208 research outputs found
The use of mobile phones in the context of a guanxi system
Despite the rapid expansion of mobile phone technologies in agricultural development contexts, little work has explored how this adoption intersects with contextualized social systems. Rural China, in particular, represents a large population of agricultural workers who are adopting mobile phone technology but have so far remained overlooked as a focus of these studies. This study addresses these gaps by conducting an in-depth qualitative study of the complex relationships between rural horticulture farmers, their buyers and government officials in China and how each has integrated mobile phone technology into their social system. The results find that while all groups have benefited from the incorporation of mobile phones, some groups enjoy more advantages than others. At the same time, the larger amount of land and the more integrated the communication technology, the more advantage the farmer enjoys in the market. Expanding these social linkages, buyers are eager for more communication through mobile phones than most of the farmers currently provide and government officials are trying to use mobile phones to promote the local agriculture development. Additionally, these farmers work within a unique social system called guanxi where reciprocal favors define the sociological structure. For most of the farmers, the introduction of mobile phones has not reduced their reliance on guanxi, although the farmers that control the largest land area are using mobile phones in ways that lessen its influence
A tight universal relation between the shape eccentricity and the moment of inertia for rotating neutron stars
Universal relations that are insensitive to the equation of state (EoS) are
useful in reducing the parameter space when measuring global quantities of
neutron stars (NSs). In this paper, we reveal a new universal relation that
connects the eccentricity to the radius and moment of inertia of rotating NSs.
We demonstrate that the universality of this relation holds for both
conventional NSs and bare quark stars (QSs) in the slow rotation approximation,
albeit with different relations. The maximum relative deviation is
approximately for conventional NSs and for QSs. Additionally, we
show that the universality still exists for fast-rotating NSs if we use the
dimensionless spin to characterize their rotation. The new universal relation
will be a valuable tool to reduce the number of parameters used to describe the
shape and multipoles of rotating NSs, and it may also be used to infer the
eccentricity or moment of inertia of NSs in future X-ray observations.Comment: 7 pages, 5 figures; accepted by Ap
FEM analysis of knife penetration through woven fabrics
In this paper, the penetration of a knife through a plain woven fabric is simulated with the finite element method to understand the process of stabbing and the mechanism of fiber breakage. The model focuses on the study of the deformation of individual yarns, and the effects of their material properties and fabric structure on the stabbing resistant force. The performance of the fabric is analyzed as a response of stabbing and the stress distributions in yarn transverse and longitudinal directions. An equation derived from energy and momentum conservations of the knife is proposed to predict the depth of the knife penetration
-mode of neutron stars in pseudo-Newtonian gravity
The equation of state (EOS) of nuclear dense matter plays a crucial role in
many astrophysical phenomena associated with neutron stars (NSs). Fluid
oscillations are one of the most fundamental properties therein. NSs support a
family of gravity -modes, which are related to buoyancy. We study the
gravity -modes caused by composition gradient and density discontinuity in
the framework of pseudo-Newtonian gravity. The mode frequencies are calculated
in detail and compared with Newtonian and general-relativistic (GR) solutions.
We find that the -mode frequencies in one of the pseudo-Newtonian treatments
can approximate remarkably well the GR solutions, with relative errors in the
order of . Our findings suggest that, with much less computational cost,
pseudo-Newtonian gravity can be utilized to accurately analyze oscillation of
NSs constructed from an EOS with a first-order phase transition between nuclear
and quark matter, as well as to provide an excellent approximation of GR
effects in core-collapse supernova (CCSN) simulations.Comment: 14 pages, 13 figures, 6 tables; accepted by PR
Historical Trends in Air Temperature, Precipitation, and Runoff of a Plateau Inland River Watershed in North China
Understanding historical trends in temperature, precipitation, and runoff is important but incomplete for developing adaptive measures to climate change to sustain fragile ecosystems in cold and arid regions, including the Balagaer River watershed on the Mongolian Plateau of northeast China. The objective of this study was to detect such trends in this watershed from 1959 to 2017. The detection was accomplished using a Mann-Kendall sudden change approach at annual and seasonal time scales. The results indicated that the abrupt changes in temperature preceded that in either runoff or precipitation; these abrupt changes occurred between 1970 and 2004. Significant (α = 0.05) warming trends were found at the minimum temperatures in spring (0.041 °C a−1), summer (0.037 °C a−1), fall (0.027 °C a−1), and winter (0.031 °C a−1). In contrast, significant decreasing trends were found in the precipitation (−1.27 mm a−1) and runoff (−0.069 mm a−1) in the summer. Marginally increasing trends were found in the precipitation in spring (0.18 mm a−1) and fall (0.032 mm a−1), whereas an insignificant decreasing trend was found in the runoffs in these two seasons. Both precipitation and runoff in the wet season exhibited a significant decreasing trend, whereas in the dry season, they exhibited a marginally increasing trend. Sudden changes in spring runoff and sudden rises in temperature are the main causes of sudden changes in basin rainfall
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