热处理对聚醚醚酮晶体结构参数及结晶度的影响

采用广角Ｘ射线衍射（ＷＡＸＤ）方法研究了不同热处理温度下聚醚醚酮（ＰＥＥＫ）的晶胞参数、微晶尺寸及结晶度的变化。根据Ｘ射线散射强度理论，运用图解多重峰方法导出了以ＷＡＸＤ方法计算ＰＥＥＫ结晶度的公式；用此公式对经不同热处理的ＰＥＥＫ样品进行计算，结果与由密度法及量热法测定的结果具有较好的可比性。     

NONTEMPLATE SYNTHESIS OF TWO N_2O_2S MACROCYCLES DERIVED FROM THIOPHENE，AND Hg（Ⅱ）， Pb（Ⅱ）， Cd（Ⅱ） COMPLEXES

ＮＯＮＴＥＭＰＬＡＴＥＳＹＮＴＨＥＳＩＳＯＦＴＷＯＮ_２Ｏ_２ＳＭＡＣＲＯＣＹＣＬＥＳＤＥＲＩＶＥＤＦＲＯＭＴＨＩＯＰＨＥＮＥ，ＡＮＤＨｇ（Ⅱ），Ｐｂ（Ⅱ），Ｃｄ（Ⅱ）ＣＯＭＰＬＥＸＥＳ￥ＬｉｎｇＺＨＡＯ；ＦｕＸｉｎＸＩＥ；ＺｈｉＱｉａｎｇＸＵ；Ｇｕａ...     

纳米级金膜微电极的制作,表征及异相催化反应

报道了纳米级金膜微电极的制作方法，用ＸＰＳ及ＳＥＭ对电极表面进行了表征，考察了该电极的循环伏安及计时电流特性，在聚吡咯修饰微带金电极上成功地实现了葡萄糖氧化酶和电子传递媒体Ｆｅ（ＣＮ）６＾３－的同时固定，并研究了ＧＯＤ／Ｆｅ（ＣＮ）６＾３－／ＰＰｙ微酶电极对葡萄糖的响应，稳态响应电流与葡萄糖浓度之间存在Ｍｉｃｈｅａｌｉｓ－Ｍｅｎｔｅｎ动力学特征。     

THE CONSTANT PHASE ELEMENT (CPE) ON MnO_2 ELECTRODE

ＴＨＥＣＯＮＳＴＡＮＴＰＨＡＳＥＥＬＥＭＥＮＴ（ＣＰＥ）ＯＮＭｎＯ_２ＥＬＥＣＴＲＯＤＥ￥ＹｕａｎＧＵＯａｎｄＸｉＸＩＡ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔｒｙ，ＸｉｎｊｉａｎｇＵｎｉｖｅｒｓｉｔｙ，Ｕｒｕｍｑｉ８３００４６）Ａｂｓｔｒａｃｔ：Ａ?..     

N，N－二乙基甲酰胺代甲基膦酸二正己酯萃取金（Ⅲ）

本文报道Ｎ，Ｎ－二乙基甲酰胺代甲基膦酸二正己酯（简称Ｅ）萃取金（Ⅱ）的各种参数，如分配比、振荡时间、相比、水相酸度及酰的种类，以及其它离子对萃取金（Ⅲ）分配比的影响。并求得了达到平衡时化合物Ｅ萃取金反应的焓变（ＯＨ）和熵变（ＯＳ）。     

气相色谱法测定作业场所空气中的黑索金

本文报道用毛细管气相色谱电子捕获鉴定器测定作业场所空气中黑索金（ＲＤＸ）含量的新方法在优化的实验条件下，ＲＤＸ在０４０１８．０ｍｇ／Ｌ范围内可进行定量分析，检测限为０．０８ｍｇ／Ｌ，变异系数为３．９８．２％（ｎ＝６），样品回收率在９０％以上     

无电解镀镍磷非晶态合金的近边结构研究

用ＤＴＡ，ＸＲＤ和ＥＸＡＦＳ方法研究无电解镀镍磷合金层结构，其中含Ｐ１０％（重量百分比）左右的Ｎｉ－Ｐ合金层是非晶态合金固溶体，Ｎｉ，Ｐ之间存在共价键作用，Ｎｉ－Ｎｉ键长０．２５ｎｍ，Ｎｉ－Ｐ键长０．２８ｎｍ经４００℃热处理１后的含Ｐ１０％的Ｎｉ－Ｐ镀层是Ｎｉ３Ｐ晶态与Ｎｉ－Ｐ非晶态的混合物，ＥＸＡＦＳ方法给出了镍磷合金层的结构，键长和配位原子情况，体现出ＥＸＡＦＳ方法在研究金属结构尤其是非晶态金     

稀土取代的复合氧化物Eu_（0．5）RE_（0．5）Fe_（0．5）Mn_（0．

利用固相反应合成了稀土取代的复合氧化物Ｅｕ_（０．５）ＲＥ_（０．５）Ｆｅ_（０．５）Ｍｎ_（０．５）Ｏ_３（ＲＥ＝Ｌａ，Ｐｒ，Ｎｄ，Ｓｍ，Ｇｄ，Ｔｂ，Ｄｙ，Ｈｏ，Ｅｒ，Ｔｍ，Ｙｂ）．测量了这些化合物的ＸＲＤ和ＸＰＳ谱。在ＸＰＳ研究中发现，稀土取代而使稀土元素本身的结合能相对于其倍半氧化物中的有所降低；在取代的复合氧化物中，随着ＲＥ离子半径的减小，Ｆｅ、Ｍｎ的结合能随之增加。     

含间位取代苯基聚醚酮酮的结晶与晶体结构研究

通过差示扫描法（ＤＳＣ）及广角Ｘ 射线衍射（ＷＡＸＤ）技术研究了含间位取代苯基聚醚酮酮（ＰＥＫｍＫ）的结晶行为与晶体结构．Ｘ 射线结果表明，从熔融态及玻璃态结晶时，ＰＥＫｍＫ只有一种晶型，其晶胞参数为：ａ＝０７６７２ｎｍ，ｂ＝０６１４９ｎｍ，ｃ＝１５９９ｎｍ．ＤＳＣ结果表明，ＰＥＫｍＫ热分析曲线都出现了熔融双峰，低熔融峰（ＤＯＷｎ）热焓占总热焓４～７％，它源于初始结晶形成的同一晶型不同厚度片晶．低熔融峰在２５０℃以上结晶转化成高熔融峰（Ｉ），ＰＥＫｍＫ平衡熔点为２９５℃     

SYNTHESIS, CHARACTERIZATION OF 2-[2-(3-NITRO-4-METHOXYLPHENYL) VINYLI-1-ME

ＳＹＮＴＨＥＳＩＳ，ＣＨＡＲＡＣＴＥＲＩＺＡＴＩＯＮＯＦ２－［２－（３－ＮＩＴＲＯ－４－ＭＥＴＨＯＸＹＬＰＨＥＮＹＬ）ＶＩＮＹＬＩ－１－ＭＥＴＨＹＬＰＹＲＩＤＩＮＩＵＭＰＥＮＴＡＡＮＤＨＥＸＡＮＩＴＲＡＴＯＲＡＲＥＥＡＲＴＨ（Ⅲ）ＣＯＭＰＬＥＸＥＳＨ...     

Yolk-shell gold nanoparticles as model materials for support-effect studies in heterogeneous catalysis: Au, @C and Au, @ZrO2 for CO oxidation as an example

The use of nanostructured yolk-shell materials offers a way to discriminate support and particle-size effects for mechanistic studies in heterogeneous catalysis. Herein, gold yolk-shell materials have been synthesized and used as model catalysts for the investigation of support effects in CO oxidation. Carbon has been selected as catalytically inert support to study the intrinsic activity of the gold nanoparticles, and for comparison, zirconia has been used as oxidic support. Au, @C materials have been synthesized through nanocasting using two different nonporous-core@mesoporous-shell exotemplates: Au@SiO(2)@ZrO(2) and Au@SiO(2)@m-SiO(2). The catalytic activity of Au, @C with a gold core of about 14 nm has been evaluated and compared with Au, @ZrO(2) of the same gold core size. The strong positive effect of metal oxide as support material on the activity of gold has been proved. Additionally, size effects were investigated using carbon as support to determine only the contribution of the nanoparticle size on the catalytic activity of gold. Therefore, Au, @C with a gold core of about 7 nm was studied showing a less pronounced positive effect on the activity than the metal oxide support effect.     

Bioinorganic and medicinal chemistry: aspects of gold(I)-protein complexes

Gold(I)-based drugs have been used successfully for the treatment of rheumatoid arthritis (RA) for several years. Although the exact mechanism of action of these gold(I) drugs for RA has not been clearly established, the interaction of these compounds with mammalian enzymes has been extensively studied. In this paper, we describe the interaction of therapeutic gold(I) compounds with mammalian proteins that contain cysteine (Cys) and selenocysteine (Sec) residues. Owing to the higher affinity of gold(I) towards sulfur and selenium, gold(I) drugs rapidly react with the activated cysteine or selenocysteine residues of the enzymes to form protein-gold(I)-thiolate or protein-gold(I)-selenolate complexes. The formation of stable gold(I)-thiolate/selenolate complexes generally lead to inhibition of the enzyme activity. The gold-thiolate/selenolate complexes undergo extensive ligand exchange reactions with other nucleophiles and such ligand exchange reactions alter the inhibitory effects of gold(i) complexes. Therefore, the effect of gold(I) compounds on the enzymatic activity of cysteine- or selenocysteine-containing proteins may play important roles in RA. The interaction of gold(I) compounds with different enzymes and the biochemical mechanism underlying the inhibition of enzymatic activities may have broad medicinal implications for the treatment of RA.     

氮杂环卡宾双核金络合物催化的胺芳基化反应

联萘胺出发合成了氮杂环卡宾双核和单核金络合物, 通过X射线的单晶衍射确定了它们的结构, 并将其应用于催化胺芳基化反应中, 以高达95%的收率得到吡咯烷类化合物. 综合上述实验结果, 发现氮杂环卡宾双核金络合物4b中存在着Au(I)-Au(I)间相互弱作用力, 而且这种弱相互作用可能对该催化反应起重要的作用, 以高收率得到吡咯烷类化合物.     

Preconcentration of gold by Mimusops elengi seed proteins

The present study has been performed to preconcentrate gold using the proteins extracted from Mimusops elengi Linn. (Family: Sapotaceae) seed by radiometric technique using ¹⁹⁸Au. Effects of buffer and pH dependence on the binding affinity of the gold have also been examined. It has been found that the binding of gold with M. elengi protein neither depends on the addition of buffer nor the composition (phosphate/citrate) of buffer. The adsorption of gold is also independent of pH of the solution. To verify the gold-protein interaction, inter-comparisons have been made between four different approaches, (1) notably extraction with anion-exchange resin Amberlite IRA 400, (2) trichloroacetic acid (TCA) precipitation, (3) isoelectric precipitation and (4) dialysis of protein after incubation with gold. Good agreement has been observed for all the cases. Binding of gold have been studied with three different concentrations of gold, 1, 10 and 50 ppm spiked with ¹⁹⁸Au.     

Gold nanoparticles with different capping systems: an electronic and structural XAS analysis

Gold nanoparticles (NPs) have been prepared with three different capping systems: a tetralkylammonium salt, an alkanethiol, and a thiol-derivatized neoglycoconjugate. Also gold NPs supported on a porous TiO(2) substrate have been investigated. X-ray absorption spectroscopy (XAS) has been used to determine the electronic behavior of the different capped/supported systems regarding the electron/hole density of d states. Surface and size effects, as well as the role of the microstructure, have been also studied through an exhaustive analysis of the EXAFS (extended X-ray absorption fine structure) data. Very small gold NPs functionalized with thiol-derivatized molecules show an increase in d-hole density at the gold site due to Au-S charge transfer. This effect is overcoming size effects (which lead to a slightly increase of the d-electron density) for high S:Au atomic ratios and core-shell microstructures where an atomically abrupt Au-S interface likely does not exist. It has been also shown that thiol functionalization of very small gold NPs is introducing a strong distortion as compared to fcc order. To the contrary, electron transfer from reduced support oxides to gold NPs can produce a higher increase in d-electron density at the gold site, as compared to naked gold clusters.     

Sorption-atomic-absorption determination of gold using VION chemisorption fibers

The sorption of gold(III) from hydrochloric acid solutions on VION chemisorption fibers containing ion-exchange and complexing groups has been studied. Using these sorbents, a combined sorption-atomic-absorption procedure for the determination of gold has been developed. The procedure has been verified in the determination of gold in gold-containing ores.     

Spectrophotometric determination of gold(iii) with p-dimethylaminobenzilidenerhodanine in hydrochloric acid-ethanol medium

The reaction between gold(III) and p-dimethylaminobenzilidenerhodanine in hydrochloric acid medium containing 20% v/v ethanol has been studied spectrophotometrically. It has been established that the process is very complicated: gold(III) is reduced to gold(I) which reacts with unchanged reagent. The value of the equilibrium constant is 2.56 +/- 0.45. Conditions are proposed for the determination of 2-8 mug of gold in 25 ml, with a standard deviation of 0.04 mug 25 ml .     

Nanostructured gold hollow microspheres prepared on dissolvable ceramic hollow sphere templates

Fifty and one-hundred micrometer diameter nanostructured gold hollow microspheres (GHSs), in >98% purity, have been prepared by using ceramic hollow spheres, CHSs, as templates. Tennanometer diameter gold nanoparticles were covalently linked to the thiol moiety of (3-mercaptopropyl)trimethoxysilane, which had been self-assembled onto the CHSs. Greater structural strength was obtained by the generation of additional gold nanoparticles, in situ on the gold nanoparticle coated CHSs (by immersing the gold nanoparticle coated CHSs into an aqueous mixture of hydroxylamine and gold chloride). GHSs were obtained by dissolving the CHSs templates. The sizes, shapes, surface areas (185.3 m2/g for CHSs and 182.9 m2/g for GHSs), pore diameters (7.7 nm for CHSs and 7.8 nm for GHSs), and pore volumes (0.41 cm3/g for CHSs and 0.36 cm3/g for GHSs) of GHSs were quite similar to their CHSs counterparts. Significantly, GHSs showed surface plasmon bands whose maximum (644 nm) shifted from that observed for the parent 10-nm gold nanoparticles (522 nm).     

Gold Electrodes for Detection of Enzyme Assays with 3‐Indoxylphosphate as Substrate

The advantageous characteristics of gold not only for its electrochemical behavior but also for the unique adsorptive protein characteristics are the basis of this paper. 3‐Indoxyl phosphate (3‐IP) has previously been demonstrated to be a very convenient substrate for the electrochemical detection, using carbon‐based electrodes, of enzymeimmunoassays (EIAs) that employ not only alkaline phosphatase (AP) but also horseradish peroxidase (HRP) as label. Combination of both: gold electrodes and 3‐IP has not been studied and it produces a very suitable detection for EIAs. The electrochemical behavior of indigo, product of the enzymatic hydrolisis of 3‐IP, has been thoroughly studied for the first time on disk and band gold electrodes. The possibility of electrodepositing gold on the bands and automation has also been considered. The detection has been applied for the determination of osteocalcin with an HRP‐based ELISA (enzyme‐linked immunosorbent assay).     

Kinetic and mechanistic investigations of the light induced formation of gold nanoparticles on the surface of TiO2

The kinetics of the formation of gold nanoparticles on the surface of pre-illuminated TiO(2) have been investigated using stopped-flow technique and steady state UV/Vis spectroscopy. Excess electrons were loaded on the employed nanosized titanium dioxide particles by UV-A photolysis in the presence of methanol serving as hole scavenger, stored on them in the absence of oxygen and subsequently used for the reduction of Au(III) ions. The formation of gold nanoparticles with an average diameter of 5 nm was confirmed after mixing of the TiO(2) nanoparticles loaded with electrons with aqueous solution of tetrachloroaureate (HAuCl(4)) by their surface plasmon absorbance band at 530 nm, as well as by XRD and HRTEM measurements. The rate of formation of the gold nanoparticles was found to be a function of the concentration of the gold ions and the concentration of the stored electrons, respectively. The effect of PVA as a stabilizer of the gold nanoclusters was also studied. The observed kinetic behavior suggests that the formation of the gold nanoparticles on the TiO(2) surface is an autocatalytic process comprising of two main steps: 1) Reduction of the gold ions by the stored electrons on TiO(2) forming gold atoms that turn into gold nuclei. 2) Growth of the metal nuclei on the surface of TiO(2) forming the gold particles. Interestingly, at higher TiO(2) electron loading the excess electrons are subsequently transferred to the deposited gold metal particles resulting in "bleaching" of their surface plasmon band. This bleaching in the surface plasmon band is explained by the Fermi level equilibration of the Au/TiO(2) nanocomposites. Finally, the reduction of water resulting in the evolution of molecular hydrogen initiated by the excess electrons that have been transferred to the previously formed gold particles has also been observed. The mechanism of the underlying multistep electron-transfer process has been discussed in detail.