微波波谱法研究分子间相互作用

微波波谱是一种微波频段的波谱学方法,近年来在研究分子系统结构及分子间弱相互作用上发展迅速,是一种高分辨率和高灵敏度的分析工具. 本文介绍了它的原理及应用,尤其是对脉冲喷射傅里叶变换微波谱仪研究范德华力配合物、氢键配合物、弱氢键配合物、卤键配合物等弱相互作用体系的微波转动谱也作了简要的综述.      

有机分子激发态非线性吸收的瞬态特性研究

提出了一种通过测量单脉冲光的输入与输出波形来研究激发态非线性吸收的新方法，用这种方法研究了纳秒脉作用下类卟啉镉溶液与甲基橙溶液的三重激发态的非线性吸收特性，前者为反饱和吸收现象，后者是由饱和吸收转化为反饱和吸收的新现象，实验结果验证了理论模拟和正确性。     

Donor-Acceptor Conjugated Linear Polyenes: A Study of Excited State Intramolecular Charge Transfer,Photoisomerization and Fluorescence Probe Properties

Numerous studies of donor-acceptor conjugated linear polyenes have been carried out with the goal to understand the exact nature of the excited state electronic structure and dynamics. In this article we discuss our endeavours with regard to the excited state intramolecular charge transfer, photoisomerization and fluorescence probe properties of various donor-acceptor substituted compounds of diphenylpolyene [Ar(CH = CH) _n Ar] series and ethenylindoles.     

Archaeological Ceramics Studied by Scanning Electron Microscopy

The use of scanning electron microscopy combined with energy dispersive X-ray fluorescence analysis in studies of archaeological pottery is discussed. The methods are described and results of their application to studies of Precolumbian glossy black pottery from northern Peru are reported in some detail.     

Electron Capture Process in Collisions of Proton with Excited State of Helium

Total and star,selective cross sections for single electron capture （SEC） from the n = 2 excited state of helium colliding by protons are calculated in the energy range of 1.0-100.0 ke V/u by using the two-center atomic orbital close-coupling method. The interaction of the active electron with helium ion is represented by a model potential. Total SEC cross sections show a monotonic decreasing trend with increasing collision energy, and display a different behavior compared with the case from the ground state of helium. It is also found that the dominant reaction channel is captured to the H（2p） state up to 40 keV//u, and then the capture to the H（1s） or H（2s） state becomes more pronounced. Moreover, the alignment dependence on the initial states is obtained for the electron capture from He（2p0） and He （2p1）.     

远红外自由电子激光太赫兹光源研究

基于射频电子直线加速器的可调谐相干太赫兹(THZ)光源实现了出光，该光源为远红外自由电子激光，具有辐射波长可设计并可以实现大范围调谐特性．利用光栅谱仪测量了受激辐射谱，中心波长为115μm，谱宽约为1％．     

飞秒瞬态吸收光谱技术研究反式对氨基偶氮苯的超快激发态动力学 (cited: 1)

利用飞秒瞬态吸收光谱技术研究了反式对氨基偶氮苯(AAB)溶解在乙醇中的超快激发态动力学．当利用400 nm光激发分子到S₂态后,由S_{211102412相似文献}   

Terahertz Radiation from Graphite Excited by Femtosecond Laser Pulses

We experimentally investigate the terahertz （THz） generation from a graphite surface induced by femtosecond laser pulses, and systematically study the dependence on the excitation power, the crystal orientation of graphite, polarization state and incident angle of optical beam. New evidence related to excitation and detection geometry is found and presented, which supports the THz generation mechanism of transient photocarrier transporting along the basal plane normal. Our observation also suggests other probable contributions by in-plane charge oscillations. The results may be helpful to explore and understand the photoelectric properties of graphite and other allotropes of carbon.     

运用NMR研究白蛋白与脂肪酸的相互作用

脂肪酸在哺乳动物的能量代谢中发挥着至关重要的作用,同时也是合成细胞膜磷脂和其他生物活性化合物的重要物质.脂肪酸在血液中的溶解度很低,主要以与蛋白质结合状态存在,白蛋白是游离脂肪酸的主要运输者和储存者.因此,研究脂肪酸和白蛋白的相互作用具有非常重要的医学和生物学意义.本文主要利用基于核磁共振（NMR）的组氨酸选择性检测技术T₂W-RD-WaterLOGSY研究天然同位素丰度人血清白蛋白（HSA）与脂肪酸的相互作用,结果发现脂肪酸结合前后,HSA的特征组氨酸谱图变化明显,部分组氨酸信号的相对强度随脂肪酸浓度的增加而不断减小,相应的滴定曲线分析表明HSA表面有两个强的脂肪酸结合位点.此外,部分谱线的化学位移变化说明HSA和脂肪酸的强结合还会引发HSA相应的构象变化.     

Fluorescence of Certain Organic Dyes Excited by Helium-Neon Laser

Fluorescence from several organic dyes (methyl violet, neutral red, thymol blue, cresol red, methyl orange, and orcein) has been observed upon irradiation with the red line from a continuous wave helium-neon laser. The process appears to involve two-photon absorption as the excitation step.     

双过氧钒配合物与2-甲基咪唑相互作用的NMR研究

为探讨过氧钒配合物上有机配体对反应平衡的影响,在模拟生理条件下（0.15 mol/L NaCl溶液）应用多核（¹H, ¹³C, 和⁵¹V）多维（COSY和DOSY）NMR以及变温技术等谱学方法研究双过氧钒配合物[OV(O₂)₂L]^n- {n=1~3, L=oxalate （缩写为oxa）, picolinate（缩写为pic）, bipyridine（缩写为bipy）, 和1,10-phenanthroline（缩写为hen）,与它们配位的含钒物种分别缩写为bpV(oxa), bpV(pic), bpV(bipy)和bpV(phen)}与2-甲基咪唑（缩写为2-Me-Imi）的相互作用,实验结果表明2-Me-Imi与4种双过氧钒配合物的反应性从强到弱的顺序为：bpV(oxa)>bpV(pic)>bpV(bipy)>bpV(phen). 研究表明金属中心上配体的配位能力和空间位阻都对反应平衡产生较大的影响, 同时竞争配位的结果导致新的六配位的过氧物种[OV(O₂)₂(2-Me-Imi)]-的生成.     

Excited Two-Mode Generalized Squeezed Vacuum State as a Squeezed Two-Variable Hermite Polynomial Excitation State

A new class of excited two-mode generalized squeezed vacuum states denoted by |r,s,m,n〉 are presented, which are obtained by repeatedly applying creation operators a ^† and b ^† on the two-mode generalized squeezed vacuum state. We find that it is just regarded as a generalized squeezed two-variable Hermite polynomial excitation on the vacuum state and its normalization constant is just a Jacobi polynomial. Their statistical properties are investigated such as squeezing properties, photon number distribution and the violations of Cauchy-Schwartz inequality. Especially, the Wigner function for |r,s,m,n〉 depending on the excitation photon numbers is discussed graphically.     

Electron Impact Ionization Cross Section for Excited State of Ne like Ions in Detailed Configuration

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The Fate of Ions as Studied by Photoion-Photoelectron Coincidence

Photoion-photoelectron coincidence (PIPECO) is a technique for selecting the internal energy of ions and studying their subsequent reactions. Some of the results and their implication obtained from the study of unimolecular decay rates are discussed.     

Optically Forbidden Excitations of 2s Electron of Neon Studied by Fast Electron Impact

The electron energy loss spectrum in the energy region of 42-48.5 eV of neon is measured with an angle-resolved fast-electron energy-loss spectrometer at an incident electron energy of 2500eV. Besides the dipole-allowed autoionization transitions of 2s^-1ap （n -= 3, 4） and 2p^-23s3p, the dipole-forbidden ones of 2s^-1ns （n = 3 - 6） and 2s^-13d are observed. The line profile parameters, i.e. Er, F and q for these transitions, are determined, and the momentum transfer dependence behaviour is discussed.     

小鼠甲醇氧化应激的电子顺磁共振的研究

建立了小鼠甲醇中毒的氧化应激模型,研究了甲醇诱导小鼠产生氧化应激状态,探讨了大黄中草药和维生素C对小鼠甲醇氧化应激的保护作用. 模型小鼠共分为5个组：空白组、对照组、甲醇应激组、大黄组、维生素C（Vc）组. 利用电子自旋捕捉技术研究了小鼠甲醇氧化应激不同模型组小鼠体内的肝、肾、脾、心、肺和脑中产生的自由基强度的变化. 结果表明： 甲醇诱发了小鼠体内自由基的产生,甲醇组和生理盐水组相比,自由基的强度明显增强（显著性差异统计指标P<0.01);而大黄和Vc对小鼠甲醇氧化应激有保护作用,大黄组、Vc 组和甲醇组相比自由基的强度则明显降低（P<0.01).     

Inner Shell Excitations of Lithium Studied by Fast Electron Impact

Electron energy loss spectra for the inner shell excitations of atomic lithium are measured at an incident electron energy of 2500eV and scattering angles of 0^o, 2^o, 4^o and 6^o. Two optically forbidden transitions of （ls2s^2）^2S and （ ls2s ^3 S）3s^2 S are observed. The generalized oscillator strength ratios for ls（2s2p^3 P）2 P^0 to 1s（ 2s2p^1 P）2 P^0 were determined, and they are independent of the momentum transfer.     

Selective Photochemical Reaction of Ortho-Iodihe Molecules Excited by Laser Radiation

Results of an experimental study the reaction between electron-excited I₂-molecules and an olefine (2-hexene) are given. It is shown that the reaction proceed with excited I₂-molecules directly and it is highly selective. Selectivity of the reaction hes been studied primarily on the basis of binding of ortho-I₂ molecules. Laser separation of ortho-I₂ and para-I₂ molecules has been accomplished in the paper.