多相催化剂的MOVS制备方法

介绍了非均匀相催化剂的ＭＯＶＳ制备方法，以该法制得的ＭｏＯ３催化剂在甲醇选择氧化制甲醛、ＣＯ加氢制高级和喹啉加氢脱氮中均显示出常规催化剂更为优异的催化性能，并探讨了ＭＯＶＳ催化剂的内在特性与催化性能的关系。     

Extraction-spectrophotometric analysis of palladium in the reprocessing waste of spent nuclear fuels using benzo-15-crown-5 and iodide

Based on the previous studies, a procedure has been established for the analysis of palladium in reprocessing waste solution of spent nuclear fuel. The sample was contacted with the extractant solution which consisted of benzo-15-crown-5, chloroform, and potasium iodide at room temperature for 1 minute. The extract was dehydrated by anhydrous Na₂SO₄ and measured spectrophotometrically versus water at 360 nm. The extractant solution used can be regenerated by KI (or NaI and Lil) for reuse. The percent extraction of palladium and apparent molar abaorptivity are 96–100% and 4·10⁴, respectively. The composition of extracted complex is [KB15C5)₂]₂·(Pd₂I₆).     

Dioxygen oxidation of hydrocarbons by a methane monooxygenase-like system: diiron complex-O_2-Zn/HOA_c-MV~(2 )

The activation of dioxygen and incorporation into hydrocarbons have been achieved under mild conditions by a methane monooxygenase (MMO)-like system using a dinuclear iron complex [Fe_2Dhist(OAc)_2]BPh_4·3H_2O as the model complex, zinc powder as the electron donor, HOAc as the proton source and methylviologen as the electron transfer agent. The results show that styrene is oxygenated predominantly to styrene oxide (1 396 mol/100 mol of the Fe_2 complex), benzaldehyde (16160) and acetophenone (986), and cyclohexane to cyclohexanol (9370) and cyclohexanone (2670). EPR studies indicate that the hypervalent ironoxo spiecs Fe~ⅣFe~Ⅳ(?)O, derived from Fe~ⅢFe~Ⅲ core via reduction, O_2-binding and protonation, is the active intermediate which inserts the activated oxygen atom into C(?)C or C—H bond giving each product. The system closely resembles MMO and its close relative hemerythrin in the aspects of reaction phenomena, EPR characteristics and product distributions. The Mn_2 analog cmplex、Fe-Zn hetero     

ADSORPTION SELECTIVITY FOR Cu~(2 ),Ni~(2 ),Co~(2 )IONS USING CROSSLINKING CHITOSAN RESINS IMPRINTED BY METAL IONS

1introductionChitosan,adeacetylatedderivativeofchitin,isnatUralpolysaccharideswithfreeaminogroups.Itcanactasanexcellentadsorbenttoadsorbnotonlyvariousorganiccompoundsincludingpolychlorinatedbiphenyls,proteinsandnucleicacids,butalsometalions[1~sl.ChitosanhasbeenwidelyemployedasaneffectivecoagulatingagentinactivatedsludgeplantSandfoodprocessingfactories,andalsoinpreparation,concentTationandpurificationofmetalionsinhydrometallurgy.Chitosanbehavesasanaturalchelatingpolymer.Chitosanundergoeschela…     

Combinational simulations of free energy of polymer solution

It is conceptually proposed that the total entropy of polymer solution is contributed from two distinct parts: the positional and the oomformational. The former can be represented analytically, while the latter can be simulated with the random self-avoiding walk model on the simple cubic lattice for multichain systems. The obtained results indicated that both the conformational entropy and the mixing heat are consistent with the scaling laws wry well.     

Synthesis and Crystal Structure of[Fe_2V (μ_3-O) (μ-O_2CCH_3)_6 (THF)_3]Cl· 3H_2O

lmTR0DUCTI0NTrivanadium(III)ox0-carb0xylat0complexeshaveattractedmuchinterestre-cently"~".Manyc0mp0unds0fthiskindhavebeensynthesizedandtheirstructural,physicalandspectr0sc0picpr0pertieshavebeenstudied.Butnone0fthiskindofcom-plexeswithmixedmeta1shavebeensynthesized.Hereinwereportthecrystalstruc-tureofthefirstmixedmeta1carboxylatocomp0undofvanadium.2EXPERIMENTAL2.1Synthesis0.l6g(lmmol)VCl3,0.32g(2mmol)FeCl3and0.48g(6mm0l)NaCO,CH,wasdisso1vedinaso1uti0n0ft0luerie(20ml),THF(lOml),ac…     

含吡啶环系西佛碱大环配合物和氮杂大环自由配体的合成

2,6-二羟甲基吡啶(1)经活性MnO_2氧化得到2,6-二甲酰基吡啶(2)。邻硝基苯酚与N-取代的二(氯乙基)胺在DMF溶液中反应,得到N-取代的1,5-二(邻硝基苯氧基)-3-氮杂戊烷(3a～3c),再经水合肼/Raney Ni还原,获得N-取代的1,5-二(邻氨基苯氧基)-3-氮杂戊烷(4a～4c)。利用Ba~(2 )作为模板离子,(2)分别与(4a～4c)反应,合成了一类新的含吡啶环系西佛碱大环配合物Ⅰ～Ⅲ,配合物Ⅰ、Ⅲ经与NaBH_4的乙醇溶液还原解络,得到氮杂大环自由配体Ⅳ和Ⅴ。所有西佛碱大环配合物和氮杂大环自由配体均经元素分析、IR、~1H NMR、MS等证实了它们的结构和组成。     

发铅含量与维生素D缺乏性佝偻病关系的探讨

探讨了铅与维生素Ｄ缺乏性佝偻病的关系。采用示波极谱法同时检测维生素Ｄ缺乏性佝偻病患儿１１８例及健康儿７６例发铅浓度。结果表明,维生素Ｄ缺乏性佝偻病患儿发铅浓度高于健康儿,且婴儿组中度佝偻病发铅浓度高于轻度佝偻病患儿,提示发铅浓度与佝偻病有一定的关系,高铅参与了营养性维生素Ｄ缺乏性佝偻病的发病机制,预防铅吸入可减少维生素Ｄ缺乏性佝偻病的发生。     

Design and synthesis of interpenetrating polymer networks for second-order nonlinear optics

There has been a tremendous recent interest in the development of second-order nonlinear optical (NLO) polymeric materials for photonic applications. However, a major drawback of second-order NLO polymers that prevents them from being used in device applications is the instability of their electric field induced dipolar alignment. The randomization of the dipole orientation leads to the decay of second-order optical nonlinearities. Numerous efforts have been made to increase the stability of the second-order NLO properties of polymers. The search for new approaches to develop NLO polymers with optimal properties has been an active research area since the past decade. A novel approach, combining the hybrid properties of high glass transition temperatures, extensively extensively crosslinked networks and permanent entanglements, based on interpenetrating polymer networks (IPN) is introduced to develop stable second-order NLO materials. Two types of IPN systems are prepared and their properties are investigated. The designing criteria and the rationale for the selection of polymers are discussed. The IPN samples show excellent temporal stability at elevated temperatures. Long-term stability of the optical nonlinearity at 100°C has been observed in these materials. Temporal stability of the NLO properties of these IPNs is synergistically enhanced. Relaxation behavior of the optical nonlinearity of an IPN system has been studied and compared with that of a typical guest/host system. The improved temporal stability of the second-order NLO properties of this IPN system is a result of the combination of the high rigidity of the polymer backbones, crosslinked matrices and permanent entanglements of the polymer networks. A slight modification of the chemical structure resulted in an improvement of the optical quality of the sample.     

尼龙1010／6及尼龙1010／66动态力学分析

通过动态力学参数温度谱,研究了尼龙１０１０／６、尼龙１０１０／６６两个共聚物系列的动态力学参数与组成的关系。研究表明尼龙１０１０／６、尼龙１０１０／６６在测试温度范围内出现三个明显的松驰转变：α、β、γ,其中各共聚物的β、γ松驰温度相差不大,而α松驰温度随组成改变有明显改变。一般均聚物的α松驰温度较高,共聚物的α松驰温度均低于均聚物,二个系列以尼龙１０１０／６（２９．８／７０．２）、尼龙１０１０／