1,195 research outputs found
Critical size of ego communication networks
With the help of information and communication technologies, studies on the
overall social networks have been extensively reported recently. However,
investigations on the directed Ego Communication Networks (ECNs) remain
insufficient, where an ECN stands for a sub network composed of a centralized
individual and his/her direct contacts. In this paper, the directed ECNs are
built on the Call Detail Records (CDRs), which cover more than 7 million people
of a provincial capital city in China for half a year. Results show that there
is a critical size for ECN at about 150, above which the average emotional
closeness between ego and alters drops, the balanced relationship between ego
and network collapses, and the proportion of strong ties decreases. This paper
not only demonstrate the significance of ECN size in affecting its properties,
but also shows accordance with the "Dunbar's Number". These results can be
viewed as a cross-culture supportive evidence to the well-known Social Brain
Hypothesis (SBH).Comment: 6 pages, 4 figures, 1 tabl
Quasi-period outflows observed by the X-Ray Telescope onboard Hinode in the boundary of an active region
Persistent outflows have recently been detected at boundaries of some active
regions. Although these outflows are suggested to be possible sources of the
slow solar wind, the nature of these outflows is poorly understood. Through an
analysis of an image sequence obtained by the X-Ray Telescope onboard the
Hinode spacecraft, we found that quasi-period outflows are present in the
boundary of an active region. The flows are observed to occur intermittently,
often with a period of 5-10 minutes. The projected flow speed can reach more
than 200 km/s, while its distribution peaks around 50 km/s. This sporadic
high-speed outflow may play an important role in the mass loading process of
the slow solar wind. Our results may imply that the outflow of the slow solar
wind in the boundary of the active region is intermittent and quasi-periodic in
nature.Comment: 5 figures, accepted by RA
(Z)-2-Hydroxy-3-(4-methoxyphenyl)acrylic acid
In the structure of the title compound, C10H10O4, inversion dimers linked by pairs of O—H⋯O hydrogen bonds link the carboxylic acid groups. Further O—H⋯O links cross-link the dimers into sheets running along the b-axis direction
(Z)-2-Acetamido-3-(4-chlorophenyl)acrylic acid
In the title compound, C11H10ClNO3, the molecule consists of a benzene ring and an acetamidoacrylic acid unit on opposite sides of the C=C double bond. In the crystal, intermolecular O—H⋯O and N—H⋯O hydrogen bonds assemble the molecules into infinite two-dimensional ribbons. These ribbons are linked into a network by intermolecular C—H⋯π contacts
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