电化学充氘引起钯阴极出现异常温升现象的解释

本文选用具有不同原始状态的钯棒作为阴极,在自制的循环水冷却式量热计中进行了7次长时间电解重水的量热实验观察,实验过程中仅观察到一次异常温升现象。在理论分析和实验的基础上,排除了化学反应和D-D聚变产生异常温升的可能性,并认为过剩热的产生是由于钯晶体内弹性应变能的释放所引起。     

EIS Study on the Electrochemical Properties of RE(Ni,Co,Mn,Ti)s Alloys (RE=La,Ce,Pr,Nd) at Different Depths of Discharge (DOD)

In the present investigation, EIS was employed to study the electrode kinetics of AB₅ typed RE (Ni, Co, Mn, Ti)₅ alloy and compare the difference of rare earth component effects when pure La, Ce, Pr or Nd was used individually for RE in the alloy respectively.     

化学计量比和放氢背压对LiBH4+xMg2NiH4体系放氢性能的影响

研究了不同化学计量比(x=0.25, 0.5, 0.75, 1.0, 1.25)和放氢背压(1×10-4和0.4 MPa)对LiBH4+xMg2NiH4复合体系吸放氢性能的影响. 结果表明, 随着化学计量比(x)的增加, 复合体系的放氢温度逐渐降低, 放氢动力学性能得到提高, 但放氢容量逐渐降低; 其中, 在1×10-4和0.4 MPa初始放氢背压下, LiBH4+0.75Mg2NiH4体系具有最佳放氢动力学性能和较高的储氢容量. 结果表明, 放氢背压和化学计量比均会对高温下液相LiBH4 与固态Mg2NiH4 的润湿性产生影响, 进而影响复合体系的放氢路径和放氢动力学性能.     

Benzimidazolium functionalized polysulfone-based anion exchange membranes with improved alkaline stability

The stability of anion exchange membranes(AEMs) is an important feature of alkaline exchange membrane fuel cells(AEMFCs), which has been extensively studied. However it remains a real challenge due to the harsh working condition. Herein, we developed a novel type of polysulfone-based AEMs with three modified 1,2-dimethylbenzimidazoliums containing different substitutes at C4-and C7-position. The results showed that the introduction of the substitutes could obviously improve the dimensional and alkaline stabilities of the corresponding membranes. The swelling ratios of resultant AEMs were all lower than 10% after water immersion. The membrane with 4,7-dimethoxy-1,2-dimethylbenzimidazolium group exhibited the highest alkaline stability. Only 9.2% loss of hydroxide conductivity was observed after treating the membrane in 1 mol·L~(-1) KOH solution at 80 °C for 336 h. Furthermore, the density functional theory(DFT) study on the three functional group models showed that the substitutes at C4-and C7-position affected the lowest unoccupied molecular orbital(LUMO) energies of the different 1,2-dimethylbenzimidazolium groups.     

Asymmetric synthesis of some new tetrahydroisoquinolinium salts

Several new tetrahydroisoquinolinium salts,analogues of atracurium,were designed and synthesized.These compounds were prepared from optically pure tetrahydropapaverine and hex-amethylene diglycidate.     

浸渍法制备钾基半焦在烟气脱硫中的循环再生

采用碳酸钾(K_2CO_3)与活化半焦通过浸渍法制备用于除去烟气SO_2的催化脱硫材料(K/ASC)。研究表明,将活化半焦(ASC)通过10%(质量分数)K_2CO_3改性获得钾基半焦(K10),其在120℃时具有良好的SO_2脱除效率,而且随着再生温度的升高(400～700℃),再生后K10的脱硫活性明显提高。K10(K10-R-600-n)的循环再生测试表明,样品在4次再生循环(K10-R-600-4)后具有最佳的脱硫性能,其硫容量为68.9 mg·g-1,比K10(55.4 mg·g-1)高24.37%。再生分析脱硫产物为物理吸附的SO_2,H_2SO_4和硫酸盐,再生后未分解的硫酸盐沉积会降低样品的脱硫活性。经过10次循环再生(K10-R-600-10),样品的硫容量为初始钾基半焦K10的70%。     

藤黄科植物中具有桥环结构的天然产物全合成研究进展

藤黄科植物中含桥环的天然产物具有独特的化学结构和明显的生物活性. 综述了近年来这类天然产物的全合成研究进展.     

高被引文章

A Cu₃(BTC)₂ (copper(Ⅱ) benzene 1, 3, 5-tricarboxylate) metal organic framework (MOF) catalyst was successfully prepared through an electrochemical route and used for selective catalytic reduction of nitrogen oxide (NO_x) with NH₃ for the first time. After systematically optimizing the reaction conditions such as solvents, voltage, electrolyte concentration, and reaction time, pure Cu₃(BTC)₂ with high crystallinity was obtained in 97.2% yield. The physicochemical properties of the catalyst were determined using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), Raman spectroscopy, in situ Fourier transform infrared (FTIR) spectroscopy, temperature-programmed desorption (TPD), and X-ray photoelectron spectroscopy (XPS). TGA results indicated that the framework was stable up to 310℃. The catalytic activity of Cu₃(BTC)₂ was evaluated using NO conversion as a model reaction. The Cu₃(BTC)₂ activation temperature significantly affected the catalytic activity. The Cu₃(BTC)₂ sample activated at 240℃ had the best catalytic activity and gave NO conversion of 90% at 220-280℃. A reaction mechanism was proposed based on the in situ FTIR spectroscopy results.     

4-[4-(2,3,4-三甲氧基苄基)哌嗪-1-基甲基]苯甲酰胍类化合物的合成 及其Na＋/H＋交换器1抑制活性

为了寻找对心肌缺血再灌注损伤具有保护作用的药物, 以苯甲酰胍为母核, 在其苯环的4位引入4-(2,3,4-三甲氧基苄基)哌嗪-1-甲基, 3位引入不同的取代苯甲酰胺基, 设计并合成了12个未见文献报道的目标化合物. 其结构经MS, IR, 1H NMR和元素分析确证. 体外血小板肿胀模型(PSA)试验结果表明, 大部分目标化合物显示出较好的Na＋/H＋交换器1 (NHE1)抑制作用, 其中化合物7g和7l抑制NHE1的IC50值分别为3.72和3.53 nmol•L－1, 是卡立泊来德(IC50＝12.1 nmol•L－1)的3.2和3.4倍.     

Preparation and Characterization of LaVO4/TiO2 Nanotubes and Their Application in Photoeatalytic Degradation of Gaseous Toluene under Visible Light

通过水热方法合成了可见光响应的LaVO4/TiO2纳米管,采用XRD,TEM,氮气吸附-脱附以及表面光电压谱对样品进行了表征.以气相甲苯为典型污染物,研究了制备样品在可见光(λ＞420 nm)条件下的光催化性能.实验结果表明,LaVO4的复合使TiO2的粒径减小,比表面积增大,光响应范围向可见光偏移.光催化实验结果表明,在可见光条件下,LaVO4/TiO2纳米管降解甲苯的效率比其它样品高,与纯TiO2纳米管相比,降解效率提高了47％.