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排序方式: 共有411条查询结果,搜索用时 15 毫秒
1.
P.A. Luque H.E. Garrafa-Gálvez O. Nava A. Olivas M.E. Martínez-Rosas A.R. Vilchis-Nestor A. Villegas-Fuentes M.J. Chinchillas-Chinchillas 《Ceramics International》2021,47(17):23861-23874
In this work, tin dioxide (SnO2) Nanoparticles (NPs) were synthesized through green synthesis, using Citrus × paradisi extract as a stabilizing (capping). The extract concentrations used were 1, 2 and 4% in relation to the aqueous solution. The resulting SnO2 NPs were used for the degradation of Methyl Orange (MO), Methylene Blue (MB) and Rhodamine B (RhB), under both solar and UV radiation. The NPs were characterized via Attenuated Total Reflectance Infrared Spectroscopy (ATR-IR), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM-SAED), the Brunauer-Emmett-Teller (BET) theory, Ultraviolet to Visible spectroscopy (UV–Vis), and Photoluminescence spectroscopy (PL); while the photocatalytic degradation was evaluated using UV-VIS. The results showed that the Citrus × paradisi extract is a good medium for the formation of SnO2 NPs. These NPs presented quasi-spherical morphology, particle sizes of 4–8 nm, with a rutile phase crystalline structure, and with banned gap of 2.69 at 3.28 eV. The NPs had excellent photocatalytic properties under solar radiation, degrading 100% of the OM in 180 min. Furthermore, under UV radiation, 100% degradation of the three dyes was achieved in a short time; 20 min for MO, and 60 min for MB and RhB. Therefore, green synthesis is a feasible medium for the formation of SnO2 NPs with good photocatalytic properties. 相似文献
2.
A direct analytical method for identification and determination of the individual volatile acids in raw sewage was developed. The proposed procedure is rapid, omitting tedious sample pretreatment and thus avoiding possible losses involved in steam distillation, evaporation or extraction. It consists of direct injection of raw sewage into a gas chromatograph, including Carbowax 20 M on acid washed Chromosorb W column and a flame ionization detector. Sample preparation is confined to addition of solid metaphosphoric acid to the raw sewage, and removal of precipitated proteins and suspended solids by centrifugation.The direct injection method proved to be practicable, accurate and rapid. Volatile acids content in raw municipal sewage in Haifa, Israel, was found to be in the range of 150–160 mg l−1, of which 120–125 mg l−1 was acetic acid, 30–33 mg l−1 propionic acid, 6–8 mg l−1 butyric acid, 2 mg l−1 isovaleric acid, and 0.5–1 mg l−1 valeric acid. 相似文献
3.
Ordóñez Álvaro Argüello Francisco Heras Dora B. Demir Begüm 《The Journal of supercomputing》2020,76(12):9478-9492
The Journal of Supercomputing - Image registration is a common task in remote sensing, consisting in aligning different images of the same scene. In the particular case of hyperspectral images, the... 相似文献
4.
Bikash Meher Sanjay Agrawal Rutuparna Panda Lingraj Dora Ajith Abraham 《International journal of imaging systems and technology》2020,30(3):558-576
Recently, the sparse representation (SR) based algorithms have gained much attention from the researchers in the area of image fusion (IF). The building of a compact discriminative dictionary plays a vital role in the sparse-based IF techniques. In this context, an efficient multimodal IF method based on improved dictionary learning is investigated. The key contributions of this paper are: (a) An improved KSVD algorithm is suggested for the dictionary learning process, (b) to reduce the computational time, only the informative patches are selected using energy feature, and (c) a novel region-based fusion scheme is suggested for the first time for the problem on hand. The suggested technique is tested with a number of multimodal images from Harvard Medical School brain database. The results are compared with state-of-the-art multiscale transform-based methods and modified SR-based methods. Unlike earlier methods, our proposed technique generates an adaptive dictionary through selection of informative patches only. This results in a compact dictionary with improved computational efficiency. The experimental results reveal that our approach outperforms other methods. The potential application of the suggested method could be in pathological images for follow-up study and better treatment planning. 相似文献
5.
6.
Jin Pan Julian Tang Miguela Caniza Jean-Michel Heraud Evelyn Koay Hong Kai Lee Chun Kiat Lee Yuguo Li Alejandra Nava Ruiz Carlos Francisco Santillan-Salas Linsey C. Marr 《Indoor air》2021,31(6):2281-2295
The incidence of several respiratory viral infections has been shown to be related to climate. Because humans spend most of their time indoors, measures of indoor climate, rather than outdoor climate, may be better predictors of disease incidence and transmission. Therefore, understanding the relationship between indoor and outdoor climate will help illuminate their influence on the seasonality of diseases caused by respiratory viruses. Indoor-outdoor relationships between temperature and humidity have been documented in temperate regions, but little information is available for tropical regions, where seasonal patterns of respiratory viral diseases differ. We have examined indoor-outdoor correlations of temperature, relative humidity (RH), and absolute humidity (AH) over a 1-year period in each of seven tropical cities. Across all cities, the average monthly indoor temperature was 25 ± 3°C (mean ± standard deviation) with a range of 20–30°C. The average monthly indoor RH was 66 ± 9% with a range of 50–78%, and the average monthly indoor AH was 15 ± 3 g/m3 with a range of 10–23 g/m3. Indoor AH and RH were linearly correlated with outdoor AH when the air conditioning (AC) was off, suggesting that outdoor AH may be a good proxy of indoor humidity in the absence of AC. All indoor measurements were more strongly correlated with outdoor measurements as distance from the equator increased. Such correlations were weaker during the wet season, especially when AC was in operation. These correlations will provide insight for assessing the seasonality of respiratory viral infections using outdoor climate data, which is more widely available than indoor data, even though transmission of these diseases mainly occurs indoors. 相似文献
7.
Nava Pliskin 《Information Systems Management》2013,30(2):51-58
Microcomputer technology has matured to a point at which its successful assimilation depends more on the proper management of personnel and less on the features of the technology. This article presents a case study that demonstrates how lead users can be identified and recruited to provide a support infrastructure to peers throughout the initiation stage within the organization. The article recommends that managers of microcomputer technology develop an understanding of different user types and apply adaptive human resource management practices 相似文献
8.
Dora Siva Prasad Nitla Stanley Ebenezer Chintada Shoba 《Transactions of the Indian Institute of Metals》2017,70(10):2601-2607
Nickel electroplating was applied to A356.2 aluminum alloy and its composites for improving its corrosion resistance. The corrosion resistance of the A356.2 and composites reinforced with rice husk ash particulates was evaluated by potentio-dynamic polarization tests in aerated 3.5% NaCl solution. Composites were fabricated by using the liquid state processing technique. Scanning electron microscopy, energy dispersive spectroscopy, techniques were used for surface analysis of the coatings before the corrosion tests and optical microscope was used to study the surface morphology of the uncoated and coated specimens after polarization tests. Results demonstrated that the nickel coated specimens exhibited higher corrosion resistance than the uncoated specimens. However, it was noticed that there was no significant change in the corrosion resistance for the nickel plated composites. 相似文献
9.
Benjamin Pettit Andrea Perna Dora Biro David J. T. Sumpter 《Journal of the Royal Society Interface》2013,10(89)
Travelling in groups gives animals opportunities to share route information by following cues from each other''s movement. The outcome of group navigation will depend on how individuals respond to each other within a flock, school, swarm or herd. Despite the abundance of modelling studies, only recently have researchers developed techniques to determine the interaction rules among real animals. Here, we use high-resolution GPS (global positioning system) tracking to study these interactions in pairs of pigeons flying home from a familiar site. Momentary changes in velocity indicate alignment with the neighbour''s direction, as well as attraction or avoidance depending on distance. Responses were stronger when the neighbour was in front. From the flocking behaviour, we develop a model to predict features of group navigation. Specifically, we show that the interactions between pigeons stabilize a side-by-side configuration, promoting bidirectional information transfer and reducing the risk of separation. However, if one bird gets in front it will lead directional choices. Our model further predicts, and observations confirm, that a faster bird (as measured from solo flights) will fly slightly in front and thus dominate the choice of homing route. Our results explain how group decisions emerge from individual differences in homing flight behaviour. 相似文献
10.
Sodium phthalamates as corrosion inhibitors for carbon steel in aqueous hydrochloric acid solution 总被引:2,自引:0,他引:2
Eugenio A. Flores Octavio Olivares Natalya V. Likhanova Marco A. Domínguez-Aguilar Noel Nava Diego Guzman-Lucero Mónica Corrales 《Corrosion Science》2011,53(12):3899-3913
Three compounds of N-alkyl-sodium phthalamates were synthesized and tested as corrosion inhibitors for carbon steel in 0.5 M aqueous hydrochloric acid. Tests showed that inhibitor efficiencies were related to aliphatic chain length and dependent on concentration. N-1-n-tetradecyl-sodium phthalamate displayed moderate efficiency against uniform corrosion, 42–86% at 25 °C and 25–60% at 40 °C. Tests indicated that compounds behave as mixed type inhibitors where molecular adsorption on steel followed Langmuir isotherm, whereas thermodynamic suggested that a physisorption process occurred. XPS analysis confirmed film formation on surface, where Fe+2 complexes and Fe+2 chelates with phthalamates prevented steel from further corrosion. 相似文献