were deposited on Si (111) substrates by microwave electron cyclotron resonance (ECR) plasma
chemical vapour deposition (CVD) process using plasma of argon and methane gases. During deposition, a d.c. self-bias was
applied to the substrates by application of 13·56 MHz rf power. DLC films deposited at three different bias voltages (−60
V, −100 V and −150 V) were characterized by FTIR, Raman spectroscopy and spectroscopic ellipsometry to study the variation
in the bonding and optical properties of the deposited coatings with process parameters. The mechanical properties such as
hardness and elastic modulus were measured by load depth sensing indentation technique. The DLC film deposited at −100 V bias
exhibit high hardness (∼ 19 GPa), high elastic modulus (∼ 160 GPa) and high refractive index (∼ 2·16–2·26) as compared to
films deposited at −60 V and −150 V substrate bias. This study clearly shows the significance of substrate bias in controlling
the optical and mechanical properties of DLC films. 相似文献