气相中Cu＋和Zn＋与SCO反应的理论研究

为更清晰地揭示M^＋与SCO基元反应的机理, 采用密度泛函B3LYP方法, 在6-311＋＋G**基组水平上研究了Cu^＋＋SCO和Zn^＋＋SCO反应体系. 对反应势能面上各驻点的几何构型进行了全优化, 用频率分析方法和内禀反应坐标(IRC)方法对过渡态进行了验证. 在Cu^＋与SCO的反应中, 对影响反应机理和反应速率的势能面交叉现象进行了讨论, 运用Hammond假设和Yoshizawa等的内禀反应坐标垂直激发的计算方法找到了势能面交叉点. 计算结果表明, C—S和C—O键的活化都是通过插入消去机理, 但C—S键的活化在能量上更占优势. 计算确认了标题反应的主通道, 所有的计算结果与实验吻合.     

染料敏化纳米薄膜太阳电池中DMPII浓度的优化

利用超微铂电极和循环伏安法及电化学阻抗谱研究了在1,2-二甲基-3-丙基咪唑碘(DMPII)的3-甲氧基丙腈(MePN)溶液中I₃^－和I^－的氧化还原行为，并对比了由不同浓度的I2和DMPII组成的电解质溶液，其染料敏化纳米薄膜太阳电池(DSCs)的光伏性能. 发现以MePN为溶剂，含1.0 mol•dm^-3 DMPII、0.12 mol•dm^-3 I2、0.10 mol•dm^-3 LiI和0.50 mol•dm^-3 4-叔丁基吡啶的电解质溶液，其DSCs的短路光电流密度为16.67 mA•cm^-3、开路电压为0.69 V、填充因子为0.70、光电转换效率达8.08%.     

COMPATIBILITY AND PHASE BEHAVIOR OF PS/SBR BLENDS H. TORSIONAL BRAID ANALYSIS

The compatibility and phase behavior of PS/SBR blends was studied with torsional braid analysis technique. The technique used in this study for preparation of braids was first developed by one of the authors, which gives more precise phase diagram as compared to other conventional methods. The results obtained are in good agreement with those obtained in our previous work.     

牛血清蛋白单层膜诱导形成网状结构的羟基磷灰石

0引言近来利用生物矿化的方法来合成具有特殊结构的晶体材料成为材料合成的一个热点[1.2]。羟基磷灰石(HAP)作为一种生物材料,广泛地存在于人和动物的骨骼和牙齿中,是生物矿化的产物。在骨骼的修复、替代和仿生抗菌陶瓷薄膜中有重要的应用[3]。因此,利用生物矿化的方法合成具有     

ICP-MS测定城市污泥中Cd和Pb的研究

近年来随着城市污水处理率不断提高,污水处理过程中的副产品污泥产量也快速增加.污泥中污染物的浓度直接关系到污泥的最终处置的选择,而与土壤、沉积物等相比,城市污泥成分很复杂,其含有的丰富有机质为其预处理增加了难度.如何快速有效地监测污泥中重金属元素的含量尚待进一步研究.本文研究利用ICP-MS测定城市污泥中重金属元素Cd、Pb.     

钙钛矿型La0.8Sr0.2FeO3中的晶格氧用于甲烷选择氧化制取合成气

 用自燃烧法制备了钙钛矿型La0．8Sr0．2FeO3催化剂．用H2－TPR考察了催化剂表面的氧消耗过程，用程序升温表面反应（TPSR）研究了甲烷与催化剂表面氧物种的反应，用在线质谱脉冲反应和甲烷／氧切换反应研究了催化剂的晶格氧选择氧化甲烷制合成气．结果表明，催化剂上存在两种氧物种，无气相氧存在时，强氧化性氧物种首先将甲烷氧化为CO2和H2O；而后提供的氧化性较弱的晶格氧具有良好的甲烷部分氧化选择性，可将甲烷氧化为合成气CO和H2（选择性可达95％以上）．在900℃下的CH4／O2切换反应结果表明，甲烷能与La0．8Sr0．2FeO3中的晶格氧反应选择性地生成CO和H2，失去晶格氧的La0．8－Sr0．2FeO3能与气相氧反应恢复其晶格氧．在合适的反应条件下，用La0．8Sr0．2FeO3催化剂的晶格氧代替分子氧按Redox模式实现甲烷选择氧化制合成气是可能的．     

TiO2胶粒在铝合金表面的电泳沉积及所制薄膜的光催化性能研究

TiO₂ membranes were prepared on aluminum-alloy thin plates by electrophoretic deposition and dip coating in a colloid solution of TiO₂, respectively. The photocatalytic activity of TiO₂ membrane was compared using ethylene as reactant, and the crystal and morphological structure of the membrane were characterized by XRD and SEM. The results showed that a more compact membrane with high loading of TiO₂ but lower photocatalytic activity of unit TiO₂ mass was obtained by electrophoresis compared with dip coating method. The addition of polyethylene glycol (PEG) to the sol of TiO₂ could improve the specific photocatalytic activity (ethylene conversion per unit mass TiO₂ and unit area of membrane piece) of the electrophoresis-membrane prepared from the sol, but could not change the specific photocatalytic activity of the dip-coating membrane from the sol. The ethylene conversion on the electrophoresis membrane prepared from the sol containing PEG (50 g·L^-1) was 9 times of that on the dip coating membrane. The effect of PEG on the properties of electrophoresis-membrane of TiO₂ was attributed to the change of electrokinetic properties of sol. Addition of PEG decreased ζ potential value of the sol and the mobility of the sol particle, increased viscidity of the colloid, thus decreasing both the electrophoresis deposition velocity of colloid particles and the electroosmosis velocity of diffuse layer of colloid particles. These favored the formation of a low compact and porous membrane on the electrode in electric field, and thus increasing the availability of TiO₂ in photocatalytic process.     

ALTERNATE PREDOMINANCE IN COMPETITION FOR CONJUGATION IN NITROGEN BRIDGE COMPOUND

It is demonstrated quantitatively that the serial number N is not m + n + 4 in the nitrogen bridge conjugated system (Ⅸ), so the lone pair of electrons on the nitrogen cannot conjugate with acenyl branch and formyl polyenic branch simultaneously. The character of UV spectra and substituent equivalents (△Ns) show that acenyl branch competes for the lone pair of electrons with formyl polyenic branch. If the length m of acenyl branch is lengthened while n keeps constant, a point where the acenyl branch is predominant over formyl polyenic branch in competition, will eventually be reached. On the other hand, the effect of the latter will become greater than the former. The effect of the two branches predominates each other alternately with the alternate increase in m and n values.     

2-(2-喹啉偶氮)-1,5-苯二酚光度法测定钢铁样品中镍

合成了新试剂 2 (2 喹啉偶氮 ) 1,5 苯二酚 (QADHB) ,并研究了其与镍的显色反应 ,在pH 9.0的氯化铵 氨水缓冲介质中 ,CTMAB存在下 ,QADHB与镍反应生成 2∶1稳定络合物 ,λmax为 5 90nm ,ε为 1.0 5× 10 5L·mol- 1·cm- 1。镍含量在 0～ 10 μg/ 2 5ml内符合比耳定律 ,方法用于钢铁样品中镍含量的测定 ,结果满意。     

钴、镍-氨基三乙酸配位聚合物Na[M(nta)]·H2O(M=Co,Ni)的水热合成、结构与磁性

由有机配体同金属离子作用构建的配位聚合物具有与无机微孔晶体类似的空旷骨架结构,并在非线性光学材料、磁性材料、超导材料及催化等诸多方面具有潜在的应用前景[1～4].在配位聚合物的合成中,配体的种类不仅直接影响到聚合物的合成,而且还涉及到聚合物的结构维数[5～7].目前,用来构建这些配合物的有机配体大多数都带有相同的可配位基团,较少应用具有两种以上的配位基团的有机配体.本文采用同时含有氮和氧两种配位原子的多齿配体氨基三乙酸[8～12],在水热条件下分别以Co2+和Ni2+作为组装基元,通过自组装合成了具有三维骨架结构的Na[M(nta)]·H2O [M=Co(1),Ni(2)]配位聚合物,并进行了结构与磁性研究.