非等温等蒸气压法及其在Pt-Zn相关系研究中的应用

非等温等蒸气压法具有集样品制备、活度测定和相关系研究为一体的特点,本文简要阐述了非等温等蒸气压法的实验原理,分析了活度实验测定的误差以及非等温等蒸气压法在合金热力学和相关系研究中的应用,并讨论了相图十分不完善的Pt-Zn二元系的相关系.     

Simultaneous Determination of Nine Flavonoids in Dalbergia odorifera by LC

A rapid and accurate HPLC method has been developed for the simultaneous determination of nine major flavonoids, namely 3-hydroxymelanettin, melanettin, stevenin, butein, isoliquiritigenin, dalbergin, 2,4-dihydroxy-5-methoxybenzophenone, pinocembrin, 4-methoxydalbergione in Dalbergia odorifera. The samples were separated on an Aglient Zorbax SB-C₁₈ column (250 × 4.6 mm, 5 m) with a gradient of acetonitrile and 1% aqueous acetic acid (/) at a flow rate of 1.0 mL min^–1 and detected at 350 nm. The complete separation was obtained within 30 min for the nine target flavonoids. All calibration curves showed good linearity (r² > 0.999) within test ranges. The repeatability was evaluated by intra- and inter-day assays and RSD values were less than 4.0%. The recoveries were between 92.0% and 104.5%. The developed method was successfully applied to the analysis of 32 commercial samples of D. odorifera.     

Synthesis and Structure of Binary Copper/Silver-Arsenic Clusters Derived from Zintl Ion As73-

Polyarsenides containing coinage metals,[As₇Cu(PPh₃)]^2-(1)and[M₂As₁₄]^4-(M=Cu,2;Ag,3),were synthesized by reactions of the nominal composition K₃As₇ with Group 11 metal complexes.The possible intermediate,cluster 1,was isolated from the solution phase through subtle changes in reaction conditions in the formation process of complex 2.Hence,we establish the pathway of the bimetallic bridged clusters[Cu₂As₁₄]^4-by the oxidation of the[As₇Cu(PPh₃)]^2-.Quantum chemical calculations reveal the presence of metallophilic interaction in clusters 2 and 3.     

黄芪及其水煎液中Cu、Mn、Zn、Fe、Se的测定和浸出率研究

用原子吸收法对黄芪及其水煎液中的Cu、Mn、Zn、Fe进行了测定 ,用紫外分光光度法测定了其中的Se ,从而得出各元素的浸出率。结果表明五种元素的浸出率为 :Cu >Zn >Mn >Se >Fe。     

Highly selective amorphous Ni-Cr-B catalyst in 2-ethylanthraquinone hydrogenation to 2-ethylanthrahydroquinone

A nanosized amorphous Ni-Cr-B catalyst prepared by the chemical reduction method exhibited superior thermal stability and selectivity in hydrogen peroxide synthesis via the anthraquinone route.     

Microwave-Assisted Elemental-Direct-Reaction Route to Nanocrystalline Copper Sulfides Cu9S8 and Cu7S4

Non-stoichiometric copper sulfides Cu₉S₈ and Cu₇S₄ nanocrystallites were synthesized by the reaction between elements S and Cu under microwave radiation for several minutes. The products were analyzed by using XRD, TEM, XPS, ICP and PL.     

Synthesis and characterization of poly (n-butyl acrylate)-poly (methyl methacrylate) latex interpenetrating polymer networks by radiation-induced seeded emulsion polymerization

A series of latex interpenetrating polymer networks (LIPNs) were prepared via a two-stage emulsion polymerization of methyl methacrylate (MMA) or mixture of MMA and n-butyl acrylate (n-BA) on crosslinked poly(n-butyl acrylate)(PBA) seed latex using ⁶⁰Co γ-ray radiation. The particles of resultant latex were produced with diameters between 150 and 250 nm. FTIR spectra identified the formation of crosslinked copolymers of PMMA or P(MMA-co-BA). Dynamic light scattering (DLS) showed that with increasing n-BA concentration in second-stage monomers, the particle size of LIPN increased. Transmission electron microscope(TEM) photographs showed that the morphology of resultant acrylate interpenetrating polymer network (IPN) latex varied from the distinct core-shell structure to homogenous particle structure with the increase of n-BA concentration, and the morphology was mainly controlled by the miscibility between crosslinked PBA seed and second-stage copolymers and polarity of P(MMA-co-BA)copolymers. In addition, differential scanning calorimeter (DSC) measurements indicated the existence of reinforced miscibility between PBA seed and P(MMA-co-BA)copolymer in prepared LIPNs.     

Atom transfer radical polymerization of methyl acrylate,methyl methacrylate and styrene in the presence of trolamine as a highly effective promoter

Transition metal-mediated atom transfer radical polymerization(ATRP) is a ‘‘living'/controlled radical polymerization. Recently, there has been widely increasing interest in reducing the high costs of catalyst separation and post-polymerization purification in ATRP. In this work, trolamine was found to significantly enhance the catalytical performance of Cu Br/N,N,N0,N0-tetrakis(2-pyridylmethyl) ethylenediamine(Cu Br/TPEN) and Cu Br/tris[2-(dimethylamino) ethylamine](Cu Br/Me6TREN). With the addition of 25-fold molar amount of trolamine relative to Cu Br, the catalyst loadings of Cu Br/TPEN and Cu Br/Me6 TREN were dramatically reduced from a catalyst-to-initiator ratio of 1 to 0.01 and 0.05,respectively. The polymerizations of methyl acrylate, methyl methacrylate and styrene still showed first-order kinetics in the presence of trolamine and produced poly(methyl acrylate), poly(methyl methacrylate) and polystyrene with molecular weights close to theoretical values and low polydispersities. These results indicate that trolamine is a highly effective and versatile promoter for ATRP and is promising for potential industrial application.     

Graphene-supported hemin as a highly active biomimetic oxidation catalyst

Well supported: stable hemin-graphene conjugates formed by immobilization of monomeric hemin on graphene, showed excellent catalytic activity, more than 10 times better than that of the recently developed hemin-hydrogel system and 100 times better than that of unsupported hemin. The catalysts also showed excellent binding affinities and catalytic efficiencies approaching that of natural enzymes.