Multiple-angle-of-incidence polarization infrared reflection-absorption spectroscopy (MAI-PIRRAS) for investigation of 6-Mercaptopurine SAMs on smooth silver surface

Multiple-angle-of-incidence polarization infrared reflection-absorption spectroscopy (MAI-PIRRAS) has been used to study the adsorption mode and structural properties of 6-Mercaptopurine (6MP) self-assembled monolayers (SAMs) on smooth silver surface. The in-plane vibrations of the 6MP SAMs show some enhancement compared with the spectrum of the solid powder of 6MP, while the out-of-plane vibrations are very weak. Assignments of the observed bands by DFT calculations show that both the thiol form and the tautomer of 6MP exist in the SAMs and adopt the S atom and the N7 or N1 atom anchoring the silver surface. In order to eliminate the influence of the angle of the incidence and obtain direct influence of the orientation of the 6MP to the spectral intensity, the adsorption intensity of the SAMs is multiplied by cos θ to obtain corrected spectra. The adsorption intensity attains to the maximum at 35–40° other than near the grazing angle. The characteristics of the spectra suggest that the SAMs of 6MP are arranged orderly in a parallel fashion with a dihedral angle of 35–40° between the ring plane and the silver surface.     

Controllable synthesis and photocatalytic activities of rod-shaped mesoporous titanosilicate composites with varied aspect ratios

Rod-shaped mesoporous titanosilicate composites （RMTSs） with controllable aspect ratios （ARs） were fabricated using cetyltrimethylammonium bromide （CTAB） and ammonium hydroxide （NH4OH） at a continuous stirring rate, resulting in ARs ranging from 1 to 5. Slowing the stirring rate or increasing the concentration of CTAB mainly impacted the length growth, whereas NH4OH affected the width growth. Photocatalytic activity studies revealed that the length of RMTSs played a more significant role than the width at lower ARs in their photocatalytic activity.     

Formation of Double-Shelled Zinc–Cobalt Sulfide Dodecahedral Cages from Bimetallic Zeolitic Imidazolate Frameworks for Hybrid Supercapacitors

Complex metal–organic frameworks used as precursors allow design and construction of various nanostructured functional materials which might not be accessible by other methods. Here, we develop a sequential chemical etching and sulfurization strategy to prepare well-defined double-shelled zinc–cobalt sulfide (Zn-Co-S) rhombic dodecahedral cages (RDCs). Yolk-shelled zinc/cobalt-based zeolitic imidazolate framework (Zn/Co-ZIF) RDCs are first synthesized by a controlled chemical etching process, followed by a hydrothermal sulfurization reaction to prepare double-shelled Zn-Co-S RDCs. Moreover, the strategy reported in this work enables easy control of the Zn/Co molar ratio in the obtained double-shelled Zn-Co-S RDCs. Owing to the structural and compositional benefits, the obtained double-shelled Zn-Co-S RDCs exhibit enhanced performance with high specific capacitance (1266 F g⁻¹ at 1 A g⁻¹), good rate capability and long-term cycling stability (91 % retention over 10,000 cycles) as a battery-type electrode material for hybrid supercapacitors.     

Large Magnetocaloric Effect in a Dense and Stable Inorganic–Organic Hybrid Cobridged by In Situ Generated Sulfate and Oxalate

A dense and stable inorganic‐organic hybrid with distorted cubic [Gd₄O₄] units as building blocks bridged by in situ generated sulfate and oxalate was synthesized. Magnetic measurements indicate that the title complex features a ?ΔS_m^max=51.49 J kg^?1 K^?1, which is among the highest values reported so far.     

Study on the Spectrophotometric Determination of Rare Earths with a New Chromogenic Reagent Dibromo-p-methyl-chlorosulfonazo(DBMCSA)

IntroductionAbstract:Anewmethodforthedeterminationofceriumsubgrouprareearthswasstudiedandreportedinthispaper.ItwasfoundthaiceriumsubgrouprareearthelementsreactwithDBMCSAin0.6mol/Lhydrochloricacidmediumtol'ormstablebluecomplexes.Theabsorbancesofequalamountsofceriumsubgrouprareearthsareclosetoeachotherattheirmaximumadsorptivewavelength(641"m).Beer'slawisobeyedfor0-20igofrareearthsin25mlofsolution.Themethodhasbeenappliedtothedeterminationofthetotalamountofceriumsubgrouprareearthsinsteelandcas…     

Modified screen-printed electrodes for the investigation of the interaction of non-electroactive quinazoline derivatives with DNA

Five morpholino-quinazoline derivatives have been investigated voltammetrically using a competition with the tris(o-phenanthroline) cobalt(III) redox marker for the accumulation at dsDNA modified screen-printed electrodes. An association of quinazolines with DNA was observed at the modified electrodes polarized by the negative potential of –0.4 V vs. Ag/AgCl. This was confirmed by a potentiometric stripping analysis based on the DNA guanine signal. Calibration curves for quinazolines within a concentration range of μmol/L were obtained with DP voltammetry using 5 × 10^–7 mol/L Co(phen)₃ ³⁺ marker. The quinazolines exhibit no effect on the DNA complex with the fluorescent thiazole orange derivative TO-PRO-3. The role of the accumulation potential in the association interaction with DNA is discussed.     

LD泵浦Cr∶YAG被动调Q556nm黄光激光器

通过对谐振腔镜镀制合理的激光薄膜,成功实现了LD泵浦Nd∶YAG1.112μm激光谱线的运转.利用LBO腔内倍频Nd∶YAG/Cr∶YAG结构获得了高重复频率被动调Q556nm全固态黄光激光器,在注入泵浦功率为1.6W时,得到平均功率51mW,脉冲宽度48ns,重复频率8.9kHz,峰值功率高达119W的脉冲黄光输出.