A maximum of 5.5 W of cw TEM_(00) mode output at 532nm has been obtained by intracavity frequency doubling with a KTP crystal in an Nd:YVO_(4) laser doubly-pumped with 20 W diode pumping power.The optical-optical conv...A maximum of 5.5 W of cw TEM_(00) mode output at 532nm has been obtained by intracavity frequency doubling with a KTP crystal in an Nd:YVO_(4) laser doubly-pumped with 20 W diode pumping power.The optical-optical conversion efficiency is 27.5%.The influence of thermal lensing at high pumping power in the end-pumped Nd:YVO_(4) laser is discussed.The Nd:YVO_(4) laser has a good power stability of 1.6%.展开更多
By using the antitrace map method,we investigate the light transmission for generalized Fibonacci multilayers.Analytical results are obtained for transmission coefficients in some special cases.We find that the transm...By using the antitrace map method,we investigate the light transmission for generalized Fibonacci multilayers.Analytical results are obtained for transmission coefficients in some special cases.We find that the transmission coefficients possess a two-cycle or six-cycle property.The cycle properties of the trace and antitrace are also obtained.展开更多
The propagation of ultrashort coherent electromagnetic pulses with broad spectral bandwidth in free space is studied by using scalar diffraction theory.It is confirmed and experimentally demonstrated that the diffract...The propagation of ultrashort coherent electromagnetic pulses with broad spectral bandwidth in free space is studied by using scalar diffraction theory.It is confirmed and experimentally demonstrated that the diffraction not only affects the spatial structure but also changes the temporal waveform of an ultra-wide-band pulse during propagation.The terahertz pulse travelling as basic mode of Gaussian beam is discussed in detail.展开更多
The performance of a passively Q-switched all-solid-state Nd:YVO_(4) laser using Cr^(4+):YAG as saturable absorber is reported.Optimum coupling operation at 1064nm resulted in 70ns pulses at 40kHz repetition rates wit...The performance of a passively Q-switched all-solid-state Nd:YVO_(4) laser using Cr^(4+):YAG as saturable absorber is reported.Optimum coupling operation at 1064nm resulted in 70ns pulses at 40kHz repetition rates with average output power of 2.1 W.A quantitative theoretical description agrees well with the experimental results.展开更多
We successfully label-free and real-time detect the capture processes of human immunoglobulin G (IgG)/goat anti-human IgG and mouse IgG/goat anti-mouse IgG antigen-antibody pairs with different concentrations using th...We successfully label-free and real-time detect the capture processes of human immunoglobulin G (IgG)/goat anti-human IgG and mouse IgG/goat anti-mouse IgG antigen-antibody pairs with different concentrations using the oblique-incidence reflectivity difference (OIRD) method,and obtain the interaction kinetics curves and the interaction times.The experimental results prove that the OIRD method is a promising technique for label-free and real-time detection of the biomolecular interaction processes and achieving the quantitative information of interaction kinetics.展开更多
目的建立超高效液相色谱-串联质谱(ultra high performance liquid chromatography tandem mass spectrometry,UPLC-ESI-MS/MS)方法同时测定白蒲黄胶囊中β-蜕皮甾酮、筋骨草甾酮C、常春藤皂苷C、刺人参皂苷S、白头翁皂苷C、C47H76O17...目的建立超高效液相色谱-串联质谱(ultra high performance liquid chromatography tandem mass spectrometry,UPLC-ESI-MS/MS)方法同时测定白蒲黄胶囊中β-蜕皮甾酮、筋骨草甾酮C、常春藤皂苷C、刺人参皂苷S、白头翁皂苷C、C47H76O17、白头翁皂苷B4、常春藤皂苷B、白头翁皂苷A3、α-常春藤皂苷、23-羟基白桦脂酸和常春藤皂苷元12种成分的含量。方法采用Phenomenex Kinetex-C18色谱柱(100×3mm,2.6mm),流动相为甲醇(0.1%甲酸)-水(0.1%甲酸),梯度洗脱,流速0.4mL/min,柱温40℃。采用电喷雾离子源进行正、负离子模式进行检测,多反应监测模式进行定量测定。离子源温度(Source Temp)为150℃,毛细管(Capillary)电压为2.0kV,离子源补偿电压(Source Offset)为50V,脱溶剂气温度(Desolvation Temp)为500℃,雾化气(Nebuliser)压力7.0Bar,接口处加热。结果在6.5min内白蒲黄胶囊中12种有效成分β-蜕皮甾酮、筋骨草甾酮C、常春藤皂苷C、刺人参皂苷S、白头翁皂苷C、C_(47)H_(76)O_(17)、白头翁皂苷B4、常春藤皂苷B、白头翁皂苷A3、α-常春藤皂苷、23-羟基白桦脂酸和常春藤皂苷元被完全分离;峰面积与其浓度呈良好的线性;平均回收率范围为97.13%～101.2%,相对标准差为1.2%～4.1%。结论该测定方法经验证分析时间短、专属性高,可为白蒲黄胶囊质量控制提供依据。展开更多
The n-type conductive BaNb_(0.3) Ti_(0.7)O_(3) thin films were grown on SrTiO_(3) (001) substrates by computer-controlled laser molecular beam epitaxy. The BaNb0.3Ti0.7O3 films with (001) orientation are epitaxially g...The n-type conductive BaNb_(0.3) Ti_(0.7)O_(3) thin films were grown on SrTiO_(3) (001) substrates by computer-controlled laser molecular beam epitaxy. The BaNb0.3Ti0.7O3 films with (001) orientation are epitaxially grown on SrTiO_(3) substrates, as confirmed by x-ray diffraction techniques. The root-mean-square surface roughness of the deposited thin films is measured to be 0.24 nm by atomic force microscopy. The resistivity, carrier concentration and mobility of the BaNb_(0.3)Ti_(0.7)O_(3) thin film are 5.9 × 10^(-4) Ω. cm, 1.8 × 10^(21)cm^(-3) and 10. 7cm^(2).V^(-1).s^(-1) at room temperature,respectively, which are the best values in Nb-doped BaTiO3 thin films reported so far to our knowledge.展开更多
We have demonstrated a diode-pumped Nd:YVO4 laser that produced 273mW cw output at 671 nm by using KTP intracavity doubling.The optical-optical efficiency of the all-solid-state red laser was 5.1%.The maximum output p...We have demonstrated a diode-pumped Nd:YVO4 laser that produced 273mW cw output at 671 nm by using KTP intracavity doubling.The optical-optical efficiency of the all-solid-state red laser was 5.1%.The maximum output power of the fundamental wave at 1342nm from Nd:YVO_(4) was 2.3W with slope-efficiency of 43%.展开更多
We report the optical oscillations with monolayer periodicity observed by an oblique-incidence reflectance difference(OIRD)technique on the epitaxial growth of Nb-doped SrTiO_(3) on SrTiO_(3) substrate.The periodicity...We report the optical oscillations with monolayer periodicity observed by an oblique-incidence reflectance difference(OIRD)technique on the epitaxial growth of Nb-doped SrTiO_(3) on SrTiO_(3) substrate.The periodicity was verified by the simultaneously measured reflection high-energy electron diffraction intensity oscillations.The OIRD oscillation damps during deposition,but can recover after the growth is interrupted for some time.We interpret the optical oscillations as a result of the periodic changes of the surface morphologies due to the two-dimensional layer-by-layer growth of thin films.展开更多
Superconducting MgB_(2) thin films were fabricated on Al_(2)O_(3)(0001)substrates under an ex situ processing conditions.Boron thin films were deposited by pulsed laser deposition followed by a post-annealing process....Superconducting MgB_(2) thin films were fabricated on Al_(2)O_(3)(0001)substrates under an ex situ processing conditions.Boron thin films were deposited by pulsed laser deposition followed by a post-annealing process.Resistance measurements of the deposited MgB_(2) films show Tc of~39 K,while scanning electron microscopy and x-ray diffraction analysis indicate that the films consist of well-crystallized grains with a highly c-axis-oriented structure.展开更多
Within the framework of the mean field theory, we study the magnetization profiles of ferromagnetic Ising films in a transverse field. By the transfer matrix method, we first derive a general nonlinear equation for ph...Within the framework of the mean field theory, we study the magnetization profiles of ferromagnetic Ising films in a transverse field. By the transfer matrix method, we first derive a general nonlinear equation for phase transition temperatures and then calculate the magnetization profiles of the system. The method proposed here can be applied to ferromagnetic films with arbitrary surface layer number, bulk layer number, exchange interaction constants and transverse fields.展开更多
Atomically regulated unit-cell by unit-cell homoepitaxial SrTiO_(3) and heteroepitaxial BaTiO_(3) films were fabricated on SrTiO_(3)(100)substrates by laser molecular beam epitaxy.The fine streak patterns and more tha...Atomically regulated unit-cell by unit-cell homoepitaxial SrTiO_(3) and heteroepitaxial BaTiO_(3) films were fabricated on SrTiO_(3)(100)substrates by laser molecular beam epitaxy.The fine streak patterns and more than 1000 cycles undamping intensity oscillation were obtained by in situ reflection high-energy electron diffraction with precisely controlled intermittence between each unit-cell layer.The surface morphology of the films was examined by atomic force microscopy.The root-mean-square surface roughness of the films is about 0.1 nm.展开更多
A pyrometric absorption method suitable for strongly absorbing films has been developed to monitor the YBa_(2)Cu_(3)O_(7-δ)film growth.This method makes use of the temperature difference between the heater and the su...A pyrometric absorption method suitable for strongly absorbing films has been developed to monitor the YBa_(2)Cu_(3)O_(7-δ)film growth.This method makes use of the temperature difference between the heater and the substrate.By deducing the absorption formula of radiation light and fitting it to the radiation intensity data measured,it is possible to monitor the film thickness and the film surface temperature during deposition.Experimental results show that this is a simple and practicable method.展开更多
Laser molecular beam epitaxy(laser MBE)technique was utilized to grow the barium titanate(BaTiO_(3),BTO)thin films on SrTiO_(3)(100)substrates.The surface morphology of the BaTiO_(3) thin films was studied by atomic f...Laser molecular beam epitaxy(laser MBE)technique was utilized to grow the barium titanate(BaTiO_(3),BTO)thin films on SrTiO_(3)(100)substrates.The surface morphology of the BaTiO_(3) thin films was studied by atomic force microscopy(AFM).Two-and three-dimensional AFM images were obtained.The root mean square surface roughness,the height profile,the histogram and the bearing ratio of the height distributions for the BaTiO_(3) thin films were analyzed in detail.The results indicate that the laser MBE thin films exhibit an atomically smooth surface.展开更多
The polarization dependence of conduction inf ersubband transitions in GaAs/AlGaAs step multiqua.ntum well structures hasJbeen studied using infrared spectroscopy.For S-polarized 45°oblique angle incidence config...The polarization dependence of conduction inf ersubband transitions in GaAs/AlGaAs step multiqua.ntum well structures hasJbeen studied using infrared spectroscopy.For S-polarized 45°oblique angle incidence configuration with respect to sample surface normal,the transverse electric(TE)active intersubband transitions were observed.Both transverse electric and transverse magnetic(TM)active intersubband transitions were obtained in P-polarized incidence at 45°angle on sample,which shows a small energy splitting between TE and TM absorption peaks.展开更多
The carbon-nitride thin films were deposited on the(100)oriented single-crystai KC1 wafers at ambient temperatures by using rf-plasma sputtering.The IR spectrum showed that the Ulins contained carbqn-nitnde bonds.The ...The carbon-nitride thin films were deposited on the(100)oriented single-crystai KC1 wafers at ambient temperatures by using rf-plasma sputtering.The IR spectrum showed that the Ulins contained carbqn-nitnde bonds.The transmission electron microscopy(TEM)and x-ray diffraction(XRD)measurements indicated the existence of predicted polycrystalline P-C_(3)N_(4) Ulins on the KC1(100)wafers.And the TEM and XRD measured lattice spacings well match the calculated data.展开更多
CaCu _(3)Ti_(4)O_(12)(CCTO)thin films were fabricated on ITO−covered MgO(100)substrates.The rectification characteristics were observed in the CCTO capacitance structure with Pt top electrodes at temperatures ranging ...CaCu _(3)Ti_(4)O_(12)(CCTO)thin films were fabricated on ITO−covered MgO(100)substrates.The rectification characteristics were observed in the CCTO capacitance structure with Pt top electrodes at temperatures ranging from 150 K to 330 K,which are attributed to the formation of a Schottky junction between n-type semiconducting CCTO and Pt due to the difference of their work functions.At low forward-bias voltage,the current-voltage characteristics of the Schottky junction follow J=JsD exp[qV/(k0T)].A strong decrease in ideality factor with the increasing temperature is obtained by linear fitting at the low bias voltage.展开更多
基金Supported by the National Advanced Materials Committee of the"863 Program"under Grant No.970311043。
文摘A maximum of 5.5 W of cw TEM_(00) mode output at 532nm has been obtained by intracavity frequency doubling with a KTP crystal in an Nd:YVO_(4) laser doubly-pumped with 20 W diode pumping power.The optical-optical conversion efficiency is 27.5%.The influence of thermal lensing at high pumping power in the end-pumped Nd:YVO_(4) laser is discussed.The Nd:YVO_(4) laser has a good power stability of 1.6%.
文摘By using the antitrace map method,we investigate the light transmission for generalized Fibonacci multilayers.Analytical results are obtained for transmission coefficients in some special cases.We find that the transmission coefficients possess a two-cycle or six-cycle property.The cycle properties of the trace and antitrace are also obtained.
基金Supported by the National Natural Science Foundation of China under Grant No.39890390the Ministry of Science and Technology of China under Grant No.G1998010102.
文摘The propagation of ultrashort coherent electromagnetic pulses with broad spectral bandwidth in free space is studied by using scalar diffraction theory.It is confirmed and experimentally demonstrated that the diffraction not only affects the spatial structure but also changes the temporal waveform of an ultra-wide-band pulse during propagation.The terahertz pulse travelling as basic mode of Gaussian beam is discussed in detail.
基金Supported by the 863 Program of National Advanced Materials Committee
文摘The performance of a passively Q-switched all-solid-state Nd:YVO_(4) laser using Cr^(4+):YAG as saturable absorber is reported.Optimum coupling operation at 1064nm resulted in 70ns pulses at 40kHz repetition rates with average output power of 2.1 W.A quantitative theoretical description agrees well with the experimental results.
基金Supported by the National Basic Research Program of China under Grant No 2007CB935701.
文摘We successfully label-free and real-time detect the capture processes of human immunoglobulin G (IgG)/goat anti-human IgG and mouse IgG/goat anti-mouse IgG antigen-antibody pairs with different concentrations using the oblique-incidence reflectivity difference (OIRD) method,and obtain the interaction kinetics curves and the interaction times.The experimental results prove that the OIRD method is a promising technique for label-free and real-time detection of the biomolecular interaction processes and achieving the quantitative information of interaction kinetics.
文摘目的建立超高效液相色谱-串联质谱(ultra high performance liquid chromatography tandem mass spectrometry,UPLC-ESI-MS/MS)方法同时测定白蒲黄胶囊中β-蜕皮甾酮、筋骨草甾酮C、常春藤皂苷C、刺人参皂苷S、白头翁皂苷C、C47H76O17、白头翁皂苷B4、常春藤皂苷B、白头翁皂苷A3、α-常春藤皂苷、23-羟基白桦脂酸和常春藤皂苷元12种成分的含量。方法采用Phenomenex Kinetex-C18色谱柱(100×3mm,2.6mm),流动相为甲醇(0.1%甲酸)-水(0.1%甲酸),梯度洗脱,流速0.4mL/min,柱温40℃。采用电喷雾离子源进行正、负离子模式进行检测,多反应监测模式进行定量测定。离子源温度(Source Temp)为150℃,毛细管(Capillary)电压为2.0kV,离子源补偿电压(Source Offset)为50V,脱溶剂气温度(Desolvation Temp)为500℃,雾化气(Nebuliser)压力7.0Bar,接口处加热。结果在6.5min内白蒲黄胶囊中12种有效成分β-蜕皮甾酮、筋骨草甾酮C、常春藤皂苷C、刺人参皂苷S、白头翁皂苷C、C_(47)H_(76)O_(17)、白头翁皂苷B4、常春藤皂苷B、白头翁皂苷A3、α-常春藤皂苷、23-羟基白桦脂酸和常春藤皂苷元被完全分离;峰面积与其浓度呈良好的线性;平均回收率范围为97.13%～101.2%,相对标准差为1.2%～4.1%。结论该测定方法经验证分析时间短、专属性高,可为白蒲黄胶囊质量控制提供依据。
文摘The n-type conductive BaNb_(0.3) Ti_(0.7)O_(3) thin films were grown on SrTiO_(3) (001) substrates by computer-controlled laser molecular beam epitaxy. The BaNb0.3Ti0.7O3 films with (001) orientation are epitaxially grown on SrTiO_(3) substrates, as confirmed by x-ray diffraction techniques. The root-mean-square surface roughness of the deposited thin films is measured to be 0.24 nm by atomic force microscopy. The resistivity, carrier concentration and mobility of the BaNb_(0.3)Ti_(0.7)O_(3) thin film are 5.9 × 10^(-4) Ω. cm, 1.8 × 10^(21)cm^(-3) and 10. 7cm^(2).V^(-1).s^(-1) at room temperature,respectively, which are the best values in Nb-doped BaTiO3 thin films reported so far to our knowledge.
基金Supported by the National Advanced Materials Commit tee of the“863 Program”(863-715-001-00).
文摘We have demonstrated a diode-pumped Nd:YVO4 laser that produced 273mW cw output at 671 nm by using KTP intracavity doubling.The optical-optical efficiency of the all-solid-state red laser was 5.1%.The maximum output power of the fundamental wave at 1342nm from Nd:YVO_(4) was 2.3W with slope-efficiency of 43%.
基金Supported by the National Natural Science Foundation of China under Grant No.60028404.
文摘We report the optical oscillations with monolayer periodicity observed by an oblique-incidence reflectance difference(OIRD)technique on the epitaxial growth of Nb-doped SrTiO_(3) on SrTiO_(3) substrate.The periodicity was verified by the simultaneously measured reflection high-energy electron diffraction intensity oscillations.The OIRD oscillation damps during deposition,but can recover after the growth is interrupted for some time.We interpret the optical oscillations as a result of the periodic changes of the surface morphologies due to the two-dimensional layer-by-layer growth of thin films.
基金Supported by a grant from the State Kay Program of China and the National Natural Science Foundation of China.
文摘Superconducting MgB_(2) thin films were fabricated on Al_(2)O_(3)(0001)substrates under an ex situ processing conditions.Boron thin films were deposited by pulsed laser deposition followed by a post-annealing process.Resistance measurements of the deposited MgB_(2) films show Tc of~39 K,while scanning electron microscopy and x-ray diffraction analysis indicate that the films consist of well-crystallized grains with a highly c-axis-oriented structure.
文摘Within the framework of the mean field theory, we study the magnetization profiles of ferromagnetic Ising films in a transverse field. By the transfer matrix method, we first derive a general nonlinear equation for phase transition temperatures and then calculate the magnetization profiles of the system. The method proposed here can be applied to ferromagnetic films with arbitrary surface layer number, bulk layer number, exchange interaction constants and transverse fields.
基金Supported by the National Natural Science Foundation of China under Grant Nos.69437010 and 59392800the Chinese Academy of Sciencesthe National Centre for R&D on Superconductivity of China.
文摘Atomically regulated unit-cell by unit-cell homoepitaxial SrTiO_(3) and heteroepitaxial BaTiO_(3) films were fabricated on SrTiO_(3)(100)substrates by laser molecular beam epitaxy.The fine streak patterns and more than 1000 cycles undamping intensity oscillation were obtained by in situ reflection high-energy electron diffraction with precisely controlled intermittence between each unit-cell layer.The surface morphology of the films was examined by atomic force microscopy.The root-mean-square surface roughness of the films is about 0.1 nm.
基金Supported by the National Centre for Research and Development on Superconductor of China.
文摘A pyrometric absorption method suitable for strongly absorbing films has been developed to monitor the YBa_(2)Cu_(3)O_(7-δ)film growth.This method makes use of the temperature difference between the heater and the substrate.By deducing the absorption formula of radiation light and fitting it to the radiation intensity data measured,it is possible to monitor the film thickness and the film surface temperature during deposition.Experimental results show that this is a simple and practicable method.
基金Supported by the National Natural Science Foundation of China under Grant Nos.59392800 and 69437101the Chinese Academy of Sciences,the National Superconducting Research Center,and the Research Grant No.94-189 RG/PHYS/AS of the Third World Academy of Sciences.
文摘Laser molecular beam epitaxy(laser MBE)technique was utilized to grow the barium titanate(BaTiO_(3),BTO)thin films on SrTiO_(3)(100)substrates.The surface morphology of the BaTiO_(3) thin films was studied by atomic force microscopy(AFM).Two-and three-dimensional AFM images were obtained.The root mean square surface roughness,the height profile,the histogram and the bearing ratio of the height distributions for the BaTiO_(3) thin films were analyzed in detail.The results indicate that the laser MBE thin films exhibit an atomically smooth surface.
基金Supported by the National Natural Science Foundation of China.
文摘The polarization dependence of conduction inf ersubband transitions in GaAs/AlGaAs step multiqua.ntum well structures hasJbeen studied using infrared spectroscopy.For S-polarized 45°oblique angle incidence configuration with respect to sample surface normal,the transverse electric(TE)active intersubband transitions were observed.Both transverse electric and transverse magnetic(TM)active intersubband transitions were obtained in P-polarized incidence at 45°angle on sample,which shows a small energy splitting between TE and TM absorption peaks.
文摘The carbon-nitride thin films were deposited on the(100)oriented single-crystai KC1 wafers at ambient temperatures by using rf-plasma sputtering.The IR spectrum showed that the Ulins contained carbqn-nitnde bonds.The transmission electron microscopy(TEM)and x-ray diffraction(XRD)measurements indicated the existence of predicted polycrystalline P-C_(3)N_(4) Ulins on the KC1(100)wafers.And the TEM and XRD measured lattice spacings well match the calculated data.
基金by the National Key Basic Research Program of China under Grant No 2011CB301802.
文摘CaCu _(3)Ti_(4)O_(12)(CCTO)thin films were fabricated on ITO−covered MgO(100)substrates.The rectification characteristics were observed in the CCTO capacitance structure with Pt top electrodes at temperatures ranging from 150 K to 330 K,which are attributed to the formation of a Schottky junction between n-type semiconducting CCTO and Pt due to the difference of their work functions.At low forward-bias voltage,the current-voltage characteristics of the Schottky junction follow J=JsD exp[qV/(k0T)].A strong decrease in ideality factor with the increasing temperature is obtained by linear fitting at the low bias voltage.
