磺化聚芳醚酮砜/ZrO2复合型质子交换膜的制备与性能

通过溶胶-凝胶法制备了纳米ZrO2无机粒子,再通过溶胶共混法制备了不同ZrO2含量的磺化聚芳醚酮砜(SPAEKS)复合膜,红外光谱显示复合膜中存在Zr-O-Zr吸收峰,扫描电镜照片显示纳米ZrO2无机粒子能够均匀地分散在SPAEKS聚合物基体中,未发生团聚现象.通过对复合膜的性能测试发现,纳米ZrO2无机粒子的引入提高...     

Exchange currents and nucleon magnetic moments

We investigate the effect of gluon and pion exchange currents on the magnetic moments of the nucleon using the constituent quark model. We also study the effect of scalar exchange currents connected with the confinement and sigma exchange potentials. We conclude that although individual exchange currents are quite large, the total exchange current contribution is relatively small, due to a cancellation of gluon, pion, and scalar exchange currents.Lecture presented at the Indian-Summer School on Interaction in Hadronic Systems, Praha (The Czech Republic), 25–31 August 1993.I would like to thank my colleagues Dr. E. Hernandez and Prof. K. Yazaki, for their collaboration in this field.     

Three-Quark Currents and Baryon Spin

We show that three-quark axial currents as required by broken SU(6) spin-flavor symmetry reduce the quark spin contribution to proton spin from \({{\Sigma}_p = 1}\) (one-quark axial current value) to \({{\Sigma}_p = 0.41(12)}\) consistent with the empirical value \({{\Sigma}_{p, exp} = 0.33(08)}\) . In the case of the \({{\Delta}^+(1232)}\) baryon, we find that three-quark axial currents increase the one-quark axial current value \({{\Sigma}_{{\Delta}^+} = 3}\) to \({{\Sigma}_{{\Delta}^+} = 3.87(22)}\) . We also calculate the quark orbital angular momenta L _u and L _d in the proton and \({{\Delta}^+}\) and interpret our results in terms of the prolate and oblate geometric shapes of these baryons consistent with their intrinsic quadrupole moments.     

燃烧法制备纳米CdFe2O4及表征

以Fe（NO3）3.9H2O和Cd（NO3）2.4H2O为原料,以柠檬酸为还原剂,采用燃烧法制备了CdFe2O4纳米粉体,用X射线粉末衍射仪（XRD）、透射电子显微镜（TEM）、红外光谱（IR）和振动样品磁强计（VSM）等手段对样品进行了表征,结果表明,样品为尖晶石型铁酸镉纳米粉体,其粒径大约为20—50nm,且具有超顺磁性。     

Birnessite和Cryptomelane型氧化锰的可控合成及其催化性能

以葡萄糖和高锰酸钾为原料,采用溶胶-凝胶法合成了birnessite(K_(1.35)MnO_2,简写为Bir)和cryptomelane(K_(0.27)MnO_2,简写为Cry)型氧化锰;采用X射线衍射、原子吸收光谱等考察了凝胶处理方法、反应物浓度比、焙烧温度和反应时间等对氧化锰晶型的影响.结果表明,采用不同方法处理凝胶可实现对Bir和Cry型氧化锰的可控合成.以不同的处理方法,葡萄糖和高锰酸钾的浓度比为O.74,反应20s制成凝胶,并在400℃焙烧2h,可分别制取高结晶度和高纯度的Bir和Cry型氧化锰.Bir和Cry型氧化锰在二甲醚燃烧反应中表现出优异的催化性能,且Cry型氧化锰的催化活性更高.     

The NA62 experiment at CERN

The goal of the NA62 experiment at CERN is to collect O(100) events of the ultrarare K\(^{+}\rightarrow \pi ^{+}\nu \bar {\nu }\) decay in two years. After a long R&D phase and a successful pilot run in 2014, the first data-taking phase took place in 2015. In this paper the importance of the experiment’s physics goal, as well as the experimental solutions adopted in order to attain it, will be reviewed.     

高效液相色谱法测定大豆磷脂类保健食品中磷脂酰胆碱

建立了高效液相色谱法测定大豆磷脂类保健品中磷脂酰胆碱含量的方法。样品经丙酮溶解去除油脂类杂质干扰后,离心弃去上层液体,残液用氮气吹干,然后用正己烷-异丙醇(1+1)混合液溶解残渣,以正相硅胶柱(250mm×4.6mm,5μm)为固定相,以乙腈-甲醇-磷酸(80+20+0.6)溶液等度洗脱分离,用紫外检测器于波长205nm处检测。磷脂酰胆碱的质量浓度在2.136g·L-1以内与其峰面积呈线性关系。应用此法分析大豆磷脂软胶囊,平均回收率在90.2%～96.1%之间;测定值的相对标准偏差(n=6)在1.2%～3.6%之间。     

铜-铈氧化还原液流电池性能

设计了一种新型Ce-Cu氧化-还原液流电池,研究了Ce³⁺/Ce⁴⁺和Cu⁰/Cu²⁺氧化还原电对的循环伏安特性,优化了电解液及电极材料,进而组装出液流电池,测试了电池的充放电性能。 结果表明,在45 mA恒电流充/放电条件下,电池放电平台电压约为1.0 V,库伦效率约100%,能量效率为75%以上,电池可稳定循环100次。     

Neutral kaon production inK + p and π+ p interactions at 250 GeV/c

The inclusive production of neutral kaons is studied inK ⁺ p and π⁺ p interactions at 250 GeV/c. Total and semi-inclusive cross sections and average kaon multiplicities are presented and compared with the data at lower energies. The longitudinal and transverse momentum distributions and their energy dependence are analyzed. The results are interpreted in the framework of recent parton models.