Absolute partial and total ionization cross sections of carbon monoxide with electron collision from 350 eV to 8000 eV

The absolute partial and total cross sections for electron impact ionization of carbon monoxide are reported for electron energies from 350 eV to 8000 eV.The product ions(CO^(+),C^(+),O^(+),CO^(2+),C^(2+),and O^(2+))are measured by employing an ion imaging mass spectrometer and two ion-pair dissociation channels(C^(+)+O^(+)and C^(2+)+O^(+))are identified.The absolute cross sections for producing individual ions and their total,as well as for the ion-pair dissociation channels are obtained by normalizing the data of CO^(+)to that of Ar^(+)from CO-Ar mixture target with a fixed 1:1 ratio.The overall errors are evaluated by considering various kinds of uncertainties.A comprehensive comparison is made with the available data,which shows a good agreement with each other over the energy ranges that are overlapped.This work presents new cross-section data with electron energies above 1000 eV.

Preliminary Measurement of the K-Shell Ionization Cross Sections of Ti by Positron Impact in the Low Energy Region

Measurements were performed of K-shell ionization cross sections of Ti element by 10～30 keV positron impact using the thick-target method. The effects of multiple scattering of incident positron and from bremsstrahlung photons and annihilation photons with the thick-target method are discussed with the Monte Carlo code PENELOPE. Meanwhile, the Monte Carlo method is also applied to determine the detection efficiencies of X- and γ-ray detectors. Our experimental K-shell ionization cross sections for Ti element are compared with the distorted-wave Born approximation （DWBA） theoretical predictions, and it is found that the agreement of the experimental data and theoretical values is good and this indicates that the experimental method adopted in this study is applicable.

双哌嗪盐类化合物电子轰击离子化质谱研究（STUDY ON BIS—PIPERAZINIUM SALTS（M2＋2Br-2HCI） BY ELECTRON IMPACT IONIZATION MASS SPECTROMETRY）

Electron impact ionization mass spectra of six new synthetic bis-piperazinium salts (M2+ 2Br-2HC1) with anti-tumor activities were obtained. Although the M+ ions and double charge ions M2+ were notobserved in E1 mass spectra, some strange ions such as [M-2]+ ions,[M-R]+ ions , [M-R-l]+ ions, [M-2R]+ ions and even [RX]+ ions presented in EIMS by decreasing the electron energy. These phenomena may be explained as R+ rearrangement and intermolecular reaction occurring in the condensed phase. We tried to describe the main routes of fragmentation and high sensitive mass spectra of the fragments oaboutthese compounds.

Mass Spectrometric Fragmentation of 1-(Benzyloxycarbonyl)amino-2-alkyl/cycloalkyl Thioacetates:a Thioester Pyrolysis-type Rearrangement under Electron Impact Ionization

The mass spectrometric fragmentation of 1-（benzyloxycarbonyl）amino-2-alkyl/cycloalkyl thioacetates has been studied with the aid of mass-analysed ion kinetic energy spectrometry under electron impact ionization. All compounds show a tendency to eliminate a ketene, thioacetic acid, and benzyl carbamate molecule, or an acetyl and benzyloxy radicals. A thioester pyrolysis-type rearrangement under electron impact ionizations was observed.

Laser Induced Photoelectron Impact Ionization In Multiphoton Ionization Process

Multiply charged ions of Ar and NO were observed in MPI experiment Of NO/Ar with TOF-MS. A delayable pulsed acceleration field wn applied tO investigate the effect of the photoelectrons on the formation of the multiply charged ions. The multiply charged ions were suggested to be produced by photoelectron impact ionization, in the region bentween the extractor grid and the repeller plate, step by step, from neutral species and lower charged ions. The 50-60ns of FWHM of the ion peaks implies that the pulse width of the photoelectrons should be shorter considering the broadening effect during the ionization process.

Calculated cross sections for the single ionization of atoms (N, Cu, As, Se, Sn, Sb, Te, I, Pb) by electron impact

By correcting some primary parameters in the semi-classical Deutsch-Mark （DM） formula, this paper calculates the absolute single electron-impact ionization cross sections of atoms N, Cu, As, Se, Sn, Sb, Te, I and Pb from threshold to 10000 eV. The calculated cross sections are compared with available experimental data and other theoretical results. An excellent agreement was achieved between the calculated and measured cross sections for these atoms over a wide range of impact energies.

Theoretical analysis on fully differential cross sections for C^(6+)impact ionization of helium

Fully differential cross sections （FDCS） are calculated within a four-body model for single ionization of helium by C6＋ impact at the incident energy of 100 MeV/a.u. （atomic unit）. The results are compared with experimental data and other theoretical predictions. It is shown that our results are in very good agreement with experiment for three small momentum transfers in the scattering plane; however, some significant discrepancies are still present at the largest momentum transfer in both the scattering plane and the perpendicular plane. In actuality, the problem has not been explained by the theory during the last decade. Accordingly, the contributions of different scattering amplitudes to FDCS are analyzed. It is found that for the largest momentum transfer the cross section arising from a destructive interference of the three amplitudes is much smaller than the experimental data. However, the cross section due to the constructive interference of two scattering amplitudes between projectile-ionized electron interaction and projectile-passive electron interaction almost approaches the experimental data.

Measurement of 8～25keV electron impact K－shell ionization cross sections of Cu and Co elements

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Cluster-assisted generation of multi-charged ions in nanosecond laser ionization of pulsed hydrogen sulfide beam at 1064 and 532 nm

The multi-charged sulfur ions of Sq^＋ （q ≤ 6） have been generated when hydrogen sulfide cluster beams are irradiated by a nanosecond laser of 1064 and 532 nm with an intensity of 10^10- 10^12W.cm^-2. S^6＋ is the dominant multicharged species at 1064 nm, while S^4＋, S^3＋ and S^2＋ ions are the main multi-charged species at 532 nm. A three-step model （i.e., multiphoton ionization triggering, inverse bremsstrahlung heating, electron collision ionizing） is proposed to explain the generation of these multi-charged ions at the laser intensity stated above. The high ionization level of the clusters and the increasing charge state of the ion products with increasing laser wavelength are supposed mainly due to the rate-limiting step, i.e., electron heating by absorption energy from the laser field via inverse bremsstrahlung, which is proportional to λ2,λA being the laser wavelength.

Fully differential cross sections for C^(6+) single ionization of helium

The three-Coulomb-wave （3C） model is applied to study the single ionization of helium by 2 MeV/amu C6＋ impact. Fully differential cross sections （FDCS） are calculated in the scattering plane and the results are compared with experimental data and other theoretical predictions. It is shown that the 3C results of the recoil peak are in very good agreement with experimental observations, and variation of the position of the binary peak with increasing momentum transfer also conforms better to the experimental results. Furthermore, the contributions of different scat- tering amplitudes are discussed. It turns out that the cross sections are strongly influenced by the interference of these amplitudes.

Relative phase effect of nonsequential double ionization in Ar by two-color elliptically polarized laser field

We investigated the nonsequential double ionization(NSDI)in Ar by two-color elliptically polarized laser field with a three-dimensional(3D)classical ensemble method.We study the relative phase effect of NSDI and distinguish two particular recollision channels in NSDI,which are recollision–impact ionization(RII)and recollision-induced excitation with subsequent ionization(RESI),according to the delay-time between the recollision and the final double ionization.The numerical results indicate that the ion momentum distribution is changed and the triangle structure is more obvious with the decrease of the relative phase.We also demonstrate that the RESI process always dominates in the whole double ionization process and the ratio of RESI and RII channels can be influenced by the relative phase.

Electron-impact single ionizaiton for W^(4+) and W^(5+)

Electron-impact single ionization cross sections for W^q＋（q = 4–5） were calculated using the flexible atomic code（FAC） in the level-to-level distorted-wave method, considering the explicit branching ratio. The calculated cross sections are compared with the available theoretical and experiment results in detail. In the case of the contribution from the same channles as the available theoretical results, all of the calculated ionization cross sections agree with the experimental measured cross sections. But the present calculated results are larger than the experimental measurement when all channels contributions are included. Some important channels excitation autoionization（EA） contributions, such as the excitation to higher higher nl subshell from 4 f and 5[s,p], were not included into the available theoretical calculation. In general, the distorted-wave（DW） results are overestimated.

Theoretical Analysis on Fully Differential Cross-Sections for C^6＋ Single Ionization of Helium

四身体的模型被用来在几何学由 100 兆电子伏 / 原子量 C6+ 影响为氦的单个电离计算充分微分的剖面图(FDCS ) 。由与试验性的数据和另外的理论作比较，我们发现四身体的模型的结果从散布飞机在在散布飞机，而是差的同意的很好的同意。因此，到 FDCS 的不同散布振幅的贡献被分析。生气的节几乎在几何学在 recoil 区域附近由于在射弹目标原子核相互作用和逐出射弹的电子相互作用之间的散布振幅的干扰趋于到试验性的结果，这被发现。特别地在垂直飞机，从在射弹目标原子核和逐出射弹的电子相互作用之间的散布振幅的干扰发源的生气的节在尖分发产出试验性的双山峰结构。然而，这个特征不能被三个振幅的干扰介绍。因此，在这几何学预言特征的四身体的模型的失败可以被归因于三个振幅的不恰当的 weighting。

Single ionization of helium atoms by energetic fully stripped carbon ions

A four-body distorted wave approximation is presented for theoretical investigations of the single ionization of groundstate helium atoms by fully stripped carbon ions at impact energies of 2 MeV/amu and 100 MeV/amu. The nine-dimensional integrals for the partial quantum-mechanical transition amplitudes of the specified reaction are reduced to some analytical expressions or one-dimensional integrals over real variables. Fully differential cross sections（FDCSs） are calculated and compared with their experimental values as well as the results obtained from other theories. Despite the simplicity and quickness of the proposed quadrature, the comparison shows that the obtained results are in reasonable agreement with the experiment and are compatible with those of other complicated theories.

中高Z元素原子、离子的电子碰撞电离与激发截面快速计算方法

中高Z元素的原子数据如碰撞电离和碰撞激发截面在聚变工程、X射线与物质相互作用等工程及研究领域有非常广泛的需求.高能量密度等离子体中存在从基态到激发态的原子和各价态离子,其碰撞电离和碰撞激发截面需要分别计算.本文以73号元素钽(Ta)为例,基于相对论性Dirac-Fock理论和扭曲波模型计算了基态Ta原子到Ta^(72+)离子在入射电子能量范围为1-150 keV的碰撞电离与碰撞激发截面,并与相关实验和理论模型符合较好.通过分析Ta的碰撞电离和碰撞激发截面数据中的规律,给出两种减少计算量的方法:对初态能级进行随机抽样、筛去贡献小的反应道,并对计算量的优化程度和误差做出评估.最终结果可在误差5%内将计算效率提高一个数量级,本文所提方法可推广至其他中高Z元素的计算.

Identifying influential spreaders in complex networks based on density entropy and community structure

In recent years,exploring the relationship between community structure and node centrality in complex networks has gained significant attention from researchers,given its fundamental theoretical significance and practical implications.To address the impact of network communities on target nodes and effectively identify highly influential nodes with strong propagation capabilities,this paper proposes a novel influential spreaders identification algorithm based on density entropy and community structure(DECS).The proposed method initially integrates a community detection algorithm to obtain the community partition results of the networks.It then comprehensively considers the internal and external density entropies and degree centrality of the target node to evaluate its influence.Experimental validation is conducted on eight networks of varying sizes through susceptible–infected–recovered(SIR)propagation experiments and network static attack experiments.The experimental results demonstrate that the proposed method outperforms five other node centrality methods under the same comparative conditions,particularly in terms of information spreading capability,thereby enhancing the accurate identification of critical nodes in networks.

W^(6+)离子的电子碰撞电离研究

采用细致能级扭曲波方法计算了W^(6+)离子基态[Kr]4d^(10)5s^(2)4f^(14)5p^(6)和亚稳态[Kr]4d^(10)5s^(2)4f145p^(5)5d^(1),[Kr]4d^(10)5s2^(4)f^(13)5p^(6)5d^(1),[Kr]4d^(10)5s^(2)4f^(14)5p^(5)5f1,[Kr]4d^(10)5s^(2)4f^(13)5p^(6)5f^(1)的电子碰撞单电离(EISI)截面.为了考虑亚稳态离子对电离的贡献,本文采用了3种模型来确定母离子束中处于长寿命能级的比值.与Pindzola和Griffin(1997 Phys.A 561654)的理论结果和Stenke等(1995 J.Phys.B:At.Mol.Opt.Phys.282711)实验结果进行比较,发现在考虑了亚稳态的贡献后本文结果与Stenke等的实验结果吻合得很好.

含铜危固废冶炼烟气中电收尘的设计及操作要点

江西兴南环保科技有限公司10万t/a含铜二次资源综合利用项目,于2021年6月生产试运行。试运行期间,针对底吹吹炼系统电收尘工艺、设备、操作和磨合的过程中的问题,在数据支撑下,进行设计、操作方面的探索,从根本上降低吨铜加工成本。

锗硅异质结双极型晶体管RF雪崩效应Mextram模型研究

传统Mextram模型基于雪崩倍增电流源Iavl来描述硅锗异质结双极晶体管的雪崩倍增效应,忽略了射频条件下因雪崩倍增相位延迟以及载流子传输时间延迟带来的集电结电感延迟问题.对硅锗异质结双极晶体管的雪崩倍增效应进行了研究,解释了导致器件集电结中出现电感延迟的物理机制.提出采用击穿电感和电阻分别表征器件的(Radio Frequency,RF)电感延迟特性和雪崩倍增载流子的贡献,建立考虑RF雪崩倍增效应的电感击穿等效电路模型,并嵌入到Mextram 505.00模型中.基于S参数来描述改进模型的验证结果,与传统模型相比,改进模型在应用频率小于35 GHz条件下,显著改善了硅锗异质结双极晶体管的增益和输出阻抗的精度,且不会对器件模型的直流特性拟合精度产生负面影响.同时从改进模型的电子击穿电感Ljcn、电子击穿电阻Rjcn、输出曲线、增益参数和输出阻抗中提取等效电路模型的敏感参数Aem和Vg.结果表明,基于RF电感击穿等效电路的Mextram 505.00改进模型可以更精确地预测射频条件下雪崩倍增效应发生时硅锗异质结双极晶体管的器件性能.