Raman scattering measurements on Se-doped GaAs epitaxial layers and semi-insulating (SI) GaAs irradi-ated by 10 Mev electrons have been investigated. Several defect-related features were observed. We suggestthat the 2...Raman scattering measurements on Se-doped GaAs epitaxial layers and semi-insulating (SI) GaAs irradi-ated by 10 Mev electrons have been investigated. Several defect-related features were observed. We suggestthat the 220 cm  ̄-1mode is attribute to As_1 which is associated, at least in part, with EL2 and EL12 defects.For Sedoped samples, the Raman peaks at 205 and 258 cm ̄-1 may be due to vibrational modes in small clus-ters of arsenic, and the 77 and 185  ̄-1modes are probably associated with disorder-activated first order Ra-man scattering.Irradiated results show that the small clusters of arsenic and disorder state are increased with in-creasing irradiation fluences. Other Raman peaks will also be discussed in this paper.展开更多
At present,two-dimensional(2D)materials have shown great application potential in numerous fields based on their physical chemical and electronic properties.Raman spectroscopy and de-rivative techniques are effective ...At present,two-dimensional(2D)materials have shown great application potential in numerous fields based on their physical chemical and electronic properties.Raman spectroscopy and de-rivative techniques are effective tools for characterizing 2D materials.Raman spectroscopy conveys lots of knowledge on 2D materials,including layer number,doping type,strain and interlayer coupling.This review summarized advanced applications of Raman spectroscopy in 2D materials.The challenges and possible applied directions of Raman spectroscopy to 2D materials are discussed in detail.展开更多
Raman scattering is a versatile and powerful technique and has been widely used in modern scientific research and vast industrial applications. It is one of the fundamental experimental techniques in condensed matter ...Raman scattering is a versatile and powerful technique and has been widely used in modern scientific research and vast industrial applications. It is one of the fundamental experimental techniques in condensed matter physics, since it can sensitively probe the basic elementary excitations in solids like electron, phonon, magnon, etc. The application of extreme conditions (low temperature, high magnetic field, high pressure, etc.) to Raman scattering, will push its capability up to an unprecedented level, because this enables us to look into new quantum phases driven by extreme conditions, trace the evolution of the excitations and their coupling, and hence uncover the underlying physics. This review contains two topics. In the first part, we will introduce the Raman facility under extreme conditions, belonging to the optical spectroscopy station of Synergetic Extreme Condition User Facilities (SECUF), with emphasis on the system design and the capability the facility can provide. Then in the second part we will focus on the applications of Raman scattering under extreme conditions to a variety of condensed matter systems such as superconductors, correlated electron systems, charge density waves (CDW) materials, etc. Finally, as a rapidly developing technique, time-resolved Raman scattering will be highlighted here.展开更多
The understanding of the structure morphology of oil-rich emulsion from enzyme-assisted extraction processing(EAEP)was a critical step to break the oil-rich emulsion structure in order to recover oil.Albeit EAEP metho...The understanding of the structure morphology of oil-rich emulsion from enzyme-assisted extraction processing(EAEP)was a critical step to break the oil-rich emulsion structure in order to recover oil.Albeit EAEP method has been applied as an alternative way to conventional solvent extraction method,the structure morphology of oil-rich emulsion was still unclear.The current study aimed to investigate the structure morphology of oil-rich emulsion from EAEP using 3 D confocal Raman imaging technique.With increasing the enzymatic hydrolysis duration from 1 to 3 h,the stability of oil-rich emulsion was decreased as visualized in the 3 D confocal Raman images that the protein and oil were mixed together.The subsequent Raman spectrum analysis further revealed that the decreased stability of oil-rich emulsion was due to the protein aggregations via SS bonds or protein-lipid interactions.The conformational transfer in protein indicated the formation of a compact structure.展开更多
We propose a simple algorithm for the precise engineering of multi-channel gain profile of Raman amplifier. By employing a linear approximation in the pump interaction calculation, together with a semi-empirical pump ...We propose a simple algorithm for the precise engineering of multi-channel gain profile of Raman amplifier. By employing a linear approximation in the pump interaction calculation, together with a semi-empirical pump power correction using the simplistic output signal spectrum measurement, excellent gain engineering capability has been demonstrated for various target gain profiles, within +/- 0.4dB of error.展开更多
Carbon-based material has been regarded as one of the most promising electrode materials for potassium-ion batteries(PIBs).However,the battery performance based on reported porous carbon electrodes is still unsatisfac...Carbon-based material has been regarded as one of the most promising electrode materials for potassium-ion batteries(PIBs).However,the battery performance based on reported porous carbon electrodes is still unsatisfactory,while the in-depth K-ion storage mechanism remains relatively ambiguous.Herein,we propose a facile“in situ self-template bubbling”method for synthesizing interlayer-tuned hierarchically porous carbon with different metallic ions,which delivers superior K-ion storage performance,especially the high reversible capacity(360.6 mAh·g^(−1)@0.05 A·g^(−1)),excellent rate capability(158.6 mAh·g^(−1)@10.0 A·g^(−1))and ultralong high-rate cycling stability(82.8%capacity retention after 2,000 cycles at 5.0 A·g^(−1)).Theoretical simulation reveals the correlations between interlayer distance and K-ion diffusion kinetics.Experimentally,deliberately designed consecutive cyclic voltammetry(CV)measurements,ex situ Raman tests,galvanostatic intermittent titration technique(GITT)method decipher the origin of the excellent rate performance by disentangling the synergistic effect of interlayer and pore-structure engineering.Considering the facile preparation strategy,superior electrochemical performance and insightful mechanism investigations,this work may deepen the fundamental understandings of carbon-based PIBs and related energy storage devices like sodium-ion batteries,aluminum-ion batteries,electrochemical capacitors,and dual-ion batteries.展开更多
文摘Raman scattering measurements on Se-doped GaAs epitaxial layers and semi-insulating (SI) GaAs irradi-ated by 10 Mev electrons have been investigated. Several defect-related features were observed. We suggestthat the 220 cm  ̄-1mode is attribute to As_1 which is associated, at least in part, with EL2 and EL12 defects.For Sedoped samples, the Raman peaks at 205 and 258 cm ̄-1 may be due to vibrational modes in small clus-ters of arsenic, and the 77 and 185  ̄-1modes are probably associated with disorder-activated first order Ra-man scattering.Irradiated results show that the small clusters of arsenic and disorder state are increased with in-creasing irradiation fluences. Other Raman peaks will also be discussed in this paper.
基金financial support from Natural Science Foundation of China(61605134)Basic Sichuan Applied Research Project(2019YJ0078)the Innovative Spark Project of Sichuan University(2018SCUH0043)
文摘At present,two-dimensional(2D)materials have shown great application potential in numerous fields based on their physical chemical and electronic properties.Raman spectroscopy and de-rivative techniques are effective tools for characterizing 2D materials.Raman spectroscopy conveys lots of knowledge on 2D materials,including layer number,doping type,strain and interlayer coupling.This review summarized advanced applications of Raman spectroscopy in 2D materials.The challenges and possible applied directions of Raman spectroscopy to 2D materials are discussed in detail.
基金Project supported by the Ministry of Science and Technology of China(Grant Nos.2016YFA0300504 and 2017YFA0302904)the National Natural Science Foundation of China(Grant Nos.11474357,11774419,11604383,and 11704401)supported by the Scientific Equipment Development Project of Chinese Academy of Sciences(Grant No.YJKYYQ20170027)
文摘Raman scattering is a versatile and powerful technique and has been widely used in modern scientific research and vast industrial applications. It is one of the fundamental experimental techniques in condensed matter physics, since it can sensitively probe the basic elementary excitations in solids like electron, phonon, magnon, etc. The application of extreme conditions (low temperature, high magnetic field, high pressure, etc.) to Raman scattering, will push its capability up to an unprecedented level, because this enables us to look into new quantum phases driven by extreme conditions, trace the evolution of the excitations and their coupling, and hence uncover the underlying physics. This review contains two topics. In the first part, we will introduce the Raman facility under extreme conditions, belonging to the optical spectroscopy station of Synergetic Extreme Condition User Facilities (SECUF), with emphasis on the system design and the capability the facility can provide. Then in the second part we will focus on the applications of Raman scattering under extreme conditions to a variety of condensed matter systems such as superconductors, correlated electron systems, charge density waves (CDW) materials, etc. Finally, as a rapidly developing technique, time-resolved Raman scattering will be highlighted here.
基金the financial support received from National Natural Science Foundation of China(No.31430067 and 31601475)China Postdoctoral Science Foundation funded project(No.2017M610200)Heilongjiang Postdoctoral Foundation(No.LBH-Z17011)
文摘The understanding of the structure morphology of oil-rich emulsion from enzyme-assisted extraction processing(EAEP)was a critical step to break the oil-rich emulsion structure in order to recover oil.Albeit EAEP method has been applied as an alternative way to conventional solvent extraction method,the structure morphology of oil-rich emulsion was still unclear.The current study aimed to investigate the structure morphology of oil-rich emulsion from EAEP using 3 D confocal Raman imaging technique.With increasing the enzymatic hydrolysis duration from 1 to 3 h,the stability of oil-rich emulsion was decreased as visualized in the 3 D confocal Raman images that the protein and oil were mixed together.The subsequent Raman spectrum analysis further revealed that the decreased stability of oil-rich emulsion was due to the protein aggregations via SS bonds or protein-lipid interactions.The conformational transfer in protein indicated the formation of a compact structure.
文摘We propose a simple algorithm for the precise engineering of multi-channel gain profile of Raman amplifier. By employing a linear approximation in the pump interaction calculation, together with a semi-empirical pump power correction using the simplistic output signal spectrum measurement, excellent gain engineering capability has been demonstrated for various target gain profiles, within +/- 0.4dB of error.
基金This work was supported by School Research Startup Expenses of Harbin Institute of Technology(Shenzhen)(No.DD29100027)the National Natural Science Foundation of China(No.52002094)+2 种基金Guangdong Basic and Applied Basic Research Foundation(No.2019A1515110756)China Postdoctoral Science Foundation(No.2019M661276)High-level Talents’Discipline Construction Fund of Shandong University(No.31370089963078).
文摘Carbon-based material has been regarded as one of the most promising electrode materials for potassium-ion batteries(PIBs).However,the battery performance based on reported porous carbon electrodes is still unsatisfactory,while the in-depth K-ion storage mechanism remains relatively ambiguous.Herein,we propose a facile“in situ self-template bubbling”method for synthesizing interlayer-tuned hierarchically porous carbon with different metallic ions,which delivers superior K-ion storage performance,especially the high reversible capacity(360.6 mAh·g^(−1)@0.05 A·g^(−1)),excellent rate capability(158.6 mAh·g^(−1)@10.0 A·g^(−1))and ultralong high-rate cycling stability(82.8%capacity retention after 2,000 cycles at 5.0 A·g^(−1)).Theoretical simulation reveals the correlations between interlayer distance and K-ion diffusion kinetics.Experimentally,deliberately designed consecutive cyclic voltammetry(CV)measurements,ex situ Raman tests,galvanostatic intermittent titration technique(GITT)method decipher the origin of the excellent rate performance by disentangling the synergistic effect of interlayer and pore-structure engineering.Considering the facile preparation strategy,superior electrochemical performance and insightful mechanism investigations,this work may deepen the fundamental understandings of carbon-based PIBs and related energy storage devices like sodium-ion batteries,aluminum-ion batteries,electrochemical capacitors,and dual-ion batteries.