An Ni-Mn-Zn alloy has been satisfactorily electrodeposited from a sulphate bath containing nickel sulphate (20–23 g dm−3), manganese sulphate (76–88 g dm−3), zinc sulphate (18–24 g dm−3), ammonium sulphate (30 g dm−3), thiourea (18g dm−3) and ascorbic acid (0.8 g dm−3) under various plating conditions, namely, current density 1.0–3.0 A dm−2; temperature 30–45° C; pH 2.7–4.2 and duration of electrolysis 15–30 min. Semibright, blackish-grey, thin films were generally
deposited with the proportion of nickel and manganese in the deposits increasing with increasing current density, temperature
and duration of electrolysis. However, the amount of zinc increased as the pH of the solution was raised. The cathode efficiency
for alloy deposition increased linearly as the temperature or the pH of the solution was decreased, whereas at any particular
pH and temperature it continuously rose with increasing current density or the time of deposition. The cathode polarization
shifted to more negative values on increasing the current density and to less negative values at higher pH values and temperatures
which consequently lowered the throwing power under the latter conditions. 相似文献
In this paper, we introduce the concept of $\lambda $-statistical convergence of order $\theta $ and strong $\lambda $-summability of order $\theta $ for the sequence of fuzzy numbers. Further the same concept is extended to the sequence of fuzzy functions and introduce the spaces like $S_\lambda ^\theta (\hat{f})$ and $\omega _{\lambda p} ^\theta (\hat{f})$. Some inclusion relations in those spaces and also the underlying relation between these two spaces are also obtained. 相似文献
A novel catalytic application of titanosilicate molecular sieves (TS-1 and TiMCM-41), in the synthesis of polycarbonate precursors like cyclic carbonates and dimethyl and diphenyl carbonates, avoiding toxic chemicals like phosgene or CO, is reported. Cyclic carbonates were prepared, over TS-1 and TiMCM-41, in high yields, by cycloaddition of CO2 to epoxides, like epichlorohydrin, propylene oxide and styrene oxide, at low temperatures and pressures. Further, transesterification of the cyclic carbonates with methanol and phenol, over TiMCM-41, yielded other polycarbonate precursors like dimethyl carbonate (DMC) and diphenyl carbonate (DPC). The cyclic carbonates could also be synthesized from the olefins in the same reactor by reacting the olefins, in the presence of TiMCM-41, with a mixture of an epoxidizing agent (like H2O2 or tert-butyl hydroperoxide) and CO2. 相似文献
IR absorption spectra of preoxidized PAN fibres have been studied in the spectral region 2–15 μ. Observed frequencies have been assigned to the different modes of vibration. The neighbouring frequencies appearing in the stretching mode region of the nitrile group has been interpreted in terms of Fermi-resonance and a basis for the correlation between their intensity ratio and the degree of oxidation has also been discussed. 相似文献
Recent years have witnessed an unprecedented proliferation of social media. People around the globe author, everyday, millions of blog posts, social network status updates, etc. This rich stream of information can be used to identify, on an ongoing basis, emerging stories, and events that capture popular attention. Stories can be identified via groups of tightly coupled real-world entities, namely the people, locations, products, etc, that are involved in the story. The sheer scale and rapid evolution of the data involved necessitate highly efficient techniques for identifying important stories at every point of time. The main challenge in real-time story identification is the maintenance of dense subgraphs (corresponding to groups of tightly coupled entities) under streaming edge weight updates (resulting from a stream of user-generated content). This is the first work to study the efficient maintenance of dense subgraphs under such streaming edge weight updates. For a wide range of definitions of density, we derive theoretical results regarding the magnitude of change that a single edge weight update can cause. Based on these, we propose a novel algorithm, DynDens, which outperforms adaptations of existing techniques to this setting and yields meaningful, intuitive results. Our approach is validated by a thorough experimental evaluation on large-scale real and synthetic datasets. 相似文献
With the advancement of image acquisition devices and social networking services, a huge volume of image data is generated. Using different image and video processing applications, these image data are manipulated, and thus, original images get tampered. These tampered images are the prime source of spreading fake news, defaming the personalities and in some cases (when used as evidence) misleading the law bodies. Hence before relying totally on the image data, the authenticity of the image must be verified. Works of the literature are reported for the verification of the authenticity of an image based on noise inconsistency. However, these works suffer from limitations of confusion between edges and noise, post-processing operation for localization and need of prior knowledge about an image. To handle these limitations, a noise inconsistency-based technique has been presented here to detect and localize a false region in an image. This work consists of three major steps of pre-processing, noise estimation and post-processing. For the experimental purpose two, publicly available datasets are used. The result is discussed in terms of precision, recall, accuracy and f1-score on the pixel level. The result of the presented work is also compared with the recent state-of-the-art techniques. The average accuracy of the proposed work on datasets is 91.70%, which is highest among state-of-the-art techniques.
International Journal of Control, Automation and Systems - The system of multiple agents working in coordination for a given task has several advantages on faster completion, fault-tolerance, etc.... 相似文献
Estimation of terrestrial water budget at global and regional scales are essential for efficient agricultural water management, flood predictions, and, hydrological modeling. In hydrological modeling, it is a challenging task to quantify the major hydrological components like runoff, evapotranspiration (ET), and total water storage (TWS) due to improper and limited availability of detailed meteorological datasets. Furthermore, there has been no consensus to answer a-decade-long critical question that a less data-intensive models can be an alternate to robust data-intensive models in data scarce conditions. This study aims at multi-model approach over the single models usage for representing the hydrological behaviour in the Kangsabati River Basin (KRB), India. It is done by applying the standard model selection criteria over various hydrological models. Two hydrological models are selected, a semi- distributed model, Variable Infiltration Capacity (VIC-3 L), and a conceptually lumped model, Identification of unit Hydrograph and Component flows from Rainfall, Evapotranspiration and Streamflow (IHACRES). Both models were calibrated against the observed daily discharge at the KRB outlet for the period of 2001–2006 and validated for 2008–2010. The results show that both VIC-3 L and IHACRES produce reasonable runoff estimates at daily and monthly time scale in the KRB. The ET estimates show that VIC-3 L and IHACRES captured the seasonal variations with the percent change of 0.4% and 6.6% respectively. As IHACRES is simpler, parsimonious, fewer parameters, and better performances, it can be useful for hydrological modeling in data-scarce regions.