Synthesis and Characterization of ZSM-5/β Co-Crystalline Zeolite

ZSM-5/β co-crystalline zeolites with different content of ZSM-5 have been synthesized by adding different amount of ZSM-5 to the synthetic system of β zeolite with NaAlO2, silica sol as the source of aluminum and silica, respectively, and TEA as the template under controlled condition of the synthesis. The ZSM-5/β co-crystalline zeolite was studied by XRD, SEM, BET and NH3-TPD. The reaction activity of toluene alkylation was investigated with a mixture of toluene-methanol as the feedstock in a pulse micro-reactor over the ZSM-5/β co-crystalline zeolite. It is found that ZSM-5/β co-crystalline zeolite has two kinds of zeolite structure including ZSM-5 and β zeolite, not in the form of a physical mixture. The pore structure of ZSM-5/β co-crystalline zeolites is different from that for β zeolite, ZSM-5 and their physical mixture. In addition, the peaks of both high and low temperature desorption of ammonia over the ZSM-5/β co-crystalline zeolite shift 23 ℃ to lower temperatures and the acid amount of its strong acid is 3% more than the physical mixture. So the ZSM-5/β co-crystalline zeolite produces the highest content of xylene, which is 10.4% higher than the physical mixture. And the ZSM-5/β co-crystalline zeolite has better selectivity for toluene alkylation and weaker de-methylation than β zeolite, ZSM-5 and their physical mixture.     

CrOx/ SBA-15介孔催化剂上丙烷在二氧化碳气氛中脱氢反应的研究

The structure and catalytic properties based on Chromium Oxide supported on mesoporous SBA-15 for oxidative dehydrogenation of propane by CO₂ have been studied by using X-ray diffraction (XRD), ultraviolet-visible diffuse reflectance spectra (UV-Vis DRS), electron spin resonance (ESR), X-ray photoelectron spectroscopy (XPS) and propane pulsing experiments in the absence of gas-phase O₂. It has been shown that propane conversion and propene yield increase with Cr loadings. The propane conversion and propene yield on CrO_x(Cr: 10wt%)/SBA-15 catalyst for oxidative dehydrogenation of propane by CO₂ at 550 ℃ reach 24.8% and 21.8%, respectively .The results of ESR, UV-Vis DRS and propane pulsing experiments indicate that Cr^Ⅲ in the CrO_x/ SBA-15 catalyst is the main active species in oxidative dehydrogenation of propane by CO₂ and Cr^Ⅵ, Cr^Ⅴ is inactive in dehydrogenation.     

Synthesis and Cytotoxicity Evaluation of Metal‐Chelator‐Bearing Flavone,Carbazole, Dibenzofuran,Xanthone, and Anthraquinone

2‐(Aryloxymethyl)‐5‐benzyloxy‐1‐methyl‐1H‐pyridin‐4‐ones 8a – 8g , 2‐(aryloxymethyl)‐5‐hydroxy‐4H‐pyran‐4‐ones 9a – 9g , and 2‐(aryloxymethyl)‐5‐hydroxy‐1‐methyl‐1H‐pyridin‐4‐ones 10a – 10g were prepared from the known 5‐benzyloxy‐2‐(hydroxymethyl)pyran‐4‐one ( 3 ) in a good overall yield. These compounds were evaluated in vitro against a three‐cell lines panel consisting of MCF7 (breast), NCI‐H460 (lung), and SF‐268 (CNS), and the active compounds passed on for evaluation in the full panel of 60 human tumor cell lines derived from nine cancer cell types. The results indicated that 5‐hydroxy derivatives are more favorable than their corresponding 5‐benzyloxy precursors ( 10a – 10g vs. 8a – 8g ), and 1‐methyl‐1H‐pyridin‐4‐ones are more favorable than their corresponding pyran‐4(1H)‐ones ( 10a – 10g vs. 9a – 9g ). Among these three types of compounds, 2‐(aryloxymethyl)‐5‐hydroxy‐1‐methyl‐1H‐pyridin‐4‐ones 10a – 10g were the most cytotoxic; they inhibited the growth of almost all the cancer cells tested. On the contrary, compound 8a (a mean GI₅₀=27.8 μM ), 8b (38.5), 8d (11.0), and 8e (30.5) are especially active against the growth of SK‐MEL‐5 (a melanoma cancer cell) with a GI₅₀ of <0.01, 5.65, 0.55, and 0.03 μM , respectively (cf. Table 2).     

Three-dimensional mesomeric networks assembled from helix-linked sheets: syntheses, structures, and magnetisms

Two new three-dimensional nickel coordination polymers, [Ni3(BTC)2(4,4'-bpy)2(H2O)5].1.5H2O (1) and [Ni(PDB)(4,4'-bpy)].0.5H2O (2)(4,4'-bpy = bipyridine, BTC = 1,2,4-benzenetricarboxylate, PDB = pyridine-3,4-dicarboxylate), have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR, TGA, and single crystal X-ray diffraction. Both compounds contain 2D scaffolding motifs, and most interestingly adjacent scaffolds are connected by infinite helical chains into unique three-dimensional mesomeric networks. Moreover, temperature-dependent magnetic susceptibilities for the two compounds were studied, and ferromagnetic interactions through syn-anti carboxylate bridges between Ni sites have been observed.     

铁缺乏症对婴幼儿智能发育的影响

为分析铁缺乏症(IDD)对婴幼儿智能发育的影响，随机抽取了6个月至3岁婴幼儿200例，按有否铁缺乏分组，比较了其与智能的关系。结果表明，铁缺乏症检出率为17．5％，铁缺乏组婴幼儿智能发育商(DQ)明显下降，与正常组比较差异有显著性，铁缺乏程度越重，DQ值越低。可见铁缺乏症对婴幼儿大脑发育造成不良影响，对该症无贫血阶段及轻度缺铁性贫血期(IDA)应予重视。     

Preparation and Porous Property of C14-Monolithic Column for Capillary Electrochromatography

Capillary electrochromatography (CEC) has been performed with a series of C₁₄, methlyacrylamide based monolithic columns. These monoliths with different porosities were prepared by in-situ copolymerization in fused-silica capillaries. The porous properties of monoliths were further observed using scanning electron micrographs (SEM) and measured using a mercury porosimeter. The effect of various alcohols as porogens on porous structural properties and chromatographic behaviors were also investigated. The effects of organic additive, pH value and ionic strength in mobile phase on electroosmosis flow (EOF) and separation were further discussed. Meanwhile, the baseline separation of 6 neutral compounds can be well obtained. In addition, the monolithic column demonstrates the high column efficiency and satisfactory reproducibility.Acknowledgements We gratefully acknowledge the support of the National Natural Science Foundation of China.     

Self‐Assembly,Spectroscopic and Electrochemical Studies of Nickel(II)‐4,8‐Diazaundecanediamide Complex

The self‐assembly of NiCl₂·6H₂O with a diaminodiamide ligand 4,8‐diazaundecanediamide (L‐2,3,2) gave a [Ni(C₉H₂₀N₄O₂)(Cl)(H₂O)] Cl·2H₂O ( 1 ). The structure of 1 was characterized by single‐crystal X‐ray diffraction analysis. Structural data for 1 indicate that the Ni(II) is coordinated to two tertiary N atoms, two O atoms, one water and one chloride in a distorted octahedral geometry. Crystal data for 1: orthorhombic, space group P 21nb, a = 9.5796(3) Å, b = 12.3463(4) Å, c = 14.6305(5) Å, Z = 4. Through NH···Cl–Ni (H···Cl 2.42 Å, N···Cl 3.24 Å, NH···Cl 158°) and OH···Cl–Ni contacts (H···Cl 2.36 Å, O···Cl 3.08 Å, OH···Cl 143°), each cationic moiety [Ni(C₉H₂₀N₄O₂) (Cl)(H₂O)]⁺ in 1 is linked to neighboring ones, producing a charged hydrogen‐bonded 1D chainlike structure. Thermogrametric analysis of compound 1 is consistent with the crystallographic observations. The electronic absorption spectrum of Ni(L‐2,3,2)²⁺ in aqueous solution shows four absorption bands, which are assigned to the ³A_2g → ³T_2g, ³T_2g → ¹Eg, ³T_2g → ³T_1g, and ³A_2g → ³T_1g transitions of triplet‐ground state, distorted octahedral nickel(II) complex. The cyclic volammetric measurement shows that Ni²⁺ is more easily reduced than Ni(L‐2,3,2)²⁺ in aqueous solution.     

一种纳米TiO2粉体防团聚的新方法

开发了一种新的低成本防团聚方法——泡沫悬浮法。对泡沫悬浮法和共沸蒸馏法的防团聚效果进行了系统比较。结果表明，泡沫悬浮法可以有效抑制煅烧过程中纳米TiO₂晶粒的粗化和一次粒径的长大。泡沫悬浮法所得纳米TiO₂的粉体还具有团聚粒径小、粒度分布窄以及比表面积大的优点。通过FTIR、TG、DTA和松装密度实验对泡沫悬浮法的防团聚机理进行了研究，提出了纳米TiO₂防团聚模型。     

Voltammetric Behavior of the Alizarin Red S Interaction with DNA and Damage to DNA

The electrochemical behavior and the interaction of alizarin red S (ARS) with calf thymus DNA was investigated on a bare glassy carbon electrode (GCE) and DNA modified GCE (DNA/GCE), respectively. ARS showed a pair of redox peaks at ?0.445 V and ?0.414 V on a bare GCE. On addition of DNA into the ARS solution, the peak current of ARS decreased and the peak potential positively shifted, but without new redox peaks appeared. The ARS reduction peak current increased with immersion time on a DNA/GCE. The results showed that ARS could interact with DNA molecules by intercalative binding mode. The equilibrium constant, binding number and the ratio of binding constant for oxidized and reduced ARS forms were obtained. The DNA damage was directly detected by appearance of guanosine and adenosine bases oxidation signal. The influence of experimental conditions on DNA damage extent was discussed in detail.     

The influences of solid-phase organic constituents on the partition of aliphatic and aromatic organic contaminants

The influence of natural organic matter (NOM) constituents on contaminant distribution coefficients was evaluated by determining the Koc values of aromatic and aliphatic organic compounds (solutes) with clays modified with both aromatic- and aliphatic-rich organic constituents. The studied compounds consisted of naphthalene, phenanthrene, n-pentane, and 2,3,4-trimethylmethane; the solid samples comprised two clays with little organic content, kaolinite and Ca-montmorillonite. Two aliphatic surfactants and three aromatic dyes, sorbed to the clays, served as reference NOM constituents. For solutes of comparable water solubilities, the organic-carbon normalized distribution coefficients (Koc) of the aliphatic solutes between sorbed aliphatic organic matter and aqueous solution slightly exceed those of the aromatic solutes. By contrast, the aromatic solutes exhibited higher Koc values than did the aliphatic compounds with sorbed aromatic-rich organic matter. The difference in Koc values could be attributed to either comparable solubility parameters or the difference in the chemical structure between nonionic organic solutes and specific components of the simulated NOM. The much higher Koc values observed for the aromatic solutes indicate that the NOM composition is a major factor determining the NOC environmental distribution.