吡唑基镁卤化物/四氢呋喃可充镁电池电解液

将不同配比的吡唑与格氏试剂反应制得的吡唑基镁卤化物/四氢呋喃(THF)溶液用作可充镁电池电解液,采用循环伏安和恒电流充放电测试研究了该电解液的镁沉积-溶出性能和氧化分解电位;并通过X射线衍射(XRD)和扫描电镜(SEM)对沉积物的组分和形貌进行了分析.结果表明,吡唑上的取代基、吡唑与格氏试剂的反应配比对电解液的电化学性能都有影响.1 mol·L-11-甲基吡唑-PhMgCl(1:1摩尔比)/THF反应配制的电解液在不锈钢(SS)集流体的阳极氧化分解电位达到2.4 V(vs Mg/Mg2+),并具有镁沉积-溶出电位低、循环稳定性高、配制方便的特点,有希望应用于实际的可充镁电池体系中.     

核壳结构聚苯胺-聚电解质-碳酸钙微球复合材料的制备、表征和应用

在包裹了聚电解质的碳酸钙微球上原位聚合苯胺,形成导电性良好的聚苯胺-聚电解质-碳酸钙（PAN/(PEs)6/CaCO3）微球。 采用扫描电子显微镜研究了聚电解质层对碳酸钙微球形貌的影响,以及苯胺单体加入量对碳酸钙-聚电解质-聚苯胺导电复合材料形貌的影响。 并用红外光谱和紫外-可见光谱等进行了结构表征。 该复合材料有良好的电催化活性,将其滴涂在玻碳电极上,修饰电极对多巴胺氧化显示了较强的催化能力,与碳酸钙修饰电极相比,其氧化峰电位负移了130 mV,平行制作5支修饰电极测定4.0 mmol/L多巴胺,相对标准偏差为4.2％。 该复合材料制备简单、重现性良好,可以构建测定多巴胺的传感器。 线性范围0.5~10.0 mmol/L,检测限0.2 mmol/L(3S/N)。     

Structure and analytical potential energy function for the ground state of the BCx (x=0, －1)

In this paper, the electronic states of the ground states and dissociation limits of BC and BC- are correctly determined based on group theory and atomic and molecular reaction statics. The equilibrium geometries, harmonic frequencies and dissociation energies of the ground state of BC and BC- are calculated by using density function theory and quadratic CI method including single and double substitutions. The analytical potential energy functions of these states have been fitted with Murrell-Sorbie potential energy function from our ab initio calculation results. The spectroscopic data （αe, ωe and ωeχe） of each state is calculated via the relation between analytical potential energy function and spectroscopic data. All the calculations are in good agreement with the experimental data.     

强化演示实验,开展大学物理研究型教学

探讨对工科大学物理研究型教学的认识以及演示实验在其中的重要作用,同时介绍我们的一些做法.     

Bifurcated Current Sheet Structure in a Quiet Time by Cluster Spacecrafts

We analyse the vertical structure of the magnetotail current sheet for two time intervals during which the Cluster spacecrafts crossed the neutral sheet in a quiet time. In the intervals, the current sheet moved slowly, and the value of the AE index was relatively small, about 40-130 nT. We find two examples of current sheets, with the current density maximum at the magnetic equator （Bx = 0）, as well as an example of off-centre or bifurcated current sheets. In the quiet time, without any fast plasma flow and without significant flapping motion, we also directly observed the bifurcated current sheet. The bifurcated current sheet is probably associated with instabilities in the current sheet. These may be important for researching the mechanism of current sheet bifurcation.     

Analysis of the Interaction between Low-Frequency Waves and Ions in the High-Altitude Cusp Region Observed by Satellite Cluster

The energy transfer between ions （protons） and low frequency waves （LFWs） in the frequency range f1 from 0.3 to 10 Hz is observed by Cluster crossing the high-altitude polar cusp. The energy transfer between low frequency waves and ions has two means. One is that the energy is transferred from low frequency waves to ions and ions energy increases, The other is that the energy is transferred from ions to low frequency waves and the ion energy decreases. lon gyratory motion plays an important role in the energy transfer processes. The electromagnetic field of f1 LFWs can accelerate or decelerate protons along the direction of ambient magnetic field and warm or refrigerate protons in the parallel and perpendicular directions of ambient magnetic field, The peak values of proton number densities have the corresponding peak values of electromagnetic energy of low-frequency waves. This implies that the kinetic Alfven waves and solitary kinetic Alfven waves possibly exist in the high-altitude cusp region.     

Coadsorption of gold with chlorine on CeO2 (111) surfaces: A first principles study

To investigate the effects of chlorine on the Au/ceria catalysts,the adsorption of gold or chlorine and their coadsorpiton on the stoichiometric and partially reduced CeO₂（111） surfaces are studied from the first principles.It is found that the adsorption of Au is significantly enhanced by the chlorine preadsorption on the stoichiometric CeO₂（111） surface;while on the partially reduced CeO₂（111） surface,the preadsorbed chlorine inhabits the oxygen vacancy（which is the preferred adsorption site for gold）,leading to a CeOCl phase and the dramatical weakening of the Au adsorption.Therefore,chlorine on the CeO₂（111） surface can affect the Au adsorption thus the activity of the Au/CeO₂ catalyst.     

S在Pt皮肤Pt3Ni(111)面吸附的第一性原理研究

采用基于密度泛函理论的第一性原理方法,计算并分析了S原子在 Pt皮肤Pt3Ni(111)面不同位置的吸附特性.结果表明：S原子在Pt皮肤Pt3Ni的fcc位吸附最强,吸附能为5. 49 eV;与S原子在纯净Pt(111)表面的吸附相比,S原子在Pt皮肤Pt3Ni表面相应吸附位置的吸附能变小、与近邻的Pt原子形成的S-Pt键变长,表明掺杂的Ni会减小相应位点S原子的吸附能,降低体系对S原子的吸附能力,进而减弱S吸附对体系催化能力的影响;态密度分析发现, S原子的吸附使得Pt基催化剂的催化活性降低,主要是S的2p电子引起的;这些结果将为后续研究Pt基合金电极抗S中毒效果以及探究S原子吸附后Pt3Ni的活性位提供依据.     

第一性原理研究O2在CrN4掺杂石墨烯上的氢化

掺杂是调制graphene催化特性的有效方法. 掺杂的Graphene, 因其具有对氧还原反应具有较高的活性, 而作为一种新型高效质子交换膜燃料电池阴极材料. 采用包含色散力校正的第一性原理的密度泛函理论方法(DFT-D)系统的研究了O2在CrN4掺杂的Graphene上的吸附和氢化特性. 结果表明: (1) O2倾向于以side-on模式吸附在Cr顶位, 形成O-Cr-O三元环结构, 吸附能为1.75 eV; (2) O2在CrN4-Gra上更倾向于直接分解成O+O, 并进一步氢化为O+OH, 反应的限速步为O2的分解, 相应的反应势垒为0.48 eV.     

FeN4掺杂对富勒烯催化特性调制的第一性原理研究

因其较好的稳定性和催化活性,非金属N与金属共掺杂的富勒烯（C60）作为新型氧化还原反应（ORR）催化剂受到了人们的广泛关注。采用基于密度泛函理论的第一性原理方法系统地研究了FeN4掺杂对C60催化特性的调制规律,揭示了O2在FeN4掺杂的C60上的吸附和氢化特性。结果表明：（1）O2倾向于以side-on模式吸附在Fe的顶位上,O-O键平行于C60的球切面,与Fe形成O-Fe-O三元环结构,对应的吸附能为1.48 eV。（2）O2的氢化反应路径可以分为两条：（i）O2先解离为O + O,然后氢化为O + OH。O2的解离为反应的速控步,势垒为2.82 eV。（ii）O2先氢化形成OOH结构,然后解离。氢化为反应的速控步,势垒为2.83 eV。