Silver(I) ion induced formation of 2-D ternary lead(II)-silver(I)-4-tolythiolate [PbAg2(μ-Stol)2(μ4-Stol)2]n from 1-D binary lead(II)-4-tolythiolate [(μ-Cl)Pb2(Stol)(μ-Stol)2]n (tol = 4-tolyl)

Treatment of [Pb(Stol)₂]_n with an equiv of [Et₄N]Cl in DMF afforded a new 1-D polymeric complex, [(μ-Cl)Pb₂(Stol)(μ-Stol)₂]_n (1), with Pb–Cl–Pb links. Interaction of 1 with a suspension of [Ag(Stol)] in DMF resulted in formation of a 2-D polymeric complex, [PbAg₂(μ-Stol)₂(μ₄-Stol)₂]_n (2), with the planar four-membered Ag₂S₂ and PbAgS₂ rings bridged by μ-Stol and μ₄-Stol ligands. Both polymeric complexes were structurally characterized by single-crystal X-ray diffraction analysis.     

Enrichment and separation of rebaudioside A from stevia glycosides by a novel adsorbent with pyridyl group

The adsorptive capacity and selectivity of a novel adsorbent with pyridyl group toward stevia glycosides were studied. The effect of polarity and physical structure of the sorbent on the selectivity was investigated in detail. Two separation methods were applied in the enrichment of rebaudioside A(RA). They were selective elution using methanol or ethanol solution as solvent, and dynamic chromatographic separation using pyridyl resin with high selectivity. Results show that the chromatographic separation method can effectively enrich RA from stevia glycoside with high content of stevioside.     

A highly efficient capillary electrophoresis-based method for size determination of water-soluble CdSe/ZnS core-shell quantum dots

This paper describes a highly efficient method for size determination of water-soluble CdSe/ZnS core-shell quantum dots (QDs) by capillary electrophoresis (CE) using polymer additive as sieving medium. The influence of some factors, such as kinds and concentrations of the sieving medium, pH, concentrations of the background electrolyte (BGE) and applied voltage, on the separation of QDs was investigated. Under the optimal separation conditions, four different sized QDs were successfully separated, and the relative standard deviation (RSD) of the migration times for these QDs was below 1.013%. In addition, an equation was fit by taking into account the correlation existing between the electrophoretic mobilities and the sizes of a set of QDs. The feasibility of this equation to measure the sizes of other QDs was confirmed by comparison with the sizes obtained by transmission electron microscopy (TEM) experiment. This work offers a novel method for size determination of QDs, and provides an important reference on the study of QDs based on CE.     

Folate-targeted optical and magnetic resonance dualmodality PCL-<Emphasis Type="Italic">b</Emphasis>-PEG micelles for tumor imaging

A biodegradable tumor targeting nano-probe based on poly（ε-caprolactone）-b-poly（ethylene glycol）block copolymer（PCL-b-PEG）micelle functionalized with a magnetic resonance imaging（MRI）contrast agent diethylenetriaminepentaacetic acid-gadolinium(DTPA-Gd³⁺)on the shell and a near-infrared（NIR）dye in the core for magnetic resonance and optical dual-modality imaging was prepared.The longitudinal relaxivity（r₁）of the PCL-b-PEG-DTPA -Gd³⁺micelle was 13.4（mmol/L）^-1s^-1,three folds of that of DTPA-Gd³⁺,and higher than that of many polymeric contrast agents with similar structures.The in vivo optical imaging of a nude mouse bearing xenografted breast tumor showed that the dual-modality micelle preferentially accumulated in the tumor via the folic acid-mediated active targeting and the passive accumulation by the enhanced permeability and retention（EPR）effect.The results indicated that the dualmodality micelle is a promising nano-probe for cancer detection and diagnosis.     

Development of Composite Adsorbents of Carbon and Intercalated Clay for N2and O2Adsorption: A Preliminary Study

Composite adsorbents of carbon and alumina intercalated montmorillonite were prepared and characterized by adsorption of N₂and O₂at various temperatures. The effects of pyrolysis, temperature, heating rate, subsequent degassing, and doping of cations and anions were investigated. The adsorption capacities of the composite adsorbents developed at higher temperatures (0 and −79°C) are found to be larger than those of normal alumina pillared clays. The experimental results showed that the framework of these adsorbents is made of alumina particles and clay sheets while the pyrolyzed carbon distributes in the space of interlayers and interpillars. The pores between the carbon particles, clay sheets, and alumina pillars are very narrow with very strong adsorption forces, leading to enhanced adsorption capacities at 0 and −79°C. The composite adsorbents exhibit features similar to those of carbonaceous adsorbents. Their pore structures, adsorption capacities, and selectivities to oxygen can be tailored by a controlled degassing procedure. Meanwhile, ions can be doped into the adsorbents to modify their adsorption properties, as usually observed for oxide adsorbents like zeolite and pillared clays. Such flexibility in pore structure tailoring is a potential advantage of the composite adsorbents developed for their adsorption and separation applications.     

聚苯乙烯键合麻黄碱-Co(Ⅱ)络合物对烯烃环氧化反应的催化作用

聚苯乙烯键合麻黄碱 Ｃｏ（Ⅱ）络合物对烯烃环氧化反应的催化作用刘庆艳刘必前何纪纲（中国科学院化学研究所北京１０００８０）关键词环氧化，分子氧，烯烃，醛，高分子催化剂烯烃的环氧化反应是将烯烃进行氧化转化的重要反应［１］．由于高分子催化剂具有与反应...     

含杀菌、吸附双功能基棉纤维的制备与性能

化学改性;吸附剂;杀菌剂;含杀菌、吸附双功能基棉纤维的制备与性能     

Investigations on the adsorbents for uremic middle molecular toxins (II)

Chitosan resins, which clinically served as adsorbents in hemo perfusion therapy, were prepared with reversed-phase suspension methodology using three differently structured crosslinking agents, methanal, glyoxal and glutaraldehyde. And the glyoxal and glutaraldehyde crosslinked chitosan resins were reduced with NaBH₄ afterwards. By analyzing the results from FTIR and SEM, it was found that the reduction treatment to the adsorbents efficiently improved the chemical stability of these chitosan resins, and the shifts in crosslinking agents exerted influences over the morphologies of the adsorbents obviously. After being put to use in the adsorption tests upon some model uremic middle molecular toxins and BSA in vitro, all three adsorbents demonstrated a fairly realistic adsorption capability to the model toxins but little to BSA. And the adsorption process reached the equilibrium in a clinically qualified short time. But the adsorption capacities of these adsorbents to the model toxins were quite different. It had been found that with the growing of fatty chain length of crosslinking agent, these adsorbents showed a gradually increased adsorption capacity to the model toxins, and the glutaraldehyde crosslinked chitosan resin behaved best.     

氨基酸在固/液界面的吸附作用

本文介绍了氨基酸在固/液界面吸附等温线的特点,氨基酸液相吸附热力学和活性炭、硅胶、二氧化钛、氧化铝、蒙脱土等自水中吸附氨基酸的机制。     

Visible light-induced thione-ene cycloaddition reaction for the surface modification of polymeric materials

A feasible method for the surface modification of polymeric materials with LDPE films as model substrates based on visible light-induced thione-ene cycloaddition reaction is proposed.