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31.
Manzoor H. Dar Ritadhi Chakravorty Showkat A. Waza Mayank Sharma Najam W. Zaidi Amrendra N. Singh Umesh S. Singh Abdelbagi M. Ismail 《Food Security》2017,9(4):711-722
Flash floods leading to complete submergence of rice plants for 10–15 days is one of the major constraints for rice production, mainly in rainfed lowland areas. In India, 30% of the rice growing area (12–14 M ha) is prone to flash flooding with average productivity of only 0.5–0.8 t ha?1. Coastal Odisha is one of the most flood prone areas of India where the paddy crop in the wet season is often devastated by flash floods, forcing farmers either to discontinue paddy cultivation or to revert to traditional varieties with very low yields. The flood tolerant variety, Swarna-Sub1 (SS1), was introduced through cluster demonstrations in some villages of the Bari block of Odisha in 2013. SS1 seeds were provided to 355 farmers in two villages affected by floods twice in 2013. The majority of the farmers cultivated SS1 in 2013 and about 75% of them persisted with the variety in 2014. There has been a steady and significant increase in paddy cultivation and yields per unit area between 2012 and 2014 and a sharp increase in paddy sales during 2013 and 2014. The present study showed that farmers preferred to cultivate low yielding traditional land races owing to their better flood tolerance and the unavailability of flood tolerant high yielding varieties (HYVs). Traditional varieties gave 30–42% higher yields than non-SS1 HYVs when flooding occurred. SS1 on the other hand offered a significant yield advantage of about twice that of traditional varieties, in both flooding and non-flooding years. There is an additional social advantage of SSI in that famers belonging to scheduled castes in flood prone villages, have greater numbers of plots that are exposed to prolonged floods. Thus they benefit proportionately more from the introduction of SS1. 相似文献
32.
An investigation is reported of the 75 at% nickel section of the Ni-Cr-Al-Ru system at 1523 and 1273 K. Constitutional data obtained by electron probe microanalysis, X-ray diffraction and microscopical examination are presented as partial isothermal sections. At 1523 K, the major part of the section consists of phase, while the aluminium-rich region contains a and+ region; the extent of the solid solution of chromium and ruthenium in totals ~ 4 at%. The ruthenium-rich corner of the section shows a two-phase region consisting of + ruthenium-rich solid solution. At 1273 K the,+ and + ruthenium regions increase in extent. The/ mismatch values in the equilibrated alloys studied lie in the range ~ –0.08 to –0.39%. Constitutional features of as-cast alloys are also reported. 相似文献
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The effect of sodium silver exchange on the electrical properties of glasses in the systems Na2O-B2O3-SiO2-Al and Na2O-B2O3-Al have been investigated. In general, the ion-exchange step lowers the resistivity as well as the activation energy for conduction. The glasses have a highly inhomogeneous structure. The ion-exchanged glasses are characterized by a semi continuous silver-rich phase. These glasses can be switched to a highly conducting state by subjecting them to a critical electric field which varies from 0.2 to 5 vcm–1 depending on temperature and the virgin glass composition. The resistivities in the highly conducting state have values in the range 3 to 10 cm with activation energies varying from 0.002 to 0.008 eV. Wagner's asymmetric polarization cell measurements show that such high conductivity is electronic in nature. 相似文献
38.
Electrical conductivity of sol-gel derived metal nanoparticles 总被引:1,自引:0,他引:1
Electrically conducting films of thickness 2 m have been prepared on ordinary glass slides by growing ultra-fine particles of iron and copper, respectively, from a suitable precursor sol. The diameters of metal particles can be varied from 3–13 nm by controlling the heat-treatment schedule of the sol coating. Resistivity measurements (d.c.) have been carried out over the temperature range 80–300 K. The resistivity values in the range 0.0001–0.0039 cm have been obtained depending on the particle diameter and the type of metal used. The effective Debye temperature D for the different nanoparticle systems have been estimated by fitting the experimental data to the Ziman equation. D is found to vary from 346–408 K for iron with the particle size in the range 3.4–9.5 nm. The values obtained for copper are 243–307 K with particle diameters covering a range of 5.9–12.6 nm. 相似文献
39.
Tanushri Chakravorty Guillaume-Alexandre Bilodeau Éric Granger 《Machine Vision and Applications》2018,29(2):247-261
In this paper, an online adaptive model-free tracker is proposed to track single objects in video sequences to deal with real-world tracking challenges like low-resolution, object deformation, occlusion and motion blur. The novelty lies in the construction of a strong appearance model that captures features from the initialized bounding box and then are assembled into anchor point features. These features memorize the global pattern of the object and have an internal star graph-like structure. These features are unique and flexible and help tracking generic and deformable objects with no limitation on specific objects. In addition, the relevance of each feature is evaluated online using short-term consistency and long-term consistency. These parameters are adapted to retain consistent features that vote for the object location and that deal with outliers for long-term tracking scenarios. Additionally, voting in a Gaussian manner helps in tackling inherent noise of the tracking system and in accurate object localization. Furthermore, the proposed tracker uses pairwise distance measure to cope with scale variations and combines pixel-level binary features and global weighted color features for model update. Finally, experimental results on a visual tracking benchmark dataset are presented to demonstrate the effectiveness and competitiveness of the proposed tracker. 相似文献
40.
A hybrid Bayesian/ frequentist approach is presented for the Simultaneous Localization and Mapping Problem (SLAM). A frequentist approach is proposed for mapping a dense environment when the robotic pose is known and then extended to the case when the pose is uncertain. The SLAM problem is then solved in two steps: 1) the robot is localized with respect to a sparse set of landmarks in the map using a Bayes filter and a belief on the robot pose is formed, and 2) this belief on the robot pose is used to map the rest of the map using the frequentist estimator. The frequentist part of the hybrid methodology is shown to have complexity linear (constant time complexity under the assumption of bounded noise) in the map components, is robust to the data association problem and is provably consistent. The complexity of the Bayesian part is kept under control owing to the sparseness of the features, which also improves the robustness of the technique to the issue of data association. The hybrid method is tested on standard datasets on the RADISH repository. 相似文献