Evolution of particle size distribution in air in the rainfall process via the moment method

Population balance equation is converted to three moment equations to describe the dynamical behavior of particle size distribution in air in the rainfall. The scavenging coefficient is expressed as a polynomial function of the particle diameter, the raindrop diameter and the raindrop velocity. The evolutions of particle size distribution are simulated numerically and the effects of the raindrop size distribution on particle size distribution are studied. The results show that the raindrops with smaller geometric mean diameter and geometric standard deviation of size remove particles much more efficiently. The particles which fall in the “greenfield gap” are the most difficult to be scavenged from the air

YouTube AV 50K: An Annotated Corpus for Comments in Autonomous Vehicles

With one billion monthly viewers, and millions of users discussing and sharing opinions, comments below YouTube videos are rich sources of data for opinion mining and sentiment analysis. We introduce the YouTube AV 50K dataset, a freely-available collections of more than 50,000 YouTube comments and metadata below autonomous vehicle (AV)-related videos. We describe its creation process, its content and data format, and discuss its possible usages. Especially, we do a case study of the first self-driving car fatality to evaluate the dataset, and show how we can use this dataset to better understand public attitudes toward self-driving cars and public reactions to the accident. Future developments of the dataset are also discussed.Comment: in Proceedings of the Thirteenth International Joint Symposium on Artificial Intelligence and Natural Language Processing (iSAI-NLP 2018

The dependence of Ni-Fe bioxide composites nanoparticles on the FeCl2 solution used

BACKGROUND: Ni(2)O(3)- γ-Fe(2)O(3) composite nanoparticles coated with a layer of 2FeCl(3)·5H(2)O can be prepared by co-precipitation and processing in FeCl(2) solution. Using vibrating sample magnetometer (VSM), X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) diffraction techniques, the dependence of the preparation on the concentration of the FeCl(2) treatment solution is revealed. RESULTS: The magnetization of the as-prepared products varied non-monotonically as the FeCl(2) concentration increased from 0.020 M to 1.000 M. The Experimental results show that for the composite nanoparticles, the size of the γ-Fe(2)O(3) phase is constant at about 8 nm, the Ni(2)O(3) phase decreased and the 2FeCl(3)·5H(2)O phase increased with increasing concentration of FeCl(2) solution. The magnetization of the as-prepared products mainly results from the γ-Fe(2)O(3) core, and the competition between the reduction of the Ni(2)O(3) phase with the increase of the 2FeCl(3)·5H(2)O phase resulted in the apparent magnetization varying non-monotonically. CONCLUSIONS: When the concentration of FeCl(2) treatment solution did not exceed 0.100 M, the products are spherical nanoparticles of size about 11 nm; their magnetization increased monotonically with increasing the concentration of FeCl(2) solution due to the decreasing proportion of Ni(2)O(3) phase

Low-energy Scattering of (D∗Dˉ∗)±(D^{*}\bar{D}^{*})^\pm System and the Resonance-like Structure Zc(4025)Z_c(4025)

In this paper, low-energy scattering of the $(D^{*}\bar{D}^{*})^\pm$ meson system is studied within L\"uscher's finite-size formalism using $N_{f}=2$ twisted mass gauge field configurations. With three different pion mass values, the $s$-wave threshold scattering parameters, namely the scattering length $a_0$ and the effective range $r_0$, are extracted in $J^P=1^+$ channel. Our results indicate that, in this particular channel, the interaction between the two vector charmed mesons is weakly repulsive in nature hence do not support the possibility of a shallow bound state for the two mesons, at least for the pion mass values being studied. This study provides some useful information on the nature of the newly discovered resonance-like structure $Z_c(4025)$ observed in various experiments.Comment: 11 pages, 6 figures. arXiv admin note: substantial text overlap with arXiv:1403.131

6β,15β-Diacet­oxy-1β,7β,13α-trihydr­oxy-7α,20-ep­oxy-ent-kaur-16-ene

The title compound, C24H34O8, a natural ent-kaurane diterpenoid, is composed of four rings with the expected cis and trans junctions. The crystal structure is stabilized by inter­molecular O—H⋯O hydrogen bonds. In addition, an intra­molecular O—H⋯O hydrogen bond occurs

Nonlinear Transport of Graphene in the Quantum Hall Regime

We have studied the breakdown of the integer quantum Hall (QH) effect with fully broken symmetry, in an ultra-high mobility graphene device sandwiched between two single crystal hexagonal boron nitride substrates. The evolution and stabilities of the QH states are studied quantitatively through the nonlinear transport with dc Hall voltage bias. The mechanism of the QH breakdown in graphene and the movement of the Fermi energy with the electrical Hall field are discussed. This is the first study in which the stabilities of fully symmetry broken QH states are probed all together. Our results raise the possibility that the v=6 states might be a better target for the quantum resistance standard.Comment: 15 pages,6 figure

Effect of siRNA interference on nerve growth factor in intervertebral disc inflammation rats

AbstractObjectiveTo investigate the inhibition effect of siRNA interference on NGF induced by inflammatory factor IL-6, and IL-1 so as to provide novel targets for clinical treatment of discogenic low back pain.MethodsThe intervertebral disc nucleus and annulus fibrosus cells of rats were separated. The cells were co-cultured with different concentrations (10 nmol/L, 20 nmol/L, 50 nmol/L, 100 nmol/L) of IL-6 and IL-1β. The NGF-siRNA was leaded into the co-cultured cells with its import ability assessed by flow cytometry instrument tests, before and after which the NGF mRNA expression was detected by real-time Q-PCR and the NGF content was detected by ELISA.ResultsFlow cytometry instrument test results showed that the NGF-siRNA cell conversion rate was 99.8%. Real-time Q-PCR detection results showed that compared with negative control group, the NGF mRNA expression of co-cultured cells treated by 10 nmol/L, 20 nmol/L, 50 nmol/L, 100 nmol/L IL-6 and IL-1β were respectively raised 3.4, 3.7, 4.7, 3.7 times which were all significantly down-regulated after the import of NGF-siRNA. EILSA detection results showed that compared with negative control group, the NGF content of co-cultured medium treated by 10 nmol/L, 20 nmol/L, 50 nmol/L, 100 nmol/L I-L6 and IL-1β were respectively raised 2.9, 3.3, 4.5, 7.4 times which were all significantly decreased after the import of NGF-siRNA.ConclusionsThese molecular biological results suggest that inflammatory factor IL-6 and IL-1β could stimulate NGF on intervertebral disc cells in vitro culture model and its efficiency is concentration dependent, while siRNA interference can inhibit the stimulation effect of IL-6 and IL-1β on intervertebral disc cell, which provides a new targets for the clinical treatment of discogenic low back pain