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.     

微量热法研究亚砷酸钠对鲫鱼肝脏线粒体的影响

Metabolic thermogenic curves of mitochondria isolated from liver tissue of Carassius auratus and the effect of different concentration of NaAsO2 on it were investigated by TAM air isothermal microcalorimeter, ampoule method, at 28.00 ℃. From the thermogenic curves, activity recovery rate constants k, the maximum heat production rate （Pmax） and the total heat produced （Q） were obtained. The values of k and Pmax decline gradually with the increase of the concentration of NaAsO2, and both of the values of Pmax and k are highly correlated to the concentration of NaAsO2. When concentration of NaAsO2 reached 16.0 μg/mL, the maximum heat production rate dropped to 70.8% of the control group, and the corresponding percentage of k was 71.4% of the control group. This experimental result indicates that the addition of NaAsO2 has restrained the metabolic activities of mitochondria in vitro.     

MS-MS检测杀虫双根施后对棉籽的污染

杀虫双(Dimehypo)化学名:2-N,N-二甲基-1,3双硫代磺酸钠基丙烷,分子式C5H11NO6S4Na2,是我国自行研制成功的一种沙蚕毒系有机杀虫剂,中等毒性,对害虫有较强的触杀作用,并兼有一定的熏蒸作用。湖北省荆州市微生物研究所将杀虫双用于根施防治棉株红铃虫,证明有一定的效果。但是由于将杀虫双直接施于土壤,因而是否会因植株对农药的吸收而造成对棉籽的污染,进而影响消费者的食用安全,这是农业生态学中必须研究的问题。本研究报道了检测棉籽中杀虫双残毒的四极杆串联质谱(DIP-MS-MS)快速定性的分析方法。     

对自旋交叉化合物[Fe(dpq)(py)2(NCS)2]·H2O·py和[Fe(dpq)(py)2(NCSe)2]·1.5H2O的研究

为了研究配体修饰对自旋交叉现象的影响,我们合成了两个Fe(Ⅱ)自旋交叉的配合物[Fe(dpq)(py)₂(NCS)₂]·H₂O·py和[Fe(dpq)(py)₂(NCSe)₂]·1.5H₂O,(dpq=二吡嗪[2,3-f:2′3′-h]喹喔啉,py=吡啶)。通过对这两个配合物磁性质和穆斯堡尔谱的研究,发现和用邻啡咯啉配体合成的配合物比较,配体的修饰对自旋交叉性质以及其临界温度     

STUDY ON THE CATIONIC POLYMERIZATION OF 1, 3-PENTADIENE INITIATED BY AlCl_3/ALKYL HALIDE SYSTEMS

The cationic polymerizations of 1, 3-pentadiene were initiated by AlCl_3 in n-hexaneat 30℃ in the presence of alkyl halides, i.e., tert-butyl chloride, tert-butyl bromide andisobutyl chloride. The effects of these halides on the polymer yield, molecular weight,crosslinking reaction, cyclization and polymer microstructure, have been investigated. Twomain side reactions, crosslinking and cyclization, were suppressed and reduced by theaddition of the halides. The proportion of 1, 4 units of polymer chains was increasedby the presence of the halides, which reduced the polymer yield and the molecular weightof polymers.     

二硝酸根二4′，5′-二氮-9′-(4，5-二(硫乙基)-1，3-二硫杂环戊烯-2-叶立德)-芴合镉的合成、结构及光谱性质

Cd(NO₃)₂·4H₂O与配体4′,5′-二氮-9′-(4，5-二(硫乙基)-1，3-二硫杂环戊烯-2-叶立德)-芴(L)在甲醇和二氯甲烷的混合溶剂中生成配合物Cd(NO₃)₂(L)₂。晶体的空间群是Pbcn(#60)，晶体学参数分别是a=1.578 7(2) nm，b=0.987 96(11) nm，c=2.719 5(3) nm。V=4.241 6(8) nm³，Z=4。2个硝酸根离子各提供1个氧原子，2个配体L各提供2个氮原子，形成了镉的6配位结构。晶体结构显示分子通过平面之间的π-π相互作用沿b轴形成柱状结构，这些柱通过中心原子镉(Ⅱ)的配位连接形成二维层状结构，再通过2个硫乙基上的短距离S…S接触进一步形成了三维结构。对其 ¹H NMR、UV-Vis和荧光光谱进行了研究。