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101.
102.
给出了反对称分子动力学模型(AMD)计算的50 Me V/nucleon112Sn+112Sn反应的分析结果。该研究是反对称分子动力学模型中统计冻结概念的部分研究结果。利用自洽法结合修正的Fisher模型,提取了发射源的温度和密度分别为T=(6.1±0.2)Me V,ρ/ρ0=0.69±0.03。通过与AMD模型计算的系统在时间演化过程中的最大密度比较,得出碎片发射源的密度远小于系统的最大密度。利用自洽法提取的温度和密度与35 Me V/nucleon的40Ca+40Ca反应系统及40 Me V/nucleon的64Zn+112Sn反应系统所提取的温度和密度非常接近。该结果表明反对称分子动力学模型中,系统在中等质量碎片形成时刻处于统计冻结体积。 相似文献
103.
This study investigates the recovery of electric resistivity in pure iron, Fe–0.6Ni and Fe–1.5Mn as related to isochronal annealing following 1 MeV proton irradiation at lower temperature than 70 K, focusing on the relationship between solute atoms and irradiation defects. Both nickel and manganese prevent stage ID recovery, which corresponds to correlated recombination. Stage II recovery is also changed by the addition of a solute, which corresponds to the migration of small interstitial clusters. In both pure iron and Fe–0.6Ni, no evident difference was observed in the stage III region, which corresponds to the migration of vacancies. In contrast, two substages appeared in the Fe–1.5Mn at a higher temperature than stage IIIB appeared in pure iron. These substages are considered to represent the release of irradiation-induced defects, which was trapped by manganese. 相似文献
104.
Formation of “Quasi” Contact or Solvent‐separated Ion Pairs in the Local Environment of Probe Molecules Dissolved in Ionic Liquids 下载免费PDF全文
Matthias Strauch Dr. Christian Roth Falk Kubatzki Prof. Dr. Ralf Ludwig 《Chemphyschem》2014,15(2):265-270
The change from “quasi” contact to “quasi” solvent‐separated ion‐pair configuration in the local environment of a probe molecule in ionic liquids depends on the varying interaction strength of the chosen anions. The ion speciation in these Coulomb fluids could be shown by combining infrared spectroscopy, density functional theory calculations, and natural bond orbital analysis using a low‐self‐clustering probe molecule. 相似文献
105.
Prof. Dr. Igor Savić Prof. Dr. Stephan Schlemmer Prof. Dr. Dieter Gerlich 《Chemphyschem》2020,21(13):1429-1435
In order to study collisions between ions and neutrals, a new Guided Ion Beam (GIB) apparatus, called NOVion, has been assembled and tested. The primary purpose of this instrument is to measure absolute cross sections at energies relevant for technical or inter- and circumstellar plasmas. New and improved results are presented for forming H3+ in collisions of H2+ with H2. Between 0.1 eV and 2 eV, our measured effective cross sections are in good overall agreement with most previous measurements. However, at higher energies, our results do not show the steep decline, recommended in the standard literature. After critical evaluation of all experimental and theoretical data, a new analytical function is proposed, describing properly the dependence of the title reaction on the collision energy up to 10 eV. 相似文献
106.
《Arabian Journal of Chemistry》2020,13(3):4811-4823
In this paper, a metakaolin-based mesoporous geopolymer (GP-CTAB) was used as adsorbent for Cu(II) and Cr(VI) through a novel and simple synthetic route using cetyltrimethylammonium bromide (CTAB) as an organic modifier. The application of GP-CTAB for the simultaneous removal of metal anions and cations in aqueous solution was studied for the first time. The results of X-ray diffraction (XRD) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, Brunauer, Emmett and Teller (BET), and Barrett, Joyner, and Halenda (BJH) methods indicate that GP-CTAB is still geopolymer even in the presence of quaternary ammonium salt cations. The material was tested to simultaneously adsorb Cu(II) and Cr(VI) from an aqueous solution. The results show that GP-CTAB can adsorb anions simultaneously without sacrificing the adsorption properties of heavy metal cations, which is superior to conventional geopolymers. The maximum theoretical adsorption capacity of GP-CTAB for Cu(II) and Cr(VI) was 108.2 mg/g and 95.3 mg/g in the binary system, respectively. It was also found that the presence of Cu(II) in the solution promoted the adsorption of Cr(VI). Given this characteristic of GP-CTAB, it has shown great application prospects in the prevention and control of heavy metal pollution. 相似文献
107.
The electrochemical polymerization technique has been successfully applied to produce conducting polymer film of controlled ion exchange properties. Polypyrrole films were prepared by electro-oxidative polymerization with doping some alkylsulfonates or Nafion. The ion exchange characteristics across polypyrrole films were examined by means of a novel electrochemical technique, namely, the in situ electrochemical quartz crystal microbalance (EQCM) method. According to EQCM measurements, exchanging ion species was found to be successfully controlled by changing the hydrophilic–hydrophobic balance of the incorporated sulfonated-based dopants. The film's characteristics became anion- to cation-exchanging as the dopants became more hydrophobic in nature. The polypyrrole–Nafion(poly(perfluoroethylene sulfonate)) composite film became to be a complete cation exchanger. 相似文献
108.
109.
制备了四种不同铒离子掺杂浓度的碲酸盐玻璃,通过测定吸收光谱计算了吸收谱线的振子强度,根据Judd-Ofelt理论计算了不同浓度下Er3 离子发光光谱的强度参数Ωi(i=2,4,6),计算了自发辐射电偶和磁偶跃迁概率、辐射寿命、荧光分支比等参数,讨论了Er3 离子浓度变化对以上这些参数的影响.测试了Er3 :4I13/2→4I15/2跃迁对应的荧光光谱和Er3 :4I13/2能级荧光寿命.最后应用McCumber理论计算了玻璃中Er3 :4I13/2→415/2跃迁对应的受激发射截面大小.结果表明:振子强度基本上随Er3 离子浓度的增大而增强;随着Er3 离子浓度的增加,自发辐射跃迁概率A基本呈现出递增的趋势,但荧光分支比β却只有很小的变化;Er3 :4I13/2→4I15/2的发射截面随Er3 离子浓度的增大而改变很小,有效线宽都在50 nm左右. 相似文献
110.