Triggered massive and clustered stars formation by together H II regions G38.91-0.44 and G39.30-1.04

We present the radio continuum, infrared, and CO molecular observations of infrared dark cloud (IRDC) G38.95-0.47 and its adjacent H II regions G38.91-0.44 (N74), G38.93-0.39 (N75), and G39.30-1.04. The Purple Mountain Observation (PMO) 13.7 m radio telescope was used to detect12CO J=1-0,13CO J=1-0 and C18O J=1-0 lines. The carbon monoxide (CO) molecular observations can ensure the real association between the ionized gas and the neutral material observed nearby. To select young stellar objects (YSOs) associated this region, we used the GLIMPSE I catalog. The13CO J=1-0 emission presents two large cloud clumps. The clump consistent with IRDC G38.95-0.47 shows a triangle- like shape, and has a steep integrated-intensity gradient toward H II regions G38.91-0.44 and G39.30-1.04, suggesting that the two H II regions have expanded into the IRDC. Four submillmeter continuum sources have been detected in the IRDC G38.95-0.47. Only the G038.95-00.47-M1 source with a mass of 117 Msun has outflow and infall motions, indicating a newly forming massive star. We detected a new collimated outflow in the clump compressed by G38.93-0.39. The derived ages of the three H II regions are 6.1*10^5yr, 2.5*10^5yr, and 9.0*10^5yr, respectively. In the IRDC G38.95-0.47, the significant enhancement of several Class I YSOs indicates the presence of some recently formed stars. Comparing the ages of these H II regions with YSOs (Class I sources and massive G038.95-00.47-M1 source), we suggest that YSOs may be triggered by G38.91-0.44 and G39.30-1.04 together, which supports the radiatively driven implosion model. It may be the first time that the triggered star formation has occurred in the IRDC compressed by two H II regions. The new detected outflow may be driven by a star cluster.Comment: 6 pages, 4 figures, Accepted for publication in A&

Edge states induce boundary temperature jump in molecular dynamics simulation of heat conduction

We point out that the origin of the commonly occurred boundary temperature jump in the application of No\'se-Hoover heat bath in molecular dynamics is related to the edge modes, which are exponentially localized at the edge of the system. If heat baths are applied to these edge regions, the injected thermal energy will be localized thus leading to a boundary temperature jump. The jump can be eliminated by shifting the location of heat baths away from edge regions. Following this suggestion, a very good temperature profile is obtained without increasing any simulation time, and the accuracy of thermal conductivity calculated can be largely improved.Comment: accepted by PRB, brief report, references added, typo correcte

PICKLING EXPERIMENTAL STUDY ON PREPARATION OF DIESEL OIL WITH PYROLYSIS OIL FROM WASTE RUBBER

The research has been done for removing asphaltene by pickling process of diesel oil from pyrolysis oil self-made by waste rubber in this paper, and the study showed that pickling effect of concentrated sulfuric acid was better than concentrated hydrochloric acid. The best pickling effect was found when the concentration of sulfuric acid was 18.4mol/L, acid to oil ratio, namely, the amount of concentration of sulfuric acid to the amount of diesel oil ratio, was 25%. This experiment proved that removing asphaltene by pickling process using concentrated sulfuric acid was remarkable

Examining Sino-Foreign Joint School Students’ Speaking Performance in the EFL Learning Environment: A case study

This study aimed to examine Sino-Foreign Joint School (SFJS) students’ speaking performance in the EFL learning environment and explore the relationship among anxiety, motivation, willingness to communicate (WTC) and English language performance of EFL students. The study adopted an explanatory sequential research design with a mixed method approach wherein data were collected via a survey and semi-structured interviews. The findings revealed that EFL students in SFJS were rather anxious when it came to speaking in English and but they possessed higher integrated motivation. The structural equation modelling analysis revealed SPCC (Self-Perceived Communication Competence) mediated WTC to their language achievement. Keywords: English as a foreign language (EFL); anxiety; motivation; willingness to speak eISSN: 2398-4287 © 2023. The Authors. Published for AMER & cE-Bs by e-International Publishing House, Ltd., UK. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), and cE-Bs (Centre for Environment-Behaviour Studies), College of Built Environment, Universiti Teknologi MARA, Malaysia. DOI: https://doi.org/10.21834/ebpj.v8i24.465