Axion Free-kick Misalignment Mechanism

We propose an alternative scenario for the axion misalignment mechanism based on the nontrivial interplay between the axion and a light dilaton in the early universe. Dark matter abundance is still sourced by the initial misalignment of the axion field, whose motion along the potential kicks the dilaton field away from its minimum, and dilaton starts to oscillate later with a delayed onset time for oscillation and a relatively large misalignment value due to the kick; eventually the dilaton dominates over the axion in their energy densities, and the dilaton is identified as dark matter. The kick effect due to axion motion is the most significant if the initial field value of dilaton is near its minimum; therefore, we call this scenario axion free-kick misalignment mechanism, where axion plays the role similar to a football player. Dark matter abundance can be obtained with a lower axion decay constant compared to the conventional misalignment mechanism.Comment: v2: 5+3 pages, 4 figures, references added, typo fixed, some improvements, results unchange

Research on Charging Process Strategy of Airborne Compressor

An air tank can be inflated with compressed air at anytime if the aircraft is equipped with an airbone compressor. . The different inlet altitude conditions and residual tank pressures both make it difficult to plan strategy about air tank filling. This paper studied the charging performance of the filling process in these complex working conditions, and proposed an inflating strategy of airborne compressor. A dynamic model is constructed to simulate the filling process of a multi-stage compressor with finite interstage volume. It takes 6 minutes to fill a tank with 2.0L volume from 0.101 MPa to 35 MPa, and startup process merely lasts 6 seconds. The experiment on the compressor was developed on the ground. The results validated with simulation values and shared similar evolution regularity of the pressure. The filling process at high altitude has been simulated. When residual bottle pressure is atmospheric pressure, with the altitude increasing from 0 km to 20km, the charging time increases from 6 minutes to more than 2 hours. Besides, the charging time is proportional to the residual pressure with a negative slope at a certain altitude. The mean torque in startup process declines with altitude rise, which proves filling at high altitude does not heavy the compressor’s load, as well as the electric machine control difficulty. Based on simulation results, a feasible working area satisfying ejection demand is proposed, which can be used to determine the charging time under any filling condition. In order to inflate the tank in thirty minutes, this airborne compressor must work under 19.7 km

The Influence of Augmented Reality Technology on the Learning Interest, Achievement of Learning Goals and Cognitive Load of Middle School Students

In order to test the influence of augmented reality technology on the learning interest achievement of learning goals and cognitive load the instruction of topographic map was taken as an example for experimental study This paper selected 427 students from 8 classes of Grade one who all come from Zhantan Middle School in Xindu District of Chengdu as experimental samples set two classes with similar level in learning as one group the one is the experimental class and the other is the control class and formed 4 groups in total The experimental classes adopted AR three-dimensional videos as teaching aids to give new lessons and the control classes adopted traditional two- dimensional videos and then the students learning interest level achievement of learning goals and cognitive load were measured The results showed that the application of AR technology in teaching could improve students learning interest and achievement of learning goals but had no effect on reducing cognitive loa

FIRM CELEBRITY, REPUTATION AND PERFORMANCE: A SOCIAL MEDIA PERSPECTIVE

Firm celebrity and reputation are considered as valuable intangible resources leading to competitive advantages. Past research usually uses indirect measures, such as Fortune ratings or questionnaire surveys to examine the relationship between celebrity and reputation with firm financial performance. The follow-ship on microblogging services, such as Twitter, provides us an opportunity to measure the two assets directly. Constructing firm celebrity as the number of followers a firm has and firm eputation as the PageRank score of the firm, we discovered that both reputation and celebrity derived from social media have shown negative effects on firms\u27 return on assets, but have positive relationships with market capitalization. This is to say, despite of their relative inabilities to generate profits, the management of firms with high reputation and level of celebrity achieved higher market values, which is one of the most important goals for all companies. Furthermore, we also compared the different effects between reputation and celebrity on firm financial performance. The results showed that the level of celebrity has a stronger positive relation with market capitalization than firm reputation. On the other hand, firm reputation has a stronger impact on cost of goods sold than celebrity

(E)-1-[(2-Chloro-5-methyl­pyridin-3-yl)methyl­ene]thiosemicarbazide

The title compound, C8H9ClN4S, which has potential insecticidal activity, was synthesized by the reaction of 2-chloro-5-methyl­nicotinaldehyde and thio­semicarbazide. In the crystal structure, the mol­ecules are linked via inter­molecular N—H⋯N, N—H⋯S and N—H⋯Cl hydrogen bonds, forming a three-dimensional network stacked down a

Synthesis and fungicidal activity of pyrazole derivatives containing 1,2,3,4-tetrahydroquinoline

Additional file 3. Structural information (CIF) for Compound 10g

Analogue to multiple electromagnetically induced transparency in all-optical drop-filter systems

We theoretically study a parallel optical configuration which includes N periodically coupled whispering-gallery-mode resonators. The model shows an obvious effect which has a direct analogy with the phenomenon of multiple electromagnetically induced transparency in quantum systems. The numerical simulations illuminate that the frequency transparency windows are sharp and highly transparent. We also briefly discuss the experimental feasibility of the current scheme in two practical systems, microrings and microdisks.Comment: 4 pages, 4 figure

An efficient DNA isolation method for tropical plants

Due to interfering components such as polysacharrides, polyphenols, etc, DNA isolation from tropical plants had been challenging. We developed a safe, universal and efficient DNA extraction method, which yielded high-quality DNA from 10 tropical plants including cassava, rubber tree, banana, etc. In the extraction buffer, 2 M NaCl was used to provide a high ionic strength reaction environment, ethylenediaminetetraacetic acid (EDTA), lauroyl sarcosine (LSS) and cetyl trimethyl ammonium bromide (CTAB) could inhibit DNase activity effectively, polyvinylpolypyrrolidone (PVPP) produced a deoxidized reaction environment, and borax enhanced the precipitation of interfering compounds. Ordinary reagents like β-mercaptoethanol, chloroform and phenol were unnecessary in this protocol, which made it safe and friendly to use. PCR and EcoR I enzyme restriction digestion results show that the obtained DNA is good enough for downstream analysis. In conclusion, this protocol is expected to be a preferable DNA extraction protocol for tropical plants.Keywords: DNA extraction, tropical plants, cetyl trimethyl ammonium bromide (CTAB)African Journal of Biotechnology Vol. 12(19), pp. 2727-273