638 research outputs found
Predicting nonlinear dynamics of optical solitons in optical fiber via the SCPINN
The strongly-constrained physics-informed neural network (SCPINN) is proposed
by adding the information of compound derivative embedded into the
soft-constraint of physics-informed neural network(PINN). It is used to predict
nonlinear dynamics and the formation process of bright and dark picosecond
optical solitons, and femtosecond soliton molecule in the single-mode fiber,
and reveal the variation of physical quantities including the energy,
amplitude, spectrum and phase of pulses during the soliton transmission. The
adaptive weight is introduced to accelerate the convergence of loss function in
this new neural network. Compared with the PINN, the accuracy of SCPINN in
predicting soliton dynamics is improved by 5-11 times. Therefore, the SCPINN is
a forward-looking method to study the modeling and analysis of soliton dynamics
in the fiber
Anomalous pressure behavior of tangential modes in single-wall carbon nanotubes
Using the molecular dynamics simulations and the force constant model we have
studied the Raman-active tangential modes (TMs) of a (10, 0) single-wall carbon
nanotube (SWNT) under hydrostatic pressure. With increasing pressure, the
atomic motions in the three TMs present obvious diversities. The pressure
derivative of E1g, A1g, and E2g mode frequency shows an increased value (), a
constant value (), and a negative value () above 5.3 GPa, respectively. The
intrinsic characteristics of TMs consumedly help to understand the essence of
the experimental T band of CNT. The anomalous pressure behavior of the TMs
frequencies may be originated from the tube symmetry alteration from D10h to
D2h then to C2h.Comment: 15 pages, 3 pages, submitted to Phys. Rev.
Hawking radiation-quasinormal modes correspondence for large AdS black holes
It is well-known that the non-strictly thermal character of the Hawking
radiation spectrum generates a natural correspondence between Hawking radiation
and black hole quasinormal modes. This main issue has been analyzed in the
framework of Schwarzschild black holes, Kerr black holes and nonextremal
Reissner-Nordstrom black holes. In this paper, by introducing the effective
temperature, we reanalysis the non-strictly thermal character of large AdS
black holes. The results show that the effective mass corresponding to the
effective temperature is approximatively the average one in any dimension. And
the other effective quantities can also be obtained. Based on the known forms
of frequency in quasinormal modes, we reanalysis the asymptotic frequencies of
the large AdS black hole in three and five dimensions. Then we get the formulas
of the Bekenstein-Hawking entropy and the horizon's area quantization with
functions of the quantum "overtone" number .Comment: 6 page
Malaria baseline survey in four special regions of northern Myanmar near China: a cross-sectional study
BACKGROUND: Epidemiological data in the border area of the northern Myanmar near China are either of little accuracy or sparse of information, due to the poor public health system in these areas, and malaria cases may be severely underestimated. This study aimed to investigate malaria prevalence and health facilities for malaria services, and to provide the baseline information for malaria control in these areas. METHODS: A cluster, randomized, cross-sectional survey was conducted in four special regions of northern Myanmar, near China: 5,585 people were selected for a malaria prevalence survey and 1,618 households were selected for a mosquito net-owning survey. Meanwhile, a total of 97 health facilities were surveyed on their malaria services. The data were analysed and descriptive statistics were used. RESULTS: A total of 761 people were found positive through microscopy test, including 290 people for Plasmodium falciparum, 460 for Plasmodium vivax, two for Plasmodium malariae, and nine for mixed infection. The average prevalence of malaria infection was 13.6% (95% CI: 12.7-14.6%). There were significant differences of prevalence of malaria infection among the different regions (P < 0.01); 38.1% (95% CI: 28.3-48.0%) of health facilities had malaria microscope examination service, and 35.1% (95% CI: 25.4-44.7%) of these had malaria treatment services, 23.7% (95% CI: 15.1-32.3%) had malaria outreach services. 28.3% (95% CI: 26.1-30.6%) of households owned one or more long-lasting insecticidal bed nets (LLINs). CONCLUSION: The prevalence of malaria infection was high in the four special regions of northern Myanmar, near China. Malaria services in health facilities in these areas were weak. ITNs/LLINs owning rate was also low. The cross-border cooperation mechanism should be further strengthened to share the epidemical data about malaria, support technical assistance, and conduct joint malaria control or elimination activities
The preprophase band-associated kinesin-14 OsKCH2 is a processive minus-end-directed microtubule motor.
In animals and fungi, cytoplasmic dynein is a processive minus-end-directed motor that plays dominant roles in various intracellular processes. In contrast, land plants lack cytoplasmic dynein but contain many minus-end-directed kinesin-14s. No plant kinesin-14 is known to produce processive motility as a homodimer. OsKCH2 is a plant-specific kinesin-14 with an N-terminal actin-binding domain and a central motor domain flanked by two predicted coiled-coils (CC1 and CC2). Here, we show that OsKCH2 specifically decorates preprophase band microtubules in vivo and transports actin filaments along microtubules in vitro. Importantly, OsKCH2 exhibits processive minus-end-directed motility on single microtubules as individual homodimers. We find that CC1, but not CC2, forms the coiled-coil to enable OsKCH2 dimerization. Instead, our results reveal that removing CC2 renders OsKCH2 a nonprocessive motor. Collectively, these results show that land plants have evolved unconventional kinesin-14 homodimers with inherent minus-end-directed processivity that may function to compensate for the loss of cytoplasmic dynein
Insights into high temperature pretreatment on cellulase processing of bamboo
Bamboo processing was performed with commercial cellulase. The properties of cellulase and the effect of high temperature pretreatment on cellulase hydrolysis of bamboo were investigated. Results indicated that cellulase hydrolysis performed fast and dramatically within 30 minutes, and then gradually reached its balance. It was found that pretreatment played an active role in cellulase processing, which enhanced the saccharification of bamboo and benefited high-molecular-weight lignin degradation and removal. Additionally, a better performance of bamboo processing was achieved under the cellulase concentration of 15IU in total reaction system of 100 ml at 50°C, pH 4.8, together with the high temperature pretreatment of 120°C for 15 minutes
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