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1.
Astronomy Letters - The emission from the Crab nebula exhibits a significant gamma-ray variability. In this paper we have analyzed this variability in terms of periodicity. Using the pulsar... 相似文献
2.
Kim I. S. Krusanova N. L. Popov V. V. Osokin A. R. Mironova I. V. 《Geomagnetism and Aeronomy》2020,60(4):441-445
Geomagnetism and Aeronomy - The color of the coronal continuum was determined from observations in order to search for manifestations of coronal expansion. A brief review of studies determining the... 相似文献
3.
Motovilov Yu. G. Golosov S. D. Datsenko Yu. S. Zverev I. S. Puklakov V. V. Fashchevskaya T. B. 《Water Resources》2020,47(5):751-762
Water Resources - An Information–Modeling Complex has been developed for the information support of managerial decision making in the field of rational use, protection, and restoration of... 相似文献
4.
The upper 30 cm of the soil profile, which hosts the majority of the root biomass, can be considered as the shallow agricultural root zone of most temperate crops. The electromagnetic wave velocity in the soil obtained from reflection hyperbolas in ground-penetrating radar (GPR) data can be used to estimate soil moisture (SM). Finding shallow hyperbolas in a radargram and minimizing the subjective error associated with the hyperbola fitting are the main challenges in this approach. Nevertheless, we were motivated by the recent improvements of hyperbola fitting algorithms, which can reduce the subjective error and processing time. To overcome the difficulty of finding very shallow hyperbolas, we applied the hyperbola fitting method to reflections ranging from 27- to 50-cm depth using a 500-MHz centre-frequency GPR and compared the estimated moisture with vertically installed, 30-cm-long time-domain reflectometry (TDR) sensors. We also compared TDR and GPR sample areas in a 2-D plane using different GPR survey types and different hyperbola depths. SM measured with TDR and GPR were not significantly different according to Mann–Whitney's test. Our analyses showed that a root mean square error of 0.03 m3 m−3 was found between the two methods. In conclusion, the proposed method might be suitable to estimate SM with an acceptable accuracy within the root zone if the soil profile is fairly uniform within the application depth range. 相似文献
5.
Jason A. Leach James M. Buttle Kara L. Webster Paul W. Hazlett Dean S. Jeffries 《水文研究》2020,34(10):2154-2175
The time it takes water to travel through a catchment, from when it enters as rain and snow to when it leaves as streamflow, may influence stream water quality and catchment sensitivity to environmental change. Most studies that estimate travel times do so for only a few, often rain-dominated, catchments in a region and use relatively short data records (<10 years). A better understanding of how catchment travel times vary across a landscape may help diagnose inter-catchment differences in water quality and response to environmental change. We used comprehensive and long-term observations from the Turkey Lakes Watershed Study in central Ontario to estimate water travel times for 12 snowmelt-dominated headwater catchments, three of which were impacted by forest harvesting. Chloride, a commonly used water tracer, was measured in streams, rain, snowfall and as dry atmospheric deposition over a 31 year period. These data were used with a lumped convolution integral approach to estimate mean water travel times. We explored relationships between travel times and catchment characteristics such as catchment area, slope angle, flowpath length, runoff ratio and wetland coverage, as well as the impact of harvesting. Travel time estimates were then used to compare differences in stream water quality between catchments. Our results show that mean travel times can be variable for small geographic areas and are related to catchment characteristics, in particular flowpath length and wetland cover. In addition, forest harvesting appeared to decrease mean travel times. Estimated mean travel times had complex relationships with water quality patterns. Results suggest that biogeochemical processes, particularly those present in wetlands, may have a greater influence on water quality than catchment travel times. 相似文献
6.
Astronomy Letters - The birth function of neutron stars in magnetic field $$B$$ is estimated for two models of the evolution of radio pulsars corresponding to different directions of evolution of... 相似文献
7.
Theoretical and Applied Climatology - Indian summer monsoon rainfall (ISMR) variability of ± 10% of its long-term mean leads to flood and drought, affecting the life and economic... 相似文献
8.
Denton Callander Julie Mooney-Somers Phillip Keen Rebecca Guy Tim Duck Benjamin R. Bavinton 《International journal of geographical information science》2020,34(11):2160-2176
ABSTRACT Gay men and lesbian women often demonstrate unique settlement patterns, forming what have been referred to as ‘gayborhoods’. This study sought to provide the first postcode-level estimates of population size and prevalence of gay and lesbian people in Australia. Data on same-gender-partnered households from the Australian Census were combined with information from six different surveys conducted from 2011 to 2017. We estimated that in 2016 there were 132,203 gay men (1.5% of adult males; 95% CI: 1.4–1.6) and 79,931 lesbian women (0.9% of adult females; 95% CI: 0.8–1.0) in Australia. While many postcodes were sparsely populated by gay and lesbian people (40.1% had prevalences of <0.1%), 24.6% were moderately populated (prevalences in the 50-95th percentile) and 2.7% were highly populated (95th percentile). By jurisdiction, the Australian Capital Territory had the highest prevalences of gay men (2.1%; 95% CI: 2.0–2.2) and lesbian women (1.5%; 95% CI: 1.4–1.6). Although the majority of highly populated postcodes were found in major cities (83.7%), some were also found in regional and remote area (16.3%). This method can be applied in other countries to enhance populate estimates. The accompanying dataset can be used to guide service delivery, conduct geographically contextualised research and develop policies relevant to gay men and lesbian women in Australia. 相似文献
9.
Natural Resources Research - Sand failure and production occurs when the formation stress exceeds the strength of the formation, which is derived majorly from the natural material that cements the... 相似文献
10.
Tumbure Akinson Bretherton Mike R. Bishop Peter Hedley Mike J. 《Natural Resources Research》2020,29(3):1561-1570
Natural Resources Research - The physical and chemical characteristics of mined phosphate rock will vary temporally as the location and nature of the ore body changes and as the type of equipment... 相似文献