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The Geometry, Vibrational Frequencies and Thermodynamic Properties of Naphthalene Based on ab initio Calculation
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作者 肖继梅 贡雪东 +1 位作者 肖鹤鸣 丘应楠 《分子科学学报》 CAS CSCD 1998年第3期50-55,共6页
采用abinitio方法,在HF/631G水平下计算了萘的几何构型和振动频率.计算所得几何构型和转动惯量与实验结果相符良好.计算所得振动频率平均比实验结果大9.5%左右;经校正(校正系数0.905)的计算频率与实... 采用abinitio方法,在HF/631G水平下计算了萘的几何构型和振动频率.计算所得几何构型和转动惯量与实验结果相符良好.计算所得振动频率平均比实验结果大9.5%左右;经校正(校正系数0.905)的计算频率与实验结果很接近.用校正后的频率计算所得不同温度下的热力学性质如标准熵、标准热容等与实验结果相吻合. 展开更多
关键词 abinitio法 分子几何构型 振动频率 热力学性质
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Investigation of analytical harmonic frequency and potential energy function, vibrational levels for the X^2∑^+ and A^2Л states of CN radical
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作者 Wang Jian-Kun Wu Zhen-Sen 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第8期2919-2924,共6页
This paper calculates the equilibrium structure and the potential energy functions of the ground state (X^2∑^+) and the low lying excited electronic state (A^2Л) of CN radical are calculated by using CASSCF met... This paper calculates the equilibrium structure and the potential energy functions of the ground state (X^2∑^+) and the low lying excited electronic state (A^2Л) of CN radical are calculated by using CASSCF method. The potential energy curves are obtained by a least square fitting to the modified Murrell-Sorbie function. On the basis of physical theory of potential energy function, harmonic frequency (ωe) and other spectroscopic constants (ωeχe, βe and αe) are calculated by employing the Rydberg-Klei-Rees method. The theoretical calculation results are in excellent agreement with the experimental and other complicated theoretical calculation data. In addition, the eigenvalues of vibrational levels have been calculated by solving the radial one-dimensional SchrSdinger equation of nuclear motion using the algebraic method based on the analytical potential energy function. 展开更多
关键词 potential energy function harmonic frequency vibrational levels algebraic method
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Ab Initio Calculations on Nitramide and Its Methyl Derivatives( Ⅱ )——The Harmonic Force Fields and Vibrational Spectra of Nitramide and Its Isotopic Derivatives
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作者 FAN Kang-nian and WANG Wen-ning (Department of Chemistry, Fudan University, Shanghai, 200433)XTAO He-ming and LI Yong-fu (Department of Chemistry, East China Institute of Technology, Nanjing, 210014) 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 1992年第4期415-421,共7页
The harmonic force field and the vibrational spectrum of nitramide were calculated by using the ab initio gradient program TEXAS at the Hartree-Fock level with a 4-21G basis set. The directly computed theoretical harm... The harmonic force field and the vibrational spectrum of nitramide were calculated by using the ab initio gradient program TEXAS at the Hartree-Fock level with a 4-21G basis set. The directly computed theoretical harmonic force field was scaled by using empirical scale factors which are transferred from other molecules and provided an a priori prediction of fundamental frequencies and intensities. The average deviations between predicted vibrational frequencies of nitramide and experimental IR spectrum in an argon matrix are 63 cm-1 for symmetric vibrations and 41 cm-1 for antisymmetric modes. A new set of scale factors was optimized in this paper. These scale factors reduced the average deviations to 2. 3 cm-1 for symmetric modes and 0. 8 cm-1 for antisymmetric ones. The vibrational spectra of three isotopic derivatives of nitramide were predicted by using the force field resulted from the optimized set of scale factors, which are in good agreement with their experimental data in an argon matrix. 展开更多
关键词 Nitramide harmonic force field vibrational spectrum
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Geometrical structures, vibrational frequencies, force constants and dissociation energies of isotopic water molecules (H_2O, HDO, D_2O, HTO, DTO, and T_2O) under dipole electric field
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作者 史顺平 张全 +4 位作者 张莉 王蓉 朱正和 蒋刚 傅依备 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第6期174-181,共8页
The dissociation limits of isotopic water molecules are derived for the ground state. The equilibrium geometries, the vibrational frequencies, the force constants and the dissociation energies for the ground states of... The dissociation limits of isotopic water molecules are derived for the ground state. The equilibrium geometries, the vibrational frequencies, the force constants and the dissociation energies for the ground states of all isotopic water molecules under the dipole electric fields from -0.05 a.u. to 0.05 a.u. are calculated using B3P86/6-311++G(3df,3pf). The results show that when the dipole electric fields change from -0.05 a.u. to 0.05 a.u., the bond length of H-O increases whereas the bond angle of H-O H decreases because of the charge transfer induced by the applied dipole electric field. The vibrational frequencies and the force constants of isotopic water molecules change under the influence of the strong external torque. The dissociation energies increase when the dipole electric fields change from -0.05 a.u. to 0.05 a.u. and the increased dissociation energies are in the order of H2O, HDO, HTO, D2O, DTO, and T2O under the same external electric fields. 展开更多
关键词 isotopic water molecules equilibrium geometry vibrational frequencies force constants dissociation energies
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Structures,Electron Affinities and Vibrational Frequencies of SF_5OX/SF_5OX^-(X=F,Cl,Br)
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作者 程素珍 徐文国 卢士香 《Journal of Beijing Institute of Technology》 EI CAS 2009年第3期333-338,共6页
The molecular structures,electron affinities,vibrational frequencies and IR intensities of the SF5OX/SF5OX-(X=F,Cl,Br)species have been determined by four different density functional theory(DFT)methods(B3LYP,BHL... The molecular structures,electron affinities,vibrational frequencies and IR intensities of the SF5OX/SF5OX-(X=F,Cl,Br)species have been determined by four different density functional theory(DFT)methods(B3LYP,BHLYP,BP86,BLYP)in conjunction with DZP++ basis set.The BHLYP method predicts the best geometry parameters.The adiabatic electron affinities(EAad)predicted by the B3LYP/DZP++ method are 4.36 eV(SF5OF),4.13 eV(SF5OCl),4.12 eV(SF5OBr),respectively.Large electron affinity implies the corresponding anions are stable.The total intensities in the near IR "window" of the anions SF5OX-(X=F,Cl,Br)at B3LYP level are 1 602 km/mol(SF5OF-),1 868 km/mol(SF5OCl-)and 1 916 km/mol(SF5OBr-),respectively,larger than those of the corresponding neutrals.It suggests that SF5OX/SF5OX-(X=F,Cl,Br)may be used to "warm" Mars. 展开更多
关键词 electron affinity density functional theory (DFT) vibrational frequency
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Theoretical Analysis on the Vibrational Resonance in Two Coupled Overdamped Anharmonic Oscillators
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作者 FANG Ci-Jun LIU Xian-Bin 《Chinese Physics Letters》 SCIE CAS CSCD 2012年第5期56-58,共3页
Under both low- and high-frequency signals,the phenomenon of vibrational resonance in two coupled overdamped anharmonic oscillators with time delay feedback is investigated.By separating the slow and fast motions,the ... Under both low- and high-frequency signals,the phenomenon of vibrational resonance in two coupled overdamped anharmonic oscillators with time delay feedback is investigated.By separating the slow and fast motions,the approximate solution of the response amplitude of the coupled oscillators is obtained,and the analytical results are in good agreement with the numerical ones.In the delay-free systems,the traditional vibrational resonance is presented,and in the delayed systems,the delay-induced periodic pattern of the vibrational resonance profile with respect to the delay parameter is revealed. 展开更多
关键词 vibrational DELAY harmonic
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Vibrational Resonance in Fractional-Order Anharmonic Oscillators
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作者 YANG Jian-Hua 《Chinese Physics Letters》 SCIE CAS CSCD 2012年第10期97-100,共4页
The phenomenon of vibrational resonance in fractional-order anharmonic oscillators is investigated.Based on the method of separating slow and fast motions,the approximate solution of the response amplitude is obtained... The phenomenon of vibrational resonance in fractional-order anharmonic oscillators is investigated.Based on the method of separating slow and fast motions,the approximate solution of the response amplitude is obtained.Both analytical and numerical results show that not only the high-frequency signal but also the fractional-order damping can induce vibrational resonance.The present results provide a new way to control periodical signals in coupled systems. 展开更多
关键词 harmonic vibrational FRACTIONAL
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High-order harmonic generation of CO_2 with different vibrational modes in an intense laser field
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作者 杜慧 张宏丹 +4 位作者 张军 刘海凤 潘雪飞 郭静 刘学深 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第11期199-203,共5页
We apply the strong-field Lewenstein model to demonstrate the high-order harmonic generation of CO2 with three vibrational modes(balance vibration,bending vibration,and stretching vibration) driven by an intense las... We apply the strong-field Lewenstein model to demonstrate the high-order harmonic generation of CO2 with three vibrational modes(balance vibration,bending vibration,and stretching vibration) driven by an intense laser field.The results show that the intensity of harmonic spectra is sensitive to molecular vibrational modes,and the high harmonic efficiency with stretching vibrational mode is the strongest.The underlying physical mechanism of the harmonic emission can be well explained by the corresponding ionization yield and the time-frequency analysis.Finally,we demonstrate the attosecond pulse generation with different vibrational modes and an isolated attosecond pulse with a duration of about 112 as is generated. 展开更多
关键词 vibrational harmonic intense stretching ionization orbital explained occupied bending tunneling
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Studies of structure,vibrational frequencies and thermodynamics of UF_6
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作者 LUChun-Hai SUNYing +1 位作者 CHENWen-Kai QIUShao-Yu 《Nuclear Science and Techniques》 SCIE CAS CSCD 2005年第3期145-148,共4页
After molecular structure of UF6 is optimized,molecular vibrational frequencies are calculated by LDA and GGA approaches. Some thermodynamic parameters are calculated based on the principle of statistic mechanics. Var... After molecular structure of UF6 is optimized,molecular vibrational frequencies are calculated by LDA and GGA approaches. Some thermodynamic parameters are calculated based on the principle of statistic mechanics. Various functionals such as PWC,VWN,VWNPB,PW91,BP,PBE,RPBE,BOP with various basis sets such as MIN,DN,DND and DNP are used. The small basis sets,MIN and DN,can arrive at self-consistency. DMol3 can save more CPU’s time and resource than all electron calculations including Hartree-Fock and DFT with Gaussian code,so it should be introduced in some research,especially on compounds of lanthanide and actinide. However,comparing with the results from classical DFT,the new calculation may accompany a rather large error. 展开更多
关键词 热力学参数 六氟铀 分子结构 变化序列
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Ab initio potential energy surface and anharmonic vibration spectrum of NF_(3)^(+)
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作者 陈艳南 徐建刚 +3 位作者 范江鹏 马双雄 郭甜 张云光 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期327-333,共7页
Potential energy surfaces(PESs), vibrational frequencies, and infrared spectra are calculated for NF_(3)^(+) using ab initio calculations, based on UCCSD(T)/cc-p VTZ combined with vibrational configuration interaction... Potential energy surfaces(PESs), vibrational frequencies, and infrared spectra are calculated for NF_(3)^(+) using ab initio calculations, based on UCCSD(T)/cc-p VTZ combined with vibrational configuration interaction(VCI). Based on an iterative algorithm, the surfaces(SURF) program adds automatic points to the lattice representation of the potential function, the one-dimensional and two-dimensional PESs are calculated after reaching a convergence threshold, finally the smooth image of the potential energy surface is fitted. The PESs accurately account for the interaction between the different modes, with the mode q_(6) symmetrical stretching vibrations having the greatest effect on the potential energy change of the whole system throughout the potential energy surface shift. The anharmonic frequencies are obtained when the VCI matrix is diagonalized. Fundamental frequencies, overtones, and combination bands of NF_(3)^(+) are calculated, which generate the degenerate phenomenon between their frequencies. Finally, the calculated anharmonic frequency is used to plot the infrared spectra.Modal antisymmetric stretching ν_(5) and symmetric stretching ν_(6) exhibit a phenomenon of large-intensity borrowing. This study can provide data to support the characterization in the laboratory. 展开更多
关键词 ab initio methods potential energy surfaces vibration frequencies coupled resonance infrared spectra
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Remote Control of Bovine Catalase Activity with Specific Frequencies of Human and Bovine Catalase with and without Bound NADP+
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作者 Thibaud Etienne d’Oultremont 《Advances in Enzyme Research》 CAS 2024年第2期17-34,共18页
Remote control enzyme technology is widely used today through resonance. In this study, we showed that the use of frequencies of the catalase enzyme itself to increase enzymatic rate is successful not only in test tub... Remote control enzyme technology is widely used today through resonance. In this study, we showed that the use of frequencies of the catalase enzyme itself to increase enzymatic rate is successful not only in test tubes but also remotely. The present study also suggests that, under optimal temperature, the use of bovine catalase frequency (the specific frequency of that enzyme) has a superior rate promoting vibration than the human catalase frequency, and so increases very significantly the chemical rate of bovine catalase (about 120% at 40˚C). It also suggests that bovine catalase subjected to bovine and human frequencies with catalase bound NADP+ experienced more resonance weight towards NADP+ and so were more slowly reduced back to catalase bound NADPH, increasing compound II formation rate, and slowing down the catalase activity rate. 展开更多
关键词 Remote Control CATALASE Frequency Rate Promoting Vibration (RPV) NADP
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高架桥车辆行驶引起的环境振动研究
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作者 万曦 代剑英 吴芳 《山西建筑》 2025年第2期154-157,共4页
随着高科技产业的快速发展,对精密工程结构中产品质量的要求日益提高,其中微振动控制成为关键因素。针对西安某微电子厂房建设项目,考虑到周边高速公路高架桥对拟建场地可能产生的微振动影响,进行了详细的现场测试与分析。通过布置测点... 随着高科技产业的快速发展,对精密工程结构中产品质量的要求日益提高,其中微振动控制成为关键因素。针对西安某微电子厂房建设项目,考虑到周边高速公路高架桥对拟建场地可能产生的微振动影响,进行了详细的现场测试与分析。通过布置测点,采用高灵敏度振动传感器和数据采集系统,记录了南北、东西和垂直方向的振动速度。测试结果表明,高速公路高架桥的微振动水平处于VC-D—VC-C之间,可为芯片厂房的选址和隔振设计提供科学依据,对类似精密工程结构的防微振设计具有参考意义。 展开更多
关键词 隔振设计 微振动 频域分析 数据采集
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掺杂对单层石墨烯纳米梁振动频率的影响
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作者 王志钦 王静 《原子与分子物理学报》 CAS 北大核心 2025年第3期67-71,共5页
石墨烯优异的力学和电学等性能,使其成为纳米机电谐振器的理想材料.通过分子动力学模拟方法研究了掺杂元素和掺杂浓度对单层石墨烯纳米梁振动特性的影响.研究结果表明,单层石墨烯纳米梁的振动频率随纳米梁长度的增加而减小,硼(B)掺杂、... 石墨烯优异的力学和电学等性能,使其成为纳米机电谐振器的理想材料.通过分子动力学模拟方法研究了掺杂元素和掺杂浓度对单层石墨烯纳米梁振动特性的影响.研究结果表明,单层石墨烯纳米梁的振动频率随纳米梁长度的增加而减小,硼(B)掺杂、硼-硼(B-B)掺杂、铍(Be)掺杂和铍-铍(Be-Be)掺杂均会导致单层石墨烯纳米梁的振动频率降低.此外,随着硼(B)/铍(Be)掺杂浓度的增加,单层石墨烯纳米梁的振动频率逐渐降低.且随着掺杂浓度的增加,硼(B)掺杂石墨烯纳米梁的振动频率和铍(Be)掺杂石墨烯纳米梁的振动频率的差异逐渐增大.这对石墨烯纳米机械谐振器、振荡器等纳米器件的设计具有一定的理论指导意义. 展开更多
关键词 石墨烯 振动频率 分子动力学
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缺陷对单层硅烯纳米梁振动频率的影响
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作者 张文博 王静 《原子与分子物理学报》 CAS 北大核心 2025年第6期76-82,共7页
由于硅纳米谐振器在量子计算、传感器、医学等方面存在广泛的应用,使其物理性质的研究具有重要意义.本文通过分子动力学模拟方法研究了掺杂元素、空位缺陷、掺杂浓度对单层硅烯纳米梁振动特性的影响.研究结果表明,单层硅烯纳米梁的振动... 由于硅纳米谐振器在量子计算、传感器、医学等方面存在广泛的应用,使其物理性质的研究具有重要意义.本文通过分子动力学模拟方法研究了掺杂元素、空位缺陷、掺杂浓度对单层硅烯纳米梁振动特性的影响.研究结果表明,单层硅烯纳米梁的振动频率随着纳米梁长度的增加而减小.单元素、双元素掺杂均会导致单层硅烯纳米梁的振动频率的增加,且随着掺杂浓度的增加纳米梁的振动频率整体呈现增大的趋势.此外,单空位缺陷会导致单层硅烯纳米梁的振动频率随着缺陷浓度的增加而减小.掺杂-单空位缺陷的单层硅烯纳米梁的振动频率则呈现了随着掺杂浓度的增加先减小后增加的变化趋势.这些变化规律均是由掺杂元素、空位缺陷以及它们共同作用的结果.此研究结果对硅烯纳米谐振器,振荡器等纳米器件的设计具有一定的理论指导意义. 展开更多
关键词 硅烯 掺杂 振动频率 分子动力学
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Structure, Stability and Vibrational Spectra of LaC_5~n(n=-1,0,+1) Clusters
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作者 武志坚 孟庆波 张思远 《分子科学学报》 CAS CSCD 1998年第1期20-24,共5页
用密度泛含方法研究了LaC5n(n=-1,0,+1)分子簇的结构和稳定性及振动光谱,对这个六原子体系提出了三种可能构型,点群结构为C2v对称性.第一个构型为La接在弯曲的C5链上,第二个是La通过二个键与C5环相连... 用密度泛含方法研究了LaC5n(n=-1,0,+1)分子簇的结构和稳定性及振动光谱,对这个六原子体系提出了三种可能构型,点群结构为C2v对称性.第一个构型为La接在弯曲的C5链上,第二个是La通过二个键与C5环相连第三个是La通过一个键与C5环相连;结果表明,第一个构型即当La接在弯曲的C5链上时能量最低.振动光谱分析指出,当n=-1时,第二个构型为局域极小值;当n=+1时,第一个和第二个构型为局域极小值;对n=0,局域极小值没有找到. 展开更多
关键词 LaC5n 结构 稳定性 振动光谱 密度泛含方法 Gausian92/dft
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Methanol Perturbing Modeling Cell Membranes Investigated using Linear and Nonlinear Vibrational Spectroscopy 被引量:1
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作者 田康振 李红春 叶树集 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2013年第1期27-34,I0003,共9页
Cell membranes play a crucial role in many biological functions of cells. A small change in the composition of cell membranes can strongly influence the functions of membrane-associated proteins, such as ion and water... Cell membranes play a crucial role in many biological functions of cells. A small change in the composition of cell membranes can strongly influence the functions of membrane-associated proteins, such as ion and water channels, and thus mediate the chemical and physical balance in cells. Such composition change could originate from the introduction of short-chain alcohols, or other anesthetics into membranes. In this work, we have applied sum frequency generation vibrational spectroscopy (SFG-VS), supplemented by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), to investigate interaction between methanol and 1,2-dimyristoyl-d54-sn-glycero-3-phosphocholine (d54-DMPC) lipid bilayers. Lipid's hydrocarbon interior is deuterated while its head group is hydrogenated. At the same time, CH3 symmetric stretch from methanol and lipid head amine group has different frequency, thus we can distinguish the behaviors of methanol, lipid head amine group, and lipid hydrocarbon interior. Based on the spectral feature of the bending mode of the water molecules replaced by methanol, we determined that the methanol molecules are intercalated into the region between amine and phosphate groups at the lipid hydrophilic head. The dipole of CH3 groups of methanol and lipid head, and the water O-H M1 adopt the same orientation directions. The introduction of methanol into the lipid hydrophilic head group can strongly perturb the entire length of the alkyl chains, resulting that the signals of CD2 and CD3 groups from both leaflets can not cancel each other. 展开更多
关键词 Sum frequency generation vibrational spectroscopy Cell membrane METHANOL INTERACTION MECHANISM
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Effect of vehicle weight on natural frequencies of bridges measured from traffic-induced vibration 被引量:16
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作者 Chul-Young Kim Dae-Sung Jung +2 位作者 Nam-Sik Kim Soon-Duck Kwon Maria Q.Feng 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2003年第1期109-116,共8页
Recently,ambient vibration test(AVT)is widely used tu estimate dynamic characteristics of large civil struc- tures.Dynamic characteristics ean be affected by various envirnnmental factors such as humidity,intensity of... Recently,ambient vibration test(AVT)is widely used tu estimate dynamic characteristics of large civil struc- tures.Dynamic characteristics ean be affected by various envirnnmental factors such as humidity,intensity of wind,and temperature.Besides these environmental conditions,tire mass of vehicles may change the measured valnes when traffic-in- duced vibration is used as a source of AVT tor bridges.The effect of vehicle mass on dynamic characteristics is investigated through traffic-induced vibration tests on three bridges;(1)three-span suspension bridge(128m+404m+128m),(2) five-span continuous steel box girder bridge(59m+3@ 95m+59m),(3)simply supported plate girder bridge(46m). Acceleration histories of each measurement location under normal traffic are recorded for 30 minutes at field.These recor- ded histories are divided into individual vibrations and are combined into two groups aceording to the level of vibration;one by heavy vehicles such as trucks and buses and the other by light vehicles such as passenger cars.Separate processing of the two groups of signals shows that,for the middle and long-span bridges,the difference can be hardly detected,but,for the short span bridges whose mass is relatively small,the measured natural frequencies can change up to 5.4%. 展开更多
关键词 ambient vibration test traffic induced vibration vehicle mass suspension bridge short-span bridge dynamic characteristics natural frequency
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Investigation of Microstructure, Natural Frequencies and Vibration Modes of Dragonfly Wing 被引量:14
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作者 H. Rajabi M. Moghadami A. Darvizeh 《Journal of Bionic Engineering》 SCIE EI CSCD 2011年第2期165-173,共9页
In the present work, a thorough investigation on the microstructural and morphological aspects of dragonfly wings was carried out using scanning electron microscope. Then, based on this study and the previous reports,... In the present work, a thorough investigation on the microstructural and morphological aspects of dragonfly wings was carried out using scanning electron microscope. Then, based on this study and the previous reports, a precise three-dimensional numerical model was developed and natural frequencies and vibration modes of dragonfly forewing were determined by finite element method. The results shown that dragonfly wings are made of a series of adaptive materials, which form a very complex composite structure. This bio-composite fabrication has some unique features and potential benefits. Furthermore, the numerical results show that the first natural frequency of dragonfly wings is about 168 Hz and bending is the predominant deformation mode in this stage. The accuracy of the present analysis is verified by comparison of calculated results with experimental data. This paper may be helpful for micro aerial vehicle design concerning dynamic response. 展开更多
关键词 insect wing natural frequency vibration mode SEM finite element method
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Laser Linewidth and Spectral Resolution in Infrared Scanning Sum Frequency Generation Vibrational Spectroscopy System
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作者 魏锋 夏文秀 +3 位作者 胡中进 李雯慧 张纪英 郑万泉 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2016年第2期171-178,I0001,共9页
Sum frequency generation vibrational spectroscopy (SFG-VS) is a robust technique for inter- facial investigation at molecular level. The performance of SFG-VS mostly depends on the spectral resolution of the SFG sys... Sum frequency generation vibrational spectroscopy (SFG-VS) is a robust technique for inter- facial investigation at molecular level. The performance of SFG-VS mostly depends on the spectral resolution of the SFG system. In this research, a simplified function was deduced to calculate the spectral resolution of picosecond SFG system and the lineshape of SFG spectra based on the Guassian shaped functions of IR beam and visible beam. The function indicates that the lineshpe of SFG spectra from nonresonant samples can be calculated by the Guassian widths of both IR beam and visible beam. And the Voigt lineshape of SFG spectra from vibrational resonant samples can be calculated by the Homogeneous broadening (Lorentzian width) and Inhomogeneous broadening (Guassian width) of vibrational modes, as well as the Guassian widths of both IR beam and visible beam. Such functions were also applied to verify the spectral resolution of the polarization-resolved and frequency-resolved picosecond SFG-VS system which was developed by our group recently. It is shown that the linewidths of IR beams that generated from current laser system are about 1.5 cm-1. The calculated spectral resolution of current picosecond IR scanning SFG-VS system is about 4.6 cm-1, which is consist with he spctral resolution shown in the spectra of cholesterol monolayer (3.5-5 cm-1). 展开更多
关键词 Lineshape calculation Sum frequency generation vibrational spectra Spectralresolution
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Tuning control system of a third harmonic superconducting cavity in the Shanghai Synchrotron Radiation Facility 被引量:4
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作者 Peng-Peng Gong Yu-Bin Zhao +6 位作者 Hong-Tao Hou Zhi-Gang Zhang Xiang Zheng Xiao-Yun Pu Kai Xu Qiang Chang Jian-Fei Liu 《Nuclear Science and Techniques》 SCIE CAS CSCD 2019年第10期123-132,共10页
Beam lifetime is dominated by Touschek scattering at the Shanghai Synchrotron Radiation Facility(SSRF).Touschek loss rate is affected by probability for scattering beyond the RF acceptance and the volume charge densit... Beam lifetime is dominated by Touschek scattering at the Shanghai Synchrotron Radiation Facility(SSRF).Touschek loss rate is affected by probability for scattering beyond the RF acceptance and the volume charge density of the bench.In the phaseⅡupgrade of the SSRF,a third harmonic superconducting cavity will be used to enhance the Touschek lifetime by lengthening the bunches.The Touschek lifetime improvement factor is affected by the voltage of a harmonic cavity.To stabilize the cavity voltage,a tuning control system was designed to control it.The design of the tuning control system was based on the SSRF third-generation low-level RF control system.Some hardware and specialized algorithms were redesigned to fit the harmonic cavity control.The design of the tuning control system is complete,and the control system has been tested.The test result shows that the fluctuation of amplitude is<±0.34%within 1.5 h,which satisfies the stability requirement. 展开更多
关键词 Passive harmonic CAVITY Low-level radio frequency SHANGHAI SYNCHROTRON Radiation Facility Touschek LIFETIME
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