Pub Date : 2022-03-27DOI: 10.15625/0868-3166/16345
The-Cang Nguyen, Samy Khennache, G. Galliéro, Tuong Tran, Luc Tuong, Phuc Nguyen, H. Hoang, Hieu Khac Ho
In this work, entropy scaling approaches for viscosity of pure Lennard-Jones (LJ) fluids and their mixtures have been investigated. To do so, we have employed reliable viscosity database available in literature for the pure LJ fluids, and performed the molecular dynamics simulation to generate viscosity database over a wide range of thermodynamic condition for the LJ mixture fluids. It has shown that for the pure LJ fluid, the entropy scaling approaches using the macroscopic properties for the reduction of viscosity yield noticeably better collapse of data than the one using the zero-density viscosity in the dense fluid region. In addition, we have developed viscosity correlations based on these approaches. It has been obtained that the correlations of macroscopic properties approaches predict the pure LJ fluid viscosity with average absolute deviation of around 4% more coming from the low-density states, whereas it is of around 8.50% more coming from the dense states for the other one. Finally, the viscosity correlations have been applied to the LJ mixtures. Interestingly, the correlations of macroscopic properties approaches are able to provide good estimations for all mixtures studied. However, it deteriorates for the viscosity of dense mixtures when the other employed.
{"title":"Entropy Scaling for Viscosity of Pure Lennard-Jones Fluids and Their Binary Mixtures","authors":"The-Cang Nguyen, Samy Khennache, G. Galliéro, Tuong Tran, Luc Tuong, Phuc Nguyen, H. Hoang, Hieu Khac Ho","doi":"10.15625/0868-3166/16345","DOIUrl":"https://doi.org/10.15625/0868-3166/16345","url":null,"abstract":"In this work, entropy scaling approaches for viscosity of pure Lennard-Jones (LJ) fluids and their mixtures have been investigated. To do so, we have employed reliable viscosity database available in literature for the pure LJ fluids, and performed the molecular dynamics simulation to generate viscosity database over a wide range of thermodynamic condition for the LJ mixture fluids. It has shown that for the pure LJ fluid, the entropy scaling approaches using the macroscopic properties for the reduction of viscosity yield noticeably better collapse of data than the one using the zero-density viscosity in the dense fluid region. In addition, we have developed viscosity correlations based on these approaches. It has been obtained that the correlations of macroscopic properties approaches predict the pure LJ fluid viscosity with average absolute deviation of around 4% more coming from the low-density states, whereas it is of around 8.50% more coming from the dense states for the other one. Finally, the viscosity correlations have been applied to the LJ mixtures. Interestingly, the correlations of macroscopic properties approaches are able to provide good estimations for all mixtures studied. However, it deteriorates for the viscosity of dense mixtures when the other employed.","PeriodicalId":10571,"journal":{"name":"Communications in Physics","volume":"109 1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72984118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-27DOI: 10.15625/0868-3166/15921
S. Nguyen, Phuoc Sang Le, T. Luu
Reconstruction and stabilization of polar oxide surfaces, such as ZnO, contribute a significant role in photocatalysis, chemical sensing, and optoelectronic applications, however their physical chemistry insight is still a puzzle in the surface science. In this work, the polar surface instability induced the morphological evolution of hydrothermally synthesized micro-rod ZnO doped with various contents of Cu2+ ion (1-10 at.%) was investigated. The transformation of micro-rod morphology from the high aspect ratio flower-like shape of the pure ZnO to the hexagonal prism-like shape of the doped ZnO was characterized by X-ray diffractometry, scanning electron microscopy and micro Raman spectroscopy. The chemically active Zn-terminated polar surface in doped samples was less positive charge density which was the main reason to cancel the electrostatic instability for the dominant growing direction. Furthermore, the schematic models of the electron transferring from the conduction band region to the electron trap centre of Cu2+, and the Zn-terminated polar surface reconstruction were proposed for the morphological evolution mechanism.
{"title":"Effect of Cu(^{2+}) Dopant on the Formation of Zinc Oxide Microrod Fabricated by a Hydrothermal Method","authors":"S. Nguyen, Phuoc Sang Le, T. Luu","doi":"10.15625/0868-3166/15921","DOIUrl":"https://doi.org/10.15625/0868-3166/15921","url":null,"abstract":"Reconstruction and stabilization of polar oxide surfaces, such as ZnO, contribute a significant role in photocatalysis, chemical sensing, and optoelectronic applications, however their physical chemistry insight is still a puzzle in the surface science. In this work, the polar surface instability induced the morphological evolution of hydrothermally synthesized micro-rod ZnO doped with various contents of Cu2+ ion (1-10 at.%) was investigated. The transformation of micro-rod morphology from the high aspect ratio flower-like shape of the pure ZnO to the hexagonal prism-like shape of the doped ZnO was characterized by X-ray diffractometry, scanning electron microscopy and micro Raman spectroscopy. The chemically active Zn-terminated polar surface in doped samples was less positive charge density which was the main reason to cancel the electrostatic instability for the dominant growing direction. Furthermore, the schematic models of the electron transferring from the conduction band region to the electron trap centre of Cu2+, and the Zn-terminated polar surface reconstruction were proposed for the morphological evolution mechanism.","PeriodicalId":10571,"journal":{"name":"Communications in Physics","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78603678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-27DOI: 10.15625/0868-3166/16508
Q. D. Tran, Sy Chuong Ho, Van Hung Dao, T. M. Duc
In this paper, we study some higher-order nonclassical properties of the superposition of three-mode photon-added trio coherent state such as antibunching, squeezing, and entanglement. The results show that in the case with fixed the higher-order, when increasing the numbers of added photons, the manifestation of the higher-order three-mode sum squeezing is more obvious, but the degrees of higher-order antibunching, and higher-order three-mode entanglement are more reduced. Besides, with fixed the numbers of photon addition to the superposition of three-mode photon-added trio coherent state, the higher-order nonclassical properties as antibunching and entanglement are more pronounced, but three-mode sum squeezing is more decreased when increasing the number of the higher-order.
{"title":"Higher-order nonclassicality in superposition of three-mode photon-added trio coherent state","authors":"Q. D. Tran, Sy Chuong Ho, Van Hung Dao, T. M. Duc","doi":"10.15625/0868-3166/16508","DOIUrl":"https://doi.org/10.15625/0868-3166/16508","url":null,"abstract":"In this paper, we study some higher-order nonclassical properties of the superposition of three-mode photon-added trio coherent state such as antibunching, squeezing, and entanglement. The results show that in the case with fixed the higher-order, when increasing the numbers of added photons, the manifestation of the higher-order three-mode sum squeezing is more obvious, but the degrees of higher-order antibunching, and higher-order three-mode entanglement are more reduced. Besides, with fixed the numbers of photon addition to the superposition of three-mode photon-added trio coherent state, the higher-order nonclassical properties as antibunching and entanglement are more pronounced, but three-mode sum squeezing is more decreased when increasing the number of the higher-order. \u0000 ","PeriodicalId":10571,"journal":{"name":"Communications in Physics","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77449616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-27DOI: 10.15625/0868-3166/16597
T. Nguyen, Anh Kha Vuong, Ngan Thien Thi Dang, Nam Nguyen, N. H. Pham, Quynh Van Nguyen, Tuan Van Dinh, V. V. Nguyen
In this paper, we present the effect of Cobalt (Co) addition on the crystallization, microstructures and magnetic properties of Mn55-xCoxBi45 (x = 0, 5, 10, 20) melt – spun ribbons. The ribbons were prepared by the melt-spinning techique and subsequent anneal at 280 oC for 5 h. The investigations by using X-ray diffraction (XRD), Differential Scanning Calorimetry (DSC) traces as well the Vibration Sample Magnetometer (VSM) measurements result in the optimal content of Co added to the MnBi system is arounf 5 %at. The larger Co content causes the eutectic Mn-Co formation which restricts the reaction between Mn and Bi to form MnBi ferromagnetic phase responsible for ribbons’ performance the saturation magnetization Ms. The maximum saturation magnetization Ms of 65emu/g and the coercivity iHc of 4.7 kOe was achived for the ribbon of Mn50Co5Bi45. The effect of Co content on the microstructures and magnetic properties of Mn55-xCoxBi45 melt – spun ribbons will be discussed in detail.
{"title":"Mn(_{55-x})Co(_x)Bi(_{45}) Melt Spun Ribbons: Microstructures and Magnetic Properties","authors":"T. Nguyen, Anh Kha Vuong, Ngan Thien Thi Dang, Nam Nguyen, N. H. Pham, Quynh Van Nguyen, Tuan Van Dinh, V. V. Nguyen","doi":"10.15625/0868-3166/16597","DOIUrl":"https://doi.org/10.15625/0868-3166/16597","url":null,"abstract":"In this paper, we present the effect of Cobalt (Co) addition on the crystallization, microstructures and magnetic properties of Mn55-xCoxBi45 (x = 0, 5, 10, 20) melt – spun ribbons. The ribbons were prepared by the melt-spinning techique and subsequent anneal at 280 oC for 5 h. The investigations by using X-ray diffraction (XRD), Differential Scanning Calorimetry (DSC) traces as well the Vibration Sample Magnetometer (VSM) measurements result in the optimal content of Co added to the MnBi system is arounf 5 %at. The larger Co content causes the eutectic Mn-Co formation which restricts the reaction between Mn and Bi to form MnBi ferromagnetic phase responsible for ribbons’ performance the saturation magnetization Ms. The maximum saturation magnetization Ms of 65emu/g and the coercivity iHc of 4.7 kOe was achived for the ribbon of Mn50Co5Bi45. The effect of Co content on the microstructures and magnetic properties of Mn55-xCoxBi45 melt – spun ribbons will be discussed in detail.","PeriodicalId":10571,"journal":{"name":"Communications in Physics","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88799792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-04DOI: 10.15625/0868-3166/16784
D. V. Loi, P. V. Dong
Dark matter must be stabilized over the cosmological timescale, which demands the existence of a stabilizing symmetry, derived by a dark charge, $D$. The existence of this dark charge may affect the quantization of electric charge, which theoretically shifts the electric charge, thus the hypercharge to a novel gauge extension, $SU(3)_Cotimes SU(2)_Lotimes U(1)_Yotimes U(1)_N$, where $N$ determines $D=T_3+N$, similar to $Q=T_3+Y$. New observation of this work is that the dark charge is broken down to two kinds of dark parity, $Z_2$ and $Z'_2$, which subsequently imply three scenarios of dark matter. The relic density and direct detection for the scenario of two-component dark matter are investigated in detail.
{"title":"Gauge Origin of Double Dark Parity and Implication for Dark Matter","authors":"D. V. Loi, P. V. Dong","doi":"10.15625/0868-3166/16784","DOIUrl":"https://doi.org/10.15625/0868-3166/16784","url":null,"abstract":"Dark matter must be stabilized over the cosmological timescale, which demands the existence of a stabilizing symmetry, derived by a dark charge, $D$. The existence of this dark charge may affect the quantization of electric charge, which theoretically shifts the electric charge, thus the hypercharge to a novel gauge extension, $SU(3)_Cotimes SU(2)_Lotimes U(1)_Yotimes U(1)_N$, where $N$ determines $D=T_3+N$, similar to $Q=T_3+Y$. New observation of this work is that the dark charge is broken down to two kinds of dark parity, $Z_2$ and $Z'_2$, which subsequently imply three scenarios of dark matter. The relic density and direct detection for the scenario of two-component dark matter are investigated in detail. ","PeriodicalId":10571,"journal":{"name":"Communications in Physics","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83278506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.15625/0868-3166/16055
P. Suthar, P. Gajjar
In the present paper, Phonon modes and elastic constant of three different concentrations of PdxNi1-xP (Pd64Ni16P20, Pd40Ni40P20 and Pd16Ni64P20) bulk metallic glass are calculated using (1) Hubbard-Beeby (HB) and (2) Takeno-Goda (TG) approach along with our well established local model potential. The Hartree (H), Farid et al (F) and Sarkar et al (S) local field correlation functions (LFCF) are employed to examine the effect of the screening function on the collective dynamics of Pd-Ni-P bulk metallic glasses. Results are also reported for phonon dispersion curve, propagation elastic wave and elastic properties viz: bulk modulus BT, modulus of rigidity G, Poisson’s ratio ξ, Young’s modulus Y, Debye temperature ƟD. However, the calculated elastic constants results agree well with other theoretical and available experimental data.
{"title":"Vibrational Dynamics of Pd-Ni-P Bulk Metallic Glasses","authors":"P. Suthar, P. Gajjar","doi":"10.15625/0868-3166/16055","DOIUrl":"https://doi.org/10.15625/0868-3166/16055","url":null,"abstract":"In the present paper, Phonon modes and elastic constant of three different concentrations of PdxNi1-xP (Pd64Ni16P20, Pd40Ni40P20 and Pd16Ni64P20) bulk metallic glass are calculated using (1) Hubbard-Beeby (HB) and (2) Takeno-Goda (TG) approach along with our well established local model potential. The Hartree (H), Farid et al (F) and Sarkar et al (S) local field correlation functions (LFCF) are employed to examine the effect of the screening function on the collective dynamics of Pd-Ni-P bulk metallic glasses. Results are also reported for phonon dispersion curve, propagation elastic wave and elastic properties viz: bulk modulus BT, modulus of rigidity G, Poisson’s ratio ξ, Young’s modulus Y, Debye temperature ƟD. However, the calculated elastic constants results agree well with other theoretical and available experimental data.","PeriodicalId":10571,"journal":{"name":"Communications in Physics","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82709759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.15625/0868-3166/16014
Binh Pham Thanh, T. Nguyen, V. Pham, H. Bui, T. Hoang, T. C. Do, Anh Tuan Nguyen
In this paper, we report a new type of refractometer based on a D-shaped fiber Bragg grating (FBG) integrated in a loop-mirror optical fiber laser. This proposed sensor is used in wavelength interrogation method, in which the D-shaped FBG is applied as a refractive index (RI) sensing probe and a mirror to select mode of laser. The D-shaped FBG is prepared by the removal of a portion of the fiber cladding covering the FBG by means of side-polishing technique. The D-shaped FBG sensing probe integrated in a loop-mirror optical fiber laser with saturated pump technique, the characteristics of sensing signals have been improved to obtain stable intensity, narrower bandwidth and higher optical signal-to-noise ratio compare to normal reflection configuration. The limit of detection (LOD) of this sensor can be achieved to 2.95 x 10-4 RIU in the refractive index (RI) range of 1.42-1.44. Accordingly, we believe that the proposed refractometer has a huge potential for applications in biochemical-sensing technique.
{"title":"Development of an Optical Fiber Sensor with a D-shaped Fiber Bragg Grating Integrated in a Loop-mirror Optical Fiber Laser as a High Sensitivity Refractometer","authors":"Binh Pham Thanh, T. Nguyen, V. Pham, H. Bui, T. Hoang, T. C. Do, Anh Tuan Nguyen","doi":"10.15625/0868-3166/16014","DOIUrl":"https://doi.org/10.15625/0868-3166/16014","url":null,"abstract":"In this paper, we report a new type of refractometer based on a D-shaped fiber Bragg grating (FBG) integrated in a loop-mirror optical fiber laser. This proposed sensor is used in wavelength interrogation method, in which the D-shaped FBG is applied as a refractive index (RI) sensing probe and a mirror to select mode of laser. The D-shaped FBG is prepared by the removal of a portion of the fiber cladding covering the FBG by means of side-polishing technique. The D-shaped FBG sensing probe integrated in a loop-mirror optical fiber laser with saturated pump technique, the characteristics of sensing signals have been improved to obtain stable intensity, narrower bandwidth and higher optical signal-to-noise ratio compare to normal reflection configuration. The limit of detection (LOD) of this sensor can be achieved to 2.95 x 10-4 RIU in the refractive index (RI) range of 1.42-1.44. Accordingly, we believe that the proposed refractometer has a huge potential for applications in biochemical-sensing technique.","PeriodicalId":10571,"journal":{"name":"Communications in Physics","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77111950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.15625/0868-3166/16343
Hieu T. Nguyen-Truong
We calculate excitation spectra of cubic perovskites ATiO3 (A = Ca, Sr, Ba, Pb). The calculations are performed within the time-dependent density functional theory, including local field effects. The theoretical calculations show that the perovskites have a plasmon mode at around 12 eV, which is not observed in experiments.
我们计算了立方钙钛矿ATiO3 (A = Ca, Sr, Ba, Pb)的激发光谱。计算是在时变密度泛函理论下进行的，包括局域场效应。理论计算表明，钙钛矿在12 eV左右具有等离子体模式，这在实验中没有观察到。
{"title":"Excitation spectra of cubic perovskite titanates","authors":"Hieu T. Nguyen-Truong","doi":"10.15625/0868-3166/16343","DOIUrl":"https://doi.org/10.15625/0868-3166/16343","url":null,"abstract":"We calculate excitation spectra of cubic perovskites ATiO3 (A = Ca, Sr, Ba, Pb). The calculations are performed within the time-dependent density functional theory, including local field effects. The theoretical calculations show that the perovskites have a plasmon mode at around 12 eV, which is not observed in experiments.","PeriodicalId":10571,"journal":{"name":"Communications in Physics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83097796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.15625/0868-3166/16049
Thanh Son Pham, Thao Duy Nguyen, D. Vu
In this article, we investigate a compact metamaterial structure for enhancing a magnetic resonant wireless power transfer (WPT) system operated at 6.5 MHz. A thin magnetic metamaterial (MM) slab placed between the transmitter (Tx) and receiver (Rx) coil can improve WPT efficiency. The metamaterial unit cell is designed by a ten-turn spiral resonator (10T-SR) loaded with an external capacitor. The resonant frequency of MM unit cells can be easily controlled by changing the capacitor value. By using the optimization approach, we achieve a significant WPT efficiency improvement at a mid-range distance. The results showed an enhancement of the magnetic field in the WPT system when MM slab was present. This demonstrates the ability to amplify the evanescent wave of MM slab, thereby improving the WPT efficiency. The transmission coefficients of WPT system at 60 cm increased from 0.5 to 0.76 with MM slab, which corresponds to a 46% improvement.
{"title":"Metamaterials for Improving Efficiency of Magnetic Resonant Wireless Power Transfer Applications","authors":"Thanh Son Pham, Thao Duy Nguyen, D. Vu","doi":"10.15625/0868-3166/16049","DOIUrl":"https://doi.org/10.15625/0868-3166/16049","url":null,"abstract":"In this article, we investigate a compact metamaterial structure for enhancing a magnetic resonant wireless power transfer (WPT) system operated at 6.5 MHz. A thin magnetic metamaterial (MM) slab placed between the transmitter (Tx) and receiver (Rx) coil can improve WPT efficiency. The metamaterial unit cell is designed by a ten-turn spiral resonator (10T-SR) loaded with an external capacitor. The resonant frequency of MM unit cells can be easily controlled by changing the capacitor value. By using the optimization approach, we achieve a significant WPT efficiency improvement at a mid-range distance. The results showed an enhancement of the magnetic field in the WPT system when MM slab was present. This demonstrates the ability to amplify the evanescent wave of MM slab, thereby improving the WPT efficiency. The transmission coefficients of WPT system at 60 cm increased from 0.5 to 0.76 with MM slab, which corresponds to a 46% improvement.","PeriodicalId":10571,"journal":{"name":"Communications in Physics","volume":"321 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80257910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.15625/0868-3166/16258
P. Ngoc
Brown dwarfs with masses below 0.075 solar masses are thought to form like low-mass stars (e.g., the Sun).However, it is still unclear how the physical formation processes occurin brown dwarfs at the ealiest stages (i.e., proto-brown dwarfs) of their formation.Up to date, only a few proto-brown dwarfs have been detected.The detection of proto-brown dwarfs offers us excellent benchmarks to studythe formation process of brown dwarfs, and thus understand their formation mechanism.In this paper, we present our identification of a proto-brown dwarf candidate in the star-forming regionrho Ophiuchus.The candidate shows a small-scale bipolar molecular outlfow that is similar to the outflows observed inother young brown dwarfs. The detection of this candidateprovides us with additional important implications for the formation mechanism of brown dwarfs.
{"title":"A proto-brown dwarf candidate in rho Ophiuchus","authors":"P. Ngoc","doi":"10.15625/0868-3166/16258","DOIUrl":"https://doi.org/10.15625/0868-3166/16258","url":null,"abstract":"Brown dwarfs with masses below 0.075 solar masses are thought to form like low-mass stars (e.g., the Sun).However, it is still unclear how the physical formation processes occurin brown dwarfs at the ealiest stages (i.e., proto-brown dwarfs) of their formation.Up to date, only a few proto-brown dwarfs have been detected.The detection of proto-brown dwarfs offers us excellent benchmarks to studythe formation process of brown dwarfs, and thus understand their formation mechanism.In this paper, we present our identification of a proto-brown dwarf candidate in the star-forming regionrho Ophiuchus.The candidate shows a small-scale bipolar molecular outlfow that is similar to the outflows observed inother young brown dwarfs. The detection of this candidateprovides us with additional important implications for the formation mechanism of brown dwarfs.","PeriodicalId":10571,"journal":{"name":"Communications in Physics","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80871107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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