H+2，H+3团簇离子在沟道条件下的背散射 质子产额测量

采用卢瑟福背散射方法，测得了每质子能量为650 keV的H⁺₂，H+₃团簇离子在Si晶体<100>和<110>沟道条件下的质子背散射能谱.结果发现，由于H⁺₂，H⁺₃团簇在晶体中的库仑爆炸和团簇效应，H⁺₂的背散射质子产额大于H ⁺的背散射产额，而H^{+< 关键词： 团簇 沟道效应 库仑爆炸 背散射}     

H+2团簇与固体相互作用的Monte Carlo模拟

讨论了H+2团簇在物质中的作用过程, 包括库仑爆炸过程、尾流势的影响和与靶原子的近碰撞等. 开发成功了一套适用于不同靶材料的Monte Carlo模拟程序, 模拟计算了H+2通过碳膜后出射粒子的能谱和角分布, 并与实验结果进行了比较.     

H+4团簇离子和它的中性团簇产物H3

报道了关于H+4团簇的实验研究结果,从H+4的分解能谱发现可能存在H3团簇.分析讨论了H+4的形成方式和可能的分解途径.     

H+5团簇离子及其中性团簇产物H3和H4

报道了H+5的实验结果.分析讨论了H+5的形成和分解途径.根据理论分析,以稳定的H+3为核心与一个或多个氢分子结合可能形成稳定的H+n氢团簇离子.另一方面,在高频离子源中, 有发生H+3与H2反应的条件.实验中,从高频离子源引出的离子束被静电加速器加速,然后用90°磁分析器选择质量数为5的离子,再将这些离子偏转20°,最后在20°方向测量它们的能谱.从能谱发现,在高频离子源中可能通过H+3与H2的离子-分子反应形成了H+5团簇离子;并且在H+5的分解产物中还发现可能存在H3和H4等中性团簇产物.     

H+4, H+5和H+7团簇离子的测量和确认

报告了H+4, H+5, H+7等团簇离子的测量结果. 确认可以由H+3与一个或多个H和H2相互作用形成较大的H+4, H+5, H+7等团簇离子.     

C60团簇与稠密等离子体相互作用的数值模拟

采用球壳层模型研究了C60团簇与稠密等离子体的相互作用．假定离子团中离子之间的位置矢量的取向是随机的，在线性化的伏拉索夫一泊松理论框架下，借助于经典的等离子体介电函数，推导出C60离子团簇的自能和阻止本领的解析表达式．通过数值求解离子团半径变化的运动方程，研究了团簇的库仑爆炸过程，并讨论了入射速度、等离子体密度和电子温度对自能、阻止本领和库仑爆炸的影响．结果发现自能中的尾流效应降低了C60团簇离子的库仑爆炸速度，甚至可以稳定C60团簇的结构．     

一维氢原子团簇模型下的兆电子伏离子与库仑爆炸： 简化的数值模拟

本文使用一维双列氢原子团簇模型对强激光场中的团簇动力学过程进行了数值模拟。计算所得的质子最大动能和能谱均与他人的计算或实验结果符合较好,但计算大为简化。表明本文所述模型适用于氢原子团簇模拟。本文亦根据逸出质子数量随入射激光强度变化的规律总结出一个描述团簇库仑爆炸的光强阈值公式。     

C60团簇与稠密等离子体相互作用的数值模拟

采用球壳层模型研究了C60团簇与稠密等离子体的相互作用.假定离子团中离子之间的位置矢量的取向是随机的,在线性化的伏拉索夫-泊松理论框架下,借助于经典的等离子体介电函数,推导出C60离子团簇的自能和阻止本领的解析表达式.通过数值求解离子团半径变化的运动方程,研究了团簇的库仑爆炸过程,并讨论了入射速度、等离子体密度和电子温度对自能、阻止本领和库仑爆炸的影响.结果发现自能中的尾流效应降低了C60团簇离子的库仑爆炸速度,甚至可以稳定C60团簇的结构.     

H3+团簇离子的实验研究

报道了H+ 3 离子通过碳膜后 ,在其中产生的各种微量产物的测量结果 ,讨论了离子与碳膜作用中的电荷交换过程 ,分析了这些微量产物的形成机理 ,证明在产物的形成中电荷交换过程起关键作用 ,研究了离子与碳膜作用中的团簇效应和尾流效应. The yields of H -, H, H 2, H + 2 and H + 3 for H + 3 ions passing through carbon foils have been measured respectively.The results show that the charge exchange process in the interaction of Hydrogen ions with carbon foils plays a key role in the formation of these products. The cluster effects and wake effect of H + 2 and H + 3 ions in carbon foils are also discussed.     

C20离子团簇在氧化物中穿行时库仑爆炸过程的理论研究

本文研究了C20团簇在几种金属氧化物（Al2O3，SiO2）中穿行时发生的库仑爆炸过程，采用线性介电响应理论，并结合Memfin形式的介电函数，得到了团簇中各组成离子的空间感应势，其中组成团簇中各组成离子的电荷分布情况由Brandt-Kitagawa有效电荷理论模型来描述。通过求解运动方程得到离子团结构随时间的演化过程，并采用Monte Carlo方法模拟了爆炸过程中的多重散射现象。我们发现，尾流效应使团簇的空间结构和电荷分布呈现非对称性。     

H3+团簇离子与固体相互作用

报道了H3+团簇通过碳膜对产生的各种产物的测量结果.分析讨论了三原子离子团簇与固体相互作用中的电荷交换过程.证明在产物的形成中,电荷交换过程起关键作用.分析研究了H3+团簇与固体作用中的团簇效应和尾流效应. 关键词： H3+团簇 电荷交换 团簇效应 尾流效应     

H2+和HD+分子体系高次谐波发射效率的理论研究

本文通过求解一维含时薛定谔方程, 比较研究了H2+和HD+分子离子体系的高次谐波发射效率. 数值计算结果表明, 在相同激光条件下, 不对称分子体系能产生更高强度的谐波谱. 此外, 借助时频分布, 电离几率和电子-核波包密度概率分布图, 对计算结果做出了合理的解释.     

Collision-induced dissociation of H 3 + ions

For collision energies between 100 and 500 eV the collision induced dissociation of H ₃ ⁺ colliding with H₂, He and Kr gas targets was measured. We obtained total cross sections and angular distributions of the charged collision fragments for the main reaction channels. H ₃ ⁺ +H₂→H⁺+2H² and H ₃ ⁺ +H₂→H ₂ ⁺ +H₂+H. An analysis of the kinetics yields that the dissociation proceeds via vibrational-rotational excitation of H ₃ ⁺ by mutually induced dipolmoments.     

Study of magnetic interactions of the Fe2+ ions and the protons of crystallization water in FeSO4.n H2O hydrates

The paper deals with a study of interactions of protons in crystallization water of paramagnetic hydrates FeSO₄.n H₂O (wheren=1, 4, 5 and 7). The interaction of protons and paramagnetic ions Fe²⁺ and the nuclear dipole-dipole interaction of protons have been studied by means of the parameters expressing the dependence of the second moment of the proton nuclear magnetic resonance (NMR) spectrum on the external magnetic field, by means of the volume magnetic susceptibilities and the relaxation timesT ₁ of the investigated series of hydrates.We are grateful to Prof. Dr. hab. Z.Pajak, director of Department of Radiospectroscopy IF UAM in Poznan, and to his coworkers Dr. J.Kapturczak, Dr. K.Jurga, Dr. S.Glowinkowski and Mgr. F.Brych for facilitating our measurements mentioned in the paper as well as for a valuable discussion.     

Determination of the ground state energies of the H 2 + , D 2 + and H 2 + molecular ions taking into account relativistic corrections

On the basis of determination of the asymptotic behavior of correlation functions of the corresponding field currents with the corresponding quantum numbers an analytic method for determination of the energy spectrum of three-body Coulomb system is suggested. Our results show that the constituent masses of particles, which we have defined as masses of particles in a bound state, differ from masses of particles in a free-state. The constituent mass to the free state mass relation for the electron is greater than the same mass relation for the proton, deuteron and triton. It was also found that this constituent electron mass has different values in each systems, i.e. in H ₂ ⁺ , D ₂ ⁺ and T ₂ ⁺ hydrogen molecular ions. The contributions of exchange and self-energy diagrams were taken into account in the determination of the energy spectrum of the three-body Coulomb system. Our results show that the self-energy diagram contribution is inversely proportional to the square of the constituent mass of particles. This contribution is sufficient for the electron and is negligible for the proton, deuteron and triton. When defining the energy and the wave function (WF), it is necessary to take into account the contributions of both the exchange and self-energy diagrams.     

Collision-induced dissociation of H 2 + ions into the fragmentations H+H(2p) and H++H(2p)

Using a photon-particle delayed coincidence method the energy distributions of H +H(2p) and H⁺+H(2p) fragment pairs have been measured arising from collisional dissociation of 10 keV H ₂ ⁺ ions incident on various target gases. H fragments in their 2p state are identified by the Lymanα radiation emitted. The distribution of H+H(2p) fragment pairs arising from dissociative charge exchange reveals a sharp increase below 0.2 eV in the center-of-mass frame of the H ₂ ⁺ ion. This is ascribed to predissociation of vibrational levels of higher H₂ Rydberg states close above then=2 dissociation limit by those H₂ Rydberg states which separate into H+H(2p) fragments. Only direct transitions into the continuum of theGK ¹ ∑ _g ⁺ state may compete. Some structure at 0.3–0.5 eV is attributed to the three statesI ¹ П _g,i ³ П _g, andh ³ bE _g ⁺ having potential barriers of this height. The distributions for H⁺+H(2p) have maxima at 3.4, 3.8, and 4.2 eV for a H₂, Ar, and He target, respectively, indicating that the 2pπ _u state as well as the 3dσ _g state ofH ₂ ⁺ is excited. The H+H(2p) process has a greater probability than the H⁺+H(2p) process for Ar and H₂ targets, though all electronic H₂ states under consideration are bound.     

Kinematics of the reaction H2O+(H2,H)H3O+

The kinematics of the reaction H₂O⁺(H₂,H)H₃O⁺ were studied in crossed-beam experiments in the low collision-energy range 0.1–2 eV (c.m.). The scattering diagrams, center-of-mass angular distributions, and product relative translational energy distributions obtained show that the reaction proceeds predominantly by the impulsive, stripping mechanism. The translational exoergicity vs. collision energy plot obeys the spectator-stripping prediction.     

Measurement of the proton NMR field shift in aqueous solutions containing Cu2+, Cr3+, Fe3+ and Mn2+ ions

There are presented measurements of the NMR field shifts for aqueous protons in aqueous solutions containing paramagnetic inorganic compounds of Cu²⁺, Cr³⁺, Fe³⁺ and Mn²⁺ ions. The measurements have been performed on samples in the form of transversally magnetized long cylinders using both the internal and external NMR standards. The experimentally determined shifts are related to the NMR field position of protons in pure water. The results for demagnetizing shifts are compared with the data which were computed from the magnetic susceptibility values (measured by magnetostatic method), the chemical shifts are compared with the results of other authors. Results of measurements indicate a small chemical shift of internal standards in some solutions.     

Relaxation of solvent protons and deuterons by protein-bound Mn2+ ions. Theory and experiment for Mn2+-concanavalin A

Despite the demonstrated utility of measurements of the magnetic field dependence of the magnetic relaxation rates of solvent protons in solutions of metalloproteins as an indicator of biochemical changes, it is becoming increasingly evident that quantitative comparisons of such data with the theory of relaxation, limited by the approximations and assumptions usually made, yield results for the strength of the solvent-paramagnetic ion interaction that generally do not make chemical sense. These results, when expressed as the number of solvent-donated ligands of the ions, usually give too large a value, typically by about twofold. It has been suggested by several investigators that a comparison of proton and deuteron relaxation rates could resolve the problem. Data are presented for the longitudinal relaxation rates of solvent protons and deuterons over more than four decades of magnetic field (from 0.01 to 270 MHz proton Larmor frequency) for solutions of Mn²⁺-concanavalin A, a protein for which the physical biochemistry is thoroughly documented, one that should be particularly tractable for such comparisons. The main conclusion is that, in the general case, there is no decade of magnetic field over which the mathematical criterion of best agreement of data with theory can be relied upon to yield quantitatively correct biochemical results; rather, biochemistry must still be a guide for elucidating relaxation pathways.