Based on the reported physical parameters for hexagonal system solids,we have calculated the effects of anisotropy on polarization of plane P-wave propagation.Herein we report the results of calculations and the newly...Based on the reported physical parameters for hexagonal system solids,we have calculated the effects of anisotropy on polarization of plane P-wave propagation.Herein we report the results of calculations and the newly observed physical phenomena.It is found that,for a given propagation,if the polarization is parallel to the wave vector,so also to the Poynting vector.In such a case,the phase velocity is identical to the energy velocity;the quasi P-wave degenerates to a pure P-wave along the propagation.It is also noted that if the polarization is parallel to the Poynting vector but not to the wave vector,the propagating wave cannot be a pure P-wave.Furthermore,the polarization in a quasi P-wave may deviate from the wave vector for more than 45°,but the deviation from the Poynting vector is always less than 45°.The energy velocity of a quasi SV-wave can be larger than that of the quasi P-wave in some propagation directions,even though the phase velocity of a quasi SV-wave may never be larger than either the phase velocity or energy velocity of the quasi P-wave.Finally,in case of parameters ε=0 and δ*≠0,the polarization of a quasi P-wave has an observed symmetry at a 45°phase angle.The anisotropy of a hexagonal system solid determines if a pure P-wave can be created and what the propagation direction is for a plane wave propagating inside such a hexagonal system solid.展开更多
This paper reports obtaining of useful and high-value materials from sesame seed cake (SSC). For this purpose, SSC sample was burned for 30 s using Nd: YAG laser with output power 60 W. The products of this process an...This paper reports obtaining of useful and high-value materials from sesame seed cake (SSC). For this purpose, SSC sample was burned for 30 s using Nd: YAG laser with output power 60 W. The products of this process and non-burned SSC were characterized by X-ray diffractometer (XRD), energy dispersive x-ray (EDX) and Fourier transform infrared (FTIR) so as to investigate its crystal structure and chemical components. XRD results of the SSC before burning process showed amorphous silica, rhombohedral phase of carbon, monoclinic phase of aluminum chloride, the hexagonal phase of moissanite-4H, (yellow, black) and hexagonal phase of graphite-2H, C (black). While the results of the burned SSC sample showed that the burning process using the power of Nd: YAG laser cased in appearing of crystalline hexagonal phase for silica and Carbon Nitride and converting the rhombohedral phase of Carbon into hexagonal phase. FTIR showed a number of absorbance peaks assigned to silica.展开更多
In the present paper, the effect of plasma absorption on lattice waves in 2D hexagonal dust crystals is investigated. The dispersion relations with the effect of plasma absorption are derived.It is found that the temp...In the present paper, the effect of plasma absorption on lattice waves in 2D hexagonal dust crystals is investigated. The dispersion relations with the effect of plasma absorption are derived.It is found that the temperature effect(electron-to-ion temperature ratio τ) enhances the frequency of the dust lattice waves, while the spatial effect(dimensionless Debye shielding parameter k) weakens the frequency of the dust lattice waves. In addition, the system stabilities under the conditions of plasma absorption are studied. It is found that the temperature effect narrows the range of instability, while the spatial effect extends this range. And the range of instability is calculated, i.e. the system will always in the stable state regardless of the value of k when τ?>?3.5. However, the system will be unstable when τ?=?1 and k> 4.1.展开更多
In this study, we report a two-dimensional (2D) hexagonal disk obtained by carbonization of Botryococcus braunii (B. braunii) residues. Carbonization at 700℃followed by naturally cooling down to room temperature unde...In this study, we report a two-dimensional (2D) hexagonal disk obtained by carbonization of Botryococcus braunii (B. braunii) residues. Carbonization at 700℃followed by naturally cooling down to room temperature under a non-inert gas flow atmosphere affords to yield this unique structure. The 2D hexagonal disks consist of more than 52% carbon and more than 25% oxygen. Slight amount of Fe, silicon and magnesium would be the trigger of the formation of hexagonal structure. Treatment of biomass residue is a challenge in the near future accompanied by the achievement of new energy technology in the industrial level. This research points out that efficient use of discharged biomass residue could create a new avenue for material science. The morphology of obtained crystals carbonized in different conditions, especially with the existence of argon flow, was also investigated.展开更多
As structural variants of famous hexagonal tungsten bronzes,hexagonal tungsten oxides(HTO)represent an important family with fascinating functional properties,such as piezoelectric,ferroelectric,pyroelectric,and nonli...As structural variants of famous hexagonal tungsten bronzes,hexagonal tungsten oxides(HTO)represent an important family with fascinating functional properties,such as piezoelectric,ferroelectric,pyroelectric,and nonlinear optical(NLO)properties.However,none of them are transparent in the deep-UV spectral region,which limits their applications.Herein,we report the first HTO-type monofluorophosphate K_(3)Sc_(3)(PO_(4))(PO_(3)F)_(2)F_(5)(I)with deep-UV transparency.Such a monofluorophosphate is NLO-active with a phase-matchable powder second harmonic generation efficiency of 0.9 times that of KH_(2)PO_(4)at 1,064 nm.Importantly,the UV-Vis reflectance spectrum indicates that it is deep-UV transparent down to 200 nm.This work pushes the transparent window of NLO materials with HTO-type structures down to the deep-UV spectral region for the first time and opens up a new door for HTO materials.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.40974078)the Physical Sciences Division at University of Chicago
文摘Based on the reported physical parameters for hexagonal system solids,we have calculated the effects of anisotropy on polarization of plane P-wave propagation.Herein we report the results of calculations and the newly observed physical phenomena.It is found that,for a given propagation,if the polarization is parallel to the wave vector,so also to the Poynting vector.In such a case,the phase velocity is identical to the energy velocity;the quasi P-wave degenerates to a pure P-wave along the propagation.It is also noted that if the polarization is parallel to the Poynting vector but not to the wave vector,the propagating wave cannot be a pure P-wave.Furthermore,the polarization in a quasi P-wave may deviate from the wave vector for more than 45°,but the deviation from the Poynting vector is always less than 45°.The energy velocity of a quasi SV-wave can be larger than that of the quasi P-wave in some propagation directions,even though the phase velocity of a quasi SV-wave may never be larger than either the phase velocity or energy velocity of the quasi P-wave.Finally,in case of parameters ε=0 and δ*≠0,the polarization of a quasi P-wave has an observed symmetry at a 45°phase angle.The anisotropy of a hexagonal system solid determines if a pure P-wave can be created and what the propagation direction is for a plane wave propagating inside such a hexagonal system solid.
文摘This paper reports obtaining of useful and high-value materials from sesame seed cake (SSC). For this purpose, SSC sample was burned for 30 s using Nd: YAG laser with output power 60 W. The products of this process and non-burned SSC were characterized by X-ray diffractometer (XRD), energy dispersive x-ray (EDX) and Fourier transform infrared (FTIR) so as to investigate its crystal structure and chemical components. XRD results of the SSC before burning process showed amorphous silica, rhombohedral phase of carbon, monoclinic phase of aluminum chloride, the hexagonal phase of moissanite-4H, (yellow, black) and hexagonal phase of graphite-2H, C (black). While the results of the burned SSC sample showed that the burning process using the power of Nd: YAG laser cased in appearing of crystalline hexagonal phase for silica and Carbon Nitride and converting the rhombohedral phase of Carbon into hexagonal phase. FTIR showed a number of absorbance peaks assigned to silica.
基金supported by National Natural Science Foundation of China (Nos. 11247016, 11763006 and 11705080)the International S&T Cooperation Program of China (No. 2015DFA61800)+1 种基金the Natural Science Foundation of JiangXi Province (Nos. 2014ZBAB202001, 20151BAB212010, 20151BAB202023 and 2015ZBAB202006)the Natural Science Foundation of JiangXi University of Technology (No. ZR15YB09)
文摘In the present paper, the effect of plasma absorption on lattice waves in 2D hexagonal dust crystals is investigated. The dispersion relations with the effect of plasma absorption are derived.It is found that the temperature effect(electron-to-ion temperature ratio τ) enhances the frequency of the dust lattice waves, while the spatial effect(dimensionless Debye shielding parameter k) weakens the frequency of the dust lattice waves. In addition, the system stabilities under the conditions of plasma absorption are studied. It is found that the temperature effect narrows the range of instability, while the spatial effect extends this range. And the range of instability is calculated, i.e. the system will always in the stable state regardless of the value of k when τ?>?3.5. However, the system will be unstable when τ?=?1 and k> 4.1.
文摘In this study, we report a two-dimensional (2D) hexagonal disk obtained by carbonization of Botryococcus braunii (B. braunii) residues. Carbonization at 700℃followed by naturally cooling down to room temperature under a non-inert gas flow atmosphere affords to yield this unique structure. The 2D hexagonal disks consist of more than 52% carbon and more than 25% oxygen. Slight amount of Fe, silicon and magnesium would be the trigger of the formation of hexagonal structure. Treatment of biomass residue is a challenge in the near future accompanied by the achievement of new energy technology in the industrial level. This research points out that efficient use of discharged biomass residue could create a new avenue for material science. The morphology of obtained crystals carbonized in different conditions, especially with the existence of argon flow, was also investigated.
基金supported by the NSFC(21833010,61975207,21921001,21971238,51872297,and 51890864)Youth Innovation Promotion of CAS(202069)+6 种基金the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(ZDBS-LYSLH024)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB20010200 and XDB20000000)Fujian Institute of Innovation(FJCXY18010201)in Chinese Academy of Sciencesthe National Key Research and Development Program of China(2019YFA0210400)Key Laboratory of Functional Crystals and Laser Technology,TIPC,CAS(FCLT 202003)Key Laboratory of New Processing Technology for Nonferrous Metal&Materials,Ministry of Education/Guangxi Key Laboratory of Optical and Electronic Materials and Devices(20KF-11)Startup Project of Doctor Scientific Research of Jiangxi Normal University(12021319)。
文摘As structural variants of famous hexagonal tungsten bronzes,hexagonal tungsten oxides(HTO)represent an important family with fascinating functional properties,such as piezoelectric,ferroelectric,pyroelectric,and nonlinear optical(NLO)properties.However,none of them are transparent in the deep-UV spectral region,which limits their applications.Herein,we report the first HTO-type monofluorophosphate K_(3)Sc_(3)(PO_(4))(PO_(3)F)_(2)F_(5)(I)with deep-UV transparency.Such a monofluorophosphate is NLO-active with a phase-matchable powder second harmonic generation efficiency of 0.9 times that of KH_(2)PO_(4)at 1,064 nm.Importantly,the UV-Vis reflectance spectrum indicates that it is deep-UV transparent down to 200 nm.This work pushes the transparent window of NLO materials with HTO-type structures down to the deep-UV spectral region for the first time and opens up a new door for HTO materials.
