The generation mechanisms of supercontinuum(SC)and the effect of the modified Raman model on SC are further analyzed in a flat dispersion photonic crystal fiber(PCF)with two-zero dispersion wavelengths(TZDWs)by introd...The generation mechanisms of supercontinuum(SC)and the effect of the modified Raman model on SC are further analyzed in a flat dispersion photonic crystal fiber(PCF)with two-zero dispersion wavelengths(TZDWs)by introducing an accurate Raman response function in the scalar nonlinear Scho?dinger equation.The results show that the introduction of Boson peak in the modified Raman gain model not only results in much rapider broadening of SC but also promotes more pump pulse energy transferred to the short wavelength region,which is related to stimulated Raman scattering.Moreover,SC generated from the PCF splits into two spectral bands,and their spectral peaks rapidly separate and broaden with the increase of incidcnt power.Double-band central wavelengths are finally located at about 850 nm and 1220 nm.The pumping energy depletion phenomenon occurs.The simulated results from the modified Raman model are in better agreement with the experimental results than that from the single-Lorentzian moder.展开更多
A scheme of double grating expanders is first proposed for high energy chirped pulse amplifiers.It is demonstrated that they can compensate for the amplifier's material dispersion up to the fourth-order,together w...A scheme of double grating expanders is first proposed for high energy chirped pulse amplifiers.It is demonstrated that they can compensate for the amplifier's material dispersion up to the fourth-order,together with a suitable grating compressor.The scheme makes it possible that the pulse expansion in Chirped pulse amplifiers(CPAs)is no longer restricted by the material dispersion,and the corresponding grating compressor can be independently optimized according to the available gratings'size and damage threshold.展开更多
We demonstrate a new loop system of the spherical wavefront(SW)correction near the beam focus to effectively improve the focusability of 0.89 PW/29.0 fs Ti:sapphire chirped pulse amplification laser.After wavefront co...We demonstrate a new loop system of the spherical wavefront(SW)correction near the beam focus to effectively improve the focusability of 0.89 PW/29.0 fs Ti:sapphire chirped pulse amplification laser.After wavefront correction,the Strehl ratio is improved to reach 0.91,and the focal spot size using the f/4 off-axis parabola is reduced to 6.34 x 6.94μm^(2)(corresponding to 1.63 x 1.78 times diffraction limitation).With full peak power of 0.89 PW,the peak intensity of 2.59 x 10^(21)W/cm^(2)is obtained.The experimental results show that the SW correction scheme near the beam focus is comparatively simple,economic and high-efficient.展开更多
A high-average-power diode-pumped narrowband regenerative chirped pulse amplifier is developed using the thin-rod Nd:YAG laser architecture for optical parametric chirped-pulse amplification(OPCPA).The effect of the e...A high-average-power diode-pumped narrowband regenerative chirped pulse amplifier is developed using the thin-rod Nd:YAG laser architecture for optical parametric chirped-pulse amplification(OPCPA).The effect of the etalons on the amplified pulse in the regenerative cavity is studied experimentally and theoretically.By inserting glass etalons of thickness 1 mm and 5 mm into the regenerative cavity,the pre-stretching pulse from anÖffner stretcher is further broadened to above 200 ps,which matches the amplification windows of the signal pulses in OPCPA and is suitable for use as a pump source in the OPCPA system.The bandwidth of the amplified pulse is 1.5 nm,and an output energy of 2 mJ is achieved at a repetition rate of 10 Hz.展开更多
Background Mast cells are implicated in the development of irritable bowel syndrome （IBS）, which is associated with the activation of the ＂neural-immune＂ system. The aim of this study was to investigate the role o...Background Mast cells are implicated in the development of irritable bowel syndrome （IBS）, which is associated with the activation of the ＂neural-immune＂ system. The aim of this study was to investigate the role of mast cells in the remodeling of cholinergic and peptidergic neurotransmitters induced by acute cold restriction stress （ACRS） post infection （PI） using mast cell deficient rats （Ws/Ws） and their wild-type controls （＋/＋）. Methods Transient intestinal infection was initiated by giving 1500 Trichinella spiralis （T.S.） larvae by gavage. ACRS was induced for 2 hours at day 100 PI. Samples of terminal ilea were prepared for H＆E staining, mast cell counting and activation and assessment of IL-113 and IL-10. Results When infected, both strains of rats experienced an acute infectious stage followed by a recovery. Histological scores were significantly higher in infected rats compared with those of the non-infected controls at day 10 PI （10 day-PI vs. control： ＋/＋： 2.75±0.17 vs. 0.42±0.09; Ws/Ws： 2.67±0.67 vs. 0.50±0.34; P 〈0.01）. In ＋/＋ rats, post-infection ACRS induced the formation of low-grade inflammation, represented by the imbalance of IL-1β and IL-10 （IL-1β： PI＋ACRS vs. control： （1812.24±561.61） vs. （1275.97±410.21） pg/g, P 〈0.05; IL-10： PI＋ACRS vs. control： （251.9±39.8） vs. （255.3±24.7） pg/g, P 〉0.05）, accompanied by hyperplasia and activation of mast cells （PI＋ACRS vs. control： 58.8±19.2 vs. 28.0±7.6; P 〈0.01）. The balance between acetylcholine （ACh） and substance P （SP） was also disturbed （ACh： PI＋ACRS vs. control： （743.94±238.72） vs. （1065.68±256.46） pg/g, P 〈0.05; SP： PI＋ACRS vs. control： （892.60±231.12） vs. （696.61±148.61） pg/g, P 〈0.05）. Nevertheless, similar changes of IL-1β/IL-10 and ACh/SP were not detected in Ws/Ws rats. Conclusion The imbalance of ACh/SP, together with the activation of mucosal immunity induced by post-infection ACRS were lacking in mast cell deficient rats, which supports the premise that mast cells play an important role in cholinergic and peptidergic remodeling in the ileum of rats.展开更多
基金Supported by the National Basic Research Program of China under Grant No 2006CB806001the Knowledge Innovation Project of Chinese Academy of Sciences under Grant No KGCX-YW-417-2Shanghai Commission of Science and Technology under Grant No 07JC14055.
文摘The generation mechanisms of supercontinuum(SC)and the effect of the modified Raman model on SC are further analyzed in a flat dispersion photonic crystal fiber(PCF)with two-zero dispersion wavelengths(TZDWs)by introducing an accurate Raman response function in the scalar nonlinear Scho?dinger equation.The results show that the introduction of Boson peak in the modified Raman gain model not only results in much rapider broadening of SC but also promotes more pump pulse energy transferred to the short wavelength region,which is related to stimulated Raman scattering.Moreover,SC generated from the PCF splits into two spectral bands,and their spectral peaks rapidly separate and broaden with the increase of incidcnt power.Double-band central wavelengths are finally located at about 850 nm and 1220 nm.The pumping energy depletion phenomenon occurs.The simulated results from the modified Raman model are in better agreement with the experimental results than that from the single-Lorentzian moder.
基金Chinese Academy of Sciences,the National Natural Science Foundation of China under Grant Nos 10734080,60921004,60908008 and 61078037the National Basic Research Program of China under Grant No 2011CB808101International S&T Cooperation Program of China under Grant No 2011DFA11300.
文摘A scheme of double grating expanders is first proposed for high energy chirped pulse amplifiers.It is demonstrated that they can compensate for the amplifier's material dispersion up to the fourth-order,together with a suitable grating compressor.The scheme makes it possible that the pulse expansion in Chirped pulse amplifiers(CPAs)is no longer restricted by the material dispersion,and the corresponding grating compressor can be independently optimized according to the available gratings'size and damage threshold.
基金Supported by the National Basic Research Program of China under Grant No 2006CB806000.
文摘We demonstrate a new loop system of the spherical wavefront(SW)correction near the beam focus to effectively improve the focusability of 0.89 PW/29.0 fs Ti:sapphire chirped pulse amplification laser.After wavefront correction,the Strehl ratio is improved to reach 0.91,and the focal spot size using the f/4 off-axis parabola is reduced to 6.34 x 6.94μm^(2)(corresponding to 1.63 x 1.78 times diffraction limitation).With full peak power of 0.89 PW,the peak intensity of 2.59 x 10^(21)W/cm^(2)is obtained.The experimental results show that the SW correction scheme near the beam focus is comparatively simple,economic and high-efficient.
基金Supported by the National Basic Research Program of China under Grant Nos.2006CB806001 and 2011CB808101the National Natural Science Foundation of China under Grant Nos.10734080,60908008 and 60921004+1 种基金the Fund of the State Key Laboratory of High Field Laser Physics and Shanghai Commission of Science and Technology under Grant Nos.07JC14055 and 09QA1406500the Scientific Research Foundation of Zhejiang University of Technology under Grant Nos.109004129 and 2011XY026.
文摘A high-average-power diode-pumped narrowband regenerative chirped pulse amplifier is developed using the thin-rod Nd:YAG laser architecture for optical parametric chirped-pulse amplification(OPCPA).The effect of the etalons on the amplified pulse in the regenerative cavity is studied experimentally and theoretically.By inserting glass etalons of thickness 1 mm and 5 mm into the regenerative cavity,the pre-stretching pulse from anÖffner stretcher is further broadened to above 200 ps,which matches the amplification windows of the signal pulses in OPCPA and is suitable for use as a pump source in the OPCPA system.The bandwidth of the amplified pulse is 1.5 nm,and an output energy of 2 mJ is achieved at a repetition rate of 10 Hz.
基金This study was supported by grants from the National Natural Science Foundation of China （No. 30470776） and the Beijing Natural Science Foundation （No. 7082102）. Part of this paper was accepted for poster presentation at the First Asian Neurogastroenterology and Motility Association （ANMA） 2009, Seoul, Korea.Acknowledgements： The authors world like to thank Prof. ZHENG Zhen-hui for establishment of animal models and Ms. CHEN Li for histological technique.
文摘Background Mast cells are implicated in the development of irritable bowel syndrome （IBS）, which is associated with the activation of the ＂neural-immune＂ system. The aim of this study was to investigate the role of mast cells in the remodeling of cholinergic and peptidergic neurotransmitters induced by acute cold restriction stress （ACRS） post infection （PI） using mast cell deficient rats （Ws/Ws） and their wild-type controls （＋/＋）. Methods Transient intestinal infection was initiated by giving 1500 Trichinella spiralis （T.S.） larvae by gavage. ACRS was induced for 2 hours at day 100 PI. Samples of terminal ilea were prepared for H＆E staining, mast cell counting and activation and assessment of IL-113 and IL-10. Results When infected, both strains of rats experienced an acute infectious stage followed by a recovery. Histological scores were significantly higher in infected rats compared with those of the non-infected controls at day 10 PI （10 day-PI vs. control： ＋/＋： 2.75±0.17 vs. 0.42±0.09; Ws/Ws： 2.67±0.67 vs. 0.50±0.34; P 〈0.01）. In ＋/＋ rats, post-infection ACRS induced the formation of low-grade inflammation, represented by the imbalance of IL-1β and IL-10 （IL-1β： PI＋ACRS vs. control： （1812.24±561.61） vs. （1275.97±410.21） pg/g, P 〈0.05; IL-10： PI＋ACRS vs. control： （251.9±39.8） vs. （255.3±24.7） pg/g, P 〉0.05）, accompanied by hyperplasia and activation of mast cells （PI＋ACRS vs. control： 58.8±19.2 vs. 28.0±7.6; P 〈0.01）. The balance between acetylcholine （ACh） and substance P （SP） was also disturbed （ACh： PI＋ACRS vs. control： （743.94±238.72） vs. （1065.68±256.46） pg/g, P 〈0.05; SP： PI＋ACRS vs. control： （892.60±231.12） vs. （696.61±148.61） pg/g, P 〈0.05）. Nevertheless, similar changes of IL-1β/IL-10 and ACh/SP were not detected in Ws/Ws rats. Conclusion The imbalance of ACh/SP, together with the activation of mucosal immunity induced by post-infection ACRS were lacking in mast cell deficient rats, which supports the premise that mast cells play an important role in cholinergic and peptidergic remodeling in the ileum of rats.
