关于放射性核素环境迁移模式有效性研究的新动态

关于放射性核素在陆地、城市、水体环境中迁移模式有效性的合作研究计划,首先由国际原子能机构(IAEA)的核燃料循环与废物处置科和核安全科于1988年发起。1988年5月由IAEA负责召开了第一届国际研究协调会议,会议期间成立了四个专门工作组,分别开展核素在陆地环境、水体环境、城市环境、多途径照射四个领域的国际协调研究工作。从1989年2月起,欧洲共同体(CEC)也参加了这项国际研究协调计划的组织工作。 1989年12月5—8日,由IAEA和CEC联合发起在维也纳召开关于“

Separation of Ions from Volatile Organic Compounds Using High-Field Asymmetric Waveform Ion Mobility Spectrometry-Mass Spectrometer

A combination of high-field asymmetric waveform ion mobility spectrometry （FAIMS） with mass spectrometer （MS） was analyzed. FAIMS separates ions from the volatile organic compounds in the gas-phase as an ion-filter for MS. The sample ions were created at ambient pressure by ion source, which was equipped with a 10.6 eV UV discharge lamp （A=116.5 nm）. The drift tube of FAIMS is composed of two parallel planar electrodes and the dimension is 10 mm×8 mm×0.5 mm. FAIMS was investigated when driven by the high-filed rectangular asymmetric waveform with the peak-to-peak voltage of 1.36 kV at the frequency of 1 MHz and the duty cycle of 30%. The acetone, the butanone, and their mixture were adopted to characterize the FAIMS-MS. The mass spectra obtained from MS illustrate that there are ion-molecular reactions between the ions and the sample neutral molecular. And the proton transfer behavior in the mixture of the acetone and the butanone is also observed. With the compensation voltage tuned from -30 V to 10 V with a step size of 0.1 V, the ion pre-separation before MS is realized.

Electromigration induced microstructure evolution and damage in asymmetric Cu/Sn-58Bi/Cu solder interconnect under current stressing

The electromigration induced microstructure evolution and damage in asymmetric Cu/Sn-58Bi/Cu solder interconnects were investigated by in-situ SEM observation, focused ion beam （FIB） microanalysis and finite element （FE） simulation. The SEM results show that the electromigration-induced local degradation of microstructures, i.e., segregation of Bi-rich phase and formation of microcracks, in the asymmetric solder interconnects is much severer than that in the symmetrical ones. FIB-SEM microanalysis reveals that the microregional heterogeneity in electrical resistance along different electron flowing paths is the key factor leading to non-uniform current distribution and the resultant electromigration damage. Theoretical analysis and FE simulation results manifest that the current crowding easily occurs at the local part with smaller resistance in an asymmetric solder interconnect. All results indicate that the asymmetric shape of the solder interconnect brings about the difference of the electrical resistance between the different microregions and further results in the severe electromigration damage.

Peak Profile Analysis in High Field Asymmetric Wave Ion Mobility Spectrometry

High field asymmetric wave ion mobility spectrometry （FAIMS） is a powerful tool to detect and characterize gas-phase ions, while the unsolvable partial differential equation of ions moving in ion drift tube poses a big challenge to FAIMS spectral peak analysis. In this work, a universal and effective model of FAIMS spectral peak profile has been proposed by introducing ion trajectory and loss height. With this model, the influence of the structure of ion drift tube, dispersion voltages, compensation voltages, and carrier gas flow rate on the FAIMS spectral peak characteristics like peak shape, full width at half maximum and peak height is analyzed and discussed. The results show that the influence of different factors on the FAIMS spectral peak profile can be qualitatively described by the model which agrees with the experimental data.

Symmetry Breaking Ground States of Bose-Einstein Condensates in 1D Double Square Well and Optical Lattice Well

We investigate the phenomena of symmetry breaking and phase transition in theground state of Bose-Einstein condensates (BECs) trapped in a double square well and in an opticallattice well, respectively. By using standing-wave expansion method, we present symmetric andasymmetric ground state solutions of nonlinear Schroedinger equation (NLSE) with a symmetric doublesquare well potential for attractive nonlinearity. In particular, we study the ground state wavefunction's properties by changing the depth of potential and atomic interactions (here we restrictourselves to the attractive regime). By using the Fourier grid Hamiltonian method, we also reveal aphase transition of BECs trapped in one-dimensional optical lattice potential.

Selection rules of electromagnetic transitions for chirality-parity violation in atomic nuclei

The nuclear Chirality-Parity(ChP) violation, a simultaneous breaking of chiral and reflection symmetries in the intrinsic frame, is investigated with a reflection-asymmetric triaxial particle rotor model. A new symmetry for an ideal ChP violation system is found and the corresponding selection rules of the electromagnetic transitions are derived. The fingerprints for the ChP violation including the nearly degenerate quartet bands and the selection rules of the electromagnetic transitions are provided. These fingerprints are examined for ChP quartet bands by taking a two-j shell h11/2 and d5/2 with typical energy spacing for A = 130 nuclei.

SPECIAL ISSUE： LANGUAGE STUDIES AND METHODS FROM THE CROSS-DISCIPLINARY PERSPECTIVE Semantic Transfer of Chinese Kinship Terms to Occupational Address Forms since the Economic Reform

Semantic transfer of kinship terms in address forms to nonkin has always been an intriguing topic to researchers from different fields, anthropologists and sociolinguists alike, whose investigations involve data from various cultures. This study focuses on eight Chinese kinship terms used in twenty-one address forms for addressing nonkin in newly created occupations and practices during the recent economic reform in China, in an attempt to identify the driving force behind such transfer. By examining the use of these kinship terms in addressing nonkin in the economic reform, this study compares its findings to those from earlier studies and has found surprisingly that except gender, the other distinctive features, such as consanguinity, affinity, seniority, and generation, have all become neutralized in the semantic transfer, driven chiefly by the nonkin＇s occupational status. The results from this study demonstrate that the ＂categorical falsity＂ evidenced in the semantic transfer of kinship terms in address forms to nonkin is in essence a manifestation of performing an attitudinal ＂speech act＂ by the general public about how the nonkin＇s occupational status is evaluated in the economic reform.